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1.
Nature ; 585(7824): E6, 2020 Sep.
Article in English | MEDLINE | ID: mdl-32826959

ABSTRACT

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

2.
Nature ; 584(7820): 201-204, 2020 08.
Article in English | MEDLINE | ID: mdl-32788739

ABSTRACT

The extreme astrophysical processes and conditions that characterize the early Universe are expected to result in young galaxies that are dynamically different from those observed today1-5. This is because the strong effects associated with galaxy mergers and supernova explosions would lead to most young star-forming galaxies being dynamically hot, chaotic and strongly unstable1,2. Here we report the presence of a dynamically cold, but highly star-forming, rotating disk in a galaxy at redshift6 z = 4.2, when the Universe was just 1.4 billion years old. Galaxy SPT-S J041839-4751.9 is strongly gravitationally lensed by a foreground galaxy at z = 0.263, and it is a typical dusty starburst, with global star-forming7 and dust properties8 that are in agreement with current numerical simulations9 and observations10. Interferometric imaging at a spatial resolution of about 60 parsecs reveals a ratio of rotational to random motions of 9.7 ± 0.4, which is at least four times larger than that expected from any galaxy evolution model at this epoch1-5 but similar to the ratios of spiral galaxies in the local Universe11. We derive a rotation curve with the typical shape of nearby massive spiral galaxies, which demonstrates that at least some young galaxies are dynamically akin to those observed in the local Universe, and only weakly affected by extreme physical processes.

3.
Phys Rev Lett ; 114(16): 165001, 2015 Apr 24.
Article in English | MEDLINE | ID: mdl-25955053

ABSTRACT

We present measurements of radio emission from cosmic ray air showers that took place during thunderstorms. The intensity and polarization patterns of these air showers are radically different from those measured during fair-weather conditions. With the use of a simple two-layer model for the atmospheric electric field, these patterns can be well reproduced by state-of-the-art simulation codes. This in turn provides a novel way to study atmospheric electric fields.

4.
Anim Health Res Rev ; 15(1): 14-38, 2014 Jun.
Article in English | MEDLINE | ID: mdl-25605277

ABSTRACT

Routine procedures carried out on piglets (i.e. castration, tail docking, teeth clipping, and ear notching) are considered painful. Unfortunately the efficacy of current pain mitigation modalities is poorly understood. The aim of this systematic review was to synthesize the existing primary scientific literature regarding the effectiveness of pain management interventions used for routine procedures on piglets. The review question was, 'In piglets under twenty-eight days old, undergoing castration, tail docking, teeth clipping, and/or methods of identification that involve cutting of the ear tissue, what is the effect of pain mitigation compared with no pain mitigation on behavioral and non-behavioral outcomes that indicate procedural pain and post-procedural pain?' A review protocol was designed a priori. Data sources used were Agricola (EBSCO), CAB Abstracts (Thomson Reuters), PubMed, Web of Science (Thomson Reuters), BIOSIS Previews (Thomson Reuters), and ProQuest Dissertations & Theses Full Text. No restrictions on year of publication or language were placed on the search. Eligible studies assessed an intervention designed to mitigate the pain of the procedures of interest and included a comparison group that did not receive an intervention. Eligible non-English studies were translated using a translation service. Two reviewers independently screened titles and abstracts for relevance using pre-defined questions. Data were extracted from relevant articles onto pre-defined forms. From the 2203 retrieved citations forty publications, containing 52 studies met the eligibility criteria. In 40 studies, piglets underwent castration only. In seven studies, piglets underwent tail docking only. In one study, piglets underwent teeth clipping only, and in one study piglets underwent ear notching only. Three studies used multiple procedures. Thirty-two trial arms assessed general anesthesia protocols, 30 trial arms assessed local anesthetic protocols, and 28 trial arms assessed non-steroidal anti-inflammatory drugs (NSAIDs) protocols. Forty-one trial arms were controls where piglets received either placebo or no treatment. Forty-five outcomes were extracted from the studies, however only the results from studies that assessed cortisol (six studies), ß-endorphins (one study), vocalisations (nine studies), and pain-related behaviors (nine studies) are reported. Other outcomes were reported in only one or two studies. Confident decision making will likely be difficult based on this body of work because lack of comprehensive reporting precludes calculation of the magnitude of pain mitigation for most outcomes.


