Could a ring treatment approach be proposed to control Taenia solium transmission in a post elimination setting? A pilot study in Zambia.

BACKGROUND: Geographically targeted Taenia solium ring approaches consisting of treating individuals within a radius of 100-meter of a cysticercosis positive pig have been trialled in Peru. This study explored if a similar approach could be proposed to control T. solium transmission in a post elimination setting in Zambia, focussing on community members' willingness to be sampled and treated. METHODOLOGY AND PRINCIPAL FINDINGS: The study was conducted in a community where elimination of active T. solium transmission was achieved. All eligible pigs and people were sampled, at 4- to 6-monthly intervals, followed by implementation of the ring treatment approach. This implied that whenever a pig was seropositive for cysticercosis during sampling, every human and pig residing in a radius of 50-meters of the seropositive pig would be treated. The results of the positive human stool samples were used to create the rings, whenever no pigs were positive. From June 2018 to October 2019, four samplings, followed by ring treatments were conducted. Between 84% and 91% of the willing people provided a stool sample, covering 46% to 59% of the total population living in the study area. Between 78% and 100% of the eligible pigs got sampled. Three ring treatments were based on porcine seropositivity and one on taeniosis results. Two to four rings were opened per sampling. During the ring treatments, between 89% and 100% of the eligible human and pig population living within a ring was treated. CONCLUSIONS: Participants were willing to participate and get treatment, once the rings were opened. However, the utility of ring treatment approaches in a post elimination setting needs further evaluation, given the lack of highly accurate diagnostic tools for porcine cysticercosis and the challenges in obtaining stool samples. The ring treatment approach adopted should be further improved before recommendations to public health authorities can be given.

Occurrence and identification of lungworms in Iranian wild boars.

This study represents the first investigation into the occurrence and identification of Metastrongylus spp. in wild boars (Sus scrofa) in Iran, utilizing both molecular and morphological methods. Thirteen wild boars from Kerman Province were examined, with 92.3% found to be infected with at least one species of Metastrongylus. Mixed infections were observed in 38.46% of the animals. Morphological and molecular analyses confirmed the presence of M. pudendotectus and M. salmi, with prevalence rates of 76.9% and 53.9%, respectively. Histopathological examination revealed transverse and longitudinal sections of Metastrongylus parasites within the airways, causing partial to complete obstruction, interstitial pneumonia, and inflammatory responses. The study also highlights the public health significance of these parasites. The higher prevalence observed compared to earlier studies suggests changes in environmental conditions, host dynamics, or agricultural practices as possible factors, warranting further investigation. The findings underscore the need for comprehensive surveillance and control measures to mitigate the risk of zoonotic transmission, particularly in regions with significant wild and domestic swine populations. This study contributes to the understanding of Metastrongylus spp. distribution and their pathological impact, emphasizing the ecological importance of wild boars and the necessity for continued monitoring and research to prevent and control infections in both animal and human populations.

Epidemiology and distribution of gastrointestinal parasites in fattening pig farms in northern Italy.

In Italy, pig breeding is characterised by intensive farms in which parasitic diseases often present a subclinical pattern, while being responsible for decreased animal welfare and great economic losses. The present study aimed to assess the prevalence of major parasites in pigs, and, for this purpose, 880 faecal samples of fattening pigs raised in 22 intensive farms located in northern Italy were collected in two different sampling sessions, at the beginning and end of the fattening cycle. For the detection of helminth eggs and coccidian oocysts, a quantitative flotation technique was used, whereas a conventional PCR was performed to confirm the identification of cestode eggs found by copromicroscopic analysis. Moreover, data regarding herd management were collected to assess risk factors for parasite occurrence. A total of 95 samples were positive for at least one parasitic taxon (10.8%); the most detected parasite was Ascaris suum (7.6%), followed by Trichuris suis (1.7%) and Cystoisospora suis (0.9%). Further, eggs with morphometric features compatible with those of Hymenolepis diminuta were detected in 16 samples (1.8%), and the analysis of sequences confirmed the identification of cestode eggs. Statistical analysis showed that large farms and those applying the all-in/all-out system were associated with a lower risk of nematode infection. This study provided data on prevalence and burden of gastrointestinal parasites in two different times of the fattening cycle. It was evidenced that endoparasites are persistent, albeit with low prevalences, and would need specific measures to reduce their effects on both animal health and productivity.

