Diversity Determination of KPC- Producing Klebsiella pneumoniae Using Multilocus Variable Number Tandem Repeat Analysis

Diversity Determination of KPC- Producing Klebsiella pneumoniae Using Multilocus Variable Number Tandem Repeat Analysis
Narjes Mohammadi Bandari,¹ Hossein Keyvani,² Mohsen Zargar,³ Mohammad Abootaleb,^4,*
1. Department of Biology, Qom Branch, Islamic Azad University, Qom, Iran
2. Department of Virology, Faculty of Medicine, Iran University of Medical Sciences, Tehran, Iran.
3. Department of Biology, Qom Branch, Islamic Azad University, Qom, Iran
4. Department of Biology, Qom Branch, Islamic Azad University, Qom, Iran
Introduction: The present study purposed at evaluating ing the genetic diversity of KPC-producing Klebsiella pneumoniae in Tehran, Iran investigated by multilocus variable-number tandem repeat analysis (MLVA).
Methods: A total of 181 isolates of K. pneumoniae were collected from different clinical samples. The antibiotic susceptibility and Modified Hodge Test (MHT) were determined according to CLSI (the clinical and laboratory standards institute) guidelines. The polymerase chain reaction (PCR) method was conducted to detect blaKPC and blaGES. K. pneumoniae isolates were typed via the MLVA method by using PCR for 8 Variable Number Tandem Repeats (VNTRs).
Results: Imipenem, with 36.5% susceptibility, was the most effective antibiotic against K. pneumoniae. 100 (55.24%) isolates had KPC positive results and 36(36 %) of them were positive for blaKPC and blaGES genes. Thirty-three MLVA genotypes were discriminated, investigation of diversity indexes (DIs) for eight loci showed that seven different alleles were the most polymorphic and the most DI was 0.349.
Conclusion: The results of the present study indicated heterogeneity among KPC-producing K. pneumoniae strains. The presence of blaKPC and blaGES in different MLVA types showed that a specific clone is not responsible for spreading the isolates and horizontal transfer occurred among these isolates.
Keywords: Klebsiella pneumoniae, Bacterial typing, Carbapenemase, MLVA, VNTR