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Li Z, Dou Y, Li Z, Yuan Y, Zhang Q, Cheng S, Cheng X, Luo J. Dose-dependent effects of different parabens on food waste biorefinery for volatile fatty acids production: Insight into specific fermentation processes, substrates transformation and microbial metabolic traits. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 946:174319. [PMID: 38936728 DOI: 10.1016/j.scitotenv.2024.174319] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2024] [Revised: 06/23/2024] [Accepted: 06/24/2024] [Indexed: 06/29/2024]
Abstract
Parabens are largely concentrated in food waste (FW) due to their large consumption as the widely used preservative. To date, whether and how they affect FW resource recovery via anaerobic fermentation is still largely unknown. This work unveiled the hormesis-like effects of two typical parabens (i.e., methylparaben and n-butylparaben) on VFAs production during FW anaerobic fermentation (i.e., parabens increased VFAs by 6.73-14.49 % at low dose but caused 82.51-87.74 % reduction at high dose). Mechanistic exploration revealed that the parabens facilitated the FW solubilization and enhanced the associated substrates' biodegradability. The low parabens enriched the functional microorganisms (e.g., Firmicutes and Actinobacteria) and upregulated those critical genes involved in VFAs biosynthesis (e.g., GCK and PK) by activating the microbial adaptive capacity (i.e., quorum sensing and two-component system). Consequently, the metabolism rates of fermentation substrates and subsequent VFAs production were accelerated. However, due to increased biotoxicity of high parabens, the functional microorganisms and relevant metabolic activities were depressed, resulting in the significant reduction of VFAs biosynthesis. Structural equation modeling clarified that microbial community was the predominant factor affecting VFAs generation, followed by metabolic pathways. This work elucidated the dose-dependent effects and underlying mechanisms of parabens on FW anaerobic fermentation, providing insights for the effective management of FW resource recovery.
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Affiliation(s)
- Ziyu Li
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing 210098, China; College of Environment, Hohai University, Nanjing 210098, China
| | - Yuting Dou
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing 210098, China; College of Environment, Hohai University, Nanjing 210098, China
| | - Zhenzhou Li
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing 210098, China; College of Environment, Hohai University, Nanjing 210098, China
| | - Yujie Yuan
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing 210098, China; College of Environment, Hohai University, Nanjing 210098, China
| | - Qin Zhang
- School of Energy and Environment, Anhui University of Technology, Ma'anshan 243000, China
| | - Song Cheng
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing 210098, China; College of Environment, Hohai University, Nanjing 210098, China
| | - Xiaoshi Cheng
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing 210098, China; College of Environment, Hohai University, Nanjing 210098, China.
| | - Jingyang Luo
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing 210098, China; College of Environment, Hohai University, Nanjing 210098, China.
