Antibiotic Resistance of Escherichia Coli Isolated from Broiler Chickens

Abstract The purpose of this study was to detect the antibiotic resistance of forty-one Escherichia coli isolates from the intestinal contents of slaughtered broiler chickens using the disk diffusion method according to Kirby-Bauer. Mueller-Hinton agar plates were inoculated with 0.1 ml overnight broth cultures of individual E. coli isolates and the disks with the following concentrations of antibiotics were applied onto them: ampicillin (10 μg), cefotaxime (30 μg), gentamicin (10 μg), streptomycin (10 μg), azithromycin (15 μg), tetracycline (30 μg), ciprofloxacin (30 μg) and levofloxacin (3 μg). After the incubation at 37 °C for 16—18 hours, the inhibition zones were measured and interpreted in accordance with the Clinical and Laboratory Standard Institute (CLSI) zone diameter breakpoints. Almost all E. coli isolates showed resistance to tetracycline (92.68 %), most of them were resistant to gentamicin (75.61 %) and levofloxacine (70.73 %). Phenotypic resistance to tetracycline was further confirmed with the help of the Polymerase Chain Reaction (PCR) procedure focused on the presence of specific tet(A) and tet(B) genes. These genes were detected in all 41 E. coli isolates. On the contrary, E. coli isolates were highly susceptible to both azithromycin and streptomycin. In conclusion, the study highlighted the role of commensal E. coli bacteria isolated from the intestines of broiler chickens as an important reservoir of tetracycline resistance genes.

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Pathotyping and Antibiotic Resistance Profiling of Escherichia coli Isolates from Children with Acute Diarrhea in Amatole District Municipality of Eastern Cape, South Africa

BioMed Research International ◽

10.1155/2020/4250165 ◽

2020 ◽

Vol 2020 ◽

pp. 1-10

Author(s):

S. A. Omolajaiye ◽

K. O. Afolabi ◽

B. C. Iweriebor

Keyword(s):

Escherichia Coli ◽

Antibiotic Resistance ◽

Antimicrobial Agents ◽

Childhood Mortality ◽

Diffusion Method ◽

Resistance Pattern ◽

Disk Diffusion Method ◽

Phenotypic Resistance ◽

E Coli ◽

Diarrheagenic Escherichia Coli

Background. Diarrhea has been reported as the leading cause of childhood mortality and morbidity globally but with disproportionate impacts in developing nations. Among bacterial etiologic agents of diarrhea, diarrheagenic Escherichia coli is the main cause of the disease among children under the age of 5 years. This study is aimed at determining the prevalence and antibiogram pattern of diarrheagenic Escherichia coli (DEC) pathotypes associated with diarrhea cases in the study area. Methods. A total of 120 presumptive isolates of E. coli were obtained from diarrheal stool samples from male and female patients below 12 years of age using chromogenic agar. Confirmation of the isolates and screening for virulence genes were determined by polymerase chain reaction (PCR) while antimicrobial susceptibility testing was performed using the disk diffusion method. The presence of antibiotic resistance genes to chloramphenicol and tetracycline among the confirmed isolates was also profiled by PCR based on the observed phenotypic resistance pattern. Results. Of the 120 presumptive isolates, 88.3% (106/120) were confirmed as E. coli through PCR. The molecular pathotyping of the confirmed isolates showed their distribution as 41% (43/106) of diffusely adhering E. coli (DAEC), 17% (18/106) of enterohemorrhagic E. coli (EHEC), 17% (18/106) of enteropathogenic E. coli (EPEC), and 10% (11/106) of enteroinvasive E. coli (EIEC), while enteroaggregative E. coli (EAEC) and enterotoxigenic E. coli (ETEC) were not detected, and the remaining 15% did not belong to any pathotype. Notably, high resistance of the isolates to commonly used antimicrobials was observed as follows: ampicillin (98%), chloramphenicol (94%), trimethoprim-sulfamethoxazole (96%), and tetracycline (90.6%), while a relatively low number of the confirmed isolates were resistant to ciprofloxacin (45%) and imipenem (36%). In addition, 94% of the isolates that exhibited phenotypic resistance against chloramphenicol harbored the catA1 resistance gene while 89% that showed resistance to tetracycline had tetA genes. Conclusions. These findings showed that DEC could be considered as the leading etiologic bacterial agent responsible for diarrhea in the study community, and the observable high degree of resistance of the isolates to antimicrobial agents is of huge significance, calling for stakeholders to adopt and consolidate the existing antimicrobial stewardship scheme of the government, in order to ensure an uncompromised public health.

