Identification of beta-lactamase genes and molecular genotyping of multidrug-resistant clinical isolates of Klebsiella pneumoniae

Azadeh Ferdosi-Shahandashti; Abazar Pournajaf; Elaheh Ferdosi-Shahandashti; Fatemeh Zaboli; Kasra Javadi

doi:10.1186/s12866-024-03679-6

Identification of beta-lactamase genes and molecular genotyping of multidrug-resistant clinical isolates of Klebsiella pneumoniae

BMC Microbiol. 2024 Dec 28;24(1):549. doi: 10.1186/s12866-024-03679-6.

Authors

Azadeh Ferdosi-Shahandashti¹, Abazar Pournajaf², Elaheh Ferdosi-Shahandashti³, Fatemeh Zaboli¹, Kasra Javadi⁴

Affiliations

¹ Department of Microbiology, Ayatollah Amoli Branch, Islamic Azad University, Amol, Iran.
² Infectious Diseases and Tropical Medicine Research Center, Health Research Institute, Babol University of Medical Sciences, Babol, Iran.
³ Biomedical and Microbial Advanced Technologies Research Center, Health Research Institute, Babol University of Medical Sciences, Babol, Iran. elaheh.ferdosi@yahoo.com.
⁴ Department of Microbiology, Faculty of Medicine, Shahed University, Tehran, Iran.

Abstract

Background: Klebsiella pneumoniae is a clinically relevant pathogen that has raised considerable public health concerns. This study aims to determine the presence of beta-lactamase genes and perform molecular genotyping of multidrug-resistant (MDR) K. pneumoniae clinical isolates.

Methods: Clinical isolates of MDR K. pneumoniae were collected from educational hospitals affiliated with Babol University of Medical Sciences. The isolates of K. pneumoniae were identified through standard microbial and biochemical tests. Antibiotic resistance was assessed using disk diffusion, modified Hodge test (MHT), combined disk, and polymerase chain reaction (PCR) methods. Enterobacterial Repetitive Intergenic Consensus (ERIC)-PCR was performed for molecular typing.

Results: A total of 42 MDR K. pneumoniae isolates were obtained from various clinical specimens. The highest antibiotic resistance was observed for ampicillin (100%), while the lowest resistance was noted for amikacin (19.04%). The MHT indicated that 38.09% of K. pneumoniae isolates produced carbapenemase enzymes. Metallo-beta-lactamase (MBL) production was found in 54.76% of isolates. Molecular detection of beta-lactamase genes revealed the presence of bla_NDM (21.42%), bla_KPC (42.85%), bla_TEM (76.19%), bla_SHV (47.16%), and bla_CTX-M (80.95%) genes. ERIC-PCR molecular typing identified seven distinct genetic patterns among the isolates.

Conclusions: This investigation demonstrates the high resistance levels of K. pneumoniae strains. The beta-lactamase genes with the highest and lowest frequencies correspond to bla_CTX-M and bla_NDM genes, respectively. ERIC-PCR dendrograms suggest a common origin for K. pneumoniae clinical isolates and the propagation of similar clones within hospital wards. These findings indicate that K. pneumoniae isolates are highly virulent, necessitating the development of more effective resistance-fighting techniques and gene transfer research.

Clinical trial number: Not applicable.

Keywords: Beta-lactamases; Carbapenemase; Genotyping techniques; Klebsiella pneumoniae; Multidrug-resistant.

MeSH terms

Adolescent
Adult
Aged
Anti-Bacterial Agents* / pharmacology
Bacterial Proteins / genetics
Drug Resistance, Multiple, Bacterial* / genetics
Female
Genotype*
Humans
Klebsiella Infections* / microbiology
Klebsiella pneumoniae* / drug effects
Klebsiella pneumoniae* / enzymology
Klebsiella pneumoniae* / genetics
Klebsiella pneumoniae* / isolation & purification
Male
Microbial Sensitivity Tests*
Middle Aged
Molecular Typing / methods
Polymerase Chain Reaction
Young Adult
beta-Lactamases* / genetics

Substances

beta-Lactamases
Anti-Bacterial Agents
Bacterial Proteins