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Xie Y, Long X, Kim Y, Harris LJ, Nitin N. Survival of Salmonella enterica and Enterococcus faecium on Abiotic Surfaces During Storage at Low Relative Humidity. J Food Prot 2024; 87:100292. [PMID: 38718984 DOI: 10.1016/j.jfp.2024.100292] [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: 02/29/2024] [Revised: 04/26/2024] [Accepted: 04/30/2024] [Indexed: 05/23/2024]
Abstract
Currently, there is limited knowledge on the survival of bacteria on surfaces during postharvest handling of dry products such as onions. Extended survival of microorganisms, coupled with a lack of established and regular, validated cleaning or sanitation methods could enable cross-contamination of these products. The aim of the study was to evaluate the survival of a potential surrogate, Enterococcus faecium, and Salmonella enterica on typical onion handling surfaces, polyurethane (PU), and stainless steel (SS), under low relative humidity. The influence of onion extract on the survival of E. faecium and Salmonella on PU and SS was also investigated. Rifampin-resistant E. faecium NRRL B-2354 and a five-strain cocktail of Salmonella suspended in 0.1% peptone or onion extract were separately inoculated onto PU and SS coupons (2 × 2 cm), at high, moderate, or low (7, 5, or 3 log CFU/cm2) levels. The inoculated surfaces were stored at ∼34% relative humidity and 21°C for up to 84 days. Triplicate samples were enumerated at regular intervals in replicate trials. Samples were enriched when populations fell below the limit of detection by plating (0.48 log CFU/cm2). Scanning electron microscopy was used to observe the cell distribution on the coupons. Reductions of E. faecium of less than ∼2 log were observed on PU and SS over 12 weeks at all inoculum levels and with both inoculum carriers. In 0.1% peptone, Salmonella populations declined by 2 to 3 log over 12 weeks at the high and moderate inoculum levels; at the low inoculum level, Salmonella could not be recovered by enrichment at 84 days. Survival of E. faecium and Salmonella was significantly (P < 0.05) enhanced over 84 days of storage when suspended in onion extract, where cells were covered by a layer of onion extract. E. faecium might have utility as a conservative surrogate for Salmonella when evaluating microbial survival on dry food-contact surfaces.
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Affiliation(s)
- Yucen Xie
- Department of Food Science and Technology, University of California, Davis, One Shields Avenue, Davis, CA 95616, USA.
| | - Xiaonuo Long
- Department of Food Science and Technology, University of California, Davis, One Shields Avenue, Davis, CA 95616, USA.
| | - Yoonbin Kim
- Department of Food Science and Technology, University of California, Davis, One Shields Avenue, Davis, CA 95616, USA.
| | - Linda J Harris
- Department of Food Science and Technology, University of California, Davis, One Shields Avenue, Davis, CA 95616, USA; Western Center for Food Safety, University of California, Davis, CA 95616, USA.
| | - Nitin Nitin
- Department of Food Science and Technology, University of California, Davis, One Shields Avenue, Davis, CA 95616, USA; Department of Agricultural and Biological Engineering, University of California, Davis, CA 95616, USA.
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2
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Gross J, Katz S, Hershberg R. Pseudomonas putida Dynamics of Adaptation under Prolonged Resource Exhaustion. Genome Biol Evol 2024; 16:evae117. [PMID: 38849986 PMCID: PMC11179108 DOI: 10.1093/gbe/evae117] [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: 07/31/2023] [Revised: 05/19/2024] [Accepted: 05/30/2024] [Indexed: 06/09/2024] Open
Abstract
Many nonsporulating bacterial species survive prolonged resource exhaustion, by entering a state termed long-term stationary phase. Here, we performed long-term stationary phase evolutionary experiments on the bacterium Pseudomonas putida, followed by whole-genome sequencing of evolved clones. We show that P. putida is able to persist and adapt genetically under long-term stationary phase. We observed an accumulation of mutations within the evolving P. putida populations. Within each population, independently evolving lineages are established early on and persist throughout the 4-month-long experiment. Mutations accumulate in a highly convergent manner, with similar loci being mutated across independently evolving populations. Across populations, mutators emerge, that due to mutations within mismatch repair genes developed a much higher rate of mutation than other clones with which they coexisted within their respective populations. While these general dynamics of the adaptive process are quite similar to those we previously observed in the model bacterium Escherichia coli, the specific loci that are involved in adaptation only partially overlap between P. putida and E. coli.
