Genomics Characterization of Colistin Resistant Escherichia coli from Chicken Meat-the First Report in the United Arab Emirates.

Plasmid-mediated colistin resistance is an emerging One Health challenge at the human-food-environment interface. In this study, 12 colistin-resistant Escherichia coli carrying mcr-1.1 gene were characterized using whole-genome sequencing. This is the first report from locally produced chicken meat in the United Arab Emirates. The characterized isolates harbored virulence-associated factors ranging from 4 to 17 genes per isolate. The multilocus sequence type 1011 was identified in 5 (41.6%) isolates. Six (50.0%) of the isolates harbored blaCTX-M-55. All of the E. coli isolates contained Incl2 plasmids. This study highlights for the first time chicken meat as a potential reservoir of mcr-1.1 carrying E. coli in the UAE. This study has implications for food safety and underscores the need for comprehensive surveillance strategies to monitor the spread of colistin resistance. Results presented in this short communication address knowledge gaps on the epidemiology of plasmid-mediated colistin resistance in the Middle East food production chain.

First Report of Colistin-Resistant Escherichia coli Carrying mcr-1 IncI2(delta) and IncX4 Plasmids from Camels (Camelus dromedarius) in the Gulf Region.

Addressing the emergence of antimicrobial resistance (AMR) poses a significant challenge in veterinary and public health. In this study, we focused on determining the presence, phenotypic background, and genetic epidemiology of plasmid-mediated colistin resistance (mcr) in Escherichia coli bacteria isolated from camels farmed in the United Arab Emirates (UAE). Fecal samples were collected from 50 camels at a Dubai-based farm in the UAE and colistin-resistant Gram-negative bacilli were isolated using selective culture. Subsequently, a multiplex PCR targeting a range of mcr-genes, plasmid profiling, and whole-genome sequencing (WGS) were conducted. Eleven of fifty camel fecal samples (22%) yielded colonies positive for E. coli isolates carrying the mcr-1 gene on mobile genetic elements. No other mcr-gene variants and no chromosomally located colistin resistance genes were detected. Following plasmid profiling and WGS, nine E. coli isolates from eight camels were selected for in-depth analysis. E. coli sequence types (STs) identified included ST7, ST21, ST24, ST399, ST649, ST999, and STdaa2. Seven IncI2(delta) and two IncX4 plasmids were found to be associated with mcr-1 carriage in these isolates. These findings represent the first identification of mcr-1-carrying plasmids associated with camels in the Gulf region. The presence of mcr-1 in camels from this region was previously unreported and serves as a novel finding in the field of AMR surveillance.

Genomic profiling of extended-spectrum ß-lactamase-producing Escherichia coli from Pets in the United Arab Emirates: Unveiling colistin resistance mediated by mcr-1.1 and its probable transmission from chicken meat - A One Health perspective.

BACKGROUND: The United Arab Emirates (UAE) has witnessed rapid urbanization and a surge in pet ownership, sparking concerns about the possible transfer of antimicrobial resistance (AMR) from pets to humans and the environment. This study delves into the whole-genome sequencing analysis of ESBL-producing E. coli strains from healthy cats and dogs in the UAE, which exhibit multidrug resistance (MDR). Additionally, it provides a genomic exploration of the mobile colistin resistance gene mcr-1.1, marking the first instance of its detection in Middle Eastern pets. METHODS: We investigate 17 ESBL-producing E. coli strains from healthy UAE pets using WGS and bioinformatics analysis to identify genes encoding virulence factors, assign diverse typing schemes to the isolates, and scrutinize the presence of AMR genes. Furthermore, we characterized plasmid contigs housing the mcr-1.1 gene and conducted phylogenomic analysis to evaluate their relatedness to previously identified UAE isolates. RESULTS: Our study unveiled a variety of virulence factor-encoding genes within the isolates, with fimH emerging as the most prevalent. Regarding ß-lactamase resistance genes, the blaCTX group 1 gene family predominated, with CTX-M-15 found in 52.9% (9/17) of the isolates, followed by CTX-M-55 in 29.4% (5/17). These isolates were categorized into multiple sequence types (STs), with the epidemic ST131 being the most frequent. The presence of the mcr-1.1 gene, linked to colistin resistance, was confirmed in two isolates. These isolates belonged to ST1011 and displayed distinct profiles of ß-lactamase resistance genes. Phylogenomic analysis revealed close connections between the isolates and those from chicken meat in the UAE. CONCLUSION: Our study underscores the presence of MDR ESBL-producing E. coli in UAE pets. The identification of mcr-1.1-carrying isolates warrants the urgency of comprehensive AMR surveillance and highlights the role of companion animals in AMR epidemiology. These findings underscore the significance of adopting a One Health approach to mitigate AMR transmission risks effectively.

