The type VI secretion system as a potential predictor of subsequent bloodstream infection of carbapenem-resistant Klebsiella pneumoniae strains on intestinal colonization.

IF 5.4 2区医学 Q1 INFECTIOUS DISEASES

Infection Pub Date : 2025-02-03 DOI:10.1007/s15010-024-02456-x

Chenfeng Zhao, Pingjuan Liu, Xiaoshu Lin, Chenyu Wan, Kang Liao, Penghao Guo, Jiankai Deng, Zhongwen Wu, Yaqin Peng, Junqi Huang, Yili Chen

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引用次数: 0

Abstract

Background: The type VI secretion system (T6SS) has been recognized as a novel virulence factor in Klebsiella pneumoniae. This study investigated the occurrence of T6SS genes in carbapenem-resistant Klebsiella pneumoniae (CRKP) strains during intestinal colonization and evaluated their effect on the development of bloodstream infections.

Methods: The study encompassed 2,385 patients admitted to the intensive care unit (ICU) and subjected to routine screening for intestinal colonization with CRKP. PFGE was employed on CRKP strains isolated from both the patients' intestine and blood cultures, confirming their genetic similarity. PCR was employed to detect the presence of carbapenemase genes, T6SS genes, and virulence genes. Quantitative real-time PCR was conducted to assess the expression levels of the core genes associated with the T6SS. The correlation between T6SS expression and sBSI was further investigated.

Results: Approximately 10% (238/2385) of ICU patients tested positive for CRKP colonization. Among patients who tested positive, 10.1% (24/238) developed CRKP-sBSI. Patients carrying T6SS-positive CRKP isolates were more commonly linked to a history of invasive procedures, antibiotic use, and immunosuppression (P < 0.05), and were strongly associated with 28-day mortality (P < 0.001). It indicated that T6SS-positive CRKP strains exhibited a higher prevalence of virulence genes, such as rmpA and iucA, compared to T6SS-negative ones (P < 0.001). Compared to the strains isolated from simple colonization group, there was a significant increase in the mRNA expression of both hcp and vgrG genes (P < 0.05) of strains from the sBSI group, suggesting the key genes of the T6SS may play a significant role in the occurrence and progression of sBSI caused by CRKP.

Conclusion: The presence of the T6SS in a CRKP strain from intestinal colonization can serve as a promising predictive marker for sBSI. Conducting screenings for CRKP in patients' intestinal flora and monitoring T6SS carriage can improve the prevention and management of CRKP bloodstream infections.

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来源期刊

Infection 医学-传染病学

CiteScore

12.50

自引率

1.30%

发文量

224

审稿时长

6-12 weeks

期刊介绍： Infection is a journal dedicated to serving as a global forum for the presentation and discussion of clinically relevant information on infectious diseases. Its primary goal is to engage readers and contributors from various regions around the world in the exchange of knowledge about the etiology, pathogenesis, diagnosis, and treatment of infectious diseases, both in outpatient and inpatient settings. The journal covers a wide range of topics, including: Etiology: The study of the causes of infectious diseases. Pathogenesis: The process by which an infectious agent causes disease. Diagnosis: The methods and techniques used to identify infectious diseases. Treatment: The medical interventions and strategies employed to treat infectious diseases. Public Health: Issues of local, regional, or international significance related to infectious diseases, including prevention, control, and management strategies. Hospital Epidemiology: The study of the spread of infectious diseases within healthcare settings and the measures to prevent nosocomial infections. In addition to these, Infection also includes a specialized "Images" section, which focuses on high-quality visual content, such as images, photographs, and microscopic slides, accompanied by brief abstracts. This section is designed to highlight the clinical and diagnostic value of visual aids in the field of infectious diseases, as many conditions present with characteristic clinical signs that can be diagnosed through inspection, and imaging and microscopy are crucial for accurate diagnosis. The journal's comprehensive approach ensures that it remains a valuable resource for healthcare professionals and researchers in the field of infectious diseases.