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Molecular types, virulence profiles and antimicrobial resistance of Escherichia coli causing bovine mastitis

Veterinary Record Open ◽

10.1136/vetreco-2019-000369 ◽

2019 ◽

Vol 6 (1) ◽

pp. e000369 ◽

Cited By ~ 5

Author(s):

Magdalena Nüesch-Inderbinen ◽

Nadine Käppeli ◽

Marina Morach ◽

Corinne Eicher ◽

Sabrina Corti ◽

...

Keyword(s):

Escherichia Coli ◽

Bovine Mastitis ◽

Tetracycline Resistance ◽

Diffusion Method ◽

Sample Population ◽

Disk Diffusion Method ◽

E Coli ◽

Phylogenetic Grouping ◽

Resistance Rates ◽

Susceptibility Profiles

BackgroundEscherichia coli is an important aetiological agent of bovine mastitis worldwide.MethodsIn this study, 82 E. coli from bovine mastitis milk samples from 49 farms were analysed for their genetic diversity using phylogenetic grouping and multilocus sequence typing. The isolates were examined by PCR for a selection of virulence factors (VFs). Antimicrobial susceptibility profiles were assessed using the disk diffusion method.ResultsThe most prevalent phylogroups were group B1 (41.5 per cent of the isolates) and group A (30.5 per cent). A variety of 35 different sequence types (STs) were identified, including ST1125 (11 per cent), ST58 (9.8 per cent), ST10 (8.5 per cent) and ST88 (7.3 per cent). Aggregate VF scores (the number of unique VFs detected for each isolate) ranged from 1 to 3 for 63.4 per cent of the isolates and were at least 4 for 12.2 per cent. For 24.4 per cent of the isolates, the score was 0. The three most frequent VFs were traT, fyuA and iutA. The majority (72 per cent) of the isolates harboured traT. The majority (68.3 per cent) of the isolates were fully susceptible to all antimicrobials tested, with 22 per cent resistant to ampicillin and 14.6 per cent to tetracycline. Resistance rates were low for gentamicin (3.7 per cent), amoxicillin/clavulanic acid (2.4 per cent) and ceftiofur (1.2 per cent), respectively.ConclusionAmong the study’s sample population, E. coli strains were genotypically diverse, even in cows from the same farm, although some STs occurred more frequently than others. Susceptibility to clinically relevant compounds remained high.

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A Preliminary Study: Antibiotic Resistance Patterns of Escherichia coli and Enterococcus Species from Wildlife Species Subjected to Supplementary Feeding on Various South African Farms

Animals ◽

10.3390/ani10030396 ◽

2020 ◽

Vol 10 (3) ◽

pp. 396 ◽

Cited By ~ 1

Author(s):

Michaela Sannettha van den Honert ◽

Pieter Andries Gouws ◽

Louwrens Christiaan Hoffman

Keyword(s):

