Swine Slaughterhouses Research Articles

Impacto econômico de lesões pleurais crônicas e consequente desqualificação de carcaças para exportação durante inspeção em frigoríficos de suínos

ABSTRACT: Chronic pleuritis is the main reason for sending pig carcasses to the Department of Final Inspection (DIF), condemnation and led to economic losses to industries and producers. Most pleura lesions detected after slaughter are sequelae from bacterial infections by agents that do not pose risks to pork consumers. The objective of the present study was to generate science-based information for decision making in the evaluation and destination of chronic pleuritis by the Federal Inspection Service (SIF). Therefore, 200 carcasses, with and without pleurisy, from a swine slaughterhouse with SIF were assessed following the visual classification of the inspection agent. The study was carried out in two stages. In stage 1, 50 carcasses with pneumonic lesions adjacent to chronic pleuritis and 50 carcasses with only chronic pleuritis lesions were evaluated, through macroscopy, histopathology, and bacterial culture. In stage 2, 50 swine carcasses with chronic pleuritis and 50 without this lesion were sampled in the parietal pleura region to bacterial culture and PCR. The economic impact of not exporting these carcasses with chronic pleuritis was also assessed. Considering the stages of evolution of the lesions, the macroscopic examination showed high correlation with the histological examination. There was no bacterial isolation through pleural swabs, regardless of the presence or not of adjacent pulmonary lesions. Isolation was restricted to the adjacent pulmonary lesions of 70% samples, with Pasteurella multocida type A found in 48% of them, followed by P. multocida type D and Streptococcus suis in 12%, and Actinobacillus pleuropneumoniae in 3%. Only Streptococcus suis DNA was detected in 5/100 samples, with no correspondence to the isolation of viable bacteria. The reliability demonstrated in the macroscopic evaluation carried out during inspection, the absence of viable bacteria in the chronic pleural lesions, and the negative economic impact suggest that carcasses with chronic pleuritis can be submitted to pleura removal, with no need of sending to DIF.

Use of an Ecosystem-Based Approach to Shed Light on the Heterogeneity of the Contamination Pattern of Listeria monocytogenes on Conveyor Belt Surfaces in a Swine Slaughterhouse in the Province of Quebec, Canada.

The role of the accompanying microbiota in the presence of Listeria monocytogenes on meat processing surfaces is not yet understood, especially in industrial production conditions. In this study, 300 conveyor belt samples from the cutting room of a swine slaughterhouse were collected during production. The samples were subjected to the detection of L. monocytogenes. Recovered strains were characterized by serogrouping-PCR, InlA Sanger sequencing and for their ability to form biofilm. A selection of isolates was compared with core genome multi-locus sequence typing analysis (cgMLST). The sequencing of the V4 region of the 16S RNA gene of the microorganisms harvested from each sample was carried out in parallel using the Illumina MiSeq platform. Diversity analyses were performed and MaAsLin analysis was used to assess the link between L. monocytogenes detection and the surrounding bacteria. The 72 isolates collected showed a low genetic diversity and important persistence characteristics. L. monocytogenes isolates were not stochastically distributed on the surfaces: the isolates were detected on three out of six production lines, each associated with a specific meat cut: the half carcasses, the bostons and the picnics. MaAsLin biomarker analysis identified the taxa Veillonella (p ≤ 0.0397) as a bacterial determinant of the presence of L. monocytogenes on processing surfaces. The results of this study revealed a heterogenous contamination pattern of the processing surfaces by L. monocytogenes and targeted a bacterial indicator of the presence of the pathogen. These results could lead to a better risk assessment of the contamination of meat products.

Genetic diversity and multidrug-resistance among Salmonella Typhimurium isolated from swine carcasses and slaughterhouses in Rio de Janeiro, Brazil.

