AmpC Beta-lactamase Production Research Articles

Occurrence, Typing, and Resistance Genes of ESBL/AmpC-Producing Enterobacterales in Fresh Vegetables Purchased in Central Israel.

Beta-lactam resistance can lead to increased mortality, higher healthcare expenses, and limited therapeutic options. The primary mechanism of beta-lactam resistance is the production of extended-spectrum beta-lactamases (ESBL) and AmpC beta-lactamases. The spread of beta-lactamase-producing Enterobacterales via the food chain may create a resistance reservoir. The aims of this study were to determine the prevalence of ESBL/AmpC-producing Enterobacterales in vegetables, to examine the association between EBSL/AmpC-producing bacteria and types of vegetables, packaging, and markets, and to investigate the genetic features of ESBL-producing isolates. The antibiotic susceptibilities were determined using VITEK. Phenotypic ESBL/AmpC production was confirmed using disk diffusion. ESBL-producing isolates were subjected to Fourier-transform infrared (FT-IR) spectroscopy and to whole genome sequencing using Oxford Nanopore sequencing technology. Of the 301 vegetable samples, 20 (6.6%) were positive for ESBL producers (16 Klebsiella pneumoniae and 4 Escherichia coli), and 63 (20.9%) were positive for AmpC producers (56 Enterobacter cloacae complex, 4 Enterobacter aerogenes/cancerogenus, and 3 Pantoea spp., Aeromonas hydrophila, and Citrobacter braakii). The blaCTX-M and blaSHV genes were most common among ESBL-producing isolates. The beta-lactamase genes of the ESBL producers were mainly carried on plasmids. Multilocus sequence typing and FT-IR typing revealed high diversity among the ESBL producers. AmpC producers were significantly more common in leafy greens and ESBL producers were significantly less common in climbing vegetables. The presence of ESBL/AmpC-producing Enterobacterales in raw vegetables may contribute to the dissemination of resistance genes in the community.

Resistome-based surveillance identifies ESKAPE pathogens as the predominant gram-negative organisms circulating in veterinary hospitals.

Healthcare-associated infections (HCAIs) associated with extended-spectrum cephalosporin-resistant gram-negative (ESC-R GN) bacteria are an emerging concern in veterinary hospitals, especially in companion animal intensive care units (ICUs). To understand the molecular epidemiology of ESC-R GN isolates in two veterinary hospitals (equine and small animal), a 6-month pilot study was performed during which fecal and environmental samples were obtained twice from selected patients, upon ICU admission and after 48 h of hospitalization. In total, 295 ESC-R GNs were analyzed using the Acuitas Resistome® Test (OpGen, Maryland, US), a PCR-based assay screening for 50 antimicrobial resistance gene families encoding for production of extended-spectrum beta-lactamase (ESBLs), TEM/SHV/OXA or AmpC beta-lactamases and carbapenemases. Combining organism identification and antimicrobial susceptibility data to genotyping results, unique "Acuitas profiles" were generated that can be used for fast typing the isolates and tracking transmission events. ESKAPE GN pathogens were the most prevalent ESC-R GN isolates circulating in both the small animal and equine hospitals, consisting of Enterobacter cloacae complex (21.7%), Pseudomonas aeruginosa (20%), Klebsiella pneumoniae (15.9%), and Acinetobacter baumannii complex (13.6%) followed by Escherichia coli (12.2%), most harboring a combination of genes encoding for beta-lactamases and ESBLs. Some ESKAPE genotypes showed likely intra-hospital transmission, including E. cloacae (two genotypes, one carrying SHV4, SHV5, and TEM7 and the other TEM1, TEM3, and TEM7 enzymes) in the equine and K. pneumoniae (SHV1, SHV5, and DHA1-positive) in the small animal ICUs, respectively. Furthermore, P. aeruginosa (carrying OXA-50), A. baumannii complex (OXA-51), and E. coli (CTX-M-1) genotypes were isolated across both hospitals, suggesting possible transfer mediated via movement of staff and students. Importantly, isolates carrying transmissible resistance to last-resort antimicrobials (i.e. carbapenems) were identified within the hospital environments, consisting of three environmental Acinetobacter spp. harboring blaOXA - 23 and one clinical E. coli with blaOXA - 48. We describe the widespread occurrence of ESKAPE gram-negative organisms in veterinary ICU patients and hospital environments. Findings from this project provide baseline data on the epidemiology of ESKAPE pathogens in veterinary settings, which can inform infection control policies to aid in patient management and prevent transmission of nosocomial infections associated with these pathogens.

Whole Genome Sequencing Reveals High Genetic Diversity, Diverse Repertoire of Virulence-Associated Genes and Limited Antibiotic Resistance Genes among Commensal Escherichia coli from Food Animals in Uganda.

