Serum from normal mammals agglutinated and immobilized nonpathogenic Leptospira biflexa and agglutinated avirulent lines of pathogenic serotypes L. icterohaemorrhagiae and L. zanoni. Virulent lines of L. icterohaemorrhagiae and L. zanoni were not affected, nor were any of three strains of L. pomona, one of which was avirulent. The active principle in serum was a beta-macroglobulin which was hea...

Fimbrial adhesion is a Virulence Determinant which is classified under Adhesins category of virulence factor of uropathogenic Escherichia coli. Afimbrial adhesin Protein with swissprot accession number P12730, of length 181 amino was selected for modeling using Bioinformatics tools. Modelled protein has been submitted to protein model database and has been assigned an accession number of PM0075...

It is generally reasoned that lethal infections caused by opportunistic pathogens develop permissively by invading a host that is both physiologically stressed and immunologically compromised. However, an alternative hypothesis might be that opportunistic pathogens actively sense alterations in host immune function and respond by enhancing their virulence phenotype. We demonstrate that interfer...

S fimbrial adhesins (Sfa) represent virulence factors of E. coli wild-type strains causing urinary tract infections and meningitis of the new born. In order to determine the influence of subinhibitory concentration of antibiotics on the expression of the sfa gene cluster, a wild-type strain carrying the lacZ gene, coding for the enzyme beta-galactosidase fused to the sfa determinant was used. T...

The role of sigmaB, an alternative sigma factor of Staphylococcus aureus, has been characterized in response to environmental stress, starvation-survival and recovery, and pathogenicity. sigmaB was mainly expressed during the stationary phase of growth and was repressed by 1 M sodium chloride. A sigB insertionally inactivated mutant was created. In stress resistance studies, sigmaB was shown to...

In order to identify the genetic basis for the attenuation of Salmonella typhimurium LT2 strains, experiments were performed to identify a gene(s) which restores virulence to an avirulent LT2 strain. These and further experiments confirmed that an rpoS mutation is the sole determinant of the attenuation of S. typhimurium LT2.

Isolated for the first time in 1982 from human gastric biopsy, Helicobacter pylori is responsible for gastritis, peptic ulcer, and gastric cancer. A pathogenicity island acquired by horizontal transfer, coding for a type IV secretion system, is a major determinant of virulence. The infection is now treated with antibiotics, and vaccines are in preparation. The geographic distribution suggests c...

Here, we report the draft genome sequence of enteropathogenic Escherichia coli (EPEC) O146 strain isolated from a 1-year-old child with acute diarrhea in Delhi who recovered completely. The multidrug transporter (mdtABCD) gene, responsible for drug resistance, is present. The strain also contains the astA gene, an additional virulence determinant.

The immunoelectrophoretic characteristics of the known cellular antigens of serotype 17, Group A streptococci have been presented. These include C, M, T, and polyglycerophosphate. In addition, three hitherto undescribed antigens of serotype 17 have been encountered. The F antigen occurs in most serotype 17 strains, has a faster electrophoretic mobility than M, appears in acid, distilled water, ...