1
|
Ramesh R, Sathiyamurthy K, Meganathan V, Athmanathan B. Induction and comparative resuscitation of viable but nonculturable state on Vibrio parahaemolyticus serotypes O3:K6 and O1:K25. Arch Microbiol 2024; 206:376. [PMID: 39141167 DOI: 10.1007/s00203-024-04102-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2024] [Revised: 07/11/2024] [Accepted: 08/03/2024] [Indexed: 08/15/2024]
Abstract
Vibrio parahaemolyticus, an important food-borne pathogens found to be associated with seafoods and marine environs. It has been a topic of debate for many decades that most pathogens are known to enter a viable but nonculturable (VBNC) state under cold temperature and nutrient limited conditions. The present study examined the time required for the induction of VBNC state and the revival strategies of both the endemic O3:K6 and O1:K25 sporadic strains of V. parahaemolyticus. The results revealed that V. parahaemolyticus survived even after 55 days of incubation in nutrient starved media such as phosphate buffered saline (PBS) and Coastal Water (CW) and could be recovered by temperature upshift method, and compared the resuscitation using Dulbecco's Modified Eagle Medium (DMEM), sheep blood serum, chitin flakes with live Artemia salina, and the results suggests that chitin plays a significant role in regulating the VBNC state. It was also confirmed by Confocal Laser Scanning Microscopy (CLSM) and Scanning Electron Microscope (SEM) analysis that VBNC cells can alter their morphology to coccoid forms in order to survive in most extreme nutrient limited environment. Further data on the promoting factors and the exact mechanism that resuscitate VBNC V. parahaemolyticus in cold natural environments and frozen foods are needed to perform a robust risk assessment.
Collapse
Affiliation(s)
- Rohini Ramesh
- School of Life Sciences, B.S.Abdur Rahman Crescent Institute of Science and Technology, GST Road, Vandalur, Chennai, Tamil Nadu, 600048, India
| | - Karuppanan Sathiyamurthy
- Department of Bio Medical Science, School of Biotechnology and Genetic Engineering, Bharathidasan University, Tiruchirappalli, Tamil Nadu, 620 024, India
| | - Velmurugan Meganathan
- Department of Cellular and Molecular Biology Lab, University of Texas Health Science Center at Tyler, Tyler, USA
| | - Baskaran Athmanathan
- School of Life Sciences, B.S.Abdur Rahman Crescent Institute of Science and Technology, GST Road, Vandalur, Chennai, Tamil Nadu, 600048, India.
| |
Collapse
|
2
|
Li L, Bae S. Quantitative detection and survival analysis of VBNC Salmonella Typhimurium in flour using droplet digital PCR and DNA-intercalating dyes. Microbiol Spectr 2024; 12:e0024924. [PMID: 38975767 PMCID: PMC11302299 DOI: 10.1128/spectrum.00249-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2024] [Accepted: 05/13/2024] [Indexed: 07/09/2024] Open
Abstract
The difficulty in detecting viable but non-culturable (VBNC) Salmonella by culture-dependent methods poses a risk to food safety. In our study, we applied a viability test to Salmonella following a lethal treatment and to flour samples inoculated with Salmonella to evaluate the effectiveness of viability polymerase chain reaction (PCR). Our findings revealed that the combination of both ddPCR and qPCR with those DNA-intercalating dyes could quantify viable cells at low concentrations when the plate counting method failed to detect them post-inactivation. Prolonged UV exposure did not induce cell membrane disruption, as confirmed with PMA-ddPCR, with insignificant differences in gene copies. However, samples exposed to DyeTox13 and DyeTox13 + EMA showed lower gene copy numbers, implying that enzymatic activity was decreased by UV exposure duration. In addition, temperature-dependent survival in flour revealed uniform decay rates and D values (time required for a 1 log reduction) of DNA in untreated samples across various temperatures. By contrast, different decay rates were observed with DNA-intercalating dyes (DyeTox13 and DyeTox13 + EMA), showing faster metabolic activity loss at higher temperatures in flour. The decay rates and D values, determined through plate counting and those DNA-intercalating dyes, indicated the potential presence of VBNC Salmonella. A strong correlation between DyeTox13 dyes and the plate counting method suggested DyeTox13 as a rapid alternative for detecting Salmonella in flour. The ddPCR with DNA-intercalating dyes could effectively evaluate Salmonella viability, facilitating more precise monitoring of VBNC in food. IMPORTANCE Salmonella, a major foodborne pathogen, poses significant risks, particularly to vulnerable groups like infants, older people, and the immunocompromised. Accurate detection is vital for public health and food safety, given its potential to cause severe and life-threatening symptoms. Our study demonstrated digital polymerase chain reaction (ddPCR) with DNA-intercalating dyes for identifying the different physiological statuses of Salmonella. Also, the application of ddPCR with DNA-intercalating dyes offers quantification of viable cells post-disinfection as an alternative method in food. Utilizing ddPCR and DNA-intercalating dyes, we enhanced the detection of VBNC Salmonella, a form often undetectable by conventional methods. This innovative approach could significantly improve the precision and efficiency of detection for viable Salmonella. By providing deeper insights into its transmission potential, our method is a critical tool in preventing outbreaks and ensuring the safety of food products. This research contributes substantially to global efforts in controlling foodborne illnesses and safeguarding public health.
Collapse
Affiliation(s)
- Liyan Li
- Department of Civil and Environmental Engineering, College of Design and Engineering, National University of Singapore, Singapore, Singapore
| | - Sungwoo Bae
- Department of Civil and Environmental Engineering, College of Design and Engineering, National University of Singapore, Singapore, Singapore
| |
Collapse
|
3
|
Zhao S, Dou C, Zhang J, Huang L, Gao Y, Du B, Cui X, Zhao H, Xue G, Ke Y, Gan L, Feng J, Feng Y, Cui J, Yan C, Xu Z, Fu T, Yu Z, Yang Y, Yuan J, You F. Multiple factors trigger the formation and resuscitation of the VBNC state in alcohol-producing Klebsiella pneumoniae. Appl Environ Microbiol 2024; 90:e0055724. [PMID: 38953658 PMCID: PMC11267895 DOI: 10.1128/aem.00557-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2024] [Accepted: 06/05/2024] [Indexed: 07/04/2024] Open
Abstract
Klebsiella pneumoniae can enter a viable but nonculturable (VBNC) state to survive in unfavorable environments. Our research found that high-, medium-, and low-alcohol-producing K. pneumoniae strains are associated with nonalcoholic fatty liver disease. However, the presence of the three Kpn strains has not been reported in the VBNC state or during resuscitation. In this study, the effects of different strains, salt concentrations, oxygen concentrations, temperatures, and nutrients in K. pneumoniae VBNC state were evaluated. The results showed that high-alcohol-producing K. pneumoniae induced a slower VBNC state than medium-alcohol-producing K. pneumoniae, and low-alcohol-producing K. pneumoniae. A high-salt concentration and micro-oxygen environment accelerated the loss of culturability. Simultaneously, both real-time quantitative PCR and droplet digital PCR were developed to compare the quantitative comparison of three Kpn strain VBNC states by counting single-copy gene numbers. At 22°C or 37°C, the number of culturable cells decreased significantly from about 108 to 105-106 CFU/mL. In addition, imipenem, ciprofloxacin, polymyxin, and phiW14 inhibited cell resuscitation but could not kill VBNC-state cells. These results revealed that the different environments evaluated play different roles in the VBNC induction process, and new effective strategies for eliminating VBNC-state cells need to be further studied. These findings provide a better understanding of VBNC-state occurrence, maintenance, detection, and absolute quantification, as well as metabolic studies of resuscitation resistance and ethanol production.IMPORTANCEBacteria may enter VBNC state under different harsh environments. Pathogenic VBNC bacteria cells in clinical and environmental samples pose a potential threat to public health because cells cannot be found by routine culture. The alcohol-producing Kpn VBNC state was not reported, and the influencing factors were unknown. The formation and recovery of VBNC state is a complete bacterial escape process. We evaluated the influence of multiple induction conditions on the formation of VBNC state and recovery from antibiotic and bacteriophage inhibition, and established a sensitive molecular method to enumerate the VBNC cells single-copy gene. The method can improve the sensitivity of pathogen detection in clinical, food, and environmental contamination monitoring, and outbreak warning. The study of the formation and recovery of VBNC-state cells under different stress environments will also promote the microbiological research on the development, adaptation, and resuscitation in VBNC-state ecology.
Collapse
Affiliation(s)
- Shuo Zhao
- School of Basic Medical Sciences, Peking University, Beijing, China
- Department of Bacteriology, Capital Institute of Pediatrics, Beijing, China
| | - Chenpu Dou
- Department of Bacteriology, Capital Institute of Pediatrics, Beijing, China
- Department of Neurosurgery, Children’s Hospital Capital Institute of Pediatrics, Beijing, China
| | - Jian Zhang
- Department of Neurosurgery, Children’s Hospital Capital Institute of Pediatrics, Beijing, China
| | - Lijuan Huang
- Department of Bacteriology, Capital Institute of Pediatrics, Beijing, China
| | - Yagang Gao
- Department of Bacteriology, Capital Institute of Pediatrics, Beijing, China
| | - Bing Du
- Department of Bacteriology, Capital Institute of Pediatrics, Beijing, China
| | - Xiaohu Cui
- Department of Bacteriology, Capital Institute of Pediatrics, Beijing, China
| | - Hanqing Zhao
- Department of Bacteriology, Capital Institute of Pediatrics, Beijing, China
| | - Guanhua Xue
- Department of Bacteriology, Capital Institute of Pediatrics, Beijing, China
| | - Yuehua Ke
- Department of Bacteriology, Capital Institute of Pediatrics, Beijing, China
| | - Lin Gan
- Department of Bacteriology, Capital Institute of Pediatrics, Beijing, China
| | - Junxia Feng
- Department of Bacteriology, Capital Institute of Pediatrics, Beijing, China
| | - Yanling Feng
- Department of Bacteriology, Capital Institute of Pediatrics, Beijing, China
| | - Jinghua Cui
- Department of Bacteriology, Capital Institute of Pediatrics, Beijing, China
| | - Chao Yan
- Department of Bacteriology, Capital Institute of Pediatrics, Beijing, China
| | - Ziying Xu
- Department of Bacteriology, Capital Institute of Pediatrics, Beijing, China
| | - Tongtong Fu
- Department of Bacteriology, Capital Institute of Pediatrics, Beijing, China
| | - Zihui Yu
- Department of Bacteriology, Capital Institute of Pediatrics, Beijing, China
| | - Yang Yang
- Department of Bacteriology, Capital Institute of Pediatrics, Beijing, China
| | - Jing Yuan
- Department of Bacteriology, Capital Institute of Pediatrics, Beijing, China
| | - Fuping You
- School of Basic Medical Sciences, Peking University, Beijing, China
| |
Collapse
|
4
|
Genc Sen O, Erdemir A. The Effectiveness of Three Different Irrigant Activation Methods in the Elimination of Enterococcus faecalis from Root Canals. Photobiomodul Photomed Laser Surg 2024. [PMID: 39007181 DOI: 10.1089/pho.2023.0189] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/16/2024] Open
Abstract
Background and Objective: Eliminating intracanal Enterococcus faecalis (E. faecalis) is challenging because of its ability to penetrate deep dentinal tubules and its high resistance to many chemicals. This study evaluated the effectiveness of conventional needle irrigation and three different irrigant activation methods in reducing E. faecalis. Methods: The root canals of extracted teeth were shaped, contaminated with E. faecalis, and incubated for three weeks. They were randomly allocated to four experimental groups of 15 teeth each according to the final irrigation method: group 1, conventional needle irrigation; group 2, passive ultrasonic (PU) irrigation; group 3, XP-endo Finisher (XPF); and group 4, laser-activated (LA) irrigation. Bacterial samples were taken and cultured before and after these final irrigation procedures. The colony-forming units were counted, and the bacterial reduction percentages of each group were calculated. The Kruskal-Wallis and Dunnet tests were used for statistical analysis. Results: All irrigant activation methods were significantly more effective than conventional needle irrigation. Although the LA group generated more negative samples than PU, there was no statistically significant difference between the LA and PU groups. LA was significantly more effective than the XPF, whereas PU and XPF were statistically similar. Conclusions: Within the limitations of this study, the final irrigation with LA and PU showed the best reductive effect on E. faecalis colonies. Considering that the LA group had more negative samples, it may be chosen as an alternative to enhance root canal disinfection, especially in difficult cases.
Collapse
Affiliation(s)
- Ozgur Genc Sen
- Dentistry Faculty, Department of Endodontics, Van Yuzuncu Yil University, Van, Turkey
| | | |
Collapse
|
5
|
Winter H, Wagner R, Ehlbeck J, Urich T, Schnabel U. Deep Impact: Shifts of Native Cultivable Microbial Communities on Fresh Lettuce after Treatment with Plasma-Treated Water. Foods 2024; 13:282. [PMID: 38254583 PMCID: PMC10815073 DOI: 10.3390/foods13020282] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2023] [Revised: 12/18/2023] [Accepted: 01/10/2024] [Indexed: 01/24/2024] Open
Abstract
Foods consumed raw, such as lettuce, can host food-borne human-pathogenic bacteria. In the worst-case, these diseases cause to death. To limit illness and industrial losses, one innovative sanitation method is non-thermal plasma, which offers an extremely efficient reduction of living microbial biomass. Unfortunately, the total viable count (TVC), one of the most common methods for quantifying antimicrobial effects, provides no detailed insights into the composition of the surviving microbial community after treatment. To address this information gap, different special agars were used to investigate the reduction efficiency of plasma-treated water (PTW) on different native cultivable microorganisms. All tested cultivable microbial groups were reduced using PTW. Gram-negative bacteria showed a reduction of 3.81 log10, and Gram-positive bacteria showed a reduction of 3.49 log10. Fungi were reduced by 3.89 log10. These results were further validated using a live/dead assay. MALDI-ToF (matrix-assisted laser-desorption-ionization time-of-flight)-based determination was used for a diversified overview. The results demonstrated that Gram-negative bacteria were strongly reduced. Interestingly, Gram-positive bacteria and fungi were reduced by nearly equal amounts, but could still recover from PTW treatment. MALDI-ToF mainly identified Pseudomonas spp. and groups of Bacillus on the tested lettuce. These results indicate that the PTW treatment could efficiently achieve a ubiquitous, spectrum-wide reduction of microbial life.
Collapse
Affiliation(s)
- Hauke Winter
- Leibniz Institute for Plasma Science and Technology (INP), Felix-Hausdorff-Strasse 2, 17489 Greifswald, Germany; (H.W.); (R.W.); (J.E.)
