Eficácia in sílico do florfenicol no tratamento de pododermatite infecciosa por Fusobacterium necrophorum em ovelhas / In sílico efficacy of florfenicol in the treatment of Fusobacterium necrophorum infectious pododermatitis in sheep

Objetivou-se comparar o efeito in silico do florfenicol nas doses de 20 e 30 mg/Kg em ovinos pelas vias intravenosa (IV) e intramuscular (IM), usando a modelagem PK/PD. Realizou-se uma simulação de Monte Carlo com base nos dados de concentração plasmática de um estudo publicado anteriormente. Calculou-se a área sob a curva (ASC) e as taxas de eficácia do florfenicol para os efeitos bacteriostático, bactericida e de erradicação bacteriológica. A dose de 20 mg/Kg IV demonstrou efeitos de erradicação de 100, 93 e 0% para CIM de 0,5, 1 e acima, respectivamente. O efeito bacteriostático foi de 99 e 90% para CIM de 4 e 2 µg/ml, enquanto o bactericida foi de 14% para CIM de 2 µg/ml. A dose de 30 mg/Kg IV apresentou 100% de erradicação para CIM de 1 µg/mL e 100% de efeito bactericida para CIM de 2 µg/mL. Há 100% de efeito bacteriostático em CIM de 4 µg/ml. As doses de 20 e 30 mg/Kg IM mostraram 100% de erradicação para CIM até 1 µg/mL e 0% para CIM maiores. O efeito bacteriostático foi mantido em 100% para uma CIM de 4 µg/mL em ambas as doses. Este estudo mostra o efeito de erradicação bacteriológica do florfenicol nas doses de 20 e 30 mg/Kg, IV e IM. Recomenda-se que seja feito um estudo de eficácia in vivo com a dose de 30mg/Kg IM em ovinos infectados por F. necrophorum com MIC superior a 2 µg/mL.

We aimed to compare the in silico effect of florfenicol at doses of 20 and 30 mg/Kg in sheep by intravenous (IV) and intramuscular (IM) routes, using PK/PD modeling. We performed a Monte Carlo simulation based on plasma concentration data from a previously published study. We calculated the area under the curve (AUC) and the efficacy rates of florfenicol to bacteriostatic, bactericidal, and bacteriological eradication effects. The dose of 20 mg/Kg IV demonstrated 100, 93, and 0% eradication effects for MICs of 0.5, 1, and above, respectively. The bacteriostatic effect was 99 and 90% for MIC of 4 and 2 µg/ml, while the bactericide was 14% for MIC of 2 µg/ml. The 30 mg/Kg IV dose showed 100% eradication for MIC of 1 µg/mL and 100% bactericidal effect for MIC of 2 µg/mL. There is a 100% of bacteriostatic effect at MIC of 4 µg/ml. Doses of 20 and 30 mg/Kg IM showed 100% eradication for MIC up to 1 µg/mL and 0% for MIC above. The bacteriostatic effect was maintained at 100% for a MIC of 4 µg/mL at both doses. This study shows the bacteriological eradication effect of florfenicol at doses of 20 and 30 mg/Kg, IV, and IM. Therefore, we recommend an in vivo efficacy study with a dose of 30mg/Kg IM in sheep infected with F. necrophorum with MIC greater than two µg/mL.

Seroprevalence of Corynebacterium pseudotuberculosis and Toxoplasma gondii in sheep in semi-arid region of Ceará state / Soroprevalência de Corynebacterium pseudotuberculosis de Toxoplasma gondii em ovinos de região semi-árida do estado do Ceará

ABSTRACT: The present study was conducted to investigate in 20 extensive sheep farms for the seroprevalence of Corynebacterium pseudotuberculosis (n=402) and Toxoplasma gondii (n=228). Enzyme-linked immunosorbent assay (ELISA) was used for the detection of antibodies to C. pseudotuberculosis/T. gondii. It was observed that C. pseudotuberculosis showed the highest prevalence in the region (34.07%) with statistically significant presence (p<0.05) in ewes. Antibodies to T. gondii was reported in 14.91% of the animals studied. About C. pseudotuberculosis/T. gondii coinfection the categories of rams showed significant (p<0.05) differences, suggesting that this gender could perpetuate the diseases in the flocks. It was concluded that the knowledge about the diseases in the region under study would facilitate the execution of prophylactic measures, especially against the diseases that pose risks to the public health and cause damages to the producer.

RESUMO: O presente estudo foi conduzido para investigar a soroprevalência em 20 fazendas de criação extensiva de ovinos quanto à presença de anticorpos para Corynebacterium pseudotuberculosis (n=402) e Toxoplasma gondii (n=228). Ensaio de imunoabsorção enzimático (ELISA) foi utilizado para a detecção de anticorpos contra C. pseudotuberculosis/T. gondii. Observou-se que C. pseudotuberculosis apresentou a maior prevalência na região (34,07%), com presença estatisticamente significante (p <0,05) nas categorias de ovelha. Anticorpos contra T. gondii foram encontrados em 14,91% dos animais estudados. Sobre a coinfecção de C. pseudotuberculosis/T. gondii, as categorias carneiro apresentaram diferenças significativas (p <0,05), sugerindo que esse gênero poderia perpetuar as doenças nos rebanhos. Concluiu-se que o conhecimento sobre as doenças na região em estudo facilitaria a execução de medidas profiláticas, principalmente contra as doenças que apresentam riscos à saúde pública e causam danos ao produtor.

Detection of the mecA gene and identification of Staphylococcus directly from blood culture bottles by multiplex polymerase chain reaction

ABSTRACT Introduction: Staphylococcus spp. - both S. aureus, including methicillin-resistant strains (MRSA) and coagulase negative staphylococci (CoNS) - are relevant agents of healthcare-associated infections. Therefore, the rapid recognition of MRSA and methicillin-resistant CoNS from blood stream infections is critically important for patient management. It is worth noting that inappropriate empiric therapy has been associated with higher in-hospital mortality. Material and methods: In this study we evaluated a multiplex polymerase chain reaction (multiplex PCR) standardized to detect Staphylococcus spp., S. aureus, and mecA gene-encoded oxacillin resistance directly from blood culture bottles. A total of 371 blood cultures with Gram-positive microorganisms confirmed by Gram-stain were analyzed. Results from multiplex PCR were compared to phenotypic characterization of isolates. Results: Staphylococcus aureus was detected in 85 (23.0%) blood cultures and CoNS in 286 (77.0%). There was 100% agreement between phenotypic and multiplex PCR identification. Forty-three (50.6%) of the 85 S. aureus carried the mecA gene and among the 286 CoNS, 225 (78.7%) were positive for the mecA gene. Conclusions: The multiplex PCR assay developed here was found to be sensitive, specific, rapid, and showed good agreement with the phenotypic results besides being less expensive. This PCR method could be used in clinical laboratories for rapid identification and initiation of specific and effective treatment, reducing patient mortality and morbidity. Furthermore, this method may reduce misuse of antimicrobial classes that are more expensive and toxic, thus contributing to the selection of antibiotic-resistant Staphylococcus spp.