scholarly journals 16S rRNA Gene Mutations Associated with Decreased Susceptibility to Tetracycline in Mycoplasma bovis

2014 ◽  
Vol 59 (2) ◽  
pp. 796-802 ◽  
Author(s):  
E. Amram ◽  
I. Mikula ◽  
C. Schnee ◽  
R. D. Ayling ◽  
R. A. J. Nicholas ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
16S Rrna ◽  
Molecular Mechanisms ◽  
Gene Mutations ◽  
Binding Pocket ◽  
Clinical Isolates ◽  
Mycoplasma Bovis ◽  
Rrna Gene ◽  
Content Type ◽  
Encoding Genes

ABSTRACTMycoplasma bovisisolates with decreased susceptibilities to tetracyclines are increasingly reported worldwide. The acquired molecular mechanisms associated with this phenomenon were investigated in 70 clinical isolates ofM. bovis. Sequence analysis of the two 16S rRNA-encoding genes (rrs3andrrs4alleles) containing the primary binding pocket for tetracycline (Tet-1 site) was performed on isolates with tetracycline hydrochloride MICs of 0.125 to 16 μg/ml. Mutations at positions A965T, A967T/C (Escherichia colinumbering) of helix 31, U1199C of helix 34, and G1058A/C were identified. Decreased susceptibilities to tetracycline (MICs, ≥2 μg/ml) were associated with mutations present at two (A965 and A967) or three positions (A965, A967, and G1058) of the tworrsalleles. Notet(M),tet(O), ortet(L) determinants were found in the genome of any of the 70M. bovisisolates. The data presented correlate (P< 0.0001) the mutations identified in the Tet-1 site of clinical isolates ofM. boviswith decreased susceptibility to tetracycline.

scholarly journals Association between 16S rRNA gene mutations and susceptibility to amikacin in Mycobacterium avium Complex and Mycobacterium abscessus clinical isolates

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Su-Young Kim ◽  
Dae Hun Kim ◽  
Seong Mi Moon ◽  
Ju Yeun Song ◽  
Hee Jae Huh ◽  
...  
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Mycobacterium Avium ◽  
Inhibitory Concentration ◽  
Gene Mutations ◽  
Mycobacterium Abscessus ◽  
Clinical Isolates ◽  
Rrna Gene ◽  
High Level ◽  
Culture Conversion

AbstractWe evaluated the association between 16S rRNA gene (rrs) mutations and susceptibility in clinical isolates of amikacin-resistant nontuberculous mycobacteria (NTM) in NTM-pulmonary disease (PD) patients. Susceptibility was retested for 134 amikacin-resistant isolates (minimum inhibitory concentration [MIC] ≥ 64 µg/ml) from 86 patients. Amikacin resistance was reconfirmed in 102 NTM isolates from 62 patients with either Mycobacterium avium complex-PD (MAC-PD) (n = 54) or M. abscessus-PD (n = 8). MICs and rrs mutations were evaluated for 318 single colonies from these isolates. For the 54 MAC-PD patients, rrs mutations were present in 34 isolates (63%), comprising all 31 isolates with amikacin MICs ≥ 128 µg/ml, but only three of 23 isolates with an MIC = 64 µg/ml. For the eight M. abscessus-PD patients, all amikacin-resistant (MIC ≥ 64 µg/ml) isolates had rrs mutations. In amikacin-resistant isolates, the A1408G mutation (n = 29) was most common. Two novel mutations, C1496T and T1498A, were also identified. The culture conversion rate did not differ by amikacin MIC. Overall, all high-level and 13% (3/23) of low-level amikacin-resistant MAC isolates had rrs mutations whereas mutations were present in all amikacin-resistant M. abscessus isolates. These findings are valuable for managing MAC- and M. abscessus-PD and suggest the importance of phenotypic and genotypic susceptibility testing.

scholarly journals Systematic Nomenclature for GGDEF and EAL Domain-Containing Cyclic Di-GMP Turnover Proteins of Escherichia coli: TABLE 1

2015 ◽  
Vol 198 (1) ◽  
pp. 7-11 ◽  
Author(s):  
Regine Hengge ◽  
Michael Y. Galperin ◽  
Jean-Marc Ghigo ◽  
Mark Gomelsky ◽  
Jeffrey Green ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Molecular Mechanisms ◽  
Bacterial Species ◽  
Content Type ◽  
E Coli ◽  
Diguanylate Cyclases ◽  
Genes Encoding ◽  
Systematic Nomenclature ◽  
K 12 ◽  
Encoding Genes

