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Yousefi Nojookambari N, Eslami G, Sadredinamin M, Vaezjalali M, Nikmanesh B, Dehbanipour R, Yazdansetad S, Ghalavand Z. Sub-minimum inhibitory concentrations (sub-MICs) of colistin on Acinetobacter baumannii biofilm formation potency, adherence, and invasion to epithelial host cells: an experimental study in an Iranian children's referral hospital. Microbiol Spectr 2024; 12:e0252323. [PMID: 38230925 PMCID: PMC10846280 DOI: 10.1128/spectrum.02523-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2023] [Accepted: 11/07/2023] [Indexed: 01/18/2024] Open
Abstract
Here, we described the efficacy of colistin sub-minimum inhibitory concentrations (sub-MICs) on biofilm-forming activity, host epithelial cell adherence, and invasion capacity of Acinetobacter baumannii strains collected from children admitted to the Children's Medical Center Hospital. Biofilm formation potency of A. baumannii clinical isolates was measured using a 96-well microtiter plate assay. Distribution of biofilm-related genes, including bap, abaI, ompA, csuE, and blaPER-1, was detected by PCR. The mRNA expression level of ompA and csuE was measured by qPCR in the presence of ¼ and ½ MICs of colistin. A. baumannii adhesion and invasion to eukaryotic host cells were phenotypically assayed at sub-MICs of colistin. Eighty percent (56/70) and 35.7% (25/70) of A. baumannii isolates were multidrug-resistant (MDR) and extensively drug-resistant (XDR) phenotypes, respectively. The strong, moderate, and weak biofilm producers of A. baumannii were 37.1% (26/70), 32.8%, (23/70), and 22.8% (16/70), respectively. The frequencies of biofilm-associated genes were 100% for abaI, ompA, and csuE, followed by 22.8% (16/70) and 24.3% (17/70) for bap and blaPER-1, respectively. The downregulation of csuE and ompA expression levels was observed in the sub-MIC of colistin. In vitro cell culture study showed a decreased capability of A. baumannii to adhere to the human epithelial cells at sub-inhibitory doses of colistin; however, none of the isolates could invade HEp-2 cells. Our study showed that the genes encoding biofilm-associated proteins undergo downregulation in expression levels after exposure to sub-MICs of colistin in A. baumannii. Longitudinal in vivo studies are needed to fully understand the clinical aspects of pathogenicity mechanisms and evolutionary dynamics of drug resistance.IMPORTANCESince the toxicity of colistin is dose dependent, there is a focus on strategies that reduce the dose while maintaining the therapeutic effect of the drug. Our findings about sub-inhibitory doses of colistin provide a novel insight into the logical use of colistin to treat and control Acinetobacter baumannii-related infections in clinical practice.
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Affiliation(s)
- Neda Yousefi Nojookambari
- Department of Microbiology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Gita Eslami
- Department of Microbiology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Mehrzad Sadredinamin
- Department of Microbiology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Maryam Vaezjalali
- Department of Microbiology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Bahram Nikmanesh
- Department of Medical Laboratory Sciences, School of Allied Medical Sciences, Tehran University of Medical Sciences, Tehran, Iran
| | - Razieh Dehbanipour
- Department of Microbiology, School of Medicine, Yasuj University of Medical Sciences, Yasuj, Iran
| | - Sajjad Yazdansetad
- Infectious Diseases Research Center, Golestan University of Medical Sciences, Gorgan, Iran
| | - Zohreh Ghalavand
- Department of Microbiology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
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Tang Z, Feng J, Rowthu SR, Zou C, Peng H, Huang C, He Y. Uncovering the anti-biofilm activity of Ilicicolin B against Staphylococcus aureus. Biochem Biophys Res Commun 2023; 684:149138. [PMID: 37897909 DOI: 10.1016/j.bbrc.2023.149138] [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: 08/09/2023] [Revised: 10/10/2023] [Accepted: 10/18/2023] [Indexed: 10/30/2023]
Abstract
The formation of bacterial biofilms reduces the entry of antibiotics into bacteria and helps bacteria tolerate otherwise lethal concentrations of antimicrobials, leading to antibiotic resistance. Therefore, clearing bacterial biofilm is an effective strategy to tackle drug resistance. Currently, there are no approved antibiotics for inhibiting bacterial biofilm formation. We found that Ilicicolin B had excellent antibacterial activity against MRSA without obvious hemolytic activity. More importantly, Ilicicolin B effectively inhibited the biofilm formation in a concentration-dependent manner by crystal violet colorimetric assay and fluorescence microscopy analysis. Exposure of Staphylococcus aureus to Ilicicolin B for 24 h reduced the protein and polysaccharide components in EPS, suggesting that Ilicicolin B disintegrated the biofilms by dissociating the EPS in a matrix. In addition, Ilicicolin B demonstrated strong antibacterial effects in a murine abscess model of S. aureus. Our findings suggest that Ilicicolin B has the potential to treat S. aureus infection by inhibiting biofilm formation.
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Affiliation(s)
- Ziyi Tang
- Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing, 400714, China
| | - Jizhou Feng
- Chongqing Key Laboratory of Natural Product Synthesis and Drug Research, School of Pharmaceutical Sciences, Chongqing University, Chongqing, 401331, China
| | - Sankara Rao Rowthu
- Chongqing Key Laboratory of Natural Product Synthesis and Drug Research, School of Pharmaceutical Sciences, Chongqing University, Chongqing, 401331, China
| | - Cheng Zou
- Chongqing Key Laboratory of Natural Product Synthesis and Drug Research, School of Pharmaceutical Sciences, Chongqing University, Chongqing, 401331, China
| | - Haibo Peng
- Chongqing Academy of Science and Technology, Chongqing, 401123, China
| | - Chao Huang
- Chongqing Key Laboratory of Natural Product Synthesis and Drug Research, School of Pharmaceutical Sciences, Chongqing University, Chongqing, 401331, China
| | - Yun He
- Chongqing Key Laboratory of Natural Product Synthesis and Drug Research, School of Pharmaceutical Sciences, Chongqing University, Chongqing, 401331, China; BayRay Innovation Center, Shenzhen Bay Laboratory, Shenzhen, 518132, China.
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Vujinović S, Graber HU, Vićić I, Vejnović B, Stevanović O, Krnjaić D, Milivojević D, Katić V. Genotypes and virulence factors in Staphylococcus aureus isolated from dairy cows with subclinical mastitis in Serbia. Comp Immunol Microbiol Infect Dis 2023; 101:102056. [PMID: 37678080 DOI: 10.1016/j.cimid.2023.102056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2023] [Revised: 08/14/2023] [Accepted: 08/26/2023] [Indexed: 09/09/2023]
Abstract
This study aimed to determine the prevalence of Staphylococcus aureus subclinical mastitis and to genotype the S. aureus isolates using the 16S-23S rRNA intergenic spacer (RS-PCR) method. In addition, the genes responsible for adherence, biofilm formation, host evasion, tissue necrosis, methicillin resistance, and enterotoxin production of S. aureus were investigated. The overall prevalence of S. aureus subclinical mastitis in lactating cows was 5.4% (95% confidence interval, CI=4.7-6.1%). An increased risk of S. aureus intramammary infection was observed on small family farms (odds ratio, OR=4.2, 95% CI=2.6-6.6, P < 0.001) and medium-sized farms (OR=3.5, 95% CI=2.2-5.7, P < 0.001). The RS-PCR analysis revealed 44 genotypes and genotype variants, of which 15 new genotypes and five new variants were detected within small and medium-sized farms. S. aureus isolates of new genotypes and genotype variants carried the clfA gene responsible for adherence at a lower frequency (64.8%) and enterotoxin-producing genes sea (20.4%), seb (14.8%) and sec (14.8%) at a higher frequency than the other known genotypes (P < 0.001), and were confirmed to carry the sej and sep genes. The spa gene was detected in all S. aureus isolates, whereas none harbored bap, ser, or tsst-1 genes. Methicillin-resistant strains of S. aureus (MRSA) were also detected, with a higher prevalence (19.2%) on large farms with more than 50 cows (P < 0.001). Using molecular techniques as diagnostic tools provides a better understanding of intramammary staphylococcal infections' occurrence, spread, and eradication.
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Affiliation(s)
- Slobodan Vujinović
- Veterinary Specialized Institute "Šabac", Vojvode Putnika 54, 15000 Šabac, Serbia
| | - Hans Ulrich Graber
- Agroscope, Research Division, Food Microbial Systems, Schwarzenburgstrasse 161, 3003 Bern, Switzerland
| | - Ivan Vićić
- University of Belgrade, Faculty of Veterinary Medicine, Bulevar oslobodjenja 18, 11000 Belgrade, Serbia.
| | - Branislav Vejnović
- University of Belgrade, Faculty of Veterinary Medicine, Bulevar oslobodjenja 18, 11000 Belgrade, Serbia
| | - Oliver Stevanović
- PI Veterinary Institute Dr Vaso Butozan Banja Luka, Branka Radicevića 18, 78000 Banja Luka, Republic of Srpska, Bosnia and Herzegovina
| | - Dejan Krnjaić
- University of Belgrade, Faculty of Veterinary Medicine, Bulevar oslobodjenja 18, 11000 Belgrade, Serbia
| | - Dušan Milivojević
- Institute of Molecular Genetics and Genetic Engineering, University of Belgrade, Vojvode Stepe 444a, 11000 Belgrade, Serbia
| | - Vera Katić
- University of Belgrade, Faculty of Veterinary Medicine, Bulevar oslobodjenja 18, 11000 Belgrade, Serbia
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Zhou W, Niu D, Gao S, Zhong Q, Liu C, Liao X, Cao X, Zhang Z, Zhang Y, Shen H. Prevalence, biofilm formation, and mass spectrometric characterization of linezolid-resistant Staphylococcus capitis isolated from a tertiary hospital in China. J Glob Antimicrob Resist 2023; 33:155-163. [PMID: 36724854 DOI: 10.1016/j.jgar.2023.01.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Revised: 12/19/2022] [Accepted: 01/23/2023] [Indexed: 01/30/2023] Open
Abstract
OBJECTIVES Linezolid-resistant Staphylococcus capitis (LRSC) has become a new challenge for clinical anti-infective therapy. The present study aimed to investigate the trends of LRSC prevalence in a tertiary hospital of China 2017-2020. The resistance mechanisms, virulence genes, biofilm formation, and mass spectrometric characteristics of LRSC isolates were also analysed. METHODS This study retrospectively analysed the antibiotic resistance trends of coagulase negative staphylococci (CoNS) isolated from clinical samples collected between 2017-2020. Antimicrobial resistance profiles were tested by micro-broth dilution and the E-test method. Antimicrobial resistance genes and virulence genes were detected by polymerase chain reaction, and dru-typing sequences were obtained by Sanger sequencing. Crystal violet staining in 96-well plates was used to detect biofilm formation ability. Mass spectrometric characterization of LRSC was analysed by matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) coupled with ClinProTools. RESULTS The linezolid resistance rate in 3575 CoNS clinical strains was 1.6%, wherein the great majority of was LRSC (91.1%, n = 51/56), with a resistant rate of 15.5% (n = 51/328) in all S. capitis isolates. In this study, 48 out of the 51 LRSC strains and 54 of 277 linezolid-susceptible S. capitis (LSSC) strains were enrolled. G2576T, C2104T, T2130A, C2163T, and T2319C mutations in the 23S rRNA V region and acquisition of cfr were the main linezolid resistant mechanisms in LRSC. The biofilm-forming ability of LRSC was more potent than LSSC, with a higher detection rate of bap (P < 0.05). Eleven mass spectrometric peaks of interest were identified by using MALDI-TOF MS and ClinProTools, which were differently distributed between LRSC and LSSC strains, with the area under the receiver operating characteristic curve of more than 0.8, especially for 5465.37 m/z. CONCLUSIONS Linezolid resistance was mediated by mutations in the 23S rRNA V region and presence of the cfr gene in LRSC strains. LRSC strains have stronger biofilm-forming ability than LSSC strains, which maybe associated with the adhesion-related gene of bap. Further, linezolid-resistant and linezolid-susceptible S. capitis could be rapidly identified with mass spectrometric characterization. To the best of our knowledge, this study is the first to document the biofilm formation ability of LRSC and the potential usefulness of MALDI-TOF MS for the discrimination of LRSC and LSSC.
