Biological properties and genetic structure of clinic isolates of Klebsiella pneumoniae species

Abstract

Klebsiella pneumoniae (Kp) species complex is a genetically and ecologically diverse group of bacteria that causes a wide range of infections in humans and animals.The aim. To carry out biological characterization and genotyping based on the study of different loci of Klebsiella pneumoniae clinical isolates.Materials and methods. The object of the study was three Klebsiella pneumoniae clinical isolates from different biotopes of patients from a regional children’s multidisciplinary hospital. We used a complex of bacteriological, molecular genetic and bioinformatic methods. Genotyping of the isolates was carried out using the Pasteur Institute service for strains of the K. pneumoniae species complex.Results. All strains were sensitive to antimicrobial drugs from carbapenem (imipenem, meropenem) and tetracycline groups (tigecycline), and demonstrated high sensitivity to the Klebsiella polyvalent bacteriophage. The antibiotic resistance of the Kp ODKB-16 and ODKB-81 isolates to seven and eight antimicrobial drugs, respectively, was registeredBased on the results of multi-locus sequence typing, all strains were assigned to Kp1 phylogroup, K2 type and differed in sequence type, scgMLST629 profile and KL type. Kp ODKB-16 strain was identified as ST-65, scgST-11107, KL2; ODKB-07 strain – as ST-219, scgST-6401, KL125KL114; ODKB-81 strain – as ST-86, scgST-2800, KL2KL30. The virulence gene clusters AbST, CbST, YbST, SmST, and RmST have been characterized only in the genome of the Kp ODKB-16 isolate, allowing it to be characterized as highly virulent with multidrug resistance (MDR). Additionally, genes responsible for the synthesis of types 1 and 3 fimbrial adhesins were registered in all strains, and ter operon loci were identified only in Kp ODKB-16. Resistome analysis showed that all strains had 2b genotype. Plasmids were found in the genomes of Kp ODKB-81 (IncI2) and ODKB-16 (IncFIA + IncFIB + IncHI1B).Conclusion. We used a comprehensive framework for genomic taxonomy of clinical isolates, which can contribute to the unification of global and regional peculiarities of the developing and microevolution of bacterial pathogens.

Keywords

• klebsiella pneumoniae species complex
• genotyping
• multilocus analysis
• multiple antibiotic resistance
• antimicrobial drugs
• virulence