Molecular Surveillance of Yersinia pestis from Stray Dogs and Cats and their Fleas in Algiers

Abstract

In recent years, plague has re-emerged in several countries around the world and remains endemic in some regions. In a natural environment, and in contact with rodents and their fleas, stray carnivores are most at risk of catching the disease and maintaining the spread of the bacillus. The objective of this study is to demonstrate the presence or absence of Yersinia pestis in stray dogs and cats in the Algiers region by molecular methods and thus contribute their role in epidemiology of this disease. Molecular research of Yersinia pestis has also been conducted on fleas from these carnivores. Preliminary identification of ectoparasites to genus and species level was performed. Real-time polymerase chain reaction targeting Yersinia pestis pla gene was used to survey the plague agent in fleas and carnivores captured as stray animals in Algiers (Algeria). Positive qPCR results were tested by PCR sequencing using glpD gene. Among 327 fleas captured from 107 dogs and 365 fleas from 140 cats, prevalence of Ctenocephalides felis was higher in cats (86,96%), whereas that of Ctenocephalides canis and Xenopsylla cheopis was higher in dogs (90,57% and 92,63% respectively). While internal and external PCR positive controls were positive, none of the 107 dogs spleen and 140 cat spleens and none of the 256 analyzed fleas were positive for Y. pestis. These results suggest that stray cats and dogs are unlikely sources for plague in Algeria contrary to that has been reported in other plague-endemic countries. This observation illustrates that plague epidemiological chain varies from one region to another