Biofilm Formation and Antibiotic Susceptibility Profile of Clinical Isolates of Staphylococcus aureus Isolated from Clinical Samples in Zaria, Nigeria

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.

Download Full-text

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

Journal of Veterinary Research ◽

10.2478/jvetres-2020-0036 ◽

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.

Download Full-text

Prevalence of constitutive and inducible clindamycin resistance among clinical isolates of Staphylococcus aureus in a tertiary care institute in North India

International Journal of Research in Medical Sciences ◽

10.18203/2320-6012.ijrms20172999 ◽

2017 ◽

Vol 5 (7) ◽

pp. 3120

Author(s):

Jeevan Shetty ◽

Zarrin Afroz

Keyword(s):

Staphylococcus Aureus ◽

Antibiotic Susceptibility ◽

Susceptibility Testing ◽

Tertiary Care ◽

Clinical Isolates ◽

Diffusion Method ◽

Clinical Samples ◽

Antibiotic Susceptibility Testing ◽

Sensitivity Testing ◽

Inducible Clindamycin Resistance

Background: Clindamycin is an important drug used in the treatment of Methicillin Sensitive Staphylococcus aureus (MSSA) as well as in Methicillin-resistant Staphylococcus aureus (MRSA) infections. This drug is widely used in the treatment of skin and soft tissue infections caused by them. Therapeutic failure caused by macrolide-lincosamine-streptogramin B constitutive and inducible clindamycin resistance (MLSBc and MLSBi) is being more commonly reported.Methods: The present study was conducted over a period of six months from October 2016 to March 2017 to know the incidence of MLSBc and MLSBi in Staphylococcus aureus (S. aureus) isolates obtained in our hospital by D-test as per CLSI guidelines. A total of 130 isolates of S.aureus were obtained from different clinical specimens which included pus/ wound swab (n=266), urine (n=577), sputum (n=225), blood (n=221), throat swab (n=71), ear/eye discharge (n=21), high vaginal swab (n=20) and body fluids (n=50). All the isolates were subjected to antibiotic sensitivity testing by Kirby Bauer’s disc diffusion method. Amoxyclav, Erythromycin, Clindamycin, Co-trimoxazole, Tetracycline, Ofloxacin, Gentamicin, Linezolid and Vancomycin were the antibiotics used.Results: Out of 130 (8.9%) isolates of S. aureus obtained from 1451 clinical samples, 82 (63.1%) were found to be MSSA and 48 (36.9%) were MRSA. Among S. aureus, 43 (33.1%) isolates showed MLSBc resistance, 22 (16.9%) isolates showed MLSBi resistance and 20 (15.4%) isolates showed MS phenotype. The remaining 45 (34.6%) isolates remained sensitive to Erythromycin. Among MSSA, MLSBc were observed in 18 (22%) isolates and MLSBi in 9 (11%) while in MRSA, MLSBc were observed in 25 (52.1%) isolates and MLSBi in 13 (27.1%) isolates. Almost all clinical isolates showed 100% sensitivity to Vancomycin and Linezolid in routine antibiotic susceptibility testing. Both MLSBc and MLSBi resistance was significantly higher (p<0.05) in MRSA than in MSSA.Conclusions: The study emphasizes the importance of conducting D test along with routine antibiotic susceptibility testing for better utilization of clindamycin in S. aureus infections.

Download Full-text

Detection of β-lactamase and antibiotic susceptibility of clinical isolates of Staphylococcus aureus

Biocatalysis and Agricultural Biotechnology ◽

10.1016/j.bcab.2018.12.012 ◽

2019 ◽

Vol 17 ◽

pp. 720-725 ◽

Cited By ~ 1

Author(s):

Amit Kumar Kesharwani ◽

Jyoti Mishra

Keyword(s):

Staphylococcus Aureus ◽

Antibiotic Susceptibility ◽

Clinical Isolates

Download Full-text

Susceptibility of Clinical Isolates of Staphylococcus aureus to Ceftaroline

JOURNAL FOR CLINICAL AND DIAGNOSTIC RESEARCH ◽

10.7860/jcdr/2021/46121.14442 ◽

2021 ◽

Author(s):

Harsha Sreedharan ◽

KB Asha Pai

Keyword(s):

Staphylococcus Aureus ◽

Tertiary Care Hospital ◽

Methicillin Resistance ◽

Descriptive Analysis ◽

Tertiary Care ◽

The United States ◽

Clinical Isolates ◽

Diffusion Method ◽

Clinical Samples ◽

Care Hospital

Introduction: Methicillin-Resistant Staphylococcus aureus(MRSA) infection is a major global healthcare problem, the prevalence of which varies from 25-50% in India. It is known to cause Skin and Soft tissue Infections (SSI), endovascular infections, endocarditis, pneumonia, septic arthritis, osteomyelitis, and sepsis. Vancomycin is the drug of choice for treating severe MRSA infections. Ceftaroline, a fifth-generation cephalosporin has been approved by the United States Food and Drug Administration (US FDA) for treating acute bacterial SSI caused by susceptible micro-organisms including MRSA, Community acquired respiratory tract infection, MRSA bacteremia and endocarditis. Aim: To assess the susceptibility of clinical isolates of S. aureusto ceftaroline, in a Tertiary Care Hospital. Materials and Methods: This prospective study was conducted in the Department of Microbiology of a Tertiary Care Hospital over a period of two months from June 2019 to July 2019. S.aureus isolates from various clinical samples were screened for methicillin resistance by disc diffusion method using cefoxitin disc and ceftaroline susceptibility of these isolates was assessed by E-strip method. The isolates were classified as ceftaroline susceptible, Susceptibility Dose Dependent (SDD) and ceftaroline resistant respectively as per CLSI guidelines. A descriptive analysis of the data was done and the results were presented as frequencies and percentages. Results: All the S.aureus isolates were found to be susceptible to ceftaroline. Methicillin Sensitive Staphylococcus aureus(MSSA) isolates had lower Minimum Inhibitory Concentration (MIC) when compared to MRSA. The highest MIC among MRSA was 0.5 μg/mL. Conclusion: Ceftaroline can be considered as an effective alternative for treatment of infections caused by MRSA.