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Affiliation(s)
- Jonathan Gross
- Rachel & Menachem Mendelovitch Evolutionary Processes of Mutation & Natural Selection Research Laboratory, Department of Genetics and Developmental Biology, the Ruth and Bruce Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa 31096, Israel
| | - Sophia Katz
- Rachel & Menachem Mendelovitch Evolutionary Processes of Mutation & Natural Selection Research Laboratory, Department of Genetics and Developmental Biology, the Ruth and Bruce Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa 31096, Israel
| | - Ruth Hershberg
- Rachel & Menachem Mendelovitch Evolutionary Processes of Mutation & Natural Selection Research Laboratory, Department of Genetics and Developmental Biology, the Ruth and Bruce Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa 31096, Israel
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3
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von Hertwig AM, Prestes FS, Nascimento MS. Comparative evaluation of the effectiveness of alcohol-based sanitizers, UV-C radiation and hot air on three-age Salmonella biofilms. Food Microbiol 2023; 113:104278. [PMID: 37098425 DOI: 10.1016/j.fm.2023.104278] [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: 07/19/2022] [Revised: 03/25/2023] [Accepted: 04/03/2023] [Indexed: 04/27/2023]
Abstract
Dry sanitation is recommended to control contamination and prevent microbial growth and biofilm formation in the low-moisture food manufacturing plants. The objective of this study was to evaluate the effectiveness of dry sanitation protocols on Salmonella three-age biofilms formed on stainless steel (SS) and polypropylene (PP). Biofilms were formed for 24, 48 and 96 h at 37 °C using a cocktail of six Salmonella strains (Muenster, Miami, Glostrup, Javiana, Oranienburg, Yoruba) isolated from the peanut supply chain. Then, the surfaces were exposed to UV-C radiation, hot air (90 °C), 70% ethanol and a commercial product based on isopropyl alcohol for 5, 10, 15 and 30 min. After 30min exposure, on PP the reductions ranged from 3.2 to 4.2 log CFU/cm2 for UV-C, from 2.6 to 3.0 log CFU/cm2 for hot air, from 1.6 to 3.2 log CFU/cm2 for 70% ethanol and from 1.5 to 1.9 log CFU/cm2 for the commercial product. On SS, after the same exposure time, reductions of 1.3-2.2 log CFU/cm2, 2.2 to 3.3 log CFU/cm2, 1.7 to 2.0 log CFU/cm2 and 1.6 to 2.4 log CFU/cm2 were observed for UV-C, hot air, 70% ethanol and commercial product, respectively. UV-C was the only treatment affected by the surface material (p < 0.05) whereas the biofilm age influenced the effectiveness of UV-C and hot air (p < 0.05). For most treatment, there was significant difference among the exposure times (p < 0.05). Overall, the fastest loss in the biofilm viability was noted in the first 5 min, followed by a tail phase. The time predicted by the Weibull model for the first decimal reduction ranged from 0.04 to 9.9 min on PP and from 0.7 to 8.5 min on SS. In addition, the Weibull model indicates that most of treatments (79%) required a long-term exposure time (>30 min) to achieve 3-log reductions of Salmonella biofilms. In summary, UV-C showed the best performance on PP whereas hot air was noted to be the most effective on SS.
