RESUMO
Aureocin A53 is an N-formylated antimicrobial peptide (AMP) produced by Staphylococcus aureus. Aureocin A53 has a broad spectrum of antimicrobial activity against human and animal pathogens. In the present study, its antagonistic activity was investigated towards 30 strains of S. aureus and 30 strains of Streptococcus spp. isolated from bovine mastitis cases in Brazil. Bovine mastitis is a disease that causes a major economic impact worldwide. Aureocin A53 inhibited the growth of all 60 strains tested, including multidrug-resistant streptococcal isolates and strains of S. aureus belonging to different pulsotypes. This AMP proved to be bactericidal against the six target strains randomly selected among staphylococci and streptococci, also exhibiting a lytic mode of action against the staphylococcal cells. Furthermore, it was determined that 2,048 AU/mL of the AMP were required to inhibit 99.99% of the cell growth of the strain less sensitive to aureocin A53. Aureocin A53 was not toxic to bovine mammary gland epithelial cells after a 24-h exposure and maintained its antimicrobial activity when tested in the excised-teat model against strains of S. aureus and Streptococcus agalactiae, the species responsible for most intramammary infections, not only in Brazil but in other countries as well. Therefore, the use of aureocin A53 in the development of new pharmacological products for the prophylaxis and/or treatment of bovine mastitis was considered promising.
Assuntos
Anti-Infecciosos , Mastite Bovina , Infecções Estafilocócicas , Feminino , Humanos , Bovinos , Animais , Staphylococcus aureus , Streptococcus agalactiae , Peptídeos Antimicrobianos , Infecções Estafilocócicas/tratamento farmacológico , Infecções Estafilocócicas/veterinária , Staphylococcus , Antibacterianos/farmacologia , Streptococcus , Anti-Infecciosos/farmacologia , Monofosfato de Adenosina/farmacologiaRESUMO
The objective of this study was to assess the control feasibility of Streptococcus agalactiae subclinical mastitis and its impact in reducing somatic cell counts (SCC) of bulk milk tank. During the lactation, 33 cows positive for Streptococcus agalactiae in microbiological culture were treated with three applications of intramammary antimicrobial containing 100.000 UI of penicillin and 150 mg of novobiocin, in an interval of 12 hours. Individual and bulk tank milk samples were collected for somatic cell count (SCC) analysis and milk yield was measured before and after treatment. Statistical analyses were performed with SAS System, version 9.2. All cows treated against S. agalactiae had microbiological cure and reduction of SCC, indicating the effectiveness of treatment. SCC in bulk tank was reduced from 829,000 to 513,000 cells/ml.(AU)
Assuntos
Animais , Feminino , Bovinos , Mastite Bovina/prevenção & controle , Mastite Bovina/terapia , Contagem de Células/veterinária , Leite/microbiologia , Anti-Infecciosos/uso terapêuticoRESUMO
Bulk tank somatic cell counts (BTSCC) is widely used to monitore the mammary gland health at the herd and regional level. The BTSCC time series from specific regions or countries can be used to compare the mammary gland health and estimate the trend of subclinical mastitis at the regional level. Three time series of BTSCC from dairy herds located in the USA and the Southeastern Brazil were evaluated from 1995 to 2014. Descriptive statistics and a linear regression model were used to evaluate the data of the BTSCC time series. The mean of annual geometric mean of BTSCC (AGM) and the percentage of dairy herds with a BTSCC greater than 400,000 cells mL-1 (%>400) were significantly different (P 0.05) according to the countries and the times series. Linear regression model used for the USA time series was statistically significant for AGM and the %>400 (P 0.05). The first and second USA time series presented an increasing and decreasing trend for AGM and the %>400, respectively. The linear regression model for the Brazil time series was not significant (P>0.05) for both dependent variables (AGM and %>400). The Brazil time series showed no increasing or decreasing trend for the AGM and %>400. Consequently, approximately 40 to 50% of the dairy herds from southeastern Brazil will not achieve the regulatory limits for BTSCC over the next years.(AU)
