ABSTRACT
BACKGROUND: Staphylococcus aureus is an important bacterium that can cause many diseases. Methicillin-resistant S.aureus (MRSA) is often sub-categorized as Hospital or Community acquired infection. MRSA causes serious problems, such as bloodstream and surgical site infections or pneumonia. OBJECTIVES: The present study aimed to identify S. aureus by 16SrRNA using PCR, estimate the antibiotic susceptibility pattern and determine the prevalence of MRSA among Hospital and community acquired infections. METHODS: A cross-sectional laboratory-based study was conducted during the period from November 2020 to January 2021. Conventional methods were used to identify S. aureus and isolate confirmation was performed by PCR targeting 16SrRNA gene. All isolated organisms were tested for their in-vitro antimicrobial susceptibility. RESULT: Among the enrolled patients (n, 300), MRSA was observed in 185 (61.7%). The highest frequency was shown in the age group over 45 years old (46.7%). The result also showed a high frequency of S. aureus among community infections (81.7%), MRSA in hospital acquired infections was 10.7% while 51% was community acquired. The antimicrobial susceptibilities against MRSA isolates showed high sensitivity to Ceftriaxone 90.0%). Most infections caused by MRSA isolates were respiratory tract infection (RTI) (28.3%) and Septicemia (22.5%). CONCLUSION: The present study highlighted a high proportion of MRSA in clinical settings at Khartoum State. Antibiotic susceptibility results showed that Ceftriaxone was the drug of choice against MRSA isolates. Overuse and misuse of antibiotics, along with self-medication, seem to be the cause of antibiotic resistance, thus should be avoided.
ABSTRACT
Aims: Pseudomonas aeruginosa is a drug resistance opportunistic bacterium. Biofilm formation is key factor for survival of P. aeruginosa in various environments. Polysaccharides may be involved in biofilm formation. The purpose of this study was to evaluate antimicrobial and anti-biofilm activities of seven plant extracts with known alpha-glucosidase inhibitory activities on different strains of P. aeruginosa. Methodology and results: Plants were extracted with methanol by the maceration method. Antimicrobial activities were determined by agar dilution and by growth yield as measured by OD560nm of the Luria Bertani broth (LB) culture with or without extracts. In agar dilution method, extracts of Quercus infectoria inhibited the growth of all, while Myrtus communis extract inhibited the growth of 3 out of 8 bacterial strains with minimum inhibitory concentration (MIC) of 1000 μg/mL. All extracts significantly (p≤0.003) reduced growth rate of the bacteria in comparison with the control without extracts in LB broth at sub-MIC concentrations (500 μg/mL). All plant extracts significantly (p≤0.003) reduced biofilm formation compared to the controls. Glycyrrhiza glabra and Q. infectoria had the highest anti-biofilm activities. No correlation between the alpha-glucosidase inhibitory activity with growth or the intensity of biofilm formation was found. Conclusion, significance and impact of study: Extracts of Q. infectoria and M. communis had the most antimicrobial, while Q. infectoria and G. glabra had the highest anti-biofilm activities. All plant extracts had anti-biofilm activities with marginal effect on growth, suggesting that the mechanisms of these activities are unrelated to static or cidal effects. Further work to understand the relation between antimicrobial and biofilm formation is needed for development of new means to fight the infectious caused by this bacterium in future.
