Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “ABATTOIRS”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 91 records · Page 5Linked to original sources
PubMed2001

The prevalence and characterization of verotoxin-producing Escherichia coli isolated from cattle and pigs in an abattoir in Hong Kong.

The aim of the study was to define the prevalence of verotoxin-producing Escherichia coli (VTEC) in cattle and pigs in a Hong Kong abattoir. Faecal and carcass samples collected from 986 cattle and 487 pigs from an abattoir were tested for verotoxin (VT) by PCR and cytotoxicity assays. VTEC was isolated from 415 and 1-8% of cattle faecal and carcass samples and from 2.1 and 0.2% of porcine faecal and carcass samples, respectively. Amongst 409 VTEC isolates from cattle, 9 were serotype O157:H7 and eaeA+. The most prevalent vt genotype among bovine VTEC was vtl+vt2 (73.8%) and in porcine VTEC was vt2e+ (30%). None of the porcine VTEC isolates and 9.3% of the bovine VTEC isolates was eaeA+. The non-O157 serogroup VTEC isolates carrying eaeA and EHEC-hlyA belonged to serogroups O172, O15, O84, O91, O110 and O121. The local dietary preference for pork or chicken (rather than beef), the low VTEC carriage in pigs, the rarity of additional virulence factors (caeA) in VTEC isolated from cattle may explain the apparently low incidence of human diarrhoeal disease associated with VTEC in Hong Kong hitherto. However, the presence of non-O157 VTEC strains carrying the eacA virulence marker in cattle highlights the fact that sole reliance on sorbitol-MacConkey agar for screening human VTEC isolates may underestimate the human disease burden. The changing dietary habits of the population in Hong Kong reinforce the need for continued vigilance.

Abattoirs↗
PubMed1998

Studies of the presence of verocytotoxic Escherichia coli O157 in bovine faeces submitted for diagnostic purposes in England and Wales and on beef carcases in abattoirs in the United Kingdom.

A survey of beef carcases in abattoirs in the UK was carried out in order to estimate the prevalence of contamination with verocytotoxin-producing Escherichia coli (VTEC) serogroup O157. Contamination with verocytotoxin-producing E. coli (VTEC) O157 was confirmed in 0.47% of the 4067 (95% confidence limits 0.22-1.00%) of neck muscle samples. A significant tendency for carcases present in the same abattoir on the same day to have similar results was found, thus suggesting cross contamination. VTEC O157 was found in 0.83% of 6495 bovine faeces samples routinely submitted for diagnostic purposes to Veterinary Investigation Centres in England and Wales. Of the samples from cattle less than 6 months old, 3.7% of 68 samples from animals without gastrointestinal disease were positive for E. coli O157, in contrast to 0.75% of 2321 samples from cases of gastrointestinal disease. No association with season or herd type (beef or dairy) was found.

Abattoirs↗
PubMed2002

The abattoir source of culturable psychrophilic Clostridium spp. causing 'blown pack' spoilage of vacuum-packed chilled venison.

AIMS: To identify the abattoir source(s) of culturable psychrophilic clostridia causing 'blown pack' spoilage of vacuum-packed chilled meats. METHODS AND RESULTS: Psychrophilic and psychrotolerant clostridia were isolated from hides, faeces and tonsils of deer slaughter stock, and from a meat plant environment. The isolates were differentiated using restriction fragment length polymorphism analysis of the 16S rDNA gene (PCR-RFLP) and 16S-23S rDNA internal transcribed spacer (ITS) analysis. PCR-RFLP group I clostridia were found to have restriction patterns indistinguishable from the patterns of 'blown pack'-causing Clostridium gasigenes DB1A(T) and R26. Gas production in packs inoculated with vegetative cells of PCR-RFLP group I clostridia was first evident after 14 days at 2 degrees C. The prevalence of these clostridia was similar in hide and faecal samples from slaughter animals, but these micro-organisms were absent from tonsils and the meat plant environment. Banding patterns of PCR-RFLP group II clostridia showed some cross-similarity with patterns of the 'blown pack'-causing micro-organism Cl. estertheticum DSM 8809(T) and Cl. estertheticum-like meat strains. The majority of clostridia in PCR-RFLP group II were found in the faeces of slaughter animals. Isolates representing PCR-RFLP group II did not, however, produce gas in vacuum packs stored at 2 degrees C for 84 days. CONCLUSIONS: The data suggest that soil particles attached to hide or present in faeces are the most probable primary reservoir from which 'blown pack' clostridia are introduced onto carcasses. Therefore, dressing procedure hygiene remains paramount in order to control the spread of psychrophilic Clostridium spp. in a meat plant. SIGNIFICANCE AND IMPACT OF THE STUDY: The paper provides information critical for controlling 'blown pack' spoilage in meat processing plants. It reports on the use of molecular techniques for determination of abattoir sources of 'blown pack'-causing clostridia.

