TEM,CTX-M,SHV Genes in ESBL-Producing Escherichia coli and Klebsiella pneumoniae Isolated from Clinical Samples in a County Clinical Emergency Hospital Romania-Predominance of CTX-M-15

Extended-spectrum beta-lactamase-producing Escherichia coli and Klebsiella pneumoniae: insights from a tertiary hospital in Southern Thailand

Broad-spectrum ampicillin-resistant and third-generation cephalosporin-resistant Enterobacteriaceae, particularly Escherichia coli and Klebsiella pneumoniae that have pathological features in humans, have become a global concern. This study aimed to investigate the prevalence, antimicrobial susceptibility, and molecular genetic features of extended-spectrum beta-lactamase (ESBL)-producing E. coli and K. pneumoniae isolates in Southern Thailand. Between January and August 2021, samples (n = 199) were collected from a tertiary care hospital in Southern Thailand. ESBL and AmpC-lactamase genes were identified using multiplex polymerase chain reaction (PCR). The genetic relationship between ESBL-producing E. coli and K. pneumoniae was determined using the enterobacterial repetitive intergenic consensus (ERIC) polymerase chain reaction. ESBL-producing E. coli and K. pneumoniae isolates were mostly collected from catheter urine samples of infected female patients. The ESBL production prevalence was highest in the medical wards (n = 75, 37.7%), followed by that in surgical wards (n = 64, 32.2%) and operating rooms (n = 19, 9.5%). Antimicrobial susceptibility analysis revealed that all isolates were resistant to ampicillin, cefotaxime, ceftazidime, ceftriaxone, and cefuroxime; 79.4% were resistant to ciprofloxacin; and 64.3% were resistant to trimethoprim-sulfamethoxazole. In ESBL-producing K. pneumoniae and E. coli, blaTEM (n = 57, 72.2%) and blaCTX-M (n = 61, 50.8%) genes were prominent; however, no blaVEB, blaGES, or blaPER were found in any of these isolates. Furthermore, only ESBL-producing K. pneumoniae had co-harbored blaTEM and blaSHV genes at 11.6%. The ERIC-PCR pattern of multidrug-resistant ESBL-producing strains demonstrated that the isolates were clonally related (95%). Notably, the presence of multidrug-resistant and extremely resistant ESBL producers was 83.4% and 16.6%, respectively. This study highlights the presence of blaTEM, blaCTX-M, and co-harbored genes in ESBL-producing bacterial isolates from hospitalized patients, which are associated with considerable resistance to beta-lactamase and third-generation cephalosporins.

IMPORTANCE

We advocate for evidence-based guidelines and antimicrobial stewardship programs to encourage rational and appropriate antibiotic use, ultimately reducing the selection pressure for drug-resistant bacteria and lowering the likelihood of ESBL-producing bacterial infections.

A computational odyssey: uncovering classical β-lactamase inhibitors in dry fruits

In the antibacterial arsenal, β-lactams have held a prominent position, but increasing resistance due to unauthorized use and genetic factors requires new strategies. Combining β-lactamase inhibitors with broad-spectrum β-lactams proves effective in combating this resistance. ESBL producers demand new inhibitors, leading to the exploration of plant-derived secondary metabolites for potent β-lactam antibiotics or alternative inhibitors. Using virtual screening, molecular docking, ADMET analysis, and molecular dynamic simulation, this study actively analyzed the inhibitory activity of figs, cashews, walnuts, and peanuts against SHV-1, NDM-1, KPC-2, and OXA-48 β-lactamases. Using AutoDock Vina, the docking affinities of various compounds for target enzymes were initially screened, revealing 12 bioactive compounds with higher affinities for the target enzymes compared to Avibactam and Tazobactam. Top-scoring metabolites, including Oleanolic acid, Protocatechuic acid, and Tannin, were subjected to MD simulation studies to further analyze the stability of the docked complexes using WebGro. The simulation coordinates, in terms of RMSD, RMSF, SASA, Rg, and hydrogen bonds formed, showed that these phytocompounds are stable enough to retain in the active sites at various orientations. The PCA and FEL analysis also showed the stability of the dynamic motion of Cα residues of phytochemical-bound enzymes. The pharmacokinetic analysis of the top phytochemicals was performed to analyze their bioavailability and toxicity. This study provides new insights into the therapeutic potential of phytochemicals of selected dry fruits and contributes to future experimental studies to identify βL inhibitors from plants.Communicated by Ramaswamy H. Sarma.

