ESBL Producers Research Articles

Extended-spectrum β-lactamase and carbapenemase producing Enterobacteriaceae among patients suspected with surgical site infection at Hospitals in Southern Ethiopia

BackgroundExtended-spectrum β-lactamase and carbapenemase-producing Enterobacteriaceae are an increasing problem for patients today. Data on clinical samples for ESBL and carbapenemase-producing Enterobacteriaceae for surgical site infection patients in developing countries are limited, including Ethiopia, mainly due to resource constraints. Hence, this study aimed to determine the prevalence of extended-spectrum beta-lactamase- and carbapenemase-producing Enterobacteriaceae among patients suspected to have surgical site infection at Hospital in Southern Ethiopia.Materials and methodsA hospital-based cross-sectional study was conducted on 422 suspected surgical site infections from June 1, 2022 to August 30, 2022 at Hospitals in Southern Ethiopia. Sociodemographic and clinical data were obtained by using a structured questionnaire. Clinical samples (pus, pus aspirates, and wound swabs) were collected aseptically and processed within 30 min by placing the swabs in sterile test tubes containing sterile normal saline (0.5 mL). Samples were cultured on blood and MacConkey agar plates. All positive cultures were characterized by colony morphology, Gram staining, and standard biochemical tests. Antimicrobial sensitivity tests were performed using Kirby Baur disk diffusion on Mueller–Hinton agar. ESBL production was confirmed using a double-disc synergy test (DDST) method. Carbapenemase production was assessed using the modified Hodge test. Logistic regression analysis was used to determine associated factors. A P-value < 0.05 were considered statistically significant.ResultBacteria belonging to the order Enterobacterales were cultured in 23.7% out of 422 patients with suspected surgical wound infection. Of all the isolates, Enterobacteriaceae (69 isolates) were the most frequent, with E. coli (29/69) followed by K. pneumoniae (14/69). Of 69 Enterobacteriaceae isolates, 66.6 % (46/69) were positive for ESBL production, and 21.7 (15/69) were positive for carbapenemase-producing Enterobacteriaceae. The majority of Enterobacteriaceae isolates showed sensitivity to meropenem (72.1%); however revealed 63.9% and 70.5% were resistant to gentamicin and ciprofloxacin, respectively. Similarly, a higher resistance rate to cefepime (91.8%), amoxicillin-clavulanic acid (98.4%), ceftriaxone (95.1%), and ceftazidime (91.8%). MDR rate of Enterobacteriaceae isolates was 25/61 (41%) among patients suspected for surgical site infection. The Multivariable analysis revealed that length of hospital stay in hospital [AOR = 3.81 (95% CI 2.08–6.95)] remained statistically significant factor associated with surgical site infection due to ESBL producing Enterobacteriaceae.ConclusionStudy results showed the severity of ESBL-producing Enterobacteriaceae is critical and CPE is alarming. Meropenem is the most effective antibiotic against the ESBL-producing Enterobacteriaceae. MDR rate of Enterobacteriaceae isolates was 61 (61%) among patients suspected for surgical site infection. Therefore, antibiotic selection should be based on the results of the culture and sensitivity tests.

Transmission of MRSA, ESBL E. coli, and C. difficile within a tertiary care hospital and across surrounding facilities in Japan: a molecular epidemiological study with the PCR-based Open-reading frame typing

Abstract Objective: To determine the regional impact of transmission of multidrug-resistant organisms (MRDOs) and Clostridioides difficile (C. difficile) among a tertiary care hospital and surrounding facilities including long-term care facilities (LTCFs). Design: Retrospective cohort study. Methods: Patients admitted to a tertiary care hospital from July 2019 to July 2021 were recruited if their clinically collected cultures grew the following pathogens: Methicillin-resistant Staphylococcus aureus (MRSA), Extended-Spectrum Beta-Lactamase (ESBL) producing Enterobacterales, Pseudomonas aeruginosa with difficult-to-treat resistance, Carbapenem-resistant Enterobaterales, Vancomycin-resistant Enterococci, and C. difficile. Patient characteristics including admission and discharge pathway were collected. For the isolates of MRSA, ESBL-producing Escherichia coli (E. coli), and C. difficile, a molecular epidemiological analysis was conducted, utilizing the PCR-based Open-Reading Frame Typing (POT) method. Results: Three hundred-five patients were identified with a total of 332 culture specimens of the target pathogens. The top three were 132 MRSA isolates (43.3%, out of 305), 97 ESBL E. coli (31.8%), and 32 ESBL Enterobacterales (non-E. coli) (10.5%). The target pathogens were more detectable within 3 days among patients admitted from LTCFs or other hospitals than those admitted from home (Odds Ratio 4.6, 95% confidence interval 2.8-7.6, p-value < 0.001). The molecular epidemiological analysis suggested the transmissions of MRSA, ESBL E. coli and C. difficile occurred 52 out of 111 patients within the in-hospital environment, and 7 out of 128 within the prehospital environment, respectively. Conclusions: MDROs/C. difficile transmission is prevalent within a tertiary care hospital and further complicated by its inter-facility transmission across surrounding LTCFs and hospitals in Japan.

