Diarrheagenic Escherichia Coli Research Articles

Detection and antibiogram profile of diarrheagenic Escherichia coli isolated from two abattoir settings in northwest Ethiopia: a one health perspective

BackgroundDiarrheagenic Escherichia coli (E. coli) is a zoonotic pathogen that contaminates abattoir workers, slaughter environments, slaughter equipment, and carcasses during abattoir processing. Infection with E. coli is associated with the consumption of contaminated food and water, and it is a potential threat to the health and welfare of both humans and animals. Hence, this study aimed to detect diarrheagenic E. coli and assess its antibiogram profile in two abattoir settings, in one health lens.MethodsA cross-sectional study in one health approach was conducted from December 2020 to June 2021. A total of 384 samples from abattoir workers’ hands, carcasses, knives, cattle feces, abattoir water and effluents were collected. Bacterial culture and biochemical tests were conducted to isolate E. coli, while conventional polymerase chain reaction was performed to identify virulence genes. The antibiogram of diarrheagenic E. coli was tested against nine antimicrobials using the Kirby Bauer disk diffusion method.ResultsA total of 115 (29.95%) E. coli were isolated from the 384 samples, and from these isolates, about 17 (14.8%) were confirmed to be diarrheagenic E. coli (DEC). Among the DEC pathotypes, nine (52.94%), five (29.4%), and three (17.65%) were Shiga toxin-producing, enterohemorrhagic, and enterotoxigenic E. coli, respectively. While 14 (82.35%) DEC isolates harbored the stx2 gene, five (29.41%) the eae gene, five (29.41%) the hlyA gene and three (17.65%) harbored the st gene. All the DEC isolates were resistant to erythromycin and vancomycin; whereas, they were susceptible to ampicillin, nalidixic acid and norfloxacin. Furthermore, 64.7% of DEC isolates showed resistance to both ceftazidime and kanamycin and 88.24% of the isolates showed multidrug resistance.ConclusionThis study detected DEC isolates having different virulence genes, which showed single and multiple antimicrobial resistance. Given the existing poor hygienic and sanitary practices along the abattoir-to-table food chain, coupled with the habit of raw meat consumption, this result indicates a potential public and animal health risk from the pathogen and antimicrobial resistance.

A metagenomic approach to unveil the association between fecal gut microbiota and short-chain fatty acids in diarrhea caused by diarrheagenic Escherichia coli in children

Diarrheagenic Escherichia coli (DEC) is the main cause of diarrhea in children under five years old. The virulence of DEC is tightly regulated by environmental signals influenced by the gut microbiota and its metabolites. Short-chain fatty acids (SCFAs) are the main metabolic product of anaerobic fermentation in the gut, but their role in DEC diarrhea has not yet been established. In this study, we determine the levels of acetate, propionate, and butyrate in stool samples from children with diarrhea caused by DEC, and we identify bacteria from the fecal gut microbiota associated with the production of SCFAs. The microbiota and SCFAs levels in stool samples obtained from 40 children with diarrhea and 43 healthy children were determined by 16S rRNA gene sequencing and HPLC, respectively. Additionally, shotgun metagenomics was used to identify metagenome-assembled genomes (MAGs) in a subgroup of samples. The results showed significantly higher levels of all SCFAs tested in diarrheal samples than in healthy controls. The abundance of Streptococcus sp., Limosilactobacillus, Blautia, Escherichia, Bacteroides, Megamonas, and Roseburia was higher in the DEC group than in healthy individuals. Functional analysis of bacteria and their main metabolic pathways made it possible to identify species MAGs that could be responsible for the detected SCFAs levels in DEC-positive diarrhea. In conclusion, based on our results and published data, we suggest that SCFAs may be important in the crosstalk between the microbiota and DEC pathogens in the gut.

