# Differential analysis of virulence and antibiotic resistance genes in ST11 CRKP and ST15 CRKP isolates from a tertiary hospital

## TL;DR

This study compares the virulence and antibiotic resistance genes in two types of CRKP bacteria to help improve treatment and infection control.

## Contribution

The study identifies distinct genetic profiles between ST11 and ST15 CRKP isolates, highlighting differences in resistance and virulence.

## Key findings

- ST11 CRKP showed higher resistance and virulence potential compared to ST15 CRKP.
- ST15 CRKP had lower resistance to cotrimoxazole and amikacin and expressed K5 capsular type.
- A hypervirulent ST15 strain was detected, indicating potential evolutionary risks.

## Abstract

To compare the virulence and resistance gene profiles between ST11 and ST15 carbapenem-resistant Klebsiella pneumoniae (CRKP) isolates from a hospital in Ningbo, China, and to provide insights for clinical treatment and infection control.

A total of 129 clinical CRKP isolates were collected and subjected to multilocus sequence typing (MLST) to identify ST11 and ST15 strains. Resistance and virulence genes were detected by PCR, and antimicrobial susceptibility was determined using the VITEK-2 Compact system.

Among the isolates, 48 were ST11 CRKP and 43 were ST15 CRKP. Both groups exhibited high resistance to ertapenem, ciprofloxacin, cefoperazone/sulbactam, imipenem, and levofloxacin. ST15 CRKP showed lower resistance to cotrimoxazole and amikacin. The carriage rate of blaKPC-2 was higher in ST11 CRKP. Virulence analysis revealed that ST11 CRKP predominantly carried the K2 capsular type, while ST15 CRKP mainly expressed K5. ST11 CRKP also showed higher prevalence of iron transporter (kfu), adhesion (kpn), and pLVPK-like plasmid genes (rmpA2, peg344, iucA).

ST11 CRKP demonstrates stronger resistance and higher virulence potential compared to ST15 CRKP. However, the detection of a hypervirulent ST15 strain indicates its potential risk for evolution. Strengthening the stewardship of carbapenem use is crucial for controlling CRKP dissemination.