Rodrigo Casquero Cunha

Sporotrichosis , a subcutaneous mycosis caused by Sporothrix spp., has emerged as a major zoonotic disease in Brazil, primarily driven by Sporothrix brasiliensis . The southern state of Rio Grande do Sul exhibits distinctive ecological and climatic conditions that may shape the persistence and distribution of this pathogen in this region. This study conducted molecular and epidemiological surveillance of feline and canine sporotrichosis in southern Rio Grande do Sul, Brazil. A total of 100 isolates from the culture collection of the Veterinary Mycology Laboratory at the Federal University of Pelotas (UFPel) were analyzed by PCR targeting the calmodulin (CAL) gene for species identification. Fourteen representative isolates were sequenced and subjected to phylogenetic analysis using the Maximum Likelihood method, including reference sequences from Brazil, Paraguay, and Argentina. Epidemiological and clinical variables, including host species, sex, lesion site, and morphology, were evaluated to characterize the epidemiological and clinical profiles of sporotrichosis in the study region. S. brasiliensis and S. schenckii were identified in 97% and 3% of the isolates, respectively. The CAL-based phylogeny confirmed the monophyly of S. brasiliensis and revealed low intraspecific variability with regional clustering among southern Brazilian isolates. When interpreted within the Southern Cone context, the topology indicated a close genetic affinity between isolates from Rio Grande do Sul and reference sequences from Argentina and Paraguay. These findings confirm the territorial expansion of S. brasiliensis across southern Brazil and emphasize the importance of molecular surveillance for detecting and tracking the circulating lineages. Continuous regional monitoring is crucial for strengthening One Health strategies and mitigating the zoonotic spread of sporotrichosis in the Southern Cone.

O carrapato-do-boi é uma espécie monoxênica. No Brasil sua presença acarreta perdas de US$ 3,2 bilhões/ano. Os prejuízos econômicos incluem perda de peso, queda na produção de leite, morte, custos com acaricidas e medicamentos. A principal ferramenta é o controle químico, no entanto, a resistência dos carrapatos aos acaricidas afeta produtores e a cadeia produtiva, além dos riscos de intoxicação do aplicador, contaminação ambiental, resíduos na carne e leite. Para implantação de um sistema produtivo com raças cruzadas, com eficiência e sustentabilidade, o produtor considera aspectos econômicos para tomada de decisão. O objetivo deste manuscrito foi mensurar benefícios econômicos do Sistema Lone Tick, oferecendo indicadores de viabilidade e eficiência econômica do sistema com sustentabilidade, para apoiar a decisão dos produtores na adoção da tecnologia e minimizar o problema do carrapato. No Bioma Pampa, o Sistema Lone Tick mostrou-se promissor por reduzir o número de carrapatos abaixo de 10, promovendo a estabilidade enzoótica para Tristeza Parasitária Bovina, diminuiu em 91,6% o número de aplicações de acaricidas, mitigando a contaminação ambiental e promoveu a redução de 64,4% dos custos operacionais. O Sistema Lone Tick atende um nicho de mercado que busca a produção agroecológica preservando a biodiversidade com uma produção extensiva sustentável.

Bovine tuberculosis (bTB) is a chronic infectious disease caused by Mycobacterium bovis , which has major veterinary, economic, and zoonotic relevance. This study aimed to characterize the histopathological patterns of bTB lesions and their association with molecular detection in cattle slaughtered in Southern Brazil. Thirty-six tissue samples with lesions suggestive of bTB were collected during municipal inspection in Pelotas, Rio Grande do Sul. Polymerase chain reaction (PCR) targeting the 16 S rRNA gene was used to detect Mycobacterium species. DNA in 35/36 samples (97.2%), whereas Ziehl–Neelsen (ZN) staining revealed acid-fast bacilli in 23/36 cases (61.1%), a statistically significant difference (McNemar’s exact test, p = 0.0018). Grossly, the lesions ranged from caseous nodules to purulent and cavitary forms. Histologically, two main morphological patterns were identified: classical granulomatous lesions with complete fibrous encapsulation (19/36, 52.8%) and disorganized granulomatous inflammation lacking complete encapsulation (17/36, 47.2%). Multinucleated giant cells were present in all ZN-positive cases, whereas neutrophilic infiltration was significantly more frequent in disorganized lesions than in classical granulomas (Fisher’s exact test, p = 0.0002), suggesting active inflammation and impaired granuloma containment. PCR showed higher sensitivity than ZN staining, detecting mycobacterial DNA even in lesions with a low bacillary load. As the assay targeted the 16 S rRNA gene, results were reported as Mycobacterium spp., and species-specific methods would be required for the definitive identification of M. bovis . These findings reinforce the diagnostic value of combining histopathology and molecular methods and emphasize the importance of recognizing atypical lesion patterns for the accurate detection of bovine tuberculosis in slaughterhouse surveillance systems.

Opportunistic infections caused by the protozoa Cryptosporidium spp. and Cystoisospora belli represent a challenge for public health, particularly in immunocompromised patients. In Brazil, a country with continental dimensions and socioeconomic diversity, the epidemiology of these intestinal coccidioses is complex and often underestimated. This review article aims to consolidate current knowledge on Cryptosporidium and Cystoisospora infections in immunocompromised individuals within the Brazilian context, addressing clinical manifestations, epidemiology, risk factors, diagnostic methods, treatment options, prevention and control strategies, and challenges related to underreporting. A thorough understanding of these aspects is crucial for improving health policies, optimizing clinical management, and reducing the morbidity and mortality associated with these parasitic diseases.

