Development of two recombinant vaccines against Clostridioides difficile infection and immunogenicity in pregnant sows and neonatal piglets.

INTRODUCTION: Clostridioides difficile is the main cause of antibiotic-associated diarrhea in humans and is a major enteropathogen in several animal species. In newborn piglets, colonic lesions caused by C. difficile A and B toxins (TcdA and TcdB, respectively) cause diarrhea and significant production losses. OBJECTIVE: The present study aimed to develop two recombinant vaccines from immunogenic C-terminal fragments of TcdA and TcdB and evaluate the immune response in rabbits and in breeding sows. Two vaccines were produced: bivalent (rAB), consisting of recombinant fragments of TcdA and TcdB, and chimeric (rQAB), corresponding to the synthesis of the same fragments in a single protein. Groups of rabbits were inoculated with 10 or 50 µg of proteins adjuvanted with aluminum or 0.85 % sterile saline in a final volume of 1 mL/dose. Anti-TcdA and anti-TcdB IgG antibodies were detected in rabbits and sows immunized with both rAB and rQAB vaccines by ELISA. The vaccinated sows were inoculated intramuscularly with 20 µg/dose using a prime-boost approach. RESULTS: Different antibody titers (p ≤ 0.05) were observed among the vaccinated groups of sows (rAB and rQAB) and control. Additionally, newborn piglets from vaccinated sows were also positive for anti-TcdA and anti-TcdB IgGs, in contrast to control piglets (p ≤ 0.05). Immunization of sows with the rQAB vaccine conferred higher anti-TcdA and anti-TcdB responses in piglets, suggesting the superiority of this compound over rAB. CONCLUSION: The synthesized recombinant proteins were capable of inducing antibody titers against C. difficile toxins A and B in sows, and were passively transferred to piglets through colostrum.

Assessment of Brazil's vesicular syndrome surveillance system: Profile of notifications and performance of the official veterinary service.

Foot-and-mouth disease (FMD) is an ailment that causes serious damage to the productive chain, and its control through vaccination is of utmost importance for its eradication. Brazil initiated the National Foot-and-Mouth Disease Surveillance Program (PNEFA) with the aim of making the country FMD-free by 2026. As part of the program, notifications of vesicular lesions became mandatory for the Official Veterinary Service (OVS), which is responsible for verifying them. Due to its size, border areas with countries that do not have FMD-free status pose a risk to Brazil and require greater attention. This study described the profile of notifications of suspected outbreaks of vesicular syndrome in Brazil and analyzed the performance of the surveillance system. The results showed 7134 registered notifications of suspected vesicular syndrome outbreaks from 2018 to 2022, with 2022 having the highest number (n = 2343 or 32.85 %). The species that generated the most notifications were swine (90.99 %), cattle and buffaloes (7.54 %), goats and sheep (1.44 %), and others (0.03 %). The sources of notification were "Veterinary medicine professionals" (61.82 %), "Owners or employees" (13.66 %), "Third parties" (8.90 %), "OVS" (7.20 %), and "others" (2.66 %). 41.69 % of notifications originated from non-border municipalities, and 58.32 % from border areas. Only the state of Paraná account for 51.73 % of the total notifications. This state also accounted for 66.70 % of the 32.47 % of notifications with a final diagnosis of "absence of clinically compatible signs or susceptible animals", indicating a certain lack of knowledge in the area, leading to unnecessary notifications and system overload. The performance of the OVS was evaluated based on the service response time from notification registration trough Logistic and Negative binomial regressions. A total of 27.83 % of notifications did not meet the Brazilian legally specified time, and the zone related to the state of Parana needs improvements in performance. The presence and peaks of Senecavirus A cases may have influenced an increased number of swine notifications and led to a decrease in OVS response time. The results demonstrate better performance of surveillance in border areas. Given the vast territory of Brazil, it is not expected that 100 % of responses occur within the legal timeframe, however, the performance of the surveillance system proved to be adequate, with 86 % complied to the legislation. The performance indicators could be used as a monitoring tool, along with indicators to demonstrate system overload. Continued education actions are crucial for strengthening PNEFA.

Ultra-diluted complex additive in the diet reveals benefits in the intestinal tract of nursery-phase piglets.