- Institute of Microbiology, Center for Functional Genomics of Microbes, University of Greifswald, 17489 Greifswald, Germany;
| | - Robert Wagner
- Leibniz Institute for Plasma Science and Technology (INP), Felix-Hausdorff-Strasse 2, 17489 Greifswald, Germany; (H.W.); (R.W.); (J.E.)
| | - Jörg Ehlbeck
- Leibniz Institute for Plasma Science and Technology (INP), Felix-Hausdorff-Strasse 2, 17489 Greifswald, Germany; (H.W.); (R.W.); (J.E.)
| | - Tim Urich
- Institute of Microbiology, Center for Functional Genomics of Microbes, University of Greifswald, 17489 Greifswald, Germany;
| | - Uta Schnabel
- Leibniz Institute for Plasma Science and Technology (INP), Felix-Hausdorff-Strasse 2, 17489 Greifswald, Germany; (H.W.); (R.W.); (J.E.)
| |
Collapse
|
6
|
Pazos-Rojas LA, Cuellar-Sánchez A, Romero-Cerón AL, Rivera-Urbalejo A, Van Dillewijn P, Luna-Vital DA, Muñoz-Rojas J, Morales-García YE, Bustillos-Cristales MDR. The Viable but Non-Culturable (VBNC) State, a Poorly Explored Aspect of Beneficial Bacteria. Microorganisms 2023; 12:39. [PMID: 38257865 PMCID: PMC10818521 DOI: 10.3390/microorganisms12010039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2023] [Revised: 12/20/2023] [Accepted: 12/22/2023] [Indexed: 01/24/2024] Open
Abstract
Many bacteria have the ability to survive in challenging environments; however, they cannot all grow on standard culture media, a phenomenon known as the viable but non-culturable (VBNC) state. Bacteria commonly enter the VBNC state under nutrient-poor environments or under stressful conditions. This review explores the concept of the VBNC state, providing insights into the beneficial bacteria known to employ this strategy. The investigation covers different chemical and physical factors that can induce the latency state, cell features, and gene expression observed in cells in the VBNC state. The review also covers the significance and applications of beneficial bacteria, methods of evaluating bacterial viability, the ability of bacteria to persist in environments associated with higher organisms, and the factors that facilitate the return to the culturable state. Knowledge about beneficial bacteria capable of entering the VBNC state remains limited; however, beneficial bacteria in this state could face adverse environmental conditions and return to a culturable state when the conditions become suitable and continue to exert their beneficial effects. Likewise, this unique feature positions them as potential candidates for healthcare applications, such as the use of probiotic bacteria to enhance human health, applications in industrial microbiology for the production of prebiotics and functional foods, and in the beer and wine industry. Moreover, their use in formulations to increase crop yields and for bacterial bioremediation offers an alternative pathway to harness their beneficial attributes.
Collapse
Affiliation(s)
- Laura Abisaí Pazos-Rojas
- Faculty of Stomatology, Meritorious Autonomous University of Puebla (BUAP), Puebla 72570, Mexico; (L.A.P.-R.); (A.R.-U.)
- Monterrey Institute of Technology, School of Engineering and Sciences, Monterrey 64700, Mexico; (A.C.-S.); (A.L.R.-C.); (D.A.L.-V.)
| | - Alma Cuellar-Sánchez
- Monterrey Institute of Technology, School of Engineering and Sciences, Monterrey 64700, Mexico; (A.C.-S.); (A.L.R.-C.); (D.A.L.-V.)
| | - Ana Laura Romero-Cerón
- Monterrey Institute of Technology, School of Engineering and Sciences, Monterrey 64700, Mexico; (A.C.-S.); (A.L.R.-C.); (D.A.L.-V.)
| | - América Rivera-Urbalejo
- Faculty of Stomatology, Meritorious Autonomous University of Puebla (BUAP), Puebla 72570, Mexico; (L.A.P.-R.); (A.R.-U.)
| | - Pieter Van Dillewijn
- Department of Environmental Protection, Estación Experimental del Zaidín, Consejo Superior de Investigaciones Científicas, 18008 Granada, Spain;
| | - Diego Armando Luna-Vital
- Monterrey Institute of Technology, School of Engineering and Sciences, Monterrey 64700, Mexico; (A.C.-S.); (A.L.R.-C.); (D.A.L.-V.)
| | - Jesús Muñoz-Rojas
- Ecology and Survival of Microorganisms Group, Laboratory of Microbial Molecular Ecology (LEMM), Center for Research in Microbiological Sciences, Institute of Sciences, Meritorious Autonomous University of Puebla (BUAP), Puebla 72570, Mexico;
| | - Yolanda Elizabeth Morales-García
- Ecology and Survival of Microorganisms Group, Laboratory of Microbial Molecular Ecology (LEMM), Center for Research in Microbiological Sciences, Institute of Sciences, Meritorious Autonomous University of Puebla (BUAP), Puebla 72570, Mexico;
- Faculty of Biological Sciences, Meritorious Autonomous University of Puebla (BUAP), Puebla 72570, Mexico
| | - María del Rocío Bustillos-Cristales
- Ecology and Survival of Microorganisms Group, Laboratory of Microbial Molecular Ecology (LEMM), Center for Research in Microbiological Sciences, Institute of Sciences, Meritorious Autonomous University of Puebla (BUAP), Puebla 72570, Mexico;
| |
Collapse
|
7
|
Haas B, James S, Parker AE, Gagnon MC, Goulet N, Labrie P. Comparison of quantification methods for an endoscope lumen biofilm model. Biofilm 2023; 6:100163. [PMID: 37941805 PMCID: PMC10630603 DOI: 10.1016/j.bioflm.2023.100163] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Revised: 10/10/2023] [Accepted: 10/18/2023] [Indexed: 11/10/2023] Open
Abstract
Biofilm has been implicated in multi-drug resistant organism outbreaks following endoscopic procedures. Automated Endoscope Reprocessors (AER) are devices validated to clean and disinfect endoscopes per applicable standards. The ISO 15883 part 4 standard guides performance testing validation of AERs, including cleaning performance using a biofilm test soil. The standard recommends assessment of biofilm reduction using protein or carbohydrate quantification methods. The aim of this study was to assess the suitability of various quantification methods using the ISO biofilm model. The ISO 15883 part 5 biofilm test soil method was used to grow biofilm within lumens representative of endoscopes channels. The biofilm was then quantified using five methods: Crystal Violet (CV), Colony Forming Units (CFU), Total Organic Carbon (TOC), protein assay with Orthophtalaldehyde (OPA), and protein assay by micro bicinchoninic acid (μBCA). The five methods were statistically analyzed for their ability to assess biofilm reduction on samples accurately and precisely. In addition, the quantification methods were compared to demonstrate statistical equivalency, and thus their suitability for assessing biofilm cleaning performance testing of AERs.
Collapse
Affiliation(s)
| | | | - Albert E. Parker
- Center for Biofilm Engineering, Montana State University, Bozeman, MT, USA
- Department of Mathematical Sciences, Montana State University, Bozeman, MT, USA
| | | | | | | |
Collapse
|
8
|
Choe H, Kamono E, Abe K, Hieda Y, Ike H, Kumagai K, Kobayashi N, Inaba Y. Accuracy of Albumin, Globulin, and Albumin-Globulin Ratio for Diagnosing Periprosthetic Joint Infection: A Systematic Review and Meta-Analysis. J Clin Med 2023; 12:7512. [PMID: 38137581 PMCID: PMC10743640 DOI: 10.3390/jcm12247512] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2023] [Revised: 11/29/2023] [Accepted: 11/30/2023] [Indexed: 12/24/2023] Open
Abstract
Periprosthetic joint infection (PJI) is one of the most intractable orthopedic diseases, partly because of the difficulty in differentiating septic from aseptic conditions. We aimed to evaluate and consolidate the diagnostic accuracy of the quantitative assessment of serum albumin (Alb), globulin (Glb), and albumin-globulin ratio (AGR), alone or in combination with the inflammatory marker, C-reactive protein (CRP), for PJI. We searched the PubMed, CINAHL, and Cochrane Library databases for studies that quantitatively measured Alb, Glb, or AGR for the diagnosis of PJI up until the 30 April 2023. A total of 2339 patients were included from 10 studies, including 845 patients with a definitive diagnosis of PJI and 1494 with non-PJI. The pooled sensitivity, specificity, and area under the curve (AUC) in the summary receiver-operating characteristic curve were as follows: 0.625, 0.732, and 0.715 for Alb; 0.815, 0.857, and 0.887 for Glb; 0.753, 0.757, and 0.875 for AGR; 0.788, 0.837, and 0.876 for CRP; 0.879, 0.890, and 0.917 for the CRP-Alb ratio; and 0.845, 0.855, and 0.908 for the CRP-AGR ratio. Serum Alb, Glb, and AGR levels are feasible and accurate diagnostic markers for PJI, and the combination of these markers with CRP levels may potentially improve preoperative serum diagnostic accuracy. Future prospective studies are required to verify these findings because of the small numbers of included studies.
Collapse
Affiliation(s)
- Hyonmin Choe
- Department of Orthopedic Surgery, Yokohama City University, 3-9 Fukuura, Kanazawa-ku, Yokohama City 236-0004, Japan; (K.A.); (Y.H.); (H.I.); (K.K.); (Y.I.)
| | - Emi Kamono
- Department of Orthopedic Surgery, Yokohama City University Medical Center, 4-57 Urahune-cho, Minami-ku, Yokohama City 232-0024, Japan; (E.K.); (N.K.)
| | - Koki Abe
- Department of Orthopedic Surgery, Yokohama City University, 3-9 Fukuura, Kanazawa-ku, Yokohama City 236-0004, Japan; (K.A.); (Y.H.); (H.I.); (K.K.); (Y.I.)
| | - Yuta Hieda
- Department of Orthopedic Surgery, Yokohama City University, 3-9 Fukuura, Kanazawa-ku, Yokohama City 236-0004, Japan; (K.A.); (Y.H.); (H.I.); (K.K.); (Y.I.)
| | - Hiroyuki Ike
- Department of Orthopedic Surgery, Yokohama City University, 3-9 Fukuura, Kanazawa-ku, Yokohama City 236-0004, Japan; (K.A.); (Y.H.); (H.I.); (K.K.); (Y.I.)
| | - Ken Kumagai
- Department of Orthopedic Surgery, Yokohama City University, 3-9 Fukuura, Kanazawa-ku, Yokohama City 236-0004, Japan; (K.A.); (Y.H.); (H.I.); (K.K.); (Y.I.)
| | - Naomi Kobayashi
- Department of Orthopedic Surgery, Yokohama City University Medical Center, 4-57 Urahune-cho, Minami-ku, Yokohama City 232-0024, Japan; (E.K.); (N.K.)
| | - Yutaka Inaba
- Department of Orthopedic Surgery, Yokohama City University, 3-9 Fukuura, Kanazawa-ku, Yokohama City 236-0004, Japan; (K.A.); (Y.H.); (H.I.); (K.K.); (Y.I.)
| |
Collapse
|
9
|
Stevenson P, Marguet M, Regulski M. Biofilm and Hospital-Acquired Infections in Older Adults. Crit Care Nurs Clin North Am 2023; 35:375-391. [PMID: 37838413 DOI: 10.1016/j.cnc.2023.05.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2023]
Abstract
Biofilm infections are a serious threat to public health, resistant to traditional treatments and host immune defenses. Biofilm infections are often polymicrobial, related to chronic wounds, medical devices (eg, knee replacements, catheters, tubes, contact lenses, or prosthetic valves) and chronic recurring diseases. Biofilms are more complex than nonadhered planktonic bacteria and produce a structure that prevents damage to the bacteria within the biofilm structure. The structure provides a hidden route to feed and nurture the bacteria allowing for ongoing spread of the bacteria.
Collapse
Affiliation(s)
- Patricia Stevenson
- Next Science™ LLC, 10550 Deerwood Park Boulevard, Suite 300, Jacksonville, FL 32256, USA.
| | - Melissa Marguet
- Next Science™ LLC, 10550 Deerwood Park Boulevard, Suite 300, Jacksonville, FL 32256, USA
| | - Matthew Regulski
- Next Science™ LLC, 10550 Deerwood Park Boulevard, Suite 300, Jacksonville, FL 32256, USA; The Wound Institute of Ocean County, 54 Bey Lea Road Tom's River, NJ 08759, USA
| |
Collapse
|
10
|
Huang M, Chen L, Ma J, Mo J, He L, Liang Q, Peng G, Tan Z. Biological functions of endophytic bacteria in Robinia pseudoacacia 'Hongsen '. Front Microbiol 2023; 14:1128727. [PMID: 37621396 PMCID: PMC10446884 DOI: 10.3389/fmicb.2023.1128727] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Accepted: 07/17/2023] [Indexed: 08/26/2023] Open
Abstract
Introduction Endophytes and their host plants have co-evolved for a very long time. This relationship has led to the general recognition of endophytes as a particular class of microbial resources. R. pseudoacacia 'Hongsen' is drought- and barren-resistant species that can be grown in both the north and south of China, efficiently addresses the ecological issues caused by China's 'southern eucalyptus and northern poplar. Up to date, cultured-dependent studies are available for the R. pseudoacacia nitrogen-fixing and other endophytes. Therefore, the present research studied the R. pseudoacacia 'Hongsen,' microbiome in detail by high-throughput sequencing and culture dependant. Methods This study examined microbial species and functional diversity in Robinia pseudoacacia 'Hongsen' using culture-dependent (isolation) and culture-independent techniques. Results A total of 210 isolates were isolated from R. pseudoacacia 'Hongsen.' These isolates were clustered into 16 groups by the In Situ PCR (IS-PCR) fingerprinting patterns. 16S rRNA gene sequence analysis of the representative strain of each group revealed that these groups belonged to 16 species of 8 genera, demonstrating the diversity of endophytes in R. pseudoacacia 'Hongsen'. 'Bacillus is the most prevalent genus among all the endophytic bacteria. High-throughput sequencing of endophytic bacteria from R. pseudoacacia 'Hongsen' of the plant and the rhizosphere soil bacteria showed that the bacterial populations of soil near the root, leaf, and rhizosphere differed significantly. The microbial abundance decreased in the endophytes as compared to the rhizosphere. We observed a similar community structure of roots and leaves. With and without root nodules, Mesorhizobium sp. was significantly different in R. pseudoacacia 'Hongsen' plant. Discussion It was predicted that R. pseudoacacia 'Hongsen' plant endophytic bacteria would play a significant role in the metabolic process, such as carbohydrate metabolism, amino acid metabolism, membrane transport, and energy metabolism.