Escherichia Coli ◽

Antibiotic Resistance ◽

Supplementary Feeding ◽

Health Concern ◽

Diffusion Method ◽

Disk Diffusion Method ◽

E Coli ◽

Wildlife Species ◽

Human Contact ◽

Resistance Patterns

Studies have shown that antibiotic resistance among wild animals is becoming a public health concern, owing to increased contact and co-habitation with domestic animals that, in turn, results in increased human contact, indirectly and directly. This type of farming practice intensifies the likelihood of antibiotic resistant traits in microorganisms transferring between ecosystems which are linked via various transfer vectors, such as rivers and birds. This study aimed to determine whether the practice of wildlife supplementary feeding could have an influence on the antibiotic resistance of the bacteria harboured by the supplementary fed wildlife, and thus play a potential role in the dissemination of antibiotic resistance throughout nature. Escherichia coli and Enterococcus were isolated from the faeces of various wildlife species from seven different farms across South Africa. The Kirby-Bauer disk diffusion method was used according to the Clinical and Laboratory Standards Institute 2018 guidelines. The E. coli (F: 57%; N = 75% susceptible) and Enterococcus (F: 67%; N = 78% susceptible) isolates from the supplementary fed (F) wildlife were in general, found to be more frequently resistant to the selection of antibiotics than from those which were not supplementary fed (N), particularly towards tetracycline (E. coli F: 56%; N: 71%/Enterococcus F: 53%; N: 89% susceptible), ampicillin (F: 82%; N = 95% susceptible) and sulphafurazole (F: 68%; N = 98% susceptible). Interestingly, high resistance towards streptomycin was observed in the bacteria from both the supplementary fed (7% susceptible) and non-supplementary fed (6% susceptible) wildlife isolates. No resistance was found towards chloramphenicol and ceftazidime.

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Antibiotic resistance and virulence genes of extraintestinal pathogenic Escherichia coli from tropical estuary, south India

The Journal of Infection in Developing Countries ◽

10.3855/jidc.5627 ◽

2015 ◽

Vol 9 (05) ◽

pp. 496-504 ◽

Cited By ~ 1

Author(s):

Divya Sukumaran ◽

Abdulla A Mohamed Hatha

Keyword(s):

Escherichia Coli ◽

Antibiotic Resistance ◽

Multidrug Resistance ◽

Virulence Factor ◽

Virulence Genes ◽

Antimicrobial Agents ◽

Diffusion Method ◽

Disk Diffusion Method ◽

E Coli ◽

Virulence Factor Genes

Introduction: Escherichia coli strains can cause a variety of intestinal and extraintestinal diseases. Extraintestinal pathogenic E. coli (ExPEC) strains have the ability to cause severe extraintestinal infections. Multidrug resistance among ExPEC could complicate human infections. Methodology: Escherichia coli strains were isolated during the period of January 2010 to December 2012 from five different stations set at Cochin estuary. Susceptibility testing was determined by the disk-diffusion method using nine different antimicrobial agents. A total of 155 strains of Escherichia coli were screened for the presence of virulence factor genes including papAH, papC, sfa/focDE, iutA,and kpsMT II associated with ExPEC. Results: Among the 155 E. coli isolates, 26 (16.77%), carried two or more virulence genes typical of ExPEC. Furthermore, 19.23% of the ExPEC isolates with multidrug resistance were identified to belong to phylogenetic groups B2 and D. Statistically significant association of iutA gene in ExPEC was found with papC (p < 0.001) and kpsMT II (p < 0.001) genes. ExPEC isolates were mainly resistant to ampicillin (23.07%), tetracycline (19.23%), co-trimoxazole (15.38%), and cefotaxime (15.38%). The adhesion genes papAH and sfa/focDE were positively associated with resistance to gentamicin, chloramphenicol, and cefotaxime (p < 0.05). Conclusions: Co-occurrence of virulence factor genes with antibiotic resistance among ExPEC poses considerable threat to those who use this aquatic system for a living and for recreation.

