Emergence of Colistin and Carbapenem Resistance in Extended-Spectrum β-Lactamase Producing Klebsiella pneumoniae Isolated from Chickens and Humans in Egypt.

This study investigated the frequency of carbapenem and colistin resistance in ESBL-producing K. pneumoniae (ESBLK) isolates recovered from chickens and their environment, contact farm workers and hospitalized patients in Egypt. Further, the phenotypic and genotypic relationships between the community and hospital-acquired K. pneumoniae isolates in the same geographical area were investigated. From 272 total samples, 37 (13.6%) K. pneumoniae isolates were identified, of which 20 (54.1%) were hypervirulent. All isolates (100%) were multidrug-resistant (MDR) with multiple antibiotic resistance (MAR) indices ranging from 0.19 to 0.94. Colistin-resistant isolates (18.9%) displayed colistin MIC values >2 μg/mL, all harbored the mcr-1 gene. All isolates from patients (13/90, 14.4%), workers (5/22, 22.7%), chickens (9/100, 9%) and the environment (10/60, 16.7%) harbored a single or multiple β-lactamase genes, blaSHV, blaTEM, blaCTX-M1 and blaOXA-1, often in combination with carbapenemase genes (blaVIM, blaNDM-1 or blaIMP; 45.9%), the mcr-1 gene (18.9%) or both (13.5%). Enterobacterial repetitive intergenic consensus (ERIC)-PCR genotyping revealed 24 distinct ERIC types (ETs) with a discrimination index of 0.961. Six ETs showed clusters of identical isolates from chicken and human sources. The increased frequency and genetic relatedness of ESBLK and carbapenemase-producing K. pneumoniae (CPK) from chickens and humans pose a public health threat that urge more prudent use of antimicrobials in chicken farms to avoid the propagation and expansion of both ESBLK and CPK from the chicken sources to humans.