Fatal Infection in an Alpaca (Vicugna pacos) Caused by Pathogenic Rhodococcus equi

Abstract

Rhodococcus (R.) equi is a pathogen primarily known for infections in equine foals, but is also present in numerous livestock species including New World camelids. Moreover, R. equi is considered an emerging zoonotic pathogen. In this report, we describe in detail a fatal rhodococcal infection in an alpaca (Vicugna pacos), to our best knowledge, for the first time. The alpaca died due to a septicemic course of an R. equi infection resulting in emaciation and severe lesions including pyogranulomas in the lungs and pericardial effusion. The onset of the infection was presumably caused by aspiration pneumonia. R. equi could be isolated from the pyogranulomas in the lung and unequivocally identified by MALDI-TOF MS analysis and partial sequencing of the 16S rRNA gene, the 16S-23S internal transcribed spacer (ITS) region and the rpoB gene. The isolate proved to possess the vapA gene in accordance with tested isolates originating from the lungs of infected horses. The R. equi isolates revealed low minimal inhibitory concentrations (MIC values) for doxycycline, erythromycin, gentamycin, neomycin, rifampicin, trimethoprim/sulfamethoxazole, tetracycline and vancomycin in antibiotic susceptibility testing. Investigations on the cause of bacterial, especially fatal, septicemic infections in alpacas are essential for adequately addressing the requirements for health and welfare issues of this New World camelid species. Furthermore, the zoonotic potential of R. equi has to be considered with regard to the One Health approach.

Commonality of Virulence-Promoting Function in Rhodococcus equi Virulence Associated Proteins (Vaps)

“…Rhodococcus equi (R. equi) is a soil-dwelling pathogenic actinomycete that causes pulmonary and extrapulmonary pyogranulomatous infections in a variety of animal species [1]. R. equi infects various animal hosts, including pigs, sheep, cattle, goats [2], and camelids [3] but is most frequently associated with life-threatening bronchopneumonial disease in foals [4]. R. equi is prevalent on horse-breeding farms worldwide and has a significant economic impact on the horse-breeding industry [5].…”

Comparison of automatic methods MALDI-TOF, VITEK2 and manual methods for the identification of intestinal microbial communities on the example of samples from alpacas (Vicugna pacos)

“…In research conducted by Guerrero-Olmos et al (11) the most prevalent bacterial genus in the alpaca gut microbiome was Enterococcus and the dominant species was Enterococcus hirae (82%), followed by other members of the genus which were neither Enterococcus faecalis nor Enterococcus faecium (11). The latest reports concern the profile of faecal bacterial microbiota, characterised by sequencing of 16S rRNA amplicons or the isolation of specific pathogenic microorganisms (5,29). However, there is a lack of research based on the isolation of the components of a living gut bacterial community in alpacas, which is highly variable impacted by the nutrition and health status of the animal (4,28).…”