For bacteria, temperature is a fairly reliable cue for entry into a vertebrate host. Many pathogenic bacteria sense elevated temperatures (37°C) and turn on virulence and metabolic genes appropriate for survival and growth within the host. A recent study demonstrated that the expression of a heme uptake protein in Shigella dysenteriae and pathogenic Escherichia coli was dependent on an RNA ther...

Four commonly used reference endotoxin standards, Escherichia coli O113:H10:K0, E. coli O55:B5, Salmonella abortusequi, and Shigella dysenteriae were compared by the USP rabbit pyrogen and the Limulus amoebocyte lysate tests. By the rabbit pyrogen test, S. abortus equi was identified as the most potent endotoxin, followed closely by E. coli O113:H10:K0 and E. coli O55:B5.

An elevated level of Shiga-like toxin I (SLT-I) production was found in 1 of 466 Escherichia coli strains studied. Among the 34 sonic lysates obtained from classical enteropathogenic E. coli, 5 produced SLT-I. The Aeromonas, Citrobacter, Edwardsiella, Enterobacter, Klebsiella, Proteus, Providencia, Pseudomonas, Salmonella, Serratia, Shigella, Yersinia, and Vibrio strains also studied were not S...

O-polysaccharides were isolated from the lipopolysaccharides of Escherichia coli O40 and Shigella dysenteriae type 9 and studied by chemical analyses along with (1)H and (13)C NMR spectroscopy. The following new structure of the O-polysaccharide of E. coli O40 was established: -->2)-beta-D-Galp-(1-->4)-beta-D-Manp-(1-->4)-alpha-D-Galp-(1-->3)-beta-D-GlcpNAc-(1--> TheO-polysaccharide structure o...

Large plasmids (120 to 140 megadaltons) associated with virulence of Shigella sonnei, S. flexneri 2a and S. dysenteriae 1 were transferred from each strain into Escherichia coli K-12 and avirulent S. flexneri 1b strains by ampicillin transposon (Tn1)-mediated conduction. Strains with the virulence plasmid could penetrate tissue culture cells irrespective of the original host of the plasmid.

A toxin that causes morphological changes in Chinese hamster ovary cells was isolated from a culture filtrate of Shigella dysenteriae 1. It was partially purified by successive column chromatography on diethylaminoethyl-cellulose, Bio-Gel A-5m, and hydroxylapatite. The toxin was separated from neurotoxin by diethylaminoethyl-cellulose column chromatography and was not lethal for mice.

Multidrug-resistant strains of Shigella dysenteriae type 1 were implicated in three outbreaks and sporadic cases of dysentery in eastern India in 2002 and 2003. After a hiatus of 14 years, this pathogen reemerged with an altered antibiotic resistance pattern. In addition to ampicillin, co-trimoxazole, tetracycline, chloramphenicol, and nalidixic acid, all the recent strains were resistant to no...

Shigellosis produces inflammatory reactions and ulceration on the intestinal epithelium followed by bloody or mucoid diarrhea. It is caused by enteroinvasive E. coli (EIEC) as well as any species of the genus Shigella, namely, S. dysenteriae, S. flexneri, S. boydii, and S. sonnei. This current species designation of Shigella does not specify genetic similarity. Shigella spp. could be easily dif...