Epidemiological factors conditioning sarcoptic mange spreading in wild boar (Sus scrofa).

Sarcoptic mange is a widely distributed disease, with numerous potential hosts among domestic and wild animals. Nowadays it is considered a neglected re-emergent infection in humans. As a difference with domestic pigs, and even with several clinical cases reported in some European countries, it seems that Eurasian wild boars (Sus scrofa) have a low susceptibility to clinical mange. However, because of a case of confirmed transmission from Spanish ibex (Capra pyrenaica) to wild boar in the province of Tarragona, we planned a large-scale ELISA survey in the neighboring Valencian Community (SE Spain). We compared 419 wild boar sera from different management systems (fenced vs. open game estates), different ages (piglets, juveniles, and adults), with different behaviour (gregarious females of all ages and male piglets vs. solitary juveniles and adult males), from areas with different wild boar densities, different wild ruminant densities and different sarcoptic mange epidemiologic situations. The whole prevalence of antibodies against sarcoptic mange in the tested wild boars was 10.5%. No significant differences were found when comparing fenced and free ranging wild boars, males and females, gregarious vs. solitary individuals or among different ages. However, wild boar density was a relevant factor. In areas with a hunting bag of <1 wild boar/km2, considered as a low density of suids, the seroprevalence was 2.94%, but rose to 11.52% in high density districts, constituting a significant difference (p = 0.037). Low wild boar populations would act as a protective factor (OR 0.233; p = 0.049) against coming into contact with the mite. The wild ruminant densities or their sarcoptic mange status did not show any effect on wild boars seroprevalence against this disease. These results reinforce the suggested host-taxon Sarcoptes scabiei specificity and the independence of host-species foci.

Combination of an enzyme-linked immunosorbent assay and an indirect fluorescence assay for a nationwide sero-survey of Toxoplasma gondii infection in pig herds in Taiwan.

Toxoplasma gondii is a zoonotic pathogen that can infect farm animals, companion animals, and humans, sometimes causing public health issues. In Taiwan, the pig industry is a vital agricultural industry, with a self-sufficiency rate of 91 %, and pigs are also food-producing animal reservoirs of Toxoplasma gondii. Infected pigs are usually asymptomatic, and abortions and death may occur in severe cases. We combined an enzyme-linked immunosorbent assay (ELISA) and an indirect fluorescence assay (IFA) to investigate the seroprevalence of Toxoplasma gondii among pig populations in Taiwan. A stratified sampling approach to determine the number of sample farms proportional to the number of pig farms in each county was employed, with 15 blood samples collected at each farm between July and September 2017. With the tested results, empirical Bayesian smoothing was utilized to assess the proportion of Toxoplasma-positive farms at the county level. Bayesian mixed-effects logistic regression models, incorporating farm and county as random effects, were employed to investigate associations between Toxoplasma test results and potential risk factors. A total of 930 serum samples from 62 pig farms were collected and tested. An overall herd prevalence of 27.4 % was shown with the seroprevalence in northern Taiwan being greater than that in southern Taiwan. The sampling month and companion dog density in 2017 were significantly associated with Toxoplasma infections in pigs. With every increase in the number of companion dogs per km² at the county level, the odds of Toxoplasma infection in pigs increased by 4.7 % (95 % CI: 1.7-8.9 %). This study demonstrated that combining ELISA for screening with IFA for confirmation is a cost-effective and time-saving method for conducting a large-scale sample investigation. This was also the first nationwide, cross-sectional study in Taiwanese pig herds to investigate Toxoplasma gondii infection.

