Extended-spectrum Beta-lactamase Research Articles

Monitoring of antimicrobial resistance in respiratory tract pathogens during the COVID-19 pandemic: A retrospective study.

To understand the distribution and antimicrobial resistance (AMR) of pathogens in respiratory samples in Changle District People's Hospital in Fujian Province in recent years, and provide empirical guidance for infection control and clinical treatment in the region. A retrospective analysis was conducted on 5137 isolates of pathogens from respiratory samples collected from 2019 to 2022. The AMR patterns were systematically analyzed. For research purposes, the data was accessed on October 12, 2023. A total of 3517 isolates were included in the study, including 811 (23.06%) gram-positive bacteria and 2706 (76.94%) gram-negative bacteria. The top 3 gram-positive bacteria were Staphylococcus aureus with 455 isolates (12.94%), Streptococcus pneumoniae with 99 isolates (2.81%), and Staphylococcus hemolytic with 99 isolates (2.81%). The top 3 gram-negative bacteria were Klebsiella pneumoniae with 815 isolates (23.17%), Pseudomonas aeruginosa with 589 isolates (16.75%), and Acinetobacter baumannii with 328 isolates (9.33%). The proportion of extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli and K pneumoniae fluctuated between 41.9% and 70.5%, and 18.6% and 20.9%, respectively. The resistance rates of E coli, K pneumoniae, P aeruginosa, and A baumannii to carbapenems were 2.36%, 8.9%, 18.5%, and 19.6%, respectively. The prevalence of methicillin-resistant S aureus (MRSA) was 48.55%, but it decreased to 38.4% by 2022. The resistance rate of Staphylococcus haemolyticus to methicillin was 100%, and 1 case of vancomycin-resistant strain was detected. K pneumoniae, P aeruginosa, A baumannii, and S aureus are the main pathogens in respiratory samples. Although the resistance rates of some multidrug-resistant strains have decreased, ESBL-producing Enterobacteriaceae, carbapenem-resistant bacteria have still increased. Therefore, it is necessary to strengthen the monitoring of pathogen resistance, promote rational use of antibiotics, and promptly report findings.

Urinary tract infections in older adults: associated factors for extended-spectrum beta-lactamase production

ObjectiveUrinary tract infections (UTIs) due to extended-spectrum beta-lactamase (ESBL) producing Escherichia coli and Klebsiella pneumoniae are among the leading causes of morbidity and mortality in older adults. Identifying associated factors for ESBL production may contribute to more appropriate empirical treatment.Materials and methodsThis was a prospective observational study. Hospitalized patients of age > 65 with community-onset or hospital-acquired upper UTI due to E. coli or Klebsiella pneumoniae were included. A multivariate analysis was performed.ResultsA total of 97 patients were included. ESBL prevalence among UTIs with E. coli or Klebsiella pneumoniae was 69.1% (n = 67). CRP values at the time of UTI diagnosis were found to be significantly higher in the ESBL-producing group (p = 0.004). The multivariate analysis revealed that male gender (OR: 2.72, CI: 1.02–7.25), prior recurrent UTI (OR: 3.14, CI: 1.21–8.14), and the development of secondary bacteremia (OR: 4.95, CI: 1.03–23.89) were major associated factors for UTI in older adults due to ESBL-producing E. coli and Klebsiella pneumoniae.ConclusionSevere UTI in older men with a history of recurrent UTI may be a warning to the clinician for ESBL production in the setting of high ESBL prevalence. Carbapenems may be prioritized in the empirical treatment of patients with known risk factors for ESBL.

Proteome analysis, genetic characterization, and antibiotic resistance patterns of Klebsiella pneumoniae clinical isolates

