Different Multidrug-Resistant Salmonella spp. Serovars Isolated from Slaughter Calves in Southern Brazil.

Bovines are carriers of Salmonella spp., a relevant foodborne pathogen, acting as contamination sources in slaughterhouses. Calves are prone to infection, and antimicrobial resistance may occur in such bacteria. This study aimed to determine the prevalence and virulence determinants of Salmonella spp. recovered from calves in the Rio Grande do Sul state, Brazil. Eighty-five calves' carcasses were evaluated (leather and veal meat). Thirteen Salmonella spp. isolates (8%) from 11 animals (13%) were obtained only from leather, indicating that contamination occurred before slaughter and that the meat was safe regarding this aspect. The serotypes S. Minnesota, S. Abony, S. Cerro, and S. Gafsa were identified, and all isolates were multidrug-resistant. The isolates had at least 19 virulence-related genes, and the blaOXA-48 resistance gene was detected in three (23%). The data suggest that treating infections caused by these bacteria may be difficult in animals from these farms and can also be an extended human health problem.

Pathological and etiological characterization of cases of bovine abortion due to sporadic bacterial and mycotic infections.

Opportunistic bacteria and fungi are commonly reported causes of bovine abortion in a small percentage of fetal losses of infectious etiology in cattle. The objective of this study was to characterize the pathological and etiological findings in fetuses aborted due to secondary bacterial and fungal infections submitted for postmortem examination between 2004 and 2019 in the State of Rio Grande do Sul, Brazil. Nineteen cases of bacterial etiology and five cases of fungal etiology were assessed. In cases of bacterial etiology, gross changes were uncommon and two different microscopic patterns were observed: (1) primary bronchopneumonia with occasional dissemination in cases of Staphylococcus sp., Streptococcus sp., and Mannheimia haemolytica infections; and (2) systemic disease with sepsis in cases of Escherichia coli and Listeria sp. infections. Aspergillus sp. was the main fungal agent identified, and cases of mycotic abortion were characterized by placentitis, dermatitis, and pneumonia. Fetal membranes were available for examination in less than half of the submissions (11/24), and placental lesions were observed in all cases. This study reaffirms the importance of postmortem examinations in the determination of causes of fetal loss in cattle and highlights pathological findings commonly observed in fetuses aborted due to sporadic bacterial and fungal agents.

Molecular survey of porcine respiratory disease complex pathogens in Brazilian wild boars.

Wild boar (Sus scrofa) is an exotic invasive species in Brazil and may be a reservoir for several pathogens, including those related to the porcine respiratory disease complex (PRDC), a critical infectious disease in pig production. The objective of this study was to investigate viral and bacterial pathogens related to PRDC in free-living wild boars from Brazil. Eighty animals were examined in search of genomes of porcine circovirus 2 (PCV2), Torque teno Sus virus 1a (TTSuV1a) and 1b (TTSuV1b), Influenza A virus (IAV), Actinobacillus pleuropneumoniae, Glaesserella parasuis, Pasteurella multocida, and Mycoplasma hyopneumoniae. The results demonstrated that 57.5% (46/80) of the animals had at least one detected pathogen, and 11.3% of them (9/80) were co-infected. TTSuV1a was the most prevalent genome, for which risk factors were associated with increased contact between wild boars and other animals. The other pathogens were detected at much lower frequencies or not detected (M. hyopneumoniae and IAV). An additional IAV serology search identified H1N1pdm09 antibodies in 35.5% (16/45) of the wild boars, bringing concern related to public health. In conclusion, wild boars are infected with pathogens that cause swine diseases, so their eventual contact with domestic pigs might risk animal production in Brazil.

Investigation of Mycobacterium bovis and Metastrongylus sp. co-infection and its relationship to tuberculosis lesions' occurrence in wild boars.

Animal tuberculosis (aTB) is a zoonotic disease characterized by granulomatous lesions on affected tissues, occurring as a consequence of immunological response to infection. Mycobacterium bovis, the main causative agent of aTB, was investigated in Brazilian wild boars with 37.7 % (29/77) positivity. Among these animals, most had no macroscopic tuberculosis-like lesions (89.6 %; 26/29). The existence of co-infections, which may alter an individual's immune response to an immunological challenge, could influence the formation of tuberculosis lesions. Therefore, we investigated Metastrongylus sp. and aTB co-infection to seek an explanation for the absence of macroscopic lesions in aTB. Of the tested animals, 77.9 % (60/77) had Metastrongylus sp., however, there was no association between its occurrence and the pattern of aTB lesions. The absence of tuberculous lesions in infected animals is worrisome, especially to hunters who handle their carcasses, potentially assuming that the animal is healthy. Studies evaluating other possibilities that can explain the absence of lesions in infected animals should be carried out to better understand these findings.

