American Society of Hirudotherapy

Bacterial flora of Hirudo medicinalis and their antibiotic sensitivities in the Middle Black Sea Region, Turkey

Microbiology article published in Annals of Plastic Surgery (2001)

Last Updated: June 18, 2026Reviewed by: ASH Editorial Board
Research article — evidence reviewArticle reference
Evidence: Preclinical (animal)Safety & Infection ControlEroglu C, Hokelek M, Guneren E, Esen S, Pekbay A, Uysal OA · Annals of plastic surgery, 2001

Abstract

The rate of infectious complications of leech therapy is almost 20% because Hirudo medicinalis has endosymbiotic bacteria. The aim of this study was to determine the bacterial flora of H. medicinalis and their antibiotic sensitivities in a region in Turkey. Sixteen adult leeches were collected in Middle Black Sea region, Turkey. They were rubbed onto blood agar plates directly under ether anesthesia to obtain surface cultures. They were then killed to obtain mouth and gut cultures. Culture swabs were applied to blood agar, eosin methylene blue agar, and ampicillin blood agar plates. Gut contents were applied to blood culture medium as well. Bacteria were isolated in 15 of 16 leech surfaces, in 7 of 16 mouths, and in 15 of 16 guts. Isolated bacteria were identified with Analytical Profile Index 32 E and Analytical Profile Index 20 NE (fermentative and nonfermentative respectively). Most common types of cultured bacteria were Aeromonas hydrophila (N = 25), Ochrobacter anthropi (N = 23), nonfermenting Gram-negative rods (N = 12), Acinetobacter lwoffi (N = 3), and A. sobria (N = 2) in 73 isolates. A standard disk diffusion test was performed on isolated bacteria. All isolates were 100% susceptible to ciprofloxacin, cefotaxime, ceftazidime, gentamicin, and trimethoprim/sulfamethoxazole. Because leeches are carriers of Aeromonas and other bacteria, appropriate antibiotic prophylaxis should be administrated to the patient who needs leech therapy. Antibacterial agents can be determined by the resistance pattern of the bacterial flora of regional H. medicinalis.

Abstract sourced from PubMed (NCBI) for the cited record. See the original publication for the authoritative version.

Publication typeJournal Article
Indexed MeSH termsAnimalsIntestinesLeechesMicrobial Sensitivity TestsMouthTurkey

Summary

Characterization of bacterial flora from 16 wild Hirudo medicinalis collected in the Middle Black Sea region of Turkey identified Aeromonas hydrophila, Ochrobacter anthropi, and other Gram-negative rods; all isolates susceptible to ciprofloxacin, cefotaxime, gentamicin, and trimethoprim/sulfamethoxazole.

Why This Matters for Hirudotherapy

This study examined the bacterial flora of 16 adult Hirudo medicinalis collected from the Middle Black Sea region of Turkey, culturing leech surfaces, mouths, and guts and identifying isolates using biochemical profiling. The most common bacteria were Aeromonas hydrophila, Ochrobacter anthropi, nonfermenting Gram-negative rods, Acinetobacter lwoffi, and A. sobria. Disk diffusion testing showed all isolates were 100% susceptible to ciprofloxacin, cefotaxime, ceftazidime, gentamicin, and trimethoprim/sulfamethoxazole. This is directly relevant to hirudotherapy safety, as infectious complications approach 20% and the authors recommend that antibiotic prophylaxis should be guided by the resistance patterns of regional leech bacterial flora. However, the study is limited to leeches from one Turkish region, used culture-dependent methods that may miss unculturable organisms, and the 16-leech sample is modest; resistance profiles may differ in leech populations from other geographic areas.

Citation

Bacterial flora of Hirudo medicinalis and their antibiotic sensitivities in the Middle Black Sea Region, Turkey.

Eroglu C, Hokelek M, Guneren E, Esen S, Pekbay A, Uysal OA · Annals of plastic surgery, 2001

Added to ASH library: May 26, 2026 · Site last updated: June 18, 2026

This website provides educational information and does not constitute medical advice, diagnosis, or treatment recommendations. Medicinal leech therapy carries clinically meaningful risks and should be performed only by qualified clinicians under institutionally approved protocols. FDA 510(k) clearance for medicinal leeches is limited to specific indications; investigational and off-label discussions are labeled accordingly. For patient-specific guidance, consult a qualified healthcare provider.