scholarly journals Enteropathogenic Escherichia coli—A Summary of the Literature

2021 ◽  
Vol 12 (1) ◽  
pp. 28-40
Author(s):  
Anca Delia Mare ◽  
Cristina Nicoleta Ciurea ◽  
Adrian Man ◽  
Bianca Tudor ◽  
Valeriu Moldovan ◽  
...  

Diarrheal disease is still a major public health concern, as it is still considered an important cause of death in children under five years of age. A few decades ago, the detection of enteropathogenic E. coli was made by detecting the O, H, and K antigens, mostly by agglutination. The recent protocols recommend the molecular methods for diagnosing EPEC, as they can distinguish between typical and atypical EPEC by identifying the presence/absence of specific virulence factors. EPEC are defined as diarrheagenic strains of E. coli that can produce attaching and effacing lesions on the intestinal epithelium while being incapable of producing Shiga toxins and heat-labile or heat-stable enterotoxins. The ability of these strains to produce attaching and effacing lesions enable them to cause localized lesions by attaching tightly to the surface of the intestinal epithelial cells, disrupting the surfaces of the cells, thus leading to the effacement of the microvilli. EPEC are classified on typical and atypical isolates, based on the presence or absence of E. coli adherence factor plasmids. All the EPEC strains are eae positive; typical EPEC strains are eae+, bfpA+, while atypical strains are eae+, bfpA−. No vaccines are currently available to prevent EPEC infections.

2021 ◽  
Vol 17 (1) ◽  
Author(s):  
Pouya Reshadi ◽  
Fatemeh Heydari ◽  
Reza Ghanbarpour ◽  
Mahboube Bagheri ◽  
Maziar Jajarmi ◽  
...  

Abstract Background Transmission of antimicrobial resistant and virulent Escherichia coli (E. coli) from animal to human has been considered as a public health concern. This study aimed to determine the phylogenetic background and prevalence of diarrheagenic E. coli and antimicrobial resistance in healthy riding-horses in Iran. In this research, the genes related to six main pathotypes of E. coli were screened. Also, genotypic and phenotypic antimicrobial resistance against commonly used antibiotics were studied, then phylo-grouping was performed on all the isolates. Results Out of 65 analyzed isolates, 29.23 % (n = 19) were determined as STEC and 6.15 % (n = 4) as potential EPEC. The most prevalent antimicrobial resistance phenotypes were against amoxicillin/clavulanic acid (46.2 %) and ceftriaxone (38.5 %). blaTEM was the most detected resistance gene (98.4 %) among the isolates and 26.15 % of the E. coli isolates were determined as multi-drug resistant (MDR). Three phylo-types including B1 (76.92 %), A (13.85 %) and D (3.08 %) were detected among the isolates. Conclusions Due to the close interaction of horses and humans, these findings would place emphasis on the pathogenic and zoonotic potential of the equine strains and may help to design antimicrobial resistance stewardship programs to control the dissemination of virulent and multi-drug resistant E. coli strains in the community.


2021 ◽  
Vol 11 (5) ◽  
pp. 583-587
Author(s):  
Kouengoua Armelle ◽  
Deguenon Esther ◽  
Dougnon T. Victorien ◽  
Farougou Souaïbou ◽  
Kpodékon Tchokponhoué Tchégninougbo Marc ◽  
...  

Bats play a very important role in the transmission of zoonosis, including Salmonella. Salmonella are responsible for salmonellosis, which is a major public health concern. They are the cause of many hospitalizations and deaths worldwide. The objective of this study was to contribute to the im-provement of the control of zoonotic strains of Salmonella in Benin. To do so, a collection of 400 bats was made and after slaughter and dissection, bacteriological analyses were made on the gut to isolate and identify the different strains of Salmonella carried by these bats. The resistance profile and the presence of specific virulence gene such invA, spvR, spvC and stn were studied. The strain Salmonella Typhimurium ATCC 14028 was used as a positive control. Of the 400 bats slaughtered, 14 isolate of Salmonella spp were identified by API gallery. Therefore, the prevalence of Salmonella strains in bats was 3.5%. Salmonella spp strains isolated showed total re-sistance to amoxicillin, clavulanic acid and also to first and second genera-tions of cephalosporins. The stn and invA genes have been found in the DNA of all strains of Salmonella isolated. The consumption of bats being a com-mon practice in Benin, the risk of virulent Salmonella strains transmission must be taken very seriously and people must be sensitized to this in order to slow down the risk of infection.


