ESBL Producers Research Articles

Dissemination of Class A Cephalosporinases and Class D Carbapenemases in Escherichia coli Isolates From a Tertiary Hospital in Sudan.

Introduction The high prevalence of urinary tract infections (UTIs) and rising resistance to beta-lactam antibiotics, which is a global therapeutic concern, are caused by Escherichia coli (E. coli) extended-spectrum beta-lactamases (ESBLs) producers. It is unclear how E. coli that produces ESBLs spreads throughout Gezira state,Sudan. The study aimed to evaluate the dissemination of class A and class D resistance genes amongE. coliand to recognize the antibacterial activity of the locally used cephalosporins and carbapenems. Methods One hundred and fifteen isolates of uropathogenicE. coliwere collected from patients who attended a tertiary hospital. The isolates were identified using colony morphology, gram staining, and biochemical tests and checked for 16S rRNA using PCR. The multidrug-resistant (MDR) testing was conducted using agar disk diffusion. Finally, the class A and D resistance genes were analyzed by multiplex PCR. Results The study enrolled 200 patients with UTIs.E. coliisolates were found in 115 (57.5%) urine specimens examined, and 60 (52.2%) of them produced resistance to most locally used antibiotics. The antibiotic resistance pattern was higher against cefepime (100%), ceftizoxime (90%), cefuroxime (81.7%), and ceftriaxone (81.7%) and had lower activity against meropenem (13.3%). The genotypic characterization of class A cephalosporinases was 85% forblaCTX-M, 70% forblaSHV, and 33.3% forblaTEM, while for class D carbapenemases, it was 10% for bothblaOXA-23andblaOXA-51. Conclusion The considerable antibiotic resistance to the cephalosporins and meropenem and the increased predominance of theblaCTX-MandblaSHVgenes are serious concerns for the health authorities. Meropenem could still be used as the drug of choice for ESBL-producing E. coli.

ESBL and carbapenemase-producing Enterobacteriaceae in infectious pleural effusions: current epidemiology at Hôpital du Mali.

Antimicrobial resistance (AMR) is a global health concern, with extended-spectrum β-lactamases (ESBLs) and carbapenemases being major contributors. Pleural infection (PI) is a severe condition in West Africa, complicated by AMR. This study aimed to investigate the prevalence and molecular characteristics of ESBL and carbapenemase-producing enterobacteria in pleural effusions in Mali. Pleural fluid samples from 526 patients with pleuritis were analyzed. Enterobacterial species were isolated and identified, and the prevalence of resistance genes (blaOXA-48, blaNDM-1, blaKPC, blaTEM, blaSHV) and virulence factors was determined. Among the patients, 110 were diagnosed with enterobacterial pleuritis. Escherichia coli, Klebsiella pneumoniae, and Proteus mirabilis were the main pathogens identified. Resistance to β-lactams and cephalosporins was high, while carbapenems showed good activity. ESBL production was detected in 33.6% of isolates, with blaTEM being the most common gene. Carbapenemase gene (blaNDM-1) was found in three isolates. The study highlights the high prevalence of multidrug-resistant bacteria and the need for appropriate antibiotic selection based on local resistance patterns. Understanding the molecular characteristics of resistance is crucial for optimizing patient care and developing effective therapeutic strategies. Further research is needed to monitor and control AMR in PIs in Mali.

Detection and Phylogenetic Analysis of Extended-Spectrum β-Lactamase (ESBL)-Genetic Determinants in Gram-Negative Fecal-Microbiota of Wild Birds and Chicken Originated at Trimmu Barrage.

