Diarrheagenic Escherichia coli Pathotypes From Children Younger Than 5 Years in Kano State, Nigeria

Diarrhoeagenic Escherichia coli associated with childhood diarrhoea in Osun state, Nigeria

INTRODUCTION

Diarrhoea is a major public health concern in developing countries, usually exacerbated by poor water, sanitation and hygiene but its aetiology is under-studied, particularly away from capital cities. We identified diarrhoeagenic Escherichia coli (DEC) from stools collected in Ile-Ife and Ilesa, Osun state, Nigeria and determined their antibiotic resistance profiles.

METHODS

Stool samples from 167 children with diarrhoea and 334 controls under the age of 5 years were cultured for Escherichia coli and Salmonella. Bacterial isolates were identified biochemically and DEC were identified by PCR. Antimicrobial susceptibility testing was by modified Kirby-Bauer disc diffusion method in accordance with the CLSI guidelines. Data were analyzed using Chi-square and Fisher's exact tests.

RESULT

Diarrhoea infection is significantly high among children under 12 months (p = 0.002), caregivers without at least primary school education (p = 0.006), breastfeeding for under 6 months (p˂0.001), and caregivers who were siblings (p = 0.004). DEC was detected in 69(41.3%) cases but only 86(25.7%) controls (p < 0.001) and more commonly recovered during the wet season (p < 0.001). Enterotoxigenic E. coli (p = 0.031), enteropathogenic E. coli (p = 0.031) and Shiga-toxin-producing E. coli (p = 0.044) were recovered more commonly from cases than controls. DEC from patients with diarrhoea were commonly resistant to sulphonamides (91.3%), trimethoprim (82.6%), and ampicillin (78.3%) but were largely susceptible to quinolones and carbapenems (97.1%).

CONCLUSION

Enteropathogenic, enterotoxigenic and Shiga toxin-producing E. coli are associated with diarrhoea in our setting, and show considerable resistance to first-line antimicrobials. Risk factors for DEC diarrhoea include infancy, inadequate breastfeeding and caregivers with education below primary school.

Comparative prevalence of diarrheagenic Escherichia coli between children below five years with close contact to food animals in Kisumu County, Kenya

Introduction

diarrheal infections in young children below five years and food animals are caused by diarrheagenic Escherichia coli strains. The study focused on understanding the association between DEC pathotypes in children below five years and food animals to establish the possibility of zoonotic transmission.

Methods

samples from 150 children who presented with diarrhea at the Kisumu County Hospital and 100 stool samples from food animals were collected and processed using culture methods. Molecular identification of the pathotypes was assayed using a primer-specific polymerase chain reaction that targeted the six virulence genes related to the diarrheagenic Escherichia coli pathotypes.

Results

one hundred and fifty-six study subjects (100 children samples and 56 food animals) samples were positive for E. coli polymerase chain reaction detection revealed a prevalence of (23%) among children below five years and a prevalence of (20%) among the food animals. Children samples showed Enteroaggregative Escherichia coli, having high phenotypic frequency of (12%) followed by Enterotoxigenic Escherichia coli, (5.3%) and Enteropathogenic Escherichia (3.3%) the least being mixed infections Enteroaggregative/Enterotoxigenic Escherichia coli and Enteroaggregative/Enteropathogenic Escherichia coli with (1.3%) respectively. The food animals found in children homesteads were detected to harbor pathogenic strains of E. coli. Enteropathogenic Escherichia coli was the most prevalent pathotypes detected in cattle (13%) followed by Enterotoxigenic Escherichia coli detected in goats at (4%) and poultry at (3%).

Conclusion

presence of diarrheagenic Escherichia coli in food animals could serve as reservoirs of transmitting these bacteria to children below five years.

Epidemiology and Risk Factors for Diarrheagenic Escherichia coli Carriage among Children in Northern Ibadan, Nigeria

Diarrhea is a leading cause of childhood morbidity in Africa, but few studies, focus on bacterial diarrheal etiology including multicountry studies that typically excluded Nigeria. We collected stool specimens from 477 children under 5 years of age, 120 with diarrhea, who were enrolled in our prospective case-control study between November 2015 and August 2019. All were attending primary health clinics on the northern outskirts of Ibadan. Up to 10 Escherichia coli isolates were obtained per specimen, and at least three of them were sequenced using Illumina whole-genome sequence technology. Genomes were assembled using SPAdes and evaluated for quality using QUAST. VirulenceFinder was used to identify virulence genes. The microbiological quality of water from 14 wells within the study area was assessed using total and coliform counts. Diarrheagenic E. coli (DEC) were isolated from 79 (65.8%) cases and 217 (60.8%) control children. A number of hybrid DEC pathotypes, Salmonella spp., Yersinia spp., and all DEC pathotypes except Shiga toxin-producing E. coli were detected, but no pathogen showed association with disease (P > 0.05). Enterotoxigenic E. coli were more commonly recovered from children without diarrhea aged below 6 months but exclusively detected in children with diarrhea aged over 9 months. Temporally linked, genetically similar enteroaggregative E. coli were isolated from children in different households in eight instances. No well water sample drawn in the study was potable. Children in northern Ibadan were commonly colonized with DEC. Access to water, proper sanitation, and vaccination against the prevailing pathogens may be critical for protecting children from the less overt consequences of enteric pathogen carriage.

