Evidence of Sharing of Klebsiella pneumoniae Strains between Healthy Companion Animals and Cohabiting Humans.

This study aimed to characterize the fecal colonization and sharing of Klebsiella pneumoniae strains between companion animals and humans living in close contact. Fecal samples were collected from 50 healthy participants (24 humans, 18 dogs, and 8 cats) belonging to 18 households. Samples were plated onto MacConkey agar (MCK) plates with and without cefotaxime or meropenem supplementation. Up to five K. pneumoniae colonies per participant were compared by pulsed-field gel electrophoresis (PFGE) after XbaI restriction. K. pneumoniae strains with unique pulse types from each participant were characterized for antimicrobial susceptibility, virulence genes, and multilocus sequence type (MLST). Fecal K. pneumoniae pulse types were compared to those of clinical K. pneumoniae strains from animal and human patients with urinary tract infections (n = 104). K. pneumoniae colonization was detected in nonsupplemented MCK in around 38% of dogs (n = 7) and humans (n = 9). K. pneumoniae strains isolated from dogs belonged to sequence type 17 (ST17), ST188, ST252, ST281, ST423, ST1093, ST1241, ST3398, and ST3399. None of the K. pneumoniae strains were multidrug resistant or hypervirulent. Two households included multiple colonized participants. Notably, two colonized dogs within household 15 (H15) shared a strain each (ST252 and ST1241) with one coliving human. One dog from H16 shared one PFGE-undistinguishable K. pneumoniae ST17 strain with two humans from different households; however, the antimicrobial susceptibility phenotypes of these three strains differed. Two main virulence genotypes were detected, namely fimH-1 mrkD ycfM entB kfu and fimH-1 mrkD ycfM entB kpn These results highlight the potential role of dogs as a reservoir of K. pneumoniae to humans and vice versa. Furthermore, to our best knowledge, this is the first report of healthy humans and dogs sharing K. pneumoniae strains that were undistinguishable by PFGE/MLST.

Klebsiella pneumoniae causing urinary tract infections in companion animals and humans: population structure, antimicrobial resistance and virulence genes.

OBJECTIVES: To characterize the population structure, antimicrobial resistance and virulence genes of Klebsiella spp. isolated from dogs, cats and humans with urinary tract infections (UTIs). METHODS: Klebsiella spp. from companion animals (n = 27) and humans (n = 77) with UTI were tested by the disc diffusion method against 29 antimicrobials. Resistant/intermediate isolates were tested by PCR for 16 resistance genes. Seven virulence genes were screened for by PCR. All Klebsiella pneumoniae from companion animals and third-generation cephalosporin (3GC)-resistant isolates from humans were typed by MLST. All Klebsiella spp. were compared after PFGE XbaI macro-restriction using Dice/UPGMA with 1.5% tolerance. RESULTS: bla CTX-M-15 was detected in >80% of 3GC-resistant strains. K. pneumoniae high-risk clonal lineage ST15 predominated in companion animal isolates (60%, n = 15/25). Most companion animal ST15 K. pneumoniae belonged to two PFGE clusters (C4, C5) that also included human strains. Companion animal and human ST15-CTX-M-15 K. pneumoniae shared a fimH-1/mrkD/entB/ycfM/kfu virulence profile, with a few (n = 4) also harbouring the yersiniabactin siderophore-encoding genes. The hospital-adapted ST11 K. pneumoniae clonal lineage was detected in a cat (n = 1) and a human (n = 1); both were MDR, had 81.1% Dice/UPGMA similarity and shared several virulence and resistance genes. Two 3GC-resistant ST348 strains with 86.7% Dice/UPGMA similarity were isolated from a cat and a human. CONCLUSIONS: Companion animals with UTI become infected with high-risk K. pneumoniae clonal lineages harbouring resistance and virulence genes similar to those detected in strains from humans. The ST15-CTX-M-15 K. pneumoniae clonal lineage was disseminated in companion animals with UTI. Caution must be applied by companion animal caretakers to avoid the spread of K. pneumoniae high-risk clonal lineages.