Extended-spectrum β-lactamases (ESBL) give rise to resistance against penicillin and cephalosporin antibiotics in multiple bacterial species. The present study was conducted to map genetic determinants and related attributes of ESBL-producing bacteria in three wild aquatic bird species and chickens at the "Trimmu Barrage" in district Jhang, Punjab province, Pakistan. To study the prevalence of ESBL-producing bacteria, a total of 280 representative samples were collected from wild bird species; cattle egrets (Bubulcus ibis), little egrets (Egretta garzetta) and common teals (Anas crecca) as well as from indigenous chickens (Gallus gallus domesticus) originating from a local wet market. The isolates were confirmed as ESBL producers using a double disc synergy test (DDST) and bacterial species were identified using API-20E and 20NE strips. A polymerase chain reaction (PCR) was used to detect ESBL genetic determinants and for genus identification via 16S rRNA gene amplification. A phenotypic antimicrobial susceptibility test was performed for ESBL-producing isolates against 12 clinically relevant antibiotics using the Kirby-Bauer disk diffusion susceptibility test. A phylogenetic tree was constructed for the sequence data obtained in this study and comparative sequence data obtained from GenBank. The overall prevalence of ESBL-producing bacteria was 34.64% (97/280). The highest percentage (44.28%; 31/70) of ESBL-producing bacteria was recovered from chickens (Gallus gallus domesticus), followed by little egrets (Egretta garzetta) (41.43%; 29/70), common teal (Anas crecca) (28.57%; 20/70) and cattle egrets (Bubulcus ibis) (24.28%; 17/70). Five different ESBL-producing bacteria were identified biochemically and confirmed via 16S rRNA gene sequencing, which included Escherichia coli (72; 74.23%), Enterobacter cloacae (11; 11.34%), Klebsiella pneumoniae (8; 8.25%), Salmonella enterica (4; 4.12%) and Pseudomonas aeruginosa (2; 2.06%). Based on PCR, the frequency of obtained ESBL genes in 97 isolates was blaCTX-M (51.55%), blaTEM (20.62%), blaOXA (6.18%) and blaSHV (2.06%). In addition, gene combinations blaCTX-M + blaTEM, blaTEM + blaOXA and blaCTX-M + blaSHV were also detected in 16.49%, 2.06% and 1.03% of isolates, respectively. The ESBL gene variation was significant (p = 0.02) in different bacterial species while non-significant in relation to different bird species (p = 0.85). Phylogenetic analysis of amino acid sequence data confirmed the existence of CTX-M-15 and TEM betalactamases. The average susceptibility of the antibiotics panel used was lowest for both Klebsiella pneumoniae (62.5% ± 24.42) and Salmonella enterica (62.5% ± 31.08) as compared to Enterobacter cloacae (65.90% ± 21.62), Pseudomonas aeruginosa (70.83% ± 33.42) and Escherichia coli (73.83% ± 26.19). This study provides insight into the role of aquatic wild birds as reservoirs of ESBL-producing bacteria at Trimmu Barrage, Punjab, Pakistan. Hence, active bio-surveillance and environment preservation actions are necessitated to curb antimicrobial resistance.

The functional repertoire of AmpR in the AmpC β-lactamase high expression and decreasing β-lactam and aminoglycosides resistance in ESBL Citrobacter freundii

Citrobacter freundii is characterized by AmpC β-lactamases that develop resistance to β-lactam antibiotics. The production of extended-spectrum β-lactamase (ESBL) is substantially high in Escherichia coli, C. freundii, Enterobacter cloacae, and Serratia marcescens, but infrequently explored in C. freundii. The present investigation characterized the ESBL C. freundii and delineated the genes involved in decrease in antibiotics resistance. We used the VITEK-2 system and Analytical Profile Index (API) kit to characterize and identify the Citrobacter isolates. The mRNA level of AmpC and AmpR was determined by RT-qPCR, and gel-shift assay was performed to evaluate protein-DNA binding. Here, a total of 26 Citrobacter strains were isolated from COVID-19 patients that showed varying degrees of antibiotic resistance. We examined and characterized the multidrug resistant C. freundii that showed ESBL production. The RT-qPCR analysis revealed that the AmpC mRNA expression is significantly high followed by a high level of AmpR. We sequenced the AmpC and AmpR genes that revealed the AmpR has four novel mutations in comparison to the reference genome namely; Thr64Ile, Arg86Ser, Asp135Val, and Ile183Leu while AmpC remained intact. The ΔAmpR mutant analysis revealed that the AmpR positively regulates oxidative stress response and decreases β-lactam and aminoglycosides resistance. The AmpC and AmpR high expression was associated with resistance to tazobactam, ampicillin, gentamicin, nitrofurantoin, and cephalosporins whereas AmpR deletion reduced β-lactam and aminoglycosides resistance. We conclude that AmpR is a positive regulator of AmpC that stimulates β-lactamases which inactivate multiple antibiotics.

Fecal Carriage of Multi-drug Resistant Escherichia coli in Healthy Children: a Community-based Study

Introduction: Escherichia coli is enteric Gram-negative bacilli, earlier recognized as non-invasive commensal. Invasive strains of E. coli have been identified and are associated with a variety of human infections. Increasing drug resistance among E. coli has been reported. Multidrug resistance is the ability of an organism to resist at least one agent in three or more antimicrobial categories. The aim of this study was to detect fecal carriage of MDR E. coli isolates among healthy school children.
 Methods: A total of 139 stool samples were collected from Rastriya Secondary School, Purano Tudikhel, Pokhara-1. Isolation, identification, and Antibiotic susceptibility test pattern of E. coli isolates were done by standard microbiological techniques. Further Extended Spectrum Beta-Lactamase test was performed by Combined Disc Test and data analysis was done by using Microsoft Excel.
 Results: A total of 106 E. coli were isolated from the stool samples. MDR E. coli were found to be 8 (7.55%) and 7 E. coli isolates were resistant to Ceftazidime which was further tested for ESBL and 5 isolates were found to be ESBL producers. The resistance of E. coli to Ampicillin, Nitrofurantoin, Ceftriaxone, Ceftazidime, Ciprofloxacin, and Gentamicin was 27.36%, 43%, 10.38%, 6.60%, 6.60%, and 2.83% respectively. Only one isolate was resistant to all antibiotics used except Imipenem.
 Conclusion: E. coli is the main Gram-negative bacteria isolated from the stool sample and identified as the main carrier of antimicrobial resistance in species comparison of Enterobacteriaceae isolated from fecal samples. Therefore, quick surveillance is needed in order to effectively handle such MDR strains. The E. coli population susceptible to all antibiotics used was a much more diverse group than the resistant and ESBL-producing E. coli.