This study aimed to assess an ultra-diluted (UD) complex, as a replacement for an antimicrobial growth promoter in diets, on growth performance, intestinal health, and inflammatory response of nursery piglets. The experiment lasted 37 days and involved 126 animals weaned at 21 ± 1.3 d, with an initial body weight of 5.62 ± 1.16 kg. Piglets were assigned to six dietary treatments in a randomized block design with seven replicates and three piglets per pen as experimental unit. The treatments were: positive control (PC)- basal diet + 120 mg/kg of chlorohydroxyquinoline; negative control (NC)- basal diet without additives; and NC containing 4.5; 6.0; 7.5 or 9.0 kg of UD additive/ton diet. Performance data were calculated, and daily diarrhea was observed. Blood samples were collected for hematological analysis. At the end of the experiment, one animal per pen was slaughtered for organ weighing, pH, and the collection of intestinal samples for histopathology. Feces and cecal contents were collected for microbiological and antibiogram analyses. There was no difference in the performance between the treatments. Throughout the study, UD levels were equal to those of PC for diarrhea occurrence. Higher levels of UD complex led to higher total leukocyte counts. The 4.5 treatment showed a reduction in total and thermotolerant Enterobacteriaceae populations in piglet feces and an increase in lactic acid bacteria compared to PC. All treatments resulted in fewer duodenal histopathological alterations than those in the NC group. The use of UD additives, especially at 4.5 kg/ton, is a good alternative to chlorohydroxyquinoline in piglet diets.

Detection and Characterization of Influenza A Virus Endemic Circulation in Suckling and Nursery Pigs Originating from Vaccinated Farms in the Same Production System.

Inactivated influenza A virus (IAV) vaccines help reduce clinical disease in suckling piglets, although endemic infections still exist. The objective of this study was to evaluate the detection of IAV in suckling and nursery piglets from IAV-vaccinated sows from farms with endemic IAV infections. Eight nasal swab collections were obtained from 135 two-week-old suckling piglets from four farms every other week from March to September 2013. Oral fluid samples were collected from the same group of nursery piglets. IAV RNA was detected in 1.64% and 31.01% of individual nasal swabs and oral fluids, respectively. H1N2 was detected most often, with sporadic detection of H1N1 and H3N2. Whole-genome sequences of IAV isolated from suckling piglets revealed an H1 hemagglutinin (HA) from the 1B.2.2.2 clade and N2 neuraminidase (NA) from the 2002A clade. The internal gene constellation of the endemic H1N2 was TTTTPT with a pandemic lineage matrix. The HA gene had 97.59% and 97.52% nucleotide and amino acid identities, respectively, to the H1 1B.2.2.2 used in the farm-specific vaccine. A similar H1 1B.2.2.2 was detected in the downstream nursery. These data demonstrate the low frequency of IAV detection in suckling piglets and downstream nurseries from farms with endemic infections in spite of using farm-specific IAV vaccines in sows.

Spatial transferability of an agent-based model to simulate Taenia solium control interventions.

BACKGROUND: Models can be used to study and predict the impact of interventions aimed at controlling the spread of infectious agents, such as Taenia solium, a zoonotic parasite whose larval stage causes epilepsy and economic loss in many rural areas of the developing nations. To enhance the credibility of model estimates, calibration against observed data is necessary. However, this process may lead to a paradoxical dependence of model parameters on location-specific data, thus limiting the model's geographic transferability. METHODS: In this study, we adopted a non-local model calibration approach to assess whether it can improve the spatial transferability of CystiAgent, our agent-based model of local-scale T. solium transmission. The calibration dataset for CystiAgent consisted of cross-sectional data on human taeniasis, pig cysticercosis and pig serology collected in eight villages in Northwest Peru. After calibration, the model was transferred to a second group of 21 destination villages in the same area without recalibrating its parameters. Model outputs were compared to pig serology data collected over a period of 2 years in the destination villages during a trial of T. solium control interventions, based on mass and spatially targeted human and pig treatments. RESULTS: Considering the uncertainties associated with empirical data, the model produced simulated pre-intervention pig seroprevalences that were successfully validated against data collected in 81% of destination villages. Furthermore, the model outputs were able to reproduce validated pig seroincidence values in 76% of destination villages when compared to the data obtained after the interventions. The results demonstrate that the CystiAgent model, when calibrated using a non-local approach, can be successfully transferred without requiring additional calibration. CONCLUSIONS: This feature allows the model to simulate both baseline pre-intervention transmission conditions and the outcomes of control interventions across villages that form geographically homogeneous regions, providing a basis for developing large-scale models representing T. solium transmission at a regional level.

