79 Microbiological effects of control measures during pork production
Why this work is in the frame
A frame that forgets how it found something cannot be audited. These are the routes that admitted this work.
Bibliographic record
Abstract
Abstract The objective of this study was to determine the prevalence of Shiga toxin-producing Escherichia coli (STEC) O157:H7 and efficacy of control measures at a pork processing facility. Outbreaks of E. coli O157:H7 associated with pork, though not common globally, have been reported multiple times in recent years in Alberta. Sampling at a commercial facility processing hogs was carried out at monthly intervals for 11 mo. At the facility, the dressed carcasses are sprayed with 5% lactic acid (LA) and immediately air-chilled after the LA spray. At each sampling time, 14 different types of samples were collected: dirt from the holding pen floor (n = 2), gloves of workers (n = 5), scalding water (n = 1), tonsils (n = 5), cecal material (n = 5), five swabs each from hides of animals after bleeding (HAB), and carcasses after scalding (CAS), before evisceration (CBE), after evisceration (CAE), before LA spray (BLA), after LA spray (ALA), 1h after LA spray (ALA1), 2h after LA spray (ALA2), and after chilling (ACH). All samples were enumerated for total plate count (TPC), Enterobacteriaceae, and E. coli using specific media for each. In addition, an aliquot of each sample was enriched and tested for the presence of the O-antigen gene (rfbE) for E. coli O157 and Shiga toxin-producing gene (stx1/stx2) using real-time PCR. Cultures positive for both rfbE and stx were further plated for the isolation of E. coli O157:H7. Of the 683 enrichment cultures, 12 were positive for both marker genes, from cecal material (n = 2), dirt (n = 4) and HAB (n = 6). However, none of these samples yielded STEC O157 isolates. Of these enrichment cultures, 69, 45 and 32 were positive for stx1, stx2, and both stx genes, respectively. Positive samples were mostly associated with HAB, cecal material and dirt. HAB was most and least contaminated in August/June and December, differing by 1 log unit for TPC (P < 0.05). Enterobacteriaceae and E. coli on HAB were also affected by month of sampling (P < 0.05), but this temporal trend differed from TPC (Table). The numbers for TPC, Enterobacteriaceae, and E. coli all decreased (P < 0.05) as the stage of carcass processing progressed. The overall reduction of TPC and E. coli was 7 and 5 log units, respectively. Scalding, LA spray and air chilling all reduced (P < 0.05) the numbers of indicator bacteria on carcasses. Of the 55 samples each collected from BLA, ALA, ALA1, ALA2, and ACH, 36, 13, 2, 1 and 0 were positive for E. coli, respectively. In conclusion, pork processing environments can be contaminated with STEC from hides, feces and holding pen, but levels of STEC O157 appear to be low. Scalding, LA spray and air chilling can be effective measures to reduce the risk of bacterial contamination of pork.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it