Prevalence of feline bartonellosis and multilocus sequence typing of Bartonella henselae isolates in urban stray cats living in Milan, Italy

Abstract

Cat scratch disease is a worldwide zoonosis caused predominatly by Bartonella henselae and in a lesser extent by B. clarridgeiae. Cats are the natural reservoir and vectors for B. henselae and B. clarridgeiae infections in humans. Genetic heterogeneity of B. henselae strains has been reported and multiple sequence types (STs) have been identified by the use of multilocus sequence typing (MLST). Particular sequence types have been more frequently associated with zoonosis than others. The aim of this study was to evaluate the prevalence of B. henselae and B. clarridgeiae infection in stray cats from Milan, Italy and to explore the genotypes of the B. henselae population for the evaluation of the potential risk of transmission to humans. Whole blood samples collected from 89 stray cats were cultured and analyzed by PCR. Sequence types of the feline B. henselae isolates were delineated using MLST. Bartonella henselae was detected in four (4.5%) cats and B. clarridgeiae was detected in one (1.1%) cat by PCR on blood samples. Coinfection by B. henselae type I and type II was identified in one cat. Four B. henselae isolates were cultured and were characterized as ST1 (2/4), ST5 (1/4) and ST8 (1/4), that are more commonly regarded as human associated or zoonosis associated STs. Typical feline associated B. henselae STs were not observed. Despite the low prevalence of B. henselae infection in stray cats from Milan, further investigation are needed to assess the risk for human health