Dynamics and chronology of Mycoplasma hyopneumoniae strain 232 infection in experimentally inoculated swine.

Direct detection of Mycoplasma hyopneumoniae through molecular tools is a growing trend for early diagnosis, highlighting the importance of knowing M. hyopneumoniae dynamics in the respiratory tract upon infection. This study focused on monitoring the infection level and its effects in different anatomic sites of the respiratory tract of experimentally infected swine in four time-points post-infection. To this end, 24 pigs were allocated to either non-inoculated group (n = 8) or inoculated group (n = 16). On day 0 post-infection (dpi), animals of the inoculated group were intratracheally inoculated with M. hyopneumoniae. Nasal swabs were collected weekly for qPCR detection of bacterial shedding. At 14, 28, 42, and 56 dpi, four animals from the inoculated group and two from the control group were necropsied. Bronchoalveolar lavage fluid (BALF) and samples from three different anatomical tracheal sections (cranial - CT, medium - MT, lower - LT) were collected for qPCR and histopathology. Bacterial loads (qPCR) in tracheal samples were: 4.47 × 102 copies∕µL (CT), 1.5 × 104- copies∕ µL (MT) and 1.4 × 104 copies∕µL (LT samples). M. hyopneumoniae quantification in BALF showed the highest load at 28 dpi (2.0 × 106 copies∕ µL). Microscopic lesions in LT samples presented the highest scores at 56 dpi and were significantly correlated with the pathogen load on 14 dpi (0.93) and 28 dpi (0.75). The greatest bacterial load of M. hyopneumoniae in CT samples and BALF was registered at 28 dpi, and it remained high in BALF and LT throughout the 56 dpi. The pathogen was able to persist during the whole experimental period, however higher estimated quantification values were registered in the lower parts of the respiratory tract, especially at 56 dpi. These findings are important for improving diagnostics, treatment, and control measures of M. hyopneumoniae infection in swine herds.

Performance of Commercial Mycoplasma hyopneumoniae Serum Enzyme-Linked Immunosorbent Assays under Experimental and Field Conditions.

Mycoplasma hyopneumoniae is an economically significant pathogen of swine. M. hyopneumoniae serum antibody detection via commercial enzyme-linked immunosorbent assays (ELISAs) is widely used for routine surveillance in commercial swine production systems. Samples from two studies were used to evaluate assay performance. In study 1, 6 commercial M. hyopneumoniae ELISAs were compared using serum samples from 8-week-old cesarean-derived, colostrum-deprived (CDCD) pigs allocated to the following 5 inoculation groups of 10 pigs each: (i) negative control, (ii) Mycoplasma flocculare (strain 27399), (iii) Mycoplasma hyorhinis (strain 38983), (iv) Mycoplasma hyosynoviae (strain 34428), and (v) M. hyopneumoniae (strain 232). Weekly serum and daily oral fluid samples were collected through 56 days postinoculation (dpi). The true status of pigs was established by PCR testing on oral fluids samples over the course of the observation period. Analysis of ELISA performance at various cutoffs found that the manufacturers' recommended cutoffs were diagnostically specific, i.e., produced no false positives, with the exceptions of 2 ELISAs. An analysis based on overall misclassification error rates found that 4 ELISAs performed similarly, although one assay produced more false positives. In study 2, the 3 best-performing ELISAs from study 1 were compared using serum samples generated under field conditions. Ten 8-week-old pigs were intratracheally inoculated with M. hyopneumoniae Matched serum and tracheal samples (to establish the true pig M. hyopneumoniae status) were collected at 7- to 14-day intervals through 98 dpi. Analyses of sensitivity and specificity showed similar performance among these 3 ELISAs. Overall, this study provides an assessment of the performance of current M. hyopneumoniae ELISAs and an understanding of their use in surveillance.

Bovine Viral Diarrhea Virus: Recent Findings about Its Occurrence in Pigs.

