scholarly journals EARLY FEATURES OF INFECTION IN LIGATED LOOPS OF THE RABBIT SMALL INTESTINE INOCULATED WITH SHIGELLA FLEXNERI 3a, ENTEROPATHOGENIC E. COLI, ESCHERICHIA COLI AND VIBRIO PARAHAEMOLYTICUS

1967 ◽  
Vol 16 (3) ◽  
pp. 101-117 ◽  
Author(s):  
SHOGO SASAKI ◽  
AKIRA GHODA ◽  
HIROMICHI YAHAGI
Keyword(s):  
Escherichia Coli ◽  
Small Intestine ◽  
Vibrio Parahaemolyticus ◽  
Shigella Flexneri ◽  
E Coli ◽  
Rabbit Small Intestine ◽  
Early Features

Escherichia coli heat-stable toxin: its effect on motility of the small intestine

1982 ◽  
Vol 242 (4) ◽  
pp. G360-G363 ◽  
Author(s):  
J. R. Mathias ◽  
J. Nogueira ◽  
J. L. Martin ◽  
G. M. Carlson ◽  
R. A. Giannella
Keyword(s):  
Escherichia Coli ◽  
Small Intestine ◽  
Action Potential ◽  
Myoelectric Activity ◽  
Complex Activity ◽  
E Coli ◽  
Heat Stable ◽  
Rabbit Small Intestine ◽  
Weight Substance

Escherichia coli heat-stable enterotoxin is a low-molecular-weight substance that has been shown to induce the active secretion of fluid and electrolytes in the small intestine. In this study, we have characterized the effects of purified E. coli heat-stable toxin (ST, strain 18D, serotype 042:K86:H37) on the motility of rabbit small intestine by using myoelectric recording techniques. Substances, such as cholera toxin, that activate the adenylate cyclase-cAMP system induced predominantly migrating action-potential complex activity. E. coli ST, a toxin that activates the guanylate cyclase-cGMP system, was infused into isolated in vivo ileal loops of New Zealand White rabbits. Inactivated toxin was also studied by exposing the ST to 1 mM dithiothreitol for 90 min. Active E. coli ST induced only repetitive bursts of action potentials. When the toxin was inactivated with dithiothreitol, no alteration in myoelectric activity was observed. We speculate that repetitive bursts of action-potential activity may represent a virulent factor of the bacterium, altering motor activity to slow transit and allowing for bacterial proliferation and invasion.

Effect of toxigenic Escherichia coli on myoelectric activity of small intestine.

1978 ◽  
Vol 235 (3) ◽  
pp. E311 ◽  
Author(s):  
T W Burns ◽  
J R Mathias ◽  
G M Carlson ◽  
J L Martin ◽  
R P Shields
Keyword(s):  
Escherichia Coli ◽  
Small Intestine ◽  
Culture Filtrate ◽  
Intestinal Motility ◽  
Myoelectric Activity ◽  
E Coli ◽  
Small Intestinal Motility ◽  
Rabbit Small Intestine ◽  
Small Intestinal ◽  
Potential Complex

When exposed to cholera toxin (CT), distal ileal loops of the rabbit small intestine showed an alteration in myoelectric activity. This alteration was defined as the migrating action potential complex (MAPC). The purpose of this study was to determine, using myoelectric recording techniques, the effects of live toxigenic Escherichia coli (TEC) on motility. Live TEC, live nontoxigenic E. coli (NTEC), and culture filtrates of these organisms were studied. Live TEC and its filtrate induced MAPC activity similar to that of CT. Live TEC induced a mean of 3.8 MAPCs/h, significantly greater than induced by live NTEC. TEC filtrate induced a mean of 14.2 MAPCs/h, significantly greater than NTEC filtrate. Heating the TEC filtrate to 100 degrees C before use resulted in a significant decrease of MAPC activity. This experiment demonstrated that live TEC and its culture filtrate altered ileal myoelectric activity. The effect may have been mediated by a heat-labile enterotoxin. This study suggests that alterations in small intestinal motility may be important in the pathogenesis of TEC diarrhea.

scholarly journals Reclassification of Shigella species as later heterotypic synonyms of Escherichia coli in the Genome Taxonomy Database

2021 ◽  
Author(s):  
Donovan H Parks ◽  
Maria Chuvochina ◽  
Peter R Reeves ◽  
Scott A Beatson ◽  
Philip Hugenholtz
Keyword(s):  
Escherichia Coli ◽  
Type Strain ◽  
Shigella Flexneri ◽  
Laboratory Strain ◽  
Single Species ◽  
Species Definition ◽  
E Coli ◽  
Shigella Species ◽  
K 12 ◽  
Common Laboratory

