Efficacy of an internal teat seal associated with a dry cow intramammary antibiotic for prevention of intramammary infections in dairy cows during the dry and early lactation periods / Eficácia de um selante interno de tetos associado a antibiótico de vaca seca na prevenção de infecções intramamárias no período seco e início de lactação em vacas leiteiras

The present study aimed to evaluate the use of an internal dry period teat seal containing bismuth subnitrate (Teatseal®, Zoetis®, Florham Park, Nova Jersey, USA) associated with a long-acting cloxacilin preparation (Orbenin® Extra dry cow, Zoetis®, Florham Park, Nova Jersey, USA), in preventing new infections during the dry-off and early postpartum period. A total of 150 Holstein cows (average production of 9,000 kg of milk per lactation), with four functional udder quarters without clinical mastitis was included in the study. All animals were dried-off 60 days before the expected calving date. Two teats positioned diagonal-contralaterally received only dry cow antibiotic, control group C (n=300) and the other two teats, treatment group T (n=300) received dry cow antibiotic and infusion with an internal teat seal. Data from SCC variable were transformed by log base-10 transformation. Duncan's test was used accepting 5% as the level of statistical significance. The occurrence of intramammary infection (IMI) and chronicity rate, and frequency of microorganisms isolated at drying and immediately postpartum in teats of group C and group T were evaluated using a non-parametric Chi-square Test, accepting 10% as the statistical significance level. There was a decrease in the occurrence of new infections in the early postpartum in cows which the sealant was used (C=19.6%, T=11.4%). In the postpartum period, Gram-negative bacteria were isolated from 16 teats in C and seven in T. The greatest reduction was observed for Escherichia coli (8 vs 1) in group T. There was no effect using the internal sealant on the frequency of isolation of environmental Streptococus. The use of sealant reduced the prevalence of subclinical mastitis cows between drying-off and the early postpartum period (C=51% versus T=42%) and resulted in a lower somatic cell count (SCC) in the treatment group when compared with the control group (T=1,073x103, C=1,793x103). The use of the internal teat seal combined with dry cow antibiotic is effective in the prevention of IMI during the dry period and early lactation and results in the reduction of SCC in immediate postpartum period. The treatment is effective in reducing infection between dry-off and the immediate postpartum caused by major and minor pathogens. However, no effect on infections caused by contagious pathogens was observed.(AU)

Objetivou-se avaliar o uso de um selante interno de tetos contendo subnitrato de bismuto (Teatseal®, Zoetis®, Florham Park, Nova Jersey, EUA) associado a um antibiótico de longa ação contendo cloxacilina (Orbenin® Extra dry cow, Zoetis®, Florham Park, Nova Jersey, EUA) em prevenir novas infecções durante o período seco e pós-parto imediato. Foram utilizadas 150 vacas Holandesas (produção média de 9,000 kg de leite por lactação), com os quatro quartos mamários funcionais e sem mastite clínica, que foram secas 60 dias antes da data prevista para o parto. O teto constituiu a unidade experimental. O grupo controle (C) foi representado por dois tetos diagonais-contralaterais (n=300), que receberam somente o antibiótico de vaca seca. Os outros dois tetos (n=300) constituíam o grupo tratado (T) e recebiam o antibiótico de vaca seca associado ao selante interno. Dados da variável contagem de células somáticas (CCS) passaram por transformação logarítmica na base 10 e foram submetidos ao teste de Duncan, aceitando-se nível de 5% de significância estatística. A ocorrência de infecções intramamárias (IIM), taxa de cronicidade e frequência de microrganismos isolados na secagem e imediatamente pós-parto nos tetos do grupo controle e tratados com selante interno foram avaliados utilizando o teste não paramétrico qui-quadrado, aceitando 10% de nível de significância. Houve redução na ocorrência de novas infecções no pós-parto imediato nos animais em que se utilizou o selante (C=19,6%, T=11,4%). No período pós-parto, foram isolados microrganismos Gram-negativo de 16 tetos no C e sete no T. A maior redução ocorreu para Escherichia coli, (8 versus 1) no grupo T. Não houve efeito da utilização do selante interno na frequência de isolamento de Streptococcus ambientais. O uso do selante reduziu a prevalência de mastite subclínica das vacas no pós-parto imediato (C=51% versus T=42%) e resultou em menor CCS no grupo tratado (T = 1.073 x 103) quando comparado com o grupo controle (C=1.793x103). O uso do selante interno combinado com antibiótico de vacas secas é eficaz na prevenção de infecções intramamárias no período seco e início de lactação e resulta na redução da CCS no período pós-parto imediato. O tratamento é eficaz na redução de infecção entre a secagem e o pós-parto imediato causada por patógenos maiores e menores. Entretanto, não tem efeito sobre infecções causadas por patógenos contagiosos.(AU)

Efficacy of an internal teat seal associated with a dry cow intramammary antibiotic for prevention of intramammary infections in dairy cows during the dry and early lactation periods / Eficácia de um selante interno de tetos associado a antibiótico de vaca seca na prevenção de infecções intramamárias no período seco e início de lactação em vacas leiteiras

