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The source of bacteria in fresh cream, and the methylene blue reduction test as a guide to hygienic quality

Published online by Cambridge University Press:  15 May 2009

H. R. Jenkins  and
R. J. Henderson
H. R. Jenkins
Affiliation:
Public Health Laboratory, Royal Infirmary, Worcester
R. J. Henderson
Affiliation:
Public Health Laboratory, Royal Infirmary, Worcester
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Summary

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One hundred and twenty-nine samples of fresh cream collected in Worcestershire were examined bacteriologically. Sixty (46·5 %) creams had counts of over 100,000 bacteria/ml. The bacteria present were of many varieties, the commonest being Bacillus spp. (aerobic spore formers), Gram-negative bacilli, staphylococci and micrococci. Since most of the creams had been either pasteurized as cream or manufactured from pasteurized milk it was thought that the many bacteria were present because of contamination after pasteurization due to three main causes; unsatisfactory or unhygienic premises, unsuitable equipment, manual handling during the filling and capping process.

The methylene blue test results related well with bacterial counts but there were seven (5·4 %) anomalous results. Although the methylene blue reduction test therefore could serve as a simple and reasonable guide to the hygienic quality of fresh cream, 5·4 % of anomalous results would perhaps make it unsuitable as a statutory test.

We thank Mr R. Colenso, M.A.P.H.E., M.A.P.H.I., Chief Public Health Inspector, and Mr H. Beckett, Milk Sampling Officer of the Worcestershire County Council, for arranging the supply of samples.

Type
Research Article
Information
Journal of Hygiene , Volume 67 , Issue 3 , September 1969 , pp. 401 - 408
Copyright
Copyright © Cambridge University Press 1969

References

Barrow, G. I. & Miller, D. C. (1967). A bacteriological study of fresh cream and cream products in Cornwall. Mon. Bull. Minist. Hlth 26, 254.Google ScholarPubMed
Barrow, G. I., Miller, D. C., Johnson, D. L. & Hingston, C. W. J. (1968). Brucella abortus in fresh cream and cream products. Br. med. J. ii, 596.CrossRefGoogle Scholar
Breed, R. S., Murray, E. G. D. & Smith, N. R. (1957). Bergey's Manual of Determinative Bacteriology, 7th ed. London: Baillière, Tindall & Cox.Google Scholar
Burman, N. P. (1967). Development of membrane filter techniques. II. Adaptation to routine and special requirements. Proc. Soc. Wat. Treat. Exam. 16, 40.Google Scholar
Colenso, R., Court, G. & Henderson, R. J. (1966), Fresh cream in Worcestershire: A bacteriological study. Mon. Bull. Minist. Hlth 25, 153.Google ScholarPubMed
Cowan, S. T. & Steel, K. J. (1966). Manual for the Identification of Medical Bacteria. Cambridge University Press.Google Scholar
Gerken, A., Coleman, J. C. & Winner, H. I. (1968). Bacteriological impurity of dairy-cream samples in London. Lancet i, 634.CrossRefGoogle Scholar
Hutchison, J. G. P., Barrow, G. I., Henderson, R. J. & Wright, A. E. (1968). The bacteriological quality of dairy creams. Lancet ii, 99.CrossRefGoogle Scholar
Milk (Special Designation) Regulations, 1963. Statutory Instrument 1963, No. 1571. London: H.M.S.O.Google Scholar
Report (1956). The nomenclature of coli-aerogenes bacteria. Report of the Coli-Aerogenes Sub-Committee of the Society for Applied Bacteriology. J. appl. Bact. 19, 108.CrossRefGoogle Scholar
Report (1958). The bacteriological examination and grading of fresh cream. Report of a working party of the Public Health Laboratory Service. Mon. Bull. Minist. Hlth 17, 77.Google Scholar
Wilson, G. S. & Miles, A. A. (1964). Topley and Wilson's Principles of Bacteriology and Immunity. 5th ed. London: Edward Arnold.Google Scholar
Wilson, G. S., Twigg, R. S., Wright, R. D., Hendrey, C. G., Colwell, M. P. & Maier, I. (1935). The bacteriological grading of milk. Spec. Rep. Ser. med. Res. Coun. No. 206.Google Scholar