Interleukin 12 receptor beta 1 (IL12Rβ1) deficiency is the most common cause of Mendelian susceptibility to mycobacterial disease (MSMD). MSMD usually predisposes affected individuals infections with weakly virulent mycobacteria such as Bacille Calmette-Guérin (BCG), environmental mycobacteria, non-typhoidal Salmonella, and certain other intracellular pathogens. presents disseminated BCG infect...

Polymorphonuclear leukocyte (PMN) cell death strongly influences the resolution of inflammatory episodes, and may exacerbate adverse pathologies in response to infection. We investigated PMN cell death mechanisms following infection by virulent group A Streptococcus (GAS). Human PMNs were infected in vitro with a clinical, virulent GAS isolate and an avirulent derivative strain, and compared fo...

We used 94 RAPD primers of different nucleotide composition to probe the genomic differences between a highly virulent P. multocida strain and an attenuated vaccine strain derived from the virulent strain after culturing the latter under increasing temperature for approximately 14,400 generations. The GC content of the vaccine strain is significantly (P < 0.05) lower than that of the virulent s...

Bursae of Fabricius were collected from 20 chickens diagnosed with infectious bursal disease virus (IBDV) infection from 15 prefectures in 1993 to 2004. Here we report the nucleotide sequence analysis of VP2 hypervariable domain of IBDV genome detected by reverse transcription-polymerase chain reaction from these samples. Ten sequences derived from 10 prefectures in 1996 to 2003 were of the cla...

Kinetic, microscopic, and biochemical studies show that virulent Ti (tumor inducing)-plasmid-containing strains of Agrobacterium attach to normal tobacco and carrot tissue culture cells. Kinetic studies showed that virulent strains of A. tumefaciens attach to the plant tissue culture cells in increasing numbers during the first 1 to 2 h of incubation of the bacteria with the plant cells. Five T...

ABSTRACT The genetic relationships between isolates of Puccinia triticina virulent on wheat with the Lr26 resistance gene were studied. The diversity within and between isolates of P. triticina from Israel, Europe, and the United States was determined by virulence on near-isogenic Thatcher lines and by random amplified polymorphic DNA. According to the molecular markers, isolates that were viru...

Based on nucleotide sequence analysis of the hemagglutinin (HA) gene from the virulent and avirulent A/chicken/Pennsylvania/83 influenza viruses, it was previously postulated that acquisition of virulence was associated with a point mutation that resulted in loss of a glycosylation site. Since there are two potential glycosylation sites in this region of the HA molecule and since all Asn-Xaa-Th...

The human gastric pathogen Helicobacter pylori has many virulence factors involved in pathogenesis, but the mechanisms regulating these virulence factors are not yet fully understood. In this study, we cloned HP1248, which is similar in sequence to Escherichia coli vacB, which was previously shown to be associated with the expression of virulence in Shigella and enteroinvasive E. coli. E. coli ...

Haemophilus parasuis is a common epiphyte of the upper respiratory tract of pigs. The factors of H. parasuis pathogenicity that enable some strains to be virulent and consequently cause a clinical disease have not been established yet. Fifteen serovars of H. parasuis have been described at present. Individual serovars differ in virulence, and considerable differences in virulence also exist wit...

Haemophilus parasuis is a Gram-negative bacterium that colonizes the upper respiratory tract of swine and is capable of causing a systemic infection, resulting in high morbidity and mortality. H. parasuis isolates display a wide range of virulence and virulence factors are largely unknown. Commercial bacterins are often used to vaccinate swine against H. parasuis, though strain variability and ...