摘要:

Summary.Pitting, spreading and domed colonies of strictly anaerobic and facultatively anaerobic strains of ‘corroding bacilli’were induced by varying the culture conditions. Colony form seemed to depend on 2 factors, the availability of certain nutrients and the condition of the bacteria at the time of inoculat

ISSN:0021-8847    

DOI:10.1111/j.1365-2672.1974.tb00419.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

Summary.Membrane filtration has become an accepted method for enumeratingEscherichia coliin water, but little published evidence could be found to judge the specificity of the method to assess faecal contamination in either fresh or saline waters. The method is used in our laboratory to monitor the extent and degree of sewage pollution in coastal areas, but there is need for information on what proportion of lactose‐fermenting colonies from seawater, developing at 44° on a 4% enriched Teepol medium, areE. colitype I. A total of 1352 colonies from seawater was tested for production of indole and for gas from lactose at 44°. In addition, 46% of the colonies were screened by the IMVEC series of tests. The proportion of colonies tested ranged from 10–100%, depending on the number of colonies on the membrane. Many of the colonies (81.9%) to which IMVEC tests were applied wereE. colitype I; a further 10.9% were Irregular type I. The practical implications of these findings are disc

ISSN:0021-8847    

DOI:10.1111/j.1365-2672.1974.tb00420.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

Summary.When sheep were held in abattoir pens, the fleece became contaminated with salmonellae within 1 day even when there was less than 1 salmonella/g of soil. Salmonellae were first shed in the faeces after 2–3 days. Both the percentage of infected sheep and the number of salmonellae/g of faeces subsequently increased rapidly. Contamination of fleece and carcasses increased with time and with the degree to which the pens were contaminated. The fleece appeared to be a significant source of salmonella contamination of the carcas

ISSN:0021-8847    

DOI:10.1111/j.1365-2672.1974.tb00421.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

Summary.Experimental evidence indicates that inhibition of active transport is responsible for the bacteriostatic action of Fentichlor againstStaphylococcus aureus. Fentichlor inhibits active transport and assimilation of glutamic acid, and assimilation of glucose under aerobic and anaerobic conditions, but inhibition of assimilation results mainly from inhibition of accumulation rather than direct action on the assimilation process. In the absence of glucose, Fentichlor dissipates the membrane proton gradient and ATP pool but, with glucose present, ATP synthesis is unaffected and although some acceleration of proton translocation occurs, only partial dissipation of the gradient results. Results indicate that Fentichlor‐mediated proton translocation prevents coupling of membrane proton movements to active transport as postulated by the chemiosmotic hypothesis. Fentichlor partially inhibits glycolysis and anaerobic ATP synthesis which may contribute to bacteriostasis under anaerobic condition

ISSN:0021-8847    

DOI:10.1111/j.1365-2672.1974.tb00422.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

Summary.A method for detecting bacterial proteinases in gel slabs after electrophoresis is described. It consists in placing the slabs on a layer of gelatin‐agar buffer, allowing hydrolysis of the gelatin to occur and then developing the areas of hydrolysis with acid mercuric chloride. To illustrate this method we chose extracellular preparations of strains ofBrevibacterium linensandMicrococcussp

ISSN:0021-8847    

DOI:10.1111/j.1365-2672.1974.tb00423.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

Summary.A study of the egg yolk reaction produced by various species of bacteria has shown that it is caused by the hydrolysis of phosphatidylcholine.Staphylococcus aureusandSerratia marcescensdegrade phosphatidylcholine by a series of hydrolytic reactions which are initiated by phosphatidylcholine: cholesterolo‐acyltransferase. The degradation of phosphatidylcholine results in the formation of a sub‐surface, opaque homogeneous zone around colonies growing on egg yolk agar and a collar of lipid material floating on the surface of egg yolk broth. This reaction may not be shown by all species growing in egg yolk media but it can be demonstrated if enzyme extracts are u

ISSN:0021-8847    

DOI:10.1111/j.1365-2672.1974.tb00424.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

Summary.The lethal and growth depressing effects of feeding raw navy beans (RNB) to Japanese quail have been shown to be due neither to poor palatability nor to dialysable, lipid or carbohydrate constituents, but to a protein material soluble at pH 3 and precipitable by saturation with (NH4)2SO4. This material proved resistant to digestion by pepsin and proteolytic bacteria but was destroyed by autoclaving at 121° for 15 min. Germfree birds given a diet containing RNB which had been fermented by coliforms grew well, indicating that toxicity of RNB is not dependent on the release by intestinal bacteria of poisons from innocuous precursors in the beans. Examination of the effects of feeding diets containing other raw legume seeds to quail have shown that toxicity is associated with the presence of high concentrations of phytohaemagglutinins (PHAs). Quail given RNB diet showed a greater incidence of liver infection than birds fed an autoclaved bean diet but bacteriological examination of gut contents of such birds revealed no marked qualitative or quantitative differences. Chemical examination of gut contents likewise revealed no marked differences. Experiments with gnotobiotic quail showed that coliforms derived from a variety of sources were capable of causing the death of birds on RNB diet and that the numbers attained in different parts of the intestine by a single coliform strain were not affected by the diet fed. The results suggest that toxicity of RNB may be due to impairment of body defence mechanisms by PHA leading to tissue invasion by normally innocuous components of the intestinal microflora

ISSN:0021-8847    

DOI:10.1111/j.1365-2672.1974.tb00425.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

ISSN:0021-8847    

DOI:10.1111/j.1365-2672.1974.tb00426.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

ISSN:0021-8847    

DOI:10.1111/j.1365-2672.1974.tb00427.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

Book reviewed in this articleChromatography ofAntibiotics, 1973. Journal of Chromatography Library Vol. I. G. H. Wagman&M. J. Weinstein, 256 pp.Introduction toMicrobiology, 1972. J. F. Wilkinson.

ISSN:0021-8847    

DOI:10.1111/j.1365-2672.1974.tb00428.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY