Molecular characterization, antimicrobial resistance and clinico-bioinformatics approaches to address the problem of extended-spectrum β-lactamase-producing Escherichia coli in western Saudi Arabia

Phenotypic and Genotypic Characterization of Extended Spectrum Beta-Lactamase-Producing Clinical Isolates of Escherichia coli and Klebsiella pneumoniae in Two Kenyan Facilities: A National Referral and a Level Five Hospital

Background

The emergence of antimicrobial resistance (AMR) and multidrug resistance (MDR) among Escherichia coli and Klebsiella pneumoniae, especially through the production of extended spectrum β-lactamases (ESBLs), limits therapeutic options and poses a significant public health threat.

Objective

The aim of this study was to assess the phenotypic and genetic determinants of antimicrobial resistance of ESBL-producing Escherichia coli and Klebsiella pneumoniae isolates from patient samples in two Kenyan Hospitals.

Methods

We collected 138 E. coli and 127 K. pneumoniae isolates from various clinical specimens at the two health facilities from January 2020 to February 2021. The isolates' ESBL production and antibiotic susceptibility were phenotypically confirmed using a standard procedure. Molecular analysis was done through conventional polymerase chain reaction (PCR) with appropriate primers for gadA, rpoB, blaTEM, blaSHV, blaOXA, blaCTX-M-group-1, blaCTX-M-group-2, blaCTX-M-group-9, and blaCTX-M-group-8/25 genes, sequencing and BLASTn analysis.

Results

Most E. coli (82.6%) and K. pneumoniae (92.9%) isolates were ESBL producers, with the highest resistance was against ceftriaxone (69.6% among E. coli and 91.3% among K. pneumoniae) and amoxicillin/clavulanic acid (70.9% among K. pneumoniae). The frequency of MDR was 39.9% among E. coli and 13.4% among K. pneumoniae isolates. The commonest MDR phenotypes among the E. coli isolates were CRO-FEP-AZM-LVX and CRO-AZM-LVX, while the FOX-CRO-AMC-MI-TGC-FM, FOX-CRO-FEP-AMC-TZP-AZM-LVX-MI and CRO-AMC-TZP-AZM-MI were the most frequent among K. pneumoniae isolates. Notably, the FOX-CRO-FEP-AMC-TZP-AZM-LVX-MI phenotype was observed in ESBL-positive and ESBL-negative K. pneumoniae isolates. The most frequent ESBL genes were blaTEM (42%), blaSHV (40.6%), and blaOXA (36.2%) among E. coli, and blaTEM (89%), blaSHV (82.7%), blaOXA (76.4%), and blaCTX-M-group-1 (72.5%) were most frequent ESBL genes among K. pneumoniae isolates. The blaSHV and blaOXA and blaTEM genotypes were predominantly associated with FOX-CRO-FEP-MEM and CRO-FEP multidrug resistance (MDR) and CRO antimicrobial resistance (AMR) phenotypes, among E. coli isolates from Embu Level V (16.7%) and Kenyatta National Hospital (7.0%), respectively.

Conclusions

The high proportion of ESBL-producing E. coli and K. pneumoniae isolates increases the utilization of last-resort antibiotics, jeopardizing antimicrobial chemotherapy. Furthermore, the antimicrobial resistance patterns exhibited towards extended-spectrum cephalosporins, beta-lactam/beta-lactamase inhibitor combinations, fluoroquinolones, and macrolides show the risk of co-resistance associated with ESBL-producing isolates responsible for MDR. Hence, there is a need for regular surveillance and implementation of infection prevention and control strategies and antimicrobial stewardship programs.

Clinical and epidemiological characteristics of multi-drug resistant Enterobacterales isolated from King Fahad Hospital of the University, AlKhobar, Saudi Arabia

Multi-drug resistant (MDR) Enterobacterales remain a major clinical problem. Infections caused by carbapenem-resistant strains are particularly difficult to treat. This study aimed to assess the clinical and epidemiological characteristics of MDR Enterobacterales isolates. A total of 154 non-repetitive clinical isolates, including Escherichia coli (n = 66), Klebsiella pneumoniae (n = 70), and other Enterobacterales (n = 18), were collected from the Diagnostic Microbiology Laboratory at King Fahad Hospital of the University. Most E. coli isolates were collected from urine specimens (n = 50, 75.8%) and resistance against the third and fourth-generation cephalosporins (ceftriaxone, ceftazidime, cefixime, and cefepime) and fluoroquinolones (ciprofloxacin and levofloxacin) was assessed. Clonal relatedness analysis using enterobacterial repetitive intergenic consensus polymerase chain reaction (ERIC-PCR) revealed two clones (E. coli A and B), each comprising two strains. Most K. pneumoniae samples were collected from respiratory specimens (27.1%, 20 samples), and the strains showed overall resistance to most of the antimicrobials tested (54%‒100%). Moreover, clonal-relatedness analysis using ERIC-PCR revealed seven major clones of K. pneumoniae. These findings suggest nosocomial transmission among some identical strains and emphasize the importance of strict compliance with infection prevention and control policies and regulations. Environmental reservoirs could facilitate this indirect transmission, which needs to be investigated.

Genomic characterization of extended spectrum beta lactamases producing multidrug-resistant Escherichia coli clinically isolated harboring chromosomally mediated CTX-M-15 from Alkharj, KSA

Extended Spectrum Beta Lactamases (ESBLs) are the most prevalent enzymes conferring resistance to beta-lactams encoded on plasmids and rarely in chromosomes. This genomic study aims to characterize Escherichia coli to identify antimicrobial resistance genes (ARG), virulence factors, and phylogenetic relationships among ESBL-positive and negative isolates of E. coli obtained from Al-Kharj, Riyadh region, Saudi Arabia. Three clinical isolates from urine and vaginal swabs were obtained and subjected to whole genome sequencing, minimum inhibitory concentration, and antibiotic sensitivity tests. The pathogenicity and ARG were discovered, and the raw genomic sequences were assembled and annotated. Two isolates (E5 and E15) were MDR and ESBLs producers; the sequence type (ST) for E5 was 58, while those for E15 and E21 were 106. Most of the virulence genes were detected as plasmid-mediated; E21 was identified with a hyper-virulent plasmid (pH 2332-166) carrying different virulence factors (TraJ, traT, iss, etsC, hlyF, and iron acquisition associated proteins), plasmids (IncFII, IncFIB, and IncFIA), and insertion sequences (ISEc31). While most of the antimicrobial resistance genes were chromosomally mediated, a rare chromosome insertion of qnrS1 and blaCTX-M-15 with co-occurrence of Tn2 and ISKpn19 was identified in the E5 isolate. The consistent preservation of these genetic elements on bacterial chromosomes and plasmids could enhance the spread of Multidrug-Resistant (MDR) strains across various Enterobacteriaceae Species. This poses a significant threat to the effectiveness of existing antimicrobial treatments.

