Infected Meat Research Articles

Hydatid cyst of the pancreas mimicking neoplasm.

Hydatid disease is a cyclozoonotic infection caused by the cestode genus Echinococcus. It occurs throughout the world and is especially common in sheep- and cattle-raising regions of Africa, Australia, New Zealand, India, the Middle East, South America, and the Mediterranean. The incidence of humans infected with hydatid disease is approximately 1-2:1000. It is higher in rural areas. Infection occurs via ingestion of infected meat. Hydatidosis is caused by sheep and cattle ingesting tapeworm eggs in dog feces. These eggs hatch in the duodenum and invade the liver, lungs, or bones of sheep and cattle. Humans are infected by ingesting the infected meat from these animals. In the organs, the embryo transforms into a cyst, which develops the germinal epithelium that produces capsules, larval forms, and eventually the infectious scolices. Although hydatid cyst of the pancreas is rare, it must be considered in the differential diagnosis of pancreatic lesions. We present a rare case.

Latest developments on Streptococcus suis: an emerging zoonotic pathogen: part 2.

First International Workshop on Streptococcus suis, Beijing, China, 12-13 August 2013. This second and final chapter of the report on the First International Workshop on Streptococcus suis follows on from Part 1, published in the April 2014, volume 9, issue 4 of Future Microbiology. S. suis is a swine pathogen and a zoonotic agent afflicting people in close contact with infected pigs or pork meat. Although sporadic cases of human infections had been reported worldwide, deadly S. suis outbreaks emerged in Asia. The severity of the disease underscores the lack of knowledge on the virulence and zoonotic evolution of this human-infecting agent. The pathogenesis of the infection, interactions with host cells and new avenues for treatments were among the topics discussed during the First International Workshop on S. suis (China 2013).

Antimicrobial Effects of Four Lactobacilli Strains Isolated from Yoghurt against E scherichia Coli O157:H7

This study aimed to isolate Lactobacillus species from yoghurt and to evaluate its antimicrobial activity against enterohemorrhagic Escherichia coli O157:H7. After incubation of different yoghurt samples in MRS (de Man, Rogosa and Sharpe) agar at 37C under anaerobic conditions, four Lactobacillus species, L. casei, L. acidophilus, L. helveticus and L. delbrueckii ssp. bulgaricus were identified. Standard growth curves of E. coli O157:H7 in proximity with lactobacilli test strains were obtained. The antibacterial effects of lactobacilli cell debris and culture supernatant against E. coli O157:H7 were determined. The results showed that the antibacterial effects of culture supernatant were stable at different temperature conditions (56–100C) for 30 and 60 min; also, it was stable at pH 3–10. With regard to the antibacterial effect of the lactobacilli strains in this study, they may help in the treatment of E. coli O157:H7-associated diseases and can be applied as a biological preservative in the food industry. Practical Applications In recent years, foodborne diseases become a health problem in most of the population. One of the most important etiologic agents of such diseases is Escherichia coli O157:H7, which can be transmitted through eating undercooked infected meat and leads to hemorrhagic diarrhea and kidney failure. There is increasing evidence that lactobacilli bacteria produce potential agents (H2O2, small organic compounds, lactic acid, etc.) that can inhibit growths of some invasive foodborne bacteria, such as enterohemorrhagic E. coli. The results of this study also confirmed these reports and showed that the use of lactobacilli bacteria is a promising way to prevent the infection of E. coli O157:H7; also, they can be used as a biological preservative in the food industry.

Tenacity of Alaria alata mesocercariae in homemade German meat products

A renewed interest in the pathogenic potential of Alaria alata mesocercariae emerged over the last 10years as a result of increased findings of this parasite in feral pigs during official examination for Trichinella spp. Cases of food associated human alariosis in North America suggest that a risk associated with the consumption of traditional raw cured products from infected wild boar meat cannot be neglected because the commonly applied preservation techniques may not necessarily kill the mesocercariae. In addition, changes in consumer behavior and new preparation methods for game meat (e.g. pink roasting and grilling) may increase the risk for food-associated parasitic infections. Thus, there is a strong need for the evaluation of the tenacity of A. alata mesocercariae against different physical and chemical influences as pertaining to common preservation and preparation techniques.Against this backdrop the aim of our work was a sound analysis of the survivability of A. alata mesocercariae during curing, fermentation, cold smoking and drying in raw cured meat products. Eighty three samples of traditional German meat products were prepared from naturally infected game meat and partly spiked with additional vital mesocercariae to achieve an adequate dose of infection. The resultant products were examined chronologically for dead and viable A. alata mesocercariae with the Alaria mesocercariae migration technique. After 24h of production, vital A. alata mesocercariae were still found in raw type sausages but no vital parasites were detected in the final products. Based on these results a possible risk for the consumer for an infection with A. alata mesocercariae through the consumption of contaminated raw cured products can be largely ruled out if the respective food technological procedures are carried out properly. However, a risk for the consumer cannot be excluded in cases of very early consumption of these products.

