Search Results (123)

Background/Objectives: Carbapenemase-producing Escherichia coli (CP-Ec) has emerged as an important contributor to the global crisis of antimicrobial resistance. Although less prevalent than carbapenemase-producing Klebsiella pneumoniae, CP-Ec exhibits marked genomic plasticity, efficient plasmid-mediated dissemination, and increasing involvement in bloodstream infections. This comprehensive review summarizes the global epidemiology, molecular features, treatment options, clonal structure and transmission dynamics of CP-Ec. Particular attention is given to the expanding repertoire of NDM, OXA-48-like, and KPC carbapenemases and their associated plasmid backbones. Key high-risk clones, including ST410, ST167 and ST131, are highlighted as drivers of international spread. Conclusions and Future Directions: CP-Ec bloodstream infections represent a growing clinical challenge, often associated with severe outcomes and limited therapeutic options, particularly for NDM producers. The emergence of treatment failures with last-resort agents further underscores the need for improved management strategies. Strengthened global surveillance, integration of genomic epidemiology, optimized antimicrobial stewardship, and targeted infection control measures are essential to limit the dissemination of CP-Ec and mitigate its impact on human health. Full article

Background/Objectives: Intestinal colonization by Enterobacteriaceae, including extended-spectrum β-lactamase-producing (ESBL-E) and carbapenemase-producing (E-CPE) strains, is an early marker of multidrug-resistant infections in neonates, particularly those transferred from lower-complexity hospitals. This study aimed to identify factors associated with intestinal Enterobacteriaceae colonization upon admission to a level IV neonatal referral unit in Colombia, with a focus on prior antibiotic exposure. Methods: We conducted a retrospective case–control study, including all neonates transferred from peripheral hospitals and screened with rectal swabs at admission. Cases were neonates colonized with Enterobacteriaceae, and controls were non-colonized neonates admitted during the same period. Multivariable logistic regression models were used to evaluate three exposure dimensions: prior antibiotic use (yes/no), number of agents, and the WHO AWaRe classification. A secondary analysis was performed to assess the factors associated with ESBL-E and E-CPE colonization. Results: Among the 435 referred neonates, 87 (20.0%) were colonized, predominantly Klebsiella pneumoniae (53.6%) and Escherichia coli (19.5%). Prior antibiotic use (aOR 3.01; 95% CI 1.47–6.37), exposure to two agents (aOR 4.13; 95% CI 1.94–8.89) and use of AWaRe Access antibiotics (aOR 22.2; 95% CI 5.83–101) were strongly associated with colonization. Longer hospitalization and central catheter use were also associated with greater colonization odds, whereas total parenteral nutrition showed a protective association. In the sub-analysis, Access, Watch, and Reserve antibiotics were independently associated with ESBL-E and E-CPE colonization. Conclusions: Among transferred neonates, prior antibiotic exposure, particularly AWaRe-classified agents, showed the strongest association with intestinal colonization by Enterobacteriaceae, including ESBL-E/CPE phenotypes. Strengthening antimicrobial stewardship in referral facilities and implementing risk-based screening at admission may help reduce colonization and limit the spread of resistance. Full article

Introduction: Rectal colonization by carbapenemase-producing carbapenem-resistant Enterobacterales (CP-CRE) is a risk factor for subsequent infections, which are associated with high mortality rates. Methods: A cross-sectional study was conducted. Rectal swabs were collected from 297 patients within 48 h of admission to eight high-prevalence CP-CRE hospital departments, with follow-up swabs taken weekly for up to 4 weeks. Species identification, antimicrobial susceptibility testing, and genetic detection of carbapenemases were performed. The genetic relationship among isolates was assessed using ERIC-PCR, combined with epidemiological data, to investigate subsequent infections. Results: Fecal carriage of CP-CRE was detected in 15.5% (46/297) of patients- All carbapenemases were metallo-betalactamases, with dominance of NDM-producing Klebsiella pneumoniae. NDM + VIM-producing Escherichia coli were also detected. Among carriers, 26.1% were colonized by two different CRE species, and 86.9% had a history of prior hospitalization. Molecular analysis revealed clonal expansion, suggesting outbreaks among colonized patients. Additionally, 17.4% (8/46) of colonized patients developed an infection, which was significantly associated with urinary catheter use (p = 0.040), mechanical ventilation (p = 0.044), and surgical procedures (p = 0.040). Conclusions: rectal colonization by CP-CRE in hospitalized patients is a serious epidemiological concern, with evidence of clonal spread and subsequent infection in colonized patients. NDM-producing K. pneumoniae was also predominant, detecting co-production of NDM + VIM in E. coli. These findings underscore the urgent need to implement epidemiological surveillance cultures to improve the prevention and control of CP-CRE infections in Cuban hospitals. Full article