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Omar A, El-Banna TE, Sonbol FI, El-Bouseary MM. Potential antivirulence and antibiofilm activities of sub-MIC of oxacillin against MDR S. aureus isolates: an in-vitro and in-vivo study. BMC Microbiol 2024; 24:295. [PMID: 39123138 PMCID: PMC11312681 DOI: 10.1186/s12866-024-03429-8] [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: 11/07/2023] [Accepted: 07/16/2024] [Indexed: 08/12/2024] Open
Abstract
BACKGROUND Multi-drug resistant Staphylococcus aureus is one of the most common causes of nosocomial and community-acquired infections, with high morbidity and mortality. Treatment of such infections is particularly problematic; hence, it is complicated by antibiotic resistance, and there is currently no reliable vaccine. Furthermore, it is well known that S. aureus produces an exceptionally large number of virulence factors that worsen infection. Consequently, the urgent need for anti-virulent agents that inhibit biofilm formation and virulence factors has gained momentum. Therefore, we focused our attention on an already-approved antibiotic and explored whether changing the dosage would still result in the intended anti-virulence effect. METHODS In the present study, we determined the antibiotic resistance patterns and the MICs of oxacillin against 70 MDR S. aureus isolates. We also investigated the effect of sub-MICs of oxacillin (at 1/4 and 1/8 MICs) on biofilm formation using the crystal violet assay, the phenol-sulphuric acid method, and confocal laser scanning microscopy (CLSM). We examined the effect of sub-MICs on virulence factors and bacterial morphology using quantitative reverse transcription polymerase chain reaction (qRT-PCR) and electron microscopy, respectively. Moreover, we studied the effect of sub-MICs of oxacillin (OX) in-vivo using a wound infection model. RESULTS Oxacillin at 1/2 MIC showed a significant decrease in bacterial viability, while 1/4 and 1/8 MICs had negligible effects on treated bacterial isolates. Treatment of MDR isolates with 1/4 or 1/8 MICs of oxacillin significantly reduced biofilm formation (64% and 40%, respectively). The treated MDR S. aureus with sub-MICs of OX exhibited a dramatic reduction in several virulence factors, including protease, hemolysin, coagulase, and toxic shock syndrome toxin-1 (TSST-1) production. The sub-MICs of OX significantly decreased (P < 0.05) the gene expression of biofilm and virulence-associated genes such as agrA, icaA, coa, and tst. Furthermore, oxacillin at sub-MICs dramatically accelerated wound healing, according to the recorded scoring of histological parameters. CONCLUSION The treatment of MDR S. aureus with sub-MICs of oxacillin can help in combating the bacterial resistance and may be considered a promising approach to attenuating the severity of S. aureus infections due to the unique anti-biofilm and anti-virulence activities.
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Affiliation(s)
- Amira Omar
- Department of Microbiology and Immunology, Faculty of Pharmacy, Tanta University, Tanta, Egypt.
| | - Tarek E El-Banna
- Department of Microbiology and Immunology, Faculty of Pharmacy, Tanta University, Tanta, Egypt
| | - Fatma I Sonbol
- Department of Microbiology and Immunology, Faculty of Pharmacy, Tanta University, Tanta, Egypt
| | - Maisra M El-Bouseary
- Department of Microbiology and Immunology, Faculty of Pharmacy, Tanta University, Tanta, Egypt.
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Carvajal LP, Rincon S, Gomez-Villegas SI, Matiz-González JM, Ordoñez K, Santamaria A, Ospina-Navarro L, Beltran J, Guevara F, Mendez YR, Salcedo S, Porras A, Valencia-Moreno A, Grennia H, Deyanov A, Baptista R, Tam VH, Panesso D, Tran TT, Miller WR, Arias CA, Reyes J. Prevalence of the Cefazolin Inoculum Effect (CzIE) in Nasal Colonizing Methicillin-Susceptible Staphylococcus aureus in Patients from Intensive Care Units in Colombia and Use of a Modified Rapid Nitrocefin Test for Detection. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2024:2024.07.11.24309236. [PMID: 39040169 PMCID: PMC11261917 DOI: 10.1101/2024.07.11.24309236] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/24/2024]
Abstract
The cefazolin inoculum effect (CzIE) has been associated with poor clinical outcomes in patients with MSSA infections. We aimed to investigate the point prevalence of the CzIE among nasal colonizing MSSA isolates from ICU patients in a multicenter study in Colombia (2019-2023). Patients underwent nasal swabs to assess for S. aureus colonization on admission to the ICU and some individuals had follow-up swabs. We performed cefazolin MIC by broth-microdilution using standard and high-inoculum and developed a modified nitrocefin-based rapid test to detect the CzIE. Whole genome sequencing was carried out to characterize BlaZ types and allotypes, phylogenomics and Agr-typing. All swabs were subjected to 16S-rRNA metabarcoding sequencing to evaluate microbiome characteristics associated with the CzIE. A total of 352 patients were included; 46/352 (13%) patients were colonized with S. aureus; 22% (10/46) and 78% (36/46) with MRSA and MSSA, respectively. Among 36 patients that contributed with 43 MSSA colonizing isolates, 21/36 (58%) had MSSA exhibiting the CzIE. BlaZ type A and BlaZ-2 were the predominant type and allotype in 56% and 52%, respectively. MSSA belonging to CC30 were highly associated with the CzIE and SNP analyses supported transmission of MSSA exhibiting the CzIE among some patients of the same unit. The modified nitrocefin rapid test had 100%, 94.4% and 97.7% sensitivity, specificity and accuracy, respectively. We found a high prevalence point prevalence of the CzIE in MSSA colonizing the nares of critically-ill patients in Colombia. A modified rapid test was highly accurate in detecting the CzIE in this patient population.