Knowledge and practices about taeniasis/cysticercosis complex within the framework of the national plan for its elimination in Colombia, 2019.

The taeniasis/cysticercosis complex (TCC) belongs to the group of neglected infectious diseases with a multifactorial transmission that includes hosts such as humans and pigs of the parasitic tapeworm (Taenia solium) and environmental factors. This study represents the first phase of the National and Cross-sectoral Plan for TCC Elimination. OBJECTIVES: To obtain data about knowledge and practices in relation to the TCC from knowledge, attitudes, and practices (KAP) surveys applied in two pilot localities for building a baseline of the potential risk factors related to identification, prevention, and control of TCC in Colombia. METHODS: A descriptive cross-sectional survey from October to November in 2019 was carried out using a structured questionnaire and random sampling by single-stage conglomerates in the municipalities of Mahates, Bolívar (n = 152) (Atlantic Region) and Mercaderes, Cauca (n = 152) (Andean Region). RESULTS: Respondents in Mahates showed moderate knowledge about TCC compared to those in Mercaderes, however, risky practices were identified in both places (consumption of pork with cysts and defecation in places other than the bathroom or latrine). Deficiency in infrastructure and failure in basic services were observed as potential risk factors for TCC transmission in both municipalities. CONCLUSION: Based on the framework of the National and Cross-sectoral Plan for TCC Elimination, adequate knowledge on identification, prevention, and control of the disease must be reinforced; cultural and ecological differences should be considered when designing communication and knowledge transmission tools. We consider that major investment should be made in improving basic services and creating sustainable modernized pig farming in Mahates and Mercaderes.

TbpBY167A-based vaccine is safe in pregnant sows and induces high titers of maternal derived antibodies that reduce Glaesserella parasuis colonization in piglets.

Glässer's disease is one of the main diseases affecting young piglets, particularly during the nursery phase, that can significantly impact pork production. Vaccination of sows has the potential to prevent Glaesserella parasuis infection during the first weeks of life that is to a substantial degree due to the transfer of maternal derived antibodies (MDA) in colostrum. In this study we compare the antibody response to two vaccines administered to pregnant sows. A subunit vaccine containing the mutant transferrin-binding protein, TbpBY167A, and an autogenous vaccine formulated with the LM96/20 strain of G. parasuis (SV4) administered on days 65 and 86 of the gestational period were safe and induced high titers of antibodies in sows. The IgG peak was reached on day 100 of gestation, and the translocation of IgG to the mammary gland was confirmed in colostrum at the time of delivery. Piglets born from vaccinated sows maintained positive IgG titers against TbpBY167A or G. parasuis SV4 for the duration of the experiment (35 days of life). Piglets born from sows vaccinated with the TbpBY167A-based vaccine had a significantly (p = 0.001) lower load of G. parasuis in the respiratory tract compared to those born from sows vaccinated with the autogenous vaccine. Finally, we demonstrate that the LM96/20 (SV4) strain is highly virulent and a primary agent of Glässer's disease.

One health approach for the surveillance of novel swine viral diseases / Uma abordagem de saúde única para a vigilância de novas doenças virais de suínos

The novel coronavirus pandemic highlighted the importance of discussing and monitoring emerging diseases to scientific society, particularly in the case of zoonotic diseases. Diseases emerge in nature and infect living beings current on all continents, even in the current scenario of biomedical research evolution. Among the most studied emerging animal diseases are the swine viral diseases, due to their high occurrence and severity. Added to this, is the economic impact on the health of pigs and in some cases on human health. The challenges of swine health include endemic diseases, foodborne and transboundary diseases. Idiopathic vesicular diseases and subclinical diseases have also been identified, either alone or in combination with other infections. Several factors have contributed to these phenomena, but failures in biosecurity, biocontainment, and herd immunity imbalances are critical and must be addressed. Viruses evolve naturally, through mutation, rearrangement, or recombination, either to become more virulent or more transmissible, or not. This review will discuss the broad field of emerging swine viral infections, how monitoring the evolution of these viral agents is of supreme importance. Also, when should a new disease or emerging agent is considered a risk to swine production? Although the evolution of pork production systems is admirable, animal diseases continue to account for 20% of the losses. Therefore, international organizations work with member countries to prevent animal diseases, ensure food supply, maintain household income, health, and preserve the future. One Health is not just a concept, but an action of surveillance and control that all countries must implement.

