O objetivo do presente estudo foi avaliar a contagem de células somáticas, a prevalência e a etiologia da mastite bubalina nas estações seca e chuvosa em um rebanho de bubalinos do município de Analândia, estado de São Paulo, Brasil. Adicionalmente, verificou-se o perfil de sensibilidade antimicrobiana dos micro-organismos isolados nas amostras de leite das búfalas. Foram avaliadas 1.042 amostras de leite de búfalas da raça Murrah pertencentes a uma propriedade rural localizada no município de Analândia-SP, obtidas no período de maio de 2011 e novembro de 2012. Após o exame físico da glândula mamária, foram realizados o teste da caneca de fundo escuro e o California Mastits Test (CMT); em seguida, foram colhidas, de forma asséptica, amostras de 50mL de leite de cada quarto mamário, para a contagem de células somáticas (CCS) em aparelho automático e exame microbiológico. Também, foi avaliado o perfil de sensibilidade antimicrobiana a ampicilina, cefoperazona, ceftiofur, enrofloxacina, gentamicina, neomicina, oxacilina, penicilina e sulfametoxazol/trimetoprim, pelo método de difusão em disco. A temperatura média e o índice pluviométrico mensais foram obtidos no Centro Integrado de Informações Agrometeorológicas (CIIAGRO) do Instituto Agronômico de Campinas (IAC). Notou-se que as amostras de leite com resultado positivo no exame microbiológico apresentaram CCS média de 137.720 células/mL, no período seco, e 190.309 células/mL, no período chuvoso. Embora tenha se constatado maior índice de isolamentos de micro-organismos nas amostras de leite obtidas no período chuvoso (69/600) do que no período seco (50/442), a frequência de isolamentos não foi influenciada significativamente pela estação do ano. Os principais gêneros de micro-organismos isolados durante o período seco foram Staphylococcus coagulase negativa (38,4%), Streptococcus agalactiae (28,8%) e Bacillus spp. (7,56%), e no período chuvoso Corynebacterium sp. (23,5%), Streptococcusspp. (32,3%) e Streptococcus agalactiae (9,24%). Verificou-se resistência a três ou mais antimicrobianos em 30,1% dos micro-organismos isolados.

The aim of this study was to evaluate somatic cell count (SCC), prevalence and etiology of mastitis in a dairy buffalo herd from Analândia, São Paulo State, Brazil, in the dry and rainy seasons. Additionally, antimicrobial susceptibility profile of microorganisms isolated from milk samples was also evaluated. 1,042 milk samples from female Murrah buffaloes in a dairy farm located in Analândia, São Paulo State, Brazil, collected between May 2011 and November 2012 were analyzed. After the mammary gland physical examination, strip cup test and California Mastitis Test (CMT) were performed. Afterwards, 50mL of milk samples from each mammary quarter were collected aseptically for SCC in automatic equipment and microbiological examination. The antimicrobial sensitivity profile to ampicillin, cefoperazone, ceftiofur, enrofloxacin, gentamicin, neomycin, oxacillin, penicillin, and sulfamethoxazole/trimethoprim was evaluated by disk diffusion method. The monthly average temperature and pluviometric index were obtained from "Centro Integrado de Informações Agrometeorológicas" (CIIAGRO) of "Instituto Agronômico de Campinas" (IAC). Milk samples with positive results in the microbiological test showed average SCC of 137,720 cells/mL in the dry period and 190,309 cells/mL in the rainy period. Although a higher number of isolated microorganisms was observed in buffalo milk samples during the rainy period (69/600) compared to the dry period (50/442), the season had no significant effect on the frequency of isolation of microorganisms. The main genera of microorganisms isolated were coagulase-negative Staphylococcus (38.4%), Streptococcus agalactiae(28.8%), and Bacillus spp. (7.56%) during the dry season and Corynebacterium sp. (23.5%), Streptococcus spp. (32.3%), and Streptococcus agalactiae (9.24%) during the rainy period. Multidrug resistance was observed in 30.1% of the isolated microorganisms.

The identification of pathogens of viral (Rotavirus, Coronavirus), parasitic (Toxocara spp.) and bacterial (Escherichia coli, Salmonella spp., Rhodococcus equi) origin shed in feces, and the virulence profile of R. equi and E. coli isolates were investigated in 200 samples of sand obtained from 40 parks, located in central region of state of Sao Paulo, Brazil, using different diagnostic methods. From 200 samples analyzed, 23 (11.5%) strains of R. equi were isolated. None of the R. equi isolates showed a virulent (vapA gene) or intermediately virulent (vapB gene) profiles. Sixty-three (31.5%) strains of E. coli were identified. The following genes encoding virulence factors were identified in E. coli: eae, bfp, saa, iucD, papGI, sfa and hly. Phylogenetic classification showed that 63 E. coli isolates belonged to groups B1 (52.4%), A (25.4%) and B2 (22.2%). No E. coli serotype O157:H7 was identified. Eggs of Toxocara sp. were found in three parks and genetic material of bovine Coronavirus was identified in one sample of one park. No Salmonella spp. and Rotavirus isolates were identified in the samples of sand. The presence of R. equi, Toxocara sp, bovine Coronavirus and virulent E. coli isolates in the environment of parks indicates that the sanitary conditions of the sand should be improved in order to reduce the risks of fecal transmission of pathogens of zoonotic potential to humans in these places.