This study, conducted in the State of Rio de Janeiro, aimed to genetically distinguish 29 isolates of S. Typhimurium isolated from 344 samples of swine carcasses by PFGE (pulse‑field gel electrophoresis) and to evaluate their antimicrobial resistance profile. Out of the 29 isolates, 26 (90%) were resistant to at least one antimicrobial. Sulfonamides (66%), nalidixic acid (66%), trimethoprim (66%) and tetracycline (52%) were the most frequent resistant drugs. Multidrug‑resistance (MDR) profile was frequent (60% of isolates). The profile Eno‑Na‑Nxn‑Fc‑C‑S‑Gm‑G‑T‑Te (14%), Cp‑Eno‑Na‑Fc‑C‑S‑G‑T‑Te (10%) and Na‑G‑T (7%) were the most frequent. Five isolates within the predominant PFGE pulsetype came from lymph nodes of distinct animals from multiple slaughterhouses indicating that this particular clone might be widespread in the Rio de Janeiro State. This paper reveals a threat to the population in the entire State and highlights the necessity of the strict control in the use of antimicrobials in swine production in the entire country.

A Retrospective Study after 10 Years (2010-2019) of Meat Inspection Activity in a Domestic Swine Abattoir in Tuscany: The Slaughterhouse as an Epidemiological Observatory.

Simple SummaryVeterinarians belonging to the Health Authorities are responsible for the safety of food of animal origin. The control activities performed at the slaughterhouse comprise inspections before and after slaughtering to verify the health and welfare of the animals and the wholesomeness of the animal products. In this study, data deriving from ten years (2010–2019) of meat inspection activity in a pig slaughterhouse in Tuscany (Italy) were analyzed to investigate the frequencies of death during transport of whole carcass and partial condemnations and their causes. In total 1,246,309 pigs from 8 different regions of Central and Northern Italy were slaughtered. The mortality rate was found to be lower than the threshold internationally recommended to ensure animal welfare and in line with the mortality values reported at the European level. Overalls 372 carcasses were condemned mainly due to erysipelas, generalized jaundice, lipomatous pseudohypertrophy, generalized abscesses, acute or generalized enteritis, and peritonitis. As regards partial condemnations, liver, lungs, and kidney were the most frequently condemned organs. The results of this study describe a non-worrying situation as regards to the investigated aspects and confirm the slaughterhouse as a privileged observation point for monitoring the trend of the main diseases over time, the results of the efforts for their control, and also the compliance with animal welfare standards.The activities performed by the Official Veterinarian at the slaughterhouse represent a useful source of data for the control of issues affecting human and animal health and welfare. This study analyzed the data deriving from ten years (2010–2019) of meat inspection in a pig slaughterhouse in Tuscany (Italy) to investigate the transport mortality rate and the frequencies and main causes of whole carcass and partial condemnations. In total, 1,246,309 pigs were slaughtered from 8 different regions of Central and Northern Italy. Overall, 1153 pigs died during transport (mortality rate 0.09%). Whole carcass condemnation affected 372 carcasses (0.03%), mainly due to erysipelas, generalized jaundice, lipomatous pseudohypertrophy, generalized abscesses, acute or generalized enteritis, and peritonitis. As regards partial condemnations, the liver was the most frequently condemned (~30% of the pigs), followed by lungs (17.3%), heart (6.9%), and kidney (0.9%). The main causes were “milk spot liver” and perihepatitis for the liver; pneumonia and pleurisy for the lungs; pericarditis and polyserositis for the heart; and polycystic kidney and nephritis for kidneys. The results of this study describe a non-worrying situation as regards the investigated aspects and confirm the slaughterhouse as a valid epidemiological observatory for monitoring the trend of the main diseases over time, the results of the efforts for their control, and the compliance with animal welfare standards.

Multidrug Resistance and Virulence Profiles of Salmonella Isolated from Swine Lymph Nodes.