High doses of highly pathogenic avian influenza virus in chicken meat are required to infect ferrets.

High pathogenicity avian influenza viruses (HPAIV) have caused fatal infections in mammals through consumption of infected bird carcasses or meat, but scarce information exists on the dose of virus required and the diversity of HPAIV subtypes involved. Ferrets were exposed to different HPAIV (H5 and H7 subtypes) through consumption of infected chicken meat. The dose of virus needed to infect ferrets through consumption was much higher than via respiratory exposure and varied with the virus strain. In addition, H5N1 HPAIV produced higher titers in the meat of infected chickens and more easily infected ferrets than the H7N3 or H7N7 HPAIV.

First report of Toxoplasma gondii seroprevalence in wild-caught Caribbean African green monkeys

Background Toxoplasma gondii is a protozoan parasite capable of infecting all warm-blooded animals. Humans can become infected by ingesting infective oocysts from the environment or contaminated food or water, or by ingesting tissue cysts in undercooked infected meat or by handling infected meat. Caribbean African green monkeys (Chlorocebus sabaeus) are present in large numbers on the island of St. Kitts in the Caribbean, and it is not uncommon for these animals to be trapped and eaten by islanders. The aim of this study was to determine T. gondii infection in Caribbean African green monkeys.FindingsSera collected from 79 wild-caught Caribbean African green monkeys were examined for T. gondii antibodies by ELISA. Antibodies were detected in 38 out of 79 (48.1%) monkeys. Significantly more females were infected than males but there was no significant effect of age or location on antibody status.ConclusionsResults indicate that Caribbean African green monkeys can be infected with T. gondii and that there is widespread environmental contamination of St. Kitts with oocysts. These monkeys could present a potential source of T. gondii infection if their meat is consumed undercooked. This is the first report of T. gondii antibodies in this species.

Travels and tourism are drivers for trichinellosis

BackgroundAcquiring trichinellosis while traveling abroad is not a new phenomenon and imported cases are regularly reported worldwide. Cases contracted abroad and reported by the French National Reference Centre for Trichinella (NRCT) are analyzed here.ResultsSince 1998, 28 imported cases, representing 37% of all cases, were reported to the NRCT, with a mean annual incidence of two cases. Between 1975 and 1998, 40 imported cases represented only 1.5% of all identified cases, but with a comparable mean annual incidence of 1.6 cases. The incidence of imported cases could even have decreased since 1998 as the number of international travelers increased during that period. Since 1998, most cases were acquired in Canada from bear meat (hunters). Some cases were acquired in West Africa from warthog meat, in Laos from pork, and one case, in Algeria, was because of the consumption of jackal meat.DiscussionThese imported cases are most likely to occur in countries where the habit of eating raw meat is common and may show a high transmission in some regions where the disease is or had become unknown (e.g. Senegal, Laos, etc.). Backpackers, adventure travelers, or hunters will certainly be at a higher risk and should be informed about the risks of eating raw meat (pork, game, or reptile meat) and should be discouraged from illegally importing potentially infected meat that could introduce the parasite in Trichinella-free areas.ConclusionTravelers can be good indicators of the emergence of the parasitosis in a given country. Imported cases are good indicators of the epidemiology of the disease in countries where the original infection occurred.

High prevalence of Toxoplasma gondii oocyst shedding in stray and pet cats (Felis catus) in Virginia, United States

BackgroundThe protozoan Toxoplasma gondii is the causative agent of toxoplasmosis, with complications varying from mental disease to death. While human infection can occur via ingestion of tissue cysts from infected meat, most human infection comes from oocysts. Cats are the only definitive host, and thus shedding of oocysts by cats provides the ultimate source of toxoplasmosis.MethodsWhile most studies in the area use seroprevalence to monitor Toxoplasma incidence in cat populations, this provides only a history of infection. This study used PCR detection of oocysts from cat feces to more accurately estimate the numbers of cats producing oocysts and thus posing an active health risk. DNA sequencing was use to confirm the identity of the PCR products.ResultsOf the 49 cats tested, 9 yielded PCR products of the expected size. Six of the nine were determined by sequence analysis to be false positives, while three products were true positives. Overall, 6% of cats examined were found to be actively shedding oocysts.ConclusionsThe incidence of oocyst shedding in the cat population studied was significantly higher than expected and higher than found in most cat populations world-wide. Of equal importance, the primers tested were shown to produce PCR products of multiple sizes and non-target products of expected size. We detected false positives at a higher rate than true positives, emphasizing the need for confirmatory analysis. Further research may produce better protocols for Toxoplasma detection from cat fecal samples.