Two strains of Nocardia spp. were isolated from bovine milk of two individual bulk tank. Molecular identification classified the strains as Nocardia farcinica and Nocardia cyriacigeorgica. The thermorresistance to boiling of the isolates was carried out and was observed bacterial growth after boiling. Our findings indicate the potential risk of pathogen transmission to humans through contaminated milk with Nocardia spp.

Routine diagnosis methods used in bovine mastitis were studied in 55 mares in lactation. The findings of strip cup test, California Mastitis Test-CMT, electronic somatic cell count-CCS, microbiological culture, and in vitro antimicrobial susceptibility profile of isolates were discussed. Streptococcus spp., Staphylococcus spp, and enterobacteria were the most common microorganisms isolated in health and CMT-positive mammary glands. Staphylococcus aureus and Arcanobacterium pyogenes were identified in two mares presenting clinical mastitis. Mean somatic cell count of eight mares without presence of microorganisms in milk was 247.57x10³/mL and 1.621,86x10³/mL in 47 mares with positive microbiological culture. Moderate concordance (63.8%) between positive reactions in CMT (1 to 3+) and microbiological culture was observed. Amicacin (78.9%), ceftiofur (74.7%), sulpha-trimetoprim (69,0%) and norfloxacin (69.0%), were the most effective drugs, while resistance of isolates was mainly observed against penicillin (64.8%), gentamycin (35.2%), azithromycin (35.2%), enrofloxacin (28.2%), and florfenicol (28.2%).

An uncommon outbreak of mastitis caused by Arcanobacterium pyogenes in 26 cows is reported. The epidemiological findings, clinical signs, microbiological exams, somatic cell count, in vitro susceptibility profile of strains, efficacy of intramammary treatment and control measures were discussed. Florfenicol (96.2%), cefoperazona (92.3%), cefaloxin (84.6%) and ceftiofur (84.6%) were the most effective antimicrobials, and neomicin (27.0%) and enrofloxacin (17.4%) the least effective antimicrobials.

O perfil de sensibilidade microbiana e a concentração inibitória mínima (MIC) da azitromicina para 42 cepas de Rhodococcus equi isoladas de potros, no Brasil, e em uma cepa-controle, foi avaliado, respectivamente, pelos métodos de difusão com discos e E-test. A azitromicina apresentou 100% de efetividade in vitro para todas as cepas em ambos os testes. As cepas de R. equi apresentaram MIC90 para azitromicina em valores <1.5µg/ml. Este estudo mostra a alta efetividade da azitromicina em linhagens de R. equi isoladas no Brasil, sugerindo o uso dessa droga como alternativa na terapia da rodococose em potros.

Avaliou-se a ocorrência de fatores de virulência e do sorotipo O157:H7 em 120 linhagens de Escherichia coli, isoladas de 80 casos de mastite clínica bovina e 40 de mastite subclínica. Verificou-se alfa-hemolisina em oito (6,7%) linhagens, isoladas de cinco casos de mastite clínica e três de mastite subclínica e em nenhuma das estirpes detectou-se enteroemolisina. A presença de sideróforos foi encontrada em 11 (9,2%) linhagens, sete de mastite clínica e quatro de subclínica. Em duas (1,7%) estirpes isoladas de mastite subclínica, identificou-se enterotoxina STa. Observou-se efeito citopático em células vero compatível com a produção de verotoxina-VT em cinco (4,2%) linhagens, duas de mastite clínica e três subclínicas. Em uma (0,8%) linhagem isolada de mastite clínica, detectou-se efeito citopático compatível com o fator necrosante citotóxico. Nenhuma estirpe apresentou-se sorbitol-negativa no MacConkey-sorbitol, tampouco aglutinou com o sorotipo O157:H7. Os antimicrobianos mais efetivos foram polimixina B (97,5%) e norfloxacina (95,8%). Observou-se multi-resistência a dois ou mais antimicrobianos em 24 (20%) estirpes, principalmente com o uso de ampicilina e ceftiofur.

