Single Carcass Research Articles

Evaluating the utility of hexapod species for calculating a confidence interval about a succession based postmortem interval estimate

Carrion insect succession patterns have long been used to estimate the postmortem interval (PMI) during a death investigation. However, no published carrion succession study included sufficient replication to calculate a confidence interval about a PMI estimate based on occurrence data. We exposed 53 pig carcasses (16±2.5 kg), near the likely minimum needed for such statistical analysis, at a site in north-central Indiana, USA, over three consecutive summer seasons. Insects and Collembola were sampled daily from each carcass for a total of 14 days, by this time each was skeletonized. The criteria for judging a life stage of a given species to be potentially useful for succession-based PMI estimation were (1) nonreoccurrence (observed during a single period of presence on a corpse), and (2) found in a sufficiently large proportion of carcasses to support a PMI confidence interval. For this data set that proportion threshold is 45/53.Of the 266 species collected and identified, none was nonreoccuring in that each showed at least a gap of one day on a single carcass. If the definition of nonreoccurrence is relaxed to include such a single one-day gap the larval forms of Necrophilaamericana, Fanniascalaris, Cochliomyia macellaria, Phormiaregina, and Luciliaillustris satisfied these two criteria. Adults of Creophilus maxillosus, Necrobiaruficollis, and Necrodessurinamensis were common and showed only a few, single-day gaps in occurrence.C.maxillosus, P.regina, and L.illustris displayed exceptional forensic utility in that they were observed on every carcass. Although these observations were made at a single site during one season of the year, the species we found to be useful have large geographic ranges. We suggest that future carrion insect succession research focus only on a limited set of species with high potential forensic utility so as to reduce sample effort per carcass and thereby enable increased experimental replication.

Size Effects in Winding Roll Formed Profiles: A Study of Carcass Production for Flexible Pipes in Offshore Industry

Carcass production of flexible offshore oil and gas pipes implies winding and interlocking of a roll formed stainless steel profile around a mandrel in a spiral shape. The location of the dividing point between the left and right half of the s-shaped profile in the finished carcass is very important as it directly influences carcass flexibility. The target location of the dividing point can be difficult to achieve since undesired degrees of freedom in the winding stage allows the profile to change geometry. The present work investigates this issue by performing production tests of a single carcass profile size on three mandrel sizes showing a size effect to be evident; smaller mandrel size increases a shift of the dividing point during initial mandrel contact in the winding stage. The cause is high strains in the open profile, which are minimized by the material moving closer to profile neutral plane. Other parameters such as profile entry angle on the mandrel and spiral pitch are likely to have significant importance. Proper dividing point position is shown to be obtainable by adjusting the profile in the roll forming stage. The profile rolling is successfully modeled by Finite Element Analysis (FEA), whereas a simplified FE-model of the subsequent winding operation shows that full interlock modeling is required for proper prediction of profile deformation.

Coleópteros (Scarabaeidae, Trogidae y Silphidae) asociados a un cadáver de lechón Sus scrofa (Linnaeus, 1758) en el bosque Los Colomos, Guadalajara, Jalisco

A Survey to known the carrion beetles associated to corpses was done in an urban forest from Guadalajara, Jalisco, Mexico. A single piglet carcass was sampled. Four species were collected Dichotomius amplicollis(Harold, 1869) (Scarabaeidae), Nicrophorus olidus Matthews, 1888 (Silphidae), Omorgus rubricans Robinson, 1946, and Trox spinulosus dentibius Robinson, 1940 (Trogidae), the last one as the most abundant species (123 specimens). Highest abundance of trogids was unusual for these kinds of studies, so more fieldwork needs to be done to explain these data.

