Genetic Analysis on the Emerging High Virulent K1 and K2 serotypes in ESBL-producing Klebsiella pneumoniae Clinical Isolates

Jeyakumar, Sharven Raj (2022) Genetic Analysis on the Emerging High Virulent K1 and K2 serotypes in ESBL-producing Klebsiella pneumoniae Clinical Isolates. [Project Paper] (Submitted)

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Abstract

Klebsiella pneumoniae is an encapsulated, gram-negative bacterium that is responsible for many life-threatening community-acquired and nosocomial infections. It can produce extended spectrum beta lactamase (ESBL), an enzyme that causes resistance against most beta- lactam antibiotics. Due to this multidrug resistance, hypervirulent K. pneumoniae began to emerge, predominantly in K1 and K2 capsular serotypes. Objective: Therefore, the study aims to determine the genetic association between K1 and K2 serotypes in ESBL-producing K. pneumoniae by sequencing and phylogenetic analysis. Methodology: A total of 194 K. pneumoniae isolates were collected from Hospital Sultanah Aminah Johor Bahru and Hospital Pengajar UPM. Antibiotics susceptibility test was conducted for ESBL screening. Multiplex polymerase chain reaction (PCR) was conducted to detect the presence of magA and K2A genes in the K. pneumoniae isolates that classifies them into K1 and K2 serotypes, respectively. Isolates that were found to be positive for ESBL phenotype and K1/K2 serotypes were selected for DNA sequencing and multilocus sequence typing (MLST) analysis. Finally, phylogenetic analysis was used to characterize the genetic association between the K1 and K2 serotypes among ESBL-producing isolates. Results: Among the 194 isolates, AST revealed that there are 89 ESBL and 105 non-ESBL producing K. pneumoniae isolates. A total of 12 out of the 89 ESBL-producing K. pneumoniae isolates were detected positive for magA or K2A gene ( K1, n = 4; K2, n= 8 ). Following phylogenetic analysis, the result showed two distinct clusters (Cluster A = All K1 serotype; Cluster B = All K2 serotype). Discussion: Although ESBL is frequently found in the hypervirulent strains of K. pneumoniae, the study showed that ESBL-producing isolates were not associated with K1 and K2 serotypes. Furthermore, seven different sequence types (ST) were identified by MLST analysis with ST23 being predominantly associated with K1 serotype. Meanwhile, K2 serotype is widespread among different STs (ST14, ST65, ST86, ST628, ST657 & ST792). Conclusion: The study showed K1 and K2 serotypes were not associated with ESBL phenotype. Following phylogenetic analysis of K1/K2 serotypes, two distinct clusters were observed. Cluster A and B consisting of all K1 and K2 serotypes, respectively.

Item Type:	Project Paper
Faculty:	Faculty of Medicine and Health Science
Depositing User:	Ms. Nor Safa'aton Saidin
Date Deposited:	22 Aug 2023 06:34
Last Modified:	22 Aug 2023 06:34
URI:	http://psaspb.upm.edu.my/id/eprint/1380

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