Salmonella spp. is a foodborne pathogen present in the pork production chain, leading to potential contamination of end products and causing salmonellosis cases and outbreaks worldwide. The emergence of multidrug-resistant (MDR) Salmonella spp., especially isolates obtained from animal origin food, is a global concern. This study aimed to isolate Salmonella from swine mesenteric lymph nodes (MLN) and to characterize the virulence and antibiotic resistance profiles. MLN samples were obtained from a swine slaughterhouse and subjected to Salmonella spp. isolation. Ten MLN samples were positive and 29 isolates were identified based on PCR (invA and ompC) and serotyping: Derby, Cerro, and Give. Pulsed-field gel electrophoresis allowed to group the isolates based on their serotypes, resulting in three major clusters. All isolates presented the virulence-related genes pefA, sipA, sopB, spaN, and pagC. Relatively high numbers of Salmonella spp. were resistant to neomycin, polymyxin B, ciprofloxacin, tetracycline, and nalidixic acid. Furthermore, 25 isolates presented simultaneous resistance to three or more antibiotic classes, being characterized as MDR. The obtained results confirmed the relevance of swine as reservoirs of Salmonella spp. in the pork production chain and demonstrated the MDR profiles of isolates. Proper control and surveillance are required to avoid the contamination of end products.

Distribution, diversity and persistence of Listeria monocytogenes in swine slaughterhouses and their association with food and human listeriosis strains.

Listeria monocytogenes is the etiological agent of listeriosis, a major foodborne disease and an important public health concern. Contamination of meat with L. monocytogenes occurs frequently at the slaughterhouse. Our aims were; 1) to investigate the distribution of L. monocytogenes in the processing areas of four swine slaughterhouses; 2) to describe the diversity of L. monocytogenes strains by pulsed-field gel electrophoresis; 3) to identify persistent L. monocytogenes strains and describe their distribution; 4) to investigate the associations between persistence of strains and their following characteristics: detection in food isolates, detection in human clinical isolates, and the presence of benzalkonium chloride (BAC) resistance genes. Various operation areas within the four swine slaughterhouses were sampled on four occasions. A total of 2496 samples were analyzed, and L. monocytogenes was successfully isolated from 243 samples. The proportion of positive samples ranged from 32 to 58% in each slaughterhouse and from 24 to 68% in each operation area. Fifty-eight different pulsotypes were identified and eight pulsotypes, present in samples collected during 4 visits, were considered persistent. The persistent pulsotypes were significantly more likely to be detected in food (P < 0.01, exact χ²) and human clinical cases (P < 0.01, exact χ²), respectively. Among pulsotypes harboring the BAC bcrABC resistance cassette or the emrE multidrug transporter gene, 42.8% were persistent compared to 4.5% for pulsotypes without these resistance genes (P < 0.01, exact χ²). Our study highlights the importance of persistent L. monocytogenes strains in the environmental contamination of slaughterhouses, which may lead to repeated contamination of meat products. It also shows that the presence of disinfectants resistance genes is an important contributing factor.

Techno-economic and performance evaluation of energy production by anaerobic digestion in Brazil: bovine, swine and poultry slaughterhouse effluents

This work describes anaerobic treatment system modeling, using up-flow anaerobic sludge blanket reactors (UASB) reactors, aiming at biogas energy use, under hydraulic retention times (HRT) of 12, 24, 48, 120 and 240 h, from bovine (slaughter capacity: less than 20, 20 to 40, 40 to 80 and more than 80 heads.h−1), swine (less than 80, 80 to 200, 200 to 400, 400 to 800 and more than 800 heads.d−1) and poultry (less than 600, 600 to 1500, 1500 to 3000 and more than 3000 heads.h−1) slaughterhouse effluents. To techno-economic potential evaluate, four scenarios were designed using the combination of maximum and minimum values for the installation of the treatment system (reactors) and the generator system. The scenarios were applied for all classes of slaughterhouses throughout HRTs established under two project concepts: i) full implementation of the treatment and generator systems and; ii) partial implementation, only the generator system. Economic viability analyzes were performed using Net Present Value (NPV), Internal Rate of Return (IRR) and Minimum Attractive Rate of Return (MARR) criteria. In scenario 1, using minimum unit values for the treatment system (USD 43.23.m−³) and the generator set (USD 287.80.KW−1) and HRT of up to 48 h, all bovine, swine and poultry slaughterhouse classes presented potential and economic viability for energy generation, with gains of up to USD 831.462.78 to bovine slaughterhouse, USD 91.977.88 to swine slaughterhouse and USD 179.150.63 to poultry slaughterhouse. The scenarios 2 and 4 result in unviability for al simulations. The scenario 3 result in viability under specific conditions of implementation (total and/or partial); HRT (12, 24, 48 h and sporadically 120); In 24-h HRT show negatives IRRs; and attractive ratio criteria (use of IRR as MARR). In simulated conditions of scenario 1 the techno-economic analysis is HRT of 24 h and HRT of 12 h in scenario 3, both with the need for post-treatment systems. HRTs of 120 and 240 h were found to be infeasible due to system size and costs involved, as well as a non-significant increase in energy generation when compared to lower HRTs.

