151
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Nastasijevic I, Mitrovic R, Buncic S. Occurrence of Escherichia coli O157 on hides of slaughtered cattle. Lett Appl Microbiol 2007; 46:126-31. [PMID: 17944857 DOI: 10.1111/j.1472-765x.2007.02270.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
AIMS To obtain the first information on the occurrence of Escherichia coli O157 on hides of slaughtered cattle in Serbia. METHODS AND RESULTS A total of 355 swabs were taken on the slaughterline from five areas of hide of each of the 71 cattle in a single commercial abattoir in Serbia. Using an ISO method incorporating enrichment and immunomagnetic separation steps, E. coli O157 was isolated from the hides of 20 animals (28 x 2%). With respect to different areas of the hides, the occurrence of the pathogen was, in decreasing order: hooves (11 x 3%), brisket (8 x 4%), rump (7 x 0%), neck (4 x 2) and flank (2 x 8%). In addition, factors that had more or less effects on the occurrence included visible dirtiness of the hide, cattle's age category, geographical origin of the animals and season. CONCLUSIONS This study revealed the presence of E. coli O157 in the beef chain in Serbia and confirmed hide as an important potential source of related contamination of beef carcasses. Therefore, incorporation of preskinning hide decontamination treatments into HACCP-based slaughterline hygiene control measures could be very useful. SIGNIFICANCE AND IMPACT OF THE STUDY The results will enable further optimization of necessary measures along the beef chain to reduce the E. coli O157 risks in Serbia.
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Affiliation(s)
- I Nastasijevic
- Institute of Meat Hygiene and Technology, Belgrade, Serbia
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152
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Baker DR, Moxley RA, Steele MB, Lejeune JT, Christopher-Hennings J, Chen DG, Hardwidge PR, Francis DH. Differences in virulence among Escherichia coli O157:H7 strains isolated from humans during disease outbreaks and from healthy cattle. Appl Environ Microbiol 2007; 73:7338-46. [PMID: 17890332 PMCID: PMC2168223 DOI: 10.1128/aem.00755-07] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Escherichia coli O157:H7 causes life-threatening outbreaks of diarrhea, hemorrhagic colitis, and hemolytic-uremic syndrome in humans and significant economic loss in agriculture and could be a potential agent of bioterrorism. Although the prevalence of E. coli O157:H7 in cattle and other species with which humans have frequent contact is high, human infections are relatively uncommon, despite a low infectious dose. A plausible explanation for the low disease incidence is the possibility that not all strains are virulent in humans. If there are substantial differences in virulence among strains in nature, then human disease may select for high virulence. We used a gnotobiotic piglet model to investigate the virulence of isolates from healthy cattle and from humans in disease outbreaks and to determine the correlation between production of Shiga toxin 1 (Stx1) and Stx2 and virulence. Overall, E. coli O157:H7 strains isolated from healthy cattle were less virulent in gnotobiotic piglets than strains isolated from humans during disease outbreaks. The amount of Stx2 produced by E. coli O157:H7 strains correlated with strain virulence as measured by a reduction in piglet survival and signs of central nervous system disease due to brain infarction. The amount of Stx1 produced in culture was not correlated with the length of time of piglet survival or with signs of central nervous system disease. We suggest that disease outbreaks select for producers of high levels of Stx2 among E. coli O157:H7 strains shed by animals and further suggest that Stx1 expression is unlikely to be significant in human outbreaks.
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Affiliation(s)
- Diane R Baker
- Department of Veterinary Science, South Dakota State University, Brookings, SD 57007, USA
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153
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Bono JL, Keen JE, Clawson ML, Durso LM, Heaton MP, Laegreid WW. Association of Escherichia coli O157:H7 tir polymorphisms with human infection. BMC Infect Dis 2007; 7:98. [PMID: 17718910 PMCID: PMC2063500 DOI: 10.1186/1471-2334-7-98] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2007] [Accepted: 08/24/2007] [Indexed: 01/03/2023] Open
Abstract
Background Emerging molecular, animal model and epidemiologic evidence suggests that Shiga-toxigenic Escherichia coli O157:H7 (STEC O157) isolates vary in their capacity to cause human infection and disease. The translocated intimin receptor (tir) and intimin (eae) are virulence factors and bacterial receptor-ligand proteins responsible for tight STEC O157 adherence to intestinal epithelial cells. They represent logical genomic targets to investigate the role of sequence variation in STEC O157 pathogenesis and molecular epidemiology. The purposes of this study were (1) to identify tir and eae polymorphisms in diverse STEC O157 isolates derived from clinically ill humans and healthy cattle (the dominant zoonotic reservoir) and (2) to test any observed tir and eae polymorphisms for association with human (vs bovine) isolate source. Results Five polymorphisms were identified in a 1,627-bp segment of tir. Alleles of two tir polymorphisms, tir 255 T>A and repeat region 1-repeat unit 3 (RR1-RU3, presence or absence) had dissimilar distributions among human and bovine isolates. More than 99% of 108 human isolates possessed the tir 255 T>A T allele and lacked RR1-RU3. In contrast, the tir 255 T>A T allele and RR1-RU3 absence were found in 55% and 57%, respectively, of 77 bovine isolates. Both polymorphisms associated strongly with isolate source (p < 0.0001), but not by pulsed field gel electrophoresis type or by stx1 and stx2 status (as determined by PCR). Two eae polymorphisms were identified in a 2,755-bp segment of 44 human and bovine isolates; 42 isolates had identical eae sequences. The eae polymorphisms did not associate with isolate source. Conclusion Polymorphisms in tir but not eae predict the propensity of STEC O157 isolates to cause human clinical disease. The over-representation of the tir 255 T>A T allele in human-derived isolates vs the tir 255 T>A A allele suggests that these isolates have a higher propensity to cause disease. The high frequency of bovine isolates with the A allele suggests a possible bovine ecological niche for this STEC O157 subset.
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Affiliation(s)
- James L Bono
- United States Department of Agriculture, Agricultural Research Service, U.S. Meat Animal Research Center, Clay Center, NE, 68933 USA
| | - James E Keen
- United States Department of Agriculture, Agricultural Research Service, U.S. Meat Animal Research Center, Clay Center, NE, 68933 USA
| | - Michael L Clawson
- United States Department of Agriculture, Agricultural Research Service, U.S. Meat Animal Research Center, Clay Center, NE, 68933 USA
| | - Lisa M Durso
- United States Department of Agriculture, Agricultural Research Service, U.S. Meat Animal Research Center, Clay Center, NE, 68933 USA
| | - Michael P Heaton
- United States Department of Agriculture, Agricultural Research Service, U.S. Meat Animal Research Center, Clay Center, NE, 68933 USA
| | - William W Laegreid
- United States Department of Agriculture, Agricultural Research Service, U.S. Meat Animal Research Center, Clay Center, NE, 68933 USA
- [Current] Department of Pathobiology, College of Veterinary Medicine, University of Illinois, 2001 South Lincoln Avenue, Urbana, IL 61802
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154
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Mather AE, Innocent GT, McEwen SA, Reilly WJ, Taylor DJ, Steele WB, Gunn GJ, Ternent HE, Reid SWJ, Mellor DJ. Risk factors for hide contamination of Scottish cattle at slaughter with Escherichia coli O157. Prev Vet Med 2007; 80:257-70. [PMID: 17485125 DOI: 10.1016/j.prevetmed.2007.02.011] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2006] [Revised: 01/19/2007] [Accepted: 02/23/2007] [Indexed: 12/22/2022]
Abstract
In the slaughter processing of cattle, contaminated hides have been identified as one of the major sources of Escherichia coli O157 carcase contamination. Logistic regression analysis was applied to data collected in a large scale study in Scotland involving 222 cattle forming 34 groups sent for slaughter from 30 farms to 10 slaughterhouses. Aspects of individual animal characteristics, farm management practices and slaughterhouse features were examined to identify potential risk factors for hide contamination at harvest. Two models were developed, the first in which slaughterhouse was modelled as a fixed effect, and a second model where slaughterhouse and farm groups were modelled as random effects. In the first model, there was a significantly increased risk of a carcase testing positive for E. coli O157 on the hide if either the hide of the carcase immediately before or after it on the line was contaminated (OR 3.6; 95% CI: 1.4-9.9). If both adjacent carcases had contaminated hides, the odds ratio for the study carcase having a contaminated hide rose to 11.5 (95% CI: 4.4-32.5). If animals were held in lairage, receiving hay as feed appeared to have a protective effect on hide contamination. Transportation to the slaughterhouse by haulier, as opposed to transport by the farmer, was associated with a 5.4 increase in the odds of E. coli O157 contamination. The use of a crush in the lairage, often employed when reading ear tags, was also found to significantly increase the odds of hide contamination with E. coli O157. In the second model, the inclusion of slaughterhouse and farm group as random effects resulted in two of the previously identified factors being associated with hide contamination. If at least one of the adjacent carcases on the line had a contaminated hide, the associated odds ratio was 6.6 (95% CI: 2.8-15.9), which rose to 22.7 (95% CI: 9.3-55.5) if both adjacent hides were contaminated. Receiving hay in lairage was found to be important to the model, although not significant in itself (OR 0.005; 95% CI: 1.2e(-6)-20.7). These results suggest that modifiable risk factors for hide contamination exist. However, in order best to reduce the prevalence of hide contamination at slaughter, individual slaughterhouse risk assessment and intervention strategies are appropriate.
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Affiliation(s)
- A E Mather
- Department of Population Medicine, Ontario Veterinary College, University of Guelph, Canada
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155
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Renter DG, Bohaychuk V, Van Donkersgoed J, King R. Presence of non-O157 Shiga toxin-producing Escherichia coli in feces from feedlot cattle in Alberta and absence on corresponding beef carcasses. CANADIAN JOURNAL OF VETERINARY RESEARCH = REVUE CANADIENNE DE RECHERCHE VETERINAIRE 2007; 71:230-5. [PMID: 17695600 PMCID: PMC1899871] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
The study objectives were to determine the prevalence and serotypes of non-O157 Shiga toxin-producing Escherichia coli (STEC) in pens of feedlot cattle and on corresponding beef carcasses. We collected 25 fecal samples from 84 pens in 21 Alberta feedlots and 40 carcass swabs from each preslaughter pen for analysis by culture and polymerase chain reaction (PCR). Non-O157 STEC were recovered from feces from 12 (14%) of the 84 pens and 12 (57%) of the 21 feedlots by examination of 1 E. coli isolate positive for 4-methylumbelliferyl-beta-beta-glucuronide per sample. Twelve non-O157 serotypes were detected, but 7 of the 15 STEC isolates lacked the accessory virulence genes eae and hlyA. Although 115 (7%) of the carcass broths were PCR-positive, no STEC isolates were recovered from the 1650 carcasses sampled. Our data indicate that multiple non-O157 STEC serotypes may be present in cattle feces, yet are unlikely to be recovered from the corresponding beef carcasses when 20 colonies per sample from PCR-positive broth cultures are analyzed.