Sequence-subtype association of multi-drug-resistant diarrheagenic Escherichia coli

Background and Objectives: Multi-drug-resistant pathogens pose a significant threat as they can rapidly spread, leading to severe healthcare-associated invasive infections. In developing countries, diarrheagenic Escherichia coli (DEC) is a major bacterial pathogen responsible for causing diarrhea. However, the outbreak of resistant strains has made the treatment of DEC infections much more challenging. This study aimed to investigate the relationship between antibiotic resistance genes and other virulence categories in E. coli strains that cause diarrhea, particularly DEC.
 Materials and Methods: The phylogenetic grouping was defined using PCR and multi-locus sequence type (MLST) meth- ods.
 Results: Among the isolates analyzed, 14 were identified as resistant and were classified into eight distinct sequence types: ST3, ST53, ST77, ST483, ST512, ST636, ST833, and ST774, indicating genetic diversity among the resistant strains. Certain sequence types, notably ST512 and ST636, were found to be associated with multiple antibiotic resistance in DEC. Regard- ing antibiotic susceptibility, strains showed the highest resistance to amoxicillin, suggesting that this antibiotic may not be effective in treating DEC infections. On the other hand, the isolates demonstrated susceptibility to amikacin and chloram- phenicol, implying that these antibiotics could be more suitable treatment options for DEC infections.
 Conclusion: The findings underscore the importance of promptly identifying antibiotic resistance patterns and their correla- tion with specific pathogenic virulence categories, as this knowledge can aid in selecting the most appropriate antibiotics for treating DEC infections. Considering the antibiotic resistance profiles and associated resistance genes is crucial in managing and containing diarrheal outbreaks and in selecting effective antibiotic therapies for DEC infections.

Characteristics of Pathogenic Escherichia coli Associated with Diarrhea in Children under Five Years in Northwestern Ethiopia.

Diarrheagenic Escherichia coli (DEC) are the leading cause of infectious diarrhea and pose a significant global, regional, and national burden of disease. This study aimed to investigate the prevalence of six DEC pathotypes in children with diarrhea and determine their antibiotic resistance patterns. Samples from 107 diarrheagenic children were collected and processed for Escherichia coli (E. coli). Single-plex PCR was used to detect target virulence genes as well as characterize and categorize DEC pathotypes. Antibiotic resistance patterns were determined by the Kirby-Bauer disk diffusion method. E. coli was detected in 79 diarrheal stool samples, accounting for 73.8% of the samples collected. Additionally, 49.4% (39 out of 79) of the isolates harbored various typical virulence factors. Results revealed six pathotypes of virulence: enterotoxigenic E. coli (ETEC) (53.8%), enteropathogenic E. coli (EPEC) (12.8%), enteroaggregative E. coli (EAEC) (10.3%), Heteropathotypes (7.8%), Shiga toxin-producing E. coli (STEC), and enterohemorrhagic E. coli (EHEC) (7.7% each). The isolates exhibited high antibiotic resistance against trimethoprim/sulfamethoxazole (82.1%), amoxicillin (79.5%), ampicillin (74.4%), gentamicin (69.2%), and streptomycin (64.1%). An overall occurrence of 84.6% of multiple-drug resistance was observed in the isolates, with resistance ranging from three to four antibiotic classes. Our findings revealed a high level of pathogenic E. coli that were highly resistant to multiple categories of antibiotics among children in the Awi zone. These findings highlight the potential role of pathogenic E. coli in childhood diarrhea in tropical low-resource settings and underscore the need for continued research on the characteristics of pathogenic and antibiotic-resistant strains.

Virulence genes, antimicrobial resistance profile, phylotyping and pathotyping of diarrheagenic Escherichia coli isolated from children in Southwest Mexico.

Diarrheagenic E. coli (DEC) strains are one of the most important etiology factors causing diarrhea in children worldwide, especially in developing countries. DEC strains have characteristic virulence factors; however, other supplemental virulence genes (SVG) may contribute to the development of diarrhea in children. Therefore, this study aimed to determine the prevalence of DEC in children with diarrhea in southwestern Mexico and to associate childhood symptoms, SVG, and pathotypes with diarrhea-causing DEC strains. DEC strains were isolated from 230 children with diarrhea aged 0-60 months from the state of Oaxaca, southwestern Mexico; clinical data were collected, and PCR was used to identify SVG and pathotypes. Antibiotic resistance profiling was performed on DEC strains. 63% of samples were DEC positive, single or combined infections (two (21%) or three strains (1.3%)) of aEPEC (51%), EAEC (10.2%), tEPEC (5.4%), DAEC (4.8%), ETEC (4.1%), EIEC (1.4%), or EHEC (0.7%) were found. Children aged ≤ 12 and 49-60 months and symptoms (e.g., fever and blood) were associated with DEC strains. SVG related to colonization (nleB-EHEC), cytotoxicity (sat-DAEC and espC-tEPEC), and proteolysis (pic-aEPEC) were associated with DECs strains. E. coli phylogroup A was the most frequent, and some pathotypes (aEPEC-A, DAEC-B), and SVG (espC-B2, and sat-D) were associated with the phylogroups. Over 79% of the DEC strains were resistant to antibiotics, and 40% were MDR and XDR, respectively. In conclusion aEPEC was the most prevalent pathotype in children with diarrhea in this region. SVG related to colonization, cytotoxicity, and proteolysis were associated with diarrhea-producing DEC strains, which may play an essential role in the development of diarrhea in children in southwestern Mexico.