Commercial Day-Old Chicks in Nigeria Are Potential Reservoirs of Colistin- and Tigecycline-Resistant Potentially Pathogenic Escherichia coli

Background: Frequent use of colistin (COL) and tetracyclines in the Nigerian poultry sector potentially triggers bacterial resistance against COL and tigecycline (TIG), which are last-line antibiotics used to treat multidrug-resistant infections. Aim/Objectives: This study aimed to isolate COL- and TIG-resistant E. coli from commercial day-old chicks distributed to poultry farmers in Nsukka Southeastern Nigeria, assess the production of extended-spectrum β-lactamase (ESBL) and carbapenemase by the isolates, and establish their pathogenic potentials. Materials and Methods: Non-duplicate cloacal swabs were systematically collected from 250 randomly selected day-old chicks. MacConkey agar with 1 µg/mL of COL and 16 µg/mL of tetracycline was used for the isolation of putative COL- and tetracycline-resistant E. coli, respectively. E. coli isolates were confirmed biochemically using the API20E Gram-negative identification kit and molecularly by polymerase chain reaction targeting the uidA gene. Phenotypic COL resistance was established using COL agar and COL disc elution tests, while TIG insusceptibility was determined with disc diffusion. ESBL and carbapenemase production was assessed by double-disc synergy and modified carbapenem inactivation methods, respectively. Pathogenic potentials were determined using phenotypic methods. Results: COL- and TIG-resistant E. coli was recovered from 95 (38.0%) and 62 (24.8%) swabs from the 250 chicks, respectively. None of the isolates were potential ESBL or carbapenemase producers. The COL-resistant isolates displayed pathogenic potentials such as biofilm formation, haemagglutination, cell surface hydrophobicity, surface layer, and gelatinase activities at rates of 30.7%, 8.4%, 33.7%, 23.5%, and 17.6%, respectively. Meanwhile, the TIG-resistant isolates exhibited their respective potentials at rates of 47.0%, 21.0%, 35.5%, 58.1%, and 43.6%. Red, dry, and rough (RDAR) was the predominant curli fimbriae, and the cellulose morphotype portrayed by both the COL- and TIG-unsusceptible potential biofilm-producing isolates. Conclusions: This study demonstrates that a significant percentage of commercial day-old chicks distributed to farmers in Nsukka, southeastern Nigeria, are colonized by potentially pathogenic COL- and TIG-resistant E. coli, which could spread to humans and the environment.

Faecal carriage of extended-spectrum beta-lactamase and carbapenemase-producing enterobacterales among HIV patients at Jimma Medical Center, Southwest Ethiopia

BackgroundEnterobacterales infections in immunocompromised individuals are associated with considerable morbidity, mortality, and health care costs. This study aimed to assess the faecal carriage of extended-spectrum β-lactamase (ESBL) and carbapenemase-producing Enterobacterales (CPE) among HIV-infected patients at Jimma Medical Center. A total of 344 stool samples were collected and inoculated on Mac-Conkey and Eosin-Methylene Blue agar and incubated at 35–37 °C aerobically. ESBL and carbapenemase production were detected using D68C ESBL/AmpC and D73C CARBA plus (Mast Group, UK).ResultsA total of 376 Enterobacterales were isolated. The prevalence of ESBL-PE and CPE carriage rate was 13.3% (50/376) and 4.3% (16/376) respectively. The highest proportion of ESBL producing isolates were found in K. pneumoniae 29.0% (9/31) followed by E. coli 13.4% (39/292). Similarly, K. pneumoniae 12.9% (4/31) was the most common carbapenem-resistant isolate followed by E. coli 3.8% (11/292). Multi-drug resistance was observed in 66.5% (250/376) of the isolates. Prior cephalosporin use (AOR = 7.9; 2.31–27.29), CD4 count (≤ 350 cells/µL) (AOR = 3.8; 1.12–12.9), and comorbidities (AOR = 2.3; 1.24–4.32) were significantly associated with ESBL production. Additionally, cephalosporin use (AOR = 6.34; 1.27–31.66) was significantly associated with the presence of CRE.ConclusionsThis study revealed a high prevalence of ESBL-PE and CPE among HIV patients, with K. pneumoniae and E. coli being the dominant isolates. MDR was common, with key risk factors being prior cephalosporin use, low CD4 counts, and comorbidities. These findings emphasize the need for enhanced infection prevention and control, regular screening, and improved antibiotic stewardship to curb the spread of resistant bacteria in immunocompromised individuals.

Highly resistant Salmonella Heidelberg circulating in broiler farms in southern Brazil.