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Antibiotic resistance in Pakistan: a systematic review of past decade

BMC Infectious Diseases ◽

10.1186/s12879-021-05906-1 ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Hazrat Bilal ◽

Muhammad Nadeem Khan ◽

Tayyab Rehman ◽

Muhammad Fazal Hameed ◽

Xingyuan Yang

Keyword(s):

Antibiotic Resistance ◽

High Resistance ◽

Clinical Laboratory ◽

World Health ◽

Diffusion Method ◽

Resistance Pattern ◽

Original Research ◽

Disk Diffusion Method ◽

Phenotypic Resistance ◽

E Coli

Abstract Background During the last six decades, extensive use of antibiotics has selected resistant strains, increasing the rate of fatal infectious diseases, and exerting an economic burden on society. This situation is widely accepted as a global problem, yet its degree is not well elucidated in many regions of the world. Up till now, no systemic analysis of Antimicrobial resistance (AMR) in Pakistan has been published. The current study aims to describe the antibiotic-resistance scenario of Pakistan from human samples of the last 10 y, to find the gaps in surveillances and methodology and recommendations for researchers and prescribers founded on these outcomes. Methods Original research articles analyzed the pattern of Antibiotic resistance of any World Health Organization (WHO) enlisted priority pathogens in Pakistan (published onward 2009 till March 2020), were collected from PubMed, Google scholar, and PakMedi Net search engines. These articles were selected based on predefined inclusion and exclusion criteria. Data about the study characteristics and antibiotic-resistance for a given bacterium were excluded from literature. Antibiotic resistance to a particular bacterium was calculated as a median resistance with 95% Confidence Interval (CI). Results Studies published in the last 10 y showed that Urinary Tract Infection (UTI) is the most reported clinical diagnosis (16.1%) in Pakistan. E. coli were reported in 28 (30.11%) studies showing high resistance to antibiotics’ first line. Methicillin-resistant Staphylococcus aureus (MRSA) was found in 49% of S. aureus’ total reported cases. Phenotypic resistance pattern has mostly been evaluated by Disk Diffusion Method (DDM) (82.8%), taken Clinical Laboratory Standards Institute (CLSI) as a breakpoint reference guideline (in 79.6% studies). Only 28 (30.11%) studies have made molecular identification of the resistance gene. blaTEM (78.94% in Shigella spp) and blaNDM-1 (32.75% in Klebsiella spp) are the prominent reported resistant genes followed by VanA (45.53% in Enterococcus spp), mcr-1 (1.61% in Acinetobacter spp), and blaKPC-2 (31.67% in E. coli). Most of the studies were from Sindh (40.86%), followed by Punjab (35.48%), while Baluchistan’s AMR data was not available. Conclusion Outcomes of our study emphasize that most of the pathogens show high resistance to commonly used antibiotics; also, we find gaps in surveillances and breaches in methodological data. Based on these findings, we recommend the regularization of surveillance practice and precise actions to combat the region’s AMR.

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Resistance to multiple first-line antibiotics among Escherichia coli from poultry in Western Algeria

Veterinary World ◽

10.14202/vetworld.2020.290-295 ◽

2020 ◽

Vol 13 (2) ◽

pp. 290-295

Author(s):

Meki Boutaiba Benklaouz ◽

Hebib Aggad ◽

Qada Benameur

Keyword(s):

