Circulation and transmission of methicillin-resistant Staphylococcus aureus among college students in Malaysia (cell phones as reservoir)

Background: Methicillin-resistant Staphylococcus aureus (MRSA) is a nosocomial pathogen of increasing risk to man.

Objective: We determined the risk of using cell phones as silent and underestimated tools for spreading MRSA in community.

Methods: One hundred swabs of cell phones were collected from college students in Malaysia. A series of identification and differentiating tests were conducted for the precise identification of MRSA bacteria. Moreover, this study compared the efficacy of the different identification tests with gold standard, PCR assay. The tests used were tube coagulase, DNase agar test, antibiogram, several routine biochemical identification tests, and PCR assays. PCR assay used specific primers for resistance or ID -related genes: mecA, ermA, ermB, ermC, msrA, linA, femA, and nuc genes.

Results: One hundred fifty bacterial isolates were collected from college students’ cell phones, non-PCR assays of identification and resistance detection revealed presence and spread of MRSA in cell phones of 14 college students. PCR-amplification of the nuc gene was used as a baseline test to detect Staphylococcus aureus. Seven isolates (50%) were detected as Staphylococcus aureus with the presence of nuc gene, and the remaining seven isolates (50%) were negative for nuc gene. However, of the seven positive nuc gene isolates, six isolates (6/14; 42.9%) were positive for mecA gene, making them MRSA. Using PCR as gold standard, the specificity and the sensitivity of antibiogram test in the detection of methicillin resistance was only 55.6% and 40%, respectively. Most of the MRSA carriers were found to study in the field of Science (33.3%) and Education (33.3%).

Conclusions: Cell phones proved to be silent tool for transferring MRSA in the community of college students in South East Asia. Moreover, PCR assay for identification of S. aureus and resistance evaluation for MRSA is superior when compared to other conventional methods.