High efficacy and enhanced synergistic activity of the novel siderophore-cephalosporin cefiderocol against multidrug-resistant and extensively drug-resistant Klebsiella pneumoniae from inpatients attending a single hospital in the United Arab Emirates.

BACKGROUND: Cefiderocol (CFDC) is a novel siderophore-cephalosporin, which usually penetrates the bacteria through the iron-uptake pathways. Data is limited on the factors affecting CFDC activity and methods for overcoming resistance development. Synergistic approaches are needed to tackle antimicrobial resistance. This study aimed to determine CFDC activity on Klebsiella pneumoniae isolates from patients attending a single hospital in the United Arab Emirates (UAE), to explore the effect of ß-lactamases on CFDC activity and to enhance CFDC susceptibility in both iron-depleted and iron-enriched conditions. METHODS: We investigated 238 K. pneumoniae strains from diverse clinical sources. ß-lactamase genes were detected by PCR. Susceptibility to CFDC and 12 comparator antibiotics were tested. Combinations of CFDC with ß-lactamase inhibitors (BLIs) and/or an outer membrane (OM) permeabilizer (polymyxin B nonapeptide) were tested in iron-depleted and iron-enriched conditions. RESULTS: CFDC exhibited efficacy of 97.9%, against multidrug-resistant (MDR), and extensively drug-resistant (XDR) strains, in addition to strains resistant to the last resort drugs such as colistin and tigecycline, including dual carbapenemase-producers (blaNDM and blaOXA-48-like) with MIC ≤ 0.06-8 µg/ml. It was effective in killing strains with single and multiple ß-lactamases; however, it lost activity in iron-enriched conditions. Synergy was achieved with dual combination of CFDC and BLIs, especially avibactam, which caused a significant reduction in MICs even in iron-enriched conditions. A significant reduction was seen with the triple combination including an OM permeabilizer plus avibactam. Killing-kinetic studies proved that the combination therapy caused dose reduction and faster killing by CFDC than the monotherapy. CONCLUSIONS: CFDC was deemed effective against MDR and XDR K. pneumoniae. Synergistic combination of CFDC with BLIs and OM permeabilizers could be effective to treat infections in iron-rich sites, but this should be investigated in vivo.

Extreme resistance to the novel siderophore-cephalosporin cefiderocol in an extensively drug-resistant Klebsiella pneumoniae strain causing fatal pneumonia with sepsis: genomic analysis and synergistic combinations for resistance reversal.

Cefiderocol (CFDC) is the first-in-class siderophore-cephalosporin. Klebsiella pneumoniae strain that is extremely resistant to CFDC (MIC: 256 µg/ml) was isolated for the first time in the United Arab Emirates from a patient with pneumonia and sepsis. It belonged to sequence-type 14 (ST14), with a novel core genome ST. Resistance was driven by the co-expression of ß-lactamases (blaNDM-1, blaOXA-232 and blaCTX-M-15) and a mutation in catecholate-siderophore receptor, utilized by CFDC to enter the bacterial cell. Synergistic combinations (ß-lactamase inhibitors, aztreonam plus CFDC) re-sensitized the bacteria to CFDC. Although CFDC resistance is multifactorial, the combination with ß-lactamase inhibitors represents a promising approach in resistance reversal for fighting superbugs.

Assessing the Prevalence and Potential Risks of Salmonella Infection Associated with Fresh Salad Vegetable Consumption in the United Arab Emirates.