The Ethnobotanical Investigation, Phytochemistry and Antioxidant Activity of a Medicinal Plant Recipe Directed against Candida albicans and Enterobacteria Stains Producing ESBL CTX-M-15 Type in Burkina Faso

Aims: The objectives are to carry out an ethnobotanical survey among traditional healers in order to choose the most recipe used in the treatment of vaginal candidiasis in cities of Burkina Faso followed by phytochemical quantification, antioxidant activity and antimicrobial of the best recipe.
 Methodology: Ethnobotanical surveys were conducted in Bobo-Dioulasso and Dédougou by semi-structured interview amount traditional healers. The extracts were obtained by ethanolic and hydroethanolic maceration. Characterization of the secondary metabolites was revealed by the tests in tubes. Polyphenolic compounds contents quantification was done by spectrophotometry using Follin-Ciocalteu reagent, aluminum trichloride and vanilic acid. The antioxidant activity was evaluated by two methods: DPPH• and FRAP. The Minimal inhibitory concentration on Enterobacteria strains was determined by the dilution method and the minimal bactericidal concentration was determined by inoculation on agar. The susceptibility test of Candida albicans strains was carried out using the disc diffusion assay.
 Results: In total, 52 traditional healers were surveyed with a predominance of men (75%) in the both cities. 38 recipes of medicinal plants have been obtained. Decoction is the most frequent method of preparation in Bobo-Dioulasso (87.5%) and in Dédougou (27.27%). The leaves (44%) and the bark of the trunk (31.82%) are respectively the most parts used of the plants. Colorimetric tests revealed the presence of compounds such as flavonoids, alkaloids, tannins and saponosides. The best results of quantification tests of total phenolics, flavonoids and tannins, were obtained with the hydroethanolic extract (80.27±20.27(mgEAG/10 mg); 0.27±0.01(mgEQ/10 mg) and 73.31±4.65 (mgEC/10 mg)). With antioxidant activity, the highest value was obtained with the DPPH radical inhibition method (85.59±0.001%). Minimal inhibitory concentration revelead that the highest value was 0.781 mg/ml and the best minimal bactericidal concentration was 3.123 mg/ml.
 Conclusion: Phytochemical and biological analysis realized could be partially justified by the recipes used in the treatment of vaginal candidiasis.

Epidemiological analysis and antimicrobial susceptibility profile of Gram-negative bacilli that cause bacteremia in Japan

We investigated the epidemiology and antimicrobial susceptibility profiles of seven major Gram-negative bacilli (Escherichia coli, Klebsiella spp., Enterobacter spp., Pseudomonas aeruginosa, Acinetobacter spp., Stenotrophomonas maltophilia, and Bacteroides spp.) that caused bacteremia in Japan. We collected clinical information and isolates from patients aged 20 years or older who developed bacteremia during a year at three Japanese university hospitals and performed microbiological examination. In total, 628 cases were included, half of which were caused by E. coli (315 isolates). P. aeruginosa (56 isolates) was isolated most frequently among non-fermenting bacteria and 33 Bacteroides spp. were isolated. Mortality rates were the highest for P. aeruginosa (7-day, 16.1%; 30-day, 26.8%). The 7- and 30-day mortality rates ranged 3.8–9.0% and 8.3–17.6%, respectively, for Enterobacterales, and they were 15.2% each for Bacteroides spp. Regarding antimicrobial resistance, Enterobacterales and Acinetobacter spp. showed susceptibility to carbapenems and amikacin (98.0–100.0%). The susceptibility rates to ceftolozane/tazobactam ranged 82.4–99.0% for Enterobacterales and 92.9% for P. aeruginosa. More than 30.0% of E. coli isolates were resistant to fluoroquinolone. Extended-spectrum β-lactamase (ESBL) producers were found in 21.0% of E. coli and approximately 80% of those were resistant to fluoroquinolones. The susceptibility of the 33 Bacteroides spp. to carbapenems, ampicillin/sulbactam, and piperacillin/tazobactam was 100.0%. Among the ESBL producers, blaCTX-M group 9 was the major subgroup in E. coli (77.3%), and blaCTX-M group 1 was detected in 18.2% of E. coli and 50.0% of Klebsiella spp. Continuous surveillance is needed to understand the epidemiology and consider appropriate therapeutic strategies.

