Invasive Neisseria meningitidis with decreased susceptibility to fluoroquinolones in South Africa, 2009

A. pleuropneumoniae. We tested this by electrotransformation of A. pleuropneumoniae 4074 with pHN61 as described above. In this transformant, the MICs of lincomycin and clindamycin increased from 16 to 128 mg/L and 4 to 64 mg/L respectively, whereas the MIC of erythromycin was unchanged (1 mg/L). The presence of pHN61 was verified by plasmid extraction and Southern blot hybridization. These results indicate the possibility of pHN61 circulating between strains of H. parasuis and A. pleuropneumoniae. In conclusion, this is the first report describing the presence of the lincosamide-inactivating gene lnu(C) in Gram-negative bacteria, and, specifically, its location on a plasmid rather than the chromosome. The presence of the lnu(C) gene on a plasmid could facilitate the spread of lincosamide resistance between and across Gram-negative bacterial species.