RESUMO

Antimicrobial resistance is a natural mechanism in microorganisms, making the treatment of infections more complex in human and veterinary medicine. Global exotic and ornamental bird markets have significantly increased, and the close relationship between pets and humans makes exploring the potential role of these birds as vectors for the spread of antimicrobial-resistant bacteria imperative. This study aimed to use culture-dependent methods to investigate cloacal bacteria and the presence of antibiotic-resistant bacteria in four breeding stocks of ornamental birds. Cloacal swab samples were collected from 53 birds (canaries = 32, cockatiels = 17, and budgies = 4) and used for culturing and isolating facultative anaerobic and/or obligatory aerobic Gram-positive and Gram-negative bacteria. The antimicrobial susceptibility profile of each isolate was determined by the disk diffusion method. Thirty-four isolates were obtained, most of which belonged to the Staphylococcus genus. Bacterial richness was higher in canaries and in one of the breeding stockings, where Gram-negative bacteria were more abundant than in the others. In addition, canaries exhibited a predominance of resistant isolates, particularly multidrug-resistant strains, probably due to prophylactic antimicrobial usage. Most Gram-negative bacteria were resistant to at least one drug tested. A vancomycin-resistant Enterococcus faecalis strain was isolated. Most Staphylococcus strains were resistant to gentamycin, followed by penicillin. Eight strains were cefoxitin-resistant, including oxacillin-resistant S. epidermidis, in which the mecA gene was detected. Understanding the prevalence of resistance in avian species is crucial in the collaborative pursuit of maintaining antibiotic effectiveness and strengthening public health defense against emerging infectious risks.

A resistência antimicrobiana é um mecanismo natural dos microrganismos, complicando o tratamento de infecções na medicina humana e veterinária. O mercado global de aves exóticas e ornamentais cresceu significativamente, e a relação próxima entre esses animais e humanos destaca a necessidade de investigar o papel das aves na disseminação de bactérias resistentes. Este estudo utilizou métodos dependentes de cultura para examinar bactérias cloacais e a presença de resistência a antibióticos em quatro plantéis de aves ornamentais. Amostras de suabe cloacal foram coletadas de 53 aves (canários = 32, calopsitas = 17, periquitos = 4) e usadas para cultivar e isolar bactérias Gram-positivas e Gram-negativas, facultativas anaeróbias e aeróbias obrigatórias. A suscetibilidade antimicrobiana foi determinada pelo método de difusão em disco. Foram obtidos 34 isolados, principalmente do gênero Staphylococcus. A riqueza bacteriana foi maior nos canários e em um dos plantéis, onde houve aumento de Gram-negativos. Canários mostraram predominância de isolados resistentes, especialmente cepas multirresistentes, provavelmente devido ao uso profilático de antimicrobianos. A maioria das bactérias Gram-negativas foi resistente a pelo menos um fármaco testado. Um Enterococcus faecalis resistente à vancomicina foi isolado. A maioria dos Staphylococcus foi resistente à gentamicina e penicilina; oito cepas foram resistentes à cefoxitina, incluindo S. epidermidis resistente à oxacilina com o gene mecA detectado. Compreender a prevalência de resistência em aves é crucial para manter a eficácia dos antibióticos e fortalecer a saúde pública contra riscos infecciosos emergentes.

RESUMO

Hepatic injuries in COVID-19 are not yet fully understood and indirect pathways (without viral replication in the liver) have been associated with the activation of vascular mechanisms of liver injury in humans infected with SARS-CoV-2. Golden Syrian hamsters are an effective model for experimental reproduction of moderate and self-limiting lung disease during SARS-CoV-2 infection. As observed in humans, this experimental model reproduces lesions of bronchointerstitial pneumonia and pulmonary vascular lesions, including endotheliitis (attachment of lymphoid cells to the luminal surface of endothelium). Extrapulmonary vascular lesions are well documented in COVID-19, but such extrapulmonary vascular lesions have not yet been described in the Golden Syrian hamster model of SARS-CoV-2 infection. The study aimed to evaluate microscopic liver lesions in Golden Syrian hamsters experimentally infected with SARS-CoV-2. In total, 38 conventional Golden Syrian hamsters, divided into infected group (n=24) and mock-infected group (n=14), were euthanized at 2-, 3-, 4-, 5-, 7-, 14-, and 15-days post infection with SARS-CoV-2. Liver fragments were evaluated by histopathology and immunohistochemical detection of SARS-CoV-2 Spike S2 antigens. The frequencies of portal vein endotheliitis, lobular activity, hepatocellular degeneration, and lobular vascular changes were higher among SARS-CoV-2-infected animals. Spike S2 antigen was not detected in liver. The main results indicate that SARS-CoV-2 infection exacerbated vascular and inflammatory lesions in the liver of hamsters with pre-existing hepatitis of unknown origin. A potential application of this animal model in studies of the pathogenesis and evolution of liver lesions associated with SARS-CoV-2 infection still needs further evaluation.

