Another gene commonly used in the development of STEC-specific DNA sensors is the eaeA gene which codes for intimin production allowing for bacteria attachment to mucous cells . Recent studies, however, concluded that the presence of this gene is not essential to cause a severe illness, showing that not all STEC causing illness outbreaks had this gene present (EFSA Panel on Biological . Less often, other virulence factors were used such as the rfbE gene coding for an O-antigen synthesis for O157 serotype, shown in the work of . An ideal STEC detection technique should, however, focus on all serotypes which potentially cause the infection. Another virulence gene was chosen by . In their sensor, STEC O157 was detected using the z3276 gene which is known for encoding a unique putative fimbrial protein allowing the adhesion to the host cell. This gene is, however, only specific to STEC O157 serotype as well which means it would fail to recognise other, potentially pathogenic STEC strains.