Survival of leptospires in commercial blood culture systems revisited

Aim—To assess the ability of commercial blood culture systems to maintain leptospires. Methods—Nine different commercial blood culture bottles were compared for their ability to maintain four leptospiral strains at two temperatures, 30°C and 37°C. Bottles were subcultured at 48 hours, and one, two, three, and four week intervals and examined microscopically for the presence of viable leptospires. Results—The results were comparable with those of an earlier study, which showed that different commercial blood culture systems varied in their ability to maintain leptospires. Conclusions—No single factor appears to influence the viability of leptospires in blood culture systems. In general, the combination of an aerobic blood culture and an incubation temperature of 30°C enhances the viability of leptospires, and hence would increase the chances of their subsequent isolation from suspected cases of leptospiraemia.