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Affiliation(s)
- Lina P. Carvajal
- Molecular Genetics and Antimicrobial Resistance Unit, Universidad El Bosque, Bogota, Colombia
| | - Sandra Rincon
- Molecular Genetics and Antimicrobial Resistance Unit, Universidad El Bosque, Bogota, Colombia
| | | | - Juan M. Matiz-González
- Molecular Genetics and Antimicrobial Resistance Unit, Universidad El Bosque, Bogota, Colombia
| | - Karen Ordoñez
- Department of Infectious Diseases, ESE Hospital Universitario, San Jorge de Pereira, Pereira, Colombia
| | - Alejandra Santamaria
- Department of Infectious Diseases, ESE Hospital Universitario, San Jorge de Pereira, Pereira, Colombia
| | | | | | - Fredy Guevara
- Servicio de Infectología, Fundación Santafe de Bogota, Bogota, Colombia
- Clinica Reina Sofia, Colsanitas, Bogota, Colombia
| | - Yardany R. Mendez
- Grupo de Investigacion en Epidemiologia Clinica de Colombia (GRECO), Universidad Pedagogica y Tecnologica de Colombia, Tunja, Colombia
- Hospital Regional de Duitama, Duitama, Colombia
| | - Soraya Salcedo
- Organizacion Clinica General del Norte, Barranquilla, Colombia
| | | | | | - Haley Grennia
- Center for Infectious Disease, Houston Methodist Research Institute, Houston, TX USA
| | - Alexander Deyanov
- Center for Infectious Disease, Houston Methodist Research Institute, Houston, TX USA
| | - Rodrigo Baptista
- Center for Infectious Disease, Houston Methodist Research Institute, Houston, TX USA
- Division of Infectious Diseases and Department of Medicine, Houston Methodist Hospital, Houston, TX USA 77030
- Department of Medicine, Weill Cornell Medical College, New York, NY
| | - Vincent H. Tam
- Departament of Pharmacy Practice and Translational Research, University of Houston, Houston, Texas, United States
| | - Diana Panesso
- Molecular Genetics and Antimicrobial Resistance Unit, Universidad El Bosque, Bogota, Colombia
- Center for Infectious Disease, Houston Methodist Research Institute, Houston, TX USA
- Division of Infectious Diseases and Department of Medicine, Houston Methodist Hospital, Houston, TX USA 77030
- Department of Medicine, Weill Cornell Medical College, New York, NY
| | - Truc T. Tran
- Center for Infectious Disease, Houston Methodist Research Institute, Houston, TX USA
- Division of Infectious Diseases and Department of Medicine, Houston Methodist Hospital, Houston, TX USA 77030
- Department of Medicine, Weill Cornell Medical College, New York, NY
| | - William R. Miller
- Center for Infectious Disease, Houston Methodist Research Institute, Houston, TX USA
- Division of Infectious Diseases and Department of Medicine, Houston Methodist Hospital, Houston, TX USA 77030
- Department of Medicine, Weill Cornell Medical College, New York, NY
| | - Cesar A. Arias
- Center for Infectious Disease, Houston Methodist Research Institute, Houston, TX USA
- Division of Infectious Diseases and Department of Medicine, Houston Methodist Hospital, Houston, TX USA 77030
- Department of Medicine, Weill Cornell Medical College, New York, NY
| | - Jinnethe Reyes
- Molecular Genetics and Antimicrobial Resistance Unit, Universidad El Bosque, Bogota, Colombia
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Grazul M, Balcerczak E, Sienkiewicz M. Analysis of the Presence of the Virulence and Regulation Genes from Staphylococcus aureus ( S. aureus) in Coagulase Negative Staphylococci and the Influence of the Staphylococcal Cross-Talk on Their Functions. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2023; 20:5155. [PMID: 36982064 PMCID: PMC10049693 DOI: 10.3390/ijerph20065155] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/12/2023] [Revised: 03/08/2023] [Accepted: 03/12/2023] [Indexed: 06/18/2023]
Abstract