High-resolution melting real-time PCR assays for subtyping of five diarrheagenic Escherichia coli by a single well in milk

Diarrheagenic Escherichia coli (DEC) is a kind of foodborne pathogen that poses a significant threat to both food safety and human health. To address the current challenges of high prevalence and difficult subtyping of DEC, this study developed a method that combined multiplex polymerase chain reaction (PCR) with high resolution melting (HRM) analysis for subtyping 5 kinds of DEC. The target genes are amplified by multiplex PCR in a single well, and HRM curve analysis was applied for distinct amplicons based on different melting temperature (Tm) values. The method enables discrimination of different DEC types based on characteristic peaks and distinct Tm values in the thermal melting curve. The assay exhibited 100% sensitivity and 100% specificity with a detection limit of 0.5-1 ng/μL. The results showed that different DNA concentrations did not influence the subtyping results, demonstrating this method owed high reliability and stability. In addition, the method was also used for the detection and subtyping of DEC in milk. This method streamlines operational procedures, shorts the detection time, and offers a novel tool for subtyping DEC.

Characterization of diarrheagenic Escherichia coli from different cattle production systems in Brazil

Diarrheagenic E. coli (DEC) can cause severe diarrhea and is a public health concern worldwide. Cattle are an important reservoir for this group of pathogens, and once introduced into the abattoir environment, these microorganisms can contaminate consumer products. This study aimed to characterize the distribution of DEC [Shiga toxin-producing E. coli (STEC), enteroinvasive E. coli (EIEC), enteropathogenic E. coli (EPEC), enterotoxigenic E. coli (ETEC), and enteroaggregative E. coli (EAEC)] from extensive and intensive cattle production systems in Brazil. Samples (n = 919) were collected from animal feces (n = 200), carcasses (n = 600), meat cuts (n = 90), employee feces (n = 9), and slaughterhouse water (n = 20). Virulence genes were detected by PCR in 10% of animal samples (94/919), with STEC (n = 81) as the higher prevalence, followed by EIEC (n = 8), and lastly EPEC (n = 5). Animals raised in an extensive system had a higher prevalence of STEC (average 48%, sd = 2.04) when compared to animals raised in an intensive system (23%, sd = 1.95) (Chi-square test, P < 0.001). From these animals, most STEC isolates only harbored stx2 (58%), and 7% were STEC LEE-positive isolates that were further identified as O157:H7. This study provides further evidence that cattle are potential sources of DEC, especially STEC, and that potentially pathogenic E. coli isolates are widely distributed in feces and carcasses during the slaughter process.

Colonization of the gut mucosa of colorectal cancer patients by pathogenic mucosa-associated Escherichia coli strains

