Broth cultures yield vs traditional approach in the workup of infectious keratitis

To elucidate whether BACTEC Peds Plus F broth, usually used for culturing body fluids in paediatric departments, can be used for corneal cultures from cases with clinically suspected infectious keratitis, and to compare yields between this method and traditional methods (blood agar, chocolate agar, a fungal media, and swab transport media).

All cases with newly diagnosed, nonviral, clinically suspected infectious keratitis with no prior antibiotic therapy, were cultured both in the BACTEC Peds Plus F broth and the traditional method. McNemar's test was used for pairwise comparisons of the rates of positive growth between the two groups.

In total, 30 eyes were included in this study. The growth rates for the traditional method and the BACTEC broth were similar (50.0 and 53.33%, respectively, P=1.0). The overall growth rate for the two methods combined was 73.33%, which is 45.29% higher than the reported yield in the literature (average of 50.47%).

Our results show that BACTEC Peds Plus F broth can be used successfully in the work-up of clinically suspected infectious keratitis. The method has, apparently, several advantages over the 'Traditional method:' time-savings, as only one medium needs to be inoculated, transportation to the laboratory is simpler as there is no need for immediate incubation, and there is no need to keep and maintain a supply of fresh agar media. This method is especially suitable for office settings and remote clinics, but also can be used in hospital setting, as an adjunct, when available, to increase the growth yield.