Subject(s)
Animal Husbandry/methods , Animal Welfare/standards , Pain Management/veterinary , Swine/physiology , Animal Husbandry/standards , Animals , Hydrocortisone/analysis , Pain Management/standards , Randomized Controlled Trials as Topic/veterinary
5.
Anim Health Res Rev ; 15(1): 39-62, 2014 Jun.
Article in English | MEDLINE | ID: mdl-25605278

ABSTRACT

Piglets reared in swine production in the USA undergo painful procedures that include castration, tail docking, teeth clipping, and identification with ear notching or tagging. These procedures are usually performed without pain mitigation. The objective of this project was to develop recommendations for pain mitigation in 1- to 28-day-old piglets undergoing these procedures. The National Pork Board funded project to develop recommendations for pain mitigation in piglets. Recommendation development followed a defined multi-step process that included an evidence summary and estimates of the efficacies of interventions. The results of a systematic review of the interventions were reported in a companion paper. This manuscript describes the recommendation development process and the final recommendations. Recommendations were developed for three interventions (CO2/O2 general anesthesia, non-steroidal anti-inflammatory drugs (NSAIDs), and lidocaine) for use during castration. The ability to make strong recommendations was limited by low-quality evidence and strong certainty about variation in stakeholder values and preferences. The panel strongly recommended against the use of a CO2/O2 general anesthesia mixture, weakly recommended for the use of NSAIDs and weakly recommended against the use of lidocaine for pain mitigation during castration of 1- to 28-day-old piglets.


Subject(s)
Animal Husbandry/methods , Pain Management/veterinary , Swine/physiology , Anesthesia, General/veterinary , Animal Husbandry/standards , Animals , Animals, Newborn , Anti-Inflammatory Agents, Non-Steroidal/administration & dosage , Evidence-Based Practice , Guidelines as Topic , Lidocaine/administration & dosage , Pain Management/standards
6.
Nature ; 481(7381): 341-3, 2012 Jan 18.
Article in English | MEDLINE | ID: mdl-22258612

ABSTRACT

The mass function of dwarf satellite galaxies that are observed around Local Group galaxies differs substantially from simulations based on cold dark matter: the simulations predict many more dwarf galaxies than are seen. The Local Group, however, may be anomalous in this regard. A massive dark satellite in an early-type lens galaxy at a redshift of 0.222 was recently found using a method based on gravitational lensing, suggesting that the mass fraction contained in substructure could be higher than is predicted from simulations. The lack of very low-mass detections, however, prohibited any constraint on their mass function. Here we report the presence of a (1.9 ± 0.1) × 10(8) M dark satellite galaxy in the Einstein ring system JVAS B1938+666 (ref. 11) at a redshift of 0.881, where M denotes the solar mass. This satellite galaxy has a mass similar to that of the Sagittarius galaxy, which is a satellite of the Milky Way. We determine the logarithmic slope of the mass function for substructure beyond the local Universe to be 1.1(+0.6)(-0.4), with an average mass fraction of 3.3(+3.6)(-1.8) per cent, by combining data on both of these recently discovered galaxies. Our results are consistent with the predictions from cold dark matter simulations at the 95 per cent confidence level, and therefore agree with the view that galaxies formed hierarchically in a Universe composed of cold dark matter.

