Synthesis of teichoic acids. VII. Synthesis of teichoic acids during spore germination

The synthesis of teichoic acids has been examined during germination in Bacillus licheniformis ATCC 9945 and in B. subtilis W-23. Teichoic acids are absent from the spores of both organisms. B. licheniformis spores lack the enzymes responsible for teichoic acid synthesis. The appearance of these enzymes during germination is correlated with the appearance of teichoic acids in the cell. The appearance of teichoic acid-synthesizing enzymes and of teichoic acids in the cell are inhibited by the addition of chloramphenicol to the germination medium. In B. subtilis W-23 the situation is similar for the synthesis of polyribitolphosphate. The synthesis of glucosyl polyribitolphosphate is only partially inhibited by chloramphenicol, puromycin, and penicillin, and uridine diphosphate-d-glucose polyribitol-phosphate glucosyl transferase can be demonstrated in spores. The possible implications of some of these observations are discussed.     

On the physiological functions of teichoic acids

The choline-containing teichoic acids of pneumococci can be modified by biosynthetic replacement of the choline residues with certain structural analogues, such as ethanolamine (EA) or the N-monomethyl- (MEA) and N-dimethyl- (DEA) amino derivatives of ethanolamine. Cells containing such analogues in their teichoic acids develop pleiomorphic alterations in several physiological properties, which include resistance to detergent-induced lysis and inhibition of cell separation (chain formation). We report here the results of physiological studies on the mechanism of these two phenomena. Our results are summarized in the following: (a) Pneumococci grown on various amino alcohols produce cell walls of identical amino sugar and amino acid composition. (b) Both choline- and EA-containing teichoic acids seem to follow the same conservative pattern of segregation during growth and cell division. (c) Lysis sensitivity of pneumococci requires the juxtaposition of lysissensitive (choline-containing) cell walls and endogenous autolysin at the cell wall growth zone. (d) Upon readdition of choline to ethanolamine-containing cells, lysis sensitivity and catalytically active (C-type) autolysin reappear in the bacteria with the same kinetics. (e) The chains of EA-grown pneumococci contain fully compartmentalized cells and normal cross walls.     

Structural characterization of teichoic acids from Lactobacillus brevis

Teichoic acids are a major constituent of the cell wall of Gram-positive bacteria. Structural characterization of lipoteichoic and teichoic acids isolated from Lactobacillus brevis was undertaken using 1D and 2D NMR experiments as well as chemical methodology. Compositional analysis indicated the presence of high amounts of glycerol, glucose, and alanine. In the case of LTA octadecenoic acid was also detected. The basic LTA/WTA structure was identified as 1,3-poly(glycerol phosphate) nonstoichiometrically substituted at C-2 of the glycerol residues with d-Ala or α-d-Glc. In the case of LTA a higher amount of Ala could be detected and partial alanylation at position C-6 of the Glc could also be observed.     

不同人类免疫缺陷病毒感染途径群体中戊型肝炎病毒的流行情况

本研究旨在了解不同人类免疫缺陷病毒(human immunodeficiency virus,HIV)感染途径群体中戊型肝炎病毒(hepatitis E virus,HEV)抗体情况,探讨HEV疫苗接种的必要性。采集HIV感染者的血清或血浆,利用酶联免疫吸附试验(enzyme-linked immunosorbent assay,ELISA)检测HEV IgG抗体、IgM抗体及抗原,荧光定量聚合酶链反应(polymerase chain reaction,PCR)检测HEV核酸,Roche高纯化HIV-1核酸定量检测试剂盒(PCR荧光法)检测HIV感染者的HIV载量。比较分析不同HIV感染途径群体中HEV流行率的差别。结果显示,HIV感染者中HEV IgG抗体的阳性率为37.4%,静脉吸毒、成分献血和传播途径不明HIV感染群体的HEV IgG抗体阳性率分别为49.3%、39.5%和30.4%。HEV核酸荧光PCR检测结果均为阴性。3种HIV感染群体之间HEV IgG抗体阳性率差异无统计学意义(χ~2=2.978,P0.05)。HEV IgG阳性与阴性感染者之间HIV载量差异无统计学意义(P0.05)。结果提示,为保护HIV感染者免受HEV感染,应考虑接种HEV疫苗。     

The occurrence of teichoic acids in streptomycetes

The presence of teichoic acids in a number of streptomycetes led to the conclusion that these biopolymers were widely spread in genus Streptomyces. The nature of the teichoic acid present in the mycelium was determined by extracting it with 10% trichloroacetic acid, precipitating it with ethanol and identifying the precipitated polymer by partial acid and alkali hydrolysis to alditol, alditol phosphates and glycosylalditol phosphates. Most strains examined in this survey contained glycerol or ribitol teichoic acids; in some cases neither type was detected.Structurally teichoic acids closely resemble those of other genera of gram-positive bacteria and in many cases represent poly(glycerol phosphate) and poly(ribitol phosphate) chains. The proportion of alditol residues bearing sugar substituents varied widely.Three species of genus Streptoverticillium contained glycerol teichoic acids. It is belived that some of the data presented in this paper might be used with some success in taxonomic studies of streptomycetes.