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Affiliation(s)
- David G Renter
- Department of Diagnostic Medicine/Pathobiology, #307 Coles Hall, College of Veterinary Medicine, Kansas State University, Manhattan, Kansas 66506, USA.
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156
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Fox JT, Renter DG, Sanderson MW, Thomson DU, Lechtenberg KF, Nagaraja TG. Evaluation of culture methods to identify bovine feces with high concentrations of Escherichia coli O157. Appl Environ Microbiol 2007; 73:5253-60. [PMID: 17574994 PMCID: PMC1950981 DOI: 10.1128/aem.00554-07] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Our objective was to evaluate methods for identifying cattle with high concentrations of Escherichia coli O157 in their feces. In two experiments, feces were collected from cattle orally inoculated with nalidixic acid (Nal)-resistant E. coli O157, and direct plating of diluted feces on sorbitol MacConkey agar with cefixime and potassium tellurite (CT-SMAC) containing Nal was considered the gold standard (GS) method. In experiment 1, methods evaluated were preenrichment direct streak, immunomagnetic separation with most probable number (MPN), and postenrichment direct streak with MPN, all using CT-SMAC. The mean concentration of Nal-resistant E. coli O157 in samples (n = 59) by use of the GS was 3.6 log10 CFU/g. The preenrichment streak detected >3.0 log10 CFU/g samples with a 74.4% sensitivity and 68.8% specificity. Postenrichment direct streak-MPN and immunomagnetic separation-MPN concentrations were correlated significantly with GS concentrations (r = 0.53 and r = 0.39, respectively). In experiment 2 (480 samples), pre- and postenrichment direct streaking performed in triplicate and spiral plating on CT-SMAC were evaluated. For preenrichment streaks, sensitivity was 79.7% and specificity was 96.7% for detecting >3.0 log10 CFU/g when the criterion was positive cultures on at least two plates. For spiral plating at that concentration, sensitivity and specificity were 83.9% and 56.3%, respectively. Postenrichment streaking performed relatively poorly. Triplicate preenrichment streaks of 1:10-diluted feces on CT-SMAC may be useful for identifying cattle shedding high concentrations of E. coli O157. Estimates of sensitivity and specificity enable appropriate application of methods and interpretation of results and may enhance applied research, surveillance, and risk assessments.
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Affiliation(s)
- J Trent Fox
- Department of Diagnostic Medicine and Pathobiology, Kansas State University, Manhattan, KS 66506, USA
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157
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Algino R, Ingham S, Zhu J. Survey of Antimicrobial Effects of Beef Carcass Intervention Treatments in Very Small State-Inspected Slaughter Plants. J Food Sci 2007; 72:M173-9. [DOI: 10.1111/j.1750-3841.2007.00386.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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158
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Ravva SV, Sarreal CZ, Duffy B, Stanker LH. Survival of Escherichia coli O157:H7 in wastewater from dairy lagoons. J Appl Microbiol 2007; 101:891-902. [PMID: 16968301 DOI: 10.1111/j.1365-2672.2006.02956.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
AIM To determine the survival of Escherichia coli O157:H7 in dairy wastewater from on-site holding lagoons equipped with or without circulating aerators. METHODS AND RESULTS Survival was monitored in dairy lagoon microcosms equipped with or without scale-size circulators. Both laboratory strains of E. coli O157:H7 and an isolate of E. coli H7 from wastewater had poor survival rates and none proliferated in water from waste lagoons with or without circulators. Furthermore, the decline of E. coli O157:H7 was not enhanced in those microcosms equipped with circulators. Strain variation in survival was observed in both circulated and settling waters. The decline rate of E. coli O157:H7 Odwalla strain increased proportionately with the inoculum load. Escherichia coli failed to establish itself in wastewater even after four sequential inoculations simulating continuous faecal input into the lagoon. The native aerobic bacteria survived longer with a decimal reduction time of 21.3 days vs either introduced or native E. coli, which declined rapidly with decimal reduction time of 0.5-9.4 days. CONCLUSIONS Escherichia coli O157:H7 failed to establish and proliferate in dairy wastewater microcosms equipped with or without circulating aerators. SIGNIFICANCE AND IMPACT OF THE STUDY This study furthers our knowledge of pathogen survival in wastewater, and suggests that proper management of wastewater before its use in irrigation is essential to reduce pathogen transfer to crops.
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Affiliation(s)
- S V Ravva
- USDA, Agriculture Research Service, Western Regional Research Center, Foodborne Contaminants Research Unit, Albany, CA 94710, USA.
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159
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Chen J, Rossman ML, Pawar DM. Attachment of enterohemorrhagic Escherichia coli to the surface of beef and a culture medium. Lebensm Wiss Technol 2007. [DOI: 10.1016/j.lwt.2005.10.011] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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160
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The effects of shelf-life enhancers on E. coli K12 survival in needle-injected, surface contaminated beef strip steaks enhanced using recycled solutions. Meat Sci 2007; 75:371-80. [DOI: 10.1016/j.meatsci.2006.06.029] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2006] [Revised: 06/21/2006] [Accepted: 06/21/2006] [Indexed: 11/17/2022]
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161
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Ravva SV, Korn A. Extractable organic components and nutrients in wastewater from dairy lagoons influence the growth and survival of Escherichia coli O157:H7. Appl Environ Microbiol 2007; 73:2191-8. [PMID: 17308194 PMCID: PMC1855652 DOI: 10.1128/aem.02213-06] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The influence of nutrients in wastewater from dairy lagoons on the survival of Escherichia coli O157:H7 was monitored. Initially, the survival of E. coli O157:H7 in wastewater from which the competing native organisms had been removed by filter sterilization or autoclaving was compared with that in wastewater from which competing organisms had not been removed. Numbers of E. coli O157:H7 or E. coli ONT (O-nontypeable):H32 cells declined rapidly in filter-sterilized water and exhibited a slower decline in nonsterile water, while the organisms proliferated in autoclaved water. Subsequently, the growth of E. coli O157:H7 strains was monitored in 300 mul of Luria-Bertani (LB) broth supplemented with incremental proportions of filter-sterilized wastewater. E. coli O157:H7 and E. coli ONT:H32 strains failed to grow in filter-sterilized wastewater, and their growth was reduced incrementally with wastewater supplementation of LB broth. Consequently, the influence of organic extracts of wastewater on the growth of E. coli O157:H7 and E. coli ONT:H32 in reduced-strength LB was monitored, followed by scale-up tests in wastewater. Acidic and basic extracts inhibited growth of both strains, while the neutral aqueous extract improved growth. However, a scale-up with a threefold increase in the acidic components supplementing the wastewater did not result in any additional decline in numbers of E. coli O157:H7 cells. When protected inside a 300-kDa dialysis tube and exposed to diffusible components, E. coli O157:H7 survived longer, with a decimal reduction time of 18.1 days, compared to 3.5 days when inoculated directly into wastewater. Although wastewater can potentially provide nutrients to naturally occurring human pathogens, the chemical components, protozoa, and coliphages in wastewater can inhibit the growth of freshly introduced pathogens from manure.
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Affiliation(s)
- Subbarao V Ravva
- USDA, Agriculture Research Service, Western Regional Research Center, Foodborne Contaminants Research Unit, 800 Buchanan Street, Albany, CA 94710, USA.
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162
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Madden RH, Murray KA, Gilmour A. Carriage of four bacterial pathogens by beef cattle in Northern Ireland at time of slaughter. Lett Appl Microbiol 2007; 44:115-9. [PMID: 17257247 DOI: 10.1111/j.1472-765x.2006.02064.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
AIMS To determine the prevalence of four bacterial zoonotic pathogens in beef cattle at time of slaughter in Northern Ireland (NI), in order to assess their potential for reducing beef safety. METHODS AND RESULTS Faeces were collected postmortem from beef cattle (n =220) at seven EU registered abattoirs. Standard enrichment culturing methods were employed, plus immunomagnetic enrichment in the case of Escherichia coli O157:H7. Campylobacter spp. were found in 52 samples (24.8%), Listeria monocytogenes in 10 (4.8%), E. coli O157:H7 in 2 (0.9%) whilst Salmonella spp. were isolated from six out of 200 samples (3.0%). Five salmonellas were Salmonella Chandans and one was Salmonella Liverpool. CONCLUSIONS Campylobacter spp. were the most frequently isolated pathogen, despite being relatively rare in beef. Genotyping showed the campylobacters to be very diverse, indicating cattle encounter campylobacters from many sources. The remaining three pathogens, which are associated with meats, occurred at relatively low frequencies, especially E. coli O157:H7. The Salmonella serovars found rarely infect humans. SIGNIFICANCE AND IMPACT OF THE STUDY The low prevalence of E. coli O157:H7 in NI beef cattle was confirmed and the reasons for this merit further study. The four pathogens should have little impact on beef quality.
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Affiliation(s)
- R H Madden
- Food Microbiology Branch, Agri-Food & Biosciences Institute, Belfast, Northern Ireland.