Commensal Escherichia coli with broad repertoire of virulence and antimicrobial resistance (AMR) genes pose serious public health risks as reservoirs of AMR and virulence. This study undertook whole genome characterization of commensal E. coli from food-producing animals in Uganda to investigate their genome variability (resistome and virulome). We established that the E. coli had high genomic diversity with 38 sequence types, 24 FimH types, and 33 O-antigen serotypes randomly distributed within three phylogroups (A, B1, and E). A greater proportion (≥93.65%) of the E. coli were resistant to amoxicillin/clavulanate and ampicillin antibiotics. The isolates were AmpC beta-lactamase producers dominated by blaEC-15 (71.88%) and tet(A) (20.31%) antimicrobial resistant genes besides a diverse armory of virulence-associated genes in the class of exotoxin, adhesins, iron uptake, and serine protease autotransporters which varied by host species. Cattle were found to be the major source of E. coli carrying Shiga toxin genes, whereas swine was the main source of E. coli carrying colicin-like Usp toxin gene. The study underscores the importance of livestock as the carrier of E. coli with antimicrobial resistance and a large repertoire of virulence traits with a potential of causing disease in animals and humans by acquiring more genetic traits.

Multidrug Resistant Escherichia coli among Urinary Samples of Patients with Urinary Tract Infection in the Microbiology Department of a Tertiary Care Center: A Descriptive Cross-Sectional Study.

Urinary Tract Infection one of the most common and manageable infections still holds its position as a major public health issue worldwide due to an increase in the number of multidrug resistant bacteria. This study aims to find out the prevalence of multidrug resistant Escherichia coli among urinary samples of patients with urinary tract infections in the microbiology Department of a tertiary care center. A descriptive cross-sectional study was carried out at a tertiary care centre from 8 August 2018 to 9 January 2019. Ethical approval was received from the Institutional Review Committee (Reference number: 123/2018). Clinically suspected cases of urinary tract infection were included in this study. A convenience sampling method was used. Point estimate and 95% Confidence Interval were calculated. Among 594 patients with urinary tract infections, the prevalence of multidrug resistant Escherichia coli was 102 (17.17%) (14.14-20.20, 95% Confidence Interval). Out of which, the production of extended-spectrum beta-lactamase and AmpC beta-lactamase were observed in 74 (72.54%), and 28 (27.45%) isolates respectively. The co-production of extended-spectrum beta-lactamases/AmpC was observed in 17 (16.67%). The prevalence of multidrug resistant Escherichia coli among patients urinary samples of patient with urinary tract infection was lower as compared to the other studies done in similar settings. antibiotics; Escherichia coli; urinary tract infection.

Analysis of Bacterial Pathogens Causing Complicating HAP in Patients with Secondary Peritonitis

Diffuse peritonitis is an acute abdominal condition characterized by high mortality. The main treatment modality is surgery, requiring a subsequent prolonged hospital stay. These patients are, among other things, at risk of developing hospital-acquired pneumonia (HAP), which considerably worsens their treatment outcomes. This study aimed to extend the existing knowledge by providing more detailed microbiological characteristics of complicating HAP in patients with secondary peritonitis, including the identification of isolated bacterial pathogens and their potential sources. The 2015-2019 retrospective study comprised all patients with an intraoperatively confirmed diagnosis of secondary diffuse peritonitis who were classified in accordance with the quick Sepsis Related Organ Failure Assessment scoring system. HAP developed in 15% of patients. The 90-day mortality rates were 53% and 24% in patients with and without HAP; respectively. The most frequent pathogens responsible for HAP were Pseudomonas aeruginosa, Klebsiella pneumoniae, Escherichia coli, Enterobacter cloacae complex and Enterococcus faecalis. Multidrug resistance to antibiotics was found in 38% of bacterial pathogens. Clonal spread of these bacterial pathogens among patients was not detected. Rather, the endogenous characteristic of HAP was confirmed. The initial antibiotic therapy of complicating HAP in patients with secondary peritonitis must be effective mainly against enterobacteria, including strains with the production of ESBL and AmpC beta-lactamases, Pseudomonas aeruginosa and Enterococcus faecalis. The study further highlighted the importance of monitoring the respiratory tract bacterial microflora in patients with secondary peritonitis. The results should be used for initial antibiotic treatment of complicating HAP instances.

Beta-Lactamase-Producing Gram-Negative Bacterial Isolates Among the Patients Attending a Tertiary Care Hospital, Kathmandu, Nepal.

