ESBL Producers Research Articles

Phenotypic and molecular characterization of enteropathogenic Escherichia coli and Salmonella spp. causing childhood diarrhoea in Awka, South-Eastern Nigeria

BackgroundDiarrhoea is a major cause of childhood disease in the developing countries. This experimental study investigated the prevalence of ESBL and MBL genes in enteropathogenic strains of Escherichia coli and Salmonella spp. isolated from diarrheagenic children in Awka, Nigeria.MethodsTwo hundred stool samples were collected from diarrhea patients in three paediatric hospitals within Awka metropolis, Nigeria. All E. coli and Salmonella spp. isolated through standard bacteriological methods were subjected to antibiotic-susceptibility testing. Double disc synergy and imipenem-EDTA combined disc tests were used to phenotypically confirm the presence of ESBL and MBL respectively. PCR amplification of β-lactamase genes was done.ResultsThe prevalence of E. coli and Salmonella species in this study were 54% and 24.5% respectively. The organisms were highly resistant to metronidazole, cefuroxime and ceftazidime, and also showed a high sensitivity to nitrofurantoin and gentamicin. ESBL production was recorded in E. coli (49%) and Salmonella spp. (51.1%) while 27 isolates of E. coli (25%) and 7 isolates of Salmonella spp. were confirmed MBL positive by the combined disk diffusion technique. Eleven E. coli and 4 Salmonella spp. co-harbored both ESBL and MBL production. The most prevalent MBL gene in this study is the blaVIM gene (18.8%) which mediate MBL production in Gram negative bacteria; and this was followed by blaSHV (12.5%), blaTEM and blaCTX-M (6.3% each) for E. coli isolates. Salmonella spp. was recorded to have blaVIM (28.8%), blaSHV (28.8%), blaTEM (14.3%) and blaCTX-M (14.3%) genes.ConclusionsThis study reveals the prevalence of enteropathogenic E. coli and Salmonella strains bacteriologically recovered from diarrheic children in Awka, Nigeria, and which were found to be multiple resistant to clinically-relevant antibiotics because they co-express ESBL and MBL genes which mediate multidrug resistance in Gram negative bacteria.

Investigation of the gallbladder for the presence of pathogenic bacteria and their antibiotic susceptibility pattern

Background: The gallbladder is an essential organ in the human body that functions as an antioxidant. Cholangitis and pyogenic cholecystitis are two significant reasons for cholecystectomy. The significance of establishing microbial cultures and antibiotic susceptibility is that suitable antibiotics can be supplied because the infection can lead to severe consequences and death if not treated properly. However, very limited data is available on this matter. Therefore, this study is an attempt to investigate the presence of bacterial pathogens causing gallbladder disease and antibacterial susceptibility patterns to assess the choice of antibiotic. Moreover, both gallbladder’s wall and bile samples were investigated for accurate results. None of the past studies have worked on the gallbladder and the bile simultaneously. Objective: A prospective analytical study was conducted from July to December 2014. Blood, MacConkey agar, and Robertson cooked medium were used to culture all the clinical samples. After 24 and 48 hours of incubation, culture plates were examined for evident growth. Standard microbiological procedures were used to identify the isolated species. Antibiotic susceptibility tests were performed, and the isolated bacteria were also examined for extended-spectrum beta-lactamase (ESBL) development. Results: Among 60 patients, 66% were positive for bacteria in the gallbladder wall or bile, or both. Gramnegative bacteria were the most commonly isolated ones. Due to ESBL production, bacteria were mainly resistant to all cephalosporins and Augmentin. However, aminoglycosides, carbapenem, and antibiotics combination were the most effective. Conclusion: It can be concluded that organisms are more resistant now due to ESBL production, so the old regimen of antibiotics might not be effective in treating them. The considerable culture-positive rate highlights the significance of acquiring bile and gallbladder wall bacterial cultures to administer the proper antibiotics at cholecystectomy. To avoid major complications like gram-negative septicemias, necessary adjustments must be made by the results of antibiotic sensitivity tests.

Evaluation of the Ability to Form Biofilms in KPC-Producing and ESBL-Producing Klebsiella pneumoniae Isolated from Clinical Samples.

The appearance of Klebsiella pneumoniae strains producing extended-spectrum β-lactamase (ESBL), and carbapenemase (KPC) has turned into a significant public health issue. ESBL- and KPC-producing K. pneumoniae's ability to form biofilms is a significant concern as it can promote the spread of antibiotic resistance and prolong infections in healthcare facilities. A total of 45 K. pneumoniae strains were isolated from human infections. Antibiograms were performed for 17 antibiotics, ESBL production was tested by Etest ESBL PM/PML, a rapid test was used to detect KPC carbapenemases, and resistance genes were detected by PCR. Biofilm production was detected by the microtiter plate method. A total of 73% of multidrug resistance was found, with the highest resistance rates to ampicillin, trimethoprim-sulfamethoxazole, cefotaxime, amoxicillin-clavulanic acid, and aztreonam. Simultaneously, the most effective antibiotics were tetracycline and amikacin. blaCTX-M, blaTEM, blaSHV, aac(3)-II, aadA1, tetA, cmlA, catA, gyrA, gyrB, parC, sul1, sul2, sul3, blaKPC, blaOXA, and blaPER genes were detected. Biofilm production showed that 80% of K. pneumoniae strains were biofilm producers. Most ESBL- and KPC-producing isolates were weak biofilm producers (40.0% and 60.0%, respectively). There was no correlation between the ability to form stronger biofilms and the presence of ESBL and KPC enzymes in K. pneumoniae isolates.