Pig Acute Phase Proteins as Non-Antibody Systemic Biomarkers of Intracellular Infections.

As an alternative to traditional serological markers, that is, antibodies, for serum-based specific diagnosis of infections, circulating non-antibody markers may be used to monitor active disease. Acute phase proteins (APPs) are a prominent class of such markers widely used for diagnosing ongoing inflammation and infection. In this chapter, basic theoretical and practical considerations on developing APP assays and using APPs as markers of ongoing infection are presented with a specific focus on intracellular infections in pigs. Examples on APP-based monitoring of infection in pigs with viruses such as porcine respiratory and reproductive syndrome virus (PRRSV), porcine endemic diarrhea virus (PEDV), and influenza A virus (IAV), as well as intracellular bacteria (Lawsonia intracellularis) and the protozoan intracellular parasites Toxoplasma gondii and Cryptosporidium parvum are presented, with an emphasis on major pig APPs C-reactive protein (CRP), haptoglobin, serum amyloid A (SAA), and pig major acute phase protein (pig-MAP). The performance of these APPs as biomarkers in a range of experimental infection studies in pigs is described as examples on their use for estimating the severity of infection, vaccine efficacy, herd health characterization, and differential diagnosis.

Acute Ascaris infection impairs the effector functions of natural killer cells in single and Salmonella co-infected pigs.

Natural killer (NK) cells play a key role in defense against Salmonella infections during the early phase of infection. Our previous work showed that the excretory/secretory products of Ascaris suum repressed NK activity in vitro. Here, we asked if NK cell functionality was influenced in domestic pigs during coinfection with Ascaris and Salmonella enterica serotype Typhimurium. Ascaris coinfection completely abolished the IL-12 and IL-18 driven elevation of IFN-γ production seen in CD16 + CD8α + perforin + NK cells of Salmonella single-infected pigs. Furthermore, Ascaris coinfection prohibited the Salmonella-driven rise in NK perforin levels and CD107a surface expression. In line with impaired effector functions, NK cells from Ascaris-single and coinfected pigs displayed elevated expression of the inhibitory KLRA1 and NKG2A receptors genes, contrasting with the higher expression of the activating NKp46 and NKp30 receptors in NK cells during Salmonella single infection. These differences were accompanied by the highly significant upregulation of T-bet protein expression in NK cells from Ascaris-single and Ascaris/Salmonella coinfected pigs. Together, our data strongly indicate a profound repression of NK functionality by an Ascaris infection which may hinder infected individuals from adequately responding to a concurrent bacterial infection.

Infection dynamics following experimental challenge of pigs orally dosed with different stages of two archetypal genotypes of Toxoplasma gondii.

Toxoplasma gondii is a food-borne zoonotic parasite widespread in a variety of hosts, including humans. With a majority of infections in Europe estimated to be meat-borne, pork, as one of the most consumed meats worldwide, represents a potential risk for consumers. Therefore, we aimed to investigate the progress of T. gondii infection and tissue tropism in experimentally infected pigs, using different T. gondii isolates and infectious stages, i.e. tissue cysts or oocysts. Twenty-four pigs were allocated to treatment in four groups of six, with each group inoculated orally with an estimated low dose of either 400 oocysts or 10 tissue cysts of two European T. gondii isolates, a type II and a type III isolate. The majority of pigs seroconverted two weeks post-inoculation. Pigs infected with the type III isolate had significantly higher levels of anti-T. gondii antibodies compared to those infected with the type II isolate. Histopathological exams revealed reactive hyperplasia of the lymphatic tissue of all pigs. Additionally, a selected set of nine tissues was collected during necropsy at 50 dpi from each of the remaining 22 pigs for T. gondii DNA detection by quantitative real-time PCR. A positive result was obtained in 29.8 % (59/139) of tested tissues. The brain was identified as the most frequently positive tissue in 63.6 % (14/22) of the animals. In contrast, liver samples tested negative in all animals. The highest mean parasite load, calculated by interpolating the average Cq values on the standard curve made of ten-fold serial dilutions of the genomic DNA, corresponding to 100 to 104 tachyzoites/µL, was observed in shoulder musculature with an estimated concentration of 84.4 [0.0-442.5] parasites per gram of tissue. The study highlights the variability in clinical signs and tissue distribution of T. gondii in pigs based on the combination of parasite stages and strains, with type III isolates, particularly oocysts, causing a stronger antibody response and higher tissue parasite burden. These findings suggest the need for further investigation of type III isolates to better understand their potential risks to humans.