Dynamics of Extended-spectrum Beta-lactamase–producing, Third-generation Cephalosporin-resistant and Tetracycline-resistant Escherichia coli in Feedlot Cattle With or Without Tylosin Administration

The impact of in-feed use of tylosin in feedlot cattle on Gram-negative foodborne bacteria is unknown. We evaluated the effect of continuous in-feed tylosin use on the concentration and prevalence of tetracycline-resistant (TETr)-, third-generation cephalosporin-resistant (3GCr)-, and extended-spectrum β-lactamase–producing (ESBLs) E. coli in feedlot cattle. A cohort of weaned calves (10 animals/group) were randomized to receive a feed ration with or without tylosin. Fecal samples, regularly collected over the entire feeding period, and pen surface and feed samples, collected at the end of the feeding period, were cultured on selective media. Enumeration and binary outcomes were analyzed by mixed effects linear regression or logistic regression, respectively, using treatment and days on feed as fixed factors, and animal ID as a random variable. Tylosin supplementation did not affect the fecal concentrations of TETrE. coli or fecal prevalence of 3GCrE. coli. However, cattle in the tylosin group were 1.5 times more likely (Odds ratio = 1.5: 95% confidence interval: 1.1–2.0) to harbor ESBLs E. coli than the control cattle. Regardless of tylosin treatment, fecal concentrations of TETrE. coli and the prevalence of 3GCr- and ESBLs-E. coli increased over time. Tylosin-supplemented feed did not affect the prevalence of TETrE. coli; 3GCr and ESBLs-E. coli were not detected from the feed samples. Most of the 3GCr- and ESBLs-E. coli isolates carried the blaCTX-M-15 gene, widely detected among ESBLs-E. coli human isolates. In summary, although in-feed tylosin use in feedlot cattle did not select for TETr- and 3GCr-E. coli, it increased the likelihood of detecting ESBL-producing E. coli. Furthermore, the study indicated that the feedlot production setting gradually increases the levels of E. coli resistant to the critically and/or important antibiotics for public health, indicating an increased risk of their dissemination beyond the feedlot environment.

Bloodstream Infections by Extendedspectrum β-lactamase-producing Klebsiella Species in Children

Infections caused by resistant Gram-negative bacteria are a serious public health problem, with Klebsiella spp. being the most common cause and increasing over the years. There is a striking increase in antibiotic resistance worldwide. The aim of this study was to retrospectively evaluate the characteristics and treatment of bloodstream infections (BSIs) caused by Klebsiella spp. and to identify possible risk factors for extended-spectrum β-lactamase (ESBL) resistance in our hospital between August 2019 and March 2023. Of 250 Klebsiella isolates, 112 (44.8%) were ESBL producers and 138 (55.2%) were ESBL nonproducers. Catheter-related BSIs (CRBSIs) accounted for 49.6% of infections and were more common in the ESBL nonproducer group. Most of the Klebsiella spp. were K. pneumoniae (233/250). Most of the infections were healthcare-associated infections (85.6%). Most patients had an underlying disease, the most common underlying disease in the ESBL-producing group was neurometabolic disease (26.8%), whereas in the ESBL-non-producing group it was malignancy (35.5%). The median age of the ESBL-producing group was 14 months and was younger (p=0.01). Previous antibiotic use in the last 30 days, especially aminoglycosides (p<0.006), β-lactam-β-lactamase inhibitor combinations (p<0.001) and cephalosporins (p<0.001), increased ESBL-resistant infection. Use of β-lactam-β-lactamase inhibitor combinations in the last 30 days increased the risk of ESBL resistance by approximately 7.4 times, and cephalosporins increased the risk by 5 times. In the ESBL-producing group, the median duration of treatment was longer at 14 days (p=0.01), and carbapenems were most commonly used (p<0.001). Thrombocytopenia (p=0.003), elevated C-reactive protein (p<0.001), CRBSI (p=0.009), presence of central venous catheter (p=0.03), urinary catheter (p<0.001), mechanical ventilation (p<0.001), intensive care admission (p=0.005), previous use of carbapenems, aminoglycosides, fluoroquinolones in the last 30 days (p=0.003, p=0.001, p=0.006, respectively) and colistin treatment (p<0.001) increased the risk of mortality. The 28-day mortality rate was 11.6%. Appropriate use of narrow-spectrum antibiotics and reduction of invasive procedures is important in reducing ESBL resistance and BSI-related mortality.

