Characterization of cefotaxime-resistant urinary Escherichia coli from primary care in South-West England 2017–18

Abstract Objectives Third-generation cephalosporin-resistant Escherichia coli from community-acquired urinary tract infections are increasingly reported worldwide. We sought to determine and characterize the mechanisms of cefotaxime resistance employed by urinary E. coli obtained from primary care, over 12 months, in Bristol and surrounding counties in South-West England. Methods Cefalexin-resistant E. coli isolates were identified from GP-referred urine samples using disc susceptibility testing. Cefotaxime resistance was determined by subsequent plating onto MIC breakpoint plates. β-Lactamase genes were detected by PCR. WGS was performed on 225 isolates and analyses were performed using the Center for Genomic Epidemiology platform. Patient information provided by the referring general practices was reviewed. Results Cefalexin-resistant E. coli (n=900) isolates were obtained from urines from 146 general practices. Following deduplication by patient approximately 69% (576/836) of isolates were cefotaxime resistant. WGS of 225 isolates identified that the most common cefotaxime-resistance mechanism was blaCTX-M carriage (185/225), followed by plasmid-mediated AmpCs (pAmpCs) (17/225), AmpC hyperproduction (13/225), ESBL blaSHV variants (6/225) or a combination of both blaCTX-M and pAmpC (4/225). Forty-four STs were identified, with ST131 representing 101/225 isolates, within which clade C2 was dominant (54/101). Ciprofloxacin resistance was observed in 128/225 (56.9%) of sequenced isolates, predominantly associated with fluoroquinolone-resistant clones ST131 and ST1193. Conclusions Most cefalexin-resistant E. coli isolates were cefotaxime resistant, predominantly caused by blaCTX-M carriage. The correlation between cefotaxime resistance and ciprofloxacin resistance was largely attributable to the high-risk pandemic clones ST131 and ST1193. Localized epidemiological data provide greater resolution than regional data and can be valuable for informing treatment choices in the primary care setting.

Download Full-text

Characterisation of cefotaxime-resistant urinary Escherichia coli from primary care in South-West England 2017-2018

10.1101/701383 ◽

2019 ◽

Cited By ~ 6

Author(s):

Jacqueline Findlay ◽

Virginia C. Gould ◽

Paul North ◽

Karen E. Bowker ◽

O. Martin Williams ◽

...

Keyword(s):

Escherichia Coli ◽

Primary Care ◽

Epidemiological Data ◽

Diagnostic Procedures ◽

Generation Cephalosporin ◽

Common Mechanism ◽

Clear Correlation ◽

E Coli ◽

South West ◽

Tract Infections

AbstractObjectivesThird-generation cephalosporin-resistant Escherichia coli from community-acquired urinary tract infections (UTI) have been increasingly reported worldwide. In this study we sought to determine and characterise the mechanisms of cefotaxime-resistance (CTX-R) employed by urinary E. coli obtained from primary care over a 12-month period, in Bristol and surrounding counties in the South West of England.MethodsCephalexin resistant (Ceph-R) E. coli isolates were identified directly from general practice (GP) referred urine samples using disc susceptibility testing as per standard diagnostic procedures. CTX-R was determined by subsequent plating onto MIC breakpoint plates. β-Lactamase genes were detected by PCR. Whole Genome Sequencing (WGS) was performed on 225 urinary isolates and analyses were performed using the Centre for Genomic Epidemiology platform. Patient information provided by the referring GPs was reviewed.ResultsDuring the study period, Ceph-R E. coli (n=900) were obtained directly from urines from 146 GPs. Seventy-percent (626/900) of isolates were CTX-R. WGS of 225 non-duplicate isolates identified that the most common mechanism of CTX-R was blaCTX-M carriage (185/225; 82.2%), predominantly blaCTX-M-15 (114/185; 61.6%), followed by carriage of plasmid mediated AmpCs (pAmpCs) (17/225; 7.6%), ESBL blaSHV variants (6/225; 2.7%), AmpC hyperproduction (13/225; 5.8%), or a combination of both blaCTX-M and pAmpC carriage (4/225; 1.8%). Forty-four sequence types (STs) were identified with ST131 representing 101/225 (45.0%) of sequenced isolates, within which the blaCTX-M-15-positive clade C2 was dominant (54/101; 53.5%). Ciprofloxacin-resistance (CIP-R) was observed in 128/225 (56.9%) of sequenced CTX-R isolates – predominantly associated with fluoroquinolone-resistant clones ST131 and ST1193.ConclusionsMost Ceph-R urinary E. colis were CTX-R, predominantly caused by blaCTX-M carriage. There was a clear correlation between CTX-R and CIP-R, largely attributable to the dominance of the high-risk pandemic clones, ST131 and ST1193 in this study. This localised epidemiological data provides greater resolution than regional data and can be valuable for informing treatment choices in the primary care setting.