First findings of Sarcocystis species in game deer and feral pigs in Australia.

Several wild game meat species, including deer and feral pigs are hunted and consumed in Australia. Feral pigs and deer are not indigenous to Australia, but they have proliferated extensively and established their presence in every state and territory. Following the report of a sambar deer displaying Sarcocystis like white cysts in its rump muscles, the present study was conducted to explore the prevalence of Sarcocystis infections in wild deer and feral pigs in the southeastern regions of Australia. Oesophagus, diaphragm, and heart tissue from 90 deer and eight feral pigs were examined visually for sarcocysts. All results were negative. PCR testing of randomly selected deer and feral pigs yielded positive results, which were subsequently supported by histopathology. This is the first study to report the presence of Sarcocystis spp. in deer and feral pigs in Australia. As no visual cysts were found on the heart or oesophagus that came back positive with PCR, infected animals, particularly those reared free-range, could be passing through meat quality checks unidentified. If people consume this meat without cooking it properly, it may lead to a human infection of Sarcocystis. However, a more targeted study focused on determining the parasite's prevalence and assessing its risks is necessary to determine if it constitutes a food safety issue. As this species has been found not only in feral pigs but also in domestic pigs, the potential for infection spreading between feral pigs and pigs in free-range livestock systems is high, potentially posing a large problem for the Australian pork industry, particularly with the increased emphasis on free-range pig husbandry. Future studies should concentrate on determining the species of Sarcocystis in feral animals commonly consumed as game meat to determine potential zoonotic risks. This could also include a more in-depth look at the prevalence of Sarcocystis infections in other game animals. Identifying where these parasites are present and to what extent, are important areas for future studies.

Disseminated Sarcocystis miescheriana infection in a finisher pig in Grenada.

Sarcocystis miescheriana infection is an important cause of carcass condemnation during meat inspection. The infection can cause morbidity and mortality in domestic pigs. In this study, an 8-month-old finisher pig was presented to a local abattoir for slaughter. Multiple white nodular lesions affecting the meat were observed, resulting in the condemnation of the carcass. Consequently, half of the carcass was submitted to the necropsy diagnostic laboratory in the School of Veterinary Medicine for further evaluation. Grossly, all superficial and deep muscle groups had severe multifocal macrocysts (3 mm × 2 mm × 1 mm) on the surface and extending deep into the skeletal musculature. Histopathology revealed moderate multifocal granulomatous and eosinophilic myositis with intralesional degenerated and intact parasites. Sample genomic DNA sequence analysis of the 18S RNA gene showed 100% identity to S. miescheriana in the GenBank. This is the first report of S. miescheriana in Grenada, West Indies.

Microscopic detection and molecular characterization of Sarcocystis miescheriana in wild boars (Sus scrofa): first report from Greece.