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Affiliation(s)
| | - Flavia S Prestes
- Faculty of Food Engineering, University of Campinas, Campinas, SP, Brazil
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Yan P, Chen X, Chelliah R, Jo KH, Shan L, Shin H, Kim S, Oh DH. Biocontrol and anti-biofilm potential of aerosols sprayed slightly acidic electrolyzed water against Cronobacter sakazakii in infant food industry. Lebensm Wiss Technol 2023. [DOI: 10.1016/j.lwt.2023.114598] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/26/2023]
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5
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Zhang X, Liu B, Ding X, Bin P, Yang Y, Zhu G. Regulatory Mechanisms between Quorum Sensing and Virulence in Salmonella. Microorganisms 2022; 10:2211. [PMID: 36363803 PMCID: PMC9693372 DOI: 10.3390/microorganisms10112211] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2022] [Revised: 11/03/2022] [Accepted: 11/07/2022] [Indexed: 08/28/2023] Open
Abstract
Salmonella is a foodborne pathogen that causes enterogastritis among humans, livestock and poultry, and it not only causes huge economic losses for the feed industry but also endangers public health around the world. However, the prevention and treatment of Salmonella infection has remained poorly developed because of its antibiotic resistance. Bacterial quorum sensing (QS) system is an intercellular cell-cell communication mechanism involving multiple cellular processes, especially bacterial virulence, such as biofilm formation, motility, adherence, and invasion. Therefore, blocking the QS system may be a new strategy for Salmonella infection independent of antibiotic treatment. Here, we have reviewed the central role of the QS system in virulence regulation of Salmonella and summarized the most recent advances about quorum quenching (QQ) in virulence attenuation during Salmonella infection. Unraveling the complex relationship between QS and bacterial virulence may provide new insight into the therapy of pathogen infection.
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Affiliation(s)
- Xiaojie Zhang
- Institute of Comparative Medicine, College of Veterinary Medicine, Yangzhou University, Yangzhou 225009, China
- Joint Laboratory of International Cooperation on Prevention and Control Technology of Important Animal Diseases and Zoonoses of Jiangsu Higher Education Institutions, Yangzhou University, Yangzhou 225009, China
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou 225009, China
- Joint International Research Laboratory of Agriculture and Agri-Product Safety, The Ministry of Education of China, Yangzhou University, Yangzhou 225009, China
| | - Baobao Liu
- Institute of Comparative Medicine, College of Veterinary Medicine, Yangzhou University, Yangzhou 225009, China
- Joint Laboratory of International Cooperation on Prevention and Control Technology of Important Animal Diseases and Zoonoses of Jiangsu Higher Education Institutions, Yangzhou University, Yangzhou 225009, China
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou 225009, China
- Joint International Research Laboratory of Agriculture and Agri-Product Safety, The Ministry of Education of China, Yangzhou University, Yangzhou 225009, China
| | - Xueyan Ding
- Institute of Comparative Medicine, College of Veterinary Medicine, Yangzhou University, Yangzhou 225009, China
- Joint Laboratory of International Cooperation on Prevention and Control Technology of Important Animal Diseases and Zoonoses of Jiangsu Higher Education Institutions, Yangzhou University, Yangzhou 225009, China
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou 225009, China
- Joint International Research Laboratory of Agriculture and Agri-Product Safety, The Ministry of Education of China, Yangzhou University, Yangzhou 225009, China
| | - Peng Bin
- Institute of Comparative Medicine, College of Veterinary Medicine, Yangzhou University, Yangzhou 225009, China
- Joint Laboratory of International Cooperation on Prevention and Control Technology of Important Animal Diseases and Zoonoses of Jiangsu Higher Education Institutions, Yangzhou University, Yangzhou 225009, China
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou 225009, China
- Joint International Research Laboratory of Agriculture and Agri-Product Safety, The Ministry of Education of China, Yangzhou University, Yangzhou 225009, China
| | - Yang Yang
- Institute of Comparative Medicine, College of Veterinary Medicine, Yangzhou University, Yangzhou 225009, China