Salmonella Heidelberg, a serotype commonly found in Southern Brazil, is characterized by its high resistance and persistence in the poultry production. This study aimed to characterize the antimicrobial resistance of S. Heidelberg strains. In total, 100 strains isolated from poultry between 2020 and 2022 were evaluated. Phenotypic analyses were performed to determine the susceptibility of 16 antimicrobial agents and detect extended-spectrum beta-lactamase (ESBL)-producing strains. Molecular analyses were performed to detect 11 antimicrobial resistance genes (using polymerase chain reaction [PCR]) and integron class 1 genes (using real-time PCR). A total of 98% of isolates was classified as multidrug-resistant. All isolates were resistant to penicillin and lincomycin. High resistance rates (> 85%) were observed for tetracycline, doxycycline, cephalexin, amoxicillin, and ceftiofur. A significant increase (p < 0.05) in antimicrobial resistance is observed for amoxicillin, cephalexin, and ceftiofur between 2020 and 2022. No significant differences (p > 0.05) were observed in antimicrobial resistance with respect to the region of isolation, season, or company. In total, 25% of isolates were ESBL producers. Integron class 1 gene was detected in only one strain, whereas sul2 was detected in 99%, tet(A) in 66%, blaTEM in 37%, strB in 17%, cmlA in 15%, and tet(B) in 11% of the strains. Other genes were not detected or were detected in < 2% of the strains. The results showed a high overall resistance, which increased over the evaluated period. The high proportions of ESBL-producing and antimicrobial resistant strains represent a risk for highly-resistant S. Heidelberg dissemination across broiler flocks.

Biofilm formation and antibiogram profile of bacteria from infected wounds in a general hospital in southern Ethiopia

Biofilm-producing bacteria associated with wound infections exhibit exceptional drug resistance, leading to an escalation in morbidity, worse clinical outcomes (including delay in the healing process), and an increase in health care cost, burdening the whole system. This study is an attempt to estimate the prevalence and the relationship between the biofilm-forming capacity and multi-drug resistance of wound bacterial isolates. The findings intended to help clinicians, healthcare providers and program planners and to formulate an evidence-based decision-making process, especially in resource-limited healthcare settings. This study was done to assess the prevalence of bacterial infections in wounds and the antibiogram and biofilm-forming capacity of those bacteria in patients with clinical signs and symptoms, attending a General Hospital in southern Ethiopia. A cross-sectional study was performed in Arba Minch General Hospital from June to November 2021. The study participants comprised 201 patients with clinically infected wounds. Demographic and clinical data were gathered via a structured questionnaire. Specimens from wounds were taken from each participant and inoculated onto a series of culture media, namely MacConkey agar, mannitol salt agar, and blood agar, and different species were identified using a number of biochemical tests. Antimicrobial susceptibility tests were performed by means of the Kirby-Bauer disc diffusion technique following the guidelines of the Clinical and Laboratory Standards Institute. A micro-titer plate method was employed to detect the extent of biofilm formation. Bivariable and multivariable logistic regression models were applied to analyse the association between dependent and independent variables, and P values ≤ 0.05 were considered as statistically significant. Data analyses were done with Statistical Package for the Social Sciences version 25. Out of the 201 clinically infected wounds, 165 were found culture-positive with an overall prevalence of 82% (95% CI: 75.9–86.9). In total, 188 bacteria were recovered; 53.1% of them were Gram-positive cocci. The often-isolated bacterial species were Staphylococcus aureus, 38.3% (n = 72), and Pseudomonas aeruginosa, 16.4% (n = 31). The Gram-positive isolates showed considerable resistance against penicillin, 70%, and somewhat strong resistance against tetracycline, 57.7%. Gram-negative isolates showed severe resistance to ampicillin, 80.68%. The overall multi-drug resistance (MDR) among isolates was 48.4%. Extended beta-lactamase (ESBL)-producing Gram-negatives and methicillin-resistant Staphylococcus aureus (MRSA) accounted for 49 and 41.67%, respectively; 62.2% of the isolates were biofilm formers and were correlated statistically with MDR, ESBL producers, and MRSA (P < 0.005). The extent of biofilm formation and the prevalence of MDR bacteria associated with infected wounds hint at a public health threat that needs immediate attention. Thus, a more balanced and comprehensive wound management approach and antimicrobial stewardship program are essential in the study setting.

Prevalence, Risk Factors and Antibiotic Resistance of Extended-Spectrum Beta-Lactamase-Producing Escherichia coli in Children Hospitalized with Urinary Tract Infection at King Abdulaziz University Hospital, Jeddah, Saudi Arabia

Background/Objectives: We aimed to assess the prevalence and risk factors for acquisition of extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli (E. coli) in children admitted with urinary tract infection (UTI) at a tertiary university hospital in Saudi Arabia, as well as to investigate antibiotic resistance patterns. Methods: This retrospective cross-sectional study involved hospitalized children aged 0–14 years from January 2018 to December 2022 with urine cultures that grew E. coli or ESBL-producing E. coli. Data of the antimicrobial susceptibility for isolated bacteria were collected. Results: This study analyzed 242 urine samples obtained from 119 children with E. coli UTIs. Of these, 20.7% (n = 50) were ESBL producers. Previous antibiotic use (last 3 months), prophylactic antibiotic use, prior UTI (last 3 months), recurrent UTIs, and underlying co-morbidities (p = 0.011, &lt;0.001, 0.025, &lt;0.001, and 0.013, respectively) had a significant relationship with increased risk of ESBL E. coli UTIs. Generally, the highest resistance rates in the ESBL-producing isolates were for ampicillin and third-generation cephalosporin. Conversely, all ESBL-positive isolates were sensitive to meropenem, with variable resistance rates to other antibiotics as amikacin, nitrofurantoin, quinolones and trimethoprim/sulfamethoxazole (2%, 8%, 56% and 64%, respectively). Conclusions: There is a high prevalence of ESBL production among children hospitalized with E. coli UTIs. Addressing ESBL UTI risk factors helps to recognize high-risk cases and enhance proper antibiotic use.