Bovine viral diarrhea virus (BVDV) is an important pathogen belonging to the Pestivirus genus, Flaviviridae family, which comprises viral species that causes an economic impact in animal production. Cattle are the natural host of BVDV and the main source of infection for pigs and other animal species. Due to its antigenic and genetic similarity with other important pestiviruses such as Classical Swine Fever Virus (CSFV), several studies have been conducted to elucidate the real role of this virus in piglets, sows, and boars, not only in the field but also in experimental infections, which will be discussed in this paper. Although BVDV does not pose a threat to pigs as it does to ruminants, the occurrence of clinical signs is variable and may depend on several factors. Therefore, this study presents a survey of data on BVDV infection in pigs, comparing information on prevalence in different countries and the results of experimental infections to understand this type of infection in pigs better.

Congenital persistent infection with bovine viral diarrhea virus not observed in piglets.

This study was designed to determine whether congenital persistent infection occurs in piglets from gilts experimentally inoculated with bovine viral diarrhea virus type 2 (BVDV-2). Six pregnant gilts were divided into 2 groups, infected (n = 4), and control (n = 2). The gilts were inoculated at 45 days gestation. Piglets were assessed for 35 days following birth with nasal swab and blood sample collections every 72 hours. Reverse transcriptase-polymerase chain reaction (RT-PCR) tests were performed for direct diagnosis of virus in blood and nasal swabs, and virus neutralization was used for antibody detection. Transplacental transmission of BVDV-2 did not occur. Piglets were born free of the virus and did not shed BVDV during the experimental period.

Infection congénitale persistante par le virus de la diarrhée virale bovine non observée chez les porcelets. Cette étude a évalué l'occurrence d'infection congénitale persistante chez des porcelets nés de cochettes inoculées expérimentalement avec le virus BVDV-2. Six cochettes gestantes ont été divisées en deux groupes, infectées (n = 4) et témoins (n = 2). L'inoculation a eu lieu à 45 jours de gestation. Les porcelets ont été évalués pendant 35 jours par prélèvement d'écouvillons nasaux et d'échantillons de sang toutes les 72 heures. Des tests d'amplification en chaîne par la polymérase avec la transcriptase réverse (RT-PCR) ont été effectués pour le diagnostic direct dans le sang et les écouvillons, et la neutralisation virale pour l'évaluation sérologique. La transmission transplacentaire de BVDV-2 n'a pas été mise en évidence car les porcelets sont nés sans virus et n'ont pas éliminé le BVDV au cours de la période expérimentale.(Traduit par les auteurs).

Early detection and differential serodiagnosis of Mycoplasma hyorhinis and Mycoplasma hyosynoviae infections under experimental conditions.

Mycoplasma hyorhinis (MHR) and Mycoplasma hyosynoviae (MHS) are common opportunistic pathogens in the upper respiratory tract and tonsils of swine. The identification of the specific species involved in clinical cases using conventional diagnostic methods is challenging. Therefore, a recombinant chimeric polypeptide based on the seven known variable lipoproteins (A-G) specific of MHR and a cocktail of surface proteins detergent-extracted from MHS cultures were generated and their suitability as antemortem biomarkers for serodiagnosis of MHR- and MHS-infection were evaluated by ELISA. M. hyorhinis and MHS ELISA performance, evaluated using serum samples collected over a 56-day observation period from pigs inoculated with MHR, MHS, M. hyopneumoniae, M. flocculare, or Friis medium, varied by assay, targeted antibody isotype, and cutoffs. The progressions of MHR and MHS clinical diseases were evaluated in relation to the kinetics of the isotype-specific antibody response in serum and bacterial shedding in oral fluids during the observation period. In pigs inoculated with MHR, bacterial DNA was detected in one or more of the 5 pens at all sampling points throughout the study, IgA was first detected at DPI 7, one week before the first clinical signs, with both IgA and IgG detected in all samples collected after DPI 14. The peak of MHS shedding (DPI 8) coincided with the onset of the clinical signs, with both IgA and IgG detected in all serum samples collected ≥ DPI 14. This study demonstrated, under experimental conditions, that both ELISAs were suitable for early detection of specific antibodies against MHR or MHS. The diagnostic performance of the MHR and MHS ELISAs varied depending on the selected cutoff and the antibody isotype evaluated. The high diagnostic and analytical specificity of the ELISAs was particularly remarkable. This study also provides insights into the infection dynamics of MHR-associated disease and MHS-associated arthritis not previously described.