Collapse
Affiliation(s)
- Minqing Huang
- College of Agriculture, South China Agricultural University, Guangzhou, China
| | - Lijing Chen
- College of Agriculture, South China Agricultural University, Guangzhou, China
| | - Jiasi Ma
- College of Agriculture, South China Agricultural University, Guangzhou, China
| | - Jingzhi Mo
- College of Agriculture, South China Agricultural University, Guangzhou, China
| | - Lu He
- College of Agriculture, South China Agricultural University, Guangzhou, China
| | - Qihua Liang
- College of Natural Resources and Environment, South China Agricultural University, Guangzhou, China
| | - Guixiang Peng
- College of Natural Resources and Environment, South China Agricultural University, Guangzhou, China
| | - Zhiyuan Tan
- College of Agriculture, South China Agricultural University, Guangzhou, China
| |
Collapse
|
11
|
Qi Z, Sun N, Liu C. Glyoxylate cycle maintains the metabolic homeostasis of Pseudomonas aeruginosa in viable but nonculturable state induced by chlorine stress. Microbiol Res 2023; 270:127341. [PMID: 36870195 DOI: 10.1016/j.micres.2023.127341] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2022] [Revised: 02/18/2023] [Accepted: 02/18/2023] [Indexed: 02/23/2023]
Abstract
Bacteria enter a viable but non-culturable (VBNC) state with low metabolic activity to cope with environmental stress (e.g., chlorine disinfection). Elucidating the mechanism and key pathway of VBNC bacteria maintaining low metabolic competence is of great significance to realize their effective control and reduce their environmental and health risks. This study discovered that the glyoxylate cycle is a key metabolic pathway for VBNC bacteria, but not for culturable bacteria. And blocking the glyoxylate cycle pathway inhibited the reactivation and led to the death of VBNC bacteria. The main mechanisms involved the breakdown of material and energy metabolism and the antioxidant system. Gas chromatography-tandem mass spectrometry analysis showed that blocking the glyoxylate cycle led to a disruption of carbohydrate metabolism and fatty acid catabolism in VBNC bacteria. As a result, the energy metabolism system of VBNC bacteria collapsed and the abundance of energy metabolites (ATP, NAD+ and NADP+) decreased significantly. Moreover, the decrease in the level of quorum sensing signaling molecules (quinolinone and N-Butanoyl-D-homoserine lactone) inhibited the synthesis of extracellular polymeric substances (EPSs) and biofilm formation. And the downregulation of glycerophospholipid metabolic competence increased the permeability of cell membranes, leading to the entry of large amounts of hypochlorous acid (HClO) into the bacteria. In addition, the down-regulation of nucleotide metabolism, glutathione metabolism, and the reduction of antioxidant enzyme content resulted in the inability to scavenge reactive oxygen species (ROS) generated by chlorine stress. The large production of ROS and the reduction of antioxidants together led to the breakdown of the antioxidant system of VBNC bacteria. In short, the glyoxylate cycle is the key metabolism pathway of VBNC bacteria for stress resistance and maintaining cellular metabolic balance, and targeting the glyoxylate cycle represents an attractive strategy for developing new and efficient disinfection methods for the control of VBNC bacteria.
Collapse
Affiliation(s)
- Zheng Qi
- School of Environmental Science and Engineering, Shandong Key Laboratory of Environmental Processes and Health, China-America CRC for Environment & Health of Shandong Province, Shandong University, 72 Jimo Binhai Road, Qingdao, Shandong 266237, PR China
| | - Na Sun
- Jining Ecology and Environment Bureau, 30 Pipashan Street, Rencheng, Jining, Shandong, PR China
| | - Chunguang Liu
- School of Environmental Science and Engineering, Shandong Key Laboratory of Environmental Processes and Health, China-America CRC for Environment & Health of Shandong Province, Shandong University, 72 Jimo Binhai Road, Qingdao, Shandong 266237, PR China; Guangdong Provincial Key Laboratory of Environmental Protection and Resources Utilization, Guangdong, PR China.
| |
Collapse
|
12
|
Bai K, Jiang N, Chen X, Xu X, Li J, Luo L. RNA-Seq Analysis Discovers the Critical Role of Rel in ppGpp Synthesis, Pathogenicity, and the VBNC State of Clavibacter michiganensis. PHYTOPATHOLOGY 2022; 112:1844-1858. [PMID: 35341314 DOI: 10.1094/phyto-01-22-0023-r] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
The viable but nonculturable (VBNC) state is a unique survival strategy of bacteria in response to stress conditions. It was confirmed that Clavibacter michiganensis, the causal agent of bacterial canker in tomato, could be induced into the VBNC state by exposure to CuSO4 in an oligotrophic solution. RNA-sequencing analysis was used to monitor the mechanisms of the VBNC state during CuSO4 induction in C. michiganensis. The results identified that numerous genes involved in stringent response, copper resistance, and stress resistance were upregulated, and some involved in cell division were downregulated significantly. The study investigated the importance of Rel, which is an essential enzyme in the synthesis of the molecular alarmone ppGpp, via the generation of a Δrel mutant and its complementation strain. Biological characterization revealed that deficiency of rel reduced the bacterial growth, production of exopolysaccharides, and pathogenicity as well as ppGpp production. The Δrel mutant increased the sensitivity to environmental stress, exhibiting reduced growth on minimal media and a propensity to enter the VBNC state in response to CuSO4. These findings have important implications for the understanding of survival mechanism and management of C. michiganensis and other phytopathogenic bacteria.
Collapse
Affiliation(s)
- Kaihong Bai
- Department of Plant Pathology, China Agricultural University, Beijing Key Laboratory of Seed Disease Testing and Control, MOA Key Lab of Pest Monitoring and Green Management, Beijing, 100193, P.R. China
| | - Na Jiang
- Department of Plant Pathology, China Agricultural University, Beijing Key Laboratory of Seed Disease Testing and Control, MOA Key Lab of Pest Monitoring and Green Management, Beijing, 100193, P.R. China
| | - Xing Chen
- Department of Plant Pathology, China Agricultural University, Beijing Key Laboratory of Seed Disease Testing and Control, MOA Key Lab of Pest Monitoring and Green Management, Beijing, 100193, P.R. China
| | - Xiaoli Xu
- Department of Plant Pathology, China Agricultural University, Beijing Key Laboratory of Seed Disease Testing and Control, MOA Key Lab of Pest Monitoring and Green Management, Beijing, 100193, P.R. China
| | - Jianqiang Li
- Department of Plant Pathology, China Agricultural University, Beijing Key Laboratory of Seed Disease Testing and Control, MOA Key Lab of Pest Monitoring and Green Management, Beijing, 100193, P.R. China
| | - Laixin Luo
- Department of Plant Pathology, China Agricultural University, Beijing Key Laboratory of Seed Disease Testing and Control, MOA Key Lab of Pest Monitoring and Green Management, Beijing, 100193, P.R. China
| |
Collapse
|
13
|
Changes in physiological states of Salmonella Typhimurium measured by qPCR with PMA and DyeTox13 Green Azide after pasteurization and UV treatment. Appl Microbiol Biotechnol 2022; 106:2739-2750. [PMID: 35262785 DOI: 10.1007/s00253-022-11850-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Revised: 01/17/2022] [Accepted: 02/26/2022] [Indexed: 11/02/2022]
Abstract
Diarrheal diseases caused by Salmonella pose a major threat to public health, and assessment of bacterial viability is critical in determining the safety of food and drinking water after disinfection. Viability PCR could overcome the limitations of traditional culture-dependent methods for a more accurate assessment of the viability of a microbial sample. In this study, the physiological changes in Salmonella Typhimurium induced by pasteurization and UV treatment were evaluated using a culture-based method, RT-qPCR, and viability PCR. The plate count results showed no culturable S. Typhimurium after the pasteurization and UV treatments, while viability PCR with propidium monoazide (PMA) and DyeTox13-qPCR indicated that the membrane integrity of S. Typhimurium remained intact with no metabolic activity. The RT-qPCR results demonstrated that invasion protein (invA) was detectable in UV-treated cells even though the log2-fold change ranged from - 2.13 to - 5.53 for PMA treatment. However, the catalytic activity gene purE was under the detection limit after UV treatment, indicating that most Salmonella entered metabolically inactive status after UV disinfection. Also, viability PCRs were tested with artificially contaminated eggs to determine physiological status on actual food matrices. DyeTox13-qPCR methods showed that most Salmonella lost their metabolic activity but retained membrane integrity after UV disinfection. RT-qPCR may not determine the physiological status of Salmonella after UV disinfection because mRNA could be detectable in UV-treated cells depending on the choice of target gene. Viability PCR demonstrated potential for rapid and specific detection of pathogens with physiological states such as membrane integrity and metabolic activity.Key Points• Membrane integrity of Salmonella remained intact with no metabolic activity after UV.• mRNA could be detectable in UV-treated cells depending on the choice of target gene.• Viability PCR could rapidly detect specific pathogens with their physiological states.
Collapse
|
14
|
Abe K, Choe H, Oba M, Tezuka T, Ike H, Kobayashi N, Inaba Y. Inflammation and nutrition based screening tests for detection of infection in cases of rapid hip destruction. Sci Rep 2022; 12:3586. [PMID: 35246574 PMCID: PMC8897466 DOI: 10.1038/s41598-022-07678-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Accepted: 02/23/2022] [Indexed: 11/17/2022] Open
Abstract
Preoperative diagnosis of infection is important for appropriate surgical treatment of patients with rapid hip destruction (RHD). We investigated whether test results, including inflammatory and nutritional markers, could be used to accurately differentiate infectious and non-infectious RHD. Fifty patients with RHD who underwent total hip arthroplasty within a year of onset were observed. Infectious RHD was defined as ≥ 2 positive serological inflammatory, microbiological, or pathological evaluations. The albumin to globulin ratio (AGR), C-reactive protein (CRP)/albumin ratio (CAR), Glasgow prognostic score (GPS), modified GPS (mGPS), prognostic nutritional index (PNI), geriatric nutritional risk index (GNRI), and platelet to lymphocyte ratio (PLR) were calculated from the blood test results. In the infectious group, the white blood cell count, platelet count, CRP level, erythrocyte sedimentation rate, CAR, GPS, mGPS, and PLR were significantly higher, while the albumin level, AGR, PNI, and GNRI were significantly lower. The CRP and albumin levels showed the highest sensitivity (1.00 for both; specificity of 0.87 and 0.73, respectively) in diagnosing infectious RHD. Combining these measurements (CAR) increased the specificity to 0.92. The accuracy of other nutritional assessments was good. Thus, nutritional assessment as well as conventional assessment of the inflammatory response can improve the accuracy of preoperative diagnosis of infectious RHD.
Collapse
Affiliation(s)
- Koki Abe
- Department of Orthopaedic Surgery, Yokohama City University, 3-9 Fukuura, Kanazawa-Ku, Yokohama, 236-0004, Japan
| | - Hyonmin Choe
- Department of Orthopaedic Surgery, Yokohama City University, 3-9 Fukuura, Kanazawa-Ku, Yokohama, 236-0004, Japan.
| | - Masatoshi Oba
- Department of Orthopaedic Surgery, Yokohama City University, 3-9 Fukuura, Kanazawa-Ku, Yokohama, 236-0004, Japan
| | - Taro Tezuka
- Department of Orthopaedic Surgery, Yokohama City University, 3-9 Fukuura, Kanazawa-Ku, Yokohama, 236-0004, Japan
| | - Hiroyuki Ike
- Department of Orthopaedic Surgery, Yokohama City University, 3-9 Fukuura, Kanazawa-Ku, Yokohama, 236-0004, Japan
| | - Naomi Kobayashi
- Department of Orthopaedic Surgery, Yokohama City University Medical Center, Yokohama, Japan
| | - Yutaka Inaba
- Department of Orthopaedic Surgery, Yokohama City University, 3-9 Fukuura, Kanazawa-Ku, Yokohama, 236-0004, Japan
| |
Collapse
|
15
|
Detection of mecA and 16S rRNA Genes Using Real-Time PCR Can Be Useful in Diagnosing Iliopsoas Abscess, Especially in Culture-Negative Cases: RT-PCR for Iliopsoas Abscess. BIOMED RESEARCH INTERNATIONAL 2022; 2022:2209609. [PMID: 35187161 PMCID: PMC8856790 DOI: 10.1155/2022/2209609] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Revised: 12/31/2021] [Accepted: 01/18/2022] [Indexed: 11/17/2022]
Abstract
The rapid detection of etiological agents is important for the successful treatment of iliopsoas abscess (IPA). The purpose of this study was to investigate the clinical utility of a real-time polymerase chain reaction (PCR) that targets the mecA gene for methicillin-resistant staphylococci (MRS) and the 16S rRNA gene for pan-bacteria. Our retrospective diagnostic study included 22 patients exhibiting IPAs and four patients with noninfectious iliopsoas mass regions who underwent computerized tomography or ultrasonography-guided biopsy and/or surgical treatment. Clinical symptoms, serum data, imaging analysis, and tissue microbiological culture were utilized for the diagnosis of IPA. The diagnostic accuracy of real-time PCR was determined based on the diagnosis of IPA and microbiological culture results. The microbiological culture was positive for 12 IPA cases that included 2 MRSA infections. Among 12 culture-positive IPA cases, 16S rRNA-PCR was positive in 12 and MRS-PCR in two. Among 10 culture-negative IPA cases, including 3 TB cases, 16S rRNA-PCR was positive in 8 and MRS-PCR in 2. In noninfectious iliopsoas mass patients, neither 16S rRNA nor MRS-PCR detected bacterial DNA. The sensitivity, specificity, positive predictive, and negative predictive values of 16S rRNA-PCR for diagnosing IPA were 0.91, 1.00, 1.00, and 0.67, respectively, while those for the diagnosis of MRS infection with MRS-PCR were 1.00, 0.92, 1.00, and 0.50, respectively. Real-time PCR targeting bacterial DNA can detect bacterial DNA in culture-negative cases and offer improved detectability of MRS infection in IPA patients.