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Affiliation(s)
- Wanqing Zhou
- Department of Laboratory Medicine, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing, Jiangsu, China
| | - Dongmei Niu
- Department of Laboratory Medicine, Nanjing Hospital of Chinese Medicine Affiliated to Nanjing University of Chinese Medicine, Nanjing, Jiangsu, China
| | - Shuo Gao
- Department of Laboratory Medicine, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing, Jiangsu, China
| | - Qiao Zhong
- Department of Laboratory Medicine, Gusu School, The Affiliated Suzhou Hospital of Nanjing Medical University, China
| | - Chang Liu
- Department of Laboratory Medicine, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing, Jiangsu, China
| | - Xiwei Liao
- Department of Infectious Diseases, Nanjing Drum Tower Hospital, Clinical College of Nanjing Medical University, Nanjing, Jiangsu, China
| | - Xiaoli Cao
- Department of Laboratory Medicine, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing, Jiangsu, China
| | - Zhifeng Zhang
- Department of Laboratory Medicine, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing, Jiangsu, China
| | - Yan Zhang
- Department of Laboratory Medicine, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing, Jiangsu, China
| | - Han Shen
- Department of Laboratory Medicine, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing, Jiangsu, China.
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Sung K, Park M, Chon J, Kweon O, Khan SA, Shen A, Paredes A. Concentration-Dependent Global Quantitative Proteome Response of Staphylococcus epidermidis RP62A Biofilms to Subinhibitory Tigecycline. Cells 2022; 11:3488. [PMID: 36359886 PMCID: PMC9655631 DOI: 10.3390/cells11213488] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Revised: 10/20/2022] [Accepted: 10/24/2022] [Indexed: 07/21/2023] Open
Abstract
Staphylococcus epidermidis is a leading cause of biofilm-associated infections on implanted medical devices. During the treatment of an infection, bacterial cells inside biofilms may be exposed to sublethal concentrations of the antimicrobial agents. In the present study, the effect of subinhibitory concentrations of tigecycline (TC) on biofilms formed by S. epidermidis strain RP62A was investigated using a quantitative global proteomic technique. Sublethal concentrations of TC [1/8 (T1) and 1/4 minimum inhibitory concentration (MIC) (T2)] promoted biofilm production in strain RP62A, but 1/2 MIC TC (T3) significantly inhibited biofilm production. Overall, 413, 429, and 518 proteins were differentially expressed in biofilms grown with 1/8 (T1), 1/4 (T2), and 1/2 (T3) MIC of TC, respectively. As the TC concentration increased, the number of induced proteins in each Cluster of Orthologous Groups (COG) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway increased. The TC concentration dependence of the proteome response highlights the diverse mechanisms of adaptive responses in strain RP62A biofilms. In both COG and KEGG functional analyses, most upregulated proteins belong to the metabolism pathway, suggesting that it may play an important role in the defense of strain RP62A biofilm cells against TC stress. Sub-MIC TC treatment of strain RP62A biofilms led to significant changes of protein expression related to biofilm formation, antimicrobial resistance, virulence, quorum sensing, ABC transporters, protein export, purine/pyrimidine biosynthesis, ribosomes, and essential proteins. Interestingly, in addition to tetracycline resistance, proteins involved in resistance of various antibiotics, including aminoglycosides, antimicrobial peptides, β-lactams, erythromycin, fluoroquinolones, fusidic acid, glycopeptides, lipopeptides, mupirocin, rifampicin and trimethoprim were differentially expressed. Our study demonstrates that global protein expression profiling of biofilm cells to antibiotic pressure may improve our understanding of the mechanisms of antibiotic resistance in biofilms.
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Affiliation(s)
- Kidon Sung
- Division of Microbiology, National Center for Toxicological Research, US FDA, Jefferson, AR 72079, USA
| | - Miseon Park
- Division of Microbiology, National Center for Toxicological Research, US FDA, Jefferson, AR 72079, USA
| | - Jungwhan Chon
- Companion Animal Health, Inje University, Gimhae 50834, Korea
| | - Ohgew Kweon
- Division of Microbiology, National Center for Toxicological Research, US FDA, Jefferson, AR 72079, USA
| | - Saeed A. Khan
- Division of Microbiology, National Center for Toxicological Research, US FDA, Jefferson, AR 72079, USA
| | - Andrew Shen
- Division of Neurotoxicology, National Center for Toxicological Research, US FDA, Jefferson, AR 72079, USA
| | - Angel Paredes
- Office of Scientific Coordination, National Center for Toxicological Research, US FDA, Jefferson, AR 72079, USA
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Liu Y, She P, Xu L, Chen L, Li Y, Liu S, Li Z, Hussain Z, Wu Y. Antimicrobial, Antibiofilm, and Anti-persister Activities of Penfluridol Against Staphylococcus aureus. Front Microbiol 2021; 12:727692. [PMID: 34489917 PMCID: PMC8418195 DOI: 10.3389/fmicb.2021.727692] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2021] [Accepted: 07/22/2021] [Indexed: 12/23/2022] Open
Abstract
Staphylococcus aureus has increasingly attracted global attention as a major opportunistic human pathogen owing to the emergence of biofilms (BFs) and persisters that are known to increase its antibiotic resistance. However, there are still no effective antimicrobial agents in clinical settings. This study investigated the antimicrobial activity of penfluridol (PF), a long-acting antipsychotic drug, against S. aureus and its clinical isolates via drug repurposing. PF exhibited strong bactericidal activity against S. aureus, with a minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of 4–8 and 16–32 μg/ml, respectively. PF could significantly inhibit biofilm formation and eradicate 24 h preformed biofilms of S. aureus in a dose-dependent manner. Furthermore, PF could effectively kill methicillin-resistant S. aureus (MRSA) persister cells and demonstrated considerable efficacy in a mouse model of subcutaneous abscess, skin wound infection, and acute peritonitis caused by MRSA. Notably, PF exerted almost no hemolysis activity on human erythrocytes, with limited cytotoxicity and low tendency to cause resistance. Additionally, PF induced bacterial membrane permeability and ATP release and further caused membrane disruption, which may be the underlying antibacterial mechanism of PF. In summary, our findings suggest that PF has the potential to serve as a novel antimicrobial agent against S. aureus biofilm- or persister-related infections.
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Affiliation(s)
- Yaqian Liu
- Department of Laboratory Medicine, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Pengfei She
- Department of Laboratory Medicine, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Lanlan Xu
- Department of Laboratory Medicine, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Lihua Chen
- Department of Laboratory Medicine, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Yimin Li
- Department of Laboratory Medicine, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Shasha Liu
- Department of Laboratory Medicine, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Zehao Li
- Department of Laboratory Medicine, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Zubair Hussain
- Department of Laboratory Medicine, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Yong Wu
- Department of Laboratory Medicine, The Third Xiangya Hospital, Central South University, Changsha, China
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Maeda M. [A Study of Outcome Measures and Establishment of Benchmarks for Antimicrobial Stewardship Programs]. YAKUGAKU ZASSHI 2021; 141:995-1000. [PMID: 34334551 DOI: 10.1248/yakushi.21-00111] [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: 11/22/2022]
Abstract
Over the past few decades, the effectiveness of antibiotics has been diminished owing to the emergence of antimicrobial resistance resulting from the overuse of antibiotics. Antimicrobial stewardship aims to improve the appropriateness of antibiotic use to reduce antimicrobial resistance and benefit patients. Antimicrobial stewardship requires structural prerequisites for implementing antimicrobial stewardship programs (ASPs), such as the presence of a multidisciplinary antimicrobial stewardship team (AST), to ensure appropriate antimicrobial use at healthcare facilities. However, manpower shortage for ASTs in most Japanese hospitals has resulted in limited implementation of ASPs. Our study provided a directive for promotion of comprehensive ASPs including various outcome measures. Our findings would provide useful benchmarks for hospitals planning to implement ASPs in Japan as well as around the world. This review provides a framework for evaluating the outcome measures and benchmarks of ASPs based on our study.
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Affiliation(s)
- Masayuki Maeda
- Division of Infection Control Sciences, Department of Clinical Pharmacy, School of Pharmacy, Showa University.,Department of Infection Prevention and Control, Showa University Hospital
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Fang R, Sun Y, Dai W, Zheng X, Tian X, Zhang X, Wang C, Cao J, Zhou T. Mutations in the MepRAB efflux system contribute to the in vitro development of tigecycline resistance in Staphylococcus aureus. J Glob Antimicrob Resist 2020; 22:631-636. [PMID: 32590185 DOI: 10.1016/j.jgar.2020.06.005] [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] [Received: 06/08/2019] [Revised: 03/24/2020] [Accepted: 06/01/2020] [Indexed: 02/07/2023] Open
Abstract
OBJECTIVE To characterize the evolutionary pathways of tigecycline (TGC) resistance and alterations in the biological characteristics of hospital-derived Staphylococcus aureus isolates under selective pressure. METHODS Three clinical S. aureus strains and one standard S. aureus strain, ATCC 29213, were used for the in vitro selection of TGC-resistant S. aureus variants with gradient concentrations of TGC. Changes in drug resistance and genetic alterations in resistance-related genes (operon mepRAB and rpsJ) in mutant strains were determined. The efflux inhibitor assay for MepA and the fitness cost, determined by comparing the growth and virulence of parental and mutant strains, were also investigated. RESULTS Mutants induced in vitro showed a 64- to 128-fold increase in the minimum inhibitory concentration (MIC) of TGC. Substitution mutations were detected in the transcriptional repressor mepR and the efflux pump gene mepA. A K57M amino acid substitution occurred in the ribosomal S10 protein-encoding gene rpsJ. The MICs of TGC in the final mutants were significantly decreased in the presence of efflux pump inhibitors. It was worth noting that growth was unaffected by TGC resistance selection in vitro, with the exception of one strain, and the MICs of other antibiotics and virulence were also unaffected. CONCLUSIONS The evolution of TGC resistance in S. aureus in vitro is associated with a loss-of-function mutation in the efflux pump transcriptional repressor mepR and a missense mutation in the efflux pump-encoding gene mepA. Our work further validated the resistance mechanisms of S. aureus to TGC and reported previously undiscovered mutations.
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Affiliation(s)
- Renchi Fang
- Department of Clinical Laboratory, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, 325035, China
| | - Yao Sun
- Department of Clinical Laboratory, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, 325035, China
| | - Weisi Dai
- Department of Clinical Laboratory, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, 325035, China
| | - Xiangkuo Zheng
- School of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, China
| | - Xuebin Tian
- School of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, China
| | - Xiucai Zhang
- Department of Clinical Laboratory, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, 325035, China
| | - Chong Wang
- Department of Clinical Laboratory, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, 325035, China
| | - Jianming Cao
- School of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, China.
| | - Tieli Zhou
- Department of Clinical Laboratory, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, 325035, China.