7.
Anim Genet ; 42(5): 521-34, 2011 Oct.
Article in English | MEDLINE | ID: mdl-21906103

ABSTRACT

Salmonella in swine is a major food safety problem, as the majority of US swine herds are Salmonella-positive. Salmonella can be shed from colonized swine and contaminate (i) neighbouring pigs; (ii) slaughter plants and pork products; (iii) edible crops when swine manure is used as a fertilizer; and (iv) water supplies if manure used as crop fertilizer runs off into streams and waterways. A potentially powerful method of addressing pre-harvest food safety at the farm level is through genetic improvement of disease resistance in animals. In this research, we describe a successful strategy for discovering genetic variation at candidate genes associated with disease resistance in pigs. This involves integrating our recent global gene expression analysis of the porcine response to Salmonella with information from the literature about important candidate genes. We identified single-nucleotide polymorphisms (SNPs) in these functional candidate genes and genotyped three independent pig populations that had data on Salmonella faecal shedding or internal burden (total n = 377) at these loci. Of 31 SNPs genotyped, 21 SNPs segregated in at least two populations with a minor allele frequency of 15% or greater. Statistical analysis revealed thirteen SNPs associated with Salmonella faecal shedding or tissue colonization, with an estimated proportion of false positives (PFP) ≤0.2. The genes with associated SNPs included GNG3, NCF2, TAP1, VCL, AMT, CCR1, CD163, CCT7, EMP1 and ACP2. These associations provide new information about the mechanisms of porcine host response to Salmonella and may be useful in improving genetic resistance to this bacterium.


Subject(s)
Bacterial Shedding , Meat/microbiology , Polymorphism, Single Nucleotide , Salmonella Infections, Animal/immunology , Sus scrofa , Swine Diseases/immunology , Animals , Food Safety , Gene Expression Profiling , Immunity, Innate
8.
J Anim Breed Genet ; 128(5): 354-65, 2011 Oct.
Article in English | MEDLINE | ID: mdl-21906181

ABSTRACT

Asymptomatic Salmonella-carrier pigs present a major problem in preharvest food safety, with a recent survey indicating >50% of swine herds in the United States have Salmonella-positive animals. Salmonella-carrier pigs serve as a reservoir for contamination of neighbouring pigs, abattoir pens and pork products. In addition, fresh produce as well as water can be contaminated with Salmonella from manure used as fertilizer. Control of Salmonella at the farm level could be through genetic improvement of porcine disease resistance, a potentially powerful method of addressing preharvest pork safety. In this research, we integrate gene expression profiling data and sequence alignment-based prediction of single nucleotide polymorphisms (SNPs) to successfully identify SNPs in functional candidate genes to test for the associations with swine response to Salmonella. A list of 2527 genes that were differentially regulated in porcine whole blood in response to infection with Salmonella enterica serovar Typhimurium were selected. In those genes, SNPs were predicted using ANEXdb alignments based on stringent clustering of all publically available porcine cDNA and expressed sequence tag (EST) sequences. A set of 30 mostly non-synonymous SNPs were selected for genotype analysis of four independent populations (n = 750) with Salmonella faecal shedding or tissue colonization phenotypes. Nine SNPs segregated with minor allele frequency ≥15% in at least two populations. Statistical analysis revealed SNPs associated with Salmonella shedding, such as haptoglobin (HP, p = 0.001, q = 0.01), neutrophil cytosolic factor 2 (NCF2 #2, p = 0.04, q = 0.21) and phosphogluconate dehydrogenase (p = 0.066, q = 0.21). These associations may be useful in identifying and selecting pigs with improved resistance to this bacterium.


Subject(s)
Computational Biology , Gene Expression Regulation , Polymorphism, Single Nucleotide , Salmonella Infections, Animal/genetics , Swine Diseases/genetics , Animals , Genotype , Swine
9.
Zoonoses Public Health ; 57(7-8): e14-22, 2010 Dec.
Article in English | MEDLINE | ID: mdl-20492478

ABSTRACT

A systematic review approach was used to evaluate the association between sub-therapeutic antibiotics in feed and Salmonella Typhimurium isolation in market-weight finisher swine raised in modern swine production systems. Fourteen challenge trials described the efficacy of different antibiotics after challenge with S. Typhimurium. The studies identified were of limited evidentiary value for the review question because they were not relevant to the review question, i.e. conducted in artificial settings on small numbers of young pigs. None of the studies reported using blinding during outcome assessment. No antibiotic regimen was evaluated more than once. The association between sub-therapeutic antibiotics and Salmonella outcomes in market-weight swine raised in modern production systems cannot be summarized using the currently available literature. Many available studies fail to report critical study design features such as blinding and/or to take into account the data generated from longitudinal studies.