Coagulase-negative staphylococci (CoNS) are increasingly becoming a public health issue worldwide due to their growing resistance to antibiotics and common involvement in complications related to invasive surgical procedures, and nosocomial and urinary tract infections. Their behavior either as a commensal or a pathogen is a result of strict regulation of colonization and virulence factors. Although functionality of virulence factors and processes involved in their regulation are quite well understood in S. aureus, little is known about them in CoNS species. Therefore, the aim of our studies was to check if clinical CoNS strains may contain virulence factors and genes involved in resistance to methicillin, that are homologous to S. aureus. Moreover, we checked the presence of elements responsible for regulation of genes that encode virulence factors typical for S. aureus in tested isolates. We also investigated whether the regulation factors produced by one CoNS isolate can affect virulence activity of other strains by co-incubation of tested isolates with supernatant from other isolates. Our studies confirmed the presence of virulence factor and regulatory genes attributed to S. aureus in CoNS isolates and indicated that one strain with an active agr gene is able to affect biofilm formation and δ-toxin activity of strains with inactive agr genes. The cognition of prevalence and regulation of virulence factors as well as antibiotic resistance of CoNS isolates is important for better control and treatment of CoNS infections.
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Affiliation(s)
- Magdalena Grazul
- Department of Pharmaceutical Microbiology and Microbiological Diagnostics, Medical University of Lodz, Muszynskiego 1 Street, 90-151 Lodz, Poland
| | - Ewa Balcerczak
- Laboratory of Molecular Diagnostics and Pharmacogenomics, Department of Pharmaceutical Biochemistry and Molecular Diagnostics, Medical University of Lodz, Muszynskiego 1 Street, 90-151 Lodz, Poland
| | - Monika Sienkiewicz
- Department of Pharmaceutical Microbiology and Microbiological Diagnostics, Medical University of Lodz, Muszynskiego 1 Street, 90-151 Lodz, Poland
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Demirci M, Yigin A, Demir C. Efficacy of antimicrobial peptide LL-37 against biofilm forming Staphylococcus aureus strains obtained from chronic wound infections. Microb Pathog 2021; 162:105368. [PMID: 34942309 DOI: 10.1016/j.micpath.2021.105368] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Revised: 12/15/2021] [Accepted: 12/17/2021] [Indexed: 12/26/2022]
Abstract
The antimicrobial peptide LL-37 showed inhibitory effects against Staphylococcus aureus strains, which often responsible for wound infections. Understanding the molecular mechanisms of biofilm-containing wound infections is important. Thus, this study aimed to investigate both the antimicrobial and biofilm efficacy of LL-37 against biofilm-positive methicillin-susceptible S. aureus (MSSA) strains and biofilm-positive methicillin-resistant S. aureus (MRSA) strains obtained from chronic wound infections and its effect on different quorum sensing and virulence genes at suboptimal concentrations. Fifteen biofilm-forming MRSA and 15 biofilm-forming MSSA strains were included in this study. The minimum inhibitory concentration (MIC) values and biofilm formation were tested by microdilution methods. Real-time PCR was performed to determine gene expression levels. MIC values for LL-37 were 89.6 mg/L and 132.3 mg/L for MSSA and MRSA strains, respectively. No statistically significant difference was found between MRSA and MSSA strains in terms of the effect of LL-37 on biofilm formation. A statistically significant difference was found between MRSA and MSSA strains for atlA, RNAIII, and agrA gene expression levels following exposure to a suboptimal concentration of LL-37. Ultimately, the required LL-37 antimicrobial concentration was quite high; however, LL-37 antibiofilm concentration may be acceptable for use in humans against biofilm-forming MRSA and MSSA strains. This is the first study to investigate to effect of a suboptimal LL-37 concentration on gene expression levels of biofilm-forming MSSA and MRSA strains. LL-37 affected quorum sensing and biofilm producing mechanisms, even at suboptimal MIC concentrations.