Urinary tract infections (UTIs) represent a major cause of morbidity among adult women, with a disproportionate burden among postmenopausal patients. Limited data exist from Eastern Europe regarding pathogen distribution, antimicrobial resistance, and treatment patterns in hospitalized women. We conducted a retrospective cohort study of 948 adult female patients hospitalized with symptomatic UTIs between January 2021 and December 2023 in a Romanian multidisciplinary hospital. Demographic, clinical, and microbiological parameters were analyzed. Pathogen identification was performed by MALDI-TOF MS, and antimicrobial susceptibility testing followed EUCAST 2024 standards. Empiric treatment strategies and subsequent therapy modifications were assessed. Postmenopausal women accounted for 78.4% of cases and exhibited higher rates of recurrent UTIs, frailty, diabetes, urinary catheterization, and prior antibiotic exposure. Escherichia coli remained the predominant pathogen (52.6%), followed by Klebsiella spp. (18.4%) and Enterococcus spp. (12.1%). ESBL-producing organisms were found in 21.4% of E. coli and 38.7% of Klebsiella isolates. Pathogen distribution differed by age: younger women had a higher proportion of E. coli, whereas postmenopausal women showed a relative increase in opportunistic/healthcare-associated pathogens, particularly Klebsiella spp. and Enterococcus spp., consistent with higher catheter exposure and comorbidity burden. Carbapenem resistance was rare but present in a small subset of Klebsiella isolates with phenotypes compatible with OXA-48-like carbapenemase production. Empiric therapy most frequently included ceftriaxone or fluoroquinolones, but 27.8% of regimens required adjustment after susceptibility results. Independent predictors of prolonged hospitalization included age > 65 years, recurrent UTI, MDR infection, urinary catheterization, and delayed targeted therapy. UTIs among hospitalized adult women—especially postmenopausal patients—are strongly influenced by comorbidity burden and antimicrobial resistance. Local resistance patterns highlight the need for evidence-based empiric treatment and rapid therapy optimization. Strengthening stewardship and preventive interventions in elderly women is essential. Full article

Foodborne pathogens remain a global public health concern, and antimicrobial resistance increases their impact. In mass-gathering cities such as Al-Madinah Al-Munawarah, contaminated ready-to-eat (RTE) fast foods can contribute to both local transmission and international spread. In this study, 300 RTE fast food samples, including shawarma, burgers, fried chicken, sandwiches, and salads, were collected from international franchises, local restaurants, and street vendors. Pathogens were identified using conventional culture combined with matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS). Antimicrobial susceptibility testing followed CLSI guidelines, and real-time PCR confirmed species identity and screened resistance determinants. Principal component analysis (PCA) and dendrogram clustering were used to assess diagnostic discrimination. Among the 300 samples, 129 (43.0%) were culture positive. The most common pathogens were Staphylococcus aureus (14.3%) and Escherichia coli (13.0%), followed by Salmonella spp. (9.0%) and Acinetobacter baumannii (6.7%). About 35% of S. aureus isolates were methicillin resistant (MRSA), and 85% of A. baumannii carried OXA-type carbapenemase genes. MALDI-TOF MS achieved 96.1% score-based identification and, with PCA, showed strong interspecies separation. PCR confirmed species identity and detected widespread resistance genes, with genotype–phenotype concordance of at least 80%. Overall, 60.5% of isolates were multidrug resistant. RTE fast foods in Al-Madinah represent reservoirs of MDR pathogens, including carbapenemase-producing A. baumannii. The combined use of MALDI-TOF MS and real-time PCR established a rapid and scalable workflow that provided reliable identification and resistance profiling in less than 24 h, compared with 48 to 72 h for conventional methods. This approach supports One Health surveillance in high-risk food settings and strengthens preparedness for mass gatherings. Full article