Longitudinal Study of Clostridium difficile and Methicillin-Resistant Staphylococcus aureus Associated with Pigs from Weaning through to the End of Processing

There has been a recent increase in community-associated infections linked to methicillin-resistant Staphylococcus aureus (MRSA) and Clostridium difficile. It is established that both pathogens can be recovered from retail pork, although it is unclear to what degree contamination is acquired at the farm in comparison to that acquired during processing. To address this gap, the following study reports on the carriage of MRSA and C. difficile on pigs from birth through to the end of processing. C. difficile was isolated from 28 (93%) of 30 pigs at 1 day of age, but prevalence declined sharply to 1 of 26 by market age (188 days). MRSA prevalence peaked at 74 days of age, with 19 (68%) of 28 pigs testing positive, but declined to 3 of 26 at 150 days of age, with no pig being detected as positive at market age. At the processing facility, C. difficile was isolated from the holding area, with a single carcass testing positive for the pathogen at preevisceration. MRSA was primarily isolated from nasal swabs with 8 (31%) carcasses testing positive at postbleed, which increased to 14 (54%) positive at postscald tanks. Only one carcass (sampled at postbleed) tested positive for MRSA, with no recovery of the pathogen from environmental samples taken. C. difficile ribotype 078 predominated in the longitudinal portion of the study, accounting for all of the 68 isolates recovered from pigs. Only three C. difficile isolates, which were identified as ribotype 078, were recovered at the slaughterhouse. MRSA spa type 539 (t034) predominated in pigs on the farm and samples taken at the slaughterhouse, accounting for 80% of all isolates recovered. The study demonstrated that both C. difficile and MRSA acquired on the farm can be transferred through to processing, although no evidence for significant cross-contamination between carcasses or the slaughterhouse environment was evident.

Carriage and dissemination of Clostridium difficile and methicillin resistant Staphylococcus aureus in pork processing

Community associated Clostridium difficile and MRSA are among the most common infection causing pathogens encountered in developed nations. It has been proposed that both pathogens may be foodborne with supporting evidence being based on the carriage in animals and recovery from meat at retail. The following reports on the incidence and dissemination routes of C. difficile and MRSA within a high capacity pork processing facility. Sampling of carcasses and processing environment was performed over two visits to the facility. C. difficile was isolated 80% (16/20) of manure samples taken within the holding area, with 45% (9/20) of holding area floor and wall samples testing positive for the pathogen. Three of the twenty carcasses (15%) sampled at post-bleed and a further 3 at post-evisceration also tested positive for C. difficile. No C. difficile were recovered from scald water samples, polisher/scraper units or on carcasses in the cold room at the end of the line. Ribotype 078 was the predominant C. difficile recovered with the remaining belonging to other ribotypes. MRSA was recovered from a single carcass at post-bleed and within the cold room, in addition to one sample taken from the holding area (overall prevalence of 2.7%). The MRSA isolates recovered from carcasses was spa t034 which is a commonly associated with pigs. The results of the study confirm that the holding area of slaughterhouse acts as a reservoir for C. difficile and MRSA although there was no evidence to suggest that the pathogens were disseminated into the processing lines. Consequently, it can be concluded that pork processing does not represent a significant risk of disseminating MRSA and C. difficile between carcasses.

A Case–Control Study of Risk Factors for Bovine Cysticercosis in Danish Cattle Herds

Bovine cysticercosis (BC) is a zoonotic, parasitic infection in cattle. Under the current EU meat inspection regulation, every single carcass from all bovines above 6 weeks of age is examined for BC. This method is costly and makes more sense in countries with higher number of BC-infected animals than in countries with few lightly infected cases per year. The aim of the present case-control study was to quantify associations between potential herd-level risk factors and BC in Danish cattle herds. Risk factors can be used in the design of a risk-based meat inspection system targeted towards the animals with the highest risk of BC. Cases (n = 77) included herds that hosted at least one animal diagnosed with BC at meat inspection, from 2006 to 2010. Control herds (n = 231) consisted of randomly selected herds that had not hosted any animals diagnosed with BC between 2004 and 2010. The answers from a questionnaire and register data from the Danish Cattle Database were grouped into meaningful variables and used to investigate the risk factors for BC using a multivariable logistic regression model. Case herds were almost three times more likely than control herds to let all or most animals out grazing. Case herds were more than five times more likely than control herds to allow their animals access to risky water sources with sewage treatment plant effluent in proximity. Case herds were also more likely to share machinery or hire contractors than control herds. The risk decreased with increasing herd size probably because the larger herds generally tend to keep cattle indoors in Denmark. The results are useful to guide future data recording that can be supplied by the farmer as food chain information and then be used for differentiated meat inspection in low- and high-risk groups, enabling development of risk-based meat inspection systems.

