scholarly journals Effect of Cattle Diet on Escherichia coli O157:H7 Acid Resistance

1999 ◽  
Vol 65 (7) ◽  
pp. 3233-3235 ◽  
Author(s):  
Carolyn J. Hovde ◽  
Paula R. Austin ◽  
Karen A. Cloud ◽  
Christopher J. Williams ◽  
Carl W. Hunt
Keyword(s):  
Escherichia Coli ◽  
Acid Resistance ◽  
Escherichia Coli O157 ◽  
E Coli ◽  
Human Infections

ABSTRACT The duration of shedding of Escherichia coli O157 isolates by hay-fed and grain-fed steers experimentally inoculated withE. coli O157:H7 was compared, as well as the acid resistance of the bacteria. The hay-fed animals shed E. coli O157 longer than the grain-fed animals, and irrespective of diet, these bacteria were equally acid resistant. Feeding cattle hay may increase human infections with E. coli O157:H7.

scholarly journals Fecal Metagenome Sequences from Lactating Dairy Cows Shedding Escherichia coli O157:H7

2018 ◽  
Vol 7 (18) ◽  
Author(s):  
Serajus Salaheen ◽  
Seon Woo Kim ◽  
Jeffrey S. Karns ◽  
Bradd J. Haley ◽  
Jo Ann S. Van Kessel
Keyword(s):  
Escherichia Coli ◽  
Dairy Cows ◽  
Causative Agent ◽  
Public Domain ◽  
Escherichia Coli O157 ◽  
Content Type ◽  
The Public ◽  
E Coli ◽  
Lactating Dairy Cows ◽  
Human Infections

Cattle are primary reservoirs of Escherichia coli O157:H7, a causative agent of severe human infections. To facilitate analyses of the communities in which this pathogen is found, we sequenced the fecal metagenomes of 10 dairy cows shedding E. coli O157:H7 and added them to the public domain.

Escherichia coli O157:H7 Strains Isolated from Environmental Sources Differ Significantly in Acetic Acid Resistance Compared with Human Outbreak Strains†‡

2009 ◽  
Vol 72 (3) ◽  
pp. 503-509 ◽  
Author(s):  
DEOG-HWAN OH ◽  
YOUWEN PAN ◽  
ELAINE BERRY ◽  
MICHAEL COOLEY ◽  
ROBERT MANDRELL ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Acetic Acid ◽  
Acetic Acid Solution ◽  
Acid Resistance ◽  
Escherichia Coli O157 ◽  
Limited Information ◽  
E Coli ◽  
Log Reduction ◽  
Acetic Acid Resistance ◽  
Acidified Foods

A number of studies on the influence of acid on Escherichia coli O157:H7 have shown considerable strain differences, but limited information has been reported to compare the acid resistance based on the different sources of E. coli O157:H7 isolates. The purpose of this study was to determine the survival of E. coli O157:H7 strains isolated from five sources (foods, bovine carcasses, bovine feces, water, and human) in 400 mM acetic acid solutions under conditions that are typical of acidified foods. The isolates from bovine carcasses, feces, and water survived acetic acid treatment at pH 3.3 and 30°C significantly (P ≤ 0.05) better than did any food or human isolates. However, resistance to acetic acid significantly increased as temperature decreased to 15°C for a given pH, with little (P ≥ 0.05) difference among the different isolation sources. All groups of E. coli O157:H7 strains showed more than 1.8- to 4.5-log reduction at pH 3.3 and 30°C after 25 min. Significantly reduced (less than 1-log reduction) lethality for all E. coli O157:H7 strain mixtures was observed when pH increased to 3.7 or 4.3, with little difference in acetic acid resistance among the groups. The addition of glutamate to the acetic acid solution or anaerobic incubation provided the best protection compared with the above conditions for all groups of isolates. These results suggest that temperature, pH, and atmospheric conditions are key factors in establishing strategies for improving the safety of acidified foods.