Klebsiella pneumoniae (K. pneumoniae) is a member of the ESKAPE group and is responsible for severe community and healthcare-associated infections. Certain Klebsiella species have very similar phenotypes, which presents a challenge in identifying K. pneumoniae. Multidrug-resistant K. pneumoniae is also a serious global problem that needs to be addressed. A total of 190 isolates were isolated from urine (n = 69), respiratory (n = 52), wound (n = 48) and blood (n = 21) samples collected from various hospitals in the Al-Qassim, Saudi Arabia, between March 2021 and October 2022. Our study aimed to rapidly and accurately detect K. pneumoniae using the Peptide Mass Fingerprinting (PMF) technique, confirmed by real-time PCR. Additionally, screening for antibiotic susceptibility and resistance was conducted. The primary methods for identifying K. pneumoniae isolates were culture, Gram staining, and the Vitek® 2 ID Compact system. An automated MALDI Biotyper (MBT) instrument was used for proteome identification, which was subsequently confirmed using SYBR green real-time polymerase chain reaction (real-time PCR) and microfluidic electrophoresis assays. Vitek® 2 AST-GN66 cards were utilized to evaluate the antimicrobial sensitivity of K. pneumoniae isolates. According to our results, Vitek® 2 Compact accurately identified 178 out of 190 (93.68%) K. pneumoniae isolates, while the PMF technique correctly detected 188 out of 190 (98.95%) isolates with a score value of 2.00 or higher. Principal component analysis was conducted using MBT Compass software to classify K. pneumoniae isolates based on their structure. Based on the analysis of the single peak intensities generated by MBT, the highest peak values were found at 3444, 5022, 5525, 6847, and 7537 m/z. K. pneumoniae gene testing confirmed the PMF results, with 90.53% detecting entrobactin, 70% detecting 16 S rRNA, and 32.63% detecting ferric iron uptake. The resistance of the K. pneumoniae isolates to antibiotics was as follows: 64.75% for cefazolin, 62.63% for trimethoprim/sulfamethoxazole, 59.45% for ampicillin, 58.42% for cefoxitin, 57.37% for ceftriaxone, 53.68% for cefepime, 52.11% for ampicillin-sulbactam, 50.53% for ceftazidime, 52.11% for ertapenem, and 49.47% for imipenem. Based on the results of the double-disk synergy test, 93 out of 190 (48.95%) K. pneumoniae isolates were extended-spectrum beta-lactamase. In conclusion, PMF is a powerful analytical technique used to identify K. pneumoniae isolates from clinical samples based on their proteomic characteristics. K. pneumoniae isolates have shown increasing resistance to antibiotics from different classes, including carbapenem, which poses a significant threat to human health as these infections may become difficult to treat.

Antibiotic Susceptibility of Klebsiella pneumonia Isolates from Hospitalized Patients in Three Referral Medical Centers in Isfahan, Iran

: Background: Klebsiella pneumoniae (K. pneumoniae) is a major cause of nosocomial and community-acquired infections (CAIs). Understanding the antibiotic susceptibility of this bacterium is essential for selecting the most effective antibiotic for associated infections. Objectives: We investigated the sensitivity of K. pneumonia (KP) isolates obtained from inpatients in Isfahan, Iran. Methods: Organism identification and antibiotic susceptibility testing were conducted using standard tests. Stratification was performed based on extended spectrum beta-lactamase (ESBL) production and the source of infection acquisition (community versus hospital). Results: A total of 437 KP isolates were investigated, of which 5.5% were pan drug resistant (PDR), 56.8% were extensively drug resistant (XDR), and 18% were ESBL producers. The isolates were most susceptible to colistin (100%), aminoglycosides (62.8%), and carbapenems (55%). Nosocomial isolates showed lower sensitivity to most of the examined antibiotics. Conclusions: The high prevalence of PDR and XDR KP strains in hospitalized patients is a major problem in the studied area.

Presence of phage-plasmids in multiple serovars of Salmonella enterica.

Evidence is accumulating in the literature that the horizontal spread of antimicrobial resistance (AMR) genes mediated by bacteriophages and bacteriophage-like plasmid (phage-plasmid) elements is much more common than previously envisioned. For instance, we recently identified and characterized a circular P1-like phage-plasmid harbouring a bla CTX-M-15 gene conferring extended-spectrum beta-lactamase (ESBL) resistance in Salmonella enterica serovar Typhi. As the prevalence and epidemiological relevance of such mechanisms has never been systematically assessed in Enterobacterales, in this study we carried out a follow-up retrospective analysis of UK Salmonella isolates previously sequenced as part of routine surveillance protocols between 2016 and 2021. Using a high-throughput bioinformatics pipeline we screened 47 784 isolates for the presence of the P1 lytic replication gene repL, identifying 226 positive isolates from 25 serovars and demonstrating that phage-plasmid elements are more frequent than previously thought. The affinity for phage-plasmids appears highly serovar-dependent, with several serovars being more likely hosts than others; most of the positive isolates (170/226) belonged to S. Typhimurium ST34 and ST19. The phage-plasmids ranged between 85.8 and 98.2 kb in size, with an average length of 92.1 kb; detailed analysis indicated a high amount of diversity in gene content and genomic architecture. In total, 132 phage-plasmids had the p0111 plasmid replication type, and 94 the IncY type; phylogenetic analysis indicated that both horizontal and vertical gene transmission mechanisms are likely to be involved in phage-plasmid propagation. Finally, phage-plasmids were present in isolates that were resistant and non-resistant to antimicrobials. In addition to providing a first comprehensive view of the presence of phage-plasmids in Salmonella, our work highlights the need for a better surveillance and understanding of phage-plasmids as AMR carriers, especially through their characterization with long-read sequencing.