Emergence of Extended-Spectrum Beta-Lactamase and Carbapenemase Producing Gram Negative Non-Fermenters at Selected Hospitals of Northeast Ethiopia: A Prospective Cross-Sectional Study.

The emergence and spread of extended-spectrum β-lactamases (ESβLs) and carbapenemase (CP) producing gram negative non-fermenters are becoming a serious public health threat globally. Infections caused by these pathogens limit treatment options and contribute to the significant morbidity and mortality. Thus, to reduce their spread, early detection of these superbugs is very crucial. This study therefore aimed to assess the prevalence of ESβLs and CP producing gram negative non-fermenters at selected hospitals of North East Ethiopia. A cross-sectional study was conducted from January to June 2021. Acinetobacter baumannii (A. baumannii) and Pseudomonas aeruginosa (P. aeruginosa) were identified using standard bacteriological techniques. ESβL and CP production were detected by combined disk diffusion and modified carbapenem inhibitory methods, respectively. Data were collected via face-to-face interview and patient card review. Chi-squared and Fisher's exact tests were calculated and p-value < 0.05 was considered statistically significant. A total of 384 patients participated in this study. Overall, 30 (7.8%) patients had positive culture for A. baumannii and P. aeruginosa. The prevalence of A. baumannii was 20 (5.2%) and that of P. aeruginosa was 10 (2.6%). From the overall isolates, 16 (53.3%) were ESβL and the proportion of carbapenemase production was 4 (13.3%). ESβL production was 8 (40%) in A. baumannii and 8 (80%) in P. aeruginosa isolates. ESβL production infections were significantly associated with hospitalization (p=0.004). Intravenous catheterization, hospitalization, and surgery had significant association with ESβL production (p<0.005). All isolates of A. baumannii and P. aeruginosa were MDR. ESβL and carbapenemase production among A. baumannii and P. aeruginosa were high in the selected hospitals. The treatment of such resistant infectious agents should be guided by antimicrobial susceptibility test in a study setting. Thus, restricted and wise use of antibiotics is highly recommended to contain the spread of these superbugs. Hospitals should develop infection prevention guidelines to prevent the spread of resistant pathogens in hospitalized patients.

Isolation and Speciation of Acinetobacter Species with Special Reference to Antibiotic Resistance in Tertiary Care Hospital

Acinetobacter can survive longer in the environment and is also known for developing resistance against agents like disinfectants and nutritional deprivation. Very restricted information about Acinetobacter is available because of their confused taxonomic status. The isolation and identification of resistance pattern help in the selection and search for new antibiotics, reducing the morbidity and mortality of patients. The present study was conducted to find the different types of resistant mechanisms in Acinetobacter species and their antimicrobial susceptibility pattern from various clinical samples. Gram's stain and biochemical reactions identified Acinetobacter isolated from various clinical samples. Antibiotic susceptibility testing was done, and their resistant pattern was observed. Phenotypic methods for drug resistance were carried out -Detection of Extended Spectrum Beta Lactamase (ESBL) by Double disc synergy test (DDST), detection of Metallo Beta Lactamase (MBL) by Imipenem with EDTA, and detection of Carbapenemase production by Modified Hodge test (MHT). The results showed that out of 150 isolates of Acinetobacter species, Acinetobacter baumannii 138 (92%) was the most common species isolated, followed by Acinetobacter lwoffii 10 (7%) and Acinetobacter hemolytic 2 (1%). Of these, 22 (15%) isolates showed ESBL production by Double disc synergy test, 80 (53%) isolates were MBL producers, and 11 (7%) were Carbapenemase producers by Modified Hodge test. The study observed that ESBL production in Acinetobacter was 22(15%) and MBL 80(53%). It demonstrated that most of the Acinetobacter isolated were found to be Multi-Drug Resistant (95%). It brings out the need for active surveillance combined to eradicate the curtail of this organism in hospital settings.

Prevalence, Microbiological Profile, and Risk Factors of Surgical Site Infections in Saudi Patients with Colorectal Cancer.

