New Technique for Biotyping

An efficient technique for biotyping, using disposable trays instead of glass tubes and agar instead of liquid media, is described.     

Biotyping of pathogenic cocci using mathematical methods

The differential information content of biological signs in the ecology of different staphylococcal and streptococcal species has been studied by the mathematical method. The method for the intraspecific differentiation of staphylococci, streptococci and gonococci into pathovars with the use of programs for the computerized analysis of the material has been proposed. The mathematical models of strain virulence in different coccal species are described.     

New Technique for Distinguishing between Human Chromosomes

A GIEMSA staining procedure that preferentially stains centromeric heterochromatin in mouse chromosomes has been described¹. This specificity was observed when fixed preparations were treated with sodium hydroxide to denature the DNA and then incubated in warm saline to allow annealing, in the presence of ³H-labelled single stranded satellite DNA or its complementary RNA. In this way mouse satellite DNA was located in the centromeric heterochromatin^1,2. It is known to consist of highly repetitive sequences³ and to anneal much more rapidly than non-repetitive DNA⁴. It seems probable, therefore, that the darker staining with Giemsa of these regions, after denaturation and annealing, indicates the presence of highly repetitive DNA.     

Biotyping of Malassezia pachydermatis strains using the killer system

The killer phenomenon has been used as epidemiological marker for Candida albicans, where hundreds of biotypes can be obtained. The objective of this study is to observe the behaviour of 30 strains of Malassezia pachydermatis isolated from dogs with otitis (15) or dermatitis (15) against 9 killer yeasts, which, when grouped in triplets produced a 3 digit code (biotype). The growth inhibition of the 30 strains of M. pachydermatis due to the effect of the killer yeasts used permitted the determination of the following biotypes: 888 (33.3%), 212 (26.7%), 111 (16.7%), 312 (6.7%), 512 (6.7%), 242 (3.3%), 311 (3.3%) and 411 (3.3%). Biotypes 888, 212 and 111 occurred most frequently in both ear canal and skin samples.     

Biotyping of Propionibacterium acnes isolated from normal human facial skin

Biochemical and serological characteristics of 128 strains of Propionibacterium acnes isolated from the facial skin of healthy Japanese volunteers were compared with the three standard strains of the American Type Culture Collection, ATCC 6919, 11827, and 11828. Accordingly, the isolated strains of P. acnes were classified into five biotypes (B1 to B5) on the basis of fermentation tests of ribose, erythritol, and sorbitol. Two serotypes were distinguished by the agglutination test. P. acnes belonging to serotype I had galactose as a cell wall sugar, whereas those of serotype II lacked galactose. The strains of serotype I were distributed among all five biotypes (B1 to B5); however, those of serotype II consisted only of one biotype (B2). A term "sero-biotype" was introduced to differentiate and carefully classify the isolates. The predominant sero-biotypes differed with the individual and region of the facial skin. In general, strains of sero-biotype IB1, IB3, IB4, and IIB2 were more frequently isolated than those of sero-biotype IB2 and IB5. Thus, for routine assay work, serotyping of P. acnes as based on erythritol and sorbitol fermentation is both practical and applicable.     

A New Technique for Orcein Banding with Acid Treatment

A rapid method for banding plant chromosomes using hydrochloric acid with orcein is suggested. The technique has been successful in both dioecious and monoecious families with short chromosomes. It involves pretreatment with an oxyquinoline-paradichlorobenzene mixture, fixation in acetic ethanol and treatment with hydrochloric acid at 60 C followed by staining with orcein. Stained chromosome bands and interbands are reproducible and species specific.     

喜树碱的碱水法提取新工艺

本文根据喜树碱在一定条件下开环和闭环的可逆性,设计了喜树碱的水法提取工艺。     

Biotyping and resistotyping for epidemiological tracing of the fecal origin of Klebsiella pneumoniae in urinary infections

Twenty-four (82.7%) out of 29 patients suffering from hospital acquired urinary infections by Klebsiella pneumoniae had the same species in their faeces. Biotyping of 24 urinary and 219 fecal strains of K. pneumoniae resulted in 50 different biotypes - an average of four biotypes per fecal sample. Ten patients (34.4%) had the same biotype in urine and faeces without any correlation with previous vesical catheterization (p greater than 0.05). Using resistotyping to four chemical compounds selected among 34 tested substances (brilliant green, malachite green, potassium tellurite and mercuric chloride) 16 different resistotypes were found. Fourteen patients (58.3%) presented the same resistotype in urine and faeces but only in five patients was there correlation with simultaneous biotyping identity. Simultaneous occurrence of identical biotypes or resistotypes in faeces and urine occurred in only 54.2% of cases. However, there was a significant association between resistance ot mercuric and tellurite ions in fecal and urinary strains isolated from the same patient (p less than 0.001).     

Comparative Characterization and Biotyping of Staphylococcus aureus Isolates from Human and Bovine Sources

One Hundred and ten alpha and/or delta-haemolytic isolates (collection 1), 50 beta haemolytic isolates (collection 2) from bovine mastitis, and 100 previously phage-typed alpha- and delta-haemolytic isolates (human collection) og Staphylococcus aureus (S. aureus) were tested and biotyped according to the scheme of Hajek & Marsalek (1971). Among collection 1 isolates, 85 (77.3 %) belonged to the human biotype A (human source). Twenty two (20 %) designated as non-allotted strains, possessed characteristics of both animal and human sources. The remaining 3 isolates (2.7 %) in this collection belonged to biotype C (animal source). All collection 2 isolates which were used as control strains for animal sources, belonged to biotype C. The human collection that contained 100 phage-typed haemolytic isolates (representing all human phage groups) were used as a control for the human source. Irrespective of their phage group, these strains predominantly produced alpha and/or delta haemolysins and belonged to the human biotype A. This study also recommended the use of a combined plasma crystal violet agar medium for the presumptive identification of S. aureus biotypes.     

A New Technique for Staining Catecholic Residues in Biological Samples

This technique for localizing catecholic residues in biological samples is based on the condensation of Besthorn's hydrazone (3-methyl-2-benzothiazolinone hydrazone hydrochloride (MBTH) with quinone residues obtained by the oxidation of catechols in the presence of ammonia. The product is a dark pink MBTH-quinone compound. This method is very sensitive and positive to catechol even at the 0.05 µg level and the final product is chemically stable.