Saleh. H. Baiu¹, Nadia. E. AL-Abdli^2,

Background and Purpose: Data on the carriage rate and antibiotic sensitivity pattern of Staphylococcus aureus strains prevalent in the community are not available for many developing countries including Libya. To estimate the extent of community S. aureus transmission, in particular methicillin-resistant S. aureus (MRSA), the prevalence of S. aureus nasal colonization in a population of healthy adults was determined. Factors associated with S. aureus nasal carriage and antibiotic sensitivity patterns of the isolates were also analyzed. Methods: A cross-sectional study involving 643 adults was conducted. Nasal swabs were examined for the presence of MRSA. Epidemiological information concerning risk factors for nasal carriage was also obtained. Antibiotic susceptibility testing was performed using the disk diffusion method according to the National Committee for Clinical Laboratory Standards guidelines. MRSA strains isolated were further subjected to Automated BD Phoenix. Results: Screening for suspected carriers of MRSA showed that most of the healthcare workers (technicians, nurses, and doctors) were asymptomatically MRSA-positive. S. aureus isolates were confirmed by various biochemical tests as per latest CLSI guidelines. Cefoxitin Disk Diffusion test was performed for the detection of methicillin resistance and antibiotic susceptibility was performed against different antibiotics as per CLSI guidelines. Statistical analyses showed that there was no significant relation between MRSA carriage and age and sex of the study population. The prevalence of MRSA nasal carriage was (21.4%) among HCWs, with some differences between hospitals, also prevalence of MRSA nasal carriage was (9.6%) among community. Hospital acquired MRSA were more susceptible to various antibiotics as compared to Community acquired MRSA. Conclusion: MRSA nasal colonization was found to be low outside of the health care environment.

Staphylococcus aureus, MRSA, health care workers, community