scholarly journals The effect of Verotoxin Producing Escherichia coli in Development of Experimental Gastroenteritis among Streptomycin Treated Murine Model: A Longitudinal Study

2016 ◽  
Vol 30 (1-2) ◽  
pp. 31-38
Author(s):  
Fahareen Binta Mosharraf ◽  
Chowdhury Rafiqul Ahsan ◽  
Jamalun Nessa ◽  
Mahmuda Yasmin
Keyword(s):  
Escherichia Coli ◽  
Large Scale ◽  
Lethal Dose ◽  
Escherichia Coli O157 ◽  
Disease Symptoms ◽  
E Coli ◽  
Sporadic Cases ◽  
Alternative Routes ◽  
Minimum Lethal Dose

Escherichia coli O157:H7 is a newly emerged pathogen, which has been recognized as a major cause of large scale epidemics and thousands of sporadic cases of gastrointestinal illness. This observation particularly calls for the in vivo examination of E. coli O157 candidates in an attempt to mimic various aspects of E. coli O157:H7 disease symptoms in humans. Healthy conventional Swiss albino mice were used for investigating the clinical manifestation exerted by stx1A and stx2A positive E. coli O157:H7 in various doses applied through three alternative routes (oral, intramuscular and intraperitoneal). The highest titer of orally added E. coli 0157:H7 (109 CFU ml-1) among the five test doses had started symptoms at the earliest time and manifested most of the classical symptoms. The symptoms started to become visible at 14th hour, increased with time and had reached moribund condition near 48th hour just before death of the host. The oral way of E. coli O157:H7 addition at the dose of 100 ?l suspension containing 1 X 109CFU ml-1 was taken as the most potent concentration in producing bacterial fatality and hence was selected as the Minimum Lethal Dose (MLD).Bangladesh J Microbiol, Volume 30, Number 1-2,June-Dec 2013, pp 31-38

scholarly journals Exploring the best possible route of infection of Verotxin producing Escherichia coli in development of experimental gastroenteritis among streptomycin treated murine model

2015 ◽  
Vol 39 (1) ◽  
pp. 53-58
Author(s):  
Fahareen Binta Mosharraf ◽  
Chowdhury Rafiqul Ahsan ◽  
Jamalun Nessa ◽  
Mahmuda Yasmin
Keyword(s):  
Escherichia Coli ◽  
Murine Model ◽  
Bacterial Infections ◽  
Lethal Dose ◽  
Bacterial Strains ◽  
E Coli ◽  
Culture Count ◽  
Alternative Routes ◽  
Academy Of Sciences ◽  
Minimum Lethal Dose

The prevalence of Escherichia coli O157:H7 induced bacteremia generate a critical problem in modern medical therapy for bacterial infections. This study sought to find out the best possible route and dose of E. coli 0157:H7 infection in experimental murine model by periodic stool and blood culture count of relevant bacterial strains. Streptomycin treated mouse model were used for investigating the clinical manifestation exerted by stx1A and stx2A positive E. coli O157:H7 with increasing doses applied through three alternative routes (oral, intramuscular and intraperitoneal). The highest titer of orally added E. coli 0157:H7 among five test doses started showing symptoms at the earliest time and reached moribund condition about 48 hours just before being dead. The oral way of E.coli O157:H7 at the dose of 100 ml suspension containing 1 ´ 109CFU ml-1 was taken as the most potent concentration in producing bacterial fatality and hence was selected as the minimum lethal dose (MLD).Journal of Bangladesh Academy of Sciences, Vol. 39, No. 1, 53-58, 2015

Effect of Tannins on the In Vitro Growth of Escherichia coli O157:H7 and In Vivo Growth of Generic Escherichia coli Excreted from Steers

2007 ◽  
Vol 70 (3) ◽  
pp. 543-550 ◽  
Author(s):  
BYENG R. MIN ◽  
WILLIAM E. PINCHAK ◽  
ROBIN C. ANDERSON ◽  
TODD R. CALLAWAY
Keyword(s):  
Escherichia Coli ◽  
Growth Rate ◽  
Bacterial Growth ◽  
Escherichia Coli O157 ◽  
Tannin Extract ◽  
Bacterial Growth Rate ◽  
Linear Effect ◽  
E Coli

