摘要:

The effect of flaming (i.e. dipping biopsy specimens in alcohol and igniting them by drawing them rapidly through an open flame) on the reduction of bacterial surface contamination and on true bacterial concentrations in underlying tissue was investigated in different sizes of liver biopsy specimens in an experimental model suitable for quantitative and statistical calculations. Different degrees of surface contamination and of bacterial concentrations in underlying tissue were examined after a varying number of flaming procedures, the study comprising a total of 400 biopsy specimens. The flaming procedure repeated three times was able to eradicate a surface contamination of up to 104E. coliper biopsy specimen, whereas a contamination of 106E. coliper biopsy specimen was reduced to only 103E. coli.Undesirable reduction in the true bacterial concentrations in tissue did not invalidate the method from a quantitative bacteriological point of view, since the median reduction in bacteria per gram tissue in biopsy specimens of 1 cm3size did not exceed a factor of 3 after three repeated flamings. It is concluded that in regard to surface sterilization the method is unreliable as a routine in postmortem bacteriological studies.

ISSN:0304-131X    

DOI:10.1111/j.1699-0463.1976.tb01904.x

出版商:Blackwell Publishing Ltd    

年代:1976

数据来源: WILEY

摘要:

Strain‐dependent variations in the ability ofBordetella bronchisepticato produce haemolysis on solid media exist. Haemolysis is strongest at an acid reaction and will not take place if the reaction is too alkaline. Peptone and glutamine inhibit haemolysis and favour growth. The vigorous growth rapidly produces an alkaline reaction which inhibits the haemolysi

ISSN:0304-131X    

DOI:10.1111/j.1699-0463.1976.tb01905.x

出版商:Blackwell Publishing Ltd    

年代:1976

数据来源: WILEY

摘要:

This study was made to compare coagglutination to precipitin test in grouping beta‐haemolytic streptococci from clinical specimens and to investigate the accuracy of the bacitracin test in identification of group A streptococci. Results of grouping 126 strains with coagglutination and precipitation were identical in all except two cases. These two strains were nongroupable with precipitation but appeared as group B and C by coagglutination. When the distribution of group A, B, C and G streptococci in various clinical sources was investigated it was found that group B strains were the most frequently (41 per cent) isolated streptococci and even in isolates from pharyngeal swabs their proportion was 33 per cent. The accuracy of the bacitracin test in identification of group A streptococci was unsatisfactory as 26/62 (42 per cent) strains reported as group A by using this test were in fact group B, C or G streptococci. One of the reasons for this high number of false positives appeared to be the medium used for the preparation of the blood agar plates. In view of the frequent occurrence of non‐A‐streptococci in clinical specimens and high incidence of false positive in the bacitracin test it is suggested that this test should be replaced by a more efficient method of serological gro

ISSN:0304-131X    

DOI:10.1111/j.1699-0463.1976.tb01906.x

出版商:Blackwell Publishing Ltd    

年代:1976

数据来源: WILEY

摘要:

Transformable (cp+) and non transformable (cp‐) variants of theNeisseria meningitidisStrain M1 could be separated on the basis of their sedimentation velocity in sucrose gradients. Thecp+ cells sedimented slightly more slowly than thecp‐ones. This supports previous observations that the change fromcp+ tocp‐is followed by alterations in cell structures. Incp+ populations, the transformable fraction banded with the bulk of the cells in sucrose gradients, indicating that the density of the phenotypically competent cell is identical to the rest of thecp+ popul

ISSN:0304-131X    

DOI:10.1111/j.1699-0463.1976.tb01907.x

出版商:Blackwell Publishing Ltd    

年代:1976

数据来源: WILEY

摘要:

The effect of metronidazole on the growth and fine structure of exponentially growing cells ofTrichomonas vaginaliswas examined. Cell division stopped about one hour after the addition of 1–4 μg/ml of metronidazole, and the cells were apparently arrested in the interphase. One to two hours after the addition of metronidazole, the movement of flagella and of the undulating membrane had decreased, but cell death had not occurred until 7–8 hours later. The fine structure of the cytoplasm was changed 30 to 60 minutes after addition of metronidazole. Proportionally, the number of polyribosomes had decreased whereas the number of single ribosomes in the cytoplasm had increased. The electron‐density of the cytoplasmic matrix was higher in cells which were treated with metronidazole than in cells from control cultures. The findings of the present study indicate that the initial effect of metronidazole onT. vag.cellsin vitrois an inhibition of cell multiplication as well as an impairment of protein syn

ISSN:0304-131X    

DOI:10.1111/j.1699-0463.1976.tb01908.x

出版商:Blackwell Publishing Ltd    

年代:1976

数据来源: WILEY

摘要:

Cells ofTreponema pertenueGauthier obtained by elution from skin lesions and lymph nodes of experimentally infected hamsters were studied in the electron microscope by means of negative staining. The cells were also examined in thin sections of skin biopsies and lymph nodes. Fimbriae were observed on the negatively stained cells. Until now fimbriae have not been demonstrated on negatively stained cells of other species ofTreponema, but at present only one strain ofT. pertenuehas been studied in our laboratory. Otherwise, the ultrastructure of theT. pertenuecells was found to be very similar, if not identical to, the substructural details observed in cells ofT. pallidumandT. cuniculi.In thin sections of skin biopsies, treponemes were observed in the intercellular spaces between cells of the stratum basale and the stratum spinosum layers of the epidermis.

ISSN:0304-131X    

DOI:10.1111/j.1699-0463.1976.tb01909.x

出版商:Blackwell Publishing Ltd    

年代:1976

数据来源: WILEY

摘要:

A comparison of two different methods in T‐typing 200 Norwegian group A strains is reported. The traditional agglutination technique was compared with the co‐agglutination method of Christensen and co‐workers. Fifty‐five strains could not be typed by either method. The typing results for 128 of the strains were in agreement. The most common T types were the following: 1, 4, 8, 12, 13, 28, and strains belonging to the T pattern 5/11/1

ISSN:0304-131X    

DOI:10.1111/j.1699-0463.1976.tb01910.x

出版商:Blackwell Publishing Ltd    

年代:1976

数据来源: WILEY

摘要:

Three different toxins were detected in culture supernatants from 11 strains ofAeromonas hydrophila.The haemolysin and the cytotoxic factor(s) interferred in the three test systems for enterotoxin, but they could be neutralized by heating at 56° C or by specific antihaemolysin

ISSN:0304-131X    

DOI:10.1111/j.1699-0463.1976.tb01911.x

出版商:Blackwell Publishing Ltd    

年代:1976

数据来源: WILEY

摘要:

Agglutinins reacting with normal and tanned sheep erythrocytes were the probable cause of false positive reactions given by 51 of 214 Liberian sera when using a commercial passive‐haem‐agglutination test for hepatitis‐B surface antigen. Absorption showed these agglutinins to be identical to those described earlier in Nigerian sera. Rheumatoid factor and anti‐sheep‐serum antibodies although present in 12 and five per cent respectively of all sera were not responsible for any false positive reactions. The practical conclusion is that such tests, based on sheep erythrocytes are unsuitable for screening this p

ISSN:0304-131X    

DOI:10.1111/j.1699-0463.1976.tb01912.x

出版商:Blackwell Publishing Ltd    

年代:1976

数据来源: WILEY