Assuntos

RESUMO

BACKGROUND: The periparturient period in dairy cows is marked by immunosuppression which increases the likelihood of infectious disorders, particularly also mastitis. An in-depth understanding of peripartum leukocyte biology is vital for the implementation of highly successful post-partum disease prevention measures. Immune checkpoint molecules, such as programmed death 1 (PD-1) and cytotoxic T-lymphocyte antigen 4 (CTLA-4), are critical inhibitory receptors expressed on immune cells, particularly T cells, that drive immunosuppressive signaling pathways. However, the potential role of immune checkpoint molecules expression in T-cells on udder health has never been explored. Thus, the association between the occurrence of new postpartum intramammary infections (IMIs) and the expression of programmed cell death protein 1 (PD-1) and cytotoxic T-lymphocyte-associated antigen-4 (CTLA-4) on blood T-cells during the peripartum period was investigated. RESULTS: In this study, the incidence of IMIs by any pathogen in early lactation was not associated with a higher expression of PD-1 and CTLA-4 in the periparturient period. However, the incidence of IMIs by major pathogens throughout the first month of lactation was significantly associated with higher expression of PD-1 at 14 days before calving (P = 0.03) and CTLA-4 at parturition (P = 0.03) by blood T-cells. Also, the expression of CTLA-4 at D0 (P = 0.012) by T-cells was associated with the occurrence of persistent IMIs during the first month of lactation. CONCLUSIONS: To our knowledge, this is the first report to investigate the expression of PD-1 and CTLA-4 by blood T-lymphocytes during the periparturient period in dairy cows and to explore their relationship with the incidence of new IMIs in the postpartum period. Thus, a comprehensive understanding of leukocyte biology during peripartum would appear to be a prerequisite for the identification of resilient dairy cows or targets innovative (immunological) non-antibiotic approaches in the transition period.

Assuntos

RESUMO

ABSTRACT Hepatic injuries in COVID-19 are not yet fully understood and indirect pathways (without viral replication in the liver) have been associated with the activation of vascular mechanisms of liver injury in humans infected with SARS-CoV-2. Golden Syrian hamsters are an effective model for experimental reproduction of moderate and self-limiting lung disease during SARS-CoV-2 infection. As observed in humans, this experimental model reproduces lesions of bronchointerstitial pneumonia and pulmonary vascular lesions, including endotheliitis (attachment of lymphoid cells to the luminal surface of endothelium). Extrapulmonary vascular lesions are well documented in COVID-19, but such extrapulmonary vascular lesions have not yet been described in the Golden Syrian hamster model of SARS-CoV-2 infection. The study aimed to evaluate microscopic liver lesions in Golden Syrian hamsters experimentally infected with SARS-CoV-2. In total, 38 conventional Golden Syrian hamsters, divided into infected group (n=24) and mock-infected group (n=14), were euthanized at 2-, 3-, 4-, 5-, 7-, 14-, and 15-days post infection with SARS-CoV-2. Liver fragments were evaluated by histopathology and immunohistochemical detection of SARS-CoV-2 Spike S2 antigens. The frequencies of portal vein endotheliitis, lobular activity, hepatocellular degeneration, and lobular vascular changes were higher among SARS-CoV-2-infected animals. Spike S2 antigen was not detected in liver. The main results indicate that SARS-CoV-2 infection exacerbated vascular and inflammatory lesions in the liver of hamsters with pre-existing hepatitis of unknown origin. A potential application of this animal model in studies of the pathogenesis and evolution of liver lesions associated with SARS-CoV-2 infection still needs further evaluation.

