1. The mef(A) gene predominates among seven macrolide resistance genes identified in gram-negative strains representing 13 genera, isolated from healthy Portuguese children.
- Author
-
Ojo KK, Ulep C, Van Kirk N, Luis H, Bernardo M, Leitao J, and Roberts MC
- Subjects
- Child, Conjugation, Genetic genetics, Culture Media, DNA, Bacterial genetics, Drug Resistance, Bacterial, Escherichia coli genetics, Gram-Negative Bacteria drug effects, Humans, Microbial Sensitivity Tests, Mouth microbiology, Portugal epidemiology, Reverse Transcriptase Polymerase Chain Reaction, Urine microbiology, Bacterial Proteins genetics, Gram-Negative Bacteria genetics, Macrolides pharmacology, Membrane Proteins genetics
- Abstract
Of the 176 randomly selected, commensal, gram-negative bacteria isolated from healthy children with low exposure to antibiotics, 138 (78%) carried one or more of the seven macrolide resistance genes tested in this study. These isolates included 79 (91%) isolates from the oral cavity and 59 (66%) isolates from urine samples. The mef(A) gene, coding for an efflux protein, was found in 73 isolates (41%) and was the most frequently carried gene. The mef(A) gene could be transferred from the donors into a gram-positive E. faecalis recipient and a gram-negative Escherichia coli recipient. The erm(B) gene transferred and was maintained in the E. coli transconjugants but was found in 0 to 100% of the E. faecalis transconjugants tested, while the other five genes could be transferred only into the E. coli recipient. The individual macrolide resistance genes were identified in 3 to 12 new genera. Eight (10%) of the oral isolates and 30 (34%) of the urine isolates for which the MICs were 2 to >500 microg of erythromycin per ml did not hybridize with any of the seven genes and may carry novel macrolide resistance genes.
- Published
- 2004
- Full Text
- View/download PDF