Background: Carbapenem-resistant Escherichia coli (CREC) producing OXA-48-like carbapenemase was first detected in Hungary in 2022. The aim of the present study was to characterize such strains isolated in 2022–2025 in Baranya County, Hungary. Methods: Antibiotic susceptibility and the whole-genome sequence (WGS) of E. coli isolates, identified as OXA-48-like carbapenemase producers using the CARBA-5 NG test, were established. The transferability of bla_OXA-48-like plasmids was tested by conjugation. Results: Of the 6722 non-repeat E. coli isolates, 6 produced an OXA-48-like carbapenemase. They exhibited variable resistance to ertapenem and were susceptible to imipenem and meropenem. WGS revealed that all OXA-48-like producer E. coli belonged to high-risk clones: two clonally related OXA-181-producer E. coli ST405 were isolated in Hospital A, three OXA-244-producing E. coli ST38 (two identical via cgMLST from Hospital B), and an OXA-48-producing E. coli ST69. The bla_OXA-48 and bla_OXA-244 genes were chromosomally located, while bla_OXA-181 was on a non-conjugative IncFIB-IncFIC plasmid. So far, the bla_OXA-181-bearing plasmid of this incompatibility type has only been described in Ghana, but all bla_OXA-48-like gene-carrying transposons in this study have already been identified in Europe and other continents. The E. coli ST38 isolates, showing close association based on core genome SNP distances to European and Qatari strains, belonged to Cluster A and harbored bla_CTX-M-27. All but the E. coli ST69 isolate had cephalosporinase gene(s). Conclusions: This study describes small-scale intra-hospital transfers of OXA-48-like carbapenemase-producer E. coli. Interestingly, E. coli ST405 of Hungary carried bla_OXA-181 on an IncFIB-IncFIC plasmid, which has only been reported from Africa so far. Full article

Background/Objectives: The environmental dissemination of antimicrobial-resistant Enterobacteriaceae poses a remarkable threat to public health. This study investigates the environmental presence and dissemination of carbapenemase-producing Enterobacteriaceae (CPE) in 30 important water bodies selected according to their interconnection with and utilization by livestock and community people in central Thailand. Methods: Water samples were collected from 30 selected water bodies. Enterobacteriaceae were isolated and screened for CPE and multidrug resistance. Carbapenemase genes (bla_NDM-5, bla_NDM-1 and bla_IMI-1) were detected and their locations (plasmid and chromosome) determined. Plasmid types were further characterized, and conjugation experiments were performed to assess transferability among bacterial species. Results: From all selected samples, six isolates (20%) were identified as multidrug-resistant CPE including one Escherichia coli, one Klebsiella pneumoniae and four Enterobacter roggenkampii carrying bla_NDM-5, bla_NDM-1 and bla_IMI-1 genes, respectively. The bla_NDM-5 and bla_NDM-1 genes were located on phage-like pO111 type plasmid and IncC plasmid, while bla_IMI-1 was located on chromosomes. The plasmids also consisted of components that closely resembled those found in resistance plasmids obtained from clinical and environmental isolates worldwide. Additionally, through plasmid conjugation experiment, carbapenemase genes were transferable with a high rate among bacterial species. Conclusions: These findings indicated that water bodies are polluted and there is an urgent need for integrated strategies to monitor and mitigate the spread of antibiotic resistance across human, animal and environmental health domains in aquatic environments. Full article