Genetic Diversity among Bacillus anthracis Soil Isolates at Fine Geographic Scales

Environmental samples were collected from carcass sites during and after anthrax outbreaks in 2000 and 2001 in the bison (Bison bison) population within Wood Buffalo National Park and the Hook Lake Region north of Wood Buffalo National Park. Bacillus anthracis spores were isolated from these samples and confirmed using phenotypic characterization and real-time PCR. Confirmed B. anthracis isolates were typed using multiple-locus variable-number tandem repeat analysis (MLVA15) and single-nucleotide-repeat analysis (SNRA). B. anthracis isolates split into two clades based on MLVA15, while SNRA allowed some isolates between carcass sites to be distinguished from each other. SNRA polymorphisms were also present within a single carcass site. Some isolates from different carcass sites having the same SNRA type had divergent MLVA types; this finding leads to questions about hierarchical typing methods and the robustness of the fine-scale typing of Bacillus anthracis.

Identification of the SNP (Single Nucleotide Polymorphism) for Fatty Acid Composition Associated with Beef Flavor-related FABP4 (Fatty Acid Binding Protein 4) in Korean Cattle.

In this study, we investigated the relationship between unsaturated fatty acids influencing beef flavor and four types of SNPs (c.280A>G, c.388G>A, c.408G>C and c.456A>G) located at exon 2, 3 and 4 of the FABP4 gene, which is a fatty acid binding protein 4 in Korean cattle (n = 513). When analyzing the relationship between single genotype, fatty acids and carcass trait, individuals of GG, GG, CC and GG genotypes that are homozygotes, had a higher content of unsaturated fatty acids and marbling scores than other genotypes (p<0.05). Then, haplotype block showed strong significant relationships not only with unsaturated fatty acids (54.73%), but also with marbling scores (5.82) in ht1×ht1 group (p<0.05). This ht1×ht1 group showed significant differences with unsaturated fatty acids and marbling scores that affected beef flavor in Korean cattle. Therefore, it can be inferred that the ht1×ht1 types might be valuable new markers for use in the improvement of Korean cattle.

Optimization of reinforcement turn-up effect on tyre durability and operating characteristics for racing tyre design

The damage occurring around the tyre bead region has been pointed out as one of the causes of critical failure during the service life of a tyre. This study investigates the influence of the carcass (body) ply turn-up and bead reinforcement turn-up around the bead region on tyre durability and operating characteristics using finite element analysis (FEA). A slick motorsport tyre with two carcass plies was modelled in ABAQUS based on the material properties obtained from tests and the profile provided by the tyre manufacturer. Various factors including the material property, the cross-section area, the spacing and angles of the reinforcement cords and the height of reinforcement turn-up, were characterized by numerical experiments using the design of experiment (DOE) method. The effects of these parameters on tyre durability and operating characteristics, in terms of mean response analysis of carcass stress, vertical stiffness, lateral stiffness, cornering stiffness and the strain energy density (SED) of elements in the critical region, were determined from the finite element tyre model. Similarly, optimum reinforcement turn-up heights were obtained and provided predictive information for tyre design purpose. Furthermore it was observed, from both experiment and prediction, that the vertical stiffness was rather high for the requirement of the Formula Student (FS) racing car. In order to reduce the tyre vertical stiffness and improve the tyre durability, an improved tyre based on the original design but with single carcass ply was proposed. The FEA results on tyre durability and operating characteristics from both the original and improved design tyres were compared. The FEA predictions indicated that the improved design model was capable of providing the required tyre characteristics as well as improved tyre durability. It is therefore proposed that the predictive technology using FEA can be utilized to optimize the tyre reinforcement turn-up effect in future tyre design.