Over the times, carbapenems have been the choice of drug for treating multidrug-resistant (MDR) and extended spectrum beta-lactamase (ESBL)-producing organisms. The current study aimed at determining the occurrence of metallo beta-lactamase (MBL) and AmpC beta-lactamase (ABL) in gram negative bacteria isolated from clinical samples. A cross-sectional study was conducted amongst the patients visiting Manmohan Memorial Medical College and Teaching Hospital (MMTH), Kathmandu, Nepal from August 2017 to January 2018. A total of 4351 samples including urine, pus, wound swab, endotracheal tip, catheter tip, and blood were collected from the patients and processed by standard conventional microbiological methods. Antibiotic susceptibility testing (AST) of the isolates was performed by Kirby-Bauer disk diffusion method. Double disc synergy test was performed on carbapenem resistant organisms to detect production of MBL and inhibitor-based test was used for the detection of ABL production. Of the 4351 samples, 421 bacterial isolates belonging to 16 different genera were recovered, of which 303 (71.97%) were Gram negative bacilli (GNB). E. coli (189/303) and S. aureus (80/118) were the most prevalent among gram negatives and gram positives, respectively. Bacterial incidence was found significantly associated with gender, specimen type, and the department where the patients were enrolled. Colistin-sulfate and polymycin-B were the most effective drug against GNB, whereas imipenem against gram positives. Prevalence of MDR and methicillin-resistant S. aureus (MRSA) was 35.15% and 60%, respectively. The prevalence of MBL and ABL-producing isolate was 11(3.6%) and 13(4.3%), respectively. Pseudomonas aeruginosa (5/11) and E. coli (9/13) were the major MBL and ABL producers, respectively. MBL and ABL production was found to be significantly associated with the age of the patient and the specimen type. A regular antibiotic surveillance activity with screening for MBL and ABL-producing bacterial isolates in the hospital settings to curb the incidence and transmission of such difficult-to-treat pathogens.

186. Klebsiella aerogenes: Are there implications to taxonomic accuracy?

Abstract Background With advances in genomics, microbiologists can accurately rename existing bacteria which may cause confusion among clinicians familiar with prior names. Limited investigation is available on the clinical impact of these name changes. University of Alabama at Birmingham Hospital microbiology updated Klebsiella aerogenes in the electronic medical record (EMR) to "Klebsiella (Enterobacter) aerogenes" to reflect change in nomenclature. Therapy selection differs between Klebsiella pneumoniae and Enterobacter spp. due to differences in Ambler Class C (AmpC) beta-lactamase production. Our Antimicrobial Stewardship Program previously implemented selective and cascaded susceptibility reporting for E. aerogenes to guide antibiotic selection which remained after nomenclature change. The goal of this study is to determine if the change led to inappropriate antibiotic use. Methods We reviewed blood culture data from May 2016-2020 which grew Enterobacter aerogenes or Klebsiella "Enterobacter" aerogenes. We excluded polymicrobial blood cultures, patients aged 18 and under, and patients who died within 48 hours of drawing blood cultures. Appropriate therapy was defined as an antibiotic with reported susceptibility with consideration of AmpC induction for a duration appropriate to clinical syndrome with minimum of 7 days. We recorded patient demographics, nature of therapy, and clinical outcomes. We performed comparative analysis with descriptive statistics to compare the two groups. Results There were 38 patients with K. aerogenes bacteremia, 21 patients prior to name change and 17 afterwards. None were ESBL. Cefepime was most often used directed inpatient therapy while oral ciprofloxacin was the most common outpatient regimen with no use of ceftriaxone. Prior to name change, there was one case (4.76%) that did not receive targeted AmpC therapy while there were two afterwards (11.8%), one of which decided by the ID consult team. Table 1 Demographics (Data presented as No. (%)) Table 2 Microbiology and Outcomes (Data presented as No. (%)) Table 3 Antimicrobial Selection. One patient that received 72 hours of appropriate therapy but died prior to completion of therapy. This was labeled labelled as appropriate therapy. Conclusion Care must be taken when taxonomic changes of clinically relevant bacteria may potentially affect optimization of antibiotics. As the ID consultants, we must be aware of these name changes and provide up to date recommendations. Cascade reporting and documentation in the EMR may be helpful to reduce morbidity related to changes in nomenclature. Disclosures Sixto M. Leal, Jr., MD, PhD, GenMark Dx: Grant/Research Support|GenMark Dx: Honoraria.

Prevalence and distribution of ampc beta-lactamase producing escherichia coli and klebsiella pneumoniae isolates obtained from urine samples at a tertiary care hospital in the caribbean.

