Journal of Applied BacteriologyVolume 34, Issue 3 p. 659-677 Influence of Production Conditions on the Bacteriological Quality of Refrigerated Farm Bulk Tank Milk—A Review S. B. Thomas, S. B. Thomas Agricultural Development and Advisory Service, Trawscoed, Aberystwyth, WalesSearch for more papers by this authorR. G. Druce, R. G. Druce Agricultural Development and Advisory Service, Trawscoed, Aberystwyth, WalesSearch for more papers by this authorMena Jones, Mena Jones Agricultural Development and Advisory Service, Trawscoed, Aberystwyth, WalesSearch for more papers by this author S. B. Thomas, S. B. Thomas Agricultural Development and Advisory Service, Trawscoed, Aberystwyth, WalesSearch for more papers by this authorR. G. Druce, R. G. Druce Agricultural Development and Advisory Service, Trawscoed, Aberystwyth, WalesSearch for more papers by this authorMena Jones, Mena Jones Agricultural Development and Advisory Service, Trawscoed, Aberystwyth, WalesSearch for more papers by this author First published: September 1971 https://doi.org/10.1111/j.1365-2672.1971.tb02329.xCitations: 12AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Citing Literature Volume34, Issue3September 1971Pages 659-677 RelatedInformation

Journal Article Incidence and Significance of Thermoduric Bacteria in Farm Milk Supplies: A Reappraisal and Review Get access S. B. Thomas, S. B. Thomas National Agricultural Advisory Service, Trawscoed, Aberystwyth, Wales Search for other works by this author on: Oxford Academic Google Scholar R. G. Druce, R. G. Druce National Agricultural Advisory Service, Trawscoed, Aberystwyth, Wales Search for other works by this author on: Oxford Academic Google Scholar G. J. Peters, G. J. Peters Milk Service, Ministry of Agriculture, Fisheries and Food, Welsh Department, Aberystwyth, Wales Search for other works by this author on: Oxford Academic Google Scholar D. G. Griffiths D. G. Griffiths Milk Service, Ministry of Agriculture, Fisheries and Food, Welsh Department, Aberystwyth, Wales Search for other works by this author on: Oxford Academic Google Scholar Journal of Applied Bacteriology, Volume 30, Issue 2, 1 August 1967, Pages 265–298, https://doi.org/10.1111/j.1365-2672.1967.tb00299.x Published: 01 August 1967 Article history Received: 28 December 1966 Published: 01 August 1967

S ummary . A series of 170 rinses and 14 milk residue deposits from poorly cleansed dairy equipment on 136 farms, giving colony counts at 30° of > 10 6 /ft 2 for rinses or /g wet wt for residues, were classified into 8 groups according to the composition and milk spoilage activity of their microflora. Five of the groups were dominated by active milk spoilage types of bacteria and three by inactive organisms. Micrococci, coryneform bacteria and aerobic sporeforming rods dominated the microflora of 1/3 of the 184 samples. Gram negative rods, including coli‐aerogenes organisms, were dominant in another 1/3, a combination of micrococci, coryneform bacteria and Gram negative rods constituted the microflora of 19% and streptococci were dominant in 10%. Active milk spoilage types of bacteria were predominant in 106 (58%) of the rinses and deposits, but inactive types forming no reaction in litmus milk in 72 h at 22° were dominant in 78 (42%).

International Journal of Dairy TechnologyVolume 19, Issue 3 p. 161-169 BACTERIOLOGICAL ASPECTS OF BULK MILK COLLECTION S. B. THOMAS, S. B. THOMAS National Agricultural Advisory Service, Trawscoed, Aberystwyth, WalesSearch for more papers by this authorR. G. DRUCE, R. G. DRUCE National Agricultural Advisory Service, Trawscoed, Aberystwyth, WalesSearch for more papers by this authorANGELA DAVIES, ANGELA DAVIES National Agricultural Advisory Service, Trawscoed, Aberystwyth, WalesSearch for more papers by this authorJ. S. BEAR, J. S. BEAR Milk Service, Agriculture House, Newtown, Montgomeryshire Paper given to the Carmarthen Branch on 29th March, 1966Search for more papers by this author S. B. THOMAS, S. B. THOMAS National Agricultural Advisory Service, Trawscoed, Aberystwyth, WalesSearch for more papers by this authorR. G. DRUCE, R. G. DRUCE National Agricultural Advisory Service, Trawscoed, Aberystwyth, WalesSearch for more papers by this authorANGELA DAVIES, ANGELA DAVIES National Agricultural Advisory Service, Trawscoed, Aberystwyth, WalesSearch for more papers by this authorJ. S. BEAR, J. S. BEAR Milk Service, Agriculture House, Newtown, Montgomeryshire Paper given to the Carmarthen Branch on 29th March, 1966Search for more papers by this author First published: July 1966 https://doi.org/10.1111/j.1471-0307.1966.tb02808.xCitations: 12AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat Citing Literature Volume19, Issue3July 1966Pages 161-169 RelatedInformation