In depth molecular interaction analyses of the complex of a proposed CTXM-inhibitor bound to the bacterial enzyme

A 'Thumb Rule for Antibiotic Design' against bacteria can be given as, 'The minimum pace of drug design ought to match the swiftness with which bacteria display cutting-edge resistance mechanisms; thereby outwitting the antibiotics and, in turn, the researchers'. Occurrence of drug resistance attributable to CXTM-variants in bacterial pathogens is widespread. In line with our above proposed thumb rule, the present article employed concatenation of virtual screening, docking and simulation to identify a potent in silico validated anti-CTXM-14 ligand. Specifically, this research used the 'MCULE' drug discovery platform to screen a total of 5 million candidate inhibitors to evaluate their binding efficacy with an antibiotic resistance enzyme, CTXM-14 found in bacterial pathogens. A new median approach between 'structure' and 'ligand'-based protocols was employed. Pharmacokinetic profiling was achieved by 'SWISS ADME'. Safety profile for humans was appraised by 'Toxicity Checker'. The complex consisting of the 'Top ligand' (obtained from the screen) harbored within the active pocket of the bacterial CTXM-14 was subjected to 60 ns molecular dynamics simulation with the aid of licensed YASARA STRUCTURE v.21.8.27. Complex tasks were performed by YANACONDA. Fine resolution figures (notably, plots generated from trajectory analyses) were constructed. Simulation snaps were acquired at every 250 picoseconds of the run. The ligand having the IUPAC name as 1-Amino-3-(4-hydroxyphenyl)pyrido[1,2-a]benzimidazole-2,4-dicarbonitrile demonstrated the overall best binding with CTXM-14. Fifteen amino acid residues were found to line the interacting pocket. Remarkably, all of these interacting residues were found to be present among the interacting residues displayed by the reference complex as well, i.e. CTXM-14:Vaborbactam complex (PDB ID 6V7H). A total of 240 simulation snaps were retrieved. The RMSD plot revealed that a plateau was achieved at 32 ns, after which the backbone RMSD fluctuations remained confined within 1.4-2 Å. Video recording of molecular actions was also achieved. In conclusion, this study provides a fresh lead molecule, 1-Amino-3-(4-hydroxyphenyl)pyrido[1,2-a]benzimidazole-2,4-dicarbonitrile against bacterial CTXM-14 protein. The study utilized a new median approach between 'structure' and 'ligand'-based drug design. The lead molecule passed ADMET conditions and an array of medicinal chemistry filters, and is further supported by a stable molecular dynamics. An acceptable skin permeation supports its probable use in antibiotic creams. Moreover, the study provides a clear 'Thumb Rule for Antibiotic Design' against bacteria, which although often assumed, can be clearly stated for the first time. Synthesis of the screening-proposed molecule followed by in-vitro and in-vivo validation is highly recommended.Communicated by Ramaswamy H. Sarma.

An Overview of Antimicrobial Resistance in Saudi Arabia (2013-2023) and the Need for National Surveillance

Antimicrobial resistance (AMR) is a well-recognized global threat. The World Health Organization (WHO) issued a report ranking the critical types of bacterial resistance that need to be monitored. Several studies from individual institutions in Saudi Arabia have reported rates of antimicrobial resistance using automated methods. However, no national surveillance study has been conducted to date using gold standard methods for antimicrobial susceptibility testing. This review summarizes AMR rates for major bacterial pathogens in Saudi Arabia and provides a justification for the need for a national surveillance project. In Saudi Arabia, AMR rates for both Gram-positive and Gram-negative bacteria are on the rise. Surveillance studies help identify AMR trends and emergence of outbreaks. The WHO has started a program, the Global Antimicrobial Resistance Surveillance System (GLASS), encouraging its member states, including Saudi Arabia, to conduct antimicrobial surveillance studies to estimate AMR rates worldwide. Of the microbiological methods used to test antimicrobial susceptibility, only broth microdilution (BMD) is considered the "gold standard." As AMR studies in Saudi Arabia are sparse, mostly limited to single centers and were conducted using automated methods, a national AMR surveillance project is needed to evaluate the current status and to inform stewardship decisions.

A Narrative Review of Healthcare-Associated Gram-Negative Infections Among Pediatric Patients in Middle Eastern Countries

INTRODUCTION

Gram-negative bacteria (GNB) have become prominent across healthcare and community settings due to factors including lack of effective infection control and prevention (ICP) and antimicrobial stewardship programs (ASPs), GNB developing antimicrobial resistance (AMR), and difficulty treating infections. This review summarizes available literature on healthcare-associated infections (HAIs) in Middle Eastern pediatric patients.

METHODS

Literature searches were performed with PubMed and Embase databases. Articles not reporting data on GNB, HAIs, pediatric patients, and countries of interest were excluded.

RESULTS

The searches resulted in 220 publications, of which 49 met the inclusion criteria and 1 additional study was identified manually. Among 19 studies across Egypt reporting GNB prevalence among pediatric patients, Klebsiella species/K. pneumoniae and Escherichia coli were typically the most common GNB infections; among studies reporting carbapenem resistance and multidrug resistance (MDR), rates reached 86% and 100%, respectively. Similarly, in Saudi Arabia, Klebsiella spp./K. pneumoniae and E. coli were the GNB most consistently associated with infections, and carbapenem resistance (up to 100%) and MDR (up to 75%) were frequently observed. In other Gulf Cooperation Council countries, including Kuwait, Oman, and Qatar, carbapenem resistance and MDR were also commonly reported. In Jordan and Lebanon, E. coli and Klebsiella spp./K. pneumoniae were the most common GNB isolates, and AMR rates reached 100%.

DISCUSSION

This review indicated the prevalence of GNB-causing HAIs among pediatric patients in Middle Eastern countries, with studies varying in reporting GNB and AMR. Most publications reported antimicrobial susceptibility of isolated GNB strains, with high prevalence of extended-spectrum beta-lactamase-producing K. pneumoniae and E. coli isolates. A review of ASPs highlighted the lack of data available in the region.

CONCLUSIONS

Enhanced implementation of ICP, ASPs, and AMR surveillance is necessary to better understand the widespread burden of antimicrobial-resistant GNB and to better manage GNB-associated HAIs across Middle Eastern countries.

Molecular interaction of a putative inhibitor with bacterial SHV, an enzyme associated with antibiotic resistance

Tackling the ever-looming threat of antibiotic resistance remains a challenge for clinicians and microbiologists across the globe. Sulfhydryl variable (SHV) is a known bacterial enzyme associated with antibiotic resistance. The SHV enzyme has many variants. The present article describes identification and molecular interaction of a putative inhibitor with the bacterial SHV enzyme as a step towards novel antibacterial drug discovery. The MCULE-platform was used for screening a collection of 5 000 000 ligand molecules to evaluate their binding potential to the bacterial SHV-1 enzyme. Estimation of pharmacokinetic features was realized with the aid of the 'SWISS ADME' tool. Toxicity-checks were also performed. The docked complex of 'the top screened out ligand' and 'the bacterial SHV-1 protein' was subjected to molecular dynamics simulation of 101 ns. The obtained ligand molecule, 1,1'-(4H,8H-Bis[1,2,5]oxadiazolo[3,4-b:3',4'-e]pyrazine-4,8-diyl)diethanone, displayed the most favourable binding interactions with bacterial SHV-1. A total of 15 amino acid residues were found to hold the ligand in the binding site of SHV-1. Noticeably, 12 of the 15 residues were found as common to the binding residues of the reference (PDB ID: 4ZAM). The RMSD values plotted against the simulation time showed that nearby 11 ns, equilibrium was reached and, thenceforth, the 'SHV-1-Top ligand' complex remained typically stable. Starting from around 11 ns and straight to 101 ns, the backbone RMSD fluctuations were found to be confined inside a range of 1.0-1.6 Å. The ligand, 1,1'-(4H,8H-Bis[1,2,5]oxadiazolo[3,4-b:3',4'-e]pyrazine-4,8-diyl)diethanone, satisfied ADMET criteria. Furthermore, the practicability of the described 'SHV-1-Top ligand' complex was reinforced by a comprehensive molecular dynamics simulation of 101 ns. This ligand hence can be considered a promising lead for antibiotic design against SHV-1 producing resistant bacteria, and thus warrants wet laboratory evaluation.