Molecular Characterization of Hetero-Pathogenic and Diarrheagenic Escherichia coli Pathotypes in Diarrheic Children under Five Years and Exposure Environment in Ogun State, South-West Nigeria

BACKGROUND

Diarrheagenic Escherichia coli (DEC) is one of the most common etiological agents of moderate-to-severe diarrhea in Low- and Middle-Income Countries (LMICs). Therefore, determining the source(s) of DEC in index cases and exposure environment is important for developing a prevention strategy. The current study aims to investigate the prevalence of DEC among children under 5 years and their exposure environment in Ogun State, Nigeria.

METHODS

Samples from 228 diarrheic children and their exposure environment were collected and screened for E. coli. Bio-chemically compatible distinct colonies were molecularly characterized using a 7-virulence-gene multiplex PCR with virulence factors (VFs) indicative of four pathotypes of E. coli: enterotoxigenic (ETEC), verotoxigenic (VTEC), enteropathogenic (EPEC), and enteroinvasive (EIEC). Representative pathotypes were subjected to antimicrobial susceptibility and over-expressed efflux pump assays.

RESULTS

One or more VFs typical of specific pathotypes were detected in 25.9% (59/228) diarrhea cases consisting of ETEC (21.5%) and EPEC (0.4%), while hetero-pathogenic pathotypes were found in 4.0% of cases. Of the food sources, 27.9% (101/362) were positive for DEC, of which ETEC accounted for 21.0%, VTEC 1.9%, EPEC 0.6%, EIEC 0.6%, and hetero-pathogenic pathotypes were 3.9%. Furthermore, ETEC was the only pathotype detected in the wastewater (4/183). Interestingly, the consumption of street-vended foods was the most significant (p = 0.04) risk factor for DEC infection in the study area. A total of 73.3% of selected DEC pathotypes showed resistance to antimicrobials, while 27.5% demonstrated over-expression of efflux pump activity.

CONCLUSION

The high prevalence of ETEC across all sources and the occurrence of hetero-pathogenic DEC in diarrheic children and food sources emphasizes the importance of establishing a better strategy for the control and prevention of diarrhea among children in low- and medium-income households.

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

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

Spatial diarrheal disease risks and antibiogram diversity of diarrheagenic Escherichia coli in selected access points of the Buffalo River, South Africa

Freshwater sources, often used for domestic and agricultural purposes in low- and middle-income countries are repositories of clinically significant bacterial pathogens. These pathogens are usually diversified in their antibiogram profiles posing public health threats. This study evaluated the spatial diarrhoeal disease risk and antibiogram diversity of diarrheagenic Escherichia coli (DEC) in four access points of the Buffalo River, Eastern Cape Province, South Africa using standard epidemiological, culture, and molecular methods. The diarrhoeal disease risk was characterised using the Monte Carlo simulation, while the antibiogram diversity was assessed using the species observed Whittaker's single alpha-diversity modelling. E. coli mean count was highest in King William's Town dam [16.0 × 102 CFU/100ml (SD: 100.0, 95% CI: 13.5 × 102 to 18.5 × 102)]. Enterohemorrhagic E. coli (stx1/stx2) was the most prevalent DEC pathotype across the study sites. A high diarrhoeal disease risk of 25.0 ×10-2 exceeding the World Health Organization's standard was recorded across the study sites. The average single and multiple antimicrobial resistance indices of the DEC to test antimicrobials were highest in the Eluxolzweni dam [0.52 (SD: 0.25, 95% CI: 0.37 to 0.67)] and King William's Town dam [0.42 (SD: 0.25, 95% CI: 0.27 to 0.57)] respectively. The prevalent antibiotic resistance genes detected were tetA, blaFOX and blaMOX plasmid-mediated AmpC, blaTEM and blaSHV extended-spectrum β-lactamases, which co-occurred across the study sites on network analysis. The phenotypic and genotypic resistance characteristics of the DEC in Maden dam (r = 0.93, p<0.00), Rooikrantz dam (r = 0.91, p<0.00), King William's Town dam (r = 0.83, p = 0.0), and Eluxolzweni dam (r = 0.91, p<0.00) were strongly correlated. At least, three phylogenetic clades of the DEC with initial steep descent alpha-diversity curves for most of the test antimicrobials were observed across the study sites, indicating high diversity. The occurrence of diversified multi drug resistant DEC with diarrhoeal disease risks in the Buffalo River substantiates the role surface water bodies play in the dissemination of drug-resistant bacterial pathogens with public health implications.

