scholarly journals Characterisation of classical enterotoxins, virulence activity, and antibiotic susceptibility of Staphylococcus aureus isolated from Thai fermented pork sausages, clinical samples, and healthy carriers in northeastern Thailand

2020 ◽  
Vol 64 (2) ◽  
pp. 289-297
Author(s):  
Wanwisa Sankomkai ◽  
Wongwarut Boonyanugomol ◽  
Kairin Kraisriwattana ◽  
Julalak Nutchanon ◽  
Kraisorn Boonsam ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antibiotic Susceptibility ◽  
Biofilm Formation ◽  
Extracellular Enzymes ◽  
Clinical Samples ◽  
Pork Sausage ◽  
Hospitalised Patients ◽  
Pork Sausages ◽  
Healthy Carriers ◽  
Northeastern Thailand

AbstractIntroductionContamination by Staphylococcus aureus of food produced from animal sources may have diverse and multifactorial causes that depend on geographical distribution. The goal of this study was to isolate and characterise S. aureus strains from contaminated fermented pork sausage, which is a local food of northeastern Thailand.Material and MethodsS. aureus strains were isolated from local pork sausage, and the presence of classical enterotoxins was determined by PCR and reversed passive latex agglutination. These results were compared with strains derived from hospitalised patients and healthy carriers. Additionally, production of extracellular enzymes and haemolysin, biofilm formation, and antibiotic susceptibility were assessed.ResultsS. aureus was identified in 36 sausage isolates (60%). The strains positive for staphylococcal enterotoxin A were more frequently found in isolates from sausage and healthy carriers than in those from patients. All tested S. aureus strains were positive for DNase, lipase, proteinase, haemolysin, and biofilm formation; notably, strains isolated from food and healthy carriers displayed similar values. Most isolates were resistant to penicillin and ampicillin, while none were to methicillin.ConclusionsThai fermented pork sausages are associated with a high risk of staphylococcal food poisoning, which may be linked to contamination caused by carriers. Dissemination of knowledge regarding best practices in sanitation and hygiene is important in local communities.

scholarly journals Molecular Investigation of Fibronectin-Binding Protein Genes and Capacity of Biofilm Production in Staphylococcus Aureus Isolated From Clinical Samples

2021 ◽  
Author(s):  
Hossein Jafari Soghondicolaei ◽  
Mohammad Ahanjan ◽  
Mehrdad Gholami ◽  
Bahman Mirzaei ◽  
Hamid Reza Goli
Keyword(s):  
Staphylococcus Aureus ◽  
Biofilm Formation ◽  
Colorimetric Assay ◽  
Binding Protein ◽  
Clinical Isolates ◽  
Diffusion Method ◽  
Clinical Samples ◽  
Biofilm Production ◽  
Fibronectin Binding Protein ◽  
Fibronectin Binding

Abstract Biofilm production increases Staphylococcus aureus resistance to antibiotics and also host defense mechanisms. The current study aims to evaluate the biofilm formation by S. aureus and to determine the prevalence of fibronectin-binding protein genes, also its correlation with drug resistance. In this study, 100 clinical isolates of S. aureus were collected. The antibiotic susceptibility pattern of the isolates was evaluated by the disk agar diffusion method. The ability of biofilm formation in the studied isolates was also determined by microplate colorimetric assay. Then, all isolates were screened by polymerase chain reaction for the fnbA and fnbB genes. Out of 100 clinical isolates of S. aureus, the highest and lowest antibiotic resistance rates were against penicillin (94%) and vancomycin (6%). Thirty-two cases were found to be multi-drug resistant (MDR) among the all strains. The ability of biofilm production was observed in 89% of the isolates. The PCR results showed that the prevalence of fnbA and fnbB genes were 91% and 17%, respectively. Moreover, 100% and 21.8% of the MDR strains harbored the fnbA and fnbB genes respectively. The ability to form biofilm in MDR isolates of S. aureus is more than non-MDR isolates, especially fnbA positive ones. As the bacteria in the biofilm are difficult to kill by antibiotics, attention to the removal or control of the biofilm production seems to be necessary.

scholarly journals Impact of sarA on Antibiotic Susceptibility of Staphylococcus aureus in a Catheter-Associated In Vitro Model of Biofilm Formation

2009 ◽  
Vol 53 (6) ◽  
pp. 2475-2482 ◽  
Author(s):  
Elizabeth C. Weiss ◽  
Horace J. Spencer ◽  
Sonja J. Daily ◽  
Brian D. Weiss ◽  
Mark S. Smeltzer
Keyword(s):  
Staphylococcus Aureus ◽  
Clinical Isolate ◽  
Antimicrobial Susceptibility ◽  
Antibiotic Susceptibility ◽  
Biofilm Formation ◽  
In Vitro Model ◽  
Susceptibility Testing ◽  
Specific Context ◽  
Vitro Model