Download Full-text

Use of a primary care online consultation system, by whom, when and why: evaluation of a pilot observational study in 36 general practices in South West England

BMJ Open ◽

10.1136/bmjopen-2017-016901 ◽

2017 ◽

Vol 7 (11) ◽

pp. e016901 ◽

Cited By ~ 30

Author(s):

Hannah B Edwards ◽

Elsa Marques ◽

William Hollingworth ◽

Jeremy Horwood ◽

Michelle Farr ◽

...

Keyword(s):

Primary Care ◽

Observational Study ◽

Waiting Times ◽

Telephone Consultation ◽

Face To Face ◽

Online Consultation ◽

South West ◽

Consultation System ◽

General Practices ◽

South West England

ObjectivesEvaluation of a pilot study of an online consultation system in primary care. We describe who used the system, when and why, and the National Health Service costs associated with its use.Design15-month observational study.SettingPrimary care practices in South West England.Results36 General practices covering 396 828 patients took part in the pilot. The online consultation website was viewed 35 981 times over the pilot period (mean 9.11 visits per 1000 patients per month). 7472 patients went on to complete an ‘e-consultation’ (mean 2.00 online consultations per 1000 patients per month). E-consultations were mainly performed on weekdays and during normal working hours. Patient records (n=485) were abstracted for eight practices and showed that women were more likely to use e-consultations than men (64.7% vs 35.3%) and users had a median age of 39 years (IQR 30–50). The most common reason for an e-consultation was an administrative request (eg, test results, letters and repeat prescriptions (22.5%)) followed by infections/immunological issues (14.4%). The majority of patients (65.2%) received a response within 2 days. The most common outcome was a face-to-face (38%) or telephone consultation (32%). The former were more often needed for patients consulting about new conditions (OR 1.56, 95% CI 1.05 to 2.27, p=0.049). The average cost of a practice’s response to an e-consultation was £36.28, primarily triage time and resulting face-to-face/telephone consultations needed.ConclusionsUse of e-consultations is very low, particularly at weekends. Unless this can be improved, any impact on staff workload and patient waiting times is likely to be negligible. It is possible that use of e-consultations increases primary care workload and costs. Online consultation systems could be developed to improve efficiency both for staff and patients. These findings have implications for software developers as well as primary care services and policy-makers who are considering investing in online consultation systems.

Download Full-text

Selection and co-selection of antibiotic resistances among Escherichia coli by antibiotic use in primary care: an ecological analysis

10.1101/573360 ◽

2019 ◽

Cited By ~ 1

Author(s):

Koen B Pouwels ◽

Berit Muller-Pebody ◽

Timo Smieszek ◽

Susan Hopkins ◽

Julie V Robotham

Keyword(s):

