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Equine strangles is a prevalent disease that affects the upper respiratory in horses and is caused by the Gram-positive bacterium Streptococcus equi. In addition to strangles, other clinical conditions are caused by the two S. equi subspecies, equi and zooepidemicus, which present relevant zoonotic potential. Treatment of infections caused by S. equi has become challenging due to the worldwide spreading of infected horses and the unavailability of effective therapeutics and vaccines. Penicillin treatment is often recommended, but multidrug resistance issues arised. We explored the whole genome sequence of 18 S. equi isolates to identify candidate proteins to be targeted by natural drug-like compounds or explored as immunogens. We considered only proteins shared among the sequenced strains of subspecies equi and zooepidemicus, absent in the equine host and predicted to be essential and involved in virulence. Of these, 4 proteins with cytoplasmic subcellular location were selected for molecular docking with a library of 5008 compounds, while 6 proteins were proposed as prominent immunogens against S. equi due to their probabilities of behaving as adhesins. The molecular docking analyses revealed the best ten ligands for each of the 4 drug target candidates, and they were ranked according to their binding affinities and the number of hydrogen bonds for complex stability. Finally, the natural 5-ring compound C25H20F3N5O3 excelled in molecular dynamics simulations for the increased stability in the interaction with UDP-N-acetylenolpyruvoylglucosamine reductase (MurB). This research paves the way to developing new therapeutics to minimize the impacts caused by S. equi infections.Communicated by Ramaswamy H. Sarma.

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The objectives of this study were to determine the prevalence of S. equi in a horse population in Colombia, to determine the risk factors associated with its detection in the guttural pouches and to report the antimicrobial susceptibility of the isolates. Fifteen farms and 137 horses >6 months of age were enrolled. Sampling was randomly, stratified and proportional to the population size of each farm. The guttural pouch (GP) was swabbed via endoscopic guidance and culture was performed. DNA extraction and conventional PCR were performed in colonies compatibles with S. equi, the PCR products were sequenced and subjected to BLAST analysis. Antimicrobial drug sensitivity was assessed using an antimicrobial disc diffusion assay including penicillin, ceftiofur, trimethoprim-sulfamethoxasole (TMS), enrofloxacin and oxytetracycline. A mixed logistic regression model was constructed to evaluate risk factors associated with the presence of S. equi. The S. equi culture prevalence in the GP was 15%; 13.5 % for S. equi subsp. equi and 1.5% for S. equi subsp. zooepidemicus. History of travel was associated with the presence of S. equi, whereas every 1-year increase in age decreased the risk for S. equi detection in the GP. All isolates were susceptible to TMS, ceftiofur and penicillin, but resistant to enrofloxacin and oxytetracycline. S. equi is present in horses in Colombia, with a high prevalence and appear to be endemic in the tested population. Younger horses and horses with recent history of travelling had higher odds of testing positive for S. equi in swabs of the GP.

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BACKGROUND: Strangles is a worldwide infectious disease caused by Streptococcus equi subsp. equi that affects the upper respiratory tract of horses. Streptococcus equi subsp. equi characterisation by seM-typing is internationally used for epidemiological studies and comparison of isolates. OBJECTIVES: To identify and to compare the seM-types of Argentinian isolates of Streptococcus equi subsp. equi. STUDY DESIGN: Investigation of bacterial isolates using molecular and phylogenetic approaches. METHODS: A total of 59 Argentinian isolates of Streptococcus equi subsp. equi obtained between 2007 and 2019 were studied by seM-typing. The sequence similarity of Argentinian seM-types and the other alleles available on the seM database was determined using BLAST and phylogenetic analysis was performed using the Neighbour-Joining algorithm. The amino acid sequences were predicted and compared with the predicted amino acid sequence of the reference strain 4047 using the MEGA 7 software and PROVEAN tool. RESULTS: Eight seM-types were found among the isolates. Only one of them (seM-61) has been previously reported and the other seven alleles (seM-129, seM-130, seM-131, seM-132, seM-133, seM-134 and seM-135) were novel seM sequences. High genetic similarity was observed among the Argentinian seM-types, with the exception of seM-130. No functional effects of amino acid differences were predicted. MAIN LIMITATIONS: The number of related and unrelated isolates per year. CONCLUSIONS: Seven novel seM-types and seM-61 that were previously reported in Brazil were circulating in Argentina which were identified as circulating in Argentinian horses between 2007 and 2019. The high genetic similarity among the Argentinian and Brazilian seM-types suggests that there is a geographical distribution of strain types. The geographical restriction of strains is likely to reflect the movement of horses between different equine disciplines and neighbouring countries.