Effect of Acid Resistance of Escherichia coli O157:H7 on Efficacy of Buffered Lactic Acid To Decontaminate Chilled Beef Tissue and Effect of Modified Atmosphere Packaging on Survival of Escherichia coli O157:H7 on Red Meat

2001 ◽  
Vol 64 (11) ◽  
pp. 1661-1666 ◽  
Author(s):  
M. UYTTENDAELE ◽  
E. JOZWIK ◽  
A. TUTENEL ◽  
L. DE ZUTTER ◽  
J. URADZINSKI ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Lactic Acid ◽  
Modified Atmosphere Packaging ◽  
Acid Resistance ◽  
Red Meat ◽  
Modified Atmosphere ◽  
Escherichia Coli O157 ◽  
The Public ◽  
E Coli ◽  
Retail Cuts

The present study examined the effect of pH-independent acid resistance of Escherichia coli O157:H7 on efficacy of buffered lactic acid to decontaminate chilled beef tissue. A varied level of acid resistance was observed among the 14 strains tested. Eight strains were categorized as acid resistant, four strains as acid sensitive, and two strains demonstrated acid-inducible acid resistance. The survival of an acid-resistant (II/45/4) and acid-sensitive (IX/8/16) E. coli O157:H7 strain on chilled beef tissue treated with 1 and 2% buffered lactic acid, sterile water, or no treatment (control) was followed. A gradual reduction of E. coli O157:H7 was noticed during the 10 days of storage at 4°C for each of the treatments. Decontamination with 1 and 2% buffered lactic acid did not appreciably affect the pathogen. Differences in the pH-independent acid resistance of the strains had no effect on the efficacy of decontamination. The effect of modified atmosphere packaging (MAP) on survival of E. coli O157:H7 in red meat was also studied. MAP (40% CO2/60% N2) or vacuum did not significantly influence survival of E. coli O157:H7 on inoculated sliced beef (retail cuts) meat compared to packing in air. The relative small outgrowth of lactic acid bacteria during storage under vacuum for 28 days did not affect survival of E. coli O157:H7. Neither lactic acid decontamination nor vacuum or MAP packaging could enhance reduction of E. coli O157:H7 on beef, thus underlining the need for preventive measures to control the public health risk of E. coli O157:H7.

Influence of Animal Origin and Lineage on Survival of Escherichia coli O157:H7 Strains in Strong and Weak Acid Challenges

2004 ◽  
Vol 67 (8) ◽  
pp. 1591-1596 ◽  
Author(s):  
CONSTANTINE E. SARIDAKIS ◽  
ROGER P. JOHNSON ◽  
ANDREW BENSON ◽  
KIM ZIEBELL ◽  
CARLTON L. GYLES
Keyword(s):  
Escherichia Coli ◽  
Acid Resistance ◽  
Weak Acid ◽  
Animal Origin ◽  
Escherichia Coli O157 ◽  
E Coli ◽  
Genome Scanning ◽  
Average Group ◽  
Average Survival ◽  
Group Survival

Twenty-five strains of Escherichia coli O157:H7 isolated from humans, cattle, and pigs were maintained in HCl (pH 2.5) and in a volatile fatty acid (VFA) mixture (pH 4.0) for up to 6 h at 37°C to assess their ability to survive in acidic conditions that simulate those of the stomach and ileum, respectively. In HCl, the average group survival of bovine strains was significantly higher than that of porcine and human strains, whereas in VFAs, porcine strains were significantly more resistant than bovine and human strains. Bovine strains exhibited significantly higher average survival in HCl than in VFAs. The average survival of strains classified as octamer-based genome scanning (OBGS) lineage II was significantly superior to that of strains classified as OBGS lineage I in HCl. The group of lineage I strains was more resistant in VFAs compared with lineage II, but only after 6 h of challenge. The possible involvement of urease in acid resistance of E. coli O157:H7 was also examined. Although the strains possessed the ureC gene, as shown by PCR, this gene did not appear to contribute to acid resistance under the conditions tested. The data indicate that there is a relationship between acid resistance and source or lineage of O157:H7 strains.

scholarly journals Human infections with verocytotoxin-producing Escherichia coli O157 – 10 years of E. coli O157 serodiagnosis

2008 ◽  
Vol 57 (11) ◽  
pp. 1389-1393 ◽  
Author(s):  
Henrik Chart ◽  
Thomas Cheasty
Keyword(s):  
Escherichia Coli ◽  
Haemolytic Uraemic Syndrome ◽  
Enteric Pathogens ◽  
Escherichia Coli O157 ◽  
Health Protection Agency ◽  
Protection Agency ◽  
E Coli ◽  
Males And Females ◽  
Human Infections ◽  
Somatic Antigens