Contagens de células somáticas de tanque (BTSCC) são amplamente utilizadas para monitorar a saúde da glândula mamária em níveis regional e de rebanho. Séries temporais de BTSCC, de regiões ou países específicos, podem ser usadas para comparar a saúde da glândula mamária e estimar a tendência de mastite subclínica em nível regional. Três séries temporais de BTSCC de rebanhos leiteiros, localizados nos EUA e na região sudeste do Brasil, foram avaliadas de 1995 a 2014. A estatística descritiva e modelos de regressão linear foram usados para avaliar as informações das séries temporais de BTSCC. A média anual geométrica de BTSCC (AGM) e a porcentagem de rebanhos com BTSCC, maior que 400.000 células mL-1 (%>400), foram significantemente diferentes (P 0,05) de acordo com os países e as séries temporais analisadas. O modelo de regressão linear usado para as séries temporais dos EUA foram estatisticamente significantes para AGM e %>400 (P 0,05). A primeira e a segunda séries temporais dos EUA apresentaram uma tendência de aumento e diminuição, tanto para AGM quanto para %>400, respectivamente. O modelo de regressão linear para as séries temporais do Brasil não foi significante (P>0,05) para ambas as variáveis dependentes (AGM e %>400). As séries temporais do Brasil não apresentaram tendência de aumento ou diminuição para AGM e %>400. Consequentemente, aproximadamente, 40 a 50% dos rebanhos leiteiros do sudeste do Brasil não alcançarão os limites regulatórios para BTSCC ao longo dos próximos anos.(AU)
Assuntos
Animais , Bovinos , Estudos de Séries Temporais , Mastite Bovina/diagnóstico , Contagem de Células/instrumentaçãoRESUMO
The objective of this study was to assess the control feasibility of Streptococcus agalactiae subclinical mastitis and its impact in reducing somatic cell counts (SCC) of bulk milk tank. During the lactation, 33 cows positive for Streptococcus agalactiae in microbiological culture were treated with three applications of intramammary antimicrobial containing 100.000 UI of penicillin and 150 mg of novobiocin, in an interval of 12 hours. Individual and bulk tank milk samples were collected for somatic cell count (SCC) analysis and milk yield was measured before and after treatment. Statistical analyses were performed with SAS System, version 9.2. All cows treated against S. agalactiae had microbiological cure and reduction of SCC, indicating the effectiveness of treatment. SCC in bulk tank was reduced from 829,000 to 513,000 cells/ml.
Assuntos
Feminino , Animais , Bovinos , Contagem de Células/veterinária , Leite/microbiologia , Mastite Bovina/prevenção & controle , Mastite Bovina/terapia , Anti-Infecciosos/uso terapêuticoRESUMO
Bulk tank somatic cell counts (BTSCC) is widely used to monitore the mammary gland health at the herd and regional level. The BTSCC time series from specific regions or countries can be used to compare the mammary gland health and estimate the trend of subclinical mastitis at the regional level. Three time series of BTSCC from dairy herds located in the USA and the Southeastern Brazil were evaluated from 1995 to 2014. Descriptive statistics and a linear regression model were used to evaluate the data of the BTSCC time series. The mean of annual geometric mean of BTSCC (AGM) and the percentage of dairy herds with a BTSCC greater than 400,000 cells mL-1 (%>400) were significantly different (P 0.05) according to the countries and the times series. Linear regression model used for the USA time series was statistically significant for AGM and the %>400 (P 0.05). The first and second USA time series presented an increasing and decreasing trend for AGM and the %>400, respectively. The linear regression model for the Brazil time series was not significant (P>0.05) for both dependent variables (AGM and %>400). The Brazil time series showed no increasing or decreasing trend for the AGM and %>400. Consequently, approximately 40 to 50% of the dairy herds from southeastern Brazil will not achieve the regulatory limits for BTSCC over the next years.