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ABSTRACT: The infection caused by Streptococcus equi, known as strangles, affects the respiratory system of horses, causing high morbidity and rapid spread among the herd. Bacterin vaccines, composed of inactivated whole cells of S. equi, have variable efficacy and duration. Infected animals produce specific antibodies against SeM, the immunodominant antigen of S. equi. This makes it a promising target for vaccine development. In this context, the objective of this work was to evaluate a vaccine combining S. equi bacterin and recombinant SeM protein. Mice were vaccinated with bacterin (S. equi ~1.2 × 108CFU/ml); rSeM protein (20g); bacterin-rSeM combination; or PBS (Control Group) and challenged with a suspension of S. equi, containing 10 × LD50. All vaccinated mice survived the challenge and produced anti-rSeM and anti-S. equi antibodies, which were assessed by indirect ELISA. The Control Group reached endpoint criteria 96 h after infection. These results demonstrate that a vaccine combining the S. equi bacterin with rSeM protein protects mice against strangles. This combination vaccine could potentially protect horses and overcome the limitations of currently available strangle vaccines.

RESUMO: A infecção causada por Streptococcus equi, denominada adenite, atinge o sistema respiratório de equinos, causando alta morbidade e rápida disseminação entre o rebanho. Vacinas bacterinas, compostas de células inteiras inativadas de S. equi apresentam eficácia e duração variáveis. Animais infectados apresentam anticorpos específicos à proteína SeM, antígeno imunodominante de S. equi, o que a torna um alvo promissor para o desenvolvimento de vacinas. Neste contexto, o objetivo deste trabalho foi avaliar uma vacina baseada na administração simultânea da bacterina e da proteína SeM recombinante. Camundongos foram vacinados com a bacterina (S. equi ~1.2 × 108CFU/ml); a proteína rSeM (20g); a bacterina e rSeM simultaneamente; ou PBS (Grupo Controle) e, posteriormente, foram desafiados com uma suspensão de S. equi contendo 10 × LD50. Todos os animais vacinados apresentaram anticorpos anti-rSeM e contra S. equi, avaliados através de ELISA indireto, e mantiveram-se e sobreviveram ao desafio letal. O Grupo Controle atingiu critérios de endpoint 96 h após a infecção. Estes resultados demonstram que uma vacina constituída de células inteiras de S. equi com rSeM protege camundongos contra adenite, sugerindo a capacidade de proteção a equinos e, possivelmente, superando as limitações das vacinas contra adenite atualmente disponíveis.

RESUMO

The infection caused by Streptococcus equi, known as strangles, affects the respiratory system of horses, causing high morbidity and rapid spread among the herd. Bacterin vaccines, composed of inactivated whole cells of S. equi, have variable efficacy and duration. Infected animals produce specific antibodies against SeM, the immunodominant antigen of S. equi. This makes it a promising target for vaccine development. In this context, the objective of this work was to evaluate a vaccine combining S. equi bacterin and recombinant SeM protein. Mice were vaccinated with bacterin (S. equi ~1.2 × 108CFU/ml); rSeM protein (20μg); bacterin-rSeM combination; or PBS (Control Group) and challenged with a suspension of S. equi, containing 10 × LD50. All vaccinated mice survived the challenge and produced anti-rSeM and anti-S. equi antibodies, which were assessed by indirect ELISA. The Control Group reached endpoint criteria 96 h after infection. These results demonstrate that a vaccine combining the S. equi bacterin with rSeM protein protects mice against strangles. This combination vaccine could potentially protect horses and overcome the limitations of currently available strangle vaccines.(AU)

A infecção causada por Streptococcus equi, denominada adenite, atinge o sistema respiratório de equinos, causando alta morbidade e rápida disseminação entre o rebanho. Vacinas bacterinas, compostas de células inteiras inativadas de S. equi apresentam eficácia e duração variáveis. Animais infectados apresentam anticorpos específicos à proteína SeM, antígeno imunodominante de S. equi, o que a torna um alvo promissor para o desenvolvimento de vacinas. Neste contexto, o objetivo deste trabalho foi avaliar uma vacina baseada na administração simultânea da bacterina e da proteína SeM recombinante. Camundongos foram vacinados com a bacterina (S. equi ~1.2 × 108CFU/ml); a proteína rSeM (20μg); a bacterina e rSeM simultaneamente; ou PBS (Grupo Controle) e, posteriormente, foram desafiados com uma suspensão de S. equi contendo 10 × LD50. Todos os animais vacinados apresentaram anticorpos anti-rSeM e contra S. equi, avaliados através de ELISA indireto, e mantiveram-se e sobreviveram ao desafio letal. O Grupo Controle atingiu critérios de endpoint 96 h após a infecção. Estes resultados demonstram que uma vacina constituída de células inteiras de S. equi com rSeM protege camundongos contra adenite, sugerindo a capacidade de proteção a equinos e, possivelmente, superando as limitações das vacinas contra adenite atualmente disponíveis.(AU)