New Insights into the Antibacterial Activity of Hydroxytyrosol Extracted from Olive Leaves: Molecular Docking Simulations of its Antibacterial Mechanisms.

This study investigated the biological activities of a hydroxytyrosol-rich extract from Olea europaea leaves, particularly its ability to eradicate severe pathogenic bacteria producing Extended-Spectrum Beta-Lactamases (ESBLs). The latter bacteria are emerging microorganisms that pose significant challenges due to their resistance to a broad range of potent therapeutic drugs. The extract was prepared through an accessible acid hydrolysis method. In vitro and In silico analyses through MIC, MBC analysis and molecular docking were conducted to evaluate the antibacterial properties. The extract showed remarkable antioxidant activity and significant antibacterial potential against reference species and ESBL bacteria. MIC and MBC calculations confirmed the extract's capacity to kill bacteria rather than just inhibit their growth. Further in silico analyzes demonstrated the high binding affinity of HT to the active sites of the gyrase B subunit and the peptidoglycan DD-transpeptidase domain from proteins located in the cytoplasm and the cell wall of the bacteria, respectively. Results confirmed the structure-activity relationship and the ability of HT to disrupt essential bacterial functions. This study validates the debated antimicrobial potential of HT and highlights its importance as a potential therapeutic agent against resistant bacteria, which is a critical area of research given the global challenge of antibiotic resistance.

Current antibiotic resistance of Enterobacteriaceae isolated at Avicenna military hospital of Marrakesh

Enterobacteriaceae are bacteria found in the digestive system, known for causing infections and displaying antibiotic resistance. The World Health Organization (WHO) identifies strains resistant to third-generation cephalosporins and carbapenems as priority pathogens. This study, conducted at Avicenne Military Hospital of Marrakech, aimed to assess the epidemiological and antibiotic resistance profiles of Enterobacteriaceae over a two-year period (May 2020 - April 2022) to inform updated antibiotic use recommendations. This retrospective study analyzed 1,626 positive bacterial isolates from various hospital departments, including medical, surgical, intensive care, emergency units, and external samples. Of these, 1,163 (71.5%) were Enterobacteriaceae, predominantly Escherichia coli, Klebsiella pneumoniae, and Enterobacter cloacae, primarily isolated from urine, pus, and blood cultures. Antibiotic resistance was assessed, revealing that 614 (52.8%) of Enterobacteriaceae were extended-spectrum beta-lactamase producers (ESBL-E), and 115 (9.9%) were carbapenemase-producing Enterobacteriaceae (CPE). The study’s findings align with existing literature, showing a higher prevalence of Enterobacteriaceae in males and frequent isolation of Escherichia coli. The rise in multidrug-resistant Enterobacteriaceae, particularly ESBL-E and CPE, poses risks such as therapeutic failure, increased morbidity and mortality, and significant economic impacts. To address this, the study emphasizes the importance of early detection, infection control measures, responsible antibiotic prescribing, and collaborative efforts across hospital departments to reduce the spread of resistant strains.

Characterization of bla NDM in two Escherichia coli ST1193 clinical isolates in the Gulf region.

Escherichia coli ST1193 is an emerging high-risk clone associated with the production of plasmid-mediated CTX-type extended-spectrum β-lactamases. However, this clone has seldom been found to contain plasmids carrying carbapenemase genes. We report two epidemiologically unlinked multidrug-resistant (MDR) clinical isolates of E. coli ST1193 with plasmids harbouring NDM-type carbapenemase genes from the Gulf region. The isolates were identified by MALDI-TOF MS and antibiotic susceptibility testing was performed using the VITEK 2/Phoenix system. A conjugation experiment was performed to assess the transferability of the resistance plasmids. Genomic DNA of both isolates was subject to Illumina sequencing; one isolate was also sequenced using Oxford Nanopore technology. Bioinformatics analyses were performed to detect antimicrobial resistance genes, and to annotate the genetic context of the NDM genes. Both isolates were resistant to carbapenems using phenotypic tests. Conjugation experiment confirmed that NDM-5-encoding plasmids of both strains could be transferred to the recipient cells. The completed NDM-5-encoding plasmid of E. coli isolate FQ71 was highly similar to several plasmids from ST410 isolates in the NCBI database. Genomic analysis revealed the presence of transposase genes and transposons in the flanking regions of the NDM genes in the plasmids. Since carbapenems constitute first-line agents for the treatment of serious infections caused by ESBL producers, E. coli ST1193 isolates co-producing ESBL and NDM-type carbapenemases represent a serious challenge for antimicrobial stewardship and infection control programmes.