Escherichia Coli ◽

Antimicrobial Agents ◽

Disk Diffusion ◽

Diffusion Method ◽

First Line ◽

Resistance Level ◽

Disk Diffusion Method ◽

E Coli ◽

Mueller Hinton Agar ◽

Western Algeria

Background and Aim: Escherichia coli can cause a number of serious infections both in human and veterinary medicine. Their management is increasingly complicated by the emergence and dissemination of multiresistance to various first-line antimicrobial agents. This study aimed to evaluate the resistance level to the commonly used antibiotics, with a focus on the first-line antimicrobial agents, in E. coli strains isolated from poultry in Western Algeria. Materials and Methods: E. coli culture was done on MacConkey agar and their identification was determined by AP20E system. For susceptibility testing, disk diffusion method to 14 antimicrobials, including first-line antibiotics, was used according to Kirby–Bauer disk diffusion method in Mueller-Hinton agar and the results were interpreted according to the Clinical and Laboratory Standards Institute guidelines. E. coli isolates were considered as multidrug resistance (MDR) when found resistant to at least one antimicrobial agent of three different families of antibiotics. Double-disk synergy and combination disk tests were used for initial screening and confirmation for extended-spectrum β-lactamases (ESBLs) production, respectively. Results: A total of 145 E. coli strains were isolated in this study. High resistance levels to various antibiotics, including commonly used first-line antimicrobial agents, were recorded in this study. The highest resistance level was observed against nalidixic acid (90.34%, n=131), followed by tetracycline (86.89%, n=126), ampicillin (82.75%, n=120), enrofloxacin (80.68%, n=117) and neomycin (80.68%, n=117), trimethoprim/sulfamethoxazole (73.79%, n=107), norfloxacin (72.41%, n=105) and cephalothin (72.41%, n=105), amoxicillin/clavulanic acid (51.72%, n=75), chloramphenicol (22.75%, n=33), nitrofurantoin (17.24%, n=25), gentamicin (13.10%, n=19), and ceftiofur (3.44%, n=5). Moreover, resistance to multiple first-line antibiotics was also demonstrated in the present study. Overall, 139 out of 145 isolates (95.86%) demonstrated MDR (resistant to at least three antibiotics). In addition, five E. coli isolates (3.44%) were confirmed to be ESBL producers. Conclusion: The alarming rate of E. coli resistant to multiple first-line antibiotics in poultry demands intensified surveillance. These results call for taking drastic measures to preserve antibiotic effectiveness and reduce the emergence risks of extensively drug-resistant and pandrug-resistant E. coli isolates.

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Antimicrobial Resistance in Uropathogenic Escherichia coli Strains Isolated from Beasat Hospital in Sanandaj, West of Iran

Journal of Pharmaceutical Research International ◽

10.9734/jpri/2020/v32i130392 ◽

2020 ◽

pp. 32-36

Author(s):

Nasrin Bahmani ◽

Noshin Abdolmaleki ◽

Afshin Bahmani

Keyword(s):

Escherichia Coli ◽

Urinary Tract Infection ◽

Antibiotic Resistance ◽

Urinary Tract ◽

Tract Infection ◽

Antimicrobial Agents ◽

Hospitalized Patients ◽

Diffusion Method ◽

Disk Diffusion Method ◽

E Coli

Background and Objectives: Urinary tract infection (UTI) is one of the most frequent infectious diseases which is caused by Gram-negative bacteria especially Escherichia coli. Multiple resistance to antimicrobial agents are increasing quickly in E. coli isolates and may complicate therapeutic strategies for UTI. The propose of this study was to determine the antibiotic resistance patterns and the multidrug-resistance (MDR) phenotypes in uropathogenic E. coli (UPEC). Materials and Methods: A total of 153 UPEC isolates were collected from both hospitalized patients (95 isolates) and outpatients (58 isolates) from March to October 2018. In order to determine the MDR among UPEC isolates, we have tested 15 antimicrobial agents on Muller Hinton agar by the disk diffusion method. Results: The percentage of MDR isolates (resistant to at least three drug classes such as fluoroquinolones, penicillins and cephalosporins) was 55.5% in the hospitalized patients and the outpatients. Antibiotic resistance to ampicillin, ceftazidime, nalidixic acid and trimethoprim/ sulfamethoxazole was higher than 60%. Meropenem, Imipenem and norfloxacin indicated markedly greater activity (93.3%, 80% and 85.6%, respectively) than other antimicrobial agents. Conclusions: Urinary tract infection due to MDR E. coli may be difficult to treat empirically due to high resistance to commonly used antibiotics, so, empirical antibiotic treatment should be reviewed periodically at local studies.

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Prevalence and antibiotic resistance profile of Shiga toxin-producing Escherichia coli isolated from diarrheal samples

Iranian Journal of Microbiology ◽

10.18502/ijm.v12i4.3931 ◽

2020 ◽

Author(s):

Farzad Esavand Heydari ◽

Mojtaba Bonyadian ◽

Hamdallah Moshtaghi ◽

Masoud Sami

Keyword(s):