The aim of this study was to investigate the prevalence and distribution of AmpC beta-lactamases (BLs) in uropathogens (E. coli and K. pneumoniae) at the University Hospital of the West Indies Jamaica (UHWI). De-duplicated consecutive urine samples, collected from January to March 2020 at the UHWI, were analyzed. Screening and phenotypic confirmatory tests were conducted using resistance to cefoxitin and the Disc Approximation Test (DAT) respectively, for isolates of interest. Multiplex PCR was performed on cefoxitin resistant (CR) isolates for the detection of bla CIT, bla MOX, bla FOX, bla ACC, and bla DHA genes. Whole genome sequencing (WGS) was used to further detect AmpC BL genes in PCR negative isolates with indeterminate phenotypic results. Sixty-four Gram negative isolates were obtained from 61 patients (55% female), aged 18 months to 88 years old. At least 35% (26) had complicated urinary tract infections. Only 7 out of 64 isolates were E. coli or K. pneumoniae, had antibiograms suggestive of possible AmpC BL production and were CR. DATs confirmed AmpC BL in two of these (1 K. pneumoniae; 1 E. coli), one tested negative (E. coli) and four had inconclusive results (K. pneumoniae). PCR detected bla DHA and bla CIT in two CR isolates. WGS further detected bla CMY-42 in one isolate. The prevalence of screened CR isolates with AmpC BL is 57.14% (4 of 7), representing 6.25% of the sample. AmpC BL producers tested had 100% susceptibility to meropenem and nitrofurantoin. AmpC BL prevalence among E. coli and K. pneumoniae, common urinary pathogens, in the studied isolates is low. Although cefoxitin screening is helpful, phenotypic screening using the DAT can yield indeterminate results best clarified by molecular testing.

PREVALENCE AND ANTIMICROBIAL SUSCEPTIBILITY OF URINARY TRACT INFECTION CASES AND FINDING OF ESBL AND AMPC β-LACTAMASES PRODUCING ESCHERICHIA COLI AND KLEBSIELLA PNEUMONIAE IN A TERTIARY CARE HOSPITAL MIZORAM

Introduction: Resistance to broad spectrum -lactams mediated by extended spectrum -lactamases (ESBL) and AmpC -lactamases enzymes is a growing threat worldwide.Aim: The aim of the study was to detect the prevalence and antimicrobial susceptibility of ESBL and AmpC -lactamase producing Escherichia coli and Klebsiellapneumoniae isolated from Urinary Tract infection Materials and Methods: A total of 288 isolates comprising of 180 Escherichia coli and 108 Klebsiellapneumoniaeisolated from various clinical samples were included. ESBL was detected by Phenotypic Conrmatory Disc Diffusion Test (PCDDT) and Double Disk Synergy Test (DDST). AmpC detection was done by AmpC disk test. Results: Out of 180 Escherichia coli, and 108 Klebsiellapneumoniaeisolates 91(50.5%) and 63(58.3%) were conrmed to be ESBL producers by PCDDT and 81(45%) and 57(52.7%) by DDST respectively. AmpC was detected in 35(19.4%) of Escherichia coli and 33(30.5%) of Klebsiellapneumoniae isolates. Co-production of ESBL and AmpC was detected in 6(3.3%) Escherichia coli and 11(10.18%) of Klebsiellapneumonia isolates. Majority of ESBL producers were from blood in both organisms. Multi drug resistance (MDR) was seen in 79.1% of ESBLEscherichiacoli and 63.5% of ESBLKlebsiellapneumoniae isolates. MDR was seen in 28(96.5%) of AmpC producing Escherichia coli and all AmpC producing Klebsiellapneumoniae isolates. Conclusion: It is essential to report ESBL and AmpC beta lactamase production along with routine susceptibility which will aid the clinicians in prescribing antibiotics.Strict adherence to the hospital antibiotic policy and good infection control practices would go a long way in curtailing the menace of drug resistance.

​Prevalence of Shigatoxigenic, Enteropathogenic and Antimicrobial Drug Resistant Escherichia coli from Captive Wild Animals of Alipore Zoo, Kolkata, India

Background: Escherichia coli is one of the intestinal microbiota in wildlife as in domestic animals and humans. The prevalent serogroups, pathogenic strains like STEC, EPEC and antimicrobial resistance is less frequently studied in captive wildlife of India. The present study was aimed to study the prevalence of STEC, EPEC and antimicrobial resistant E. coli from captive wild animals in a zoo in Kolkata, India. Methods: This study was done during March 2019 to June 2019 for E. coli from faecal samples of captive wild birds and mammals. The pathotypes STEC and EPEC were detected for the presence of stx1, stx2 and eae virulence genes, respectively. Extended spectrum beta- lactamases, ampC beta-lactamases production and antimicrobial susceptibility were detected by standard phenotypic methods. Result: In this study, some E.coli isolates were found harbouring genes for ETEC and EPEC. Extended spectrum beta- lactamases and ampC beta-lactamases were produced by some isolates. Most E. coli isolates were detected multidrug-resistant but were mostly sensitive to gentamicin and amikacin. This study demonstrated that captive wild animals harbour potentially pathogenic E. coli that were resistant for many antimicrobials.