PHENOTYPIC DETECTION OF ESBL AND AMPC BETA LACTAMASES AMONG GRAM-NEGATIVE ISOLATES FROM CLINICAL SAMPLES IN A TERTIARY CARE HOSPITAL

Objectives: Drug-resistant Gram-negative bacilli expressing extended-spectrum beta-lactamases (ESBLs) and AmpC pose a serious therapeutic threat in nosocomial infections. Cost-effective screening methods are a boon to patients. This study aims to detect gram-negative bacilli and their antibiotic sensitivity patterns, as well as detect the ESBL and AmpC-producing isolates among Gram-negative bacilli. Methods: A prospective study was conducted with 150 samples. Gram-negative bacilli were isolated, and their antibiotic sensitivity tests were performed by the Kirby–Bauer disk diffusion method. Potential ESBL producers were screened using Ceftazidime disc, and AmpC producers were screened by Cefoxitin discs by the disc diffusion method. ESBL producers were confirmed by the combined disc diffusion assay method using ceftazidime and ceftazidime/Clavulanic acid disc. AmpC producers were confirmed by the Cefoxitin Cloxacillin Double Disc Synergy Test. Results: About 38% of 150 samples were gram-negative bacilli, of which 40.35% were Escherichia coli, followed by Pseudomonas aeruginosa (35.08%). Maximum sensitivity by E. coli was found toward imipenem, meropenem, and cotrimoxazole. P. aeruginosa showed maximum sensitivity toward piperacillin/tazobactam, imipenem, meropenem, and ceftazidime. 28.07% of Gram-negative isolates were ESBL producers, with E. coli (11 isolates) being the maximum, and 15.78% were AmpC producers, with E. coli (four isolates) being the maximum. Seven isolates were both ESBL and AmpC producers. Conclusion: Routine screening and timely reporting of ESBL and AmpC producers help in preventing the spread of multidrug-resistant strains. Antibiotic resistance surveillance helps in the implementation of strict infection control and prevention practices.

Non-invasive surveillance of shared pathogens in the Eurasian brown bear (Ursus arctos) human interface

Multi-host communities are perfect scenarios for the emergence and spread of pathogens, threatening the recovery of endangered, isolated, or inbred populations, such as the brown bear (Ursus arctos) in northwestern Spain. The population recovery in recent years has forced bears to occupy highly anthropized areas, increasing their interaction with human and domestic animals, with potential consequences for global health. During 2022–2023 a survey of parasites, bacteria and viruses shared between wildlife, domestic animals and humans was performed in this population using non-invasive surveillance, i.e., bear fecal samples (n = 73) and sponge-based sampling of trees (n = 42; 14 rubbed trees and 28 control trees). Pathogen detection rates were defined as the percentage of qPCR or culture-positive samples. Generalized linear models were fitted to assess their relationship with environmental variables including dispersion of the human population, and percentage of agricultural and periurban habitats in a 6 km-buffer around each sample. Canine Adenovirus type 1 (45.2%), Giardia spp. (15.1%), Salmonella spp. (12.3%), and extended-spectrum-beta-lactamases (ESBL) Escherichia coli (1.4%) were identified in fecal samples. In contrast, only five sponges from three rubbed and two control trees resulted positive to E. coli (14.3%). The results suggest that several pathogens are common in the Cantabrian brown bear population and that anthropization of the territory modulates their prevalence and richness.The effective design of management programs for bear conservation will require a one-health approach, in which genetic analysis of non-invasive samples can be key tools for the sanitary surveillance at the wildlife-livestock-human interface.

