Nasal screening and survey of pre-clinical medical students from Malaysia for nasal carriage of coagulase positive MRSA and rate of nasal colonization with Staphylococcus species

摘要

Background: MRSA has long been implicated in the spread of nosocomial and community acquired infections which pose a threat for the emergence of carriers among the community and hospitals. This study was aimed at screening for methicillin resistant Staphylococcus aureus (MRSA) in students hailing from Malaysia, and characterizing the rate of carrier state along with nasal colonization with Staphylococcus species, among the different ethnicities of pre-clinical medical students before their entry into the clinical phase of their study. Methods: 157 students were involved in the study. Samples were collected from the anterior nares of student volunteers. Biochemical tests were done to isolate Staphylococcus aureus. Species confirmation for Staphylococcus aurues was done using the tube coagualse test and the DNase test. Coagualse positive Staphylococci were subjected to oxacillin agar screen method to screen for MRSA.Results: Out of 157 specimens, Staphylococcus species were isolated from 156 (99.3%) specimens, and one specimen showed no isolation of Staphylococcus species; 37 (23.7%) were Coagulase positive Staphylococcus aureus (CoPS), and 119 (76.2%) were Coagualse negative Staphylococcus species (CoNS). Of the total of 37 isolates of Coagualse positive Staphylococcus aureus, none were found to be resistant to methicillin (0%). All the 37 (100%) strains of CoPS isolated were methicillin susceptible Staphylococcus aureus (MSSA). The nasal carriage of CoPS among ethnic student communities were observed to be 22 (34.3%) in the Chinese; followed by Indians 12 (16.0%), and Malay 3 (17.6%).Conclusions: The study revealed that out of the total specimens collected from student volunteers, none were carriers for MRSA. The highest percentage of nasal carriage for CoPS among the three main ethnicities of Malaysia was observed to be among the Chinese. All CoPS obtained were MSSA, while the highest rate of nasal colonisation with CoNS was observed in the Indian community. Screening should be made an essential protocol in order to assess and curb the in-flux of carrier transmitted drug resistant strains of Staphylococci from the community to the hospital setting.