JMT-1: a novel, spherical lytic halotolerant phage isolated from Yuncheng saline lake

ABSTRACT This work described a novel halotolerant phage, JMT-1, with a spherical morphology. JMT-1, which was isolated from a hypersaline lake, could produce clear plaques on Chromohalobacter sp. LY7-3. The purified virions are spherical, have no visible tail, and are about 30-50 nm in diameter. JMT-1 has a wide host range, and this study showed that the phage can infect at least five halophilic bacteria. The proteins of JMT-1 were analyzed using sodium dodecyl sulfate polyacrylamide gel electrophoresis, and six proteins were detected. Results show that JMT-1 is a bacteriophage with a linear double-stranded DNA. Meanwhile, the genome is approximately 23 kb in length and is sensitive to the restriction endonucleases Bam I, EcoR I, Hind III and Kpa I. JMT-1 has a high titer, approaching 1.5 × 109 pfu/mL after dilution to 10−6 pfu/mL. The phage is also sensitive to chloroform but not to temperature, pH, and lowered salt concentration. JMT-1 is a spherical lytic halotolerant phage with a wide host range and has the tolerance to specific extreme environments. These data could provide references for studying phage resources in extreme environments and would also provide the useful methods for isolation and identification of other valuable phage in the salt lake environment.

Preliminar characterization of a new virus isolated from the spinal fluid of patients with meningitis in Säo Paulo, Brazil

De dezembro de 1982 a março de 1983 um total de 138 pacientes com idade de 4 meses a 57 anos foram atendidos em diferentes hosptais de Säo Paulo com sintomas de meningite asséptica. Um agente transmissível foi isolado de 35 das 53 amostras de líquor. A replicaçäo desse novo vírus ou de um grupo de vírus relacioandos antigenicamente com características semelhantes foi detectada através do efeito citopático produzido em cultura de células de MDCK. O agente isolado demonstrou ter um diâmtro em torno de 40 nm quando examinado ao microscópio eletrônico através da coloraçäo negativa. Nenhuma atividade hemaglutinante foi detectada em pH 7,2 com hemácias humanas de cobaias ou de galinha e em pH 6,0 - 7,2 com hemácias de ganso. Esse agente näo se mostrou patogênico ao camundongo recém-nascido e adulto, era sensível ao clorofórmio e näo foi inibido pelo BuDR, o que indica conter o genoma RNA