Indigenous bacterial flora of medicinal leeches and their susceptibilities to 15 antimicrobial agents.

Surface bacterial flora, as well as homogenates, of medical leeches, Hirudo medicinalis and Hirudinaria manillensis, were surveyed and the susceptibility of these isolates to 15 antimicrobial agents was examined. Aeromonas spp. were isolated from all leeches, and Pseudomonas fluorescens and other glucose-non-fermenting gram-negative rods (NF-GNR) were frequent isolates. Isolates were highly resistant to cephalosporins but susceptible to carbapenems, aminoglycosides and ofloxacin. The results indicate that prophylaxis with antimicrobial agents active against Aeromonas spp. and NF-GNR is necessary to avoid opportunist infections caused by indigenous leech flora during medical leech therapy on immunocompromised patients.