RESUMO

Leptospirosis, caused by Leptospira, is a zoonotic disease that, in horses, is linked to abortions, uveitis, and sporadic occurrences of liver and kidney disease, often resulting in significant economic losses for farmers. Research on the prevalence of leptospirosis in horses in the central-west region of Brazil has been relatively scarce. Thus, the present study aimed to determine the prevalence of leptospirosis in equine herds in the state of Goiás (Central Brazil). Blood samples were collected from 894 equids at 294 randomly selected farms divided into three different strata according to their herd characteristics. The microscopic agglutination test for the detection of anti-Leptospira agglutinins was carried out and the results showed that among the 294 sampled farms, 213 (72.9%; CI 95% 71.7-78.9) had one or more animals positive for leptospirosis, and of the 894 horses sampled, 513 (61.6%; CI 95% 54.3-69.0) were seropositive for leptospirosis. Djasiman, Icterohaemorrhagiae, and Australis were the most prevalent serogroups. The results showed a high prevalence of seropositive animals and a widespread distribution of positive farms in the state of Goiás. Thus, environmental sanitation measures and health education to prevent and control equine leptospirosis in the state are required.

RESUMO

Little is known about the influence of the urban environments on bat species 'ecology. The urbanization process potentially lead to critical ecological changes in bat communities' intra and interspecific pathogenic transmissions dynamics. To date, the monitoring of pathogens in bats in Brazil has only been done with bats found dead or alive in households, from rabies surveillance systems. The present work aimed to investigate how urbanization influenced bat richness, relative abundance and pathogen occurrence. Most captured bats were Phyllostomidae, especially Sturnira lilium, Artibeus lituratus, A. fimbriatus, Glossophaga soricina, and Platyrrhinus lineatus, among others. From preserved-rural towards urban areas the lesser the bat richness, the higher the relative abundance of the captured bats. Noise level, luminosity and relative humidity correlated with bat abundance. The proportion of genders, sexually active bats and their size (weight, right forearm length, and body condition index) were stable throughout the investigation. Still, the proportion of pregnant females was higher in Spring and the number of juveniles in Summer, evidencing the seasonality of reproduction. Several Enterobacteria were isolated, evidencing a significant role of bats in the circulation of pathogens of medical and veterinary interest. These results are crucial in the pursuit of a harmonious coexistence between humans, bats and domestic animals in areas with different levels of anthropization.

Assuntos

RESUMO

Bovine brucellosis, mainly caused by Brucella abortus, is a worldwide distribution anthropozoonosis that causes great economic losses. In 2001, Brazil launched the National Program for the Control and Eradication of Brucellosis and Tuberculosis (PNCEBT). Contemporaneously, a great effort to characterize the epidemiology of the disease in Brazilian states was started. In the state of Rondônia, a first epidemiological study was carried out in 2004, revealing a prevalence of 35.2% of infected herds and 6.22% of seropositive females. In 2014, after a successful heifer vaccination program with strain 19 (S19), a second study detected a reduction in the prevalence of infected herds to 12.3% and of seropositive females to 1.9%. The present study aimed to quantify and compare the costs and benefits related to the control of bovine brucellosis in the state through an accounting analysis. Vaccinating heifers and performing serological tests to move animals were computed as private costs. The expenditures of the state official veterinary service for brucellosis control were considered public cost. The considered benefits of lowering prevalence were decreased cow replacement, decreased abortions, decreased perinatal and cow mortality, and increased milk production. Considering private and public costs, the net present value (NPV) was estimated at US$ 18.3 million, the internal rate of return (IRR) was calculated at 23%, and the benefit-cost ratio (BCR) was 1.7. When considering only the private costs, the NPV was US$34.9 million, the IRR was 49%, and the BCR was 3.0, meaning that the bovine producer had a return of 3 for each unit of currency invested. The results showed that the bovine brucellosis control measures implemented in the state of Rondônia, which had as its main strategy the vaccination of heifers with S19, produced highly advantageous economic results. The state should continue with its vaccination program, stimulating the use of the RB51 vaccine in addition to S19, to achieve further reductions in prevalence at low cost.

Assuntos

RESUMO

Brucellosis in equines, including horses, donkeys, and mules, is characterized by abscesses in tendons, bursae, and joints. Reproductive disorders, which are common in other animals, are rare in both males and females. Joint breeding of horses, cattle, and pigs was found as the main risk factor for equine brucellosis, with the transmission from equines to cattle or among equines possible, although unlikely. Hence, evaluation of the disease in equines can be considered an indirect indicator of the effectiveness of brucellosis control measures employed for other domestic species. Generally, the disease in equines reflects disease status in the sympatric domestic species, mainly cattle. It is important to note that in equines, the disease has no validated diagnostic test, which limits the interpretation of available data. Finally, it is important to mention that equines also represent significant Brucella spp. infection sources for humans. Considering the zoonotic aspect of brucellosis, the significant losses due to infection, and the representativeness of horses, mules, and donkeys in the society, as well as the continuous efforts to control and eradicate the disease in livestock, in this review, we covered the various aspects of brucellosis in equines and compile the sparse and diffuse information on the subject.