Extended Spectrum β-Lactamase: Tackling Antibiotic Resistance and Overcoming Treatment Challenges

Antibiotics, also known as antibacterials, kill or inhibit bacterial growth but are ineffective against viruses, fungi, or parasites, often leading to misuse. They are categorized by molecular structure, mode of action, and spectrum of activity. Antimicrobial Resistance (AMR) occurs when pathogens no longer respond to antimicrobial drugs, arising naturally or through acquisition. Resistance mechanisms include enzymatic (most common), genetic and physical. Bacteria produce various β-lactamases, such as Extended Spectrum β-lactamases (ESBLs), AmpC enzymes, and carbapenemase to exert resistance to Beta-Lactam (βL) class of antibiotics. ESBL families include TEM, SHV, and CTX-M, with E. coli being the most prevalent host. Any Gram-Negative Bacteria (GNB) can be an ESBL producer, but most common ones are the Enterobacteriaceae including Escherichia coli, Klebsiella pneumoniae, Klebsiella oxytoca and Proteus mirabilis. ESBL-producing Enterobacteriaceae (ESBL-E) resist penicillin, aztreonam, and cephalosporins except cephamycins and carbapenems, posing a significant public health risk. Genetic resistance mechanisms involve random mutations and horizontal gene transfer through either of the following processes namely conjugation, transformation, transduction. Physical mechanisms include efflux pump production and decreased porin channels. In some microbiological laboratories, ESBL production are often not determined, rather resistance based on MIC values to third generation Cephalosporins are considered as resistance due to ESBL production. Antibiotic use in agriculture and medicine has increased Multi-drug resistant (MDR) ESBL-producing E. coli and evidenced in retail meat and among meat shop employees. Community-acquired ESBL-E infections are a growing concern, with hospital transmission primarily occurring among patients sharing rooms with ESBL carriers. Empirical and definitive therapies for ESBL-E infections must be adjusted based on Antibiotic Susceptibility Testing (AST). The MERINO trial identified urinary tract infections as the most common source of ESBL-E bacteremia, with E. coli being predominant. For critically ill patients with non-urinary tract infections, Meropenem or Imipenem-cilastatin are recommended. For uncomplicated UTIs, Nitrofurantoin, Cotrimoxazole, and Piperacillin-Tazobactam (Pip-Taz) are effective, while Cotrimoxazole, Fluoroquinolones, and Ceftolozane-tazobactam are suitable for complicated UTIs. New β-lactamase inhibitors like avibactam, vaborbactam, and relebactam are promising for treatment. Misuse of antibiotics, such as inappropriate dosing and duration, contributes to AMR, a growing global challenge. Deaths from AMR, estimated at 1.27 million in 2019, could reach 10 million by 2050. ESBLs drive the use of broad-spectrum antibiotics, accelerating resistance development. Inadequate therapy exacerbates infections, leading to prolonged hospital stays, complications, and increased mortality. Balancing new drug development with resistance emergence is crucial to combat AMR.

Evaluation of the CARBA PAcE test, a colorimetric imipenem hydrolysis test for rapid detection of carbapenemase activity.

There is an urgent need for accurate and fast diagnostic tests to identify carbapenemase-producing bacteria. Here, we evaluated a colorimetric imipenem hydrolysis test, called the CARBA PAcE test, to detect carbapenemase-producing Gram-negative bacteria (GNB). We tested a collection of 270 GNB isolates with a characterized carbapenemase content. Our testing set included 205 carbapenemase-producing, carbapenemase-resistant Enterobacterales (CP CRE) with 40 Klebsiella pneumoniae carbapenemase (KPC), 49 New Delhi metallo beta lactamase (NDM), 49 OXA-48-like, 15 Verona integron-mediated metallo-β-lactamase (VIM), three IMP, 43 IMI, six isolates producing more than one carbapenemase, and 65 non-carbapenemase-producing Enterobacterales (20 ESBL producers, 35 non-carbapenemase-producing, carbapenem-resistant [non-CP CRE], and 10 carbapenem-susceptible Enterobacterales [non-CP, non-CSE, third-generation cephalosporin and carbapenem susceptible]). We compared the performances of the CARBA PAcE test, the qualitative colorimetric β-CARBA test, and the modified CarbaNP test to a gold standard of carbapenemase gene detection by PCR. Specificities of all tests were high: 95.4% (62/65) for CARBA PAcE test, 98.5% (64/65) for β-CARBA test, and 100% (65/65) for the modified CarbaNP test. Sensitivity varied by carbapenemase: all three tests had a sensitivity of 100% for NDM, VIM, and IMP and 97.5% for KPC. Sensitivity to detect IMI was 0% for the CARBA PAcE and β-CARBA tests and 11.6% for the modified CarbaNP test. Sensitivity to detect OXA-48-like was 89.7% for the CARBA PAcE test, 87.7% for the β-CARBA test, and 14.2% for the modified CarbaNP test. Reading the results of the CARBA PAcE assay was difficult. The CARBA PAcE assay is highly sensitive for detecting NDM, VIM, IMP, and KPC, but slightly less sensitive for OXA-48-like. It does not detect IMI. It is highly specific, and its overall diagnostic accuracy is similar to that of β-CARBA. Its operational advantages are rapid turnaround time, ease of use, and long shelf life, but reading of results is subjective.IMPORTANCEWe evaluated the ability of the CARBA PAcE test to detect carbapenemases in 274 Gram-negative isolates with a known carbapenemase content. Specificity was high for all carbapenemases tested (96.9%). Sensitivity was high for KPC, NDM, VIM, and IMP (97.5-100%); but lower for OXA-48-like (89.7%). Activity of IMI could not be detected. Taken together, our results indicate that CARBA PAcE is a useful alternative in regions where NDM and KPC are predominant. The limitations of the test are difficulty in reading results and incompatibility with mSuperCARBA.