Background/Objectives: Antimicrobial resistance (AMR) threatens global public health. This systematic review and meta-analysis, as part of the “ENVIRE” project (interventions to control the dynamics of antimicrobial resistance from chickens through the environment), assesses the prevalence of phenotypic and genotypic resistance, including extended-spectrum beta-lactamases (ESBLs), AmpC beta-lactamases, carbapenemases, colistin, and fluoroquinolone resistance, in broiler chickens and their environment. Methods: The analysis covers the years 2002–2022, focusing on Escherichia (E.) coli, Klebsiella spp., Enterobacter spp., and Citrobacter spp. in fecal, meat, environmental, and other-than-feces samples from observational studies published in PubMed and Web of Science. Quality assessment was performed using the Alberta Heritage Foundation criteria. Results: Data from 170 studies, conducted in Europe, North Africa, and North America, were included. The most frequently studied resistance was to beta-lactam, with focus on ESBL-producing and AmpC beta-lactamase isolates. The pooled prevalence of ESBL-resistant E. coli observed in meat samples at 41% and in fecal samples at 38% demonstrated significant heterogeneity between the studies. The negative binomial regression analysis of prevalence data revealed significantly higher ESBL-producing E. coli rates in European meat samples compared to North African samples. Conclusions: This systematic review revealed substantial variation in prevalence and emphasizes the need for standardized surveillance systems and robust study designs. Full article

Uropathogenic Escherichia coli (UPEC) is the leading cause of urinary tract infections (UTIs) and a major contributor to the global antimicrobial resistance crisis. The increasing prevalence of multidrug-resistant (MDR) strains, including expanded-spectrum β-lactamases (ESBL) and carbapenemase-producing isolates, severely limits treatment options. This review provides an overview on the key molecular mechanisms of UPEC antibiotic resistance, such as enzymatic inactivation, target-site mutations, efflux pump activity, and biofilm formation. Beyond conventional antibiotics, special emphasis is placed on phytochemical strategies as promising alternatives. Flavonoids, alkaloids, terpenoids, and essential oils exhibit antibacterial, anti-adhesive, and antibiofilm properties. These natural bioactive compounds modulate motility, suppress fimbrial expression, inhibit quorum sensing, and enhance antibiotic efficacy, acting both as standalone agents and as adjuvants. Current in vitro and in vivo studies highlight the potential of plant-derived compounds and biologically based therapies to combat UPEC. However, challenges related to standardization, bioavailability, and clinical validation remain unresolved. Integrating molecular mechanistic insights with advanced phytochemical research may offers a sustainable and effective strategy for mitigating UPEC antibiotic resistance. Full article

Background and Objectives: Catheter-associated urinary tract infections (CAUTIs) caused by extended-spectrum beta-lactamase (ESBL)-producing and carbapenem-resistant Enterobacterales (CRE) significantly contribute to global rates of UTI. This study aimed to compare the prevalence and trends of ESBL-producing Enterobacterales and CRE in patients with CAUTIs and non-CAUTIs. Materials and Methods: A retrospective review of 4262 UTI-positive urine cultures was conducted at King Fahad Hospital of the University, Al Khobar, Saudi Arabia (January 2022–November 2023). Demographic, clinical, and microbiological data were obtained from hospital records. Antimicrobial susceptibility was tested using the Vitek^® System; ESBL and CRE were identified using Ezy MIC™ strips and Xpert^® Carba-R assay, respectively. Results: ESBL-producing Enterobacterales accounted for 11.3% of cases; CRE comprised 1.8%. ESBL was significantly more prevalent in non-catheterized patients and those in emergency care. CRE was significantly associated with catheterized patients and inpatient settings. Escherichia coli and Klebsiella pneumoniae were the predominant ESBL-producing and CRE isolates, respectively. bla-OXA-48 was the most frequently detected carbapenemase gene (66.7%). ESBL was prevalent in younger, non-catheterized females, suggesting increasing community transmission. Conversely, CRE were primarily observed in older, catheterized inpatients, emphasizing the role of invasive devices in resistance spread. Conclusions: These findings highlight the importance of targeted infection control and early catheter removal to mitigate resistance trends. Full article