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The infection caused by Streptococcus equi, known as strangles, affects the respiratory system of horses, causing high morbidity and rapid spread among the herd. Bacterin vaccines, composed of inactivated whole cells of S. equi, have variable efficacy and duration. Infected animals produce specific antibodies against SeM, the immunodominant antigen of S. equi. This makes it a promising target for vaccine development. In this context, the objective of this work was to evaluate a vaccine combining S. equi bacterin and recombinant SeM protein. Mice were vaccinated with bacterin (S. equi ~1.2 × 108CFU/ml); rSeM protein (20μg); bacterin-rSeM combination; or PBS (Control Group) and challenged with a suspension of S. equi, containing 10 × LD50. All vaccinated mice survived the challenge and produced anti-rSeM and anti-S. equi antibodies, which were assessed by indirect ELISA. The Control Group reached endpoint criteria 96 h after infection. These results demonstrate that a vaccine combining the S. equi bacterin with rSeM protein protects mice against strangles. This combination vaccine could potentially protect horses and overcome the limitations of currently available strangle vaccines.(AU)

A infecção causada por Streptococcus equi, denominada adenite, atinge o sistema respiratório de equinos, causando alta morbidade e rápida disseminação entre o rebanho. Vacinas bacterinas, compostas de células inteiras inativadas de S. equi apresentam eficácia e duração variáveis. Animais infectados apresentam anticorpos específicos à proteína SeM, antígeno imunodominante de S. equi, o que a torna um alvo promissor para o desenvolvimento de vacinas. Neste contexto, o objetivo deste trabalho foi avaliar uma vacina baseada na administração simultânea da bacterina e da proteína SeM recombinante. Camundongos foram vacinados com a bacterina (S. equi ~1.2 × 108CFU/ml); a proteína rSeM (20μg); a bacterina e rSeM simultaneamente; ou PBS (Grupo Controle) e, posteriormente, foram desafiados com uma suspensão de S. equi contendo 10 × LD50. Todos os animais vacinados apresentaram anticorpos anti-rSeM e contra S. equi, avaliados através de ELISA indireto, e mantiveram-se e sobreviveram ao desafio letal. O Grupo Controle atingiu critérios de endpoint 96 h após a infecção. Estes resultados demonstram que uma vacina constituída de células inteiras de S. equi com rSeM protege camundongos contra adenite, sugerindo a capacidade de proteção a equinos e, possivelmente, superando as limitações das vacinas contra adenite atualmente disponíveis.(AU)

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Este trabalho relata o desenvolvimento e a avaliação de um ensaio imunoenzimático (ELISA) como ferramenta auxiliar no controle da adenite equina. Foi avaliada a presença de anticorpos anti-Streptococcus equi subsp. equi em equinos com doença clínica de garrotilho, portadores assintomáticos e potros vacinados. Equinos doentes demonstraram absorbâncias médias superiores (P<0,05) às médias observadas nas demais categorias examinadas. Equinos portadores assintomáticos apresentaram valores médios de absorbância superiores (P<0,05) aos animais com cultura negativa. Logo após a vacinação, potros apresentaram elevação nos níveis de anticorpos, seguida de um decréscimo nos níveis 90 dias após a segunda vacinação. O "Cell ELISA" foi eficiente para a detecção de anticorpos em equinos expostos a antígenos de S. equi, diferenciando-se de infecções por S. zooepidemicus. O "Cell ELISA" mostrou-se uma alternativa clínica para o diagnóstico indireto da adenite equina, diferenciando-se, entre equinos assintomáticos, os potenciais portadores da infecção. Os resultados observados em potros vacinados confirmam o potencial de utilização desse teste como ferramenta em programas de vacinação contra garrotilho pelo monitoramento de rebanhos pós-vacinação. Esses resultados sugerem que o "Cell ELISA" é uma promissora ferramenta auxiliar no controle da adenite equina.(AU)

This study reports the development and evaluation of the use of "Cell ELISA" as a tool for clinical interpretation for the control of strangles. The presence of anti-S. equi antibodies was evaluated in horses with strangles, in asymptomatic carriers and in vaccinated foals. Equine positive for strangle showed higher average of absorbance (P<0.05) when compared with the average for the other categories of horses studied. Asymptomatic S. equi equine carriers had higher average of absorbance (P<0.05) than equines with negative culture. After vaccination, foals presented an increase in antibody levels, followed by a decrease in antibody levels 90 days post the second vaccination. The "Cell ELISA" was efficient for the detection of antibodies in horses exposed to S. equi antigens, differentiating infections with S. zooepidemicus. Thus, the test might be a clinical tool for indirect diagnosis of the strangles, differentiating, between the asymptomatic horses, the potential carriers of infection. The results observed in vaccinated foals confirm the potential use of this test as an auxiliary instrument for strangles vaccination programs based in the serological monitoring of the herd after immunization. These results suggest that the "Cell ELISA" is a promising auxiliary tool in the control of equine adenitis.(AU)