A pandemia do novo coronavírus enfatizou a importância que a discussão e a vigilância de doenças emergentes representam para a sociedade científica, especialmente no caso de doenças zoonóticas. Mesmo no atual cenário de evolução da pesquisa biomédica, as doenças surgem na natureza e infectam os seres vivos em todos os continentes. Entre as doenças animais emergentes mais estudadas estão as doenças virais suínas, devido à sua alta ocorrência e gravidade. Soma-se a isso o impacto econômico na saúde dos suínos e, em alguns casos, na saúde humana. Os desafios da saúde suína incluem doenças endêmicas, doenças transmitidas por alimentos e doenças transfronteiriças. Além disso, doenças vesiculares idiopáticas e doenças subclínicas foram identificadas isoladamente ou em co-infecções. Vários fatores desencadearam esses fenômenos, mas falhas na biossegurança, biocontenção e desequilíbrio na imunidade do rebanho são fundamentais e devem ser corrigidos. Os vírus evoluem naturalmente, por mutação, rearranjo ou recombinação, para se tornarem mais virulentos ou mais transmissíveis, ou não. Esta revisão discutirá o amplo campo de infecções virais suínas emergentes e como o monitoramento da evolução desses agentes virais é de suma importância. Além disso, quando considerar uma nova doença ou agente emergente um risco para a suinocultura. A evolução dos sistemas de produção de suínos é admirável, mas as doenças dos animais ainda respondem por 20% das perdas. Portanto, as organizações internacionais trabalham com os países membros para prevenir doenças animais, garantir o abastecimento de alimentos, manter a renda familiar, a saúde e preservar o futuro. Saúde Única não é apenas um conceito, mas uma ação de vigilância e controle que todos os países devem implementar.

Effect of sow mass vaccination against Mycoplasma hyopneumoniae on the humoral immune response of newborn piglets.

Pneumonia caused by Mycoplasma (M.) hyopneumoniae is one of the major respiratory diseases in swine production. Commercial vaccines for M. hyopneumoniae are widely used in weaned piglets to reduce lung lesions and clinical signs in the downstream flow; however, no information regarding the effect of mass immunization of the breeding herd is available. The aim of this work was to evaluate a mass vaccination protocol for M. hyopneumoniae on the humoral response of sows and their offspring 24 h post-partum (trial registration number 40156). A total of 52 sows from two different farms (13 primiparous and 13 multiparous sows on each farm), one with mass vaccination (MVF) and one without mass vaccination against M. hyopneumoniae (control farm (CF)) were enrolled in this study. Five piglets from each litter were selected, resulting in 260 piglets. Blood was collected from sows and piglets 24 h post-partum for M. hyopneumoniae antibody detection by ELISA. The results showed that primiparous sows from MVF had higher antibody titers compared to multiparous sows of the same farm, and multiparous and primiparous sows from the CF. Similar results were evidenced in their offspring. The findings of this study suggest that mass vaccination results in a more robust serologic response on primiparous sows, which could be the main target of vaccination strategies for the breeding herd.

Pig vaccination strategies based on enterotoxigenic Escherichia coli toxins.

Enterotoxigenic Escherichia coli (ETEC) are responsible for diarrhea in humans as well as in farm animals. ETEC infections in newborn, suckling, and especially in post-weaning piglets are associated with reduced growth rate, morbidity, and mortality. ETEC express virulence factors as adhesin and enterotoxins that play a central role in the pathogenic process. Adhesins associated with pigs are of diverse type being either fimbrial or non-fimbrial. Enterotoxins belong to two groups: heat-labile (LT) and heat-stable (ST). Heterogeneity of ETEC strains encompass expression of various fimbriae (F4, F5, F6, F18, and F41) and enterotoxins (LT, STa, STb, and EAST1). In the late years, attempts to immunize animals against neonatal and post-weaning diarrhea were focused on the development of anti-adhesin strategies as this is the initial step of ETEC pathogenesis. Although those vaccines demonstrated some protection against ETEC infections, as enterotoxins are pivotal to the virulence of ETEC, a new generation of vaccinal molecules, which include adhesin and one or more enterotoxins, were recently tested. Some of these newly developed chimeric fusion proteins are intended to control as well human diarrhea as enterotoxins are more or less common with the ones found in pigs. As these could not be tested in the natural host (human), either a mouse or pig model was substituted to evaluate the protection efficacy. For the advancement of pig vaccine, mice were sometimes used for preliminary testing. This review summarizes advances in the anti-enterotoxin immunization strategies considered in the last 10 years.

