ABSTRACT
Four different mycotoxins (patulin, T-2 toxin, diacetoxyscirpenol and roquefortine) were used to study growth inhibitory effects on a melanin precursor overproducer mutant of the ciliate Tetrahymena thermophila. This strain is especially sensitive to diacetoxyscirpenol and T-2 toxin. The secretion capacity of melanin precursors into the culture medium by this mutant and its biosensor capacity are very useful characteristics to elaborate a rapid bioassay to detect some specific mycotoxins.
Subject(s)
Biological Assay/methods , Biosensing Techniques , Melanins , Mycotoxins/analysis , Animals , Mutation , Sensitivity and Specificity , Tetrahymena thermophila/geneticsABSTRACT
The microbiological quality of the River Riato (Spain) was evaluated. The influence of cattle that roam free in the warm season was marked. The degree of faecal pollution in the river was higher than predicted from the river basin geographical characteristics. The counts of faecal indicators greatly increased when the cattle were allowed to roam free. Counts of enterobacteria and faecal coliforms ranged from 10(3) to 10(6)/100 ml. Faecal streptococci counts were smaller (less than 10/100 ml). Escherichia coli and Pseudomonas aeruginosa were isolated from all samples. Streptococcus bovis was also isolated but not Strep. faecalis.
Subject(s)
Bacteria/growth & development , Enterobacteriaceae/growth & development , Feces/microbiology , Water Microbiology , Water Pollution , Ammonia/analysis , Animals , Cattle , Colony Count, Microbial , Fresh Water/analysis , Hydrogen-Ion Concentration , Oxygen/analysis , Pseudomonas/isolation & purification , Spain , Streptococcus/growth & development , TemperatureABSTRACT
The efficiency of Baird-Parker agar, mannitol-salt agar, Vogel-Johnson agar and Giolitti-Cantoni broth for the detection of Staphylococcus aureus from food samples, was studied by comparing the numbers of Staphylococcus recovered from the samples, the degree of selectivity reached and the recovery of coagulase and thermonuclease positive staphylococci. Lowest counts of Staphylococcus were obtained with Giolitti-Cantoni broth. The mannitol-salt agar proved to be the most efficient media system with respect to the number of staphylococci recovered and the degree of selectivity reached. None of these media was highly selective for the isolation and detection of S. aureus; therefore, it is necessary to identify the isolated colonies in all cited media, in order to use rightly the current guidelines for microbiological quality of foods.
Subject(s)
Culture Media , Food Microbiology , Staphylococcus aureus/isolation & purification , Animals , Bacterial Proteins/analysis , Bacteriological Techniques , Coagulase/analysis , Food Handling , Meat/microbiology , Meat Products/microbiology , Micrococcal Nuclease/analysis , Milk/microbiology , Sensitivity and Specificity , Staphylococcus aureus/growth & development , Vegetables/microbiologyABSTRACT
In order to analyze the significance of the microbial content of pharmaceutical raw materials contributed to the finished pharmaceutical products, we have carried out a study of contamination taking into account aerobic bacteria, anaerobic bacteria and fungi. None or only low numbers of pathogenic microorganisms was found in most analyzed products but in some materials, specially those of natural origin, we have detected high bacterial and fungal contamination. Microorganisms of the genus Bacillus have been the aerobic bacteria most frequently isolated; Bifidobacterium and Clostridium were the most common anaerobic bacteria and with respect to the fungi, Penicillium and Aspergillus have been found with the highest frequency. These microorganisms can produce problems in pharmaceutical finished products, due to their enzymatic or toxigenic activities.
