Background: Community acquired methicillin-resistant
Staphylococcus aureus (CA-MRSA) is a major global problem. This study attempted
to investigate the prevalence of nasal carriage of Staphylococcus aureus and
methicillin-resistant Staphylococcus aureus (MRSA) strains among 360 healthy
university students at An-Najah National University, Palestine. For the purpose
of comparing the staphylococcal cassette chromosome methicillin resistant
determinant (SCCmec) type of MRSA, 46 clinical MRSA isolates were also included
in this study.
Methods: Susceptibility testing was performed by the disc diffusion method. The
genetic association of MRSA isolates was investigated by SCCmec typing. A
selected number of isolates were also used to amplify and sequence mecA. Results Nasal carriage of S aureus was found in 86 of
360 students (24%). MRSA accounted for 9% of S aureus isolates. All 86 strains
of S aureus were sensitive to vancomycin. Resistance to penicillin G,
amoxicillin/clavulanic acid, ciprofloxacin, erythromycin, and clindamycin was
found in 98%, 93%, 33%, 23%, and 12% of the isolates, respectively. Resistance
rates of the MRSA isolates were as follows: 100% resistant to penicillin G and
amoxicillin/clavulanic acid, 96% to ethromycin, 52% to clindamycin, and 48% to
ciprofloxacin. No vancomycin-resistant isolates were identified. In our study,
nearly half (52%) of the MRSA isolates belonged to SCCmec types IVa and V.
However, SCCmec types II and III are represented by 48%, whereas SCCmec type I
was completely absent.
Conclusion: The findings of this study indicate the existence of SCCmec type
IVa in both student nasal carriers and health care settings. This emphasizes
the need for implementation of a revised set of control measures in both
settings. Moreover, the rational prescription of appropriate antibiotics should
also be considered.