The effect of commercially available chestnut and mimosa tannins in vitro (experiment 1) or in vivo (experiment 2) on the growth or recovery of Escherichia coli O157:H7 or generic fecal E. coli was evaluated. In experiment 1, the mean growth rate of E. coli O157:H7, determined via the measurement of optical density at 600 nm during anaerobic culture in tryptic soy broth at 37°C, was reduced (P < 0.05) with as little as 400 μg of either tannin extract per ml of culture fluid. The addition of 200, 400, 600, 800, and 1,200 μg of tannins per ml significantly (P < 0.01) reduced the specific bacterial growth rate when compared with the nontannin control. The specific growth rate decreased with increasing dose levels up to 800 μg of tannins per ml. Bacterial growth inhibition effects in chestnut tannins were less pronounced than in mimosa tannins. Chestnut tannin extract addition ranged from 0 to 1,200 μg/ml, and a linear effect (P < 0.05) was observed in cultures incubated for 6 h against the recovery of viable cells, determined via the plating of each strain onto MacConkey agar, of E. coli O157:H7 strains 933 and 86-24, but not against strain 6058. Similar tests with mimosa tannin extract showed a linear effect (P < 0.05) against the recovery of E. coli O157:H7 strain 933 only. The bactericidal effect observed in cultures incubated for 24 h with the tannin preparations was similar, although it was less than that observed from cultures incubated for 6 h. When chestnut tannins (15 g of tannins per day) were infused intraruminally to steers fed a Bermuda grass hay diet in experiment 2, fecal E. coli shedding was lower on days 3 (P < 0.03), 12 (P = 0.08), and 15 (P < 0.001) when compared with animals that were fed a similar diet without tannin supplementation. It was concluded that dietary levels and sources of tannins potentially reduce the shedding of E. coli from the gastrointestinal tract.

scholarly journals Use of In Vivo-Induced Antigen Technology for Identification of Escherichia coli O157:H7 Proteins Expressed during Human Infection

2005 ◽  
Vol 73 (5) ◽  
pp. 2665-2679 ◽  
Author(s):  
Manohar John ◽  
Indira T. Kudva ◽  
Robert W. Griffin ◽  
Allen W. Dodson ◽  
Bethany McManus ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Vaccine Development ◽  
Human Infection ◽  
Escherichia Coli O157 ◽  
Standard Laboratory ◽  
E Coli ◽  
Phase Culture ◽  
Stool Specimens

ABSTRACT Using in vivo-induced antigen technology (IVIAT), a modified immunoscreening technique that circumvents the need for animal models, we directly identified immunogenic Escherichia coli O157:H7 (O157) proteins expressed either specifically during human infection but not during growth under standard laboratory conditions or at significantly higher levels in vivo than in vitro. IVIAT identified 223 O157 proteins expressed during human infection, several of which were unique to this study. These in vivo-induced (ivi) proteins, encoded by ivi genes, mapped to the backbone, O islands (OIs), and pO157. Lack of in vitro expression of O157-specific ivi proteins was confirmed by proteomic analysis of a mid-exponential-phase culture of E. coli O157 grown in LB broth. Because ivi proteins are expressed in response to specific cues during infection and might help pathogens adapt to and counter hostile in vivo environments, those identified in this study are potential targets for drug and vaccine development. Also, such proteins may be exploited as markers of O157 infection in stool specimens.

Growth of Escherichia coli O157:H7 and Listeria monocytogenes in Packaged Fresh-Cut Romaine Mix at Fluctuating Temperatures during Commercial Transport, Retail Storage, and Display

2014 ◽  
Vol 77 (2) ◽  
pp. 197-206 ◽  
Author(s):  
WENTING ZENG ◽  
KEITH VORST ◽  
WYATT BROWN ◽  
BRADLEY P. MARKS ◽  
SANGHYUP JEONG ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Listeria Monocytogenes ◽  
Large Scale ◽  
Microbial Growth ◽  
Escherichia Coli O157 ◽  
Temperature Profiles ◽  
E Coli ◽  
Leafy Greens ◽  
Retail Display ◽  
Fluctuating Temperatures