2019 ◽  
Author(s):  
Elizabeth Muligisa Muonga ◽  
Geoffrey Mainda ◽  
Mercy Mukuma ◽  
Geoffrey Kwenda ◽  
Bernard Hang'ombe ◽  
...  

Abstract Background Antimicrobial resistance (AMR) of foodborne pathogens is of public health concern, especially in developing countries like Zambia. This study was undertaken to determine the resistance profiles of Escherichia coli ( E. coli ) and Salmonella isolated from dressed broiler chickens purchased from open markets and supermarkets in Zambia.Results A total of 189 E. coli and five Salmonella isolates were isolated. Identification and confirmation of the isolates was done using Analytical Profile Index (API 20E) (Biomerieux ® ) and 16S rRNA sequencing. Antimicrobial susceptibility tests (AST) were performed using the Kirby Bauer disk diffusion technique using a panel of 10 different antibiotics and multiplex PCR was used to determine the presence of three target genes encoding for resistance: tetA, Sul1 and CTXM. AST results were entered and analyzed in WHONET 2018 software. A total of 189 E. coli and five Salmonella isolates were identified. Among the E. coli isolates, Tetracycline recorded the highest resistance of 79.4%, followed by Ampicillin 51.9%, Trimethoprim/Sulfamethoxazole 49.7%, Nalidixic Acid 24.3%, Chloramphenicol 16.4%, Cefotaxime 16.4%, Ciprofloxacin 10.1%, Colistin 7.4%, Amoxicillin/Clavulanic acid 6.9%, and Imipenem 1.1%. Two of the five Salmonella isolates were resistant to at least one antibiotic. Forty- seven (45.2%) of the isolates possessed at least one of the targeted resistance genes.Conclusion This study has demonstrated the presence of AMR E. coli and Salmonella on raw broiler chickens from both open markets and supermarkets. Such resistance is of public health concern and measures need to be put in place to regulate the use of these antimicrobials in poultry production.


2014 ◽  
Vol 82 (12) ◽  
pp. 5308-5316 ◽  
Author(s):  
Lisa T. Read ◽  
Rachel W. Hahn ◽  
Carli C. Thompson ◽  
David L. Bauer ◽  
Elizabeth B. Norton ◽  
...  

ABSTRACTEnterotoxigenicEscherichia coli(ETEC) is a significant cause of diarrheal disease and death, especially in children in developing countries. ETEC causes disease by colonizing the small intestine and producing heat-labile toxin (LT), heat-stable toxin (ST), or both LT and ST (LT+ST). The majority of ETEC strains produce both ST and LT. Despite the prevalence of LT+ST-producing organisms, few studies have examined the physiologic or immunologic consequences of simultaneous exposure to these two potent enterotoxins. In the current report, we demonstrate that when LT and ST are both present, they increase water movement into the intestinal lumen over and above the levels observed with either toxin alone. As expected, cultured intestinal epithelial cells increased their expression of intracellular cyclic GMP (cGMP) when treated with ST and their expression of intracellular cyclic AMP (cAMP) when treated with LT. When both toxins were present, cGMP levels but not cAMP levels were synergistically elevated compared with the levels of expression caused by the corresponding single-toxin treatment. Our data also demonstrate that the levels of inflammatory cytokines produced by intestinal epithelial cells in response to LT are significantly reduced in animals exposed to both enterotoxins. These findings suggest that there may be complex differences between the epithelial cell intoxication and, potentially, secretory outcomes induced by ETEC strains expressing LT+ST compared with strains that express LT or ST only. Our results also reveal a novel mechanism wherein ST production may reduce the hosts' ability to mount an effective innate or adaptive immune response to infecting organisms.