Effect of Investigator Disturbance in Experimental Forensic Entomology: Carcass Biomass Loss and Temperature

Often carrion decomposition studies are conducted using a single carcass or a few carcasses sampled repeatedly through time to reveal trends in succession community composition. Measurements of biomass and other abiotic parameters (e.g., temperature) are often collected on the same carcasses but are rarely a focal point of the studies. This study investigated the effects that repeated sampling during experiments have on the decomposition of carrion, measured as both gross biomass (carcass plus fauna) and net biomass (carcass only), on carcasses disturbed on every visit (with weighing only or also with the collection of fauna) and on carcasses disturbed only once. Each trial lasted at least 21 days, with samples taken in triplicate. Rat carcasses used in this study were placed in the field on the same day and either weighed on every visit or ignored until a given day. Internal and ambient air temperatures were recorded on each carcass at the time of sampling and on undisturbed carcasses using temperature loggers. The presence of succession fauna did not result in significant biomass loss on most days; however, there were individual days early in decomposition (days 3 through 6) when the succession fauna comprised a large portion of the gross biomass. With the exception of biomass loss by the emigration of maggots on days 4 and 5, neither repeated weighing of the carcasses nor repeated weighing and faunal sampling of the carcasses statistically affected the rate of biomass loss. Internal temperatures of carcasses sampled repeatedly were frequently 2-5°C lower than those that had not been disturbed, and ambient temperatures differed significantly depending on the location of measurement device. Results indicate that methods used historically for biomass loss determination in experimental forensic entomology studies are adequate, but further refinements to experimental methodology are desirable.

Association between leptin gene single nucleotide polymorphisms and carcass traits in pigs

It was investigated the association between leptin gene single nucleotide polymorphisms (SNPs) T2411C and T3266G with carcass traits in F2 pigs obtained by crossing native Brazilian Piau with commercial sows composed of Landrace, Large White and Pietrain breeds. Association analyses were performed using a statistical model that included genotype, sex, and batch as fixed effects, sire and error as random effects. The T2411C SNP was associated with skinless and fatless boston shoulder weight (BSW), backfat thickness at last rib, 6.5 cm from the midline (P2), skinless and fatless picnic shoulder weight, and sirloin weight (SLW). The T3266G mutation was associated with slaughter age, bacon weight, BSW, midline backfat thickness between last and last but one lumbar vertebra, midline backfat thickness at last rib, P2 and rib weight. Phenotypic associations were also performed by combining genotypes for both SNPs. Associations with P2, carcass yield, total boston shoulder weight, and SLW were observed. The results obtained demonstrate that the SNPs analyzed have potential to be explored as markers for carcass composition in pigs.

Single carcass of Mammuthus primigenius with lithic artifacts in the Upper Pleistocene of northern Italy

This paper presents the find of a Mammuthus primigenius carcass and associated Mousterian implements from the Last Glacial site of Asolo, in north-eastern Italy. We review the exploitation of proboscidean carcasses at Lower and Middle Paleolithic sites of Africa, Europe and the Levant, including evidence of elephant killing, and summarize recent research on hafting and use of Mousterian points as spearheads already before the end of the Middle Pleistocene. The bones and implements from Asolo are described in detail; we provide information on other Italian sites with mammoth remains and on the Mousterian record of the north-eastern quadrant of the peninsula. A possible impact fracture has been detected on a Levallois point from Asolo; its interpretation is based on comparisons to similar scars found on spear points of verified function from archaeological sites of later age, and on experimental material. We conclude that the evidence of Asolo is consistent with information from a number of Western European sites supporting a picture of Neanderthals as capable hunters of large game, such as woolly mammoth.

