scholarly journals Gonorrhea among Men Who Have Sex with Men: Outbreak Caused by a Single Genotype of Erythromycin‐ResistantNeisseria gonorrhoeaewith a Single–Base Pair Deletion in themtrRPromoter Region

2000 ◽  
Vol 181 (6) ◽  
pp. 2080-2082 ◽  
Author(s):  
Minsheng Xia ◽  
William L. H. Whittington ◽  
William M. Shafer ◽  
King K. Holmes
Keyword(s):  
Base Pair ◽  
Single Base ◽  
Base Pair Deletion ◽  
Single Genotype ◽  
Single Base Pair ◽  
Sex With Men

scholarly journals Overexpression of the MtrC-MtrD-MtrE Efflux Pump Due to an mtrR Mutation Is Required for Chromosomally Mediated Penicillin Resistance in Neisseria gonorrhoeae

2002 ◽  
Vol 184 (20) ◽  
pp. 5619-5624 ◽  
Author(s):  
Wendy L. Veal ◽  
Robert A. Nicholas ◽  
William M. Shafer
Keyword(s):  
Neisseria Gonorrhoeae ◽  
Base Pair ◽  
Efflux Pump ◽  
Penicillin Resistance ◽  
Single Base ◽  
Base Pair Deletion ◽  
Resistance To Penicillin ◽  
Single Base Pair ◽  
High Level ◽  
Level Resistance

ABSTRACT The importance of the mtrCDE-encoded efflux pump in conferring chromosomally mediated penicillin resistance on certain strains of Neisseria gonorrhoeae was determined by using genetic derivatives of penicillin-sensitive strain FA19 bearing defined mutations (mtrR, penA, and penB) donated by a clinical isolate (FA6140) expressing high-level resistance to penicillin and antimicrobial hydrophobic agents (HAs). When introduced into strain FA19 by transformation, a single base pair deletion in the mtrR promoter sequence from strain FA6140 was sufficient to provide high-level resistance to HAs (e.g., erythromycin and Triton X-100) but only a twofold increase in resistance to penicillin. When subsequent mutations in penA and porIB were introduced from strain FA6140 into strain WV30 (FA19 mtrR) by transformation, resistance to penicillin increased incrementally up to a MIC of 1.0 μg/ml. Insertional inactivation of the gene (mtrD) encoding the membrane transporter component of the Mtr efflux pump in these transformant strains and in strain FA6140 decreased the MIC of penicillin by 16-fold. Genetic analyses revealed that mtrR mutations, such as the single base pair deletion in its promoter, are needed for phenotypic expression of penicillin and tetracycline resistance afforded by the penB mutation. As penB represents amino acid substitutions within the third loop of the outer membrane PorIB protein that modulate entry of penicillin and tetracycline, the results presented herein suggest that PorIB and the MtrC-MtrD-MtrE efflux pump act synergistically to confer resistance to these antibiotics.

Identification of a single base pair deletion (40 del G) in exon 1 of the ferrochelatase gene in patients with erythropoietic protoporphyria

1993 ◽  
Vol 2 (9) ◽  
pp. 1495-1496 ◽  
Author(s):  
David J. Todd ◽  
Anne E. Hughes ◽  
Kevin T. Ennls ◽  
Alana J. Ward ◽  
Desmond Burrows ◽  
...  
Keyword(s):  
Base Pair ◽  
Erythropoietic Protoporphyria ◽  
Single Base ◽  
Base Pair Deletion ◽  
Exon 1 ◽  
Single Base Pair

scholarly journals SEQUENCING STUDIES OF ICR-170 MUTAGENIC SPECIFICITY IN THE am (NADP-SPECIFIC GLUTAMATE DEHYDROGENASE) GENE OF NEUROSPORA CRASSA

Genetics ◽  
1986 ◽  
Vol 113 (1) ◽  
pp. 45-51
Author(s):  
Philip A Burns ◽  
Jane H Kinnaird ◽  
Brian J Kilbey ◽  
John R S Fincham
Keyword(s):  
Neurospora Crassa ◽  
Base Pair ◽  
Uv Light ◽  
Base Pairs ◽  
Single Base ◽  
Base Pair Deletion ◽  
Dehydrogenase Gene ◽  
Sequencing Studies ◽  
Single Base Pair ◽  
Base Pair Insertion

