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Motomura Y, Miyazaki M, Kamada M, Morimoto S, Nakamura Y, Satho T, Takata T, Kashige N. Genotypic Shift and Diversification of MRSA Blood Stream Isolates in a University Hospital Setting: Evidence from a 12-Year Observational Study. Antibiotics (Basel) 2024; 13:670. [PMID: 39061352 PMCID: PMC11273934 DOI: 10.3390/antibiotics13070670] [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: 06/29/2024] [Revised: 07/13/2024] [Accepted: 07/17/2024] [Indexed: 07/28/2024] Open
Abstract
There have been few reports regarding the long-term trends in the genotypes of methicillin-resistant Staphylococcus aureus (MRSA) bloodstream isolates. Therefore, this study was performed to investigate the longitudinal trends in the genotypes of MRSA bloodstream isolates obtained from hospitalized patients during a 12-year study period from 2010 to 2021 at a tertiary care university hospital. Over the 12-year period from 2010 to 2021, we conducted a genetic investigation focusing on 245 MRSA strains isolated from the blood of hospitalized patients. The genotypes of the MRSA bloodstream isolates were determined by Staphylococcal Cassette Chromosome mec (SCCmec) typing, accessory gene regulator (agr) typing, PCR-based ORF typing (POT), and multilocus sequence typing (MLST). Strains with the same POT type detected in two or more isolates were designated as epidemic clones, while strains without a common POT type were classified as sporadic clones. Until 2015, isolates with SCCmec II/agr II were prevalent, but isolates with SCCmec IV/agr III increased from 2016. A total of 128 strains (52%) were identified as epidemic clones, while 117 strains (48%) were classified as sporadic clones. The detection rate of sporadic clones increased significantly since 2016 (p < 0.05). The epidemic clones were classified into three clusters, with MRSA of clonal complex (CC) 1 being prominent after 2016. This study showed that the genotypes of MRSA bloodstream isolates underwent a shift from SCCmec II/agr II type to SCCmec IV/agr III type, with a notable increase in MRSA of CC1, after 2016. There was a significant increase in the proportion of sporadic strains among the isolates, suggesting the diversification of genotypes.
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Affiliation(s)
- Yuka Motomura
- Faculty of Pharmaceutical Sciences, Fukuoka University, Fukuoka 814-0180, Japan; (Y.M.); (M.M.); (T.S.); (N.K.)
| | - Motoyasu Miyazaki
- Faculty of Pharmaceutical Sciences, Fukuoka University, Fukuoka 814-0180, Japan; (Y.M.); (M.M.); (T.S.); (N.K.)
- Department of Pharmacy, Fukuoka University Chikushi Hospital, Fukuoka 818-8502, Japan
| | - Mitsuhiro Kamada
- Department of Pharmacy, Fukuoka University Hospital, Fukuoka 814-0180, Japan;
| | - Shinichi Morimoto
- Department of Emergency and Critical Care Medicine, Faculty of Medicine, Fukuoka University, Fukuoka 814-0180, Japan; (S.M.); (Y.N.)
| | - Yoshihiko Nakamura
- Department of Emergency and Critical Care Medicine, Faculty of Medicine, Fukuoka University, Fukuoka 814-0180, Japan; (S.M.); (Y.N.)
| | - Tomomitsu Satho
- Faculty of Pharmaceutical Sciences, Fukuoka University, Fukuoka 814-0180, Japan; (Y.M.); (M.M.); (T.S.); (N.K.)
| | - Tohru Takata
- Department of Oncology, Hematology, and Infectious Diseases, Fukuoka University Hospital, Fukuoka 814-0180, Japan
- Department of Infection Control, Fukuoka University Hospital, Fukuoka 814-0180, Japan
| | - Nobuhiro Kashige
- Faculty of Pharmaceutical Sciences, Fukuoka University, Fukuoka 814-0180, Japan; (Y.M.); (M.M.); (T.S.); (N.K.)
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2
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Pardo L, Mota MI, Parnizari A, Varela A, Algorta G, Varela G. Detection of Vancomycin Resistance among Methicillin-Resistant Staphylococcus aureus Strains Recovered from Children with Invasive Diseases in a Reference Pediatric Hospital. Antibiotics (Basel) 2024; 13:298. [PMID: 38666974 PMCID: PMC11047724 DOI: 10.3390/antibiotics13040298] [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: 01/31/2024] [Revised: 02/28/2024] [Accepted: 03/08/2024] [Indexed: 04/29/2024] Open
Abstract
Vancomycin is the cornerstone in treating methicillin-resistant Staphylococcus aureus (MRSA) infections. However, therapeutic failures can occur when MRSA strains with decreased susceptibility to glycopeptides (DSG) are involved. The aim of this study was to detect and characterize DSG in MRSA recovered from children with invasive diseases at a reference pediatric hospital between 2009 and 2019. Fifty-two MRSA strains were screened using agar plates with vancomycin 3 and 4 mg/L (BHI-3 and BHI-4); the VITEK2 system; and standard and macro E-tests. Suspicious hVISA were studied by population analysis profiling-area under the curve (PAP-AUC), and wall thickness was analyzed by transmission electron microscopy. Neither VRSA nor VISA were detected in this set. As only three strains met the hVISA criteria, the PAP-AUC study included 12 additional MRSA strains that grew one colony on BHI-4 plates or showed minimum inhibitory concentrations of vancomycin and/or teicoplanin ≥ 1.5 mg/L. One strain was confirmed as hVISA by PAP-AUC. The wall thickness was greater than the vancomycin-susceptible control strain; it belonged to ST30 and carried SCCmec IV. As expected, a low frequency of hVISA was found (1.9%). The only hVISA confirmed by PAP-AUC was not detected by the screening methods, highlighting the challenge that its detection represents for microbiology laboratories.
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Affiliation(s)
- Lorena Pardo
- Bacteriology and Virology Academic Unit, Facultad de Medicina, Universidad de la República, Montevideo 11600, Uruguay; (M.I.M.); (A.P.)
- Pediatric “C” Academic Unit, Facultad de Medicina, Universidad de la República, Montevideo 11600, Uruguay
| | - María Inés Mota
- Bacteriology and Virology Academic Unit, Facultad de Medicina, Universidad de la República, Montevideo 11600, Uruguay; (M.I.M.); (A.P.)
- Bacteriology Laboratory, “Pereira Rossell” Pediatric Hospital, Montevideo 11600, Uruguay; (A.V.); (G.A.)
| | - Andrés Parnizari
- Bacteriology and Virology Academic Unit, Facultad de Medicina, Universidad de la República, Montevideo 11600, Uruguay; (M.I.M.); (A.P.)
| | - Adriana Varela
- Bacteriology Laboratory, “Pereira Rossell” Pediatric Hospital, Montevideo 11600, Uruguay; (A.V.); (G.A.)
| | - Gabriela Algorta
- Bacteriology Laboratory, “Pereira Rossell” Pediatric Hospital, Montevideo 11600, Uruguay; (A.V.); (G.A.)
| | - Gustavo Varela
- Bacteriology and Virology Academic Unit, Facultad de Medicina, Universidad de la República, Montevideo 11600, Uruguay; (M.I.M.); (A.P.)