Taenia solium taeniasis/cysticercosis: From parasite biology and immunology to diagnosis and control.

Infection with the pork tapeworm (Taenia solium) is responsible for a substantial global burden of disease, not only restricted to its impact on human health, but also resulting in a considerable economic burden to smallholder pig farmers due to pig cysticercosis infection. The life-cycle, parasitology and immunology of T. solium are complex, involving pigs (the intermediate host, harbouring the larval metacestode stage), humans (the definitive host, harbouring the adult tapeworm, in addition to acting as accidental intermediate hosts) and the environment (the source of infection with eggs/proglottids). We review the parasitology, immunology, and epidemiology of the infection associated with each of the T. solium life-cycle stages, including the pre-adult/adult tapeworm responsible for human taeniasis; post-oncosphere and cysticercus associated with porcine and human cysticercosis, and the biological characteristics of eggs in the environment. We discuss the burden associated, in endemic settings, with neurocysticercosis (NCC) in humans, and the broader cross-sectoral economic impact associated both with NCC and porcine cysticercosis, the latter impacting food-value chains. Existing tools for diagnostics and control interventions that target different stages of the T. solium transmission cycle are reviewed and their limitations discussed. Currently, no national T. solium control programmes have been established in endemic areas, with further work required to identify optimal strategies according to epidemiological setting. There is increasing evidence suggesting that cross-sectoral interventions which target the parasite in both the human and pig host provide the most effective approaches for achieving control and ultimately elimination. We discuss future avenues for research on T. solium to support the attainment of the goals proposed in the revised World Health Organisation neglected tropical diseases roadmap for 2021-2030 adopted at the 73rd World Health Assembly in November 2020.

Establishment of a production process for a novel vaccine candidate against Lawsonia intracellularis

BACKGROUND: Lawsonia intracellularis remains a problem for the swine industry worldwide. Previously, we designed and obtained a vaccine candidate against this pathogen based on the chimeric proteins: OMP1c, OMP2c, and INVASc. These proteins formed inclusion bodies when expressed in E. coli, which induced humoral and cellular immune responses in vaccinated pigs. Also, protection was demonstrated after the challenge. In this study, we established a production process to increase the yields of the three antigens as a vaccine candidate. RESULTS: Batch and fed-batch fermentations were evaluated in different culture conditions using a 2 L bioreactor. A fed-batch culture with a modified Terrific broth medium containing glucose instead of glycerol, and induced with 0.75 mM IPTG at 8 h of culture (11 g/L of biomass) raised the volumetric yield to 627.1 mg/L. Under these culture conditions, plasmid-bearing cells increased by 10% at the induction time. High efficiency in cell disruption was obtained at passage six using a high-pressure homogenizer and a bead mill. The total antigen recovery was 64% (400 mg/L), with a purity degree of 70%. The antigens retained their immunogenicity in pigs, inducing high antibody titers. CONCLUSIONS: Considering that the antigen production process allowed an increment of more than 70-fold, this methodology constitutes a crucial step in the production of this vaccine candidate against L. intracellularis.

Quantifying the dynamics of pig movements improves targeted disease surveillance and control plans.

Tracking animal movements over time may fundamentally determine the success of disease control interventions. In commercial pig production growth stages determine animal transportation schedule, thus it generates time-varying contact networks showed to influence the dynamics of disease spread. In this study, we reconstructed pig networks of one Brazilian state from 2017 to 2018, comprising 351,519 movements and 48 million transported pigs. The static networks view did not capture time-respecting movement pathways. For this reason, we propose a time-dependent network approach. A susceptible-infected model was used to spread an epidemic over the pig network globally through the temporal between-farm networks, and locally by a stochastic model to account for within-farm dynamics. We propagated disease to calculate the cumulative contacts as a proxy of epidemic sizes and evaluate the impact of network-based disease control strategies in the absence of other intervention alternatives. The results show that targeting 1,000 farms ranked by degree would be sufficient and feasible to diminish disease spread considerably. Our modelling results indicated that independently from where initial infections were seeded (i.e. independent, commercial farms), the epidemic sizes and the number of farms needed to be targeted to effectively control disease spread were quite similar; indeed, this finding can be explained by the presence of contact among all pig operation types The proposed strategy limited the transmission the total number of secondarily infected farms to 29, over two simulated years. The identified 1,000 farms would benefit from enhanced biosecurity plans and improved targeted surveillance. Overall, the modelling framework provides a parsimonious solution for targeted disease surveillance when temporal movement data are available.