Subject(s)
Anti-Bacterial Agents/therapeutic use , Salmonella Infections, Animal/prevention & control , Salmonella typhimurium/drug effects , Swine Diseases/prevention & control , Swine/microbiology , Animal Feed , Animals , Body Weight , Food Safety , Salmonella typhimurium/isolation & purification
10.
Prev Vet Med ; 87(3-4): 213-28, 2008 Nov 17.
Article in English | MEDLINE | ID: mdl-18667253

ABSTRACT

This review summarizes evidence for associations between Salmonella prevalence in market-weight swine and changes in feeding management practices or feed characteristics. A systematic review of the topic was conducted with the goal of minimizing the impact of bias on the review conclusions. Potential interventions included feed withdrawal from swine prior to slaughter, feed acidification, heat treatment of feed, pelletized feed versus mash, course versus fine grind, and wet versus dry feeds. In the reviewed literature, Salmonella prevalence was measured either by culture or by the presence of antibodies to Salmonella. The evidentiary value of studies was assessed, and studies that failed to meet predetermined standards were excluded. 7694 potentially relevant references were identified by an extensive literature search; however, 2623 references that were not published in English were excluded, because funds for translation were not available. Of the remaining references, only 277 were considered relevant to the review topic by two independent reviewers, and assessed for methodological quality. During quality assessment, 233 references were excluded because they failed to report design features that limit the introduction of bias or were conducted in a non-target population such as gnotobiotic, neonatal, nursery, or recently weaned pigs and sows. Forty-four publications passed the quality assessment conducted by 2 independent reviewers, but only 15 of the 44 publications reported studies that tested hypotheses associated with feeding management practices and feed characteristics and Salmonella prevalence in market-weight swine. The most common study design was cross-sectional (7/15). The included studies failed to provide strong evidence of an association between any of the potential interventions and Salmonella prevalence, due to the potential for confounding, and the failure to document temporal association between the intervention and Salmonella prevalence. The strongest evidence of an association was found for feed form, i.e. the use of non-pelleted may be potential interventions associated with reduced Salmonella prevalence. The uncertainty is primarily based on studies containing moderate to low evidentiary value or insufficient numbers of tested individuals, resulting in a low degree of confidence that results could be extrapolated to the target population. Therefore, the conclusion of the review is that there should be a low level of comfort among qualified scientists that the claimed association between non-pelleted feed and reduced Salmonella prevalence is scientifically valid. There is no strong evidence regarding associations between presence of Salmonella and the other feed characteristics examined.


Subject(s)
Animal Feed/analysis , Animal Husbandry/methods , Animal Husbandry/trends , Salmonella Infections, Animal/epidemiology , Salmonella/isolation & purification , Swine Diseases/epidemiology , Swine Diseases/microbiology , Animals , Swine
11.
Genes Brain Behav ; 7(7): 810-20, 2008 Oct.
Article in English | MEDLINE | ID: mdl-19125866

ABSTRACT

Down syndrome (DS), caused by trisomy of human chromosome 21 (chr21), is the most common genetic cause of intellectual disability. The Ts65Dn mouse model of DS is trisomic for orthologs of 94 chr21-encoded, confirmed protein-coding genes and displays a number of behavioral deficits. Recently, Ts65Dn mice were shown to be hypersensitive to the locomotor stimulatory effects of the high-affinity N-methyl-d-aspartate (NMDA) receptor (NMDAR) channel blocker, MK-801. This is consistent with the functions of several chr21 proteins that are predicted directly or indirectly to impact NMDAR function or NMDAR-mediated signaling. In this study, we show that a second mouse model of DS, the Ts1Cje, which is trisomic for 70 protein-coding genes, is also hypersensitive to MK-801. To investigate the molecular basis for the responses to MK-801, we have measured levels of a subset of chr21 and phosphorylated non-chr21 proteins, in the cortex and hippocampus of Ts65Dn and Ts1Cje mice and euploid controls, with and without treatment with MK-801. We show that in euploid mice, the chr21-encoded proteins, TIAM1 and DYRK1A, and phosphorylation of AKT, ERK1/2 and the transcription factor ELK are involved in the MK-801 response. However, in both Ts65Dn and Ts1Cje mice, levels of phosphorylation are constitutively elevated in naïve, unstimulated mice, and the MK-801-induced changes in TIAM1 and DYRK1A and in phosphorylation are either absent or abnormal, with both genotype and brain-region-specific patterns. These results emphasize the complexities of the pathway perturbations that arise with segmental trisomy.