Comprehensive Profiling of Klebsiella in Surface Waters from Northern Portugal: Understanding Patterns in Prevalence, Antibiotic Resistance, and Biofilm Formation

This study investigates the prevalence of resistance and virulence genes in Klebsiella isolates from surface waters in Northern Portugal, within the broader context of freshwater quality challenges in Southern Europe. The aim of this research is to explain how Klebsiella dynamics, antibiotic resistance, and biofilm formation interact in surface waters. Antimicrobial susceptibility was examined using the Kirby–Bauer disk diffusion method against 11 antibiotics and screening for Extended-Spectrum Beta-Lactamase (ESBL) production using the double-disk synergy. PCR was employed to detect resistance and virulence genes, while biofilm production was assessed using the microplate method. Out of 77 water isolates, 33 Klebsiella (14 Klebsiella spp. and 19 K. pneumoniae strains) were isolated. ESBL production was observed in 36.8% of K. pneumoniae and 28.6% of Klebsiella spp. High resistance rates to blaCTX-U were observed in both. The papC gene was prevalent, signifying potential environmental risks. Biofilm production averaged 81.3% for K. pneumoniae and 86.9% for Klebsiella spp. These findings underscore the intricate interplay between Klebsiella’s dynamics and freshwater quality, with ESBL’s prevalence raising concerns about waterborne dissemination and public health implications. This work supports the need for vigilance of Klebsiella in surface waters in Southern Europe.

Molecular detection of Klebsiella pneumoniae producing extended-spectrum beta-lactamase isolated from bat feces from the Tanjung Ringgit bat cave, Lombok Island, Indonesia

Background and Aim: Bats are a reservoir for the pathogenic bacteria Klebsiella pneumoniae and can spread it through feces that fall in nests/caves, carried, and dropped while they fly near human settlements, and from their saliva. The emergence and spread of multidrug resistance (MDR) strains of K. pneumoniae indicate that resistant to antibiotics, especially extended-spectrum beta-lactamase (ESBL), is considered an important global health threat. The aim of this study was to determine the presence of the gene encoding extended beta-lactamase in K. pneumoniae isolated from fresh bat feces collected from the Tanjung Ringgit bat cave, East Lombok. Materials and Methods: In this study, 150 fresh fecal samples were analyzed using standard microbiological techniques for the presence of K. pneumoniae. K. pneumoniae-positive isolates were subjected to antibiotic sensitivity testing, followed by molecular detection using polymerase chain reaction. Results: This study showed that 14 (9.3%) of 150 samples were positive for K. pneumoniae. Ten of the 14 samples (71.4%) were MDR isolates and 6 (42.9%) had the blaSHV gene identified. Conclusion: The presence of K. pneumoniae isolated from fresh bat feces, which is MDR and has the blaSHV gene encoding ESBL indicates that bats can be a reservoir for the transmission of MDR and ESBL bacteria has an impact on public health in the study area. Keywords: bat, blaSHV, extended-spectrum beta-lactamase, Klebsiella pneumoniae, public health.

A five-year retrospective antibiogram review in the paediatric burns unit at a tertiary South African Hospital

BackgroundThere is a global concern regarding increasing colonization and/or infection of paediatric burns patients with multi-drug-resistant organisms, especially in Africa. Surveillance of antimicrobial resistant patterns enables clinicians to opt for the most appropriate empiric antimicrobial agent according to the unit’s susceptibility profile. ObjectiveThis study sought to compile unit-specific antibiograms comparing the organism prevalence and their antimicrobial resistance trends in the paediatric burns unit, Chris Hani Baragwanath Academic Hospital (CHBAH) from January 2015 to December 2019. MethodsA retrospective, laboratory-based review was conducted of bacterial and fungal isolates including antimicrobial susceptibility testing (AST) data from blood cultures and tissue samples. Enterobacterales, non-fermenters, gram-positive organisms, and yeasts were analysed as a percentage of total positive blood cultures comparing 2015–2017 to 2018–2019 data. Analysis of antimicrobial resistance trends was performed for extended-spectrum beta-lactamases (ESBLs), carbapenem-resistant Enterobacterales (CRE), extensively-drug-resistant (XDR) Acinetobacter baumannii, and meticillin-resistant Staphylococcus aureus (MRSA) for the years 2015, 2017, and 2019. ResultsA total of 1243 blood culture isolates were studied with A.baumannii (208/1243;17 %), coagulase negative staphylococci (141/1243; 11 %) and Candida auris (53/1243; 4 %) representing the predominant gram-negative bacteria, gram-positive bacteria, and yeast, respectively. A significant decrease in ESBLs (p = 0.00) was noted with a rise in CREs (p = 0.00) during the study period. Majority of the A. baumannii were XDR (≥77 %) despite an appreciable decrease. A notable decrease in MRSA (p = 0.00) isolates was observed. pseudomonas aeruginosa (72/275; 26 %) was the leading organism recovered from a total of 275 tissue isolates. ConclusionThe results of this study encourage review of the current antimicrobial choices in the unit for empiric antibacterial cover. Due to the low numbers of yeasts, we cannot comment on the institution of early antifungal strategies. We support reinforced infection prevention and control practices as well as antimicrobial stewardship initiatives.