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Este trabalho relata o desenvolvimento e a avaliação de um ensaio imunoenzimático (ELISA) como ferramenta auxiliar no controle da adenite equina. Foi avaliada a presença de anticorpos anti-Streptococcus equi subsp. equi em equinos com doença clínica de garrotilho, portadores assintomáticos e potros vacinados. Equinos doentes demonstraram absorbâncias médias superiores (P<0,05) às médias observadas nas demais categorias examinadas. Equinos portadores assintomáticos apresentaram valores médios de absorbância superiores (P<0,05) aos animais com cultura negativa. Logo após a vacinação, potros apresentaram elevação nos níveis de anticorpos, seguida de um decréscimo nos níveis 90 dias após a segunda vacinação. O "Cell ELISA" foi eficiente para a detecção de anticorpos em equinos expostos a antígenos de S. equi, diferenciando-se de infecções por S. zooepidemicus. O "Cell ELISA" mostrou-se uma alternativa clínica para o diagnóstico indireto da adenite equina, diferenciando-se, entre equinos assintomáticos, os potenciais portadores da infecção. Os resultados observados em potros vacinados confirmam o potencial de utilização desse teste como ferramenta em programas de vacinação contra garrotilho pelo monitoramento de rebanhos pós-vacinação. Esses resultados sugerem que o "Cell ELISA" é uma promissora ferramenta auxiliar no controle da adenite equina.(AU)

This study reports the development and evaluation of the use of "Cell ELISA" as a tool for clinical interpretation for the control of strangles. The presence of anti-S. equi antibodies was evaluated in horses with strangles, in asymptomatic carriers and in vaccinated foals. Equine positive for strangle showed higher average of absorbance (P<0.05) when compared with the average for the other categories of horses studied. Asymptomatic S. equi equine carriers had higher average of absorbance (P<0.05) than equines with negative culture. After vaccination, foals presented an increase in antibody levels, followed by a decrease in antibody levels 90 days post the second vaccination. The "Cell ELISA" was efficient for the detection of antibodies in horses exposed to S. equi antigens, differentiating infections with S. zooepidemicus. Thus, the test might be a clinical tool for indirect diagnosis of the strangles, differentiating, between the asymptomatic horses, the potential carriers of infection. The results observed in vaccinated foals confirm the potential use of this test as an auxiliary instrument for strangles vaccination programs based in the serological monitoring of the herd after immunization. These results suggest that the "Cell ELISA" is a promising auxiliary tool in the control of equine adenitis.(AU)

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Background: Ailments that affect guttural pouches (GPs) include congenital malformations, tumors, and, especially, infections. Clinical signs of disorders of the GPs are not always specific, and include nasal secretion, epistaxis, and enlargement of regional lymph nodes. Deficient diagnosis and treatment tend to limit life expectancy. Some cases can lead to terminal exsanguination due to progression of the disorder if not diagnosed or if treatment fails. Unusual presentations may occur, and these cases require knowledge for prompt action and determination of the prognosis. The objective of this work is to report one of these unusual cases: epistaxis caused by rupture of the GP by a pharyngeal abscess.Case: A 6-year-old mare was presented for examination exhibiting purulent nasal secretion that had been ongoing for approximately 45 days (which had been treated as strangles for 7 days) and intermittent epistaxis for the past 20 days. When the mare was taken to the Veterinary Hospital, it also exhibited dysphagia with purulent nasal secretion mixed with the ingested food, a body condition score of 3/9, wheezing, mild ataxia, anemia (2.8 million RBCs/mm3 ; hematocrit = 14%), leukopenia (4,600 WBCs/mm3), and hyperfibrinogenemia (600 mg/dL). Upper airway endoscopy revealed presence of blood in the anterior third of the trachea, a blood clot in the left GP, and absence of bacterial of fungal plaques. Analysis of the bloody material collected from the GP showed presence of cocci bacteria and neutrophils. The treatment initially implemented was antibiotic therapy with enrofloxacin. Epistaxis worsened on the day following admission. Blood transfusion was carried out, but this procedure was not effective as profuse acute hemorrhage took place and led to death of the patient 48 h after admission. At necropsy, the left GP was laden with blood clots and serous/bloody content, and exhibited a circular/cylindrical lesion in its retropharyngeal portion.[...](AU)

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Background: Ailments that affect guttural pouches (GPs) include congenital malformations, tumors, and, especially, infections. Clinical signs of disorders of the GPs are not always specific, and include nasal secretion, epistaxis, and enlargement of regional lymph nodes. Deficient diagnosis and treatment tend to limit life expectancy. Some cases can lead to terminal exsanguination due to progression of the disorder if not diagnosed or if treatment fails. Unusual presentations may occur, and these cases require knowledge for prompt action and determination of the prognosis. The objective of this work is to report one of these unusual cases: epistaxis caused by rupture of the GP by a pharyngeal abscess.Case: A 6-year-old mare was presented for examination exhibiting purulent nasal secretion that had been ongoing for approximately 45 days (which had been treated as strangles for 7 days) and intermittent epistaxis for the past 20 days. When the mare was taken to the Veterinary Hospital, it also exhibited dysphagia with purulent nasal secretion mixed with the ingested food, a body condition score of 3/9, wheezing, mild ataxia, anemia (2.8 million RBCs/mm3 ; hematocrit = 14%), leukopenia (4,600 WBCs/mm3), and hyperfibrinogenemia (600 mg/dL). Upper airway endoscopy revealed presence of blood in the anterior third of the trachea, a blood clot in the left GP, and absence of bacterial of fungal plaques. Analysis of the bloody material collected from the GP showed presence of cocci bacteria and neutrophils. The treatment initially implemented was antibiotic therapy with enrofloxacin. Epistaxis worsened on the day following admission. Blood transfusion was carried out, but this procedure was not effective as profuse acute hemorrhage took place and led to death of the patient 48 h after admission. At necropsy, the left GP was laden with blood clots and serous/bloody content, and exhibited a circular/cylindrical lesion in its retropharyngeal portion.[...]