Prevalence and Risk Factors Associated with Multidrug Resistance and Extended-Spectrum β-lactamase Producing E. coli Isolated from Healthy and Diseased Cats

Household cats have been identified as potential antimicrobial resistance (AMR) reservoirs, and the extended-spectrum β-lactamases (ESBL) producing E. coli circulating among cats has been more frequently reported globally, but the factors linked to its colonization remain poorly understood. Thus, the objectives of this study were to determine E. coli shedding and the occurrence of multidrug resistant (MDR)- and ESBL-producing E. coli, as well as to determine risk factors associated with colonization of MDR and ESBL-producing E. coli isolated from both healthy and diseased cats in the Eastern Province of Saudi Arabia. In a cross-sectional study, 2000 swabs were collected from five anatomical regions (anus, skin, ear canal, nares, and conjunctival sac) of 209 healthy and 191 diseased cats that were admitted to a veterinary clinic in the Eastern Province of Saudi Arabia. In addition, each cat owner filled out a questionnaire about their cat's demographics, management, health status, and antimicrobial usage. E. coli was detected in 165 (41.3%) of all cats, including 59 (28.2%) healthy and 106 (55.5%) diseased cats. In total, 170 E. coli isolates were found in healthy (35.3%) and diseased (64.7%) cats. Susceptibility testing revealed that 123 (72.4%) of the E. coli isolates were resistant to at least one of the tested antimicrobials. Overall, 17.6% (30/170) of E. coli isolates were MDR, with 10 (5.9%) and 20 (11.8%) isolates found in healthy and diseased cats, respectively. However, only 12 (7.1%) E. coli isolates were resistant to cefotaxime and harbored the bla_CTX-M gene (ESBL-producer), with seven (4.1%) in healthy and five (2.9%) in diseased cats. Risk factor analysis showed that the odds of MDR and ESBL-producing E. coli were (20 and 17) and (six and eight) times higher when the family and cats were previously treated with antimicrobials, respectively. The presence of a child in the cat's family was also linked to an increased risk of MDR E. coli colonization (OR = 3.4). In conclusion, a high frequency of MDR and ESBL-producing E. coli was detected among healthy and diseased cats in Saudi Arabia, raising concerns about transmission to humans and supporting the need of a "One Health" approach to address the potential threats of cats as AMR reservoirs.

Extended Spectrum- and Carbapenemase-Based β-Lactam Resistance in the Arabian Peninsula-A Descriptive Review of Recent Years

Antimicrobial resistance (AMR) is a global problem that also includes countries of the Arabian Peninsula. Of particular concern, is the continuing development of extended-spectrum β-lactamases (ESBLs) in the countries of this region. Additionally, antibiotic treatment options for ESBL-producing bacteria are becoming limited, primarily due to the continuing development of carbapenem resistance (CR), carbapenems being frequently used to treat such infections. An overview of recent publications (2018-2021) indicates the presence of ESBL and/or CR in patients and hospitals in most countries of the Arabian Peninsula, although the delay between microbial isolation and publication inevitably makes an accurate analysis of the current situation rather difficult. However, there appears to be greater emphasis on CR (including combined ESBL and CR) in recent publications. Furthermore, although publications from Saudi Arabia are the most prevalent, this may simply reflect the increased interest in ESBL and CR within the country. Enhanced ESBL/CR surveillance is recommended for all countries in the Arabian Peninsula.

MALDI-TOF MS for Rapid Analysis of Bacterial Pathogens Causing Urinary Tract Infections in the Riyadh Region

The successful treatment of bacterial disease is relied on selecting a suitable drug based on the type of bacteria and antimicrobial susceptibility testing. The study’s objective was to identify bacterial isolates from urine samples of patients from the community, followed by antimicrobial susceptibility testing of the isolated bacteria. A total of seventy urine samples were received in the clinical microbiology laboratory; out of which 18 culture-positive cultures and by direct identification using MALDI-TOF MS (Matrix Assisted Laser Desorption Ionization Time of Flight Mass Spectrometry) were identified. Of 18 identified bacteria, 17 (94%) were pathogenic. The culture demonstrated that the major species detected in urine samples were Escherichia coli, Klebsiella pneumoniae, Enterococcus faecalis, and Aeromonas caviae. E. coli (72.2%) was the most common bacterium retrieved from urine samples followed by K. pneumoniae (16.6%). Interestingly, all the isolates, except Enterococcus faecalis, were resistant to erythromycin. The isolates 8 of 13 (61.5%) were resistant to both of the cotrimoxazole and tetracycline. We performed MLST (Multi-locus Sequence Typing) typing of 13 E. coli isolates to study their genetic relatedness and diversity. MLST typing of E. coli showed a total of nine different STs (Sequence Types), which showed the diversity among them. ST 129 was the most common ST found in three E. coli isolates. In our study, two isolates with ST 1126 and ST 1432 represented the global clonal complex 155. MALDI-TOF MS provided dependable results for identifying the bacteria up to species level from urine samples by indirect culture methods. Such local surveillances are highly recommended for empirical therapy awareness and determining isolates’ level of resistance.

Sheep and goat milk in Jordan is a reservoir of multidrug resistant extended spectrum and AmpC beta-lactamases Escherichia coli

Limited data is available on the prevalence and antimicrobial resistance of extended spectrum (ESBL) and AmpC β-lactamases Escherichia coli in sheep and goats in Jordan. This study determined the molecular prevalence and antimicrobial-resistance of ESBL and AmpC β-lactamases E. coli in 155 sheep and goat flocks across Jordan by testing 948 milk samples. The samples were enriched in MacConkey broth, and then plated on MacConkey agar with cefotaxime. The presence of ESBL and AmpC genes in the E. coli isolates was determined by PCR and the resistance toward critically important antimicrobials was tested by disc diffusion. In total, 1016 E. coli isolates were isolated from the cefotaxime supplemented MacConkey, 382 isolates harbored ESBL genes and 54 harbored bla_CMY. The prevalence of bla_CTX-M, bla_TEM, bla_CMY and bla_SHVE. coli in the milk samples were 33.5 %, 31.7 %, 5.7 %. and 1.1 %, respectively. At the flock level, 30.3 % flocks had β-lactamase E. coli, specifically 25.2 %, 20.7 %, 5.2 % and 2.6 % had bla_CTX-M, bla_TEM, bla_CMY and blaSHV E. coli, respectively. About 52.2 % of the isolates harbored both bla_CTX-M and bla_TEM. A high percentage (>59 %) of ESBL and AmpC β-lactamases E. coli resisted sulfamethoxazole/trimethoprim, tetracycline and nalidixic acid. Overall, 93.5 % and 96.3 % of ESBL and AmpC E. coli were resistant to ≥1 another antimicrobial class and 44.5 % and 44.4 % were resistant to ≥3 another antimicrobial class, respectively. This study shows that sheep and goat milk is a reservoir of multidrug resistant ESBL and AmpC β-lactamases E. coli, thus good hygienic practices and judicious antimicrobials use are important in small ruminants' farming.