Collapse
|
16
|
Chen W, Jin Y, Xu D, Li W, Pan C, Li Y, Kang D, Zhang M, Zeng Z, Shan S, Zheng P. Underlying function regulators of anaerobic granular sludge: Starvation and dormancy. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 807:151024. [PMID: 34662610 DOI: 10.1016/j.scitotenv.2021.151024] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2021] [Revised: 10/08/2021] [Accepted: 10/12/2021] [Indexed: 06/13/2023]
Abstract
Anaerobic granular sludge (AnGS) is the core of anaerobic granular sludge bed system. In this study, the effect and its mechanism of stopping substrate supply on function of AnGS were investigated. The cutoff of exogenous substrate supply triggered AnGS to enter the dormant state. Some methanization microorganisms sporulated. The number and activity of methanization microorganisms based on 16S rDNA and 16S rRNA/16S rDNA ratio declined and stayed at 45.5% and 0.06% (bacteria), 48.7% and 0.39% (archaea) of the initial vegetative value, respectively. The resuming of exogenous substrate supply promoted AnGS to restore the vegetative state. The spores disappeared. The specific methanization activity of AnGS returned to the original level of 35.82 mL-CH4/g-VSS·d, but the delay time for gas production (DTGS) was prolonged from 9.54 to 18.04 h (0-132 d). The dormancy of methanization microorganisms was the main cause for the fluctuation of apparent function and the stability of intrinsic function of AnGS under starvation stress. The dormancy stabilized the structure and sustained the methanization community of AnGS via the reduction of EPS (structure binder/energy reserve) consumption.
Collapse
Affiliation(s)
- Wenda Chen
- Department of Environmental Engineering, College of Environmental & Resource Sciences, Zhejiang University, Hangzhou, China
| | - Yihao Jin
- Department of Environmental Engineering, College of Environmental & Resource Sciences, Zhejiang University, Hangzhou, China
| | - Dongdong Xu
- Department of Environmental Engineering, College of Environmental & Resource Sciences, Zhejiang University, Hangzhou, China
| | - Wenji Li
- Department of Environmental Engineering, College of Environmental & Resource Sciences, Zhejiang University, Hangzhou, China
| | - Chao Pan
- Department of Environmental Engineering, College of Environmental & Resource Sciences, Zhejiang University, Hangzhou, China
| | - Yiyu Li
- Department of Environmental Engineering, College of Environmental & Resource Sciences, Zhejiang University, Hangzhou, China
| | - Da Kang
- Department of Environmental Engineering, College of Environmental & Resource Sciences, Zhejiang University, Hangzhou, China
| | - Meng Zhang
- Advanced Environmental Biotechnology Centre, Nanyang Environment & Water Research Institute, Nanyang Technological University, Singapore
| | - Zhuo Zeng
- Department of Environmental Science & Engineering, Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Sichuan, China
| | - Shengdao Shan
- Key Lab Recycling & Ecotreatment Waste Biomass Zh, Zhejiang University of Science & Technology, Hangzhou 310023, China
| | - Ping Zheng
- Department of Environmental Engineering, College of Environmental & Resource Sciences, Zhejiang University, Hangzhou, China.
| |
Collapse
|
17
|
Zhao S, Zhang J, Li Z, Han Y, Kan B. Enumeration of Viable Non-Culturable Vibrio cholerae Using Droplet Digital PCR Combined With Propidium Monoazide Treatment. Front Cell Infect Microbiol 2021; 11:753078. [PMID: 34796126 PMCID: PMC8592976 DOI: 10.3389/fcimb.2021.753078] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Accepted: 10/12/2021] [Indexed: 11/24/2022] Open
Abstract
Many bacterial species, including Vibrio cholerae (the pathogen that causes cholera), enter a physiologically viable but non-culturable (VBNC) state at low temperature or in conditions of low nutrition; this is a survival strategy to resist environmental stress. Identification, detection, and differentiation of VBNC cells and nonviable cells are essential for both microbiological study and disease surveillance/control. Enumeration of VBNC cells requires an accurate method. Traditional counting methods do not allow quantification of VBNC cells because they are not culturable. Morphology-based counting cannot distinguish between live and dead cells. A bacterial cell possesses one copy of the chromosome. Hence, counting single-copy genes on the chromosome is a suitable approach to count bacterial cells. In this study, we developed quantitative PCR-based methods, including real-time quantitative PCR (qPCR) and droplet digital PCR (ddPCR), to enumerate VBNC V. cholerae cells by counting the numbers of single-copy genes in samples during VBNC-state development. Propidium monoazide (PMA) treatment was incorporated to distinguish dead cells from viable cells. Both PCR methods could be used to quantify the number of DNA copies/mL and determine the proportion of dead cells (when PMA was used). The methods produced comparable counts using three single-copy genes (VC1376, thyA, and recA). However, ddPCR showed greater accuracy and sensitivity than qPCR. ddPCR also allows direct counting without the need to establish a standard curve. Our study develops a PMA-ddPCR method as a new tool to quantify VBNC cells of V. cholerae. The method can be extended to other bacterial species.
Collapse
Affiliation(s)
| | | | | | | | - Biao Kan
- State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| |
Collapse
|
18
|
ARICAN B, SAZAK ÖVEÇOĞLU H. In Vitro Comparison of the Antimicrobial Effects of Different Root Canal Medicaments on Enterococcus faecalis and Candida albicans. CUMHURIYET DENTAL JOURNAL 2021. [DOI: 10.7126/cumudj.912285] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
|
19
|
Bosch J, Varliero G, Hallsworth JE, Dallas TD, Hopkins D, Frey B, Kong W, Lebre P, Makhalanyane TP, Cowan DA. Microbial anhydrobiosis. Environ Microbiol 2021; 23:6377-6390. [PMID: 34347349 DOI: 10.1111/1462-2920.15699] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Revised: 07/29/2021] [Accepted: 07/31/2021] [Indexed: 12/28/2022]
Abstract
The loss of cellular water (desiccation) and the resulting low cytosolic water activity are major stress factors for life. Numerous prokaryotic and eukaryotic taxa have evolved molecular and physiological adaptions to periods of low water availability or water-limited environments that occur across the terrestrial Earth. The changes within cells during the processes of desiccation and rehydration, from the activation (and inactivation) of biosynthetic pathways to the accumulation of compatible solutes, have been studied in considerable detail. However, relatively little is known on the metabolic status of organisms in the desiccated state; that is, in the sometimes extended periods between the drying and rewetting phases. During these periods, which can extend beyond decades and which we term 'anhydrobiosis', organismal survival could be dependent on a continued supply of energy to maintain the basal metabolic processes necessary for critical functions such as macromolecular repair. Here, we review the state of knowledge relating to the function of microorganisms during the anhydrobiotic state, highlighting substantial gaps in our understanding of qualitative and quantitative aspects of molecular and biochemical processes in desiccated cells.
Collapse
Affiliation(s)
- Jason Bosch
- Centre for Microbial Ecology and Genomics, Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Pretoria, 0002, South Africa
| | - Gilda Varliero
- Centre for Microbial Ecology and Genomics, Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Pretoria, 0002, South Africa
| | - John E Hallsworth
- Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, 19 Chlorine Gardens, Belfast, Northern Ireland, BT9 5DL, UK
| | - Tiffany D Dallas
- Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, 19 Chlorine Gardens, Belfast, Northern Ireland, BT9 5DL, UK
| | | | - Beat Frey
- Rhizosphere Processes Group, Swiss Federal Research Institute WSL, Birmensdorf, 8903, Switzerland
| | - Weidong Kong
- State Key Laboratory of Tibetan Plateau Earth System Science (LATPES), Institute of Tibetan Plateau Research, Chinese Academy of Sciences (CAS), Beijing, 100101, China
| | - Pedro Lebre
- Centre for Microbial Ecology and Genomics, Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Pretoria, 0002, South Africa
| | - Thulani P Makhalanyane
- Centre for Microbial Ecology and Genomics, Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Pretoria, 0002, South Africa
| | - Don A Cowan
- Centre for Microbial Ecology and Genomics, Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Pretoria, 0002, South Africa
| |
Collapse
|
20
|
Haditsch U, Roth T, Rodriguez L, Hancock S, Cecere T, Nguyen M, Arastu-Kapur S, Broce S, Raha D, Lynch CC, Holsinger LJ, Dominy SS, Ermini F. Alzheimer's Disease-Like Neurodegeneration in Porphyromonas gingivalis Infected Neurons with Persistent Expression of Active Gingipains. J Alzheimers Dis 2021; 75:1361-1376. [PMID: 32390638 PMCID: PMC7369049 DOI: 10.3233/jad-200393] [Citation(s) in RCA: 57] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
BACKGROUND Porphyromonas gingivalis (P. gingivalis) and its gingipain virulence factors have been identified as pathogenic effectors in Alzheimer's disease (AD). In a recent study we demonstrated the presence of gingipains in over 90% of postmortem AD brains, with gingipains localizing to the cytoplasm of neurons. However, infection of neurons by P. gingivalis has not been previously reported. OBJECTIVE To demonstrate intraneuronal P. gingivalis and gingipain expression in vitro after infecting neurons derived from human inducible pluripotent stem cells (iPSC) with P. gingivalis for 24, 48, and 72 h. METHODS Infection was characterized by transmission electron microscopy, confocal microscopy, and bacterial colony forming unit assays. Gingipain expression was monitored by immunofluorescence and RT-qPCR, and protease activity monitored with activity-based probes. Neurodegenerative endpoints were assessed by immunofluorescence, western blot, and ELISA. RESULTS Neurons survived the initial infection and showed time dependent, infection induced cell death. P. gingivalis was found free in the cytoplasm or in lysosomes. Infected neurons displayed an accumulation of autophagic vacuoles and multivesicular bodies. Tau protein was strongly degraded, and phosphorylation increased at T231. Over time, the density of presynaptic boutons was decreased. CONCLUSION P. gingivalis can invade and persist in mature neurons. Infected neurons display signs of AD-like neuropathology including the accumulation of autophagic vacuoles and multivesicular bodies, cytoskeleton disruption, an increase in phospho-tau/tau ratio, and synapse loss. Infection of iPSC-derived mature neurons by P. gingivalis provides a novel model system to study the cellular mechanisms leading to AD and to investigate the potential of new therapeutic approaches.
Collapse
Affiliation(s)
| | | | | | - Sandy Hancock
- Laboratory for Neurotoxicity Studies, Virginia-Maryland College of Veterinary Medicine, Virginia Tech, Blacksburg, VA, USA
| | - Thomas Cecere
- Laboratory for Neurotoxicity Studies, Virginia-Maryland College of Veterinary Medicine, Virginia Tech, Blacksburg, VA, USA
| | - Mai Nguyen
- Cortexyme, Inc., South San Francisco, CA, USA
| | | | - Sean Broce
- Cortexyme, Inc., South San Francisco, CA, USA
| | | | | | | | | | | |
Collapse
|
21
|
Zhang XH, Ahmad W, Zhu XY, Chen J, Austin B. Viable but nonculturable bacteria and their resuscitation: implications for cultivating uncultured marine microorganisms. MARINE LIFE SCIENCE & TECHNOLOGY 2021; 3:189-203. [PMID: 37073345 PMCID: PMC10077291 DOI: 10.1007/s42995-020-00041-3] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/23/2020] [Accepted: 03/25/2020] [Indexed: 05/03/2023]
Abstract
Culturing has been the cornerstone of microbiology since Robert Koch first successfully cultured bacteria in the late nineteenth century. However, even today, the majority of microorganisms in the marine environment remain uncultivated. There are various explanations for the inability to culture bacteria in the laboratory, including lack of essential nutrients, osmotic support or incubation conditions, low growth rate, development of micro-colonies, and the presence of senescent or viable but nonculturable (VBNC) cells. In the marine environment, many bacteria have been associated with dormancy, as typified by the VBNC state. VBNC refers to a state where bacteria are metabolically active, but are no longer culturable on routine growth media. It is apparently a unique survival strategy that has been adopted by many microorganisms in response to harsh environmental conditions and the bacterial cells in the VBNC state may regain culturability under favorable conditions. The resuscitation of VBNC cells may well be an important way to cultivate the otherwise uncultured microorganisms in marine environments. Many resuscitation stimuli that promote the restoration of culturability have so far been identified; these include sodium pyruvate, quorum sensing autoinducers, resuscitation-promoting factors Rpfs and YeaZ, and catalase. In this review, we focus on the issues associated with bacterial culturability, the diversity of bacteria entering the VBNC state, mechanisms of induction into the VBNC state, resuscitation factors of VBNC cells and implications of VBNC resuscitation stimuli for cultivating these otherwise uncultured microorganisms. Bringing important microorganisms into culture is still important in the era of high-throughput sequencing as their ecological functions in the marine environment can often only be known through isolation and cultivation.
Collapse
Affiliation(s)
- Xiao-Hua Zhang
- College of Marine Life Sciences and Institute of Evolution & Marine Biodiversity, Ocean University of China, Qingdao, 266003 China
- Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266071 China
- Frontiers Science Center for Deep Ocean Multispheres and Earth System, Ocean University of China, Qingdao, 266100 China
| | - Waqar Ahmad
- College of Marine Life Sciences and Institute of Evolution & Marine Biodiversity, Ocean University of China, Qingdao, 266003 China
| | - Xiao-Yu Zhu
- College of Marine Life Sciences and Institute of Evolution & Marine Biodiversity, Ocean University of China, Qingdao, 266003 China
| | - Jixiang Chen
- School of Petrochemical Engineering, Lanzhou University of Technology, Lanzhou, 730050 China
| | - Brian Austin
- Institute of Aquaculture, University of Stirling, Stirling, FK9 4LA Scotland, UK
| |
Collapse
|
22
|
Ng WJ, Tan CT, Bae S. Effects of monochloramine on culturability, viability and persistence of Pseudomonas putida and tap water mixed bacterial community. Appl Microbiol Biotechnol 2021; 105:3799-3810. [PMID: 33885926 DOI: 10.1007/s00253-021-11251-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Revised: 02/18/2021] [Accepted: 03/21/2021] [Indexed: 11/26/2022]
Abstract
Bacterial biofilms are able to persist in drinking water distribution systems (DWDS) even if disinfectants such as monochloramine are used to inhibit bacterial colonization and biofilm formation. While studies have determined the monochloramine concentrations required to inhibit bacterial biofilms, not much is known about how bacterial biofilms develop resistance towards monochloramine. This study covers the development of resistance to monochloramine in both single species and mixed bacterial biofilms. Through culturability tests and flow cytometry, exposing bacterial biofilms to monochloramine disinfection using a sub-lethal concentration (1.5 mg/L Cl2, experimentally determined) was sufficient to cause an increase of the monochloramine's inhibitory concentrations by as much as two times than what is initially required to inhibit biofilm growth. Through persister cultures and 16S rRNA next generation sequencing (NGS) studies, mixed bacterial biofilms experienced to monochloramine exposure resulted in more bacterial genera becoming persistent and resistant towards monochloramine. Through this study, bacterial genera that were persistent towards monochloramine were suggested to share common traits including the ability (1) to readily enter a persister or viable but non-culturable (VBNC) state and (2) to form biofilms primarily comprising proteinaceous extra-polymeric substances (EPS). Both of these traits also suggested that selected bacterial genera tended to be more persistent to monochloramine and produce EPS. This study advances our understanding of bacterial biofilm resistance towards monochloramine and showed the importance of maintaining monochloramine concentrations in DWDS to prevent the development of bacterial resistance towards monochloramine. KEY POINTS: • Monochloramine-resistant biofilm was developed after sub-lethal disinfection. • Mixed-species culture experienced monochloramine showed more persistence to monochloramine. • Ability to enter a persister/VBNC state is a common trait of persistent bacteria genera.
