High prevalence of encoding RhoA-targeting toxin in clinical isolates of Staphylococcus aureus

Description

Staphylococcus aureus, a major causative agent of human infection, produces a large array of virulence factors, including various toxins. Among them, the host RhoA GTPase ADP-ribosylating EDIN toxins are considered as potential virulence factors. Using the polymerase chain reaction (PCR) assay, we analyzed the virulence profile of 256 isolates from various clinical sites of infections. We developed specific primers to detect the three isoforms of -encoding genes. We found a prevalence of 14% (36 bacteria) of -encoding genes among these clinical isolates. Strikingly, we found that 90% of all -bearing isolates carried the type-C allele. Both the types and the profile of virulence factors of these -positive isolates are highly variable. Notably, we show for the first time that -positive isolates were more frequently recovered from deep-seated infections than other types of infections. Our present work, thus, strongly suggests that the presence of is a risk factor of dissemination in tissues and, thus, represents a predictive marker for a pejorative evolution of staphylococcal infections.

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