Pathogenicity and Competitive Fitness of Salmonella enterica Serovar 4,[5],12:i:- Compared to Salmonella Typhimurium and Salmonella Derby in Swine.

Since 2014, Salmonella 4,[5],12:i:- has emerged as the most common serovar of Salmonella enterica identified from swine samples submitted to veterinary diagnostic laboratories in the United States. To compare the pathogenicity of S. 4,[5],12:i:- in swine to the known pathogenic Salmonella Typhimurium and lesser pathogenic Salmonella Derby, 72 pigs (20 per Salmonella serovar treatment and 12 controls) were inoculated with either S. Typhimurium, S. 4,[5],12:i:-, S. Derby, or sham-inoculated and followed for up to 28 days thereafter via rectal temperature, fecal scoring, and fecal culture. Animals were euthanized on days 2, 4, or 28 to determine the gross and histopathologic signs of disease and tissue colonization. The results clearly demonstrate that for the isolates selected, serovar 4,[5],12:i:- possesses similar ability as serovar Typhimurium to cause clinical disease, colonize the tonsils and ileocecal lymph nodes, and be shed in the feces of infected swine past resolution of clinical disease. To compare the competitive fitness of S. 4,[5],12:i:- to S. Typhimurium in swine when co-infected, 12 pigs were co-inoculated with equal concentrations of both S. Typhimurium and S. 4,[5],12:i and followed for up to 10 days thereafter. When co-inoculated, serovar 4,[5],12:i:- was consistently detected in the feces of a higher percentage of pigs and at higher concentrations than serovar Typhimurium, suggesting an increased competitive fitness of 4,[5],12:i:- relative to serovar Typhimurium when inoculated simultaneously into naïve pigs. Whole genome sequencing analysis of the isolates used in these studies revealed similar virulence factor presence in all S. 4,[5],12:i:- and S. Typhimurium isolates, but not S. Derby, providing additional evidence for similar pathogenicity potential between serovars 4,[5],12:i:- and Typhimurium. Altogether, this data strongly supports the hypothesis that S. 4,[5],12:i:- is a pathogen of swine and suggests a mechanism through increased competitive fitness for the increasing identification of Salmonella 4,[5],12:i:- in swine diagnostic samples over the past several years.

Evidence of persistent Müllerian duct syndrome in a Yorkshire terrier / Evidencias de síndrome de persistencia del conducto Mülleriano en un Yorkshire terrier / Evidências de sindrome do ducto Mülleriano persistente em um Yorkshire terrier

Abstract Anamnesis: A one-year-old female Yorkshire terrier, weighing 2.2 kg, was referred for evaluation of an abnormal structure in the inguinal region. Clinical and laboratory findings: Upon examination, the structure -similar to a penis- was found protruding from the preputial orifice. Physical, laboratory, ultrasound, and radiographic examinations were performed. The initial suspicion was a case of sexual development disorder, so the dog was referred for exploratory laparotomy and karyotyping. Treatment approach: During the surgical procedure, two macroscopically similar structures were found at the caudal pole of the left and right kidneys. These tissues were attached to two structures similar to the uterine horns, caudally fused to a body in the pelvic cavity. All the tissue was removed and submitted for histopathological examination, revealing the presence of typical seminiferous tubules (testis) and proliferative endometrial glands (uterine tubes). Subsequently, a surgical correction procedure was performed to cover the penile tissue and avoid damage by exposure and contact. Conclusion: This case reports unique information on diagnosis and therapeutic approach in a Yorkshire terrier with persistent Müllerian duct syndrome (PMDS). Because they are unusual, sexual development disorders are challenging in terms of diagnostic and therapy, making this report a valuable tool for veterinarians.

