Cloning, sequencing and expression of the CAMP factor gene of Streptococcus uberis

The gene coding for the CAMP factor from a strain of Streptococcus uberis (ATCC 9927) was cloned in Escherichia coli. Chromosomal DNA from Streptococcus uberis was used to construct a gene library in plasmid pTZ18R and six CAMP-reaction positive clones were obtained from a total of 10 000 transformants. One clone, pJLD21, was subcloned and the CAMP factor gene was located in a 3.2 kb BamHl fragment. The nucleotide sequence of Streptococcus uberis CAMP factor gene was determined and the deduced amino acid sequence is highly homologous to the corresponding Streptococcus agalactiae protein. Immunoblot analysis revealed that the recombinant strain pJLD21 expressed a protein with a molecular weight of 28 000. Antibodies raised against purified Streptococcus uberis CAMP factor cross-reacted with Streptococcus agalactiae protein B. (C) 1996 Academic Press Limited.