Molecular identification of Mycobacterium spp. isolated from Brazilian wild boars.

Wild boars (Sus scrofa) are susceptible to mycobacterial infections, including tuberculous and non-tuberculous mycobacteria. Recently, Mycobacterium spp. infections were described in Brazilian wild boars, which can act as bacterial reservoirs. Here, we aim to characterize 15 Mycobacterium spp. isolates from Brazilian wild boars' tissues through partial sequencing of the heat shock protein 65 (hsp65) gene and phylogenetic analysis. The isolates were classified as M. tuberculosis (33.3%), M. colombiense (33.3%), M. avium subsp. hominissuis (13.3%), M. parmense (13.3%) and M. mantenii (6.66%). The isolates classified as M. tuberculosis were confirmed as variant bovis by PCR. At phylogenetic analysis some isolates formed separated clades, indicating genetic variability. Different Mycobacterium species were recovered from wild boars circulating in Brazil, including mycobacteria associated to zoonotic infections, such as M. tuberculosis. In addition, this is the first report in Brazilian wild boars on M. mantenii and M. parmense detection, two recently described pathogenic mycobacteria. However, the isolates' genetic diversity-i.e. identities lower than 100% when compared to reference sequences-suggests that other genotyping tools would allow a deeper characterization. Nonetheless, the reported data contributes to the knowledge on mycobacterial infections in wild boars from Brazil.

Tuberculosis outbreak in intensive swine farming from southern Brazil / Surto de tuberculose em suínos de criação intensiva no Sul do Brasil

ABSTRACT: Mycobacterium tuberculosis var. bovis is the etiologic agent of animal tuberculosis (aTB), a neglected zoonotic disease. Animal tuberculosis can affect many species, including swine. aTB-consistent granulomas in these animals lead to carcass disposal, generating economic losses and posing risks to human health. In the present study, an aTB outbreak was identified at an intensive swine farming operation in Southern Brazil. Inspection during swine slaughter revealed aTB-suspected lesions, which were collected for diagnosis by histology, PCR, and bacterial isolation. The animals had no clinical signs of tuberculosis. Granulomatous lesions were identified in 0.73% (59/8,071) of the slaughtered swine, and were confirmed by histology. Nine samples were further examined by PCR and bacterial isolation, with 44.4% and 55.5% positive results, respectively. Data from abattoirs subjected to federal surveillance show an aTB prevalence in Brazil of <0.001%. The present data thus indicate a swine aTB outbreak in intensive breeding. Swine infection can be related to exposure to infected animals or to contaminated food or environment. Biosecurity measures must be taken to avoid aTB transmission. Although certified swine breeding farms adopt such measures, this report indicates that constant monitoring is crucial, and greater control in swine breeding and finishing units is required to prevent outbreaks and spread of tuberculosis.

RESUMO: Mycobacterium bovis é o agente etiológico da tuberculose animal (aTB), uma doença zoonótica negligenciada. A tuberculose animal pode afetar muitas espécies, incluindo suínos. Os granulomas compatíveis com a aTB nesses animais levam ao descarte de carcaças, gerando perdas econômicas e trazendo riscos à saúde humana. No presente estudo, um surto de aTB foi identificado em um sistema de criação intensiva de suínos na região Sul do Brasil. A inspeção durante um abate de suínos revelou lesões suspeitas de tuberculose, as quais foram coletadas para diagnóstico por histologia, PCR e isolamento bacteriano. Os animais não apresentavam sinais clínicos de tuberculose. Lesões granulomatosas foram identificadas em 0,73% (59/8.071) dos suínos abatidos, e foram confirmadas pela histologia. Nove amostras foram posteriormente examinadas por PCR e isolamento bacteriano, com 44,4% e 55,5% de resultados positivos, respectivamente. Dados de frigoríficos submetidos à vigilância federal demostram prevalência da aTB de < 0,001% no Brasil. Os dados presentes indicam, portanto, um surto de aTB em suínos de criação intensiva. A infecção em suínos pode estar relacionada à exposição a animais infectados, alimentos ou ambientes contaminados. Medidas de biossegurança devem ser tomadas para evitar a transmissão da aTB. Embora as granjas suinícolas certificadas adotem tais medidas, este relato indica que o monitoramento constante é crucial, e maior controle nas unidades de criação e terminação de suínos é necessário para prevenir surtos e disseminação da tuberculose.