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Affiliation(s)
- Mehmet Demirci
- Kirklareli University, Medical Faculty, Department of Medical Microbiology, Kirklareli, Turkey.
| | - Akin Yigin
- Harran University, Faculty of Veterinary, Department of Genetics, Sanlıurfa, Turkey
| | - Cemil Demir
- Mardin Artuklu University, Vocational Higher School of Health Services, Department of Medical Services and Techniques, Mardin, Turkey
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6
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Bhowmik D, Chetri S, Pandey P, Das BJ, Wangkheimayum J, Choudhury NA, Singha KM, Chanda DD, Bhattacharjee A. Expressional Pattern of psm-mec System in Methicillin-Resistant Staphylococcus aureus Under Oxacillin Stress. Curr Microbiol 2021; 78:528-533. [PMID: 33388933 DOI: 10.1007/s00284-020-02336-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Accepted: 12/14/2020] [Indexed: 11/28/2022]
Abstract
The psm-mec element and other regulatory factors such as sarA, agrA, and RNAIII are responsible for maintaining the genetic framework for enhanced virulence of MRSA. psm-mec is found predominantly in the staphylococcal cassette chromosome (SCCmec). sarA, agrA, and RNAIII control gene expression to facilitate adaptation in certain environment. Genome-wide approaches have shown that expression of virulence factors is frequently regulated at transcriptional, translational level, and mRNA degradation level. In this study, transcriptional responses of psm-mec gene in accordance with other regulatory factors sarA, agrA, and RNAIII were observed under normal conditions as well as when exposed to 2 μg/ml and 6 μg/ml of oxacillin stress. One-way t-test was carried out for analysing RQ values obtained through real-time PCR. This study showed downregulation of psm-mec gene and upregulation of other regulatory genes at lower concentration of oxacillin. However, this was reverse when exposed against higher concentration of oxacillin. It was observed from the study that the expression of virulence factors were dependent on each other under different concentration of oxacillin. Thus, this study highlights that psm-mec, sarA, agrA, and RNAIII gene are under direct control of antibiotic pressure in a concentration-dependent manner.