International Journal of Dairy TechnologyVolume 19, Issue 4 p. 222-224 BULK MILK COLLECTION: BACTERIOLOGICAL QUALITY OF MILK ON ARRIVAL AT CREAMERIES IN ROAD TANKERS S. B. THOMAS, S. B. THOMAS National Agricultural Advisory Service, Trawscoed, AberystwythSearch for more papers by this authorR. G. DRUCE, R. G. DRUCE National Agricultural Advisory Service, Trawscoed, AberystwythSearch for more papers by this authorE. OWEN-JONES, E. OWEN-JONES Central Dairies, Newtown, MontgomeryshireSearch for more papers by this author S. B. THOMAS, S. B. THOMAS National Agricultural Advisory Service, Trawscoed, AberystwythSearch for more papers by this authorR. G. DRUCE, R. G. DRUCE National Agricultural Advisory Service, Trawscoed, AberystwythSearch for more papers by this authorE. OWEN-JONES, E. OWEN-JONES Central Dairies, Newtown, MontgomeryshireSearch for more papers by this author First published: October 1966 https://doi.org/10.1111/j.1471-0307.1966.tb01848.xCitations: 5AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat Citing Literature Volume19, Issue4October 1966Pages 222-224 RelatedInformation

Summary. The examination of a series of 713 milk bottles cleansed by hand washing at producer‐retailer farm dairies showed that though nearly 60% attained satisfactory bacteriological standards, about 30% gave high colony counts (>600/bottle), while coli‐aerogenes organisms were found in 17% and milk spoilage organisms in 25% of them. The microflora of efficiently cleansed bottles, with colony counts of <200/bottle, was dominated by micrococci and aerobic sporeforming rods. Only 3.7% of the 259 cultures from these bottles gave acid reactions in litmus milk in 72 h at 22°. Inefficiently cleansed bottles, with colony counts of >600/bottle, had quite a different type of microflora which was usually dominated by Gram negative rods (achromobacteria, nonfluorescent pseudomonads and flavobacteria). A much higher proportion (19%) of the 393 cultures from these bottles gave acid reactions in litmus milk.

Summary: The incidence of the main types of bacteria among 2,856 isolated on Yeastrel‐milk agar incubated at 30° from 121 rinses of dairy equipment cleansed by chemical methods, showed that micrococci were dominant in low colony count (<104/ft2) rinses of equipment treated by immersion cleaning in caustic soda or cleansed in detergent‐hypochlorite solutions, whereas nonpigmented Gram‐negative rods were dominant in low count rinses of equipment cleansed with detergent‐sterilizers containing quaternary ammonium compounds. Gram‐negative rods were dominant and streptococci frequent in high count (<2·5 × 105/ft2) rinses irrespective of the chemical used. A high proportion of the streptococci and coli‐aerogenes organisms gave acid reactions in litmus milk after 72 h at 22°, many of the anaerogenic Gram‐negative rods and several of the aerobic sporeformers gave proteolytic reactions, whereas the majority of the micrococci, corynebacteria and other asporogenous Gram‐positive rods showed no change. Bacteria isolated from high count rinses were more active in producing milk spoilage reactions at 22° than those isolated from low count rinses.

Summary: The classification of 1,466 bacteria, isolated on Yeastrel‐milk agar incubated at 30° from 68 rinses of steam sterilized dairy equipment taken at five farms, showed that micrococci were dominant, with corynebacteria and aerobic sporeforming rods frequent, representatives of these three groups constituting 73% of the isolates. The microflora was characterized by the dominance of organisms which were relatively inactive in milk. Typical milk souring organisms such as lactic streptococci and coli‐aerogenes organisms were rarely isolated, but anaerogenic Gram‐negative rods resembling Achromobacter, Pseudomonas and Flavobacterium were not uncommon on milking machine clusters and on a cooling unit. The glass recorder jars contained a relatively high proportion of sporeformers.