Members of the genus Shigella have high genomic similarity to Escherichia coli and are often considered to be atypical members of this species. In an attempt to retain Shigella species as recognizable entities, they were reclassified as Escherichia species in the Genome Taxonomy Database (GTDB) using an operational average nucleotide identity (ANI)-based approach nucleated around type strains. This resulted in nearly 80% of E. coli genomes being reclassified to new species including the common laboratory strain E. coli K-12 (to 'E. flexneri') because it is more closely related to the type strain of Shigella flexneri than it is to the type strain of E. coli. Here we resolve this conundrum by treating Shigella species as later heterotypic synonyms of E. coli, present evidence supporting this reclassification, and show that assigning E. coli/Shigella strains to a single species is congruent with the GTDB-adopted genomic species definition.

scholarly journals Ocorrência de bactérias patogênicas e deteriorantes em sashimi de salmão: avaliação de histamina e de susceptibilidade a antimicrobianos

2020 ◽  
Vol 23 ◽  
Author(s):  
Karina Silva Cordeiro ◽  
Lygia Silva Galeno ◽  
Cáritas de Jesus Silva Mendonça ◽  
Isabel Azevedo Carvalho ◽  
Francisca Neide Costa
Keyword(s):  
Escherichia Coli ◽  
Salmo Salar ◽  
Vibrio Parahaemolyticus ◽  
E Coli

Resumo O estudo das condições higiênico sanitárias de alimentos cárneos consumidos crus, como o sashimi, é necessário para definir sua qualidade e possíveis consequências para a saúde humana. Foram coletadas 60 amostras de sashimi de salmão (Salmo salar), de dez restaurantes na cidade de São Luís, Maranhão - Brasil, sendo seis de cada local. As amostras foram analisadas para contagem de coliformes a 35 °C, coliformes a 45 °C e Staphylococcus coagulase positiva e negativa, identificação da presença de Escherichia coli, Salmonella sp., Vibrio parahaemolyticus e Aeromonas spp, teste de suscetibilidade a antimicrobianos dos isolados e quantificação de histamina nas amostras. Os resultados mostraram elevadas contagens de coliformes a 35 °C e 12 amostras com >102 NMP/g de coliformes a 45 °C, presença de E. coli e de Salmonella sp. em 3 amostras cada, ausência de V. parahaemolyticus e Staphylococcus coagulase positiva e contagem de Staphylococcus coagulase negativa entre <20 e 5,0x104 UFC/g, presença de Aeromonas spp. em 95% das amostras, sendo 60 isolados A. hydrophila e 6 A. caviae. Para suscetibilidade aos antimicrobianos, os isolados de E. coli foram sensíveis a CPM, CTX, LVX, PPT e SUT, dois resistentes a AMP; um resistente a GEN, um a AMI e um a AMC. Os isolados de Salmonella foram sensíveis a AMC, CPM, CFO, CRX, GEN, LVX e PPT, um resistente a AMI e um a AMP e SUT. Os isolados de Aeromonas foram resistentes em média a cinco dos antimicrobianos, sendo a AMP (97%), a CRX (90,9%) e a AMC (77,3%), e 81,8% foram sensíveis ao CPM. Os níveis de histamina variaram de 44,06 ± 0,74 a 505,46 ± 8,83 mg/kg, sendo 21 das amostras com níveis superiores a 100 mg/kg. As amostras apresentaram condições higiênicos sanitárias insatisfatórias e riscos para a saúde pública, por identificação de bactérias patogênicas e elevadas concentrações de histamina capazes de causar intoxicação escombróide, e ainda, isolados com multirresistência aos antimicrobianos testados.

scholarly journals High Resolution Melt Assays to Detect and Identify Vibrio parahaemolyticus, Bacillus cereus, Escherichia coli, and Clostridioides difficile Bacteria

2020 ◽  
Vol 8 (4) ◽  
pp. 561
Author(s):  
Allison C. Bender ◽  
Jessica A. Faulkner ◽  
Katherine Tulimieri ◽  
Thomas H. Boise ◽  
Kelly M. Elkins
Keyword(s):  
Escherichia Coli ◽  
High Resolution ◽  
Bacillus Cereus ◽  
Vibrio Parahaemolyticus ◽  
Bacterial Species ◽  
Human Pathogens ◽  
High Resolution Melt ◽  
E Coli ◽  
Clostridioides Difficile ◽  
Sensitivity Specificity