Contagens de células somáticas de tanque (BTSCC) são amplamente utilizadas para monitorar a saúde da glândula mamária em níveis regional e de rebanho. Séries temporais de BTSCC, de regiões ou países específicos, podem ser usadas para comparar a saúde da glândula mamária e estimar a tendência de mastite subclínica em nível regional. Três séries temporais de BTSCC de rebanhos leiteiros, localizados nos EUA e na região sudeste do Brasil, foram avaliadas de 1995 a 2014. A estatística descritiva e modelos de regressão linear foram usados para avaliar as informações das séries temporais de BTSCC. A média anual geométrica de BTSCC (AGM) e a porcentagem de rebanhos com BTSCC, maior que 400.000 células mL-1 (%>400), foram significantemente diferentes (P 0,05) de acordo com os países e as séries temporais analisadas. O modelo de regressão linear usado para as séries temporais dos EUA foram estatisticamente significantes para AGM e %>400 (P 0,05). A primeira e a segunda séries temporais dos EUA apresentaram uma tendência de aumento e diminuição, tanto para AGM quanto para %>400, respectivamente. O modelo de regressão linear para as séries temporais do Brasil não foi significante (P>0,05) para ambas as variáveis dependentes (AGM e %>400). As séries temporais do Brasil não apresentaram tendência de aumento ou diminuição para AGM e %>400. Consequentemente, aproximadamente, 40 a 50% dos rebanhos leiteiros do sudeste do Brasil não alcançarão os limites regulatórios para BTSCC ao longo dos próximos anos.
Assuntos
Animais , Bovinos , Estudos de Séries Temporais , Mastite Bovina/diagnóstico , Contagem de Células/instrumentaçãoRESUMO
ABSTRACT: Bulk tank somatic cell counts (BTSCC) is widely used to monitore the mammary gland health at the herd and regional level. The BTSCC time series from specific regions or countries can be used to compare the mammary gland health and estimate the trend of subclinical mastitis at the regional level. Three time series of BTSCC from dairy herds located in the USA and the Southeastern Brazil were evaluated from 1995 to 2014. Descriptive statistics and a linear regression model were used to evaluate the data of the BTSCC time series. The mean of annual geometric mean of BTSCC (AGM) and the percentage of dairy herds with a BTSCC greater than 400,000 cells mL-1 (%>400) were significantly different (P<0.05) according to the countries and the times series. Linear regression model used for the USA time series was statistically significant for AGM and the %>400 (P<0.05). The first and second USA time series presented an increasing and decreasing trend for AGM and the %>400, respectively. The linear regression model for the Brazil time series was not significant (P>0.05) for both dependent variables (AGM and %>400). The Brazil time series showed no increasing or decreasing trend for the AGM and %>400. Consequently, approximately 40 to 50% of the dairy herds from southeastern Brazil will not achieve the regulatory limits for BTSCC over the next years.
RESUMO: Contagens de células somáticas de tanque (BTSCC) são amplamente utilizadas para monitorar a saúde da glândula mamária em níveis regional e de rebanho. Séries temporais de BTSCC, de regiões ou países específicos, podem ser usadas para comparar a saúde da glândula mamária e estimar a tendência de mastite subclínica em nível regional. Três séries temporais de BTSCC de rebanhos leiteiros, localizados nos EUA e na região sudeste do Brasil, foram avaliadas de 1995 a 2014. A estatística descritiva e modelos de regressão linear foram usados para avaliar as informações das séries temporais de BTSCC. A média anual geométrica de BTSCC (AGM) e a porcentagem de rebanhos com BTSCC, maior que 400.000 células mL-1 (%>400), foram significantemente diferentes (P<0,05) de acordo com os países e as séries temporais analisadas. O modelo de regressão linear usado para as séries temporais dos EUA foram estatisticamente significantes para AGM e %>400 (P<0,05). A primeira e a segunda séries temporais dos EUA apresentaram uma tendência de aumento e diminuição, tanto para AGM quanto para %>400, respectivamente. O modelo de regressão linear para as séries temporais do Brasil não foi significante (P>0,05) para ambas as variáveis dependentes (AGM e %>400). As séries temporais do Brasil não apresentaram tendência de aumento ou diminuição para AGM e %>400. Consequentemente, aproximadamente, 40 a 50% dos rebanhos leiteiros do sudeste do Brasil não alcançarão os limites regulatórios para BTSCC ao longo dos próximos anos.