From 1997 to 2007, the Laboratory of Enteric Pathogens (LEP), Health Protection Agency, UK, received sera from 2148 patients for testing for antibodies to the LPS of verocytotoxin-producing Escherichia coli (VTEC) O157. A total of 676 (31.5 %) sera had antibodies binding the LPS of E. coli O157 and the majority of patients were below the age of 10 years, a trend observed for both males and females. Antibody-positive patients had haemolytic uraemic syndrome (HUS) in 79.3 % of cases and most of these presented with the atypical (D−) form of HUS. Nine patients were shown to have antibodies to the LPS of E. coli belonging to serogroups O26 (4), O103 (2), O111 (1) and O145 (2) and one patient had antibodies to the somatic antigens of both E. coli O26 and O103. The serodiagnosis of infections with E. coli O157 and other VTEC continues to be an important adjunct to bacteriology. Where clinicians suspect the involvement of a VTEC in disease, patients' sera should be submitted to the LEP for analysis without delay.

scholarly journals Indirect Transmission of Escherichia coli O157:H7 Occurs Readily among Swine but Not among Sheep

2008 ◽  
Vol 74 (8) ◽  
pp. 2488-2491 ◽  
Author(s):  
Nancy A. Cornick ◽  
Hung VuKhac
Keyword(s):  
Escherichia Coli ◽  
Direct Contact ◽  
Infected Animal ◽  
Swine Manure ◽  
Escherichia Coli O157 ◽  
E Coli ◽  
Indirect Transmission ◽  
Pork Products ◽  
Infected Donor ◽  
Human Infections

ABSTRACT Transmission of Escherichia coli O157:H7 among reservoir animals is generally thought to occur either by direct contact between a naïve animal and an infected animal or by consumption of food or water containing the organism. Although ruminants are considered the major reservoir, there are two reports of human infections caused by E. coli O157:H7 linked to the consumption of pork products or to the contamination of fresh produce by swine manure. The objective of this study was to determine whether E. coli O157:H7 could be transmitted to naïve animals, both sheep and swine, that did not have any direct contact with an infected donor animal. We recovered E. coli O157:H7 from 10/10 pigs with nose-to-nose contact with the infected donor or animals adjacent to the donor and from 5/6 naïve pigs that were penned in the same room as the donor pig but 10 to 20 ft away. In contrast, when the experiment was repeated with sheep, E. coli O157:H7 was recovered from 4/6 animals that had nose-to-nose contact with the infected donor or adjacent animals and from 0/6 naïve animals penned 10 to 20 ft away from the donor. These results suggest that E. coli O157:H7 is readily transmitted among swine and that transmission can occur by the creation of contaminated aerosols.

Effects of Diet on Rumen Proliferation and Fecal Shedding of Escherichia coli O157:H7 in Calves

2000 ◽  
Vol 63 (12) ◽  
pp. 1630-1636 ◽  
Author(s):  
SUZANA TKALCIC ◽  
CATHY A. BROWN ◽  
BARRY G. HARMON ◽  
ANANT V. JAIN ◽  
ERIC P. O. MUELLER ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Fatty Acid ◽  
Volatile Fatty Acid ◽  
Rumen Fluid ◽  
Rapid Development ◽  
Acid Resistance ◽  
Escherichia Coli O157 ◽  
Fecal Shedding ◽  
E Coli ◽  
The Impact

Calves inoculated with Escherichia coli O157:H7 and fed either a high-roughage or high-concentrate diet were evaluated for rumen proliferation and fecal shedding of E. coli O157:H7. Calves fed the high-roughage diet had lower mean rumen volatile fatty acid concentrations and higher rumen pH values than did calves fed the high-concentrate diet. Despite these differences in rumen conditions, the calves fed the high-roughage diet did not have greater rumen populations of E. coli O157: H7 and did not exhibit increased or longer fecal shedding compared with the calves fed the high-concentrate diet. Two calves shedding the highest mean concentrations of E. coli O157:H7 were both fed the high-concentrate diet. There was a significant (P < 0.05) positive correlation between fecal shedding and rumen volatile fatty acid concentration in calves fed a high-concentrate diet. The effects of diet on E. coli O157:H7 proliferation and acid resistance were investigated using an in vitro rumen fermentation system. Rumen fluid collected from steers fed a high-roughage diet, but not from steers fed a high-concentrate diet, supported the proliferation of E. coli O157:H7. Rumen fluid from steers fed a high-concentrate diet rapidly induced acid resistance in E. coli O157:H7. The impact of diet on fecal shedding of E. coli O157:H7 is still unclear and may depend on dietary effects on fermentation in the colon and on diet-induced changes in the resident microflora. However, rapid development of acid tolerance by E. coli O157:H7 in the rumens of calves fed high-concentrate diets, allowing larger populations to survive passage through the acidic abomasum to proliferate in the colon, may be one factor that influences fecal shedding in cattle on feed.