Abattoirs↗
PubMed2003

The prevalence and spread of Escherichia coli O157:H7 at a commercial beef abattoir.

AIMS: To investigate the prevalence and virulence characteristics of Escherichia coli O157:H7 after a number of beef process operations at a commercial Irish abattoir. METHODS AND RESULTS: Two 12-month studies were carried out. The first study (study 1) examined the prevalence of E. coli O157:H7 at up to six sites on carcasses at eight stages of the dressing, washing, chilling and boning process. The second study (study 2) examined the prevalence of E. coli O157:H7 in bovine faeces and rumen contents post-slaughter and on dressed, washed carcasses. Isolates from both studies were phage-typed and the presence of genes encoding verocytotoxin, enterohaemolysin and intimin production was determined. E. coli O157:H7 was isolated from four of 36 carcasses in study 1. E. coli O157:H7 was detected during hide removal and was detected at multiple carcass sites and multiple process stages, including boning. On two carcasses, contamination was first detected at the bung following its freeing and tying. All isolates from study 1 were phage type (PT) 2, eaeAO157 and ehlyA positive, but were verocytotoxin 1 (VT1) and verocytotoxin 2 (VT2) negative. In study 2, E. coli O157:H7 was isolated from 2.4% of faecal, 0.8% of rumen and 3.2% of carcass samples. In some cases, isolates recovered from the faeces of a particular animal, the resulting carcass and adjacent carcasses on the line had the same phage typing and virulence characteristic profile patterns. All isolates from study 2 were eaeAO157 and ehlyA positive and only one isolate was VT1 and VT2 negative. Most isolates were PT 32. A higher frequency of positive isolations was noted from samples taken during spring and late summer. CONCLUSION: These studies show that in a typical Irish beef abattoir, carcass contamination with E. coli O157:H7 can occur during hide removal and bung tying and this contamination can remain on the carcass during subsequent processing. SIGNIFICANCE AND IMPACT OF THE STUDY: This study provides data that is necessary for the understanding of how E. coli O157:H7 contamination of beef occurs.

Abattoirs↗
PubMed2005

Conventional approach for abattoir wastewater treatment.

Detailed physico-chemical studies on abattoir effluent using lime, alum, ferrous sulphate and an anionic polyelectrolyte were tried individually and in combination. Among the coagulants tried, lime resulted in good settling of the sludge. At 400 mg l(-1) of lime dose, the Suspended Solids (SS), Biochemical Oxygen Demand (BOD) and Chemical Oxygen Demand (COD) removals were found to be 41.9%, 38.9% and 36.1%, respectively. Best results were obtained with lime and ferrous sulphate in a combination ratio of 400:100 mg l(-1), and the COD reduction of 36.1% at 400 mg l(-1) of lime, further improved to 56.8%. Lime and alum dose of 400:50 mg l(-1) resulted in an increased COD reduction of 42.6% compared to 36.1% at lime dose of 400 mg l(-1). However, the same lime dose with ferrous sulphate addition of 100 mg l(-1) resulted in an increased COD reduction of 56.8% compared to 36.1%. This is a more efficient option for abattoir wastewater treatment and also cost effective. Ferrous sulphate with anionic polyelectrolyte resulted in good removals. Though it is a costly chemical, the dose needed is just half that of lime and just 0.1 mg l(-1) of anionic polyelectrolyte resulted in good reductions in SS, BOD and COD of 54.2%, 49.6% and 43.8% respectively. Studies indicated that the lime and ferrous sulphate in the combination of 400:100 mg l(-1), and ferrous sulphate and polyelectrolyte in the combination of 100:0.1 mg l(-1) are the two feasible options. Lime in combination with alum can also be applied but resultant sludge volume would be more.

Abattoirs↗
PubMed2005

Variable abattoir conditions affect Salmonella enterica prevalence and meat quality in swine and pork.