Some strains of Escherichia coli are known to be involved in the pathogenesis of colorectal cancer (CRC). The aim of current study was to compare the general characteristics of the E. coli from CRC patients and healthy participants. A total of 96 biopsy samples from 48 CRC patients and 48 healthy participants, were studied. The clonality of the E. coli isolates was analyzed by Enterobacterial repetitive intergenic consensus-based PCR (ERIC-PCR) method. The strains were tested by PCR to determine the prevalence of different virulence factors. According to the results of ERIC-PCR analysis, (from the 860 E. coli isolates) 60 strains from CRC patients and 41 strains from healthy controls were identified. Interestingly, the majority of the strains of both groups were in the same cluster. Enteropathogenic E. coli (EPEC) was detected significantly more often in CRC patients (21.6 %) than in healthy participants (2.4 %) (p < 0.05). The Enteroaggregative E. coli (EAEC) was found in 18.33 % of the strains of CRC patients. However, other pathotypes were not found in the E. coli strains of both groups. Furthermore, all the studied genes encoding for virulence factors seemed to be more prevalent in the strains belonging to CRC patients. Among the virulence genes, the statistical difference regarding the frequency of fuyA, chuA, vat, papC, hlyA and cnf1 genes was found significant (p < 0.05). In conclusion, E. coli strains that carry extraintestinal pathogenic E. coli (ExPEC) and diarrheagenic E. coli (DEC) multiple virulence factors colonize the gut mucosa of CRC patients.

Features of &lt;i&gt;ESCHERICHIA COLI&lt;/i&gt; samples from patients with diarrheal syndrome in the Republic of Guinea

Introduction. Diarrheal diseases are a global public health issue and cause 15% of deaths in children under 5 years old, of which about 80% occur in the regions of Africa and Southeast Asia. According to the Global Enteric Multicentre Study (GEMS) conducted in a number of African countries, one of the leading pathogens of high risk of death in infants and young children is diarrheagenic E. coli (DEC). In recent decades, antimicrobial resistance (AMR) has become globally ubiquitous. The Republic of Guinea urgently needs large-scale studies devoted to assessing DEC distribution and antibiotic resistance. The purpose of the study is to assess the pattern of E. coli infections and to test the susceptibility to antibiotics in strains of diarrheagenic E. coli sampled from individuals residing in the Republic of Guinea.&#x0D; Materials and methods. From 2019 to 2022, we studied 724 samples of faeces of patients with acute diarrhea, among them 72 (9.9%) children aged 1–5 years, 128 (17.7%) children aged 6–17 years, and 524 (72.4%) people aged 18 years and older; a method of polymerase chain reaction (PCR) was applied with the use of the AmpliSense® Escherichioses-FL reagent kit to identify the genetic determinants of DEC: EPEC, EHEC, ETEC, EIEC, and EAgEC (Central Research Institute of Epidemiology of Rospotrebnadzor, Russia). Susceptibility to 15 antimicrobial agents was found by the disc-diffusion method using Mueller–Hinton agar (Russia) and Oxoid discs (UK). Results were interpreted according EUCAST criteria, versions 2019–2022 (https://www.eucast.org/ast_of_bacteria/previous_versions_of_documents).&#x0D; Results. For the period from 2019 to 2022, the percentage of E. coli infections in the etiological pattern of acute intestinal infections amounted to 51.7%. In the age-related manner, DEC was significantly more common in young children aged 0–5 (96.9%, p 0.05) as compared to school age children aged 6–17 (53.9%) and adults (45.6%). In all years of observation, EAgEC strains prevailed, accounting for 38.4%. Other DEC pathotypes, EPEC, ETEC, EIEC and STEC, accounted for 27.2%, 17.5%, 11.8%, and 5.1%, respectively. DEC strains are susceptible to meropenem, amikacin, and nitrofurantoin. The activity of other antibiotics ranged from 11.3% for ampicillin, 28.3% for trimethoprim-sulfamethoxazole, and 34.0% for tetracycline to 73.6% for cephalosporins, 84.0% for aminoglycosides, and 98.1% for fluorinated quinolones.&#x0D; Conclusion. To reduce the burden of diarrheal diseases in the Republic of Guinea, it may be necessary to conduct targeted epidemiological and microbiological studies to identify DEC and monitor the development of antimicrobial resistance of E. coli infection pathogens in the population.