ABSTRACT Mutation of the staphylococcal accessory regulator (sarA) in Staphylococcus aureus limits but does not abolish the capacity of the organism to form a biofilm. As a first step toward determining whether this limitation is therapeutically relevant, we carried out in vitro studies comparing the relative susceptibility of an S. aureus clinical isolate (UAMS-1) and its isogenic sarA mutant (UAMS-929) in the specific context of a catheter-associated biofilm. The antibiotics tested were daptomycin, linezolid, and vancomycin, all of which were evaluated by using concentrations based on the MIC defined as the breakpoint for a susceptible strain of S. aureus (≤1.0, ≤2.0, and ≤4.0 μg/ml for daptomycin, vancomycin, and linezolid, respectively). Mutation of sarA had no significant impact on the MIC of UAMS-1 for any of the targeted antibiotics, as defined by Etest antimicrobial susceptibility testing. However, mutation of sarA did result in a significant increase in antimicrobial susceptibility to all targeted antibiotics when they were tested in the specific context of a biofilm. Additionally, whether susceptibility was assessed by using UAMS-1 or its sarA mutant, daptomycin was found to be more effective against established S. aureus biofilms than either linezolid or vancomycin.

scholarly journals Biofilm formation by clinically isolated Staphylococcus Aureus from India

2018 ◽  
Vol 12 (12) ◽  
pp. 1062-1066 ◽  
Author(s):  
Alasthimannahalli Gangadhara Triveni ◽  
Mendem Suresh Kumar ◽  
Chavadi Manjunath ◽  
Channappa T Shivannavar ◽  
Subhaschandra M Gaddad
Keyword(s):  
Staphylococcus Aureus ◽  
Congo Red ◽  
Biofilm Formation ◽  
Quantitative Estimation ◽  
Microtiter Plate ◽  
Clinical Samples ◽  
Specific Method ◽  
Qualitative And Quantitative ◽  
Etiological Agents

Introduction: Staphylococcal biofilms are prominent cause for acute and chronic infection both in hospital and community settings across the world. Current study explores biofilm formation by Staphylococcus aureus isolates from clinical samples by different methods. Methodology: Standard techniques used for the characterization of S.aureus. Qualitative and quantitative biofilm formation was assessed by Congo red Agar, Tube and Microtiter plate methods. Results: A total of 188 clinical isolates of S.aureus were screened for biofilm formation and 72 (38.29%) of them were found to be biofilm producers, 34 (18.08%) strong, 38 (20.21%) moderate. The remaining 116 (61.7%) were weak/ non biofilm producers. Maximum biofilm formers were recorded in pus samples (39.06%), followed by isolates from blood (38.23%) and urine (34.61%). Statistical analysis for the formation of biofilm indicated that Microtiter plate method is the most sensitive and specific method for screening biofilm production. Conclusions: Biofilm formation is one of the influential virulence factor in staphylococcal pathogenesis and persistence. Microtiter plate and Congo red agar remain as reliable methods for the qualitative and quantitative estimation of biofilm formation. Monitoring of biofilm formation in various etiological agents will help in determining the severity of infection.

scholarly journals Antimicrobial Resistance Patterns and Plasmid Profiles of Methicillin Resistant Staphylococcus aureus Isolated from Clinical Samples

2019 ◽  
Vol 7 (1) ◽  
pp. 8-14
Author(s):  
Gaurav Agrahari ◽  
Amrit Koirala ◽  
Roshan Thapa ◽  
Mahesh Kumar Chaudhary ◽  
Reshma Tuladhar
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Resistance ◽  
Antibiotic Susceptibility ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Plasmid Profile ◽  
Diffusion Method ◽  
Clinical Samples ◽  
Methicillin Resistant ◽  
Plasmid Profiles ◽  
Resistance Patterns

Methicillin-resistant Staphylococcus aureus (MRSA), showing resistance to several antibiotics is a global health problem associated with considerable mortality and morbidity. Antibiotic susceptibility test is a commonly used method to characterize MRSA in epidemiologic studies. Additionally, plasmid profile has been reported to be useful in tracing the epidemiology of antibiotic resistance. This research was conducted to determine the antimicrobial resistance patterns and plasmid profiles of MRSA isolated from clinical samples at KIST Medical College, Imadol, Kathmandu, Nepal. All the clinical specimens sent to the laboratory were processed by standard microbiological techniques and antibiotic susceptibility testing was done by the modified Kirby Bauer disc diffusion method. Further, plasmid profiling was done by Alkaline-lysis method. A total of 27 (38.02%) MRSA were isolated from 71 S. aureus positive samples. MRSA showed the highest resistance towards penicillin (92.60%) and ampicillin (92.60%). In contrast, high levels of sensitivity were shown towards vancomycin (85.19%) and tetracycline (85.19%). Out of 27 MRSA positive samples, single plasmids were isolated from only 6 (22.22%) MRSA isolates. Antibiograms alone are inadequate to accomplish the characterization of MRSA during epidemiological studies. However, plasmid profile analysis in conjunction with the antibiotic susceptibility pattern is valuable in the epidemiological investigation of MRSA, and for reducing MRSA prevalence and treatment cost.

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