Research suggests that abattoir holding pens pose significant Salmonella enterica risk to swine immediately preharvest. The goal of this study was to evaluate those factors related to holding that increased the prevalence of S. enterica in swine at slaughter. To accomplish this goal, we focused on holding time and flooring. Our objectives were to (1) compare Salmonella enterica prevalence among pigs held for short (15-45 min) versus long (up to 4 h) periods before slaughter; and (2) determine the impact of flooring (slatted vs. concrete) as it relates to the prevalence of S. enterica. The study consisted of seven repetitions at a large volume (11,000 head/day) Midwest abattoir. Each repetition consisted of one truck load of pigs (n = 170) sorted into one of three groups: (1) animals held for a short time (15-45 min) on solid floors (short-hold); (2) animals held for 4 +/- 0.5 h on slatted floors; and (3) animals held for 4 +/- 0.5 h on solid concrete floors. At slaughter, samples were collected from 30 pigs in each group. Cecal contents (20 mL), feces (20 g), and the ileocecal lymph node were cultured for S. enterica. Additionally, the effect of holding time on meat quality parameters (loin pH at 35 min and 6 h, color, drip loss) was evaluated for the first four replicates. The proportion of S. enterica-positive samples was highest (p < 0.05) in the cecum of pigs held on solid concrete floors (72.4%), and slightly less for pigs held on slatted floors (63.3%). Animals held for less than 45 min before slaughter demonstrated the lowest proportion of S. enterica-positive samples (52.9%). The pig prevalence, as measured by any one of the three samples being positive, was significantly different (p < 0.05) between animals held on solid floors (81%) and those animals held for 45 min or less before slaughter (69%). Meat quality, as measured by multiple parameters, was adversely affected by lack of a rest period. The mean 24-h pH was significantly lower for the short-hold group compared to the other two groups. The mean Minolta L and the drip loss were significantly higher in the short-hold group. From this and other studies, it appears that elimination of the holding process is not feasible S. enterica control option, given current U.S. harvesting systems.

Abattoirs↗
PubMed2000

Risk factors for abattoir condemnation of turkey carcasses due to cyanosis in southern Ontario.

Cyanosis is a category of condemnation for poultry, as defined by Agriculture and Agrifood Canada. A retrospective study to examine the seasonal patterns and trends for turkey cyanosis condemnation was conducted for the years 1987 to 1995 with the use of condemnation records made available by a single abattoir in Ontario. Condemnation for cyanosis had a significant seasonal pattern, with major losses occurring in the colder months (October to March). A prospective longitudinal study was conducted during January to March and October to December 1996 in the same abattoir and the 75 turkey farms that contracted to process their birds through it and all the 913 truckloads of turkeys processed in these two 3-mo periods. The data from this prospective study were used for multivariate modeling of the effects of potential risk factors on the incidence of cyanosis. Risk factors (at P < or = 0.05) included bird type (broiler age turkeys, mature toms, and mature hens compared to toms and hens), ambient temperature (cold: -9.9 to 0.0 C and very cold: < or =-10.0 C compared to mild: >0.0 C), clean-out lot (the last shipped from a poultry house), shipping time > or =8 h, and emaciation (proportion of turkeys in the lot condemned for insufficient muscle mass). The crate density was a sparing factor, and an increase in turkey density during shipping resulted in a lower incidence of cyanosis. This study suggested that the number of turkeys condemned for cyanosis was associated with cold, shipping stress, and subclinical syndromes.

Abattoirs↗
PubMed2000

An outbreak of skin sepsis in abattoir workers caused by an 'unusual' strain of Streptococcus pyogenes.

An outbreak of indolent skin infections due to an 'unusual' serological type of Streptococcus pyogenes that lasted for 3 months and affected eight workers in an abattoir is described. The group A streptococcal (GAS) isolates were serotyped as M-type 59; however, they possessed a T-protein pattern (T5/27/44) that is not commonly associated with M-type 59. Further genotypic characterisation studies revealed that all eight isolates were indistinguishable by pulsed-field gel electrophoresis (PFGE) and possessed the emm gene encoding for the M-type 59. Once identified, and after a combination of penicillin treatment, exclusion of workers with lesions and reinforcement of standard hygiene precautions, no further cases developed. Although common in the 1970s and 1980s, streptococcal infections in this situation are now reported infrequently. This report serves to highlight the issues surrounding working practices in abattoirs.

Abattoirs↗
PubMed1989

Incidence of aeromonads in samples from an abattoir processing lambs.