Productivity increase in a large size slaughterhouse: a simulation approach applying lean manufacturing

PurposeThe main purpose of this paper is to develop a study of the determination of the most appropriate execution steps, necessary for the construction of modelling, simulation and optimization for the specific area of slaughter line balancing. And through the developed model to demonstrate the application of simulation to increase productivity in a large-size swine slaughterhouse, focusing on operator stations balancing. The built model may be applied to support the management of the plant, allowing to evaluate and decide the optimized scenario that meets current needs considering operational cost, production demand and productivity.Design/methodology/approachFor the research development, the selected software supports the characteristics of the evaluated process, in this case, a discreet simulation with stochastics variables. The studied plant was modelled door by door, from the swine reception until the packaging area. The research methodology was based on lean manufacturing (LM) principles, particularly in workstations balancing, by optimizing the idle time of the operators, comparing with the cycle time of each task, in the evaluated workstations.FindingsThe achieved result with the modelling and simulation was the increase of 11.89% in plant productivity through manpower optimization. The study indicates that the simulation applied with LM concepts as operative stations balancing and value stream map can be a very useful tool to support decision-making for productivity improvement.Originality/valueThis study approaches how modelling and simulation can support decision-making to implement improvements associated to workforce balancing optimization, especially in the studied area (agribusiness, animal slaughter). The studied process presents great variability associated with the processing time of each phase, making the analysis and modelling more complex. The number of workstations involved, with more than 800 employees, is an important point in the research, considering that cases with higher values than the case presented were not identified in literature.

Antimicrobial and Disinfectant Susceptibility of Salmonella Serotypes Isolated from Swine Slaughterhouses.

Salmonella remains one of the most common foodborne pathogens worldwide, and its resistance to antimicrobials and disinfectants has increased considerably over the years. Thus, monitoring its resistance to products commonly used in swine production is indispensable for the development of strategies to reduce the occurrence of bacterial resistance. In this context, our aim was to detect Salmonella at different points in swine slaughterhouses, identify the main serotypes, and evaluate their resistance to disinfectants and antimicrobials used in swine production. Salmonella at the processing plants was detected by conventional microbiology. Salmonella strains were tested for susceptibility to peracetic acid (0.5% and 1%), quaternary ammonium (0.5%), and seven antimicrobials. Twenty-eight percent of the samples were positive for Salmonella, with the most identified serotypes being Salmonella Derby, Salmonella Typhimurium, and monophasic Salmonella Typhimurium. All tested strains were susceptible to both concentrations of peracetic acid, but only 28% were susceptible to quaternary ammonium. Sixteen percent of the strains were susceptible to all tested antimicrobials. Only enrofloxacin was efficient in inhibiting the growth of all strains. The highest number of non-susceptible strains was to amoxicillin, followed by chloramphenicol, florfenicol, and doxycycline. Thirty-six percent of the strains were classified as multidrug-resistant. Salmonella were detected in all slaughtering processes, and important serotypes were recovered, including Salmonella Typhimurium, Salmonella Derby, monophasic Salmonella Typhimurium, and Salmonella Infantis. We observed high rates of resistance to quaternary ammonium and to important antimicrobial agents. Salmonella Typhimurium and Salmonella Infantis were the most resistant serotypes.

Exposure assessment of Salmonella spp. in fresh pork meat from two abattoirs in Colombia.