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163
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Wicklund R, Paulson D, Rojas M, Brewer M. The effects of shelf-life enhancers on E. coli K12 survival in needle-injected, surface contaminated beef strip steaks enhanced using recycled solutions. Meat Sci 2007; 75:273-82. [DOI: 10.1016/j.meatsci.2006.07.012] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2006] [Revised: 07/14/2006] [Accepted: 07/17/2006] [Indexed: 11/15/2022]
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164
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Gutierrez-Bañuelos H, Anderson RC, Carstens GE, Slay LJ, Ramlachan N, Horrocks SM, Callaway TR, Edrington TS, Nisbet DJ. Zoonotic bacterial populations, gut fermentation characteristics and methane production in feedlot steers during oral nitroethane treatment and after the feeding of an experimental chlorate product. Anaerobe 2007; 13:21-31. [PMID: 17208022 DOI: 10.1016/j.anaerobe.2006.11.002] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2006] [Revised: 11/09/2006] [Accepted: 11/10/2006] [Indexed: 11/27/2022]
Abstract
Nitroethane inhibits the growth of certain zoonotic pathogens such as Campylobacter and Salmonella spp., foodborne pathogens estimated to cause millions of human infections each year, and enhances the Salmonella- and Escherichia coli-killing effect of an experimental chlorate product being developed as a feed additive to kill these bacteria immediately pre-harvest. Limited studies have shown that nitroethane inhibits ruminal methane production, which represents a loss of 2-12% of the host's gross energy intake and contributes to global warming and destruction of the ozone layer. The present study was conducted to assess the effects of 14-day oral nitroethane administration, 0 (0X), 80 (1X) or 160 (2X)mg nitroethane/kg body weight per day on ruminal and fecal E. coli and Campylobacter, ruminal and fecal methane-producing and nitroethane-reducing activity, whole animal methane emissions, and ruminal and fecal fermentation balance in Holstein steers (n=6 per treatment) averaging 403+/-26 (SD) kg BW. An experimental chlorate product was fed the day following the last nitroethane administration to determine effects on E. coli and Campylobacter. The experimental chlorate product decreased (P<0.001) fecal, but not ruminal (P>0.05) E. coli concentrations by 1000- and 10-fold by 24 and 48 h, respectively, after chlorate feeding when compared to pre-treatment concentrations (>5.7 log(10) colony forming units/g). No effects (P>0.05) of nitroethane or the experimental chlorate product were observed on fecal Campylobacter concentrations; Campylobacter were not recovered from ruminal contents. Nitroethane treatment decreased (P<0.01) ruminal (8.46, 7.91 and 4.74+/-0.78 micromol/g/h) and fecal (3.90, 1.36 and 1.38+/-0.50 micromol/g/h) methane-producing activity for treatments 0X, 1X and 2X, respectively. Administration of nitroethane increased (P<0.001) nitroethane-reducing activity in ruminal, but not fecal samples. Day of study affected ruminal (P<0.0001) but not fecal (P>0.05) methane-producing and nitroethane-reducing activities (P<0.01); treatment by day interactions were not observed (P>0.05). Ruminal accumulations of acetate decreased (P<0.05) in 2X-treated steers when compared with 0X- and 1X-treated steers, but no effect (P>0.05) of nitroethane was observed on propionate, butyrate or the acetate to propionate ratio. Whole animal methane emissions, expressed as L/day or as a proportion of gross energy intake (%GEI), were unaffected by nitroethane treatment (P>0.05), and were not correlated (P>0.05) with ruminal methane-producing activity. These results demonstrate that oral nitroethane administration reduces ruminal methane-producing activity but suggest that a microbial adaptation, likely due to an in situ enrichment of ruminal nitroethane-reducing bacteria, may cause depletion of nitroethane, at least at the 1X administration dose, to concentrations too low to be effective. Further research is warranted to determine if the optimization of dosage of nitroethane or related nitrocompouds can maintain the enteropathogen control and anti-methanogen effect in fed steers.
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165
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Varela-Hernández JJ, Cabrera-Diaz E, Cardona-López MA, Ibarra-Velázquez LM, Rangel-Villalobos H, Castillo A, Torres-Vitela MR, Ramírez-Alvarez A. Isolation and characterization of Shiga toxin-producing Escherichia coli O157:H7 and non-O157 from beef carcasses at a slaughter plant in Mexico. Int J Food Microbiol 2007; 113:237-41. [PMID: 17007951 DOI: 10.1016/j.ijfoodmicro.2006.06.028] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2005] [Revised: 03/14/2006] [Accepted: 06/13/2006] [Indexed: 11/30/2022]
Abstract
The contamination of beef carcasses with Shiga toxin-producing O157:H7 and non-O157 Escherichia coli (STEC) obtained from a slaughter plant in Guadalajara, Mexico was investigated. A total of 258 beef carcasses were sampled during a 12-month period. All samples were assayed for STEC by selective enrichment in modified tryptone soy broth supplemented with cefixime, cefsulodin and vancomycin, followed by plating on Sorbitol MacConkey Agar supplemented with cefixime and tellurite (CT-SMAC). Simultaneously, all samples were assayed by immunomagnetic separation (IMS) and plated on CT-SMAC and CHROMagar. The presence of the stx1, stx2, eaeA and hly933 genes, recognized as major virulence factors of STEC, was tested for O157:H7 and non-O157 E. coli isolates by multiplex polymerase chain reaction (PCR). STEC was detected in two (0.8%) samples. One of these STEC isolates corresponded to the serotype O157:H7 showing stx2, eaeA and hyl933 genes. The other isolate corresponded to non-O157 STEC and only had the stx1 gene. Thirteen carcasses (5%) were positive for nonmotile E. coli O157 and 7 (2.7%) were positive for E. coli O157:H7. The presence of O157:H7 and non-O157 STEC on beef carcasses in this slaughter plant in Guadalajara, Mexico, emphasizes the importance of implementing the Hazard Analysis and Critical Control Point (HACCP) system, as well as the need for implementing, evaluating, and validating antimicrobial interventions to reduce the presence of potential pathogenic microorganisms.
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Affiliation(s)
- J J Varela-Hernández
- Departamento de Ciencias Básicas, Centro Universitario de la Ciénega, Universidad de Guadalajara (Postgrado Interinstitucional en Ciencias Pecuarias), Av. Universidad 1115, Ocotlán, Jalisco, Mexico C. P. 47840.
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166
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Keen JE, Durso LM, Meehan TP. Isolation of Salmonella enterica and Shiga-toxigenic Escherichia coli O157 from feces of animals in public contact areas of United States zoological parks. Appl Environ Microbiol 2007; 73:362-5. [PMID: 17071798 PMCID: PMC1797120 DOI: 10.1128/aem.01563-06] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2006] [Accepted: 10/17/2006] [Indexed: 11/20/2022] Open
Abstract
The fecal prevalence of subclinical Salmonella enterica and Shiga-toxigenic Escherichia coli O157 among animals in human-animal contact exhibits at institutions in the United States accredited by the Association of Zoos and Aquariums was estimated to assess public health risk. The prevalence was less than 0.6% for both zoonotic pathogens among 997 animals sampled at 36 exhibits.
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Affiliation(s)
- James E Keen
- U.S. Department of Agriculture-Agricultural Research Service, U.S. Meat Animal Research Center, P.O. Box 166, Clay Center, NE 68933, USA.
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167
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Preslaughter spray-washing effects on physiological stress responses and skin and carcass microbial counts in goats. Small Rumin Res 2007. [DOI: 10.1016/j.smallrumres.2005.08.022] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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168
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Reinstein S, Fox JT, Shi X, Nagaraja TG. Prevalence of Escherichia coli O157:H7 in gallbladders of beef cattle. Appl Environ Microbiol 2006; 73:1002-4. [PMID: 17158626 PMCID: PMC1800778 DOI: 10.1128/aem.02037-06] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Gallbladders and rectal contents were collected from cattle (n=933) at slaughter to determine whether the gallbladder harbors Escherichia coli O157:H7. Both gallbladder mucosal swabs and homogenized mucosal tissues were used for isolation. Only five gallbladders (0.54%) were positive for E. coli O157:H7. Fecal prevalence averaged 7.1%; however, none of the cattle that had E. coli O157:H7 in the gallbladder was positive for E. coli O157:H7 in feces. Therefore, the gallbladder does not appear to be a common site of colonization for E. coli O157:H7 in beef cattle.
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Affiliation(s)
- S Reinstein
- Department of Diagnostic Medicine and Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan, KS 66506-5606, USA
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169
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Edrington TS, Callaway TR, Ives SE, Engler MJ, Looper ML, Anderson RC, Nisbet DJ. Seasonal Shedding ofEscherichia coliO157:H7 in Ruminants: A New Hypothesis. Foodborne Pathog Dis 2006; 3:413-21. [PMID: 17199523 DOI: 10.1089/fpd.2006.3.413] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Seasonal shedding of Escherichia coli O157:H7 in ruminants is well documented; however, viable explanations for this phenomenon are lacking. The fecal prevalence of E. coli O157:H7 in ruminants is the highest in the summer months, decreasing to low or undetectable levels in the winter. To determine if day length is correlated to seasonal shedding, nine reports of E. coli O157:H7 prevalence in cattle were selected for similarity of sampling technique, culture methodology, cattle type, and ability to determine approximate sampling month and location, representing three regions in North America (southern Canada, midwestern United States, and the southern United States/Mexico). Correlation and regression analysis revealed a positive correlation existed between day length (r = 0.67; R2 = 0.45; P = 0.0009) and, to a lesser extent, ambient temperature (r = 0.43; R2 = 0.19; P = 0.05) and E. coli O157:H7 prevalence. Based on these results, a study was conducted in a commercial feedlot to examine the effect of artificial lighting on E. coli O157 prevalence. Four pens of cattle received approximately 5 hours of artificial lighting daily (in addition to the natural light) for 60 days and four pens served as controls. Freshly voided fecal samples (representing approximately 30% of the steers/pen) were collected from the pen floor and cultured for E. coli O157 after 25 and 53 days of artificial lighting and 28 and 43 days following cessation of the lighting treatment. Fecal prevalence of E. coli O157 remained constant in the lighted pens whereas prevalence was lower (P < 0.01) in the control treatment after 53 days of lighting. Forty-three days following cessation of the lighting treatment, prevalence decreased in the lighted treatment group to levels comparable (P > 0.20) to control levels. Understanding the mechanisms underlying the seasonality of this important foodborne pathogen will enable the implementation of effective control strategies when it is most prevalent.
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Affiliation(s)
- Tom S Edrington
- Food and Feed Safety Research Unit, Southern Plains Agricultural Research Center, USDA-ARS, College Station, Texas 77845, USA.
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170
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Raya RR, Varey P, Oot RA, Dyen MR, Callaway TR, Edrington TS, Kutter EM, Brabban AD. Isolation and characterization of a new T-even bacteriophage, CEV1, and determination of its potential to reduce Escherichia coli O157:H7 levels in sheep. Appl Environ Microbiol 2006; 72:6405-10. [PMID: 16957272 PMCID: PMC1563603 DOI: 10.1128/aem.03011-05] [Citation(s) in RCA: 111] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Bacteriophage CEV1 was isolated from sheep resistant to Escherichia coli O157:H7 colonization. In vitro, CEV1 efficiently infected E. coli O157:H7 grown both aerobically and anaerobically. In vivo, sheep receiving a single oral dose of CEV1 showed a 2-log-unit reduction in intestinal E. coli O157:H7 levels within 2 days compared to levels in the controls.