The genus Sarcocystis includes protozoan parasites with an indirect life cycle. Sarcocystis spp. can infect various animal species and humans, causing sarcocystosis, a parasitosis of economic importance and zoonotic concern. Wild boars can act as intermediate hosts for Sarcocystis miescheriana and the zoonotic Sarcocystis suihominis that infects humans by consumption of raw or undercooked infected swine meat. In the present study, the diaphragmatic muscle tissue of 123 wild boars hunted in Greece was examined to determine the frequency of Sarcocystis spp. The samples were examined by tissue compression and molecular techniques. Under light microscopy, 34 out of 123 (27.6%) wild boars tested positive for Sarcocystis spp., while a higher infection prevalence (75%) was revealed by multiplex PCR performed in 100 of the samples. The partial mtDNA cox1 gene (~ 1100 bp) of 20 samples tested positive for S. miescheriana by multiplex PCR was amplified and sequenced. Sarcocystis miescheriana was identified as the only species involved in these infections. This is the first study on the prevalence of Sarcocystis spp. in wild animals in Greece. Further, large-scale surveys are needed to assess the prevalence and species of this parasite in Greece and to design efficient control and preventive measures in a One Health perspective.

First report of Echinococcus granulosus genotype 1 in a wild boar (Sus scrofa) from China.

Echinococcosis is a worldwide disease endemic to the western region of China. In 2023, echinococcosis was detected in one of 27 wild boars (Sus scrofa) in Yili Prefecture, Xinjiang, northwestern China. Histopathological staining and full sequence mitochondrial (mt) analysis were used to determine the infection genotype. Echinococcus granulosus was detected in the wild boar liver, and the cystic lesion characteristics indicated the E. granulosus genotype (G1). This case is the first confirmation of wild boar serving as a transmitter for the G1 genotype of E. granulosus within China. These findings suggest that surveillance is needed to assess the risk of E. granulosus sensu lato transmission to humans and wild animals.

Complete sequencing of the Cryptosporidium suis gp60 gene reveals a novel type of tandem repeats-Implications for surveillance.

Cryptosporidiosis is an infectious enteric disease caused by species (some of them zoonotic) of the genus Cryptosporidium that in many countries are under surveillance. Typing assays critical to the surveillance of cryptosporidiosis typically involve characterization of Cryptosporidium glycoprotein 60 genes (gp60). Here, we characterized the gp60 of Cryptosporidium suis from two samples-a human and a porcine faecal sample-based on which a preliminary typing scheme was developed. A conspicuous feature of the C. suis gp60 was a novel type of tandem repeats located in the 5' end of the gene and that took up 777/1635 bp (48%) of the gene. The C. suis gp60 lacked the classical poly-serine repeats (TCA/TCG/TCT), which is usually subject to major genetic variation, and the length of the tandem repeat made a typing assay incorporating this region based on Sanger sequencing practically unfeasible. We therefore designed a typing assay based on the post-repeat region only and applied it to C. suis-positive samples from suid hosts from Norway, Denmark, and Spain. We were able to distinguish three different subtypes; XXVa-1, XXVa-2, and XXVa-3. Subtype XXVa-1 had a wider geographic distribution than the other subtypes and was also observed in the human sample. We think that the present data will inform future strategies to develop a C. suis typing assay that could be even more informative by including a greater part of the gene, including the tandem repeat region, e.g., by the use of long-read next-generation sequencing.

A combination of GRA3, GRA6 and GRA7 peptides offer a useful tool for serotyping type II and III Toxoplasma gondii infections in sheep and pigs.

The clinical consequences of toxoplasmosis are greatly dependent on the Toxoplasma gondii strain causing the infection. To better understand its epidemiology and design appropriate control strategies, it is important to determine the strain present in infected animals. Serotyping methods are based on the detection of antibodies that react against segments of antigenic proteins presenting strain-specific polymorphic variations, offering a cost-effective, sensitive, and non-invasive alternative to genotyping techniques. Herein, we evaluated the applicability of a panel of peptides previously characterized in mice and humans to serotype sheep and pigs. To this end, we used 51 serum samples from experimentally infected ewes (32 type II and 19 type III), 20 sheep samples from naturally infected sheep where the causative strain was genotyped (18 type II and 2 type III), and 40 serum samples from experimentally infected pigs (22 type II and 18 type III). Our ELISA test results showed that a combination of GRA peptide homologous pairs can discriminate infections caused by type II and III strains of T. gondii in sheep and pigs. Namely, the GRA3-I/III-43 vs. GRA3-II-43, GRA6-I/III-213 vs. GRA6-II-214 and GRA6-III-44 vs. GRA6-II-44 ratios showed a statistically significant predominance of the respective strain-type peptide in sheep, while in pigs, in addition to these three peptide pairs, GRA7-II-224 vs. GRA7-III-224 also showed promising results. Notably, the GRA6-44 pair, which was previously deemed inefficient in mice and humans, showed a high prediction capacity, especially in sheep. By contrast, GRA5-38 peptides failed to correctly predict the strain type in most sheep and pig samples, underpinning the notion that individual standardization is needed for each animal species. Finally, we recommend analyzing for each animal at least 2 samples taken at different time points to confirm the obtained results.

