A total of 100 fresh eviscerated whole market chickens, purchased one per week over a 5-week period from each of 20 different food stores in the Ontario and Ohio regions, were examined for the presence of Campylobacter jejuni. The microorganism was recovered from 62 and 54% of the chickens in Ontario and Ohio, respectively.

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To establish an enrichment system of high efficiency for recovery of Campylobacter jejuni from market chickens, the effects of the temperature, duration of incubation, and pH of the enrichment culture on the isolation of the bacterium were evaluated. Whole chickens or chicken parts in plastic bags were individually rinsed, and the washings filtered through cheesecloth. The cells were separated from the washings by centrifugation, and the pellet was inoculated into 100 mL of enrichment broth. Isolation of C. jejuni from poultry samples was significantly increased by incubating these samples in an enrichment medium at 42 degrees C as opposed to 35 degrees C; for 48 h as opposed to 24 h or 72 h; and at pH 7.0 as opposed to pH 6.0, 6.5, 7.5, or 8.0.

A total of 1204 cultures comprising 16 genera were surveyed for production of thermonuclease (TNase) in milk. Cultures other than Staphylococcus capable of TNase production were restricted to two genera, Streptococcus and Bacillus. Nineteen percent of 338 group D streptococci comprising four species (85% of which were Streptococcus faecalis) and 17% of 60 streptococci belonging to other groups produced TNase. Nine percent of 130 Bacillus cultures comprising six species produced the enzyme. On the other hand, 99% of coagulase-positive staphylococci produced TNase and only 18% of the coagulase-negative staphylococci produced the enzyme. The amount of TNase produced by streptococci and bacilli was significantly lower than that produced by coagulase-positive staphylococci. The pH profile of the streptococci and Bacillus TNases was similar to that of the staphylococcal TNase; each enzyme exhibited a minor peak at pH 7.0 and a broad major peak ranging from pH 8.5 to 10. The nuclease produced by coagulase-positive Staphylococcus was more heat stable than the nucleases produced by Streptococcus and Bacillus; there was little loss in activity of the staphylococcal enzyme after 60 min at 100 degrees C, whereas 50% of the activity of the streptococcal and Bacillus nucleases was destroyed in 40-60 min and 60-80 min, respectively.

The elimination kinetics of the methyl esters of diethyldithiocarbamic acid (Me-DDC) and its monothio analogue (Me-DTC) has been compared in ten alcoholic patients after a single oral dose of 400 mg disulfiram (Antabuse). Erythrocyte aldehyde dehydrogenase (ALDH) activity was continuously followed in the subjects until complete inactivation. The relation between individual steady-state concentrations of Me-DTC in plasma, blood acetaldehyde concentration and the dose of disulfiram sufficient to give the disulfiram alcohol reaction was investigated in 12 healthy volunteers treated with increasing doses of disulfiram and then challenged with ethanol. The mean peak plasma concentration of Me-DDC occurred at 1.8 h and its plasma half-life was 6.3 h. The corresponding values for Me-DTC were 3.3 h and 11.2 h, respectively. This suggests oxidative formation of Me-DTC from Me-DDC. In alcoholics with a rapid decrease in erythrocyte ALDH activity (in less than 5 days), the mean peak plasma concentration of Me-DTC was 278 nmol.l-1, whereas the peak concentration was below the detection limit in subjects with a prolonged inactivation time (7-20 days). The healthy volunteers were divided into three groups of four subjects, with clinically valid disulfiram alcohol reactions at 100, 200, and 300 mg doses of disulfiram, respectively. The mean plasma concentrations of Me-DTC at steady-state were proportional to the disulfiram doses given, compared within groups at different doses, and between groups at equal and different optimal doses of the drug. The concentrations of Me-DTC were significantly increased, as compared above, whereas the blood concentrations of acetaldehyde were not significantly increased.(ABSTRACT TRUNCATED AT 250 WORDS)

The inhibitory effect of cocoa powder on 102 organisms belonging to 13 genera was determined. All organisms tested were inhibited by 5% cocoa. Shigella, Staphylococcus, Micrococcus, and Bacillus were the most sensitive. The degree of inhibition depended on the organism, temperature of incubation, and the medium in which the cocoa powder was suspended. Of six media tested, lactose broth and nutrient broth were the most inhibitory, while non-fat dry milk was the least inhibitory. Supplementing NB with tryptone or casein reduced the toxicity of cocoa.

A procedure involving the use of citrate-buffered lactose broth (pH 6.5) containing an analogue of a beta-galactoside (4-chloro-2-cyclopentylphenyl beta-D-galactopyranoside) has been developed for the enrichment of Shigella in competition with a 100-fold higher population of Escherichia coli. The system makes use of the beta-galactosidase activity of E. coli which hydrolyzes the phenolic derivative of beta-galactoside to galactose and an aglycone moiety (4-chloro-2-cyclopentylphenol) which is toxic to E. coli but is tolerated by Shigella. The procedure is particularly effective in the enrichment of S. sonnei and S. flexneri; S. dynsenteriae and S. boydii are enriched to a lesser extent.

A previously described procedure for the selective enrichmen of Shigella in competition with E. coli has been modified and tested with a total of 48 strains of the four Shigella species. The new enrichment medium consists of 1,5-strength trypticase soy broth, 1 mM 4-chloro-2-cyclopentylphenyl beta-D-galactopyranoside (CPPG), 0.25% lactose, and 0.1 M citrate buffer (pH 6.2). In competition with a 1000-fold higher population of E. coli than Shigella, 42 of 48 strains from the four species of Shigella were selectively enriched by the new method. Different lots of CPPG did not appear to affect the performance of the medium.