Over one hundred bacterial species have been determined to comprise the human microbiota in a healthy individual. Bacteria including Escherichia coli, Bacillus cereus, Clostridioides difficile, and Vibrio parahaemolyticus are found inside of the human body and B. cereus and E. coli are also found on the skin. These bacteria can act as human pathogens upon ingestion of contaminated food or water, if they enter an open wound, or antibiotics, and environment or stress can alter the microbiome. In this study, we present new polymerase chain reaction (PCR) high-resolution melt (HRM) assays to detect and identify the above microorganisms. Amplified DNA from C. difficile, E. coli, B. cereus, and V. parahaemolyticus melted at 80.37 ± 0.45 °C, 82.15 ± 0.37 °C, 84.43 ± 0.50 °C, and 86.74 ± 0.65 °C, respectively. A triplex PCR assay was developed to simultaneously detect and identify E. coli, B. cereus, and V. parahaemolyticus, and cultured microorganisms were successfully amplified, detected, and identified. The assays demonstrated sensitivity, specificity, reproducibility, and robustness in testing.

scholarly journals Cold Shock Induces Chromosomal qnr in Vibrio Species and Plasmid-Mediated qnrS1 in Escherichia coli

2019 ◽  
Vol 63 (12) ◽  
Author(s):  
Hee-Chang Jang ◽  
Yin Wang ◽  
Chunhui Chen ◽  
Laura Vinué ◽  
George A. Jacoby ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Bacterial Community ◽  
Vibrio Parahaemolyticus ◽  
Cold Shock ◽  
Vibrio Vulnificus ◽  
Wild Type ◽  
Induced Expression ◽  
Content Type ◽  
E Coli ◽  
Dna Damaging Agents

ABSTRACT qnr genes are found in aquatic bacteria and were present in the bacterial community before the introduction of synthetic quinolones. Their natural functions are unknown. We evaluated expression of chromosomal qnr in Vibrio species in response to environmental stresses and DNA-damaging agents. Subinhibitory concentrations of quinolones, but not other DNA-damaging agents, increased expression of chromosomal qnr by more than five times in Vibrio parahaemolyticus, Vibrio vulnificus, and Vibrio mytili. Cold shock also induced expression of qnr in V. parahaemolyticus, V. vulnificus, and V. mytili, as well as expression of qnrS1 in Escherichia coli. qnrS1 induction by cold shock was not altered in ΔihfA or ΔihfB mutants or in a strain overexpressing dnaA, all of which otherwise directly modulate qnrS1 induction by ciprofloxacin. In contrast, the level of qnrS1 induction by cold shock was reduced in a ΔcspA mutant in the cold shock regulon compared to the wild type. In conclusion, cold shock and quinolones induce expression of chromosomal qnr in Vibrio species and of the related qnrS1 gene in E. coli.

scholarly journals Genomic Subtraction To Identify and Characterize Sequences of Shiga Toxin-Producing Escherichia coli O91:H21

2002 ◽  
Vol 68 (5) ◽  
pp. 2316-2325 ◽  
Author(s):  
Nathalie Pradel ◽  
Sabine Leroy-Setrin ◽  
Bernard Joly ◽  
Valérie Livrelli
Keyword(s):  
Escherichia Coli ◽  
Dna Sequences ◽  
Shiga Toxin ◽  
Shigella Flexneri ◽  
Virulence Determinants ◽  
E Coli ◽  
Virulence Plasmids ◽  
Subtraction Procedure ◽  
Uremic Syndrome ◽  
Genomic Subtraction

ABSTRACT To identify Shiga toxin-producing Escherichia coli genes associated with severe human disease, a genomic subtraction technique was used with hemolytic-uremic syndrome-associated O91:H21 strain CH014 and O6:H10 bovine strains. The method was adapted to the Shiga toxin-producing E. coli genome: three rounds of subtraction were used to isolate DNA fragments specific to strain CH014. The fragments were characterized by genetic support analysis, sequencing, and hybridization to the genome of a collection of Shiga toxin-producing E. coli strains. A total of 42 fragments were found, 19 of which correspond to previously identified unique DNA sequences in the enterohemorrhagic E. coli EDL933 reference strain, including 7 fragments corresponding to prophage sequences and others encoding candidate virulence factors, such a SepA homolog protein and a fimbrial usher protein. In addition, the subtraction procedure yielded plasmid-related sequences from Shigella flexneri and enteropathogenic and Shiga toxin-producing E. coli virulence plasmids. We found that lateral gene transfer is extensive in strain CH014, and we discuss the role of genomic mobile elements, especially bacteriophages, in the evolution and possible transfer of virulence determinants.

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