Work

Detection of hypervirulent Klebsiella pneumoniae among clinical isolates from select infections using virulence gene markers

Year: 2025

Type: article

Abstract: Objectives Hypervirulent Klebsiella pneumoniae (hvKp) is a distinct pathotype of K. pneumoniae associated with community-acquired infections, and it generally exhibits susceptibility to antimicrobial agents. The objective of the study was to identify hvKp and determine the antibiotic susceptibility profiles of these isolates. Materials and Methods A total of 150 K. pneumoniae isolates were obtained from community-acquired infections. All isolates were subjected to string test and antimicrobial susceptibility test using Kirby–Bauer disc diffusion. Final confirmation was done using polymerase chain reaction (PCR), targeting three hvKp-specific virulence genes (p rmpA, iucA, and peg344). Statistical analysis The associations between the string test and virulence genes were assessed using the Chi-square test. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of the string test were calculated using PCR as the gold standard. Results Among the 150 isolates, 62 (41.3%) were identified as hvKp. Abscesses (29) and pneumonia (22) were the most common clinical conditions, with neck abscesses as the predominant site. Of the 62 hvKp isolates, only 44 were string test-positive. Surprisingly, 22 string test-positive isolates lacked these genes, while 18 string test-negative isolates carried virulence genes. The sensitivity, specificity, PPV, and NPV of the string test were 66.7%, 78.5%, 71%, and 75%, respectively. Three hvKp isolates were multidrug-resistant. Conclusions Accurate detection of hvKp is critical in clinical settings due to its association with severe community-acquired infections, including deep-seated abscesses and pneumonia. The string test lacks both sensitivity and specificity, making it unreliable for hvKp identification. Therefore, the detection of virulence genes remains the gold standard. Early and precise diagnosis is essential for guiding appropriate treatment, including targeted antibiotic therapy and necessary drainage procedures for abscesses. The presence of multidrug resistance in certain isolates is a cause for concern, necessitating strict infection control measures to prevent the spread of such strains.

Source: Journal of Laboratory Physicians

DOI: 10.25259/jlp_241_2024

Authors: Soundarya Rajamanickam, Meerabai Manoharan, Maanasa Bhaskar, Sujatha Sistla

Institutions: ACS Medical College and Hospital, Jawaharlal Institute of Post Graduate Medical Education and Research, Vinayaka Missions University, Aarupadai Veedu Medical College & Hospital

Language: English

Topic: Antibiotic Resistance in Bacteria

Subfield: Molecular Medicine

Field: Biochemistry, Genetics and Molecular Biology

Domain: Life Sciences

SDG: Good health and well-being

Open Access status: gold

Estimated APC paid: $200