Salmonella spp. prevails as the main cause of raw meat foodborne illnesses. Implementation of food safety management systems such as Hazard Analysis and Critical Control Points in swine abattoirs can help to mitigate pathogen exposure. The objective of the present study was to evaluate the impact of the HACCP system in slaughterhouses in Colombia on reducing Salmonella spp. exposure due to the consumption of fresh pork meat. Two slaughtering plants with a different degree of HACCP implementation were selected and a quantitative microbiological mapping was built by collecting 820 samples of Salmonella spp. enumeration at different processing stages. The overall Salmonella spp. mean concentration was 1.15 ± 0.55 log MPN/g, with no significant differences among plants (P > 0.05). Deficiencies during carcass disinfection and temperature during distribution of meat cuts from the slaughterhouse lacking of HACCP resulted in a significant increase of Salmonella spp. prevalence (20-40%) (P < 0.05). Processing stages with the highest pathogen prevalence were transport (28-32%) and hanging (16-36%). The exposure assessment model estimated a higher degree of pathogen contamination at the time of consumption in meat cuts from the slaughterhouse without HACCP (3.36 versus 3.68 log MPN/g) and 10-fold increase in the probability a consumer would acquire a contaminated portion (0.011 versus 0.105). Implementation of the HACCP system in swine slaughterhouses represents tangible Salmonella spp. reduction control and public health protection measures.

TREATMENT OF WASTEWATER FROM SWINE AND POULTRY SLAUGHTERHOUSES

&lt;p&gt;The meat processing industry produces large volumes of slaughterhouse wastewater (SWW). For this reason, water and wastewater treatment has become crucial for the continuing development of the society. The present study reveals the water pollution degree from poultry and the swine slaughterhouses from Bacau (Romania). The possibility of reducing the quantity of pollutants by the active sludge treatment method is also presented. The efficiency of this treatment processes was evaluated through the following parameters: biochemical oxygen demand (BOD&lt;sub&gt;5&lt;/sub&gt;), chemical oxygen demand (COD), total suspended solids (TSS), turbidity, both before and after the active sludge treatment.&lt;/p&gt;

Parasit Gastrointestinal pada Hewan Ternak di Tempat Pemotongan Hewan Kabupaten Sigi, Sulawesi Tengah

Disease in lifestock due to gastrointestinal parasites can cause economic loss and harmful for health of breeders or people who eat meat from these animals. . Slaughterhouse is an important place for monitoring parasitism in livestock, surveillance of disease in livestock and zoonoosis. Previous studies showed that some people living nearby a swine slaughterhouse were infected with Ascaris lumbricoides and Trichuris trichura. Based on those results, it is required to study about the gastrointestinal parasites in livestock which could transmit to human in Slaughterhouse in Jono Oge Village and Biromaru Slaughterhouse, Sigi regency. This study was a cross-sectional design, and fecal samples collection were carried out on 97 cattles, 33 pigs and 33 goats slaughtered at slaughterhouse of Sigi, Central Sulawesi. Samples from cattleswere examined according to sedimentation method, while those from pigs and goats were examined using Ritchie method. Single infections by Facsiola sp., Paramphistomum sp., Trichuris sp., Oesophagustomum sp., Ascaris sp., Eimeria sp., and Balantidium sp. were found in cattle and pigs. In cattle, dual infections were found which caused by Strongyloidea sp. and Paramphistomum sp., Trichuris sp. and Paramphistomum sp., Fasciola sp. and Paramphistomum sp. A mixed infection also observed in cattles which caused by Paramphistomum sp., Fasciola sp., and Trichuris sp. while Trichostrongylus sp., was found in goat&#x0D;

Antimicrobial resistance profiles and characteristics of integrons in Escherichia coli strains isolated from a large-scale centralized swine slaughterhouse and its downstream markets in Zhejiang, China