The Prevalence of Multidrug-Resistant Escherichia coli Producing ESBL among Male and Female Patients with Urinary Tract Infections in Riyadh Region, Saudi Arabia

The Escherichia coli that produces extended-spectrum lactamases (ESBL-E. coli) can develop resistance to many antibiotics. The control of ESBL-E. coli disorders is challenging due to their restricted therapeutic approaches, so this study aims to determine the prevalence and pattern of the antibiotic resistance of ESBL-E. coli among male and female patients with urinary tract infections in Riyadh, Saudi Arabia. During the period of 2019 to 2020 at King Fahd Medical City, Riyadh, 2250 urine samples from patients with urinary tract infections (UTIs) were collected, and microbial species were cultured and identified using standard biochemical techniques. A double-disc synergy test was used to identify ESBL-producing strains of E. coli, and an in vitro method and the clinical laboratory standard institute (CLSI) criteria were employed to determine the resistance of these strains to antimicrobial drugs. ESBL-E. coli was detected in 510 (33.49%) of the 1523 E. coli isolates, 67.27% of which were recovered from women and 33.7% of which were recovered from men. A total of 284 (55.69%) ESBL-E. coli isolates were found in patients under 50 years of age, and 226 (44.31%) were found in patients over 50 years of age. Nearly all the isolates of ESBL-E. coli were resistant to cephalosporins (ceftriaxone, cefotaxime, cefepime, cefuroxime, and cephalothin) and penicillin (ampicillin), whereas the majority of the isolates were sensitive to several carbapenems (imipenem, meropenem, and ertapenem), aminoglycosides (amikacin), and nitrofurantoins. The development of antibiotic resistance by ESBL-E. coli, the most frequent pathogen linked to urinary tract infections, plays a crucial role in determining which antibiotic therapy is appropriate.

Molecular Characterization of Extended Spectrum β-Lactamase (ESBL) and Virulence Gene-Factors in Uropathogenic Escherichia coli (UPEC) in Children in Duhok City, Kurdistan Region, Iraq

Background: The presence of extended-spectrum β-lactamase (ESBL)-producing bacteria among uropathogens is significantly increasing in children all over the world. Thus, this research was conducted to investigate the prevalence of E. coli and their antimicrobial susceptibility pattern, and both genes of ESBL-producing E. coli resistant and virulence factor in UTIs patients among children in Duhok Province, Kurdistan, Iraq. Method: a total of 67 E. coli were identified from 260 urine samples of pediatric patients diagnosed with UTIs aged (0−15 years) which were collected from Heevi Pediatric Teaching Hospital, from August 2021 to the end of February 2022. Result: a high proportion of UPEC infections at ages <5 years and the rates among girls (88%) were significantly higher than those among the boys. A wide variety of E. coli are resistant to most antibiotics, such as Amoxicillin, Ampicillin and Tetracycline, and 64% of them were positive for ESBL. Interestingly, the presence of both the ESBL marker genes (blaTEM, and blaCTX-M) as well as both virulence marker genes (pai and hly) were detected in above 90% of E. coli. Conclusion: the data illustrate an alarming increase in UPEC with ESBL production and the emergence of multidrug-resistant drugs in the early age of children. The public health sectors should further monitor the guidelines of using antibiotics in Kurdistan, Iraq.

Bacterial Community and Genomic Analysis of Carbapenem-Resistant Acinetobacter baumannii Isolates from the Environment of a Health Care Facility in the Western Region of Saudi Arabia

The escalating transmission of hospital-acquired infections, especially those due to antimicrobial-resistant bacteria, is a major health challenge worldwide. In this study, a culturomic analysis of bacterial community in a tertiary care hospital in the western region of Saudi Arabia is performed using environmental samples. The genome sequencing of four Acinetobacter baumannii was performed on isolates recovered from an intensive care unit (ICU) environment and clinical samples. A total of 361 bacterial isolates from surface and air samples were identified by MALDI-TOF technique or 16S rRNA gene sequencing. The isolates were classified into 70 distinct species, including ESKAPE pathogens. Resistance in Gram-positive isolates was mainly found to be against benzylpenicillin, azithromycin, ampicillin, and trimethoprim/sulfamethoxazole. Carbapenem- and multidrug-resistant isolates of A. baumannii and Klebsiella pneumonia were found on the ICU surfaces. Genome sequencing revealed that the carbapenem-resistant A. baumannii isolate from ICU environment was linked with those of clinical origin. The isolate Ab133-HEnv was classified as a novel sequence type (ST2528) based on a new allele of Oxf_gdhB-286. Three beta-lactam-antibiotic-resistance genes, bla_ADC-25, bla_OXA-23, and bla_OXA-66, were found in most of the analyzed genomes. Collectively, the results of this study highlight the spread of antimicrobial-resistant nosocomial pathogens in a health care facility in Saudi Arabia.

Antibiotic-resistance genes in E. coli strains in GCC countries: A meta-analysis

Background:

Antimicrobial resistance (AMR) in Escherichia coli is an alarming issue worldwide, including in the Gulf Cooperation Council (GCC) countries, yet the prevailing gene patterns have not recently been reviewed. This study was conducted to determine and report on the dominant E. coli antimicrobial resistant gene patterns in GCC countries.

Method:

A scoping review identified the predominant AMR genes in GCC countries: CTX M, TEM, SHV, NDM, OXA, and VIM genes. For the systematic review, two authors independently searched Scopus, PubMed, Google Scholar, Science Direct, and Web of Science for interventional, clinical, or observational studies on the chosen AMR-conferring genes in E. coli published from GCC countries between January 2013 and June 2019, when the last search was carried out. The search strategy followed the PRISMA guidelines. The risk of bias was assessed using a 6-item standardized checklist. Random-effects modeling was used for all analyses.

Results:

A total 32 studies were included in the final synthesis of evidence. Overall, CTX-M (53.8%) was the most prevalent gene in the region followed TEM (40.6%), NDM-1 (28.4%), OXA (24.3%), VIM (8.5%), and SHV (7.8%). Most included studies were from Saudi Arabia: CTX-M was again most common with a prevalence of 46.8% from 5442 isolates.

Conclusion:

The risk of bias analysis showed a mean quality score of 4.25 ± 0.75, indicating high-quality in studies included in this meta-analysis. This review found that CTX-M gene is the most common AMR-conferring gene in E. coli strains from most GCC countries.