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Affiliation(s)
- Raul R Raya
- The Evergreen State College, Olympia, WA 98505, USA
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171
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Sanderson MW, Sargeant JM, Shi X, Nagaraja TG, Zurek L, Alam MJ. Longitudinal emergence and distribution of Escherichia coli O157 genotypes in a beef feedlot. Appl Environ Microbiol 2006; 72:7614-9. [PMID: 17056682 PMCID: PMC1694217 DOI: 10.1128/aem.01412-06] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The purpose of this study was to describe the prevalence and longitudinal distribution of Escherichia coli O157 in feedlot cattle and the feedlot environment. Pen floors, water tanks, other cattle in the feedlot, feed, and bird feces were sampled for 2 weeks prior to entry of the study cattle. Twelve pens of study cattle were sampled twice weekly. At each sample time cattle feces, water from tanks in each pen, bunk feed, feed components, bird feces, and houseflies were collected. Bunk feed samples were collected before and after cattle had access to the feed. Overall, 28% of cattle fecal samples, 3.9% of bird fecal samples, 25% of water samples, 3.4% of housefly samples, 1.25% of bunk feed before calf access, and 3.25% of bunk feed samples after cattle had access to the feed were positive for E. coli O157. Genetic analysis of E. coli O157 isolates was done using pulsed-field gel electrophoresis (PFGE). PFGE types identified in sampling of the feedlot prior to calf entry were different than the majority of types identified following calf entry. A single strain type predominated in the samples collected after entry of the cattle. It was first identified 5 days after entry of the first pen of cattle and was subsequently identified in all pens. Data support that the incoming cattle introduced a new strain that became the predominant strain in the feedlot.
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Affiliation(s)
- Michael W Sanderson
- Department of Clinical Sciences, Kansas State University, Clinical Sciences, 111B Mosier Hall, Manhattan, KS 66506, USA.
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172
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Kiermeier A, Bobbitt J, Vanderlinde P, Higgs G, Pointon A, Sumner J. Use of routine beef carcase Escherichia coli monitoring data to investigate the relationship between hygiene status of incoming stock and processing efficacy. Int J Food Microbiol 2006; 111:263-9. [PMID: 16949171 DOI: 10.1016/j.ijfoodmicro.2006.05.006] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2005] [Revised: 04/06/2006] [Accepted: 05/14/2006] [Indexed: 11/28/2022]
Abstract
In Australian export-registered abattoirs microbiological monitoring is carried out within the E. coli and Salmonella Monitoring (ESAM) program. During the calendar year 2003, the ESAM database indicated a national prevalence of Escherichia coli of around 3.0% for steers/heifers and 7.1% for cows/bulls. An investigation was carried out to attempt to elucidate why some establishments had E. coli prevalence markedly higher or markedly lower than the national average. The investigation was based on a questionnaire completed by fifteen export establishments which provided data on livestock, processing, operator training and management. The responses were verified by site visits and then evaluated for their relationship with ESAM data on E. coli in two stages. In stage 1, E. coli prevalence for each abattoir was plotted against each variable recorded by the questionnaire; no single variable was a reasonable predictor for prevalence of E. coli on carcases. In stage 2, variables influencing contamination were grouped under two categories: contamination on incoming livestock (Problem variables) together with the ability of the plant's process to deal with such contamination (Process variables). The analysis prompted two main conclusions. Firstly, plants with a large incoming problem with livestock (long haul, high tag score and proportion of cows/bulls slaughtered) plus "poor" processes had higher than average E. coli prevalence. Secondly, plants with hot water decontamination systems had low E. coli prevalence even when there was a substantial incoming problem with livestock, such as a relatively high proportion of cows/bulls.
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Affiliation(s)
- Andreas Kiermeier
- South Australian Research & Development Institute, 33 Flemington Street, Glenside, SA 5065, Australia.
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173
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von Müffling T, Smaijlovic M, Nowak B, Sammet K, Bülte M, Klein G. Preliminary study of certain serotypes, genetic and antimicrobial resistance profiles of verotoxigenic Escherichia coli (VTEC) isolated in Bosnia and Germany from cattle or pigs and their products. Int J Food Microbiol 2006; 117:185-91. [PMID: 17011059 DOI: 10.1016/j.ijfoodmicro.2006.08.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The aim of this study was to gather more information on the spread of VTEC serotypes, genetic profiles and resistance patterns from pigs or pork and from cattle or beef in different areas, and to improve detection of the source of outbreaks with a wider data pool. Of 130 Escherichia coli samples isolated from a cattle slaughter house and beef retail products in Sarajevo, Bosnia and Herzegovina (BiH), seven were identified as verotoxigenic (VTEC). In comparison, 22 VTEC of 264 E. coli isolates were isolated from bovine faeces (14) and beef products (8) from Germany. Furthermore 23 VTEC of 76 isolates were identified from pig carcasses (10), faeces (9) and pork products (4) from Germany. Gene detection and serotyping were carried out in our laboratory and in the National Reference Laboratory. Antimicrobial resistance was tested with the dilution method in microtitre plates. All porcine isolates belonged to serotypes thus far not associated with human disease. Bovine VTEC were either serotypes commonly associated with human diseases (O157:H7, O103:H2, O157:H-) or rare serotypes. One serotype (O96:H19) was found only in isolates from Sarajevo. Most German VTEC, especially those of porcine origin, had only vtx2 genes, whereas all Bosnian isolates had vtx1 and vtx2 genes. The eae gene was found only in "classical" VTEC serotypes. All 52 VTEC (100%) investigated were resistant to the three sulfonamides tested; porcine isolates were mainly resistant to oxytetracycline (43%) and chlortetracycline (37%), bovine isolates mainly to trimethoprim/sulfamethoxazole and ampicillin (10% each). If sulfonamide resistances are disregarded, more than half (53.8%) of porcine VTEC were multiresistant and one-fourth (25%) of German bovine isolates, but none of the Bosnian bovine isolates. The results show the considerable spread of resistances in VTEC. These results also point out the necessity of gathering data from different geographical areas in order to be able to identify typical local variations in serotypes or gene expression and thus to trace human infections more quickly to their source.
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Affiliation(s)
- Theda von Müffling
- Department of Food Quality and Safety, University of Veterinary Medicine Hannover, Foundation, Bischofsholer Damm 15, 30173 Hannover, Germany.
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174
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Carney E, O'Brien SB, Sheridan JJ, McDowell DA, Blair IS, Duffy G. Prevalence and level of Escherichia coli O157 on beef trimmings, carcasses and boned head meat at a beef slaughter plant. Food Microbiol 2006; 23:52-9. [PMID: 16942986 DOI: 10.1016/j.fm.2004.12.001] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2004] [Accepted: 12/27/2004] [Indexed: 11/20/2022]
Abstract
This study investigated the prevalence and level of Escherichia coli O157 on samples of beef trimmings (n=1351), beef carcasses (n=132) and bovine head meat (n=132) in a beef slaughter plant in Ireland. The survey also included an assessment of the prevalence of virulence genes in the E. coli O157 isolates obtained. Samples were examined for the presence of E. coli O157 by direct plating on SMAC-CT and by enrichment/immunomagnetic separation (IMS) with plating of recovered immunobeads onto SMAC-CT agar. Presumptive E. coli O157 isolates were confirmed by PCR targeting a range of genes i.e. vt1, vt2, eaeA, hlyA, fliC(h7) and portions of the rfb (O-antigen encoding) region of E. coli O157. Enterobacteriaceae on head meat samples were estimated by direct plating onto Violet Red Bile Glucose agar. E. coli O157 was recovered from 2.4% (32/1351) of beef trimmings samples, at concentrations ranging from<0.70-1.61 log10 cfu g(-1). Of the 32 positive isolates, 31 contained the eaeA and hylA genes while 30/32 contained the fliC(h7) gene and 31/32 contained vt1 or vt2, or both vt genes. E. coli O157 was recovered from 3.0% (4/132) of carcass samples, at concentrations ranging from <0.70-1.41 log10 cfu g(-1). All of the carcass isolates contained the eaeA, hylA and fliC(h7) genes. E. coli O157 was recovered from 3.0% (3/100) of head meat samples, at concentrations of 0.7-1.0 log10 cfu g(-1). All of the head meat isolates contained the eaeA, hylA, fliC(h7) and vt2 genes. No head meat isolates contained the vt1 gene. Head meat samples (n=100) contained Enterobacteriaceae, at concentrations ranging from 0.70-3.0 log10 cfu g(-1). Overall, the qualitative and quantitative data obtained for E. coli O157 on beef trimming samples in this study could be employed as part of a quantitative risk assessment model.
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Affiliation(s)
- E Carney
- The National Food Centre, Dunsinea, Castleknock, Teagasc, Ashtown, Dublin 15, Ireland
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175
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Sargeant JM, Shi X, Sanderson MW, Renter DG, Nagaraja TG. Pulsed-Field Gel Electrophoresis Patterns ofEscherichia coliO157 Isolates from Kansas Feedlots. Foodborne Pathog Dis 2006; 3:251-8. [PMID: 16972773 DOI: 10.1089/fpd.2006.3.251] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
This study investigated the prevalence and distribution of Escherichia coli O157 genetic types within and among feedlots using pulsed-field gel electrophoresis to separate XbaI-digested DNA. The study population consisted of 300 pens of cattle in 30 feedlots in Kansas that were sampled (feces, water, and water sediment) within a month of being shipped for slaughter. The prevalence of E. coli O157 was 8.5% in feces, 3.1% in water, and 4.5% in water sediment samples. A total of 424 E. coli O157 isolates were characterized by pulsed-field gel electrophoresis, and 139 subtypes (100% Dice similarity with no band differences) were identified. The majority of subtypes (70/139) was identified only once, but nine were identified 10 or more times. Identical subtypes were recovered from both feces and water tanks in 10 feedlots. The majority of subtypes were identified in only one feedlot, and the number of subtypes ranged from one to 23 within a feedlot and from one to seven within a pen. There were 10 feedlots with at least 15 positive samples. In these 10 feedlots, the most common subtype accounted for 16.9-78.6% of the isolates. Common subtypes differed among feedlots. In eight of the 10 feedlots, the most common subtype was identified in multiple pens. The results support a complex ecology for E. coli O157 in feedlot operations, with factors associated with exposure and transmission likely acting at a common level for multiple feedlots, within feedlots, and within pens of cattle.