Bloodstream Infections by Extended-spectrum β-lactamase-producing Klebsiella Species in Children

Infections caused by resistant Gram-negative bacteria are a serious public health problem, with Klebsiella spp. being the most common cause and increasing over the years. There is a striking increase in antibiotic resistance worldwide. The aim of this study was to retrospectively evaluate the characteristics and treatment of bloodstream infections (BSIs) caused by Klebsiella spp. and to identify possible risk factors for extended-spectrum β-lactamase (ESBL) resistance in our hospital between August 2019 and March 2023. Of 250 Klebsiella isolates, 112 (44.8%) were ESBL producers and 138 (55.2%) were ESBL nonproducers. Catheter-related BSIs (CRBSIs) accounted for 49.6% of infections and were more common in the ESBL nonproducer group. Most of the Klebsiella spp. were K. pneumoniae (233/250). Most of the infections were healthcare-associated infections (85.6%). Most patients had an underlying disease, the most common underlying disease in the ESBL-producing group was neurometabolic disease (26.8%), whereas in the ESBL-non-producing group it was malignancy (35.5%). The median age of the ESBL-producing group was 14 months and was younger (p=0.01). Previous antibiotic use in the last 30 days, especially aminoglycosides (p<0.006), β-lactam-β-lactamase inhibitor combinations (p<0.001) and cephalosporins (p<0.001), increased ESBL-resistant infection. Use of β-lactam-β-lactamase inhibitor combinations in the last 30 days increased the risk of ESBL resistance by approximately 7.4 times, and cephalosporins increased the risk by 5 times. In the ESBL-producing group, the median duration of treatment was longer at 14 days (p=0.01), and carbapenems were most commonly used (p<0.001). Thrombocytopenia (p=0.003), elevated C-reactive protein (p<0.001), CRBSI (p=0.009), presence of central venous catheter (p=0.03), urinary catheter (p<0.001), mechanical ventilation (p<0.001), intensive care admission (p=0.005), previous use of carbapenems, aminoglycosides, fluoroquinolones in the last 30 days (p=0.003, p=0.001, p=0.006, respectively) and colistin treatment (p<0.001) increased the risk of mortality. The 28-day mortality rate was 11.6%. Appropriate use of narrow-spectrum antibiotics and reduction of invasive procedures is important in reducing ESBL resistance and BSI-related mortality.

Resistance of Clinical Isolates of Escherichia coli and Klebsiella pneumoniae in “Boucle du Mouhoun, Burkina Faso”: one year's Experience in Antibiotic Resistance Surveillance

Introduction: Escherichia coli and Klebsiella pneumoniae account for a large proportion of clinically isolated pathogenic bacteria. However, their resistance to antibiotics is increasingly becoming a global health threat. The aim of this study was to describe the current antibiotic resistance profile of these two species. Materials and method: This was a retrospective descriptive study at the Dedougou regional hospital. The results of antibiotics susceptibility testing of non-redundant clinical isolates of Enterobacteriaceae were used. Bacteria were isolated and identified using standard bacteriology methods. The antibiogram was performed by the Kirby-Bauer method and the interpretation was made according to the recommendations of the Antibiogram Committee of the French Microbiology Society (CASFM 2017). Data were entered into WHOnet 2018 and analysed using EPI-INFO 7.2.4.0. Results: A total of 138 non-redundant Enterobacteriaceae strains were isolated, of which almost 90% were E. coli (75.4%) and Klebsiella pneumoniae (13.8%). The most frequent resistance was observed with amoxicillin + clavulanic acid (81.3%), ceftriaxone (66.7%) and cotrimoxazole (82.9%). E. coli showed very high resistance to ampicillin (95.2%). Relatively moderate to high resistance was also observed with ciprofloxacin 69.1% and gentamicin 39%. The most active antibiotics were imipenem and cefoxitin, with resistance frequencies of 2.4% and 5.7% of all strains respectively. ESBL-producing strains were the most frequently encountered phenotypes (59.3%), followed by high-level penicillinases (19.5%). 3GC resistance was associated to ESBL production in almost 90% of cases, and both ciprofloxacin and gentamicin resistance were significantly associated with 3GC resistance (p<0.001). Conclusion: Escherichia coli and Klebsiella pneumoniae are the main enterobacteria isolated in clinics. The production of extended-spectrum beta-lactamases is their main mechanism of resistance to beta-lactam antibiotics.

Trends in Antibiotic-Resistant Bacteria Isolated from Screening Clinical Samples in a Tertiary Care Hospital over the 2018-2022 Period.

