Identification of Bacteria and Select Viruses Harbored by Medicinal Leeches (Hirudo verbana)

Leeches have been used to complement medical therapies for many years, however there is little data on the microorganisms they may harbor as part of their flora. The study aims were to (1) identify the presence of bacteria and (2) the presence of Hepatitis B and C viruses (HBV and HCV) in medicinal leeches using traditional bacteriological assays, Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF MS) and quantitative PCR (qPCR). Samples obtained from the body surface, intestine, and jaws from 10 Hirudo verbana leeches were aseptically cultured using traditional microbiological assays. Bacterial isolates were identified using the MALDI-TOF technique and the presence of HBV and HCV was analyzed using qPCR. The primary bacterium isolated from the sampled leeches were Aeromonas veronii (A. veronii) which was isolated from the jaws, gut and body surface of all leeches. Other bacteria isolated at a lower frequency from various parts were Chryseobacterium gleum, Ochrobactrum anthropi, Moraxella osloensis, Microbacterium oxydans, Kytococcus sedentarius, Rhizobium radiobacter, Staphylococcus hominis, Citrobacter and Bacillus. No anaerobic bacteria or hepatitis viruses were detected. Interestingly, some of the bacterial species identified in this study have been implicated in hospital acquired infections and are of particular risk to immunocompromised patients. The recovery of potential human pathogens from within medicinal leeches is a public health concern and consequently their use should be restricted and avoided in susceptible individuals or a prophylactic treatment should be applied.