Multiplex PCR screening for virulence genes of Klebsiella pneumoniae isolated from microbiota of diseased and healthy people

Abstract

Introduction. Klebsiella pneumoniae in human microbiota may appear as a part of commensal microbiota, and as hypervirulent pathogen, for example, hypermucoid pathotype. This pathotype is characterized by certain genetic determinants, leading to the possibility of detecting the pathogenic potential of isolates by PCR. Aim of the study: to evaluate and compare pathogenic potential of K. pneumoniae isolates from practically healthy people, patients with inflammatory bowel disease (IBD) and extraintestinal infections (ExII).Materials and methods. Testing was performed with the set of nucleotides for multiplex PCR analysis targeting eight potentially virulent genes with the following functions: ferrum uptake (ybsT, kfu, iutA), adhesion and invasion (mrkD), hypermucoid phenotype and virulent serotypes (mrkD, magA, rmpA, k2) and metabolism of allantoin (allS). PCR assay was used to screen Klebsiella pneumoniae isolates from feces of patients with IBD (69 isolates) and of practically healthy people (68 isolates), and multiresistant isolates from biological material (blood, urine, surgical wounds, bronchoalveolar lavage) of patients with extraintestinal infections (mrExII, 25 isolates).Results. Results of the testing demonstrated association of four of targeted determinants with the patients diagnoses. YbtS gene was significantly more often found in isolates from IBD (р = 0.024) and mrExII (p 0.001) groups. RmpA gene was significantly more often detected in IBD group (р = 0.038). Extraintestinal infectious isolates were significantly (р ≤ 0.001) enriched with mrkD and allS genes (р = 0.032).Conclusion. The most potentially virulent group was isolated from patients with extraintestinal infections, the least virulent — isolates from feces of practically healthy people. The most frequently detected virulence genes were involved in adhesion and hypermucoid phenotype formation.