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3
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Rozaini AZA, Abdulhameed A, Deivasigamani R, Nadzreen N, Zin NM, Kayani AA, Buyong MR. Dielectrophoresis microbial characterization and isolation of Staphylococcus aureus based on optimum crossover frequency. Electrophoresis 2023; 44:1220-1233. [PMID: 37259263 DOI: 10.1002/elps.202200276] [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: 08/01/2022] [Revised: 04/19/2023] [Accepted: 04/29/2023] [Indexed: 06/02/2023]
Abstract
Characterization of antibiotic-resistant bacteria is a significant concern that persists for the rapid classification and analysis of the bacteria. A technology that utilizes the manipulation of antibiotic-resistant bacteria is key to solving the significant threat of these pathogenic bacteria by rapid characterization profile. Dielectrophoresis (DEP) can differentiate between antibiotic-resistant and susceptible bacteria based on their physical structure and polarization properties. In this work, the DEP response of two Gram-positive bacteria, namely, Methicillin-resistant Staphylococcus aureus (MRSA) and Methicillin-susceptible S. aureus (MSSA), was investigated and simulated. The DEP characterization was experimentally observed on the bacteria influenced by oxacillin and vancomycin antibiotics. MSSA control without antibiotics has crossover frequencies (f x 0 ${f_{x0}}$ ) from 6 to 8 MHz, whereas MRSA control is from 2 to 3 MHz. Thef x 0 ${f_{x0}}$ changed when bacteria were exposed to the antibiotic. As for MSSA, thef x 0 ${f_{x0}}$ decreased to 3.35 MHz compared tof x 0 ${f_{x0}}$ MSSA control without antibiotics, MRSA,f x 0 ${f_{x0}}$ increased to 7 MHz when compared to MRSA control. The changes in the DEP response of MSSA and MRSA with and without antibiotics were theoretically proven using MyDEP and COMSOL simulation and experimentally based on the modification to the bacteria cell walls. Thus, the DEP response can be employed as a label-free detectable method to sense and differentiate between resistant and susceptible strains with different antibiotic profiles. The developed method can be implemented on a single platform to analyze and identify bacteria for rapid, scalable, and accurate characterization.
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Affiliation(s)
- Arash Zulkarnain Ahmad Rozaini
- Institute of Microengineering and Nanoelectronics (IMEN), Universiti Kebangsaan Malaysia, Bangi, Selangor, Malaysia
- Center for Diagnostic, Therapeutic and Investigative Studies, Faculty of Health Sciences, Universiti Kebangsaan Malaysia, Kuala Lumpur, Malaysia
| | - Abdullah Abdulhameed
- Center for Communication Systems and Sensing, King Fahd University of Petroleum & Minerals, Dhahran, Saudi Arabia
| | - Revathy Deivasigamani
- Institute of Microengineering and Nanoelectronics (IMEN), Universiti Kebangsaan Malaysia, Bangi, Selangor, Malaysia
| | - Nurulhuda Nadzreen
- Institute of Microengineering and Nanoelectronics (IMEN), Universiti Kebangsaan Malaysia, Bangi, Selangor, Malaysia
| | - Noraziah Mohamad Zin
- Center for Diagnostic, Therapeutic and Investigative Studies, Faculty of Health Sciences, Universiti Kebangsaan Malaysia, Kuala Lumpur, Malaysia
| | - Amin Ahmad Kayani
- Functional Materials and Microsystems Research Group and the Micro Nano Research Facility, RMIT University, Melbourne, Australia
- ARC Research Hub for Connected Sensors for Health, RMIT University, Melbourne, Australia
| | - Muhamad Ramdzan Buyong
- Institute of Microengineering and Nanoelectronics (IMEN), Universiti Kebangsaan Malaysia, Bangi, Selangor, Malaysia
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Ju M, Joseph T, Hansanant N, Geng M, Williams M, Cothrell A, Buhrow AR, Austin F, Smith L. Evaluation of analogs of mutacin 1140 in systemic and cutaneous methicillin-resistant Staphylococcus aureus infection models in mice. Front Microbiol 2022; 13:1067410. [PMID: 36590413 PMCID: PMC9794991 DOI: 10.3389/fmicb.2022.1067410] [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: 10/11/2022] [Accepted: 11/21/2022] [Indexed: 12/15/2022] Open
Abstract
Mutacin 1140 (Mu1140) is a potent antibiotic against Gram-positive bacteria, such as Staphylococcus aureus. The antibiotic is produced by the oral bacterium Streptococcus mutans and is a member of the epidermin family of type AI lantibiotics. The antibiotic exerts its inhibitory activity by binding to the cell wall precursor lipid II, blocking cell wall synthesis, and by disrupting bacterial membranes. In previous studies, the novel K2A and R13A analogs of Mu1140 have been identified to have superior pharmacokinetic properties compared to native Mu1140. In this study, the use of a combined formulation of the Mu1140 K2A and R13A analogs was shown to be more effective at treating MRSA bacteremia than the native Mu1140 or vancomycin. The analogs were also shown to be effective in treating an MRSA skin infection. The use of K2A and R13A analogs may provide a future alternative for treating serious Gram-positive bacterial infections. In a previous study, the Mu1140 analogs were shown to have significantly longer drug clearance times, leading to higher plasma concentrations over time. These properties warranted further testing to determine whether the analogs are effective for the treatment of systemic MRSA and acute skin infections. In this study, Mu1140 analogs were shown to be more effective than currently available treatments for systemic and skin MRSA infections. Further, the study clearly shows that the new analogs are superior to native Mu1140 for the treatment of a systemic MRSA infection. These findings support continued drug product development efforts using the K2A and R13A Mu1140 analogs, and that these analogs may ameliorate the outcome of serious bacterial infections.
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Affiliation(s)
- Min Ju
- Antimicrobial Division, Sano Chemicals Inc., Bryan, TX, United States
| | - Thushinari Joseph
- Department of Biology, Texas A&M University, College Station, TX, United States
| | - Nopakorn Hansanant
- Department of Biology, Texas A&M University, College Station, TX, United States
| | - Mengxin Geng
- Department of Biology, Texas A&M University, College Station, TX, United States
| | - McKinley Williams
- Department of Biology, Texas A&M University, College Station, TX, United States
| | - Andrew Cothrell
- Department of Biology, Texas A&M University, College Station, TX, United States
| | - Andrew Riley Buhrow
- Antimicrobial Division, Sano Chemicals Inc., Bryan, TX, United States,Department of Biology, Texas A&M University, College Station, TX, United States
| | - Frank Austin
- College of Veterinary Medicine, Mississippi State University, Mississippi State, MS, United States
| | - Leif Smith
- Antimicrobial Division, Sano Chemicals Inc., Bryan, TX, United States,Department of Biology, Texas A&M University, College Station, TX, United States,*Correspondence: Leif Smith,
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Xie N, Jiang L, Chen M, Zhang G, Liu Y, Li J, Huang X. In vitro and in vivo Antibacterial Activity of Linezolid Plus Fosfomycin Against Staphylococcus aureus with Resistance to One Drug. Infect Drug Resist 2021; 14:639-649. [PMID: 33658805 PMCID: PMC7917344 DOI: 10.2147/idr.s290332] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Accepted: 01/14/2021] [Indexed: 12/29/2022] Open
Abstract
Objective The purpose of this study is to assess the in vitro/vivo activities of linezolid plus fosfomycin against Staphylococcus aureus (S. aureus) isolates with varying susceptibility to the study drugs. Methods The increasing concentration stepwise method was used to induce S. aureus resistant strains. The in vitro antibacterial activity of linezolid combined with fosfomycin against S. aureus in vitro was studied by time-kill curve and PAE. The transmission electron microscopy (TEM) was employed to observe the cell morphology of bacteria treated with drug, and the changes of cell wall thickness were recorded. The Galleria mellonella infection model was established to demonstrate the in vivo efficacy of linezolid and fosfomycin against S. aureus with varying susceptibility. Results The antibiotic combination showed excellent synergistic or additive effects on the original and the linezolid-resistant strain, but showed indifferent effect for fosfomycin-resistant strain. TEM images showed that fosfomycin alone and in combined could reduce the cell wall thickness of the strains resistant to linezolid and cell lysis, while linezolid increases the cell wall thickness of the strains resistant to fosfomycin. In the Galleria mellonella infection model, the survival rate of the antibiotic combined was improved compared with that of the single drug. There was a good correlation between in vivo efficacy and in vitro susceptibility. Conclusion The type of interaction expressed in the test combination was highly dependent on fosfomycin resistance.