Escherichia Coli ◽

Primary Care ◽

Antibiotic Resistance ◽

Urinary Tract ◽

Respiratory Tract ◽

Urinary Tract Infections ◽

Respiratory Tract Infections ◽

Antibiotic Use ◽

E Coli ◽

Tract Infections

AbstractThe majority of studies that link antibiotic usage and resistance focus on simple associations between the resistance against a specific antibiotic and the use of that specific antibiotic. However, the relationship between antibiotic use and resistance is more complex. Here we evaluate which antibiotics, including those mainly prescribed for respiratory tract infections, are associated with increased resistance among Escherichia coli isolated from urinary samples.Monthly primary care prescribing data were obtained from National Health Service (NHS) Digital. Positive E. coli records from urine samples in English primary care (n=888,207) between April 2014 and January 2016 were obtained from the Second Generation Surveillance System. Elastic net regularization was used to evaluate associations between prescribing of different antibiotic groups and resistance against amoxicillin, cephalexin, ciprofloxacin, co-amoxiclav and nitrofurantoin at the clinical commissioning group (CCG) level. England is divided into 209 CCGs, with each NHS practice prolonging to one CCG.Amoxicillin prescribing (measured in DDD/ 1000 inhabitants / day) was positively associated with amoxicillin (RR 1.03, 95% CI 1.01 – 1.04) and ciprofloxacin (RR 1.09, 95% CI 1.04 – 1.17) resistance. In contrast, nitrofurantoin prescribing was associated with lower levels of resistance to amoxicillin (RR 0.92, 95% CI 0.84 – 0.97). CCGs with higher levels of trimethoprim prescribing also had higher levels of ciprofloxacin resistance (RR 1.34, 95% CI 1.10 – 1.59).Amoxicillin, which is mainly (and often unnecessarily) prescribed for respiratory tract infections is associated with increased resistance against various antibiotics among E. coli causing urinary tract infections. Our findings suggest that when predicting the potential impact of interventions on antibiotic resistances it is important to account for use of other antibiotics, including those typically used for other indications.Author summaryAntibiotic resistance is increasingly recognised as a threat to modern healthcare. Effective antibiotics are crucial for treatment of serious bacterial infections and are necessary to avoid that complicated surgical procedures and chemotherapy becoming life-threatening. Antibiotic use is one of the main drivers of antibiotic resistance. The majority of antibiotic prescriptions are prescribed in primary care, however, a large proportion of these antibiotic prescriptions are unnecessary. Understanding which antibiotics are causing antibiotic resistance to what extent is needed to prevent under- or over-investment in interventions lowering use of specific antibiotics, such as rapid diagnostic tests for respiratory tract infection.We have statistically evaluated which antibiotics are associated with higher and lower levels of antibiotic resistance against common antibiotics among Escherichia coli bacteria sampled from the urinary tract by comparing antibiotic prescribing and resistance in different geographical areas in England. Our model shows that amoxicillin, the most commonly used antibiotic in England and mainly used for respiratory tract infections, is associated with increased resistance against several other antibiotics among bacteria causing urinary tract infections. The methods used in this study, that overcome several of the limitations of previous studies, can be used to explore the complex relationships between antibiotic use and antibiotic resistance in other settings.

Download Full-text

Plasmid-Mediated OqxAB Is an Important Mechanism for Nitrofurantoin Resistance in Escherichia coli

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.02156-15 ◽

2015 ◽

Vol 60 (1) ◽

pp. 537-543 ◽

Cited By ~ 28

Author(s):

Pak-Leung Ho ◽

Ka-Ying Ng ◽

Wai-U Lo ◽

Pierra Y. Law ◽

Eileen Ling-Yi Lai ◽

...

Keyword(s):

Escherichia Coli ◽

Efflux Pump ◽

Geometric Mean ◽

Resistance Mechanism ◽

Multidrug Resistant ◽

Resistance Mechanisms ◽

Content Type ◽

E Coli ◽

High Level ◽

Tract Infections

ABSTRACTIncreasing consumption of nitrofurantoin (NIT) for treatment of acute uncomplicated urinary tract infections (UTI) highlights the need to monitor emerging NIT resistance mechanisms. This study investigated the molecular epidemiology of the multidrug-resistant efflux geneoqxABand its contribution to nitrofurantoin resistance by usingEscherichia coliisolates originating from patients with UTI (n= 205; collected in 2004 to 2013) and food-producing animals (n= 136; collected in 2012 to 2013) in Hong Kong. TheoqxABgene was highly prevalent among NIT-intermediate (11.5% to 45.5%) and -resistant (39.2% to 65.5%) isolates but rare (0% to 1.7%) among NIT-susceptible (NIT-S) isolates. In our isolates, theoqxABgene was associated with IS26and was carried by plasmids of diverse replicon types. Multilocus sequence typing revealed that the clones ofoqxAB-positiveE. coliwere diverse. The combination ofoqxABandnfsAmutations was found to be sufficient for high-level NIT resistance. Curing ofoqxAB-carrying plasmids from 20 NIT-intermediate/resistant UTI isolates markedly reduced the geometric mean MIC of NIT from 168.9 μg/ml to 34.3 μg/ml. In the plasmid-cured variants, 20% (1/5) of isolates withnfsAmutations were NIT-S, while 80% (12/15) of isolates withoutnfsAmutations were NIT-S (P= 0.015). The presence of plasmid-basedoqxABincreased the mutation prevention concentration of NIT from 128 μg/ml to 256 μg/ml and facilitated the development of clinically important levels of nitrofurantoin resistance. In conclusion, plasmid-mediatedoqxABis an important nitrofurantoin resistance mechanism. There is a great need to monitor the dissemination of this transferable multidrug-resistant efflux pump.