Temperature abuse during commercial transport and retail sale of leafy greens negatively impacts both microbial safety and product quality. Consequently, the effect of fluctuating temperatures on Escherichia coli O157:H7 and Listeria monocytogenes growth in commercially-bagged salad greens was assessed during transport, retail storage, and display. Over a 16-month period, a series of time-temperature profiles for bagged salads were obtained from five transportation routes covering four geographic regions (432 profiles), as well as during retail storage (4,867 profiles) and display (3,799 profiles). Five different time-temperature profiles collected during 2 to 3 days of transport, 1 and 3 days of retail storage, and 3 days of retail display were then duplicated in a programmable incubator to assess E. coli O157:H7 and L. monocytogenes growth in commercial bags of romaine lettuce mix. Microbial growth predictions using the Koseki-Isobe and McKellar-Delaquis models were validated by comparing the root mean square error (RMSE), bias, and the acceptable prediction zone between the laboratory growth data and model predictions. Monte Carlo simulations were performed to calculate the probability distribution of microbial growth from 8,122,127,472 scenarios during transport, cold room storage, and retail display. Using inoculated bags of retail salad, E. coli O157:H7 and L. monocytogenes populations increased a maximum of 3.1 and 3.0 log CFU/g at retail storage. Both models yielded acceptable RMSEs and biases within the acceptable prediction zone for E. coli O157:H7. Based on the simulation, both pathogens generally increased <2 log CFU/g during transport, storage, and display. However, retail storage duration can significantly impact pathogen growth. This large-scale U.S. study—the first using commercial time/temperature profiles to assess the microbial risk of leafy greens—should be useful in filling some of the data gaps in current risk assessments for leafy greens.

Selection of In Vivo Expressed Genes of Escherichia coli O157:H7 Strain EDL933 in Ground Meat under Elevated Temperature Conditions

2012 ◽  
Vol 75 (10) ◽  
pp. 1743-1750 ◽  
Author(s):  
ANDREA KROJ ◽  
HERBERT SCHMIDT
Keyword(s):  
Escherichia Coli ◽  
Elevated Temperatures ◽  
Genomic Library ◽  
Transport Processes ◽  
Enterohemorrhagic Escherichia Coli ◽  
Escherichia Coli O157 ◽  
Ground Meat ◽  
E Coli ◽  
Selection Of

Enterohemorrhagic Escherichia coli O157:H7 strains are important foodborne pathogens that are often transmitted to humans by the ingestion of raw or undercooked meat of bovine origin. To investigate adaptation of this pathogen during persistence and growth in ground meat, we established an in vivo expression technology model to identify genes that are expressed during growth in this food matrix under elevated temperatures (42°C). To improve on the antibiotic-based selection method, we constructed the promoter trap vector pAK-1, containing a promoterless kanamycin resistance gene. A genomic library of E. coli O157:H7 strain EDL933 was constructed in pAK-1 and used for promoter selection in ground meat. The 20 in vivo expressed genes identified were associated with transport processes, metabolism, macromolecule synthesis, and stress response. For most of the identified genes, only hypothetical functions could be assigned. The results of our study provide the first insights into the complex response of E. coli O157:H7 to a ground meat environment under elevated temperatures and establish a suitable vector for promoter studies or selection of in vivo induced promoters in foods such as ground meat.

scholarly journals Long Polar Fimbriae Contribute to Colonization by Escherichia coli O157:H7 In Vivo

2004 ◽  
Vol 72 (10) ◽  
pp. 6168-6171 ◽  
Author(s):  
Dianna M. Jordan ◽  
Nancy Cornick ◽  
Alfredo G. Torres ◽  
Evelyn A. Dean-Nystrom ◽  
James B. Kaper ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Parent Strain ◽  
Escherichia Coli O157 ◽  
Intestinal Colonization ◽  
E Coli ◽  
Gnotobiotic Piglets

ABSTRACT The contribution of long polar fimbriae to intestinal colonization by Escherichia coli O157:H7 was evaluated in sheep, conventional pigs, and gnotobiotic piglets. E. coli O157:H7 strains with lpfA1 and lpfA2 mutated were recovered in significantly lower numbers and caused fewer attachment and effacement lesions than the parent strain.