To assess the putative impact of the COVID-19 pandemic on multidrug-resistant (MDR) bacteria recovered from routine screening samples and, more globally, the trends in time to first positive screening sample and carriage duration of those bacteria in patients admitted to a tertiary hospital, data from laboratory results were retrospectively mined over the 2018-2022 period. No significant differences could be found in the number of positive patients or MDR isolates per year, time to positive screening, or carriage duration. Extended-spectrum beta-lactamase producers were dominant throughout the studied period but their relative proportion decreased over time as well as that of meticillin-resistant Staphylococcus aureus. Meanwhile, carbapenemase-producing enterobacteria (CPE) proportion increased. Among the 212 CPE isolates, Klebsiella pneumoniae and Escherichia coli were the more frequent species but, beginning in 2020, a significant rise in Enterobacter cloacae complex and Citrobacter freundii occurred. OXA48 was identified as the leading carbapenemase and, in 2020, a peak in VIM-producing enterobacteria linked to an outbreak of E. cloacae complex during the COVID-19 pandemic was singled out. Finally, a worrisome rise in isolates producing multiple carbapenemases (NDM/VIM and mostly NDM/OXA48) was highlighted, especially in 2022, which could lead to therapeutic dead-ends if their dissemination is not controlled.

Drug Resistance Analysis of Pathogens Isolated from Pediatric Patients in Mexico

Abstract Objective To analyze the resistance to antimicrobials in clinical isolates from pediatric patients in Mexico. Methods Susceptibility data from relevant specimens were collected in the pediatric population over 6 months from 25 centers from 17 states of Mexico and analyzed using the WHONET 5.6 software. Data were stratified into three age groups: younger than 2 years, 2 to 6 years, and 6 to 18 years. Results For Escherichia coli, the infant/toddler group had higher resistance rates to ampicillin, ampicillin-sulbactam, cefuroxime, cefepime, gentamicin, quinolones (p < 0.001), amoxicillin/clavulanic acid (p = 0.003), and ceftazidime (p = 0.004) than the other two age groups. Additionally, a high proportion of extended-spectrum β-lactamase (ESBL)-producing isolates for E. coli (75.3%) was detected in this age group. Comparable results were observed for Klebsiella pneumoniae, with higher resistance to ampicillin-sulbactam, ceftazidime, gentamicin, cefepime, trimethoprim-sulfamethoxazole, carbapenems (p = 0.001) and amoxicillin/clavulanic acid (p = 0.023) in the infant/toddler group. Moreover, a high proportion of ESBL producers (76%) was detected in this age group. Regarding wards, E. coli and K. pneumoniae had the highest carbapenem resistance in the ICU area, and Acinetobacter baumannii had the highest carbapenem resistance in medical wards. Conclusion High antibiotic resistance rates were detected in the infant/toddler group. This report presents baseline data for future prospective surveillance studies of antimicrobial resistance in pediatric patients in Mexico.

Trends in Antimicrobial Resistance in a Tertiary Care Hospital of Assam, India

Antimicrobial resistance (AMR) in bacterial pathogens has emerged as a challenge in health care settings resulting in high rates of morbidity and mortality. The aim of the present study was to describe the trends and burden of AMR in a tertiary care hospital. A retrospective observational study was undertaken from October 2018 to March 2021 in a clinical microbiology laboratory where local priority pathogens and their antimicrobial resistance patterns were analyzed. Organism identification and antimicrobial susceptibility testing were performed as per Clinical and Laboratory Standards Institute guidelines. Out of 9948 isolates, Enterobacteriaceae (58%) were mostly isolated followed by Staphylococci (18.6%), Non-fermenting gram negative bacilli (NFGNB) (13.7%), and Enterococci (8.4%) respectively. Highest isolation was from inpatient department (61.3%); 31.5% from outpatient, and 7.2 % from intensive care units. Klebsiella pneumoniae (26.9%) was most isolated organism, mostly from respiratory samples; Escherichia coli was isolated mostly from urine (40.7%). Almost half of the Enterobacteriaceae isolates were extended spectrum beta-lactamase producers while >50% of Enterobacteriaceae and NFGNB isolates were resistant to one or more Carbapenems. Frequency of Methicillin resistant Staphylococcus aureus was 44.7% , Vancomycin resistant Enterococci was 1.2%. A rising trend of resistance to cephalosporins and carbapenems along with fluoroquinolones was observed. Our study has witnessed a high prevalence of Gram negative pathogens with increasing resistance to commonly applied antimicrobials during the surveillance period which can act as a guiding tool in devising local antimicrobial priorities, antibiotic policy, and proper antimicrobial prescribing practices.

Abundance and prevalence of ESBL coding genes in patients undergoing first line eradication therapy for Helicobacter pylori.