Subject(s)
Behavior, Animal/physiology , Dizocilpine Maleate/pharmacology , Down Syndrome/genetics , Down Syndrome/psychology , Excitatory Amino Acid Antagonists/pharmacology , Animals , Behavior, Animal/drug effects , Blotting, Western , Data Interpretation, Statistical , Dose-Response Relationship, Drug , Individuality , Mice , Mice, Inbred C3H , Mice, Inbred C57BL , Phosphorylation
12.
Prev Vet Med ; 82(3-4): 198-212, 2007 Dec 14.
Article in English | MEDLINE | ID: mdl-17604857

ABSTRACT

Physical and reproductive conditions of cull sows (3158) from two U.S. Midwestern harvest plants were assessed. Body condition, feet, shoulders, teeth, lungs, and reproductive tracts were visually evaluated for gross lesions on harvested sows. PROC FREQ (SAS, Cary, NC) was used to calculate the frequency of each binary trait event. Pearson chi-square tests were used to test the alternative hypothesis that a linear association existed between binary traits and body condition score (BCS). The most common foot lesions observed were rear (n=2064, 67.5%) and front (n=1024, 32.9%) heel lesions. Cracked hooves were found on the front feet of 703 (22.6%) and rear feet of 552 (18.1%) sows. Rear digital overgrowth was observed in 644 (21.1%) sows. The most common reproductive gross lesion observed among harvested cull sows was acyclic ovaries (n=277, 9.0%). Presence of acyclic ovaries increased (p<0.01) as BCS decreased. Cystic ovaries were found in 192 (6.3%) sows, which increased (p<0.01) as BCS increased. Pneumonia was observed in 298 (9.7%) sows, and increased in frequency as BCS decreased (p<0.01). The most frequently observed shoulder lesion among harvested cull sows was shoulder abrasions (n=394, 12.5%). The presence of shoulder abrasions increased (p<0.01) as BCS decreased. The prevalence of reproductive lesions detected in the present study was less than the reported percentage of sows culled for reproductive failure from previous studies based on record keeping summaries.


Subject(s)
Swine Diseases/pathology , Abattoirs , Animals , Body Composition , Female , Foot Diseases/pathology , Foot Diseases/veterinary , Genital Diseases, Female/pathology , Genital Diseases, Female/veterinary , Hoof and Claw/pathology , Midwestern United States , Pregnancy , Skin Diseases/pathology , Skin Diseases/veterinary , Swine , Tooth Diseases/pathology , Tooth Diseases/veterinary
13.
J Food Prot ; 69(7): 1717-9, 2006 Jul.
Article in English | MEDLINE | ID: mdl-16865909

ABSTRACT

The quantity of Salmonella recoverable from three lairage pens in a swine abattoir was determined. Using dry four-ply cotton gauze pads measuring 10 by 10 cm, 100 fecal slurry samples were collected from each of the three pens. Salmonella recovery was expressed as the log CFU per milliliter of sample. Mean values were 2.5 log CFU/ml in pen A, 2.7 log CFU/ ml in pen B, and 0.89 log CFU/ml in pen C. Median values were 2.6 log CFU/ml in pen A, 2.0 log CFU/ml in pen B, and below the detectable limit in pen C. In pen C, Salmonella was not recoverable from a high number of samples. Pen B results suggested spatial dependency, i.e., samples close together were more similar than samples farther apart. These results indicate that Salmonella concentrations vary within and between lairage pens. Because of the limited number of pens assessed, it was not possible to identify factors that were associated with the observed variation in Salmonella concentrations within and between pens. However, this variation suggests that numeroussamples are required to adequately describe the concentration of Salmonella in a lairage pen.