Discerning the dissemination mechanisms of antibiotic resistance genes through whole genome sequencing of extended-spectrum beta-lactamase (ESBL)-producing E. coli isolated from veterinary clinics and farms in South Korea

Extended-spectrum beta-lactamase (ESBL)-producing bacteria are resistant to most beta-lactams, including third-generation cephalosporins, limiting the treatment methods against the infections they cause. In this study, we performed whole genome sequencing of ESBL-producing E. coli to determine the mechanisms underlying the dissemination of antibiotic resistance genes. We analyzed 141 ESBL-producing isolates which had been collected from 16 veterinary clinics and 16 farms in South Korea. Long- and short-read sequencing platforms were used to obtain high-quality assemblies. The results showed that blaCTX-M is the dominant ESBL gene type found in South Korea. The spread of blaCTX-M appears to have been facilitated by both clonal spread between different host species and conjugation. Most blaCTX-M genes were found associated with diverse mobile genetic elements that may contribute to the chromosomal integration of the genes. Diverse incompatibility groups of blaCTX-M-harboring plasmids were also observed, which allows their spread among a variety of bacteria. Comprehensive whole genome sequence analysis was useful for the identification of the most prevalent types of ESBL genes and their dissemination mechanisms. The results of this study suggest that the propagation of ESBL genes can occur through clonal spread and plasmid-mediated dissemination, and that suitable action plans should be developed to prevent further propagation of these genes.

Effect of UV-C disinfection and copper plating on healthcare-associated infections in a NICU with high ESBL infections

IntroductionHealthcare-associated infections (HCAIs) in neonates are frequent and highly lethal, in particular those caused by extended spectrum beta-lactamase (ESBL) producing bacteria. We evaluated the beneficial effects of ultraviolet C (UV-C) disinfection and copper adhesive plating on HCAIs in the Neonatal Intensive Care Unit (NICU) of a third level paediatric hospital in Mexico City, both in combination of hand-hygiene (HH) and prevention bundles. MethodsAll NICU patients were included. There were 4 periods (P): P1: HH monitoring and prevention bundles; P2: P1+UV-C disinfection; P3: P2+Copper adhesive plating on frequent-contact surfaces and P4: Monitoring of P3 actions. Results552 neonates were monitored during 15,467 patient days (PD). HCAI rates decreased from 11.03/1000 PD in P1 to 5.35/1000 PD in P4 (p=0.006). HCAIs with bacterial isolates dropped from 5.39/1000 PD in PI to 1.79/1000 PD in P4 (p=0.011). UV-C and copper were associated with significant HCAI prevention (RR 0.49, CI95% 0.30–0.81, p=0.005) and with lesser HCAIs with bacterial isolates (RR 0.33, CI95% 0.14–0.77, p=0.011). ConclusionsCopper adhesive plating combined with UV-C disinfection were associated with a drop in HCAI rates and with the elimination of ESBL-caused HCAIs. Hence, we propose that these strategies be considered in MDRO proliferation preventions.

Prevalence and predictors of multidrug-resistant bacteremia in liver cirrhosis.