Emergence of bla TEM, bla CTX-M, bla SHV and bla OXA genes in multidrug-resistant Enterobacteriaceae and Acinetobacter baumannii in Saudi Arabia

Multidrug-resistant (MDR) patterns due to extended-spectrum β-lactamase (ESBL) production in pathogenic bacteria are now becoming prevalent in hospitals worldwide, posing a public health challenge. The aim of the present study was to determine the antibiotic susceptibility patterns and distribution of the bla _TEM, bla _CTX-M, bla _SHV and bla _OXA ESBL resistance genes in MDREnterobacteriaceae and Acinetobacter baumannii (A. baumannii). A cross-sectional study was conducted between September 2017 and August 2018 in the King Abdullah Hospital (Bisha, Saudi Arabia). Bacterial isolates were collected from the clinical samples of patients; these were identified and screened for ESBL production and their antibiotic susceptibility was examined using standard microbiology methods. Multiplex-PCR runs were performed to identify genes encoding ESBL producers. DNA sequencing analysis was used to identify the specific gene variants. Of the 274 isolates, 173 (63.1%) exhibited MDR patterns to different antibiotics. A. baumannii revealed the highest resistance rates for cefuroxime (100%), gentamicin (88%) and amikacin (86%). Klebsiella pneumoniae (K. pneumoniae) isolates had the highest resistance rates for cefuroxime (98%), aztreonam and trimethoprim/sulfamethoxazole (87% for each). Escherichia coli (E. coli) exhibited high resistance rates for trimethoprim/sulfamethoxazole (92%) and cefuroxime (87%). Of the 173 MDR isolates, 78 (45.1%) exhibited ESBL production. Of these, 88.9% (72/78) carried ESBL genes. The most prevalent gene-encoding isolates were bla _TEM (84.7%), followed by bla _CTX-M (33.3%), bla _SHV (2.7%) and bla _OXA-1 (1.4%). A single bla _TEM gene was predominantly produced by K. pneumoniae (60.7%), A. baumannii (78.9%) and Proteus mirabilis (80%), whereas bla _CTX-M was harbored by E. coli (33.3%). The co-existence of two different genes in a single bacterium was revealed in 22.2% of isolates, commonly between bla _TEM and bla _CTX-M (19.4%). Sequencing analysis revealed that bla _CTX-M-15 and bla _TEM-1 were predominant variants of the bla _CTX-M and bla _TEM genes, respectively. The present study revealed a diversity of ESBL genes in Gram-negative bacterial isolates, with bla _TEM being the most prevalent type. The emergence of various ESBL genes with several co-existing genotypes is alarming, rendering extensive surveillance studies necessary to understand the transmission and epidemiology of such resistant gene-carrying isolates.

Drug susceptibility and molecular epidemiology of Escherichia coli in bloodstream infections in Shanxi, China

Objectives

We carried out a retrospective study to investigate the drug susceptibility and genetic relationship of clinical Escherichia coli isolates from patients with BSIs in Shanxi, China.

Methods

E. coli isolates causing BSIs were consecutively collected from June 2019 to March 2020. Antimicrobial susceptibility testing was performed by broth microdilution method. PCR was used to detect antimicrobial resistance genes coding for extended-spectrum β-lactamases (ESBLs), phylogenetic groups and seven housekeeping genes of E. coli.

Results

A total of 76 E. coli were collected. Antimicrobial susceptibility testing revealed that the top six E. coli resistant antibiotics were ampicillin (90.7%), ciprofloxacin (69.7%), cefazolin (65.7%), levofloxacin (63.1%), ceftriaxone and cefotaxime (56.5%). Among the 76 isolates, 43 produced ESBLs. Molecular analysis showed that CTX-M-14 was the most common ESBLs, followed by CTX-M-15 and CTX-M-55. Phylogenetic group D (42.2%) predominated, followed by group B2 (34.2%), group A (18.4%) and group B1 (5.2%). The most prevalent sequence types (STs) were ST131 (15/76), ST69 (12/76) and ST38 (6/76).

Conclusions

This study is the first to report the phenotypic and molecular characteristics of E. coli isolated from BSIs in Shanxi, China. Our results indicated a high prevalence of MDR in E. coli strains isolated from BSIs and a serious spread of ESBL genes in Shanxi, especially the epidemiological bla _CTX-M. Phylogenetic analysis indicated genetic diversity among E. coli BSIs isolates.

Identification of metallo-β-lactamases and AmpC production among Escherichia coli strains isolated from hemodialysis patients with urinary tract infection

Background

This study aimed to identify metallo-β-lactamases (MBLs) and AmpC β-lactamases-producing Escherichia coli isolates obtained from hemodialysis (HD) patients with urinary tract infections (UTI).

Methods and results

A total of 257 HD patients with UTI were included in this study, from which 47 E. coli isolates were collected. Antibiotic susceptibility was tested by disc diffusion method. MBLs and AmpC production were phenotypically detected by imipenem-ethylenediaminetetracetate and cefoxitin/boronic acid assays, respectively. The presence of MBLs and AmpC genes was examined by polymerase chain reaction (PCR). Fosfomycin and ampicillin were the most and the least effective antibiotics against E. coli isolates, respectively. Moreover, 61.7% (29/47) of E. coli isolates were multidrug-resistant with seven different antibiotypes. Antibiotype V (AMP–CIP–IMP–MEM–CPD–CRO–CTX–GEN–LEV–SXT–TOB) was the most prevalent profile. Besides, 24 (51.1%) isolates were simultaneously resistant to imipenem and meropenem. Phenotypic assay showed MBL production in 16 (66.7%) of the 24 carbapenem-resistant E. coli isolates. The distribution of MBL genes in carbapenem-resistant E. coli was as follows: bla_IMP 18 (72%), bla_VIM 7 (28%), and bla_NDM 1 (4%). AmpC was detected in 61.7% (29/47) of the isolates using the phenotypic method. The presence of AmpC genes was confirmed by PCR in only 26 of 29 (86.7%) AmpC producers. The frequencies of bla_DHA-1, bla_ACC, and bla_CMY-2 were 6 (20.7%), 11 (37.9%), and 21 (72.4%), respectively.

Conclusions

The emergence of MBL and AmpC coproducing E. coli isolates calls for an urgent surveillance program for timely diagnosis and screening of these genes in our healthcare systems.

"Occurrence of bla CTX-MGp1 and bla CTX-MGp26 in third generation cephalosporin-resistant and carbapenem- resistant bacterial isolates from southwest region of Saudi Arabia-a preliminary study"

This study was intended to identify the genes responsible for ESBL- and carbapenemase-producing bacterial isolates obtained from Jizan region. A hospital-based cross-sectional study was conducted over a period of 3 months (15th November 2018–15th February 2019). Fifty non-duplicate, 3rd-generation cephalosporin and carbapenem-resistant isolates were collected from microbiology lab of a tertiary care hospital in Jizan province and were screened for ESBLs and MBLs by phenotypic methods (CDT). The positive isolates (by phenotypic method) were then scanned for the presence of bla_ESBLs and bla_NDM-₁ genes, respectively, by PCR.

As a result, 10% isolates showed imipenem-cephalosporin co-resistance whereas 92% (46/50) of isolates were found to be ESBL producers by CDT. The maximum occurrence was observed for bla_CTX-M (70%), followed by bla_SHV (16%) and least occurrence was noted for bla_TEM (12%). Moreover, 97% isolates (34/35) were of bla_CTX-MGroup1 but one isolate showed the presence of bla_CTX-M Group26. Despite the co-resistance of cephalosporin and carbapenem, 14% (7/50) were found to be MBL producer on phenotypic detection by Combination Disc Test (CDT), whereas all the isolates were found to be negative for bla_NDM-1. Hence bla_CTX-MGroup1 is present in quite high fraction followed by bla_SHV in the bacterial isolates of Jizan region. Moreover, the occurrence of bla_CTX-M Group1 and bla_CTX-M Group26 in clinical isolates from the Jizan region of Saudi Arabia has been reported for the first time.

