The objective of this study was to describe the epidemiological situation of bovine tuberculosis in Mato Grosso do Sul. The State was divided into three regions, Pantanal, Planalto Norte, and Planalto Sul. In each region, properties were randomly chosen and a pre-established number of animals were also randomly selected; these animals were submitted to the intradermal comparative cervical tuberculin diagnostic test. In total, 17,121 animals from 938 properties were tested. In cases of inconclusive results, the animals were retested with the same diagnostic procedure within a minimum interval of 60 days. An epidemiological questionnaire was administered in the properties sampled to investigate possible risk factors for the disease. In the State, the prevalence of infected herds was 1.3% (95% confidence interval [CI]: 0.72-2.37%) and that of infected animals was 0.035% (95% CI: 0.017-0.069%). Point estimates indicated a higher concentration of infected herds (2.61%; 95% CI: 1.31-5.15%) and infected animals (0.132%; 95% CI: 0.055-0.315%) in the Planalto Sul region, which has a predominance of dairy properties. The prevalence of herds infected with bovine tuberculosis was found to be associated with the production of milk, with technification in the mode of production represented by the use of mechanical milking. Thus, it is recommended that the State adopt strategies for the eradication of bovine tuberculosis, with the structuring of the surveillance system for detection and mitigation of infected herds, incorporating risk-based surveillance elements. ResumoO objetivo do presente estudo foi descrever a situação epidemiológica da tuberculose bovina no Mato Grosso do Sul. O estado foi dividido em três regiões, Pantanal, Planalto Norte e Planalto Sul. Em cada região, propriedades foram sorteadas aleatoriamente e, dentro dessas, selecionou-se também de forma aleatória um número pré-estabelecido de animais, os quais foram submetidos ao teste Tuberculínico Cervical Comparativo. No total, foram testados 17.121 animais, provenientes de 938 propriedades. Os animais que resultaram inconclusivos foram retestados com o mesmo procedimento diagnóstico em intervalo mínimo de 60 dias. Nas propriedades amostradas foi aplicado um questionário epidemiológico para averiguar possíveis fatores de risco para a enfermidade. No estado, a prevalência de focos foi de 1,3% [0,72; 2,37%] e a de animais 0,035% [0,017; 0,069%]. As estimativas pontuais indicaram uma maior concentração de focos (2,61% [1,31; 5,15%]) e de animais (0,132% [0,055; 0,315%]) na região Planalto Sul, que tem predomínio de propriedades leiteiras. Verificou-se que a condição do foco de tuberculose bovina está associada à produção de leite, com sofisticação no modo de produção representado pela utilização de ordenha mecânica. Assim, recomenda-se que o estado adote estratégias de erradicação, com a estruturação de sistema de vigilância para detecção e saneamento de focos, incorporando elementos de vigilância baseada em risco. Palavras-chave: Brasil. Fatores de risco...

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Although Brazil has one of the largest buffalo populations in the Americas, buffalo leptospirosis is still poorly explored when compared to that in bovines; thus, the aim of this research was to carry out a large serological study for leptospirosis in this species in the Brazilian Amazon. For this, we collected 1,405 serum samples from buffaloes raised in the Amazon delta region, which is considered a major area of buffalo production in Brazil. The test used was a microscopic agglutination test (MAT) adopting 34 Leptospira antigens, some of which have never been tested for buffaloes in Brazil, including autochthonous strains; in total, 20 serogroups were evaluated. From the total of 1,405 serum samples, 894 (63.6%) reacted in the MAT to at least one of the 20 serogroups, and 511 (36.4%) did not react. The serogroups Sejroe, Autumnalis and Pomona were the most prevalent, with titres ranging from 100 to 12,800, and the autochthonous strains used were not significant in relation to the reference serovars. Leptospirosis in buffaloes seems to have a serological profile similar to leptospirosis in cattle, mainly due to the prevalence of the Sejroe serogroup; however, the results of this study suggested that in the Brazilian Amazon, Leptospira strains that are serologically distinct from the autochthonous strains isolated in the southeastern region of Brazil may be circulating in these animals. Other serovars could also be inserted into the panel of antigens used in MAT for serological studies on buffaloes.