The Transmission of Animal African Trypanosomiasis in Two Districts in the Forest Zone of Ghana.

Animal African trypanosomiasis, also known as nagana, is caused by Trypanosoma species, which cause significant clinical diseases and lead to losses in animal production. We carried out a cross-sectional survey to investigate the composition of vectors and parasite diversity in two districts in the eastern region of Ghana where pigs and cattle were exposed to tsetse bites. We performed cytochrome c oxidase subunit 1 polymerase chain reaction (PCR) to identify tsetse species and internal transcribed spacer 1 PCR to identify Trypanosoma species. Also, we investigated the source of tsetse blood meal based on mitochondrial cytochrome b gene sequence analysis. A total of 229 tsetse, 65 pigs, and 20 cattle were investigated for trypanosomes. An overall vector density of 4.3 tsetse/trap/day was observed. A trypanosome prevalence of 58.9% (95% CI = 52.5-65.1%), 46.2% (95% CI = 34.6-58.1%), and 0.0% (95% CI = 0.0-16.1%) in tsetse, pigs, and cattle, respectively, was detected. Trypanosoma congolense was predominant, with a prevalence of 33.3% (95% CI = 73.3-86.5%) in tsetse. There was evidence of multiple infections in tsetse and pigs. Approximately 39% of the tsetse were positive for multiple infections of T. congolense and Trypanosoma simiae. Parasite prevalence in pigs across the communities was high, with significant differences associated between locations (χ2 = 28.06, 95% CI = 0.05-0.81, P = 0.0009). Tsetse blood meal analysis revealed feeding on domestic Sus scrofa domesticus (pigs) and Phacochoerus africanus (warthogs). Infective tsetse may transmit trypanosomes to livestock and humans in the communities studied.

Alleviating Pentatrichomonas hominis-induced damage in IPEC-J2 cells: the beneficial influence of porcine-derived lactobacilli.

Pentatrichomonas hominis is a common intestinal parasitic protozoan that causes abdominal pain and diarrhea, and poses a zoonotic risk. Probiotics, known for enhancing immunity and pathogen resistance, hold promise in combating parasitic infections. This study aimed to evaluate two porcine-derived probiotics, Lactobacillus reuteri LR1 and Lactobacillus plantarum LP1, against P. hominis infections in pigs. Taxonomic identity was confirmed through 16 S rRNA gene sequencing, with L. reuteri LR1 belonging to L. reuteri species and L. plantarum LP1 belonging to L. plantarum species. Both probiotics exhibited robust in vitro growth performance. Co-culturing intestinal porcine epithelial cell line (IPEC-J2) with these probiotics significantly improved cell viability compared with the control group. Pre-incubation probiotics significantly enhanced the mRNA expression of anti-oxidative response genes in IPEC-J2 cells compared with the PHGD group, with L. reuteri LR1 and L. plantarum LP1 significantly up-regulating CuZn-SOD、CAT and Mn-SOD genes expression (p < 0.05). The anti-oxidative stress effect of L. reuteri LR1 was significantly better than that of L. plantarum LP1 (p < 0.05). Furthermore, pre-incubation with the probiotics alleviated the P. hominis-induced inflammatory response. L. reuteri LR1 and L. plantarum LP1 significantly down-regulated IL-6、IL-8 and TNF-α gene expression(p < 0.05) compared with the PHGD group. The probiotics also mitigated P. hominis-induced apoptosis. L. reuteri LR1 and L. plantarum LP1 significantly down-regulated Caspase3 and Bax gene expression (p < 0.05), significantly up-regulated Bcl-2 gene expression (p < 0.05) compared with the PHGD group. Among them, L. plantarum LP1 showed better anti-apoptotic effect. These findings highlight the probiotics for mitigating P. hominis infections in pigs. Their ability to enhance anti-oxidative responses, alleviate inflammation, and inhibit apoptosis holds promise for therapeutic applications. Simultaneously, probiotics can actively contribute to inhibiting trichomonal infections, offering a novel approach for preventing and treating diseases such as P. hominis. Further in vivo studies are required to validate these results and explore their potential in animal and human health.