Resection surgery in patients with colorectal cancer (CRC) patients is associated with potential complications, including surgical site infection (SSI). To estimate the prevalence rate of SSI, identify the common pathogens responsible for SSI, and determine potential risk factors for SSI development in a cohort from Saudi Arabia. Patients with CRC who underwent bowel resection surgery at King Abdulaziz Medical City, Riyadh, between January 01, 2016, and December 31, 2019, were retrospectively included. Demographics, comorbidities, surgical procedure data, and the results of preoperative laboratory tests were retrospectively collected from medical records through the health information system. The study population was divided into two groups: those who developed SSI and those who did not. A total of 92 patients with CRC who underwent resection surgery were included, of which 54 (58.7%) were males. The median age was 65 (IQR 55.5-75.0) years. SSI was observed in 25 (27.2%) patients. The most frequently isolated organisms were Escherichia coli and Pseudomonas aeruginosa, followed by Klebsiella pneumoniae, vancomycin-sensitive Enterococcus faecium, and methicillin-resistant Staphylococcus aureus. Three E. coli isolates were producers of extended-spectrum beta-lactamases, and two K. pneumoniae isolates exhibited a multidrug resistance profile. Low preoperative serum albumin level was identified as a significant independent risk factor for developing SSI (AOR = 0.853, 95% CI = 0.748-0.973, P = 0.0181). The study found a notable prevalence of SSI among the included patients. Gram-negative bacteria were more involved in SSI events and were also associated with drug-resistance patterns. Gut microbiota bacteria were most commonly involved in SSIs. Low preoperative serum albumin levels predicted the development of postoperative SSI, and thus its close monitoring and management before surgery could reduce the SSIs.

Pathogenic Bacteria and Their Antibiotic Resistance Patterns in Milk, Yoghurt and Milk Contact Surfaces in Debre Berhan Town, Ethiopia.

Bacterial contamination of milk is a primary culprit for causing foodborne illnesses, presenting a significant health hazard for millions of individuals around the globe. The level and variety of microorganisms present in raw milk determine its degree of contamination and the potential health risks it poses. A cross-sectional survey was conducted from February to August. A questionnaire was used to collect data on socio-demographic characteristics and hygiene practices from milk distributors and traders. Raw milk, yoghurt, swabs from milk containers and drinking cups were collected and processed for bacterial isolation and identification, antibiotic susceptibility testing, MDR screening and confirmation, ESBL screening and confirmation. Finally, all data were pooled and analyzed using SPSS software version 25. A total of 120 samples of fresh milk, yogurt and cotton swabs from milk containers and cups were collected. A total of 80 bacterial isolates were isolated from 120 samples. Among the bacteria isolated, S. aureus 17 (21.3%), E. coli 17 (21.3%), S. epidermidis 14 (17.5%), Klebsiella spp. 9 (11.3%) and Salmonella spp. 7 (8.8%) were detected most often. High rate of contamination was observed in fresh milk 23 (28.8%) and yogurt 23 (28.8%). All isolates were resistant to at least one antibiotic tested. Comparatively, high rates of resistance were observed in all isolates to the most commonly prescribed antibiotics in Ethiopia. However, lower rates of resistance have been observed for recently introduced antibiotics in Ethiopia. Of the isolates, 20 (25.0%) were resistant to eight or more antibiotics. While 16 (20.0%), 12 (15.0%), 9 (11.3%) isolates were resistant to two, three and five antibiotics, respectively. Of the bacteria isolated, 52/80 (65.0%) were MDR, 25/49 (51.0%) were screened for ESBL production, and 20/49 (40.8%) isolates were confirmed as ESBL producer. This study showed a high rate ofbacterial isolates along with MDR and ESBL-producing strains in raw milk, yoghurt, milk container swabs and drinking cup swab samples, associated with poor hygiene and sanitation practices.

Colonization of Residents and Staff of an Italian Long-Term Care Facility and an Adjacent Acute Care Hospital Geriatrics Unit by Multidrug-Resistant Bacteria.

In 2022, we undertook a point prevalence screening study for Enterobacterales with extended-spectrum β-lactamases (ESBLs), high-level AmpC cephalosporinases and carbapenemases, and also methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE) in a long-term care facility (LTCF) and the associated acute-care hospital Geriatrics unit in Bolzano, Northern Italy. Urine samples and rectal, inguinal, oropharyngeal, and nasal swabs were plated on selective agar plates. Metadata of the patients, including demographic data, were collected, and risk factors for colonization were determined. ESBL, AmpC, carbapenemase, and quinolone resistance genes were investigated by the HybriSpot 12 PCR AUTO System. The following colonization percentages by multidrug-resistant (MDR) bacteria have been found in LTCF residents: all MDR organisms, 59.5%; ESBL producers, 46.0% (mainly CTX-M-type enzymes); carbapenemase producers, 1.1% (one Klebsiella pneumoniae with KPC-type); MRSA, 4.5%; VRE, 6.7%. Colonization by MDR bacteria was 18.9% for LTCF staff and 45.0% for Geriatrics unit patients. Peripheral vascular disease, the presence of any medical device, cancer, and a Katz Index of 0 were significant risk factors for colonization of LTCF residents by MDR bacteria in univariate and/or multivariate regression analysis. To conclude, the ongoing widespread diffusion of MDR bacteria in the LTCF suggests that efforts should be strengthened on MDR screening, implementation of infection control strategies, and antibiotic stewardship programs targeting the unique aspects of LTCFs. ClinicalTrials.gov ID: 0530250-BZ Reg01 30/08/2022.