Download Full-text

Evaluation of Antibiotic Resistance Pattern, Alginate and Biofilm Production in Clinical Isolates of Pseudomonas aeruginosa

Iranian Journal of Public Health ◽

10.18502/ijph.v50i2.5349 ◽

2021 ◽

Author(s):

Fateme DAVARZANI ◽

Navid SAIDI ◽

Saeed BESHARATI ◽

Horieh SADERI ◽

Iraj RASOOLI ◽

...

Keyword(s):

Pseudomonas Aeruginosa ◽

Biofilm Formation ◽

Bacterial Resistance ◽

Antimicrobial Agents ◽

Clinical Isolates ◽

Diffusion Method ◽

Clinical Samples ◽

Resistance Pattern ◽

Alginate Production ◽

Opportunistic Bacteria

Background: Pseudomonas aeruginosa is one of the most common opportunistic bacteria causing nosocomial infections, which has significant resistance to antimicrobial agents. This bacterium is a biofilm and alginate producer. Biofilm increases the bacterial resistance to antibiotics and the immune system. Therefore, the present study was conducted to investigate the biofilm formation, alginate production and antimicrobial resistance patterns in the clinical isolates of P. aeruginosa. Methods: One hundred isolates of P. aeruginosa were collected during the study period (from Dec 2017 to Jul 2018) from different clinical samples of the patients admitted to Milad and Pars Hospitals at Tehran, Iran. Isolates were identified and confirmed by phenotypic and genotypic methods. Antimicrobial susceptibility was specified by the disk diffusion method. Biofilm formation and alginate production were measured by microtiter plate and carbazole assay, respectively. Results: Sixteen isolates were resistant to all the 12 studied antibiotics. Moreover, 31 isolates were MultidrugResistant (MDR). The highest resistance rate was related to ofloxacin (36 isolates) and the least resistance was related to piperacillin-tazobactam (21 isolates). All the isolates could produce the biofilm and alginate. The number of isolates producing strong, medium and weak biofilms was equal to 34, 52, and 14, respectively. Alginate production was more than 400 μg/ml in 39 isolates, 250-400 μg/ml in 51 isolates and less than 250 μg/ml in 10 isolates. Conclusion: High prevalence of MDR, biofilm formation, and alginate production were observed among the clinical isolates of P. aeruginosa. The results also showed a significant relationship between the amount of alginate production and the level of biofilm formation.

Download Full-text

Prevalence of Methicillin Resistant and Virulence Determinants in Clinical Isolates of Staphylococcus aureus

The Open Infectious Diseases Journal ◽

10.2174/1874279301810010108 ◽

2018 ◽

Vol 10 (1) ◽

pp. 108-115

Author(s):

Manjunath Chavadi ◽

Rahul Narasanna ◽

Ashajyothi Chavan ◽

Ajay Kumar Oli ◽

Chandrakanth Kelmani. R

Keyword(s):

Staphylococcus Aureus ◽

Cell Morphology ◽

Methicillin Resistance ◽

Protein A ◽

Clinical Isolates ◽

Clinical Samples ◽

Virulence Determinants ◽

Methicillin Resistant ◽

Alternative Medicines ◽

Mrsa Strains

Introduction:Methicillin-resistantStaphylococcus aureus(MRSA) is the major threat that is a result of the uncontrolled use of antibiotics causing a huge loss in health, so understanding their prevalence is necessary as a public health measure.Objective:The aim of this study was to determine the prevalence of methicillin-resistant MRSA and virulence determinant among associatedS. aureusfrom the clinical samples obtained from various hospital and health care centers of the Gulbarga region in India.Materials and Methods:All the collected samples were subjected for the screening ofS. aureusand were further characterized by conventional and molecular methods including their antibiotic profiling. Further, the response of methicillin antibiotic on cell morphology was studied using scanning electron microscopy.Results:A total 126S. aureuswas isolated from the clinical samples which showed, 100% resistant to penicillin, 55.5% to oxacillin, 75.3% to ampicillin, 70.6% to streptomycin, 66.6% to gentamicin, 8.7% to vancomycin and 6.3% to teicoplanin. The selected MRSA strains were found to possessmecA(gene coding for penicillin-binding protein 2A) andfemA(factor essential for methicillin resistance)genetic determinants in their genome with virulence determinants such as Coagulase (coa) and the X region of the protein A (spa)gene. Further, the methicillin response in resistantS. aureusshowed to be enlarged and malformed on cell morphology.Conclusion:The molecular typing of clinical isolates ofS. aureusin this study was highly virulent and also resistant to methicillin; this will assist health professionals to control, exploration of alternative medicines and new approaches to combat Staphylococcal infections more efficiently by using targeted therapy.

Download Full-text