Bacterial and Fungal Keratitis in a Tertiary Care Hospital from Romania

Infectious keratitis is a significant global problem that can lead to corneal blindness and visual impairments. This study aimed to investigate the etiology of infectious bacterial and fungal keratitis, identify the causative pathogens and their antimicrobial resistance patterns, and analyze the risk factors associated with the development of infectious keratitis. The study was observational and retrospective, involving 226 eyes from 223 patients presented at the Ophthalmology Clinic of the County Clinical Emergency Hospital of Craiova, Romania. The inclusion criteria included corneal ulceration/abscess/infiltrate present on slit-lamp examination and positive microbiological sampling for bacteria or fungi. The study found that the most common causes of infectious keratitis were coagulase-negative staphylococci (35.40%), Staphylococcus aureus (11.06%), and Pseudomonas aeruginosa (14.16%). The Gram-positive bacteria showed high resistance rates to penicillin, moderate rates to gentamycin and clindamycin, and low resistance to chinolones. The Gram-negative bacteria were highly resistant to ampicillin and amoxicillin-clavulanic acid, while third-generation cephalosporins, quinolones, and carbapenems were effective. Systemic antibiotics, such as vancomycine, piperacillin-tazobactam, amikacin, and ceftazidime, show promise against keratitis with low resistance rates, whereas carbapenems and topical aminoglycosides had higher resistance, leaving moxifloxacin as a potential topical option for Gram-positive bacteria and Pseudomonas aeruginosa, albeit with resistance concerns for Klebsiella spp. Although fungal keratitis was rare, Fusarium spp. and Candida albicans were the leading fungal pathogens, with incidences of 2.65% and 2.21%, respectively. Candida albicans was broadly susceptible to most antifungals, while Fusarium solani, Curvularia lunata, and Alternaria alternata exhibited resistance to many antifungals. Amphotericin B and caspofungin can be used as systemic antifungals in fungal keratitis. The study also identified risk factors for keratitis such as ocular trauma (65.92%, OR: 2.5), contact lens wear (11.94%, OR: 1.8), and corneal scarring/leukoma (10.17%, OR: 1.6). Keratitis was more frequent in individuals over 60 years old. The findings of this study have implications for the development of effective diagnostic, therapeutic, and preventive strategies for infectious keratitis.

Treated municipal wastewater as a source of high-risk and emerging multidrug-resistant clones of E. coli and other Enterobacterales producing extended-spectrum β-lactamases

Extended-spectrum β-lactamase (ESBL)-producing Enterobacterales are a major public health problem, and wastewater from municipal wastewater treatment plants (WWTPs) is a potential means of spreading them into the environment and community. Our objective was to isolate ESBL-producing E. coli and other Enterobacterales from wastewater after treatment at Croatia's largest WWTP and to characterize these isolates by phenotypic and genotypic testing. Of the 200 bacterial isolates, 140 were confirmed as Enterobacterales by MALDI-TOF MS, with Escherichia coli and Klebsiella spp. predominating (69% and 7%, respectively). All 140 enterobacterial isolates were multidrug-resistant (MDR) and produced ESBLs. The most prevalent ESBL genes among the isolates tested were blaCTX-M-15 (60%), blaTEM-116 (44%), and blaCTX-M-3 (13%). Most isolates (94%) carried more than one ESBL gene in addition to blaCTX-M. Genes encoding plasmid-mediated AmpC, most notably blaEBC, were detected in 22% of isolates, whereas genes encoding carbapenemases (blaOXA-48, blaNDM-1, blaVIM-1) were less represented (10%). In E. coli, 9 different sequence types (ST) were found, with the emerging high-risk clones ST361 (serotype A-O9:H30) and pandemic ST131 (serotype B2-O25:H4) predominating (32% and 15%, respectively). Other high-risk E. coli clones included ST405 (3%), ST410 (3%), CC10 (3%), ST10 (3%), and ST38 (2%), and emerging clones included ST1193 (2%) and ST635 (2%). Whole-genome sequencing of three representative E. coli from two dominant clone groups (ST361 and ST131) and one extensively drug-resistant K. oxytoca revealed the presence of multiple plasmids and resistance genes to several other antibiotic classes, as well as association of the blaCTX-M-15 gene with transposons and insertion sequences. Our findings indicate that treated municipal wastewater contributes to the spread of emerging and pandemic MDR E. coli clones and other enterobacterial strains of clinical importance into the aquatic environment, with the risk of reintroduction into humans.