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The strangles is an infectious disease that affects horses from all ages and causes important economic losses in the equine-related business. The aim of this work was to evaluate the immunogenicity of the recombinant M protein from Streptococcus equi (rSeM) co-administered with the recombinant heat-labile enterotoxin B subunit from Escherichia coli (rLTB) in mice and horses. A total of 72 female Balb-c mice were divided into eight groups and 18 horses were divided into six groups. The animals were inoculated by intramuscular (IM) or intranasal (IN) routes with different treatments of rSeM, rLTB and/or Al(OH)3. The results obtained in both species, independent of administration routes, demonstrated that rSeM + rLTB had higher levels of specific serum immunoglobulins, however, in mucosal immunity the increase was not identified. Thus, the use of rSeM as vaccine antigen and rLTB as adjuvant can be a potential tool in the control of equine strangles.(AU)

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The strangles is an infectious disease that affects horses from all ages and causes important economic losses in the equine-related business. The aim of this work was to evaluate the immunogenicity of the recombinant M protein from Streptococcus equi (rSeM) co-administered with the recombinant heat-labile enterotoxin B subunit from Escherichia coli (rLTB) in mice and horses. A total of 72 female Balb-c mice were divided into eight groups and 18 horses were divided into six groups. The animals were inoculated by intramuscular (IM) or intranasal (IN) routes with different treatments of rSeM, rLTB and/or Al(OH)3. The results obtained in both species, independent of administration routes, demonstrated that rSeM + rLTB had higher levels of specific serum immunoglobulins, however, in mucosal immunity the increase was not identified. Thus, the use of rSeM as vaccine antigen and rLTB as adjuvant can be a potential tool in the control of equine strangles.(AU)

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The aim of this study was to estimate the prevalence of equine strangles and to identify associated risk factors for this disease through a cross-sectional study of nasal swabs. Nasal swabs (n=1010) from healthy equines (absence of nasal discharge, lymphadenopathy and cough) from 341 farms were plated on 5% blood agar; of these horses, 24 were identified as positive for Streptococcus equi through isolation, PCR and DNA sequencing. The estimated prevalence for individual animals was 2.3%, and for herds, it was 5.86%. Statistical analysis identified the following as associated risk factors: the number of group events that were attended by the equines (PR: 1.06); the sharing of food containers (PR: 3.74); and at least one previous positive diagnosis of strangles on the farm (PR: 3.20). These results constitute an epidemiological contribution to the horse industry and may support measures for the future control of the disease.

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Strangles is a disease of the respiratory tract of horses caused by Streptococcus equi. The disease has high morbidity and low lethality, and produces economic losses due to low performance and high cost treatment. This research focused on evaluate antibiotic resistance of Streptococcus equi from the nasal cavity of healthy horses from the region Fernandópolis São Paulo. Fifty (50) mongrel healthy horses, ageing from twelve to twenty four (12-24) months were used. Samples from the nasal cavity of each animal were obtained using sterile swabs and after were cultured on blood agar base plus 5% defibrinated sheep blood. Plates that showed mucous colonies and Beta- hemolytic were tested using Gram stain method, the catalase test, and identified by the system API Rapid ID thirty-two 32 Strep. All isolates were analyzed by plate difusion. Sixty seven of the obtained isolates were Streptococcus equi subspecies equi and zooepidemicus. There was higher prevalence of S. subsp equi zooepidemicus (p < 0.001). Most isolates of S. equi subsp equi were antibiotical multiresistant with significant differences between different antibiotics (p < 0.005), whereas higher susceptibility was observed in isolated S. subsp equi zooepidemicus (p < 0.05). The results showed that both subspecies of Streptococcus equi are part of the normal flora of the nasal cavity of horses, and that they differ in susceptibility to antibiotics.(AU)