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Affiliation(s)
| | - Shiela Chetri
- Department of Microbiology, Assam University, Silchar, Assam, India
| | - Piyush Pandey
- Department of Microbiology, Assam University, Silchar, Assam, India
| | | | | | | | - K Melson Singha
- Department of Microbiology, Silchar Medical College and Hospital, Silchar, Assam, India
| | - Debadatta Dhar Chanda
- Department of Microbiology, Silchar Medical College and Hospital, Silchar, Assam, India
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Gupta A, Bansal M, Wagle B, Sun X, Rath N, Donoghue A, Upadhyay A. Sodium Butyrate Reduces Salmonella Enteritidis Infection of Chicken Enterocytes and Expression of Inflammatory Host Genes in vitro. Front Microbiol 2020; 11:553670. [PMID: 33042060 PMCID: PMC7524895 DOI: 10.3389/fmicb.2020.553670] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2020] [Accepted: 08/27/2020] [Indexed: 12/14/2022] Open
Abstract
Salmonella Enteritidis (SE) is a facultative intracellular pathogen that colonizes the chicken gut leading to contamination of carcasses during processing. A reduction in intestinal colonization by SE could result in reduced carcass contamination thereby reducing the risk of illnesses in humans. Short chain fatty acids such as butyrate are microbial metabolites produced in the gut that exert various beneficial effects. However, its effect on SE colonization is not well known. The present study investigated the effect of sub-inhibitory concentrations (SICs) of sodium butyrate on the adhesion and invasion of SE in primary chicken enterocytes and chicken macrophages. In addition, the effect of sodium butyrate on the expression of SE virulence genes and selected inflammatory genes in chicken macrophages challenged with SE were investigated. Based on the growth curve analysis, the two SICs of sodium butyrate that did not reduce SE growth were 22 and 45 mM, respectively. The SICs of sodium butyrate did not affect the viability and proliferation of chicken enterocytes and macrophage cells. The SICs of sodium butyrate reduced SE adhesion by ∼1.7 and 1.8 Log CFU/mL, respectively. The SE invasion was reduced by ∼2 and 2.93 Log CFU/mL, respectively in chicken enterocytes (P < 0.05). Sodium butyrate did not significantly affect the adhesion of SE to chicken macrophages. However, 45 mM sodium butyrate reduced invasion by ∼1.7 Log CFU/mL as compared to control (P < 0.05). Exposure to sodium butyrate did not change the expression of SE genes associated with motility (flgG, prot6E), invasion (invH), type 3 secretion system (sipB, pipB), survival in macrophages (spvB, mgtC), cell wall and membrane integrity (tatA), efflux pump regulator (mrr1) and global virulence regulation (lrp) (P > 0.05). However, a few genes contributing to type-3 secretion system (ssaV, sipA), adherence (sopB), macrophage survival (sodC) and oxidative stress (rpoS) were upregulated by at least twofold. The expression of inflammatory genes (Il1β, Il8, and Mmp9) that are triggered by SE for host colonization was significantly downregulated (at least 25-fold) by sodium butyrate as compared to SE (P < 0.05). The results suggest that sodium butyrate has an anti-inflammatory potential to reduce SE colonization in chickens.
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Affiliation(s)
- Anamika Gupta
- Department of Poultry Science, University of Arkansas, Fayetteville, AR, United States
| | - Mohit Bansal
- Department of Poultry Science, University of Arkansas, Fayetteville, AR, United States
| | - Basanta Wagle
- Department of Poultry Science, University of Arkansas, Fayetteville, AR, United States
| | - Xiaolun Sun
- Department of Poultry Science, University of Arkansas, Fayetteville, AR, United States
| | - Narayan Rath
- Poultry Production and Product Safety Research Unit, United States Department of Agriculture-Agriculture Research Station, Fayetteville, AR, United States
| | - Annie Donoghue
- Poultry Production and Product Safety Research Unit, United States Department of Agriculture-Agriculture Research Station, Fayetteville, AR, United States
| | - Abhinav Upadhyay
- Department of Animal Science, University of Connecticut, Storrs, CT, United States
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Relationship between Vancomycin MIC and Virulence Gene Expression in Clonal Complexes of Methicillin-Susceptible Staphylococcus aureus Strains Isolated from Left-Sided Endocarditis. Antimicrob Agents Chemother 2020; 64:AAC.01579-19. [PMID: 31907181 DOI: 10.1128/aac.01579-19] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2019] [Accepted: 12/10/2019] [Indexed: 12/15/2022] Open
Abstract