Penile Tuberculosis in a Bull.

We describe a case of penile tuberculosis in a bull. The prepuce was thickened, firm and pale with multifocal to coalescent caseous nodules, and the inguinal and mesenteric lymph nodes were moderately enlarged. Lesions in the prepuce, penis and lymph nodes were characterized by multifocal to coalescent areas of caseous necrosis and marked granulomatous inflammation. Acid-fast bacilli were seen within necrotic foci and Langhans giant cells. Mycobacteriumtuberculosis var. bovis was identified in inguinal lymph nodes by the polymerase chain reaction technique and by bacterial isolation. Although rare, tuberculosis should be considered in the differential diagnosis of granulomatous lesions in the genital tract of bulls.

A molecular strategy to optimize bovine tuberculosis post-mortem diagnosis and the exposure to Mycobacterium tuberculosis variant bovis.

Bovine tuberculosis (bTB) is a zoonotic disease caused by Mycobacterium tuberculosis var. bovis, for which the definitive diagnosis is accomplished by bacterial isolation, which has biosafety issues and requires long time. Thus, diagnostic methods with potential to be faster and more efficient can represent an advance in bTB epidemiological knowledge and decrease exposure to M. tuberculosis var. bovis. This study aimed to validate a molecular test for bTB post-mortem diagnosis, as a strategy to reduce waste in bovine production. A total of 185 tissues from animals of infected herds or with suspected lesions at abattoir were evaluated through bacterial isolation, PCR and histopathology. PCR and histopathology showed sensitivities of 45.1% and 71.2%, respectively, and specificities of 83.3% and 83.0%, respectively, when compared to bacterial isolation. The combination of both tests resulted in enhanced specificity and positive predictive values.Therefore, PCR in conjunction with histopathology may be used as screening, in which concordant results can be considered conclusive, and discordant results may be submitted to bacterial isolation.

Mycobacterium tuberculosis var. tuberculosis infection in two captive black capuchins (Sapajus nigritus) in Southern Brazil.

Tuberculosis is a common zooanthroponosis in humans with a high incidence in Brazil, but it may also affect non-human primates (NHPs), of which Old World primates are most commonly involved. Nonetheless, its occurrence in New World primates is unknown, and therefore, this study aimed to describe the infection by Mycobacterium tuberculosis variant tuberculosis in two captive black capuchin monkeys (Sapajus nigritus) in Southern Brazil. The primates were housed in the same enclosure, wherein close contact with humans frequently occurred, and presented apathy, anorexia, and death in a clinical course of 15 days to 2 months. At the necropsy, the tracheobronchial lymph nodes were markedly enlarged and firm to hard and on the cut surface had a caseous aspect. The lungs exhibited two injury patterns: multifocal and disseminated. Microscopically, the lungs exhibited multifocal to coalescing necrotic granulomas and non-necrotic granulomas, with multiple acid-fast bacilli within the cytoplasm of epithelioid macrophages and multinucleated giant cells. Bacilli were also labeled upon immunohistochemistry (IHC) for Mycobacterium tuberculosis. Microbiological culture of lung samples from both cases yielded colonies compatible with M. tuberculosis. The isolates were identified as M. tuberculosis var. tuberculosis through polymerase chain reaction (PCR). Although tuberculosis is poorly described in New World primates, M. tuberculosis var. tuberculosis may cause a highly contagious and progressive disease with high mortality in black capuchin monkeys (S. nigritus).

Valvular endocarditis associated with Helcococcus ovis in a cow in Southern Brazil / Endocardite vegetativa associada à Helcococcus ovis em uma vaca no Sul do Brasil

ABSTRACT: A 4-year-old cow with a history of breathing difficulty, progressive weight loss, and muffled heart sound was treated for a period of two weeks, but died and underwent necropsy examination. Macroscopic examination revealed heart with vegetative proliferative lesion firmly adhered to pulmonary valve, lungs with marked consolidation, and the presence of thrombus in vessels. There were grade II ulcers in abomasal mucosa associated to blood clots. Microscopic examination revealed marked thickening of the pulmonary valve due to the proliferation of fibrous connective tissue, inflammatory neutrophil infiltration, fibrin deposition, and a significant number of coccoid basophilic bacteria. Septic thromboemboli were present in the large and small pulmonary blood vessels suggestive of embolic pneumonia. The bacterial culture of the valve showed growth of small, nonhemolytic colonies that demonstrated satellitism to coagulase-negative staphylococci contaminating colonies, which were subjected to 16S gene sequencing and were compatible with Helcococcus ovis in GenBank. This was the first report of H. ovis endocarditis in cattle in South America.