Clonal relatedness of Proteus mirabilis strains causing urinary tract infections in companion animals and humans.

Proteus mirabilis is a major cause of urinary tract infection (UTI) in humans and companion animals. This study aimed to evaluate the antimicrobial resistance, virulence and clonal relatedness of P. mirabilis isolated from dogs, cats and humans with UTI. P. mirabilis isolated from companion animals (N = 107) and humans (N = 76) with UTI were compared by PFGE analysis after overnight NotI macro-restriction using Dice/UPGMA with a 1.5% tolerance. Strains were characterized for antimicrobial resistance by disk diffusion. Twenty-four resistance genes and four virulence genes were screened by PCR. Thirty-nine clusters (similarity >80%) and 73 single pulse-types were detected. Nine clusters included P. mirabilis isolated from community and hospital patients, including strains with 100% similarity. A high number of clusters (43.6%, n = 17/39) included strains from companion animals and humans. Similarity between some companion animal and human strains varied between 80-100%. One strain from a dog was 100% similar to one human community-acquired P. mirabilis. One P. mirabilis from a cat was found to be 94.7% and 92.4% similar to community and hospital patient strains, respectively. P. mirabilis CMY-2-producers did not cluster all together. Nevertheless, cluster C36 included five P. mirabilis from companion animals (similarity 85.8%-95.7%), of which, four (80%) were multidrug-resistant CMY-2-producers. This study shows that companion animals and humans become infected with closely related P. mirabilis strains. The high number of clusters containing companion animals and human strains points to the zoonotic nature of P. mirabilis. These results underline the potential role of companion animals as reservoirs and in the dissemination of uropathogenic P. mirabilis to humans and vice versa.

Increase in antimicrobial resistance and emergence of major international high-risk clonal lineages in dogs and cats with urinary tract infection: 16 year retrospective study.

Objectives: To evaluate temporal trends in antimicrobial resistance, over 16 years, in bacteria isolated from dogs and cats with urinary tract infection (UTI) and the clonal lineages of bacteria harbouring critical antimicrobial resistance mechanisms. Methods: Antimicrobial susceptibility testing was conducted for 948 bacteria isolated from dogs and cats with UTI (1999-2014). Resistance mechanisms were detected by PCR, namely ESBL/AmpC in third-generation cephalosporin (3GC)-resistant Escherichia coli and Proteus mirabilis, mecA in methicillin-resistant staphylococci, and aac(6')-Ieaph(2″)-Ia and aph(2″)-1d in high-level gentamicin-resistant (HLGR) enterococci. Resistant bacteria were typed by MLST, and temporal trends in E. coli and Enterobacteriaceae antimicrobial resistance were determined by logistic regression. Results: Enterobacteriaceae had a significant temporal increase in resistance to amoxicillin/clavulanate, 3GCs, trimethoprim/sulfamethoxazole, fluoroquinolones, gentamicin and tetracycline (P < 0.001). An increase in MDR was also detected (P < 0.0001). 3GC resistance was mainly caused by the presence of blaCTX-M-15 and blaCMY-2 in E. coli and the presence of blaCMY-2 in P. mirabilis. Two major 3GC-resistant E. coli clonal lineages were detected: O25b:H4-B2-ST131 and ST648. The mecA gene was detected in 9.2% (n = 11/119) of Staphylococcus spp., including MRSA clonal complex (CC) 5 (n = 2) and methicillin-resistant Staphylococcus epidermidis CC5 (n = 4). A temporal increase in MDR methicillin-resistant Staphylococcus pseudintermedius was detected (P = 0.0069). Some ampicillin-resistant and/or HLGR Enterococcus spp. were found to belong to hospital-adapted CCs, namely Enterococcus faecalis ST6-CC6 (n = 1) and Enterococcus faecium CC17 (n = 8). Conclusions: The temporal increase in antimicrobial resistance and in MDR bacteria causing UTI in dogs and cats creates important therapeutic limitations in veterinary medicine. Furthermore, the detection of MDR high-risk clonal lineages raises public health concerns since companion animals with UTI may contribute to the spread of such bacteria.