The Nosocomial Transmission of Carbapenem-Resistant Gram-Negative Bacteria in a Hospital in Baoding City, China
Background: The global rise of multidrug-resistant Gram-negative bacteria, particularly non-fermenting species and carbapenemase-producing Enterobacteriaceae, poses a significant challenge to hospital infection control. Methods: In this study, a total of 89 <i>Acinetobacter</i> spp. isol...
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| Main Authors: | , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2025-07-01
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| Series: | Microbiology Research |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2036-7481/16/7/147 |
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| Summary: | Background: The global rise of multidrug-resistant Gram-negative bacteria, particularly non-fermenting species and carbapenemase-producing Enterobacteriaceae, poses a significant challenge to hospital infection control. Methods: In this study, a total of 89 <i>Acinetobacter</i> spp. isolates, 14 <i>Pseudomonas aeruginosa</i>, and 14 carbapenem-resistant Enterobacteriaceae isolates were collected from patients in a tertiary hospital. Whole-genome sequencing and antimicrobial susceptibility testing were conducted. Resistance mechanisms and evolutionary relationships were analyzed using phylogenetic analysis and genetic context mapping. Results: Among the non-fermenting isolates, <i>A. baumannii</i> exhibited high resistance to carbapenems, clustering into distinct clonal groups enriched with genes associated with biofilm formation and virulence genes. <i>P. aeruginosa</i> isolates harbored fewer resistance genes but carried notable mutations in the efflux pump systems and the <i>oprD</i> gene. In Enterobacteriaceae, four <i>bla</i><sub>NDM</sub> alleles were identified within a conservative structural sequence, while <i>bla</i><sub>KPC-2</sub> was located in a non-Tn<i>4401</i> structure flanked by IS<i>481</i>- and IS<i>1182</i>-like insertion sequences. Phylogenetic analysis revealed that <i>bla</i><sub>NDM</sub>-positive <i>E. coli</i> strains were closely related to susceptible lineages, indicating horizontal gene transfer. Conversely, <i>K. pneumoniae</i> isolates harboring <i>bla</i><sub>KPC-2</sub> formed a tight clonal cluster, suggesting clonal expansion. Conclusions: The study reveals distinct transmission patterns between resistance genes: horizontal dissemination of <i>bla</i><sub>NDM</sub> and clonal expansion of <i>bla</i><sub>KPC-2</sub> in <i>K. pneumoniae</i>. These findings emphasize the need for resistance-gene-specific genomic surveillance and infection control strategies to prevent further nosocomial dissemination. |
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| ISSN: | 2036-7481 |