Improved knowledge of local epidemiology and predicting risk factors of multidrug-resistant (MDR) bacteria are required to optimize the management of infections. This study examined local epidemiology and antibiotic resistance patterns of liver cirrhosis (LC) patients and evaluated the predictors of MDR bacteremia in Korea. This was a retrospective study including 140 LC patients diagnosed with bacteremia between January 2017 and December 2022. Local epidemiology and antibiotic resistance patterns and the determinants of MDR bacteremia were analyzed using logistic regression analysis. The most frequently isolated bacteria, from the bloodstream, were Escherichia coli (n = 45, 31.7%) and Klebsiella spp. (n = 35, 24.6%). Thirty-four isolates (23.9%) were MDR, and extended-spectrum beta-lactamase E. coli (52.9%) and methicillin-resistant Staphylococcus aureus (17.6%) were the most commonly isolated MDR bacteria. When Enterococcus spp. were cultured, the majority were MDR (MDR 83.3% vs. 16.7%, p = 0.003), particularly vancomycin-susceptible Enterococcus faecium. Antibiotics administration within 30 days and/or nosocomial infection was a significant predictor of MDR bacteremia (OR: 3.40, 95% CI: 1.24-9.27, p = 0.02). MDR bacteremia was not predicted by sepsis predictors, such as positive systemic inflammatory response syndrome (SIRS) or quick Sequential Organ Failure Assessment (qSOFA). More than 70% of strains that can be treated with a third-generation cephalosporin have been cultured. In cirrhotic patients, antibiotic administration within 30 days and/or nosocomial infection are predictors of MDR bacteremia; therefore, empirical administration of broad-spectrum antibiotics should be considered when these risk factors are present.

Molecular characterization of carbapenemase and extended spectrum beta-lactamase producing Acinetobacter baumannii isolates causing surgical site infections in Ethiopia

BackgroundAcinetobacter baumannii is an opportunistic pathogen that can cause a variety of nosocomial infections in humans. This study aimed to molecularly characterize extended-spectrum beta-lactamase (ESBL) producing and carbapenem-resistant Acinetobacter species isolated from surgical site infections (SSI).MethodsA multicentre cross-sectional study was performed among SSI patients at four hospitals located in Northern, Southern, Southwest, and Central parts of Ethiopia. The isolates were identified by microbiological methods and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). Antibiotic susceptibility was determined using disk diffusion. The presence of phenotypic ESBL and carbapenemase production was detected by employing standard microbiological tests, including combined disk diffusion (CDT). ESBL and carbapenem resistance determinants genes were studied by polymerase chain reaction (PCR) and sequencing.ResultsA total of 8.7% Acinetobacter species were identified from 493 culture-positive isolates out of 752 SSI wounds. The species identified by MALDI-TOF MS were 88.4% A. baumannii, 4.7% Acinetobacter pittii, 4.7% Acinetobacter soli, and 2.3% Acinetobacter lactucae. Of all isolates 93% were positive for ESBL enzymes according to the CDT. Using whole genome sequencing 62.8% of the A. baumannii harbored one or more beta-lactamase genes, and 46.5% harbored one or more carbapenemase producing genes. The distribution of beta-lactamases among Acinetobacter species by hospitals was 53.8%, 64.3%, 75%, and 75% at JUSH, TASH, DTCSH, and HUCSH respectively. Among ESBL genes, blaCTX−M alleles were detected in 21.4% of isolates; of these 83.3% were blaCTX−M−15. The predominant carbapenemase gene of blaOXA type was detected in 24 carbapenem-resistant A. baumannii followed by blaNDM alleles carried in 12 A. baumannii with blaNDM−1 as the most common.ConclusionsThe frequency of Acinetobacter species that produce metallobetalactamases (MBLs) and ESBLs that were found in this study is extremely scary and calls for strict infection prevention and control procedures in health facilities helps to set effective antibiotics stewardship.

Coexistence of a nonresistance-conferring IncI1 plasmid favors persistence of the blaCTX-M-bearing IncFII plasmid in Escherichia coli.

So far, plasmid-carried blaCTX-M is still the most common extended-spectrum beta-lactamase (ESBL) genotype in clinical settings worldwide. Except for the widespread use of third-generation cephalosporins, the interaction between coexisting plasmids can also affect the long-term stable existence of the blaCTX-M gene; however, the study on that is still sparse. In the present study, we assess the interaction of coinhabitant plasmids blaCTX-M-IncFII and nonresistance-IncI1. Our results confirmed that the increased fitness advantages of strain C600FII+I1 were attributable to the cohabitant nonresistance-IncI1 plasmid, which largely reduced the intracellular ATP levels of host bacteria, thus decreasing the rep gene expression of the blaCTX-M-IncFII plasmid, its copy numbers, and mating efficiencies, while the higher fitness advantages of strain C600FII+I1 enhanced the persistence of the blaCTX-M-IncFII plasmid. The results indicate that the nonresistance-IncI1 plasmid contributes to the long-term existence of the blaCTX-M-IncFII plasmid, implying a potentially new strategy for controlling the spread of resistance plasmids in clinical settings by targeting nonresistance plasmids.