Molecular epidemiology and antimicrobial susceptibility of diarrheagenic Escherichia coli isolated from children under age five with and without diarrhea in Central Ethiopia

BACKGROUND

Diarrhea is a serious health problem in children, with the highest mortality rate in sub-Saharan Africa. Diarrheagenic Escherichia coli (DEC) is among the major bacterial causes of diarrhea in children under age five. The present study aims to determine molecular epidemiology and antimicrobial resistance profiles of DEC and identify contributing factors for acquisition among children under age five in Central Ethiopia.

METHODS

A health facility-centered cross-sectional study was conducted in Addis Ababa and Debre Berhan, Ethiopia, from December 2020 to August 2021. A total of 476 specimens, 391 from diarrheic and 85 from non-diarrheic children under age five were collected. Bacterial isolation and identification, antimicrobial susceptibility, and pathotype determination using polymerase chain reaction (PCR) were done.

RESULTS

Of the 476 specimens analyzed, 89.9% (428/476) were positive for E. coli, of which 183 were positive for one or more genes coding DEC pathotypes. The overall prevalence of the DEC pathotype was 38.2% (183/476). The predominant DEC pathotype was enteroaggregative E. coli (EAEC) (41.5%, 76/183), followed by enterotoxigenic E. coli (21.3%, 39/183), enteropathogenic E. coli (15.3%, 28/183), enteroinvasive E. coli (12.6%, 23/183), hybrid strains (7.1%, 13/183), Shiga toxin-producing E. coli (1.6%, 3/183), and diffusely-adherent E. coli (0.6%, 1/183). DEC was detected in 40.7% (159/391) of diarrheic and 28.2% (24/85) in non-diarrheic children (p = 0.020). The majority of the DEC pathotypes were resistant to ampicillin (95.1%, 174/183) and tetracycline (91.3%, 167/183). A higher rate of resistance to trimethoprim-sulfamethoxazole (58%, 44/76), ciprofloxacin (22%, 17/76), ceftazidime and cefotaxime (20%, 15/76) was seen among EAEC pathotypes. Multidrug resistance (MDR) was detected in 43.2% (79/183) of the pathotypes, whereas extended spectrum ß-lactamase and carbapenemase producers were 16.4% (30/183) and 2.2% (4/183), respectively.

CONCLUSION

All six common DEC pathotypes that have the potential to cause severe diarrheal outbreaks were found in children in the study area; the dominant one being EAEC with a high rate of MDR.

Diarrhoeal pathogens in the stools of children living with HIV in Ibadan, Nigeria

Introduction

Diarrhoea can be debilitating in young children. Few aetiological investigations in Africans living with human immunodeficiency virus (HIV) have been performed since antiretrovirals became widely available.

Methods

Stool specimens from children with diarrhoea living with HIV, and HIV-uninfected controls, recruited at two hospitals in Ibadan, Nigeria, were screened for parasites and occult blood, and cultured for bacteria. Following biochemical identification of at least five colonies per specimen, diarrhoeagenic Escherichia coli and Salmonella were confirmed by PCR. Data were line-listed and comparisons were made using Fisher's Exact test.

Results

Only 10 children living with HIV could be enrolled during the 25-month study period and 55 HIV-uninfected children with diarrhoea were included for comparison. The most common pathogens overall were enteroaggregative E. coli (18/65, 27.7%), enteroinvasive E. coli (10/65, 15.4%), Cryptosporidium parvum (8/65, 12.3%) and Cyclospora cayetanensis (7/65, 10.8%). At least one pathogen was detected from seven of ten children living with HIV and 27 (49.1%) HIV-uninfected children. Parasite detection was associated with HIV positive status (p=0.03) with C. parvum specifically recovered more commonly from children living with HIV (p=0.01). Bacterial-parasite pathogen combinations were detected in specimens from four of ten children living with HIV but only 3(5.5%) HIV-uninfected children (p=0.009). Stools from five of ten children living with HIV and 7(12.7%) HIV-negative children (p = 0.014) contained occult blood.