Resumen Anamnesis: Una hembra Yorkshire terrier de un año de edad y 2,2 kg de peso fue remitida para evaluación de una estructura anormal en la región inguinal. Hallazgos clínicos y de laboratorio: Tras el examen, se encontró una estructura similar a un pene sobresaliendo del orificio prepucial. Se realizó examen clínico, paraclínico, ecografía y radiografía abdominal. El diagnóstico presuntivo inicial fue trastorno del desarrollo sexual, por lo que la perra fue remitida para laparotomía exploratoria y cariotipaje. Abordaje terapéutico: Durante el procedimiento quirúrgico se encontraron dos estructuras macroscópicas similares en la región caudal de ambos riñones. Estos tejidos se unían a dos estructuras similares a los cuernos uterinos, caudalmente fusionados a un cuerpo en la cavidad pélvica. Se retiró todo el tejido y se envió para examen histopatológico, revelando la presencia de túbulos seminíferos típicos (testículos) y glándulas endometriales proliferativas (tubos uterinos). Posteriormente se realizó un procedimiento quirúrgico de corrección para cubrir el tejido peneano y evitar daños por exposición y contacto. Conclusión: Este informe aporta información única sobre el diagnóstico y el enfoque terapéutico en un Yorkshire terrier con síndrome de persistencia del conducto Mülleriano (PMDS). Dado que los trastornos del desarrollo sexual son inusuales y plantean un desafío diagnóstico y terapéutico, este reporte puede representar una valiosa herramienta para los veterinarios.

Resumo Anamnese: Uma fêmea Yorkshire terrier de 1 ano de idade, com 2,2 kg de peso e uma estrutura anormal na região inguinal, similar ao orifício prepucial. Achados clínicos e laboratoriais: Após o exame, uma estrutura semelhante a um pênis foi encontrada saindo do orifício prepucial. Foram realizados exames físicos, laboratoriais, ecográficos e radiográficos. A suspeita inicial seria um caso de desordem do desenvolvimento sexual, pelo que a cadela foi encaminhada para laparotomia exploratória e cariotipagem. Abordagem terapêutica: Durante o procedimento cirúrgico macroscopicamente duas estruturas semelhantes foram encontradas: uma na região caudal do rim direito e outro na região caudal do rim esquerdo. Estes tecidos encontravam-se ligados a duas estruturas semelhantes aos cornos uterinos, caudalmente fusionados a um corpo na cavidade pélvica. Todo o tecido foi removido e enviado para exame histopatológico e revelou a presença de túbulos seminíferos típicos (testículos) e glândulas endometriais proliferativas (tubas uterinas). Subsequentemente, foi realizado procedimento cirúrgico de correção para cobrir o tecido peniano e evitar danos por exposição e contato. Conclusão: Este relatório aporta informações únicas sobre diagnóstico e abordagem terapêutica em um Yorkshire terrier com síndrome de persistência do ducto de Müller (PMDS). Distúrbios do desenvolvimento sexual são anomalias incomuns que representam um desafio diagnóstico e terapêutico considerando este relato uma ferramenta valiosa para os veterinários.

Evidence of bovine viral diarrhea virus transmission by back pond water in experimentally infected piglets / Evidência da transmissão do vírus da diarreia viral bovina através da lâmina d'água em leitões experimentalmente infectados

Swine can be infected by bovine viral diarrhea virus (BVDV). However, transmission routes among pigs are still unknown. The objective of the present study was to induce experimental infection of BVDV-1 in weaned piglets and to assess the potential transmission through pen back pond water, used to facilitate heat exchange of the pigs housed in barns. Two repetitions (BP1 and BP 2) were performed using 12 piglets proven to be free BVDV (n=6 per repetition) allocated into three groups: control, sentinels and infected with two piglets each. The piglets were placed in stainless steel isolators. The infected group received an inoculum containing BVDV-1, Singer strain. The piglets remained in the cabinets for 25 days, during which samples of nasal swab were collected daily and blood sampled weekly. At the end, the piglets were euthanized, necropsied and organ fragments were collected for histopathology, immunohistochemistry and RT-PCR. In the first experiment (BP1) the infected animals shed the virus between days 6 and 21 post-infection. Regarding the sentinel group, shedding occurred in only one piglet, on the 20th day after infection, and seroconversion was observed on the 25th day post-infection. In BP2, infected piglets I3 and I4 shed the virus on days 4 and 21 post-infection, respectively. Only one sentinel piglet (S3) she the virus on day 13 post-infection. Therefore, it was concluded that pigs can become infected with BVDV-1 and shed potentially infectious viral particles consequently, being able to transmit the virus to other pigs through back pond water.(AU)

