Emergence of Nosocomial Pneumonia Caused by Colistin-Resistant Escherichia coli in Patients Admitted to Chest Intensive Care Unit

Abstract

(1) Background: Colistin is a last-resort antibiotic used in treating multidrug-resistant Gram-negative infections. The growing emergence of colistin resistance in Escherichia coli (E. coli) represents a serious health threat, particularly to intensive care unit (ICU) patients. (2) Methods: In this work, we investigated the emergence of colistin resistance in 140 nosocomial E. coli isolated from patients with pneumonia and admitted to the chest ICU over 36 months. Virulence and resistance-related genes and E. coli pathotypes in colistin-resistant and colistin-sensitive isolates were determined. (3) Results: Colistin resistance was observed in 21/140 (15%) of the nosocomial E. coli isolates. The MIC50 of the resistant strains was 4 mg/L, while MIC90 was 16 mg/L. Colistin-resistant isolates were also co-resistant to amoxicillin, amoxicillin/clavulanic, aztreonam, ciprofloxacin, and chloramphenicol. The mechanism of colistin resistance was represented by the presence of mcr-1 in all resistant strains. Respectively, 42.9% and 36.1% of colistin-resistant and colistin-sensitive groups were extended-spectrum β-lactamase (ESBL) producers, while 23.8% and 21% were metallo β-lactamase (MBL) producers. blaTEM-typewas the most frequently detected ESBL gene, while blaIMP-type was the most common MBL in both groups. Importantly, most resistant strains showed a significantly high prevalence of astA (76.2%), aggR (76.2%), and pic (52.4%) virulence-related genes. Enteroaggregative E. coli (76%) was the most frequently detected genotype among the colistin-resistant strains. (4) Conclusion: The high colistin resistance rate observed in E. coli strains isolated from patients with nosocomial pneumonia in our university hospital is worrisome. These isolates carry different drug resistance and virulence-related genes. Our results indicate the need for careful monitoring of colistin resistance in our university hospital. Furthermore, infection control policies restricting the unnecessary use of extended-spectrum cephalosporins and carbapenems are necessary.

The Impact of COVID-19 on the Profile of Hospital-Acquired Infections in Adult Intensive Care Units

“…The only drugs that exhibited fairly low overall resistance rates were linezolid and colistin. Linezolid resistance across Europe and worldwide remains low [23,24], but colistin-resistant HAIs in ICUs are becoming a concern [25,26]. Colistin plays a crucial role in treatment of MDR infections, and efforts toward determining colistin resistance on a larger scale are ongoing [27].…”

A Versatile Approach for the Synthesis of Antimicrobial Polymer Brushes on Natural Rubber/Graphene Oxide Composite Films via Surface-Initiated Atom-Transfer Radical Polymerization

“…The cationic portion of the zwitterionic groups interacts with negatively charged bacterial cell membranes to result in the effect of cell lysis [ 52 , 53 , 54 ]. Gram-negative bacterium E. coli and Gram-positive bacterium S. aureus are common and representative infection strains [ 55 ], which are used to evaluate the antibacterial effect of the NR/GO and NR/GO-PSBMA films. Antibacterial activity was determined through the use of the disc diffusion assay of NR/GO films and NR/GO-PSBMA films ( Figure 5 ).…”

Screening of mcr-1 among Gram-Negative Bacteria from Different Clinical Samples from ICU Patients in Alexandria, Egypt: One-Year Study

“…The first report of mcr-1 from a clinical isolate in Egypt was provided in 2016 by Elnahriry et al (2016) . Then, different studies reported the presence of mcr-1 among E. coli clinical isolates in Egypt, including Anan et al (2021) , who found only four (7.5%) E. coli harboring mcr-1 among colistin-resistant isolates, and El-Mokhtar et al (2021) who reported that all their studied E. coli isolates resistant to colistin carried mcr-1 . Moreover, another study reported the presence of mcr-1 in one E. coli and one K. pneumoniae isolate among their 450 enterobacterial isolates ( Zafer et al 2019 ).…”