Discussion

Even though children living with HIV present infrequently to Ibadan health facilities with diarrhoea, their greater propensity for mixed and potentially invasive infections justifies prioritizing laboratory diagnosis of their stools.

Epidemiological investigations of diarrhea in children in Praia city, Cape Verde

Introduction

Diarrheal disease is a major cause of infant mortality and morbidity in Africa and results primarily from contaminated food and water sources, but its prevalence predictors in Cape Verde are not completely known. For this reason, this study aimed to identify the etiological agents of diarrhea in Cape Verdean children and assess its associated risk factors.

Methods

A survey questionnaire was used, and a total of 105 stool samples from children with diarrhea aged 0-12 years at the Central Hospital of Praia (Santiago, Cape Verde) were analyzed. The analyses were carried out using Biofire FilmArray Gastrointestinal Panels. Possible risk factors for these pathogens were analyzed using logistic regression, chi-square tests, or Fisher's exact test.

Results

Among the bacteria, enteroaggregative Escherichia coli (45.71%; 95% CI: 36.71-56.70), enteropathogenic E. coli (40%; 95% CI: 30.56-50.02), Shigella/enteroinvasive E. coli (29.52%; 95% CI: 21.02-39.22), E. coli enterotoxigenic (12.38%; 95% CI: 6.76-20.24), Campylobacter sp. (10.48%; 95% CI: 5.35-1.97), Vibrio sp. (4.76%; 95% CI: 1.56-10.76), Clostridioides difficile (3.81%; 95% CI: 1.05-9.47), Vibrio cholerae (2.86%; 0.59-8.12), Shiga-like toxin-producing E. coli (2.86%; 0.59-8.12) and Salmonella sp. (0.95%; 0.02-5.19) were identified; four viruses, Rotavirus A (28.57%; 95% CI: 20.18-38.21), Sapovirus I. II. IV and V (11.43%; 95% CI: 6.05-19.11), Norovirus GI.GII (6.67%; 95% CI: 2.72-13.25) and Adenovirus F 40.41 (6.67%; 95% CI: 2.72-13.25) were also observed. All the pathogens detected in this study were found in coinfections. Significant associations with risk factors were found; specifically, having a bathroom at home reduced the risk of Campylobacter sp., having animals at home increased the risk of Shigella/EIEC infection, and drinking bottled water reduced the risk of Sapovirus infection.

Discussion

From the findings of this study, it can be concluded that, in Cape Verde, there is a high prevalence and diversity of pathogens among children. Our results could help to establish an adequate diagnosis and effective treatments for diarrheal disease.

Phylogrouping and characterization of Escherichia coli isolated from colonic biopsies and fecal samples of patients with flare of inflammatory bowel disease in Iran

Background

Although the etiopathogenesis of inflammatory bowel disease (IBD) is still poorly understood, Escherichia coli has been described as a potential causative microorganism in IBD pathogenesis and also disease progression, offering a potential therapeutic target for disease management. Therefore, we conducted this study to investigate the pathotypes, phylogenetic groups, and antimicrobial resistance of E. coli isolates from patients with IBD in Iran.

Methods

Fecal and biopsy colonic samples were collected from IBD patients experiencing flare-up episodes referred to Taleghani hospital in Tehran, Iran, between August 2020 and January 2021. Identification of E. coli strains was performed based on biochemical and molecular methods. Antibiotic susceptibility testing was performed as recommended by the Clinical and Laboratory Standards Institute. Phylogrouping and pathotyping of each isolate were carried out using polymerase chain reaction (PCR) and multilocus sequence typing (MLST) assays.

Results

A total of 132 non-duplicate E. coli strains were isolated from 113 IBD patients, including 96 ulcerative colitis (UC), and 17 Crohn’s disease (CD) patients. In our study, 55% of CD-related E. coli and 70.5% of UC-related isolates were non-susceptible to at least three or more unique antimicrobial classes, and were considered as multidrug-resistant (MDR) strains. E. coli strains exhibited a high level of resistance to cefazolin, ampicillin, tetracycline, ceftazidime, ciprofloxacin, and cefotaxime. Enterotoxigenic E. coli (ETEC) and diffusely adherent E. coli (DAEC) were the most prevalent pathotypes, and groups B2 and D were the predominant phylogroups.

Conclusion

In the present study, we found that E. coli strains that colonize the gut of Iranian patients with IBD most frequently belonged to phylogenetic groups B2 and D. We also conclude that E. coli isolates from IBD patients have been revealed to be resistant to commonly used antibiotics, in which most of them harbored strains that would be categorized as MDR.