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Vollaro A, Esposito A, Antonaki E, Iula VD, D’Alonzo D, Guaragna A, De Gregorio E. Steroid Derivatives as Potential Antimicrobial Agents Against Staphylococcus aureus Planktonic Cells. Microorganisms 2020; 8:E468. [PMID: 32218320 PMCID: PMC7232480 DOI: 10.3390/microorganisms8040468] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Revised: 03/22/2020] [Accepted: 03/23/2020] [Indexed: 12/28/2022] Open
Abstract
In this work, the antibacterial activity of deflazacort and several of its synthetic precursors was tested against a panel of bacterial pathogens responsible for most drug-resistant infections including Staphylococcus aureus, Enterococcus spp., Acinetobacter baumannii, Pseudomonas aeruginosa, Klebsiella pneumoniae, Escherichia coli, and Enterobacter spp. The derivative of deflazacort, PYED-1 (pregnadiene-11-hydroxy-16α,17α-epoxy-3,20-dione-1) showed the best antibacterial activity in a dose-dependent way. We focused on the action of PYED-1 against S. aureus cells. PYED-1 exhibited an additive antimicrobial effect with gentamicin and oxacillin against the methicillin-resistant S. aureus isolate 00717. In addition to its antimicrobial effect, PYED-1 was found to repress the expression of several virulence factors of S. aureus, including toxins encoded by the hla (alpha-haemolysin), hlb (beta-haemolysin), lukE-D (leucotoxins E-D), and sea (staphylococcal enterotoxin A) genes, and cell surface factors (fnbB (fibronectin-binding protein B) and capC (capsule biosynthesis protein C)). The expression levels of autolysin isaA (immunodominant staphylococcal antigen) were also increased.
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Affiliation(s)
- Adriana Vollaro
- Department of Molecular Medicine and Medical Biotechnology, University of Naples Federico II, Via S. Pansini 5, 80131 Naples, Italy; (A.V.); (E.A.)
| | - Anna Esposito
- Department of Chemical Sciences, University of Naples Federico II, Via Cintia, 80126 Naples, Italy; (A.E.); (D.D.)
| | - Eleni Antonaki
- Department of Molecular Medicine and Medical Biotechnology, University of Naples Federico II, Via S. Pansini 5, 80131 Naples, Italy; (A.V.); (E.A.)
| | - Vita Dora Iula
- Complex Operative Unit of Clinical Pathology, “Ospedale del Mare-ASL NA1 Centro”, 80147 Naples, Italy;
| | - Daniele D’Alonzo
- Department of Chemical Sciences, University of Naples Federico II, Via Cintia, 80126 Naples, Italy; (A.E.); (D.D.)
| | - Annalisa Guaragna
- Department of Chemical Sciences, University of Naples Federico II, Via Cintia, 80126 Naples, Italy; (A.E.); (D.D.)
| | - Eliana De Gregorio
- Department of Molecular Medicine and Medical Biotechnology, University of Naples Federico II, Via S. Pansini 5, 80131 Naples, Italy; (A.V.); (E.A.)
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Hua X, Jia Y, Yang Q, Zhang W, Dong Z, Liu S. Transcriptional Analysis of the Effects of Gambogic Acid and Neogambogic Acid on Methicillin-Resistant Staphylococcus aureus. Front Pharmacol 2019; 10:986. [PMID: 31572177 PMCID: PMC6753875 DOI: 10.3389/fphar.2019.00986] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Accepted: 07/31/2019] [Indexed: 11/13/2022] Open
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) infection is a major threat to human health, as this bacterium has developed resistance to a variety of conventional antibiotics. This is especially true of MRSA biofilms, which not only exhibit enhanced pathogenicity but also are resistant to most antibiotics. In this work, we demonstrated that two natural products with antitumor activity, namely, gambogic acid (GA) and neogambogic acid (NGA), have significant inhibitory activity toward MRSA. GA and NGA can not only effectively inhibit planktonic MRSA strains in vivo and in vitro, but also have strong inhibitory effects on MRSA biofilms formation. By transcriptome sequencing, Q-RT-PCR and PRM, we found that GA and NGA could reduce the expression of S. aureus virulence factors by inhibiting the saeRS two-component, thus achieving inhibition of MRSA. We found that GA and NGA had anti-MRSA activity in vivo and in vitro and identified saeRS to be the target, indicating that saeRS inhibitors may be used to treat biofilm-related infections.
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Affiliation(s)
- Xin Hua
- Division of Bacterial Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
- College of Life Science, Northeast Forestry University, Harbin, China
| | - Yue Jia
- Division of Bacterial Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Qin Yang
- Division of Bacterial Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Wanjiang Zhang
- Division of Bacterial Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Zhimin Dong
- Innovation Team of Livestock and Poultry Epidemic Disease Prevention and Control, Tianjin Animal Science and Veterinary Research Institute, Tianjin, China
| | - Siguo Liu
- Division of Bacterial Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
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11
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Wang FD, Wu PF, Chen SJ. Distribution of virulence genes in bacteremic methicillin-resistant Staphylococcus aureus isolates from various sources. JOURNAL OF MICROBIOLOGY, IMMUNOLOGY, AND INFECTION = WEI MIAN YU GAN RAN ZA ZHI 2019; 52:426-432. [PMID: 30686615 DOI: 10.1016/j.jmii.2019.01.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Revised: 01/04/2019] [Accepted: 01/06/2019] [Indexed: 11/17/2022]
Abstract
BACKGROUND/PURPOSE Methicillin-resistant Staphylococcus aureus (MRSA) can encode proteins which directly bind bacteria to many tissues and medical devices or catheters to trigger pathogenesis. However, the relationship between genetic backgrounds and virulent factors in MRSA isolates remained incompletely understood yet. METHODS MRSA isolates were collected from blood cultures of patients with infective endocarditis, bone/joint infection, skin/soft tissue infection, or catheter-related bacteremia in hemodialysis at a tertiary medical center between 2005 and 2011. MRSA isolates were characterized by the methods of spa, multilocus sequence, and staphylococcal cassette chromosome mec (SCCmec) typing. Identification of virulence gene expression was measured by Power SYBR Green PCR Master Mix. RESULTS Overall collected were 136 MRSA bacteremic isolates, including those from the cases of infective endocarditis (n = 23), bone/joint infection (n = 49), skin/soft tissue infection (n = 20), or catheter-related bacteremia in patients with acute kidney injury or end-stage renal stage receiving hemodialysis (n = 54). CC8-ST239-MRSA-SCCmec type III-spa type t037 was the most prevalent type observed in all of 136 MRSA bacteremic isolates. The prevalent genes in the group of infective endocarditis were clfA, clfB, fnbA, ebpS, eap, emp, sae, and eno; bone/joint infections clfA, emp, sae, and eno; skin/soft tissue infection eno; hemodialysis catheter-related bacteremia clfA and sae. The distribution of each gene was not statically different among four groups. CONCLUSIONS A major MRSA lineage, CC8-ST239-MRSA-SCCmec type III-spa type t037, is noted among bacteremic MRSA isolates. No disease-specific virulent genes can be identified.
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Affiliation(s)
- Fu-Der Wang
- Division of Infectious Diseases, Department of Medicine, Taipei Veterans General Hospital, Taipei 112, Taiwan; School of Medicine, National Yang-Ming University, Taipei 112, Taiwan.
| | - Ping-Feng Wu
- Division of Infectious Diseases, Department of Medicine, Taipei Veterans General Hospital, Taipei 112, Taiwan; School of Medicine, National Yang-Ming University, Taipei 112, Taiwan
| | - Su-Jung Chen
- Division of Infectious Diseases, Department of Medicine, Taipei Veterans General Hospital, Taipei 112, Taiwan; School of Medicine, National Yang-Ming University, Taipei 112, Taiwan
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12
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Kitti T, Seng R, Thummeepak R, Boonlao C, Jindayok T, Sitthisak S. Biofilm Formation of Methicillin-resistant Coagulase-Negative Staphylococci Isolated from Clinical Samples in Northern Thailand. J Glob Infect Dis 2019; 11:112-117. [PMID: 31543653 PMCID: PMC6733194 DOI: 10.4103/jgid.jgid_118_18] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Background: Methicillin-resistant coagulase-negative staphylococci (MR-CoNS) are multidrug-resistant bacteria that are difficult to treat because of their ability to form biofilms. Objectives: In the present study, we evaluated the antibiotic-resistant phenotypes, biofilm-forming ability, and biofilm associated genes of 55 clinical MR-CoNS isolates obtained from two hospitals in Thailand. Materials and Methods: MALDI-TOF-MS and tuf gene sequencing were performed to determine the species of all isolates. Biofilm production was determined using Congo red agar (CRA) and the microtiter plate (MTP) assay. Biofilm-associated genes were characterized using polymerase chain reaction (PCR). Results: Among the 55 MR-CoNS isolates, five species were identified as Staphylococcus haemolyticus (34.5%), Staphylococcus epidermidis (32.7%), Staphylococcus capitis (18.2%), Staphylococcus cohnii (9.1%), and Staphylococcus hominis (5.5%). The antimicrobial susceptibility pattern of MR-CoNS isolates indicated high resistance to cefoxitin (100%), penicillin (98.2%), erythromycin (96.4%), ciprofloxacin (67.3%), sulfamethoxazole/trimethoprim (67.3%), gentamicin (67.3%), and clindamycin (63.6%). All the isolates were susceptible to vancomycin and linezolid. The biofilm production was detected in 87.3% isolates through the CRA method and in 38.1% isolates through the MTP assay. The prevalence rates of icaAD, bap, fnbA, and cna were 18.2%, 12.7%, 47.3%, and 27.3%, respectively. There were significant differences in the presence of these biofilm-associated genes among the MR-CoNS isolates. Moreover, quantitative biofilm formation was significantly different among MR-CoNS species. Conclusion: The present study revealed that biofilm-associated genes are important for biofilm biomass in MR-CoNS isolates, and the findings of this study are essential for finding new strategies to control biofilm formation and prevent the spread of MR-CoNS infectious diseases.
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Affiliation(s)
- Thawatchai Kitti
- Department of Microbiology and Parasitology, Faculty of Oriental Medicine, Chiang Rai College, Bangkok, Thailand
| | - Rathanin Seng
- Department of Microbiology and Immunology, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Rapee Thummeepak
- Department of Microbiology and Parasitology, Faculty of Medical Sciences, Naresuan University, Chiang Rai, Thailand
| | - Chalermchai Boonlao
- Department Clinical Microbiology, Chiangrai Prachanukroh Hospital, Chiang Rai, Thailand
| | - Thanyasiri Jindayok
- Division of Clinical Pathology, Faculty of Medicine, Naresuan University, Phitsanulok, Thailand
| | - Sutthirat Sitthisak
- Department of Microbiology and Parasitology, Faculty of Medical Sciences, Naresuan University, Chiang Rai, Thailand.,Centre of Excellence in Medical Biotechnology, Faculty of Medical Science, Naresuan University, Phitsanulok, Thailand
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13
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Influence of subinhibitory concentrations of NH125 on biofilm formation & virulence factors of Staphylococcus aureus. Future Med Chem 2018; 10:1319-1331. [PMID: 29846088 DOI: 10.4155/fmc-2017-0286] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
AIM l-benzyl-3-cetyl-2-methylimidazolium iodide (NH125) can inhibit Staphylococcus aureus growth. We investigated the effects of sub-MIC concentrations of NH125 on S. aureus biofilm and virulence. Methodology & results: Three strains of S. aureus were tested. Sub-lethal concentrations of NH125 repressed biofilm formation. At partial sub-MICs, NH125 downregulated the expression of most virulence, while strain-dependent effects were found in the production of α-hemolysin, δ-hemolysin, coagulase and nuclease. In Galleria mellonella model, methicillin-resistant S. aureus pre-exposed to NH125 demonstrated significantly lower killing (p = 0.032 for 1/16 and 1/8 MICs; 0.008 for 1/4 MIC; and 0.001 for 1/2 MIC). CONCLUSION Sub-MIC concentrations of NH125 inhibited biofilm formation and virulence of S. aureus. These findings provide further support for evaluating the clinical efficacy of NH125 in staphylococcal infection.
