Exploring the Antibiotic Resistance Profile of Clinical Klebsiella pneumoniae Isolates in Portugal

Abstract

While antibiotic resistance is rising to dangerously high levels, resistance mechanisms are spreading globally among diverse bacterial species. The emergence of antibiotic-resistant Klebsiella pneumoniae, mainly due to the production of antibiotic-inactivating enzymes, is currently responsible for most treatment failures, threatening the effectiveness of classes of antibiotics used for decades. This study assessed the presence of genetic determinants of β-lactam resistance in 102 multi-drug resistant (MDR) K. pneumoniae isolates from patients admitted to two central hospitals in northern Portugal from 2010 to 2020. Antimicrobial susceptibility testing revealed a high rate (>90%) of resistance to most β-lactam antibiotics, except for carbapenems and cephamycins, which showed antimicrobial susceptibility rates in the range of 23.5–34.3% and 40.2–68.6%, respectively. A diverse pool of β-lactam resistance genetic determinants, including carbapenemases- (i.e., blaKPC-like and blaOXA-48-like), extended-spectrum β-lactamases (ESBL; i.e., blaTEM-like, blaCTX-M-like and blaSHV-like), and AmpC β-lactamases-coding genes (i.e., blaCMY-2-like and blaDHA-like) were found in most K. pneumoniae isolates. blaKPC-like (72.5%) and ESBL genes (37.3–74.5%) were the most detected, with approximately 80% of K. pneumoniae isolates presenting two or more resistance genes. As the optimal treatment of β-lactamase-producing K. pneumoniae infections remains problematic, the high co-occurrence of multiple β-lactam resistance genes must be seen as a serious warning of the problem of antimicrobial resistance.

Inverse Association between the Existence of CRISPR/Cas Systems with Antibiotic Resistance, Extended Spectrum β-Lactamase and Carbapenemase Production in Multidrug, Extensive Drug and Pandrug-Resistant Klebsiella pneumoniae

“…All specimens were cultured on blood agar, MacConkey agar and Eosin Methylene blue agar (Merck, Darmstadt, Germany) and incubated at 37 °C for 24–48 h. K. pneumoniae isolates were identified using morphological and cultural criteria and standard biochemical tests including Gram stain, lysine iron agar (LIA), triple sugar iron (TSI) agar, ornithine decarboxylase and urea/citrate utilization [ 49 ]. The VITEK ® 2 Compact B System (BioMérieux, Marcy-l’Etoile, France) was used for the confirmative and final identification of K. pneumoniae isolates using VITEK ® 2 GN ID cards [ 6 ].…”

“…Two of the main resistance mechanisms developed by K. pneumoniae are the production of extended spectrum β-lactamase (ESBL) and carbapenemase enzymes [ 6 ]. Different variants of these enzymes are capable of inhibiting the action of various β-lactams, including cephalosporins, penicillins, monobactams and carbapenems, which are among the most prescribed antibiotics globally [ 6 , 7 ]. Infections caused by ESBL-producing K. pneumoniae are typically treated with carbapenems.…”

Molecular Insights into β-Lactams Resistance inKlebsiella pneumoniaeClinical Isolates with a Focus on Multidrug Resistance and Virulence

“…Likewise, in a study carried out with 102 isolates obtained from two Portuguese hospitals, the presence of resistance rates > 90% was verified for all beta-lactam drugs tested, except for cephalosporins: cefoxitin (40.2%), cefotetan (68.6%) and carbapenems: ertapenem (23.5%), imipenem (32.4%), meropenem (34.3%) and doripenem (33.3%) [21].…”

Evaluation of Antimicrobial Resistance of Different Phylogroups of Escherichia coli Isolates from Feces of Breeding and Laying Hens

“…The DNA template was obtained as described in 4.2; 2 µL of the DNA suspension was used for PCR in a final volume of 20 µL, containing 1.5 mM MgCl 2 , 1x Taq buffer, 0.25 µM primers, 1.25 U Taq (NZYTech), 0.25 mM dNTPs (NZYTech), and DNase-free water. The PCR conditions were as follows, according to Oliveira et al [87]: 95 • C, 5 min; 30 cycles of 94 • C, 30 s; 60 • C, 30 s; 72 • C, 30 s; and 72 • C, 5 min. A 2% agarose gel (NZYTech) in 1x TAE (NZYTech) was prepared containing 5 µL/100 mL of GreenSafe Premium (NZYTech).…”