- Joint Laboratory of International Cooperation on Prevention and Control Technology of Important Animal Diseases and Zoonoses of Jiangsu Higher Education Institutions, Yangzhou University, Yangzhou 225009, China
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou 225009, China
- Joint International Research Laboratory of Agriculture and Agri-Product Safety, The Ministry of Education of China, Yangzhou University, Yangzhou 225009, China
| | - Guoqiang Zhu
- Institute of Comparative Medicine, College of Veterinary Medicine, Yangzhou University, Yangzhou 225009, China
- Joint Laboratory of International Cooperation on Prevention and Control Technology of Important Animal Diseases and Zoonoses of Jiangsu Higher Education Institutions, Yangzhou University, Yangzhou 225009, China
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou 225009, China
- Joint International Research Laboratory of Agriculture and Agri-Product Safety, The Ministry of Education of China, Yangzhou University, Yangzhou 225009, China
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6
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Byun KH, Na KW, Ashrafudoulla M, Choi MW, Han SH, Kang I, Park SH, Ha SD. Combination treatment of peroxyacetic acid or lactic acid with UV-C to control Salmonella Enteritidis biofilms on food contact surface and chicken skin. Food Microbiol 2021; 102:103906. [PMID: 34809938 DOI: 10.1016/j.fm.2021.103906] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Revised: 09/11/2021] [Accepted: 09/15/2021] [Indexed: 12/15/2022]
Abstract
The risk of salmonellosis is expected to increase with the rise in the consumption of poultry meat. The aim of this study was to investigate the combination treatment of peroxyacetic acid (PAA) or lactic acid (LA) with UV-C against Salmonella Enteritidis biofilms formed on food contact surface (stainless steel [SS], silicone rubber [SR], and ultra-high molecular weight polyethylene [UHMWPE]) and chicken skin. The biofilm on food contact surface and chicken skin was significantly decreased (P < 0.05) by combination treatment of PAA or LA with UV-C. Combination treatment of PAA (50-500 μg/mL) with UV-C (5 and 10 min) reduced 3.10-6.41 log CFU/cm2 and LA (0.5-2.0%) with UV-C (5 and 10 min) reduced 3.35-6.41 log CFU/cm2 of S. Enteritidis biofilms on food contact surface. Salmonella Enteritidis biofilms on chicken skin was reduced around 2 log CFU/g with minor quality changes in color and texture by combination treatment of PAA (500 μg/mL) or LA (2.0%) with UV-C (10 min). Additional reduction occurred on SS and UHMWPE by PAA or LA with UV-C, while only LA with UV-C caused additional reduction on chicken skin. Also, it was visualized that the biofilm on food contact surface and chicken skin was removed through field emission scanning electron microscopy (FESEM) and death of cells constituting the biofilm was confirmed through confocal laser scanning microscopy (CLSM). These results indicating that the combination treatment of PAA or LA with UV-C could be used for S. Enteritidis biofilm control strategy in poultry industry.
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Affiliation(s)
- Kye-Hwan Byun
- Department of Food Science and Technology, Advanced Food Safety Research Group, Chung-Ang University, Daeduk-myun, Ansung, Nae-ri, Brain Korea 21 Plus, Kyunggido, 17546, Republic of Korea
| | - Kyung Won Na
- Department of Food Science and Technology, Advanced Food Safety Research Group, Chung-Ang University, Daeduk-myun, Ansung, Nae-ri, Brain Korea 21 Plus, Kyunggido, 17546, Republic of Korea
| | - Md Ashrafudoulla
- Department of Food Science and Technology, Advanced Food Safety Research Group, Chung-Ang University, Daeduk-myun, Ansung, Nae-ri, Brain Korea 21 Plus, Kyunggido, 17546, Republic of Korea
| | - Min Woo Choi
- Department of Food Science and Technology, Advanced Food Safety Research Group, Chung-Ang University, Daeduk-myun, Ansung, Nae-ri, Brain Korea 21 Plus, Kyunggido, 17546, Republic of Korea
| | - Sang Ha Han
- Department of Food Science and Technology, Advanced Food Safety Research Group, Chung-Ang University, Daeduk-myun, Ansung, Nae-ri, Brain Korea 21 Plus, Kyunggido, 17546, Republic of Korea
| | - Iksoon Kang
- Department of Animal Science, California Polytechnic State University, San Luis Obispo, CA, 93407, USA
| | - Si Hong Park
- Food Science and Technology, Oregon State University, Corvallis, OR, United States
| | - Sang-Do Ha
- Department of Food Science and Technology, Advanced Food Safety Research Group, Chung-Ang University, Daeduk-myun, Ansung, Nae-ri, Brain Korea 21 Plus, Kyunggido, 17546, Republic of Korea.