ABSTRACT The acridine half-mustard ICR-170-induced reversion of the mutant am15, which has a single base-pair deletion, at a frequency of between 9 and 28 × 10-6. In each of three classes of revertants, the mutagen had induced the insertion of a (see PDF) base pair at a (see PDF) site. The mutant am6, which has a single base pair insertion, is known to be revertible, with UV light, by deletion of a (see PDF) base pair at a (see PDF) site. This mutant reverted with ICR-170 at a frequency of 0.1 × 10-6. These results show that ICR-170 is able to induce addition frameshifts in Neurospora crassa within short, monotonous runs of G:C base pairs, but indicate a lack of deletion activity at such sequences.

scholarly journals Novel single base-pair deletion in exon 1 of XK gene leading to McLeod syndrome with chorea, muscle wasting, peripheral neuropathy, acanthocytosis and haemolysis

2014 ◽  
Vol 339 (1-2) ◽  
pp. 220-222 ◽  
Author(s):  
Sarah Wiethoff ◽  
Georgia Xiromerisiou ◽  
Conceição Bettencourt ◽  
Anna Kioumi ◽  
Iakovos Tsiptsios ◽  
...  
Keyword(s):  
Peripheral Neuropathy ◽  
Base Pair ◽  
Muscle Wasting ◽  
Single Base ◽  
Base Pair Deletion ◽  
Exon 1 ◽  
Single Base Pair

A single base-pair deletion in the WFS1 gene causes Wolfram syndrome

2011 ◽  
Vol 24 (5-6) ◽  
Author(s):  
Katherine Pitt ◽  
Chela James ◽  
Inderpal S. Kochar ◽  
Akshay Kapoor ◽  
Shilpi Jain ◽  
...  
Keyword(s):  
Base Pair ◽  
Wolfram Syndrome ◽  
Single Base ◽  
Base Pair Deletion ◽  
Single Base Pair ◽  
Wfs1 Gene

scholarly journals Multiple Mechanisms of Phase Variation of PorA inNeisseria meningitidis

2000 ◽  
Vol 68 (12) ◽  
pp. 6685-6690 ◽  
Author(s):  
Arie van der Ende ◽  
Carla T. P. Hopman ◽  
Jacob Dankert
Keyword(s):  
Sequence Analysis ◽  
Base Pair ◽  
Phase Variation ◽  
The Other ◽  
Body Parts ◽  
Coding Region ◽  
Homopolymeric Tract ◽  
Single Base ◽  
Base Pair Deletion ◽  
Single Base Pair

ABSTRACT Previously, we reported that PorA expression in Neisseria meningitidis is modulated by variation in the length of the homopolymeric tract of guanidine residues between the −35 and −10 regions of the promoter or by deletion of porA. To reveal additional mechanisms of variation in PorA expression, the meningococcal isolates from 41 patients and 19 carriers were studied. In addition, at least 3 meningococcal isolates from different body parts of each of 11 patients were analyzed. Sequence analysis of theporA promoter showed that the spacer between the −35 and −10 regions varies in length between 14 and 24 bp. PorA expression was observed in strains with a porA promoter spacer of 16 to 24 bp. All but one strain with a porA promoter spacer of 16 to 20 bp and undetectable PorA expression have a homopolymeric tract of 8 or 6 instead of 7 adenine residues in the porA coding region. The other PorA-negative strain had a single-base-pair deletion in the coding region. The highest level of PorA expression was observed in strains with a promoter spacer of 17 or 18 bp. PorA expression was reduced twofold in strains with a porA promoter spacer of 16 or 19 bp. Strains with a 16-bp promoter spacer with substitutions in the polyguanidine tract displayed increased levels of PorA expression compared to strains with a homopolymeric tract of guanidine residues in the porA promoter. In conclusion, meningococci display multiple mechanisms for varying PorA expression.

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