The dissemination of ESBL and carbapenemase-producing Klebsiella pneumoniae is a worldwide concern. Multidrug-resistant (MDR) K. pneumoniae UTIs in companion animals raise great concerns regarding their role as reservoirs and in the spread of such bacteria. The aim of this study was to evaluate the within-household sharing of ESBL-producing MDR K. pneumoniae from a UTI infected cat.

Antimicrobial susceptibility testing of the uropathogenic bacteria was conducted by microdilution methods according to CLSI and screening for the presence of CTX-M ESBL was performed by PCR and sequencing. Fecal samples from the infected cat (ICat) and co-habiting pets (cat-1, dog-1, dog-2) were collected for detection and quantification of colonization by the infection K. pneumoniae strain. Environment swabs from the animals' food/water bowls and bedding were also collected. Samples were serially diluted and cultured in MacConkey agar plates containing 1.5 µg/mL cefotaxime (CTX). Negative samples were grown in enrichment media prior to plating to detect low levels of colonization. When positive, up to five K. pneumoniae colonies were obtained for further analysis. Unique clones were resolved by PFGE-XbaI macro-restriction using Dice/UPGMA clustering analysis.

A cat with history of urolithiases underwent a subcutaneous ureteral bypass system (SUB) implantation. During SUB maintenance, a UTI by K. pneumoniae was diagnosed. The K. pneumoniae was a CTX-M-15 producer with MDR phenotype. Fecal samples from the infected cat (ICat) were positive for CTX-resistant K. pneumoniae. Samples from dog-1 and dog-2 prior and after ICat treatment were all negative, thus no colonization was detected. Regarding cat-1, only one sample collection was possible (during ICat treatment), yet it revealed a high fecal burden of CTX-resistant E. coli and K. pneumoniae. PFGE-XbaI analysis showed a similarity index of 100% between CTX-resistant K. pneumoniae from cat-1 feces and K. pneumoniae from ICat urine, thus proving the colonization/transfer. Furthermore, 100% similar CTX-resistant K. pneumoniae was also detected from the cat's bedding.

To our best knowledge, this is the first study reporting the sharing of MDR K. pneumoniae between infected and healthy pets from the same household. Same-species transfer of MDR K. pneumoniae was likely due to sharing of litterbox and bedding, thus special control measures should be implemented in these environments. The high colonization with 3GCr Enterobacteriaceae of the co-habiting healthy cat further increases the spread of MDR K. pneumoniae.

Disclosures

Disclosures to report
Acknowledgements: With financial support of CIISA and FCT through Project UID/CVT/00276/2013 and JPIAMR/0002/2016. AB and CM hold FCT PhD grants SFRH/BD/113142/2015 and SFRH/BD/77886/2011, respectively.