Evidence of Community-Wide Spread of Multi-Drug Resistant Escherichia coli in Young Children in Lusaka and Ndola Districts, Zambia

Increased antimicrobial resistance (AMR) has been reported for pathogenic and commensal Escherichia coli (E. coli), hampering the treatment, and increasing the burden of infectious diarrhoeal diseases in children in developing countries. This study focused on exploring the occurrence, patterns, and possible drivers of AMR E. coli isolated from children under-five years in Zambia. A hospital-based cross-sectional study was conducted in the Lusaka and Ndola districts. Rectal swabs were collected from 565 and 455 diarrhoeic and healthy children, respectively, from which 1020 E. coli were cultured and subjected to antibiotic susceptibility testing. Nearly all E. coli (96.9%) were resistant to at least one antimicrobial agent tested. Further, 700 isolates were Multi-Drug Resistant, 136 were possibly Extensively-Drug Resistant and nine were Pan-Drug-Resistant. Forty percent of the isolates were imipenem-resistant, mostly from healthy children. A questionnaire survey documented a complex pattern of associations between and within the subgroups of the levels of MDR and socio-demographic characteristics, antibiotic stewardship, and guardians' knowledge of AMR. This study has revealed the severity of AMR in children and the need for a community-specific-risk-based approach to implementing measures to curb the problem.

Antimicrobial Resistance Rates and Surveillance in Sub-Saharan Africa: Where Are We Now?

Introduction

Although antimicrobials have traditionally been used to treat infections and improve health outcomes, resistance to commonly used antimicrobials has posed a major challenge. An estimated 700,000 deaths occur globally every year as a result of infections caused by antimicrobial-resistant pathogens. Antimicrobial resistance (AMR) also contributes directly to the decline in the global economy. In 2019, sub-Saharan Africa (SSA) had the highest mortality rate (23.5 deaths per 100,000) attributable to AMR compared to other regions.

Methods

We searched PubMed for articles relevant to AMR in pathogens in the WHO-GLASS list and in other infections of local importance in SSA. In this review, we focused on AMR rates and surveillance of AMR for these priority pathogens and some of the most encountered pathogens of public health significance. In addition, we reviewed the implementation of national action plans to mitigate against AMR in countries in SSA.

Results and Discussion

The SSA region is disproportionately affected by AMR, in part owing to the prevailing high levels of poverty, which result in a high burden of infectious diseases, poor regulation of antimicrobial use, and a lack of alternatives to ineffective antimicrobials. The global action plan as a strategy for prevention and combating AMR has been adopted by most countries, but fewer countries are able to fully implement country-specific action plans, and several challenges exist in many settings.

Conclusion

A concerted One Health approach will be required to ramp up implementation of action plans in the region. In addition to AMR surveillance, effective implementation of infection prevention and control, water, sanitation, and hygiene, and antimicrobial stewardship programs will be key cost-effective strategies in helping to tackle AMR.

Molecular Study to Detect Escherichia coli in Diarrheic Children and its Antibiotic Resistance

Diarrheal diseases can lead to infections and cause morbidity and mortality in children. Diarrheagenic Escherichia coli (DEC) is an etiological agent, which is considered the major causative agent of diarrhea in children in some developing countries. The aims of this work were to estimate Escherichia coli (E. coli) causing diarrhea in children less than 5 years old, and to detect some biofilm virulence factors and the effect of some antibiotics. For the methodology, a total of 112 specimens were collected from children from two health centers, Al-Zahraa Teaching Hospital and Public Health Laboratory (located in Al-Kut city/ and the Wasit province in Iraq). All specimens were grown on simple and rich media. A total of 43 (38.4%) E. coli isolates were identified using different traditional methods, such as biochemical tests and 16S rRNA sequencing. Polymerase chain reaction (PCR) testing was used to detect some virulence factor genes that play an important role in the pathogenesis of diarrheic E. coli e.g., 16S rRNA, bfpA, and eaeA. In this study, several antibiotics were used to estimate the sensitivity and resistivity of E. coli isolates. A total of 43 isolates were fully identified as E. coli. These samples were used to detect the virulence factor genes, and 31 (72.1%) and 29 (29.4%) isolates carried bfpA and eaeA, respectively. The preponderance of E. coli isolates were completely resistant to penicillin 43 (100%). Additionally, 33 (76.7%) and 27 (62.8%) isolates were resistant to cephalothin and amoxycillin-clavulanic acid, respectively. Furthermore, the isolates of E. coli isolates showed different levels of sensitivity to antibiotics, including polymyxin B 40 (93%), norfloxacin 38 (88.4%), gentamycin 26 (60.4%), and meropenem 22 (51.2%). In conclusion, diarrheagenic E. coli isolates were the prevalent among diarrheic children. Most isolates showed varying results for the presence of virulence factors. In addition, all isolates were resistant to penicillin and sensitive to polymyxin B.