Socioeconomic Factors Contributing to Antibiotic Resistance in China: A Panel Data Analysis

The relationship between socioeconomic factors and antibiotic resistance (ABR) prevalence remains a knowledge gap in China. In this study, our aim was to examine the association between ABR prevalence and socioeconomic factors across 30 provinces in mainland China. We used two measures of level of ABR: the proportion of methicillin-resistant Staphylococcus aureus (MRSA), third-generation cephalosporin-resistant Escherichia coli (3GCREC), and third-generation cephalosporin-resistant Klebsiella pneumoniae (3GCRKP), and the aggregate resistance. The data of ABR prevalence, education, gross domestic product (GDP) per capita, out-of-pocket (OOP) health expenditure, physician density, hospital bed density, and public toilet density during 2014 and 2018 in 30 provinces in mainland China were included. We examined the association between ABR prevalence and potential contributing socioeconomic factors using panel data modeling. In addition, we explored this relationship in the eastern, central, and western economic zones. Our results indicated that GDP per capita was significantly positively correlated with ABR in mainland China and the eastern economic zone; however, significantly positive associations did not exist in the central and western economic zones. Surprisingly, both higher GDP per capita and higher OOP health expenditure were associated with a higher level of MRSA, but a lower level of 3GCREC; higher physician density was associated with a lower level of MRSA, but a higher level of 3GCREC. In addition, ABR prevalence presented a decline trend during 2014 and 2018. Our study showed the potential associ-ations between resistance and GDP per capita, OOP health expenditure, physician density. It high-lights that the social and economic determinants can be of importance in tacking the development and spread of ABR in mainland China.

High Throughput Virtual Screening and Molecular Dynamics Simulation for Identifying a Putative Inhibitor of Bacterial CTX-M-15

Background: Multidrug resistant bacteria are a major therapeutic challenge. CTX-M-type enzymes are an important group of class A extended-spectrum β-lactamases (ESBLs). ESBLs are the enzymes that arm bacterial pathogens with drug resistance to an array of antibiotics, notably the advanced-generation cephalosporins. The current need for an effective CTX-M-inhibitor is high. Objective: The aim of the current study was to identify a promising anti-CTX-M-15 ligand whose chemical skeleton could be used as a ‘seed-molecule’ for future drug design against resistant bacteria. Methods: Virtual screening of 5,000,000 test molecules was performed by ‘MCULE Drug Discovery Platform’. ‘ADME analyses’ was performed by ‘SWISS ADME’. TOXICITY CHECKER of MCULE was employed to predict the safety profile of the test molecules. The complex of the ‘Top inhibitor’ with the ‘bacterial CTX-M-15 enzyme’ was subjected to 102.25 ns molecular dynamics simulation. This simulation was run for 3 days on a HP ZR30w workstation. Trajectory analyses were performed by employing the macro ‘md_analyze.mcr’ of YASARA STRUCTURE version 20.12.24.W.64 using AMBER14 force field. YANACONDA macro language was used for complex tasks. Figures, including RMSD and RMSF plots, were generated. Snapshots were acquired after every 250 ps. Finally, two short videos of ‘41 s’ and ‘1 min and 22 s’ duration were recorded. Results: 5-Amino-1-(2H-[1,2,4]triazino[5,6-b]indol-3-yl)-1H-pyrazole-4-carbonitrile, denoted by the MCULE-1352214421-0-56, displayed the most efficient binding with bacterial CTX-M-15 enzyme. This screened molecule significantly interacted with CTX-M-15 via 13 amino acid residues. Notably, nine amino acid residues were found common to avibactam binding (the reference ligand). Trajectory analysis yielded 410 snapshots. The RMSD plot revealed that around 26 ns, equilibrium was achieved and, thereafter, the complex remained reasonably stable. After a duration of 26 ns and onwards until 102.25 ns, the backbone RMSD fluctuations were found to be confined within a range of 0.8–1.4 Å. Conclusion: 5-Amino-1-(2H-[1,2,4]triazino[5,6-b]indol-3-yl)-1H-pyrazole-4-carbonitrile could emerge as a promising seed molecule for CTX-M-15-inhibitor design. It satisfied ADMET features and displayed encouraging ‘simulation results’. Advanced plots obtained by trajectory analyses predicted the stability of the proposed protein-ligand complex. ‘Hands on’ wet laboratory validation is warranted.

Distribution of Extended-Spectrum β-Lactamase (ESBL)-Encoding Genes among Multidrug-Resistant Gram-Negative Pathogens Collected from Three Different Countries

The incidence of Extended-spectrum β-lactamase (ESBL)-encoding genes (blaCTX-M and blaTEM) among Gram-negative multidrug-resistant pathogens collected from three different countries was investigated. Two hundred and ninety-two clinical isolates were collected from Egypt (n = 90), Saudi Arabia (n = 162), and Sudan (n = 40). Based on the antimicrobial sensitivity against 20 antimicrobial agents from 11 antibiotic classes, the most resistant strains were selected and identified using the Vitek2 system and 16S rRNA gene sequence analysis. A total of 85.6% of the isolates were found to be resistant to more than three antibiotic classes. The ratios of the multidrug-resistant strains for Egypt, Saudi Arabia, and Sudan were 74.4%, 90.1%, and 97.5%, respectively. Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa showed inconstant resistance levels to the different classes of antibiotics. Escherichia coli and Klebsiella pneumoniae had the highest levels of resistance against macrolides followed by penicillins and cephalosporin, while Pseudomonas aeruginosa was most resistant to penicillins followed by classes that varied among different countries. The isolates were positive for the presence of the blaCTX-M and blaTEM genes. The blaCTX-M gene was the predominant gene in all isolates (100%), while blaTEM was detected in 66.7% of the selected isolates. This work highlights the detection of multidrug-resistant bacteria and resistant genes among different countries. We suggest that the medical authorities urgently implement antimicrobial surveillance plans and infection control policies for early detection and effective prevention of the rapid spread of these pathogens.

Pet and Stray Dogs as Reservoirs of Antimicrobial-Resistant Escherichia coli

The close contact between dogs and humans creates the best bridge for interspecies transmission of antimicrobial-resistant bacteria. The surveillance of its resistance including the detection of extended-spectrum beta-lactamases (ESBLs) in Escherichia coli as indicator bacteria is an important tool to control the use of antimicrobials. The aim of this research was to evaluate the E. coli resistance in strains by phenotypic methods, isolated from pet and stray dogs of La Plata city, Argentina. Faecal samples were collected using rectal swabs from 50 dogs with owners (home dogs = HD) and 50 homeless dogs (stray dogs = SD). They were cultured in 3 MacConkey agar plates, with and without antibiotics (ciprofloxacin and cefotaxime). 197 strains were isolated, of which only 95 strains were biochemically identified as E. coli, 46 strains were from HD, and 49 were from SD. Antimicrobial susceptibility was evaluated by the Kirby-Bauer disk diffusion method. The most prevalent resistance was for tetracycline, streptomycin, and ampicillin. In both groups, the level of resistance to 3rd generation cephalosporins was high, and there were multiresistant strains. There was a higher level of antimicrobial resistance in strains from SD compared to HD. There were 8% of strains suspected of being ESBLs among samples of HD and 36% of SD. One (2%) of the strains isolated from HD and 11 (22%) from SD were phenotypically confirmed as ESBL. Pets and stray dogs are a potential source of E. coli antibiotic resistance in Argentina; therefore, its surveillance must be guaranteed.

