RESUMO
The infection of two Helicobacter pylori strains with a phage-containing supernate of the lysogenic H. pylori strain IMMi 290/89 resulted in a lytic cycle and propagation of phage HP1. In negatively-stained preparations, the empty phage heads measured 55-60 nm in diameter and mature heads measured 50 nm. The flexible, striated phage tail was c. 170 nm in length and 9.5 nm in diameter. The phage showed a mean density of 1.40 g/cm3 in sucrose-density gradients and contained double-stranded DNA c. 22,000 bp in length.
Assuntos
Bacteriófagos/crescimento & desenvolvimento , Helicobacter pylori , Bacteriófagos/isolamento & purificação , Bacteriófagos/ultraestrutura , DNA Viral/isolamento & purificação , Lisogenia , Ensaio de Placa Viral , Ativação ViralRESUMO
Transesterification of bacterial fatty acids to methyl esters with trimethylsulphonium hydroxide (TMSH) was compared with a conventional method for the identification of Legionella species by capillary gas chromatography. There was an extensive coincidence in the gas chromatographic profiles of bacterial fatty acid methyl esters (FAMEs) obtained by the two methods. However, the TMSH procedure needs less initial material and is much more simple and rapid. The chromatographic pattern of FAMEs obtained from a single colony is sufficient for the identification of the genus Legionella, and L. pneumophila can be clearly distinguished from other Legionella species.
Assuntos
Ácidos Graxos/análise , Legionella/isolamento & purificação , Compostos de Sulfônio/química , Cromatografia Gasosa , Legionella/químicaRESUMO
H. pylori cells grown on cholesterol-free medium adsorb cholesterol from serum, egg yolk, and VDRL reagent. The binding of cholesterol does not influence the hydrophobicity of the cells. The haemagglutinating activity is slightly diminished. The cell-bound haemolytic activity is completely inhibited. The affinity of H. pylori for cholesterol probably acts as factor of chemotaxis and adherence.
Assuntos
Colesterol/metabolismo , Helicobacter pylori/metabolismo , Adsorção , Aderência Bacteriana , Quimiotaxia , Cromatografia Gasosa , Meios de Cultura , Ésteres , Ácidos Graxos/análise , Helicobacter pylori/química , Hemaglutinação , Hemólise , Humanos , Propriedades de SuperfícieRESUMO
Gas-liquid chromatography of cellular fatty acids is a useful tool for the identification of bacteria. Derivatization of bacterial fatty acids to methyl esters by conventional techniques is usually time-consuming and complicated. A new one-step technique using trimethyl-sulfonium hydroxide allows the direct formation of fatty acid methyl esters within 1-2 min. Some random examples of profiles demonstrate that straight, branched, saturated, unsaturated, hydroxy and cyclopropyl fatty acids match conventional preparations well. The method is a very sensitive one, since only a few colonies are sufficient for preparation of fatty acid methyl esters.