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Vaishampayan A, de Jong A, Wight DJ, Kok J, Grohmann E. A Novel Antimicrobial Coating Represses Biofilm and Virulence-Related Genes in Methicillin-Resistant Staphylococcus aureus. Front Microbiol 2018; 9:221. [PMID: 29497410 PMCID: PMC5818464 DOI: 10.3389/fmicb.2018.00221] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Accepted: 01/30/2018] [Indexed: 12/20/2022] Open
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) has become an important cause of hospital-acquired infections worldwide. It is one of the most threatening pathogens due to its multi-drug resistance and strong biofilm-forming capacity. Thus, there is an urgent need for novel alternative strategies to combat bacterial infections. Recently, we demonstrated that a novel antimicrobial surface coating, AGXX®, consisting of micro-galvanic elements of the two noble metals, silver and ruthenium, surface-conditioned with ascorbic acid, efficiently inhibits MRSA growth. In this study, we demonstrated that the antimicrobial coating caused a significant reduction in biofilm formation (46%) of the clinical MRSA isolate, S. aureus 04-02981. To understand the molecular mechanism of the antimicrobial coating, we exposed S. aureus 04-02981 for different time-periods to the coating and investigated its molecular response via next-generation RNA-sequencing. A conventional antimicrobial silver coating served as a control. RNA-sequencing demonstrated down-regulation of many biofilm-associated genes and of genes related to virulence of S. aureus. The antimicrobial substance also down-regulated the two-component quorum-sensing system agr suggesting that it might interfere with quorum-sensing while diminishing biofilm formation in S. aureus 04-02981.
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Affiliation(s)
- Ankita Vaishampayan
- Life Sciences and Technology, Beuth University of Applied Sciences Berlin, Berlin, Germany
| | - Anne de Jong
- Department of Molecular Genetics, University of Groningen, Groningen, Netherlands
| | - Darren J. Wight
- Institute of Virology, Free University of Berlin, Berlin, Germany
| | - Jan Kok
- Department of Molecular Genetics, University of Groningen, Groningen, Netherlands
| | - Elisabeth Grohmann
- Life Sciences and Technology, Beuth University of Applied Sciences Berlin, Berlin, Germany
- Division of Infectious Diseases, University Medical Center Freiburg, Freiburg, Germany
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15
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Antimicrobial activity of 1,3,4-oxadiazole derivatives against planktonic cells and biofilm of Staphylococcus aureus. Future Med Chem 2018; 10:283-296. [PMID: 29334249 DOI: 10.4155/fmc-2017-0159] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
AIM Staphylococcus aureus is a major cause of severe hospital-acquired infections, and biofilm formation is an important part of staphylococcal pathogenesis. Therefore, developing new antimicrobial agents against both planktonic cells and biofilm of S. aureus is a major challenge. RESULTS Three 1,3,4-oxadiazole derivatives exhibited antimicrobial activity against seven S. aureus strains in vitro, with minimum inhibitory concentrations ranging from 4 to 32 μg/ml. At 4 × minimum inhibitory concentration, all compounds killed cells within 24 h, demonstrating bactericidal activity. In addition to their effects against planktonic cells, these compounds prevented biofilm formation in a dose-dependent manner, with inhibitory concentrations for biofilm formation ranging from 8 to 32 μg/ml. Interestingly, higher concentrations of these compounds were effective against mature biofilms and all compounds downregulated the transcription of the biofilm-related gene spa. CONCLUSION We report three new 1,3,4-oxadiazole derivatives that have bactericidal activity and could provide as alternatives to combat S. aureus.
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Abstract
Staphylococcus aureus is often involved in severe infections, in which the effects of bacterial virulence factors have great importance. Antistaphylococcal regimens should take into account the different effects of antibacterial agents on the expression of virulence factors and on the host's immune response. A PubMed literature search was performed to select relevant articles on the effects of antibiotics on staphylococcal toxin production and on the host immune response. Information was sorted according to the methods used for data acquisition (bacterial strains, growth models, and antibiotic concentrations) and the assays used for readout generation. The reported mechanisms underlying S. aureus virulence modulation by antibiotics were reviewed. The relevance of in vitro observations is discussed in relation to animal model data and to clinical evidence extracted from case reports and recommendations on the management of toxin-related staphylococcal diseases. Most in vitro data point to a decreased level of virulence expression upon treatment with ribosomally active antibiotics (linezolid and clindamycin), while cell wall-active antibiotics (beta-lactams) mainly increase exotoxin production. In vivo studies confirmed the suppressive effect of clindamycin and linezolid on virulence expression, supporting their utilization as a valuable management strategy to improve patient outcomes in cases of toxin-associated staphylococcal disease.
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17
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Nosanov L, Jo D, Randad P, Moffatt L, Carney B, Ortiz R, Shupp J. Effectiveness of a Glycylcycline Antibiotic for Reducing the Pathogenicity of Superantigen-Producing Methicillin-Resistant Staphylococcus aureus in Burn Wounds. EPLASTY 2017; 17:e27. [PMID: 28943993 PMCID: PMC5600145] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Objective: Burn-injured patients are highly susceptible to infectious complications, which are often associated with increased morbidity and mortality. Rates of antibiotic resistance have increased, and resistant species such as methicillin-resistant Staphylococcus aureus provide additional challenges in the form of virulence factors. Proteins can disrupt local healing, leading to systemic immune disruption. To optimize outcomes, treatments that reduce pathogenicity must be identified. This study aims to compare a glycylcycline antibiotic-tigecycline-with clindamycin for effectiveness in treating superantigenic methicillin-resistant Staphylococcus aureus in burn wounds. Methods: Sprague-Dawley rats received paired 2 × 2-cm burn wounds, which were subsequently inoculated with known virulence factor-producing methicillin-resistant Staphylococcus aureus or media alone on postinjury day 1. Infected animals received twice-daily tigecycline (high or low dose), twice-daily clindamycin (high or low dose), or saline alone (positive controls). Daily sampling and imaging assessments were performed. Results: Bacterial counts and toxin levels were reduced significantly in antibiotic-treated groups relative to positive controls (P < .001). Results from day 7 showed measurable toxin levels in clindamycin-treated, but not tigecycline-treated, wounds. Imaging analysis revealed a return of wound perfusion in tigecycline-treated animals similar to the sham animals. Transcript analysis using polymerase chain reaction and polymerase chain reaction arrays demonstrated downregulation of gene expression in antibiotic-treated animals as compared with positive controls. Conclusions: Overall, this study supports the use of tigecycline in the treatment of methicillin-resistant Staphylococcus aureus-infected burn wounds. While both protein synthesis inhibitors are effective, tigecycline appears to be superior in controlling toxin levels, enabling better wound healing.
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Affiliation(s)
- Lauren B. Nosanov
- aThe Burn Center, Department of Surgery, MedStar Washington Hospital Center, Washington, DC,bFirefighters’ Burn and Surgical Research Laboratory, MedStar Health Research Institute, Washington, DC
| | - Daniel Y. Jo
- bFirefighters’ Burn and Surgical Research Laboratory, MedStar Health Research Institute, Washington, DC
| | - Pranay R. Randad
- bFirefighters’ Burn and Surgical Research Laboratory, MedStar Health Research Institute, Washington, DC
| | - Lauren T. Moffatt
- bFirefighters’ Burn and Surgical Research Laboratory, MedStar Health Research Institute, Washington, DC,cDepartment of Biochemistry and Molecular & Cellular Biology, Georgetown University School of Medicine, Washington, DC
| | - Bonnie C. Carney
- bFirefighters’ Burn and Surgical Research Laboratory, MedStar Health Research Institute, Washington, DC,cDepartment of Biochemistry and Molecular & Cellular Biology, Georgetown University School of Medicine, Washington, DC
| | - Rachel T. Ortiz
- bFirefighters’ Burn and Surgical Research Laboratory, MedStar Health Research Institute, Washington, DC
| | - Jeffrey W. Shupp
- aThe Burn Center, Department of Surgery, MedStar Washington Hospital Center, Washington, DC,bFirefighters’ Burn and Surgical Research Laboratory, MedStar Health Research Institute, Washington, DC,Correspondence:
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18
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Quantitative Expression Analysis of SpA, FnbA and Rsp Genes in Staphylococcus aureus: Actively Associated in the Formation of Biofilms. Curr Microbiol 2017; 74:1394-1403. [DOI: 10.1007/s00284-017-1331-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2016] [Accepted: 08/07/2017] [Indexed: 10/19/2022]
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19
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Szczuka E, Jabłońska L, Kaznowski A. Effect of subinhibitory concentrations of tigecycline and ciprofloxacin on the expression of biofilm-associated genes and biofilm structure of Staphylococcus epidermidis. MICROBIOLOGY-SGM 2017; 163:712-718. [PMID: 28481197 PMCID: PMC5817252 DOI: 10.1099/mic.0.000453] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Staphylococcus epidermidis is a leading cause of foreign body-associated infections. This is related to the bacterium's ability to form biofilms on synthetic materials. Bacteria within a biofilm may be exposed to subinhibitory concentrations (sub-MICs) of antibiotics because of an agent's limited penetration into the biofilm core. Here, we investigated the effect of sub-MICs of tigecycline and ciprofloxacin on the expression of biofilm-associated genes, i.e. icaA, altE and sigB, and the biofilm structure of five clinical isolates of S. epidermidis. For most tested isolates, the expression of these genes increased after exposure to 0.25 MIC and 0.5 MIC tigecycline. A slight decrease in icaAmRNA levels was observed only in two isolates in the presence of 0.25 MIC tigecycline. The effect of ciprofloxacin exposure was isolate-dependent. At 0.5 MIC, ciprofloxacin induced an increase of sigB and icaAmRNA levels in three of the five tested isolates. At the same time, expression of the altE gene increased in all isolates (from 1.3-fold to 42-fold, depending on the strain). Confocal laser scanning microscopy analysis indicated that sub-MIC ciprofloxacin decreased biofilm formation, whereas tigecycline stimulated this process. Our data suggest that sub-MIC tigecycline may have bearing on the outcome of infections.
