Virulence factors, molecular characteristics, and resistance mechanisms of carbapenem-resistant Pseudomonas aeruginosa isolated from pediatric patients in Shanghai, China.

Publisher: BioMed Central Country of Publication: England NLM ID: 100966981 Publication Model: Electronic Cited Medium: Internet ISSN: 1471-2180 (Electronic) Linking ISSN: 14712180 NLM ISO Abbreviation: BMC Microbiol Subsets: MEDLINE

Original Publication: London : BioMed Central, [2001-

Pseudomonas aeruginosa*/genetics ; Pseudomonas aeruginosa*/drug effects ; Pseudomonas aeruginosa*/isolation & purification ; Pseudomonas aeruginosa*/pathogenicity ; Virulence Factors*/genetics ; Carbapenems*/pharmacology ; Pseudomonas Infections*/microbiology ; Pseudomonas Infections*/epidemiology ; Pseudomonas Infections*/drug therapy ; Anti-Bacterial Agents*/pharmacology; China/epidemiology ; Porins/genetics ; Bacterial Proteins/genetics ; Drug Resistance, Multiple, Bacterial/genetics ; Humans ; Multilocus Sequence Typing ; Child ; Child, Preschool ; Microbial Sensitivity Tests ; Male ; Female ; Infant ; Adolescent

Background: The investigation into virulence factors, clinical and molecular characteristics, and resistance mechanisms of carbapenem-resistant Pseudomonas aeruginosa (CRPA) in pediatric populations is currently inadequate.
Purpose: This study aimed to investigate the virulence factors, clinical and molecular characteristics, and resistance mechanisms of 135 CRPA isolates in Shanghai, China.
Methods: Analysis of virulence-associated genes and multilocus sequence typing (MLST) provided epidemiological and molecular insights into the isolates. Resistance mechanisms were identified via PCR, sequencing, and qRT-PCR.
Results: The predominant resistance mechanism to carbapenems was the decreased production of outer membrane porin OprD (75.6%), accompanied by mutational inactivation of the oprD (87.4%). However, elevated production of AmpC (7.4%) and mexB overexpression (5.2%) were uncommon. Thirty-five sequence types (STs) were identified, with clonal complex 244 (CC244;59.3%) representing the majority of infections. Sixteen virulence factor genes were detected, with a significant portion of isolates (40.7%) concurrently possessing Toxin A (toxA), Elastase B (lasB), Exoenzyme S (exoS), staphylolysin (lasA), and Pilin (pilA). Almost all CC244 isolates carried toxA (100%), exoS (100%), pilA (100%), lasB (98.6%), and lasA (82.5%) while all ST2100, ST274, ST1129, ST446, and ST2069 isolates contained exoY. CC244 + isolates exhibited significantly increased antibiotic resistance, and the isolates from diseased or discharged patients showed comparatively higher resistance than others, except against gentamicin. Most patients (71.9%) received combination therapy, with 65.2% achieving clinical cure or improvement.
Conclusion: This study predominantly identified OprD-mediated carbapenem resistance in pediatric patients. The CRPA isolates were characterized by a variety of STs and a widespread distribution of virulence-associated genes. CC244 demonstrated significantly higher resistance, with potential outbreaks occurring in 2018 and 2019. These findings could aid in managing nosocomial CRPA infections and enhancing clinical practices.
(© 2025. The Author(s).)

Declarations. Ethics approval and consent to participate: This study was conducted in accordance with the ethical standards of the Declaration of Helsinki. Informed consent was waived by the Ethics Committee of the Children’s Hospital of Fudan University because only bacterial isolates recovered from routine diagnostic laboratory tests were assessed. The study was approved by the Ethics Committee of the Children’s Hospital of Fudan University, Shanghai, China (Approval number (2021)372). Consent for publication: Not applicable. Competing interests: The authors declare no competing interests.

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2021YFC2701800, 2021YFC2701805 National Key Research and Development Program of China; GWVI-2.1.2 the three year action plan

Keywords: P. aeruginosa; Carbapenem resistance; Efflux pump; Pediatric patients; Virulence genes

0 (Virulence Factors)
0 (Carbapenems)
0 (Anti-Bacterial Agents)
0 (Porins)
0 (Bacterial Proteins)
148412-32-2 (OprD protein, Pseudomonas aeruginosa)

Date Created: 20250312 Date Completed: 20250512 Latest Revision: 20250512

20260130

PMC11895140

10.1186/s12866-025-03856-1

40069638