RESUMO: Um bovino, fêmea, 4 anos com histórico de dificuldade respiratória, perda de peso progressiva e som cardíaco abafado, foi tratado por um período de duas semanas, porém veio a óbito e foi submetido a exame de necropsia. No exame macroscópico, notou-se coração com lesão proliferativa vegetativa firmemente aderida em valva pulmonar, pulmões com consolidação acentuada, e presença de trombos no interior de vasos. Havia ainda úlcera abomasal grau II em mucosa associada a coágulo sanguíneo. No exame microscópico notou-se acentuado espessamento da valva pulmonar por proliferação de tecido conjuntivo fibroso, infiltrado inflamatório de neutrófilos, deposição de fibrina e acentuado número de miríades bacterianas basofílicas cocoides. Tromboembolia séptica foi vista no interior de vasos pulmonares de pequeno e médio calibre, sugestivo de pneumonia embólica. Em cultivo bacteriano da valva notou-se crescimento de colônias pequenas, não hemolíticas que demonstravam satelitismo a colônias contaminantes de estafilococos coagulase negativa, essas foram submetidas ao sequenciamento do gene 16S e foram compatíveis com Helcococcus ovis no GenBank. Este foi o primeiro relato de endocardite por H. ovis em bovino na América do Sul.

Bacterial endocarditis and increased cardiac troponin I levels in a brown howler monkey (Alouatta guariba clamitans) with an interventricular septal defect.

A brown howler monkey (Alouatta guariba clamitans) was presented with lethargy, hyporexia, cough and heart murmur. The complementary tests and necropsy revealed pleuropneumonia, bacterial endocarditis and interventricular septal defect. To the best of our knowledge, this is the first report of increased cardiac troponin I levels in this species.

Mannheimia haemolytica pleuropneumonia in goats associated with shipping stress / Pleuropneumonia por Mannheimia haemolytica em caprinos associada ao estresse de transporte

ABSTRACT: This study described the epidemiological, clinical, pathological and bacteriological aspects of Mannheimia haemolytica pleuropneumonia in goats associated with shipping stress. Forty goats transported from the Northeast to the Southern region of Brazil died during shipment, or 2-3 days after unloading. Clinical signs included dyspnea, mucopurulent nasal discharge, and coughing. All goats were necropsied, and multiple tissues were collected for histopathological analysis and involved agent identifications. All lungs showed pulmonary consolidation, predominantly affecting the cranioventral lobes, in addition to the marked fibrinous pleuritis, pleural thickening, and pleural adhesions, that affected 90% of the goats. Histologically, there was fibrino-suppurative pleuropneumonia characterized by a diffuse neutrophilic infiltrate admixed with fibrin. Non-hemolytic [85% (34/40)] and hemolytic [15% (6/40)] species were obtained in bacteriological culture. Fir Mannheimia spp. was reported in 26 isolates and subsequently confirmed as M. haemolytica (99% identity), after amplification and partial sequencing of the 16S rDNA gene. Stress may trigger the development of bacterial pleuropneumonia in goats, and non-hemolytic strains of M. haemolytica may cause this condition in goats with severe immunosuppression.

RESUMO: Descreve-se os aspectos epidemiológicos, clínicos, patológicos e bacteriológicos da pleuropneumonia por Mannheimia haemolytica em caprinos, após transporte prolongado. Quarenta caprinos transportados da região Nordeste para a região Sul do Brasil morreram durante a viagem ou 2-3 dias após o desembarque. Clinicamente, observou-se dispneia, secreção nasal mucopurulenta e tosse. Na necropsia foram coletados múltiplos fragmentos de órgãos para análises histopatológicas e identificação do agente envolvido. Todos os pulmões apresentaram consolidação pulmonar predominantemente em região cranioventral, associada à deposição acentuada de fibrina, espessamento e aderência pleurais em 90% dos casos. Histologicamente, havia pleuropneumonia fibrinossupurativa caracterizada por infiltrado neutrofílico difuso associado à fibrina. Colônias não hemolíticas [85% (34/40)] e hemolíticas [15% (6/40)] foram obtidas pelo isolamento bacteriológico. Mannheimia spp. foi isolada em 26 amostras, os quais posteriormente foram confirmados como Mannheimia haemolytica (99% de identidade), pela amplificação e sequenciamento parcial do gene 16S rDNA. O estresse pode favorecer o desenvolvimento de pleuropneumonia bacteriana em caprinos, e cepas não hemolíticas de M. haemolytica podem causar doença em animais com imunodepressão acentuada.