Identification of the conjugative mef gene in clinical Acinetobacter juniiand Neisseria gonorrhoeae isolates

The mef gene, originally described for gram-positive organisms and coding f or an efflux pump, has been identified in clinical isolates of Acinetobacte r junii and Neisseria gonorrhoeae. These strains could transfer the mef gen e at frequencies ranging from 10(-6) to 10(-9) into one or more of the foll owing recipients: gram-negative Moraxella catarrhalis, Neisseria perflava/s icca and Neisseria mucosa and gram-positive Enterococcus faecalis. Three St reptococcus pneumoniae strains could transfer the mef gene into Eikenella c orrodens, Haemophilus influenzae, Kingella denitrificans, M. catarrhalis, N eisseria meningitidis, N. perflava/sicca, and N. mucosa at similar frequenc ies. The mef gene can thus be transferred to and expressed in a variety of gram-negative recipients.