A fresh look at meat flavor

Hundreds of compounds contribute to the flavor and aroma of meat. Complex interactions between various compounds influence the perception of meat flavor. Inherent flavor of a meat product can be influenced by oxidation, lipid content, feeding/diet, myoglobin, and pH. Diet plays an important role in both ruminants and nonruminants. New research reveals important relationships in flavor among multiple muscles within a single animal carcass. This animal effect includes the presence of off-flavors. Diets high in polyunsaturated fatty acids may be contributing to the appearance of off-flavors in beef. Compounds associated with liver-like off-flavor notes in beef have been identified in raw tissue.

Finding the message in intricacy: The association of lithics and fauna on Lower Paleolithic Multiple Carcass Sites

This paper examines alternative models for the interpretation of Lower Paleolithic Multiple Carcass Sites based on analysis of the site of Holon, Israel. The nature of the lithic and faunal assemblages found at Holon are most consistent with a palimpsest site that represents repeated occupations of a marsh edge location by both hominids and carnivores, the remains of which have been moderated by natural agencies. It is argued that ambush hunting by hominids was likely to have been one of the activities involved in the accumulation of lithic and faunal remains on the site. A comparison of the lithic assemblage found at Holon with the lithic assemblages from Lower Paleolithic Single Carcass Sites suggest differences between the activities that took place on these sites and the type of activities that took place at Holon.

Interpreting pachyderm single carcass sites in the African Lower and Early Middle Pleistocene record: A multidisciplinary approach to the site of Nadung’a 4 (Kenya)

Nadung’a 4 is one of the single carcass pachyderm sites recorded in East Africa during the Lower and Early Middle Pleistocene. The site has yielded an abundant lithic assemblage in close association with the partial carcass of an elephant. Conjoined pedological, geoarchaeological, spatial, technological, and taphonomical analyses have been carried out to address the relationship between hominids and elephant. The resulting data are consistent with a non-fortuitous association between both categories of remains. The lithic artefacts do not match a classical Acheulean tool-kit, as would be expected for the time period ascribed to the site, and the functional patterns inferred from their analysis make this site radically different from other purported butchery sites. The implications of these original features are discussed.

Development of Methods for the Recovery of Escherichia coli O157:H7 and Salmonella from Beef Carcass Sponge Samples and Bovine Fecal and Hide Samples

Culture methods were developed for the concurrent recovery of Escherichia coli O157:H7 and Salmonella from bovine carcass, hide, and fecal samples. Several enrichment conditions were tested for the overall growth of pure cultures; tryptic soy broth for 2 h at 25°C and then for 6 h at 42°C was the protocol selected for use. Immunomagnetic separation (IMS) was incorporated for sensitivity and selectivity, along with a post-IMS enrichment for the recovery of Salmonella as recommended by the manufacturer. Selective agars for plating after IMS were chosen on the basis of ease of target colony identification. Sorbitol MacConkey agar supplemented with cefixime and potassium tellurite and Rainbow agar supplemented with novobiocin and potassium tellurite were chosen for the recovery of E. coli O157:H7. Brilliant green agar with sulfadiazine and Hektoen enteric agar supplemented with novobiocin were selected for the recovery of Salmonella. The resulting methods were evaluated along with standard or previously used methods for the recovery of E. coli O157:H7 and Salmonella from bovine hide and fecal samples and carcass sponge samples. The Meats Research Unit (MRU) methods performed at least as well as the established methods, except that a secondary enrichment in tetrathionate (TT) broth prior to IMS was required for the optimal recovery of Salmonella from feces. Thus, the MRU and MRU-TT methods are effective in the recovery of both E. coli O157: H7 and Salmonella from a single bovine carcass, hide, or fecal sample.