Assuntos

RESUMO

Glanders is an anthropozoonosis caused by the bacteria Burkholderia mallei, affecting mainly equids. It has been eradicated in North America, Australia, and Western Europe, but continues to occur sporadically in countries in Asia, Africa, the Middle East, and South America. Its notification is mandatory by the World Organization for Animal Health. After 30 years, the disease reappeared in Brazil in 1999 and, thereafter, 1,413 outbreaks have been reported. However, the epidemiological situation of the disease in the country is not adequately known. Thus, 2718 animals from 654 properties in the state of Pará were randomly selected by sampling and examined using a serial protocol with Complement Fixation and Western Blot serological tests. The prevalence of properties infected with glanders in the state was estimated at 1.68% [0.84; 3.33] and of seropositive animals at 0.50% [0.27; 0.94]. The introduction of animals was individualized as a risk factor for disease introduction in the properties (OR = 5.9 [1.4; 25.5]). Despite the low prevalence of infected properties and seropositive animals, the state must review actions to fight the disease, considering that the strategies implemented have not affected the endemic balance of the disease. This process must involve all public and private agents interested in the topic.

RESUMO

This study aimed to assess the effects of different spray-dried plasma (SDP) feeding programmes to pigs on performance, intestinal histomorphology and faecal bacterial shedding after an Escherichia coli K88 challenge. A total of 96 piglets (5.77 ± 0.01 kg) were weaned at 21 days of age (Day 0) and challenged with 3 ml of 1 × 1010 CFU of E. coli K88 in total 3.0 × 1010 CFU/animal on Days 0, 2 and 4. Pigs were fed nursery diets containing 0.0%, 3.0%, 6.0% or 9.0% SDP from weaning to 35 days of age; 0.0%, 1.5%, 3.0% or 4.5% SDP from 36 to 49 days; and the same control diet (without SDP), for the last 10 days of the experiment (50-59 days of age). Performance was measured from 35 to 59 days of age and faecal bacterial shedding and intestinal histomorphometry were evaluated at Days 28 and 49 of age respectively. From 21 to 35 days of age, there was a linear effect for body weight (BW) and average daily gain (ADG), a trend of linear effect for average daily feed intake (ADFI) and a quadratic effect for feed:gain ratio (FG). From 21 to 49 days, the 9.0:4.5% and 6.0:3.0% SDP feeding programmes improved BW, ADG and FG when compared to the other treatments. At 59 days of age, BW and ADG were increased by the two highest SDP feeding programmes. The 9.0:4.5% SDP feeding programme increased ADFI from 21 to 59 days of age, with 6.0:3.0% being intermediate and the other two treatments being lowest. The CFU counts of E. coli/g of faeces decreased linearly with increasing addition of SDP. These results indicate that an extended inclusion of increased SDP levels in post-weaning diets can improve growth potential and decrease bacterial shedding induced by E. coli K88.

Assuntos

RESUMO

The present study explored the predictive values of milk leukocyte differentials (MLD) as a basis for improving the diagnosis of intramammary infections (IMIs) and subclinical mastitis. Quarter milk samples were collected for bacteriological analysis, quarter somatic cell count (qSCC), and MLD. The MLD were assessed using the cytospin technique, direct microscopic smears, and flow cytometry. The predictive values of each single leukocyte population and useful potential indices that could better reflect immune complexity were also calculated. Changes in the percentage of any leukocyte alone failed to substantially improve the predictive value of qSCC in diagnosing IMIs. Although certain parameters increased the area under the receiver operating characteristic curve (ROC curve) as a result of increased specificity values, a slight reduction in sensitivity was observed. The so-called CD8 complex was a unique parameter which improved both the sensitivity (78.79 %) and the specificity (80.77 %) in IMI diagnosis, resulting in the highest area under the ROC curve (0.87). To diagnose subclinical mastitis, the percentage of macrophages and the sum of the percentage PMNLs and T CD8+ cells divided by the percentage of macrophages showed the highest predictive values (sensitivity = 79.63, specificity = 73.68, and area under the ROC curve = 0.83) in the differentiation of the inflammatory condition status of cows. In conclusion, this study provides further insights into using T CD8+ lymphocytes in diagnosing bovine IMIs, combined with PMNLs and macrophages. The antidromic trend of macrophages vs. PMNLs and T CD8+ lymphocytes due to the increasing qSCCs was crucial to differentiating quarters under both inflammatory and non-inflammatory conditions.