Veterinary clinic surfaces as reservoirs of multi-drug- and biocide-resistant Gram-negative bacteria.

This cross-sectional study was carried out to determine the common Gram-negative bacteria (GNB) contaminating veterinary clinic environments, and to evaluate the susceptibility of the isolates to commonly used antibiotics and biocides. A total of 62 swab samples were collected from different frequently touched surfaces in the 4 veterinary clinics visited. The samples were processed for isolation and identification of GNB using standard microbiological procedures. The susceptibility of the isolates to disinfectants and antibiotics was determined using agar dilution and disc diffusion techniques, respectively. A total of 114 GNB were isolated from the 4 clinics with isolation rates of 21.9, 22.8, 23.7 and 31.6% in clinics A, B, C and D, respectively. The surfaces of treatment tables were more contaminated (16.7 %) than receptionist/clinician desks (15.8%), weighing balances (10.5 %), door handles (7.9 %), drip stands (7.9 %), handwashing basins (7.0 %) and client chairs (7.0%). The surface-contaminating isolates were distributed into 20 genera, with members of Enterobacteriaceae predominating (n=97). Fifty-nine per cent of the isolates were resistant to the disinfectant Septol, while 5.3 and 0.9% were resistant to Purit and Dettol disinfectants, respectively. Multiple drug resistance was observed among 99% of the isolates with approximately 100% resistance to beta-lactams. Phenotypic expression of extended-spectrum (3.5 %) and AmpC beta-lactamase (38.6 %) production was detected. These findings highlight the role of clinic environments in serving as reservoirs for potential pathogens and sources for the spread of multi-drug resistant GNB.

Prevalence of various Beta-lactamases in Enterobacteriaceae in a tertiary care hospital in South India: A Cross-sectional study

Antimicrobial resistance among bacteria has constantly increased over the years with emergence of novel resistance mechanism among these versatile organisms. Identifying the resistance pattern of the isolates both regionally and globally is essential for the institution of appropriate antimicrobial therapy. This study was conducted to assess the prevalence of beta-Lactamase enzymes among species of Enterobacteriaceae.312 consecutive isolates belonging to the family of Enterobacteriaceae were included in the study conducted over a period of one year. After preliminary antibiotic susceptibility testing using standard guidelines, production of various beta-Lactamase enzymes was assessed by phenotypic methods.22.76% of the isolates were found to be Extended-Spectrum Beta-Lactamase producers, 37.82% were AmpC Beta-Lactamase producers and 7.37% of the isolates produced the Carbapenemase enzyme.Our study estimates the prevalence of various beta-Lactamase enzymes in isolates of Enterobacteriaceae in a tertiary care centre. The increase in production of these enzymes among bacteria necessitates the implementation of strict adherence to antibiotic policy and infection control measures.

Prevalence of plasmid-mediated AmpC beta-lactamases in Enterobacteria isolated from urban and rural folks in Uganda

Background: AmpC beta-lactamase-producing bacteria are associated with increased resistance to third-generation cephalosporins. Here, we describe plasmid-mediated AmpC beta-lactamase-producing enterobacteria isolated from urban and rural dwellers in Uganda.Methods: Stool and urine from 1,448 individuals attending outpatient clinics in Kampala and two rural districts in central Uganda were processed for isolation of Escherichia coli and Klebsiella. Following antibiotic susceptibility testing, cefoxitin resistant isolates, and amoxicillin/clavulanate resistant but cefoxitin susceptible isolates, were tested for AmpC beta-lactamase production using the cefoxitin-cloxacillin double-disc synergy test. Carriage of plasmid-mediated AmpC beta-lactamase-encoding genes (pAmpC) and extended spectrum beta-lactamase (ESBL) encoding genes was determined by PCR.Results: Nine hundred and thirty E. coli and 55 Klebsiella were recovered from the cultured samples, yielding 985 isolates investigated (one per participant). One hundred and twenty-nine isolates (13.1%, 129/985) were AmpC beta-lactamase producers, of which 111 were molecularly characterized for pAmpC and ESBL gene carriage. pAmpC genes were detected in 60% (67/111) of the AmpC beta-lactamase producers; pAmpC genes were also detected in 18 AmpC beta-lactamase non-producers and in 13 isolates with reduced susceptibility to third-generation cephalosporins, yielding a total of 98 isolates that carried pAmpC genes. Overall, the prevalence of pAmpC genes in cefoxitin resistant and/or amoxicillin/clavulanate resistant E. coli and Klebsiella was 59% (93/157) and 26.1% (5/23), respectively. The overall prevalence of pAmpC-positive enterobacteria was 10% (98/985); 16.4% (45/274) in Kampala, 6.2% (25/406) Kayunga, and 9.2% (28/305) Mpigi. Ciprofloxacin use was associated with carriage of pAmpC-positive bacteria while residing in a rural district was associated with protection from carriage of pAmpC-positive bacteria.Conclusion: pAmpC beta-lactamase producing enterobacteria are prevalent in urban and rural dwellers in Uganda; therefore, cefoxitn should be considered during routine susceptibility testing in this setting.