Collapse
Affiliation(s)
- Wei Jie Ng
- Department of Civil and Environmental Engineering, National University of Singapore, 1 Engineering Drive 2, #07-03 E1A, Singapore, 117576, Singapore
| | - Ching Thong Tan
- Department of Civil and Environmental Engineering, National University of Singapore, 1 Engineering Drive 2, #07-03 E1A, Singapore, 117576, Singapore
| | - Sungwoo Bae
- Department of Civil and Environmental Engineering, National University of Singapore, 1 Engineering Drive 2, #07-03 E1A, Singapore, 117576, Singapore.
| |
Collapse
|
23
|
Wang M, Chen H, Liu S, Xiao L. Removal of pathogen and antibiotic resistance genes from waste activated sludge by different pre-treatment approaches. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 763:143014. [PMID: 33190880 DOI: 10.1016/j.scitotenv.2020.143014] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Revised: 09/12/2020] [Accepted: 10/07/2020] [Indexed: 05/13/2023]
Abstract
In wastewater treatment plants, most of the pathogens and antibiotic resistant genes (ARGs) transferred into and concentrated in waste activated sludge (WAS), which would cause severe public health risks. In this study, the capabilities of several WAS pre-treatment approaches to inactivate coliforms/E. coli and ARGs, as well as the subsequent regrowth of coliforms/E. coli and ARGs/intI1 in treated sludge were investigated. The results showed that electro-Fenton (EF), with continuous hydroxyl radical generation, could efficiently inactivate coliforms/E. coli in 60 min (about 4 log units), followed by methanol (MT), anode oxidization (AO), and acidification (AT). Kinetic analysis showed that the inactivation mainly occurred in the first 10 min. However, the efficiencies of all studied pre-treatment approaches on inactivating ARGs/intI1 (<2 log units) were lower than coliforms/E. coli, whilst EF still had the highest efficiency of ARGs/intI1 reduction. Mechanical ultrasound treatment (ULS) could not inactivate coliforms/E. coli in WAS, but it could efficiently reduce ARGs/intI1. High regrowth rates of coliforms/E. coli were observed in the treated WAS in 10 days, but the abundances of ARGs/intI1 continuously reduced during the after-treatment incubation. Our study showed that EF could efficiently disinfect potential pathogens, however, the reduction of ARGs/intI1 in WAS need further investigation.
Collapse
Affiliation(s)
- Min Wang
- State Key laboratory of Pollution Control & Resources Reuse, School of the Environment, Nanjing University, Nanjing 210023, PR China
| | - Huiping Chen
- State Key laboratory of Pollution Control & Resources Reuse, School of the Environment, Nanjing University, Nanjing 210023, PR China
| | - Shulei Liu
- State Key laboratory of Pollution Control & Resources Reuse, School of the Environment, Nanjing University, Nanjing 210023, PR China
| | - Lin Xiao
- State Key laboratory of Pollution Control & Resources Reuse, School of the Environment, Nanjing University, Nanjing 210023, PR China.
| |
Collapse
|
24
|
Guo L, Wan K, Zhu J, Ye C, Chabi K, Yu X. Detection and distribution of vbnc/viable pathogenic bacteria in full-scale drinking water treatment plants. JOURNAL OF HAZARDOUS MATERIALS 2021; 406:124335. [PMID: 33160785 DOI: 10.1016/j.jhazmat.2020.124335] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Revised: 10/15/2020] [Accepted: 10/16/2020] [Indexed: 05/22/2023]
Abstract
Viable but non-culturable (VBNC) bacteria have attracted widespread attention since they are inherently undetected by traditional culture-dependent methods. Importantly, VBNC bacteria could resuscitate under favorable conditions leading to significant public health concerns. Although the total number of viable bacteria has been theorized to be far greater than those that can be cultured, there have been no reports quantifying VBNC pathogenic bacteria in full-scale drinking water treatment plants (DWTPs). In this work, we used both culture-dependent and quantitative PCR combination with propidium monoazide (PMA) dye approaches to characterize cellular viability. Further, we established a method to quantify viable pathogens by relating specific gene copies to viable cell numbers. Ratios of culturable bacteria to viable 16S rRNA gene copies in water and biological activated carbon (BAC) biofilms were 0-4.75% and 0.04-56.24%, respectively. The VBNC E. coli, E. faecalis, P. aeruginosa, Salmonella sp., and Shigella sp. were detected at levels of 0-103 cells/100 mL in source water, 0-102 cells/100 mL in chlorinated water, and 0-103 cells/g in BAC biofilms. In addition, differences between the total and viable community structures after ozonation and chlorination were investigated. The relative abundance of opportunistic pathogens such as Mycobacterium, Sphingomonas, etc. increased in final water, likely due to their chlorine resistance. In summary, we detected significant quantities of viable/VBNC opportunistic pathogens in full-scale DWTPs, confirming that traditional, culture-dependent methods are inadequate for detecting VBNC bacteria. These findings suggest a need to develop and implement rapid, accurate methods for the detection of VBNC pathogenic bacteria in DWTPs to ensure the safety of drinking water.
Collapse
Affiliation(s)
- Lizheng Guo
- Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Kun Wan
- Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | | | - Chengsong Ye
- College of Environment & Ecology, Xiamen University, Xiamen 361102, China
| | - Kassim Chabi
- Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xin Yu
- Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China; College of Environment & Ecology, Xiamen University, Xiamen 361102, China.
| |
Collapse
|
25
|
Innovative Control of Biofilms on Stainless Steel Surfaces Using Electrolyzed Water in the Dairy Industry. Foods 2021; 10:foods10010103. [PMID: 33419000 PMCID: PMC7825347 DOI: 10.3390/foods10010103] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Revised: 12/31/2020] [Accepted: 12/31/2020] [Indexed: 12/17/2022] Open
Abstract
Biofilms on food-contact surfaces can lead to recurrent contamination. This work aimed to study the biofilm formation process on stainless steel plates used in the dairy industry: 304 surface finish 2B and electropolished; and the effect of a cleaning and disinfection process using alkaline (AEW) and neutral (NEW) electrolyzed water. Milk fouling during heat processing can lead to type A or B deposits, which were analyzed for composition, surface energy, thickness, and roughness, while the role of raw milk microbiota on biofilm development was investigated. Bacteria, yeasts, and lactic acid bacteria were detected using EUB-338, PF2, and Str-493 probes, respectively, whereas Lis-637 probe detected Listeria sp. The genetic complexity and diversity of biofilms varied according to biofilm maturation day, as evaluated by 16S rRNA gene sequence, denaturing gradient gel electrophoresis, and fluorescence in situ hybridization microscopy. From analysis of the experimental designs, a cleaning stage of 50 mg/L NaOH of AEW at 30 °C for 10 min, followed by disinfection using 50 mg/L total available chlorine of NEW at 20 °C for 5 min is a sustainable alternative process to prevent biofilm formation. Fluorescence microscopy was used to visualize the effectiveness of this process.
Collapse
|
26
|
Ríos-Castillo AG, Ripolles-Avila C, Rodríguez-Jerez JJ. Evaluation of bacterial population using multiple sampling methods and the identification of bacteria detected on supermarket food contact surfaces. Food Control 2021. [DOI: 10.1016/j.foodcont.2020.107471] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
|
27
|
Affiliation(s)
- Shao-Ting Jerry Tsang
- Department of Orthopaedic Surgery, University of Edinburgh, Edinburgh, UK.,Department of Trauma and Orthopaedics, Royal Infirmary of Edinburgh, Edinburgh, UK
| | | |
Collapse
|
28
|
Alotaibi GF. Occurrence of Potentially Pathogenic Bacteria in Epilithic Biofilm Forming Bacteria isolated from Porter Brook River-stones, Sheffield, UK. Saudi J Biol Sci 2020; 27:3405-3414. [PMID: 33304149 PMCID: PMC7715045 DOI: 10.1016/j.sjbs.2020.09.030] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2020] [Revised: 09/13/2020] [Accepted: 09/14/2020] [Indexed: 10/24/2022] Open
Abstract
Biofilms in aquatic ecosystems develop on wet benthic surfaces and are primarily comprised of various allochthonous microorganisms, including bacteria embedded within a self-produced matrix of extracellular polymeric substances (EPS). In such environment, where there is a continuous flow of water, attachment of microbes to surfaces prevents cells being washed out of a suitable habitat with the added benefits of the water flow and the surface itself providing nutrients for growth of attached cells. When watercourses are contaminated with pathogenic bacteria, these can become incorporated into biofilms. This study aimed to isolate and identify the bacterial species within biofilms retrieved from river-stones found in the Porter Brook, Sheffield based on morphological, biochemical characteristics and molecular characteristics, such as 16S rDNA sequence phylogeny analysis. Twenty-two bacterial species were identified. Among these were 10 gram-negative pathogenic bacteria, establishing that potential human pathogens were present within the biofilms. Klebsiella pneumoniae MBB9 isolate showed the greatest ability to form a biofilm using a microtiter plate-based crystal violet assay. Biofilm by K. pneumoniae MBB9 formed rapidly (within 6 h) under static conditions at 37 °C and then increased up to 24 h of incubation before decreasing with further incubation (48 h), whereas the applied shear forces (horizontal orbital shaker; diameter of 25 mm at 150 rpm) had no effect on K. pneumoniae MBB9 biofilm formation.
Collapse
Affiliation(s)
- Ghazay F. Alotaibi
- Department of Molecular Biology and Biotechnology, The University of Sheffield, Sheffield S10 2TN, United Kingdom
- Department of Environment and Marine Biology, Saline Water Desalination Technologies Research Institute, P.O. 8328 Al-Jubail 31951 Al-Jubail, Saudi Arabia
| |
Collapse
|
29
|
Pereira TC, Dijkstra RJB, Petridis X, Sharma PK, van de Meer WJ, van der Sluis LWM, de Andrade FB. Chemical and mechanical influence of root canal irrigation on biofilm removal from lateral morphological features of simulated root canals, dentine discs and dentinal tubules. Int Endod J 2020; 54:112-129. [PMID: 32880989 PMCID: PMC7839520 DOI: 10.1111/iej.13399] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Accepted: 08/26/2020] [Indexed: 01/08/2023]
Abstract
Aim To investigate the anti‐biofilm efficacy of irrigation using a simulated root canal model, the chemical effect of irrigants against biofilms grown on dentine discs and their impact on biofilm viscoelasticity, the efficacy of the irrigants in decontaminating infected dentinal tubules and the capacity of bacteria to regrow. Methodology Biofilm removal, viscoelastic analysis of remaining biofilms and bacterial viability were evaluated using a simulated root canal model with lateral morphological features, dentine discs and a dentinal tubule model, respectively. Experiments were conducted using a two‐phase irrigation protocol. Phase 1: a modified salt solution (RISA) and sodium hypochlorite (NaOCl) were used at a low flow rate to evaluate the chemical action of the irrigants. Ultrasonic activation (US) of a chemically inert solution (buffer) was used to evaluate the mechanical efficacy of irrigation. Phase 2: a final irrigation with buffer at a high flow rate was performed for all groups. Optical coherence tomography (OCT), low load compression testing (LLCT) and confocal scanning laser microscopy analysis were used in the different models. One‐way analysis of variance (anova) was performed for the OCT and LLCT analysis, whilst Kruskal–Wallis and Wilcoxon ranked tests for the dentinal tubule model. Results US and high flow rate removed significantly more biofilm from the artificial lateral canal. For biofilm removal from the artificial isthmus, no significant differences were found between the groups. Within‐group analysis revealed significant differences between the steps of the experiment, with the exception of NaOCl. For the dentine discs, no significant differences regarding biofilm removal and viscoelasticity were detected. In the dentinal tubule model, NaOCl exhibited the greatest anti‐biofilm efficacy. Conclusions The mechanical effect of irrigation is important for biofilm removal. An extra high flow irrigation rate resulted in greater biofilm removal than US in the artificial isthmus. The mechanical effect of US seemed to be more effective when the surface contact biofilm–irrigant was small. After the irrigation procedures, the remaining biofilm could survive after a 5‐day period. RISA and NaOCl seemed to alter post‐treatment remaining biofilms.
Collapse
Affiliation(s)
- T C Pereira
- Department of Dentistry, Endodontics and Dental Materials, Bauru School of Dentistry, University of São Paulo, Bauru, Brazil.,Center for Dentistry and Oral Hygiene, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - R J B Dijkstra
- Center for Dentistry and Oral Hygiene, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - X Petridis
- Center for Dentistry and Oral Hygiene, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - P K Sharma
- Department of Biomedical Engineering, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - W J van de Meer
- Department of Orthodontics, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - L W M van der Sluis
- Center for Dentistry and Oral Hygiene, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - F B de Andrade
- Department of Dentistry, Endodontics and Dental Materials, Bauru School of Dentistry, University of São Paulo, Bauru, Brazil
| |
Collapse
|
30
|
Zhao YM, Patange A, Sun DW, Tiwari B. Plasma-activated water: Physicochemical properties, microbial inactivation mechanisms, factors influencing antimicrobial effectiveness, and applications in the food industry. Compr Rev Food Sci Food Saf 2020; 19:3951-3979. [PMID: 33337045 DOI: 10.1111/1541-4337.12644] [Citation(s) in RCA: 68] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Revised: 08/20/2020] [Accepted: 09/16/2020] [Indexed: 12/19/2022]
Abstract
Novel nonthermal inactivation technologies have been increasingly popular over the traditional thermal food processing methods due to their capacity in maintaining microbial safety and other quality parameters. Plasma-activated water (PAW) is a cutting-edge technology developed around a decade ago, and it has attracted considerable attention as a potential washing disinfectant. This review aims to offer an overview of the fundamentals and potential applications of PAW in the agri-food sector. A detailed description of the interactions between plasma and water can help to have a better understanding of PAW, hence the physicochemical properties of PAW are discussed. Further, this review elucidates the complex inactivation mechanisms of PAW, including oxidative stress and physical effect. In particular, the influencing factors on inactivation efficacy of PAW, including processing factors, characteristics of microorganisms, and background environment of water are extensively described. Finally, the potential applications of PAW in the food industry, such as surface decontamination for various food products, including fruits and vegetables, meat and seafood, and also the treatment on quality parameters are presented. Apart from decontamination, the applications of PAW for seed germination and plant growth, as well as meat curing are also summarized. In the end, the challenges and limitations of PAW for scale-up implementation, and future research efforts are also discussed. This review demonstrates that PAW has the potential to be successfully used in the food industry.