Gut colonization and subsequent infection of neonates caused by extended-spectrum beta-lactamase-producing Escherichia coli and Klebsiella pneumoniae

The gut microbiota harbors diverse bacteria considered reservoirs for antimicrobial resistance genes. The global emergence of extended-spectrum beta-lactamase (ESBL)-producing Enterobacterales (ESBL-PE) significantly contributes to healthcare-associated infections (HAIs). We investigated the presence of ESBL-producing Escherichia coli (ESBL-PEco) and ESBL-producing Klebsiella pneumoniae (ESBL-PKpn) in neonatal patients' guts. Furthermore, we identified the factors contributing to the transition towards ESBL-PEco and ESBL-PKpn-associated healthcare-associated infections (HAIs). The study was conducted from August 2019 to February 2020, in a Neonatal Intensive Care Unit of the Hospital Infantil de México Federico Gómez. Rectal samples were obtained upon admission, on a weekly basis for a month, and then biweekly until discharge from the neonatology ward. Clinical data, culture results, and infection information were gathered. We conducted antimicrobial tests, multiplex PCR assay, and pulsed-field gel electrophoresis (PFGE) to determine the antimicrobial resistance profile and genetic relationships. A comparison between the group's controls and cases was performed using the Wilcoxon and Student t-tests. Of the 61 patients enrolled, 47 were included, and 203 rectal samples were collected, identifying 242 isolates. In 41/47 (87%) patients, colonization was due to ESBL-PEco or ESBL-PKpn. And nine of them developed HAIs (22%, 9/41). ESBL-PEco resistance to cephalosporins ranged from 25.4% to 100%, while ESBL-PKpn resistance varied from 3% to 99%, and both bacteria were susceptible to carbapenems, tigecillin, and colistin. The prevalent bla CTX-M-group-1 gene accounted for 77.2% in ESBL-PEco and 82.2% in ESBL-PKpn, followed by bla TEM 50% and bla OXA-1 43.8% in ESBL-PEco and bla TEM 80.2% and bla SHV 76.2% in ESBL-PKpn. Analysis of clonality revealed identical colonizing and infection isolates in only seven patients. Significant risk factors included hospital stay duration, duration of antibiotic treatment, and invasive device usage. Our findings suggest high ESBL-PEco and ESBL-PKpn rates of colonization often lead to infection in neonates. Attention should be paid to patients with ESBL-PE.

"One Health" perspective on prevalence of co-existing extended-spectrum β-lactamase (ESBL)-producing Escherichia coli and Klebsiella pneumoniae: a comprehensive systematic review and meta-analysis

BACKGROUND

The Escherichia coli (E. coli) and Klebsiella pneumoniae (K. pneumoniae) bacterial isolates that produce extended-spectrum β-lactamases (ESBLs) contribute to global life-threatening infections. This study conducted a systematic review and meta-analysis on the global prevalence of ESBLs in co-existing E. coli and K. pneumoniae isolated from humans, animals and the environment.

METHODS

The systematic review protocol was registered in the International Prospective Register of Systematic Reviews (PROSPERO) [ID no: CRD42023394360]. This study was carried out following the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines. One hundred and twenty-six eligible studies published on co-existing antibiotic resistance in E. coli and K. pneumoniae between 1990 and 2022 were included.

RESULTS

The pooled prevalence of ESBL-producing E. coli and K. pneumoniae was 33.0% and 32.7% for humans, 33.5% and 19.4% for animals, 56.9% and 24.2% for environment, 26.8% and 6.7% for animals/environment, respectively. Furthermore, the three types of resistance genes that encode ESBLs, namely blaSHVblaCTX-M,blaOXA, and blaTEM, were all detected in humans, animals and the environment.

CONCLUSIONS

The concept of "One-Health" surveillance is critical to tracking the source of antimicrobial resistance and preventing its spread. The emerging state and national surveillance systems should include bacteria containing ESBLs. A well-planned, -implemented, and -researched alternative treatment for antimicrobial drug resistance needs to be formulated.

Evaluation of Potential Factors Influencing the Dissemination of Multidrug-Resistant Klebsiella pneumoniae and Alternative Treatment Strategies

The increasing reports of multidrug-resistant Klebsiella pneumoniae have emerged as a public health concern, raising questions about the potential routes for the evolution and dissemination of the pathogenic K. pneumoniae into environmental reservoirs. Potential drivers of the increased incidence of antimicrobial-resistant environmental K. pneumoniae include the eminent global climatic variations as a direct or indirect effect of human activities. The ability of microorganisms to adapt and grow at an exponential rate facilitates the distribution of environmental strains with acquired resistant mutations into water systems, vegetation, and soil which are major intersection points with animals and humans. The bacterial pathogen, K. pneumoniae, is one of the critical-priority pathogens listed by the World Health Organization, mostly associated with hospital-acquired infections. However, the increasing prevalence of pathogenic environmental strains with similar characteristics to clinical-antibiotic-resistant K. pneumoniae isolates is concerning. Considering the eminent impact of global climatic variations in the spread and dissemination of multidrug-resistant bacteria, in this review, we closely assess factors influencing the dissemination of this pathogen resulting in increased interaction with the environment, human beings, and animals. We also look at the recent developments in rapid detection techniques as part of the response measures to improve surveillance and preparedness for potential outbreaks. Furthermore, we discuss alternative treatment strategies that include secondary metabolites such as biosurfactants and plant extracts with high antimicrobial properties.

