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Biomedical subjects

N F Millis

Publications and source records attributed to N F Millis.

17 recordsLinked to original sources
PubMed1981

Survey of bacteria in private swimming pools.

In a survey of the bacteria in swimming pools treated with either chlorine or Baquacil in private gardens in Melbourne, the water was frequently found to be at the incorrect pH and to contain biocides at suboptimal concentrations. The general bacterial flora count was commonly greater than 200 per mL; only 14% of chlorine-treated pools and 27% of Baquacil-treated pools consistently gave counts of less than 200 per mL. Coliforms were detected in 66% of chlorine-treated pools and in 22% of Baquacil-treated pools. Escherichia coli was detected in 32% of chlorine-treated pools and 8% of Baquacil-treated pools. Staphylococcus aureus was detected in 36% of chlorine-treated pools and in 8% of Baquacil-treated pools. Pseudomonas aeruginosa was detected in 7% of chlorine-treated pools, but not at all in Baquacil-treated pools. When the biocides were maintained at the correct concentration, the indicator organisms were well controlled by both biocides. This survey indicates that owners of pools need to be made aware that their pools can harbour potentially pathogenic bacteria unless biocides are constantly maintained at the correct concentration. Baquacil generally remains above the minimum recommended concentration for approximately 14 days between routine additions, whereas chlorine can dissipate from the pool within hours of addition on hot sunny days. This probably contributed to the superior over-all performance of Baquacil in this survey.

Biguanides↗
PubMed1977

alpha-Pinene metabolism by Pseudomonas putida.

By using metabolically altered mutants and acrylate, novel putative intermediates of alpha-pinene metabolism by Pseudomonas putida PIN11 were detected. They were characterized as 3-isopropylbut-3-enoic acid and (zeta)-2-methyl-5-isopropylhexa-2,5-dienoic acid.

Acrylates↗
PubMed1977

Succession of Streptococcus bovis strains with differing bacteriophage sensitivities in the rumens of two fistulated sheep.

The bacteriophage sensitivity of the Streptococcus bovis population resident in the rumens of two fistulated sheep was monitored for 112 days. During this time, three changes in the bacteriophage sensitivity of S. bovis occurred in the absence of detectable bacteriophages. Identical changes in bacteriophage sensitivity occurred simultaneously in both animals and, except for the relatively short periods of changeover in phage sensitivity, the S. bovis population in the rumens of the two sheep was homogeneous with respect to phage sensitivity.

Animals↗
PubMed1976

Growth kinetics of a yeast grown on glucose or hexadecane.

The kinetics of growth of a Torulopsis sp. was investigated in a continuous culture with glucose or hexadecane as the carbon source; growth was limited by either carbon or nitrogen. The relationship between the concentration of the limited substrate and the steady-state growth rate of the organism was examined and tested against various models of growth. No existing model was found to describe the growth accurately and a new model has been proposed: (see article). It is postulated that this behavior would result from a simple first order reaction between the reactants of the rate-limiting enzymic reaction of the organism's metabolism.

Alkanes↗
PubMed1976

Characterization of Streptococcus bovis bacteriophages.

About 25 Streptococcus bovis bacteriophages were isolated from abattoir wastes, bovine rumen fluid, and lysogenic strains of S. bovis. Eight phages were selected and characterized by morphology, stability, rate of adsorption, single-step growth curve, serum neutralization, and antigenic relationship. Two distinct morphological phage types were found, one of which has not been previously reported for group D streptococci.

Abattoirs↗
PubMed1976

Lysogeny in Streptococcus bovis.

Forty-eight strains of Streptococcus bovis were tested for induction with mitomycin C. Eleven inducible strains were found and the lysates of all 11 contained bacteriophage-like particles. The lysate of one strain also contained large numbers of particles which closely resembled polyheads. Eight of the lysates produced zones of inhibition on indicator strains and viable bacteriophages were detected in six lysates. The sources of the S. bovis were ovine and bovine rumen fluid (23 strains), ovine and bovine feces (5 strains), blood cultures from human endocarditis (8 strains), and a wide variety of other sources (12 strains). Only 1 of 23 rumen S. bovis strains was lysogenic, which suggests that lysogenic S. bovis strains are not an important source of bacteriophages in the rumen.

Animals↗
PubMed1976

Bacteriocins of Streptococcus bovis.

Forty-seven strains of Streptococcus bovis were tested for bacteriocin production. Fourteen were found to produce bacteriocins, while all 47 were sensitive to at least one of these bacteriocins. The bacteriocins, on the basis of their host range on S. bovis strains, formed six groups. A representative of each group was selected and characterized by temperature stability, sensitivity to trypsin and lipase, sedimentation by centrifugation, ability to pass through dialysis tubing, host range on other bacterial species, and conditions for production in liquid media. A correlation between mannitol fermentation and bacteriocin production was noted.

Bacteriocins↗