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The source of Yersinia spp. in pasteurized milk: an investigation at a dairy

Published online by Cambridge University Press:  15 May 2009

M. H. Greenwood ,
W. L. Hooper  and
J. C. Rodhouse
M. H. Greenwood
Affiliation:
Public Health Laboratory, Poole General Hospital, Poole BH15 2JB
W. L. Hooper
Affiliation:
Public Health Laboratory, Poole General Hospital, Poole BH15 2JB
J. C. Rodhouse
Affiliation:
Food Hygiene Laboratory, Central Public Health Laboratory, 61 Colindale Avenue, London NW9 5HT
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Pasteurized bottled milk supplied by a single dairy was frequently found to be contaminated with Yersinia spp. Investigations were carried out at the dairy in an effort to pinpoint the source of these organisms. Viable counts obtained from milk bottle rinses indicated that bottle washing was often unsatisfactory, and on one occasion Y. frederiksenii was isolated from the pooled rinse water of six bottles. Samples of milk were taken on arrival at the dairy and at various stages following pasteurization. Heat resistance tests carried out on strains of yersinia isolated from pasteurized milk indicated that they would not survive the pasteurization process. However two strains of yersinia were isolated from a sample of milk taken immediately after pasteurization but before bottling. The thermograph indicated that the time/temperature conditions applied during pasteurization were adequate. The presence of yersinia strains in the milk at this stage therefore suggests that undetectable levels of raw milk were being allowed to contaminate the pasteurized milk. The absence of yersinia in cartoned samples produced on the same day as contaminated bottled samples indicated that environmental contamination of the bottle filler valve also may have occurred at times. Results of this investigation indicate that increased vigilance is required to ensure proper operation of pasteurizers and bottle washers.

Type
Research Article
Information
Epidemiology & Infection , Volume 104 , Issue 3 , June 1990 , pp. 351 - 360
Copyright
Copyright © Cambridge University Press 1990

References

REFERENCES

1.Greenwood, MH, Hooper, WL. Yersinia spp. in foods related environments. Food Mierobiol 1985; 2: 263–9.Google Scholar
2.Walker, SJ, Gilmour, A. The incidence of Yersinia enterocolitica and Yersinia enteroeolitica-like organisms in raw and pasteurized milk in Northern Ireland. J Appl Bacteriol 1986; 61: 133–8.CrossRefGoogle ScholarPubMed
3.Lovett, J., Bradshaw, JG, Peeler, JT. Thermal inactivation of Yersinia enterocolitica in milk. Appl Environ Microbiol 1982; 44: 517–19.Google Scholar
4.Stern, NJ, Pierson, MD, Kotula, AW. Growth and competitive nature of Yersinia enterocolitica in whole milk. J Food Sci 1980; 45: 972–4.Google Scholar
5.Greenwood, MH, Hooper, WL. Excretion of Yersinia spp. associated with consumption of pasteurized milk. Epidemiol Infect 1990; 104: 345–50.CrossRefGoogle ScholarPubMed
6.Greenwood, MH, Hooper, WL. The use of alkalinity and incubation at 9°C for improved recovery of Yersinia spp. from faeces. Epidemiol Infect 1988. 101: 53–8.CrossRefGoogle Scholar
7.Bercovier, H., Mollaret, HH. Yersinia. In: Krieg, NR, Holt, JG. eds. Bergey's manual of systematic bacteriology, Vol 1. Baltimore: Williams and Wilkins. 1984: 498–506.Google Scholar
8.Wauters, G, Le Minor, L, Chalon, AM. Antigenes somatique et flagellaires des Yersinia enterocolitica. Ann Inst Pasteur 1971; 120: 631–42.Google Scholar
9.Wauters, G, Le Minor, L, Chalon, AM, Lassen, J. Supplement au scheme antigenique de Yersinia enterocolitica. Ann Inst Pasteur 1972; 122: 951–6.Google Scholar
10. Anon. The rinse method for the examination of washed milk bottles. Ministry of Agriculture and Fisheries 1974; Technique No, B743/T.P.B.Google Scholar
11.Hughes, D. Isolation of Yersinia enterocolitica from milk and a dairy farm in Australia. J Appl Bacteriol 1979; 46: 125–30.CrossRefGoogle Scholar
12.Fernandez, Garayzabal JF., Dominguez, Rodriguez L, Vazquez, Boland JA., Rodriguez, Ferri EF, Briones, Dieste V., Blanco, Cancelo JL., Suarez, Fernandez G. Survival of Listeria monocytogenes in raw milk treated in a pilot plant size pasteurizer. J Appl Bacteriol 1987: 63: 533–7.Google Scholar
13. Anon. Pasteurizing Plant Manual. Society of Dairy Technology. 1983.Google Scholar