The present study aimed to evaluate the use of an internal dry period teat seal containing bismuth subnitrate (Teatseal®, Zoetis®, Florham Park, Nova Jersey, USA) associated with a long-acting cloxacilin preparation (Orbenin®Extra dry cow, Zoetis®, Florham Park, Nova Jersey, USA), in preventing new infections during the dry-off and early postpartum period. A total of 150 Holstein cows (average production of 9,000 kg of milk per lactation), with four functional udder quarters without clinical mastitis was included in the study. All animals were dried-off 60 days before the expected calving date. Two teats positioned diagonal-contralaterally received only dry cow antibiotic, control group C (n=300) and the other two teats, treatment group T (n=300) received dry cow antibiotic and infusion with an internal teat seal. Data from SCC variable were transformed by log base-10 transformation. Duncans test was used accepting 5% as the level of statistical significance. The occurrence of intramammary infection (IMI) and chronicity rate, and frequency of microorganisms isolated at drying and immediately postpartum in teats of group C and group T were evaluated using a non-parametric Chi-square Test, accepting 10% as the statistical significance level. There was a decrease in the occurrence of new infections in the early postpartum in cows which the sealant was used (C=19.6%, T=11.4%). In the postpartum period, Gram-negative bacteria were isolated from 16 teats in C and seven in T. The greatest reduction was observed for Escherichia coli (8 vs 1) in group T. There was no effect using the internal sealant on the frequency of isolation of environmental Streptococus. The use of sealant reduced the prevalence of subclinical mastitis cows between drying-off and the early postpartum period (C=51% versus T=42%) and resulted in a lower somatic cell count (SCC) in the treatment group when compared with the control group (T=1,073x103, C=1,793x103)...(AU)

Objetivou-se avaliar o uso de um selante interno de tetos contendo subnitrato de bismuto (Teatseal®, Zoetis®, Florham Park, Nova Jersey, EUA) associado a um antibiótico de longa ação contendo cloxacilina (Orbenin® Extra dry cow, Zoetis®, Florham Park, Nova Jersey, EUA) em prevenir novas infecções durante o período seco e pós-parto imediato. Foram utilizadas 150 vacas Holandesas (produção média de 9,000 kg de leite por lactação), com os quatro quartos mamários funcionais e sem mastite clínica, que foram secas 60 dias antes da data prevista para o parto. O teto constituiu a unidade experimental. O grupo controle (C) foi representado por dois tetos diagonais-contralaterais (n=300), que receberam somente o antibiótico de vaca seca. Os outros dois tetos (n=300) constituíam o grupo tratado (T) e recebiam o antibiótico de vaca seca associado ao selante interno. Dados da variável contagem de células somáticas (CCS) passaram por transformação logarítmica na base 10 e foram submetidos ao teste de Duncan, aceitando-se nível de 5% de significância estatística. A ocorrência de infecções intramamárias (IIM), taxa de cronicidade e frequência de microrganismos isolados na secagem e imediatamente pós-parto nos tetos do grupo controle e tratados com selante interno foram avaliados utilizando o teste não paramétrico qui-quadrado, aceitando 10% de nível de significância. Houve redução na ocorrência de novas infecções no pós-parto imediato nos animais em que se utilizou o selante (C=19,6%, T=11,4%). No período pós-parto, foram isolados microrganismos Gram-negativo de 16 tetos no C e sete no T. A maior redução ocorreu para Escherichia coli, (8 versus 1) no grupo T. Não houve efeito da utilização do selante interno na frequência de isolamento de Streptococcus ambientais...(AU)

Mode of action and in vitro susceptibility of mastitis pathogens to macedocin ST91KM and preparation of a teat seal containing the bacteriocin

Mastitis is considered to be the most economically costly disease affecting the dairy industry. Regular dosage of animals with antibiotics, including use of prophylactic concentrations, may select for resistant strains. The purpose of this study was to determine the mode of action of a new bacteriocin (macedocin ST91KM), to evaluate the antimicrobial resistance of mastitis pathogens to antibiotics commonly used in treatment remedies, and to introduce the possible use of an alternative antimicrobial agent. The bacteriocin macedocin ST91KM, produced by Streptococcus gallolyticus subsp. macedonicus ST91KM, is bactericidal to Streptococcus agalactiae, Streptococcus dysgalactiae, Streptococcus uberis and Staphylococcus aureus associated with mastitis infections, including strains resistant to methicillin and oxacillin. Sensitive cells were deformed and secreted nucleotides, K+ and -galactosidase when exposed to macedocin ST91KM. Adsorption of the peptide to target cells decreased in the presence of solvents, suggesting that receptors on the cell surfaces have lipid moieties. No adsorption was recorded in the presence of MgCl2, KI and Na2CO3, suggesting that ionic strength plays an important role. A teat seal preparation containing macedocin ST91KM effectively released the peptide and inhibited the growth of S. agalactiae. Macedocin ST91KM could form the basis for alternative dry cow therapy to prevent mastitis infections in dairy cows as it is effective against pathogens that display resistance to conventional antibiotic therapy.