EPIZOOTIOLOGICAL CHARACTERISTICS OF TRICHINELLOSIS OF DOMESTIC PIGS IN THE REPUBLIC OF SRPSKA

Trichinellosis is parasitic disease aff ecting wildlife, domestic animals and humans, caused by the nematode of the genus Trichinella. Primary infection route is consumption of infected meat, thus trichinellosis represents a considerable health and economic problem. In the Republic of Srpska, the most common source of human infection is the meat of domestic pigs. Since recently, an increasing number of trichinellosis outbreaks have been attributed to consumption of meat of wild animals, which corresponds with the situation in other countries. During the last decade of the 20th century, numerous outbreaks involving large number of infected people have been reported. In the period 2001-2010, 1256 cases of animal trichinellosis were reported, 1166 of which were identifi ed in domestic swine. In the municipality of Bijeljina, 656 cases were reported, which makes 56.26% of the total number of domestic pig infections recorded in the Republic of Srpska. The latest fi ndings about the incidence of various Trichinella species in wild and domestic animals in Europe indicate that, regardless of application of preventive measures such as proper animal management and veterinary control of meat aft er slaughter, this disease remains the major health problem in this area.

SANEAMIENTO Y DETOXIFICACIÓN DE CARNE DE ALPACA (Vicugna pacos) CON SARCOCISTOSIS MEDIANTE TRATAMIENTOS FÍSICOS Y QUÍMICOS DE USO DOMÉSTICO

Physical and chemical methods of home use techniques for sanitation and detoxification of alpaca meat infected with macrocysts of Sarcocystis aucheniae were evaluated. The physical treatments were boiling and baking at 80 °C for 5 minutes and freezing for 10, 15 and 20 days; and the chemical treatments were salting for 15 and 30 days, and marinated for 24 hours. Dogs were fed with bouts of treated alpaca meat containing 180-200 macrocysts and the presence of oocysts were analyzed in faeces for 18 days. Besides, macrocysts lisates were injected to rabbits to evaluate the detoxifying effect of treatments on the protein content of the macrocysts. Only the physical treatments proved to be effective in sanitizing alpaca infected meat, whereas the toxin biological activity could not be altered.

Zoonotic foodborne parasites and their surveillance

Humans suffer from several foodborne helminth zoonotic diseases, some of which can be deadly (e.g., trichinellosis, cerebral cysticercosis) while others are chronic and cause only mild illness (e.g., intestinal taeniosis). The route of infection is normally consumption of the parasite's natural host as a human food item (e.g., meat). The risk for infection with these parasites is highest wherever people have an inadequate knowledge of infection and hygiene, poor animal husbandry practices, and unsafe management and disposal of human and animal waste products. The design of surveillance and control strategies for the various foodborne parasite species, and the involvement of veterinary and public health agencies, vary considerably because of the different life cycles of these parasites, and epidemiological features. Trichinella spiralis, which causes most human trichinellosis, is acquired from the consumption of pork, although increasingly cases occur from eating wild game. For cysticercosis, however, the only sources for human infection are pork (Taenia solium) or beef (T. saginata). The chief risk factor for infection of humans with these parasites is the consumption of meat that has been inadequately prepared. For the pig or cow, however, the risk factors are quite different between Trichinella and Taenia. For T. spiralis the major source of infection of pigs is exposure to infected animal meat (which carries the infective larval stage), while for both Taenia species it is human faecal material contaminated with parasite eggs shed by the adult intestinal stage of the tapeworm. Consequently, the means for preventing exposure of pigs and cattle to infective stages of T. spiralis, T. solium, and T. saginata vary markedly, especially the requirements for ensuring the biosecurity of these animals at the farm. The surveillance strategies and methods required for these parasites in livestock are discussed, including the required policy-level actions and the necessary collaborations between the veterinary and medical sectors to achieve a national reporting and control programme.