Occurrence and Characteristics of the Extended-spectrum Beta-lactamase-producing Enterobacterale in a Hospital Setting

Objectives:

Infectious diseases caused by ESBL-producing Enterobacterale are an emerging problem worldwide, which increase hospital costs, empirical treatment failure, together with rates of morbidity and mortality. The aims of this study were to determine the antibiotic-resistant patterns and the frequency of blaTEM, blaCTX-M and blaSHV genes among Enterobacterale.

Methods:

A total of 239 non-repeated clinical isolates of the Enterobacterale family, including 202 (84.5%) Escherichia coli and Klebsiella pneumoniae 25 (12.3%) were collected. Identification and susceptibility tests were carried out on 60 (25.9%) ESBL phenotypes using biomérieux VITEK® 2 compact system. Isolates showing ESBL positivity by the phenotypic method were all screened for blaTEM, blaCTX-M and blaSHV genes by PCR.

Results:

The prevalence of ESBL-producing Enterobacterale isolates was found to be 25.9%. These ESBL-producing isolates displayed an increasing rate of resistance for aminopenicillins (ampicillin) (96.3%), followed by piperacillin-tazobactam (54.2%), amoxicillin/clavulanic acid (45.8), the cephalosporin groups, ceftriaxone (52.4%), ceftazidime (46.7%), and fluoroquinolone (ciprofloxacin) (42.7%). Both the organisms showed a higher susceptibility to the carbapenems (Imipenem) and aminoglycosides (Amikacin). Out of the 62 ESBL positive isolates, 11 (17.7%) carried the TEM gene, 22 (35.5%) carried the CTX-M gene alone, 8 (12.9%) carried both TEM and CTX-M genes, 1(1.6%) carried both SHV and CTX-M genes, and 20 (32.3%) carried the TEM, SHV, and CTX-M genes. SHV gene alone was not reported in any of the isolates.

Conclusion:

The study indicated a moderate occurrence of ESBL-producing Enterobacterale with CTX-M being the most dominant gene. The co-existence of all three genes on many occasions suggested the carriage of multiple plasmids with three resistance genes that might pose a serious epidemiological, clinical and public health threat.

Treatment Failure in Urinary Tract Infections: A Warning Witness for Virulent Multi-Drug Resistant ESBL- Producing Escherichia coli

Background

Global increase in the prevalence of virulent extended-spectrum beta-lactamase (ESBL)-producing uropathogenic Escherichia coli (UPEC), which is also multi-drug resistant (MDR), leads to increase in severity of urinary tract infections (UTIs), decrease in the efficacy of the first-line antibiotics, and therefore increase in the morbidity and mortality rates.

Methods

We investigated the distribution of ESBL-producing UPEC in 78 E. coli isolates from community-acquired UTI patients in southern Iran. The prevalence of three major ESBL genes, antimicrobial resistance patterns against 15 conventional antibiotic disks, and the presence of 11 important virulence genes that involve in the development and progression of UTIs were evaluated in these isolates.

Results

Of the UPECs, 34.6% were ESBL-positive and 96.3% of the ESBL-producers were MDR. Among the ESBL-producers, 100% harbored bla_CTX-M, 63% harbored bla_SHV, and 11.1% harbored bla_TEM genes. ESBL-producers showed a higher level of resistance to the tested cephalosporins, fluoroquinolones, trimethoprim-sulfamethoxazole, and tetracycline than non-ESBL producers. All isolates were resistant to the tested penicillins. Prevalence of resistance to about two-third of the tested antibiotics was higher than 50% and 93.6% of the isolates were MDR. High prevalence of virulence factors particularly the adhesins (82.1% csgA, 73.1% fimH genes) and siderophore (73.1% sitA gene) was seen in the UPECs. But fortunately in MDR isolates, the virulence score and prevalence of hemagglutinin (tsh), hemolysin toxin (hlyD) and invasin (ibeA) genes were lower than in non-MDR UPECs. Shockingly, among the 15 common antibiotics, only nitrofurantoin (<20% resistance) could be recommended as an appropriate drug for the treatment of UTIs due to our ESBL-producer UPECs.

Conclusion

The alarming level of virulent MDR ESBL-producer E. coli strains in this study necessitates the performing of an antibiotic stewardship program, regional screening of ESBL-producers and their virulence properties to select appropriate antibiotic, or designing new therapeutic methods for UTIs by inactivation of the essential virulence factors of UPECs.

Emergence of Escherichia coli ST131 Causing Urinary Tract Infection in Western Asia: A Systematic Review and Meta-Analysis

Escherichia coli sequence type (ST) 131 is considered a high-risk pandemic clone and frequently extended-spectrum β-lactamase (ESBL)-producing clone that is strongly associated with the global dissemination of CTX-M-15 type. The emergence of ST131 has become a public health threat because this clonal group typically exhibits multiple virulence factors and antimicrobial resistance. Therefore, this study aimed to analyze the literature published on the estimation of the prevalence of clone ST131 among E. coli strains isolated from patients with urinary tract infections in western Asia. A systematic search was carried out to identify eligible articles in the Web of Science, PubMed, Scopus, Embase, and Google Scholar electronic databases from January 2010 to December 2018. Next, 13 articles meeting the inclusion criteria were selected for data extraction and analysis by Comprehensive Meta-Analysis Software. The included studies were conducted in Iran, Jordan, Kuwait, Pakistan, Saudi Arabia, Turkey, and Yemen. In all studies, the pooled prevalence of ST131 was 24.6% (95% CI: 13.5%-40.4%) in wild type isolates, 42.7% (95% CI: 32.5%-53.5%) among ESBLs-producing isolates, and 64.8% (95% CI: 36%-85.5%) among multiple-drug resistant (MDR) isolates. Moreover, the prevalence of ST131 isolates carrying CTX-M-15 type was 68% (95% CI: 48.4%-82.8%). Our study indicated the high prevalence of broadly disseminated ST131 clone among MDR and ESBLs isolates in western Asia. Moreover, O25b was the predominant ST131 clone type, which was mostly associated with CTX-M-15 type.

Prevalence and molecular characteristics of sequence type 131 clone among clinical uropathogenic Escherichia coli isolates in Riyadh, Saudi Arabia

Background

The antimicrobial resistance of extraintestinal pathogenic Escherichia coli (ExPEC) has progressively been reported worldwide. This resistance has been ascribed to global dissemination of a single E. coli clone, namely E. coli sequence type 131 (E. coli ST131). The main goal of this study is to determine the prevalence and molecular traits of ST131 and its subclones among E. coli clinical urine isolates in Riyadh, Saudi Arabia.

Methods

Sixty E. coli urine isolates, of different extended spectrum β-lactamase (ESBL) carriage, were involved in this study. Molecular characterization was carried out to determine the ST131 status, phylogenetic groups and virulence carriage of these isolates. ST131 isolates were further tested to evaluate the prevalence of different phylogenetic groups, subclones and virulence carriage.

Results

Group B2 was the most common phylogroup from which E. coli isolates derived. Overall, 37 of 60 (61.7%) isolates belonged to ST131 clones. Of these, 19 (31.7%) isolates were from the H30 subclone, including 10 (16.7%) H30 non-Rx and 9 (15%) H30Rx. The remaining 18 (30%) ST131 isolates belonged to other non H30 subclones. H30 subclone was significantly higher in the virulence carriage in comparison to non H30 ST131 subclones.