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7
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Girbal M, Strawn LK, Murphy CM, Schaffner DW. Wet versus Dry Inoculation Methods Have a Significant Effect of Listeria monocytogenes Growth on Many Types of Whole Intact Fresh Produce. J Food Prot 2021; 84:1793-1800. [PMID: 34115865 DOI: 10.4315/jfp-21-187] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Accepted: 06/08/2021] [Indexed: 11/11/2022]
Abstract
ABSTRACT Listeria monocytogenes causes relatively few outbreaks linked to whole fresh produce but triggers recalls each year in the United States. There are limited data on the influence of wet versus dry inoculation methods on pathogen growth on whole produce. A cocktail of five L. monocytogenes strains that included clinical, food, and environmental isolates associated with foodborne outbreaks and recalls was used. Cultures were combined to target a final wet inoculum concentration of 4 to 5 log CFU/mL. The dry inoculum was prepared by mixing wet inoculum with 100 g of sterile sand and drying for 24 h. Produce investigated belonged to major commodity families: Ericaceae (blackberry, raspberry, and blueberry), Rutaceae (lemon and mandarin orange), Rosaceae (sweet cherry), Solanaceae (tomato), Brassaceae (cauliflower and broccoli), and Apiaceae (carrot). Whole intact, inoculated fruit and vegetable commodities were incubated at 2, 12, 22, and 35 ± 2°C. Commodities were sampled for up to 28 days, and the experiment was replicated six times. The average maximum growth increase was obtained by measuring the maximum absolute increase for each replicate within a specific commodity, temperature, and inoculation method. Data for each commodity, replicate, and temperature were used to create primary growth or survival models describing the lag phase and growth or shoulder and decline as a function of time. Use of a liquid inoculum (versus dry inoculum) resulted in a markedly increased L. monocytogenes growth rate and growth magnitude on whole produce surfaces. Temperature highly influenced this difference: a greater effect seen with more commodities at higher temperatures (22 and 35°C) versus lower temperatures (2 and 12°C). These findings need to be explored for other commodities and pathogens. The degree to which wet or dry inoculation techniques more realistically mimic contamination conditions throughout the supply chain (e.g., production, harvest, postharvest, transportation, or retail) should be investigated. HIGHLIGHTS
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Affiliation(s)
- Marina Girbal
- Department of Food Science, 65 Dudley Road, Rutgers University, New Brunswick, New Jersey 08901
| | - Laura K Strawn
- Department of Food Science & Technology, 1230 Washington Street S.W., Blacksburg, Virginia 24061, USA
| | - Claire M Murphy
- Department of Food Science & Technology, 1230 Washington Street S.W., Blacksburg, Virginia 24061, USA
| | - Donald W Schaffner
- Department of Food Science, 65 Dudley Road, Rutgers University, New Brunswick, New Jersey 08901
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Bhullar MS, Shaw A, Mendonca A, Monge A, Nabwire L, Thomas-Popo E. Shiga Toxin-Producing Escherichia coli in the Long-Term Survival Phase Exhibit Higher Chlorine Tolerance and Less Sublethal Injury Following Chlorine Treatment of Romaine Lettuce. Foodborne Pathog Dis 2021; 18:276-282. [PMID: 33471590 DOI: 10.1089/fpd.2020.2873] [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] [Indexed: 11/12/2022] Open
Abstract
The extent of chlorine inactivation and sublethal injury of stationary-phase (STAT) and long-term survival-phase (LTS) cells of Shiga toxin-producing Escherichia coli (STEC) in vitro and in a lettuce postharvest wash model was investigated. Four STEC strains were cultured in tryptic soy broth supplemented with 0.6% (w/v) yeast extract (TSBYE; 35°C) for 24 h and 21 d to obtain STAT and LTS cells, respectively. Minimum bactericidal concentration (MBC) and dose-response assays were performed to determine chlorine's antibacterial efficacy against STAT and LTS cells. Chlorine solutions (pH 6.5) and romaine lettuce were each inoculated with STAT and LTS cells to obtain initial populations of ∼7.8 log colony-forming units (CFU)/mL. Survivors in chlorine solutions were determined after 30 s. Inoculated lettuce samples were held at 22°C ± 1°C for 2 h or 20 h and then exposed to chlorine (10-40 ppm) for 60 s. Survivors were enumerated on nonselective and selective agar media following incubation (35°C, 48 h). The MBC for STAT and LTS cells was 0.04 and 0.08 ppm, respectively. Following exposure (30 s) to chlorine at 2.5, 5.0, and 10 ppm, STAT cells were reduced to <1.0 log CFU/mL, whereas LTS survivors were at 5.10 (2.5 ppm), 3.71 (5.0 ppm), and 2.55 (10 ppm) log CFU/mL. At 20 and 40 ppm chlorine, greater log CFU reductions of STAT cells (1.64 and 1.85) were observed compared with LTS cells (0.94 and 0.83) after 2 h of cell contact with lettuce (p < 0.05), but not after 20 h. Sublethal injury in STEC after chlorine (40 ppm) treatment was lower in LTS compared with STAT survivors (p < 0.05). Compared with STAT cells, LTS cells of STEC seem to have higher chlorine tolerance as planktonic cells and as attached cells depending on cell contact time on lettuce. In addition, a higher percentage of LTS cells, compared with STAT cells, survive in a noninjured state after chlorine (40 ppm) treatment of lettuce.
