Investigation of carbapenemase and mcr-1 genes in carbapenem-resistant Klebsiella pneumoniae isolates

Abstract

Introduction: Carbapenem-resistant Klebsiella pneumoniae are a major problem. We aimed to investigate carbapenemase-encoding genes and transferable mcr-1 genes among 57 carbapenem-resistant Klebsiella pneumoniae (CRKP) isolates from hospitalized patients.
 Methodology: Antibiotic susceptibility tests were performed by Phoenix (BD). Results for ertapenem and colistin were confirmed by gradient diffusion and microdilution methods. Carbapenemase and mcr-1 genes were investigated by Polymerase Chain Reaction (PCR).
 Results: Thirty-two (56.14%) isolates were from intensive care units (ICU). Antibiotic resistance rates by Phoenix: 52.63% for amikacin; 73.69% trimethoprim sulfamethoxazole; 91.23% cefepime; 82.46% tigecycline; 59.65% colistin. Carbapenemases positivity: 82.45% (47) for blaOXA-48, 40.35% (23) blaOXA-55, 3.50% (2) blaOXA-51, 1.75% (1) blaOXA-23, 1.75% (1) blaOXA-24, 1.75% (1) blaIMP. blaOXA-58, blaKPC, blaNDM-1, and blaVIM were not detected. Twenty (35.08%) isolates had both blaOXA-48 and blaOXA-55. Three isolates were mcr-1 (+) and blaOXA-48 (+). One mcr-1 (+) isolates was blaOXA-51 (+). One colistin sensitive isolate determined by Phoenix, was found colistin resistant by microdilution.
 Conclusion: OXA-48 and OXA-55 co-harboring isolates and mcr-1 gene (+) isolates were spreading. Automated colistin susceptibility results should be confirmed by microdilution method. Resistance mechanisms in Enterobacteriaceae should be determined and the isolates should be monitored by molecular epidemiological methods. Effective infection control measures will contribute to reduce risk of antibiotic resistant bacterial infections and dissemination of antibiotic resistance.

Emergence of carbapenemase-producing and colistin resistant Klebsiella pneumoniae ST101 high-risk clone in Turkey

“…We detected two ST types, ST101 (95.6%) and ST147 (4.4%) in carbapenem and colistin resistant K. pneumoniae. In Turkey, a few study investigated mcr-1 to -3 genes among carbapenem and colistin resistant K. pneumoniae isolates and only Arabacı et al, determined mcr-1 positive KRCP (5.2%) [44,[51][52][53]. In this study, we investigated mcr-1 to -8 genes in colistin and carbapenem resistant K. pneumoniae and reported the molecular characteristics of mcr-1 positive CRKP.…”

Phylogenomics, Epigenomics, Virulome, and Mobilome of Gram-negative Bacteria Co-resistant to Carbapenems and Polymyxins: A One-Health Systematic Review and Meta-analyses

“…OXA-48 was reported to have lower activity against carbapenem but, showed increased activity when it co-exists with ESBLs 19 . Our result showed that OXA-48 was coupled with ESBLs in most isolates (Figure 4), which supports their resistance to carbapenems.…”

“…After sample collection, bacteria were cultured, followed by DNA extraction, gene amplification and whole-genome sequencing. For antibiotic susceptibility tests (AST), most studies employed the broth microdilution method (BMD) to determine colistin resistance 19,22,[50][51][52] . The genomic sequences were also used to identify carbapenemases and colistin resistance mechanisms, as well as assign sequence types (ST) of clones based on multi-locus sequence typing (MLST) 53 .…”

Characterization of a Clinical Enterobacter hormaechei Strain Belonging to Epidemic Clone ST418 Co-carrying blaNDM-1, blaIMP-4 and mcr-9.1

“…As of now, ten different mcr variants noted from mcr-1 to mcr-10 have been described (6)(7)(8). Of more concern, coexistence of mcr and carbapenemase genes has been sporadically reported (9). For instance, mcr-1, mcr-3.5, and bla NDM−5 are found in an Escherichia coli isolate (10), mcr-4.3 and bla NDM−1 are co-identi ed in a clinical E. cloacae isolate from China (11), and bla VIM−4 and mcr-9 are found in an E. hormaechei isolate in USA (12).…”