Composite structure of Streptococcus pneumoniae containing the erythromycin efflux resistance gene mefI and the chloramphenicol resistance gene catQ.
In recent years mef genes, encoding efflux pumps responsible for M-type macrolide resistance, have been investigated extensively for streptococci. mef(I) is a recently described mef variant detected in particular isolates of Streptococcus pneumoniae instead of the more common mef(E) and mef(A). This study shows that mef(I) is located in a new composite genetic element, whose sequence was completely analyzed and the left and right junctions determined, demonstrating a unique genetic organization. The new composite structure (30,505 bp), designated the 5216IQ complex, consists of two halves: a left one (15,316 bp) formed by parts of the known transposons Tn5252 and Tn916, and a right one (15,115 bp) formed by a new fragment, designated the IQ element. While the defective Tn916 contained a silent tet(M) gene, the IQ element, ending with identical transposase genes on both sides and containing the mef(I) gene with an adjacent new msr(D) gene variant and a catQ chloramphenicol acetyltransferase gene, was completely different from the genetic elements carrying other mef genes in pneumococci. This is the first report demonstrating catQ in S. pneumoniae and showing its linkage with a mef gene. Analysis of the chromosomal region beyond the left junction revealed an organization more similar to that of S. pneumoniae strain TIGR4 than to that of strain R6. The 5216IQ complex was apparently nonmobile, with no detectable transfer of erythromycin resistance being obtained in repeated transformation and conjugation assays.
Mingoia
Marina
M
Institute of Microbiology and Biomedical Sciences, Polytechnic University of Marche Medical School, Via Tronto 10/A, 60020 Ancona, Italy.
Vecchi
Manuela
M
Cochetti
Ileana
I
Tili
Emily
E
Vitali
Luca A
LA
Manzin
Aldo
A
Varaldo
Pietro E
PE
Montanari
Maria Pia
MP
D000900:Anti-Bacterial Agents / Q000378:metabolism / Q000493:pharmacokinetics / Q000494:pharmacology; D002702:Chloramphenicol Resistance / Q000235:genetics*; D004251:DNA Transposable Elements / Q000235:genetics; D004269:DNA, Bacterial / Q000235:genetics; D024881:Drug Resistance, Bacterial / Q000235:genetics; D004917:Erythromycin / Q000378:metabolism / Q000493:pharmacokinetics / Q000494:pharmacology*; D023061:Gene Order; D005798:Genes, Bacterial / Q000235:genetics; D008826:Microbial Sensitivity Tests; D008969:Molecular Sequence Data; D016366:Open Reading Frames / Q000235:genetics; D016133:Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D013296:Streptococcus pneumoniae / Q000187:drug effects* / Q000235:genetics*
D000900:Anti-Bacterial Agents; D004251:DNA Transposable Elements; D004269:DNA, Bacterial; D004917:Erythromycin
Antimicrob Agents Chemother. 1996 Nov;40(11):2562-6
8913465
Antimicrob Agents Chemother. 1996 Aug;40(8):1817-24
8843287
Antimicrob Agents Chemother. 1997 Oct;41(10):2251-5
9333056
Adv Exp Med Biol. 1997;418:1029-32
9331826
Antimicrob Agents Chemother. 1998 Jun;42(6):1493-4
9624500
Antimicrob Agents Chemother. 1998 Sep;42(9):2312-8
9736555
Antimicrob Agents Chemother. 2005 Oct;49(10):4203-9
16189099
J Antimicrob Chemother. 2005 Nov;56(5):841-6
16172106
Antimicrob Agents Chemother. 2005 Dec;49(12):4999-5006
16304164
J Antimicrob Chemother. 2006 Mar;57(3):443-9
16431859
Antimicrob Agents Chemother. 2007 Apr;51(4):1209-16
17261630
J Antimicrob Chemother. 2007 Jul;60(1):127-31
17483548
Mol Microbiol. 2000 Jan;35(2):251-9
10652087
Antimicrob Agents Chemother. 2000 Sep;44(9):2585-7
10952626
J Infect Dis. 2001 Jul 1;184(1):56-65
11398110
Science. 2001 Jul 20;293(5529):498-506
11463916
Antimicrob Agents Chemother. 2002 Sep;46(9):2727-34
12183222
J Clin Microbiol. 2002 Sep;40(9):3313-8
12202572
Antimicrob Agents Chemother. 2003 Sep;47(9):2844-9
12936983
Microb Drug Resist. 2003 Fall;9(3):243-7
12959402
J Clin Microbiol. 2003 Nov;41(11):5188-91
14605159
J Infect Dis. 2003 Dec 15;188(12):1898-908
14673771
Antimicrob Agents Chemother. 2004 Jun;48(6):2037-42
15155196
J Clin Microbiol. 2004 Aug;42(8):3570-4
15297499
J Bacteriol. 1991 Mar;173(5):1617-22
1847905
Antimicrob Agents Chemother. 1992 Apr;36(4):769-78
1323953
J Bacteriol. 1994 Aug;176(16):5145-50
8051031
Trends Microbiol. 1995 Jun;3(6):229-36
7648031
Mol Microbiol. 1996 Dec;22(5):867-79
8971709