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Affiliation(s)
- Manreet Singh Bhullar
- Department of Food Science and Human Nutrition, Iowa State University, Ames, Iowa, USA
| | - Angela Shaw
- Department of Food Science and Human Nutrition, Iowa State University, Ames, Iowa, USA
| | - Aubrey Mendonca
- Department of Food Science and Human Nutrition, Iowa State University, Ames, Iowa, USA
- Interdepartmental Microbiology Graduate Program, Iowa State University, Ames, Iowa, USA
| | - Ana Monge
- Department of Food Science and Human Nutrition, Iowa State University, Ames, Iowa, USA
| | - Lillian Nabwire
- Department of Food Science and Human Nutrition, Iowa State University, Ames, Iowa, USA
| | - Emalie Thomas-Popo
- Interdepartmental Microbiology Graduate Program, Iowa State University, Ames, Iowa, USA
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Cui L, Wang X, Huang D, Zhao Y, Feng J, Lu Q, Pu Q, Wang Y, Cheng G, Wu M, Dai M. CRISPR- cas3 of Salmonella Upregulates Bacterial Biofilm Formation and Virulence to Host Cells by Targeting Quorum-Sensing Systems. Pathogens 2020; 9:pathogens9010053. [PMID: 31936769 PMCID: PMC7168661 DOI: 10.3390/pathogens9010053] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2019] [Revised: 01/05/2020] [Accepted: 01/07/2020] [Indexed: 12/16/2022] Open
Abstract
Salmonella is recognized as one of the most common microbial pathogens worldwide. The bacterium contains the clustered regularly interspaced short palindromic repeats (CRISPR)-CRISPR-associated (Cas) systems, providing adaptive immunity against invading foreign nucleic acids. Previous studies suggested that certain bacteria employ the Cas proteins of CRISPR-Cas systems to target their own genes, which also alters the virulence during invasion of mammals. However, whether CRISPR-Cas systems in Salmonella have similar functions during bacterial invasion of host cells remains unknown. Here, we systematically analyzed the genes that are regulated by Cas3 in a type I-E CRISPR-Cas system and the virulence changes due to the deletion of cas3 in Salmonella enterica serovar Enteritidis. Compared to the cas3 gene wild-type (cas3 WT) Salmonella strain, cas3 deletion upregulated the lsrFGBE genes in lsr (luxS regulated) operon related to quorum sensing (QS) and downregulated biofilm-forming-related genes and Salmonella pathogenicity island 1 (SPI-1) genes related to the type three secretion system (T3SS). Consistently, the biofilm formation ability was downregulated in the cas3 deletion mutant (Δcas3). The bacterial invasive and intracellular capacity of Δcas3 to host cells was also reduced, thereby increasing the survival of infected host cells and live chickens. By the transcriptome-wide screen (RNA-Seq), we found that the cas3 gene impacts a series of genes related to QS, the flagellum, and SPI-1-T3SS system, thereby altering the virulence phenotypes. As QS SPI-1-T3SS and CRISPR-Cas systems are widely distributed in the bacteria kingdom, our findings extend our understanding of virulence regulation and pathogenicity in mammalian hosts for Salmonella and potentially other bacteria.
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Affiliation(s)
- Luqing Cui
- The Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan 430070, China; (L.C.); (X.W.); (Y.Z.); (J.F.)
