First Microbiological and Molecular Identification of Rhodococcus equi in Feces of Nondiarrheic Cats

Abstract EN

Rhodococcus equi is responsible for infections in multiple-host animals.

In humans, the prevalence of rhodococcus has increased worldwide and represents an emergent risk.

R.

equi is a soil-borne opportunistic bacterium isolated from feces of a wide variety of domestic species, except cats; thus, there is no known potential risk of its transmission from humans.

Here, the mono- and cooccurrence of Rhodococcus equi and other bacteria and selected virulence markers were investigated in feces of nondiarrheic cats from urban (n=100) and rural (n=100) areas.

Seven (7/200=3.5%) R.

equi isolates were recovered in ceftazidime, novobiocin, and cycloheximide (CAZ-NB) selective media, exclusively of cats from three distinct farms (p=0.01), and these cats had a history of contact with horses and their environment (p=0.0002).

None of the R.

equi isolates harbored hosted-adapted plasmid types associated with virulence (pVAPA, pVAPB, and pVAPN).

One hundred seventy-five E.

coli isolates were identified, and 23 atypical enteropathogenic E.

coli (aEPEC), 1 STEC (Shiga-toxin producing E.

coli), and 1 EAEC (enteroaggregative E.

coli) were detected.

Eighty-six C.

perfringens type A isolates were identified, and beta-2 and enterotoxin were detected in 21 and 1 isolates, respectively.

Five C.

difficile isolates were identified, one of which was toxigenic and ribotype 106.

The main cooccurring isolates in cats from urban areas were E.

coli and C.

perfringens A (26/100=26%), E.

coli and C.

perfringens type A cpb2+ (8/100=8%), and aEPEC (eae+/escN+) and C.

perfringens type A (5/100=5%).

In cats from farms, the main cooccurring isolates were E.

coli and C.

perfringens type A (21/100=21%), E.

coli and C.

perfringens type A cpb2+ 8/100=8%), and E.

coli and R.

equi (4/100=4%).

We identified, for the first time, R.

equi in nondiarrheic cats, a finding that represents a public health issue because rhodococcus has been reported in both immunosuppressed and immunocompetent humans, particularly people living with HIV/AIDS.