Risk factors for Beta-lactam and carbapenem-resistant bacteria causing post-burn infections

Background: Burn patients are predisposed to infection because of the loss of skin barrier protection and low immunity. This study aims to evaluate the risk factors of post-burn infections due to beta-lactam and carbapenem-resistant bacteria (CR) isolated from a major burn unit.Methods: The descriptive study was conducted at Jinnah Hospital Lahore’s Burn and Reconstructive Surgery Centre (JB &amp; RSC) and the Institute of Microbiology and Molecular Genetics (MMG), University of the Punjab, Lahore. The clinical specimens of wound swabs, including the age, gender, socio-economic status, residence, occupation, hospital stay, wards, burn degree, total burnt surface area (TBSA%), etiology of burn, and other factors were recorded. Antimicrobial susceptibility testing (AST), ESBL and CR screening (Beta- lactam and carbapenem resistant bacteria) were performed using CLSI guidelines 2017.Results: The most dominant strain was Pseudomonas spp. 26.5% (n=106), followed by 15% (n=60) Klebsiella spp., and 7.5% (n=30) Acinetobacter spp. with ESBL-producing strains. Compared to nosocomial infections, community-acquired infections were observed in 314 (78.5%) patients with more ESBL production. There was a significant relation between burnt people having an age of ≤ 29 years with ESBL (p=0.985) and carbapenemases (p=0.694) infections. None of the other factors, like low socioeconomic status and more hospital stays had a significant correlation (p &gt; 0.05).Concluded: It has been concluded that MDR gram-negative strains play a serious role in burn infections and demand suitable methods to decrease their number. Pseudomonas spp. was the most common post-burn infection causing bacteria. Unfortunately, a high frequency of burn infections was observed in the patients at a young age.Keywords: Post burn infections; Gram negative; MDR; Beta- lactam; Carbapenem resistant

Enterobacterales Producing ESBLs and AmpC in Fresh Vegetables from Tebessa City, Algeria.

This study aimed to evaluate the contamination levels of fresh products by ESBLs-producing Enterobacterales (ESBLs-E) or AmpC-producing Enterobacterales and characterize ESBLs genes. A total of 132 samples (67 vegetables and 65 fruits) were collected from markets in Tebessa, eastern Algeria. Among the samples, 16 third-generation cephalosporin-resistant Enterobacterales isolates were identified with a prevalence of 19.40% in vegetable samples, while there was no positive finding in fruit samples. Isolates showed resistance to most β-lactams, and all of them displayed multidrug resistance. Phenotypic tests for ESBLs detection, using double-disk synergy test and double-disk test were positive for 14 strains, including Klebsiella pneumoniae (n = 5), Klebsiella oxytoca (n = 4), Klebsiella terrigena (n = 2), Kluyvera spp. (n = 2), and Enterobacter cloacae (n = 1). Two AmpC-producing strains (Citrobacter freundii and E. cloacae) were identified through the AmpC disk test. Contamination rates of vegetables by ESBLs-E and AmpC-producing Enterobacterales were 19.40% and 2.98%, respectively. PCR results showed the presence of at least one ESBL gene in seven selected strains, with the dominance of blaCTX-M gene. Notably, K. pneumoniae strains showed the co-occurrence of two or three genes. Sequencing identified uncommon variants of ESBLs genes for the first time in Algeria, including blaCTX-M-79 (2/7), blaCTX-M-107 (2/7), blaCTX-M-117 (2/7), blaTEM-112 (1/7), blaTEM-125 (2/7), blaTEM-194 (1/7), and blaSHV-176 (3/7).

Conventionally Reared Wallon Meat Lambs Carry Transiently Multi-Drug-Resistant Escherichia coli with Reduced Sensitivity to Colistin Before Slaughter.