Molecular markers of acute intestinal infections in HIV-infected patients in the Chechen Republic

Introduction. Diarrheal syndrome is the most characteristic symptom of HIV infection, which occurs in 70% of patients and is often fatal. The severity of diarrheal syndrome, irrespective of immune status, is usually determined by specific microorganisms colonising the gastrointestinal tract.&#x0D; The objective of this study is to assess the prevalence of classical pathogens of acute intestinal infections in diarrheal syndrome in HIV-infected residents of the Chechen Republic (Grozny).&#x0D; Materials and methods. Stool samples (n = 191) of HIV-infected patients with a history of diarrheal syndrome were studied by real-time PCR with two kits of reagents: "AmpliSens OKI screen-FL" for the detection of DNA/RNA of Shigella spp./EIEC, Salmonella spp., Campylobacter spp., Adenovirus, Rotavirus, Norovirus and Astrovirus; "AmpliSens Escherichiosis-FL" for the detection of diarrheagenic E. coli (DEC) DNA of five pathogroups: EPEC, EHEC, ETEC, EIEC, EAgEC.&#x0D; Results. Genetic markers of the acute intestinal infection pathogens were detected in 20.9% of the examined individuals. In patients aged 0–7 years and 18–24 years, DNA/RNA of the tested pathogens were not detected. DNA of bacterial pathogens accounted for 93.9%, RNA of viral pathogens — 6.1%. The etiological structure of bacterial infections was represented by a significant predominance of DEC (84.8%) compared to 10.9% of Campylobacter spp. and 4.4% of Salmonella spp. The structure of viral infections included 66.7% Rotavirus and 33.3% Norovirus. Genetic markers of Adenovirus and Astrovirus have not been identified. In 77.5% of HIV-infected patients, diarrheal syndrome was caused by one pathogen (mono-infection), but in nine examined patients (22.5%) it had a combined etiology.&#x0D; Conclusion. The etiology of acute intestinal infections in HIV-infected patients of the Chechen Republic includes bacterial and viral pathogens, in every fifth the cause of diarrheal disease was DEC. Due to diarrhea in HIV-infected people being a polyetiological disease, it is necessary to introduce a comprehensive, fast, reliable, and affordable method for identifying a wide range of pathogens that cause secondary infections.

Detection of Some Virulence Genes in Diarrheagenic Escherichia Coli Pathotypes in Children Under Five Years in Aleppo City

Diarrheagenic Escherichia coli (DEC) strains can be classified into six main pathotypes based on their specific virulence properties. These pathotypes are associated with certain serotypes and exhibit distinct epidemiological and clinical features. The identification of DEC cannot be based solely on cultural and biochemical criteria, as they are indistinguishable from the non-pathogenic E. coli. However, the presence of virulence genes and DNA sequences specific to DEC can be used to determine its identity. The aim of this study is to investigate the prevalence of Diarrheagenic Escherichia coli (DEC) pathotypes among infected children under 5 years living in the city of Aleppo Syria. From June 2020 to September 2021, one hundred samples of diarrheal were collected from children under five years suffering from diarrhea admitted at Aleppo University Hospital and from some private laboratories in Aleppo city. Escherichia coli pathotypes were detected by using multiplex polymerase chain reaction and Phylogenetic genes were detected by Triplex PCR. The frequency of diarrheagenic E. coli   was (48%), the most frequently isolated pathotypes were atypical enteropathogenic E. coli. (42%), followed by enterotoxigenic E. coli (4%), and enteroinvasive E. coli (2%). Enterohemorrhagic E. coli, enteroaggregative E. coli and Diffusely Adherent E. coli were not detected in any sample (0%). The most prevalent phylogenetic group of E. coli   was "Phylogenetic group B2" which represented (62%), followed by "Phylogenetic group D" that comprised 33%, followed by "Phylogenetic group A" strains (3%). Strains of the "Phylogenetic group B1" were rare (2%). This study revealed that DEC strains contribute to cause diarrheal diseases in children, EPEC is the most commonly identified DEC strain. B2 and D groups are the most prevalent phylogenetic groups. In addition, they are virulent because these groups are associated with the presence of several virulence factors.

Why are so many enteric pathogen infections asymptomatic? Pathogen and gut microbiome characteristics associated with diarrhea symptoms and carriage of diarrheagenic E. coli in northern Ecuador

