Eighty Salmonella Enteritidis strains isolated from broiler carcasses between May 1995 and April 1996 in the State of Rio Grande do Sul, Brazil, were tested for antibiotic susceptibility using the disk diffusion method. Resistance to colistin, novobiocin, erythromycin and tetracycline was observed in 100% of the isolates. The strains showed intermediate resistance at different levels to kanamycin (1.25%), enrofloxacin (3.75%), neomycin (3.75%), fosfomycin (20%), sulphonamides (86.25%) and nitrofurantoin (90%). Resistance to ciprofloxacin, norfloxacin, gentamicin, polymyxin B, sulphametrim and sulphazotrim was not found. Since resistance to antibiotics especially those introduced in the last decades, was detected, it is recommended that their use must be based on the results of resistance tests or minimum inhibitory concentration tests.

The purpose of this study was to determine the prevalence of environmental mastitis in dauy herds and identify the main environmental pathogens, and to evaluate the influence of season, housing and management. A total of 20 310 quarters of 5216 animals from 52 dairy herds in 32 counties was examined. Milk samples were aseptically collected for laboratory examination from mammary glands testing positive to any of the field tests. From these, 736 environmental infections were identified. The most frequently isolated environmental pathogens were algae of the genus htothcca sp. (41.2%), Sbcptmccus nberis (21.

The present study was carried out to evaluate the occurrence of Salmonellae in broiler chicken carcasses and to determine the antimicrobial resistance profile of the isolated strains. Twenty-five out of the 260 broiler chicken carcasses samples (9.6%) were positive for Salmonella. S. Enteritidis was the most frequent serovar. Nineteen Salmonella isolates were tested for antimicrobial resistance, and the results indicated that 94.7% were resistant to at least one antimicrobial agent. Resistance to streptomycin (73.7%), nitrofurantoin (52.3%), tetracycline (31.6%), and nalidixic acid (21%) were the prevalent amongst Salmonella strains tested.

The purpose of this survey was to describe the occurrence of bovine mastitis caused by Prototheca zopfii in Goiás State, Brazil. Samples of milk, environment and udder were taken from a herd of 120 Holstein cows. Sabourauds dextrose agar plates were incubated under aerobic conditions at 37 degrees C/96 h, for microbiological analysis. Somatic cell count and milk composition were also determined. Histological sections from two udders were stained with HE and PAS. Prototheca zopfii was identified in six cows whose milk had a watery appearance. They also showed a pronounced decrease in milk yield, fat and lactose. Pronounced infiltration of mononuclear cells, atrophy of alveoli and fibrosis were observed. The presence of this agent in other herds in the State is highly likely.

The present study was carried out to evaluate the occurrence of Salmonellae in raw broiler parts and to determine the antimicrobial resistance profile of the isolated strains. Twenty-four (39.3%) broiler parts samples were positive for Salmonella and twenty-five Salmonella strains were isolated, since two different serovars were detected in one single positive sample. Salmonella Enteritidis was the most prevalent serovar. Among Salmonella Enteritidis isolates, 95.2% belonged to Phage Type 4 (PT4) (20/21) and 4.8% to PT7 (1/21). Twenty-two (88%) strains of Salmonella were resistant to at least one antimicrobial agent, generating eight different resistance patterns. The S. Typhimurium (n: 1) and S. Hadar (n: 3) isolates presented multiple resistance. Three S. Enteritidis isolates were susceptible to all antimicrobials tested, two were resistant only to tetracycline. The high prevalence of Salmonella in the broiler parts strenghtens the importance of the use of good manufacturing practices (GMP), and HACCP. The results also emphasize the need for the responsible use of antimicrobials in animal production.