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Affiliation(s)
- J M Sargeant
- Department of Diagnostic Medicine and Pathobiology, Kansas State University, Manhattan, Kansas, USA.
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176
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Callaway TR, Edrington TS, Brabban AD, Keen JE, Anderson RC, Rossman ML, Engler MJ, Genovese KJ, Gwartney BL, Reagan JO, Poole TL, Harvey RB, Kutter EM, Nisbet DJ. Fecal Prevalence ofEscherichia coliO157,Salmonella, Listeria,and Bacteriophage InfectingE. coliO157:H7 in Feedlot Cattle in the Southern Plains Region of the United States. Foodborne Pathog Dis 2006; 3:234-44. [PMID: 16972771 DOI: 10.1089/fpd.2006.3.234] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Escherichia coli O157:H7, Salmonella, and Listeria are foodborne pathogens of critical importance that often colonize cattle. E. coli O157:H7 can be specifically killed by lytic bacteriophage, and lytic bacteriophage treatment has been suggested as a pre-harvest intervention strategy to reduce foodborne pathogens in cattle. To date, no systematic approach to determine the incidence of E. coli O157:H7-infecting lytic bacteriophage has been published. Therefore, the current study was designed to determine (1) the incidence of E. coli O157, Salmonella spp., and Listeria and (2) the incidence of E. coli O157:H7-infecting bacteriophage in the feces of feedlot steers in commercial feedlots in the United States. Fecal samples (n=60) were collected from four feedlots in two Southern Great Plains states (total (n=240 fecal samples). Salmonella and E. coli O157:H7 were found in 3.8% and 11.7% of the fecal samples, respectively. Bacteriophage targeting E. coli O157:H7 were found in all four feedlots, in 15% of the individual fecal samples, and in 55% of the cattle pens. Our results indicate that such bacteriophage are widespread in feedlot cattle, suggesting that further research into the ecological role of bacteriophage in the gastrointestinal tract is needed.
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Affiliation(s)
- T R Callaway
- Food and Feed Safety Research Unit, USDA/ARS, College Station, Texas 77845, USA.
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177
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Edrington TS, Looper ML, Duke SE, Callaway TR, Genovese KJ, Anderson RC, Nisbet DJ. Effect of Ionophore Supplementation on the Incidence ofEscherichia coliO157:H7 andSalmonellaand Antimicrobial Susceptibility of Fecal Coliforms in Stocker Cattle. Foodborne Pathog Dis 2006; 3:284-91. [PMID: 16972777 DOI: 10.1089/fpd.2006.3.284] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
To examine the effect of ionophore supplementation on fecal shedding of Escherichia coli O157:H7 and Salmonella, crossbred beef calves (n=113; mean body weight [BW], 243 kg) were fed a mineral supplement with ionophore (1.76 g lasalocid/kg) for 61 days (d). Control calves received an identical mineral supplement without lasalocid. Calves were pastured on fescue/bermudagrass paddocks and supplemented with a corn/wheat midds/soybean meal supplement (1.5% of BW/d). Upon arrival, cattle were fed a commercial receiving ration containing 1 g chlorotetracycline/kg for 10 d. Sick calves were administered one or a combination of the following: Nuflor (florfenicol), Baytril (eurofloxacin), Micotil (tilmicosin), or LA 200 (oxytetracycline). Fecal samples were collected immediately prior to ionophore supplementation, approximately midway and at the end of the experimental period (60 d total ionophore feeding) for isolation of E. coli O157:H7 and Salmonella. Putative fecal coliforms were also isolated at these sampling times and examined for antimicrobial susceptibility. The study was replicated over a two year period (year 1, n=53 head; year 2, n=60 head). Ionophore supplementation had no effect (p>0.10) on the incidence of calves shedding E. coli O157:H7 or Salmonella. The percentage of calves shedding E. coli O157:H7 varied throughout the experimental period from 0 to 30%, while Salmonella was cultured from only three calves over the 2-year experimental period. Antimicrobial susceptibility profiles of putative fecal coliforms were consistent with antibiotic treatments administered during the study (observed resistance to chlortetracycline, florfenicol, oxytetracycline), while only one treatment effect was observed. Ionophore treatment resulted in a significantly higher number of coliform isolates resistant to ampicillin compared to controls in year 1, but not year 2. A number of fecal coliform isolates demonstrated resistance to multiple antibiotics, however, this was not affected (p>0.10) by ionophore supplementation. Mineral intakes, BW gain, and the number of sick calves were similar (p>0.10) among treatments. Ionophore supplementation had no affect on fecal shedding of E. coli O157:H7 or Salmonella and a negligible impact on antimicrobial susceptibility patterns of fecal coliforms in beef calves.
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Affiliation(s)
- T S Edrington
- Food and Feed Safety Research Unit, Southern Plains Agricultural Research Center, USDA/ARS, College Station, Texas 77845, USA.
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178
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Duffy G, Cummins E, Nally P, O’ Brien S, Butler F. A review of quantitative microbial risk assessment in the management of Escherichia coli O157:H7 on beef. Meat Sci 2006; 74:76-88. [DOI: 10.1016/j.meatsci.2006.04.011] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2006] [Revised: 04/24/2006] [Accepted: 04/24/2006] [Indexed: 12/12/2022]
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179
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Chahed A, China B, Mainil J, Daube G. Prevalence of enterohaemorrhagic Escherichia coli from serotype O157 and other attaching and effacing Escherichia coli on bovine carcasses in Algeria. J Appl Microbiol 2006; 101:361-8. [PMID: 16882143 DOI: 10.1111/j.1365-2672.2006.02954.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
AIMS Bovine meat is the principal source of human contamination of attaching and effacing Escherichia coli, including enterohaemorrhagic E. coli O157. The aim was to study the prevalence of these strains on bovine carcasses in Algeria. METHODS AND RESULTS Two-hundred and thirty carcasses were swabbed and analysed by classical microbiological methods for total E. coli counts and for the presence of pathogenic E. coli. The E. coli counts were high, with a 75th percentile of 444.75 CFUs cm(-2). For pathogenic E. coli, more than 7% of the tested carcasses were positive for E. coli O157. Eighteen E. coli O157 strains were isolated and typed by multiplex PCR. The main isolated pathotype (78%) was eae+ stx2+ ehxA+. In addition to E. coli O157, other attaching and effacing E. coli (AEEC) were also detected from carcasses by colony hybridization after pre-enrichment and plating on sorbitol MacConkey agar using eae, stx1 and stx2 probes. Thirty carcasses (13%) on the 230 analysed harboured at least one colony positive for one of the tested probes. These positive carcasses were different from those positive for E. coli O157. Sixty-six colonies (2.9%) positive by colony hybridization were isolated. The majority (60.6%) of the positive strains harboured an enteropathogenic E. coli-like pathotype (eae+ stx-). Only three enterohaemorrhagic E. coli (EHEC)-like (eae+ stx1+) colonies were isolated from the same carcass. These strains did not belong to classical EHEC serotypes. CONCLUSIONS In this study, the global hygiene of the slaughterhouse was low, as indicated by the high level of E. coli count. The prevalence of both E. coli O157 and other AEEC was also high, representing a real hazard for consumers. SIGNIFICANCE AND IMPACT OF THE STUDY This is the first study of this type in Algeria, which indicates that the general hygiene of the slaughterhouse must be improved.
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Affiliation(s)
- A Chahed
- Faculty of Veterinary Medicine, Department of Food Sciences, Laboratory of Microbiology, University of Liège, Sart Tilman, Liege, Belgium
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180
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Echeverry A, Loneragan GH, Wagner BA, Brashears MM. Effect of intensity of fecal pat sampling on estimates of Escherichia coli O157 prevalence. Am J Vet Res 2006; 66:2023-7. [PMID: 16379641 DOI: 10.2460/ajvr.2005.66.2023] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To evaluate site-to-site variation within fecal pats from cattle with regard to detection of Escherichia coli O157 and determine the effect on the accuracy of prevalence estimates of assay of multiple samples collected from the same fecal pat. SAMPLE POPULATION 120 freshly voided fecal pats collected from 2 beef feedlots. Procedures-5 samples were systematically collected from each fecal pat and analyzed for E coli O157 via selective preenrichment techniques, immunomagnetic separation, and biochemical tests. Presumptive isolates were definitively identified via agglutination assays and polymerase chain reaction techniques. Best estimators of prevalence were calculated from the distribution of E coli O157-positive samples per pat. RESULTS Of the 120 fecal pats, 96, 13, 4, 2, 3, and 2 fecal pats had 0, 1, 2, 3, 4, and 5 E coli O157-positive samples, respectively. The greatest estimate of E coli O157 prevalence (20%) was achieved when all 5 samples were assessed; this estimate represented a 2.4- fold increase in prevalence, compared with that provided via analysis of 1 sample/pat (8.2%). Compared with assessment of 5 sites/pat, the relative sensitivity of detecting an E coli O157-positive fecal pat via analysis of 1 site/pat was 40.1%. CONCLUSIONS AND CLINICAL RELEVANCE Results suggest that estimates of E coli O157 prevalence derived from sampling of 1 location/pat are likely underestimates of the true prevalence of this pathogen in fecal pats (and by extension, cattle). Additional research is warranted to confirm these results in situations of high and low prevalence and across different feedlots.
