nystatin-a1 and Mastitis--Bovine

Bovine mastitis caused by Prototheca spp. can assume high significance because of economic losses and the potential risk to public health. Studies on the susceptibility of Prototheca spp. to antimicrobials have demonstrated its high level of resistance. We report the susceptibility of bovine isolates of Prototheca wickerhamii and Prototheca zopfii to amphotericin B and nystatin, 2 antifungal agents commonly used in the control of protothecosis, and discuss the results. After subculture, minimum inhibitory concentrations of both antifungal drugs were determined using macrodilution and agar diffusion methods. The inoculum concentration was standardized by determination of colony-forming units per milliliter. Nystatin showed more efficacy than amphotericin B in inhibiting P. wickerhamii growth. In contrast, growth inhibition of P. zopfii was similar for both antifungal agents. This study demonstrates different in vitro susceptibility patterns of P. wickerhamii and P. zopfii, reinforcing the necessity for more investigation into drugs that can be used with clinical efficacy.

Topics: Amphotericin B; Animals; Anti-Infective Agents; Cattle; Female; Mammary Glands, Animal; Mastitis, Bovine; Microbial Sensitivity Tests; Nystatin; Prototheca

A total of 1045 milk samples collected from infected and non infected quarters of 269 cows were investigated. This study showed that 4.7% of samples possessed cells of Prototheca spp. (10(6)cells/ml). The presence of other pathogenic microorganisms was also monitored. Prototheca spp. isolates were classified on the basis of current taxonomic guidelines and identified as P. zopfii. Susceptibility tests carried out in vitro by using 25 antibiotic compounds revealed that the strains of P. zopfii. were susceptible only to nystatin and amphotericin B (58 and 33% of total strains, respectively). The present study represents the first large-scale investigation carried out in Italy on the isolation of this achlorophyllous yeast-like microalga in milk samples produced by dairy herds.

Topics: Amphotericin B; Animals; Cattle; Female; Mastitis, Bovine; Milk; Nystatin; Prototheca

A brief review of the classification of the genus Prototheca is followed by a report on a case of protothecosis in cattle. A pure culture of Prototheca was isolated from the milk of the affected quarter. Despite the fact that the alga showed some sensitivity of nystatin in vitro, the mastitis failed to disappear on treatment with this agent. In the discussion, the incidence of Prototheca infection in man and animals and the appearance of infections with this facultatively pathogenic alga are reviewed.

Topics: Animals; Cattle; Chlorophyta; Female; Mastitis, Bovine; Milk; Nystatin

Topics: Animals; Aspergillus; Aspergillus fumigatus; Cattle; Female; Mastitis, Bovine; Nystatin; Saccharomyces

Topics: Animals; Candida; Candidiasis; Cattle; Germany, East; Mammary Glands, Animal; Mastitis, Bovine; Milk; Nystatin; Penicillins; Tetracycline; Yeasts