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Affiliation(s)
- Ewa Szczuka
- Department of Microbiology, Institute of Experimental Biology, Faculty of Biology, Adam Mickiewicz University, Poznań, Poland
| | - Lucyna Jabłońska
- Department of Microbiology, Institute of Experimental Biology, Faculty of Biology, Adam Mickiewicz University, Poznań, Poland
| | - Adam Kaznowski
- Department of Microbiology, Institute of Experimental Biology, Faculty of Biology, Adam Mickiewicz University, Poznań, Poland
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20
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In vitro and in vivo antibiofilm effect of copper nanoparticles against aquaculture pathogens. BIOCATALYSIS AND AGRICULTURAL BIOTECHNOLOGY 2017. [DOI: 10.1016/j.bcab.2017.04.013] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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21
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LaSalvia MT, Branch-Elliman W, Snyder GM, Mahoney MV, Alonso CD, Gold HS, Wright SB. Does Adjunctive Tigecycline Improve Outcomes in Severe-Complicated, Nonoperative Clostridium difficile Infection? Open Forum Infect Dis 2017; 4:ofw264. [PMID: 28480257 PMCID: PMC5413996 DOI: 10.1093/ofid/ofw264] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2016] [Accepted: 12/28/2016] [Indexed: 01/31/2023] Open
Abstract
Severe Clostridium difficile infection is associated with a high rate of mortality; however, the optimal treatment for severe- complicated infection remains uncertain for patients who are not candidates for surgical intervention. Thus, we sought to evaluate the benefit of adjunctive tigecycline in this patient population using a retrospective cohort adjusted for propensity to receive tigecycline. We found that patients who received tigecycline had similar outcomes to those who did not, although the small sample size limited power to adjust for comorbidities and severity of illness.
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Affiliation(s)
- Mary T LaSalvia
- Division of Infectious Diseases and.,Harvard Medical School, Boston, Massachussetts
| | - Westyn Branch-Elliman
- Division of Infectious Diseases and.,VA Boston Healthcare System, Massachussetts.,Harvard Medical School, Boston, Massachussetts
| | - Graham M Snyder
- Division of Infectious Diseases and.,Harvard Medical School, Boston, Massachussetts
| | - Monica V Mahoney
- Department of Pharmacy, Beth Israel Deaconess Medical Center, Boston, Massachussetts
| | - Carolyn D Alonso
- Division of Infectious Diseases and.,Harvard Medical School, Boston, Massachussetts
| | - Howard S Gold
- Division of Infectious Diseases and.,Harvard Medical School, Boston, Massachussetts
| | - Sharon B Wright
- Division of Infectious Diseases and.,Harvard Medical School, Boston, Massachussetts
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Maeda M, Shoji H, Shirakura T, Takuma T, Ugajin K, Fukuchi K, Niki Y, Ishino K. Analysis of Staphylococcal Toxins and Clinical Outcomes of Methicillin-Resistant Staphylococcus aureus Bacteremia. Biol Pharm Bull 2017; 39:1195-200. [PMID: 27374293 DOI: 10.1248/bpb.b16-00255] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
It is well known that methicillin-resistant Staphylococcus aureus (MRSA) produces many virulence factors, such as hemolysins, leukocidins, proteases, enterotoxins, exfoliative toxins, and immune-modulatory factors. The aim of study was to identify staphylococcal pathogenicity that may affect the prognosis of patients with MRSA bacteremia. We obtained 149 MRSA strains from blood cultures between January 2009 and December 2014 in our institution. We collected information on patient characteristics, laboratory data, staphylococcal toxin genes, and susceptibility of the strain toward anti-MRSA agent and analyzed them as factors contributing to 30-d mortality. The "survival" and "dead" groups consisted of 103 and 46 patients, respectively. Multiple logistic regression analysis showed a four-fold increase in the risk of mortality in patients exhibiting isolated MRSA with staphylococcal enterotoxins (SEs) genes as well as toxic shock syndrome toxin-1 (TSST-1) genes [odds ratio: 3.89; 95% confidence interval: 1.20-12.60; p=0.024]. Kaplan-Meier analysis also showed significantly higher mortality in patient with isolated MRSA with SEs and TSST-1 genes. After adjusting for confounders, the coexistence of SEs and TSST-1 were independently associated with the 30-d mortality compared with treatment and susceptibility. The coexistence of superantigenic toxin genes greatly affects the clinical course and prognosis of patients with MRSA bacteremia.
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Affiliation(s)
- Masayuki Maeda
- Division of Infection Control Sciences, Department of Pharmacotherapeutics, School of Pharmacy, Showa University
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Sub-Optimal Treatment of Bacterial Biofilms. Antibiotics (Basel) 2016; 5:antibiotics5020023. [PMID: 27338489 PMCID: PMC4929437 DOI: 10.3390/antibiotics5020023] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2015] [Revised: 05/08/2016] [Accepted: 06/13/2016] [Indexed: 01/22/2023] Open
Abstract
Bacterial biofilm is an emerging clinical problem recognized in the treatment of infectious diseases within the last two decades. The appearance of microbial biofilm in clinical settings is steadily increasing due to several reasons including the increased use of quality of life-improving artificial devices. In contrast to infections caused by planktonic bacteria that respond relatively well to standard antibiotic therapy, biofilm-forming bacteria tend to cause chronic infections whereby infections persist despite seemingly adequate antibiotic therapy. This review briefly describes the responses of biofilm matrix components and biofilm-associated bacteria towards sub-lethal concentrations of antimicrobial agents, which may include the generation of genetic and phenotypic variabilities. Clinical implications of bacterial biofilms in relation to antibiotic treatments are also discussed.
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Diversity of Virulence Factors Associated with West Australian Methicillin-Sensitive Staphylococcus aureus Isolates of Human Origin. BIOMED RESEARCH INTERNATIONAL 2016; 2016:8651918. [PMID: 27247944 PMCID: PMC4876210 DOI: 10.1155/2016/8651918] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/01/2015] [Revised: 07/01/2015] [Accepted: 07/12/2015] [Indexed: 11/23/2022]
Abstract
An extensive array of virulence factors associated with S. aureus has contributed significantly to its success as a major nosocomial pathogen in hospitals and community causing variety of infections in affected patients. Virulence factors include immune evading capsular polysaccharides, poly-N-acetyl glucosamine, and teichoic acid in addition to damaging toxins including hemolytic toxins, enterotoxins, cytotoxins, exfoliative toxin, and microbial surface components recognizing adhesive matrix molecules (MSCRAMM). In this investigation, 31 West Australian S. aureus isolates of human origin and 6 controls were analyzed for relative distribution of virulence-associated genes using PCR and/or an immunoassay kit and MSCRAMM by PCR-based typing. Genes encoding MSCRAMM, namely, Spa, ClfA, ClfB, SdrE, SdrD, IsdA, and IsdB, were detected in >90% of isolates. Gene encoding α-toxin was detected in >90% of isolates whereas genes encoding β-toxin and SEG were detectable in 50–60% of isolates. Genes encoding toxin proteins, namely, SEA, SEB, SEC, SED, SEE, SEH, SEI, SEJ, TSST, PVL, ETA, and ETB, were detectable in >50% of isolates. Use of RAPD-PCR for determining the virulence factor-based genetic relatedness among the isolates revealed five cluster groups confirming genetic diversity among the MSSA isolates, with the greatest majority of the clinical S. aureus (84%) isolates clustering in group IIIa.
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Gogoi-Tiwari J, Waryah CB, Eto KY, Tau M, Wells K, Costantino P, Tiwari HK, Isloor S, Hegde N, Mukkur T. Relative distribution of virulence-associated factors among Australian bovine Staphylococcus aureus isolates: Potential relevance to development of an effective bovine mastitis vaccine. Virulence 2016; 6:419-23. [PMID: 26103596 DOI: 10.1080/21505594.2015.1043508] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Affiliation(s)
- Jully Gogoi-Tiwari
- a School of Biomedical Sciences; Faculty of Health Sciences; Curtin Health Innovation Research Institute; CHIRI Biosciences Research Precinct; Curtin University ; Perth , Australia
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The degree of virulence does not necessarily affect MRSA biofilm strength and response to photodynamic therapy. Microb Pathog 2016; 91:54-60. [DOI: 10.1016/j.micpath.2015.11.012] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2015] [Revised: 11/05/2015] [Accepted: 11/09/2015] [Indexed: 12/25/2022]
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Lázaro-Díez M, Remuzgo-Martínez S, Rodríguez-Mirones C, Acosta F, Icardo JM, Martínez-Martínez L, Ramos-Vivas J. Effects of Subinhibitory Concentrations of Ceftaroline on Methicillin-Resistant Staphylococcus aureus (MRSA) Biofilms. PLoS One 2016; 11:e0147569. [PMID: 26800524 PMCID: PMC4723258 DOI: 10.1371/journal.pone.0147569] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2015] [Accepted: 01/05/2016] [Indexed: 11/19/2022] Open
Abstract
Ceftaroline (CPT) is a novel cephalosporin with in vitro activity against Staphylococcus aureus. Ceftaroline exhibits a level of binding affinity for PBPs in S. aureus including PBP2a of methicillin-resistant S. aureus (MRSA). The aims of this study were to investigate the morphological, physiological and molecular responses of MRSA clinical strains and MRSA biofilms to sub-MICs (1/4 and 1/16 MIC) of ceftaroline by using transmission, scanning and confocal microscopy. We have also used quantitative Real-Time PCR to study the effect of sub-MICs of ceftaroline on the expression of the staphylococcal icaA, agrA, sarA and sasF genes in MRSA biofilms. In one set of experiments, ceftaroline was able to inhibit biofilm formation in all strains tested at MIC, however, a strain dependent behavior in presence of sub-MICs of ceftaroline was shown. In a second set of experiments, destruction of preformed biofilms by addition of ceftaroline was evaluated. Ceftaroline was able to inhibit biofilm formation at MIC in all strains tested but not at the sub-MICs. Destruction of preformed biofilms was strain dependent because the biofilm formed by a matrix-producing strain was resistant to a challenge with ceftaroline at MIC, whereas in other strains the biofilm was sensitive. At sub-MICs, the impact of ceftaroline on expression of virulence genes was strain-dependent at 1/4 MIC and no correlation between ceftaroline-enhanced biofilm formation and gene regulation was established at 1/16 MIC. Our findings suggest that sub-MICs of ceftaroline enhance bacterial attachment and biofilm formation by some, but not all, MRSA strains and, therefore, stress the importance of maintaining effective bactericidal concentrations of ceftaroline to fight biofilm-MRSA related infections.
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Affiliation(s)
- María Lázaro-Díez
- Servicio de Microbiología, Hospital Universitario Marqués de Valdecilla and Instituto de Investigación Marqués de Valdecilla (IDIVAL), Santander, Cantabria, Spain
| | - Sara Remuzgo-Martínez
- Servicio de Microbiología, Hospital Universitario Marqués de Valdecilla and Instituto de Investigación Marqués de Valdecilla (IDIVAL), Santander, Cantabria, Spain
| | - Cristina Rodríguez-Mirones
- Servicio de Microbiología, Hospital Universitario Marqués de Valdecilla and Instituto de Investigación Marqués de Valdecilla (IDIVAL), Santander, Cantabria, Spain
- Red Española de Investigación en Patología Infecciosa (REIPI), Instituto de Salud Carlos III, Madrid, Spain
| | - Felix Acosta
- Grupo de Investigación en Acuicultura, Universidad de Las Palmas de Gran Canaria, Arucas, Gran Canaria, Spain
| | - Jose M. Icardo
- Departamento de Anatomía y Biología Celular, Universidad de Cantabria, Santander, Cantabria, Spain
| | - Luis Martínez-Martínez
- Servicio de Microbiología, Hospital Universitario Marqués de Valdecilla and Instituto de Investigación Marqués de Valdecilla (IDIVAL), Santander, Cantabria, Spain
- Red Española de Investigación en Patología Infecciosa (REIPI), Instituto de Salud Carlos III, Madrid, Spain
- Departamento de Biología Molecular, Universidad de Cantabria, Santander, Cantabria, Spain
| | - José Ramos-Vivas
- Servicio de Microbiología, Hospital Universitario Marqués de Valdecilla and Instituto de Investigación Marqués de Valdecilla (IDIVAL), Santander, Cantabria, Spain
- Red Española de Investigación en Patología Infecciosa (REIPI), Instituto de Salud Carlos III, Madrid, Spain
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Rohinishree YS, Negi PS. Effect of licorice extract on cell viability, biofilm formation and exotoxin production by Staphylococcus aureus. Journal of Food Science and Technology 2015; 53:1092-100. [PMID: 27162389 DOI: 10.1007/s13197-015-2131-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Revised: 11/29/2015] [Accepted: 12/01/2015] [Indexed: 12/22/2022]
Abstract
Staphylococcus aureus is one of the most significant clinical pathogen, as it causes infections to humans and animals. Even though several antibiotics and other treatments have been used to control S. aureus infections and intoxication, bacterium is able to adapt, survive and produces exotoxins. Licorice (Glycyrrhiza glabra L.) has been used traditionally in various medicinal (antimicrobial) preparations, and Glycyrrhizic acid (GA) is the major active constituents present in it. In the present investigation the effect of licorice extract on methicillin susceptible S. aureus (FRI 722) and methicillin resistant S. aureus (ATCC 43300) growth and toxin production was studied. The MIC of licorice extract was found to be 0.25 and 2.5 mg GA ml(-1) against S. aureus FRI 722 and S. aureus ATCC 43300, respectively. Inhibition of biofilm formation was observed even at very low concentration (25 μg GA ml(-1)). Gradual decrease in expression and production of exotoxins such as α and β hemolysins and enterotoxin B was observed with the increasing concentrations of licorice extract, however, suboptimal concentration induced the expression of some of the virulence genes. This study indicated efficacy of licorice extract in controlling growth and pathogenicity of both methicillin susceptible and methicillin resistant S. aureus, however, the mechanisms of survival and toxin production at suboptimal concentration needs further study.