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Affiliation(s)
- Na Xie
- Department of Basic and Clinical Pharmacology, School of Pharmacy, Anhui Medical University, Hefei, Anhui, People's Republic of China
| | - Lifang Jiang
- Department of Basic and Clinical Pharmacology, School of Pharmacy, Anhui Medical University, Hefei, Anhui, People's Republic of China
| | - Mingtao Chen
- Department of Basic and Clinical Pharmacology, School of Pharmacy, Anhui Medical University, Hefei, Anhui, People's Republic of China
| | - Guijun Zhang
- Department of Basic and Clinical Pharmacology, School of Pharmacy, Anhui Medical University, Hefei, Anhui, People's Republic of China
| | - Yanyan Liu
- Department of Infectious Diseases, The First Affiliated Hospital of Anhui Medical University, Hefei, Anhui, People's Republic of China
| | - Jiabin Li
- Department of Infectious Diseases, The First Affiliated Hospital of Anhui Medical University, Hefei, Anhui, People's Republic of China
| | - Xiaohui Huang
- Department of Basic and Clinical Pharmacology, School of Pharmacy, Anhui Medical University, Hefei, Anhui, People's Republic of China
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6
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Rossato AM, Primon-Barros M, Dias CAG, d'Azevedo PA. Vancomycin MIC and agr dysfunction in invasive MRSA infections in southern Brazil. Braz J Microbiol 2020; 51:1819-1823. [PMID: 33074551 DOI: 10.1007/s42770-020-00384-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Accepted: 10/14/2020] [Indexed: 10/23/2022] Open
Abstract
In methicillin-resistant Staphylococcus aureus (MRSA) treatment, the vancomycin minimum inhibitory concentration (MIC) increase, vancomycin heteroresistance (hVISA) presence, and accessory gene regulator (agr) dysfunction are predictors of vancomycin therapy failure. This study evaluated the association between vancomycin MIC (≥ 1.0 μg/mL) and agr dysfunction in invasive MRSA isolates. Vancomycin MIC, hVISA phenotype, agr group, and function were determined in 171 MRSA isolates obtained between 2014 and 2019 from hospitals in Porto Alegre, Brazil. All MRSA were susceptible to vancomycin; 16.4% of these had MIC ≥ 1.0 μg/mL. Seventeen MRSA isolates expressed the hVISA phenotype; 35.3% of them had MIC of 1.5 μg/mL. agr groups I (40.9%) and II (47.1%) were the most found groups for MRSA and hVISA isolates, respectively. The proportion of MRSA with vancomycin MIC ≥ 1.0 μg/mL in agr group II was significantly higher than in agr groups I and III (p = 0.002). agr dysfunction was observed in 4.7% (8/171) of MRSA, especially those with vancomycin MIC ≥ 1.0 μg/mL (p < 0.001). In addition, six isolates (35.3%; 6/17) with hVISA phenotype presented agr dysfunction, which was significantly higher than that in non-hVISA phenotype (p < 0.001). In conclusion, agr dysfunction in MRSA is associated with vancomycin MIC ≥ 1.0 μg/mL and hVISA phenotype, which suggests that agr dysfunction might confer potential advantages on MRSA to survive in invasive infections.
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Affiliation(s)
- Adriana Medianeira Rossato
- Basic Health Department, Postgraduate Program in Health Sciences of Porto Alegre (PPGCS), Federal University of Health Science of Porto Alegre (UFCSPA), Porto Alegre, RS, Brazil.
| | - Muriel Primon-Barros
- Basic Health Department, Postgraduate Program in Health Sciences of Porto Alegre (PPGCS), Federal University of Health Science of Porto Alegre (UFCSPA), Porto Alegre, RS, Brazil
| | - Cícero Armídio Gomes Dias
- Basic Health Department, Postgraduate Program in Health Sciences of Porto Alegre (PPGCS), Federal University of Health Science of Porto Alegre (UFCSPA), Porto Alegre, RS, Brazil
| | - Pedro Alves d'Azevedo
- Basic Health Department, Postgraduate Program in Health Sciences of Porto Alegre (PPGCS), Federal University of Health Science of Porto Alegre (UFCSPA), Porto Alegre, RS, Brazil
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7
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Alsaeed A, Wright G, Deneer H, Rubin JE, Sanche SE, Blondeau JM. Methicillin-resistant Staphylococcus aureus replication in the presence of high (≥32 µg/ml) drug concentration of vancomycin as seen by electron microscopy. J Chemother 2020; 32:179-187. [PMID: 32393118 DOI: 10.1080/1120009x.2020.1761191] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) has unfortunately become a common pathogen in many healthcare facilities. In many institutions, vancomycin remains the preferred agent for treating serious MRSA infections including bacteraemia with or without endocarditis. The mutant prevention concentration (MPC) testing ≥109 colony forming units of bacteria, describes the antimicrobial drug concentration blocking the growth of the least susceptible cell from high density bacterial populations. With blood culture isolates of MRSA, we discovered strains with MPC values ≥32 µg/ml and viable cells could be readily recovered from agar plates containing 32 µg/ml of vancomycin. To investigate MRSA strains surviving in high concentrations of vancomycin on drug containing agar plates, we utilized electron microscopy to measure cell wall thickness as this has been previously reported as a potential mechanism of resistance1 along with septum thickening. Our data shows MRSA replication from high density bacterial populations in the presence of ≥32 µg/ml of vancomycin. Such observations may explain vancomycin failure in some patients and/or persistent bacteraemia and could potentially question the use of this drug in some critically ill patients in favour of an alternative agent.