Bovine tuberculosis (bTB), caused by Mycobacterium bovis, poses significant health risks to humans and animals and leads to substantial economic losses in livestock. This study analyzed the condemnation of cattle carcasses due to lesions suggestive of bTB in state-inspected abattoirs in Rio Grande do Sul, Brazil, using data from the Secretaria da Agricultura, Pecuária, Produção Sustentável e Irrigação (SEAPDR-RS) from 2015 to 2023. Data was assessed by year and by seven state mesoregions: Central East (CE), Central West (CW), Metropolitan (MET), Northeast (NE), Northwest (NW), Southeast (SE), and Southwest (SW). Financial losses were estimated based on annual cattle prices (USD/kg) in the state, assuming an average carcass weight of 247.5 kg. Over the study period, 15,351,729 cattle were slaughtered, with 42,692 carcasses condemned due to suspected bTB, yielding an overall condemnation rate of 0.28%, varying from 0.009% (SW in 2015) to 2.67% (SE in 2023). Notably, condemnation rates increased between 2019 and 2022, with peak rates in 2022 (1.64%) and 2023 (1.50%). Estimated financial losses totaled approximately USD 18.3 million during this period. Our findings highlighted the ongoing impact of bovine tuberculosis on cattle production, emphasizing the need for strengthened control measures to address concerning fluctuations in condemnation rates and associated financial losses.

Hemotropic mycoplasmas are small, pleomorphic, gram-negative, epierithrocytic bacteria that infect a wide variety of animals, including domestic cats. These microorganisms cause the disease known as feline hemotropic mycoplasmosis (MHF), also called feline infectious anemia. The objective of the study was to use PCR assays based on amplification of 16S rDNA to detect the species Mycoplasma haemofelis (Mhf) and 'Candidatus Mycoplasma haemominutum' (CMhm) in felines treated at a clinic specialized exclusively in cats in the city of Pelotas, Rio Grande do Sul. Furthermore, the research aimed to identify potential risk factors associated with the infection. A total of 253 blood samples from domestic felines were analyzed, of which 76 samples (30%) were positive for at least one species. The most detected hemoplasma was CMhm, with 51/253 (20.1%), followed by Mhf, with 23/253 (9.1%). Mhf and CMhm co-infection was detected in 2/253 (0.8%) samples. Felines with access to the street, presence of ectoparasites, co-infection with FeLV, FIV and other diseases (unhealthy animals) were more likely to be infected by hemoplasmas.

A leptospirose é uma zoonose de distribuição mundial, prevalente em regiões tropicais e subtropicais. A infecção em humanos e animais ocorre pelo contato com urina, solo úmido, água de superfície e lama contaminados. Cães desempenham um papel crucial na epidemiologia da leptospirose humana, atuando como reservatórios de leptospiras patogênicas. Este estudo teve como objetivo realizar o diagnóstico sorológico, bacteriológico e molecular da leptospirose clínica em um cão. Um canino SRD, macho, de quatro anos, foi admitido com prostração, falta de apetite, diarreia e vômitos, apresentando protocolo vacinal desatualizado. Amostras de sangue e urina foram coletadas para a realização do Teste de Soroaglutinação Microscópica (MAT), cultivo bacteriano e da Reação em Cadeia da Polimerase (PCR). O MAT revelou títulos reagentes para os sorovares Canicola (1:400) e Icterohaemorrhagiae (1:200), enquanto a PCR amplificou LipL32 na amostra de urina, um gene específico de leptospiras patogênicas. O diagnóstico sorológico foi essencial para a definição do tratamento, embora o isolamento bacteriano não tenha sido possível, mesmo observando-se células morfologicamente e com movimentos compatíveis com leptospiras. Os sinais clínicos do animal, relatados pelo tutor e confirmados no exame clínico, são compatíveis com infecção pelo sorovar Canicola. Dessa forma, o estudo destaca a importância do MAT e da PCR como ferramentas fundamentais para o diagnóstico da leptospirose, permitindo rápida intervenção terapêutica e contribuindo para a compreensão do caso clínico.

Uma zoonose mundial, a leptospirose é causada por espiroquetas patogênicas do gênero Leptospira. Ratos atuam como reservatórios, geralmente assintomáticos, abrigando a espiroqueta em seus túbulos renais. Animais domésticos, como cães, servem como portadores, excretando Leptospira na urina de forma intermitente ou contínua, contaminando o ambiente. O método mais utilizado para diagnosticar a leptospirose é o MAT, considerado o teste padrão-ouro. Neste estudo, foram utilizadas 240 amostras de soro de cães. Foram fornecidas informações sobre os animais, incluindo sexo, 151 fêmeas e 89 machos, idade, raça e área de residência, indicando que todos os animais eram domiciliados. Do total de soros, 56 testaram positivo no MAT com um título igual ou superior a 1:100. Entre os sorovares mais prevalentes, Canicola com 51,7% das reações, seguido por Grippotyphosa com 46,4% e Icterohaemorrhagiae com 41,07%. Os sorovares restantes representaram 21,4% das reações combinadas. Quanto à classificação por gênero, dos 56 soros reativos, 37 pertenciam a fêmeas e 19 a machos. Dada a sua condição de zoonose, a preocupação contínua com a transmissão e, especialmente, a prevenção da leptospirose em cães é imperativa para evitar sua disseminação em centros urbanos e áreas sujeitas a inundações, como Pelotas.