RESUMO
There is an increasing incidence in the number of community-acquired methicillin-resistant Staphylococcus aureus (MRSA) infections in the United States. Skin and soft tissue infections caused by MRSA are often perceived as being preceded by a spider bite. Several possibilities exist to explain this phenomenon, including 1) spiders introduce MRSA into the bite wound and thereby serve as a potential vehicle or vector for MRSA; 2) MRSA colonization is an event secondary to the spider bite; and 3) the spider bite is a misguided way for patients or their physicians to explain the initial lesion of their skin or soft tissue infection. We hypothesized that if spiders were able to serve as vehicles or vectors for MRSA infections, they would be colonized with this pathogen. To test this hypothesis, we captured common household spiders and determined the patterns of normal microbial flora isolated from them. Spiders were collected from several homes by their occupants, photographed for identification, and cultured for external and internal microbial flora. Of > 100 spiders collected, none was found to carry Staphylococcus aureus or MRSA. Relatively low numbers of microbial flora were isolated, and only a single isolate with pathogenic potential in humans (Aeromonas spp.) was isolated. Common house spiders are unlikely to be a source of MRSA.