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Affiliation(s)
- Amal Alsaeed
- University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Glenda Wright
- Pathology and Laboratory Medicine, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Harry Deneer
- Pathology and Laboratory Medicine, University of Saskatchewan, Saskatoon, Saskatchewan, Canada.,Division of Clinical Microbiology, Royal University Hospital and Saskatchewan Health Authority, Saskatoon, Saskatchewan, Canada
| | - Joseph E Rubin
- Veterinary Microbiology, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Stephen E Sanche
- Division of Clinical Microbiology, Royal University Hospital and Saskatchewan Health Authority, Saskatoon, Saskatchewan, Canada.,Medicine, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Joseph M Blondeau
- Pathology and Laboratory Medicine, University of Saskatchewan, Saskatoon, Saskatchewan, Canada.,Division of Clinical Microbiology, Royal University Hospital and Saskatchewan Health Authority, Saskatoon, Saskatchewan, Canada.,Departments of Microbiology and Immunology, University of Saskatchewan, Saskatoon, Saskatchewan, Canada.,Ophthalmology, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
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8
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Kuehl R, Morata L, Meylan S, Mensa J, Soriano A. When antibiotics fail: a clinical and microbiological perspective on antibiotic tolerance and persistence of Staphylococcus aureus. J Antimicrob Chemother 2020; 75:1071-1086. [PMID: 32016348 DOI: 10.1093/jac/dkz559] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Staphylococcus aureus is a major human pathogen causing a vast array of infections with significant mortality. Its versatile physiology enables it to adapt to various environments. Specific physiological changes are thought to underlie the frequent failure of antimicrobial therapy despite susceptibility in standard microbiological assays. Bacteria capable of surviving high antibiotic concentrations despite having a genetically susceptible background are described as 'antibiotic tolerant'. In this review, we put current knowledge on environmental triggers and molecular mechanisms of increased antibiotic survival of S. aureus into its clinical context. We discuss animal and clinical evidence of its significance and outline strategies to overcome infections with antibiotic-tolerant S. aureus.
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Affiliation(s)
- Richard Kuehl
- Service of Infectious Diseases, Hospital Clinic of Barcelona, University of Barcelona, IDIBAPS, Barcelona, Spain
- Department of Infectious Diseases and Hospital Epidemiology, University Hospital Basel, Basel, Switzerland
| | - Laura Morata
- Service of Infectious Diseases, Hospital Clinic of Barcelona, University of Barcelona, IDIBAPS, Barcelona, Spain
| | - Sylvain Meylan
- Department of Infectious Diseases and Hospital Epidemiology, University Hospital Basel, Basel, Switzerland
- Division de Maladies Infectieuses, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland
| | - Josep Mensa
- Service of Infectious Diseases, Hospital Clinic of Barcelona, University of Barcelona, IDIBAPS, Barcelona, Spain
| | - Alex Soriano
- Service of Infectious Diseases, Hospital Clinic of Barcelona, University of Barcelona, IDIBAPS, Barcelona, Spain
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9
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Shen WJ, Deshpande A, Hevener KE, Endres BT, Garey KW, Palmer KL, Hurdle JG. Constitutive expression of the cryptic vanGCd operon promotes vancomycin resistance in Clostridioides difficile clinical isolates. J Antimicrob Chemother 2020; 75:859-867. [PMID: 31873741 PMCID: PMC7069472 DOI: 10.1093/jac/dkz513] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Revised: 11/01/2019] [Accepted: 11/09/2019] [Indexed: 12/19/2022] Open
Abstract
OBJECTIVES To describe, for the first time (to the best of our knowledge), the genetic mechanisms of vancomycin resistance in clinical isolates of Clostridioides difficile ribotype 027. METHODS Clinical isolates and laboratory mutants were analysed: genomically to identify resistance mutations; by transcriptional analysis of vanGCd, the vancomycin resistance operon encoding lipid II d-alanine-d-serine that is less bound by vancomycin than native lipid II d-alanine-d-alanine; by imaging of vancomycin binding to cell walls; and for changes in vancomycin bactericidal activity and autolysis. RESULTS Vancomycin-resistant laboratory mutants and clinical isolates acquired mutations to the vanSR two-component system that regulates vanGCd. The substitutions impaired VanSR's function, resulting in constitutive transcription of vanGCd. Resistance was reversed by silencing vanG, encoding d-alanine-d-serine ligase in the vanGCd operon. In resistant cells, vancomycin was less bound to the cell wall septum, the site where vancomycin interacts with lipid II. Vancomycin's bactericidal activity was reduced against clinical isolates and laboratory mutants (64 and ≥1024 mg/L, respectively) compared with WT strains (4 mg/L). Truncation of the potassium transporter TrkA occurred in laboratory mutants, which were refractory to autolysis, accounting for their survival in high drug concentrations. CONCLUSIONS Ribotype 027 evolved first-step resistance to vancomycin by constitutively expressing vanGCd, which is otherwise silent. Experimental evolutions and bactericidal assays show that ribotype 027 can acquire mutations to drastically enhance its tolerance to vancomycin. Thus, further epidemiological studies are warranted to examine the extent to which vancomycin resistance impacts clinical outcomes and the potential for these strains to evolve higher-level resistance, which would be devastating.
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Affiliation(s)
- Wan-Jou Shen
- Center for Infectious and Inflammatory Diseases, Institute of Biosciences and Technology, Texas A&M Health Science Center, Houston, TX 77030, USA
| | - Aditi Deshpande
- Center for Infectious and Inflammatory Diseases, Institute of Biosciences and Technology, Texas A&M Health Science Center, Houston, TX 77030, USA
| | - Kirk E Hevener
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Tennessee Health Science Center, Memphis, TN 38105, USA
| | - Bradley T Endres
- Department of Pharmacy Practice and Translational Research, College of Pharmacy, University of Houston, Houston, TX 77204, USA
| | - Kevin W Garey
- Department of Pharmacy Practice and Translational Research, College of Pharmacy, University of Houston, Houston, TX 77204, USA
| | - Kelli L Palmer
- Department of Biological Sciences, University of Texas at Dallas, Richardson, TX 75080, USA
| | - Julian G Hurdle
- Center for Infectious and Inflammatory Diseases, Institute of Biosciences and Technology, Texas A&M Health Science Center, Houston, TX 77030, USA
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10
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Orazi G, O'Toole GA. "It Takes a Village": Mechanisms Underlying Antimicrobial Recalcitrance of Polymicrobial Biofilms. J Bacteriol 2019; 202:e00530-19. [PMID: 31548277 PMCID: PMC6932244 DOI: 10.1128/jb.00530-19] [Citation(s) in RCA: 88] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Chronic infections are frequently caused by polymicrobial biofilms. Importantly, these infections are often difficult to treat effectively in part due to the recalcitrance of biofilms to antimicrobial therapy. Emerging evidence suggests that polymicrobial interactions can lead to dramatic and unexpected changes in the ability of antibiotics to eradicate biofilms and often result in decreased antimicrobial efficacy in vitro In this review, we discuss the influence of polymicrobial interactions on the antibiotic susceptibility of biofilms, and we highlight the studies that first documented the shifted antimicrobial susceptibilities of mixed-species cultures. Recent studies have identified several mechanisms underlying the recalcitrance of polymicrobial biofilm communities, including interspecies exchange of antibiotic resistance genes, β-lactamase-mediated inactivation of antibiotics, changes in gene expression induced by metabolites and quorum sensing signals, inhibition of the electron transport chain, and changes in properties of the cell membrane. In addition to elucidating multiple mechanisms that contribute to the altered drug susceptibility of polymicrobial biofilms, these studies have uncovered novel ways in which polymicrobial interactions can impact microbial physiology. The diversity of findings discussed highlights the importance of continuing to investigate the efficacy of antibiotics against biofilm communities composed of different combinations of microbial species. Together, the data presented here illustrate the importance of studying microbes as part of mixed-species communities rather than in isolation. In light of our greater understanding of how interspecies interactions alter the efficacy of antimicrobial agents, we propose that the methods for measuring the drug susceptibility of polymicrobial infections should be revisited.