Leptospirosis is a disease of worldwide distribution that affects man and several animal species. Domestic and wild animals can behave as reservoirs of the agent. The aim of this study was to evaluate the frequency of anti-Leptospira spp. antibodies in dogs and wild small mammals from rural properties and conservation units of three municipalities of Rio Grande do Sul State, Brazil. Sera were collected from 192 domestic dogs and 132 small mammals, namely rodents of the Cricetidae and Caviidae families and marsupials of the Didelphidae family. The study used Microscopic Agglutination Test (MAT) against 23 serovars of Leptospira spp. Overall, 9.90% (19/192) dogs, and 1.51% (2/132) small mammals were seropositive. Leptospira interrogans serovar Australis was the most frequent serovar in dogs and antibodies against L. interrogans serovar Pomona were detected in a dog and a small mammal belonging to the same municipality. We conclude that in the regions studied the frequency of seropositivity in dogs is low, and leptospires do not seem to be circulating in small mammals, yet, further research is necessary to assess the real role that these animals may have for leptospirosis in the studied areas. This is the first serological survey in small mammals, including wild rodents, in the area that encompasses conservation units of great importance to Rio Grande do Sul state.

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The microscopic agglutination test (MAT) used for the serological diagnosis of leptospirosis, as a robust and inexpensive method, is still the reality in many laboratories worldwide. Both the performance and the interpretation of the MAT vary from region to region, making standardization difficult. The prediction of the probable infecting serogroup using this test is indispensable for elucidating the epidemiology of the disease; however, in veterinary medicine, many studies consider any reaction detected with a titer of 100, which may ultimately overestimate some serogroups. Thus, the aim of this study was to evaluate the usefulness of the ranking technique for predicting the probable infecting serogroup identified by the MAT, eliminating cross reactions with other serogroups. Leptospira strains (12 samples) were inoculated in hamsters, and after 30 days, serology was performed by the MAT for these animals to confirm the infecting serogroup. Using the ranking technique, the probable infectious serogroup found with the MAT was the same as that in which the strains of inoculated leptospires belonged; additionally, the technique can be applied in epidemiological studies involving herds.

Background: Leptospirosis is an endemic zoonosis in Brazil, with great impact in human and animal health. Although dogs are frequently infected by pathogenic Leptospira, the current epidemiological understanding of canine leptospirosis is mainly based on serological tests that predict the infecting serogroup/serovar. Thus, the present study aimed at identifying the causative agent for severe cases of canine leptospirosis in a highly endemic area through the isolation and characterization of the isolated strains. Results: Urine, serum and blood samples were collected from 31 dogs with suspected acute leptospirosis treated at the Veterinary Hospital Service of Santo Amaro University between 2018 and 2019. Acute infection was confirmed in 17 dogs (54.8%) by the associated use of Polymerase Chain Reaction (PCR), Microscopic Agglutination (MAT) and bacteriological culture. Eleven dogs (35.5%) had titers ≥800, with the most frequent serogroups being Autumnalis and Icterohaemorrhagiae (n = 4 each) and Canicola (n = 2). Leptospires were recovered from four dogs, and Multilocus Sequence Analysis (MLSA) revealed infection caused by L. interrogans, which were further characterized as serogroups Canicola (n=1) and Icterohaemorrhagiae (n=3). Conclusion: The identification of circulating strains in poverty-stricken locations with humans living in rural-urban interfaces may assist local authorities to implement effective prevention policies. The identity of the isolates and serological pattern of MAT titers found among the suspected dogs suggest that dogs are highly exposed to the serogroup Icterohaemorrhagiae, also indicating possible circulation of serogroups not yet isolated in Brazil, notably serogroup Autumnalis.

In the current context of deforestation and fire in the Amazon, buffaloes could be a cost-effective and sustainable alternative for cattle production in the region, as they can convert low-quality foods and be raised in floodplain areas. However, little is known about the reproductive diseases that affect these animals; thus, the purpose of this study was to perform the molecular characterization of Leptospira spp. in the urogenital tract of water buffaloes (Bubalus bubalis) raised in the Amazon River Delta region in Brazil. Samples were collected from 114 kidneys, 204 ovaries, and 160 uterine swabs of slaughtered buffaloes in the Macapá microregion of Amapá State (Brazil) and were subjected to PCR to detect bacterial DNA. Positive amplicons were sequenced to identify Leptospira species. Among the total samples, 11/473 were PCR positive (2.3%), including 10 kidney samples and one uterine swab sample. DNA sequencing identified two pathogenic species from the kidney samples: L. interrogans, accounting for 60.0% (6/10) of these samples, and L. borgpetersenii, accounting for 20.0% (2/10), while 20.0% (2/10) were identified only at the genus level. The bacterium in the uterine swab sample was identified as L. interrogans with genetic proximity to strains belonging to the serovar Hardjo. This is the first report of leptospires species identified in buffaloes from the Amazon River Delta region and revealed that these animals may be carriers of different pathogenic Leptospira species, similar to bovines, including showing genital colonization.