Phenotypic characterization and epidemiology of extended-spectrum β-lactamase-producing Enterobacteriaceae strains from urinary tract infections in Garoua, Cameroon.

The emergence of extended-spectrum beta-lactamase-producing Enterobacteriaceae (ESBL-E) is causing increased morbidity and mortality around the world as a result of therapeutic failures. ESBL-E are priority pathogens due to their multidrug resistance (MDR). In Northern Cameroon, ESBL-producing bacteria, particularly in urinary tract infections (UTIs), are being increasingly isolated. This study aimed to retrospectively determine the prevalence of multi-drug resistant ESBL strains isolated from UTIs in Northern Cameroon and to evaluate the effectiveness of the ATB UR Gallery of BioMérieux in diagnosing ESBL-E in clinical settings. Standard microbiology protocols and statistical tools were utilized to identify ESBL-producing bacteria and characterize their phenotypic susceptibility and resistance profiles in the study population. Out of the 144 enterobacteria isolates successfully cultured, 59 (41%) were identified as MDR strains. The ATB UR EU gallery identified 33 (23%) multi-drug resistant ESBL-producing strains, while the double synergy test identified 35 strains without disc reconciliation and 38 strains after reconciliation. The most prevalent ESBL-E isolate was Escherichia coli, accounting for 77.1% of the isolates, followed by Klebsiella pneumoniae (20%) and Enterobacter aerogenes (2.9%). Additionally, the study revealed the emergence of Imipenem resistance (5.7%), a critical last-resort antibiotic. However, all ESBL strains were sensitive to Fosfomycin (FSF/FOS), demonstrating its potential as an effective therapeutic option. Moreover, 37% of the ESBL producers exhibited co-resistance to over 20 different antibiotics. This study provides valuable insights into the prevalence and susceptibility patterns of ESBL-E associated with UTIs in Northern Cameroon. These insights emphasizes the importance of implementing appropriate treatment guidelines and antimicrobial stewardship measures to mitigate the spread and impact of MDR ESBL-producing strains on public health.

Bacteriological Profile and Detection of β-Lactamase Producing Bacteria Isolated from Blood Samples of Neonates

The clinical impact of β-lactamase has become a public health problem around the world in terms of increased morbidity and mortality, especially in the child population. This study was aimed at determining the bacteriological profile and detection of β-lactamase producing bacteria isolated from the blood samples of neonates. For this study, a total of 1335 blood samples of neonates admitted in NICU, SCBU, and sepsis-suspected neonates visiting Paropakar Maternity and Women’s Hospital, Thapathali, Kathmandu, Nepal were collected and processed. Blood culture was performed and the identification of bacteria was done by following standard microbiological methods. Antibiotic susceptibility testing was done by using the Kirby Bauer Disk Diffusion method and confirmation of ESBL, MBL, and KPC-producing bacteria was done by Combined Disk Test. The prevalence rate of neonatal sepsis was found to be 17%. K. pneumoniae 116 (50.2%) was the predominant Gram-negative bacteria followed by K. oxytoca 31 (13.4%) whereas S. aureus 39 (16.9%) was the predominant Gram-positive bacteria causing neonatal sepsis. Among 182 Gram-negative bacterial isolates, 69 (37.9%), 22 (12.1%), and 14(31.1%) were found to be ESBL, MBL, and KPC producers respectively. K. oxytoca (54.8%), Enterobacter spp. (25%) and Citrobacter spp. (14.3%) were the predominant ESBL, MBL, and KPC producers respectively. The co-production of ESBL, MBL, and KPC was also found among the 5 Gram-negative bacteria. Colistin, Meropenem, and Imipenem seem to be the choice of the drug against Gram-negative bacteria, whereas Vancomycin and Cefoxitin seem to be the choice of the drug against Gram-positive bacteria. Therefore, to lessen the burden of antibiotic resistance, it is essential to conduct regular antimicrobial susceptibility surveillance, periodic reviews of hospital settings, and early detection of beta-lactamase-producing bacteria. Int. J. Appl. Sci. Biotechnol. Vol 11(2): 66-77.