Antimicrobial resistance (AMR) poses a critical global health challenge, with carbapenemase-producing Enterobacterales (CPE) representing one of the most urgent threats. While Klebsiella pneumoniae and Escherichia coli have been the focus of most surveillance programs, Enterobacter spp., members of the Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, Enterobacter spp., and Escherichia coli (ESKAPEE) group, remain an underrecognized but increasingly important reservoir of carbapenemase genes in Europe. Despite being categorized by the World Health Organization (WHO) as “critical-priority” pathogens, Enterobacter spp. are largely excluded from major AMR surveillance frameworks, creating blind spots in detection and control. This review summarizes the taxonomy, intrinsic resistance mechanisms, and clinical relevance of Enterobacter spp., with a particular focus on carbapenemase epidemiology across Europe. We highlight the distribution and genetic context of major carbapenemases, including VIM, OXA-48-like, KPC, and NDM, and discuss emerging or minor enzymes such as IMI, FRI, GES, and IMP. Epidemiological data reveal shifting dominance patterns over time, with VIM enzymes consolidating their prevalence after 2015, while OXA-48-like and KPC declined, and NDM gained ground. The genetic diversity of Enterobacter spp., coupled with their ability to act as both nosocomial pathogens and silent intestinal or environmental reservoirs, facilitates the dissemination of carbapenemase genes via epidemic plasmids and clonal expansion. Addressing the growing impact of carbapenemase-producing Enterobacter spp. requires their systematic inclusion in national and international monitoring programs, expanded use of genomic epidemiology in clinical microbiology, and better alignment between research, clinical practice, and policy. A One Health approach is essential to curb the spread of carbapenemases across human, environmental, and animal reservoirs, and to safeguard the remaining therapeutic options. Full article

Antimicrobial resistance (AMR) is a significant public health concern in companion animals, yet systematic surveillance in North Macedonia is lacking. This study investigated the prevalence of resistance in Escherichia coli isolated from 112 fecal samples from dogs in six shelters in North Macedonia and evaluated the associated risk factors, providing the first baseline dataset for this population. High resistance was observed for sulfamethoxazole (68.75%), ampicillin (52.68%), and ciprofloxacin (41.07%). Multidrug resistance was present in 50% of the isolates, with 17 (15.17%) confirmed as ESBL producers. Additionally, 18 isolates (16.1%) were identified as AmpC producers, 16 of which carried the blaCMY-2 gene. Notably, 72.2% of ESBL/AmpC isolates were resistant to ertapenem despite the absence of carbapenemase genes, a finding that warrants further investigation. Risk factors such as shared housing, longer shelter stays, and frequent empirical antimicrobial use were identified as probable contributors to the carriage of ESBL-/AmpC-producing E. coli. None of the shelters had antimicrobial stewardship protocols or routine diagnostic testing, revealing critical gaps in infection control and antimicrobial practices. These findings underscore the urgent need for antimicrobial stewardship and surveillance in North Macedonia’s companion animal populations within the One Health framework. Full article

Background: The Enterobacteriaceae family is the most heterogeneous group of Gram-negative bacilli, with both environmental and clinical relevance. Although many of these species are part of the normal intestinal microbiota, species such as Escherichia coli, Klebsiella pneumoniae, and Proteus mirabilis are among the most common opportunistic pathogens, frequently responsible for nosocomial infections, including urinary tract infections, bacteraemia, and pneumonia. Based on these concerns, these species are increasingly being studied for their ability to develop antimicrobial resistance, often mediated by extended spectrum β-lactamase or carbapenemase production. The present study aims to analyse the antimicrobial resistance profiles of Enterobacteriaceae isolated from a southern Italian hospital focusing on the species of major clinical importance. Methods: A retrospective analysis was carried out on biological samples collected between 2019 and 2023 at the Microbiology Laboratory of the San Pio Hospital, Vasto (Italy). Eight hundred ninety patients were included, with an average age of 73 years. Bacterial identification was carried out using bacterial culture and biochemical methods, while antimicrobial sensitivity was assessed by using the automated Walk Away System. Results: The most frequently isolated species were Escherichia coli (63.2%), Klebsiella spp. (21.9%), and Proteus spp. (8.8%). All isolates showed resistance to at least one antimicrobial and most to more than four. The highest resistance rates were observed for Cefotaxime (16.0%), followed by Ampicillin (15.6%) and Ciprofloxacin (13.2%). Conclusions: The high prevalence of antimicrobial resistance among clinically relevant Enterobacteriaceae species is a growing clinical challenge. The results of this study, which describe the trend of resistance among Enterobacteriaceae in a local hospital, could help to raise awareness highlighting the urgent need for more advanced diagnostic tools and new therapeutic strategies to treat infections caused by multi-resistant microorganisms. Full article