Journal of Applied BacteriologyVolume 26, Issue 1 p. 66-68 The History of The Society for Applied Bacteriology from 1931 to 1945 S. B. Thomas, S. B. Thomas National Agricultural Advisory Service, Trawscoed, Aberystwyth, WalesSearch for more papers by this author S. B. Thomas, S. B. Thomas National Agricultural Advisory Service, Trawscoed, Aberystwyth, WalesSearch for more papers by this author First published: April 1963 https://doi.org/10.1111/j.1365-2672.1963.tb01156.xCitations: 4AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Citing Literature Volume26, Issue1April 1963Pages 66-68 RelatedInformation

The classification of the predominant types of bacteria found in 87 farm milk supplies, examined within 8–10 hr of production, was done by plating on Yeastrel‐milk agar, incubating for 72 hr at 30° and picking 24 colonies at random from each countable plate for detailed study. Although the results indicate some general trends, such as the predominance of micrococci in milk of low count (< 2 times 104 colonies/ml), the co‐dominance of streptococci, corynebacteria and micrococci in milk with colony counts between 2 times 104 and 2 times 105/ml, and the dominance of nonpigmented Gram‐negative rods and streptococci in the high count milks (2 times 105–5 times 106 colonies/ml), several milk samples, irrespective of colony count level, had a characteristic individual microflora dominated by either corynebacteria, aerobic sporeformers, coli‐aerogenes organisms, fluorescent pseudomonads or flavobacteria.

SUMMARY: A series of co‐operative experiments was conducted to compare the bacterial colony counts of soil obtained by workers in different laboratories, using soil extract agar and other media for the determinations.In the earlier experiments it was not possible to obtain a reasonable degree of reproducibility of results between laboratories even when the plating technique was carefully prescribed. By modification and more rigid standardization of the technique closer agreement was obtained in subsequent experiments. It is suggested that when co‐operative investigations are contemplated the participating laboratories should check their technique by the examination of ‘control’ soils.No evidence could be obtained to support the suggestion that higher colony counts are obtained by the use of soil extract media containing extract prepared from the same soil as the sample tested. The source appears to be immaterial so long as the soil for extract preparation is not of extreme type and has been well manured and cultivated.

SUMMARYThe coli‐aerogenes organisms content, determined by plating on violet red‐bile agar, of surface soil from a polluted site (heavily grazed pasture) often exceeded 104/g at 30° and 103/g at 37°. Escherichia coli I was present but in a small proportion only. High coli‐aerogenes counts were much less frequent in unpolluted soil (enclosed Forestry Plantation), and E. coli I was relatively rare. The classification of 1,917 strains isolated from colonies on VRB agar at 30° and at 37° showed that Klebsiella cloacae was very much the dominant species in both sites when the plates were incubated at 30°, whereas Citrobacter freundii I and K. cloacae were co‐dominant when incubation was at 37°. E. coli II constituted a relatively high proportion of the strains from both sites but, due to the very marked dominance of these three types, E. coli I was rarely isolated by the method employed, even from the polluted soil. The very high incidence of non‐lactose‐fermenters, particularly among the dominant types, was the outstanding characteristic of the strains isolated, even with incubation at 37°. Only 29% formed acid and gas in MacConkey's broth within 2 days at 37°, while 59% formed acid and gas within 5 days at 30° but failed to do so in 2 days at 37°. There was a much higher incidence of coli‐aerogenes organisms in soil from the unpolluted site during summer than during winter, and this is attributed to possible multiplication of 37° negative strains of the more common types.

International Journal of Dairy TechnologyVolume 12, Issue 3 p. 146-148 FLAVOUR OF RAW MILK S. B. THOMAS, S. B. THOMAS National Agricultural Advisory Service and Milk Service, Trawscoed, AberystwythSearch for more papers by this authorD. G. GRIFFITHS, D. G. GRIFFITHS National Agricultural Advisory Service and Milk Service, Trawscoed, AberystwythSearch for more papers by this authorK. J. MORGAN, K. J. MORGAN National Agricultural Advisory Service and Milk Service, Trawscoed, AberystwythSearch for more papers by this author S. B. THOMAS, S. B. THOMAS National Agricultural Advisory Service and Milk Service, Trawscoed, AberystwythSearch for more papers by this authorD. G. GRIFFITHS, D. G. GRIFFITHS National Agricultural Advisory Service and Milk Service, Trawscoed, AberystwythSearch for more papers by this authorK. J. MORGAN, K. J. MORGAN National Agricultural Advisory Service and Milk Service, Trawscoed, AberystwythSearch for more papers by this author First published: July 1959 https://doi.org/10.1111/j.1471-0307.1959.tb00042.xAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat Volume12, Issue3July 1959Pages 146-148 RelatedInformation

SUMMARY: Butter made on farms and at creameries was examined microbiologically within 24 hr of production. The overall care exercised in the manufacture of the butter was reflected in the results obtained with the various tests used. Colony counts of psychrophiles, coli‐aerogenes organisms, and yeasts and moulds were the most useful and economical tests for providing information on the standard of hygiene during manufacture, and they gave some indication of the potential keeping quality of the butter. The following satisfactory levels are recommended for creamery butter: psychrophiles <103/g, coli‐aerogenes organisms <10/g and yeasts and moulds <50/g.