Characterization of diarrheagenic Escherichia coli with special reference to antimicrobial resistance isolated from hospitalised diarrheal patients in Kolkata (2012-2019), India

AIMS

This study analyzes the prevalence and antimicrobial resistance (AMR) of major diarrheagenic Escherichia coli (DEC) pathotypes detected in hospitalized diarrheal patients in Kolkata, India, during 2012-2019.

METHODS AND RESULTS

A total of 8,891 stool samples were collected from the Infectious Diseases Hospital, Kolkata and screened for the presence of enteric pathogens. Multiplex-PCR identified the presence of DEC in 7.8% of the samples, in which ETEC was most common (47.7%) followed by EAEC (38.4%) and EPEC (13.9%). About 54% cases were due to sole DEC infections. Majority of the mixed DEC infections was caused by the Vibrio spp. (19.1%) followed by Rotavirus (14.1%) and Campylobacter spp. (8.4%). ETEC and EAEC were associated significantly with diarrhea in children <5 years of age, whereas EPEC and also ETEC were prevalent in patients aged between 5 and 14 years. AMR profile showed high prevalence of multidrug resistance (MDR) among DEC (56.9%) in which 9% were resistant to antibiotics of six different antimicrobial classes. Screening of the AMR conferring genes of DEC showed the presence of bla_CTX-M3 (30.2%) in highest number followed by bla_TEM (27.5%), tetB (18%), sul2 (12.6%), strA (11.8%), aadA1 (9.8%), bla_OXA-1 (9%), dfrA1 (1.6%) and bla_SHV (1.2%).

CONCLUSIONS

These findings highlighted the high prevalence of MDR in major DEC pathotypes that could be considered as the leading etiologic bacterial agent responsible for diarrhea and suggests a significant public health threat.

SIGNIFICANCE AND IMPACT OF THE STUDY

The results of this study can help to improve the understanding of the epidemiology of DEC infections in patients with diarrhea. Monitoring of AMR surveillance needs special attention because the DEC isolates were highly resistant to commonly used antimicrobials in the treatment of diarrhea.

Characterization of Escherichia coli from Water and Food Sold on the Streets of Maputo: Molecular Typing, Virulence Genes, and Antibiotic Resistance

The aim of this study was to investigate the pathogenic potential and antibiotic resistance of 59 Escherichia coli isolates from ready-to-eat (RTE) street food (n = 31) and drinking water (n = 28) sold in the city of Maputo, Mozambique. The isolates were characterized by XbaI subtyping analysis via pulsed field gel electrophoresis. Multiplex PCRs were performed targeting five virulence genes (stx, lt, st, astA, and eae) and three groups of antibiotic-resistant genes, namely ß-lactamases (extended-spectrum ß-lactamase and AmpC), tetracycline (tetA, tetB, and tetM) and sulfamethoxazole/trimethoprim (sul1, sul2, and sul3). The stx virulence gene, encoding the Shiga/Vero (VT) toxin produced by the verotoxin-producing E. coli (VTEC), was identified with similar frequency in isolates from food (5/31) and water (6/28). The highest percentages of resistant isolates from food and water were found for ß-lactams imipenem (35.5 and 39.3%, respectively) and ampicillin (39.3 and 46.4%, respectively). Multidrug resistance was observed in 31.3% of the isolates, being higher in E. coli isolates from water (45.5%) compared to RTE street food isolates (19.2%). Virulence genes were detected in 73% of the multidrug-resistant isolates. Concerning antibiotic-resistant genes, ESBL was the most frequent (57.7%) among β-lactamases while tetA was the most frequent (50%) among non-β-lactamases.

Real-time multiplex PCR assay reveals the increased prevalence of Campylobacter spp and diarrhoeagenic Escherichia coli in humans from Vellore, South India