Two hundred and thirty three samples of lamb carcasses, livers, kidneys and faeces, collected at a local abattoir, were examined to determine the incidence of motile Aeromonas spp. Wash water from the abattoir was also tested. Direct plating on starch ampicillin agar and enrichment in alkaline peptone water were used. The incidence of aeromonads was low. They were detected only after enrichment in 5/47 faecal samples and 11/50 carcass samples. The 41 strains of Aeromonas isolated were identified to species level and 93% of them were able to grow at 5 degrees C. The ability to produce both haemolysin and enterotoxin was species-related and was more common in Aeromonas hydrophila and A. sobria strains than in A. caviae strains.

Abattoirs↗
PubMed2002

Use of a marker organism to model the spread of central nervous system tissue in cattle and the abattoir environment during commercial stunning and carcass dressing.

Due to concerns about a link between variant Creutzfeldt-Jakob disease in humans and similar prion protein-induced disease in cattle, i.e., bovine spongiform encephalopathy (BSE), strict controls are in place to exclude BSE-positive animals and/or specified risk materials including bovine central nervous system (CNS) tissue from the human food chain. However, current slaughter practice, using captive bolt guns, may induce disruption of brain tissues and mobilize CNS tissues into the bovine circulatory system, leading to the dispersion of CNS tissues (including prion proteins) throughout the derived carcass. This project used a marker (antibiotic-resistant) strain of Pseudomonas fluorescens to model the effects of commercial captive bolt stunning procedures on the movement of mobilized CNS material within slaughtered animals and the abattoir environment. The marker organism, introduced by injection through the bolt entry aperture or directly using a cartridge-fired captive bolt, was detected in the slaughter environment immediately after stunning and in the abattoir environment at each subsequent stage of the slaughter-dressing process. The marker organism was also detected on the hands of operatives; on slaughter equipment; and in samples of blood, organs, and musculature of inoculated animals. There were no significant differences between the results obtained by the two inoculation methods (P < 0.05). This study demonstrates that material present in, or introduced into, the CNS of cattle during commercial captive bolt stunning may become widely dispersed across the many animate and inanimate elements of the slaughter-dressing environment and within derived carcasses including meat entering the human food chain.

Abattoirs↗
PubMed1999

Influence of the number of days spent training in an abattoir with access to live cows on the efficiency of do-it-yourself artificial insemination.

Data relating to 35,389 inseminations carried out in the first three years after inseminators were trained were collected by postal questionnaire from 94 do-it-yourself (DIY) artificial inseminators in the UK. The mean calving rate from 14,528 inseminations they carried out on 92 farms in the first year after they were trained was 59.4 per cent (range 5 to 92 per cent). In the second year the mean calving rate from 11,515 inseminations by 64 inseminators was 62.3 per cent (range 33 to 88 per cent), and in the third year the mean calving rate from 9346 inseminations by 49 inseminators was 64.6 per cent (range 41 to 92 per cent). There was an increase of 5.2 per cent in the mean calving rate over the three years with an overall mean calving rate of 61.5 per cent. Each trainee carried out an average of 376 inseminations (range 20 to 800) during the three years. Thirteen instructors were responsible for the tuition and the average time the trainees spent in an abattoir with access to live cows was 2.88 days, with a range from none to five days. For the trainees who spent up to three days training in an abattoir there was an increase of 5.9 per cent in the calving rate they achieved in their first year for every day they spent training with access to live cows (P < 0.005), but there were no significant effects on the outcome of their inseminations in their second or third years.

Abattoirs↗
PubMed2003

Abattoir-based survey of contagious bovine pleuropneumonia in cattle in Turkey.

Blood samples collected from 945 cattle at four local abattoirs in Turkey were examined for contagious bovine pleuropneumonia (CBPP) by the complement fixation test (CFT) and competitive ELISA (cELISA). In addition, the carcases of the animals were examined macroscopically at the abattoirs and 62 lung samples which had lesions suggestive of CBPP were collected for bacteriological culture. To identify suspicious isolates the PCR was used in addition to the routine biochemical tests. By the CFT, two of the 945 serum samples were seropositive, and by the cELISA, four of them were seropositive. In the bacteriological culture of the lungs, growth was observed in 18 (29 per cent) of the samples by the observation of turbidity in the broths. However, when these broths were inoculated into an agar base, growth was observed in only three (4.8 per cent) samples. These isolates were identified as Mycoplasma species on the basis of biochemical tests. In the PCR analysis of DNA extracted from the broths, none of the isolates was identified as Mycoplasma mycoides subspecies mycoides small colony or one of the members of the M mycoides cluster, but amplification was obtained in only eight (44.4 per cent) of 18 samples, using Mycoplasma-genus specific primers. These DNA samples were examined further with primers specific to 16S rRNA and were then sequenced and compared with the databanks; DNA homologies at different levels were observed in five samples, with Mycoplasma alkalescens, Mycoplasma canadense, Mycoplasma bovis and Mycoplasma bovigenitalium.

