Impact and Diversity of ESBL-Producing Klebsiella pneumoniae Recovered from Raw Chicken Meat Samples in Türkiye

Abstract

The interrelationship between human, animal and environmental sectors leads to the spread of antibiotic resistance due to selective pressures, evolutionary traits and genomic evolution. In particular, the frequent use of antibiotics in livestock inevitably influences the emergence of specific resistance determinants in human strains, associated with reduced treatment options in clinical therapy. In this study, ESBL-producing Klebsiella pneumoniae strains isolated from chicken meat samples were evaluated for public health implications in Türkiye. Whole-genome sequencing was used for genetic dissection and phylogenetic comparison of their genomes. The isolates were assigned to four MLST types (ST147, ST37, ST2747 and ST219); two of them were found to represent the ST147 clone associated with severe human infections worldwide. In addition to cephalosporins, high resistance levels to quinolones/fluoroquinolones were identified phenotypically, caused by acquired resistance genes and chromosomal point variations. One isolate was also found to carry the qacE∆1 efflux transporter gene, which confers tolerance to quaternary ammonium compounds. The detection of virulence genes (i.e., that coding for enterobactin) associated with the pathogenicity of K. pneumoniae suggests a public health impact. Thus, comprehensive information on the occurrence and impact of K. pneumoniae from livestock is needed to derive appropriate management strategies for consumer protection. In this study, it was shown that poultry meat serves as a reservoir of clinically emerging multidrug-resistant high-risk clones.

Keywords: K. pneumoniae; One Health; consumer protection; food; multidrug resistance; risk evaluation; zoonosis.

Figure 1

XbaI-PFGE dendrogram for K. pneumoniae isolates. The scale indicates the percentage of identity.

Figure 2

Organization of the independent genetic backgrounds comprising the (i) CTX-M-15, (ii) OXA-1 and (iii) SVH enzyme-encoding regions in the K. pneumoniae isolates. Arrows indicate the presence of the predicted coding sequences (CDS). Functional prediction of the gene products is indicated in the figure. DNA regions exhibiting sequence identity of >90% between the genomes are linked in grey.

Figure 3

Phylogenetic relationship between genome sequences of K. pneumoniae chicken meat isolates and genome sequences of isolates from human infections in Türkiye. Genomes clustering with reference sequences of the database are indicated with orange.