Epidemiology and antimicrobial resistance patterns of bacterial meningitis among hospitalized patients at a tertiary care hospital in Saudi Arabia: a six-year retrospective study.

Bacterial meningitis poses significant medical challenges due to its acute inflammatory nature and potential for severe neurological complications, emphasizing the need for prompt diagnosis and treatment. Limited data exists on its epidemiology and antimicrobial resistance trends among hospitalized patients in Saudi Arabia. This study aimed to investigate these factors at a tertiary care hospital over six years. A retrospective analysis was conducted on cerebrospinal fluid samples results from 222 bacterial meningitis cases among hospitalized patients between 2018 and 2023. Demographic, clinical, microbiological data, and antibiotic susceptibility patterns were collected and analyzed. Pseudomonas aeruginosa (43%) was the predominant pathogen isolated. Neonates (16%) and children (47%) were most affected population. Nosocomial meningitis accounted for 92% of cases, mainly in the intensive care settings (50.45%). Extended-spectrum beta-lactamase was the leading resistance pattern (12.2%). Seasonal variation was observed, with a peak incidence in October-November. The study highlights the substantial burden of bacterial meningitis among hospitalized patients, especially among high-risk groups. Emerging antimicrobial resistance emphasizes the need for optimized surveillance and stewardship. Future prospective research employing molecular techniques across multiple centers in the country is warranted to enhance understanding and guide public health strategies in Saudi Arabia.

Efficacy of an inulin-based treatment on intestinal colonization by multidrug-resistant E. coli: insight into the mechanism of action

ABSTRACT Inulin, an increasingly studied dietary fiber, alters intestinal microbiota. The aim of this study was to assess whether inulin decreases intestinal colonization by multidrug resistant E. coli and to investigate its potential mechanisms of action. Mice with amoxicillin-induced intestinal dysbiosis mice were inoculated with extended spectrum beta-lactamase producing E. coli (ESBL-E. coli). The combination of inulin and pantoprazole (IP) significantly reduced ESBL-E. coli fecal titers, whereas pantoprazole alone did not and inulin had a delayed and limited effect. Fecal microbiome was assessed using shotgun metagenomic sequencing and qPCR. The efficacy of IP was predicted by increased abundance of 74 taxa, including two species of Adlercreutzia. Preventive treatments with A. caecimuris or A. muris also reduced ESBL-E. coli fecal titers. Fecal microbiota of mice effectively treated by IP was enriched in genes involved in inulin catabolism, production of propionate and expression of beta-lactamases. They also had increased beta-lactamase activity and decreased amoxicillin concentration. These results suggest that IP act through production of propionate and degradation of amoxicillin by the microbiota. The combination of pantoprazole and inulin is a potential treatment of intestinal colonization by multidrug-resistant E. coli. The ability of prebiotics to promote propionate and/or beta-lactamase producing bacteria may be used as a screening tool to identify potential treatments of intestinal colonization by multidrug resistant Enterobacterales.

Genetic Analyses of Rare ESBL ST628 Klebsiella pneumoniae Detected during a Protracted Nosocomial Outbreak in the United Kingdom

Klebsiella pneumoniae (K. pneumoniae) cultures from a hospital-wide outbreak in the UK, which lasted for over 12 months, were sequenced. We sought to sequence and genetically characterise the outbreak strain. Antibiotic Susceptibility Testing (AST) was performed on 65 K. pneumoniae isolates saved from the outbreak. All isolates were sequenced using the Oxford Nanopore Technologies (ONT) MinION flowcell: 10 isolates, including the isolate with the earliest collection date in 2017, were additionally sequenced on the NovaSeq 6000 platform to build high-accuracy nanopore-illumina assemblies. Among the sequenced strains, 60 were typed as ST628. 96.6% (n = 58/60) ST628 strains harboured a large ~247-kb FIB(K) plasmid carrying up to 11 antimicrobial resistance genes, including the extended-spectrum beta-lactamase (ESBL) gene, blaCTX-M-15. Clonality between the outbreak isolates was confirmed using single nucleotide polymorphism (SNP) typing. The outbreak strains were phylogenetically related to clinical ST628 strains identified in 2012, 6 years prior to the outbreak. A rare ESBL K. pneumoniae K2 ST628 strain harbouring a multi-drug resistant (MDR) plasmid encoding the ESBL gene blaCTX-M-15 was detected across multiple independent wards during the protracted nosocomial outbreak. Surveillance of this strain is recommended to prevent future nosocomial outbreaks.