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Affiliation(s)
- Yadahalli Shrihari Rohinishree
- Fruit and Vegetable Technology Department, Council of Scientific and Industrial Research- Central Food Technological Research Institute, Mysore, 570 020 India
| | - Pradeep Singh Negi
- Fruit and Vegetable Technology Department, Council of Scientific and Industrial Research- Central Food Technological Research Institute, Mysore, 570 020 India
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Tan X, Qin N, Wu C, Sheng J, Yang R, Zheng B, Ma Z, Liu L, Peng X, Jia A. Transcriptome analysis of the biofilm formed by methicillin-susceptible Staphylococcus aureus. Sci Rep 2015; 5:11997. [PMID: 26149474 PMCID: PMC4493712 DOI: 10.1038/srep11997] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2014] [Accepted: 06/08/2015] [Indexed: 11/23/2022] Open
Abstract
Biofilm formation is regarded as one of the major determinants in the prevalence of methicillin-resistant Staphylococcus aureus (MRSA) as pathogens of medical device-related infection. However, methicillin-susceptible S. aureus (MSSA) can also form biofilm in vitro and such biofilms are resistant to vancomycin. Hence, researching the possible mechanisms of MSSA biofilm formation is urgent and necessary. Here, we used S. aureus ATCC25923 as the model strain, and studied gene expression profiles in biofilms after the treatment of ursolic acid and resveratrol using RNA-seq technology. The results showed that only ursolic acid could inhibit biofilm formation, which differed from their applied on the multiple clinical drugs resistant MRSA biofilm. RNA-seq data was validated by examining the expression of six genes involved in biofilm formation by qRT-PCR. These data analysis indicated that the mechanism of the MSSA biofilm formation was different from that of the MRSA, due to absence of accessory gene regulator (agr) function. These findings suggest that biofilms of S. aureus with agr dysfunction may be more resistant than those with agr function. Therefore, the infection from clinical MSSA may be recalcitrant once forming biofilm. Further study is necessary to uncover the mechanisms of biofilm formation in other clinical S. aureus.
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Affiliation(s)
- Xiaojuan Tan
- School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing 210094, China
| | - Nan Qin
- State Key Laboratory for Diagnosis and Treatment of Infectious Disease, the First Affiliated Hospital, Zhejiang University, Hangzhou 310003, China
| | - Chunyan Wu
- Realbio Genomics Institute, Shanghai 200050, China
| | - Jiyang Sheng
- School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing 210094, China
| | - Rui Yang
- School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing 210094, China
| | - Beiwen Zheng
- State Key Laboratory for Diagnosis and Treatment of Infectious Disease, the First Affiliated Hospital, Zhejiang University, Hangzhou 310003, China
| | - Zhanshan Ma
- Kunming Institute of Zoology, Chinese Academy of Science, Kunming 650223, China
| | - Lin Liu
- State Key Laboratory for Diagnosis and Treatment of Infectious Disease, the First Affiliated Hospital, Zhejiang University, Hangzhou 310003, China
| | - Xinhua Peng
- School of Chemical Engineering, Nanjing University of Science and Technology, Nanjing 210094, China
| | - Aiqun Jia
- School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing 210094, China
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Hua X, Chen Q, Li X, Yu Y. Global transcriptional response of Acinetobacter baumannii to a subinhibitory concentration of tigecycline. Int J Antimicrob Agents 2014; 44:337-44. [DOI: 10.1016/j.ijantimicag.2014.06.015] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2013] [Revised: 05/08/2014] [Accepted: 06/16/2014] [Indexed: 11/15/2022]
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Shen F, Tang X, Wang Y, Yang Z, Shi X, Wang C, Zhang Q, An Y, Cheng W, Jin K, Liu M, Guo N, Yu L. Phenotype and expression profile analysis of Staphylococcus aureus biofilms and planktonic cells in response to licochalcone A. Appl Microbiol Biotechnol 2014; 99:359-73. [PMID: 25256617 DOI: 10.1007/s00253-014-6076-x] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2014] [Revised: 09/04/2014] [Accepted: 09/07/2014] [Indexed: 11/28/2022]
Abstract
Staphylococcus aureus is one of the most important pathogens in humans and animals. The formation of biofilm by S. aureus is considered an important mechanism of antimicrobial resistance. Therefore, finding effective drugs against the biofilm produced by S. aureus has been a high priority. Licochalcone A (LAA), a natural plant product, was reported to have antibacterial activities and showed good activity against all 21 tested strains of S. aureus biofilm and planktonic cells. To detect the possible molecular mechanism of LAA against S. aureus biofilm or planktonic cells, Affymetrix GeneChips were used to determine the global comparative transcription of S. aureus biofilm and planktonic cells triggered by treatment with sub-bactericidal and sub-inhibitory concentrations of LAA, respectively. LAA significantly altered (greater than a 2- or less than -2-fold change) the expression of 693 genes in planktonic cells and 817 genes in biofilm. The levels of genes encoding autolysis-associated proteins, cell wall proteins, pathogenic factors, protein synthesis genes, and enzymes involved in capsule synthesis were significantly altered in LAA-treated S. aureus. Furthermore, some differences observed in the microarray analysis were verified by real-time RT-PCR. To our knowledge, this is the first observation of phenotype and expression profiles of S. aureus biofilm and planktonic cells in response to LAA treatment.
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Affiliation(s)
- Fengge Shen
- Key Laboratory of Zoonosis Research, Ministry of Education, Institute of Zoonosis, College of Veterinary Medicine, College of Animal Science and Department of Food Quality and Safety, Jilin University, Changchun, China
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Bovicin HC5 and nisin reduce Staphylococcus aureus adhesion to polystyrene and change the hydrophobicity profile and Gibbs free energy of adhesion. Int J Food Microbiol 2014; 190:1-8. [PMID: 25173449 DOI: 10.1016/j.ijfoodmicro.2014.08.004] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2014] [Revised: 08/01/2014] [Accepted: 08/02/2014] [Indexed: 12/25/2022]
Abstract
Staphylococcus aureus is an opportunistic pathogen often multidrug-resistant that not only causes a variety of human diseases, but also is able to survive on biotic and abiotic surfaces through biofilm communities. The best way to inhibit biofilm establishment is to prevent cell adhesion. In the present study, subinhibitory concentrations of the bacteriocins bovicin HC5 and nisin were tested for their capability to interfere with the adhesion of S. aureus to polystyrene. Subinhibitory dosages of the bacteriocins reduced cell adhesion and this occurred probably due to changes in the hydrophobicity of the bacterial cell and polystyrene surfaces. After treatment with bovicin HC5 and nisin, the surfaces became more hydrophilic and the free energy of adhesion (∆G(adhesion)) between bacteria and the polystyrene surface was unfavorable. The transcriptional level of selected genes was assessed by RT-qPCR approach, revealing that the bacteriocins affected the expression of some important biofilm associated genes (icaD, fnbA, and clfB) and rnaIII, which is involved in the quorum sensing mechanism. The conditioning of food-contact surfaces with bacteriocins can be an innovative and powerful strategy to prevent biofilms in the food industry. The results are relevant for food safety as they indicate that bovicin HC5 and nisin can inhibit bacterial adhesion and consequent biofilm establishment, since cell adhesion precedes biofilm formation.
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Qin N, Tan X, Jiao Y, Liu L, Zhao W, Yang S, Jia A. RNA-Seq-based transcriptome analysis of methicillin-resistant Staphylococcus aureus biofilm inhibition by ursolic acid and resveratrol. Sci Rep 2014; 4:5467. [PMID: 24970710 PMCID: PMC4073122 DOI: 10.1038/srep05467] [Citation(s) in RCA: 99] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2013] [Accepted: 05/21/2014] [Indexed: 02/08/2023] Open
Abstract
Bacterial biofilms are particularly problematic since they become resistant to most available antibiotics. Hence, novel potential antagonists to inhibit biofilm formation are urgent. Here the influences of two natural products, ursolic acid and resveratrol, on biofilm of the clinical methicillin-resistant Staphylococcus aureus (MRSA) isolate were investigated using RNA-seq, and the differentially expressed genes were analyzed using Cuffdiff. The results showed that ursolic acid inhibition of biofilm formation may reduce amino acids metabolism and adhesins expression and resveratrol may disturb quorum sensing (QS) and the synthesis of surface proteins and capsular polysaccharides. In addition, the transcriptome analysis of resveratrol and the combination of resveratrol with vancomycin inhibition of established biofilm revealed that resveratrol would disturb the expression of genes related to QS, surface and secreted proteins, and capsular polysaccharides. These findings suggest that ursolic acid and resveratrol could be useful to be adjunct therapies for the treatment of MRSA biofilm-involved infections.