ABSTRACT A high proportion of enteric infections, including those caused by diarrheagenic Escherichia coli (DEC), are asymptomatic for diarrhea. The factors responsible for the development of diarrhea symptoms, or lack thereof, remain unclear. Here, we used DEC isolate genome and whole stool microbiome data from a case–control study of diarrhea in Ecuador to examine factors associated with diarrhea symptoms accompanying DEC carriage. We investigated i) pathogen abundance, ii) gut microbiome characteristics, and iii) strain-level pathogen characteristics from DEC infections with diarrhea symptoms (symptomatic infections) and without diarrhea symptoms (asymptomatic infections). We also included data from individuals with and without diarrhea who were not infected with DEC (uninfected cases and controls). i) E. coli relative abundance in the gut microbiome was highly variable, but higher on-average in individuals with symptomatic compared to asymptomatic DEC infections. Similarly, the number and relative abundances of virulence genes in the gut were higher in symptomatic than asymptomatic DEC infections. ii) Measures of microbiome diversity were similar regardless of diarrhea symptoms or DEC carriage. Proteobacterial families that have been described as pathobionts were enriched in symptomatic infections and uninfected cases, whereas potentially beneficial taxa, including the Bacteroidaceae and Bifidobacteriaceae, were more abundant in individuals without diarrhea. An analysis of high-level gene functions recovered in metagenomes revealed that genes that were differentially abundant by diarrhea and DEC infection status were more abundant in symptomatic than asymptomatic DEC infections. iii) DEC isolates from symptomatic versus asymptomatic individuals showed no significant differences in virulence or accessory gene content, and there was no phylogenetic signal associated with diarrhea symptoms. Together, these data suggest signals that distinguish symptomatic from asymptomatic DEC infections. In particular, the abundance of E. coli, the virulence gene content of the gut microbiome, and the taxa present in the gut microbiome have an apparent role.

Risk factors for diarrheagenic Escherichia coli infection in children aged 6-24 months in peri-urban community, Nairobi, Kenya.

Escherichia coli commonly inhabits the gut of humans and animals as part of their microbiota. Though mostly innocuous, some strains have virulence markers that make them pathogenic. This paper presents results of a cross-sectional epidemiological study examining prevalence of diarrheagenic E. coli (DEC) pathotypes in stool samples of asymptomatic healthy children (n = 540) in Dagoretti South subcounty, Nairobi, Kenya. E. coli was cultured and pathotyped using PCR to target specific virulence markers associated with Shiga-toxin, enteropathogenic, enterotoxigenic, enteroaggregative, entero-invasive and diffusely adherent E. coli. Overall prevalence of DEC pathotypes was 20.9% (113/540) with enteropathogenic E. coli being the most prevalent (34.1%), followed by enteroaggregative E. coli (23.5%) and Shiga-toxin producing E. coli (22.0%) among positive samples. We found evidence of co-infection with multiple pathotypes in 15% of the positive samples. Our models indicated that at the household level, carriage of DEC pathotypes in children was associated with age group [12-18 months] (OR 1.78; 95%CI 1.03-3.07; p = 0.04), eating matoke (mashed bananas) (OR 2.32; 95%CI 1.44-3.73; p = 0.001) and pulses/legumes (OR 1.74; 95%CI 1.01-2.99; p = 0.046) while livestock ownership or contact showed no significant association with DEC carriage (p>0.05). Our findings revealed significant prevalence of pathogenic DEC circulating among presumptive healthy children in the community. Since there has been no previous evidence of an association between any food type and DEC carriage, unhygienic handling, and preparation of matoke and pulses/legumes could be the reason for significant association with DEC carriage. Children 12-18 months old are more prone to DEC infections due to exploration and hand-to-mouth behavior. A detailed understanding is required on what proportion of positive cases developed severe symptomatology as well as fatal outcomes. The co-infection of pathotypes in the rapidly urbanizing environment needs to be investigated for hybrid or hetero-pathotype circulation that have been implicated in previous infection outbreaks.

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.

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. 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. 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. 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.

Resistance and Virulence Surveillance in Escherichia coli Isolated from Commercial Meat Samples: A One Health Approach.