Subject(s)
Abattoirs , Hygiene , Salmonella Infections, Animal/epidemiology , Salmonella/isolation & purification , Swine Diseases/epidemiology , Abattoirs/standards , Animals , Colony Count, Microbial/veterinary , Environmental Microbiology , Feces/microbiology , Salmonella Infections, Animal/microbiology , Swine , Swine Diseases/microbiology
14.
Foodborne Pathog Dis ; 2(1): 77-81, 2005.
Article in English | MEDLINE | ID: mdl-15992301

ABSTRACT

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.


Subject(s)
Abattoirs/standards , Floors and Floorcoverings , Food Microbiology , Meat/standards , Salmonella enterica/isolation & purification , Animals , Cecum/microbiology , Consumer Product Safety , Environmental Microbiology , Food Contamination/prevention & control , Humans , Prevalence , Quality Control , Swine , Time Factors
15.
J Food Prot ; 67(7): 1489-93, 2004 Jul.
Article in English | MEDLINE | ID: mdl-15270507

ABSTRACT

This study was designed to compare Salmonella enterica prevalence in sows held in a holding pen at the abattoir for approximately 2 h (hold sows) with sows slaughtered immediately after transport to the abattoir (no-hold sows). Cull sows (n = 160) were sampled from four sampling periods over 8 weeks (February to March 2002) at the abattoir. Sows originated from an integrated swine farm and were sent to a live-hog market and then to the slaughter facility. Before testing, sows entered the abattoir pen and four 100-cm2 four-ply gauze squares were placed randomly on the pen floor for S. enterica culture. Sows were alternatively assigned to the hold or no-hold group. Samples collected from sows during slaughter were ileocecal lymph node, cecal contents, transverse colon contents, subiliac lymph node, sponge swabs of the left and right carcass section (300 cm2), and chopped meat. Overall, S. enterica was isolated from 44% (35 of 80) of the no-hold sows, which was significantly less (P < 0.05) than 59% (47 of 80) of the held sows. Also, no-hold sows had a lower cecal content prevalence (39%, 31 of 80) compared with that (55%, 44 of 80) of held sows (P < 0.05). S. enterica serovars isolated from no-hold sows were Brandenburg (n = 16), Derby (n = 12), Hadar (n = 8), Infantis (n = 6), Johannesburg (n = 3), 6,7:z10-monophasic (n = 3), and Typhimurium (n = 1). S. enterica serovars isolated from held sows (n = 61 isolates) were Derby (n = 19), 6,7: z10-monophasic (n = 15), Brandenburg (n = 10), Infantis (n = 6), Hadar (n = 5), Johannesburg (n = 4), and Tennessee (n = 2). Serovars recovered from the pen were Reading (n = 6), Derby (n = 4), Uganda (n = 2), and Manhattan (n = 2). Results of this study suggest that holding pens contribute to increased S. enterica carriage in cull sows. Abattoir holding pens might be an important control point for S. enterica in the ground pork production chain.


Subject(s)
Abattoirs , Food Microbiology , Salmonella Infections, Animal/epidemiology , Salmonella enterica/isolation & purification , Swine Diseases/epidemiology , Animals , Cecum/microbiology , Colon/microbiology , Disease Reservoirs/veterinary , Feces/microbiology , Female , Lymph Nodes/microbiology , Prevalence , Serotyping , Swine , Time Factors , Transportation
17.
Epidemiol Infect ; 132(1): 127-35, 2004 Jan.
Article in English | MEDLINE | ID: mdl-14979598

ABSTRACT

The study objective was to evaluate three methods of Salmonella enterica prevalence estimation in swine herds (faecal culture, culture of abattoir-collected samples, and serum ELISA). From each of six swine herds, we necropsied approximately 100 finishing pigs (> 70 kg); one-half on farm and the other half at the abattoir, after transport and approximately 2.5 h holding. We collected the same samples for S. enterica culture at both locations (1 g faecal, 10 g caecal contents, ileocaecal lymph nodes, superficial inguinal lymph nodes, 25 g of gluteal muscle for serum ELISA). On farm, the 1 g faecal sample only detected 13.3% (2/15) of all positive pigs necropsied on farm. However, with abattoir and on-farm results combined, the faecal sample detected 57.4% (74/129) of positive pigs. Abattoir-collected samples provided prevalence estimates much higher than on-farm collected samples (39.9 vs. 5.3%; P < 0.001). This study shows that faecal samples have a low sensitivity for detecting infected pigs and that abattoir-collected samples overestimate the on-farm S. enterica prevalence. For most herds, serology overestimated the on-farm culture prevalence.