SUMMARY: When 108 samples of individual farm milk supplies were held at 3—5° for 72 hr, 35·2% showed increases in coli‐aerogenes organisms of over one‐hundredfold and 10·2% increases of more than one‐thousandfold. The coli‐aerogenes microflora after refrigeration was dominated by Klebsiella cloacae and K. aerogenes I. While some strains of all the coli‐aerogenes types isolated showed growth, though sometimes scanty, on yeast‐dextrose agar in 5 days at 3—5°, the majority of the strains of K. cloacae showed luxuriant growth under these conditions and can be considered as typical facultative psychrophiles of milk.

SUMMARY: A series of 825 cultures of coli‐aerogenes bacteria isolated at 30° and a series of 735 cultures isolated at 37° from 645 samples of farm water supplies were classified according to the recommendations of the Coliform Sub‐Committee of the Society for Applied Bacteriology (Report, 1949). Klebsiella constituted 50% of the cultures isolated at 30°, whereas Escherichia coli I was the dominant type, forming 57%, among the cultures isolated at 37°. It would thus appear that isolation at 30° is as selective for Klebsiella as isolation at 37° is for Escherichia. Coli‐aerogenes organisms, mainly 37° negative strains of Citrobacter freundii I and K. cloacae, were found in waters of high sanitary quality derived from protected springs and wells; but the coli‐aerogenes microflora of polluted water was dominated by E. coli I, which formed 43% of the isolates at 30° and 76% of those at 37°. The results for a series of fortnightly samples from 11 farm water supplies showed a marked seasonal variation in the incidence of different types isolated at 30°; E. coli I formed a higher proportion in summer than in winter, while 37° negative strains of Klebsiella and Citrobacter formed a higher proportion in winter than in summer.

International Journal of Dairy TechnologyVolume 11, Issue 2 p. 85-87 TANK CHLORINATION OF UPLAND FARM WATER SUPPLIES D. L. BOWEN, D. L. BOWEN N.A.A.S. & N.M.T.S., Trawscoed, AberystwythSearch for more papers by this authorL. F. BATTLE, L. F. BATTLE N.A.A.S. & N.M.T.S., Trawscoed, AberystwythSearch for more papers by this authorS. B. THOMAS, S. B. THOMAS N.A.A.S. & N.M.T.S., Trawscoed, AberystwythSearch for more papers by this author D. L. BOWEN, D. L. BOWEN N.A.A.S. & N.M.T.S., Trawscoed, AberystwythSearch for more papers by this authorL. F. BATTLE, L. F. BATTLE N.A.A.S. & N.M.T.S., Trawscoed, AberystwythSearch for more papers by this authorS. B. THOMAS, S. B. THOMAS N.A.A.S. & N.M.T.S., Trawscoed, AberystwythSearch for more papers by this author First published: April 1958 https://doi.org/10.1111/j.1471-0307.1958.tb02559.xCitations: 1AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Citing Literature Volume11, Issue2April 1958Pages 85-87 RelatedInformation

SUMMARY: A series of 1,040 cultures of coli‐aerogenes bacteria isolated at 30° from farm dairy equipment and raw milk was classified according to the recommendations of the Coliform Sub‐Committee of the Society for Applied Bacteriology (Report, 1949). The distribution of species and types isolated from milk did not differ materially from that for dairy equipment, Klebsiella cloacae, K. aerogenes and Citrobacter freundii being the dominant species, while the incidence of Escherichia coli was relatively low. There was no marked seasonal incidence of any type, though E. coli I formed a slightly higher proportion of the coli‐aerogenes microflora in winter, whereas K. aerogenes I was slightly higher in summer. Many of the cultures of the dominant types, K. cloacae, K. aerogenes I and Cit. freundii I, did not form acid and gas from lactose in two days at 37°. Consequently 37° negative, anaerogenic and paracolon strains constituted a relatively high proporton (49%) of the coli‐aerogenes microflora.