Mastitis is the principal disease affecting dairy herds worldwide. The aim of the present study was to characterize phenotypic and genotypic features associated with resistance to antimicrobials in Staphylococcus spp. isolated from 2064 milk samples of 525 lactating cows in the Northeast of Brazil. Of the 218 isolates analyzed, 57.8% were characterized as Staphylococcus aureus, 28% as coagulase-positive staphylococci other than S. aureus (oCPS), and 14.2% as coagulase-negative staphylococci (CNS). The test for susceptibility to antimicrobials showed amoxicillin (32.6%) to be the less effective drug in vitro, and the multi-drug resistance (MDR) rate for beta-lactams varied from 0 to 0.75. The genotypic characterization showed that 93.1% of the samples were tested positive for the blaZ gene, while none amplified mecA. The antibiotic efflux mechanism was observed in 0.9% of isolates. The biofilm formation was found in 3.7 and 96.3% of samples, respectively, on Congo red agar and on the microplate adhesion test, while the icaD gene was present in 92.2% of Staphylococcus spp. The high frequency of blaZ gene observed in this study was associated with the resistance of most Staphylococcus spp. to one or more of the beta-lactams tested, which are routinely used in Brazilian herds for mastitis treatment. The biofilm formation was also detected in the isolates analyzed being an important characteristic for pathogenicity and antimicrobial resistance of bacteria.

The purpose of this paper was to study the etiology of mastitis, determine the antimicrobial susceptibility profile of Staphylococcus spp. and to identify the risk factors associated with infection in dairy cows in the states of Bahia and Pernambuco, Brazil. From the 2,064 milk samples analyzed, 2.6% were associated with cases of clinical mastitis and 28.2% with subclinical mastitis. In the microbiological culture, Staphylococcus spp. (49.1%) and Corynebacterium spp. (35.3%) were the main agents found, followed by Prototheca spp. (4.6%) and Gram negative bacilli (3.6%). In the antimicrobial susceptibility testing, all 218 Staphylococcus spp. were susceptible to rifampicin and the least effective drug was amoxicillin (32.6%). Multidrug resistance to three or more drugs was observed in 65.6% of Staphylococcus spp. The risk factors identified for mastitis were the extensive production system, not providing feed supplements, teat drying process, not disinfecting the teats before and after milking, and inadequate hygiene habits of the milking workers. The presence of multiresistant isolates in bovine milk demonstrates the importance of the choice and appropriate use of antimicrobial agents. Prophylactic and control measures, including teat antisepsis and best practices for achieving hygienic milking should be established in order to prevent new cases of the disease in herds.INDEX TERMS: Staphylococcus spp., multidrug resistance, mammary gland, risk factors.

