摘要:

The influence of three different feeds, wheat straw, sorghum and berseem, on total and cellulolytic bacterial counts in the buffalo rumen at different time intervals from 0 to 8 h after feeding was studied. Berseem feeding supported maximum growth of rumen bacteria in general and cellulolytic bacteria in particular. Wheat straw supported the poorest growth.The types of cellulolytic bacteria recovered from the rumen of adult buffaloes wereRuminococcus albus, R. flavefaciens, Bacteroides succinogenes, Butyrivibrio fibrisolvens, Clostridium lochheadii, Cl. longisporumand otherClostridiumspp. Cellulolytic cocci were present in smaller numbers than rod forms in the rumen of wheat‐straw‐fed buffaloes, whereas the cocci outnumbered rod forms in sorghum‐and berseem‐fed bu

ISSN:0021-8847    

DOI:10.1111/j.1365-2672.1983.tb01294.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

摘要:

Gram negative budding bacteria with a characteristic morphology have been observed in the caeca of chickens, turkeys, ducks and guinea fowl at levels between 0–4 and 24% of the total flora. Using strict anaerobic techniques a detailed study has been made of the organisms isolated from the caeca of chickens aged between 15 and 44 d. The majority of isolates were identified asGemmiger formicilis, the strains being divided into twomajor types according to the relative amounts of butyric acid and lactic acid produced from glucose. A second group of isolates could not be related to any known species.Amongst properties of ecological interest studied were limiting temperatures for growth, ammonia utilization, ability to utilize various carbon sources and survival in environments outside the intestine.Attempts to produce a selective medium for the isolation of these organisms when present at less than 2% of the total flora were unsuccessfu

ISSN:0021-8847    

DOI:10.1111/j.1365-2672.1983.tb01295.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

摘要:

Human teeth in an artificial mouth were inoculated withStreptococcus mutansBHT,Streptococcus mitiorLPA‐1, or sequentially with both organisms. Incubation was continued for 90 h. Mixed populations were largest when a nutrient supplement containing 5–0% (w/v) sucrose was supplied. Fewer organisms were recovered from experiments with synthetic saliva only, or when a supplement containing 0–05% (w/v) glucose was available. The inoculation sequence determined the total viable count and a larger population resulted whenStrep, mutanswas the initial colonizer (P<0–01).Strep, mutanswas always able to become established even when super‐infected on to a 24 h plaque ofStrep, mitior.The final proportion ofStrep mutanswas lower when it was the superinfecting organism and the sucrose (P<0–01) or glucose (P<0–05) nutrient supplement was provided. This work confirms the importance of inoculation sequence and presence of sugars in plaque accumulation and demonstrates the fundamental role of microbial interactions in

ISSN:0021-8847    

DOI:10.1111/j.1365-2672.1983.tb01296.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

摘要:

Menaquinone mixtures of microbial origin were separated according to the chain length and the degree of hydrogenation of the polyisoprenyl side‐chain by reversephase partition high performance liquid chromatography. Menaquinones can be measured easily and sensitively by the chromatographic system described her

ISSN:0021-8847    

DOI:10.1111/j.1365-2672.1983.tb01297.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

摘要:

Nine isolates ofErwinia chrysanthemifrom rotting potato tubers were compared with six type or reference strains of this species. Phenotypic properties of the potato isolates closely agreed with those ofErw. chrysanthemipv.zeaeand with the characteristics proposed for Dickey's infrasubspecific subdivision IV (1979) and Samson&Nassan‐Agha's biovar 3 (1978), whereZea mayswas among the most common host species. Pathogenicity tests on 20 ornamental and agricultural species showed onlyCyclamensp. andZ. maysto be susceptible. In Ouchterlony double diffusion tests, antisera to whole live cells of one potato strain reacted with four of the six pathovars ofErw. chrysanthemi.Tuber isolates did not produce blackleg symptoms in inoculated stems. The rationale of intensive pathogenicity testing is discusse

ISSN:0021-8847    

DOI:10.1111/j.1365-2672.1983.tb01298.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

摘要:

The development of the microflora of smoked pork loin and frankfurter sausage was followed during storage in vacuum, N2and CO2atmospheres at 4°C. The total aerobic count on the smoked pork loin reached 107organisms/g after 37 d in vacuum, 43 d in N2and 49 d in CO2. The corresponding value for the sausage was 77 d in vacuum, while the growth stopped at 6 times 104organisms/g after 98 d in N2, and at 4 times 102organisms/g after 48 d in CO2.The predominant organisms on the fresh products wereBacillusspp., coryneform bacteria,Flavobacteriumspp. andPseudomonasspp.At the end of the storage time the microflora on both products in the three gas atmospheres, consisted mainly ofLactobacillusspp. and two large groups of organisms that could not be identified as any described genus. Some of the unidentified strains could be classified as aLactobacillussp. after subsequent subculturing on laboratory media.The numbers ofLactobacillusspp. at the end of storage decreased in the order, CO2>N2>vacuum.Lactobacillus viridescensgenerally constituted a substantial part of theLactobacillusflora (5–72%). On the sausages two large uniform groups of unidentifiable homofermentativeLactobacillusspp. were also fou