The occurrence of different virulence factors and O157:H7 serotype investigation in 120 Escherichia coli strains isolated from clinical (80 cases) and subclinical (40 cases) bovine mastitis was evaluated. Alpha-haemolysin was detected in 8 (6.7%) strains (5 clinical and 3 subclinical cases). None strain showed enterohaemolysin production. E. coli growth under iron restriction conditions (siderophores production) was observed in 11 (9.2%) strains (7 clinical and 4 subclinical cases). STa enterotoxin was detected in 2 (1.7%) strains from subclinical cases. Cytotoxic effect in vero cells compatible with verotoxin-VT production was observed in 5 (4.2%) strains (2 clinical and 3 subclinical cases). One strain (0.8%) isolated from clinical mastitis showed cytophatic effect in vero cells compatible with cytotoxic-necrotic-factor production. None strain showed non-sorbitol fermenting colonies using sorbitol MacConkey agar and agglutination with specific anti-sera for E. coli O157:H7 serotype investigation. Polymixin B (97.5%) and norfloxacin (95.8%) were the most effective drugs. Multiple-drug resistance for 2 or more antimicrobials was observed in 24 (20.0%) strains, mainly with use of ampicillin and ceftiofur.

RESUMO Avaliou-se a etiologia de bactérias aeróbicas e fúngica e a sensibilidade microbiana in vitro de agentes bacterianos, de 207 éguas com endometrite. Obteve-se o isolamento microbiano em 75 (36,5%) amostras de secreção uterina. Isolou-se com maior freqüência Streptococcus beta-hemolítico (32,0%), Escherichia coli (17,3%) e Corynebacterium spp. (12,0%). Dentre os agentes de origem fúngica identificou-se Candida albicans (4,0%) e Geotrichum candidum(1,3%). No teste in vitro de sensibilidade microbiana, a norfloxacina (77,0%), a ampicilina (72,3%) e a gentamicina (63,5%) foram os antimicrobianos mais efetivos. Estreptomicina (68,75%), sulfadiazina/trimetoprim (50,5%) e penicilina G (48,7%) apresentaram os maiores índices de resistência frente aos agentes. O presente estudo ratifica a complexidade etiológica na gênese de infecções uterinas na espécie eqüina, e a importância do perfil in vitro de sensibilidade microbiana, como subsídio para procedimentos terapêuticos.

ABSTRACT Microbiological exams of the uterine secretion of 207 mares were evaluated. From 75 (36.2%) positive cultures, the most common microorganisms isolated were Streptococcus beta-hemolytic (32.0%), Escherichia coli (17.3%) and Corynebacteriumspp. (12.0%). Candida albicans (4.0%) and Geotrichum candidum (1.0%) were the most frequent fungi isolated. Norfloxacin (77.0%), ampicillin (72.3%) and gentamicin (63.5%) were the most effective antimicrobials for bacterial agents. Streptomycin (68.7%), sulfadiazine/trimethoprim (50.0%) and penicillin G (48.7%) showed high values of resistance. The present study confirms the etiologic complex of uterine infections mares as well as the importance of the in vitro antimicrobial sunceptibility profile as an aide in therapy.

A concentração inibitória mínima-MIC em 30 estirpes de Pseudomonas aeruginosa isoladas de mastite bovina foi avaliada utilizando o E-test padrão e o método modificado, pela adição de Tris-EDTA e DMSO. Os métodos modificados apresentaram redução significativa da MIC das estirpes utilizando a gentamicina, a ciprofloxacina e a norfloxacina.

Fistulous wither secretions from three horses were tested by the plate agglutination (PAT), tube agglutination (SAT), buffered plate-Rose Bengal (RBPT) and 2-mercaptoethanol (2-ME) tests, comparatively with standard agglutination tests. In the modified tests, titers were increased in the PAT, SAT and 2-ME tests and positive reaction was observed in RBPT. Brucella abortus was isolated from the secretion of fistulous withers collected from one animal. These results suggest that the modified tests may be used as alternative tests to diagnose brucellosis in horses with fistulous withers.

In vitro antimicrobial susceptibility of strains of Pseudomonas aeruginosa by standard diffusion disk test and a modified method, by the addition Tris-EDTA, was evaluated. Increase in sensitivity of agent using modified method was observed mainly in aminoglycosides (amikacin, gentamicin, tobramycin), quinolones (ofloxacin and norfloxacin) and cephalosporins (cefoperazone and ceftazidime) groups. by standard diffusion disk test and a modified method, by the addition Tris-EDTA, was evaluated. Increase in sensitivity of agent using modified method was observed mainly in aminoglycosides (amikacin, gentamicin, tobramycin), quinolones (ofloxacin and norfloxacin) and cephalosporins (cefoperazone and ceftazidime) groups.