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Affiliation(s)
- Giulia Orazi
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA
| | - George A O'Toole
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA
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11
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Abstract
Abstract
An increasing problem in the field of health protection is the emergence of drug-resistant and multi-drug-resistant bacterial strains. They cause a number of infections, including hospital infections, which currently available antibiotics are unable to fight. Therefore, many studies are devoted to the search for new therapeutic agents with bactericidal and bacteriostatic properties. One of the latest concepts is to search for this type of substances among toxins produced by venomous animals. In this approach, however, special attention is paid to snake venom because it contains molecules with antibacterial properties. Thorough investigations have shown that the phospholipases A2 (PLA2) and l-amino acids oxidases (LAAO), as well as fragments of these enzymes, are mainly responsible for the bactericidal properties of snake venoms. Some preliminary research studies also suggest that fragments of three-finger toxins (3FTx) are bactericidal. It has also been proven that some snakes produce antibacterial peptides (AMP) homologous to human defensins and cathelicidins. The presence of these proteins and peptides means that snake venoms continue to be an interesting material for researchers and can be perceived as a promising source of antibacterial agents.
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Silveira ACO, Caierão J, Silva CI, Anzai EK, McCulloch JA, d'Azevedo PA, Sincero TCM. Impact of mutations in hVISA isolates on decreased susceptibility to vancomycin, through population analyses profile - area under curve (PAP-AUC). Diagn Microbiol Infect Dis 2019; 95:114854. [PMID: 31366440 DOI: 10.1016/j.diagmicrobio.2019.06.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2018] [Revised: 04/10/2019] [Accepted: 06/06/2019] [Indexed: 10/26/2022]
Abstract
We analyzed sequences of graSR, vraSR, walKR and rpoB genes in hVISA from Brazil. Five isolates showed mutations in at least one gene. rpoB H481N and graS T224I were the most frequent mutations, followed by graR D148Q and walK A468T. Our study reinforces the heterogeneity of genetic patterns among hVISA.
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Affiliation(s)
- A C O Silveira
- UFSC - Federal University of Santa Catarina, Florianópolis, - SC, Brazil; FURB - Regional University of Blumenau, Blumenau, - SC, Brazil.
| | - J Caierão
- UFRGS - Federal University of Rio Grande do Sul, Porto Alegre, - RS, Brazil
| | - C I Silva
- UFSC - Federal University of Santa Catarina, Florianópolis, - SC, Brazil
| | - E K Anzai
- FURB - Regional University of Blumenau, Blumenau, - SC, Brazil
| | - J A McCulloch
- USP - University of São Paulo, São Paulo, - SP, Brazil
| | - P A d'Azevedo
- UFCSPA - Federal University of Health Sciences of Porto Alegre, Porto Alegre, - RS, Brazil
| | - T C M Sincero
- UFSC - Federal University of Santa Catarina, Florianópolis, - SC, Brazil
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Scott JE, O'Toole GA. The Yin and Yang of Streptococcus Lung Infections in Cystic Fibrosis: a Model for Studying Polymicrobial Interactions. J Bacteriol 2019; 201:e00115-19. [PMID: 30885933 PMCID: PMC6509657 DOI: 10.1128/jb.00115-19] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The streptococci are increasingly recognized as a core component of the cystic fibrosis (CF) lung microbiome, yet the role that they play in CF lung disease is unclear. The presence of the Streptococcus milleri group (SMG; also known as the anginosus group streptococci [AGS]) correlates with exacerbation when these microbes are the predominant species in the lung. In contrast, microbiome studies have indicated that an increased relative abundance of streptococci in the lung, including members of the oral microflora, correlates with impacts on lung disease less severe than those caused by other CF-associated microflora, indicating a complex role for this genus in the context of CF. Recent findings suggest that streptococci in the CF lung microenvironment may influence the growth and/or virulence of other CF pathogens, as evidenced by increased virulence factor production by Pseudomonas aeruginosa when grown in coculture with oral streptococci. Conversely, the presence of P. aeruginosa can enhance the growth of streptococci, including members of the SMG, a phenomenon that could be exacerbated by the fact that streptococci are not susceptible to some of the frontline antibiotics used to treat P. aeruginosa infections. Collectively, these studies indicate the necessity for further investigation into the role of streptococci in the CF airway to determine how these microbes, alone or via interactions with other CF-associated pathogens, might influence CF lung disease, for better or for worse. We also propose that the interactions of streptococci with other CF pathogens is an ideal model to study clinically relevant microbial interactions.
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Affiliation(s)
- Jessie E Scott
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA
| | - George A O'Toole
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA
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De la Rosa-Zamboni D, Ochoa SA, Laris-González A, Cruz-Córdova A, Escalona-Venegas G, Pérez-Avendaño G, Torres-García M, Suaréz-Mora R, Castellanos-Cruz C, Sánchrez-Flores YV, Vázquez-Flores A, Águila-Torres R, Parra-Ortega I, Klünder-Klünder M, Arellano-Galindo J, Hernández-Castro R, Xicohtencatl-Cortes J. Everybody hands-on to avoid ESKAPE: effect of sustained hand hygiene compliance on healthcare-associated infections and multidrug resistance in a paediatric hospital. J Med Microbiol 2018; 67:1761-1771. [PMID: 30372411 DOI: 10.1099/jmm.0.000863] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
PURPOSE Hand hygiene is the most important strategy for preventing healthcare-associated infections (HCAIs); however, the impact of hand hygiene in middle-income countries has been poorly described. In this work, we describe the impact of the programme 'Let's Go for 100' on hand hygiene adherence, HCAIs rates and multidrug-resistant (MDR) bacteria, including the molecular typing of methicillin-resistant Staphylococcus aureus (MRSA) strains. METHODOLOGY A multimodal, hospital-wide hand hygiene programme was implemented from 2013. 'Let's Go for 100' involved all healthcare workers and encompassed education, awareness, visual reminders, feedback and innovative strategies. Monthly hand hygiene monitoring and active HCAI surveillance were performed in every ward. Molecular typing of MRSA was analysed by pulsed-field gel electrophoresis (PFGE).Results/Key findings. Hand hygiene adherence increased from 34.9 % during the baseline period to 80.6 % in the last 3 months of this study. The HCAI rate decreased from 7.54 to 6.46/1000 patient-days (P=0.004). The central line-associated bloodstream infection (CLABSIs) rate fell from 4.84 to 3.66/1000 central line-days (P=0.05). Negative correlations between hand hygiene and HCAIs rates were identified. The attack rate of MDR-ESKAPE group bloodstream infections decreased from 0.54 to 0.20/100 discharges (P=0.024). MRSA pulsotypes that were prevalent during the baseline period were no longer detected after the 5th quarter, although new strains were identified. CONCLUSIONS A multimodal hand hygiene programme in a paediatric hospital in a middle-income country was effective in improving adherence and reducing HCAIs, CLABSIs and MDR-ESKAPE bloodstream infections. Sustaining hand hygiene adherence at a level of >60 % for one year limited MRSA clonal transmission.
