Study the association between virulence genes and antibiotic resistance in hypervirulent Klebsiella pneumoniae isolates

This study wants to find out how classical and hypervirulent Klebsiella pneumoniae strains differ by looking at specific virulence genes (K1, K2, iutA, p-rmpA, c-rmpA, and magA) and how they react to antibiotics. We collected 132 K. pneumoniae isolates from various sources in six hospitals in Baghdad, Iraq, and conducted a cross-sectional study. We used a string test to determine hyper-mucoviscosity and the Vitek2 system for identification and antibiotic susceptibility testing. The virulence genes were identified using conventional PCR. Most isolates (46.2%) were collected from urine, with fewer isolates from umbilical, abscess, and tissue biopsies (0.8%). The antibiotic susceptibility test showed the highest resistance to beta-lactamase and folic acid inhibitors, while minocycline had the lowest resistance. The susceptibility patterns included extensive drug resistance (XDR) in 30.3% of the strains, multidrug resistance (MDR) in 22.7%, and pan-drug resistance (PDR) in 12.1%. We found that 3.8% of the strains were hypervirulent K. pneumoniae, with 20% having a hyper-mucoviscous phenotype. Additionally, 96.2% were classified as classical K. pneumoniae, and 70.1% had a hyper-mucoviscous phenotype. Among the hypervirulent strains, 80% showed extensive drug resistance and multidrug resistance patterns, compared to 64.6% in classical strains. The study confirmed an association between hypervirulent K. pneumoniae strains and resistance patterns. Despite the classification of only five strains as hypervirulent, 80% exhibited multiple drug resistance patterns. Identifying hypervirulent strains and determining their antibiotic susceptibility patterns is crucial for managing therapy and preventing outbreaThe novelty of this study is highlighted by the significant increase in extensively drug-resistant (XDR) patterns observed in K. pneumoniae, along with the emergence of hypervirulent strains that exhibit extensive drug resistance and multidrug resistance, which harbor different virulence genes.nes. These findings show a significant increase in extensively drug-resistant patterns, indicating that resistance to K. pneumoniae is growing in hospitals in Iraq compared to recent studies.