The spread of extended-spectrum beta-lactamases (ESBLs) in nosocomial and community-acquired enterobacteria is an important challenge for clinicians due to the limited therapeutic options for infections that are caused by these organisms. Here, we developed a panel of ESBL coding genes, evaluated the abundance and prevalence of ESBL encoding genes in patients undergoing H. pylori eradication therapy, and summarized the effects of eradication therapy on functional profiles of the gut microbiome. To assess the repertoire of known beta lactamase (BL) genes, they were divided into clusters according to their evolutionary relation. Primers were designed for amplification of cluster marker regions, and the efficiency of this amplification panel was assessed in 120 fecal samples acquired from 60 patients undergoing H. pylori eradication therapy. In addition, fecal samples from an additional 30 patients were used to validate the detection efficiency of the developed ESBL panel. The presence for majority of targeted clusters was confirmed by NGS of amplification products. Metagenomic sequencing revealed that the abundance of ESBL genes within the pool of microorganisms was very low. The global relative abundances of the ESBL-coding gene clusters did not differ significantly among treatment states. However, at the level of each cluster, classical ESBL producers such as Klebsiella sp. for blaOXY (p = 0.0076), Acinetobacter sp. for blaADC (p = 0.02297) and others, differed significantly with a tendency to decrease compared to the pre- and post-eradication states. Only 13 clusters were common across all three datasets, suggesting a patient-specific distribution profile of ESBL-coding genes. The number of AMR genes detected in the post-eradication state was higher than that in the pre-eradication state, which could be attributed, at least in part, to the therapy. This study demonstrated that the ESBL screening panel was effective in targeting ESBL-coding gene clusters from bacterial DNA and that minor differences exist in the abundance and prevalence of ESBL-coding gene levels before and after eradication therapy.

Factors associated with infections by multidrug-resistant bacteria in Hospital "Vicente Corral Moscoso", Cuenca, 2018-2019

Factors associated with infections by multidrug-resistant bacteria in Hospital "Vicente Corral Moscoso", Cuenca, 2018-2019

DETECTION OF EXTENDED SPECTRUM BETA LACTAMASES-PRODUCING KLEBSIELLA PNEUMONIAE ISOLATES IN CHRONIC OBSTRUCTIVE PULMONARY DISEASES PATIENTS

Objective: Chronic obstructive pulmonary disease (COPD) is the leading cause of morbidity and mortality worldwide which includes chronic bronchitis and emphysema. 80% of acute exacerbation of COPD (AECOPD) are triggered by respiratory viruses, atypical bacteria, and aerobic Gram-positive and Gram-negative bacteria. The aim of our study was to analyze the prevalence and antimicrobial susceptibility testing of Klebsiella pneumoniae and detection of extended spectrum beta lactamases (ESBL)-producing K. pneumoniae isolates from COPD patients. Methods: Sputum samples received from seventy-five diagnosed cases of COPD from the department of General Medicine and Chest Medicine, TSRM MCH and RC, Trichy, from March 2022 to August 2022. Direct Gram stain was done for all sputum samples. The suitable sputum samples were cultured. The identification of organism and antimicrobial susceptibility testing was done by standard microbiological techniques. Results: Out of seventy-five cases, 64% were males and 36% were females. Forty-seven were sputum positive, and the prevalence of Gram- negative bacteria was 64%. K. pneumoniae was the most common bacteria isolated (42.2%), followed by Pseudomonas aeruginosa (15.5%). Antimicrobial susceptibility testing of K. pneumoniae was sensitive to imipenem (78.94%), aminoglycosides (78.94%), amoxycillin-clavulinic acid (63.15%), ciprofloxacin (57.89%), Piperacillin-Taxobactam (57.89%), and the phenotypic tests showed 13 (68%) isolates were ESBL producers. Conclusion: This study showed that K. pneumoniae and P. aeruginosa are the most common organisms associated with AECOPD and increased rate of ESBL producers were observed.

Occurrence of plasmid-mediated fosfomycin resistance (fos genes) among Escherichia coli isolates, Portugal

To evaluate the occurrence of plasmid-mediated fos genes among fosfomycin-resistant Escherichia coli isolates collected from patients in Lisbon, Portugal, and characterize the fos-positive strains. A total of 19 186 E. coli isolates were prospectively collected between April 2022 and January 2023 from inpatients and outpatients at a private laboratory in Lisbon. Fosfomycin resistance was initially assessed by semi-automated systems and further confirmed by the disc diffusion method. Resistant isolates were investigated for plasmid-mediated fos genes (fosA1-fosA10, fosC and fosL1-fosL2) and extended-spectrum beta-lactamases (ESBLs) by PCR and sequencing. Multilocus sequence typing was performed to evaluate the clonal relationship among fos-carrying isolates. Out of the 19 186 E. coli isolates, 100 were fosfomycin-resistant (0.5%), out of which 15 carried a fosA-like gene (15%). The most prevalent fosfomycin-resistant determinant was fosA3 (n=11), followed by fosA4 (n=4). Among the 15 FosA-producing isolates, 10 co-produced an ESBL (67%), being either of CTX-M-15 (n=8) or CTX-M-14 (n=2) types. The fosA3 gene was carried on IncFIIA-, IncFIB-, and IncY-type plasmids, whereas fosA4 was always located on IncFIB-type plasmids. Most FosA4-producing isolates belonged to a single sequence type ST2161, whereas isolates carrying the fosA3 gene were distributed into nine distinct genetic backgrounds. The prevalence of fosfomycin-resistant E. coli isolates is still low in Portugal. Notably, 15% of fosfomycin-resistant isolates harbour a transferable fosA gene, among which there is a high rate of ESBL producers, turning traditional empirical therapeutical options used in Portugal (fosfomycin and amoxicillin-clavulanic acid) ineffective.