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Affiliation(s)
- Daniela De la Rosa-Zamboni
- 1Departamento de Epidemiología. Hospital Infantil de México Federico Gómez. Dr. Márquez 162, Col. Doctores, Cuauhtémoc 06720. Ciudad de México, México
| | - Sara A Ochoa
- 2Laboratorio de Investigación en Bacteriología Intestinal, Hospital Infantil de México Federico Gómez, Dr. Márquez 162, Col. Doctores, Cuauhtémoc 06720. Ciudad de México, México
| | - Almudena Laris-González
- 1Departamento de Epidemiología. Hospital Infantil de México Federico Gómez. Dr. Márquez 162, Col. Doctores, Cuauhtémoc 06720. Ciudad de México, México
| | - Ariadnna Cruz-Córdova
- 2Laboratorio de Investigación en Bacteriología Intestinal, Hospital Infantil de México Federico Gómez, Dr. Márquez 162, Col. Doctores, Cuauhtémoc 06720. Ciudad de México, México
| | - Gerardo Escalona-Venegas
- 2Laboratorio de Investigación en Bacteriología Intestinal, Hospital Infantil de México Federico Gómez, Dr. Márquez 162, Col. Doctores, Cuauhtémoc 06720. Ciudad de México, México
| | - Georgina Pérez-Avendaño
- 1Departamento de Epidemiología. Hospital Infantil de México Federico Gómez. Dr. Márquez 162, Col. Doctores, Cuauhtémoc 06720. Ciudad de México, México
| | - Margarita Torres-García
- 1Departamento de Epidemiología. Hospital Infantil de México Federico Gómez. Dr. Márquez 162, Col. Doctores, Cuauhtémoc 06720. Ciudad de México, México
| | - Roselia Suaréz-Mora
- 1Departamento de Epidemiología. Hospital Infantil de México Federico Gómez. Dr. Márquez 162, Col. Doctores, Cuauhtémoc 06720. Ciudad de México, México
| | - Carmen Castellanos-Cruz
- 3Laboratorio Central de Bacteriología, Hospital Infantil de México Federico Gómez, Dr. Márquez 162, Col. Doctores, Cuauhtémoc 06720. Ciudad de México, México
| | - Yadhira V Sánchrez-Flores
- 1Departamento de Epidemiología. Hospital Infantil de México Federico Gómez. Dr. Márquez 162, Col. Doctores, Cuauhtémoc 06720. Ciudad de México, México
| | - Adalberto Vázquez-Flores
- 1Departamento de Epidemiología. Hospital Infantil de México Federico Gómez. Dr. Márquez 162, Col. Doctores, Cuauhtémoc 06720. Ciudad de México, México
| | - Rosalinda Águila-Torres
- 1Departamento de Epidemiología. Hospital Infantil de México Federico Gómez. Dr. Márquez 162, Col. Doctores, Cuauhtémoc 06720. Ciudad de México, México
| | - Israel Parra-Ortega
- 3Laboratorio Central de Bacteriología, Hospital Infantil de México Federico Gómez, Dr. Márquez 162, Col. Doctores, Cuauhtémoc 06720. Ciudad de México, México
| | - Miguel Klünder-Klünder
- 4Subdirección de Investigación, Hospital Infantil de México Federico Gómez, Dr. Márquez 162, Col. Doctores, Cuauhtémoc 06720. Ciudad de México, México
| | - José Arellano-Galindo
- 5Departamento de Infectología, Hospital Infantil de México Federico Gómez, Dr. Márquez 162, Col. Doctores, Cuauhtémoc 06720. Ciudad de México, México
| | - Rigoberto Hernández-Castro
- 6Departamento de Ecología de Agentes Patógenos, Hospital General Dr. Manuel Gea González, Tlalpan, 14080, Ciudad de México, México
| | - Juan Xicohtencatl-Cortes
- 2Laboratorio de Investigación en Bacteriología Intestinal, Hospital Infantil de México Federico Gómez, Dr. Márquez 162, Col. Doctores, Cuauhtémoc 06720. Ciudad de México, México
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Krishna A, Holden MTG, Peacock SJ, Edwards AM, Wigneshweraraj S. Naturally occurring polymorphisms in the virulence regulator Rsp modulate Staphylococcus aureus survival in blood and antibiotic susceptibility. MICROBIOLOGY (READING, ENGLAND) 2018; 164:1189-1195. [PMID: 30028663 PMCID: PMC6230762 DOI: 10.1099/mic.0.000695] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/27/2018] [Accepted: 07/03/2018] [Indexed: 01/20/2023]
Abstract
Nasal colonization by the pathogen Staphylococcus aureus is a risk factor for subsequent infection. Loss of function mutations in the gene encoding the virulence regulator Rsp are associated with the transition of S. aureus from a colonizing isolate to one that causes bacteraemia. Here, we report the identification of several novel activity-altering mutations in rsp detected in clinical isolates, including for the first time, mutations that enhance agr operon activity. We assessed how these mutations affected infection-relevant phenotypes and found loss and enhancement of function mutations to have contrasting effects on S. aureus survival in blood and antibiotic susceptibility. These findings add to the growing body of evidence that suggests S. aureus 'trades off' virulence for the acquisition of traits that benefit survival in the host, and indicates that infection severity and treatment options can be significantly affected by mutations in the virulence regulator rsp.
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Affiliation(s)
- Aishwarya Krishna
- MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London, UK
| | - Matthew T. G. Holden
- Wellcome Trust Sanger Institute, Hinxton, UK
- School of Medicine, University of St Andrews, St Andrews, UK
| | - Sharon J. Peacock
- Wellcome Trust Sanger Institute, Hinxton, UK
- London School of Hygiene and Tropical Medicine, London, UK
| | - Andrew M. Edwards
- MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London, UK
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16
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The antibacterial activity of LI-F type peptide against methicillin-resistant Staphylococcus aureus (MRSA) in vitro and inhibition of infections in murine scalded epidermis. Appl Microbiol Biotechnol 2018; 102:2301-2311. [DOI: 10.1007/s00253-017-8669-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2017] [Revised: 11/14/2017] [Accepted: 11/15/2017] [Indexed: 01/10/2023]
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17
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García AB, Viñuela-Prieto JM, López-González L, Candel FJ. Correlation between resistance mechanisms in Staphylococcus aureus and cell wall and septum thickening. Infect Drug Resist 2017; 10:353-356. [PMID: 29089777 PMCID: PMC5655128 DOI: 10.2147/idr.s146748] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Purpose The aim of the present study is to examine cell wall and septum thickening of methicillin-sensitive Staphylococcus aureus (MSSA), methicillin-resistant S. aureus (MRSA), and methicillin- and linezolid-resistant S. aureus (MLRSA) isolates by transmission electron microscopy to correlate the association of resistance mechanisms with major changes in the morphology of membrane or septum. Materials and methods MSSA, MRSA, and MLRSA strains obtained from clinical samples of an outbreak that occurred in 2010 at the Intensive Care Unit of our Hospital were thawed and sown at 37°C in blood agar overnight. After that, they were washed, pelleted, and treated with a fixer solution. Pellets were dehydrated and finally embedded in resin. Transmission electron microscopy was used to characterize cell wall and septum thickening in all isolates. The comparison between the measurements obtained for each group was performed by a Kruskal–Wallis test and a post hoc Dunn–Bonferroni’s pairwise comparison method. Results Differences in cell wall and septum thickness were statistically significant (P<0.001 and P<0.001, respectively) between the three groups. Moreover, significant differences were detected in wall and septum thickness between the MSSA and MRSA strains (P<0.001 and P<0.001, respectively) and between the MSSA and MLRSA strains (P<0.001 and P<0.001, respectively) but not between the MRSA and MLRSA strains (P=0.386 and P=0.117). Conclusion In this analysis, we correlate the resistance mediated by alterations in the cell membrane of S. aureus (methicillin-resistant, for example) with a greater thickness of the wall or septum. The resistance added to linezolid did not determine significant changes in the characteristics of the wall or septum with respect to those strains resistant only to methicillin.