The Prevalence of blaCTX-M, blaTEM Genes in Bacteria Isolated From Bladder Cancer Patients with Urinary Tract Infections

Urinary tract infections (UTIs) are among the most prevalent infections in cancer patients . Two hundred urine samples were taken from patients with bladder cancer between the dates of 1 April 2021 and 15 October 2021 while they were enrolled in third floor Ghazi Al- Hariri Hospital, Medical City, Baghdad Province, and private clinics in Nasiriyah Province (100 from patients treated with MMC and 100 from patients treated with BCG). Forty urine samples were taken from patients with UTI without Bladder Ca (control). The most commonly pathogens were Escherichia coli , followed by Klebsiella pneumoniae , Pseudomonas aeruginosa and Staphyllococcus aureus and other genera of UTI bacterium. The total ESBLs Producers in the current study from 40 isolates was (27)72.5%.The highest ESBLs Producer in all Groups was E.coli followed by K.pneumoniae and P.aeruginosae . According to PCR out of 38 Clinical specimen from all groups , results of the bla CTX-M gene indicated its presence in 21 isolate(55.2%),while the presence of bla TEM gene was 26(68.4%) of total isolates.

Molecular Analysis of Fosfomycin Resistance Among Escherichia coli Isolates from Urinary Tract Infections in Kidney Transplant Patients During 2019 - 2020

Background: This study aimed to estimate the prevalence of fosfomycin resistance and the frequency of extended-spectrum beta-lactamase (ESBL) production in Escherichia coli isolates from three kidney transplant patients (KTPs) in Tehran. Methods: Sixty clinical isolates of uropathogenic E. coli were collected from three kidney transplant centers in Tehran between April and May 2019. Antimicrobial susceptibility testing (AST), minimum inhibitory concentration (MIC) of fosfomycin, and screening for ESBL production were conducted following the protocols established by the Clinical and Laboratory Standards Institute (CLSI). The presence of the blaTEM, blaSHV, blaCTX-M, fosA3, and fosC2 genes was evaluated using polymerase chain reaction (PCR) and sequencing. Additionally, mutations in the murA, glpT, uhpT, and cya genes were assessed. The activity of the carbohydrate phosphate transporter was measured using the real-time PCR assay. Results: According to the AST results, ampicillin showed the highest resistance rate (86%), while ertapenem and doripenem exhibited complete susceptibility (100%). According to the E-test, 1.6% of E. coli isolates were resistant to fosfomycin. Furthermore, 33.4% of E. coli isolates in KTPs were ESBL producers, with the most frequent occurrence of the blaTEM gene (55%). Additionally, mutations were identified in the murA, uhpT, and glpT genes of resistant samples. No plasmid genes for fosA3 and fosC2 were detected. The expression of the uhpT gene increased 32-fold in a susceptible isolate, as determined by qPCR. Conclusions: The high resistance of E. coli isolates from urinary tract infections (UTIs) of KTPs to β-lactam antibiotics remains a significant clinical challenge. However, no correlation was found between ESBL production and resistance to fosfomycin. The resistance rate to fosfomycin was low, and the primary cause of resistance was mutations in chromosomal genes.

Prevalence and genetic characterization of clinically relevant extended-spectrum β-lactamase-producing Enterobacterales in the Gulf Cooperation Council countries

IntroductionAmong Gram-negative bacteria (GNB), Enterobacterales (Enterobacterales), such as Escherichia coli (E. coli) and Klebsiella pneumoniae (K. pneumoniae), are the most clinically relevant pathogens in healthcare settings. Infections secondary to these pathogens are widely common but multidrug resistance (MDR) in Enterobacterales has become a significant challenge with increased morbidity, mortality, and cost of management. The escalating global prevalence of MDR in Enterobacterales has led to limited treatment options, raising an urgent need for novel antimicrobial therapy(s) and detailed studies exploring underlying resistance mechanisms. In Enterobacterales, the prime antimicrobial resistance mechanism against β-lactam antibiotics is mainly the production of β-lactamases, particularly extended-spectrum β-lactamases (ESBLs). Although the Gulf region is witnessing major challenges from infections secondary to MDR GNB, the extent of the problem has not been fully evaluated. Therefore, this review aims to address the prevalence and genetic characterization of ESBL-producing Enterobacterales in the Gulf Cooperation Council (GCC) countries.MethodsPubMed® (National Library of Medicine, Bethesda, MD, USA) search was conducted, which looked for academic articles discussing the epidemiology of MDR Enterobacterales in the GCC countries, published in the last 5 years.Results and conclusionsIn GCC countries there is a high prevalence rate of MDR Enterobacterales, particularly ESBLs. Prevalence rates of ESBL-producing Enterobacterales among the Enterobacterales in general clinical samples in the GCC region is 21.6%–29.3%, with a slightly higher prevalence rate in intensive care unit patients (17.3–31.3%) and in patients with urinary tract infections (25.2%–31.7%). ESBL carriers have also been noted in the general community. ESBL-producing Enterobacterales from the GCC region show high levels of resistance to ampicillin, aztreonam, third-/fourth-generation cephalosporins, fluoroquinolones, and trimethoprim-sulfamethoxazole. Intermediate resistance rates are observed against nitrofurantoin, piperacillin/tazobactam, and gentamicin, with increasing resistance observed against tigecycline. The isolates demonstrate low-level resistance to carbapenems, fosfomycin, colistin, and amikacin. Enterobacterales isolates that are concomitant ESBL producers and are carbapenem resistant have been increasingly reported and demonstrate alarmingly increased antibiotic resistance patterns compared with ESBL Enterobacterales. The most prevalent genes for ESBL resistance in the Enterobacterales isolates in the GCC region are: blaCTX-M (subtype group 1) followed by/co-dominated by blaTEM and blaSHV, whereas the most common carbapenem-resistant genes are blaOXA-48 and blaNDM-1.