Evidence of potentially unrelated AmpC beta-lactamase producing Enterobacteriaceae from cattle, cattle products and hospital environments commonly harboring the blaACC resistance determinant.

The occurrence and genetic relatedness of AmpC beta-lactamase producing Enterobacteriaceae isolated from clinical environments, groundwater, beef, human and cattle faeces were investigated. One hundred seventy-seven (177) samples were collected and cultured on MacConkey agar. A total of 203 non-repetitive isolates were characterised using genus/species-specific PCRs and the identified isolates were subjected to antibiotic susceptibility testing. The production of AmpC beta-lactamases was evaluated using cefoxitin disc, confirmed by the D96C detection test and their encoding genes detected by PCR. The D64C extended-spectrum beta-lactamases (ESBL) test was also performed to appraise ESBLs/AmpC co-production. The genetic fingerprints of AmpC beta-lactamase producers were determined by ERIC-PCR. A total of 116 isolates were identified as E. coli (n = 65), Shigella spp. (n = 36) and Klebsiella pneumoniae (n = 15). Ciprofloxacin resistance (44.4–55.4%) was the most frequent and resistance against the Cephem antibiotics ranged from 15–43.1% for E. coli, 25–36.1% for Shigella spp., and 20–40% for K. pneumoniae. On the other hand, these bacteria strains were most sensitive to Amikacin (0%), Meropenem (2.8%) and Piperacillin-Tazobactam (6.7%) respectively. Nineteen (16.4%) isolates comprising 16 E. coli and 3 Shigella spp. were confirmed as AmpC beta-lactamase producers. However, only E. coli isolates possessed the corresponding resistance determinants: blaACC (73.7%, n = 14), blaCIT (26%, n = 5), blaDHA (11%, n = 2) and blaFOX (16%, n = 3). Thirty-four (27.3%) Enterobacteriaceae strains were confirmed as ESBL producers and a large proportion (79.4%, n = 27) harboured the blaTEM gene, however, only two were ESBLs/AmpC co-producers. Genetic fingerprinting of the AmpC beta-lactamase-producing E. coli isolates revealed low similarity between isolates. In conclusion, the findings indicate the presence of AmpC beta-lactamase-producing Enterobacteriaceae from cattle, beef products and hospital environments that commonly harbour the associated resistance determinants especially the blaACC gene, nonetheless, there is limited possible cross-contamination between these environments.

THE PREVALENCE OF EXTENDED-SPECTRUM BETA-LACTAMASES AND AMBLER CLASS C BETA-LACTAMASES IN ENUGU AND EBONYI STATES OF NIGERIA

Over the years, antibiotics have been among the primary drugs used to treat or prevent infections in animals and humans. Over the years, ESBL and AmpC producing isolates have become common microorganisms in medical institutions. They have contributed immensely to the clinical challenges caused by nosocomial infections with minimal therapeutic options.The present study investigated the prevalence of extended-spectrum beta-lactamases and Ambler class C beta-lactamases in the Enugu and Ebonyi States of Nigeria. A total of fifty isolates comprising 27 clinical and 23 environmental isolates were screened and observed for the presence of ESBL and AmpC producing isolates. The production of either of the two enzymes was detected by observing zones of inhibition in diameter. The findings showed the presence of ESBL and AmpC producing isolates in the clinical and environmental samples tested. The study concludes that ESBL and AmpC beta-lactamases production by resistant bacterial isolates (especially the Gram-negatives) remain the prevalent mechanism in bacterial resistance to beta-lactam drugs. The study recommends that adequate and appropriate detection and monitoring of ESBL and AmpC producing enzymes within the communities.

