Isolation and characterisation of carbapenem-resistant Xanthomonas citri pv. mangiferaeindicae-like strain gir from the faecal material of giraffes.

The purpose of this study was to determine if giraffes (Giraffa camelopardalis) living in captivity at the Jacksonville Zoo and Gardens, Jacksonville, FL were colonised with carbapenem-resistant bacteria and, if found, to identify underlying genetic mechanisms contributing to a carbapenem-resistant phenotype. Faecal samples from seven giraffes were examined for carbapenem-resistant bacteria. Only one isolate (a Xanthomondaceae) was found to be carbapenem-resistant by antibiotic susceptibility testing. This isolate was selected for additional characterization, including whole genome sequencing (WGS). Based on average nucleotide identity, the bacterium was identified as Xanthomonas citri pv. mangiferaeindicae-like strain gir. Phenotypic carbapenemase tests and PCR for the most common carbapenemase genes produced negative results, suggesting that carbapenem resistance was mediated by another mechanism. Resistance gene profile analysis of WGS results confirmed these results. Among identified resistance genes, a chromosomal class A beta-lactamase with 71% identity to the penP beta-lactamase gene from Xanthomonas citri ssp. citri was identified, which could contribute to a carbapenem-resistant phenotype.

Analysis of the Microbial Diversity in the Fecal Material of Giraffes.

Using bacterial and fungal tag-encoded FLX-Titanium amplicon pyrosequencing, the microbiota of the fecal material of seven giraffes living in captivity at the Jacksonville Zoo and Gardens, Jacksonville, FL was investigated. In all samples, the most predominant bacterial phylum was the Firmicutes followed by Bacteroidetes. The most predominant fungi were members of the phylum Ascomycota followed by Neocallimastigomycota in five of seven samples. The reverse was true in the other two samples.