Os suínos podem ser infectados pelo vírus da diarreia viral bovina (BVDV). No entanto, as vias de transmissão entre os suínos são ainda desconhecidas. O objetivo do presente estudo foi induzir a infecção experimental de BVDV-1 em leitões desmamados e avaliar a potencial transmissão pela lâmina d'água, que ajuda na troca de calor dos suínos alojados em baias. Duas repetições do experimento (BP1 e BP2) foram realizadas com 12 animais comprovadamente livres de BVDV (n=6 por repetição) alocados em três grupos: controle, sentinelas e infectados, com dois animais cada. Os animais foram mantidos em isoladores de aço inoxidável. O grupo infectado recebeu um inóculo contendo BVDV-1, estirpe Singer. Os animais permaneceram nos isoladores durante 25 dias e, durante esse período, amostras de suabe nasal foram coletadas diariamente e sangue coletado semanalmente. No final, os animais foram eutanasiados, necropsiados e fragmentos de órgãos foram coletados para histopatologia, imuno-histoquímica e RT-PCR. No primeiro experimento (BP1), os animais infectados excretaram partículas virais entre os dias 6 e 21 pós-infecção. Quanto ao grupo sentinela, a excreção ocorreu apenas em um animal, no 20º dia pós-infecção, e a soroconversão foi observada no 25º dia pós-infecção. Na BP2, os animais infectados I3 e I4 excretaram partículas virais nos dias 4 e 21 pós-infecção, respectivamente. Apenas um animal sentinela (S3) apresentou excreção no dia 13 pós-infecção. Concluiu-se que os suínos podem se infectar com BVDV-1 e excretar partículas virais potencialmente infecciosas, sendo capazes de transmitir o vírus a outros suínos através da lâmina d'água.(AU)

Occurrence of anti-Brucella antibodies in intensive pig farming and in non-technified pig herds / Ocorrência de anticorpos anti-Brucella em suínos de granjas comercias e de criações de subsistência

The aim of this study was to determine the occurrence of antibodies anti-Brucella in 1,940 swine blood samples. Out of the 1,940 sera samples, 1,594 were from 30 intensive pig farming from seven different states, collected during the slaughtering of animals, and 346 samples from 56 non-technified (subsistence) pig herds from Jaboticabal region, São Paulo State, Brazil. All samples were tested by Buffered Plate Acidified Antigen (BPAA) and considered positive in case of agglutination. If positive, the samples were tested by Complement Fixation Reaction (CFR) as a confirmatory test. Out of the 1,594, two were positive for BPAA but negative for CFR, so the occurrence was 0%. Among the 346 samples, two were positive for BPAA but only one was positive in the confirmatory test, whith a titer of 1:8. Thus, the occurrence was 0.29%, an important result to demonstrate the improvement of the sanitary status of Brazilian non-technified pig herds, despite the low conditions of production.(AU)

O presente estudo foi realizado com o objetivo de se determinar a ocorrência de anticorpos anti-Brucella spp. em 1.940 amostras de sangue de suínos, das quais 1.594 amostras eram de 30 granjas comerciais, de sete diferentes Estados, coletadas durante o abate dos animais, e 346 amostras de 56 criações de subsistência da região de Jaboticabal, Estado de São Paulo, Brasil. Todas as amostras foram submetidas ao teste do Antígeno Acidificado Tamponado (AAT) e consideradas positivas caso ocorresse aglutinação. Quando positivas, as amostras eram submetidas ao teste de Reação de Fixação de Complemento (RFC) como teste confirmatório. Dentre as 1.594 amostras de suínos de granjas comerciais, duas se mostraram sensíveis ao AAT, porém, quando foram submetidas à RFC, ambas apresentaram reação negativa, levando a uma porcentagem de ocorrência de 0%. Já entre as 346 amostras de criações de subsistência, duas foram positivas ao AAT, sendo que apenas uma apresentou reação positiva no teste confirmatório, cujo título foi de 1:8. Desta forma, a ocorrência foi de 0,29%, resultado importante para demonstrar a melhoria do status sanitário dos rebanhos de subsistência brasileiros, apesar das condições precárias em que vivem.(AU)