2020 ◽  
Author(s):  
Elizabeth Muligisa Muonga ◽  
Geoffrey Mainda ◽  
Mercy Mukuma ◽  
Geoffrey Kwenda ◽  
Bernard Hang'ombe ◽  
...  

Abstract BackgroundAntimicrobial resistance (AMR) of foodborne pathogens is of public health concern, especially in developing countries such as Zambia. This study was undertaken to determine the antimicrobial resistance profiles of Escherichia coli ( E. coli ) and Salmonella isolated from raw retail broiler chicken carcasses purchased from open and supermarkets in Zambia.ResultsA total of 189 E. coli and five Salmonella isolates were isolated. Identification and confirmation of the isolates were done using Analytical Profile Index (API 20E) (Biomerieux ® ) and 16S rRNA sequencing. Antimicrobial susceptibility tests (AST) were performed using the Kirby Bauer disk diffusion technique using a panel of 10 antibiotics. Multiplex PCR was used to determine the presence of three target genes encoding for resistance: tet A, Sul 1 and bla CTX-M . WHONET 2018 software was used to analyse AST results. The E. coli isolates were mostly resistant to tetracycline (79.4%), ampicillin (51.9%), and trimethoprim/sulfamethoxazole (49.7%). Two of the five Salmonella isolates were resistant to at least one antibiotic. Forty- seven (45.2%) of the 104 isolates that were screened for the presence of the resistant genes possessed at least one of the targeted resistance genes.ConclusionThis study has demonstrated the presence of AMR E. coli and Salmonella on raw retail broiler chicken carcasses from open and supermarkets, which is of public health concern.


Author(s):  
Akebe Luther King ABIA ◽  
Eunice UBOMBA-JASWA

Background: Fomites (including money) can transmit diseases to humans. How the nature of money influences contamination has not been adequately demonstrated. Moreover, such studies in church settings are non-existent. Thus, we studied how money collected from a church could serve as human disease transmission vehicles. Methods: Overall, 284 money samples (currency notes and coins) were collected during two Sundays in the months of Nov and Dec 2015 from a church congregation in Pretoria, Gauteng, South Africa. The presence of potentially pathogenic bacteria and fungi were investigated using culture (Colilert® method) and molecular methods (Sanger sequencing). Scanning Electron Microscopy (SEM) was used to visualize the possible positions of the bacteria on various parts of a currency note. Results: Of the 192 samples (first sampling round), 76 (39.6%) were positive for E. coli. Smaller notes (R10) recorded the highest E. coli counts per note. Of the 92 notes analyzed for potentially pathogenic bacteria and fungi (second sampling round), 76 (82%) showed growth on at least one of the six culture media used. Sequencing revealed three bacterial (Bacillus, Staphylococcus and Corynebacterium) and two fungal (Clavispora and Rhodotorula) genera. SEM revealed that microorganisms could enter cracks of creased notes. Conclusion: Unlike previous studies conducted where recent contamination could occur, the current study shows that microorganisms can survive on money; samples were collected from a church, where little or no exchange takes place. Moreover, using SEM demonstrates that aged and creased notes favor attachment of bacteria to money and could be of public health concern by transmitting disease within a given population.


1983 ◽  
Vol 245 (4) ◽  
pp. G492-G498 ◽  
Author(s):  
R. A. Giannella ◽  
M. Luttrell ◽  
M. Thompson

This study was performed to determine whether receptors for Escherichia coli heat-stable enterotoxin (ST) exist on intestinal epithelial cells. Binding sites for 125I-ST were found on rat jejunal and ileal villus cells. Binding was rapid, reversible, linear with cell number, saturable, and temperature dependent. Significant degradation of 125I-ST occurred when incubated with cells at 37 degrees C but not at 25 degrees C. Binding was specific to ST since binding of 125I-ST was competitively inhibited by increasing concentrations of human or porcine ST but not by E. coli heat-labile, cholera, or staphylococcal enterotoxins. Addition of excess unlabeled ST to cells preincubated with 125I-ST resulted in dissociation of much but not all of the bound 125I-ST. Binding of 125I-ST to jejunal and ileal cells occurs with two affinities, and this is due to the phenomenon of negative cooperativity. The potency of ST for inhibiting the binding of 125I-ST was identical to the potency of ST in stimulating cGMP production. These data support the existence of receptors for ST on intestinal cells, and these receptors may be involved in the action of ST.