Posttransplantation Hepatitis E

In developed countries, acute hepatitis E virus (HEV) infections are increasingly reported mostly due to zoonotic genotypes 3 and 4 strains (1). Risk factors for these sporadic cases include consumption of raw or undercooked infected meat or direct contact with infected animals (1). In immunocomprom

Toxocara spp. seroprevalence in sheep from southern Brazil

Visceral toxocariasis is a neglected parasitic zoonosis that occurs through the ingestion of embryonated Toxocara spp. eggs. A wide range of animal species can act as paratenic hosts for this ascarid. The main risk factor for humans is the ingestion of the eggs from contaminated soil; however, infection can also occur through the ingestion of contaminated raw or undercooked infected meat from paratenic hosts. The aim of this study was to verify the presence of Toxocara spp.-specific antibodies in sheep and to determine the risk factors associated with the infection of sheep in Rio Grande do Sul (a major sheep-producing and sheep-consuming state) in southern Brazil. Serum samples collected from 1,642 sheep were tested using an IgG enzyme-linked immunosorbent assay based on the excretory-secretory Toxocara canis antigen. Seroprevalence was 29.0% (477/1,642), and every farm included in the study contained at least one seropositive animal. These results indicate that T. canis infection is widely distributed among sheep herds in Rio Grande do Sul and that it represents a potential risk to human health.

Fate and Transport of Toxoplasma gondii Oocysts in Seasonally Snow Covered Watersheds: A Conceptual Framework from a Melting Snowpack to the Canadian Arctic Coasts

Toxoplasma gondii is a zoonotic protozoan that causes serious illness in humans and infects animals worldwide, including the Canadian Arctic. Indeed, high prevalence of infection amongst Inuit has been recorded, possibly due to consumption of raw infected seal meat. Here we explore the hypothesis that T. gondii oocysts contaminate the coastal marine environment via surface runoff from across the boreal watershed, particularly during the snowmelt period. We propose a conceptual framework of the different processes governing the fate and transport of T. gondii oocysts from the melting snowpack to the Canadian arctic coast via the freshwater runoff. This framework identifies the feasibility of a transmission pathway of oocysts from contaminated soil to the marine environment, but also the complexity and multiplicity of mechanisms involved. In addition, the framework identifies knowledge gaps for guiding future studies on T. gondii oocysts. Furthermore, this work could be used as a tool to investigate the possible estuarine contamination by other faeces-borne pathogens transported via the spring freshet in seasonally snow covered watersheds.

PREVALENCE OFSALMONELLA ENTERICASEROVAR ALBANY IN CAPTIVE ZOO WILD ANIMALS IN THE CULIACÁN ZOO IN MEXICO

Salmonellosis is an important zoonotic disease but little is known about the role that free-living animals play as carriers of this pathogen. Moreover, the primary route of infection in the wild needs to be elucidated. The aim of this study was to determine the source and the route of transmission of Salmonella enterica serovar Albany (S. Albany) infection in captive zoo wild animals in the Culiacán Zoo. A total of 267 samples were analyzed including 220 fecal samples from zoo animals, 15 fecal samples from rodents, 5 pooled samples each of two insects (Musca domestica and Periplaneta americana), and 22 samples of animal feed. We detected S. Albany in 28 (10.5%) of the samples analyzed, including in samples from raw chicken meat. Characterization of isolates was performed by serotyping and pulsed-field gel electrophoresis. All isolates shared a single pulsed-field gel electrophoresis profile, indicating a possible common origin. These data suggest that the infected meat consumed by the wild felines was the primary source of infection in this zoo. It is likely that the pathogen was shed in the feces and disseminated by insects and rats to other locations in the zoo.

A study on the suitability of inactivated Trichinella spiralis larvae for proficiency samples

The consumption of raw or undercooked Trichinella infected meat, especially pork and horse meat, can have important implications for public health. Therefore each animal carcass from a Trichinella susceptible species intended for human consumption must be examined for Trichinella. Laboratories carrying out testing of official control samples must undergo a quality assurance program and should regularly participate in proficiency testing schemes. To date, Trichinella proficiency samples are prepared with live larvae, which, as a level 2 pathogen, require specific shipping and disinfection procedures. Therefore, the suitability of using inactivated Trichinella larvae as proficiency samples was tested. We found that Trichinella larvae treated with 2% formaldehyde for 24h had lost their infectivity and showed a comparable recovery rate to naïve larvae after artificial digestion, albeit with a prolonged sedimentation time.