Characterization of avian pathogenic Escherichia coli isolates based on biofilm formation, ESBL production, virulence-associated genes, and phylogenetic groups.

Escherichia coli is a part of both animal and human commensal microbiota. Avian pathogenic E. coli (APEC) is responsible for colibacillosis in poultry, an economically important disease. However, the close similarities among APEC isolates make it difficult to differentiate between pathogenic and commensal bacteria. The aim of this study was to determine phenotypic and molecular characteristics of APEC isolates and to compare them with their in vivo pathogenicity indices. A total of 198 APEC isolates were evaluated for their biofilm-producing ability and extended-spectrum β-lactamase (ESBL) production phenotypes. In addition, 36 virulence-associated genes were detected, and the isolates were classified into seven phylogenetic groups using polymerase chain reaction. The sources of the isolates were not associated with biofilms, ESBL, genes, or phylogroups. Biofilm and ESBL production were not associated with pathogenicity. Group B2 had the highest pathogenicity index. Groups B2 and E were positively associated with high-pathogenicity isolates and negatively associated with low-pathogenicity isolates. In contrast, groups A and C were positively associated with apathogenic isolates, and group B1 was positively associated with low-pathogenicity isolates. Some virulence-associated genes showed positive or negative associations with specific phylogenetic groups. None of the individual techniques produced results that correlated with the in vivo pathogenicity index. However, the combination of two techniques, namely, detection of virulence-associated genes and the phylogenetic groups, could help the classification of the isolates as pathogenic or commensal.

Detection of blaCTX-M genes in ESBL-producing Klebsiella isolates from animals in Croatia.

This study investigated the frequency of third-generation cephalosporin resistance in Klebsiella spp. isolated from animals in Croatia and the presence of blaCTX-M genes. A total of 711 enteric bacteria were isolated from clinical samples, and Klebsiella spp. isolates accounted for 6.9% (n = 49). Thirteen Klebsiella isolates (26.5%) were ESBL producers, nine isolates from the Klebsiella pneumoniae species complex (69.2%), and four (30.8%) Klebsiella oxytoca isolates. All carried the blaCTX-M-15 gene, and antimicrobial susceptibility testing revealed them as multidrug resistant. All were resistant to all tested cephalosporins, fluoroquinolones, aminoglycosides and aztreonam, 92.3% showed resistance to tetracycline, 84.6% to trimethoprim-sulfamethoxazole and 69.2% to nitrofurantoin. No isolate showed resistance to imipenem and meropenem. It can be concluded that ESBL-producing Klebsiella expressing the blaCTX-M gene are not rare among Klebsiella isolates from animals in Croatia.

Investigation of Delafloxacin Resistance in Multidrug-Resistant Escherichia coli Strains and the Detection of E. coli ST43 International High-Risk Clone.

Delafloxacin is a novel fluoroquinolone agent that is approved for clinical application. In this study, we analyzed the antibacterial efficacy of delafloxacin in a collection of 47 Escherichia coli strains. Antimicrobial susceptibility testing was performed by the broth microdilution method and minimum inhibitory concentration (MIC) values were determined for delafloxacin, ciprofloxacin, levofloxacin, moxifloxacin, ceftazidime, cefotaxime, and imipenem. Two multidrug-resistant E. coli strains, which exhibited delafloxacin and ciprofloxacin resistance as well as extended-spectrum beta-lactamase (ESBL) phenotype, were selected for whole-genome sequencing (WGS). In our study, delafloxacin and ciprofloxacin resistance rates were 47% (22/47) and 51% (24/47), respectively. In the strain collection, 46 E. coli were associated with ESBL production. The MIC50 value for delafloxacin was 0.125 mg/L, while all other fluoroquinolones had an MIC50 value of 0.25 mg/L in our collection. Delafloxacin susceptibility was detected in 20 ESBL positive and ciprofloxacin resistant E. coli strains; by contrast, E. coli strains that exhibited a ciprofloxacin MIC value above 1 mg/L were delafloxacin-resistant. WGS analysis on the two selected E. coli strains (920/1 and 951/2) demonstrated that delafloxacin resistance is mediated by multiple chromosomal mutations, namely, five mutations in E. coli 920/1 (gyrA S83L, D87N, parC S80I, E84V, and parE I529L) and four mutations in E. coli 951/2 (gyrA S83L, D87N, parC S80I, and E84V). Both strains carried an ESBL gene, blaCTX-M-1 in E. coli 920/1 and blaCTX-M-15 in E. coli 951/2. Based on multilocus sequence typing, both strains belong to the E. coli sequence type 43 (ST43). In this paper, we report a remarkable high rate (47%) of delafloxacin resistance among multidrug-resistant E. coli as well as the E. coli ST43 international high-risk clone in Hungary.