MurA, uhpT, glpT and fosA Genes of Fosfomycin Resistance in Multi-drug Resistant E. coli Isolated from Hematological Malignancies' Patients with Blood Stream Infection

Aim: To estimate the prevalence of murA, uhpT, glpT and fosA resistance genes of fosfomycin in multidrug resistant Escherichia coli isolated from patients suffering from hematological malignancies with on top blood stream infection together with correlating this distribution to the rate of expression of AmpC, ESBLs and MBLs in such isolates.
 Methods: 205 blood samples collected from patients with underlying hematological malignancies were cultured to isolate E. coli strains. Multidrug resistance was detected. PCR was done to determine fosfomycin resistance genes; murA, uhpT, glpT and fosA.
 Results: A total of 83 (40.5%) E. coli strains were isolated from blood samples. 58 (69.9%) were found to be multidrug resistant. AmpC beta-lactamase production was deduced in 15 (25.8%) isolates. 43 (74.1%) isolates were ESBLs producers whereas 9 (15.5%) were MBL class A carbapene-mases producers. Depending on PCR results, murA gene was detected in one isolate (1.7%), uhpT gene in 3 (5.2%), glpT gene in 4 (6.9%) whereas fosA gene was found in 7 E. coli strains (12.1%).
 Conclusion: Fosfomycin is a promising antibiotic with limited degree of prevalence of its resistant genes; however disseminating resistance might increase in multidrug resistant E. coli

Burden of Multidrug Resistant Escherichia coli among Patients with Urinary Tract Infections in a Tertiary Care Centre- A Retrospective Analysis

Introduction: Multidrug Resistant (MDR) Escherichia coli isolates causing Urinary Tract Infections (UTIs), capable of producing Extended Spectrum Beta Lactamase (ESBL), AmpC beta lactamase and resistance to carbapenems pose serious challenges to the clinicians causing worse clinical scenarios. The detection of these isolates has prime importance in infection control and improving therapeuticmanagementofpatients,astheirprevalenceisincreasing worldwide. Injudicious use of antibiotics has led to selective pressure, resulting in the emergence of antibiotic resistance in gram negative bacteria globally. This rise in antimicrobial resistance has decreased the options for empirical therapy, causing a global health concern in infections associated with ESBL producing and AmpC producing isolates. Aim: To investigate the burden of ESBL producing, AmpC beta-lactamase producing, carbapenem resistant, and MDR Escherichia coli isolated from urine samples in a tertiary care centre. Materials and Methods: The present retrospective study conducted from January to December 2019. A total of 10,535 urine samples were received during the study period, to find out the burden of drug resistant Escherichia coli isolates in urine samples, analyse their antibiogram and patients’ socio-demographic information. Records of microscopic observations to antibiogram of each isolate was noted down from the register for urine samples, and further analysed. The data was coded, verified, entered and analysed using Statistical Package for Social Sciences (SPSS) version 18.0. Results: Among the total urine samples (10,535), 1434 (13.6%) Escherichia coli isolates were identified, of which 553 (38.6%) were found to be ESBL producing, 497 (34.6%) AmpC beta- lactamase producing, 172 (12%) Carbapenem resistant, and 765 (53.3%) MDR. Majority of the isolates were from the age group of 51-60 years 288 (20.08%). The least susceptibility of the isolates was detected against penicillin G 1410 (98.3%), followed by ampicillin 1160 (80.9%) and cephazolin 74 (67.9%). Among the MDR isolates, the maximum drug resistance (398, 52%) was seen in penicillin, cephems, quinolones and Folate pathway antagonist group of antimicrobials. Conclusion: Identification of the drug resistant isolates is of high priority and crucial for therapeutic management of the patients, and infection control. Stringent antimicrobial stewardship policies and judicious use of antimicrobials can decrease the spread of antimicrobial resistant genes in the hospital environment.

Phenotypic and Molecular Characterization of AmpC β-Lactamases among Escherichia coli a Prospective Study in Southeast Iran.

Escherichia coli (E. coli) causes serious health problems due to the high rate of its resistance to common antibiotics. AmpC β-lactamases are important cephalosporinases, encoded by E. coli chromosome, that cause resistance to cefoxitin, cephalothin, most penicillins, cefazolin, and beta-lactamase inhibitor-beta-lactams. This study aimed to detect AmpC β-lactamases among E. coli strains at three educational hospitals in Iran. Two hundred and thirty samples were recovered from the three educational hospitals in Zahedan City in southeast Iran. Sixty E. coli strains were identified by biochemical and differential tests. E. coli strains with extended-spectrum β-lactamases (ESBLs) were selected by disk-diffusion agar method and combined diffuse disc test. Finally, selected isolates were screened by polymerase chain reaction (PCR) for the common AmpC genotypes MOX, FOX, CIT, DHA, EBC, and ACC. Out of 60 E. coli strains, 13 isolates (21.7%) were ESBL positive and 7 strains (11.6%) were phenotypically AmpC beta-lactamase producers. Three isolates had CIT (23.1%), 5 had DHA (38.5%), 4 had EBC (30.8%), and 1 had ACC (7.7%) genotypes. The high prevalence of AmpC-producing E. coli strains in hospital settings is an important challenge for health care systems. Data about beta-lactamase producers that are crucial for controlling bacterial resistance should be upgraded.

