Occurrence and Characteristics of Carbapenem-Resistant Klebsiella pneumoniae Strains Isolated from Hospitalized Patients in Poland-A Single Centre Study

Prevalence of extended-spectrum β-lactamase and carbapenem-resistant Klebsiella pneumoniae in clinical samples

OBJECTIVES

To assess the prevalence of these resistant strains in the overall isolates of Klebsiella pneumoniae (K. pneumoniae) in hospital settings.

METHODS

This retrospective study was conducted from November 2020 to November 2021. The identification and antibiotic susceptibility testing were performed using standard laboratory methods according to the EUCAST standards. The detection of ESBL and carbapenemase production was performed using phenotypic methods such as E-test, combined-disk test with various inhibitors (ROSCO Diagnostica A/S), chromogenic medium for the detection of ESBL/carbapenemase-producing Enterobacteriaceae (CPE) isolates, and the VITEK 2 Compact system (BioMerieux).

RESULTS

944 isolates of K. pneumoniae were detected in various clinical specimens. Among these, ESBL-producing strains were detected in 349/944 (37%), whereas carbapenem- resistant strains in 188/944 (20%) of the isolates. The remaining isolates (407/944 [43%]) belonged to the wild type. ESBL isolates were the most common in wound swabs (138 [39.5%]), whereas CRKP isolates in screening samples (110 [58.5%]). The majority of ESBL isolates were detected in surgical departments (105 [30.1%]), whereas CRKP isolates in adult intensive care unit departments (79 [42.%]).

CONCLUSION

Our results show an increasing frequency of CRKP strains. This presents a significant issue in terms of infection prevention and control in hospital settings.

Virulence analysis and antibiotic resistance of Klebsiella pneumoniae isolates from hospitalised patients in Poland

Klebsiella pneumoniae (KP) is a nosocomial pathogen causing difficult-to-treat infections. The presence of virulence genes and antibiotic resistance of 109 KP isolates from hospitalized patients were investigated. Among them, 68.8% were multi-drug resistant (MDR) and 59.6% produced extended-spectrum beta-lactamases (ESBLs). Metallo-β-lactamases (MBLs) were produced by 22% of isolates (mainly from anus), including 16.5% of isolates producing New Delhi metallo-β-lactamase (NDM-1). The genes encoding adhesins (fimH-91.7%, mrkD-96.3%), enterobactin (entB-100%) and yersiniabactin (irp-1-88%) were frequently identified. The genes encoding salmochelin (iroD-9.2%, iroN-7.3%) and colibactin (clbA, clbB-0.9%) were identified rarely. Iron acquisition system-related kfu gene and wcaG gene involved in capsule production were identified in 6.4% and 11% of isolates, respectively. The rmpA gene associated with hypermucoviscosity was present in 6.4% of isolates. In 19.2% of isolates magA gene was detected, specific for K1 capsule serotype, while 22.9% of isolates showed K2 capsule serotype. The rmpA, iroD or iroN genes being diagnostic biomarkers for hypervirulent KP (hvKP) were detected in 16.5% of isolates. We found that 55.5% of hvKP were MDR and produced ESBLs, thus hospital KP isolates pose a serious threat to the healthcare system.