Major efforts have been made to reduce the use of colistin in livestock since the discovery of the plasmid-borne mobile colistin resistance (mcr) gene in E. coli a decade ago, to curb the burden of its potential transmission to other bacterial species, spread between animals, humans and the environment. This study explored the longitudinal prevalence and characteristics of colistin-resistant and extended-spectrum beta-lactamase-producing (ESBL) E. coli via in vivo fecal and ex vivo carcass swabs from two batches of conventional indoor and organic outdoor Wallon meat sheep from birth to slaughter in 2020 and 2021. Antimicrobial susceptibility testing via broth microdilution revealed that n = 16/109 (15%) E. coli isolates from conventional meat lamb fecal samples had a reduced colistin sensitivity (MIC = 0.5 μg/mL) and thereof, n = 9/109 (8%) were multi-drug-resistant E. coli, while no resistant isolates were recovered from their carcasses. Sequencing revealed causative pmrB genes, indicating that the reduced sensitivity to colistin was not plasmid-borne. While the sample size was small (n = 32), no colistin-resistant and ESBL-producing E. coli were isolated from the organic meat sheep and their carcasses, potentially due to the different husbandry conditions. Prudent and judicious antimicrobial use and strict slaughter hygiene remain imperative for effective risk management to protect consumers in a sustainable One Health approach.

Escherichia coli Occurrence and Antimicrobial Resistance in a Swine Slaughtering Process.

The swine production chain can be a reservoir of antimicrobial-resistant Escherichia coli, which transfers resistance genes to other bacteria, serving as an important biomarker in the One Health approach. This study aimed to identify the frequency and antimicrobial resistance profile of E. coli in the swine production chain, assess the presence of extended-spectrum beta-lactamases (ESBL), and compare resistance profiles across different sample types. A total of 622 samples of swine carcasses from various points of the slaughter process (n = 400), swine feces (n = 100), commercial cuts (n = 45), environment (n = 67), and feces from employees (n = 10) of a pig slaughterhouse certified by the Federal Inspection Service, located in São Paulo state, Brazil, were collected. A total of 1260 E. coli isolates were obtained from the samples, with 73.6% of the samples testing positive. The agar disk diffusion test was performed with 10 different classes of antimicrobials. To confirm the production of ESBLs, the isolates were submitted to a double-disk synergism test using cefotaxime, ceftazidime, and amoxicillin with clavulanic acid. Of the total isolates, 80.71% were multidrug resistant. All ESBL-producing isolates were multidrug resistant and resistant to amoxicillin, tetracycline, and chloramphenicol. Isolates from human feces samples had less chance of being multidrug resistant than samples from other sources. The diversity of resistance profiles was verified in the samples, not clustering according to the sources, except for human feces isolates that clustered, evidencing lower antimicrobial resistance variability of these samples. Antimicrobial resistance is significantly present in the pork production chain, necessitating a comprehensive multidisciplinary approach to effectively mitigate risks within the One Health framework.

A worrisome prevalence of extended-spectrum β-lactamase producers in patients with biliary obstruction and cholangitis: Phenotypic and molecular characterization of biliary Escherichia coli and Klebsiella pneumoniae isolates

Background & aimsThe alarming rise of antibiotic resistance presents a substantial and worrisome issue within the context of biliary obstruction, specifically in the treatment of cholangitis. This abovementioned scenario underscores the critical importance of addressing extended spectrum β-lactamase (ESBL) producers in the biliary system to adequately tackle cholangitis using third-generation cephalosporins. Hence, we aimed to determine the frequency of ESBL and carbapenemases among biliary Escherichia coli and Klebsiella pneumoniae isolated from patients with biliary obstruction. MethodsIn this cross-sectional study, bile samples were collected via aspiration from patients diagnosed with biliary obstruction during the endoscopic retrograde cholangiopancreatography (ERCP) procedure. Subsequent culturing of these samples was performed, followed by phenotypic and molecular assessments for the detection of ESBL- and carbapenemase-producing strains of E. coli and K. pneumoniae. ResultsApproximately 23.5 % of patients with biliary obstruction harbored biliary ESBL-producers, with the majority (70.2 %) being diagnosed with cholangitis. Moreover, 2.1 % of patients had biliary carbapenemase-producing K. pneumoniae strains. Molecular analysis confirmed the high prevalence of blaCTX-M and blaTEM in E. coli, and blaTEM and blaSHV in K. pneumoniae. Additionally, the presence of biliary K. pneumoniae harboring blaKPC, blaNDM, and blaIMP was observed. ConclusionOur study reveals a noteworthy observation that over half of patients experiencing biliary obstruction harbor ESBL-producing bacteria in their biliary tract. Notably, we discovered a significant link between ESBL producers and the risk of cholangitis. These findings raise important concerns regarding the suitability of employing third-generation cephalosporins as initial treatment for cholangitis and other similar biliary infections.

Assessment of community-acquired urinary tract infections treatment in the emergency department: a retrospective study.

