Extensive evaluation of fastidious anaerobic bacteria recovery from the Copan eSwab® transport system

Anaerobic infections are difficult to diagnose and treat, because of the often slow in vitro growth, the polymicrobial nature and the increasing antimicrobial resistance. Furthermore because of their fastidiousness, anaerobic bacteria often stay unrecognized in clinical practice. Clinical specimens potentially harboring these species require special handling to permit satisfactory recovery of these potential important pathogens. In a clinical setting, temporary storage and transportation to the laboratory are unavoidable before these specimens can be cultured. In the current study we expand the knowledge about the recovery of a wide range of clinically relevant anaerobic bacteria from an eSwab® container after different storage durations and temperatures. Our findings support the use of the eSwab® container as a relative short-term storage unit for anaerobic species. When stored at 2-4 °C immediately after inoculation, all anaerobic species (except for Clostridium clostridioforme) can be recovered from the liquid Amies medium until 1 day post-specimen collection. Because most samples in the clinical setting are processed in this time span, the eSwab® container is sufficiently capable of retaining viability in daily routine. However; because of inevitable centralization of clinical laboratories, adequate storage of these specimens for an extended period of time will be essential in the future. Therefore in certain cases, when viability is desired for longer periods (> 1 day), storage of the containers at 2-4 °C is certainly advisable.