This study aimed to investigate the occurrence and characteristics of Salmonella isolates in salad vegetables in the United Arab Emirates (UAE). Out of 400 samples tested from retail, only 1.25% (95% confidence interval, 0.41-2.89) were found to be positive for Salmonella, all of which were from conventional local produce, presented at ambient temperature, and featured as loose items. The five Salmonella-positive samples were arugula (n = 3), dill (n = 1), and spinach (n = 1). The Salmonella isolates from the five samples were found to be pan-susceptible to a panel of 12 antimicrobials tested using a disc diffusion assay. Based on whole-genome sequencing (WGS) analysis, only two antimicrobial resistance genes were detected-one conferring resistance to aminoglycosides (aac(6')-Iaa) and the other to fosfomycin (fosA7). WGS enabled the analysis of virulence determinants of the recovered Salmonella isolates from salad vegetables, revealing a range from 152 to 165 genes, collectively grouped under five categories, including secretion system, fimbrial adherence determinants, macrophage-inducible genes, magnesium uptake, and non-fimbrial adherence determinants. All isolates were found to possess genes associated with the type III secretion system (TTSS), encoded by Salmonella pathogenicity island-1 (SPI-1), but various genes associated with the second type III secretion system (TTSS-2), encoded by SPI-2, were absent in all isolates. Combining the mean prevalence of Salmonella with information regarding consumption in the UAE, an exposure of 0.0131 salmonellae consumed per person per day through transmission via salad vegetables was calculated. This exposure was used as an input in a beta-Poisson dose-response model, which estimated that there would be 10,584 cases of the Salmonella infection annually for the entire UAE population. In conclusion, salad vegetables sold in the UAE are generally safe for consumption regarding Salmonella occurrence, but occasional contamination is possible. The results of this study may be used for the future development of risk-based food safety surveillance systems in the UAE and to elaborate on the importance for producers, retailers, and consumers to follow good hygiene practices, particularly for raw food items such as leafy salad greens.

Cracking the Code: Unveiling the Diversity of Carbapenem-Resistant Klebsiella pneumoniae Clones in the Arabian Peninsula through Genomic Surveillance.

The rise of antimicrobial resistance is a global challenge that requires a coordinated effort to address. In this study, we examined the genetic similarity of carbapenem-resistant Klebsiella pneumoniae (CRKP) in countries belonging to the Gulf Cooperation Council (GCC) to gain a better understanding of how these bacteria are spreading and evolving in the region. We used in silico genomic tools to investigate the occurrence and prevalence of different types of carbapenemases and their relationship to specific sequence types (STs) of CRKP commonly found in the region. We analyzed 720 publicly available genomes of multi-drug resistant K. pneumoniae isolates collected from six GCC countries between 2011 and 2020. Our findings showed that ST-14 and ST-231 were the most common STs, and 51.7% of the isolates carried blaOXA-48-like genes. Additionally, we identified rare carbapenemase genes in a small number of isolates. We observed a clonal outbreak of ST-231 in Oman, and four Saudi isolates were found to have colistin resistance genes. Our study offers a comprehensive overview of the genetic diversity and resistance mechanisms of CRKP isolates in the GCC region that could aid in developing targeted interventions to combat this pressing global issue.

Contamination Levels and Phenotypic and Genomic Characterization of Antimicrobial Resistance in Escherichia coli Isolated from Fresh Salad Vegetables in the United Arab Emirates.

Contaminated fresh produce has been identified as a vehicle for human foodborne illness. The present study investigated the counts, antimicrobial resistance profile, and genome-based characterization of Escherichia coli in 11 different types of fresh salad vegetable products (n = 400) sampled from retailers in Abu Dhabi and Dubai in the United Arab Emirates. E. coli was detected in 30% of the tested fresh salad vegetable items, with 26.5% of the samples having an unsatisfactory level (≥100 CFU/g) of E. coli, notably arugula and spinach. The study also assessed the effect of the variability in sample conditions on E. coli counts and found, based on negative binominal regression analysis, that samples from local produce had a significantly higher (p-value < 0.001) E. coli count than imported samples. The analysis also indicated that fresh salad vegetables from the soil-less farming system (e.g., hydroponic and aeroponic) had significantly (p-value < 0.001) fewer E. coli than those from traditional produce farming. The study also examined the antimicrobial resistance in E. coli (n = 145) recovered from fresh salad vegetables and found that isolates exhibited the highest phenotypic resistance toward ampicillin (20.68%), tetracycline (20%), and trimethoprim-sulfamethoxazole (10.35%). A total of 20 (13.79%) of the 145 E. coli isolates exhibited a multidrug-resistant phenotype, all from locally sourced leafy salad vegetables. The study further characterized 18 of the 20 multidrug-resistant E. coli isolates using whole-genome sequencing and found that the isolates had varying numbers of virulence-related genes, ranging from 8 to 25 per isolate. The frequently observed genes likely involved in extra-intestinal infection were CsgA, FimH, iss, and afaA. The ß-lactamases gene blaCTX-M-15 was prevalent in 50% (9/18) of the E. coli isolates identified from leafy salad vegetable samples. The study highlights the potential risk of foodborne illness and the likely spread of antimicrobial resistance and resistance genes associated with consuming leafy salad vegetables and emphasizes the importance of proper food safety practices, including proper storage and handling of fresh produce.

Boosting the Antibacterial Activity of Azithromycin on Multidrug-Resistant Escherichia coli by Efflux Pump Inhibition Coupled with Outer Membrane Permeabilization Induced by Phenylalanine-Arginine ß-Naphthylamide.