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Affiliation(s)
- Alejandro Echeverry
- Department of Animal and Food Sciences, Texas Tech University, Lubbock, TX 79409, USA
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181
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LeJeune JT, Hancock DD, Besser TE. Sensitivity of Escherichia coli O157 detection in bovine feces assessed by broth enrichment followed by immunomagnetic separation and direct plating methodologies. J Clin Microbiol 2006; 44:872-5. [PMID: 16517869 PMCID: PMC1393073 DOI: 10.1128/jcm.44.3.872-875.2006] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In order to more precisely predict food safety risks, the fecal presence of food-borne pathogens among animals at slaughter must be correctly determined. Quantification of Escherichia coli O157 is also desirable. In two separate experiments, detection and enumeration of a nalidixic acid-resistant strain of E. coli O157 in bovine feces was assessed by culture on MacConkey agar supplemented with nalidixic acid (MACnal) and compared to overnight broth enrichment followed by immunomagnetic separation (IMS) and to direct plating of dilutions of bovine feces onto sorbitol MacConkey agar containing cefixime and tellurite (SMACct). The sensitivity of detection of E. coli O157 by both direct plating and IMS was highly dependent upon the initial concentration of the target organism in the sample. Sensitivity of detection by IMS was poor below 100 CFU/g but was better, and not affected by initial E. coli O157 numbers, above this concentration. Sensitivity of detection of E. coli O157 in bovine feces at low initial concentrations is very poor for both direct plating and IMS. Direct plating of dilutions of bovine feces on SMACct can be used to determine the magnitude of fecal E. coli excretion among cattle excreting greater than 100 CFU/g. Among positive samples identified by direct plating on SMACct, the direct counts of E. coli O157:H7 were highly correlated with the estimates obtained with the MACnal plates (r = 0.88, P < 0.001). Because the majority of cattle excrete less than 10(2) CFU E. coli O157/g feces, most studies, including those using IMS methods, probably grossly underestimate the prevalence of E. coli O157 in cattle.
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Affiliation(s)
- Jeffrey T LeJeune
- Food Animal Health Research Program, Ohio Agricultural Research and Development Center, The Ohio State University, 1680 Madison Ave., Wooster, Ohio 44691, USA.
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182
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Ferens WA, Cobbold R, Hovde CJ. Intestinal Shiga toxin-producing Escherichia coli bacteria mitigate bovine leukemia virus infection in experimentally infected sheep. Infect Immun 2006; 74:2906-16. [PMID: 16622229 PMCID: PMC1459712 DOI: 10.1128/iai.74.5.2906-2916.2006] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2005] [Revised: 02/08/2006] [Accepted: 02/22/2006] [Indexed: 11/20/2022] Open
Abstract
Ruminants often carry gastrointestinal Shiga toxin (Stx)-producing Escherichia coli (STEC). Stxs belong to a large family of ribosome-inactivating proteins (RIPs), found in many plants and some bacteria. Plant RIPs, secreted into extracellular spaces, limit the spread of viruses through plant tissues by penetrating and killing virally infected cells. Previously, we showed Stx activity against bovine leukemia virus (BLV)-infected cells in vitro and hypothesized that STEC bacteria have antiviral activity in ruminant hosts. Here, we investigated the impact of STEC on the initial phases of BLV infection in sheep. Sheep were treated with biweekly oral doses of E. coli O157:H7 (an STEC) or an isogenic stx mutant strain. A different group of sheep were similarly treated with five naturally occurring ovine STEC isolates or stx-negative E. coli. Intestinal STEC bacteria were enumerated and identified by standard fecal culture and DNA hybridization. Oral STEC treatment did not always result in carriage of STEC, although many animals consistently presented with >10(4) CFU/g feces. BLV viremia was assessed by spontaneous lymphocyte proliferation (SLP) in cultures of blood mononuclear cells and by syncytium formation in cocultures of the same with F-81 indicator cells. SLP was lower (P < 0.05) and syncytia were fewer (P < 0.05) in STEC-treated sheep than in untreated sheep. Both lower SLP and fewer syncytia positively correlated with fecal STEC numbers. Average weight gain post-BLV challenge was higher in STEC-treated sheep than in untreated sheep (P < 0.05). These results support the hypothesis that in ruminants, intestinal STEC bacteria have antiviral activity and mitigate BLV-induced disease.
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Affiliation(s)
- Witold A Ferens
- Department of Microbiology, Molecular Biology and Biochemistry, University of Idaho, Moscow, ID 83844-3052, USA
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183
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Keen JE, Wittum TE, Dunn JR, Bono JL, Durso LM. Shiga-toxigenic Escherichia coli O157 in agricultural fair livestock, United States. Emerg Infect Dis 2006; 12:780-6. [PMID: 16704838 PMCID: PMC3293435 DOI: 10.3201/eid1205.050984] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
Agricultural fairs exhibiting livestock are increasingly implicated in human Shiga-toxigenic Escherichia coli O157:H7 (STEC O157:H7) outbreaks. To estimate livestock STEC O157:H7 prevalence at US fairs, we collected 2,919 fecal specimens at 29 county fairs in 2 states and at 3 state fairs in 2002. Fly pools were also collected. STEC O157:H7 was isolated from livestock at 31 (96.9%) of 32 fairs, including 11.4% of 1,407 cattle, 1.2% of 1,102 swine, 3.6% of 364 sheep and goats, and 5.2% of 154 fly pools. Cattle, swine, and flies at some fairs shared indistinguishable STEC O157:H7 isolate subtypes. In 2003, a total of 689 ambient environmental samples were collected at 20 fairgrounds 10-11 months after 2002 livestock sampling while fairgrounds were livestock-free. Four beef barn environmental samples at 3 fairgrounds yielded STEC O157:H7. These data suggest that STEC O157 is common and transmissible among livestock displayed at agricultural fairs and persists in the environment after the fair.
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Affiliation(s)
- James E Keen
- Agricultural Research Service, US Meat Animal Research Center, United States Department of Agriculture, Clay Center, NE 68933, USA.
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184
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EDWARDS JESSICARENEE, FUNG DANIELY. PREVENTION AND DECONTAMINATION OF ESCHERICHIA COLI O157:H7 ON RAW BEEF CARCASSES IN COMMERCIAL BEEF ABATTOIRS. ACTA ACUST UNITED AC 2006. [DOI: 10.1111/j.1745-4581.2006.00037.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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185
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Schultz CL, Edrington TS, Schroeder SB, Hallford DM, Genovese KJ, Callaway TR, Anderson RC, Nisbet DJ. Effect of the thyroid on faecal shedding of E. coli O157:H7 and Escherichia coli in naturally infected yearling beef cattle. J Appl Microbiol 2006; 99:1176-80. [PMID: 16238748 DOI: 10.1111/j.1365-2672.2005.02705.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
AIMS To determine if thyroid function affects faecal shedding of Escherichia coli O157:H7. METHODS AND RESULTS Eight yearling cattle (n = 4 per treatment group), previously identified as shedding E. coli O157:H7, received either 0 or 10 mg 6-N-propyl-2-thiouracil (PTU) kg(-1) BW day(-1) for 14 days to reduce serum concentrations of the thyroid hormones, T(3) and T(4). Animals were monitored daily for changes in faecal shedding of E. coli O157:H7 and E. coli (EC) for the 14-day treatment period and an additional 7 days post-treatment. Body weight was measured weekly and serum concentrations of T(3) and T(4) were determined every 3 days. No differences in faecal shedding of E. coli O157:H7 were observed during the 14-day treatment period. However, compared with control animals, a greater percentage of PTU-treated cattle ejected E. coli O157:H7 on day 16 (100 vs 25%) and 18 (75 vs 0%) of the post-treatment period. Serum T(3) was lower in PTU-treated cattle during the 14-day treatment period and greater on day 18 of the post-treatment period. CONCLUSION Cattle with chemically altered thyroid hormones had similar shedding patterns of faecal E. coli O157:H7 and EC during the 14-day treatment period. However, faecal shedding of E. coli O157:H7 tended to be greater, and serum concentrations of T(3), were greater for PTU-treated cattle immediately following the termination of PTU treatment. SIGNIFICANCE AND IMPACT OF THE STUDY Short-term chemical inhibition of thyroid hormones had minimal effects on faecal shedding of E. coli O157:H7 in naturally infected cattle. However, a hyperthyroid state as observed postdosing might play a role in the seasonal shedding of E. coli O157:H7 in cattle.
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Affiliation(s)
- C L Schultz
- USDA/ARS-Southern Plains Agricultural Research Center, College Station, TX 77845, USA
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186
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Wells JE, Berry ED, Varel VH. Effects of common forage phenolic acids on Escherichia coli O157:H7 viability in bovine feces. Appl Environ Microbiol 2006; 71:7974-9. [PMID: 16332775 PMCID: PMC1317379 DOI: 10.1128/aem.71.12.7974-7979.2005] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Ruminant animals are carriers of Escherichia coli O157:H7, and the transmission of E. coli O157:H7 from cattle to the environment and to humans is a concern. It is unclear if diet can influence the survivability of E. coli O157:H7 in the gastrointestinal system or in feces in the environment. Feces from cattle fed bromegrass hay or corn silage diets were inoculated with E. coli O157:H7, and the survival of this pathogen was analyzed. When animals consumed bromegrass hay for <1 month, viable E. coli O157:H7 was not recovered after 28 days postinoculation, but when animals consumed the diet for >1 month, E. coli O157:H7 cells were recovered for >120 days. Viable E. coli O157:H7 cells in feces from animals fed corn silage were detected until day 45 and differed little with the time on the diet. To determine if forage phenolic acids affected the viability of E. coli O157:H7, feces from animals fed corn silage or cracked corn were amended with common forage phenolic acids. When 0.5% trans-cinnamic acid or 0.5% para-coumaric acid was added to feces from silage-fed animals, the E. coli O157:H7 death rate was increased significantly (17-fold and 23-fold, respectively) compared to that with no addition. In feces from animals fed cracked corn, E. coli O157:H7 death rates were increased significantly with the addition of 0.1% and 0.5% trans-cinnamic acid (7- and 13-fold), 0.1% and 0.5% p-coumaric acid (3- and 8-fold), and 0.5% ferulic acid (3-fold). These data suggest that phenolic acids common to forage plants can decrease viable counts of E. coli O157:H7 shed in feces.
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Affiliation(s)
- J E Wells
- U.S. Department of Agriculture, Agricultural Research Service, U.S. Meat Animal Research Center, P.O. Box 166, Clay Center, NE 68933, USA.