Conclusion

This study reported the prevalence and traits of clinical E. coli ST131 main subclones in Saudi Arabia. It also demonstrated the high prevalence of E. coli ST131 locally, and found different virulence genotypes and antimicrobial resistance phenotypes among ST131 subclones. In the future, preforming whole genome sequence-based studies on ST131 and its subclones is crucial to elucidate factors that drive the success of these organisms.

Understanding the Epidemiology of Multi-Drug Resistant Gram-Negative Bacilli in the Middle East Using a One Health Approach

In the last decade, extended-spectrum cephalosporin and carbapenem resistant Gram-negative bacilli (GNB) have been extensively reported in the literature as being disseminated in humans but also in animals and the environment. These resistant organisms often cause treatment challenges due to their wide spectrum of antibiotic resistance. With the emergence of colistin resistance in animals and its subsequent detection in humans, the situation has worsened. Several studies reported the transmission of resistant organisms from animals to humans. Studies from the middle east highlight the spread of resistant organisms in hospitals and to a lesser extent in livestock and the environment. In view of the recent socio-economical conflicts that these countries are facing in addition to the constant population mobilization; we attempt in this review to highlight the gaps of the prevalence of resistance, antibiotic consumption reports, infection control measures and other risk factors contributing in particular to the spread of resistance in these countries. In hospitals, carbapenemases producers appear to be dominant. In contrast, extended spectrum beta lactamases (ESBL) and colistin resistance are becoming a serious problem in animals. This is mainly due to the continuous use of colistin in veterinary medicine even though it is now abandoned in the human sphere. In the environment, despite the small number of reports, ESBL and carbapenemases producers were both detected. This highlights the importance of the latter as a bridge between humans and animals in the transmission chain. In this review, we note that in the majority of the Middle Eastern area, little is known about the level of antibiotic consumption especially in the community and animal farms. Furthermore, some countries are currently facing issues with immigrants, poverty and poor living conditions which has been imposed by the civil war crisis. This all greatly facilitates the dissemination of resistance in all environments. In the one health concept, this work re-emphasizes the need to have global intervention measures to avoid dissemination of antibiotic resistance in humans, animals and the environment in Middle Eastern countries.

Genomic and antimicrobial resistance genes diversity in multidrug-resistant CTX-M-positive isolates of Escherichia coli at a health care facility in Jeddah

BACKGROUND

Whole genome sequencing has revolutionized epidemiological investigations of multidrug-resistant pathogenic bacteria worldwide. Aim of this study was to perform comprehensive characterization of ESBL-positive isolates of Escherichia coli obtained from clinical samples at the King Abdulaziz University Hospital utilizing whole genome sequencing.

METHODS

Isolates were identified by MALDI-TOF mass spectrometry. Genome sequencing was performed using a paired-end strategy on the MiSeq platform.

RESULTS

Nineteen isolates were clustered into different clades in a phylogenetic tree based on single nucleotide polymorphisms in core genomes. Seventeen sequence types were identified in the extended-spectrum β-lactamase (ESBL)-positive isolates, and 11 subtypes were identified based on distinct types of fimH alleles. Forty-one acquired resistance genes were found in the 19 genomes. The bla_CTX-M-15 gene, which encodes ESBL, was found in 15 isolates and was the most predominant resistance gene. Other antimicrobial resistance genes (ARGs) found in the isolates were associated with resistance to tetracycline (tetA), aminoglycoside [aph(3″)-Ib, and aph(6)-Id], and sulfonamide (sul1, and sul2). Nonsynonymous chromosomal mutations in the housekeeping genes parC and gyrA were commonly found in several genomes.

CONCLUSION

Several other ARGs were found in CTX-M-positive E. coli isolates confer resistance to clinically important antibiotics used to treat infections caused by Gram-negative bacteria.

Evaluation of gut bacterial community composition and antimicrobial resistome in pregnant and non-pregnant women from Saudi population

Background: Gut microbiota (GM) has recently been described as a functional reservoir of antimicrobial resistant genes (ARGs). However, the ARG-carrying bacterial species in the human gut has been poorly studied. This study, for the first time, is reporting bacterial communities' composition and antimicrobial resistome in the stool samples of pregnant and non-pregnant (NP) Saudi females. Methods: Gut bacterial community composition was analyzed by 16S amplicon sequencing and culturomics. High throughput MALDI-TOF technique was used for identification of the isolates from stool samples and evaluated for resistance against 13 antibiotics using the agar dilution method. Clinically important ARGs were PCR amplified from genomic DNA of the stool samples using gene-specific primers. Results: 16S amplicon sequencing revealed that GM of pregnant and NP women were predominantly comprised of phyla Firmicutes, Bacteroidetes, Proteobacteria, and Actinobacteria. Bacterial diversity decreased in pregnant groups, whereas phylum Bacteroidetes declined significantly (p<0.05) in the first trimester. We noticed a relatively high abundance of butyrate-producing bacteria (eg, Faecalibacterium spp. and Eubacterium spp.) in the gut of pregnant women, whereas Prevotella copri was found at significantly (p<0.01) higher abundance in NP women. Moreover, about 14,694 isolates were identified and classified into 132 distinct species. The majority of the species belonged to phyla Firmicutes and Proteobacteria. About 8,125 isolates exhibited resistance against antibiotics. Out of 73 resistant-species, Enterococcus was the most diverse genus and Escherichia coli was the highly prevalent bacterium. The majority of the isolates were resistant to antibiotics; trimethoprim/sulfamethoxazole, cycloserine, and cefixime. ARGs encoding resistance against aminoglycoside, macrolide, quinolone, β-lactam, and tetracycline antibiotics were predominantly found in genomic DNA of the stool samples. Conclusion: We conclude that pregnancy-associated GM modulations may help to sustain a healthy pregnancy, but a higher proportion of antibiotic resistance could be deleterious for both maternal and fetal health.

Prevalence of Cefepime-Resistant Escherichia coli in Iran: A Meta-Analysis (2007-2016)

BACKGROUND

Cefepime-resistant Escherichia coli (E. coli) is one of the seven important types of microbial resistance. This meta-analysis study was conducted to identify the prevalence of cefepime-resistant E. coli in Iran during 2007-2016.

METHODS

Studies published were searched in Persian databases (including Magiran, and SID) and international databases (including PubMed, ScienceDirect, and Scopus). The selected studies included all types of laboratory methods. Moreover, the random effects model (DerSimonian Laird method) was used to addresses the high heterogeneity (50% < I²) between the reviewed studies. The collected data were categorized into different subgroups on the basis of the year of study and province. Data analysis was performed using the Statsdirect software.

RESULTS

Overall, 516 articles were selected from the searched medical databases. After reviewing and applying the inclusion criteria, irrelevant papers were excluded and the remaining 26 studies were meta-analyzed. The overall prevalence of cefepime-resistant E. coli was 53.42% (95%: 43.35, 63.35), ranging from 25% (95%CI: 21.67, 28.55) in 2009 to 61.95% (95%CI: 56.62, 67.09) in 2016.

CONCLUSION

The prevalence of cefepime-resistant E. coli in Iran has had an increasing and alarming trend during the recent years. Therefore, it is necessary to use practical strategies and interventions to control and monitor cefepime-resistant E. coli in the country.