Subject(s)
Salmonella Infections, Animal/diagnosis , Salmonella Infections, Animal/epidemiology , Salmonella enterica , Swine Diseases/diagnosis , Swine Diseases/epidemiology , Abattoirs , Animals , Antibodies, Bacterial/blood , Autopsy , Bias , Cecum/microbiology , Enzyme-Linked Immunosorbent Assay , Feces/microbiology , Ileum/microbiology , Lymph Nodes/microbiology , Population Surveillance/methods , Prevalence , Risk Factors , Salmonella Infections, Animal/blood , Salmonella Infections, Animal/microbiology , Salmonella enterica/genetics , Salmonella enterica/immunology , Sensitivity and Specificity , Seroepidemiologic Studies , Serotyping , Specimen Handling/methods , Specimen Handling/standards , Swine , Swine Diseases/blood , Swine Diseases/microbiology
18.
Appl Environ Microbiol ; 69(8): 4489-94, 2003 Aug.
Article in English | MEDLINE | ID: mdl-12902233

ABSTRACT

The objective of this study was to determine whether abattoir pens can provide a Salmonella enterica infection source during the 2 to 4 h of preharvest holding. Previous work has suggested that pigs may be getting infected, but little has been reported on the environmental contamination of abattoir holding pens. For 24 groups of pigs studied ( approximately 150 animals/group) at two high-capacity abattoirs, six pooled fecal samples (n, 10 per pool) were collected from each transport trailer immediately after pigs were unloaded. Holding pens were sampled (one drinking water sample and six pooled floor samples consisting of swabs, residual liquid, and feces) prior to entry of study pigs for the routine holding period ( approximately 2.5 h). After slaughter, cecal contents and ileocecal lymph nodes were collected, on the processing line, from 30 pigs in each studied group. All samples were cultured for the isolation and identification of S. enterica by primary enrichment in GN-Hajna and tetrathionate broths, secondary enrichment in Rappaport-Vassiliadis broth, and plating on brilliant green sulfa and xylose-lysine-tergitol-4 agars, followed by biochemical and serological identification. The study pens were highly contaminated with S. enterica; all holding pens sampled had at least one positive sample. Additionally, 33% (8 of 24) of drinking water samples were positive for S. enterica. All 24 groups of pigs had S. enterica-positive cecal contents and ileocecal lymph nodes, including those groups from transport trailers with no positive samples. From pigs, trailers, and pens, 586 isolates representing 36 different Salmonella serovars were isolated. Of the 353 isolates from pigs (109 from ileocecal lymph nodes plus 244 from cecal contents), 19% were identified as belonging to the same serovars as those isolated from the respective pens; 27% were identified as belonging to the same serovars as those isolated from the trailers. Sixteen percent of the unique serovars were isolated from both pigs and pens, suggesting that pens served as the infection source. This study demonstrates highly contaminated abattoir holding pens and watering sources. It also demonstrates that holding pens can serve as an infection source. This study identifies the abattoir holding pens as a significant hazard and a potential control point for Salmonella contamination in the preharvest pork production chain.


Subject(s)
Environmental Microbiology , Meat/microbiology , Salmonella enterica/isolation & purification , Animals , Swine
19.
J Food Prot ; 66(7): 1134-8, 2003 Jul.
Article in English | MEDLINE | ID: mdl-12870744

