By making use of the increased phagocytosis which follows the exposure of HeLa cells to tissue culture media containing selected horse sera, it was possible to introduce all of the mycobacterial species studied into the cells, where many of them proceeded to grow. Fully virulent strains of tubercle bacilli filled much of the cytoplasm in a few days and formed characteristic cords not seen with ...

Studies on Salmonella infections in mice showed that the injected bacteria are cleared rapidly from the circulation, and may be found mainly in the liver, and spleen, the principal organs of the reticuloendothelial system (RES) (1). Investigations of the fate of the bacteria in these organs revealed that whereas the population of a virulent strain of Salmonella increases, that of an avirulent s...

Cytokinin activity in the culture medium of four pathogenic strains of Corynebacterium fascians varied from 168 to 0.4 mug of kinetin (6-furfurylaminopurine) equivalents per liter, as compared to 0.2 in an avirulent control. N(6)-Isopentenyladenine was the predominant cytokinin in the medium of all five strains, and its increased production was correlated with the degree of pathogenicity; howev...

Insecticide susceptibility and virulence to resistant rice varieties were determined and evaluated in the brown planthopper (BPH) and the whitebacked planthopper (WBPH), collected from Asian countries (Japan, China, Taiwan, northern Vietnam, southern Vietnam, and Philippines) in 2006. Insecticide susceptibility was determined by a topical application method using four insecticides. Virulence to...

BACKGROUND The use of prototypic strains is common among laboratories studying infectious agents as it promotes consistency for data comparability among and between laboratories. Schu S4 is the prototypic virulent strain of Francisella tularensis and has been used extensively as such over the past six decades. Studies have demonstrated virulence differences among the two clinically relevant sub...

Chronic or hard to heal wounds are very susceptible to infections. Due to the biofilm mode of growth in these wound, conventional therapies, such as antibiotics, do not eradicate the bacteria. New therapeutics must be developed to be able to combat these infections and one way might be to control or inhibit bacterial communication, so called quorum sensing. Possible quorum sensing inhibitors ca...

The Pasteurella multocida capsular type A isolates can cause pneumonia and bovine respiratory disease (BRD). In this study, comparative genomics analysis was carried out to identify the virulence genes in two different virulent P. multocida capsular type A isolates (high virulent PmCQ2 and low virulent PmCQ6). The draft genome sequence of PmCQ2 is 2.32 Mbp and contains 2,002 protein-coding gene...