Prevention of 5-fluorouracil-induced infection with indigenous Escherichia coli in tumor-bearing mice by nonspecific immunostimulation

1992 ◽  
Vol 38 (8) ◽  
pp. 774-778 ◽  
Author(s):  
Koji Nomoto ◽  
Teruo Yokokura ◽  
Kikuo Nomoto
Keyword(s):  
Escherichia Coli ◽  
Lactobacillus Casei ◽  
Lethal Dose ◽  
Systemic Infection ◽  
Specific Pathogen Free ◽  
E Coli ◽  
Tumor Bearing ◽  
Lethal Toxicity ◽  
Specific Pathogen

We have previously reported that the lethal toxicity of 5-fluorouracil (5-FU) in specific-pathogen-free mice is due to an indigenous infection with Escherichia coli (K. Nomoto, T. Yokokura, Y. Yoshikai, et al. Can. J. Microbiol. 37: 244–247, 1991). In the present study, we demonstrate that nonspecific immunostimulation augments host resistance against the lethal toxicity of 5-FU in tumor-bearing mice. Intravenous administration of a preparation of heat-killed Lactobacillus casei (LC 9018), a nonspecific immunostimulant, at a dose of 20 mg/kg to BALB/c mice augmented their resistance against the lethal toxicity of 5-FU if the preparation was injected into the mice 10–40 days before administration of 5-FU. Injection of LC 9018 into BALB/c mice bearing Meth A fibrosarcoma also enhanced their resistance against the lethality of 5-FU. Systemic infection with E. coli was induced in all of the 5-FU-treated tumor-bearing mice 10 days or more after administration of the drug at a lethal dose of 500 mg/kg, and it was accompanied by an overgrowth of the bacteria in the intestine. Treatment of tumor-bearing mice with LC 9018 resulted in decreased rates of occurrence of systemic infection with E. coli and inhibition of overgrowth of the bacteria in the intestine after administration of 5-FU. A single administration of either LC 9018 or 5-FU significantly inhibited the growth of Meth A cells in vivo, and a combined antitumor effect was shown in the mice treated with both 5-FU and LC 9018. Key words: tumor-bearing mice, fluorouracil, nonspecific immunostimulation, indigenous infection, Escherichia coli.

scholarly journals Isolation and Antimicrobial Susceptibility Profile of Escherichia coli O157 : H7 from Raw Milk of Dairy Cattle in Holeta District, Central Ethiopia

2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Ashenafi Ababu ◽  
Dereje Endashaw ◽  
Haben Fesseha
Keyword(s):  
Escherichia Coli ◽  
Dairy Cattle ◽  
Antimicrobial Susceptibility ◽  
Large Scale ◽  
Raw Milk ◽  
Herd Size ◽  
Escherichia Coli O157 ◽  
Cross Sectional ◽  
E Coli ◽  
Antimicrobial Susceptibility Profile

A cross-sectional study was conducted in small, medium, and large-scale dairy farms of Holeta district to isolate, identify, and antimicrobial susceptibility profile of Escherichia coli O157 : H7 in raw milk of dairy cattle. A total of 210 lactating cows were selected for raw milk samples, and 19% (40/210) were found to be positive for E. coli whereas 5.2% (11/210) were confirmed as E. coli O157 : H7 positive using the Escherichia coli O157 latex test. Accordingly, all E. coli was highly susceptible to Ciprofloxacin (100%), Gentamycin (100%), Oxytetracycline (100%), and Tetracycline (63.63%). Furthermore, the resistance of 72.73%, 54.54%, 54.54%, and 45.45% was developed to Cefoxitin, Sulphamethoxazole, Cloxacillin, and Streptomycin, respectively. Factors such as parity, age, body condition, herd size, milk yield, udder hygiene, and udder lesion showed a statistically significant ( p < 0.05 ) association with the occurrence of E. coli infection in dairy cattle. In conclusion, in this study, a higher prevalence of Escherichia coli O157 : H7 and its drug susceptibility profile is an alarm for the health of the public, and awareness creation to the farm owners and the community is recommended.