Escherichia coli is a key indicator of food hygiene, and its monitoring in meat samples points to the potential presence of antimicrobial-resistant strains capable of causing infections in humans, encompassing resistance profiles categorized as serious threats by the Centers for Disease Control and Prevention (CDC), such as Extended-Spectrum Beta-Lactamase (ESBL)-a problem with consequences for animal, human, and environmental health. The objective of the present work was to isolate and characterize ESBL-producing E. coli strains from poultry, pork, and beef meat samples, with a characterization of their virulence and antimicrobial resistance profiles. A total of 450 meat samples (150 chicken, 150 beef, and 150 pork) were obtained from supermarkets and subsequently cultured in medium supplemented with cefotaxime. The isolated colonies were characterized biochemically, followed by antibiogram testing using the disk diffusion technique. Further classification involved biofilm formation and the presence of antimicrobial resistance genes (blaCTX-M, AmpC-type, mcr-1, and fosA3), and virulence genes (eaeA, st, bfpA, lt, stx1, stx2, aggR, iss, ompT, hlyF, iutA, iroN, fyuA, cvaC, and hylA). Statistical analysis was performed via the likelihood-ratio test. In total, 168 strains were obtained, with 73% originating from chicken, 22% from pork, and 17% from beef samples. Notably, strains exhibited greater resistance to tetracycline (51%), ciprofloxacin (46%), and fosfomycin (38%), apart from β-lactams. The detection of antimicrobial resistance in food-isolated strains is noteworthy, underscoring the significance of antimicrobial resistance as a global concern. More than 90% of the strains were biofilm producers, and strains carrying many ExPEC genes were more likely to be biofilm formers (OR 2.42), which increases the problem since the microorganisms have a greater chance of environment persistence and genetic exchange. Regarding molecular characterization, bovine samples showed a higher prevalence of blaCTX-M-1 (OR 6.52), while chicken strains were more likely to carry the fosA3 gene (OR 2.43, CI 1.17-5.05) and presented between 6 to 8 ExPEC genes (OR 2.5, CI 1.33-5.01) compared to other meat samples. Concerning diarrheagenic E. coli genes, two strains harbored eae. It is important to highlight these strains, as they exhibited both biofilm-forming capacities and multidrug resistance (MDR), potentially enabling colonization in diverse environments and causing infections. In conclusion, this study underscores the presence of β-lactamase-producing E. coli strains, mainly in poultry samples, compared to beef and pork samples. Furthermore, all meat sample strains exhibited many virulence-associated extraintestinal genes, with some strains harboring diarrheagenic E. coli (DEC) genes.

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.

Influence of animal production systems on the presence of pathogenic strains of Escherichia coli in the bovine production chain

Among the main pathogens involved in food outbreaks worldwide is diarrheagenic Escherichia coli (DEC). Cattle are considered natural reservoirs of DEC, and, during the slaughter stages, they can be a source of contamination for the carcass and final product. The objective of this work was to evaluate the influence of beef cattle production systems in Southeast Brazil, in the presence of diarrheagenic strains of Escherichia coli. A total of 485 samples were collected at the following points: post-bleeding (A), post-evisceration (B), post-final washing (C), meat cuts (D), bovine feces (F), surfaces (S), feces human (H) and wastewater (AR), from a cattle slaughterhouse, analyzing animals from two production systems: intensive and extensive. The samples were characterized in terms of pathotypes, phylogroups, and serogroups and analyzed using the chi-square test (p < 0.05). 126 samples were positive for E. coli, with points F (100%) and H (80%) being the points with the highest positivity. Only at point F was DEC identified (n = 35), with 28% of the animals in the intensive system and 38% in the extensive system positive for STEC, and 4% of the animals in the extensive system positive for EIEC, with no statistical difference between the production systems. Regarding phylogroups, B1 was the most detected in both systems, with 24% positivity in the intensive system and 68% in the extensive system. Serogroups O113 and O104 were detected, both in 4% of animals raised in an intensive system and in 6% of those in an extensive system. In view of the results, even with the identification of STEC and EIEC in the animals' feces, there was no difference between the rearing systems, with regard to pathotypes, phylogroups, and serogroups.