Assuntos

RESUMO

This study evaluated the genetic diversity and antimicrobial susceptibility of Staphylococcus aureus isolates from dairy cows in Minas Gerais, Brazil. Thirty-seven isolates from five municipalities (8 herds) were genotyped using multi-locus sequence typing (MLST) and susceptibility to 12 antimicrobial agents was tested using the disk diffusion method. High resistance rates for penicillin [75.68% (28/37)], ampicillin [70.27% (26/37)], and tetracycline [70.27% (26/37)] were detected. Multidrug resistance was observed in seven [18.92% (7/37)] isolates, and two were suggestive of Methicillin-resistant Staphylococcus aureus (MRSA). Among the 37 isolates, 33 novel sequence types (ST) and two known STs (ST126 and ST746) were identified in MLST. The clonal complexes more frequently observed were: CC97 [78.38%; (29/37)], CC1 [8.11%; (3/37)] and CC5 [5.40%; (2/37)]. Minimum­spanning tree (MST) analysis according to data from municipalities, herds, and resistance patterns for all isolates did not show any clustering pattern. However, the MST comparing all Brazilian S. aureus isolates deposited in the PubMLST database and from this study depicted an association between the genotype and strain origin (clinical sample). Isolates from this study that belong to CC97 were close to database isolates from milk and dairy products, while those that belong to CC1 and CC5 were close to database isolates from human sources and the environment of dairy farms or industries. In conclusion, our results showed a high rate of resistance to penicillins and tetracyclines and great genetic diversity among the S. aureus isolates from bovine mastitis genotyped in the present study.

Este estudo teve como objetivo avaliar a diversidade genética e a suscetibilidade a antimicrobianos de cepas de Staphylococcus aureus isoladas de vacas leiteiras em Minas Gerais, Brasil. Trinta e sete cepas provenientes de cinco municípios (oito rebanhos) foram genotipadas usando a técnica multi-locus sequence typing (MLST) e a suscetibilidade a 12 antimicrobianos foi avaliada pelo método de difusão em disco. Foram detectadas altas taxas de resistência para penicilina [75,68% (28/37)], ampicilina [70,27% (26/37)] e tetraciclina [70,27% (26/37)] entre os isolados. A multirresistência foi observada em sete [18,92% (7/37)] isolados e dois foram classificados como sugestivos de Staphylococcus aureus resistente à meticilina (MRSA). Entre os 37 isolados, 33 novos sequence types (ST) e dois STs conhecidos (ST126 e ST746) foram identificados pelo MLST. Os complexos clonais mais frequentemente observados foram: CC97 [78,38%; (29/37)], CC1 [8,11%; (3/37)] e CC5 [5,40%; (2/37)]. Foi construída uma minimum­spanning tree (MSTs) com todos isolados estudados e esta não mostrou padrão de agrupamento quando comparada com dados epidemiológicos como municípios e rebanho, do qual foi isolado, e perfis de resistência a antimicrobianos. Uma segunda MST foi construída comparando os isolados deste estudo e todas as cepas de S. aureus depositadas no banco de dados PubMLST provenientes do Brasil, que mostrou associação entre o genótipo, STs e a origem da cepa. Foi possível observar entre os isolados do estudo que, aqueles que pertenciam ao CC97, eram geneticamente mais próximos das cepas depositadas no PubMLST isoladas de leite e de produtos lácteos, enquanto aqueles que pertenciam aos CC1 e CC5 estavam mais próximos a cepas isoladas de humanos ou do ambiente de fazendas e indústrias de laticínios. Em conclusão, nossos resultados mostraram um alto índice de resistência às penicilinas e tetraciclinas e grande diversidade genética entre as cepas de S. aureus isoladas de casos de mastite bovina.