The global spread of multidrug-resistant (MDR) bacteria increases the demand for the discovery of new antibiotics and adjuvants. Phenylalanine-arginine ß-naphthylamide (PAßN) is an inhibitor of efflux pumps in Gram-negative bacteria, such as the AcrAB-TolC complex in Escherichia coli. We aimed to explore the synergistic effect and mechanism of action of PAßN combined with azithromycin (AZT) on a group of MDR E. coli strains. Antibiotic susceptibility was tested for 56 strains, which were screened for macrolide resistance genes. Then, 29 strains were tested for synergy using the checkerboard assay. PAßN significantly enhanced AZT activity in a dose-dependent manner in strains expressing the mphA gene and encoding macrolide phosphotransferase, but not in strains carrying the ermB gene and encoding macrolide methylase. Early bacterial killing (6 h) was observed in a colistin-resistant strain with the mcr-1 gene, leading to lipid remodeling, which caused outer membrane (OM) permeability defects. Clear OM damage was revealed by transmission electron microscopy in bacteria exposed to high doses of PAßN. Increased OM permeability was also proven by fluorometric assays, confirming the action of PAßN on OM. PAßN maintained its activity as an efflux pump inhibitor at low doses without permeabilizing OM. A non-significant increase in acrA, acrB, and tolC expression in response to prolonged exposure to PAßN was noted in cells treated with PAßN alone or with AZT, as a reflection of bacterial attempts to counteract pump inhibition. Thus, PAßN was found to be effective in potentiating the antibacterial activity of AZT on E. coli through dose-dependent action. This warrants further investigations of its effect combined with other antibiotics on multiple Gram-negative bacterial species. Synergetic combinations will help in the battle against MDR pathogens, adding new tools to the arsenal of existing medications.

Enumeration, antimicrobial resistance and genomic characterization of extended-spectrum ß-lactamases producing Escherichia coli from supermarket chicken meat in the United Arab Emirates.

The occurrence and counts of extended-spectrum ß-lactamase (ESBL)-producing Escherichia coli in retail chicken sold in the United Arab Emirates (UAE) were investigated in this study. Results indicated that 79.68 % of chicken carcasses (251/315) sampled from UAE supermarkets harbored ESBL-producing E. coli. About half (51.75 % [163/315]) of the tested samples had an ESBL-producing E. coli count range between ≥3 log10 and < 5 log10 CFU/g. The antimicrobial resistance profiles of a subset of 100 isolates showed high rates of non-susceptibility to clinically significant antibiotics, particularly ciprofloxacin (80 %) and cefepime (46 %). Moreover, 7 % of the isolates exhibited resistance to colistin, with PCR-based screening revealing the presence of the mcr-1 gene in all colistin-resistant isolates. Multiplex PCR screening identified blaCTX-M and blaTEM genes as the most frequently presented genes among the phenotypically confirmed ESBL-producing E. coli. Further whole-genome sequencing and bioinformatic analysis of 27 ESBL-producing E. coli isolates showed that the gene family blaCTX group 1 was the most prevalent, notably CTX-M-55 (55.55 % [15/27]), followed by CTX-M-15 (22.22 % [6/27]). The most common sequence types (STs) were ST359 and ST1011, with three evident clusters identified based on phylogenomic analysis, aligned with isolates from specific production companies. Analysis of plasmid incompatibility types revealed IncFIB, IncFII, Incl2, and IncX1 as the most commonly featured plasmids. The findings of this study indicate a noticeable prevalence and high counts of ESBL-producing E. coli in chicken sampled from supermarkets in the UAE. The high rates of antimicrobial resistance to clinically important antibiotics highlight the potential public health risk associated with consuming chicken contaminated with ESBL-producing E. coli. Overall, this study emphasizes the importance of continued antimicrobial resistance monitoring in the UAE food chain and calls for further exposure risk assessment of the consumption of ESBL-producing E. coli via chicken meat.

Genomic characterization of molecular markers associated with antimicrobial resistance and virulence of the prevalent Campylobacter coli isolated from retail chicken meat in the United Arab Emirates.