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187
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You JY, Moon BM, Oh IG, Baek BK, Li LG, Kim BS, Stein BD, Lee JH. Antimicrobial resistance of Escherichia coli O157 from cattle in Korea. Int J Food Microbiol 2006; 106:74-8. [PMID: 16300850 DOI: 10.1016/j.ijfoodmicro.2005.05.013] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2004] [Revised: 02/21/2005] [Accepted: 05/26/2005] [Indexed: 11/26/2022]
Abstract
Of 45 Escherichia coli O157 isolates from cattle feces, which were collected between May 2000 and September 2003 in Korea, 32 were resistant to at least 1 antibiotic and 28 were resistant to 4 or more antibiotics, with 32, 30 and 30 of the isolates being resistant to streptomycin, tetracycline and sulfisoxazole, respectively. Two isolates were resistant to fluoroquinolones and to 10 or more of the 22 other antimicrobial agents that were tested. Thirteen antimicrobial resistant patterns were observed. The most frequent resistance type, which was found for 11 isolates, was streptomycin-tetracycline-kanamycin-ampicillin-piperacillin-cephalothin-sulfisoxazole-ticarcillin. Polymerase chain reaction (PCR) analysis of the isolates for E. coli O157 virulence markers revealed that 25 of the resistant E. coli O157 isolates tested positive for stx2 or both stx1 and stx2 genes. These findings suggest that many of the resistant E. coli O157 isolates might cause disease in humans.
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Affiliation(s)
- Ju-Yeon You
- Veterinary Public Health, College of Veterinary Medicine, Chonbuk National University, Chonju, 561-756, Republic of Korea
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188
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Durso LM, Reynolds K, Bauer N, Keen JE. Shiga-toxigenic Escherichia coli O157:H7 infections among livestock exhibitors and visitors at a Texas County Fair. Vector Borne Zoonotic Dis 2005; 5:193-201. [PMID: 16011437 DOI: 10.1089/vbz.2005.5.193] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
We report an agricultural fair-associated shiga-toxigenic Escherichia coli O157:H7 (STEC O157) outbreak that was unusual in that it affected both livestock exhibitors and visitors. Twenty-five human cases of STEC O157 infection were detected after the Fort Bend County Fair in Rosenberg, Texas, which ran from 9/26/03 to 10/04/03. Seven cases were culture-confirmed. There were four hemolytic uremic syndrome (HUS) cases, and one thrombotic thrombocytopenic purpura (TTP) case. Cases ranged in age from 18 months to 67 years. Twenty-two (88%) cases were female. Analysis of unmatched case-control data linked STEC O157 infection with visiting fair livestock exhibit areas and with multiple fair visits. All outbreak-related isolates were of a single STEC O157 subtype. Fair Ground environmental sampling and culture for STEC O157, conducted 46 days after the end of the Fair, yielded multiple STEC O157 isolates, including the outbreak subtype. Livestock exhibitors and fair visitors should follow guidelines to reduce the risk of transmission of STEC O157 at agricultural fairs.
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Affiliation(s)
- Lisa M Durso
- USDA, ARS, U.S. Meat Animal Research Center, Clay Center, Nebraska 68933, USA
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189
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Prevalence of Shiga toxin-producing Escherichia coli in beef. Meat Sci 2005; 71:676-89. [DOI: 10.1016/j.meatsci.2005.05.012] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2005] [Revised: 05/12/2005] [Accepted: 05/12/2005] [Indexed: 01/28/2023]
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190
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Sawires YS, Songer JG. Clostridium perfringens: insight into virulence evolution and population structure. Anaerobe 2005; 12:23-43. [PMID: 16701609 DOI: 10.1016/j.anaerobe.2005.10.002] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2005] [Revised: 10/07/2005] [Accepted: 10/11/2005] [Indexed: 11/29/2022]
Abstract
Clostridium perfringens is an important pathogen in veterinary and medical fields. Diseases caused by this organism are in many cases life threatening or fatal. At the same time, it is part of the ecological community of the intestinal tract of man and animals. Virulence in this species is not fully understood and it does seem that there is erratic distribution of the toxin/enzyme genes within C. perfringens population. We used the recently developed multiple-locus variable-number tandem repeat analysis (MLVA) scheme to investigate the evolution of virulence and population structure of this species. Analysis of the phylogenetic signal indicates that acquisition of the major toxin genes as well as other plasmid-borne toxin genes is a recent evolutionary event and their maintenance is essentially a function of the selective advantage they confer in certain niches under different conditions. In addition, it indicates the ability of virulent strains to cause disease in different host species. More interestingly, there is evidence that certain normal flora strains are virulent when they gain access to a different host species. Analysis of the population structure indicates that recombination events are the major tool that shapes the population and this panmixia is interrupted by frequent clonal expansion that mostly corresponds to disease processes. The signature of positive selection was detected in alpha toxin gene, suggesting the possibility of adaptive alleles on the other chromosomally encoded determinants. Finally, C. perfringens proved to have a dynamic population and availability of more genome sequences and use of comparative proteomics and animal modeling would provide more insight into the virulence of this organism.
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Affiliation(s)
- Youhanna S Sawires
- Department of Veterinary Science and Microbiology, University of Arizona, Room 207, 1117 East Lowell Street, Tucson AZ 85721, USA.
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191
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Effects of experimental chlorate preparations as feed and water supplements on Escherichia coli colonization and contamination of beef cattle and carcasses. Food Microbiol 2005. [DOI: 10.1016/j.fm.2004.09.002] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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192
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Samelis J, Sofos JN, Kendall PA, Smith GC. Survival or growth of Escherichia coli O157:H7 in a model system of fresh meat decontamination runoff waste fluids and its resistance to subsequent lactic acid stress. Appl Environ Microbiol 2005; 71:6228-34. [PMID: 16204542 PMCID: PMC1265993 DOI: 10.1128/aem.71.10.6228-6234.2005] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2004] [Accepted: 05/25/2005] [Indexed: 11/20/2022] Open
Abstract
A potential may exist for survival of and resistance development by Escherichia coli O157:H7 in environmental niches of meat plants applying carcass decontamination interventions. This study evaluated (i) survival or growth of acid-adapted and nonadapted E. coli O157:H7 strain ATCC 43895 in acetic acid (pH 3.6 +/- 0.1) or in water (pH 7.2 +/- 0.2) fresh beef decontamination runoff fluids (washings) stored at 4, 10, 15, or 25 degrees C and (ii) resistance of cells recovered from the washings after 2 or 7 days of storage to a subsequent lactic acid (pH 3.5) stress. Corresponding cultures in sterile saline or in heat-sterilized water washings were used as controls. In acetic acid washings, acid-adapted cultures survived better than nonadapted cultures, with survival being greatest at 4 degrees C and lowest at 25 degrees C. The pathogen survived without growth in water washings at 4 and 10 degrees C, while it grew by 0.8 to 2.7 log cycles at 15 and 25 degrees C, and more in the absence of natural flora. E. coli O157:H7 cells habituated without growth in water washings at 4 or 10 degrees C were the most sensitive to pH 3.5, while cells grown in water washings at 15 or 25 degrees C were relatively the most resistant, irrespective of previous acid adaptation. Resistance to pH 3.5 of E. coli O157:H7 cells habituated in acetic acid washings for 7 days increased in the order 15 degrees C > 10 degrees C > 4 degrees C, while at 25 degrees C cells died off. These results indicate that growth inhibition by storage at low temperatures may be more important than competition by natural flora in inducing acid sensitization of E. coli O157:H7 in fresh meat environments. At ambient temperatures in meat plants, E. coli O157:H7 may grow to restore acid resistance, unless acid interventions are applied to inhibit growth and minimize survival of the pathogen. Acid-habituated E. coli O157:H7 at 10 to 15 degrees C may maintain a higher acid resistance than when acid habituated at 4 degrees C. These responses should be evaluated with fresh meat and may be useful for the optimization of decontamination programs and postdecontamination conditions of meat handling.
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Affiliation(s)
- John Samelis
- National Agricultural Research Foundation, Dairy Research Institute, Katsikas, 452 21 Ioannina, Greece.
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193
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Abstract
The emergence of enterohaemorrhagic Escherichia coli (EHEC) as major human pathogens began with the identification of serotype O157:H7 in the early 1980s as the cause of various food-borne outbreaks of severe intestinal disease. The key virulence factors include verocytotoxins (Vt) and effectors and adhesins associated with type III secretion systems. Tracing the origins of human outbreaks reveals that the primary source of this organism is the ruminant gastro-intestinal tract and a variety of transmission routes to humans have been identified. The epidemiology of E. coli O157:H7 within cattle and other ruminants has been studied extensively and the prevalence of non-O157:H7 serotypes contrasts with the observed dominance of E. coli O157:H7 amongst human EHEC isolates. Although there is some evidence that EHEC cause disease in young animals, the high prevalence of Vt within healthy ruminants suggests that this is not a virulence factor within these species. An understanding of the mechanisms underpinning EHEC persistence within their natural reservoir hosts and the development of a molecular understanding of EHEC biology and evolution could eventually allow a reduction in the incidence of human disease and may reduce future threats. The use of animal models to replicate and study human EHEC pathogenesis is described.
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Affiliation(s)
- Stuart W Naylor
- Animal Health Group, Scottish Agricultural College, West Mains Road, Edinburgh, EH9 3JG, UK.
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194
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Greenquist MA, Drouillard JS, Sargeant JM, Depenbusch BE, Shi X, Lechtenberg KF, Nagaraja TG. Comparison of rectoanal mucosal swab cultures and fecal cultures for determining prevalence of Escherichia coli O157:H7 in feedlot cattle. Appl Environ Microbiol 2005; 71:6431-3. [PMID: 16204574 PMCID: PMC1265949 DOI: 10.1128/aem.71.10.6431-6433.2005] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2005] [Accepted: 05/24/2005] [Indexed: 11/20/2022] Open
Abstract
We compared fecal samples with samples collected with rectoanal mucosa swabs (RAMS) to determine the prevalence of Escherichia coli O157 in feedlot cattle (n = 747). Escherichia coli O157 was detected in 9.5% of samples collected with RAMS and 4.7% of samples tested by fecal culture. Pulsed-field gel electrophoresis analysis of isolates suggested that the strains colonizing the rectoanal junction were the same as those from the feces. Mucosal swab sampling was more sensitive than fecal sampling for determining the prevalence of E. coli O157 in feedlot cattle.
