Performance of Selected Chemical Compounds in Eliciting Feeding of Asian Buffalo Leech, Hirudinaria manillensis

Preventing infective complications following leech therapy: elimination of symbiotic Aeromonas spp. from the intestine of Hirudo verbana using antibiotic feeding

BACKGROUND

Hirudotherapy is often used successfully in modern medicine, especially in plastic and reconstructive surgery. However, Aeromonas infections are the most common complications of post-operative leech application. Hence, prophylactic antibiotic administration is recommended before and during leech therapy. It has been confirmed that patient safety and achieving the desired therapeutic effect depend mainly on the microbiologic purity of the animals used. The aims of this study were to find a safe and practical way to eradicate symbiotic Aeromonas spp. occuring in the intestine of Hirudo verbana.

METHODS

Leeches were fed artificially with 1.5 mL of sterile defibrinated sheep blood supplemented with ciprofloxacin (CIP) or cefotaxime (CTX), at bacteriostatic concentrations of 0.2 mcg/mL or 1.5 mcg/mL, and bactericidal concentrations of 20 mcg/mL or 50 mcg/mL, respectively. Bacteria were isolated from the leech intestines before and after feeding at different time intervals: 1, 7, 14, 21, and 28 d.

RESULTS

Biochemical identification of bacterial isolates from water samples and intestines of H. verbana using the API-NE20 test showed that A. veronii biovar sobria was predominant. Bacteria belonging to the genus Aeromonas were detected in all control leeches. The results showed that optimum eradication of bacteria from leech intestines was obtained using 20 mcg/mL of CIP and 50 mcg/mL of CTX, which decreased the number of Aeromonas spp. to undetectable levels for two weeks after feeding in all treated leeches. A statistically significant reduction in the number of bacterial colonies (p<0.0001) was observed in leeches treated with bacteriostatic concentrations of CIP or CTX; no bacterial growth was found on the plates after only seven days of feeding with antibiotics. All water samples in which the leeches were kept before treatment were contaminated with Aeromonas spp., whereas these samples were negative after antibiotic feeding of animals.

CONCLUSIONS

All leeches were ready to take a blood meal after treatment, suggesting the possibility of using ciprofloxacin-treated or cefotaxime-treated leeches instead of chemoprophylaxis in patients undergoing hirudotherapy.

Morphological and genetic variations of the freshwater leech, Hirudinaria spp., in Peninsular Malaysia

In this study the genetic diversity of local freshwater leeches (Hirudinaria spp.) was inferred using mtDNA COI gene analysis and compared with the gross external variations of 26 freshwater leech specimens obtained from the wild and leech farms. Based on a neighbor-joining tree generated from 516 COI base sequences, four distinct clades of Hirudinaria were seen with interspecific genetic divergence in the range of 7.6-14.5%. The external morphological variations based on the presence of stripes, location of gonopores, and anus separated the samples into four morphologically distinct groups matching the four clades obtained from the molecular data. Two black stripes at the ventral region were observed only in specimens found clustered with clades that contained the GenBank-reported H. manillensis, whereas the brown or dark green coloration without stripes on the ventral region was seen in samples that clustered with H. javanica and H. bpling clades.

Phylogenetic placement of a new species of Asian buffalo leech (Arhynchobdellida:Hirudinidae), and confirmation of human-mediated dispersal of a congener to the Caribbean

A new species of the genus Hirudinaria from Thailand is distinguished from its congeners by the dorsal colour pattern and reproductive structures. Scanning electron microscopy provided novel information on the jaw morphology of Hirudinaria bpling, sp. nov. and also of the previously described Hirudinaria manillensis. During the study, the genus name Hirudinaria in reference to leeches was found to be a homonym and, in this case, precedence is reversed. Phylogenetic analyses based on the nuclear genes 18S rDNA and 28S rDNA as well as the mitochondrial genes 12S rDNA and cytochrome c oxidase I, supported the new species as nested within the monophyletic genus Hirudinaria. Two individuals from the Caribbean, nominally identified as H. manillensis, included in the phylogenetic analyses were strongly supported as members of that species.