RESUMOObjetivou-se neste estudo identificar os fatores de risco associados à mastite infecciosa caprina no sertão do Estado da Bahia. Foram visitadas 13 propriedades, totalizando 320 cabras em lactação e 640 metades mamárias. Amostras de leite foram coletadas após prévia antissepsia do teto e processadas utilizando-se as técnicas convencionais para o isolamento e identificação dos micro-organismos. Para o estudo dos fatores de risco foram aplicados questionários com perguntas referentes ao manejo sanitário dos rebanhos. A análise de fatores de risco foi efetuada em duas etapas: análise univariada e multivariada. A frequência de animais positivos para o exame microbiológico do leite foi de 29,06% (93/320), sendo que o percentual de amostras positivas foi de 18,44% (118/640). Foram isolados 118 micro-organismos, sendo o gênero Staphylococcus o mais frequente. Na análise univariada para fator de risco, quanto à variável assistência veterinária, os caprinos de propriedades sem assistência veterinária apresentaram maiores frequências de positividade para a mastite. Para a variável local de ordenha, observou-se que a positividade para a mastite foi menor quando se realizava a ordenha em plataforma. Na análise multivariada, observou-se que a predominância de animais mestiços constitui fator de risco para mastite (OR = 1,907; p = 0,010). Faz-se necessária a difusão de tecnologias direcionadas para melhoria das condições de higiene da ordenha, ambiente e do próprio ordenhador, objetivando a redução dos índices da mastite infecciosa nos rebanhos e consequentemente a garantia da qualidade sanitária dos produtos obtidos a partir do leite de cabra produzido em pequenas propriedades rurais. PALAVRAS-CHAVE: Epidemiologia, mastite, pequenos ruminantes. ABSTRACT RISK FACTORS FOR INFECTIOUS MASTITIS IN DAIRY GOATS RAISED IN BAHIA STATE,BRAZIL. The present study was aimed to identify risk factors associated to infectious mastitis in goats in a semiarid region of Bahia State, Brazil. Milk samples were taken from a total of 320 animals and 640 teats on 13 dairy goat farms. The samples were collected after teat disinfection, and were submitted to standard culture and identification of microorganisms. To evaluate the sanitary management an epidemiological questionnaire was used. The risk-factor analysis was performed in two steps: univariate and multivariate. The frequency of animals and mammary glands positive for the microbiologic exam was 29.06% (93/320) and 18.44% (118/640), respectively. One hundred eighteen bacteria were isolated, Staphylococcus spp. being the most prevalent. In the univariate risk-factor analysis, in regard to veterinary support, goats from farms without technical support presented higher frequencies to mastitis. In regard to the place of milking, a lower frequency of mastitis was detected where milking platforms were used. In the multivariate analysis, the predominance of mixed breeds was observed as an important risk factor for mastitis (OR = 1.907; p = 0.010). The spread of technology is necessary for better...

To verify the occurrence of caseous lymphadenitis in sheep and goats on farms of Pernambuco, Brazil, and in animals slaughtered in two Brazilian cities (Petrolina/PE and Juazeiro/BA), and to characterize the susceptibility profile of Corynebacterium pseudotuberculosis to disinfectants and antimicrobials, and its relationship with biofilm production were the objectives of this study. 398 samples were tested for sensitivity to antimicrobial drugs, disinfectants, and biofilm production. Among the 108 samples collected on the properties, 75% were positive for C. pseudotuberculosis. Slaughterhouse samples indicated an occurrence of caseous lymphadenitis in 15.66% and 6.31% for animals slaughtered in Petrolina and Juazeiro respectively. With respect to antimicrobials, the sensitivity obtained was 100% for florfenicol and tetracycline; 99.25% for enrofloxacin, ciprofloxacin and lincomycin; 98.99% for cephalothin; 98.74% for norfloxacin and sulfazotrim; 97.74% for gentamicin; 94.22% for ampicillin; 91.71% for amoxicillin; 91.21% for penicillin G; 89.19% for neomycin and 0% for novobiocin. In analyzes with disinfectants, the efficiency for chlorhexidine was 100%, 97.20% for quaternary ammonium, 87.40% for chlorine and 84.40% for iodine. 75% of the isolates were weak or non-biofilm producers. For the consolidated biofilm, found that iodine decreased biofilm formation in 13 isolates and quaternary ammonia in 11 isolates. The reduction of the biofilm formation was observed for iodine and quaternary ammonium in consolidated biofilm formation in 33% and 28% of the isolates, respectively. The results of this study highlight the importance of establishing measures to prevent and control the disease.

