Summary Recently, a putative new pestivirus species, provisionally named as Atypical Porcine Pestivirus (APPV), was associated with the congenital tremor in piglets in North America and consequently in Europe and Asia. The present research aimed to describe the detection and characterization of APPV employing NS5B gene partial sequencing, gross pathology and histologic examination of piglets displaying congenital tremor from two different farms of Southern Brazil. No gross lesions were observed, and the histological findings revealed moderate vacuolization of the white matter of the cerebellum. RT‐PCR followed by DNA sequencing and a phylogenetic analysis confirmed the presence of APPV in samples from the two farms, which the samples were distinct in nature. Phylogenetic reconstruction reinforced the high genetic variability within the APPVs previously reported. This is the first report of APPV in South America suggesting that this new group of viruses may be widespread in swine herds in other countries as it is in Brazil.

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The aim of this study was to assess the frequency and association of virulence factors of Escherichia (E.) coli isolated from weaned piglets with diarrhea and to correlate it with fecal consistency. A total of 152 rectal swabs were collected from 25-40 day-old piglets with diarrhea, in farms of Southern Brazil. Phenotypical and molecular techniques were used for bacterial isolation, characterization and classification of enterotoxigenic E. coli (ETEC) pathotypes. Statistical analysis was carried out to determine the frequency of virulence factors and virotypes, of fimbriae F4, F5, F6, F18, F41 and toxins LT, STa, STb and STx2e. Out of 456 E. coli isolates, 287 (62.9%) samples showed significant growth of E. coli. Among them, 194 (67.6%) samples showed at least one virulence factor, indicating that ETEC is an important etiological agent of diarrhea in weaned piglets. Higher frequencies were found of fimbria F4 and F18 and enterotoxins LT, STa and STb. Significant association was found to F4, LT, STa and STb; between F18 and STa and STx2e; between F5 and LT, STa and STb. The most frequent virotypes were F18-STa, F4-LT-STa-STb, F4-STa, F4-LT-STb and F18-STa-STx2e. Beta-hemolysis was observed in 47.4% of samples and there was significant association between hemolytic samples and virulence factors F4, F18, STa and STx2e. Regarding fecal consistency, there was significant association of liquid feces and F4 fimbria, STa toxin and virotypes F4-STa and F4-F5-LT-STa-STb. Since there was significant association of ETEC and liquid feces in nursery piglets, it is important to prioritize the sampling of liquid feces for the diagnosis etiologic cause of diarrhea.

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A high prevalence of pneumonic lesions has been reported to affect slaughtered pigs in southern Brazil. In order to identify which microorganisms have been causing those lesions, 30 pig lungs presenting pneumonic gross lesions were collected from five different slaughterhouses, totaling 150 lungs. Samples for bacterial isolation, molecular, histopathologic and immunohistochemistry (IHC) evaluation were taken from each lung. The pneumonic lesion scoring ranged from 1.53 to 2.83. The most frequent histopathological lesions found was the concomitant Influenza A virus (IAV) and Mycoplasma hyopneumoniae infection, corresponding to 55.3% (83/150), and Pasteurella multocida type A was isolated in 54.2% (45/83) of these cases. In 102 samples (68%), there was histopathologic suggestion of involvement of more than one infectious agent. M. hyopneumoniae was the most frequent agent associated with pneumonic lesions, being present in 92.1% (94/102) of the lungs with coinfections, followed by IAV in 89.2% (91/102). Besides the coinfections, IAV lesions were observed also in six samples without another pathogenic microorganism detected. A total of 46 samples with acute and subacute IAV suspected lesions in histopathological examination were assessed for IHC and real time RT-PCR for IAV. A total of 35% (16/46) of them were positive by IHC and 13% (6/46) by real time RT-PCR. Regarding M. hyopneumoniae, 79.3% (119/150) of samples were positive by qPCR and 84.9% (101/119) of them also presented M. hyopneumoniae suspected lesions in the histopathological examination. The results of this study suggest the importance of IAV in respiratory diseases in finishing pigs, even though this virus is more frequently reported in the nursery phase. In addition, our results emphasize the importance of lung coinfections in finishing pigs.

Background: Staphylococcus (S.) aureus is an important nosocomial pathogen in humans and animals worldwide. The commonest class of antibiotics used to treat staphylococcal infections is the β-lactams. Frequently, S. aureus strains show high resistance to methicillin and other β-lactam antibiotics, called “Methicillin-resistant Staphylococcus aureus” (MRSA). Although MRSA has emerged at slower rate in domestic animals, it has frequently been found in the nasal cavity of healthy piglets and its transmission between pigs and swine handlers has already been studied. The aim of this work was to assess the presence of MRSA in finishing pigs in the state of Rio Grande do Sul, Brazil.Materials, Methods & Results: A total of 350 nasal swabs were collected from 10 to 20 week old finishing pigs. Sampling was performed in five pig farms in northeast Rio Grande do Sul State, Brazil. Swabs were stored in tubes without transport medium and carried to the laboratory under refrigeration. The specimens were cultured in selective and differential Agar (Baird Parker) and then were incubated at 37ºC for 48 h. After isolation of typical colonies of S. aureus, they were inoculated in BHI (Brain Heart Infusion) broth at 37ºC for 24 h and tested for tube coagulase activity. Coagulase positive samples were selected for growth in Oxacillin Resistant Screening Agar (ORSA) supplemented with 2 mg/L of oxacillin. This media contains aniline blue to demonstrate mannitol fermentation. Oxacillin and 5.5% NaCl have the capacity to reduce the growth of non-staphylococcal bacteria, selecting for MRSA.  Blue colonies growth after 24 to 48 h of incubation at 37ºC indicate the presence of positive MRSA strains. Specimens with at least one colony growing in ORSA within 48 h were considered resistant. Linear regression was performed in order to identify the association between herd size and MRSA frequency (SAS 9.4, 2012). Growth of S. aureus occurred on 18.0% of the samples and differences among farms were found. However, after incubation in ORSA only 18 (5.1%) were MRSA positive, ranging from zero to 12.5% among farms.  Significant correlation between herd size and MRSA frequency (adjusted r² = 0.978; P = 0.001) was observed.Discussion: In a previous study in pig herds in Brazil examining swine nasal swabs, 22.5% was positive for S. aureus and none for MRSA. One of 5 farms tested in our work also had no positive animals and 4 of them showed low frequencies, ranging from 1.7% to 12.5% with an average of 5.1%. Our results were similar to those found in Asian countries, but were very different from European data. Some factors can be associated with MRSA frequency in pig farms, such as dust, air contamination, poor hygiene, age, herd size, replacement rate and number of sources. In the present work we found a strong positive correlation (r² adjusted = 0.978; P = 0.001) between herd size and MRSA frequency, such as detected by previous authors. It might occur due to a higher risk of bacterial introduction and higher pressure of infection, easing dissemination of MRSA. Herd size may be a crucial factor to explain the frequencies found, since farms had very similar facilities and handling practices. Although the average frequency has been low in this work when compared to other countries, MRSA was present in almost all farms. This bacteria is able to transmit mecA gene to S. aureus susceptible populations, increasing MRSA frequencies over time.

Staphylococcus hyicus is the causative agent of porcine exudative epidermitis. This disorder affects animals in all producing countries and presents a widespread occurrence in Brazil. This study evaluated strains from a historical collection in order to detect the presence of exfoliative-toxin-encoding genes (SHETB, ExhA, ExhB, ExhC, ExhD), characterize the strains using PFGE, and determine their respective antimicrobial resistance profiles. The results obtained from the evaluation of 77 strains from 1982 to 1987 and 103 strains from 2012 reveal a significant change in resistance profiles between the two periods, especially regarding the antimicrobial classes of fluoroquinolones, amphenicols, lincosamides, and pleuromutilins. The levels of multidrug resistance observed in 2012 were significantly higher than those detected in the 1980s. It was not possible to correlate the resistance profiles and presence of genes encoding toxins with the groups obtained via PFGE. Only 10.5% of the strains were negative for exfoliative toxins, and different combinations of toxins genes were identified. The changes observed in the resistance pattern of this bacterial species over the 30-year period analyzed indicate that S. hyicus could be a useful indicator in resistance monitoring programs in swine production. In a country with animal protein production such as Brazil, the results of this study reinforce the need to establish consistent monitoring programs of antimicrobial resistance in animals, as already implemented in various countries of the world.

Introduction: Collecting swabs from skin lesions for bacteriological examination is frequently performed to the diagnosis of exudative epidermitis. This method is fast and non-invasive, but it depends directly on the viability of bacteria in clinical samples, which can be influenced by storage and shipment temperatures and the time of transportation. The aim of this study was to assess the capacity of four commercial transport media and swabs with no transport medium to preserve Staphylococcus hyicus (S. hyicus) for up to 10 days at room temperature and under refrigeration. Methodology: Samples were stored in swabs with no transport medium and four transport media (Amies, Amies with charcoal, Cary Blair and Stuart) for 10 days at room temperature and under refrigeration. Swabs were plated in Tween 80 Agar and colonies counted. Results: Samples kept in transport media showed better performance (P < 0.05) under refrigeration. Storage under refrigeration in Amies medium showed better results than all other transport media and swabs (P < 0.05). Amies medium and swabs with no transport medium showed comparable results in room temperature (P > 0.05). In additional, refrigerated Amies medium and swabs with no transport medium at room temperature showed high performance for up to nine and three storage days, respectively. Conclusions: The recovery of S. hyicus in samples stored in Amies medium under refrigeration was higher when compared to other transport media. In addition, swabs with no transport medium could also be indicated when samples are stored at room temperature within three days.