P11 Evaluation of in vitro activity of double β-lactam ‘therapy’ in Escherichia coli: what is the association between ‘synergy’ and in vitro susceptibility?

Abstract Background Emerging antimicrobial resistance is a leading cause of patient morbidity/mortality worldwide. A potential strategy in the treatment of resistant infections is the use of combination antibiotics, with the hope of achieving greater in vitro activity, including synergy. It is currently assumed that combinations generating the greatest synergistic effect in vitro will be associated with the greatest improvement in in vitro susceptibility (as defined by EUCAST—see Methods). The aim of this study was to determine if this was indeed the case. Methods We systematically determined the relationship between double β-lactam therapy against 7 Escherichia coli strains of variable resistance in vitro (4 clinical/3 purchased). This included fully susceptible and low-level resistance isolates (N = 4), extended-spectrum β-lactamase producers (ESBLs) (N = 2) and carbapenemase producers (CPEs) (N = 1). For each of 10 β-lactam antibiotics, the MIC was determined individually, and subsequently in combination, using the MTS™ ‘cross’ synergy method (Liofilchem, 2012). The fractional inhibitory concentration (FIC) was calculated by dividing the MIC of each drug in combination by the MIC of each drug alone and adding the results. See Figure 1. Results were analysed according to EUCAST clinical breakpoints to determine if synergistic combinations correlated with a potentially improved in vitro susceptibility phenotype. A susceptibility phenotype improvement was defined: R/R or R/I or I/I monotherapy, improving to R/S, I/S or S/S combination therapy (where S = susceptible, I = intermediate and R = resistant). Results Overall, 86/630 (13.7%) combinations showed synergy; 408/630 (64.7%) = additive; 136/630 (21.6%) = indifferent. No antagonism was identified. Synergy was most detected in ESBL producers (32% of combinations; Figure 2) and less frequently in CPEs (2% combinations) and fully susceptible isolates (4% combinations). 31/630 (5%) combinations showed improvement in EUCAST susceptibility between mono/combination therapy (according to our definitions). Of these 31 combinations, 8 (26%) were synergistic, 15 (48%) additive and 8 (26%) indifferent (by FIC index). Of 599/630 combinations that showed no improvement in susceptibility, 78 (13%) = synergistic, 393 (65.6%) = additive and 128 (21.4%) = indifferent. It is however important to note that in 284/630 (45%), initial monotherapy susceptibility was S/S (i.e. further improvement not possible). Synergy was more common in combinations that improved EUCAST susceptibility versus those that did not; χ2, P = 0.04). Ceftazidime/avibactam + amoxicillin was the combination most commonly associated with synergy (12/86 synergistic combinations). Conclusions In the β-lactam combinations tested, synergy or additive effects were common (78.4%), similar to our previous work with Fosfomycin/β-Lactam combinations (89%), but higher than fosfomycin/non-β-lactam combinations (28%). Synergy was most detected in ESBL producers with most synergistic combinations containing one/two β-lactamase inhibitors. Overall, however, this rarely leads to an improvement in in vitro susceptibility by EUCAST criteria and is highly bug–drug–drug combination dependent. Further work using alternative validating methodology and in more isolates is required.

Bacterial Profile and Antibiotic Use in Catheter-Associated Urinary Tract Infection Patients at a Tertiary Referral Hospital in Surabaya, Indonesia

Highlights: This study examined patients with catheter-associated urinary tract infections (CAUTI) to find the prevalent bacteria and the frequency of antibiotic use. Extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli sensitive to amikacin was found to be the most common pathogen in CAUTI, while ceftriaxone was the most commonly used antibiotic. Abstract Catheter-associated urinary tract infection (CAUTI) is the most typical type of infection associated with healthcare. This infection constitutes a significant health problem due to its complications and frequent recurrence. The high annual incidence of CAUTI leads to infectious complications and a high cost of treatment. Antibiotic-resistant bacteria further complicate the problem because multiresistant pathogenic bacteria are often responsible for these infections. Moreover, the lack of a comprehensive case reporting system in Indonesia hinders the determination of CAUTI incidence. This study aimed to determine the bacterial profile and antibiotic use in CAUTI patients (n=22) at the Internal Medicine Inpatient Unit of Dr. Soetomo General Academic Hospital, Surabaya, Indonesia. This retrospective descriptive study collected data from patient medical records to describe the incidence, type of bacteria, sensitivity patterns, and antibiotic use in CAUTI patients. The data collection process included collecting medical records, recording information on data collection sheets, and recapitulating and analyzing the data. The criteria for CAUTI diagnosis were a bacterial count of ≥105 CFU/mL and a catheterization that lasted more than 48 hours. Samples were selected using non-probability sampling, also known as saturation sampling. Meanwhile, variables analyzed in this study were the type of pathogenic bacteria, antibiotics used, age, and sex. Descriptive analysis was employed to analyze the data. The findings suggested that the most common bacteria were Escherichia coli, with eight of nine bacteria showing extended-spectrum beta-lactamase (ESBL) production. Female patients aged 35–65 years were the majority of the CAUTI patients. Amikacin was the antibiotic with the highest sensitivity (90.9%), while ceftriaxone was the most common type of antibiotic administered to the patients. In addition, intravenous (IV) administration was the most common route of antibiotic administration, with an average therapy duration of seven days. In conclusion, identifying the type of pathogenic bacteria and performing antibiotic susceptibility testing can help minimize antibiotic resistance and prevent more severe complications in CAUTI patients.