663. Improved Detection of ESBL and AmpC Beta-Lactamase Producing Isolates of Enterobacteriaceae in Pediatric Patients with Bloodstream Infections Using Combined Genotypic and Phenotypic Antimicrobial Susceptibility Testing

BackgroundInfections secondary to pathogens resistant to third-generation cephalosporins (3GC), such as extended-spectrum (ESBL) and AmpC β-lactamase (AmpC) producing Enterobacteriaceae, are increasing. Currently, there are no recommendations regarding identification of AmpC in Citrobacter, Enterobacter, Morganella and Serratia spp. (CEMS organisms). This study’s aim was to increase the detection of AmpC and ESBL producing Enterobacteriaceae in blood cultures from pediatric population by combining genotypic with phenotypic antimicrobial susceptibility testing (AST).MethodsAll first time Enterobacteriaceae isolates recovered from blood cultures of pediatric patients at CCHMC between January 2017 and December 2018 were evaluated. The Check-MDR CT103XL assay was used to determine the presence of AmpC and ESBL. AST was performed using the Vitek 2 platform. Phenotypic ESBL resistance was defined by resistant to either ceftriaxone of ceftazidime using CLSI breakpoints. Combined cefoxitin resistance with ceftriaxone or ceftazidime resistance was used to define phenotypic AmpC (EUCAST standards).ResultsThere were 170 isolates, from 147 patients, with 21 (12.4%) AmpC and 18 (10.6%) ESBL genes detected. Using AST, 11 (6.5%) and 26 (15.3%) isolates met AmpC and ESBL phenotypic criteria respectively. However, 14 of the isolates with AmpC genes detected and 2 of isolates with ESBL genes detected failed to meet phenotypic criteria. In addition, 4 (19%) of 21 AmpC isolates were susceptible to cefoxitin and 3GC while both E. coli and S. marcescens genotypic ESBL isolates were susceptible to 3GC.Number of AmpC- and ESBL- Producing Isolates Detected Using Phenotypic Method a,b, Genotypic Method and Combined Testing ConclusionWe identified 16 (9.4%) isolates with resistance genes detected but that failed to meet phenotypic criteria.Without molecular testing, patients with these isolates may have been treated with 3GC which could have resulted in treatment failure.The addition of genotypic testing to AST improved the identification of AmpC and ESBL organisms and provided clinically relevant data to guide treatment of resistant organisms. Combined testing is also beneficial for infection control and epidemiological purposes.Disclosures All Authors: No reported disclosures

Isolation and molecular characterization of multidrug-resistant Escherichia coli from chicken meat

Antibiotic-resistant Escherichia coli (E. coli) are common in retail poultry products. In this study, we aimed to isolate and characterize multidrug resistant (MDR) E. coli in raw chicken meat samples collected from poultry shops in Sylhet division, Bangladesh, as well as to determine correlation between resistance phenotype and genotype. A total of 600 chicken meat swabs (divided equally between broiler and layer farms, n = 300 each) were collected and the isolates identified as E. coli (n = 381) were selected. Disc diffusion antimicrobial susceptibility assay showed resistance of these isolates to ampicillin, erythromycin, tetracycline, streptomycin, trimethoprim-sulfamethoxazole, chloramphenicol, and gentamicin. Polymerase chain reaction (PCR) identified several antibiotic resistance genes (ARGs) in our isolates. Among these ARGs, the prevalence of tetA (for tetracycline) was the highest (72.58%) in broiler chicken isolates, followed by sul1 (for sulfonamide; 44.16%), aadA1 (for streptomycin; 33.50%), ereA (for erythromycin; 27.41%), aac-3-IV (for gentamicin; 25.38%), and the two genes cmlA (24.87%) and catA1 (8.63%) for chloramphenicol. On the other hand, the respective prevalence in layer chicken isolates were 82.06%, 47.83%, 35.87%, 35.33%, 23.91%, 19.02%, and 5.43%. Furthermore, 49.23% of the isolates from broiler chicken were MDR, with the presence of multiple antibiotic resistance genes, including 3 (40.11%) and 4 (9.13%) genes. On the other hand, 51.09% of layer chicken E. coli isolates were MDR, with 3, 4 or 5 ARGs detected in 36.41%, 14.13%, and 0.54% of the isolates, respectively. We also found that 12.8% of broiler chicken E. coli isolates and 7.61% of layer chicken isolates carried genes coding for extended-spectrum SHV beta-lactamases. Lastly, we report the presence of the AmpC beta-lactamase producing gene (CITM) in 4.56% and 3.26% of broiler and layer chicken E. coli isolates, respectively. We found significant correlations between most of the antimicrobial resistant phenotypes and genotypes observed among the investigated E. coli isolates. Our findings highlight the need for the prudent use of antimicrobials in chickens to minimize the development of antibiotic-resistant bacterial strains.