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Affiliation(s)
- Ana Belén García
- Department of Clinical Microbiology, Hospital Clínico San Carlos, Complutense University, Madrid, Spain
| | | | - Laura López-González
- Department of Clinical Microbiology, Hospital Clínico San Carlos, Complutense University, Madrid, Spain
| | - Francisco Javier Candel
- Department of Clinical Microbiology, Hospital Clínico San Carlos, Complutense University, Madrid, Spain.,Health Research Institute, Hospital Universitario San Carlos, Madrid, Spain
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Pseudomonas aeruginosa Alters Staphylococcus aureus Sensitivity to Vancomycin in a Biofilm Model of Cystic Fibrosis Infection. mBio 2017; 8:mBio.00873-17. [PMID: 28720732 PMCID: PMC5516255 DOI: 10.1128/mbio.00873-17] [Citation(s) in RCA: 129] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
The airways of cystic fibrosis (CF) patients have thick mucus, which fosters chronic, polymicrobial infections. Pseudomonas aeruginosa and Staphylococcus aureus are two of the most prevalent respiratory pathogens in CF patients. In this study, we tested whether P. aeruginosa influences the susceptibility of S. aureus to frontline antibiotics used to treat CF lung infections. Using our in vitro coculture model, we observed that addition of P. aeruginosa supernatants to S. aureus biofilms grown either on epithelial cells or on plastic significantly decreased the susceptibility of S. aureus to vancomycin. Mutant analyses showed that 2-n-heptyl-4-hydroxyquinoline N-oxide (HQNO), a component of the P. aeruginosa Pseudomonas quinolone signal (PQS) system, protects S. aureus from the antimicrobial activity of vancomycin. Similarly, the siderophores pyoverdine and pyochelin also contribute to the ability of P. aeruginosa to protect S. aureus from vancomycin, as did growth under anoxia. Under our experimental conditions, HQNO, P. aeruginosa supernatant, and growth under anoxia decreased S. aureus growth, likely explaining why this cell wall-targeting antibiotic is less effective. P. aeruginosa supernatant did not confer additional protection to slow-growing S. aureus small colony variants. Importantly, P. aeruginosa supernatant protects S. aureus from other inhibitors of cell wall synthesis as well as protein synthesis-targeting antibiotics in an HQNO- and siderophore-dependent manner. We propose a model whereby P. aeruginosa causes S. aureus to shift to fermentative growth when these organisms are grown in coculture, leading to reduction in S. aureus growth and decreased susceptibility to antibiotics targeting cell wall and protein synthesis. Cystic fibrosis (CF) lung infections are chronic and difficult to eradicate. Pseudomonas aeruginosa and Staphylococcus aureus are two of the most prevalent respiratory pathogens in CF patients and are associated with poor patient outcomes. Both organisms adopt a biofilm mode of growth, which contributes to high tolerance to antibiotic treatment and the recalcitrant nature of these infections. Here, we show that P. aeruginosa exoproducts decrease the sensitivity of S. aureus biofilm and planktonic populations to vancomycin, a frontline antibiotic used to treat methicillin-resistant S. aureus in CF patients. P. aeruginosa also protects S. aureus from other cell wall-active antibiotics as well as various classes of protein synthesis inhibitors. Thus, interspecies interactions can have dramatic and unexpected consequences on antibiotic sensitivity. This study underscores the potential impact of interspecies interactions on antibiotic efficacy in the context of complex, polymicrobial infections.
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Perumal Samy R, Stiles BG, Franco OL, Sethi G, Lim LH. Animal venoms as antimicrobial agents. Biochem Pharmacol 2017; 134:127-138. [DOI: 10.1016/j.bcp.2017.03.005] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Accepted: 03/07/2017] [Indexed: 12/21/2022]
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Britt NS, Patel N, Shireman TI, El Atrouni WI, Horvat RT, Steed ME. Relationship between vancomycin tolerance and clinical outcomes in Staphylococcus aureus bacteraemia. J Antimicrob Chemother 2016; 72:535-542. [PMID: 27999028 DOI: 10.1093/jac/dkw453] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2016] [Revised: 09/18/2016] [Accepted: 09/23/2016] [Indexed: 12/29/2022] Open
Abstract
BACKGROUND Previous data have demonstrated the clinical importance of vancomycin MIC values in Staphylococcus aureus bacteraemia (SAB); however, the impact of vancomycin tolerance (VT) is unknown. OBJECTIVES To compare the frequency of clinical failure between patients with VT and non-VT isolates in SAB. METHODS This was a retrospective cohort study of patients with SAB, excluding treatment <48 h or polymicrobial bacteraemia. The primary outcome was clinical failure (composite of 30 day mortality, non-resolving signs and symptoms, and 60 day recurrence). Vancomycin MIC and MBC were determined by broth microdilution. The association between VT (MBC/MIC ≥32) and clinical failure was evaluated by multivariable Poisson regression. RESULTS Of the 225 patients, 26.7% had VT isolates. VT was associated with clinical failure (48.0% overall) in unadjusted analysis [68.3% (n = 41/60) versus 40.6% (n = 67/165); P < 0.001] and this relationship persisted in multivariable analysis (adjusted risk ratio, 1.74; 95% CI, 1.36-2.24; P < 0.001). The association between VT and clinical failure was also consistent within strata of methicillin susceptibility [methicillin susceptible (n = 125, risk ratio, 1.67; 95% CI, 1.20-2.32; P = 0.002); methicillin resistant (n = 100, risk ratio, 1.69; 95% CI, 1.14-2.51; P = 0.010)]. Among methicillin-susceptible SAB cases treated with β-lactam therapy, VT remained associated with clinical failure (risk ratio, 1.77; 95% CI, 1.19-2.61; P = 0.004). CONCLUSIONS VT was associated with clinical failure in SAB, irrespective of methicillin susceptibility or definitive treatment. VT may decrease the effectiveness of cell-wall-active therapy or be a surrogate marker of some other pathogen-specific factor associated with poor outcomes. Future research should evaluate if bactericidal non-cell-wall-active agents improve outcomes in VT SAB.