The pork production chain and raw pork products are among the most important reservoirs of antimicrobial-resistant microorganisms. This study investigated the antimicrobial resistance profiles and integrons and their associated gene cassettes of Escherichia coli isolated from a large-scale centralized swine slaughterhouse in Zhejiang, China and its downstream markets. A total of 300 E. coli isolates were identified from 720 samples. No E. coli isolates were detected on the slaughtering line or at downstream supermarkets. Of the 300 E. coli isolates collected from lairages and downstream open markets, 242 (80.67%) were classified as multi-drug resistant (MDR). In addition, the prevalence of multi-drug resistance was significantly different (p < 0.05) and antimicrobial resistance profiles varied among the different sampling points. Furthermore, of 300 E. coli strains, 76 (25.33%) were positive for class 1 integrons and nine (3.00%) were positive for class 2 integrons. Three different gene cassettes were detected in class 1 integrons and one gene cassette was detected in class 2 integrons. Our study demonstrates that E. coli isolates from lairages and open markets are frequently MDR, and suggests that precautionary measures and hygienic environments are necessary to prevent the spread of antimicrobial-resistant microorganisms and their mobile genetic elements through the food chain.

Using ANOVA to Evaluate the Effects of Swine Slaughterhouse Wastewater Conditions on Algae Growth

Using ANOVA to Evaluate the Effects of Swine Slaughterhouse Wastewater Conditions on Algae Growth

TREATMENT OF WASTEWATER FROM SWINE AND POULTRY SLAUGHTERHOUSES

The meat processing industry produces large volumes of slaughterhouse wastewater (SWW). For this reason, water and wastewater treatment has become crucial for the continuing development of the society. The present study reveals the water pollution degree from poultry and the swine slaughterhouses from Bacau (Romania). The possibility of reducing the quantity of pollutants by the active sludge treatment method is also presented. The efficiency of this treatment processes was evaluated through the following parameters: biochemical oxygen demand (BOD5), chemical oxygen demand (COD), total suspended solids (TSS), turbidity, both before and after the active sludge treatment.

Interventions for preventing occupational irritant hand dermatitis.

Interventions for preventing occupational irritant hand dermatitis.

Applying Response Surface Methodology to Optimize the Treatment of Swine Slaughterhouse Wastewater by Electrocoagulation

Applying Response Surface Methodology to Optimize the Treatment of Swine Slaughterhouse Wastewater by Electrocoagulation

Isolation and molecular characterization of Arcobacter butzleri and Arcobacter cryaerophilus from the pork production chain in Brazil

ABSTRACT: Arcobacter is an emerging zoonotic pathogen, and the major transmission routes to humans are the handling or consumption of contaminated raw/undercooked food products of animal origin, water and seafood. The isolation and identification of Arcobacter species are not routine in clinical laboratories; therefore, its true incidence in human infections may be underestimated. The present study aimed to isolate and characterize Arcobacter from carcasses and fecal samples collected at swine slaughterhouses and from meat markets in São Paulo State, Brazil. The isolates were identified using multiplex-PCR to differentiate the species and analyzed by single-enzyme amplified fragment length polymorphism (SE-AFLP). Arcobacter spp. were isolated from 73.0% of swine carcasses, 4% of fecal samples and 10% of pork samples. A. butzleri was the most prevalent species identified, followed by A. cryaerophilus. Interestingly, the carcasses presented higher frequency of A. butzleri isolation, whereas only A. cryaerophilus was isolated from fecal samples. SE-AFLP enabled the characterization of A. butzleri and A. cryaerophilus into 51 and 63 profiles, respectively. The great genetic heterogeneity observed for both species corroborates previous reports. This study confirms the necessity for a standard isolation protocol and the improvement of molecular tools to further elucidate Arcobacter epidemiology.

