Nucleotide sequence and characterization of erythromycin resistance determinant that encodes macrolide 2'-phosphotransferase I in Escherichia coli

ABSTRACT Rickettsia prowazekii, the etiologic agent of epidemic typhus, is an obligate, intracytoplasmic, parasitic bacterium. Recently, the transformation of this bacterium via electroporation has been reported. However, in these studies identification of transformants was dependent upon either selection of an R. prowazekii rpoB chromosomal mutation imparting rifampin resistance or expression of the green fluorescent protein and flow cytometric analysis. In this paper we describe the expression inR. prowazekii of the Escherichia coli ereBgene. This gene codes for an erythromycin esterase that cleaves erythromycin. To the best of our knowledge, this is the first report of the expression of a nonrickettsial, antibiotic-selectable gene inR. prowazekii. The availability of a positive selection for rickettsial transformants is an important step in the characterization of genetic analysis systems in the rickettsiae.

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Aph(3′)-IIc, an Aminoglycoside Resistance Determinant from Stenotrophomonas maltophilia

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.00795-06 ◽

2006 ◽

Vol 51 (1) ◽

pp. 359-360 ◽

Cited By ~ 42

Author(s):

Aki Okazaki ◽

Matthew B. Avison

Keyword(s):

Escherichia Coli ◽

Clinical Isolate ◽

Stenotrophomonas Maltophilia ◽

Resistance Determinant ◽

Aminoglycoside Resistance ◽

Aminoglycoside Phosphotransferase

ABSTRACT We report the characterization of an intrinsic, chromosomally carried aph(3′)-IIc gene from Stenotrophomonas maltophilia clinical isolate K279a, encoding an aminoglycoside phosphotransferase enzyme that significantly increases MICs of kanamycin, neomycin, butirosin, and paromomycin when expressed in Escherichia coli. Disruption of aph(3′)-IIc in K279a results in decreased MICs of these drugs.

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Identification and characterization of ssb and uup mutants with increased frequency of precise excision of transposon Tn10 derivatives: nucleotide sequence of uup in Escherichia coli.

Journal of Bacteriology ◽

10.1128/jb.179.9.2892-2899.1997 ◽

1997 ◽

Vol 179 (9) ◽

pp. 2892-2899 ◽

Cited By ~ 22

Author(s):

M Reddy ◽

J Gowrishankar

Keyword(s):

Escherichia Coli ◽

Nucleotide Sequence ◽

Precise Excision ◽

Identification And Characterization

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Characterization of Mutations Contributing to Sulfathiazole Resistance in Escherichia coli

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.42.1.88 ◽

1998 ◽

Vol 42 (1) ◽

pp. 88-93 ◽

Cited By ~ 39

Author(s):

Gayatri Vedantam ◽

Gordon G. Guay ◽

Natasha E. Austria ◽

Stella Z. Doktor ◽

Brian P. Nichols

Keyword(s):

Escherichia Coli ◽

Amino Acid Position ◽

Resistance Determinant ◽

Nucleotide Sequence Analysis ◽

Wild Type ◽

Secondary Resistance ◽

E Coli ◽

Additional Mutation ◽

Membrane Bound

ABSTRACT A sulfathiazole-resistant dihydropteroate synthase (DHPS) present in two different laboratory strains of Escherichia colirepeatedly selected for sulfathiazole resistance was mapped tofolP by P1 transduction. The folP mutation in each of the strains was shown to be identical by nucleotide sequence analysis. A single C→T transition resulted in a Pro→Ser substitution at amino acid position 64. Replacement of the mutantfolP alleles with wild-type folP significantly reduced the level of resistance to sulfathiazole but did not abolish it, indicating the presence of an additional mutation(s) that contributes to sulfathiazole resistance in the two strains. Transfer of the mutant folP allele to a wild-type background resulted in a strain with only a low level of resistance to sulfathiazole, suggesting that the presence of the resistant DHPS was not in itself sufficient to account for the overall sulfathiazole resistance in these strains of E. coli. Additional characterization of an amplified secondary resistance determinant, sur, present in one of the strains, identified it as the previously identified bicyclomycin resistance determinant bcr, a member of a family of membrane-bound multidrug resistance antiporters. An additional mutation contributing to sulfathiazole resistance,sux, has also been identified and has been shown to affect the histidine response to adenine sensitivity displayed by thesepurU strains.

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