RESUMO
A convenient and rapid method for screening and identifying rod mutants of Bacillus subtilis is described. At the restrictive temperature (45 degrees C), all rod mutants of B. subtilis screened lost their ability to sporulate. The morphology and colour of mutant colonies grown on sporulation agar plates differed from those of rod+ cells, which were able to sporulate even at elevated temperature. These characteristics provide an alternative approach for the identification of rod mutants in B. subtilis culture by streaking the cells onto a minimal glucose agar plate and incubating at the restrictive temperature. After 30 h of incubation at this temperature, rod mutants are easily identified. This method will facilitate the screening and isolation of rod mutants of B. subtilis.
Assuntos
Bacillus subtilis/citologia , Bacillus subtilis/genética , Técnicas Bacteriológicas , Parede Celular/genética , Bacillus subtilis/isolamento & purificação , Proteínas de Bactérias/genética , Proteínas de Bactérias/fisiologia , Parede Celular/metabolismo , Parede Celular/ultraestrutura , Cor , Meios de Cultura/química , Mutação , Peptídeo Hidrolases/genética , Peptídeo Hidrolases/metabolismo , Esporos Bacterianos/genética , Esporos Bacterianos/crescimento & desenvolvimento , TemperaturaRESUMO
Acute haemorrhagic conjunctivitis occurred in epidemic in Hong Kong in 1971 and 1975 respectively. Two picornaviruses, the Enterovirus type 70 and an antigenic variant of Coxsackie virus type A24, were isolated during the 1971 outbreak, while only the latter virus was detected in the 1975 outbreak. In 1972 and 1974, sporadic cases of conjunctivitis associated with Enterovirus type 70 were observed. Serological survey in late 1975 showed a high proportion of the population might still be susceptible to both viruses. Recrudescence of the disease is conceivable when environmental condition is favourable for the spread of these viruses.