ABSTRACT

The objective of this study was to examine the prevalence of Salmonella enterica in cull sows at various stages from the farm to the abattoir. Cull sows (n=181) were sampled over 10 weeks. Fecal samples (10 g each) were collected on the farm ca. 24 h before loading and at the live-hog market ca. 3 h before loading. Samples (ileocecal lymph nodes, cecal contents, feces from the transverse colon, ventral thoracic lymph nodes, subiliac lymph nodes, sponge swabs of the left and right carcass sections, and chopped meat) were collected at the abattoir. The percentages of positive fecal samples on the farm and at the live-hog market were 3% (5 of 181 samples) and 2% (3 of 181 samples), respectively. After transport from the live-hog market (10 h) and holding at the abattoir (6 h), 41% (74 of 180) of cull sows yielded S. enterica in one or more sampled tissues. The isolation rate for total cecal contents (33%; 60 of 180 samples) was significantly (P<0.05) higher than those for ileocecal lymph nodes (7%; 12 of 181 samples), feces (11%; 20 of 181 samples), and ventral thoracic and subiliac lymph nodes (2%; 4 of 181 samples). Before a 2% lactic acid carcass wash (lasting 8 to 9 s), 14% (25 of 180) of carcasses were positive, compared with 7% (12 of 179) after the wash (P<0.05). Two S. enterica serotypes, Derby and Infantis, were found on the farm and at the live-hog market. At the abattoir, 12 serotypes that had not previously been found on the farm or at the live-hog market were recovered. The results of this study demonstrate that transport and holding practices may contribute to an increase in S. enterica infection prior to slaughter to levels much higher than those found on the farm.


Subject(s)
Abattoirs , Salmonella Infections, Animal/epidemiology , Salmonella enterica/isolation & purification , Swine Diseases/epidemiology , Transportation , Animals , Cecum/microbiology , Colon/microbiology , Feces/microbiology , Female , Food Microbiology , Lymph Nodes/microbiology , Prevalence , Salmonella Infections, Animal/microbiology , Serotyping , Swine , Swine Diseases/microbiology , Time Factors
20.
Pediatr Neurosurg ; 38(4): 195-205, 2003 Apr.
Article in English | MEDLINE | ID: mdl-12646739

ABSTRACT

BACKGROUND: Temporal lobectomy in adults is an accepted form of treatment for patients with intractable complex partial seizures. There have been few long-term studies of children undergoing temporal lobectomy for epilepsy. METHODS: We reviewed the pediatric cases of temporal lobectomy for intractable epilepsy performed by the Comprehensive Epilepsy Program at the University of Alberta Hospitals between 1988 and 2000. All patients had preoperative and postoperative clinical evaluations, seizure charts, drug levels, EEG, CT/MRI, long-term video EEG monitoring and neuropsychological testing. The patients were reassessed at 6 weeks, 6 months and 1 year postoperatively, then yearly. The duration of follow up was 1-10 years (mean 5 years). RESULTS: Forty-two patients were studied (25 males and 17 females). Age at surgery ranged from 18 months to 16 years. The interictal EEG was abnormal in 38 of the 42 patients. Twenty-two patients had focal epileptic discharge and 1 had generalized epileptic discharge. Focal slowing was seen in 9 patients and diffuse slowing in 5 patients. CT scan was abnormal in 17 of 39 patients and normal in 22 of 39. MRI was abnormal in 34 of 42 patients and normal in 8 of 42. Pathology included brain tumors in 14 patients, mesial temporal sclerosis in 8, focal cortical dysplasia in 4, tuberous sclerosis in 4, dual pathology in 4, porencephalic cyst in 1 and normal pathology or gliosis in 6. Thirty-three of 42 patients (78%) were seizure-free following surgery and an additional 5 (12%) had a decrease in seizure frequency. Three patients had complications, but there were no deaths. CONCLUSION: Temporal lobectomy is a safe and effective treatment for children with intractable complex partial seizures. Seventy-eight percent of patients are seizure-free following the surgery and there are few complications. MRI is superior to CT scan for detection of temporal lobe pathology yet failed to detect abnormalities in some patients. The most common pathologies found were brain tumors, mesial temporal sclerosis and developmental lesions. In addition to seizure control, many patients experienced improvement in cognitive and psychosocial function following surgery.


Subject(s)
Anterior Temporal Lobectomy , Epilepsy/surgery , Adolescent , Adult , Age Factors , Child , Child, Preschool , Electroencephalography , Epilepsy/diagnosis , Epilepsy/physiopathology , Female , Follow-Up Studies , Humans , Infant , Magnetic Resonance Imaging , Male , Outcome Assessment, Health Care , Retrospective Studies , Time Factors , Tomography, X-Ray Computed
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