Download Full-text

Trends in the diagnosis and management of hypertension: repeated primary care survey in South West England

British Journal of General Practice ◽

10.3399/bjgp17x690461 ◽

2017 ◽

Vol 67 (658) ◽

pp. e306-e313 ◽

Cited By ~ 12

Author(s):

Natasha Mejzner ◽

Christopher E Clark ◽

Lindsay FP Smith ◽

John L Campbell

Keyword(s):

Primary Care ◽

Allied Health Professionals ◽

Nice Guidelines ◽

Care Organisation ◽

South West ◽

Care Survey ◽

Quality And Outcomes ◽

General Practices ◽

Diagnosis Of Hypertension ◽

South West England

BackgroundPrevious surveys identified a shift to nurse-led care in hypertension in 2010. In 2011 the National Institute for Health and Care Excellence (NICE) recommended ambulatory (ABPM) or home (HBPM) blood pressure (BP) monitoring for diagnosis of hypertension.AimTo survey the organisation of hypertension care in 2016 to identify changes, and to assess uptake of NICE diagnostic guidelines.Design and settingQuestionnaires were distributed to all 305 general practices in South West England.MethodResponses were compared with previous rounds (2007 and 2010). Data from the 2015 Quality and Outcomes Framework (QOF) were used to compare responders with non-responders, and to explore associations of care organisation with QOF achievement.ResultsOne-hundred-and-seventeen practices (38%) responded. Responders had larger list sizes and greater achievement of the QOF target BP ≤150/90 mmHg. Healthcare assistants (HCAs) now monitor BP in 70% of practices, compared with 37% in 2010 and 19% in 2007 (P<0.001). Nurse prescribers alter BP medication in 26% of practices (11% in 2010, none in 2007; P<0.001). Of the practices, 89% have access to ABPM, but only 71% report confidence in interpreting results. Also, 87% offer HBPM, with 93% of these confident in interpreting results.ConclusionIn primary care BP monitoring has devolved from GPs and nurses to HCAs. One in 10 practices are not implementing NICE guidelines on ABPM and HBPM for diagnosis of hypertension. Most practices express confidence interpreting HBPM results but less so with ABPM. The need for education and quality assurance for allied health professionals is highlighted, and for training in ABPM interpretation for GPs.

Download Full-text

Persistent Pandemic Lineages of Uropathogenic Escherichia coli in a College Community from 1999 to 2017

Journal of Clinical Microbiology ◽

10.1128/jcm.01834-17 ◽

2018 ◽

Vol 56 (4) ◽

pp. e01834-17 ◽

Cited By ~ 22

Author(s):

Reina Yamaji ◽

Julia Rubin ◽

Erika Thys ◽

Cindy R. Friedman ◽

Lee W. Riley

Keyword(s):

Escherichia Coli ◽

Drug Susceptibility ◽

Uropathogenic Escherichia Coli ◽

Drug Resistant ◽

Content Type ◽

E Coli ◽

College Community ◽

Small Set ◽

Ciprofloxacin Resistance ◽

Tract Infections

ABSTRACT The incidence of drug-resistant community-acquired urinary tract infections (CA-UTI) continues to increase worldwide. In 1999 to 2000, a single lineage of uropathogenic Escherichia coli (UPEC) sequence type 69 (ST69) caused 51% of trimethoprim-sulfamethoxazole-resistant UTI in a Northern California university community. We compared the clonal distributions of UPEC and its impact on antimicrobial resistance prevalence in the same community during two periods separated by 17 years. We analyzed E. coli isolates from urine samples from patients with symptoms of UTI who visited a health service between September 2016 and May 2017 and compared them to UPEC isolates collected similarly between October 1999 and March 2000. Isolates were tested for antimicrobial drug susceptibility and genotyped by multilocus sequence typing. In 1999 to 2000, strains belonging to ST95, ST127, ST73, ST69, ST131, and ST10 caused 125 (56%) of 225 UTI cases, while the same STs caused 148 (64%) of 233 UTI cases in 2016 to 2017. The frequencies of ampicillin resistance and ciprofloxacin resistance rose from 24.4% to 41.6% (P < 0.001) and from 0.9% to 5.1% (P < 0.003), respectively. The six STs accounted for 78.6% and 72.7% of these increases, respectively. Prevalence of drug-resistant UTI in this community appears to be largely influenced by a small set of dominant UPEC STs circulating in the same community 17 years apart. Further research to determine the origin and reasons for persistence of these dominant genotypes is necessary to combat antimicrobial-resistant CA-UTI.