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Affiliation(s)
- Nan Qin
- State Key Laboratory for Diagnosis and Treatment of Infectious Disease, the First Affiliated Hospital, Zhejiang University, Hangzhou 310003, China
- These authors contributed equally to this work
| | - Xiaojuan Tan
- School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing 210094, China
- These authors contributed equally to this work
| | - Yinming Jiao
- Department of Bioinformatics, State Key Laboratory of Plant Physiology and Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou 310058, China
- These authors contributed equally to this work
| | - Lin Liu
- State Key Laboratory for Diagnosis and Treatment of Infectious Disease, the First Affiliated Hospital, Zhejiang University, Hangzhou 310003, China
- NGS Sequencing Department, Beijing Genomics Institute (BGI), Shenzhen 518083, China
| | - Wangsheng Zhao
- Clinical Laboratory Department of the First Affiliated Hospital, Nanjing Medical University, Nanjing 210029, China
| | - Shuang Yang
- NGS Sequencing Department, Beijing Genomics Institute (BGI), Shenzhen 518083, China
| | - Aiqun Jia
- School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing 210094, China
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Reiter KC, Sant’Anna FH, d’Azevedo PA. Upregulation of icaA, atlE and aap genes by linezolid but not vancomycin in Staphylococcus epidermidis RP62A biofilms. Int J Antimicrob Agents 2014; 43:248-53. [DOI: 10.1016/j.ijantimicag.2013.12.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2013] [Revised: 10/30/2013] [Accepted: 12/02/2013] [Indexed: 10/25/2022]
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Kreis CA, Raschke MJ, Roßlenbroich SB, Tholema-Hans N, Löffler B, Fuchs T. Therapy of intracellular Staphylococcus aureus by tigecyclin. BMC Infect Dis 2013; 13:267. [PMID: 23738922 PMCID: PMC3694521 DOI: 10.1186/1471-2334-13-267] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2013] [Accepted: 06/03/2013] [Indexed: 11/30/2022] Open
Abstract
Background In the fields of traumatology and orthopaedics staphylococci are the most frequently isolated pathogens. Staphylococcus aureus and Staphylococcus epidermidis are known to be the major causative agents of osteomyelitis. The increasing number of multiresistant Staphylococcus aureus and resistant coagulase-negative staphylococci as a trigger of complicated osteomyelitis and implant-associated infections is a major problem. Antibiotic therapy fails in 20% of cases. Therefore the development of novel antibiotics becomes necessary. Methods This study analyses tigecyclin, the first antibiotic of the glycylines, as a potential therapy for osteomyelitis caused by multiresistant Staphylococcus aureus. Therefore its intracellular activity and the potential use in polymethylmetacrylate-bone cement are examined. The intracellular activity of tigecyclin is determined by a human osteoblast infection model. The investigation of the biomechanical characteristics is conducted concerning the ISO 5833-guidelines. Results Tigecyclin shows in vitro an intracellular activity that ranges between the antimicrobial activity of gentamicin and rifampicin. A significant negative effect on the biomechanical characteristics with an impaired stability is detected after adding tigecyclin to polymethylmetacrylate-bone cement with a percentage of 1.225% per weight. Conclusions This study shows that tigecyclin might be a potent alternative for the systemic therapy of osteomyelitis and implant-associated infections whereas the local application has to be reconsidered individually.
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Affiliation(s)
- Carolin A Kreis
- Department of Trauma, Hand and Reconstructive Surgery, University Hospital of Muenster, Waldeyerstr. 1, 48149, Muenster, Germany.
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Babra C, Tiwari J, Costantino P, Sunagar R, Isloor S, Hegde N, Mukkur T. Human methicillin-sensitiveStaphylococcus aureusbiofilms: potential associations with antibiotic resistance persistence and surface polysaccharide antigens. J Basic Microbiol 2013; 54:721-8. [DOI: 10.1002/jobm.201200557] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2012] [Accepted: 01/19/2013] [Indexed: 11/09/2022]
Affiliation(s)
- Charlene Babra
- School of Biomedical Sciences, Faculty of Health Sciences; Curtin Health Innovation Research Institute, West Australian Biomedical Research Institute, Curtin University, Bentley Campus; Perth WA Australia
| | - Jully Tiwari
- School of Biomedical Sciences, Faculty of Health Sciences; Curtin Health Innovation Research Institute, West Australian Biomedical Research Institute, Curtin University, Bentley Campus; Perth WA Australia
| | - Paul Costantino
- School of Biomedical Sciences, Faculty of Health Sciences; Curtin Health Innovation Research Institute, West Australian Biomedical Research Institute, Curtin University, Bentley Campus; Perth WA Australia
| | - Raju Sunagar
- Ella Foundation; Genome Valley; Turkapally, Shameerpet Mandal, Hyderabad Andhra Pradesh India
| | - Shrikrishna Isloor
- Department of Veterinary Microbiology; Karnataka Veterinary, Animal and Fisheries Sciences University; Hebbal, Bengaluru Karnataka India
| | - Nagendra Hegde
- Ella Foundation; Genome Valley; Turkapally, Shameerpet Mandal, Hyderabad Andhra Pradesh India
| | - Trilochan Mukkur
- School of Biomedical Sciences, Faculty of Health Sciences; Curtin Health Innovation Research Institute, West Australian Biomedical Research Institute, Curtin University, Bentley Campus; Perth WA Australia
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Otto MP, Martin E, Badiou C, Lebrun S, Bes M, Vandenesch F, Etienne J, Lina G, Dumitrescu O. Effects of subinhibitory concentrations of antibiotics on virulence factor expression by community-acquired methicillin-resistant Staphylococcus aureus. J Antimicrob Chemother 2013; 68:1524-32. [PMID: 23508621 DOI: 10.1093/jac/dkt073] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
OBJECTIVES To examine the effect of subinhibitory concentrations (sub-MICs) of antistaphylococcal drugs on Panton-Valentine leucocidin (PVL), α-haemolysin (Hla) and protein A (SpA) expression by community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA). METHODS Five clinical isolates representing the main worldwide CA-MRSA clones were grown with sub-MICs (1/8, 1/4 and 1/2 MIC) of five antibiotics (clindamycin, daptomycin, linezolid, tigecycline and vancomycin). After 4 and 6 h of incubation, culture pellets were used for relative quantitative RT-PCR with primers specific for pvl, hla, spa and gyrB. The PVL, Hla and SpA concentrations were measured in the supernatant (for PVL and Hla) and in the cell pellet (for SpA) using specific ELISAs. RESULTS For all strains tested, clindamycin and linezolid dramatically reduced mRNA levels of PVL and SpA. Tigecycline also decreased the PVL and SpA mRNA levels of 3/5 and 4/5 strains tested, respectively, whereas daptomycin and vancomycin had no significant effect. PVL and SpA quantification confirmed the concentration-dependent inhibition of PVL and SpA production by clindamycin and, to a lesser extent, by linezolid and tigecycline. Only clindamycin decreased Hla mRNA expression, whereas linezolid, tigecycline and daptomycin showed heterogeneous strain-dependent results, and vancomycin had no significant effect. Analysis of the Hla level revealed a stronger concentration-dependent inhibition of Hla release by clindamycin than by linezolid. CONCLUSIONS The effect of sub-MICs on virulence expression depended on the antibiotic and the virulence factor. Clindamycin and linezolid consistently suppressed the expression of different virulence factors by CA-MRSA, whereas tigecycline specifically suppressed PVL expression. Daptomycin and vancomycin seem to have no significant effects at these concentrations.
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Affiliation(s)
- Marie Pierre Otto
- Centre National de Référence des Staphylocoques, Faculté de Médecine Lyon Est, Université de Lyon, Lyon F-69008, France
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Perturbation of Staphylococcus aureus gene expression by the enoyl-acyl carrier protein reductase inhibitor AFN-1252. Antimicrob Agents Chemother 2013; 57:2182-90. [PMID: 23459481 DOI: 10.1128/aac.02307-12] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
This study examines the alteration in Staphylococcus aureus gene expression following treatment with the type 2 fatty acid synthesis inhibitor AFN-1252. An Affymetrix array study showed that AFN-1252 rapidly increased the expression of fatty acid synthetic genes and repressed the expression of virulence genes controlled by the SaeRS 2-component regulator in exponentially growing cells. AFN-1252 did not alter virulence mRNA levels in a saeR deletion strain or in strain Newman expressing a constitutively active SaeS kinase. AFN-1252 caused a more pronounced increase in fabH mRNA levels in cells entering stationary phase, whereas the depression of virulence factor transcription was attenuated. The effect of AFN-1252 on gene expression in vivo was determined using a mouse subcutaneous granuloma infection model. AFN-1252 was therapeutically effective, and the exposure (area under the concentration-time curve from 0 to 48 h [AUC(0-48)]) of AFN-1252 in the pouch fluid was comparable to the plasma levels in orally dosed animals. The inhibition of fatty acid biosynthesis by AFN-1252 in the infected pouches was signified by the substantial and sustained increase in fabH mRNA levels in pouch-associated bacteria, whereas depression of virulence factor mRNA levels in the AFN-1252-treated pouch bacteria was not as evident as it was in exponentially growing cells in vitro. The trends in fabH and virulence factor gene expression in the animal were similar to those in slower-growing bacteria in vitro. These data indicate that the effects of AFN-1252 on virulence factor gene expression depend on the physiological state of the bacteria.
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Coral-Associated Bacteria as a Promising Antibiofilm Agent against Methicillin-Resistant and -Susceptible Staphylococcus aureus Biofilms. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2012; 2012:862374. [PMID: 22988476 PMCID: PMC3439993 DOI: 10.1155/2012/862374] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/10/2012] [Accepted: 07/10/2012] [Indexed: 11/29/2022]
Abstract
The current study deals with the evaluation of two coral-associated bacterial (CAB) extracts to inhibit the biofilm synthesis in vitro as well as the virulence production like hemolysin and exopolysaccharide (EPS), and also to assess their ability to modify the adhesion properties, that is cell surface hydrophobicity (CSH) of methicillin-resistant (MRSA) and -susceptible Staphylococcus aureus (MSSA). Out of nine CAB screened, the ethyl acetate extract of CAB-E2 (Bacillus firmus) and CAB-E4 (Vibrio parahemolyticus) have shown excellent antibiofilm activity against S. aureus. CAB-E2 reduced the production of EPS (57–79%) and hemolysin (43–70%), which ultimately resulted in the significant inhibition of biofilms (80–87%) formed by both MRSA and MSSA. Similarly, CAB-E4 was also found to decrease the production of EPS (43–57%), hemolysin (43–57%) and biofilms (80–85%) of test pathogens. CLSM analysis also proved the antibiofilm efficacy of CAB extracts. Furthermore, the CAB extracts strongly decreased the CSH of S. aureus. Additionally, FT-IR analysis of S. aureus treated with CAB extracts evidenced the reduction in cellular components compared to their respective controls. Thus, the present study reports for the first time, B. firmus—a coral-associated bacterium, as a promising source of antibiofilm agent against the recalcitrant biofilms formed by multidrug resistant S. aureus.
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Enhancement of antistaphylococcal activities of six antimicrobials against sasG-negative methicillin-susceptible Staphylococcus aureus: an in vitro biofilm model. Diagn Microbiol Infect Dis 2012; 74:101-5. [PMID: 22770653 DOI: 10.1016/j.diagmicrobio.2012.05.034] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2011] [Revised: 05/21/2012] [Accepted: 05/24/2012] [Indexed: 11/23/2022]
Abstract
This study was designed to evaluate antimicrobial activities against methicillin-susceptible Staphylococcus aureus in both sessile and planktonic forms and to detect genes associated with this biofilm phenotype. Minimal biofilm inhibition and eradication concentrations (MBIC and MBEC, respectively) were determined by an in vitro biofilm model, and icaA, atlA, and sasG genes were detected by polymerase chain reaction. Vancomycin and tigecycline presented better biofilm inhibitory activity (MBIC range: 4-8 μg/mL) (P ≤ 0.05) and lower MBEC/MIC ratios (P ≤ 0.001) than other antimicrobials. All isolates harbored icaA and atlA, whereas sasG was present only in strong biofilm formers (P ≤ 0.05). Interestingly, antimicrobial activities against sasG- weak biofilm formers were significantly higher than those against sasG+ strong biofilm formers (P ≤ 0.05), demonstrating that number of cells in a biofilm matrix affected the antimicrobial activity, which was also variable, and might be associated with specific genetic determinants. To our knowledge, this was the first study reporting the presence of sasG in clinical isolates of S. aureus in South America.
