Disease relevance of pefA

• A virulence plasmid was identified in a multidrug-resistant Salmonella enterica serotype Typhimurium strain carrying the spvC, rck, and pefA virulence genes and two class 1 integrons linked to the Tn21 and Tn1696 transposons [1].
• One Enteritidis isolate of phage type 14b which failed to hybridize pefA in dot (colony) hybridization experiments was demonstrated to be plasmid free [2].
• The nucleotide sequence of a DNA fragment that contains the fimA gene, encoding the major fimbrial subunit, of Serratia marcescens IA506 and associated flanking sequences has been elucidated [3].
• For this, the vaccine strain was genetically engineered to express chimeric fimbriae carrying the transmissible gastroenteritis virus (TGEV) C (379-388) and A (521-531) epitopes of the spike protein inserted into the 987P major fimbrial subunit FasA [4].

High impact information on pefA

• Regulation of the gene, fimA, encoding the major fimbrial subunit of S. typhimurium S6704 was examined by using a lambda fimA-lacZ lysogen [5].
• Southern hybridization of plasmids extracted from Enteritidis demonstrated that the pefA gene probe hybridized strongly an atypical SAP of 80 kb in size harboured by one Enteritidis isolate of phage-type 9b, whereas the typical SAP of 58 kb in size harboured by 48 Enteritidis isolates hybridized weakly [2].
• The pefA gene which encoded the serotype associated plasmid (SAP) mediated fimbrial major subunit antigen of Salmonella enterica serotype Typhimurium shared genetic identity with 128 of 706 salmonella isolates as demonstrated by dot (colony) hybridization [2].
• Nucleotide sequence analysis demonstrated that the pefA alleles of Typhimurium and Enteritidis phage-type 4 shared 76% DNA nucleotide and 82% deduced amino acid sequence identity [2].
• The cstAH gene cluster determining CS3 biosynthesis has been previously cloned and sequenced and it has been shown that cstH encodes the major fimbrial subunit and cstA-G encode an assembly cassette [6].

References