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The detection of streptococci in air

Published online by Cambridge University Press:  15 May 2009

R. E. O. Williams  and
Ann Hirch
R. E. O. Williams
Affiliation:
Air Hygiene Unit, Public Health Laboratory Service, Colindale, London, N.W.9
Ann Hirch
Affiliation:
Air Hygiene Unit, Public Health Laboratory Service, Colindale, London, N.W.9
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To estimate the number of viable streptococci present in the air of occupied places, airborne bacteria were collected in a slit-sampler on a nutrient agar medium containing 5% sucrose, 5% horse serum, 0·25 mg./100 ml. crystal violet, and 1·0/100 ml. potassium tellurite. This medium inhibits the great majority of the staphylococci and micrococci found in the air. On it colonies of Strep. salivarius are readily recognized by their mucoid form. The number of other streptococci was estimated by picking and examining a random sample of the colonies.

Streptococci were recognized in the sample by three different methods: (1) by microscopic examination of a nigrosin film made from the original colony; (2) by examination of a nigrosin film and also subculturing the colony to a ditch plate having blood agar on one side and serum agar containing 40% or bile on the other; or (3) by subculture to bile-agar ditch plates alone, the bile agar in this case containing aesculin and ferric citrate. By method (1) streptococci could be distinguished from micrococci; by methods (2) and (3) this distinction could be made with more confidence, and in addition enterococci could be distinguished from other streptococci.

A number of tests of the efficiency of the method were carried out, and it was concluded that some 20–40% of the viable streptococci in the air were missed.

The standard errors of the mean of a number of streptococcal counts in schoolrooms were calculated and found to be of the order of 14% of the mean when our standard routine was followed; increasing the size of the sample of colonies picked for examination by 30% would probably have had only a trivial effect on the standard error of the mean, since the greater part of the variation was due to differences between the counts in different rooms.

Type
Research Article
Information
Journal of Hygiene , Volume 48 , Issue 4 , December 1950 , pp. 504 - 524
Copyright
Copyright © Cambridge University Press 1950

References

REFERENCES

Bourdillon, R. B., Lidwell, O. M. & Lovelock, J. E. (with others) (1948). Studies in air hygiene. Spec. Rep. Ser. med. Res. Coun., Lond., no. 262. London: H.M.S.O.Google Scholar
Bourdillon, R. B., Lidwell, O. M. & Thomas, J. C. (1941). A slit sampler for collecting and counting air-borne bacteria. J. Hyg., Camb., 41, 197.CrossRefGoogle ScholarPubMed
Buchbinder, L., Solowey, Mathilde & Solotorovsky, M. (1938). Alpha hemolytic streptococci of air. Their variant forms, origin, and numbers per cubic foot of air in several types of locations. Amer. J. publ. Hlth, 28, 61.CrossRefGoogle ScholarPubMed
Edwards, S. J. (1933). Studies on bovine mastitis. IX. A selective medium for the diagnosis of Streptococcus mastitis. J. comp. Path. 46, 211.CrossRefGoogle Scholar
Fisher, R. A. (1948). The Design of Experiments. Edinburgh: Oliver and Boyd.Google Scholar
Gordon, M. H. (1904). Report on a bacterial test for estimating pollution of air. Report of the Medical Officer in 32nd Report of Local Government Board, 1902–3, p. 421, London.Google Scholar
Gordon, M. H. (1906). Investigation of the ventilation of the debating chamber of the House of Commons. Appendix to Cd. 3055. London: H.M.S.O.Google Scholar
Hamilton, Alice (1905). Dissemination of streptococci through invisible sputum. J. Amer. med. Ass. 44, 1108.CrossRefGoogle Scholar
Lidwell, O. M. (1950). Slit sampler for long-period sampling of air for bacteria. Lancet, 1, 130.Google Scholar
M'Leod, J. W. & Gordon, J. (1922). On the production of peroxides by pneumococci and other bacteria. J. Path. Bact. 25, 139.Google Scholar
Miles, A. A. & Misra, S. S. (1938). The estimation of the bactericidal power of the blood. J. Hyg., Camb., 38, 732.Google ScholarPubMed
Packer, R. A. (1943). The use of sodium azide (NaN3) and crystal violet in a selective medium for streptococci and Erysipelothrix rhusiopathiae. J. Bact. 46, 343.CrossRefGoogle Scholar
Rabl, R. & Seelemann, M. (1949). Über das Vorkommen bestimmter ‘unvollstäandig haemolysiender’ Streptokokken- und Diplokokkenarten bei Mensch und Tier sowie über ihre Bedeutung als Infektionserreger. Zbl. Bakt. (1 Abt. Orig.), 154, 186.Google Scholar
Rantasalo, I. (1947). Isolation of streptococci by the use of nutrient media containing thallium salts. Ann. Med. intern. Fennicae, 36, 341.Google ScholarPubMed
Shattock, P. M. Frances (1949). The streptococci of group D; the serological grouping of Streptococcus bovis, and observations on serologically refractive group D strains. J. gen. Microbiol. 3, 80.CrossRefGoogle Scholar
Sherman, J. M., Niven, C. F. Jr., & Smiley, K. L. (1943). Streptococcus salivarius and other non-haemolytic streptococci of the human throat. J. Bact. 45, 249.CrossRefGoogle ScholarPubMed
Tinsdale, G. F. W. (1947). A new medium for the isolation and identification of C. diphtheriae based on the production of hydrogen sulphide. J. Path. Bact. 59, 461.CrossRefGoogle Scholar
Todd, E. W. & Hewitt, L. F. (1932). A new culture medium for the production of antigenic streptococcal haemolysim. J. Path. Bact. 35, 973.CrossRefGoogle Scholar
Torrey, J. C. & Lake, M. (1941). Streptococci in air as an indicator of nasopharyngeal contamination. J. Amer. med. Ass. 117, 1425.CrossRefGoogle Scholar
Wells, Dorothy B. (1941). A confirmed test for streptococci from air. J. Bact. 42, 436.Google Scholar
Wells, W. F. (1933). Apparatus for study of the bacterial behaviour of air. Amer. J. publ. Hlth. 23, 58.Google Scholar
Wells, W. F. & Wells, Mildred W. (1936). Air-borne infection. J. Amer. med. Ass. 107, 1698, 1805.CrossRefGoogle Scholar
Wells, W. F., Phelps, E. B., Robertson, Elizabeth C. & Winslow, C.-E. A. (1941). Report of subcommittee on bacteriological procedures in air analysis. Quantitating Gordon's bacterial test for estimating pollution of air. Amer. J. publ. Hlth, Year-Book, 31, 129.Google Scholar
Wells, W. F., Phelps, E. B., Robertson, Elizabeth C. & Winslow, C.-E. A. (1942). Report of subcommittee on bacteriological procedures in air analysis. Amer. J. publ. Hlth, Year-Book, 32, 137.Google Scholar
Winslow, C.-E. A. & Robinson, E. (1910). An investigation of the extent of the bacterial pollution of the atmosphere by mouth spray. J. infect. Dis. 7, 17.CrossRefGoogle Scholar