RESUMO
Bacteria of the genus Staphylococcus are one of the major pathogens causing bovine mastitis. In recent decades, resistance of this genus to oxacillin (methicillin) has been a matter of concern due to the possibility of reducing the effectiveness of mastitis treatments and the transfer of resistance determinants to other bacteria. Oxacillin resistance was studied in 170 staphylococci from bovine milk samples, including 79 Staphylococcus aureus and 91 coagulase-negative staphylococci (CNS). The susceptibility profile of 10 antimicrobial agents used in veterinary practice was determined by the Etest method. In addition to the Etest, the phenotypic characterization of oxacillin resistance was tested using the cefoxitin disk diffusion test. All isolates were screened by PCR to detect the mecA gene in 2 different regions of the gene. The isolates with an oxacillin minimum inhibitory concentration ≥0.5 µg/mL or resistant to cefoxitin were identified by sequencing a 536-bp fragment of the 16S rRNA gene. This group of isolates was also evaluated for the presence of blaZ and mecC genes. Molecular analysis of the mecA gene was carried out by typing of the staphylococcal cassette chromosome mec (SCCmec). The relatedness of the mecA-positive isolates was evaluated by macrorestriction of chromosomal DNA followed by pulsed-field gel electrophoresis. With the exception of penicillin and oxacillin, 86% of the isolates showed susceptibility to cephalothin, gentamicin, erythromycin, sulfonamide, trimethoprim-sulfamethoxazole, and tetracycline. All S. aureus isolates were susceptible to oxacillin, whereas 47% (n=43) of the CNS isolates were resistant. The CNS isolates showed a higher resistance to cephalothin, erythromycin, tetracycline, and gentamicin in comparison with S. aureus. The mecA gene was only detected in 10 CNS isolates, identified as Staphylococcus epidermidis, and classified into 3 pulsotypes (A, B, and C) and 4 subtypes (A1, B1, B2, and B3). Among the isolates with an oxacillin resistance phenotype, 12 were positive for the blaZ gene, and 9 of them were mecA-positive. Two of the oxacillin-resistant isolates amplified the mecA homolog gene of Staphylococcus sciuri and none amplified mecC. Three SCCmec types, I, IV, and V, were found. Our results suggest that Staphylococcus epidermidis can be a reservoir for mecA for other Staphylococcus species. Studies investigating the molecular and phenotypic profile of antimicrobial resistance in staphylococcal species should be performed for controlling the spread of resistance and the selection of appropriate therapeutic measures.
Assuntos
Antibacterianos/farmacologia , Mastite Bovina/microbiologia , Resistência a Meticilina/genética , Leite/microbiologia , Infecções Estafilocócicas/veterinária , Staphylococcus epidermidis/isolamento & purificação , Animais , Brasil/epidemiologia , Bovinos , Cefoxitina/farmacologia , Feminino , Mastite Bovina/epidemiologia , Testes de Sensibilidade Microbiana/veterinária , Oxacilina/farmacologia , Penicilina G/farmacologia , RNA Ribossômico 16S/genética , Infecções Estafilocócicas/epidemiologia , Infecções Estafilocócicas/microbiologia , Staphylococcus epidermidis/genéticaRESUMO
Minas Gerais é o mais extenso dos quatro estados que compõem a região sudeste do Brasil, com o maior efetivo caprino dessa região. A caracterização dos aspectos sanitários da caprinocultura foi realizada em 84 rebanhos leiteiros em 81 municípios e 200 rebanhos de carne em 70 municípios de Minas Gerais. Um questionário foi preenchido para cada rebanho, requisitando informações sobre a fazenda, o rebanho e proprietario, realizado por veterinários do Instituto Mineiro de Agropecuaria (IMA). . Um banco de dados foi desenvolvido em Windows Excel e analisado utilizando o programa Epi-Info. Comparaçãoes entre variáveis categoricas foram feitas com teste de Qui-quadrado. A identificação individual dos animais era realizada em 73,8% das propriedades leiteiras e em 7,5% das propriedades de corte, o uso da quarentena em 15,5% e 4,0%, o isolamento de animais doentes em 30,9% e 11,0%, a solicitação de certificados sanitarios na aquisição de novos animais em 28,6% e 1,5%, o monitoramento veterinário em 52,4% e 1,5%, respectivamente. Os principais problemas sanitários relatados, nas propriedades leiteiras e de carne foram, respectivamente, aborto (50,0% e 49,5%), mastite (41,7% e 19,0%), pneumonia (37,4% e 16,5%), diarreia (34,5% e 16,5% ) e a linfadenite caseosa (20,2% e 43,0%).(AU)