2018 ◽  
Author(s):  
Alline R. Pacheco ◽  
Jacob E. Lazarus ◽  
Brandon Sit ◽  
Stefanie Schmieder ◽  
Wayne I. Lencer ◽  
...  

AbstractEnterohemorrhagicEscherichia coli(EHEC) has two critical virulence factors – a type III secretion system (T3SS) and Shiga toxins (Stx) – that are required for the pathogen to colonize the intestine and cause diarrheal disease. Here, we carried out a genome-wide CRISPR/Cas9 loss-of-function screen to identify host loci that facilitate EHEC infection of intestinal epithelial cells. Many of the guide RNAs identified targeted loci known to be associated with sphingolipid biosynthesis, particularly for production of globotriaosylceramide (Gb3), the Stx receptor. Two loci (TM9SF2 and LAPTM4A) with largely unknown functions were also targeted. Mutations in these loci not only rescued cells from Stx-mediated cell death, but also prevented cytotoxicity associated with the EHEC T3SS. These mutations interfered with early events associated with T3SS and Stx pathogenicity, markedly reducing entry of T3SS effectors into host cells and binding of Stx. The convergence of Stx and T3SS onto overlapping host targets provides guidance for design of new host-directed therapeutic agents to counter EHEC infection.ImportanceEnterohemorrhagicEscherichia coli(EHEC) has two critical virulence factors – a type III secretion system (T3SS) and Shiga toxins (Stx) – that are required for colonizing the intestine and causing diarrheal disease. We screened a genome-wide collection of CRISPR mutants derived from intestinal epithelial cells and identified mutants with enhanced survival following EHEC infection. Many had mutations that disrupted synthesis of a subset of lipids (sphingolipids) that includes the Stx receptor globotriaosylceramide (Gb3), and hence protect against Stx intoxication. Unexpectedly, we found that sphingolipids also mediate early events associated with T3SS pathogenicity. Since antibiotics are contraindicated for the treatment of EHEC, therapeutics targeting sphingolipid biosynthesis are a promising alternative, as they could provide protection against both of the pathogen’s key virulence factors.


2014 ◽  
Vol 143 (3) ◽  
pp. 505-514 ◽  
Author(s):  
M. TSENG ◽  
P. M. FRATAMICO ◽  
L. BAGI ◽  
D. MANZINGER ◽  
J. A. FUNK

SUMMARYThis descriptive longitudinal study was conducted to investigate the faecal shedding of Shiga toxin-producingE. coli(STEC) in finishing swine and to characterize the swine STEC isolates that were recovered. Three cohorts of finishing swine (n = 50/cohort; total 150 pigs) were included in the longitudinal study. Individual faecal samples were collected every 2 weeks (8 collections/pig) from the beginning (pig age 10 weeks) to the end (pig age 24 weeks) of the finishing period. STEC isolates were recovered in at least one sample from 65·3% (98/150) of the pigs, and the frequency distribution of first-time STEC detection during the finishing period resembled a point-source outbreak curve. Nineteen O:H serotypes were identified among the STEC isolates. Most STEC isolates (n = 148) belonged to serotype O59:H21 and carried thestx2egene. One O49:H21 STEC isolate carried thestx2eandeaegenes. High prevalence rates of STEC during the finishing period were observed, and STEC isolates in various non-O157 serogroups were recovered. These data enhance understanding of swine STEC epidemiology, and future research is needed to confirm whether or not swine STEC are of public health concern.


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