Large-scale analysis of putative plasmids in clinical multidrug-resistant Escherichia coli isolates from Vietnamese patients

Introduction

In the past decades, extended-spectrum beta-lactamase (ESBL)-producing and carbapenem-resistant (CR) Escherichia coli isolates have been detected in Vietnamese hospitals. The transfer of antimicrobial resistance (AMR) genes carried on plasmids is mainly responsible for the emergence of multidrug-resistant E. coli strains and the spread of AMR genes through horizontal gene transfer. Therefore, it is important to thoroughly study the characteristics of AMR gene-harboring plasmids in clinical multidrug-resistant bacterial isolates.

Methods

The profiles of plasmid assemblies were determined by analyzing previously published whole-genome sequencing data of 751 multidrug-resistant E. coli isolates from Vietnamese hospitals in order to identify the risk of AMR gene horizontal transfer and dissemination.

Results

The number of putative plasmids in isolates was independent of the sequencing coverage. These putative plasmids originated from various bacterial species, but mostly from the Escherichia genus, particularly E. coli species. Many different AMR genes were detected in plasmid contigs of the studied isolates, and their number was higher in CR isolates than in ESBL-producing isolates. Similarly, the bla_KPC-2, bla_NDM-5, bla_OXA-1, bla_OXA-48, and bla_OXA-181 β-lactamase genes, associated with resistance to carbapenems, were more frequent in CR strains. Sequence similarity network and genome annotation analyses revealed high conservation of the β-lactamase gene clusters in plasmid contigs that carried the same AMR genes.

Discussion

Our study provides evidence of horizontal gene transfer in multidrug-resistant E. coli isolates via conjugative plasmids, thus rapidly accelerating the emergence of resistant bacteria. Besides reducing antibiotic misuse, prevention of plasmid transmission also is essential to limit antibiotic resistance.

Antimicrobial Resistance in Romania: Updates on Gram-Negative ESCAPE Pathogens in the Clinical, Veterinary, and Aquatic Sectors

Multidrug-resistant Gram-negative bacteria such as Acinetobacter baumannii, Pseudomonas aeruginosa, and members of the Enterobacterales order are a challenging multi-sectorial and global threat, being listed by the WHO in the priority list of pathogens requiring the urgent discovery and development of therapeutic strategies. We present here an overview of the antibiotic resistance profiles and epidemiology of Gram-negative pathogens listed in the ESCAPE group circulating in Romania. The review starts with a discussion of the mechanisms and clinical significance of Gram-negative bacteria, the most frequent genetic determinants of resistance, and then summarizes and discusses the epidemiological studies reported for A. baumannii, P. aeruginosa, and Enterobacterales-resistant strains circulating in Romania, both in hospital and veterinary settings and mirrored in the aquatic environment. The Romanian landscape of Gram-negative pathogens included in the ESCAPE list reveals that all significant, clinically relevant, globally spread antibiotic resistance genes and carrying platforms are well established in different geographical areas of Romania and have already been disseminated beyond clinical settings.