scholarly journals Regional Immune Response to Immunization with Escherichia coli O157:H7-Derived Intimin in Cattle

2013 ◽  
Vol 20 (4) ◽  
pp. 562-571 ◽  
Author(s):  
Kathryn G. Boland ◽  
Andrea N. Hayles ◽  
Claire B. Miller ◽  
Tovah Kerr ◽  
Wendy C. Brown ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Immune Responses ◽  
Lymph Nodes ◽  
Effective Means ◽  
Human Infection ◽  
Escherichia Coli O157 ◽  
Content Type ◽  
E Coli ◽  
Local Responses ◽  
Human Infections

ABSTRACTEscherichia coliO157:H7 is an enteric pathogen of animals and humans that can result in deadly sequelae. Cattle are asymptomatic carriers and shedders of the bacteria and serve as an important reservoir of human infection.E. coliO157:H7 colonizes the gastrointestinal tract, most frequently at the rectoanal junction mucosa in cattle. Vaccination is a potentially highly effective means of decreasing cattle colonization and shedding and thereby decreasing human infections. Currently available vaccines are administered subcutaneously or intramuscularly, and immune responses have been evaluated solely by systemic immunoglobulin responses. This study evaluated local and systemic lymphoproliferative responses in addition to immunoglobulin responses following subcutaneous or mucosal (rectal) immunization withE. coliO157:H7 outer membrane protein intimin over three trials. In all three trials, significant local and systemic lymphoproliferative responses (P< 0.05) occurred following immunization in the majority of animals, as well as significant immunoglobulin responses (P< 0.001) in all animals. Surprisingly, local responses in the mesorectal lymph nodes were very similar between the subcutaneous and mucosal immunization groups. Moreover, the responses in mesorectal lymph nodes appeared targeted rather than generalized, as minimal or no significant responses were observed in the associated prescapular lymph nodes of subcutaneously immunized animals. The results indicate that both subcutaneous and mucosal immunizations are effective methods of inducing immune responses againstE. coliO157:H7 in cattle.

scholarly journals Genetic Diversity among Escherichia coli O157:H7 Isolates and Identification of Genes Linked to Human Infections

2007 ◽  
Vol 76 (2) ◽  
pp. 845-856 ◽  
Author(s):  
Guanghui Wu ◽  
Ben Carter ◽  
Muriel Mafura ◽  
Ernesto Liebana ◽  
Martin J. Woodward ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Genetic Diversity ◽  
Comparative Genomic ◽  
Escherichia Coli O157 ◽  
Microarray Hybridization ◽  
E Coli ◽  
Genomic Microarray ◽  
K 12 ◽  
Human Infections ◽  
Dominant Genes

ABSTRACT An Escherichia coli oligonucleotide microarray based on three sequenced genomes was validated for comparative genomic microarray hybridization and used to study the diversity of E. coli O157 isolates from human infections and food and animal sources. Among 26 test strains, 24 (including both Shiga toxin [Stx]-positive and -negative strains) were found to be related to the two sequenced E. coli O157:H7 strains, EDL933 and Sakai. However, these strains showed much greater genetic diversity than those reported previously, and most of them could not be categorized as either lineage I or II. Some genes were found more often in isolates from human than from nonhuman sources; e.g., ECs1202 and ECs2976, associated with stx2AB and stx1AB, were in all isolates from human sources but in only 40% of those from nonhuman sources. Some (but not all) lineage I-specific or -dominant genes were also more frequently associated with isolates from human. The results suggested that it might be more effective to concentrate our efforts on finding markers that are directly related to infection rather than those specific to certain lineages. In addition, two Stx-negative O157 cattle isolates (one confirmed to be H7) were significantly different from other Stx-positive and -negative E. coli O157:H7 strains and were more similar to MG1655 in their gene content. This work demonstrates that not all E. coli O157:H7 strains belong to the same clonal group, and those that were similar to E. coli K-12 might be less virulent.

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