Detection of bacteriocin production by wild-type M. catarrhalis strains. (A) Fifteen M. catarrhalis strains tested for bacteriocin production with strain O35E as the indicator strain. Thirteen of these strains were positive as shown here together with two negative strains (V1118 and O46E). (B) Agarose DNA gel electrophoretic analysis of PCR products obtained from four bacteriocin-positive strains (lane 1, ETSU-5; lane 2, FIN 2341; lane 3, O12E; lane 4, V1120) and 4 bacteriocin-negative strains (lane 6, FIN 2344; lane 7, O35E; lane 8, O46E; lane 9, V1118) with the oligonucleotide primers AA247 (binds within mcbA) and pLQ510-rp1 (binds within mcbC). Lane 5 contains a set of DNA size markers.