Zoonotic Taenia infections with focus on cysticercosis due to Taenia solium in swine and humans.

Zoonotic taeniasis caused by the adult stage of Taenia solium, Taenia saginata or Taenia asiatica are considered neglected tropical diseases by the World Health Organization. The life cycle of these 3 metazoan species is very similar and includes an intermediate host: pigs in the case of T. solium and T. asiatica, and cattle in the case of T. saginata. By eating meat (pork/T. solium, T. asiatica; beef/T. saginata) containing live cysticerci, humans develop taeniasis, which is practically asymptomatic but is the main risk factor for intermediate hosts to become infected. T. saginata causes bovine cysticercosis, while T. solium and T. asiatica cause swine cysticercosis, of veterinary and economic importance. T. solium cysticerci cause neurological disease in humans: neurocysticercosis. Cysticerci develop after ingesting microscopic eggs released from a human tapeworm carrier. Here we describe the life stages of the parasites, diagnosis, pathogenesis, symptomatology of neurocysticercosis, and prevention and control measures. Highlighting the need to validate diagnostic tools, treatments and vaccination in endemic areas, with the challenge of addressing the most vulnerable populations that lack resources. If people understand the transmission route, avoid eating uncooked or insufficiently cooked meat and have adequate hygienic habits, the life cycle of the 3 zoonotic Taenia species may be interrupted. In addition, we describe the growing field of immune response and immunomodulation elicited by the parasites, which may provide essential tools for diagnosis, treatment, control of taeniasis/cysticercosis, as well as for identification of parasite-derived immunomodulators that could aid in the treatment of emerging inflammatory diseases worldwide.

Uso racional de antibióticos para tratamento de infecção urinária em porcas / Rational use of antibiotics for treatment of urinary infection in sows

O caráter endêmico das infecções urinárias (IU) em porcas faz com que seja rotina o uso de terapias antimicrobianas coletivas via ração, as quais geram subdoses que não promovem a cura e contribuem para a seleção de bactérias resistentes aos antibióticos. O uso de terapia individual é procedimento mais adequado a ser realizado nos animais com IU. Com este estudo objetivou-se avaliar a ocorrência de IU em matrizes alojadas na região Oeste do Paraná e a eficácia e custo-benefício do tratamento individual. Foram selecionadas 353 fêmeas, de cinco rebanhos distintos, submetidas à coleta de urina no terço final da gestação pelo método de micção espontânea. As amostras foram analisadas física e quimicamente com o uso de tiras reagentes, sendo que a presença de nitrito foi determinante de positividade para IU. Os animais com IU tiveram a urina submetida a avaliação bacteriológica, foram tratados com medicação parenteral (marbofloxacina - dose única - 8 mg/kg) e submetidos a nova coleta de urina 24h, 48h e sete dias após a primeira. IU foi observada em 4,53% das fêmeas avaliadas (16/353). Escherichia coli e Stretococcus sp. foram os agentes isolados com maior frequência. Sete dias após o uso da marbofloxacina 87,5% (14/16) dos animais foram negativos para IU, o que demonstra a eficácia do controle parenteral da IU. O diagnóstico associado à terapia individual em detrimento da medicação coletiva apresentou custo-benefício altamente vantajoso, possibilitou reduzir drasticamente o número de animais medicados e apresentou eficiência no controle da IU. Desta forma se conclui que é possível fazer uso racional de antibióticos mediante o tratamento apenas de porcas comprovadamente positivas para IU. Isto reduz o número de animais medicados desnecessariamente e reduz o custo em função do uso de antimicrobianos apenas em animais enfermos.