ISSN:0021-8847    

DOI:10.1111/j.1365-2672.1983.tb01299.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

摘要:

A defined solid medium has been used to examine the responses ofAureobasidium pullulans, Saccharomyces cerevisiaeandSporobolomyces roseusto cadmium, copper and zinc. Experiments where aliquot volumes of metal salt solutions were added to wells in the centre of agar plates revealed marked differences between these organisms. The yeast‐like fungusA. pullulanswas the least sensitive butS. cerevisiaewas more sensitive to cadmium than zinc: the reverse was true forS. roseus.Quantitative data, which complemented the qualitative results, were obtained by measurement of metal concentrations in the plate

ISSN:0021-8847    

DOI:10.1111/j.1365-2672.1983.tb01300.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

摘要:

Mycobacterium smegmatisATCC 607 was grown at 27 and 37°C, with and without exogenous unsaturated fatty acids, viz. elaidic, oleic and palmitoleic acids, added to the growth medium. The total lipid content ofM. smegmatisATCC 607 was lower at 27°C, and with added oleic acid, when compared with the controls, but higher in presence of palmitoleic acid. At 37°C no significant differences were noted in the total lipid content. In general, the total lipid content was lower with all of the fatty acid supplementations at both 27 and 37°C. The phosphatidylethanolamine content was slightly higher at 27°C in the presence of elaidic or palmitoleic acid, but was markedly lower with oleic acid supplementation at 37°C. The cardiolipin content was lower in the presence of any of the fatty acids at 27°C, and higher in the medium supplemented with elaidic or oleic acid at 37°C. The unsaturated to saturated fatty acids ratio was higher with palmitoleic acid supplementation at 27°C, but remained unchanged in cells grown at 37°C. The modifications in mycobacterial lipids are a reflection of the organism's ability to adapt to changing growth c

ISSN:0021-8847    

DOI:10.1111/j.1365-2672.1983.tb01301.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

摘要:

In 1976 two major modifications were introduced in the composition and use of Rappaport's magnesium chloride—malachite green enrichment medium for salmonellas. One modification consisted of the reduction to one‐third of the amount of malachite green contained in the original formulation of Rappaport's medium, and the other in the incubation at 43 instead of 37°C. Since 1980, the modified medium incubated at 43°C is known as RV (Rappaport—Vassiliadis) enrichment medium for salmonellas.From 1977 to 1981, in eleven studies, the RV enrichment broth has been compared to the standardized Muller‐Kauffmann tetrathionate broth (MK broth) recommended as a reference method by the International Standards Organization, for the isolation of salmonellas from meat products, after pre‐enrichment in buffered peptone water. In all these studies the RV broth was superior to the MK broth in the isolation of salmonellas from naturally contaminated meat products (bovine minced meat, pork sausages, mesenteric lymph nodes, chicken carcases), sewage and faeces of healthy pigs, after pre‐enrichment in buffered peptone water. This superiority was statistically significant in seven of the eleven trials. Furthermore, in three more investigations the RV medium was compared with Oxoid selenite broth, with Difco tetrathionate broth and Difco selenite‐cystine broth. In all these three investigations the RV medium was superior for isolation of salmonellas, after pre‐enrichment, from naturally contaminated meat products and animal feeds. The superiority was statistically highly significant.When dealing with meat products, the RV medium in 10 ml volume inoculated with 0.1 ml of the pre‐enrichment medium, proved to be as effective as the RV medium in 100 ml volume, inoculated with 1 ml of pre‐enrichment medium, and clearly superior to the MK broth in 100 ml quantity.In all these studies involving enrichment in RV medium, MK broth, Difco tetrathionate broth, Oxoid selenite broth, incubated at 43°C and Difco selenite‐cystine broth incubated at 37°C, the RV medium proved to be highly specific. This means that the RV medium inhibits much more strongly the competing organisms, (including ‘Proteus hauseri’) which are lactose‐ and sucrose‐negative on the selective media and which may

ISSN:0021-8847    

DOI:10.1111/j.1365-2672.1983.tb01302.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

摘要:

Antibiotic‐resistantEsch. coliwere found in 10.6% of milk samples collected from 998 farms in the west of Scotland. The incidence of bothEsch. coliand antibiotic‐resistantEsch. coliin milk was higher when the cattle were housed day and night than when they were outdoors. Of the 1125Esch. coliisolates tested 22.2% were antibiotic resistant and of these 42.4% were resistant to more than one antibiotic.Escherichia colicarrying up to six resistance determinants were isolated. The possible implications to animal and human health are discus

ISSN:0021-8847    

DOI:10.1111/j.1365-2672.1983.tb01303.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY