No abstract

BackgroundDiarrhea in piglets directly affects commercial swine production. The disease results from the interaction of pathogens with the host immune system and is also affected by management procedures. Several pathogenic agents such as Campylobacter spp., Clostridium perfringens, Escherichia coli, Salmonella spp., group A rotavirus (RV-A), coronaviruses (transmissible gastroenteritis virus; porcine epidemic diarrhea virus), as well as nematode and protozoan parasites, can be associated with disease cases.ResultsAll bacterial, viral, protozoan, and parasitic agents here investigated, with the exception of Salmonella spp. as well as both coronaviruses, were detected in varying proportions in piglet fecal samples, and positive animals were equally distributed between case and control groups. A statistically significant difference between case and control groups was found only for Cystoisospora suis (p = 0.034) and Eimeria spp. (p = 0.047). When co-infections were evaluated, a statistically significant difference was found only for C. perfringens β2 and C. suis (p = 0.014).ConclusionsThe presence of pathogens in piglets alone does not determine the occurrence of diarrhea episodes. Thus, the indiscriminate use of antibiotic and anthelminthic medication should be re-evaluated. This study also reinforces the importance of laboratory diagnosis and correct interpretation of results as well as the relevance of control and prophylactic measures.

ABSTRACT:Peccaries and pigs, Tayassuidae and Suidae respectively, diverged approximately one million years ago from a common ancestor. Because these families share some pathogens, peccaries can act as reservoirs of infectious pathogens for domestic and wild swine. We evaluated the presence of swine infectious agents in the spleen and lung tissues of white-lipped peccaries (WLP; Tayassu pecari) and collared peccaries (CP; Pecari tajacu) in Brazil. Samples from 10 adult CP and three WLP, which had been hunted by locals or hit by motor vehicles, were obtained from two free-ranging Brazilian populations. The samples were tested by PCR for Mycoplasma hyopneumoniae, Bordetella bronchiseptica, Pasteurella multocida, porcine circovirus 2 (PCV2), Suid herpesvirus 1 (SuHV-1), and porcine parvovirus (PPV). Positive samples were sequenced. Both species were negative for PPV and B. bronchiseptica and positive for PCV2 and SuHV-1. The lungs of two animals were positive for M. hyopneumoniae and P. multocida. This report is the first demonstration of PCV2 and SuHV-1 swine viruses and of M. hyopneumoniae and P. multocida bacteria in peccaries. One factor contributing to this detection was access to tissue samples, which is uncommon. The role of these infectious agents in peccaries is unknown and further epidemiologic studies should be performed. This study identified several infectious agents in peccaries and highlighted the importance of the tissue type used to detect pathogens.

Diagnosisto detect porcine transmissible gastroenteritis virus (TGEV) by optical and transmission electron microscopy techniques.

Serum samples collected from 358 wild boars (Sus scrofa) in breeding farms in São Paulo, southeast Brazil, from 1998 to 2001, were tested for antibodies against pseudorabies virus (PRV) by means of serum neutralization (SN) and enzyme-linked immunobsorbent assay (ELISA). Seropositive animals were detected in three of seven herds analyzed. Overall seroprevalence as assessed by SN was 30.7%, ranging from 25.2% to 100% for the herds that presented seropositive animals. Indirect ELISA detected lower seroprevalence (19.3%). Sensitivity and specificity of ELISA were equal to 57.3% and 97.6%, respectively. Agreement was equal to 85.2% (P<0.0001). These results showed that PRV infections occurred in farmed feral swine in southeast Brazil, and affect pseudorabies eradication program.

The myxomatosis is a contagious worldwide disease caused by poxvirus which infects domestic and wild rabbits.In the present study we present two distinct outbreaks of myxomatosis when raising rabbits, one for commercial purpose of production of meat and skins and, another one for the commercialization of ornamental rabbits. The observed signs were ocular, auricular, nasal, testis lesions and many times scattered throughout the body of the animals. The lesions were characterized by formation of nodules that by palpation disclosed gummy or gelatinous aspect. At the transmission electron microscopy, all the skin and crust samples were analyzed by negative staining technique. A great number of particles with morphology similar to the poxvirus, some enveloped in a brick-shaped and irregular disposition of tubules on the external membrane, measuring 300x240 nm on the average were visualized. Ultrathin sections revealed the presence of intracytoplasmic inclusion bodies surrounded by membrane containing oval particles, measuring 270 x 130 nm, containing nucleus or an internal biconcave (dumbbell-shaped) core. Immature particles (empty), surrounded by membrane were also observed. In addition, intracytoplasmic electron dense inclusion bodies containing viral particles budding of dense amorphous material and intranuclear fibrillar or "digital" inclusions showing a regular striation and arranged in groups were found in the middle of granular material. The nuclei were deformed with densely condensed chromatin forming amorphous and electron dense inclusion bodies. In the immunocytochemistry technique, the antigen-antibody reaction was strongly marked by the particles of colloidal gold, emphasizing the viral particles. The techniques used in this study were important in the diagnosis of the affected animals.

No abstract

No abstract