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Watkins RR, David MZ, Salata RA. Current concepts on the virulence mechanisms of meticillin-resistant Staphylococcus aureus. J Med Microbiol 2012; 61:1179-1193. [PMID: 22745137 DOI: 10.1099/jmm.0.043513-0] [Citation(s) in RCA: 118] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Meticillin-resistant Staphylococcus aureus (MRSA) strains are prevalent bacterial pathogens that cause both health care and community-associated infections. Increasing resistance to commonly prescribed antibiotics has made MRSA a serious threat to public health throughout the world. The USA300 strain of MRSA has been responsible for an epidemic of community-associated infections in the US, mostly involving skin and soft tissue but also more serious invasive syndromes such as pneumonia, severe sepsis and endocarditis. MRSA strains are particularly serious and potentially lethal pathogens that possess virulence mechanisms including toxins, adhesins, enzymes and immunomodulators. One of these is Panton-Valentine leukocidin (PVL), a toxin associated with abscess formation and severe necrotizing pneumonia. Earlier studies suggested that PVL was a major virulence factor in community-associated MRSA infections. However, some recent data have not supported this association while others have, leading to controversy. Therefore, investigators continue to search for additional mechanisms of pathogenesis. In this review, we summarize the current understanding of the biological basis of MRSA virulence and explore future directions for research, including potential vaccines and antivirulence therapies under development that might allow clinicians to more successfully treat and prevent MRSA infections.
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Affiliation(s)
- Richard R Watkins
- Division of Infectious Diseases, Akron General Medical Center, Akron, OH 44302, USA
| | - Michael Z David
- Departments of Medicine and Health Studies, The University of Chicago, Chicago, IL, USA
| | - Robert A Salata
- Division of Infectious Diseases and HIV Medicine, University Hospitals Case Medical Center, Cleveland, OH, USA
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Efficacy of tigecycline and vancomycin in experimental catheter-related Staphylococcus epidermidis infection: microbiological and electron microscopic analysis of biofilm. Int J Antimicrob Agents 2012; 39:338-42. [DOI: 10.1016/j.ijantimicag.2012.01.001] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2011] [Revised: 11/12/2011] [Accepted: 01/02/2012] [Indexed: 11/21/2022]
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Daptomycin and tigecycline have broader effective dose ranges than vancomycin as prophylaxis against a Staphylococcus aureus surgical implant infection in mice. Antimicrob Agents Chemother 2012; 56:2590-7. [PMID: 22371896 DOI: 10.1128/aac.06291-11] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Vancomycin is widely used for intravenous prophylaxis against surgical implant infections. However, it is unclear whether alternative antibiotics used to treat methicillin-resistant Staphylococcus aureus (MRSA) infections are effective as prophylactic agents. The aim of this study was to compare the efficacies of vancomycin, daptomycin, and tigecycline as prophylactic therapy against a methicillin-sensitive S. aureus (MSSA) or MRSA surgical implant infection in mice. MSSA or MRSA was inoculated into the knee joints of mice in the presence of a surgically placed medical-grade metallic implant. The efficacies of low- versus high-dose vancomycin (10 versus 110 mg/kg), daptomycin (1 versus 10 mg/kg), and tigecycline (1 versus 10 mg/kg) intravenous prophylaxis were compared using in vivo bioluminescence imaging, ex vivo bacterial counts, and biofilm formation. High-dose vancomycin, daptomycin, and tigecycline resulted in similar reductions in bacterial burden and biofilm formation. In contrast, low-dose daptomycin and tigecycline were more effective than low-dose vancomycin against the implant infection. In this mouse model of surgical implant MSSA or MRSA infection, daptomycin and tigecycline prophylaxis were effective over a broader dosage range than vancomycin. Future studies in humans will be required to determine whether these broader effective dose ranges for daptomycin and tigecycline in mice translate to improved efficacy in preventing surgical implant infections in clinical practice.
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Wand ME, Bock LJ, Turton JF, Nugent PG, Sutton JM. Acinetobacter baumannii virulence is enhanced in Galleria mellonella following biofilm adaptation. J Med Microbiol 2011; 61:470-477. [PMID: 22194338 DOI: 10.1099/jmm.0.037523-0] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The opportunistic nosocomial pathogen Acinetobacter baumannii is responsible for a growing number of infections; however, few of its potential virulence factors have been identified, and how this organism causes infection remains largely unknown. Bacterial biofilms are often an important component in infection and persistence but there is no conclusive evidence to link biofilm formation with virulence and severity of infection in Acinetobacter. To investigate this link, several clinical isolates were assessed in biofilm culture models and were tested for virulence in the insect model Galleria mellonella. In both systems, the profiles showed significant differences between strains, but no correlation was observed between virulence and the ability to form biofilms. In contrast, A. baumannii cells from a biofilm produced higher mortality rates than an equivalent number of planktonic cells. Relative to planktonic cells, A. baumannii biofilm cultures also showed reduced sensitivity to antibiotics normally used in the treatment of A. baumannii, especially colistin. This model, therefore, provides a suitable system to investigate the link between biofilm growth and various factors influencing virulence during A. baumannii infection.
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Affiliation(s)
- Matthew E Wand
- Health Protection Agency, Microbiology Services Division, Porton Down, Salisbury SP4 0JG, UK
| | - Lucy J Bock
- Health Protection Agency, Microbiology Services Division, Porton Down, Salisbury SP4 0JG, UK
| | - Jane F Turton
- Health Protection Agency, Microbiology Services Division, HPA Colindale, London NW9 5EQ, UK
| | - Philip G Nugent
- Health Protection Agency, Microbiology Services Division, Porton Down, Salisbury SP4 0JG, UK
| | - J Mark Sutton
- Health Protection Agency, Microbiology Services Division, Porton Down, Salisbury SP4 0JG, UK
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Antibiotic modulation of the plasminogen binding ability of viridans group streptococci. Antimicrob Agents Chemother 2011; 56:458-63. [PMID: 22037854 DOI: 10.1128/aac.00452-11] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The ability of viridans group streptococci to bind human plasminogen and its subsequent activation into plasmin may contribute to the pathogenesis of infective endocarditis (IE) by leading to a decreased stability of the streptococcal vegetation and facilitating dehiscence of emboli. At levels greater than or equal to their MICs, penicillin, vancomycin, and linezolid are efficacious in the treatment of streptococcal endocarditis. However, at sub-MICs, antibiotics can modulate the expression of bacterial genes, including virulence-associated genes, which can have counterproductive effects on the treatment of endocarditis. The effects of 1/8× and 1/4× MICs of penicillin, vancomycin, and linezolid on the plasminogen binding ability of IE isolates Streptococcus mitis 881/956, Streptococcus oralis 12601, and Streptococcus sanguinis 12403 were assessed phenotypically and the expression of plasminogen receptors α-enolase and glyceraldehyde 3-phosphate dehydrogenase of S. oralis 12601 when exposed to 1/4× MIC of penicillin, was analyzed through quantitative reverse transcription (qRT)-PCR. The plasminogen binding ability of S. mitis 881/956 and S. sanguinis 12403 remained unaffected by exposure to sub-MICs of all of the antibiotics tested, while that of S. oralis 12601 was significantly enhanced by all of the antibiotics tested at sub-MICs. qRT-PCR analysis of S. oralis 12601 demonstrated an upregulation of the eno and gapdh genes, indicating an overexpression of plasminogen receptors. These findings suggest that for some endocarditis isolates, the effect of antibiotic sub-MICs, in addition to a reduced antibacterial effect, may influence the clinical response to nonsurgical therapy. It remains difficult to accurately predict isolate responses to sub-MIC antimicrobials since there appears to be interspecies variation.
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Wecke T, Mascher T. Antibiotic research in the age of omics: from expression profiles to interspecies communication. J Antimicrob Chemother 2011; 66:2689-704. [DOI: 10.1093/jac/dkr373] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
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Goss CH, Muhlebach MS. Review: Staphylococcus aureus and MRSA in cystic fibrosis. J Cyst Fibros 2011; 10:298-306. [PMID: 21719362 DOI: 10.1016/j.jcf.2011.06.002] [Citation(s) in RCA: 147] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2011] [Revised: 05/27/2011] [Accepted: 06/03/2011] [Indexed: 01/31/2023]
Abstract
BACKGROUND Staphylococcus aureus (S. aureus) is one of the earliest bacteria detected in infants and children with cystic fibrosis (CF). The rise of methicillin resistant S. aureus (MRSA) in the last 10 years has caused a lot of attention to this organism. RESULTS The aim of this review is to provide a general overview of methicillin sensitive S. aureus (MSSA) and MRSA, discuss special aspects of S. aureus in cystic fibrosis, and to review treatment concepts. Microbiology of the organism will be reviewed along with data regarding the epidemiology of both MSSA and MRSA. Antibiotic treatments both in regards to acute management and eradication of MSSA and MRSA will be reviewed. Prophylaxis of MSSA in CF remains controversial. Treatment with anti-staphylococcal agents reduces the infection rate with MSSA but may lead to a higher rate of infection with P. aeruginosa. In regards to MRSA, there is a paucity of clinical data regarding approaches to eradication. CONCLUSIONS To advance the care of CF patients, controlled clinical trials are urgently needed to find the optimal approach to treating CF patients who are infected with either MSSA or MRSA.
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Nithya C, Devi MG, Karutha Pandian S. A novel compound from the marine bacterium Bacillus pumilus S6-15 inhibits biofilm formation in gram-positive and gram-negative species. BIOFOULING 2011; 27:519-528. [PMID: 21614700 DOI: 10.1080/08927014.2011.586127] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Biofilm formation is a critical problem in nosocomial infections and in the aquaculture industries and biofilms show high resistance to antibiotics. The aim of the present study was to reveal a novel anti-biofilm compound from marine bacteria against antibiotic resistant gram-positive and gram-negative biofilms. The bacterial extract (50 μg ml(-1)) of S6-01 (Bacillus indicus = MTCC 5559) showed 80-90% biofilm inhibition against Escherichia coli, Shigella flexneri, Proteus mirabilis and S6-15 (Bacillus pumilus = MTCC 5560) showed 80-95% biofilm inhibition against all the 10 tested organisms. Furthermore, they also reduced the hydrophobicity index and extracellular polymeric substances (EPS) production. Structural elucidation of the active principle in S6-15 using GC-MS, (1)H NMR, and (13)C NMR spectral data revealed it to be 4-phenylbutanoic acid. This is the first report of 4-phenylbutanoic acid as a natural product. The purified compound (10-15 μg ml(-1)) showed potential activity against a wide range of biofilms. This study for the first time, reports a novel anti-biofilm compound from a marine bacterium with wide application in medicine and the aquaculture industry.
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Affiliation(s)
- Chari Nithya
- Department of Biotechnology, Alagappa University, Karaikudi, India
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Abstract
PURPOSE OF REVIEW A multidisciplinary approach to the treatment and management of biofilms has resulted from the growing appreciation of the role that biofilms play in modern medicine. Conventional antimicrobial agents are generally ineffective against biofilms, and as a result novel laboratory-based and clinical strategies have emerged. The purpose of this review is to analyse the recent literature relating to novel treatment strategies targeting the growing spectrum of clinically relevant biofilms. RECENT FINDINGS Microscopy and molecular techniques have provided greater insights into identifying the key bacterial and fungal biofilm pathogens. Knowledge of these microorganisms has provided a foundation for the development of specific molecules, often microbial derived, with antimicrobial and/or biofilm disruptive properties, augmenting conventional antibiotics treatments. The validity of some such rationally designed therapeutics has been explored in clinical trials. SUMMARY Biofilms are inherently difficult to treat, and mechanical disruption is the mainstay of clinical management. With scientific progress in molecular microbiology, there is an abundance of newly discovered molecules and pathways, providing novel therapeutic and prophylactic targets.
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