Characterization of ESBL-Producing Escherichia coli and Klebsiella pneumoniae Isolated from Clinical Samples in a Northern Portuguese Hospital: Predominance of CTX-M-15 and High Genetic Diversity

Abstract

Background: Enterobacteriaceae are major players in the spread of resistance to β-lactam antibiotics through the action of CTX-M β-lactamases. We aimed to analyze the diversity and genetic characteristics of ESBL-producing Escherichia coli and Klebsiella pneumoniae isolates from patients in a Northern Portuguese hospital. Methods: A total of 62 cefotaxime/ceftazidime-resistant E. coli (n = 38) and K. pneumoniae (n = 24) clinical isolates were studied. Identification was performed by MALDI-TOF MS. Antimicrobial susceptibility testing against 13 antibiotics was performed. Detection of ESBL-encoding genes and other resistance genes, phylogenetic grouping, and molecular typing (for selected isolates) was carried out by PCR/sequencing. Results: ESBL activity was detected in all 62 E. coli and K. pneumoniae isolates. Most of the ESBL-producing E. coli isolates carried a blaCTX-M gene (37/38 isolates), being blaCTX-M-15 predominant (n = 32), although blaCTX-M-27 (n = 1) and blaCTX-M-1 (n = 1) were also detected. Two E. coli isolates carried the blaKPC2/3 gene. The lineages ST131-B2 and ST410-A were detected among the ESBL-producing blood E. coli isolates. Regarding the 24 ESBL-producing K. pneumoniae isolates, 18 carried a blaCTX-M gene (blaCTX-M-15, 16 isolates; blaCTX-M-55, 2 isolates). All K. pneumoniae isolates carried blaSHV genes, including ESBL-variants (blaSHV-12 and blaSHV-27, 14 isolates) or non-ESBL-variants (blaSHV-11 and blaSHV-28, 10 isolates); ten K. pneumoniae isolates also carried the blaKPC2/3 gene and showed imipenem-resistance. ESBL-positive E. coli isolates were ascribed to the B2 phylogenetic group (82%), mostly associated with ST131 lineage and, at a lower rate, to ST410/A. Regarding K. pneumoniae, the three international lineages ST15, ST147, and ST280 were detected among selected isolates. Conclusions: Different ESBL variants of CTX-M (especially CTX-M-15) and SHV-type (specially SHV-12) were detected among CTX/CAZR E. coli and K. pneumoniae isolates, in occasions associated with carbapenemase genes (blaKPC2/3 gene).

A Descriptive Analysis of Urinary ESBL-Producing-Escherichia coli in Cerdanya Hospital

“…While bla CTX-M-15 is considered to be predominant, followed by bla CTX-M-14 , among our isolates, bla CTX-M-14 was more frequent than bla CTX-M-15 , in agreement with previously reported data from Spain [ 34 ] and China [ 35 ], which identified bla CTX-M-14 as the main ESBL in E. coli of adults with acquired UTIs. It may be noted that no acquired AmpC β-lactamase-producing E. coli were present in our collection, in agreement with a Portuguese study [ 36 ], performed with both clinical and non-clinical isolates [ 37 , 38 , 39 ].…”

“…Furthermore, E. coli isolates from clone ST131 belonged to the phylogenetic group B2. Other studies have shown that E. coli ST131/CTX-M-15/B2/ fimH30 is the most disseminated E. coli clonal group worldwide and that it contains an extensive antimicrobial resistance profile [ 36 , 54 , 55 ].…”

Epidemiology, Environmental Risks, Virulence, and Resistance Determinants of Klebsiella pneumoniae From Dairy Cows in Hubei, China

“…The development of antibiotic resistance is inseparable from the existence and spread of resistance genes. Our results show that bla TEM and bla SHV are present in mostly K. pneumoniae and bla CTX–M–15 is the main CTX-M gene detected, which is similar to the results of previous studies ( Timofte et al, 2014 ; Carvalho et al, 2021 ). These extended-spectrum β-lactamase (ESBL) resistance genes can lead to resistance by hydrolysis of penicillins and cephalosporins ( Algammal et al, 2020a ).…”

Early Response of Antimicrobial Resistance and Virulence Genes Expression in Classical, Hypervirulent, and Hybrid hvKp-MDR Klebsiella pneumoniae on Antimicrobial Stress

“…Two strains of ST23 K1 and ST23 K57 are characterized as hybrid hvKp-MDR. Thus, the data obtained in this study indicate the ongoing formation of hybrid K. pneumoniae on the base of the ST23 genetic line, which was already defined in the last decade [7,22,35,45].…”

“…All K. pneumoniae isolates carried bla SHV genes, including extended-spectrum beta-lactamase (ESBL) variant bla SHV-12 , broad-spectrum variants bla SHV-28 and bla SHV-33 , and narrow-spectrum variants bla SHV-67 and bla SHV-190 . These alleles of bla SHV genes were previously described in Portugal, Turkey, China, Russia, and Spain [ 22 , 35 , 36 ]. Three K. pneumoniae isolates (ST395 K47 , ST147 K64 , and ST23 K1 ) carried the bla TEM-1B , bla CTX-M-15 , and bla OXA-1 genes.…”