Campylobacter is a major cause of gastroenteritis worldwide, with broiler meat accounting for most illnesses. Antimicrobial intervention is recommended in severe cases of campylobacteriosis. The emergence of antimicrobial resistance (AMR) in Campylobacter is a concerning food safety challenge, and monitoring the trends of AMR is vital for a better risk assessment. This study aimed to characterize the phenotypic profiles and molecular markers of AMR and virulence in the prevalent Campylobacter species contaminating chilled chicken carcasses sampled from supermarkets in the United Arab Emirates (UAE). Campylobacter was detected in 90 (28.6%) out of 315 tested samples, and up to five isolates from each were confirmed using multiplex PCR. The species C. coli was detected in 83% (75/90) of the positive samples. Whole-genome sequencing was used to characterize the determinants of AMR and potential virulence genes in 45 non-redundant C. coli isolates. We identified nine resistance genes, including four associated with resistance to aminoglycoside (aph(3')-III, ant(6)-Ia, aph(2″)-Ib, and aac(6')-Im), and three associated with Beta-lactam resistance (blaOXA-61, blaOXA-193, and blaOXA-489), and two linked to tetracycline resistance (tet(O/32/O), and tet(O)), as well as point mutations in gyrA (fluoroquinolones resistance), 23S rRNA (macrolides resistance), and rpsL (streptomycin resistance) genes. A mutation in gyrA 2 p.T86I, conferring resistance to fluoroquinolones, was detected in 93% (42/45) of the isolates and showed a perfect match with the phenotype results. The simultaneous presence of blaOXA-61 and blaOXA-193 genes was identified in 86.6% (39/45) of the isolates. In silico analysis identified 7 to 11 virulence factors per each C. coli isolate. Some of these factors were prevalent in all examined strains and were associated with adherence (cadF, and jlpA), colonization and immune evasion (capsule biosynthesis and transport, lipooligosaccharide), and invasion (ciaB). This study provides the first published evidence from the UAE characterizing Campylobacter virulence, antimicrobial resistance genotype, and phenotype analysis from retail chicken. The prevalent C. coli in the UAE retail chicken carries multiple virulence genes and antimicrobial resistance markers and exhibits frequent phenotype resistance to macrolides, quinolones, and tetracyclines. The present investigation adds to the current knowledge on molecular epidemiology and AMR development in non-jejuni Campylobacter species in the Middle East and globally.

Elucidating the effect of iron acquisition systems in Klebsiella pneumoniae on susceptibility to the novel siderophore-cephalosporin cefiderocol.

BACKGROUND: Cefiderocol (CFDC) is a novel siderophore-cephalosporin, effective against multidrug-resistant Gram-negative bacteria. As it has a siderophore side chain, it can utilize iron acquisition systems for penetration of the bacterial outer membrane. We aimed to elucidate the role of siderophores and iron uptake receptors in defining Klebsiella pneumoniae susceptibility to CFDC. METHODS: Initially, 103 K. pneumoniae strains were characterized for susceptibility to different antibiotics including CFDC. CFDC minimum inhibitory concentrations (MIC) were determined in iron-depleted and iron-enriched conditions. Iron uptake genes including siderophores, their receptors, ferric citrate (fecA) and iron uptake (kfu) receptors were detected by PCR in all the strains. For 10 selected strains, gene expression was tested in iron-depleted media with or without CFDC treatment and compared to expression in iron-enriched conditions. RESULTS: CFDC exhibited 96.1% susceptibility, being superior to all the other antibiotics (MIC50: 0.5 and MIC90: 4 µg/ml). Only three strains (2.9%) were intermediately susceptible and a pandrug resistant strain (0.97%) was resistant to CFDC (MIC: 8 and 256 µg/ml, respectively). The presence of kfu and fecA had a significant impact on CFDC MIC, especially when co-produced, and if coupled with yersiniabactin receptor (fyuA). CFDC MICs were negatively correlated with enterobactin receptor (fepA) expression and positively correlated with expression of kfu and fecA. Thus, fepA was associated with increased susceptibility to CFDC, while kfu and fecA were associated with reduced susceptibility to CFDC. CFDC MICs increased significantly in iron-enriched media, with reduced expression of siderophore receptors, hence, causing less drug uptake. CONCLUSION: Iron acquisition systems have a significant impact on CFDC activity, and their altered expression is a factor leading to reduced susceptibility. Iron concentration is also a major player affecting CFDC susceptibility; therefore, it is essential to explore possible ways to improve the drug activity to facilitate its use to treat infections in iron-rich sites.

Discerning the role of polymyxin B nonapeptide in restoring the antibacterial activity of azithromycin against antibiotic-resistant Escherichia coli.