Collapse
Affiliation(s)
- Yi-Ming Zhao
- Food Refrigeration and Computerised Food Technology (FRCFT), School of Biosystems and Food Engineering, University College Dublin, National University of Ireland, Belfield, Dublin, Ireland.,Food Chemistry and Technology Department, Teagasc Food Research Centre Ashtown, Dublin, Ireland
| | - Apurva Patange
- Food Chemistry and Technology Department, Teagasc Food Research Centre Ashtown, Dublin, Ireland
| | - Da-Wen Sun
- Food Refrigeration and Computerised Food Technology (FRCFT), School of Biosystems and Food Engineering, University College Dublin, National University of Ireland, Belfield, Dublin, Ireland
| | - Brijesh Tiwari
- Food Chemistry and Technology Department, Teagasc Food Research Centre Ashtown, Dublin, Ireland
| |
Collapse
|
31
|
Polymicrobial infections and microbial patterns in infected nonunions - a descriptive analysis of 42 cases. BMC Infect Dis 2020; 20:667. [PMID: 32912204 PMCID: PMC7488339 DOI: 10.1186/s12879-020-05386-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Accepted: 08/30/2020] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Frequencies of polymicrobial infection and pathogens evidenced in course of infected nonunion treatment are largely unknown. Therefore, this study aims at investigating microbial patterns in infected nonunions. METHODS Surgically treated patients with long bone infected nonunion admitted between January 2010 and March 2018 were included in the study. Microbiological culture and polymerase-chain-reaction results of tissue samples of initial and follow-up revision surgeries were assessed and compared with patient and treatment characteristics. RESULTS Forty two patients with a mean age of 53.9 ± 17.7 years were included. In six patients (14.3%) polymicrobial infection was evident. A change of pathogens evidenced in course of the treatment occurred in 21 patients (50%). In 16 patients (38.1%) previously detected bacteria could be determined by microbial testing after further revision surgery. Staphylococcus aureus was most often detected (n = 34, 30.6%), followed by Enterococcus spp. (n = 25, 22.5%) and Staphylococcus epidermidis (n = 18, 16.2%). Five Staphylococcus aureus were resistant to methicillin (MRSA). In patients without polymicrobial infection or further germ detection in course of the treatment, 86.4% of the infections were due to Staphylococcus spp.. Infections due to Streptococcus spp. and gram-negative bacteria were only present in patients with polymicrobial infection and germ-change in course of the treatment. CONCLUSION A low rate of polymicrobial infections was evidenced in the present study. Germ-change often occurs in course of revision surgeries. Prospective studies with more sensitive diagnostic tools are necessary to elucidate the therapeutical relevance of microbiological testing results for surgical as well as medical treatment in infected nonunions.
Collapse
|
32
|
Khezri M, Rezaei M, Mohabbati Mobarez A, Zolfaghari M. Viable but non culturable state and expression of pathogenic genes of
Escherichia coli
O157
:
H7
in salted silver carp. J Food Saf 2020. [DOI: 10.1111/jfs.12843] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Mohammad Khezri
- Department of Seafood Processing, Faculty of Marine Sciences Tarbiat Modares University Noor Iran
| | - Masoud Rezaei
- Department of Seafood Processing, Faculty of Marine Sciences Tarbiat Modares University Noor Iran
| | | | - Mehdi Zolfaghari
- Faculty of Fisheries and Environmental Sciences Agricultur and Natural Resource University of Gorgan Gorgan Iran
| |
Collapse
|
33
|
Faille C, Brauge T, Leleu G, Hanin A, Denis C, Midelet G. Comparison of the performance of the biofilm sampling methods (swab, sponge, contact agar) in the recovery of Listeria monocytogenes populations considering the seafood environment conditions. Int J Food Microbiol 2020; 325:108626. [DOI: 10.1016/j.ijfoodmicro.2020.108626] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Revised: 03/29/2020] [Accepted: 03/30/2020] [Indexed: 11/25/2022]
|
34
|
Pannella G, Lombardi SJ, Coppola F, Vergalito F, Iorizzo M, Succi M, Tremonte P, Iannini C, Sorrentino E, Coppola R. Effect of Biofilm Formation by Lactobacillus plantarum on the Malolactic Fermentation in Model Wine. Foods 2020; 9:E797. [PMID: 32560415 PMCID: PMC7353508 DOI: 10.3390/foods9060797] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Revised: 06/11/2020] [Accepted: 06/15/2020] [Indexed: 11/16/2022] Open
Abstract
Biofilm life-style of Lactobacillus plantarum (L. plantarum) strains was evaluated in vitro as a new and suitable biotechnological strategy to assure L-malic acid conversion in wine stress conditions. Sixty-eight L. plantarum strains isolated from diverse sources were assessed for their ability to form biofilm in acid (pH 3.5 or 3.2) or in ethanol (12% or 14%) stress conditions. The effect of incubation times (24 and 72 h) on the biofilm formation was evaluated. The study highlighted that, regardless of isolation source and stress conditions, the ability to form biofilm was strain-dependent. Specifically, two clusters, formed by high and low biofilm producer strains, were identified. Among high producer strains, L. plantarum Lpls22 was chosen as the highest producer strain and cultivated in planktonic form or in biofilm using oak supports. Model wines at 12% of ethanol and pH 3.5 or 3.2 were used to assess planktonic and biofilm cells survival and to evaluate the effect of biofilm on L-malic acid conversion. For cells in planktonic form, a strong survival decay was detected. In contrast, cells in biofilm life-style showed high resistance, assuring a prompt and complete L-malic acid conversion.
Collapse
Affiliation(s)
- Gianfranco Pannella
- Department of Agricultural, Environmental and Food Sciences (DiAAA), University of Molise, via De Sanctis snc, 86100 Campobasso, Italy; (G.P.); (S.J.L.); (F.V.); (M.S.); (P.T.); (C.I.); (E.S.); (R.C.)
| | - Silvia Jane Lombardi
- Department of Agricultural, Environmental and Food Sciences (DiAAA), University of Molise, via De Sanctis snc, 86100 Campobasso, Italy; (G.P.); (S.J.L.); (F.V.); (M.S.); (P.T.); (C.I.); (E.S.); (R.C.)
| | - Francesca Coppola
- Department of Agricultural Sciences, Grape and Wine Science Division, University of Naples “Federico II”, Viale Italia, 83100 Avellino, Italy;
| | - Franca Vergalito
- Department of Agricultural, Environmental and Food Sciences (DiAAA), University of Molise, via De Sanctis snc, 86100 Campobasso, Italy; (G.P.); (S.J.L.); (F.V.); (M.S.); (P.T.); (C.I.); (E.S.); (R.C.)
| | - Massimo Iorizzo
- Department of Agricultural, Environmental and Food Sciences (DiAAA), University of Molise, via De Sanctis snc, 86100 Campobasso, Italy; (G.P.); (S.J.L.); (F.V.); (M.S.); (P.T.); (C.I.); (E.S.); (R.C.)
| | - Mariantonietta Succi
- Department of Agricultural, Environmental and Food Sciences (DiAAA), University of Molise, via De Sanctis snc, 86100 Campobasso, Italy; (G.P.); (S.J.L.); (F.V.); (M.S.); (P.T.); (C.I.); (E.S.); (R.C.)
| | - Patrizio Tremonte
- Department of Agricultural, Environmental and Food Sciences (DiAAA), University of Molise, via De Sanctis snc, 86100 Campobasso, Italy; (G.P.); (S.J.L.); (F.V.); (M.S.); (P.T.); (C.I.); (E.S.); (R.C.)
| | - Caterina Iannini
- Department of Agricultural, Environmental and Food Sciences (DiAAA), University of Molise, via De Sanctis snc, 86100 Campobasso, Italy; (G.P.); (S.J.L.); (F.V.); (M.S.); (P.T.); (C.I.); (E.S.); (R.C.)
| | - Elena Sorrentino
- Department of Agricultural, Environmental and Food Sciences (DiAAA), University of Molise, via De Sanctis snc, 86100 Campobasso, Italy; (G.P.); (S.J.L.); (F.V.); (M.S.); (P.T.); (C.I.); (E.S.); (R.C.)
| | - Raffaele Coppola
- Department of Agricultural, Environmental and Food Sciences (DiAAA), University of Molise, via De Sanctis snc, 86100 Campobasso, Italy; (G.P.); (S.J.L.); (F.V.); (M.S.); (P.T.); (C.I.); (E.S.); (R.C.)
| |
Collapse
|
35
|
Kadkhodaei S, Siavoshi F, Akbari Noghabi K. Mucoid and coccoid Helicobacter pylori with fast growth and antibiotic resistance. Helicobacter 2020; 25:e12678. [PMID: 31880001 DOI: 10.1111/hel.12678] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/02/2019] [Revised: 12/03/2019] [Accepted: 12/05/2019] [Indexed: 12/31/2022]
Abstract
BACKGROUND In this study, one Helicobacter pylori isolate, from gastric biopsy of a dyspeptic patient that turned into mucoid-coccoid (MC) form upon consecutive subcultures, was identified. The culturability, antibiotic resistance, and lipid contents of MC were compared with those of non-mucoid (NM) spiral H pylori. MATERIALS AND METHODS Mucoid-coccoid and NM H pylori were subcultured on Brucella blood agar (BBA) and incubated under aerobic and microaerobic atmospheres at 37°C. Cultures were examined for colony characteristics and bacterial morphology after 1-3 days. The isolates were identified by biochemical tests and detection of H pylori-16S rDNA. Antibiogram was performed with currently used antibiotics for H pylori eradication. Cellular lipid contents were extracted and analyzed by gas chromatography. RESULTS Compared with pin-pointed and glistening colonies of NM H pylori that appeared under microaerobic conditions, MC H pylori grew well in consecutive subcultures under aerobic and microaerobic atmospheres and produced white patches of mucoid colonies. MC exhibited coccoid and NM spiral morphology. Both isolates were catalase, oxidase, and urease positive and contained 16S rDNA. Compared with NM that was susceptible to almost all the antibiotics, MC was resistant to all the antibiotics. Lipid analyses showed high frequency of unsaturated fatty acids and cholesterol in MC. CONCLUSIONS Coccoid forms with high fatty acid and cholesterol contents that show resistance to antibiotics might resist against other stressful conditions such as gastric acidity and immune response. Moreover, mucoid property may enhance resistance of coccoids to stresses. With mucoid-coccoid lifestyle, H pylori may establish a chronic infection refractory to antimicrobial therapy.
Collapse
Affiliation(s)
- Sara Kadkhodaei
- Department of Microbiology, School of Biology, University College of Sciences, Tehran University, Tehran, Iran
| | - Farideh Siavoshi
- Department of Microbiology, School of Biology, University College of Sciences, Tehran University, Tehran, Iran
| | - Kambiz Akbari Noghabi
- Department of Molecular Genetics, National Institute of Genetic Engineering and Biotechnology (NIGEB), Tehran, Iran
| |
Collapse
|
36
|
Han L, Wang K, Ma L, Delaquis P, Bach S, Feng J, Lu X. Viable but Nonculturable Escherichia coli O157:H7 and Salmonella enterica in Fresh Produce: Rapid Determination by Loop-Mediated Isothermal Amplification Coupled with a Propidium Monoazide Treatment. Appl Environ Microbiol 2020; 86:e02566-19. [PMID: 32005729 PMCID: PMC7082562 DOI: 10.1128/aem.02566-19] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2019] [Accepted: 01/21/2020] [Indexed: 11/20/2022] Open
Abstract
Escherichia coli O157:H7 and Salmonella enterica are leading causes of foodborne outbreaks linked to fresh produce. Both species can enter the "viable but nonculturable" (VBNC) state that precludes detection using conventional culture-based or molecular methods. In this study, we assessed propidium monoazide-quantitative PCR (PMA-qPCR) assays and novel methods combining PMA and loop-mediated isothermal amplification (LAMP) for the detection and quantification of VBNC E. coli O157:H7 and S. enterica in fresh produce. The performance of PMA-LAMP assays targeting the wzy gene of E. coli O157:H7 and the agfA gene of S. enterica and the performance of PMA-qPCR assays were compared in pure culture and spiked tomato, lettuce, and spinach. No cross-reaction was observed in the specificity tests. The values representing the limit of detection (LOD) seen with PMA-LAMP were 9.0 CFU/reaction for E. coli O157:H7 and 4.6 CFU/reaction for S. enterica in pure culture and were 5.13 × 103 or 5.13 × 104 CFU/g for VBNC E. coli O157:H7 and 1.05 × 104 or 1.05 × 105 CFU/g for VBNC S. enterica in fresh produce, representing results comparable to those obtained by PMA-qPCR. Standard curves showed correlation coefficients ranging from 0.925 to 0.996, indicating a good quantitative capacity of PMA-LAMP for determining populations of both bacterial species in the VBNC state. The PMA-LAMP assay was completed with considerable economy of time (30 min versus 1 h) and achieved sensitivity and quantitative capacity comparable to those seen with a PMA-qPCR assay. PMA-LAMP is a rapid, sensitive, and robust method for the detection and quantification of VBNC E. coli O157:H7 and S. enterica in fresh produce.IMPORTANCE VBNC pathogenic bacteria pose a potential risk to the food industry because they do not multiply on routine microbiological media and thus can evade detection in conventional plating assays. Both E. coli O157:H7 and S. enterica have been reported to enter the VBNC state under a range of environmental stress conditions and to resuscitate under favorable conditions and are a potential cause of human infections. PMA-LAMP methods developed in this study provide a rapid, sensitive, and specific way to determine levels of VBNC E. coli O157:H7 and S. enterica in fresh produce, which potentially decreases the risks related to the consumption of fresh produce contaminated by enteric pathogens in this state. PMA-LAMP can be further applied in the field study to enhance our understanding of the fate of VBNC pathogens in the preharvest and postharvest stages of fresh produce.