Worldwide absence of canonical benzimidazole resistance-associated mutations within ß-tubulin genes from Ascaris.

BACKGROUND: The giant roundworm Ascaris is an intestinal nematode, causing ascariasis by infecting humans and pigs worldwide. Recent estimates suggest that Ascaris infects over half a billion people, with chronic infections leading to reduced growth and cognitive ability. Ascariasis affects innumerable pigs worldwide and is known to reduce production yields via decreased growth and condemnation of livers. The predominant anthelminthic drugs used to treat ascariasis are the benzimidazoles. Benzimidazoles interact with ß-tubulins and block their function, and several benzimidazole resistance-associated mutations have been described in the ß-tubulins of ruminant nematodes. Recent research on ascarids has shown that these canonical benzimidazole resistance-associated mutations are likely not present in the ß-tubulins of Ascaris, Ascaridia or Parascaris, even in phenotypically resistant populations. METHODS: To further determine the putative absence of key ß-tubulin polymorphisms, we screened two ß-tubulin isotypes of Ascaris, highly expressed in adult worms. Using adult and egg samples of Ascaris obtained from pigs and humans worldwide, we performed deep amplicon sequencing to look for canonical resistance-associated mutations in Ascaris ß-tubulins. Subsequently, we examined these data in closer detail to study the population dynamics of Ascaris and genetic diversity within the two isotypes and tested whether genotypes appeared to partition across human and pig hosts. RESULTS: In the 187 isolates, 69 genotypes were found, made up of eight haplotypes of ß-tubulin isotype A and 20 haplotypes of isotype B. Single nucleotide polymorphisms were seen at 14 and 37 positions for ß-tubulin isotype A and isotype B, respectively. No evidence of any canonical benzimidazole resistance-associated mutations was found in either human- or pig-derived Ascaris isolates. There was, however, a difference in the genetic diversity of each isotype and distribution of ß-tubulin genotypes between human- and pig-derived Ascaris. Statistical tests of population differentiation show significant differences (p < 0.001) between pig- and human-derived worms; however, more diversity was seen between worms from different populations than worms from different hosts. CONCLUSIONS: Our work suggests an absence of canonical ß-tubulin mutations within Ascaris, but alternative modes of anthelminthic resistance may emerge necessitating continued genetic scrutiny alongside monitoring of drug efficacy.

Development and evaluation of time-resolved rapid immunofluorescence test for detection of TSOL18 specific antibody in porcine cysticercosis infections.