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Affiliation(s)
- M A Greenquist
- Department of Diagnostic Medicine/Pathobiology, 305 Coles Hall, Kansas State University, Manhattan, KS 66506-5606, USA
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195
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Gilbert RA, Tomkins N, Padmanabha J, Gough JM, Krause DO, McSweeney CS. Effect of finishing diets on Escherichia coli populations and prevalence of enterohaemorrhagic E. coli virulence genes in cattle faeces. J Appl Microbiol 2005; 99:885-94. [PMID: 16162240 DOI: 10.1111/j.1365-2672.2005.02670.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
AIM To determine the effect of different carbohydrate-based finishing diets on fermentation characteristics and the shedding of Escherichia coli and enterohaemorrhagic E. coli (EHEC) virulence genes in cattle faeces. METHODS AND RESULTS The size of faecal E. coli populations and fermentation characteristics were ascertained in three experiments where cattle were maintained on a range of finishing diets including high grain, roughage, and roughage + molasses (50%) diets. Increased E. coli numbers, decreased pH and enhanced butyrate and lactate fermentation pathways were associated with grain diets, whereas roughage and roughage + molasses diets resulted in decreased concentrations of ehxA, eaeA and stx(1) genes, this trend remaining at lairage. In one experiment, faecal E. coli numbers were significantly lower in animals fed roughage and roughage + molasses, than animals fed grain (4.5, 5.2 and 6.3 mean log10 g(-1) digesta respectively). In a second experiment, faecal E. coli numbers were 2 log lower in the roughage and roughage + molasses diets compared with grain-fed animals prior to lairage (5.6, 5.5 and 7.9 mean log10 g(-1) digesta respectively) this difference increasing to 2.5 log at lairage. CONCLUSIONS The type of dietary carbohydrate has a significant effect on E. coli numbers and concentration of EHEC virulence genes in faeces of cattle. SIGNIFICANCE AND IMPACT OF THE STUDY The study provides a better understanding of the impact finishing diet and commercial lairage management practices may have on the shedding of E. coli and EHEC virulence factors, thus reducing the risk of carcass contamination by EHEC.
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Affiliation(s)
- R A Gilbert
- CSIRO Livestock Industries, Queensland Bioscience Precinct, Brisbane, Qld, Australia.
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196
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La Ragione RM, Patel S, Maddison B, Woodward MJ, Best A, Whitelam GC, Gough KC. Recombinant anti-EspA antibodies block Escherichia coli O157:H7-induced attaching and effacing lesions in vitro. Microbes Infect 2005; 8:426-33. [PMID: 16298154 DOI: 10.1016/j.micinf.2005.07.009] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2005] [Accepted: 07/13/2005] [Indexed: 12/28/2022]
Abstract
Intimin and EspA proteins are virulence factors expressed by attaching and effacing Escherichia coli (AEEC) such as enteropathogenic and enterohaemorrhagic E. coli. The EspA protein makes up a filament structure forming part of the type III secretion system (TTSS) that delivers effector proteins to the host epithelial cell. Bacterial surface displayed intimin interacts with translocated intimin receptor in the host cell membrane leading to intimate attachment of the bacterium and subsequent attaching and effacing lesions. Here, we have assessed the use of recombinant monoclonal antibodies against E. coli O157:H7 EspA and intimin for the disruption of AEEC interaction with the host cell. Anti-gamma intimin antibodies did not reduce either adhesion of E. coli O157:H7 to host cell mono-layers or subsequent host cell actin rearrangement. Anti-EspA antibodies similarly had no effect on bacterial adhesion however they had a marked effect upon E. coli O157:H7-induced host cell actin rearrangement, where both monoclonal and polyclonal antibodies completely blocked cytoskeletal changes within the host cell. Furthermore, these anti-EspA antibodies were shown to reduce actin rearrangement induced by some but not all other AEEC serotypes tested. Both polyclonal and monoclonal antibodies could be used to label E. coli O157 EspA filaments and these immunoreagents did not inhibit the formation of such filaments. This is the first report of monoclonal antibodies to EspA capable of disrupting the TTSS function of E. coli O157:H7.
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Affiliation(s)
- Roberto M La Ragione
- Veterinary Laboratories Agency, Department of Food and Environmental Safety, Woodham Lane, New Haw, Addlestone, Surrey KT15 3NB, UK
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197
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Gannon VPJ, Duke GD, Thomas JE, Vanleeuwen J, Byrne J, Johnson D, Kienzle SW, Little J, Graham T, Selinger B. Use of in-stream reservoirs to reduce bacterial contamination of rural watersheds. THE SCIENCE OF THE TOTAL ENVIRONMENT 2005; 348:19-31. [PMID: 16162311 DOI: 10.1016/j.scitotenv.2004.12.076] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 12/10/2004] [Indexed: 05/04/2023]
Abstract
An investigation into bacterial water quality problems was conducted on an interconnected stream and irrigation system within the Oldman River Basin of southern Alberta, Canada. Levels of indicator bacteria, including fecal coliforms, generic Escherichia coli and fecal streptococci, were repeatedly measured in streams and irrigation return canals of this river basin during the summer of 2001. Bacterial-loading segments of the irrigation/stream system were identified through a comparison of indicator bacteria levels in pairs of upstream and downstream sites. Mann-Whitney U-tests indicated that reservoirs significantly reduced bacterial counts. A temporal comparison of E. coli counts and river discharges suggested that these indicator bacteria do not originate from within in-stream sediments. Site-specific as well as cumulative inputs from a variety of non-point sources are likely to be responsible for the high downstream levels of indicator bacteria in this water system. The use of management practices such as in-stream reservoirs may significantly reduce contamination, and increase the quality of limited rural water supplies to allow their reuse and safe discharge into downstream water sources. The identification of bacteria-loading river/canal segments could also be used to prioritize restoration projects.
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Affiliation(s)
- V P J Gannon
- Laboratory for Foodborne Zoonoses, Population and Public Health Branch, Health Canada, Lethbridge, Alberta
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198
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Oliver SP, Jayarao BM, Almeida RA. Foodborne pathogens in milk and the dairy farm environment: food safety and public health implications. Foodborne Pathog Dis 2005; 2:115-29. [PMID: 15992306 DOI: 10.1089/fpd.2005.2.115] [Citation(s) in RCA: 415] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
Abstract
Milk and products derived from milk of dairy cows can harbor a variety of microorganisms and can be important sources of foodborne pathogens. The presence of foodborne pathogens in milk is due to direct contact with contaminated sources in the dairy farm environment and to excretion from the udder of an infected animal. Most milk is pasteurized, so why should the dairy industry be concerned about the microbial quality of bulk tank milk? There are several valid reasons, including (1) outbreaks of disease in humans have been traced to the consumption of unpasteurized milk and have also been traced back to pasteurized milk, (2) unpasteurized milk is consumed directly by dairy producers, farm employees, and their families, neighbors, and raw milk advocates, (3) unpasteurized milk is consumed directly by a large segment of the population via consumption of several types of cheeses manufactured from unpasteurized milk, (4) entry of foodborne pathogens via contaminated raw milk into dairy food processing plants can lead to persistence of these pathogens in biofilms, and subsequent contamination of processed milk products and exposure of consumers to pathogenic bacteria, (5) pasteurization may not destroy all foodborne pathogens in milk, and (6) inadequate or faulty pasteurization will not destroy all foodborne pathogens. Furthermore, pathogens such as Listeria monocytogenes can survive and thrive in post-pasteurization processing environments, thus leading to recontamination of dairy products. These pathways pose a risk to the consumer from direct exposure to foodborne pathogens present in unpasteurized dairy products as well as dairy products that become re-contaminated after pasteurization. The purpose of this communication is to review literature published on the prevalence of bacterial foodborne pathogens in milk and in the dairy environment, and to discuss public health and food safety issues associated with foodborne pathogens found in the dairy environment. Information presented supports the model in which the presence of pathogens depends on ingestion of contaminated feed followed by amplification in bovine hosts and fecal dissemination in the farm environment. The final outcome of this cycle is a constantly maintained reservoir of foodborne pathogens that can reach humans by direct contact, ingestion of raw contaminated milk or cheese, or contamination during the processing of milk products. Isolation of bacterial pathogens with similar biotypes from dairy farms and from outbreaks of human disease substantiates this hypothesis.
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Affiliation(s)
- S P Oliver
- Food Safety Center of Excellence and Department of Animal Science, 59 McCord Hall, The University of Tennessee, Knoxville, TN 37996, USA.
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Sanderson MW, Sargeant JM, Nagaraja TG. Effect of pooling bovine fecal samples on the sensitivity of detection of E. coli O157:H7. Vet Microbiol 2005; 110:125-30. [PMID: 16140477 DOI: 10.1016/j.vetmic.2005.08.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2005] [Revised: 07/12/2005] [Accepted: 08/01/2005] [Indexed: 11/16/2022]
Abstract
To assess the effect of pooling fecal samples on the sensitivity of detection of E. coli O157:H7, 12 calves, inoculated orally with 10(8)cfu per calf of nalidixic acid resistant E. coli O157:H7, were used to provide positive fecal samples. After inoculation, calves were sampled twice weekly. Negative fecal samples were from calves at a local dairy. Samples from inoculated calves were incubated without pooling or were mixed with known negative fecal samples in a 1:4 ratio or a 2:3 ratio (positive:negative) for detection of E. coli O157:H7. Samples were enriched 6h in Gram negative broth with vancomycin, cefixime, and cefsoludin, underwent immunomagnetic separation with Dynabeads, and were plated onto sorbitol MacConkey agar with cefixime, and tellurite (SMACct). Morphologically typical colonies were plated onto blood agar, incubated overnight at 37 degrees C and an indole test was performed on each colony. Indole positives colonies were plated on SMAC agar with 20 microg/ml nalidixic acid (SMACnal). Colonies that grew on SMACnal were confirmed by O157 agglutination. Sensitivity of detection in non-pooled samples was 77%. Samples pooled 1:4 and 2:3 with negative samples were 55 and 52% sensitive, respectively. Pooling decreased sensitivity of detection for E. coli O157:H7 in bovine fecal samples (P<0.01). A deterministic binomial probability model was developed to assess the probability of detecting pens of cattle shedding E. coli O157 using a pooling protocol or individual samples. Pooling decreased sensitivity of detection at low pen prevalence compared to individual samples but was similar at high prevalence.
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Affiliation(s)
- M W Sanderson
- Department of Clinical Sciences, Kansas State University, Veterinary Medical Teaching Hospital, 103J Mosier Hall, Manhattan, KS, USA.
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Loneragan G, Brashears M. Pre-harvest interventions to reduce carriage of E. coli O157 by harvest-ready feedlot cattle. Meat Sci 2005; 71:72-8. [DOI: 10.1016/j.meatsci.2005.04.005] [Citation(s) in RCA: 82] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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