Collapse
Affiliation(s)
- Lu Han
- Food, Nutrition and Health Program, Faculty of Land and Food Systems, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Kaidi Wang
- Food, Nutrition and Health Program, Faculty of Land and Food Systems, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Lina Ma
- Food, Nutrition and Health Program, Faculty of Land and Food Systems, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Pascal Delaquis
- Agriculture and Agri-Food Canada, Summerland Research and Development Centre, Summerland, British Columbia, Canada
| | - Susan Bach
- Agriculture and Agri-Food Canada, Summerland Research and Development Centre, Summerland, British Columbia, Canada
| | - Jinsong Feng
- Food, Nutrition and Health Program, Faculty of Land and Food Systems, The University of British Columbia, Vancouver, British Columbia, Canada
- Department of Microbiology and Immunology, The University of British Columbia, Vancouver, British Columbia, Canada
- Michael Smith Laboratories, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Xiaonan Lu
- Food, Nutrition and Health Program, Faculty of Land and Food Systems, The University of British Columbia, Vancouver, British Columbia, Canada
| |
Collapse
|
37
|
Xu D, Kang D, Ding A, Li Y, Yu T, Li W, Zeng Z, Guo L, Zheng P. Response of FANIR system to starvation stress: "Dormancy". WATER RESEARCH 2020; 171:115380. [PMID: 31865124 DOI: 10.1016/j.watres.2019.115380] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2019] [Revised: 12/03/2019] [Accepted: 12/07/2019] [Indexed: 06/10/2023]
Abstract
Anaerobic ammonium oxidation (Anammox) process has been successfully applied in the nitrogen removal from high-strength wastewaters. However, little information is available for its treatment of low-strength wastewaters. In this study, a Famine Anammox NItrogen Removal (FANIR) system was developed to investigate the effect of long-term substrate starvation at the low nitrogen concentration (the influent total nitrogen was set at ∼1 mg/L). The results showed that the response of FANIR system to the starvation stress took on two phases: the functional decline phase (0-54 day) and the functional stabilization phase (62-116 day). Over the two phases, the Nitrogen Removal Rate (NRR) of anammox reactor firstly dropped sharply; and then came to a constant level. The activity and settleability of Anammox Granular Sludge (AnGS) firstly deteriorated seriously, and then stayed in a stable range. The relative abundance of Anaerobic Ammonium Oxidation Bacteria (AnAOB) firstly decreased markedly, and then approached a steady state with the change of dominant genus from Candidatus Brocadia to Candidatus Kuenenia. The abundance of 16S rRNA gene and hzs gene of AnAOB and their transcription level firstly declined largely as well, and then became stable with the 16S rRNA gene, hzs gene, 16S rRNA and hzs-mRNA of AnAOB at 23.9%, 9.1%, 1.2% and 1.0% of the initial value, respectively. To our delight, the behavior of FANIR system in the functional stabilization phase was proved indeed consistent with the feature for AnAOB to enter the dormancy state. These findings are helpful to understand the physiology of AnAOB over the starvation stress and to promote the extension of anammox process to the treatment of low-strength wastewaters.
Collapse
Affiliation(s)
- Dongdong Xu
- Department of Environmental Engineering, College of Environmental & Resource Sciences, Zhejiang University, Hangzhou, China
| | - Da Kang
- Department of Environmental Engineering, College of Environmental & Resource Sciences, Zhejiang University, Hangzhou, China
| | - Aqiang Ding
- Department of Environmental Science College of Resource and Environmental Science, Chongqing University, Chongqing, China
| | - Yiyu Li
- Department of Environmental Engineering, College of Environmental & Resource Sciences, Zhejiang University, Hangzhou, China
| | - Tao Yu
- Department of Environmental Engineering, College of Environmental & Resource Sciences, Zhejiang University, Hangzhou, China
| | - Wenji Li
- Department of Environmental Engineering, College of Environmental & Resource Sciences, Zhejiang University, Hangzhou, China
| | - Zhuo Zeng
- Department of Environmental Engineering, College of Environmental & Resource Sciences, Zhejiang University, Hangzhou, China
| | - Leiyan Guo
- Department of Environmental Engineering, College of Environmental & Resource Sciences, Zhejiang University, Hangzhou, China
| | - Ping Zheng
- Department of Environmental Engineering, College of Environmental & Resource Sciences, Zhejiang University, Hangzhou, China.
| |
Collapse
|
38
|
Abstract
Pseudomonas putidais a fast-growing bacterium found mostly in temperate soil and water habitats. The metabolic versatility ofP. putidamakes this organism attractive for biotechnological applications such as biodegradation of environmental pollutants and synthesis of added-value chemicals (biocatalysis). This organism has been extensively studied in respect to various stress responses, mechanisms of genetic plasticity and transcriptional regulation of catabolic genes.P. putidais able to colonize the surface of living organisms, but is generally considered to be of low virulence. A number ofP. putidastrains are able to promote plant growth. The aim of this review is to give historical overview of the discovery of the speciesP. putidaand isolation and characterization ofP. putidastrains displaying potential for biotechnological applications. This review also discusses some major findings inP. putidaresearch encompassing regulation of catabolic operons, stress-tolerance mechanisms and mechanisms affecting evolvability of bacteria under conditions of environmental stress.
Collapse
|
39
|
Wang B, Liu S, Sui Z, Wang J, Wang Y, Gu S. Rapid Flow Cytometric Detection of Single Viable Salmonella Cells in Milk Powder. Foodborne Pathog Dis 2020; 17:447-458. [PMID: 32004087 DOI: 10.1089/fpd.2019.2748] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Salmonella, a highly virulent food-borne pathogen transmitted through food, can cause severe infectious diseases in a large number of people through a single outbreak, due to its low infective doses. In this study, a flow cytometry (FCM)-based method was developed for the rapid detection of single viable Salmonella cells with dual staining of fluorescein isothiocyanate (FITC)-labeled anti-Salmonella antibody and propidium iodide (PI) dyes. The FCM-based method includes 6 h of pre-enrichment, 40 min of target cell isolation, and 20 min of dual staining and FCM analysis. The developed method demonstrated high specificity for the detection of 23 Salmonella strains and 22 food-borne pathogenic non-Salmonella strains. Furthermore, the analyses of 30 samples of milk powder artificially contaminated with single Salmonella cells, 123 samples of retail milk powder, and 6 samples of Salmonella-positive milk powder were performed by the FCM-based as well as traditional plate-based methods for testing the efficiency of the methods. The two methods yielded similar results for the detection of pathogens in all milk powder samples. In conclusion, the developed FCM-based method was found to be efficient in detecting single viable Salmonella cells in milk powder within 7 h. The proposed dual-color FITC assay combined with pre-enrichment offers a great potential for the rapid and sensitive detection of other pathogens in dairy products.
Collapse
Affiliation(s)
- Bin Wang
- Center for Advanced Measurement Science, National Institute of Metrology, Beijing, China.,Research Center for Ginseng Genetic Resources Development and Utilization, Jilin Agricultural University, Changchun, China
| | - Siyuan Liu
- Center for Advanced Measurement Science, National Institute of Metrology, Beijing, China
| | - Zhiwei Sui
- Center for Advanced Measurement Science, National Institute of Metrology, Beijing, China
| | - Jing Wang
- Center for Advanced Measurement Science, National Institute of Metrology, Beijing, China
| | - Yi Wang
- Research Center for Ginseng Genetic Resources Development and Utilization, Jilin Agricultural University, Changchun, China
| | - Shaopeng Gu
- Shanxi Key Laboratory of Environmental Veterinary Medicine, College of Animal Science and Veterinary Medicine, Shanxi Agricultural University, Taigu, China
| |
Collapse
|
40
|
Dong K, Pan H, Yang D, Rao L, Zhao L, Wang Y, Liao X. Induction, detection, formation, and resuscitation of viable but non‐culturable state microorganisms. Compr Rev Food Sci Food Saf 2019; 19:149-183. [DOI: 10.1111/1541-4337.12513] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2019] [Revised: 10/21/2019] [Accepted: 11/14/2019] [Indexed: 01/05/2023]
Affiliation(s)
- Kai Dong
- Beijing Advanced Innovation Center for Food Nutrition and Human HealthCollege of Food Science and Nutritional EngineeringChina Agricultural University Beijing China
- College of Food Science and Nutritional EngineeringChina Agricultural University Beijing China
- Key Lab of Fruit and Vegetable ProcessingMinistry of Agriculture and Rural Affairs Beijing China
| | - Hanxu Pan
- Beijing Advanced Innovation Center for Food Nutrition and Human HealthCollege of Food Science and Nutritional EngineeringChina Agricultural University Beijing China
- College of Food Science and Nutritional EngineeringChina Agricultural University Beijing China
- Key Lab of Fruit and Vegetable ProcessingMinistry of Agriculture and Rural Affairs Beijing China
| | - Dong Yang
- Beijing Advanced Innovation Center for Food Nutrition and Human HealthCollege of Food Science and Nutritional EngineeringChina Agricultural University Beijing China
- College of Food Science and Nutritional EngineeringChina Agricultural University Beijing China
- Key Lab of Fruit and Vegetable ProcessingMinistry of Agriculture and Rural Affairs Beijing China
| | - Lei Rao
- Beijing Advanced Innovation Center for Food Nutrition and Human HealthCollege of Food Science and Nutritional EngineeringChina Agricultural University Beijing China
- College of Food Science and Nutritional EngineeringChina Agricultural University Beijing China
- Key Lab of Fruit and Vegetable ProcessingMinistry of Agriculture and Rural Affairs Beijing China
| | - Liang Zhao
- College of Food Science and Nutritional EngineeringChina Agricultural University Beijing China
- Key Lab of Fruit and Vegetable ProcessingMinistry of Agriculture and Rural Affairs Beijing China
| | - Yongtao Wang
- College of Food Science and Nutritional EngineeringChina Agricultural University Beijing China
- Key Lab of Fruit and Vegetable ProcessingMinistry of Agriculture and Rural Affairs Beijing China
| | - Xiaojun Liao
- Beijing Advanced Innovation Center for Food Nutrition and Human HealthCollege of Food Science and Nutritional EngineeringChina Agricultural University Beijing China
- College of Food Science and Nutritional EngineeringChina Agricultural University Beijing China
- Key Lab of Fruit and Vegetable ProcessingMinistry of Agriculture and Rural Affairs Beijing China
| |
Collapse
|
41
|
Guo L, Ye C, Cui L, Wan K, Chen S, Zhang S, Yu X. Population and single cell metabolic activity of UV-induced VBNC bacteria determined by CTC-FCM and D 2O-labeled Raman spectroscopy. ENVIRONMENT INTERNATIONAL 2019; 130:104883. [PMID: 31229870 DOI: 10.1016/j.envint.2019.05.077] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2019] [Revised: 05/19/2019] [Accepted: 05/30/2019] [Indexed: 06/09/2023]
Abstract
The occurrence of viable but non-culturable (VBNC) bacteria will result in significant underestimation of viable bacterial counts in drinking water. Whereas, much is unknown in characterizing their viability. In this study, two environmental isolates (Aeromonas sp. and Pseudomonas sp.) and two model strains (E. coli and S. aureus) were induced into VBNC state by UV irradiation. Then, their metabolic activity was determined by 5-cyano-2,3-ditolyl tetrazolium chloride combination flow cytometry (CTC-FCM) and D2O-labeled Raman spectroscopy, respectively, at both population and single cell levels. The results showed that almost all strains could enter VBNC state irradiated by ≥ 5 mJ/cm2 UV. When determined by CTC-FCM, the population metabolic activity for each strain did not vary significantly (p > 0.05) unless the UV dose reached 200 mJ/cm2. Their single cell activity spectrum narrowed slightly, as indicated by changes in the standard deviation of the logarithmic normal distribution (σ) of 0.015-0.033. This minute difference suggested the CTC-FCM method was suitable for assessing the essential viability of VBNC bacteria. With respect to Raman method, an obvious dose-response effect was recorded. With the UV dosages increased from 10 to 200 mJ/cm2, the CD/(CD + CH) for the four strains were reduced to between 95.7% and 47.9% of unirradiated controls, depending on strain and UV dose. Meanwhile, the single cellular Raman spectrum showed much more heterogeneously metabolic activity distribution, with some cells even entering metabolic "silence". Considering the ubiquitous participation of water in biochemical processes, the Raman method was more appropriate in assessing the overall metabolic activity. The above findings can not only be a reference for VBNC mechanism studies, but also have the potential in optimizing disinfection and other bacterial removal processes.
Collapse
Affiliation(s)
- Lizheng Guo
- Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China; University of Chinese Academy of Sciences, Beijing 100049, PR China
| | - Chengsong Ye
- Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China
| | - Li Cui
- Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China
| | - Kun Wan
- Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China; University of Chinese Academy of Sciences, Beijing 100049, PR China
| | - Sheng Chen
- Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China; University of Chinese Academy of Sciences, Beijing 100049, PR China
| | - Shenghua Zhang
- Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China.
| | - Xin Yu
- Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China.
| |
Collapse
|
42
|
Pazos-Rojas LA, Muñoz-Arenas LC, Rodríguez-Andrade O, López-Cruz LE, López-Ortega O, Lopes-Olivares F, Luna-Suarez S, Baez A, Morales-García YE, Quintero-Hernández V, Villalobos-López MA, De la Torre J, Muñoz-Rojas J. Desiccation-induced viable but nonculturable state in Pseudomonas putida KT2440, a survival strategy. PLoS One 2019; 14:e0219554. [PMID: 31323038 PMCID: PMC6641147 DOI: 10.1371/journal.pone.0219554] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2019] [Accepted: 06/26/2019] [Indexed: 01/21/2023] Open
Abstract
The potential of Pseudomonas putida KT2440 to act as a plant-growth promoter or as a bioremediator of toxic compounds can be affected by desiccation. In the present work, the bacterial survival ratio (BSR) in response to air desiccation was evaluated for P. putida KT2440 in the presence of different protectors. The BSR in the presence of nonreducing disaccharides, such as trehalose, was high after 15 days of desiccation stress (occurring at 30°C and 50% relative humidity), whereas in the absence of a protector the bacterial counts diminished to nondetectable numbers (ca 2.8 log CFU/mL). The LIVE/DEAD staining method showed that bacteria protected with trehalose maintained increased numbers of green cells after desiccation while cells without protection were all observed to be red. This indicated that nonprotected bacteria had compromised membrane integrity. However, when nonprotected bacteria subjected to 18 days of desiccation stress were rehydrated for a short time with maize root exudates or for 48 h with water (prolonged rehydration), the bacterial counts were as high as that observed for those not subjected to desiccation stress, suggesting that the cells entered the viable but nonculturable (VBNC) state under desiccation and that they returned to a culturable state after those means of rehydration. Interestingly an increase in the green color intensity of cells that returned to a culturable state was observed using LIVE/DEAD staining method, indicating an improvement in their membrane integrity. Cellular activity in the VBNC state was determined. A GFP-tagged P. putida strain expressing GFP constitutively was subjected to desiccation. After 12 days of desiccation, the GFP-tagged strain lost culturability, but it exhibited active GFP expression, which in turn made the cells green. Furthermore, the expression of 16S rRNA, rpoN (housekeeping), mutL, mutS (encoding proteins from the mismatch repair complex), and oprH (encoding an outer membrane protein) were examined by RT-PCR. All evaluated genes were expressed by both types of cells, culturable and nonculturable, indicating active molecular processes during the VBNC state.