A adenite equina, popularmente chamada de garrotilho, é uma enfermidade contagiosa, causada pela bactéria Streptococcus equi. A enfermidade é conhecida por ter alta morbidade e baixa letalidade e seus prejuízos econômicos devem-se à perda de performance e alto custo do tratamento. O objetivo deste trabalho foi avaliar a presença e o perfil de resistência a antibióticos de Streptococcus equi da cavidade nasal de equinos hígidos da região de Fernandópolis SP. Foram utilizados 50 equinos hígidos sem raça definida e com idade entre 12 a 24 meses. De cada animal foram colhidas amostras de exsudato da cavidade nasal por meio de swabs esterilizados e em seguida colocados em tubos contendo ágar base acrescido com 5% de sangue ovino desfibrinado. Os isolados que apresentaram colônias mucosas e Beta -hemolíticas foram analisados pela coloração de Gram, submetidos ao teste da catalase, e identificados pelo sistema API Rapid ID 32 Strep. Todos os isolados foram avaliados em difusão em placa. Foram isolados sessenta e sete amostras de Streptococcus equi, das subespécies equi e zooepidemicus. Verificou-se prevalência maior de S. equi subesp zooepidemicus (p < 0,001). A maioria dos isolados de S. equi subespécies equi foram mutirresistentes, havendo diferenças significativas entre os diferentes antibióticos (p < 0,005), enquanto que foi verificada maior susceptibilidade nos isolados S. eqequi subespécies zooepidemicus (p < 0,05). Os resultados obtidos mostraram que ambas as subespécies deStreptococcus equi fazem parte da microbiota normal da cavidade nasal de equinos, e que as mesmas diferemquanto a susceptibilidade aos antibióticos.(AU)

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Strangles is a disease of the respiratory tract of horses caused by Streptococcus equi. The disease has high morbidity and low lethality, and produces economic losses due to low performance and high cost treatment. This research focused on evaluate antibiotic resistance of Streptococcus equi from the nasal cavity of healthy horses from the region Fernandópolis São Paulo. Fifty (50) mongrel healthy horses, ageing from twelve to twenty four (12-24) months were used. Samples from the nasal cavity of each animal were obtained using sterile swabs and after were cultured on blood agar base plus 5% defibrinated sheep blood. Plates that showed mucous colonies and Beta- hemolytic were tested using Gram stain method, the catalase test, and identified by the system API Rapid ID thirty-two 32 Strep. All isolates were analyzed by plate difusion. Sixty seven of the obtained isolates were Streptococcus equi subspecies equi and zooepidemicus. There was higher prevalence of S. subsp equi zooepidemicus (p < 0.001). Most isolates of S. equi subsp equi were antibiotical multiresistant with significant differences between different antibiotics (p < 0.005), whereas higher susceptibility was observed in isolated S. subsp equi zooepidemicus (p < 0.05). The results showed that both subspecies of Streptococcus equi are part of the normal flora of the nasal cavity of horses, and that they differ in susceptibility to antibiotics.

A adenite equina, popularmente chamada de garrotilho, é uma enfermidade contagiosa, causada pela bactéria Streptococcus equi. A enfermidade é conhecida por ter alta morbidade e baixa letalidade e seus prejuízos econômicos devem-se à perda de performance e alto custo do tratamento. O objetivo deste trabalho foi avaliar a presença e o perfil de resistência a antibióticos de Streptococcus equi da cavidade nasal de equinos hígidos da região de Fernandópolis SP. Foram utilizados 50 equinos hígidos sem raça definida e com idade entre 12 a 24 meses. De cada animal foram colhidas amostras de exsudato da cavidade nasal por meio de swabs esterilizados e em seguida colocados em tubos contendo ágar base acrescido com 5% de sangue ovino desfibrinado. Os isolados que apresentaram colônias mucosas e Beta -hemolíticas foram analisados pela coloração de Gram, submetidos ao teste da catalase, e identificados pelo sistema API Rapid ID 32 Strep. Todos os isolados foram avaliados em difusão em placa. Foram isolados sessenta e sete amostras de Streptococcus equi, das subespécies equi e zooepidemicus. Verificou-se prevalência maior de S. equi subesp zooepidemicus (p < 0,001). A maioria dos isolados de S. equi subespécies equi foram mutirresistentes, havendo diferenças significativas entre os diferentes antibióticos (p < 0,005), enquanto que foi verificada maior susceptibilidade nos isolados S. eqequi subespécies zooepidemicus (p < 0,05). Os resultados obtidos mostraram que ambas as subespécies deStreptococcus equi fazem parte da microbiota normal da cavidade nasal de equinos, e que as mesmas diferemquanto a susceptibilidade aos antibióticos.

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RESUMO

The present report describes a 2-month-old foal which signs of respiratory infectious disease, bilateral retropharyngeal swelling and nasal mucopurulent discharge, suggesting guttural pouch empyema. The owners reported that the foal lived in a herd that experienced an outbreak of strangles. Foals younger than 3 months are usually protected against infectious diseases, however in this case, the foal was exposed to an environment heavily populated by Streptococcus equi equi during the outbreak of strangles. Although uncommon in such young animals, the foal was infected and developed a primary bilateral guttural pouch empyema, without signs of lymph nodes alteration.

O presente trabalho descreve o caso de um potro de dois meses de idade com sinais de infecção respiratória, distensão bilateral da região retrofaríngea e secreção nasal mucopurulenta, sugerindo empiema de bolsa gutural. Os proprietários relataram que o potro pertencia a uma tropa que havia sido acometida por garrotilho recentemente. Potros com menos de 3 meses de idade são normalmente protegidos contra as doenças infecciosas, no entanto, este potro foi exposto a um ambiente altamente contaminado por Streptococcus equi equi durante o surto de garrotilho. Embora incomum em animais tão jovens, o potro foi infectado e desenvolveu um empiema primário de bolsa gutural, não havendo sinais de acometimento dos linfonodos.