- Department of Biomedical Sciences, University of North Dakota School of Medicine and Health Sciences, Grand Forks, ND 58203, USA;
| | - Xiangru Wang
- The Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan 430070, China; (L.C.); (X.W.); (Y.Z.); (J.F.)
| | - Deyu Huang
- MOA Key Laboratory of Food Safety Evaluation/National Reference Laboratory of Veterinary Drug Residue (HZAU), Huazhong Agricultural University, Wuhan 430070, China; (D.H.); (Q.L.); (Y.W.); (G.C.)
| | - Yue Zhao
- The Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan 430070, China; (L.C.); (X.W.); (Y.Z.); (J.F.)
| | - Jiawei Feng
- The Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan 430070, China; (L.C.); (X.W.); (Y.Z.); (J.F.)
| | - Qirong Lu
- MOA Key Laboratory of Food Safety Evaluation/National Reference Laboratory of Veterinary Drug Residue (HZAU), Huazhong Agricultural University, Wuhan 430070, China; (D.H.); (Q.L.); (Y.W.); (G.C.)
| | - Qinqin Pu
- Department of Biomedical Sciences, University of North Dakota School of Medicine and Health Sciences, Grand Forks, ND 58203, USA;
| | - Yulian Wang
- MOA Key Laboratory of Food Safety Evaluation/National Reference Laboratory of Veterinary Drug Residue (HZAU), Huazhong Agricultural University, Wuhan 430070, China; (D.H.); (Q.L.); (Y.W.); (G.C.)
| | - Guyue Cheng
- MOA Key Laboratory of Food Safety Evaluation/National Reference Laboratory of Veterinary Drug Residue (HZAU), Huazhong Agricultural University, Wuhan 430070, China; (D.H.); (Q.L.); (Y.W.); (G.C.)
| | - Min Wu
- Department of Biomedical Sciences, University of North Dakota School of Medicine and Health Sciences, Grand Forks, ND 58203, USA;
- Correspondence: (M.W.); (M.D.); Tel.: +1-701-777-4875 (M.W.); +86-027-8767-2232 (M.D.); Fax: +1-701-777-2382 (M.W.); +86-027-8767-2232 (M.D.)
| | - Menghong Dai
- The Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan 430070, China; (L.C.); (X.W.); (Y.Z.); (J.F.)
- Correspondence: (M.W.); (M.D.); Tel.: +1-701-777-4875 (M.W.); +86-027-8767-2232 (M.D.); Fax: +1-701-777-2382 (M.W.); +86-027-8767-2232 (M.D.)
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10
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Igo MJ, Schaffner DW. Quantifying the Influence of Relative Humidity, Temperature, and Diluent on the Survival and Growth of Enterobacter aerogenes. J Food Prot 2019; 82:2135-2147. [PMID: 31729917 DOI: 10.4315/0362-028x.jfp-19-261] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Survival of bacteria on surfaces plays an important role in the cross-contamination of food. Temperature, relative humidity (RH), surface type, and inoculum diluent can affect bacterial survival. This study was conducted to examine how temperature, RH, and diluent affect the survival of Enterobacter aerogenes on stainless steel, polyvinyl chloride, and ceramic tile. Although surface type had little effect on survival, temperature had a clear effect. E. aerogenes survival was highest at 7°C and 15 and 50% RH on all surfaces. Some diluents allowed growth under high RH conditions. Cell populations in distilled water inoculated onto each surface decreased initially compared with populations in 1% phosphate-buffered saline (PBS) and 0.1% peptone broth. At 15 and 50% RH, cell populations in 1% PBS declined more sharply after 120 h than did those 0.1% peptone, but populations in both diluents had similar declines up to 3 weeks. Cell populations in 0.1% peptone had the greatest growth and reached the highest population density (∼8 log CFU/mL). Cell populations in PBS and distilled water increased by ∼2 log CFU/mL. When cells in 0.1% peptone were inoculated onto stainless steel at 100% RH, populations increased to ∼7 log CFU per coupon, whereas cells in 1% PBS increased to ∼5 log CFU per coupon followed by a decline over 3 weeks. DMFit and GInaFiT software modeled inactivation on surfaces at all conditions other than 100% RH at 21°C. These findings have important implications for experiments in which microorganisms are inoculated onto foods or food contact surfaces because the growth observed may be affected more by the inoculum diluent at high or uncontrolled RH than by the type of inoculated surface.
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Affiliation(s)
- Matthew J Igo
- Department of Food Science, Rutgers University, 65 Dudley Road, New Brunswick, New Jersey 08901, USA
| | - Donald W Schaffner
- Department of Food Science, Rutgers University, 65 Dudley Road, New Brunswick, New Jersey 08901, USA
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