Antimicrobial resistance is a global public health threat. Antibiotic development pipeline has few new drugs; therefore, using antibiotic adjuvants has been envisioned as a successful method to preserve existing medications to fight multidrug-resistant (MDR) pathogens. In this study, we investigated the synergistic effect of a polymyxin derivative known as polymyxin B nonapeptide (PMBN) with azithromycin (AZT). A total of 54 Escherichia coli strains were first characterized for macrolide resistance genes, and susceptibility to different antibiotics, including AZT. A subset of 24 strains was then selected for synergy testing by the checkerboard assay. PMBN was able to re-sensitize the bacteria to AZT, even in strains with high minimum inhibitory concentrations (MIC: 32 to ≥128 µg/ml) for AZT, and in strains resistant to the last resort drugs such as colistin and meropenem. The fractional inhibitory concentration index was lower than 0.5, demonstrating that PMBN and AZT combinations had a synergistic effect. The combinations worked efficiently in strains carrying mphA gene encoding macrolide phosphotransferase which can cause macrolide inactivation. However, the combinations were inactive in strains having an additional ermB gene encoding macrolide methylase which causes ribosomal drug target alteration. Killing kinetics study showed a significant reduction of bacterial growth after 6 h of treatment with complete killing achieved after 24 h. Transmission electron microscopy showed morphological alterations in the bacteria treated with PMBN alone or in combination with AZT, with evidence of damage to the outer membrane. These results suggested that PMBN acted by increasing the permeability of bacterial outer membrane to AZT, which was also evident using a fluorometric assay. Using multiple antimicrobial agents could therefore be a promising strategy in the eradication of MDR bacteria. PMBN is a good candidate for use with other antibiotics to potentiate their activity, but further studies are required in vivo. This will significantly contribute to resolving antimicrobial resistance crisis.

Early Years of Carbapenem-Resistant Enterobacterales Epidemic in Abu Dhabi.

Recent studies showed that the current endemic of carbapenem-resistant Enterobacterales (CRE) in the Emirate of Abu Dhabi is dominated by highly resistant Klebsiella pneumoniae clones ST14, ST231, and CC147, respectively. In the absence of continuous, molecular typing-based surveillance, it remained unknown whether they lately emerged and rapidly became dominant, or they had been present from the early years of the endemic. Therefore, antibiotic resistance, the presence of carbapenemase and 16S methylase genes, and the sequence types of CRE strains collected between 2009 and 2015 were compared with those collected between 2018 and 2019. It was found that members of these three clones, particularly those of the most prevalent ST14, started dominating already in the very early years of the CRE outbreak. Furthermore, while severely impacting the overall antibiotic resistance patterns, the effect of these clones was not exclusive: for example, increasing trends of colistin or decreasing rates of tigecycline resistance were also observed among nonclonal isolates. The gradually increasing prevalence of few major, currently dominating clones raises the possibility that timely, systematic, molecular typing-based surveillance could have provided tools to public health authorities for an early interference with the escalation of the local CRE epidemic.

First report from supermarket chicken meat and genomic characterization of colistin resistance mediated by mcr-1.1 in ESBL-producing, multidrug-resistant Salmonella Minnesota.

Plasmid-borne colistin resistance is considered one of the most complex public health concerns worldwide. Several studies reported the presence of the mcr-1.1 harboring Salmonella from the foodstuffs worldwide; still, there is a knowledge gap about the occurrence of these isolates in the Middle East. In this study, we report an mcr-1.1-mediated colistin resistance in two multidrug-resistant (MDR) S. Minnesota (denoted as Sal_2 and Sal_10), with both being also extended-spectrum ß-lactamase (ESBL) producing. These isolates have been recovered from two independent samples out of 315 chilled chicken meat tested from retail supermarkets in the United Arab Emirates (UAE). Based on whole-genome sequencing (WGS) analysis, both isolates belonged to the same Sequence Type (ST) ST548. They shared the same genes encoding resistance to the following antimicrobials: polymyxin (mcr-1.1), phenicol (floR), quinolone (qnrB19), aminoglycoside (aac(6')-Iaa), tetracycline (tet(A)), and sulfonamide (sul2). However, the isolates featured different patterns of ß-lactamase resistance genes, which included blaCTX-M-55 (ESBL-ß-lactamase) and blaCMY-2 (AmpC-ß-lactamase) in the isolate Sal_2, and blaTEM-215 (ESBL-ß-lactamase) in the isolate Sal_10. WGS analysis inferred that both S. Minnesota isolates in this study carry an IncX4 plasmid harboring the mcr-1.1 variant. To understand the possible origin of the two mcr-1.1 carrying S. Minnesota isolated from retail chicken meat in this study, we conducted a phylogenomic analysis using available genomes of S. enterica, which harbored mcr-1.1 gene (n = 240, from the Middle East and Asian countries) deposited in the NCBI database. We found that Sal_2 and Sal_10 independently clustered together with other isolates detected in China, mainly from the chicken origin and to a lesser extent from human clinical origin. The finding of mcr-producing colistin-resistant strains in retail chicken meat warrants a more comprehensive One Health investigations involving strains from animals, retail food chains, and human clinical isolates at the national level in the UAE.