Escherichia Coli ◽

Antibiotic Resistance ◽

Shiga Toxin ◽

Virulence Genes ◽

Enterohemorrhagic Escherichia Coli ◽

Diffusion Method ◽

Disk Diffusion Method ◽

Resistance Profile ◽

E Coli ◽

Antibiotic Resistance Profile

Background and Objectives: Enterohemorrhagic Escherichia coli (EHEC) causes bloody and non-bloody diarrhea, intestinal infection and extraintestinal complications in humans. This study aimed to isolate and evaluate the prevalence of E. coli O157: H7 and other Shiga toxin-producing E. coli (STEC) and identify the virulence genes (stx1, stx2, hly and eaeA) from patients with diarrhea. Also, the antibiotic resistance profile of the isolated strains was evaluated. Materials and Methods: A total of 100 stool samples were collected from patients with acute diarrhea referring to the hospital and clinics in Isfahan County, Iran. Phenotypic tests and PCR assay were used for detection of E. coli O157: H7 and other Shiga toxin-producing E. coli. The presence of virulence genes (stx1, stx2, hly and eaeA) were identified by PCR. The antibiotic resistance profile of the isolates was determined using the agar disk diffusion method. The results were analyzed descriptively by Sigma stat version 4 software. Results: Seventy - eight out of 100 samples (78%) were contaminated with E. coli. E. coli O157 was isolated from five samples (6.4%), of which only two strains (2.56%) were identified as E. coli O157: H7. According to the results, out of two E. coli O157: H7 isolates, one (50%) isolate contained eaeA and two isolates (100%) contained Stx1, Stx2, hlyA genes. Out of three (3.84%) E. coli O157: HN, one of the isolate (33.3%) contained stx1 and, two isolates (66.7%) were positive for hlyA genes. Also, the results revealed that six strains (7.69%) were non-O157: H7 STEC, of which two isolates (33.3%) contained stx1 and four isolates (66.7%) were positive for stx2 and hlyA genes. The results of antibiogram tests revealed that all of the STEC isolates (100%) were sensitive to imipenem followed by kanamycin, gentamicin and nitrofurantoin (91%). High resistance (54.5%) to ampicillin and ciprofloxacin was observed among the STEC isolates. Conclusion: The results of the current study showed that although the prevalence of E. coli O157: H7 was low among patients with diarrhea, the other STEC strains with relative resistance to antibiotics are more prevalent.

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Circulation of oxytetracycline- and ciprofloxacin-resistant commensal Escherichia coli strains in broiler chickens and farm environments, Bangladesh

Veterinary World ◽

10.14202/vetworld.2020.2395-2400 ◽

2020 ◽

Vol 13 (11) ◽

pp. 2395-2400

Author(s):

Avijit Das ◽

Pangkaj Kumar Dhar ◽

Avijit Dutta ◽

Mohammad Shah Jalal ◽

Priya Ghosh ◽

...

Keyword(s):

