Phenotypic and Genetic Characterization of Klebsiella pneumoniae Isolates from Wild Animals in Central Italy

Abstract

Despite Klebsiella pneumoniae being widely recognized as a nosocomial pathogen, there is a critical lack in defining its reservoirs and sources of infections. Most studies on risk factors have focused on multidrug-resistant (MDR) isolates and clinically-oriented questions. Over a two-year period, we sampled 131 wild animals including mammal and bird species from three regions of Central Italy. All typical colonies isolated from the analytical portions were confirmed by real-time PCR and identified by MALDI-TOF mass spectrometry (MALDI-TOF MS). All confirmed K. pneumoniae isolates were tested for antimicrobial susceptibility to 29 antimicrobials and subjected to whole genome sequencing. Typical colonies were detected in 17 samples (13%), which were identified as K. pneumoniae (n = 16) and as K. quasipneumoniae (n = 1) by MALDI-TOF MS. The antimicrobial susceptibility profile showed that all the isolates were resistant to β-lactams (ceftobiprole, cloxacillin, cefazolin) and tetracycline; resistance to ertapenem and trimethoprim was observed and nine out of 16 K. pneumoniae isolates (56.2%) were classified as MDR. Genomic characterization allowed the detection of fluoroquinolone resistance-associated efflux pumps, fosfomycin and β-lactamase resistance genes, and virulence genes in the overall dataset. The cluster analysis of two isolates detected from wild boar with available clinical genomes showed the closest similarity. This study highlights the link between humans, domestic animals, and wildlife, showing that the current knowledge on this ecological context is lacking and that the potential health risks are underestimated.

Prevalence of antimicrobial resistance and virulence genes in Klebsiella pneumoniae and Congenetic Raoultella Isolates from captive giant pandas

“…Chiaverini A et al isolated 16 K . pneumoniae strains from wild animals (15 mammals and one bird), of which 56.2% (9/16) were classified as MDRs, with rates of resistance to tetracycline, trimethoprim and β-lactams of 18.8%–100.0% [ 39 ]. The reason for the low isolation rates of MDR strains in this study may be because captive giant pandas do not live in groups so bacterial spread between individuals is low, or it may be because of their better habitat.…”

Prevalence and Phenotypic Antimicrobial Resistance among ESKAPE Bacteria and Enterobacterales Strains in Wild Birds

“…The prevalence we recorded was in line with the findings of other authors. In particular, Chiaverini et al [ 44 ] in a very recent study conducted in central Italy isolated from Pica Pica a strain of K. pneumoniae , which showed resistance to several antimicrobials. Similarly, Foti et al in 2017 [ 18 ] reported two strains of K. pneumoniae , isolated from cloacal samples of migratory birds in Italy, and exhibiting resistance to 14 molecules.…”

Multi-approach methods to predict cryptic carbapenem resistance mechanisms in Klebsiella pneumoniae detected in Central Italy

“…Kp isolates from wild animals were collected in the framework of regional plans of epidemiological surveillance and monitoring of diseases in wild fauna, in the frame of the national plan of surveillance of West Nile disease and Usutu for bird species ( Chiaverini et al, 2022 ). In food, food-producing environments, and feed, Kp isolates were detected during monitoring plans for foodborne pathogens.…”

“…Limited data are available on Kp isolates outside the clinical setting, but Rodrigues et al (2022) highlighted that transmission can occur between clinical settings and MDR strains from foods. Moreover, Chiaverini et al (2022) reported the presence of one MDR strain from a wild boar in Italy.…”