Bacterial Flora of Hirudo medicinalis and Their Antibiotic Sensitivities in the Middle Black Sea Region, Turkey

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.

Culture-Independent Characterization of the Digestive-Tract Microbiota of the Medicinal Leech Reveals a Tripartite Symbiosis

“…Subsequent studies supported the presence of one dominant microbe, an Aeromonas species which was consistently present in medicinal leeches, but disagreed in two aspects, i.e., the identity of the Aeromonas species and the presence of other microbes in the leech midgut (11,12,14,29). Case reports identified Aeromonas hydrophila infections associated with the clinical use of medicinal leeches, but these studies often used commercial phenotypic tests that do not accurately identify Aeromonas to the species level (1,7,29).…”

“…A second controversial point has been the complexity of the midgut microbiota. A few studies implementing nonquantitative approaches reported the presence of additional bacterial species in the midgut (11), while other studies reported only Aeromonas spp. (14).…”

Spatial and Temporal Population Dynamics of a Naturally Occurring Two-Species Microbial Community inside the Digestive Tract of the Medicinal Leech

“…From the leech crop, researchers repeatedly isolated a pure culture of an Aeromonas species which we identified as Aeromonas veronii bv. sobria (␥-Proteobacteria, Aeromonadaceae) and had reported that only this bacterium inhabits the leech digestive tract (11,12,15,29). Recently, a PCR-based approach discovered the presence of a second symbiont, an "unculturable" Rikenella-like bacterium (clone PW3, with an 89.7% 16S rRNA gene identity to Rikenella microfusus [Bacteroidetes, Rikenellaceae]), in the crop (42).…”

An overview of leech and its therapeutic applications

“…In contrary, a study performed by Eroglu and colleagues which implemented a non-quantitative approach, reported the presence of additional bacterial species in the midgut, besides Aeromonas sp [69].…”