Escherichia Coli ◽

Food Chain ◽

Broiler Chickens ◽

Human Infection ◽

Diffusion Method ◽

Feed Water ◽

Disk Diffusion Method ◽

Chain Reactions ◽

E Coli ◽

Resistant Strains

Background and Aim: The emergence of antimicrobial resistance (AMR) in commensal organism, such as Escherichia coli of food animals, is an alarming issue for global health. It increases the possibility of transmitting AMR determinant(s) to human bacterial pathogens by transferable genetic materials, particularly by plasmids. Hence, it is important to know which resistant genes are being carried by commensal organisms in food chain in a country and their level of temporal loads. As a result, pre-emptive measures can be advocated with an aim to reduce their risks in their primary source of circulation which consequently would benefit the public health. Materials and Methods: Commensal E. coli strains from broiler chickens on randomly selected 30 farms and the farm environments were examined for the frequencies of isolation of resistant strains to oxytetracycline and ciprofloxacin. Five birds were randomly selected from each farm to collect cloacal swab samples (total of 150 samples). Furthermore, a total of 150 environmental samples comprising one each from feed, water, soil, litter, and litter damping site of each farm were screened for the isolation of commensal E. coli strains. Strains thus obtained were initially tested for their resistance to oxytetracycline and ciprofloxacin by Kirby–Bauer disk diffusion method. Oxytetracycline-resistant strains were further screened for the presence of resistance determining genes, namely, tetA, tetB, and tetC by uniplex polymerase chain reactions. Risks associated with the isolation frequency of oxytetracycline- and ciprofloxacin-resistant E. coli were also assessed by univariable logistic regression analysis. Results: The results revealed that all E. coli isolates, regardless of the source of origin, were resistant to oxytetracycline, while 78.4% (95% confidence interval [CI] 69.1-85.5%) showed resistance to ciprofloxacin. All the randomly selected (20) oxytetracycline-resistant strains harbored the tetA gene, whereas tetB and tetC were reported in three and two isolates, respectively. After univariable analysis, only one variable, that is, strain 1 of broiler chickens compared to two other strains was found to be positively associated with the isolation of ciprofloxacin-resistant E. coli (odds ratio 12.75 [95% CI 1.0- 157.1], p=0.047). Conclusion: Resistance emerged against oxytetracycline and ciprofloxacin in commensal E. coli strains circulating in live poultry and farm environments in Bangladesh seems to be very high. Thus, human infection with drug-resistant E. coli strains through food chain will critically compromise the therapeutic measures currently available.

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Molecular detection of blaCTX-M gene to predict phenotypic cephalosporin resistance and clinical outcome of Escherichia coli bloodstream infections in Vietnam

Annals of Clinical Microbiology and Antimicrobials ◽

10.1186/s12941-021-00466-3 ◽

2021 ◽

Vol 20 (1) ◽

Author(s):

Trinh Van Son ◽

Nguyen Dang Manh ◽

Ngo Tat Trung ◽

Dao Thanh Quyen ◽

Christian G. Meyer ◽

...

Keyword(s):

Escherichia Coli ◽

Clinical Outcome ◽

Bloodstream Infections ◽

Diffusion Method ◽

M Gene ◽

Disk Diffusion Method ◽

Phenotypic Resistance ◽

E Coli ◽

Multiplex Pcr Assay ◽

Esbl Producers

Abstract Background Blood stream infections (BSI) caused by Extended Spectrum Beta-Lactamases (ESBLs) producing Enterobacteriaceae is a clinical challenge leading to high mortality, especially in developing countries. In this study, we sought to describe the epidemiology of ESBL-producing Escherichia coli strains isolated from Vietnamese individuals with BSI, to investigate the concordance of genotypic-phenotypic resistance, and clinical outcome of ESBL E. coli BSI. Methods A total of 459 hospitalized patients with BSI were screened between October 2014 and May 2016. 115 E. coli strains from 115 BSI patients were isolated and tested for antibiotic resistance using the VITEK®2 system. The ESBL phenotype was determined by double disk diffusion method following the guideline of Clinical and Laboratory Standards Institute. Screening for beta-lactamase (ESBL and carbapenemase) genes was performed using a multiplex-PCR assay. Results 58% (67/115) of the E. coli strains were ESBL-producers and all were susceptible to both imipenem and meropenem. Resistance to third-generation cephalosporin was common, 70% (81/115) were cefotaxime-resistant and 45% (52/115) were ceftazidime-resistant. blaCTX-M was the most common ESBL gene detected (70%; 80/115) The sensitivity and specificity of blaCTX-M-detection to predict the ESBL phenotype was 87% (76–93% 95% CI) and 54% (39–48% 95% CI), respectively. 28%% (22/80) of blaCTX-M were classified as non-ESBL producers by phenotypic testing for ESBL production. The detection of blaCTX-M in ESBL-negative E. coli BSI was associated with fatal clinical outcome (27%; 6/22 versus 8%; 2/26, p = 0.07). Conclusion A high prevalence of ESBL-producing E. coli isolates harbouring blaCTX-M was observed in BSI patients in Vietnam. The genotypic detection of blaCTX-M may have added benefit in optimizing and guiding empirical antibiotic therapy of E. coli BSI to improve clinical outcome.

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