Download Full-text

Avian Pathogenic Escherichia coli (APEC): An Overview of Virulence and Pathogenesis Factors, Zoonotic Potential, and Control Strategies

Pathogens ◽

10.3390/pathogens10040467 ◽

2021 ◽

Vol 10 (4) ◽

pp. 467

Author(s):

Dipak Kathayat ◽

Dhanashree Lokesh ◽

Sochina Ranjit ◽

Gireesh Rajashekara

Keyword(s):

Escherichia Coli ◽

Current Status ◽

Neonatal Meningitis ◽

Clear Understanding ◽

Zoonotic Potential ◽

Secretion Systems ◽

Avian Pathogenic Escherichia Coli ◽

E Coli ◽

Pathogenic Escherichia Coli ◽

Tract Infections

Avian pathogenic Escherichia coli (APEC) causes colibacillosis in avian species, and recent reports have suggested APEC as a potential foodborne zoonotic pathogen. Herein, we discuss the virulence and pathogenesis factors of APEC, review the zoonotic potential, provide the current status of antibiotic resistance and progress in vaccine development, and summarize the alternative control measures being investigated. In addition to the known virulence factors, several other factors including quorum sensing system, secretion systems, two-component systems, transcriptional regulators, and genes associated with metabolism also contribute to APEC pathogenesis. The clear understanding of these factors will help in developing new effective treatments. The APEC isolates (particularly belonging to ST95 and ST131 or O1, O2, and O18) have genetic similarities and commonalities in virulence genes with human uropathogenic E. coli (UPEC) and neonatal meningitis E. coli (NMEC) and abilities to cause urinary tract infections and meningitis in humans. Therefore, the zoonotic potential of APEC cannot be undervalued. APEC resistance to almost all classes of antibiotics, including carbapenems, has been already reported. There is a need for an effective APEC vaccine that can provide protection against diverse APEC serotypes. Alternative therapies, especially the virulence inhibitors, can provide a novel solution with less likelihood of developing resistance.

Download Full-text

Antimicrobial activity of Syzygium aromaticum L. essential oil on extended-spectrum beta-lactamases-producing Escherichia coli

Bulletin of the National Research Centre ◽

10.1186/s42269-020-00458-x ◽

2020 ◽

Vol 44 (1) ◽

Author(s):

E. L. Mejía-Argueta ◽

J. G. Santillán-Benítez ◽

M. M. Canales-Martinez ◽

A. Mendoza-Medellín

Keyword(s):

Escherichia Coli ◽

Essential Oil ◽

Genetic Material ◽

Gastrointestinal Diseases ◽

Syzygium Aromaticum ◽

Antibiotic Resistant ◽

Plant Essential Oils ◽

E Coli ◽

Extended Spectrum ◽

Tract Infections

Abstract Background To test the antimicrobial potential of clove essential oil that has been less investigated on antimicrobial-resistant organisms (extended-spectrum β-lactamase-ESBL-producing Escherichia coli), we collected 135 ESBL-producing Escherichia coli strains given that E. coli is the major organism increasingly isolated as a cause of complicated urinary and gastrointestinal tract infections, which remains an important cause of therapy failure with antibiotics for the medical sector. Then, in this study, we evaluated the relationship between the antibacterial potential activity of Syzygium aromaticum essential oil (EOSA) and the expression of antibiotic-resistant genes (SHV-2, TEM-20) in plasmidic DNA on ESBL-producing E. coli using RT-PCR technique. Results EOSA was obtained by hydrodistillation. Using Kirby-Baüer method, we found that EOSA presented a smaller media (mean = 15.59 mm) in comparison with chloramphenicol (mean = 17.73 mm). Thus, there were significant differences (p < 0.0001). Furthermore, EOSA had an antibacterial activity, particularly on ECB132 (MIC: 10.0 mg/mL and MBC: 80.0 mg/mL), and a bacteriostatic effect by bactericidal kinetic. We found that the expression of antibiotic-resistant gene blaTEM-20 was 23.52% (4/17 strains) and no expression of blaSHV-2. EOSA presented such as majority compounds (eugenol, caryophyllene) using the GC–MS technique. Conclusions Plant essential oils and their active ingredients have potentially high bioactivity against a different target (membranes, cytoplasm, genetic material). In this research, EOSA might become an important adjuvant against urinary and gastrointestinal diseases caused by ESBL-producing E. coli.