Assuntos

RESUMO

A mpox (varíola dos macacos ou monkeypox) é uma zoonose causada por um orthopoxvírus, da espécie Monkeypox virus (MPXV). Historicamente, primatas não humanos (PNHs) e, principalmente, roedores selvagens participam da manutenção do ciclo de transmissão em regiões endêmicas da África. Na atual epidemia de mpox em países não endêmicos, incluindo o Brasil, o ciclo epidemiológico apresenta transmissão direta de MPXV entre seres humanos, sem a participação de PNHs. O objetivo da revisão é apresentar informações históricas e o estado-da-arte da mpox com o intuito de orientar e fornecer subsídios sobre a doença aos médicos-veterinários, outros profissionais de saúde e a população em geral, além de desmitificar a participação dos PNHs, uma vez que estes não participam do ciclo de transmissão da doença em países não endêmicos.(AU)

Mpox (monkeypox) is a zoonotic disease caused by an orthopoxvirus, species Monkeypox virus (MPXV). Historically, non-human primates (NHPs) and wild rodents participate in maintaining the transmission cycle in endemic regions of Africa. In the current epidemic of human mpox in non-endemic countries, including Brazil, the epidemiological cycle of human mpox shows direct transmission of the MPXV between humans, without the participation of NHPs. The objective of this review is to present historical information and the state-of-the-art of human mpox to guide and provide subsidies about the disease to veterinarians, other health professionals and the population in general, in addition to demystifying the participation of PNHs in the HM transmission cycle in non-endemic countries.(AU)

Assuntos

RESUMO

ABSTRACT: This study evaluated the genetic diversity and antimicrobial susceptibility of Staphylococcus aureus isolates from dairy cows in Minas Gerais, Brazil. Thirty-seven isolates from five municipalities (8 herds) were genotyped using multi-locus sequence typing (MLST) and susceptibility to 12 antimicrobial agents was tested using the disk diffusion method. High resistance rates for penicillin [75.68% (28/37)], ampicillin [70.27% (26/37)], and tetracycline [70.27% (26/37)] were detected. Multidrug resistance was observed in seven [18.92% (7/37)] isolates, and two were suggestive of Methicillin-resistant Staphylococcus aureus (MRSA). Among the 37 isolates, 33 novel sequence types (ST) and two known STs (ST126 and ST746) were identified in MLST. The clonal complexes more frequently observed were: CC97 [78.38%; (29/37)], CC1 [8.11%; (3/37)] and CC5 [5.40%; (2/37)]. Minimum‐spanning tree (MST) analysis according to data from municipalities, herds, and resistance patterns for all isolates did not show any clustering pattern. However, the MST comparing all Brazilian S. aureus isolates deposited in the PubMLST database and from this study depicted an association between the genotype and strain origin (clinical sample). Isolates from this study that belong to CC97 were close to database isolates from milk and dairy products, while those that belong to CC1 and CC5 were close to database isolates from human sources and the environment of dairy farms or industries. In conclusion, our results showed a high rate of resistance to penicillins and tetracyclines and great genetic diversity among the S. aureus isolates from bovine mastitis genotyped in the present study.

RESUMO: Este estudo teve como objetivo avaliar a diversidade genética e a suscetibilidade a antimicrobianos de cepas de Staphylococcus aureus isoladas de vacas leiteiras em Minas Gerais, Brasil. Trinta e sete cepas provenientes de cinco municípios (oito rebanhos) foram genotipadas usando a técnica multi-locus sequence typing (MLST) e a suscetibilidade a 12 antimicrobianos foi avaliada pelo método de difusão em disco. Foram detectadas altas taxas de resistência para penicilina [75,68% (28/37)], ampicilina [70,27% (26/37)] e tetraciclina [70,27% (26/37)] entre os isolados. A multirresistência foi observada em sete [18,92% (7/37)] isolados e dois foram classificados como sugestivos de Staphylococcus aureus resistente à meticilina (MRSA). Entre os 37 isolados, 33 novos sequence types (ST) e dois STs conhecidos (ST126 e ST746) foram identificados pelo MLST. Os complexos clonais mais frequentemente observados foram: CC97 [78,38%; (29/37)], CC1 [8,11%; (3/37)] e CC5 [5,40%; (2/37)]. Foi construída uma minimum‐spanning tree (MSTs) com todos isolados estudados e esta não mostrou padrão de agrupamento quando comparada com dados epidemiológicos como municípios e rebanho, do qual foi isolado, e perfis de resistência a antimicrobianos. Uma segunda MST foi construída comparando os isolados deste estudo e todas as cepas de S. aureus depositadas no banco de dados PubMLST provenientes do Brasil, que mostrou associação entre o genótipo, STs e a origem da cepa. Foi possível observar entre os isolados do estudo que, aqueles que pertenciam ao CC97, eram geneticamente mais próximos das cepas depositadas no PubMLST isoladas de leite e de produtos lácteos, enquanto aqueles que pertenciam aos CC1 e CC5 estavam mais próximos a cepas isoladas de humanos ou do ambiente de fazendas e indústrias de laticínios. Em conclusão, nossos resultados mostraram um alto índice de resistência às penicilinas e tetraciclinas e grande diversidade genética entre as cepas de S. aureus isoladas de casos de mastite bovina.