ESBL-Producing Enterobacterales at the Human–Domestic Animal–Wildlife Interface: A One Health Approach to Antimicrobial Resistance in Piauí, Northeastern Brazil

The use, misuse, and overuse of antimicrobials is one of the main public health threats of the 21st century. We investigated the risk factor of the presence of extended-spectrum, cephalosporin-resistant Enterobacterales in feces of non-domestic and domestic birds and other domestic animals in Piauí State, northeast Brazil. We collected a total of 387 cloacal and rectal swab samples of free-living birds, domestic birds, and domestic mammals in five municipalities: Amarante, Água Branca, Lagoa Alegre, Parnaíba, and Teresina. A total of 59/387 (15.2%) of these samples harbored extended spectrum beta-lactamase (ESBL)-producing Enterobacterales. Using the MALDI-TOF technique, we identified fifty-seven samples as Escherichia coli and two samples as Klebsiella pneumoniae. Teresina and Parnaíba had the highest prevalence of animals with resistant bacteria (32.1% and 27.1%, respectively) and highest exposure risk factor (OR of 16.06 and 8.58, respectively, and p < 0.001 for all). Multidrug-resistant, ESBL-producing Enterobacterales were observed in 72.8% of the samples (43/59). For the free-living birds, the positive samples belonged to a great kiskadee (Pitangus sulphuratus) and a semipalmated sandpiper (Calidris pusilla) in migratory and resident species, respectively. For domestic animals, the swine samples showed the highest prevalence of antimicrobial resistance. The lack of access to veterinary care and information regarding antimicrobial therapy, along with the easy access to antimicrobials without medical prescription, favors the inadequate use of antimicrobials in Piauí.

Microbiological and molecular genetic characteristics of Klebsiella pneumoniae isolates, extracted under conditions of cardiac surgery hospital

Klebsiella pneumoniae is one of the main causative agents of healthcare-associated infections (HAI) worldwide. The study was aimed at molecular characterization of beta-lactam antibiotic resistance in K. pneumoniae isolated in the cardiac surgery hospital, identify hypervirulent isolates and assess isolate genetic relatedness. K. pneumoniae isolated from the clinical material of patients (n = 50) at cardiac surgery departments as well as anesthesiology and reanimation department treated at the cardiovascular surgery hospital in Perm from July 2021 to December 2022 were analyzed. Bacteriological studies were performed on an automatic analyzer WalkAway-96Plus (Beckman Coulter, USA). The sensitivity to thirteen antimicrobials, production of extended-spectrum beta-lactamases (ESBL) and multidrug resistance (MDR) phenotype were assessed. The string test was used to screen hypermucoviscous K. pneumoniae. Isolate relatedness (ERIC-PCR), presence of beta-lactamase genes (blaTEM, blaCTX-M, blaSHV, blaOXA, blaKPC, blaVIM-2, blaIMP-1, blaNDM-1), as well as genes associated with hypervirulence (prmpA, iucA, peg-344, wzyK2, magA) were analyzed by PCR. Amplifications were performed in a DNA Engine Dyad Thermal Cycler (Bio-Rad, USA). Gel documentation system Gel-Doc XR (Bio-Rad, USA) was used for band visualization and data documentation. According to the study results, it was found that carbapenem-resistant isolates accounted for almost 76% of all isolates, the ESBL-phenotype had 90%, and MDR-phenotype — 88% of studied isolates. According to the string test results, 8% of K. pneumoniae isolates had a hypermucoviscous phenotype. As for genes associated with hypervirulence, it was shown that the iucA gene was the most common, amplified in 54% of isolates, prmpA was detected in 38% of isolates, 48% of isolates had wzyK2 or magA genes encoding capsular type K1/K2. Almost a third of K. pneumoniae samples contained a combination of the rmpA and iucA genes, and they were isolated more often in the group of patients with active infection. Only carbapenem-sensitive microorganisms had hypermucoviscous phenotype, K1 capsular type, and a combination of prmpA, iucA, peg-344 genes, whereas the K2 capsular type was most common among carbapenem-resistant K. pneumoniae. Based on molecular genetic typing, it was found that 24% of K. pneumoniae isolates were assigned to four genome groups of identical cultures, 76% of the isolates had individual profiles. Closely related isolates were found among patients from different departments that indicates a potential pathogen circulation in the closed circuit “surgery department–department of anesthesiology” and “reanimation–surgery department”.