Enumeration, Antimicrobial Resistance, and Virulence Genes Screening of Enterococcus spp. Isolated from Retail Chicken Carcasses in the United Arab Emirates.

Enterococci have recently emerged as nosocomial pathogens worldwide. Their ubiquitous nature determines their frequent finding in foods as contaminants. In this study, we aimed to determine the counts, species diversity, antimicrobial resistance profile, and to screen for a set of virulence genes among enterococci. Enterococcus were identified from 75.7% (125/165) of chilled chicken carcasses, belonging to seven companies, sampled from retail markets in Abu Dhabi Emirate, United Arab Emirates (U.A.E.). Overall, the samples, with a mean Enterococcus count of 2.58 log10 colony-forming unit (CFU)/g with a standard deviation of ±1.17 log10 CFU/g. Among the characterized Enterococcus isolates (n = 90), Enterococcus faecalis was the predominant species (51.1%), followed by Enterococcus faecium (37.8%). Using Vitek2 automated antimicrobial sensitivity panel, we found none of the E. faecalis nor E. faecium to be resistant to ampicillin, teicoplanin, vancomycin, or tigecycline. A third of the E. faecalis (28.3%) and E. faecium (35.3%) were resistant to high-level gentamicin. Over half of E. faecalis (54.3%) were resistant to ciprofloxacin, and the same was in about a third of E. faecium isolates (29.4%). Linezolid resistance was identified in 10 E. faecalis and 7 E. faecium isolates belonging to samples from three companies. All of the linezolid-resistant isolates harbored oxazolidinone resistance optrA gene. Virulence-associated genes (asa1 and gelE) were significantly (p < 0.05) more detected among E. faecalis compared to E. faecium isolates recovered in this study. Over half of the E. faecalis (25/46) and E. faecium (20/34) isolates were identified as multidrug-resistant. This study provides further insight into virulence genes and their association with the dissemination of multidrug-resistant E. faecalis and E. faecium in supermarket chicken meat in the U.A.E. This is probably the first description of the optrA gene in enterococci from supermarket chicken meat in the U.A.E. and from Arab countries. This study adds to the regional and global understanding of antimicrobial resistance spread in foods of animal origin.

The first nationwide surveillance of carbapenem-resistant Enterobacterales in the United Arab Emirates - increased association of Klebsiella pneumoniae CC14 clone with Emirati patients.

OBJECTIVES: To assess the current prevalence, distribution, and main clonal types of carbapenem-resistant Enterobacterales (CRE) in the United Arab Emirates. METHODS: A total of 504 CRE collected over a 9-month period in 15 hospitals were studied. Antibiotic susceptibility and the presence of common carbapenemase, 16S methylase, and mobile colistin resistance genes were assessed. Selected strains forming larger clusters by pulsed field gel electrophoresis were subjected to whole genome sequencing to identify their sequence types and core genome MLST. RESULTS: Strains expressing OXA and NDM type carbapenemases and 16S methylases were present in all major hospitals. Considerable interhospital differences were noticed, suggesting the role of specific clones. A total of three major Klebsiella pneumoniae clones (CC14, ST231, and CC147) were identified, accounting for 48.6% of all CRE. All clones were significantly more resistant than sporadic isolates. CC14 strains exhibited a significant association with Emirati patients. CONCLUSIONS: Nearly half of CRE infections in the country are due to a limited number of clones. The data indicate the possibility of interhospital transmission, combined in some hospitals with inadequate stewardship practices. The study also revealed an association of the largest, most resistant clone (CC14) with Emirati patients. The specific reasons for it should be clarified by further investigations.

Molecular Characterization of MCR-1 Producing Enterobacterales Isolated in Poultry Farms in the United Arab Emirates.