Urinary tract infection (UTI) is one of the most common medical complaints in the emergency department (ED). The aim of this study was to assess the real indication of an initial broad-spectrum treatment administered in the ED for hospitalized patients with a diagnosis of community-acquired UTI (CAUTI). This is a monocentric observational retrospective study conducted in the ED of one of the largest tertiary care centers in Lebanon, on a two-year period, including adult patients admitted to the hospital for a CAUTI. The primary outcome was to evaluate the need of downgrading empirical antibiotherapy started in the ED. Secondary outcomes included a description of CAUTIs characteristics: prevalence and risk factors for (extended spectrum beta lactamases) ESBL-related infection, complicated and uncomplicated UTIs, empirical and targeted treatment, and finally the rate of adherence to local guidelines. The most isolated strains on urine cultures were gram negative bacilli (GNB) with 29.1% producing ESBL; 69.4% of patients received an ESBL-targeting empirical treatment in the ED, in agreement with local guidelines, 46% of which needed a downgrade. Amikacin adjunction was only indicated in 42.8% of the cases. Patients who received antibiotics in the last 6 months had a 2.36 times higher risk of developing an ESBL-related infection. This study showed a high adherence rate to local recommendations suggesting the use of empirical ESBL-targeting antibiotherapy even in uncomplicated UTIs. However, the frequent need of de-escalation highlights the importance of establishing an efficient multi-drug resistant (MDR) bacteria surveillance system in the community in order to elaborate a stewardship program with more solid local guidelines.

Detecting and Reporting Extended Spectrum Beta-Lactamases Producers: Evaluation of Three Approaches and the Clinical Impact

Abstract Introduction/Objective Since the COVID-19 pandemic, bacteria producing extended spectrum beta-lactamases (ESBLs) have increased &amp;gt;30%. Laboratories can perform phenotypic microbroth dilution or molecular approaches to identify ESBL producers. However, the gold standard is a laborious double disc synergy test. We evaluated the concordance among the three approaches, the clinical impact, and justification of reporting ESBL producers. Methods/Case Report Seventy-eight ESBL producers identified by microbroth dilution (MicroScan WalkAway, Beckman Coulter, Brea, California, USA) or detection of blaCTX-M gene from blood cultures (BCID2 Panel, BioFire, Biomerieux, Salt Lake City, Utah, USA) were tested using double disc synergy test retrospectively. Concordance among the methods evaluated. Discordant cases were reviewed with subsequent patient chart review. Results (if a Case Study enter NA) Tested isolates included E. coli (n=44, 57%), K. pneumoniae (n=19, 24%), K. oxytoca (n=7, 9%), and P. mirabilis (n=8, 10%). Concordance between microbroth dilution and disk diffusion was 86% (67/78). For isolates with genotypic testing (n=16), concordance with microbroth dilution and disk diffusion was 93% and 88%, respectively. Overall concordance was 88%. There were 12 isolates (E. coli:8, P. mirabilis: 2, and K. pneumoniae:2) with discordant results from one method. The susceptibility profile of discordant isolates revealed resistance to ceftriaxone or ceftazidime (11/12), penicillin (11/12), and aztreonam (6/12); 10/12 isolates were resistant to at least 2 groups of these antibiotics, a phenotype of ESBL producers. Clinical teams acknowledged presence of ESBLs in 83% (10/12) of cases and 58% (7/12) warranted treatment with meropenem or combinational therapy. Infection prevention implemented contact isolate procedures in all cases. Conclusion Our current in-house methods (e.g., microbroth dilution and genotypic testing) are still justified for ESBL testing to optimize patient care in a timely fashion. In the minor cases with discordant results, clinical care was unaffected. Laboratory workflow changes need to take laboratory efficiency, patient outcomes, and actionable clinical changes into consideration.

Detection of virulence factors and antimicrobial susceptibility pattern of clinically significant Klebsiella pneumoniae isolates in a tertiary care hospital

Introduction: Klebsiella pneumoniae is associated with a variety of infections across all age groups, both in community and hospital settings. Many strains of K. pneumoniae produce virulence factors such as a capsule, siderophores, biofilm, and hypermucoviscosity, which facilitate adhesion, invasion, and colonization. Additionally, the rising antibiotic resistance in K. pneumoniae strains poses a significant challenge, limiting treatment options. This study aims to identify the virulence factors and assess the antimicrobial susceptibility of clinically significant K. pneumoniae isolates. Materials and Methods: K. pneumoniae isolates were obtained from urine, sputum, blood, cerebrospinal fluid, pus swabs/aspirates, and tissue samples. Standard biochemical tests were performed for identification. Capsule formation, hypermucoviscosity, siderophore production, and biofilm formation were detected phenotypically. Antibiotic susceptibility testing was carried out using the disk diffusion method, and primary and confirmatory tests were conducted for extended-spectrum beta-lactamases (ESBL) and carbapenemase production. Results: Capsule formation, hypermucoviscosity, siderophore production, and biofilm formation were detected in 100%, 15%, 40%, and 15% of the isolates, respectively. Of the isolates, 40% were multidrug-resistant, 55% produced ESBL, 8% expressed AmpC beta-lactamase, and 10% produced carbapenemase. Conclusion: Capsule formation was the most prevalent virulence factor, followed by siderophore production. The majority of K. pneumoniae isolates demonstrated susceptibility to amikacin, piperacillin-tazobactam, and carbapenems. However, 40% of the isolates were multidrug-resistant, with ESBL production being the most common resistance mechanism.