-Goat and sheep production in the semi-arid northeast of Brazil has shown great economic potential. However, health problems can compromise the productivity of these animals. Given the scarcity of studies about the occurrence of these diseases, the aim of the present study was to analyze the serological diagnosis of anti-Brucella and anti-lentivirus antibodies among small ruminants in municipalities located in the Brazilian states of Bahia and Pernambuco. The samples were collected from local slaughterhouses and dairy farms. In total, 997 serum samples from animals in slaughterhouses and dairy herds were collected. In order to diagnose the caprine arthritis encephalitis virus (CAEV), the samples underwent agarose gel immunodiffusion (AGID) testing. The buffered acidified antigen test (goats) and agarose gel immunodiffusion test (sheep) were used to detect anti-Brucella abortus and B. ovis antibodies following the methodology recommended by the Institute of Technology of Paraná (TECPAR). With anti-CAEV antibodies, seropositivity rates of 4.1% and 2.2% were recorded for animals from the slaughterhouses and dairy farms, respectively. None of the animals (goats or sheep) were positive for anti-B. abortus antibodies. With B. ovis, a seropositivity rate of 6.5% (n = 13) was recorded among the 199 sheep serum samples. Results of the present study confirmed the presence of the CAE virus in the meat and dairy herds studied, although the prevalence was low. Natural infection by B. abortus did not occur in the goat and sheep herds assessed. Seropositivity for B. ovis was confirmed, although prevalence was low. Direct tests are required to diagnose ovine brucellosis.Keywords: Brucellosis. CAEV. Goats. Sheep. Serology. ANTICORPOS ANTI-Lentivírus, Brucella abortus E B. ovis EM PEQUENOS RUMINANTES CRIADOS EM PERNAMBUCO E BAHIARESUMO -Alguns problemas de ordem sanitária ainda comprometem a produtividade de caprinos e ovinos. Sendo assim, foi realizado um estudo de diagnóstico sorológico da presença de anticorpos anti-lentivírus e antiBrucella em pequenos ruminantes localizados em municípios dos estados da Bahia e Pernambuco. As coletas foram realizadas em estabelecimentos de abate e em propriedades rurais com produção de leite, totalizando 997 amostras de soro. Para o diagnóstico do CAEV, as amostras foram submetidas ao teste de Imunodifusão em Gel de Agarose (IDGA). Para a pesquisa de anticorpos anti-Brucella abortus e Brucella ovis, foram utilizadas as técnicas do Antígeno Acidificado Tamponado (caprinos) e Imunodifusão em Gel de Agarose (ovinos), utilizando-se antígeno e metodologia recomendada pelo Instituto de Tecnologia do Paraná-TECPAR. Na pesquisa de anticorpos anti-CAEV, observou-se uma soropositividade de 4,1 e 2,2% para os animais oriundos de estabelecimentos de abate e de propriedades leiteiras, respectivamente. Quanto à pesquisa de anticorpos anti-B.abortus em caprinos e ovinos, não se observou nenhum animal positivo. Em relação a B. ovis, pesquisada em 199 amostras de soro ovino, obteve-se uma soroposivid...

This study aimed to evaluate the in vitro efficacy of commercial disinfectants on Staphylococcus spp., isolated from mastitis cases in goats, and to associate the observed resistance with the presence of the icaD gene. Broth microdilution was employed to evaluate the in vitro antimicrobial activity of the disinfectants, whereas the Congo Red technique was used for the evaluation of biofilm production and amplification of the icaD gene. All evaluated samples were sensitive to disinfectants, with the following ranges of activity: quaternary ammonium (0.13 - 21.33 µg/ml), chlorhexidine (4.00 - 313.00 µg/ml) and iodine (190.00 - 12500.00 µg/ml); however, the sodium hypochlorite-based disinfectant showed no bactericidal activity in the concentration range from 15.0 to 0.03 µg/ml. The icaD gene presented a frequency of 14.7% in the isolate samples. Fisher’s exact test showed a significant effect of the relation between the minimum bactericidal concentration value of the quaternary ammonium-based disinfectant and the presence/absence of the icaD gene (P <0.01). Commercial disinfectants with quaternary ammonium, chlorhexidine and iodine active ingredients presented in vitro activity even at concentrations lower than those recommended by the manufacturers. Therefore, the periodic evaluation of the sensitivity profile of the disinfectants must be performed.