Approbation of the improved staining technique for trematode maritas during parasitological studies in domestic carnivores in the Lipetsk region

Abstract

The purpose of the research is to validate an optimized protocol for studying helminths using an improved staining method to improve the quality of diagnostics of trematodosis caused by representatives of the Opisthorchidae family. An additional objective was to study the prevalence of infection of definitive hosts within the identified focus of opisthorchiasis in the Lipetsk region.
Materials and methods. Liver samples from 10 cats and 5 dogs that died in the Sosna River area (Lipetsk region), where an opisthorchiasis focus had previously been identified, were examined. Helminthological dissection was performed using the Skryabin method. The isolated trematode metacercariae were stained using an improved, previously patented technique based on the method of B. V. Romashov et al. (2003), using Gooch crucibles to improve the quality and convenience of staining. Morphometric studies and species identification of trematodes were carried out. The level of infection was assessed using the indices of number, intensity and prevalence of infection.
Results and discussion. A higher prevalence of infection (60%) was found in cats compared to dogs (20%). Among cats, the dominant species was Pseudamphistomum truncatum (infection rate 20.1 ind.). Opisthorchis felineus and Metorchis bilis were also identified. P. truncatum (infection rate 60 ind.) and O. felineus were identified in the infected dog. The improved staining method reduced the examination time and improved the quality of visualization of trematode morphology. The results obtained indicate a wide distribution of P. truncatum among animals of the Lipetsk region and emphasize the significant role of domestic cats as the main reservoirs of infection.