Antimicrobial resistance (AMR), particularly due to extended-spectrum β-lactamases (ESBLs) and carbapenemases (CPs), poses a critical threat to global health. This study aimed to characterize the molecular epidemiology, resistance profiles, and genomic features of ESBL- and CP-producing Escherichia coli and Klebsiella pneumonaie (ESBL/CP-Ec/Kp) isolates from a Spanish hospital (2020–2024) and explore links to environmental reservoirs like white storks foraging at a nearby landfill. A total of 121 clinical Ec/Kp isolates (55 ESBL-Ec, 1 CP-Ec, 35 ESBL-Kp, 17 CP-Kp, 13 ESBL+CP-Kp) underwent phenotypic testing, PCR, and whole-genome sequencing (WGS). Analyses included phylogenomics (cgMLST), detection of AMR genes, plasmid typing, and comparative genomics. Among ESBL-Ec, bla_CTX-M-15 was the most prevalent (60.0%), and one CP-Ec carrying bla_NDM-5 was identified. WGS of 44 selected ESBL/CP-Ec isolates revealed a variety of AMR genes, and 56.8% of isolates carried class one integrons (56.8%). IncF-type plasmids predominated, and 84.1% of isolates were assigned as ExPEC/UPEC. The lineage ST131 dominated (75%), with IncF-bla_CTX-M-15-carrying plasmids. Among the 18 ESBL/CP-Kp isolates sequenced, the lineage ST307 was the most frequent (44.4%), followed by ST15 and ST11, carrying a diversity of AMR determinants and plasmids (IncFIB(K), IncL, ColpVC). Virulence included ybt loci in ICEKp; hypervirulence genes were absent. Genomic analysis of 62 clinical isolates (44 Ec, 18 Kp) showed close phylogenetic links to stork-derived strains, with ST131-Ec and ST307-Kp from humans and birds differing just by ≤22 and ≤10 ADs, respectively, with a conserved plasmid content (i.e., IncL-bla_OXA-48, IncFIB(K)-bla_CTX-M-15). High-risk ESBL/CP-Ec/Kp clones persist across clinical and environmental contexts. WGS-based surveillance is key for understanding AMR spread and guiding interventions. Results support a One Health approach to combat AMR through cross-sector collaboration. Full article

Background: This study aimed to (a) assess the prevalence of multidrug-resistant (MDR) Enterobacteriaceae in the waters of two rivers and wastewater treatment plants (WWTPs) in a region of Catalonia, Spain; (b) genetically characterize the MDR strains; and (c) compare extended-spectrum β-lactamase (ESBL)-producing Escherichia coli isolates from environmental and human sources. Methods: A total of 62 samples were collected from the influent and effluent of 31 WWTPs and 29 river water samples from 11 sites. Simultaneously, 382 hospitalized patients were screened for MDR Enterobacteriaceae using rectal swabs. All isolates underwent antibiotic susceptibility testing and whole-genome sequencing. Results: MDR Enterobacteriaceae were detected in 48.4% of WWTP samples, with 18.5% ESBL-producing E. coli and 1.5% (one sample) OXA-48-producing K. pneumoniae in influents, and 12.8% ESBL-producing E. coli in effluents. In river waters, 5.6% of samples contained ESBL-producing E. coli and 1.4% (1 sample) contained VIM-producing Enterobacter cloacae complex strains. Among patients, 10.2% (39/382) carried MDR Gram-negative bacilli, of which 66.7% were ESBL-producing E. coli. In aquatic ecosystems E. coli ST131 (13.3%) and ST162 (13.3%) were the most common strains, while in humans the common were E. coli ST131 (33.3%), ST69 (11.1%) and ST410 (7.4%) in humans. The most frequent environmental antibiotic resistance genes (ARG) were bla_CTX-M-15 (24%) and bla_TEM-1B (20%), while the most common ARGs were bla_TEM-1B (20.4%), bla_CTX-M15 (18.4%) and bla_CTX-M-27 (14.3%). IncF plasmids were predominant in environmental and human strains. Conclusions: ESBL-producing E. coli and carbapenemase-producing Enterobacteriaceae are present in aquatic environments in the region. Phylogenetic similarities between environmental and clinical strains suggest a possible similar origin. Further studies are necessary to clarify transmission routes and environmental impact. Full article