Multidrug-Resistant ESBL-Producing E. coli in Clinical Samples from the UK

Globally, cephalosporin therapy failure is a serious problem for infection control. One causative agent of cephalosporin-resistant infections is multidrug-resistant (MDR) E. coli producing extended-spectrum β-lactamases (ESBLs) and/or plasmid-encoded AmpC (pAmpC) β-lactamases. We evaluated the occurrence of ESBL/pAmpC genetic determinants in phenotypically MDR E. coli isolated from clinical samples of blood, faeces, ear effusion, urine and sputum from a UK hospital. Phenotypic resistance profiling for 18 antibiotics (from seven classes) showed that 32/35 isolates were MDR, with resistance to 4-16 of the tested antibiotics. Of the isolates, 97.1% showed resistance to ampicillin, 71.4% showed resistance to co-amoxiclav, cefotaxime, ceftazidime and ceftiofur, and 68.5% showed resistance to cefquinome. bla_CTX-M, bla_TEM and bla_OXA-1 genes were detected in 23, 13 and 12 strains, respectively, and Intl1 was detected in 17 isolates. The most common subtypes among the definite sequence types were CTX-M-15 (40%) and TEM-1 (75%). No E. coli isolates carried pAmpC genes. Significant correlations were seen between CTX-M carriage and cefotaxime, ceftiofur, aztreonam, ceftazidime and cefquinome resistance; between bla_CTX-M, bla_TEM and bla_OXA-1 carriage and ciprofloxacin resistance; and between Intl1 carriage and trimethoprim/sulfamethoxazole resistance. Thus, MDR phenotypes may be conferred by a relatively small number of genes. The level and pattern of antibiotic resistance highlight the need for better antibiotic therapy guidelines, including reduced use and improved surveillance.

Resistance to Some New Drugs and Prevalence of ESBL- and MBL-Producing Enterobacteriaceae Uropathogens Isolated from Diabetic Patients

Diabetes is a leading non-communicable disease and a risk factor for relapsing infections. The current study was aimed at investigating the prevalence and antibiotic susceptibility of carbapenem-resistant (CR) uropathogens of the family Enterobacteriaceae in diabetic patients. The data of 910 bacterial isolates was collected from diagnostic laboratories during January 2018 to December 2018. The bacterial isolates were identified using traditional methods including colonial characteristics, biochemical tests, and API (20E). Antimicrobial susceptibility and phenotypic characterization of ESBL, MBLs, and KPC was determined by utilizing CLSI recommended methods. The phenotypically positive isolates were further analyzed for resistance-encoding genes by manual PCR and Check-MDR CT103XL microarray. Susceptibility to colistin and cefiderocol was tested in accordance with CLSI guidelines. The data revealed that most of the patients were suffering from type 2 diabetes for a duration of more than a year and with uncontrolled blood sugar levels. Escherichia coli and Klebsiella pneumoniae were the most frequently encountered pathogens, followed by Enterobacter cloacae and Proteus mirabilis. More than 50% of the isolates showed resistance to 22 antibiotics, with the highest resistance (>80%) against tetracycline, ampicillin, and cefazolin. The uropathogens showed less resistance to non-β-lactam antibiotics, including amikacin, fosfomycin, and nitrofurantoin. In the phenotypic assays, 495 (54.3%) isolates were found to be ESBL producers, while ESBL-TEM and -PER were the most prevalent ESBL types. The resistance to carbapenems was slightly less (250; 27.5%) than ESBL producers, yet more common amongst E. coli isolates. MBL production was a common feature in carbapenem-resistant isolates (71.2%); genotypic characterization also validated this trend. The isolates were found to be sensitive against the new drugs, cefiderocol and eravacycline. with 7−28% resistance, except for P. mirabilis which had 100% resistance against eravacycline. This study concludes that a few types of ESBL and carbapenemases are common in the uropathogens isolated from the diabetic patients, and antibiotic stewardship programs need to be revisited, particularly to cure UTIs in diabetic patients.

Molecular Genetic Epidemiology of an Emerging Antimicrobial-Resistant Klebsiella pneumoniae Clone (ST307) Obtained from Clinical Isolates in Central Panama

Klebsiella pneumoniae has been among the main pathogens contributing to the burden of antimicrobial resistance (AMR) in the last decade, and K. pneumoniae AMR strains predominantly cluster in the ST258 clonal complex. However, ST307 is emerging as an important high-risk clone. In Central America, there have been few studies on the molecular epidemiology of the K. pneumoniae strains involved in infections.

MATERIALS AND METHODS

We conducted an epidemiological study in three reference hospitals in the central region of Panama, using isolates of K. pneumoniae involved in infections, and identifying their AMR profile, associated clinical risk factors, and molecular typing using a multilocus sequence typing (ST) scheme.

RESULTS

Six STs were detected: 307 (55%), 152, 18, 29, 405, and 207. CTX-M-15- and TEM-type beta-lactamases were identified in 100% of ESBL-producing strains; substitutions in gyrA Ser83Ile and parC Ser80Ile were identified in all ST307s; and in ST152 gyrA Ser83Phe, Asp87Ala, and parC Ser80Ile, the qnrB gene was detected in all strains resistant to ciprofloxacin.

CONCLUSIONS

We present the first report on ST307 in three reference hospitals in the central region of Panama, which is a high-risk emerging clone and represents a public health alert for potential difficulties in managing K. pneumoniae infections in Panama, and which may extend to other Central American countries.