Freeze-tolerance of Trichinella muscle larvae in experimentally infected wild boars

Freeze-tolerance of encapsulated Trichinella muscle larvae (ML) is mainly determined by Trichinella species, but is also influenced by host species, the age of the infection and the storage time and temperature of the infected meat. Moreover, the freeze-tolerance of the encapsulated species appears to be correlated to the development of thick capsule walls which increases with age. An extended infection period and the muscle composition in some hosts (e.g. herbivores) may provide freeze-avoiding matrices due to high carbohydrate contents. The present experiment compares freeze-tolerance of Trichinella spiralis and Trichinella britovi ML in wild boar meat 24 weeks post inoculation (wpi). Three groups of four wild boars were infected with 200, 2000 or 20,000 ML of T. britovi (ISS 1575), respectively. Additionally, three wild boars were inoculated with 20,000 ML of T. spiralis (ISS 004) and two animals served as negative controls. All wild boars were sacrificed 24 wpi. Muscle samples of 70g were stored at −21°C for 19, 30 and 56h, and for 1–8 weeks. Larvae were recovered by artificial digestion. Their mobilities were recorded using Saisam® image analysis software and their infectivities were evaluated using mouse bioassays. Samples frozen for 19, 30 and 56h allowed recovery of mobile ML, but samples frozen for 1 or 2 weeks did not. Correspondingly, only T. spiralis and T. britovi larvae isolated from wild boar meat frozen for 19, 30 and 56h established in mice. This study showed that freezing at −21°C for 1 week inactivated T. spiralis and T. britovi ML encapsulated in wild boar meat for24 weeks.

Comparison of multiplex polymerase chain reaction and immunoassay to detect Salmonella spp., S. Typhimurium, and S. Enteritidis in Thai chicken meat

The multiplex PCR (mPCR), enzyme-linked immunosorbent assay (ELISA) and immunomagnetic separation enzyme-linked immunosorbent assay (IMS-ELISA) were developed for the detection of Salmonella spp. and two specific serovars S. Typhimurium and S. Enteritidis. The detection limits of the mPCR without the pre-enriched step was at 10 5 cfu/ml, whereas developed immunoassays demonstrated positive results at 10 5 , 10 6 , and 10 7 cfu/ml by ELISA and at 10 4 , 10 4 , and 10 6 cfu/ml by IMS-ELISA for detecting Salmonella spp., S. Typhimurium, and S. Enteritidis, respectively. The mPCR did not produce any nonspecific amplified products when tested against other related species of bacteria. In this study, the developed IMS-ELISA gave more sensitivity but less specificity than the mPCR assay. The methods are useful for the rapid detection of salmonellae in naturally infected chicken meat in Thailand.

Larvas output and influence of human factor in reliability of meat inspection by the method of artificial digestion

On the basis of the performed analyses of the factors that contributed the infected meat reach food chain, we have found out that the infection occurred after consuming the meat inspected by the method of collective samples artificial digestion by using a magnetic stirrer (MM). In this work there are presented assay results which show how modifications of the method, on the level of final sedimentation, influence the reliability of Trichinella larvas detection in the infected meat samples. It has been shown that use of inadequate laboratory containers for larva collecting in final sedimentation and change of volume of digestive liquid that outflow during colouring preparations, can significantly influence inspection results. Larva detection errors ranged from 4 to 80% in presented the experimental groups in regard to the control group of samples inspected by using MM method, which had been carried out completely according to Europe Commission procedure No 2075/2005, where no errors in larva number per sample was found. We consider that the results of this work will contribute to the improvement of control of the method performance and especially of the critical point during inspection of meat samples to Trichinella larvas in Serbia.

First report of Trichinella pseudospiralis in Poland, in red foxes (Vulpes vulpes)

Nematode worms of the genus Trichinella are one of the most widespread zoonotic pathogens. Natural transmission between hosts can only occur through the ingestion of infected meat. To date, two Trichinella species are known to be etiological agents of disease among domestic animals and wildlife in Poland: T. spiralis and T. britovi. In the last decades, since the administration of an oral vaccination against rabies, the red fox population in Poland has increased exponentially. The study area covers the Nowy Targ region: a mountainous area (585-1138 m above the sea) in southern Poland. Of 24 red foxes examined in the study, four were infected with Trichinella isolates: three were identified as T. britovi and one as T. pseudospiralis. The muscle of red foxes infected with T. britovi harboured 2.75, 3.11, 4.4 LPG and with T. pseudospiralis 0.36 LPG. Trichinella larvae were identified at species level by genomic and mitochondrial multiplex PCR, the products of which were sequenced for comparison with other sequences available in GenBank. The sequences obtained from the Polish T. pseudospiralis isolate, deposited in GenBank under the accession numbers JQ809660.1 and JQ809661.1, matched sequences already published in GenBank. Sequence comparison showed a 100% match with the large subunit ribosomal RNA gene of T. pseudospiralis isolate ISS 013, and a 96-95% match with those of T. pseudospiralis isolates ISS 141 and ISS 470. This is the first report of the identification of T. pseudospiralis larvae from red fox in Poland.