Correlation between Escherichia coli resistant gene isolated from stool samples of children under five years and that from consumed water

Diarrheagenic Escherichia coli (DEC) causes enteric infections and diarrhea, especially in young children. Kenya reports around 2.6 million cases and 7,000 deaths annually due to diarrhea. Antibiotic-resistant DEC strains are a significant public health concern, complicating treatment. The objective of this research was to correlate children's water consumption and antimicrobial-resistant DEC development. The study sampled 1124 children under five with diarrhea in Nakuru, Kenya, using a case-control design. Among 384 eligible children, 192 cases showed Amoxicillin-resistant DEC. Water samples from households were collected and analyzed for DEC presence. The samples were filtered, plated onto MacConkey agar, and subcultured onto Eosin Methylene Blue agar for further analysis. The DEC pathotypes were identified based on morphological and biochemical characteristics, and antibiotic resistance was assessed using the Kirby-Bauer disk diffusion method. The study revealed a strong correlation of 11.613 (95 % Confidence Interval [CI]: 6.495–20.765, p-value: 0.000) between microbial burden in vended water (water sold by vendors) used by different households consumption and antimicrobial resistance in DEC. Water sources showed a high prevalence of DEC, primarily Enteroaggregative, enteropathogenic, enterotoxigenic, and enteroinvasive E. coli. DEC isolates also exhibited varying antibiotic resistance, and genes like blaCTX-M, blaTEM, and blaSHV were identified using PCR. The Spearman correlation coefficient was one, showing that resistance genes in water and stool were perfectly correlated. The study emphasizes the significance of improving water quality, hygiene, and antibiotic-resistant bacteria control to prevent and manage DEC and infectious diseases in Kenya. To combat outbreaks, effective surveillance and rapid reaction procedures are essential. The findings help to shape public health policies and initiatives.

A modern view of diarrheagenic &lt;i&gt;Escherichia coli&lt;/i&gt; — a causative agent of acute intestinal infections

Acute intestinal infections caused by Escherichia coli affect the gastrointestinal tract, leading to development of diarrheal syndrome, intoxication, and, in some cases, generalization of the pathological process. Diarrheagenic E. coli (DEC) strains differ from non-pathogenic (commensal) strains by the presence of specific virulence genes, pathogenesis characteristics, clinical and epidemiological manifestations of the diseases they cause. Based on the virulence determinants, 6 pathogenic DEC groups are distinguished: enteropathogenic, enterotoxigenic, enteroinvasive, shiga toxin-producing, enteroaggregative, diffusely adherent E. coli strains. The strains of each pathogenic group have distinct pathogenic mechanisms responsible for inflammatory processes in different compartments of the human intestine, which are clinically manifested as diarrheal syndrome. This paper presents a review of current scientific publications on epidemiology, pathogenesis, genetic properties, and antigenic characteristics of pathogenic E. coli. Although DEC biological properties have been extensively studied, many aspects require deeper insights to develop effective laboratory-based diagnostic techniques, treatment methods, epidemic control measures, and prevention strategies against E. coli infections.

Antibiotic utilization and resistance in diarrheagenic Escherichia coli isolated from children under 5 Years in Nakuru County: a case-control study

Background: Children under the age of 5 years continue to suffer the ravaging effects of microbial resistance. Majority of the infections associated with this age are of bacterial and viral nature. Highest mortalities in this age group are those associated with enteric and diarrheal diseases. Diarrheagenic Escherichia coli (DEC) is among the leading causes of these diseases due to their ubiquitous nature. Methods: The study adopted a case-control design and aimed at investigating antibiotic utilization and resistance in DEC strains isolated from children under 5 years in Nakuru County. A total sample size of 384 children were considered. Stool samples from anal swabs were obtained and cultured on Eosin Methylene Blue (EMB). Antimicrobial susceptibility testing was done using the Kirby-Bauer disk diffusion method to segregate the resistant DEC isolates against amoxicillin, ampicillin, erythromycin, cefoxitin and nalidixic acid. Results: All the DEC (n=192, 100%) strains were resistant to amoxicillin, n=168, 87.5% were resistant to ampicillin, n=156, 81.3% to erythromycin n=72, 37.5% to cefoxitin and only n=64, 33.3% to nalidixic acid. Based on demographic factors, it was that observed self-medication leads among factors contributing to the observed trend in antimicrobial resistance (AMR). Other factors such the length of antibiotic use did not show any level of significance (p&lt;0.05). Conclusions: Thus, we conclude that a conglomerate of several factors is associated with the rising cases of AMR among the DEC strains. Notably, the use of first-line antibiotics especially the β-lactams poses a critical health concern being the most resisted class of antibiotics. Therefore, the current study unravels the need to remediate the effects of AMR among the DEC strains through proper formulation and implementation of guidelines on antibiotic usage.