BACKGROUND: Porcine cysticercosis, a serious zoonotic parasitic disease, is caused by the larvae of Taenia solium and has been acknowledged by the World Organization for Animal Health. The current detection methods of Cysticercus cellulosae cannot meet the needs of large-scale and rapid detection in the field. We hypothesized that the immunofluorescence chromatography test strip (ICS) for detecting Cysticercus cellulosae, according to optimization of a series of reaction systems was conducted, and sensitivity, specificity, and stability testing, and was finally compared with ELISA. This method utilizes Eu3+-labeled time-resolved fluorescent microspheres (TRFM) coupled with TSOL18 antigen to detect TSOL18 antibodies in infected pig sera. RESULTS: ICS and autopsy have highly consistent diagnostic results (n = 133), as determined by Cohen's κ analysis (κ = 0.925). And the results showed that the proposed ICS are high sensitivity (0.9459) with specificity (0.9792). The ICS was unable to detect positive samples of other parasites. It can be stored for at least six months at 4℃. CONCLUSIONS: In summary, we established a TRFM-ICS method with higher sensitivity and specificity than indirect ELISA. Results obtained from serum samples can be read within 10 min, indicating a rapid, user-friendly test suitable for large-scale field detection.

Ascaris suum infection in juvenile pigs elicits a local Th2 response in a setting of ongoing Th1 expansion.

Ascaris spp. undergo extensive migration within the body before establishing patent infections in the small intestinal tract of humans and pigs. However, whether larval migration is critical for inducing efficient type 2 responses remains poorly understood. Therefore, we investigated systemic versus local adaptive immune responses along the hepato-tracheal migration of Ascaris suum during primary, single infections in conventionally raised pigs. Neither the initial invasion of gut tissue nor migration through the liver resulted in discernable Th2 cell responses. In contrast, lung-stage larvae elicited a Th2-biased pulmonary response, which declined after the larvae had left the lungs. In the small intestine, we observed an accumulation of Th2 cells upon the arrival of fourth-stage larvae (L4) to the small intestinal lumen. In parallel, we noticed robust and increasing Th1 responses in circulation, migration-affected organs, and draining lymph nodes. Phenotypic analysis of CD4+ T cells specifically recognizing A. suum antigens in the circulation and lung tissue of infected pigs confirmed that the majority of Ascaris-specific T cells produced IL-4 (Th2) and, to a much lesser extent, IL-4/IFN-g (Th2/1 hybrids) or IFN-g alone (Th1). These data demonstrate that lung-stage but not the early liver-stage larvae lead to a locally restricted Th2 response. Significant Th2 cell accumulation in the small intestine occurs only when L4 complete the body migration. In addition, Th2 immunity seems to be hampered by the concurrent, nonspecific Th1 bias in growing pigs. Together, the late onset of Th2 immunity at the site of infection and the Th1-biased systemic immunity likely enable the establishment of intestinal infections by sufficiently large L4 stages and pre-adult worms, some of which resist expulsion mechanisms.

Serology survey of Ascaris suum and Trichinella spiralis in rural pigs in Southwestern Mexico.

BACKGROUND: Parasitic diseases of pigs are a public and veterinary health problem. Helminths influence pork production, whereas backyard pigs can transmit these parasites. OBJECTIVES: This work aimed to investigate the prevalence of antibodies against Ascaris suum and Trichinella spiralis in backyard pigs from Jamiltepec, Region de la Costa, Oaxaca, in Southwestern Mexico. METHODS: Six hundred sixty-four serum samples were obtained from backyard pigs from 23 rural villages distributed in 5 municipalities; samples were taken in a non-probabilistic manner with the owner's consent. The presence of serum antibodies against a total extract of A. suum adult worm was determined by ELISA. In contrast, antibodies to the excretion-secretion products of the T. spiralis muscle larva were determined by Western blot. RESULTS: The global seroprevalence for A. suum was 5.12% and 2.41% for T. spiralis; however, antibodies were only found in 8 villages and distributed in 3 municipalities. The highest frequency of positivity for Ascaris was found in the municipality of Santa Catarina Mechoacán (13.01%), whereas, in Santa María Huazalotitlán, the highest frequency of positivity for Trichinella was found (5.75%). In San Andrés, frequencies were 7.23% and 4.82%, respectively. No statistical differences were observed between populations. CONCLUSIONS: Our data suggest that helminth transmission is restricted by locality. However, further studies must be conducted to understand the factors limiting this transmission to promote pork meat production in parasite-free zones.