scholarly journals Adherence of Escherichia coli O157:H7 Mutants In Vitro and in Ligated Pig Intestines

2009 ◽  
Vol 75 (15) ◽  
pp. 4975-4983 ◽  
Author(s):  
Xianhua Yin ◽  
James R. Chambers ◽  
Roger Wheatcroft ◽  
Roger P. Johnson ◽  
Jing Zhu ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Virulence Genes ◽  
Cultured Cells ◽  
Escherichia Coli O157 ◽  
Wild Type ◽  
Wild Type Level ◽  
E Coli

ABSTRACT There are contradictory literature reports on the role of verotoxin (VT) in adherence of enterohemorrhagic Escherichia coli O157:H7 (O157 EHEC) to intestinal epithelium. There are reports that putative virulence genes of O island 7 (OI-7), OI-15, and OI-48 of this pathogen may also affect adherence in vitro. Therefore, mutants of vt2 and segments of OI-7 and genes aidA 15 (gene from OI-15) and aidA 48 (gene from OI-48) were generated and evaluated for adherence in vitro to cultured human HEp-2 and porcine jejunal epithelial (IPEC-J2) cells and in vivo to enterocytes in pig ileal loops. VT2-negative mutants showed significant decreases in adherence to both HEp-2 and IPEC-J2 cells and to enterocytes in pig ileal loops; complementation only partially restored VT2 production but fully restored the adherence to the wild-type level on cultured cells. Deletion of OI-7 and aidA 48 had no effect on adherence, whereas deletion of aidA 15 resulted in a significant decrease in adherence in pig ileal loops but not to the cultured cells. This investigation supports the findings that VT2 plays a role in adherence, shows that results obtained in adherence of E. coli O157:H7 in vivo may differ from those obtained in vitro, and identified AIDA-15 as having a role in adherence of E. coli O157:H7.

Escherichia coli O157:H7 Populations in Ruminants Can Be Reduced by Orange Peel Product Feeding†

2011 ◽  
Vol 74 (11) ◽  
pp. 1917-1921 ◽  
Author(s):  
TODD R. CALLAWAY ◽  
JEFFERY A. CARROLL ◽  
JOHN D. ARTHINGTON ◽  
TOM S. EDRINGTON ◽  
MICHELLE L. ROSSMAN ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Pathogenic Bacteria ◽  
Intervention Strategy ◽  
Orange Peel ◽  
Escherichia Coli O157 ◽  
Citrus Peel ◽  
Fecal Shedding ◽  
E Coli ◽  
Foodborne Pathogenic Bacteria

Foodborne pathogenic bacteria such as Escherichia coli O157:H7 are threats to the safety of beef. Citrus peel and dried orange pulp are by-products from citrus juice production that have natural antimicrobial effects and are often incorporated into least-cost ration formulations for beef and dairy cattle. This study was designed to determine if orange peel and pulp affected E. coli O157:H7 populations in vivo. Sheep (n = 24) were fed a cracked corn grain–based diet that was supplemented with a 50-50 mixture of dried orange pellet and fresh orange peel to achieve a final concentration (dry matter basis, wt/wt) of 0, 5, or 10% pelleted orange peel (OP) for 10 days. Sheep were artificially inoculated with 1010 CFU of E. coli O157:H7 by oral dosing. Fecal shedding of E. coli O157:H7 was measured daily for 5 days after inoculation, after which all animals were humanely euthanized. At 96 h postinoculation, E. coli O157:H7 shedding was reduced (P &lt; 0.05) in sheep fed 10% OP. Populations of inoculated E. coli O157:H7 were reduced by OP treatment throughout the gastrointestinal tract; however, this reduction reached significant levels in the rumen (P &lt; 0.05) of sheep fed 10% OP diets. Cecal and rectal populations of E. coli O157:H7 were reduced (P &lt;0.05) by inclusion of both 5 and 10% OP diets. Our results demonstrate that orange peel products can be used as a preharvest intervention strategy as part of an integrated pathogen reduction scheme.

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