Download Full-text

1671. Diagnosis and management of Escherichia coli bacteriuria at a Veterans Affairs hospital

Open Forum Infectious Diseases ◽

10.1093/ofid/ofaa439.1849 ◽

2020 ◽

Vol 7 (Supplement_1) ◽

pp. S821-S821

Author(s):

Niyati H Shah ◽

Brooke K Decker ◽

Gaetan Sgro ◽

Monique Y Boudreaux-Kelly ◽

...

Keyword(s):

Escherichia Coli ◽

Antibiotic Treatment ◽

High Yield ◽

Comorbid Conditions ◽

Provider Education ◽

Transmitted Infection ◽

Physician Practices ◽

E Coli ◽

Diagnosis And Management ◽

Tract Infections

Abstract Background The IDSA recommends against screening for and treating ASB in all patients except for those pregnant or undergoing urologic procedures. Nevertheless, antibiotic treatment of ASB is widespread. We conducted a retrospective analysis of physician practices in diagnosis and management of Escherichia coli (E. coli) ASB in a male Veteran population, and compared outcomes in ASB patients treated or not treated with antibiotics. Methods Patients with an E. coli positive urine culture during an ED visit or inpatient admission from 01/2017 to 12/2017 were screened. Patients admitted to the intensive care unit or diagnosed with a sexually transmitted infection, pyelonephritis, prostatitis, or epididymitis/orchitis were excluded. A total of 163 patients were included. Demographics, clinical comorbidities and severity of illness, and outcomes were compared in ASB patients managed with or without antibiotics. ANOVA and Chi-square or Fisher’s exact tests were utilized for comparing measurements. Results ASB was present in 92/163 patients. The majority (74%) of these patients were given antibiotics. Regardless of qSOFA score or alternate infection, there were no significant differences in outcomes between ASB patients treated or not treated with antibiotics: 3-month mortality (15% vs 21%; p = 0.53), emergence of newly resistant bacterial pathogens (7% vs 13%; p = 0.43), recurrent urinary tract infections (61% vs 50%; p = 0.72), clearance of urinary pathogens (75% vs 58%; p = 0.45), length of hospital stay (7 vs 6 days, p = 0.67). Factors that were predictive of physician treatment of ASB included patient comorbid conditions such as benign prostatic hyperplasia, pyuria, and the absence of hematuria. The incidence of adverse events with antibiotic treatment of ASB was low. Conclusion The rate of antibiotic treatment of E. coli ASB in male veterans is high. Outcomes do not differ among ASB patients managed with or without antibiotics. Future studies examining outcomes in patients prescribed antibiotics for multiple episodes of ASB may yield differences, particularly in emergence of resistant pathogens. Focusing on patients with comorbid conditions who are not critically ill would be a high yield target for provider education to reduce ASB treatment. Disclosures All Authors: No reported disclosures

Download Full-text

Iron Acquisition of Urinary Tract Infection Escherichia coli Involves Pathogenicity in Caenorhabditis elegans

Microorganisms ◽

10.3390/microorganisms9020310 ◽

2021 ◽

Vol 9 (2) ◽

pp. 310

Author(s):

Masayuki Hashimoto ◽

Yi-Fen Ma ◽

Sin-Tian Wang ◽

Chang-Shi Chen ◽

Ching-Hao Teng

Keyword(s):

Escherichia Coli ◽

Urinary Tract ◽

Caenorhabditis Elegans ◽

Large Scale ◽

Iron Acquisition ◽

Infection Model ◽

High Throughput Analysis ◽

E Coli ◽

C Elegans ◽

Tract Infections

Uropathogenic Escherichia coli (UPEC) is a major bacterial pathogen that causes urinary tract infections (UTIs). The mouse is an available UTI model for studying the pathogenicity; however, Caenorhabditis elegans represents as an alternative surrogate host with the capacity for high-throughput analysis. Then, we established a simple assay for a UPEC infection model with C. elegans for large-scale screening. A total of 133 clinically isolated E. coli strains, which included UTI-associated and fecal isolates, were applied to demonstrate the simple pathogenicity assay. From the screening, several virulence factors (VFs) involved with iron acquisition (chuA, fyuA, and irp2) were significantly associated with high pathogenicity. We then evaluated whether the VFs in UPEC were involved in the pathogenicity. Mutants of E. coli UTI89 with defective iron acquisition systems were applied to a solid killing assay with C. elegans. As a result, the survival rate of C. elegans fed with the mutants significantly increased compared to when fed with the parent strain. The results demonstrated, the simple assay with C. elegans was useful as a UPEC infectious model. To our knowledge, this is the first report of the involvement of iron acquisition in the pathogenicity of UPEC in a C. elegans model.

Download Full-text