Abattoirs↗
PubMed2005

Persistence of Salmonella Typhimurium DT120 in abattoir paddocks holding sheep.

In the summer of 1999 there was an outbreak of Salmonella Typhimurium DT120 in people in the north of England which was unusual in being sensitive to antimicrobial drugs. The outbreak was linked to mutton and lamb from a local abattoir, and attention focused on four holding paddocks used to retain sheep before slaughter. In November 1999, samples of soil and faeces were taken from these paddocks and samples of faeces were taken from the concrete race leading from them. Salmonella Typhimurium was isolated from 59 of the 100 samples. Between January 2000 and October 2000 seven visits were made to the abattoir at each of which 100 samples were taken from the paddocks and concrete race and examined for the presence of Salmonella. The paddocks remained heavily contaminated with S Typhimurium DT120 until April when there was a marked reduction in the recovery of the organism. By June the contamination was minimal and by August it had disappeared, and the organism was not recovered in September or October.

Abattoirs↗
PubMed1983

An outbreak of campylobacter enteritis among the staff of a poultry abattoir in Sweden.

In the middle of June 1980 an explosive outbreak of campylobacter enteritis occurred among the staff of a poultry abattoir in southern Sweden. In all 37 cases of acute gastroenteritis originating from the abattoir were reported and Campylobacter jejuni was isolated from the stools in 24 of them. When the outbreak occurred, a large proportion of the ordinary staff had been replaced by inexperienced teenagers working during their holidays. A specially big slaughter had also taken place the same week as these inexperienced workers had started. The holiday workers contracted the disease to a greater extent (71%) than the ordinary staff (29%). An overall screening revealed 5 asymptomatic carriers among the ordinary staff. In 3 cases secondary spread was found.

Abattoirs↗
PubMed2000

Aerobiology of a high-line speed cattle abattoir.

The operation of the high-line speed cattle abattoir studied follows a plant-created hazard analysis and critical control point (HACCP) plan that is recognized by the Canadian Food Inspection Agency. Measurement of bioaerosols is not a part of this plan. In this study CFUs in air of selected abattoir processes were enumerated after impinging air onto tryptic soy agar plates with a slit air sampler for 10 to 20 min. The total viable count (TVC) per liter of air was calculated for each sample following incubation at 30 degrees C for 24 h. Monthly samples were collected on the hide removal floor and the carcass dressing floor from March 1998 to April 1999. Mud tag, dirt, and wetness of incoming hides were scored subjectively on the hide removal floor. The other processes were sampled in 3 separate months. The TVC at two locations on the hide removal floor (center of hide removal floor [CHF] and top of hide puller [THP]) had a strong association to each other (r = 0.84; P < 0.001). The mean TVC at the CHF and THP was 10.0 and 11.5, respectively, and the TVC for individual samples ranged from 2 to 42 at these locations. The TVC means for all the other processes ranged from 0.01 to 0.7. Tag and TVC on the hide removal floor had a different seasonal distribution with TVC being highest in the warm months (April to October 1998) and lowest for November to April 1999. No significant relations between TVC and the dirt and wetness variables were evident for the CHF and THP locations on the hide removal floor. It was concluded that the control of aerosols in the hide removal floor should be treated as a critical control point in the HACCP plan.

Abattoirs↗
PubMed2002

Potential for the spread of Escherichia coli O157, Salmonella, and Campylobacter in the lairage environment at abattoirs.

