Phenotypic and molecular characterization of Klebsiella spp. isolates causing community-acquired infections

Abstract

Klebsiella spp. isolates from community-acquired infections were characterized. A total of 39 Klebsiella spp. isolates were obtained from outpatients at four rural hospitals in Mexico (2013–2014). The biochemical tests identified all as being K. pneumoniae. The molecular multiplex-PCR test identified 36 (92.4%) K. pneumoniae isolates and one (2.5%) K. variicola isolate, and phylogenetic analysis of the rpoB gene identified two isolates (5.1%) belonging to K. quasipneumoniae subsp. quasipneumoniae and K. quasivariicola. The last one was confirmed by phylogenetic analysis of six-loci concatenated genes. Mostly the isolates were multidrug resistant; however, a minority were extended-spectrum β-lactamase producing (10.2%). The extended-spectrum β-lactamase CTX-M-15 gene was identified in these isolates. Analysis of biofilm production and the hypermucoviscosity phenotype showed a total of 35 (92.3%) and seven (17.9%) of the isolates were positive for these phenotypes respectively. The K2 (4/39, 10.2%), K5 (2/39, 5.1%) and K54 (1/39, 2.5%) serotypes were identified in seven (17.9%) of the isolates, and only 28.5% (2/7) hypermucoviscous isolates were positive for the K2 and K5 serotypes. In general, the sequence type (ST) analysis and phylogenetic analysis of seven multilocus sequence typing loci were heterogeneous; however, ST29 was the most prevalent ST in the analysed isolates, accounting for 19% (4/21) of the total isolates. Two of the four ST29 isolates had the hypermucoviscosity phenotype. The virulence factors for fimbriae were the most prevalent, followed by siderophores. Community-acquired infections are caused by various species from Klebsiella genus, with different profiles of antibiotic resistance and heterogeneous virulence factors.

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

“…For this reason, future comparative studies should include K. pneumoniae strains from other clinical origins to further understand the role of dogs as reservoirs of pathogenic K. pneumoniae. In fact, the K. pneumoniae clonal lineages detected in dogs from this study have been previously isolated from several types of human infections besides UTI (39,(42)(43)(44).…”

“…The detection of a high-risk K. pneumoniae clonal lineage colonizing a healthy dog highlights its possible role as a reservoir. Furthermore, other K. pneumoniae clonal lineages that were detected in dogs, namely ST188, ST252, ST281, ST423, and ST1093, have also been previously implicated in human infections (39,(41)(42)(43)(44).…”

High Prevalence of Multidrug-Resistant Klebsiella pneumoniae Harboring Several Virulence and β-Lactamase Encoding Genes in a Brazilian Intensive Care Unit

“…Hasan et al (2014) described a clonal expansion of CC147 by Verone integron-encoded metallo-beta-lactamase (VIM)-producing K. pneumoniae strains isolated from Greece. ST392 has been reported worldwide as an emergent clone associated with the spreading KPC-producing K. pneumoniae (Yang et al, 2013; Di Mento et al, 2018; Garza-Ramos et al, 2018). In Brazil, ST392 was previously reported in a KPC-2-producing K. pneumoniae harboring the mcr- 1 gene.…”

Global Evolution of Pathogenic Bacteria With Extensive Use of Fluoroquinolone Agents

“…Finally, similarly to MRSA, in community-acquired Klebsiella infections the more virulent and less resistant strains of "nonmajor ST" K. pneumoniae will dominate, like ST23 and ST65 (Zhao et al, 2016;Chen Y.T. et al, 2017;Garza-Ramos et al, 2018;Shi et al, 2018) in which high-level resistance to fluoroquinolones has not been reported to date.…”