Data on the prevalence of MCR-producing Enterobacterales of animal origin are scarce from the Arabian Peninsula. We investigated the presence and variety of such strains from fecal specimens of poultry collected in four farms in the United Arab Emirates. Colonies from ten composite samples per farm grown on colistin-supplemented plates were PCR-screened for alleles of the mcr gene. Thirty-nine isolates selected based on species, colony morphology, and plasmid profile were subjected to whole genome sequencing. The panel of their resistance and virulence genes, MLST and cgMLST were established. Transferability and incompatibility types of the MCR-plasmids were determined. mcr-1.1 positive strains were identified in 36 of the 40 samples. Thirty-four multi-drug resistant Escherichia coli of 16 different sequence types, two Escherichia albertii, two Klebsiella pneumoniae and one Salmonella minnesota were identified. Beyond various aminoglycoside, tetracycline, and co-trimoxazole resistance genes, seven of them also carried ESBL genes and one blaCMY-2. Six IncHI2, 26 IncI2 and 4 IncX4 MCR-plasmids were mobilized, in case of the IncHI2 plasmids co-transferring ampicillin, chloramphenicol and tetracycline resistance. The diversity of mcr-1 positive strains suggest a complex local epidemiology calling for a coordinated surveillance including animals, retail meat and clinical cases.

Emergence and Genomic Characterization of the First Reported optrA-Carrying Linezolid-Resistant Enterococci Isolated from Retail Broiler Meat in the United Arab Emirates.

The foodborne transfer of resistant genes from enterococci to humans and their tolerance to several commonly used antimicrobials are of growing concern worldwide. Linezolid is a last-line drug for managing complicated illnesses resulting from multidrug-resistant Gram-positive bacteria. The optrA gene has been reported in enterococci as one of the acquired linezolid resistance mechanisms. The present study uses whole-genome sequencing analysis to characterize the first reported isolates of linezolid-resistant E. faecium (n = 6) and E. faecalis (n = 10) harboring the optrA gene isolated from samples of supermarket broiler meat (n = 165) in the United Arab Emirates (UAE). The sequenced genomes were used to appraise the study isolates' genetic relatedness, antimicrobial resistance determinants, and virulence traits. All 16 isolates carrying the optrA gene demonstrated multidrug-resistance profiles. Genome-based relatedness classified the isolates into five clusters that were independent of the isolate sources. The most frequently known genotype among the isolates was the sequence type ST476 among E. faecalis (50% (5/10)). The study isolates revealed five novel sequence types. Antimicrobial resistance genes (ranging from 5 to 13) were found among all isolates that conferred resistance against 6 to 11 different classes of antimicrobials. Sixteen different virulence genes were found distributed across the optrA-carrying E. faecalis isolates. The virulence genes in E. faecalis included genes encoding invasion, cell adhesion, sex pheromones, aggregation, toxins production, the formation of biofilms, immunity, antiphagocytic activity, proteases, and the production of cytolysin. This study presented the first description and in-depth genomic characterization of the optrA-gene-carrying linezolid-resistant enterococci from retail broiler meat in the UAE and the Middle East. Our results call for further monitoring of the emergence of linezolid resistance at the retail and farm levels. These findings elaborate on the importance of adopting a One Health surveillance approach involving enterococci as a prospective bacterial indicator for antimicrobial resistance spread at the human-food interface.

Diversity of carbapenem-resistant Klebsiella pneumoniae ST14 and emergence of a subgroup with KL64 capsular locus in the Arabian Peninsula.

To understand the reasons of successful spread of carbapenem-resistant Klebsiella pneumoniae ST14 (CRKP-ST14) in countries of the Arabian Peninsula, the resistome, capsular locus, carbapenemase carrying plasmid types, and core genome of isolates from the region were compared to global isolates. Thirty-nine CRKP-ST14 strains isolated from 13 hospitals in the United Arab Emirates, Bahrain, and Saudi Arabia were selected for whole genome sequencing on Illumina MiSeq platform based on the variety of carbapenemase genes carried and plasmids bearing these genes. Their resistome, capsular locus, and core genome MLST were compared to 173 CRKP-ST14 genomes available in public databases. The selected 39 CRKP-ST14 produced either NDM-1, OXA-48, OXA-162, OXA-232, KPC-2, or co-produced NDM-1 and an OXA-48-like carbapenemase. cgMLST revealed three clusters: 16 isolates from five UAE cities (C1), 11 isolates from three UAE cities and Bahrain (C2), and 5 isolates from Saudi Arabia (C3), respectively, and seven singletons. Resistance gene profile, carbapenemase genes, and their plasmid types were variable in both C1 and C2 clusters. The majority of CRKP-ST14 had KL2, but members of the C2 cluster and two further singletons possessed KL64 capsular locus. Based on cgMLST comparison of regional and global isolates, CRKP-ST14 with KL64 from four continents formed a distinct cluster, suggesting a recent emergence and spread of this variant. Our findings confirmed clonal transmission coupled with likely horizontal gene transfer in carbapenem-resistant Klebsiella pneumoniae ST14. Dissemination of this genetically flexible, highly resistant clone warrants further monitoring.