RESUMO

Bovine tuberculosis (bTB) impacts considerably animal production and one health worldwide. To describe the prevalence, risk factors, and spatial pattern of the disease in the state of Paraná, Brazil, a cross-sectional study was conducted from September 2018 to February 2019. The area was divided into seven regions. Within each region, farms were randomly selected, and a predetermined number of cows was selected and tested by a comparative cervical tuberculin test. 17,210 animals were tested across 1757 farms. Herd prevalence of bTB-infected herds in Paraná was 2.5% [1.87-3.00%]. It has varied from 0.8 to 3.98% among seven regions, with clustering being detected in the west, central, and northeast areas. Animal prevalence was 0.35% [0.21-0.59%] and has varied from 0.08 to 0.6% among the pre-set regions. No major shifts in the prevalence of bTB were detected since 2007. Large-sized herds, dairy production, and feeding with whey were detected to be correlated with the presence of bTB. Exclusively among dairy herds, veterinary assistance from cooperatives, possession of self-owned equipment to cool milk, and feeding with whey were correlated with the disease. Considering these results, it is recommended that the state of Paraná seek to implement a surveillance system for the detection of bTB-infected herds transforming them into free ones, if possible, incorporating elements of risk-based surveillance. Health education is also recommended to inform farmers about the risks of introducing animals without testing and of feeding raw whey to calves.

Assuntos

RESUMO

Extracellular proteolytic enzymes are produced by a variety of pathogenic microorganisms, and contribute to host colonization by modulating virulence. Here, we present a first characterization of leptolysin, a Leptospira metalloprotease of the pappalysin family identified in a previous exoproteomic study. Comparative molecular analysis of leptolysin with two other pappalysins from prokaryotes, ulilysin and mirolysin, reveals similarities regarding calcium, zinc, and arginine -binding sites conservation within the catalytic domain, but also discloses peculiarities. Variations observed in the primary and tertiary structures may reflect differences in primary specificities. Purified recombinant leptolysin of L. interrogans was obtained as a ~50 kDa protein. The protease exhibited maximal activity at pH 8.0 and 37°C, and hydrolytic activity was observed in the presence of different salts with maximum efficiency in NaCl. Substrate specificity was assessed using a small number of FRET peptides, and showed a marked preference for arginine residues at the P1 position. L. interrogans leptolysin proteolytic activity on proteinaceous substrates such as proteoglycans and plasma fibronectin was also evaluated. All proteins tested were efficiently degraded over time, confirming the protease´s broad-spectrum activity in vitro. In addition, leptolysin induced morphological alterations on HK-2 cells, which may be partially attributed to extracellular matrix (ECM) degradation. Hemorrhagic foci were observed in the dorsal skin of mice intradermally injected with leptolysin, as a plausible consequence of ECM disarray and vascular endothelium glycocalyx damage. Assuming that leptospiral proteases play an important role in all stages of the infectious process, characterizing their functional properties, substrates and mechanisms of action is of great importance for therapeutic purposes.

Assuntos

RESUMO

Producing specific antibodies in chickens is an attractive approach for diagnosis or therapeutic applications. Besides the high immunoglobulin Y (IgY) yield transferred to the egg yolk and its suitability for large-scale production, such an approach is more bioethical for animal maintenance. The IgY technology offers new possibilities for application in human and veterinary diagnostics and therapeutics, including strategies for treating severe intestinal diseases in children, particularly in emerging countries. Herein, we describe the production and purification of polyclonal antibodies against rotavirus group A (RVA) in immunised hens aiming at its application in prophylaxis and treatment of rotavirus-induced diarrhoea. For this purpose, we inoculated Rhodia laying chickens (Gallus gallus domesticus) with two or three doses of RVA combined with adjuvants or only adjuvants (control group). As the egg-laying period began, the yolk protein purification processes yielded a high concentration of specific IgY, the highest titre resulting from the group of hens that received three doses of the immunogen. The purified IgY blocked the functional activity of RVA in MA-104 cells, thus confirming the neutralisation ability. Therefore, anti-RVA IgY could be a promising candidate for pre- and post-exposure prevention or treatment of rotavirus-induced diarrhoea.