RESUMO

The present report describes a 2-month-old foal which signs of respiratory infectious disease, bilateral retropharyngeal swelling and nasal mucopurulent discharge, suggesting guttural pouch empyema. The owners reported that the foal lived in a herd that experienced an outbreak of strangles. Foals younger than 3 months are usually protected against infectious diseases, however in this case, the foal was exposed to an environment heavily populated by Streptococcus equi equi during the outbreak of strangles. Although uncommon in such young animals, the foal was infected and developed a primary bilateral guttural pouch empyema, without signs of lymph nodes alteration.(AU)

O presente trabalho descreve o caso de um potro de dois meses de idade com sinais de infecção respiratória, distensão bilateral da região retrofaríngea e secreção nasal mucopurulenta, sugerindo empiema de bolsa gutural. Os proprietários relataram que o potro pertencia a uma tropa que havia sido acometida por garrotilho recentemente. Potros com menos de 3 meses de idade são normalmente protegidos contra as doenças infecciosas, no entanto, este potro foi exposto a um ambiente altamente contaminado por Streptococcus equi equi durante o surto de garrotilho. Embora incomum em animais tão jovens, o potro foi infectado e desenvolveu um empiema primário de bolsa gutural, não havendo sinais de acometimento dos linfonodos.(AU)

Assuntos

RESUMO

Strangles is an economically important horse disease caused by Streptococcus equi subsp. equi. The diagnosis can be confirmed either directly by bacterial isolation and PCR or by ELISA, which is an indirect method based on the detection of serum antibodies. The aim of this study was to clone, express and characterize the SeM protein of Streptococcus equi subsp. equi, evaluate its use as antigen in indirect ELISA and determine its performance to distinguish sera of negative, vaccinated and positive animals. This was initially performed by cloning the gene encoding the SeM protein and its expression in Escherichia coli. Subsequently, the protein produced was characterized and used as antigen in ELISA. Serum samples for evaluation were taken from 40 negative foals, 46 horses vaccinated with a commercial vaccine against strangles and 46 horses diagnosed with the disease. The test showed high specificity and sensitivity, allowing discrimination between negative and positive, positive and vaccinated animals, and vaccinated animals and negative sera. Thus, it was concluded that the protein produced rSeM, which can be used as antigen for disease diagnosis, and the described ELISA might be helpful to evaluate the immune status of the herd...

A adenite equina é uma enfermidade economicamente importante de equinos, causada por Streptococcus equi subsp. equi. Seu diagnóstico pode ser confirmado de forma direta, por meio de isolamento bacteriano e de PCR, ou de forma indireta, por meio de ELISA, método baseado na detecção de anticorpos séricos. O objetivo deste estudo foi clonar, expressar e caracterizar a proteína SeM de Streptococcus equi subsp. equi, avaliar sua utilização como antígeno em um ELISA indireto e determinar a capacidade do teste de distinguir soros de animais negativos, vacinados e positivos. Para tal, foi inicialmente realizada a clonagem do gene que codifica para a proteína SeM e sua expressão em Escherichia coli. Posteriormente, a proteína produzida foi caracterizada e utilizada como antígeno em um teste de ELISA indireto. Para avaliação do teste, foram utilizadas amostras de soro de 40 potros negativos, de 46 equinos vacinados com uma vacina comercial contra adenite equina e de 46 equinos com diagnóstico da doença. O teste demonstrou alta sensibilidade e especificidade, permitindo discriminar entre soros negativos e positivos, positivos e de animais vacinados, e negativos e de animais vacinados. Assim, conclui-se que a proteína rSeM produzida pode ser usada como antígeno para o diagnóstico da enfermidade e que o ELISA descrito pode ser útil para avaliar o estado imunológico do rebanho...

Assuntos

RESUMO

Strangles is an economically important horse disease caused by Streptococcus equi subsp. equi. The diagnosis can be confirmed either directly by bacterial isolation and PCR or by ELISA, which is an indirect method based on the detection of serum antibodies. The aim of this study was to clone, express and characterize the SeM protein of Streptococcus equi subsp. equi, evaluate its use as antigen in indirect ELISA and determine its performance to distinguish sera of negative, vaccinated and positive animals. This was initially performed by cloning the gene encoding the SeM protein and its expression in Escherichia coli. Subsequently, the protein produced was characterized and used as antigen in ELISA. Serum samples for evaluation were taken from 40 negative foals, 46 horses vaccinated with a commercial vaccine against strangles and 46 horses diagnosed with the disease. The test showed high specificity and sensitivity, allowing discrimination between negative and positive, positive and vaccinated animals, and vaccinated animals and negative sera. Thus, it was concluded that the protein produced rSeM, which can be used as antigen for disease diagnosis, and the described ELISA might be helpful to evaluate the immune status of the herd.(AU)