Introduction. Bacterial dysentery is one of the greatest causes of morbidity and mortality worldwide. Campylobacter spp. and diarrhoeagenic Escherichia coli (DEC) are recognised as the most common causes of bacterial enteritis in developing countries including India.Hypothesis/Gap statement. Rapid and accurate identification of dysentery causing organisms using molecular methods is essential for better disease management, epidemiology and outbreak investigations.Aim. In view of the limited information available on the dysentery causing agents like Campylobacter spp., enterohemorrhagic E. coli (EHEC)/enteropathogenic E. coli (EPEC) and enteroinvasive E. coli (EIEC)/Shigella in India, this study was undertaken to investigate the presence of these pathogens in human and poultry stool samples by molecular methods.Methodology. In total, 400 human stool samples and 128 poultry samples were studied. Microaerophilic culture along with real-time multiplex PCR with the targets specific to the genus Campylobacter, Campylobacter jejuni, Campylobacter coli, EHEC, EPEC and EIEC/Shigella was performed. Further species confirmation was done using MALDI-TOF MS.Results. On microaerophilic culture, C. coli was isolated in one human sample and two C. jejuni and one C. fetus in poultry samples. On PCR analysis, among human stool samples, typical EPEC (42%) was predominantly seen followed by Campylobacter spp. (19%) and EIEC/Shigella (10%). In contrast, Campylobacter spp. (41%) was predominant in poultry samples, followed by typical EPEC (26%) and EIEC/Shigella (9%). Poly-infections with Campylobacter spp. and DEC were also observed among both sources.Conclusion. The present study documented the increased prevalence of Campylobacter spp. in humans compared with the results of previous studies from India. Typical EPEC was found to be predominant in children less than 5 years of age in this study. The high prevalence of coinfections in the current study indicates that a multiple aetiology of diarrhoea is common in our settings.

Acute Infectious Gastroenteritis: The Causative Agents, Omics-Based Detection of Antigens and Novel Biomarkers

Acute infectious gastroenteritis (AGE) is among the leading causes of mortality in children less than 5 years of age worldwide. There are many causative agents that lead to this infection, with rotavirus being the commonest pathogen in the past decade. However, this trend is now being progressively replaced by another agent, which is the norovirus. Apart from the viruses, bacteria such as Salmonella and Escherichia coli and parasites such as Entamoeba histolytica also contribute to AGE. These agents can be recognised by their respective biological markers, which are mainly the specific antigens or genes to determine the causative pathogen. In conjunction to that, omics technologies are currently providing crucial insights into the diagnosis of acute infectious gastroenteritis at the molecular level. Recent advancement in omics technologies could be an important tool to further elucidate the potential causative agents for AGE. This review will explore the current available biomarkers and antigens available for the diagnosis and management of the different causative agents of AGE. Despite the high-priced multi-omics approaches, the idea for utilization of these technologies is to allow more robust discovery of novel antigens and biomarkers related to management AGE, which eventually can be developed using easier and cheaper detection methods for future clinical setting. Thus, prediction of prognosis, virulence and drug susceptibility for active infections can be obtained. Case management, risk prediction for hospital-acquired infections, outbreak detection, and antimicrobial accountability are aimed for further improvement by integrating these capabilities into a new clinical workflow.

The design of multiepitope vaccines from plasmids of diarrheagenic Escherichia coli against diarrhoea infection: Immunoinformatics approach

Diarrhoea infection is a major global health public problem and is caused by many organisms including diarrheagenic Escherichia coli pathotypes. The common problem with diarrhoea is the drug resistance of pathogenic bacteria, the most promising alternative means of preventing drug resistance is vaccination. However, there has not been any significant success in the prevention of diarrhoea caused by E. coli through vaccination. Epitope-based vaccine is gaining more attention due to its safety and specificity. Sequence variation of protective antigens of the pathogen has posed a new challenge in the development of epitope-based vaccines against the infection, leading to the necessity of multiepitope based design. In this study, immunoinformatics tools were used to design multiepitope vaccine candidates from plasmid genome sequences of multiple pathotypes of E. coli species involved in diarrhoea infections. The ability of the identified epitopes to be used as a cross-protect multiepitope vaccine was achieved by identifying conserved, immunogenic and antigenic peptides that can elicit CD4⁺ T-cell, CD8⁺ T-cell and B-cell and bind to MHC I and II HLA alleles. The molecular docking results of T-cell epitopes showed their well binding affinity to receptive protein and with a wider population coverage. The different multiepitope-based vaccines (MEVCs) candidates were constructed and based on the types of epitope linker they contained. The MEVCs exhibited very good binding interactions with the human immune receptor. Among multiepitope vaccines constructed, MEVC6, MEVCA and MEVCB are more promising as potential vaccine candidates for cross-protection against gastrointestinal infections according to the computational study. It is also hoped that after validation and testing, the predicted multiepitope-based vaccine candidates will probably resolve the challenge of immunological heterogeneity facing enteric vaccine development.