Collapse
Affiliation(s)
- Laura Abisaí Pazos-Rojas
- Ecology and Survival of Microorganisms Research Group (ESMRG), Laboratorio de Ecología Molecular Microbiana (LEMM), Centro de Investigaciones en Ciencias Microbiológicas (CICM), Instituto de Ciencias (IC), Benemérita Universidad Autónoma de Puebla (BUAP), Puebla, Mexico
- Centro de Investigación en Biotecnología Aplicada, Instituto Politécnico Nacional, Tepetitla, Tlaxcala, Mexico
- Licenciatura en Biotecnología, Facultad de Ciencias Biológicas, BUAP, Puebla, Mexico
| | | | - Osvaldo Rodríguez-Andrade
- Ecology and Survival of Microorganisms Research Group (ESMRG), Laboratorio de Ecología Molecular Microbiana (LEMM), Centro de Investigaciones en Ciencias Microbiológicas (CICM), Instituto de Ciencias (IC), Benemérita Universidad Autónoma de Puebla (BUAP), Puebla, Mexico
| | - Lesther Emanuel López-Cruz
- Ecology and Survival of Microorganisms Research Group (ESMRG), Laboratorio de Ecología Molecular Microbiana (LEMM), Centro de Investigaciones en Ciencias Microbiológicas (CICM), Instituto de Ciencias (IC), Benemérita Universidad Autónoma de Puebla (BUAP), Puebla, Mexico
| | | | - Fábio Lopes-Olivares
- Núcleo de Desenvolvimento de Insumos Biológicos para a Agricultura (NUDIBA), Universidade Estadual do Norte Fluminense Darcy Ribeiro (UENF), Rio de Janeiro, Brazil
| | - Silvia Luna-Suarez
- Centro de Investigación en Biotecnología Aplicada, Instituto Politécnico Nacional, Tepetitla, Tlaxcala, Mexico
| | - Antonino Baez
- Ecology and Survival of Microorganisms Research Group (ESMRG), Laboratorio de Ecología Molecular Microbiana (LEMM), Centro de Investigaciones en Ciencias Microbiológicas (CICM), Instituto de Ciencias (IC), Benemérita Universidad Autónoma de Puebla (BUAP), Puebla, Mexico
| | - Yolanda Elizabeth Morales-García
- Ecology and Survival of Microorganisms Research Group (ESMRG), Laboratorio de Ecología Molecular Microbiana (LEMM), Centro de Investigaciones en Ciencias Microbiológicas (CICM), Instituto de Ciencias (IC), Benemérita Universidad Autónoma de Puebla (BUAP), Puebla, Mexico
- Licenciatura en Biotecnología, Facultad de Ciencias Biológicas, BUAP, Puebla, Mexico
| | - Verónica Quintero-Hernández
- Ecology and Survival of Microorganisms Research Group (ESMRG), Laboratorio de Ecología Molecular Microbiana (LEMM), Centro de Investigaciones en Ciencias Microbiológicas (CICM), Instituto de Ciencias (IC), Benemérita Universidad Autónoma de Puebla (BUAP), Puebla, Mexico
- CONACYT, ESMRG, LEMM, CICM, IC, BUAP, Puebla, México
| | | | - Jesús De la Torre
- Department of Environmental Protection, CSIC-Estación Experimental del Zaidín, Granada, Spain
| | - Jesús Muñoz-Rojas
- Ecology and Survival of Microorganisms Research Group (ESMRG), Laboratorio de Ecología Molecular Microbiana (LEMM), Centro de Investigaciones en Ciencias Microbiológicas (CICM), Instituto de Ciencias (IC), Benemérita Universidad Autónoma de Puebla (BUAP), Puebla, Mexico
- * E-mail:
| |
Collapse
|
43
|
Kumar SS, Ghosh AR. Assessment of bacterial viability: a comprehensive review on recent advances and challenges. Microbiology (Reading) 2019; 165:593-610. [DOI: 10.1099/mic.0.000786] [Citation(s) in RCA: 55] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Affiliation(s)
- Shravanthi S. Kumar
- Department of Integrative Biology, School of Bio Sciences and Technology, Vellore Institute of Technology, Vellore-632014, Tamil Nadu, India
| | - Asit Ranjan Ghosh
- Department of Integrative Biology, School of Bio Sciences and Technology, Vellore Institute of Technology, Vellore-632014, Tamil Nadu, India
| |
Collapse
|
44
|
Guo MT, Kong C. Antibiotic resistant bacteria survived from UV disinfection: Safety concerns on genes dissemination. CHEMOSPHERE 2019; 224:827-832. [PMID: 30851534 DOI: 10.1016/j.chemosphere.2019.03.004] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Revised: 02/23/2019] [Accepted: 03/02/2019] [Indexed: 05/03/2023]
Abstract
Antibiotic resistant bacteria (ARB) and antibiotic resistance genes (ARGs) are the emerging contaminants leading to a serious worldwide health problem. Although disinfection like ultraviolet (UV) irradiation could remove part of ARB and ARGs, there still are residual ARB and ARGs in the effluent of wastewater treatment plants. Conjugative transfer is main concern of the risk of ARGs and little is known about the effects of UV disinfection on the transfer ability of the non-inactivated ARB in the effluent which will enter the environment. Hence the influences of UV irradiation and reactivation on ARB conjugative transfer ability were studied under laboratory condition, focusing on the survival bacteria from UV irradiation and the reactivated bacteria, as well as their descendants. The experimental results imply that even 1 mJ/cm2 UV disinfection can significantly decrease the conjugative transfer frequency of the survival bacteria. However, viable but not culturable state cells induced by UV can reactivate through both photoreactivation and dark repair and retain the same level of transfer ability as the untreated strains. This finding is essential for re-considering about the post safety of UV irradiated effluent and microbial safety control strategies were required.
Collapse
Affiliation(s)
- Mei-Ting Guo
- State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, 200092, Shanghai, China.
| | - Cen Kong
- State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, 200092, Shanghai, China
| |
Collapse
|
45
|
Golpayegani A, Douraghi M, Rezaei F, Alimohammadi M, Nodehi RN. Propidium monoazide-quantitative polymerase chain reaction (PMA-qPCR) assay for rapid detection of viable and viable but non-culturable (VBNC) Pseudomonas aeruginosa in swimming pools. JOURNAL OF ENVIRONMENTAL HEALTH SCIENCE & ENGINEERING 2019; 17:407-416. [PMID: 31297217 PMCID: PMC6582174 DOI: 10.1007/s40201-019-00359-w] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2018] [Accepted: 02/21/2019] [Indexed: 05/17/2023]
Abstract
Lack of culturability in the viable but non-culturable (VBNC) bacteria and the ability to regain infectivity in favourable conditions is one of the new challenges of public health providers for Pseudomonas aeruginosa monitoring in environmental samples. Propidium monoazide quantitative polymerase chain reaction (PMA-qPCR) is one of the promising methods for timely detection of VBNC pathogens in environmental samples. We developed and used a method for the first time to detection of VBNC P. aeruginosa in swimming pool water samples using a membrane filter (MF). Moreover, the dominant model of the distribution of colonies on the MF and the effect of the culture medium and MF type on colony recovery by MF were evaluated. Swimming pool samples were subjected to conventional culture-based, qPCR and PMA-qPCR methods and the results were compared for the presence of VBNC P. aeruginosa in the samples. The positivity rate was 21% and 75% for P. aeruginosa in water samples as confirmed by standard culture-based and qPCR methods, respectively. Furthermore, of 24 samples, 9 (37.5%) were positive for VBNC P. aeruginosa. The developed qPCR/PMA-qPCR assay can detect the VBNC bacteria directly from aquatic samples and may result in better monitoring of recreational waters.
Collapse
Affiliation(s)
- Abdolali Golpayegani
- Department of Environmental Health Engineering, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
- Vice-Chancellor for Health, Bam University of Medical Sciences, Bam, Iran
- Environmental Health Engineering Research Center, Kerman University of Medical Sciences, Kerman, Iran
| | - Masoumeh Douraghi
- Division of Microbiology, Department of Pathobiology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| | - Farhad Rezaei
- Department of Virology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| | - Mahmood Alimohammadi
- Department of Environmental Health Engineering, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
- Center for Water Quality Research (CWQR), Institute for Environmental Research (IER), Tehran University of Medical Sciences, PO Box 14155-6446, Tehran, Iran
| | - Ramin Nabizadeh Nodehi
- Department of Environmental Health Engineering, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
- Center for Water Quality Research (CWQR), Institute for Environmental Research (IER), Tehran University of Medical Sciences, PO Box 14155-6446, Tehran, Iran
| |
Collapse
|
46
|
Liu S, Sui Z, Lin J, Huo N, Yang J, Wang B, Gu S. Rapid detection of single viableEscherichia coliO157:H7 cells in milk by flow cytometry. J Food Saf 2019. [DOI: 10.1111/jfs.12657] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Siyuan Liu
- Shanxi Key Laboratory of Environmental Veterinary Medicine, College of Animal Science and Veterinary MedicineShanxi Agricultural University Taigu Shanxi China
- Center for Advanced Measurement ScienceNational Institute of Metrology Beijing China
| | - Zhiwei Sui
- Center for Advanced Measurement ScienceNational Institute of Metrology Beijing China
| | - Jing Lin
- Department of BiometrologyInstitute of Measurement and Testing Technology Nanjing Jiangsu China
| | - Nairui Huo
- Shanxi Key Laboratory of Environmental Veterinary Medicine, College of Animal Science and Veterinary MedicineShanxi Agricultural University Taigu Shanxi China
| | - Jiayi Yang
- Center for Advanced Measurement ScienceNational Institute of Metrology Beijing China
| | - Bin Wang
- Center for Advanced Measurement ScienceNational Institute of Metrology Beijing China
- Research Center for Ginseng Genetic Resources Development and UtilizationJilin Agricultural University Jilin China
| | - Shaopeng Gu
- Shanxi Key Laboratory of Environmental Veterinary Medicine, College of Animal Science and Veterinary MedicineShanxi Agricultural University Taigu Shanxi China
| |
Collapse
|
47
|
Race J, Zilm P, Ratnayake J, Fitzsimmons T, Marchant C, Cathro P. Efficacy of laser and ultrasonic-activated irrigation on eradicating a mixed-species biofilm in human mesial roots. AUST ENDOD J 2019; 45:317-324. [PMID: 30623530 DOI: 10.1111/aej.12334] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/24/2018] [Indexed: 12/16/2022]
Abstract
This study investigated the efficacy of Er,Cr:YSGG laser and ultrasonic activated irrigation on eradicating a mixed-species biofilm grown in root canals with complex anatomy. The biofilm was grown over 4-weeks in the root canals of decoronated human mandibular molar teeth. Control roots received no further treatment. The remaining roots were chemomechanically prepared using different irrigating protocols: 4% NaOCl and 15% EDTAC with ultrasonic activated irrigation and laser activated irrigation using power settings of 0.5 W and 0.75 W. Cellular viability was determined using serial plating. One tooth from each group was subjected to qualitative SEM analysis. Quantification by culturing revealed significant differences between control group and all other treatment groups. This study demonstrated that chemomechanical irrigation with laser and ultrasonic activated irrigation significantly reduced the bacterial load from complex root canal systems; however, there were no significant differences found between the experimental groups.
Collapse
Affiliation(s)
- Jonathan Race
- School of Dentistry, Faculty of Health Science, The University of Adelaide, Adelaide, South Australia, Australia
| | - Peter Zilm
- School of Dentistry, Faculty of Health Science, The University of Adelaide, Adelaide, South Australia, Australia
| | | | - Tracy Fitzsimmons
- School of Dentistry, Faculty of Health Science, The University of Adelaide, Adelaide, South Australia, Australia
| | - Ceilidh Marchant
- School of Dentistry, Faculty of Health Science, The University of Adelaide, Adelaide, South Australia, Australia
| | - Peter Cathro
- School of Dentistry, Faculty of Health Science, The University of Adelaide, Adelaide, South Australia, Australia.,Faculty of dentistry, The University of Otago, Dunedin, New Zealand
| |
Collapse
|
48
|
Casasola-Rodríguez B, Ruiz-Palacios GM, Pilar RC, Losano L, Ignacio MR, Orta de Velásquez MT. Detection of VBNC Vibrio cholerae by RT-Real Time PCR based on differential gene expression analysis. FEMS Microbiol Lett 2018; 365:5046420. [DOI: 10.1093/femsle/fny156] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2017] [Accepted: 06/26/2018] [Indexed: 12/27/2022] Open
Affiliation(s)
- Beatriz Casasola-Rodríguez
- Coordinación de Ingeniería Ambiental, Instituto de Ingeniería, Universidad Nacional Autónoma de México, Av. Universidad No. 3000, Ciudad universitaria, C.P. 04510 CDMX, México
| | - Guillermo M Ruiz-Palacios
- Departamento de Infectología, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Vasco de Quiroga 15, Belisario Domínguez Sección XVI, 14080 Tlalpan, CDMX, México
| | - Ramos-Cervantes Pilar
- Departamento de Infectología, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Vasco de Quiroga 15, Belisario Domínguez Sección XVI, 14080 Tlalpan, CDMX, México
| | - Luis Losano
- Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Av. Universidad s/n, Chamilpa, 62210 Cuernavaca, Mor., México
| | - Monje-Ramírez Ignacio
- Coordinación de Ingeniería Ambiental, Instituto de Ingeniería, Universidad Nacional Autónoma de México, Av. Universidad No. 3000, Ciudad universitaria, C.P. 04510 CDMX, México
| | - María Teresa Orta de Velásquez
- Coordinación de Ingeniería Ambiental, Instituto de Ingeniería, Universidad Nacional Autónoma de México, Av. Universidad No. 3000, Ciudad universitaria, C.P. 04510 CDMX, México
| |
Collapse
|
49
|
In vitro antimicrobial effects and mechanisms of direct current air-liquid discharge plasma on planktonic Staphylococcus aureus and Escherichia coli in liquids. Bioelectrochemistry 2018; 121:125-134. [DOI: 10.1016/j.bioelechem.2018.01.012] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2017] [Revised: 01/18/2018] [Accepted: 01/24/2018] [Indexed: 12/20/2022]
|
50
|
|