Diversity of Campylobacter Isolates from Retail Poultry Carcasses and from Humans as Demonstrated by Pulsed-Field Gel Electrophoresis

Campylobacter spp. are a major contaminant of poultry. Eating undercooked chicken and handling raw poultry have been identified as risk factors for campylobacteriosis in humans. Previous studies have found Campylobacter spp. on 90% of poultry carcasses. In the present study, pulsed-field gel electrophoresis (PFGE) was used to assess the genetic diversity of strains on retail poultry carcasses. PFGE patterns of isolates from campylobacteriosis cases were compared to those from the poultry isolates. Over a 1-year study period (March 2000 through February 2001), whole fresh young chickens (n = 72) were obtained from three retail outlets in an urban community in the south-central United States. Campylobacter spp. were isolated from 82% of these carcasses. Strains (n = 70) were defined on the basis of their PFGE pattern. Sixty-seven percent of the carcasses from which Campylobacter spp. were isolated were contaminated with more than one PFGE-distinguishable strain. During the 1-year study period, most of the PFGE patterns (59%) were limited to isolates obtained from a single carcass. Forty-one percent of the PFGE-distinguishable strains were recovered from more than one carcass. Ninety-seven percent of the carcasses contaminated with the same strain were purchased at the same time from the same store. To examine the degree of genetic stability, four strains were followed in vitro over an estimated 1,000 doublings. The PFGE pattern of one of these isolates underwent minor changes during in vitro growth. The data indicate extensive variability in the PFGE patterns of Campylobacter spp. isolated from humans and from poultry carcasses. In spite of difficulties caused by such diversity and the fact that some carcasses are contaminated with more than one strain, the pattern variation provides a useful method for linking a particular strain to its source.

A multifocal outbreak of trichinellosis linked to horse meat imported from North America to France in 1993.

An outbreak of 538 cases of trichinellosis occurred in France in December 1993. Seven cases developed neurotrichinosis and 23 had cardiologic complications. No deaths were recorded. Two patients had a positive muscle biopsy showing living Trichinella larvae. One of them was typed as Trichinella spiralis. A case-control study showed that horse meat was the only meat associated with illness (odds ratio = 80.7). The risk of illness increased with the amount of horse meat eaten and when it was consumed raw. The cases, which were spread out in five foci, bought horse meat from five butchers who had received parts of a single horse carcass imported in November 1993 from Canada. The Trichinella International Screening Program, implemented since 1985 after two similar episodes involving a thousand cases, failed to detect the incriminated horse carcass. This new horse meat-related outbreak led to modifications of the internationally recommended screening methods whereby the weight of meat samples tested was increased.

Avian botulism--another perspective.

Waterfowl botulism is unique among intoxications because toxin produced within its victims leads to secondary poisoning of other birds. Because of this phenomenon, the epizootiology of the carcass-maggot cycle of botulism resembles that of an infectious disease and the reproductive rate (R) of the disease could be defined as the average number of secondary intoxications attributable to a single carcass introduced into a marsh. I propose that toxin production and botulism occur commonly at a low level in many marshes and that factors which influence R determine when the disease expands into a large epizootic. A model that incorporates the number of carcasses occurring in a marsh, the probability of a carcass containing spores, the probability of a carcass persisting until toxin-bearing maggots emerge, and the contact rate between live birds and toxin, may be useful for predicting the extent of secondary poisoning, for identifying questions for research, and as a theoretical basis for management.

Microbial quality of lamb carcasses during processing and the acridine orange direct count technique (a modified DEFT) for rapid enumeration of total viable counts

This study was designed to set up a hazard analysis and critical control points (HACCP) system for sheep slaughtering operations at four different plants in Ireland and to determine the differences plants in terms of microbial contamination. A single carcass area, the abdomen, was examined by swabbing and a microbiological profile was determined at different stages along the slaughter line. The level of contamination was assessed from the total bacteria counts, Enterobacteriaceae and Listeria spp. For the total counts, a modified direct epifluorescent filter technique (acridine orange direct count technique (AODC)) was developed and tested. No significant differences were found among plants in the level of bacterial contamination. This was observed for all groups of organisms. The rapid direct technique (AODC) was found to be very successful. A correlation coefficient of 0.87 was obtained for this method and the standard plate count. Each test could be carried out in about 10–15 min and could be used to predict the standard plate count.