Effects of ppk1 deletion on the drug susceptibility of uropathogenic Escherichia coli producing ESBLs

To investigate the effect and the mechanism of ppk1 gene deletion on the drug susceptibility of uropathogenic Escherichia coli producing extended-spectrum beta-lactamases (ESBLs-UPEC). The study was an experimental study. From March to April 2021, a strain of ESBLs-UPEC (genotype was TEM combined with CTX-M-14) named as UE210113, was isolated from urine sample of the patient with urinary tract infection in the Laboratory Department of Guangzhou Eighth People's Hospital, meanwhile its ppk1 gene knock-out strain Δpk1 and complemented strain Δpk1-C were constructed by suicide plasmid homologous recombination technique, which was used to study the effect of ppk1 gene on ESBLs-UPEC drug sensitivity and its mechanism. The drug susceptibility of UE210113, Δpk1, and Δpk1-C were measured by Vitek2 Compact System and broth microdilution method. The quantitative expression of ESBLs, outer membrane protein and multidrug efflux systems encoding genes of UE210113, Δpk1 and Δpk1-C were performed by using qRT-PCR analysis. By using two independent sample Mann-Whitney U test, the drug susceptibility results showed that, compared with UE210113 strain, the sensitivities of Δpk1 to ceftazidime, cefepime, tobramycin, minocycline and cotrimoxazole were enhanced (Z=-2.121,P<0.05;Z=-2.236,P<0.05;Z=-2.236,P<0.05;Z=-2.121,P<0.05), and the drug susceptibility of Δpk1-C restored to the same as which of UE210113 (Z=0,P>0.05). The expression levels of ESBLs-enconding genes blaTEM and blaCTX-M-14 in Δpk1 were significantly down-regulated compared with UE210113, but the expression was not restored in Δpk1-C. The expression of outer membrane protein gene omp F in Δpk1 was significantly up-regulated, while the expression of omp A and omp C were down-regulated. The results showed that the expression of multidrug efflux systems encoding genes tol C, mdt A and mdtG were down-regulated in Δpk1 compared with UE210113. The expression of all of the outer membrane protein genes and the multidrug efflux systems genes were restored in Δpk1-C. In conclusion,the lost of ppk1 gene can affect the expression of the outer membrane protein and multidrug efflux systems encoding genes of ESBLs-UPEC, which increase the sensitivity of ESBLs-UPEC to various drugs.

High frequency and molecular characterization of ESBL-producing Enterobacteriaceae isolated from wound infections in North Lebanon

ABSTRACT Background Extended-spectrum beta-lactamases producing Enterobacteriaceae (ESBL-PE) represent a major problem in wound infections. Here, we investigated the prevalence and molecular characterization of ESBL-PE associated with wound infections in North Lebanon. Research design and methods A total of 103 non-duplicated E. coli and K. pneumoniae strains isolated from 103 patients with wound infections, were collected from seven hospitals in North Lebanon. ESBL-producing isolates were detected using a double-disk synergy test. In addition, multiplex polymerase chain reaction (PCR) was used for the molecular detection of ESBLs genes. Results E. coli was the predominant bacteria (77.6%), followed by K. pneumoniae (22.3%). The overall prevalence of ESBL-PE was 49%, with a significantly higher rate among females and elderly patients. K. pneumoniae was the common MDR and ESBL-producer bacteria (86.95% and 52.17%) compared to E. coli (77.5% and 47.5%). Most of the isolated ESBL producers harbored multiple resistant genes (88%), where blaCTX-M was the most predominant gene (92%), followed by blaTEM (86%), blaSHV (64%), and blaOXA genes (28%). Conclusions This is the first data on the ESBL-PE prevalence associated with wound infections in Lebanon, showing the emergence of multidrug-resistant ESBL-PE, the dominance of multiple gene producers, and the widespread dissemination of blaCTX-M and blaTEM genes.