Higher vancomycin MICs have been associated with more complicated courses and higher mortality rates in patients with Staphylococcus aureus bacteremia and infective endocarditis (IE). The aim of this study was to investigate whether the strains belonging to the cohort of 93 patients from a previously published study in which patients with strains with vancomycin MICs of ≥1.5 μg/ml presented higher mortality rates and systemic emboli than patients with strains with vancomycin MICs of <1.5 μg/ml had specific patterns of virulence factors, clonal complex (CC) types, or the ability to form biofilms. Vancomycin MICs were determined by Etest, and the isolates underwent spa typing to infer the CC, biofilm studies, a thrombin-induced platelet microbicidal assay, and multiplex PCR for the presence of virulence genes. We found no differences in genes encoding adhesins, toxins, or other putative virulence genes according to the vancomycin MIC group. CC30, CC34, and CC45 represented nearly half of the isolates, and there was no association with the vancomycin MIC. agr subgroups I and III predominated, with no association with the vancomycin MIC. Isolates with higher vancomycin MICs exhibited a poorer ability to form biofilms with and without the presence of vancomycin (2.03 versus 2.48 [P < 0.001], respectively, for isolates with higher vancomycin MICs and 2.60 versus 2.87 [P = 0.022], respectively, for isolates with lower vancomycin MICs). In the multivariable analysis, efb and V8 were risk factors for major emboli (adjusted odds ratio [aOR] = 7.5 and 95% confidence interval [CI] = 1.2 to 46.6 for efb, and aOR = 3.9 and 95% CI = 1.1 to 14.1 for V8), whereas no genotypic predictors of in-hospital mortality were found. No clear associations between genes encoding virulence factors, agr type, clonal complexes, mortality, and major embolic events according to vancomycin MIC group were found.
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Wang LJ, Yang X, Qian SY, Liu YC, Yao KH, Dong F, Song WQ. Identification of hemolytic activity and hemolytic genes of Methicillin-resistant Staphylococcus aureus isolated from Chinese children. Chin Med J (Engl) 2020; 133:88-90. [PMID: 31923109 PMCID: PMC7028192 DOI: 10.1097/cm9.0000000000000571] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Indexed: 11/25/2022] Open
Affiliation(s)
- Li-Juan Wang
- Pediatric Intensive Care Unit, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, Beijing 100045, China
| | - Xin Yang
- Pediatric Intensive Care Unit, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, Beijing 100045, China
| | - Su-Yun Qian
- Pediatric Intensive Care Unit, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, Beijing 100045, China
| | - Ying-Chao Liu
- Pediatric Intensive Care Unit, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, Beijing 100045, China
| | - Kai-Hu Yao
- Beijing Key Laboratory of Pediatric Respiratory Infection Diseases, Key Laboratory of Major Diseases in Children, Ministry of Education, National Clinical Research Center for Respiratory Diseases, National Key Discipline of Pediatrics (Capital Medical University), Beijing Pediatric Research Institute, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, Beijing 100045 China
| | - Fang Dong
- Bacteriology Laboratory, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, Beijing 100045, China
| | - Wen-Qi Song
- Bacteriology Laboratory, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, Beijing 100045, China
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10
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Streptomycin mediated biofilm inhibition and suppression of virulence properties in Pseudomonas aeruginosa PAO1. Appl Microbiol Biotechnol 2019; 104:799-816. [PMID: 31820066 DOI: 10.1007/s00253-019-10190-w] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2019] [Revised: 09/09/2019] [Accepted: 10/07/2019] [Indexed: 12/15/2022]
Abstract
Pseudomonas aeruginosa is known as an opportunistic pathogen whose one of the antibiotic resistance mechanisms includes biofilm formation and virulence factor production. The present study showed that the sub-minimum inhibitory concentration (sub-MIC) of streptomycin inhibited the formation of biofilm and eradicated the established mature biofilm. Streptomycin at sub-MIC was also capable of inhibiting biofilm formation on the urinary catheters. In addition, the sub-MIC of streptomycin attenuated the bacterial virulence properties as confirmed by both phenotypic and gene expression studies. The optimal conditions for streptomycin to perform anti-biofilm and anti-virulence activities were proposed as alkaline TSB media (pH 7.9) at 35 °C. However, sub-MIC of streptomycin also exhibited a comparative anti-biofilm efficacy in LB media at similar pH level and temperature. Furthermore, this condition also improved the biofilm inhibition and eradication properties of streptomycin, tobramycin and tetracycline towards the biofilm formed by a clinical isolate of P. aeruginosa. Findings from the present study provide an important insight for further studies on the mechanisms of biofilm inhibition and dispersion of pre-existing biofilm by streptomycin as well as tobramycin and tetracycline under a specific culture environment.