The endemic character of urinary infections (UI) in sows makes collective antimicrobial therapies via feed a routine. This, however, generates sub-doses unable to heal and contribute to the selection of antibiotic-resistant bacteria. The use of individual therapy is the most appropriate procedure to be performed on animals with UI. With this study, we aimed to evaluate the occurrence of UI in sows housed in the western region of Paraná and the efficacy and cost-benefit of individual treatment. A total of 353 females were selected from five different herds, submitted to urine collection in the final third of pregnancy by spontaneous urination method. The samples were analyzed physically and chemically with the use of reagent strips, and the presence of nitrite was a determinant for positivity for UI. The animals with UI had urine submitted to a bacteriological evaluation, were treated with parenteral medication (marbofloxacin - single dose - 8 mg/kg), and submitted to a new urine collection 24h and 48h after the first. UI was observed in 4.53% of the females evaluated (16/353). Escherichia coli and Streptococcus sp. were the most frequently isolated agents. Seven days after the use of marbofloxacin 87.5% (14/16) of the animals were negative for UI, which demonstrates the efficacy of UI parenteral control. The diagnosis associated with individual therapy at the expense of collective medication was highly cost-effective, made it possible to drastically reduce the number of medicated animals, and was efficient in controlling UI. Thus, it is concluded that it is possible to make rational use of antibiotics by treating only sows that are proven to be positive for UI. This reduces the number of unnecessarily medicated animals and reduces the cost due to the use of antimicrobials only in sick animals.

Protection against Toxoplasma gondii cysts in pigs immunized with rROP2 plus Iscomatrix.

This study aimed to evaluate the humoral immune response in pigs immunized intranasally and intramuscularly with recombinant Toxoplasma gondii rROP2 protein in combination with the adjuvant Iscomatrix. Twelve mixed breed pigs divided into three groups (n=4) were used, G1 received recombinant ROP2 proteins (200 µg/dose) plus Iscomatrix, G2 received PBS plus Iscomatrix, and G3 as the control group. The intranasal (IN) and intramuscular (IM) routes were used. Animals were challenged orally with VEG strain oocysts and treated on day three after challenge. Fever, anorexia, and prostration were the clinical signs observed in all animals. All the G1 animals produced antibodies above the cut-off on the day of the challenge, while the G2 and G3 remained below the cut-off. Better partial protection against parasitemia and cyst tissue formation was observed in G1 than G3. The protection factors against tissue cyst formation were 40.0% and 6.1% for G1 and G2, respectively, compared to G3. In conclusion, there were not systemic antibody responses in pigs with IN immunization with rROP2+Iscomatrix; however, after IM immunization, those animals produced higher titers than animal controls. We associated these results with partial protection obtained against parasitemia and tissue cysts formation.

Application of network analysis and cluster analysis for better prevention and control of swine diseases in Argentina.

RATIONALE/BACKGROUND: Though much smaller than the bovine industry, the porcine sector in Argentina involves a large number of farms and represents a significant economic sector. In recent years Argentina has implemented a national registry of swine movements amongst other measures, in an effort to control and eventually eradicate endemic Aujesky's disease. Such information can prove valuable in assessing the risk of transmission between farms for endemic diseases but also for other diseases at risk of emergence. METHODS: Shipment data from 2011 to 2016 were analyzed in an effort to define strategic locations and times at which control and surveillance efforts should be focused to provide cost-effective interventions. Social network analysis (SNA) was used to characterize the network as a whole and at the individual farm and market level to help identify important nodes. Spatio-temporal trends of pig movements were also analyzed. Finally, in an attempt to classify farms and markets in different groups based on their SNA metrics, we used factor analysis for mixed data (FAMD) and hierarchical clustering. RESULTS: The network involved approximate 136,000 shipments for a total of 6 million pigs. Over 350 markets and 17,800 production units participated in shipments with another 83,500 not participating. Temporal data of shipments and network metrics showed peaks in shipments in September and October. Most shipments where within provinces, with Buenos Aires, Cordoba and Santa Fe concentrating 61% of shipments. Network analysis showed that markets are involved in relatively few shipments but hold strategic positions with much higher betweenness compared to farms. Hierarchical clustering yielded four groups based on SNA metrics and node characteristics which can be broadly described as: 1. small and backyard farms; 2. industrial farms; 3. markets; and 4. a single outlying market with extreme centrality values. CONCLUSION: Characterizing the network structure and spatio-temporal characteristics of Argentine swine shipments provides valuable information that can guide targeted and more cost-effective surveillance and control programs. We located key nodes where efforts should be prioritized. Pig network characteristics and patterns can be used to create dynamic disease transmission models, which can both be used in assessing the impact of emerging diseases and guiding efforts to eradicate endemic ones.

Short communication: a modified Vaccinia virus Ankara-based Porcine circovirus 2 vaccine elicits strong antibody response upon prime-boost homologous immunization in a preclinical model.

