Genomic characterization of virulence toxins of multidrug resistant Staphylococcus species isolated from the nasal passages of students of medicine

Abstract

Nasal carriage of Staphylococcus aureus/Methicillin-resistant Staphylococcus aureus (S. aureus/MRSA) poses a major risk for the transmission and infection of this pathogen especially in hospital setting. The new emerging of multidrug resistant coagulase negative staphylococci is another problem of concern. The main objective of this study was to investigate the colonization of S. aureus/MRSA along with multidrug resistant Staphylococcus species among healthy individuals students of Faculty of Medicine/ University of Kufa and to determine their susceptibility patterns to common antibiotics and virulence genes. A total of 145 medicine students have been volunteered and nasal swabs were collected from all apparently healthy students. Samples were cultured on selective media for proper identification of S. aureus. The rate of nasal colonization with multidrug resistant Staphylococcus strains was 8.28%. higher rate was recorded by females comparing to males 75% and 25% respectively with a male to female ratio=1:3. MRSA recorded the highest rate 6 (4.14%) followed by S. heamolyticus 5 (3.44%) and the least S.warnni 1 (0.68%). All Staphylococcus isolates were resist to Penicillin 12 (100 %). Oxacillin 12 (93.33%) Ceftizoxime 10 (83.33%) Ciprofloxacin 2 (16.66%) Cefoxitin 12 (100%) Amoxicillin 12 (100%) Clarithromycin 2(16.66%) Amoxicillin-clavulanic acid 2(16.66%). Monoplex PCR results and Genotypic characterization for the genes responsible for antibiotic resistance (MecA ) and the Panton-Valentine Leukocidin revealed that all the isolated strains 12 (100%) have those genes including the non-aureus staphylococci. Results revealed that our students were carriers not for MRSA but also of multidrug resistant coagulase negative Staphylococci, these results emphasized the necessity of an annual structured survey of such cases among healthcare providers including undergraduate students to control spreading of resistant strains.