Carbapenem and colistin-resistant bacteria in North Lebanon: Coexistence of mcr-1 and NDM-4 genes in Escherichia coli.

INTRODUCTION: The increasing incidence of infections caused by multidrug-resistant bacteria is considered a global health problem. This study aimed to investigate this resistance in Gram-negative bacteria isolated from patients hospitalized in North-Lebanon. METHODOLOGY: All isolates were identified using the matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Antibiotic susceptibility testing was achieved using disk diffusion, E-test and Broth microdilution methods. Phenotypic detection of carbapenemase was carried out using the CarbaNP test. RT-PCR, standard-PCR and sequencing were performed to detect resistance genes and oprD gene. Conjugal transfer was carried out between our isolates and Escherichia coli J53 to detect the genetic localization of resistance genes. MLST was conducted to determine the genotype of each isolate. RESULTS: Twenty-three carbapenem-resistant Enterobacterales of which eight colistin-resistant Escherichia coli, and Twenty carbapenem-resistant Pseudomonas aeruginosa were isolated. All isolates showed an imipenem MIC greater than 32 mg/mL with MICs for colistin greater than 2 mg/L for E. coli isolates. All the Enterobacterales isolates had at least one carbapenemase-encoding gene, with E. coli isolates coharboring blaNDM-4 and mcr-1 genes. Moreover, 16/20 Pseudomonas aeruginosa harbored the blaVIM-2 gene and 18/20 had mutations in the oprD gene. MLST revealed that the isolates belonged to several clones. CONCLUSIONS: We report here the first description in the world of clinical E. coli isolates coharboring blaNDM-4 and mcr-1 genes, and K. pneumoniae isolates producing NDM-6 and OXA-48 carbapenemases. Also, we describe the emergence of NDM-1-producing E. cloacae in Lebanon. Screening for these isolates is necessary to limit the spread of resistant microorganisms in hospitals.

Bacterial infection during wars, conflicts and post-natural disasters in Asia and the Middle East: a narrative review.

Introduction: Bacterial infections resulting from wars and natural disasters represent a major public health problem. Over the past 50 years, Asia and the Middle East have suffered several wars. Moreover, East-Asian countries are considered the most natural disaster-prone countries in the world.Areas covered: This review focuses on bacterial infection occurring during wars and after natural disasters, among refugees, wounded citizens and soldiers as well as the prevention and control measures that must be taken.Expert opinion: During wars, refugees and soldiers represent the two main sources of bacterial infections. Refugees coming from countries with a high prevalence of antimicrobial resistance can spread these pathogens to their final destination. In addition, these refugees living in inadequate shelters can contribute to the spread of bacterial infections. Moreover, some factors including the presence of fixed imported fragments; environmental contamination and nosocomial transmissions, play a key role in the dissemination of bacteria among soldiers. As for natural disasters, several factors are associated with increased bacterial transmissions such as the displacement of large numbers of people into over-crowded shelters, high exposure to disease vectors, lack of water and sanitation. Here, we carry out a systematic review of the bacterial infections that follow these two phenomena.

Intestinal carriage of colistin-resistant Enterobacteriaceae at Saint Georges Hospital in Lebanon.

OBJECTIVES: The increase in resistance to antibiotics has led to the revival of colistin as the last option for treatment, which automatically led to an increase of colistin-resistant, Gram-negative bacteria. In this study, we report the presence of clinical colistin-resistant Enterobacteriaceae isolated from a Lebanese hospital. METHODS: From 23 rectal swabs, eight colistin-resistant clinical strains (five Escherichia coli, two Enterobacter cloacae, and one Klebsiella pneumoniae) were isolated. Antibiotic susceptibility testing was performed using the disk diffusion method and Etest. The broth microdilution method was used to determine colistin susceptibility. Reverse transcription polymerase chain reaction (RT-PCR), standard PCR and sequencing were used to investigate genes encoding for extended-spectrum ß-lactamases, carbapenemases and colistin resistance. Genotyping of these isolates was conducted by multilocus sequence typing (MLST). RESULTS: Results of antibiotic susceptibility testing revealed that all isolates were resistant to colistin. They had MICs for colistin that ranged from 8 to 32 mg/L. Real-time PCR results showed that five strains harboured blaTEM-1 and one strain harboured blaTEM-163. Moreover, four strains were positive for blaCTX-M-15, blaCTX-M-103 and blaCTX-M-189, and K. pneumoniae harboured blaSHV-1. Observed colistin resistance was linked to amino acid substitutions into protein sequences of pmrA/B, phoP/Q, and mgrB. Interestingly, we report here a mutation in the mgrB regulator and pmrA/B, phoP/Q in colistin-resistant E. cloacae and E. coli clinical isolates for the first time in Lebanon. CONCLUSION: This study highlights the presence of colistin-resistant Gram-negative bacteria in a Lebanese hospital, which is worrisome. An urgent strategy needs to be adopted to avoid the spread of such bacteria.

First Detection of Colistin-Resistant Klebsiella pneumoniae in Association with NDM-5 Carbapenemase Isolated from Clinical Lebanese Patients.

This study aims to describe the molecular mechanisms of carbapenem and colistin resistance in Klebsiella pneumoniae strains isolated from hospitalized patients in Lebanon. We report in this study the first description of NDM-5 producing carbapenem-resistant K. pneumoniae ST383, as well as the presence of two out of five isolates resistant to colistin due to mutations in the amino acid sequences of proteins (PmrB, PhoQ, and MgrB). Therefore, screening of such isolates may be effective in limiting the spread of these resistant microorganisms in hospitalized patients and within the community.

Investigation of multidrug-resistant ST2 Acinetobacter baumannii isolated from Saint George hospital in Lebanon.

BACKGROUND: Acinetobacter baumannii is an opportunistic pathogen causing various nosocomial infections. The spread of multidrug-resistant A. baumannii is a major public health problem. The aim of this study was to investigate the molecular epidemiology and the genetic support of multidrug-resistant A. baumannii isolates collected from Saint-Georges Hospital in Lebanon. METHODS: Between January and August 2016, 31 A. baumannii isolates were collected from sputum samples of patients infected with ventilator-associated pneumonia (VAP) and treated with colistin-carbapenem combination therapy. Antibiotic susceptibility testing was performed using the disk diffusion method. Carbapenemases, extended spectrum ß-lactamases encoding genes and mcr-1/2 genes were investigated by RT-PCR and standard PCR. The epidemiological relatedness of the strains was studied using MLST analysis. RESULTS: Most of the isolates exhibited multidrug-resistant phenotypes. All the isolates were carbapenem-resistant and among them, 30 carried the class D carbapenemase blaoxa-23 gene while one isolate carried blaoxa-72 gene. MLST results revealed three sequence types, namely ST2, ST699, and ST627. Isolates having ST2 were the most prevalent clone (29/31, 93.5%). CONCLUSIONS: This study shows a nosocomial spread of multidrug-resistant A. baumannii ST2 having blaOXA-23 gene in Saint-George in Lebanon. Monitoring and control measures need to be adopted to avoid the spread of A. baumannii to patients.