A adenite equina é uma enfermidade economicamente importante de equinos, causada por Streptococcus equi subsp. equi. Seu diagnóstico pode ser confirmado de forma direta, por meio de isolamento bacteriano e de PCR, ou de forma indireta, por meio de ELISA, método baseado na detecção de anticorpos séricos. O objetivo deste estudo foi clonar, expressar e caracterizar a proteína SeM de Streptococcus equi subsp. equi, avaliar sua utilização como antígeno em um ELISA indireto e determinar a capacidade do teste de distinguir soros de animais negativos, vacinados e positivos. Para tal, foi inicialmente realizada a clonagem do gene que codifica para a proteína SeM e sua expressão em Escherichia coli. Posteriormente, a proteína produzida foi caracterizada e utilizada como antígeno em um teste de ELISA indireto. Para avaliação do teste, foram utilizadas amostras de soro de 40 potros negativos, de 46 equinos vacinados com uma vacina comercial contra adenite equina e de 46 equinos com diagnóstico da doença. O teste demonstrou alta sensibilidade e especificidade, permitindo discriminar entre soros negativos e positivos, positivos e de animais vacinados, e negativos e de animais vacinados. Assim, conclui-se que a proteína rSeM produzida pode ser usada como antígeno para o diagnóstico da enfermidade e que o ELISA descrito pode ser útil para avaliar o estado imunológico do rebanho.(AU)

Assuntos

RESUMO

As características fenotípicas [morfológicas, bioquímicas, susceptibilidade aos antimicrobianos, índice de resistência múltipla aos antimicrobianos (IRMA), concentração inibitória mínima (CIM) e concentração bactericida mínima (CBM) da benzilpenicilina] de 38 isolados de Streptococcus equi oriundos de amostras clínicas de animais com adenite equina foram alvo deste estudo. A fenotipia demonstrou três padrões de colônias, três biotipos de fermentação de carboidratos e variação de 0 a 0,4 no IRMA. Todos os isolados de S. equi demonstraram sensibilidade à penicilina, tanto pelo método de disco difusão quanto pelo método de microdiluição. A CIM e CBM média de benzilpenicilina foi de 0,0095μg/mL e 0,0267μg/mL para S. equi subesp. equi e de 0,0128μg/mL e 0,0380μg/mL para S. equi subesp. zooepidemicus. Os valores de CIM e CBM diferiram entre as subespécies (p<0,05). O diâmetro do halo de inibição de penicilina demonstrou relação com a CIM (ì=0,03638 - 0,00072x) para S. equi subesp. equi. Também foi demonstrada relação entre o diâmetro do halo de inibição de penicilina com a CBM para S. equi subesp. equi (ì=0,10931- 0,00223x). Entretanto para as amostras de S. equi subesp. zooepidemicus esta relação somente foi verificada para a CBM (ì=0,1322 - 0,00271x). A CIM de benzilpenicilina frente às amostras isoladas da região Central, Planalto e Sul do estado do Rio Grande do Sul foram estatisticamente semelhantes, mas diferiram do isolado do estado do Paraná, sugerindo o caráter atípico desta cepa. Todos os isolados de S. equi são sensíveis à penicilina e sulfazotrim, confirmando a eleição destes antimicrobianos para o tratamento das infecções por este agente na clínica veterinária. Os resultados obtidos não dispensam a utilização prudente dos antimicrobianos.

Phenotypic characteristics [morphology, biochemical fermentation, antimicrobial susceptibility, index of multiple resistances to antimicrobials (IMRA), minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of benzilpenicillin] of 38 Streptococcus equi isolates from clinical samples of horses with strangles were the aim of this study. The phenotypic analyses demonstrated three colony patterns, three carbohydrate fermentation biotypes and IMRA variation from 0 to 0.4. All the isolates of S. equi demonstrated sensitivity to penicillin, both by the disc diffusion method and microdilution method. The average MIC and MBC for benzilpenincillin were of 0.0095μg/mL and 0.0267μg/mL for S. equi subsp. equi and of 0.0128μg/mL and 0.0380μg/mL for S. equi subsp. zooepidemicus. The values of MIC and MBC differed between the subspecies (p<0.05). The diameter of penicillin inhibition halo demonstrated a relation with the MIC (ì=0.03638 - 0.00072x) for Streptococcus equi subsp. equi. A relation between the diameter of the inhibition halo of penincillin was also observed with the MBC for S. equi subsp. equi (ì=0.10931 - 0.00223x). However for the samples of S. equi subsp. zooepidemicus this relation was only verified with the MBC (ì=0.1322 - 0.00271x). The MIC of benzilpenicillin of the samples isolated from the Central, Planalto and South regions of Rio Grande do Sul were statistically similar, although different from the Paraná state sample, suggesting the atypical character of this strain. All the S. equi isolates are sensitive to penicillin and sulfazotrim, confirming these as antibiotics of choice for the treatment of infections caused by this agent in the clinical veterinary practice. The results obtained do not discard the prudent use of antimicrobials.

Assuntos