Porcine circovirus 2 (PCV2) infections are related to a number of syndromes and clinical manifestations, generally known as Porcine circovirus-associated diseases, which are related to losses in the swine industry. There are commercially available vaccines and new vaccines being tested, however, persistency of the PCV2 as an important pig pathogen, and the growing number of affected farms in different countries have suggested that there is room for vaccine improvement. In this study, we describe the construction and testing of a recombinant live vaccine based on a modified Vaccinia virus Ankara (MVA) vector expressing the PCV2b capsid protein (CAP). Using a two-dose homologous vaccination regimen, in mice, we demonstrated that the vaccine induced high titers of anti-PCV2 antibodies. The vaccine is stable upon lyophilization, and, together with the good immunogenicity potential observed, the results support further evaluation of the MVA-CAP vaccine in the target species.

Porcine Parvovirus.

Porcine parvovirus (PPV) is considered the main cause of reproductive disorders in pigs, which are summarized under the acronym SMEDI (stillbirth, mummification, embryonic death, and infertility). In this review the biology of the virus and its structure, pathogenic potential and strain variation, as well as the disease induced by the virus, are described. Known aspects of pathogenesis, diagnosis and prevention, particularly by vaccination, are summarized. Furthermore, in recent years 'new' parvoviruses (PPV2 to 7) have been described in pigs. They have been detected in pigs from various parts of the world and their association with clinical signs or disease will be discussed.

Protection against Toxoplasma gondii cysts in pigs immunized with rROP2 plus Iscomatrix / Proteção contra cistos de Toxoplasma gondii em suínos imunizados com rROP2 associado à Iscomatrix

Abstract This study aimed to evaluate the humoral immune response in pigs immunized intranasally and intramuscularly with recombinant Toxoplasma gondii rROP2 protein in combination with the adjuvant Iscomatrix. Twelve mixed breed pigs divided into three groups (n=4) were used, G1 received recombinant ROP2 proteins (200 µg/dose) plus Iscomatrix, G2 received PBS plus Iscomatrix, and G3 as the control group. The intranasal (IN) and intramuscular (IM) routes were used. Animals were challenged orally with VEG strain oocysts and treated on day three after challenge. Fever, anorexia, and prostration were the clinical signs observed in all animals. All the G1 animals produced antibodies above the cut-off on the day of the challenge, while the G2 and G3 remained below the cut-off. Better partial protection against parasitemia and cyst tissue formation was observed in G1 than G3. The protection factors against tissue cyst formation were 40.0% and 6.1% for G1 and G2, respectively, compared to G3. In conclusion, there were not systemic antibody responses in pigs with IN immunization with rROP2+Iscomatrix; however, after IM immunization, those animals produced higher titers than animal controls. We associated these results with partial protection obtained against parasitemia and tissue cysts formation.

Resumo O objetivo deste estudo foi avaliar a resposta imune humoral em suínos imunizados pelas vias intranasal e intramuscular com proteínas recombinantes rROP2 do Toxoplasma gondii associadas ao adjuvante Iscomatrix. Doze suínos cruzados divididos em 3 grupos (n=4) foram utilizados. O G1 recebeu proteína recombinante ROP2 (200mg/dose) associada ao adjuvante Iscomatrix; o G2 recebeu PBS associado ao Iscomatrix; e o G3 foi o grupo controle. As vias intranasal (IN) e intramuscular (IM) foram utilizadas. Os animais foram desafiados por via oral com a cepa VEG e tratados no dia três após o desafio. Febre, anorexia e prostração foram os sinais clínicos observados em todos os animais. Todos os animais do G1 produziram anticorpos acima do ponto de corte no dia do desafio, enquanto os animais do G2 e G3 permaneceram abaixo do ponto de corte no desafio. Proteção parcial contra parasitemia e formação de cistos teciduais foram observadas nos suínos do G1 comparados ao G3. Os fatores de proteção contra a formação de cistos teciduais foram 40,0% e 6,1% no G1 e G2, respectivamente, comparados com o G3. Como conclusão, não houve estimulação da resposta imune humoral sistêmica nos suínos após as imunizações IN com rROP2+Iscomatrix. Estes animais, porém, após a imunização IM, produziram títulos de anticorpos mais altos que os animais controles. Esses resultados foram associados a uma proteção parcial contra a parasitemia e formação de cistos teciduais.