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11
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Wang G, Li L, Wang X, Li X, Zhang Y, Yu J, Jiang J, You X, Xiong YQ. Hypericin enhances β-lactam antibiotics activity by inhibiting sarA expression in methicillin-resistant Staphylococcus aureus. Acta Pharm Sin B 2019; 9:1174-1182. [PMID: 31867163 PMCID: PMC6900551 DOI: 10.1016/j.apsb.2019.05.002] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2019] [Revised: 05/11/2019] [Accepted: 05/20/2019] [Indexed: 01/11/2023] Open
Abstract
Bacteremia is a life-threating syndrome often caused by methicillin-resistant Staphylococcus aureus (MRSA). Thus, there is an urgent need to develop novel approaches to successfully treat this infection. Staphylococcal accessory regulator A (SarA), a global virulence regulator, plays a critical role in pathogenesis and β-lactam antibiotic resistance in Staphylococcus aureus. Hypericin is believed to act as an antibiotic, antidepressant, antiviral and non-specific kinase inhibitor. In the current study, we investigated the impact of hypericin on β-lactam antibiotics susceptibility and mechanism(s) of its activity. We demonstrated that hypericin significantly decreased the minimum inhibitory concentrations of β-lactam antibiotics (e.g., oxacillin, cefazolin and nafcillin), biofilm formation and fibronectin binding in MRSA strain JE2. In addition, hypericin significantly reduced sarA expression, and subsequently decreased mecA, and virulence-related regulators (e.g., agr RNAⅢ) and genes (e.g., fnbA and hla) expression in the studied MRSA strain. Importantly, the in vitro synergistic effect of hypericin with β-lactam antibiotic (e.g., oxacillin) translated into in vivo therapeutic outcome in a murine MRSA bacteremia model. These findings suggest that hypericin plays an important role in abrogation of β-lactam resistance against MRSA through sarA inhibition, and may allow us to repurpose the use of β-lactam antibiotics, which are normally ineffective in the treatment of MRSA infections (e.g., oxacillin).
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Affiliation(s)
- Genzhu Wang
- Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, CA 90502, USA
- Beijing Key Laboratory of Antimicrobial Agents, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China
| | - Liang Li
- Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, CA 90502, USA
| | - Xiukun Wang
- Beijing Key Laboratory of Antimicrobial Agents, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China
| | - Xue Li
- Beijing Key Laboratory of Antimicrobial Agents, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China
| | - Youwen Zhang
- Beijing Key Laboratory of Antimicrobial Agents, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China
| | - Jie Yu
- Beijing Key Laboratory of Antimicrobial Agents, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China
| | - Jiandong Jiang
- Beijing Key Laboratory of Antimicrobial Agents, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China
- State Key Laboratory of Bioactive Substances and Function of Natural Medicine, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China
| | - Xuefu You
- Beijing Key Laboratory of Antimicrobial Agents, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China
- Corresponding authors. Tel.: +86 10 67061033, fax: +86 10 67017302 (Xuefu You); Tel.: +1 310 2223545 (Yan Q. Xiong).
| | - Yan Q. Xiong
- Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, CA 90502, USA
- Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
- Corresponding authors. Tel.: +86 10 67061033, fax: +86 10 67017302 (Xuefu You); Tel.: +1 310 2223545 (Yan Q. Xiong).
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