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Affiliation(s)
- Nicholas S Britt
- Department of Pharmacy Practice, University of Kansas School of Pharmacy, 2010 Becker Drive, Lawrence, KS, USA.,Department of Preventive Medicine and Public Health, University of Kansas School of Medicine, 3901 Rainbow Boulevard, Kansas City, KS, USA
| | - Nimish Patel
- Department of Pharmacy Practice, Albany College of Pharmacy and Health Sciences, 106 New Scotland Avenue, Albany, NY, USA
| | - Theresa I Shireman
- Department of Preventive Medicine and Public Health, University of Kansas School of Medicine, 3901 Rainbow Boulevard, Kansas City, KS, USA
| | - Wissam I El Atrouni
- Department of Medicine, Division of Infectious Diseases, University of Kansas School of Medicine, 3901 Rainbow Boulevard, Kansas City, KS, USA
| | - Rebecca T Horvat
- Department of Pathology and Laboratory Medicine, University of Kansas School of Medicine, 3901 Rainbow Boulevard, Kansas City, KS, USA
| | - Molly E Steed
- Department of Pharmacy Practice, University of Kansas School of Pharmacy, 2010 Becker Drive, Lawrence, KS, USA
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Wolf AJ, Liu GY, Underhill DM. Inflammatory properties of antibiotic-treated bacteria. J Leukoc Biol 2016; 101:127-134. [PMID: 27576461 DOI: 10.1189/jlb.4mr0316-153rr] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2016] [Revised: 08/02/2016] [Accepted: 08/05/2016] [Indexed: 12/12/2022] Open
Abstract
Antibiotics have proven to be enormously effective tools in combating infectious diseases. A common roadblock to the effective use of antibiotics is the development of antibiotic resistance. We have recently observed that the very mechanism by which methicillin-resistant Staphylococcus aureus (MRSA) becomes antibiotic resistant causes the organism to be more inflammatory to innate immune cells. In this review, we offer some thoughts on the ways in which antibiotics have been observed to influence immune responses to bacteria.
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Affiliation(s)
- Andrea J Wolf
- F. Widjaja Foundation Inflammatory Bowel and Immunobiology Research Institute, Cedars-Sinai Medical Center, Los Angeles, California, USA.,Division of Immunology, Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, California, USA; and
| | - George Y Liu
- Division of Immunology, Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, California, USA; and.,Division of Pediatric Infectious Diseases, Cedars-Sinai Medical Center, Los Angeles, California, USA
| | - David M Underhill
- F. Widjaja Foundation Inflammatory Bowel and Immunobiology Research Institute, Cedars-Sinai Medical Center, Los Angeles, California, USA; .,Division of Immunology, Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, California, USA; and
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22
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Fisher JF, Mobashery S. β-Lactam Resistance Mechanisms: Gram-Positive Bacteria and Mycobacterium tuberculosis. Cold Spring Harb Perspect Med 2016; 6:cshperspect.a025221. [PMID: 27091943 DOI: 10.1101/cshperspect.a025221] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The value of the β-lactam antibiotics for the control of bacterial infection has eroded with time. Three Gram-positive human pathogens that were once routinely susceptible to β-lactam chemotherapy-Streptococcus pneumoniae, Enterococcus faecium, and Staphylococcus aureus-now are not. Although a fourth bacterium, the acid-fast (but not Gram-positive-staining) Mycobacterium tuberculosis, has intrinsic resistance to earlier β-lactams, the emergence of strains of this bacterium resistant to virtually all other antibiotics has compelled the evaluation of newer β-lactam combinations as possible contributors to the multidrug chemotherapy required to control tubercular infection. The emerging molecular-level understanding of these resistance mechanisms used by these four bacteria provides the conceptual framework for bringing forward new β-lactams, and new β-lactam strategies, for the future control of their infections.
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Affiliation(s)
- Jed F Fisher
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556-5670
| | - Shahriar Mobashery
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556-5670
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Cázares-Domínguez V, Ochoa SA, Cruz-Córdova A, Rodea GE, Escalona G, Olivares AL, Olivares-Trejo JDJ, Velázquez-Guadarrama N, Xicohtencatl-Cortes J. Vancomycin modifies the expression of the agr system in multidrug-resistant Staphylococcus aureus clinical isolates. Front Microbiol 2015; 6:369. [PMID: 25999924 PMCID: PMC4419724 DOI: 10.3389/fmicb.2015.00369] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2015] [Accepted: 04/11/2015] [Indexed: 01/08/2023] Open
Abstract
Staphylococcus aureus is an opportunistic pathogen that colonizes human hosts and causes a wide variety of diseases. Two interacting regulatory systems called agr (accessory gene regulator) and sar (staphylococcal accessory regulator) are involved in the regulation of virulence factors. The aim of this study was to evaluate the effect of vancomycin on hld and spa gene expression during the exponential and post-exponential growth phases in multidrug-resistant (MDR) S. aureus. Methods: Antibiotic susceptibility was evaluated by the standard microdilution method. The phylogenetic profile was obtained by pulsed-field gel electrophoresis (PFGE). Polymorphisms of agr and SCCmec (staphylococcal cassette chromosome mec) were analyzed by multiplex polymerase chain reaction (PCR). The expression levels of hld and spa were analyzed by reverse transcription-PCR. An enzyme-linked immunosorbent assay (ELISA) was performed to detect protein A, and biofilm formation was analyzed via crystal violet staining. Results: In total, 60.60% (20/33) of S. aureus clinical isolates were MDR. Half (10/20) of the MDR S. aureus isolates were distributed in subcluster 10, with >90% similarity among them. In the isolates of this subcluster, a high prevalence (100%) for the agrII and the cassette SCCmec II polymorphisms was found. Our data showed significant increases in hld expression during the post-exponential phase in the presence and absence of vancomycin. Significant increases in spa expression, protein A production and biofilm formation were observed during the post-exponential phase when the MDR S. aureus isolates were challenged with vancomycin. Conclusion: The polymorphism agrII, which is associated with nosocomial isolates, was the most prevalent polymorphism in MDR S. aureus. Additionally, under our study conditions, vancomycin modified hld and spa expression in these clinical isolates. Therefore, vancomycin may regulate alternative systems that jointly participate in the regulation of these virulence factors.
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Affiliation(s)
- Vicenta Cázares-Domínguez
- Laboratorio de Investigación en Bacteriología Intestinal, Hospital Infantil de México Federico Gómez México DF, Mexico
| | - Sara A Ochoa
- Laboratorio de Investigación en Bacteriología Intestinal, Hospital Infantil de México Federico Gómez México DF, Mexico
| | - Ariadnna Cruz-Córdova
- Laboratorio de Investigación en Bacteriología Intestinal, Hospital Infantil de México Federico Gómez México DF, Mexico
| | - Gerardo E Rodea
- Laboratorio de Investigación en Bacteriología Intestinal, Hospital Infantil de México Federico Gómez México DF, Mexico
| | - Gerardo Escalona
- Laboratorio de Investigación en Bacteriología Intestinal, Hospital Infantil de México Federico Gómez México DF, Mexico
| | - Alma L Olivares
- Laboratorio de Infectología, Hospital Infantil de México Federico Gómez México DF, Mexico
| | | | | | - Juan Xicohtencatl-Cortes
- Laboratorio de Investigación en Bacteriología Intestinal, Hospital Infantil de México Federico Gómez México DF, Mexico
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