The high cross-transmission in methicillin resistant Staphylococcus aureus between healthy and patient communities

Methicillin-resistant Staphylococcus aureus (MRSA) is one of the main causes of high mor- tality and morbidity in hospitals. This study was aimed to examine virulence factors, molecular typing, and the antibiotic resistance pattern of MRSA isolates in hemodialysis patients and healthy communities.

Total of 231 and 400 nasal samples were obtained from hemodialysis patients and healthy com- munities, respectively. Virulence factors profile was examined in two groups by PCR reaction. Enterobacterial Repetitive Intergenic Consensus (ERIC-PCR) was used as a molecular typing approach.

Overall, 35.49% (82/231) of hemodialysis patients were positive for S. aureus, and 47.56% (39/82) of isolates were positive for mecA. In a healthy community, 15% (60/400) of samples were positive for S. aureus, and 36.66% (22/60) were positive for mecA. The frequency of MDR was significantly higher in patients group (p-value < 0.00001). The frequency of pvl (p.value = 0.003932, P<0.05) and tsst-1 (p.value = 0.003173, p < .05) were significantly higher in patients group. The highest frequency virulence factors in healthy individuals were related to hla (68.33%, 41/60), hlb (53.33%, 32/60), and Acme/arcA (46.66%) genes. Two groups were clustered by the ERIC-PCR method into 7 clusters and 2 single isolate with a 0.74 similarity index. Based on the results, each cluster was combination with healthy and patient isolates.

Our findings indicate a notable variation in the frequency of virulence factors between S. aureus isolates ob- tained from dialysis patients and the healthy community.