Disease relevance of espB

• Human (n = 22) and bovine (n = 31) strains were genotyped for carriage of the genes for Shiga-like toxin types 1, 2, and 2c; E. coli secreted protein genes espA, espB, and espP; the enterohemolysin gene; eae (intimin); ast (enteroaggregative E. coli stable toxin [EAST]); and genes for common E. coli adhesins [1].
• Citrobacter rodentium espB is necessary for signal transduction and for infection of laboratory mice [2].

High impact information on espB

• To investigate the role of Esp proteins in disease, mutations in espA and espB were constructed in rabbit EPEC serotype O103 and infection characteristics were compared to that of the wild-type strain using histology, scanning and transmission electron microscopy, and confocal laser scanning microscopy in a weaned rabbit infection model [3].
• It has been previously shown that the EPEC eaeB (espB) gene encodes a secreted protein required for signal transduction and adherence, while eaeA encodes intimin, an EPEC membrane protein that mediates intimate adherence and contributes to focusing of cytoskeletal proteins beneath bacteria [4].
• Membrane insertion of Tir, secreted under low Ca(2+) conditions, is therefore independent of Esp. Furthermore, espB and espD mutant strains of EPEC, unable to form the translocation pore, still translocate Tir into host cells membranes [5].
• To determine whether different domains of EspB are responsible for different functions, 42 plasmids carrying mutated espB were introduced into an espB deletion mutant [6].
• In this study, C. rodentium espB has been cloned and its nucleotide sequence has been determined [2].

Biological context of espB

• Complementation with plasmids containing EPEC espA or/and espB genes into RDEC-1 mutant strains demonstrated that they were functionally interchangeable, although the EPEC proteins mediated higher levels of invasion [7].
• We report here the construction by allelic exchange of an EPEC O103 strain mutated in espB and tir, two essential virulence genes [8].

Anatomical context of espB

• The C. rodentium espB mutant exhibited reduced cell association and had no detectable fluorescent actin staining activity on cultured cell monolayers [2].
• Neither the ability to rearrange phosphotyrosine proteins nor that to be internalized into epithelial cells was evident following coincubation with another STEC O157:H7 strain or with the nonsignaling espB mutant of EPEC [9].
• Lysates obtained from Shiga-like toxin-producing E. coli, E. coli RDEC-1, Citrobacter rodentium, and an EPEC espB insertion mutant all inhibited IL-2 and IL-4 production by mitogen-stimulated lymphoid cells [10].
• We have cloned and determined the nucleotide sequences of the espA, espB and espD homologues from an E. coli strain (4221) isolated from a dog which manifested the attaching and effacing lesions in the small intestine [11].
• The espB PCR assay detected as little as 0.3 colony-forming units of C. rodentium [12].

Other interactions of espB

• Based on gene typing, we observed 7 different eae espA espB tir pathotypes among the 12 STEC strains and described the new espAbetav variant [13].
• The microarray was also tested for its ability to distinguish among phylogenetic groups of genes by using gene probes derived from the attaching-and-effacing locus (espA, espB, tir) [14].

Analytical, diagnostic and therapeutic context of espB

• Molecular cloning and sequencing of STEC espB alleles from two different serotypes showed that the encoded polypeptides were about 80% homologous [15].
• In the PCR analysis, two markers (cesT/eae and espB genes) were found together in more strains (25.4%) than either were found alone [16].

References