Assuntos

RESUMO

The aim of this systematic review was to investigate the prevalence of leptospirosis among stray and sheltered dogs worldwide. Six databases were searched, which resulted in the retrieval of 476 articles. Sixty articles were selected for analysis according to 10 quality criteria. Among the selected papers, 26 papers [43.4% (26/60)] met five of the 10 quality criteria established, 10 papers [16.7% (10/60)] met three criteria, nine papers [15.0% (9/60)] met four criteria, six papers [10.0% (6/60)] met six criteria, four papers [6.7% (4/60)] met eight criteria, and three papers [5.0% (3/60)] met nine of the 10 criteria, whereas two papers [1.7% (1/60)] met two and seven [1.7% (1/60)] criteria. Publications originated mainly from the Americas [45.0% (27/60)] and in the last 16 years (2003-2019) [81.7% (49/60)], and most of the sampled dogs were stray dogs [65.0% (39/60)]. The most commonly used diagnostic test for leptospirosis was the microscopic agglutination test [78.4% (47/60)] followed by polymerase chain reaction [21.7% (13/60)], and the most common serovars were Canicola [71.4% (35/49)], Icterohaemorrhagiae [65.3% (32/49)], Grippotyphosa [40.8% (20/49)], and Pomona [40.8% (20/49)]. In conclusion, our results showed that Leptospira spp. are present in unowned dogs worldwide; however, the low-methodological quality of the recovered cross-sectional studies precluded a meta-analysis.

Assuntos

RESUMO

Bats are the only flying mammalian animals and are distributed worldwide. Bats are well-known hosts of several zoonotic viruses and bacteria, including Leptospira sp. Here, we performed a systematic review and a meta-analysis of evidence of Leptospira sp. infection in bats by examining studies published between 1964 and 2021. We reported the frequencies of various species and serogroups on all continents, several species and feeding habits of bats, and different diagnostic tools. Together, 33 papers from all continents with seven to 2077 individuals from one to 31 species were included. Molecular detection was conducted in most studies, followed by MAT (Microscopic Agglutination Test) and isolation and identification. Molecular characterization of Leptospira sp. revealed L. borgpetersenii as the most frequent species. Moreover, 179 positive samples for MAT contained the most likely infecting serogroups described, particularly the Australis serogroup. The percentage of positive tests in isolation and identification ranged between 0% and 0.5%. The highest frequency of Leptospira infection among the continents was observed in Asia, whereas South America had the lowest percentage. Finally, Nycteridae and Rhinonycteridae were the most frequently infected bat families. Our study provides valuable information about the epidemiology of Leptospira sp. infection in bats.

Assuntos

RESUMO

BACKGROUND: Human leptospirosis is responsible for great losses and deaths, especially in developing countries, which can be mitigated by knowing the correct health indicators and climate influence on the disease. METHODS: Leptospirosis cases and deaths, population and precipitation were recovered from different databases (2007-2019). Annual incidence, mortality and case fatality rates (CFRs) of human leptospirosis and average precipitation were calculated for Brazil and its regions. Time series analysis using an moving average with external variable (ARMAX) model was used to analyse the monthly contribution and precipitation influence over leptospirosis cases for each Brazilian region and for the whole country. A forecast model to predict cases for 2020 was created for Brazil. RESULTS: Human leptospirosis exhibited heterogeneous distribution among Brazilian regions, with most cases occurring during the rainy season and precipitation influenced the disease occurrence in all regions but the South. The forecast model predicted 3276.99 cases for 2020 (mean absolute percentage error 14.680 and root mean square error 53.013). Considering the annual average for the period, the leptospirosis incidence was 1913 cases per 100 000 inhabitants, mortality was 0.168 deaths per 100 000 inhabitants and the CFR was 8.83%. CONCLUSIONS: The models built can be useful for planning leptospirosis surveillance and control actions for the whole country and its regions and, together with the health indicators, revealed no uniform epidemiological situation of leptospirosis in Brazil.

Assuntos