Minas Gerais is the largest one out of the four states that comprise the southeastern region of Brazil, with the bigest goat herd of this region. The characterization of health aspects of dairy goat husbandry was done in 84 dairy herds in 81 municipalities and 200 beef herds in 70 municipalities in the State of Minas Gerais. A questionnaire was filled out for each herd, requesting data regarding the farm, the herd and the farmer by the veterinarians within the Agriculture and Livestock Institute of Minas Gerais (Instituto Mineiro de Agropecuária IMA). A data bank was developed in Windows Excel and analyzed using the Epi-Info system. Comparisons of categorical variables were based on Chi-square test. The individual identification of the animals was done at 73.8% of dairy farms and at 7.5% of beef farms, use of quarentine at 15.5% and 4.0%, isolation of sick animals at 30.9% and 11.0%, requisition of sanitary certificate in the acquisition of new animals at 28.6% and 1.5%, regular veterinary monitoring at 52.4% and 1.5%, respectively. The main health problems reported at dairy and beef farms, respectively, were abortion (50.0% and 49.5%), mastitis (41.7% and 19.0%), pneumonia (37.4% and 16.5%), diarrhea (34.5% and 16.5%) and caseous lymphadenitis (20.2% and 43.0%).(AU)
Assuntos
Animais , Ruminantes , Criação de Animais Domésticos , Vigilância Sanitária , Aborto Animal , Mastite/veterinária , Pneumonia/veterinária , Diarreia/veterinária , Linfadenite/veterináriaRESUMO
Minas Gerais é o mais extenso dos quatro estados que compõem a região sudeste do Brasil, com o maior efetivo caprino dessa região. A caracterização dos aspectos sanitários da caprinocultura foi realizada em 84 rebanhos leiteiros em 81 municípios e 200 rebanhos de carne em 70 municípios de Minas Gerais. Um questionário foi preenchido para cada rebanho, requisitando informações sobre a fazenda, o rebanho e proprietario, realizado por veterinários do Instituto Mineiro de Agropecuaria (IMA). . Um banco de dados foi desenvolvido em Windows Excel e analisado utilizando o programa Epi-Info. Comparaçãoes entre variáveis categoricas foram feitas com teste de Qui-quadrado. A identificação individual dos animais era realizada em 73,8% das propriedades leiteiras e em 7,5% das propriedades de corte, o uso da quarentena em 15,5% e 4,0%, o isolamento de animais doentes em 30,9% e 11,0%, a solicitação de certificados sanitarios na aquisição de novos animais em 28,6% e 1,5%, o monitoramento veterinário em 52,4% e 1,5%, respectivamente. Os principais problemas sanitários relatados, nas propriedades leiteiras e de carne foram, respectivamente, aborto (50,0% e 49,5%), mastite (41,7% e 19,0%), pneumonia (37,4% e 16,5%), diarreia (34,5% e 16,5% ) e a linfadenite caseosa (20,2% e 43,0%).
Minas Gerais is the largest one out of the four states that comprise the southeastern region of Brazil, with the bigest goat herd of this region. The characterization of health aspects of dairy goat husbandry was done in 84 dairy herds in 81 municipalities and 200 beef herds in 70 municipalities in the State of Minas Gerais. A questionnaire was filled out for each herd, requesting data regarding the farm, the herd and the farmer by the veterinarians within the Agriculture and Livestock Institute of Minas Gerais (Instituto Mineiro de Agropecuária IMA). A data bank was developed in Windows Excel and analyzed using the Epi-Info system. Comparisons of categorical variables were based on Chi-square test. The individual identification of the animals was done at 73.8% of dairy farms and at 7.5% of beef farms, use of quarentine at 15.5% and 4.0%, isolation of sick animals at 30.9% and 11.0%, requisition of sanitary certificate in the acquisition of new animals at 28.6% and 1.5%, regular veterinary monitoring at 52.4% and 1.5%, respectively. The main health problems reported at dairy and beef farms, respectively, were abortion (50.0% and 49.5%), mastitis (41.7% and 19.0%), pneumonia (37.4% and 16.5%), diarrhea (34.5% and 16.5%) and caseous lymphadenitis (20.2% and 43.0%).