Virulence genes present in German outbreak strain

German outbreak strain 0104:H4, is very unusal, a hybrid of enteroaggregative Ecoli (EAEC) and Shigela toxin producing Ecoli (STEC), it’s genetic composition very simillar to EAEC but carries the stx producing prophage. It’s believed thta the presence of combination of adhesion proteins and shigela toxin, is what makes this strain very virulent compare to other strains. The BRIG image produced to show virulence gene comparison of different Ecoli pathgenic and non pathogenic strain, shows the presence of stxpaa genes which are encoded by STEC propahges and many other virulence genes present in EAEC i.e. especpesc It also shows the presence of some unique virulence genes, long polar fimbriae, lpf (A,B,D,E), which seems to be missing in other strains in the BRIG image but there’s a mention of these in some EHEC strains. 0104:H4 strain, doesnt show presence of LEE pathogenicity island commonly present in EHEC strains, containing intimin (eae) playing important role is adhesion of bacteria in itestitinal cells which is supported by well documented evidences.

Q2 Long polar fimbriae B (LpfB) gene, it’s biological function and relevance to virulence of the strain

The long polar fimbriae genes encode intestinal adhesins and are important virulence factors in pathogenic E-coli. the exact mode of action of lpf is not well known but there’s enough evidence documented about their role in adhesion of EHEC strains to the intestinal epithelium. The presence of lpf alleles in LEE-negative strains shows it’s the potential role as an important adhesin. ‘Long polar fimbriae (Lpf) are found to be involved in the key steps of EHEC pathogenesis, such as adhesion, translocation or inflammation.’ (Valerie et al., Scientific Reports volume 7, Article number: 44655 (2017)). The lpf1 operon contains six genes ( lpfABCC′DE) similar in sequence and gene order to the Salmonella lpfABCDE genes (Navarro-Garcia et al., microbiolspec November 2014 vol. 2 no. 6 doi:10.1128/microbiolspec.EHEC-0008-2013). Also, it has been shown that lpfB1 encoded fimbriae are important for adherence to epithelial cells presence of this operon is closely related to stx2A (https://doi.org/10.3389/fmicb.2018.01416). The German outbreak, virulence gene association study using BRIG, showed the presence of long polar fimbriae, lpf (A, B, D, E), probably encoded by lpf1 operon like 0157:H7 strain.

Taxonomy and function of lpfB protein, UNiprot