DETECTION OF DIARRHEAGENIC ESCHERICHIA COLI IN HUMAN DIARRHEIC STOOL AND DRINKING WATER SAMPLES IN OUAGADOUGOU, BURKINA FASO

Background:

The presence of diarrheagenic Escherichia coli (DEC) in drinking water, is a grave public health problem. This study was aimed at characterization of diarrheagenic Escherichia coli isolated from drinking water and faecal samples from diarrheic patients in Ouagadougou, Burkina Faso.

Materials and Methods:

A total of 242 water samples consisting of 182 potable sachets and 60 from boreholes were collected in the period between October 2018 and April 2019 in the city of Ouagadougou. Faecal samples were also collected from 201 diarrheic patients visiting National Public Health Laboratory for a biological diagnosis by coproculture. The presence of virulence genes associated with DEC was determined by 16-plex polymerase chain reaction from bacteria culture.

Results:

From drinking water, we found 17% (42/242) Escherichia coli isolates in which 1% (2/242) DEC were detected. Among analyzed samples (182 sachet water versus 60 borehole water), the two DEC (01 ETEC and 01 EPEC) were detected in sachet water. DEC were detected in 20% (40/201) of patients. Enteroaggregative Escherichia coli (EAEC) were mostly detected in 10% followed by Enteropathogenic Escherichia coli (EPEC) in 4%, Enteroinvasive Escherichia coli (EIEC) in 2%, and Shiga toxin-producing Escherichia coli (STEC) 0.5%. However, Enterotoxigenic Escherichia coli (ETEC) was not detected alone, but in co-infections with EAEC.

Conclusion:

The present study documented the prevalence of Escherichia coli pathovars associated in patients with diarrhea, and shows that drinking water might be a source of DEC transmission in human.

Prevalence, phylogeny, and antimicrobial resistance of Escherichia coli pathotypes isolated from children less than 5 years old with community acquired- diarrhea in Upper Egypt

Background

Diarrhoea, affecting children in developing countries, is mainly caused by diarrheagenic Escherichia coli (DEC). This study principally aimed to determine the prevalence of DEC pathotypes and Extended-spectrum β-lactamase (ESBL) genes isolated from children under 5 years old with diarrhea.

Methods

A total of 320 diarrhoea stool samples were investigated. E. coli isolates were investigated for genes specific for enterotoxigenic E. coli (ETEC), enteropathogenic E. coli (EPEC), enteroaggregative E. coli (EAEC), enteroinvasive E. coli (EIEC) and enterohemorrhagic E. coli (EHEC) using polymerase chain reaction (PCR). Furthermore, antimicrobial susceptibility testing, detection of antibiotic resistance-genes and phylogenetic typing were performed.

Results

Over all, DEC were isolated from 66/320 (20.6%) of the children with diarrhoea. EAEC was the predominant (47%), followed by typical EPEC (28.8%) and atypical EPEC (16.6%). Co-infection by EPEC and EAEC was detected in (7.6%) of isolates. However, ETEC, EIEC and EHEC were not detected. Phylogroup A (47%) and B2 (43.9%) were the predominant types. Multidrug-resistance (MDR) was found in 55% of DEC isolates. Extended-spectrum β-lactamase (ESBL) genes were detected in 24 isolates (24 blaTEM and 15 blaCTX-M-15). Only one isolate harbored AmpC β-lactamase gene (DHA gene).

Conclusion

The study concluded that, EAEC and EPEC are important causative agents of diarrhoea in children under 5 years. MDR among DEC has the potential to be a big concern.

Virulence Profiles of Diarrheagenic Escherichia coli Isolated from the Western Region of Ghana

Diarrheagenic Escherichia coli (DEC), an important agent of infectious diarrhea, is constantly evolving, making its periodic monitoring necessary. However, the DEC genotypes in Ghana remain uncharacterized. We focused on characterizing the molecular serotypes, virulence factors, multilocus sequence types, and the phylogenetic relatedness among different DEC pathotypes recovered from stool samples of pediatric patients with symptoms of diarrhea from the Western region of Ghana. We detected all five common DEC pathotypes, with the majority of the isolates being enterotoxigenic E. coli (ETEC) harboring the heat-labile enterotoxin gene. The DEC strains exhibited diverse serotypic identity with novel and previously reported outbreak strains. Sequence types (ST) ST38, ST316, and ST1722 were most prevalent, and clonal complex 10 (CC10) was the most common CC. A close evolutionary distance was observed among most of the isolates. Coli surface antigen 6 was the most prevalent (44%, n = 11) ETEC-specific colonization factor. Nearly all the isolates harbored lpfA, and the frequencies of other virulence genes such as pap and cnf1 were 7.9% and 18.4%, respectively. This study provides insights into the important and novel genotypes circulating in the Western region of Ghana that should be monitored for public health.