Prevalences of Escherichia coli O157, Salmonella spp., and Campylobacter spp. were examined in 270 swabs taken from selected sites along the unloading-to-slaughter routes of animal movement in lairages of six commercial abattoirs, three for cattle and three for sheep. The overall prevalences of the pathogens in the respective lairage environments were compared with those for 270 swabs from the pelts of 90 lambs examined in the present study and 270 swabs from the hides of 90 cattle examined in a previous study that were slaughtered at the same abattoirs on the same days. Also, the results obtained were analyzed with the aim of identifying critical points at which animal-environment-animal transfer of the pathogens in lairages occurs. The results showed that (i) the overall prevalences of E. coli O157, Salmonella spp., and Campylobacter spp. were 27.2, 6.1, and 1.1%, respectively, in cattle lairages and 2.2, 1.1, and 5.6%, respectively, in sheep lairages; (ii) the overall prevalences of the three pathogens on cow hides (28.8, 17.7, and 0%, respectively) and sheep pelts (5.5, 7.8, and 0%, respectively) were higher than the overall prevalences in the respective lairage environments; (iii) the most frequently contaminated sites in cattle lairages were holding pen floors (50% of swabs positive for one or more pathogens), entrance gates of stun boxes (27.8% of swabs positive for one or more pathogens), and stun box floors (22.2% of swabs positive for one or more pathogens); (iv) the most frequently contaminated sites in sheep lairages were unloading ramp floors, holding pen floors, and water troughs (33.3, 22.2, and 22.2%, respectively); and (v) overall, cattle lairages and cow hides were more frequently contaminated with the pathogens than were lamb lairages and lamb pelts. Further research is needed to develop strategies for the incorporation of pathogen control in lairages into integrated microbial meat safety systems.

Abattoirs↗
PubMed2003

Microbial quality of ostrich carcasses produced at an export-approved South African abattoir.

The aim of this study was to evaluate the microbial quality of ostrich carcasses produced in a South African export-approved ostrich abattoir. Ninety surface samples were collected from 30 ostrich carcasses at three processing points in the abattoir: after skinning, after evisceration, and after chilling. Samples were evaluated for aerobic plate counts, for levels of Pseudomonas spp., Enterobacteriaceae, and Staphylococcus aureus, and for the presence of Escherichia coli. Surface counts (means +/- standard deviations) at postskinning, postevisceration, and postchilling processing points were, respectively, 4.32 +/- 0.62, 4.21 +/- 0.63, and 4.57 +/- 0.48 log CFU/cm2 for total aerobes; 2.82 +/- 1.65, 2.86 +/- 1.53, and 3.75 +/- 0.94 log CFU/ cm2 for Pseudomonas spp.; 2.89 +/- 0.78, 2.90 +/- 0.53, and 2.38 +/- 0.67 log CFU/cm2 for S. aureus; and 2.55 +/- 1.53, 2.78 +/- 1.31, and 2.73 +/- 1.46 log CFU/cm2 for Enterobacteriaceae. Statistically significant differences were detected between the counts for the postskinning and postchilling processing points and between the counts for the postevisceration and postchilling processing points for total aerobes, Pseudomonas spp., and S. aureus. Of practical significance was the increase in Pseudomonas spp. counts on samples collected after chilling. Seventeen of 90 samples (18.8%) tested positive for E. coli. Counts for E. coli-positive samples ranged from 1.0 to 3.79 log CFU/cm2, with a mean count of 2.15 +/- 0.94 log CFU/cm2. The majority of the samples testing positive for E. coli were collected after evisceration.

Abattoirs↗
PubMed2005

An investigation of Escherichia coli O157 contamination of cattle during slaughter at an abattoir.

The extent of contamination with Escherichia coli O157 was determined for 100 cattle during slaughter. Samples from 25 consecutively slaughtered cattle from four unrelated groups were collected from the oral cavity, hide, rumen, feces after evisceration, and pre- and postchill carcass. Ten random fecal samples were collected from the pen where each group of animals was held at the abattoir. E. coli O157 was detected using automated immunomagnetic separation (AIMS), and cell counts were determined using a combination of most probable number (MPN) and AIMS. E. coli O157 was isolated from 87 (14%) of the 606 samples collected, including 24% of 99 oral cavity samples, 44% of 100 hides, 10% of 68 fecal samples collected postevisceration, 6% of 100 prechill carcass swabs, and 15% of 40 fecal samples collected from holding pens. E. coli O157 was not isolated from rumen or postchill carcass samples. E. coli O157 was isolated from at least one sample from each group of cattle tested, and the prevalence in different groups ranged from less than 1 to 41%. The numbers of E. coli O157 differed among the animals groups. The group which contained the highest fecal (7.5 x 10(5) MPN/g) and hide (22 MPN/cm2) counts in any individual animal was the only group in which E. coli O157 was isolated from carcasses, suggesting a link between the numbers of E. coli O157 present and the risk of carcass contamination. Processing practices at this abattoir were adequate for minimizing contamination of carcasses, even when animals were heavily contaminated with E. coli O157.

Abattoirs↗