Campylobacter coli in Swine Slaughtering Flowchart and Research of cdt Genes

Background: Campylobacter spp. are among the microorganisms most commonly associated with foodborne disease. Campylobacter spp. isolation from pigs during the slaughter and final products have been reported in several countries, including Brazil. However, very little is known about the sources of contamination in the slaughtering flowchart and how these microorganisms are spread in processing plants. Considering the possibility of the pigs carry Campylobacter spp. since the farm or its products are contaminated in the slaughterhouse, this study had as aim to track Campylobacter spp. in pig slaughtering flowchart to understand the behavior of these pathogens in the production line.Materials, Methods &amp; Results: Forty animals of 10 lots, four from each lot, were followed during slaughter. Stool samples were collected from the floor of each enclosure where the pigs were housed on the farm and immediately after stunning on slaughterhouse. Samples from carcass surface were collected after removal of the animals from scrap machine, after evisceration and before the refrigeration chamber. It was also collected surface samples from jowls and samples from the scalding tank water before and after the passage of animals. The swabs containing samples were plated onto Columbia agar supplemented with activated charcoal, oxygen reduction solution and antibiotics supplement, and incubated at 42°C for 48 h under microaerobic conditions. The colonies which presented with a shiny and moist appearance were analyzed by Gram staining for identification of Campylobacter by morphology, and then tested for catalase and oxidase. The Campylobacter isolates were identified for species C. jejuni or C. coli by PCR. Bands profiles were determined by rep-PCR and used to compare the strains. Campylobacter was isolated from 19 (9.5%) of the 200 pig samples analyzed, seven (36.8%) of the rectum, seven (36.8%) after evisceration and five (26.3%) before the refrigeration chamber. Campylobacter was not isolated from jowls and from scalding tank water. All isolates were C. coliand cdtnegative.Persistence of strains originating from the farm and cross contaminations during the slaughtering flowchart was identified by the analysis of the bands profiles obtained by rep-PCR.Discussion: C. coli was the species of Campylobacter present in the swine intestinal tract and in the swine slaughterhouse. The animals, once contaminated, can carry the microorganism during the stages of the slaughtering flowchart. The farm where the animals came from is an important source of contamination during processing, however cross contamination also plays a relevant role. The evisceration was considered the most critical stage, due to the greater number of isolates obtained after this procedure, what emphasize the importance of the hygienic-sanitary management in this stage. Campylobacter spp. can survive, despite not being able to multiply, in foods at refrigeration temperatures (-1 to 5°C) for one to three weeks. Therefore, the high percentage of isolates obtained from the carcass before the refrigeration chamber may represent a problem, since the contamination of the carcasses that enter in this sector can be maintained until the food reaches the consumer. There was no similarity between strains isolated from different lots, indicating that there were no persistence of strains both in the farm and in the slaughterhouse.

The prevalence and load of Salmonella, and key risk points of Salmonella contamination in a swine slaughterhouse in Jiangsu province, China

We investigated Salmonella contamination in a slaughterhouse in Jiangsu province (China) by analysing prevalences, loads, and serotypes of Salmonella isolates. In total, 480 samples were collected, with total prevalence of 25.4%. High Salmonella prevalence and load were observed at exsanguination and splitting stages (40.6% and 75.0%; 2.50 ± 0.94 and 2.24 ± 0.72 logMPN/m2, respectively), with low prevalence and load at dehairing, flaming, and chilling stages (2.5%, 5.0%, and 15.0%; 1.39 ± 0.42, 1.36 ± 0.31, and 1.38 ± 0.30 logMPN/m2, respectively). The Salmonella prevalence and load increased substantially from flaming to splitting stage. Six serovars were represented among 122 Salmonella isolates; S. Derby and S. Typhimurium were predominant and were subtyped using PFGE and CRISPR typing approaches. Fourteen PFGE clusters were identified, with discrimination indices (DI) of 0.929 and 0.976 for S. Derby and S. Typhimurium, respectively. Clusters A1, A2, B, C1, C3, C4, D1, F, I, J, L1, M2, and N2 indicated the isolates from same sampling visit were distributed in same cluster. Cluster D1 and K showed that the strains isolated from splitter and carcass swab-samples were highly resemble. Salmonella serovars with the same CRISPR type were mostly isolated after splitting (represented by Dercr 1, Dercr 2, Dercr 3, Tycr 1, Tycr 2, Tycr 3, Tycr 4, and Tycr 6). Our findings revealed that introduced Salmonella was the major source of swine carcass contamination; three slaughtering steps (polishing, rectal drilling, and evisceration) between flaming and splitting were important risk points for Salmonella release, post-splitting slaughtering processes were major contamination risk points, and the splitter was a contamination factor. Our data suggest routes for controlling Salmonella contamination in a swine slaughterhouse.