Multidrug-resistant and extended-spectrum beta-lactamase-producing Enterobacteriaceae isolated from chicken droppings in poultry farms at Gondar City, Northwest Ethiopia.

The poultry sector is one of the largest and fastest-growing agricultural sub-sector, especially in developing countries like Ethiopia. In poultry production, poultry farmers use sub-optimum doses of antibiotics for growth promotion and disease prevention purpose. This indiscriminate use of antibiotics in poultry farms contributes to the emergence of antibiotic-resistant bacteria, which has adverse implications for public health. Therefore, this study is aimed to assess multidrug resistance and extended-spectrum beta-lactamase-producing Enterobacteriaceae from chicken droppings in poultry farms. A total of 87 pooled chicken-dropping samples were collected from poultry farms from March to June 2022. Samples were transported with buffered peptone water. Selenite F broth was used for the enrichment and isolation of Salmonella spp. Isolates were cultured and identified by using MacConkey agar, Xylose lysine deoxycholate agar, and routine biochemical tests. Kirby-Bauer disk diffusion technique and combination disk test were used for antibiotic susceptibility testing and confirmation of extended-spectrum beta-lactamase production, respectively. Data were entered using Epi-data version 4.6 and then exported to SPSS version 26 for analysis. Out of 87 pooled chicken droppings, 143 Enterobacteriaceae isolates were identified. Of these, E. coli accounts for 87 (60.8%), followed by Salmonella spp. 23 (16.1%), P. mirabilis 18 (12.6%) and K. pneumoniae 11 (7.7%). A high resistance rate was observed for ampicillin 131 (91.6%), followed by tetracycline 130 (90.9), and trimethoprim-sulfamethoxazole 94 (65.7%). The overall multidrug resistance rate was 116/143 (81.1%; 95% CI: 74.7-87.5). A total of 12/143 (8.4%; CI: 3.9-12.9) isolates were extended-spectrum beta-lactamase producers, with 11/87 (12.6%) E. coli and 1/11 (9.1%) K. pneumoniae. High prevalence of multi-drug resistant isolates was observed. This study alarms poultry as a potential reservoir of extended-spectrum beta-lactamase-producing Enterobacteriaceae, which might shed and contaminate the environment through faecal matter. Prudent use of antibiotics should be implemented to manage antibiotic resistance in poultry production.

Study of Plasmid-Mediated Extended-Spectrum Beta-Lactamase-Producing Clinical Strains of Enterobacteriaceae From Tabuk Region.

Extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae threaten infection treatment globally. This study aims to assess ESBLs-E prevalence and multidrug-resistant organisms (MDR) in clinical specimens from Tabuk, KSA. A cross-sectionalresearchwascarriedoutin March-May 2023.Acollectiveof 90 Enterobacteriaceae isolates were identified from clinicalspecimens.The specimen was identified by standard methods. The Enterobacteriaceae member was screed for ESBL production by screening and confirmatory as per the Clinical and Laboratory Standards Institute (CLSI). E. coli was the most common isolate, followed by Proteus mirabilis and Citrobacter sp, Klebsiella oxytoca, Klebsiella pneumonia, Proteus vulgaris and Morganella morganii. Among the sample, the majority of isolates were from urine (47.8%) followed by pus (25.6%) and the least from other body fluids (6.7%). The E. coli showed the highest average antibiotic resistance (73.7%) among all the antibiotics used followed by P. mirabilis (70.4%), K. pneumoniae (70%), P. vulgaris (69.8%), M. morganii and Citrobacter (69.4% both), and K. oxytoca (68.8%). There was a 41.2% average reduction in ESBL positivity from phenotypic to confirmatory test results. The highest reduction was observed among M. morganii (66.7%) and the least was observed in E. coli (17.1%). Most of the ESBL-producing isolates were found mainly in blood and urine samples. The most frequent ESBL-producing Enterobacteriaceae were K. pneumoniae and E. coli. The best options for treating Enterobacteriaceae that produce ESBL are Amoxicillin, Amikacin, and Cefoxitin. ESBL-producing isotopes showed a high resistance rate to cefepimeand cefotaxime compared to non-ESBL producers. It is of utmost importance to implement reliable infection control measures in healthcare institutions nationwide.