In recent years,Escherichia colihas served as one of a few model bacterial species for studying cyclic di-GMP (c-di-GMP) signaling. The widely usedE. coliK-12 laboratory strains possess 29 genes encoding proteins with GGDEF and/or EAL domains, which include 12 diguanylate cyclases (DGC), 13 c-di-GMP-specific phosphodiesterases (PDE), and 4 “degenerate” enzymatically inactive proteins. In addition, six new GGDEF and EAL (GGDEF/EAL) domain-encoding genes, which encode two DGCs and four PDEs, have recently been found in genomic analyses of commensal and pathogenicE. colistrains. As a group of researchers who have been studying the molecular mechanisms and the genomic basis of c-di-GMP signaling inE. coli, we now propose a general and systematicdgcandpdenomenclature for the enzymatically active GGDEF/EAL domain-encoding genes of this model species. This nomenclature is intuitive and easy to memorize, and it can also be applied to additional genes and proteins that might be discovered in various strains ofE. coliin future studies.

scholarly journals Phenotypic, Genotypic, and Antimicrobial Characteristics of Streptococcus halichoeri Isolates from Humans, Proposal To Rename Streptococcus halichoeri as Streptococcus halichoeri subsp. halichoeri, and Description of Streptococcus halichoeri subsp. hominis subsp. nov., a Bacterium Associated with Human Clinical Infections

2016 ◽  
Vol 54 (3) ◽  
pp. 739-744 ◽  
Author(s):  
P. L. Shewmaker ◽  
A. M. Whitney ◽  
B. W. Humrighouse
Keyword(s):  
16S Rrna ◽  
Type Strain ◽  
Sequence Similarity ◽  
Clinical Isolates ◽  
Whole Genome Sequence ◽  
Rrna Gene ◽  
Whole Genome ◽  
Sequencing Analysis ◽  
Whole Genome Analysis ◽  
Content Type

Phenotypic, genotypic, and antimicrobial characteristics of six phenotypically distinct human clinical isolates that most closely resembled the type strain ofStreptococcus halichoeriisolated from a seal are presented. Sequencing of the 16S rRNA,rpoB,sodA, andrecNgenes; comparative whole-genome analysis; conventional biochemical and Rapid ID 32 Strep identification methods; and antimicrobial susceptibility testing were performed on the human isolates, the type strain ofS.halichoeri, and type strains of closely related species. The six human clinical isolates were biochemically indistinguishable from each other and showed 100% 16S rRNA,rpoB,sodA, andrecNgene sequence similarity. Comparative 16S rRNA gene sequencing analysis revealed 98.6% similarity toS. halichoeriCCUG 48324T, 97.9% similarity toS. canisATCC 43496T, and 97.8% similarity toS. ictaluriATCC BAA-1300T. A 3,530-bp fragment of therpoBgene was 98.8% similar to theS. halichoeritype strain, 84.6% to theS. canistype strain, and 83.8% to theS.ictaluritype strain. TheS. halichoeritype strain and the human clinical isolates were susceptible to the antimicrobials tested based on CLSI guidelines forStreptococcusspecies viridans group with the exception of tetracycline and erythromycin. The human isolates were phenotypically distinct from the type strain isolated from a seal; comparative whole-genome sequence analysis confirmed that the human isolates wereS. halichoeri. On the basis of these results, a novel subspecies,Streptococcushalichoerisubsp.hominis, is proposed for the human isolates andStreptococcus halichoerisubsp.halichoeriis proposed for the gray seal isolates. The type strain of the novel subspecies is SS1844T= CCUG 67100T= LMG 28801T.

scholarly journals Mutations in a 23S rRNA Gene of Chlamydia trachomatis Associated with Resistance to Macrolides

2004 ◽  
Vol 48 (4) ◽  
pp. 1347-1349 ◽  
Author(s):  
O. Y. Misyurina ◽  
E. V. Chipitsyna ◽  
Y. P. Finashutina ◽  
V. N. Lazarev ◽  
T. A. Akopian ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Chlamydia Trachomatis ◽  
Gene Mutations ◽  
Clinical Isolates ◽  
23S Rrna ◽  
Rrna Gene ◽  
In Vitro Susceptibility ◽  
23S Rrna Gene ◽  
Mixed Populations

ABSTRACT For six clinical isolates of Chlamydia trachomatis, in vitro susceptibility to erythromycin, azithromycin, and josamycin has been determined. Four isolates were resistant to all the antibiotics and had the mutations A2058C and T2611C (Escherichia coli numbering) in the 23S rRNA gene. All the isolates had mixed populations of bacteria that did and did not carry 23S rRNA gene mutations.

scholarly journals Emergence of Various NDM-Type-Metallo-β-Lactamase-Producing Escherichia coli Clinical Isolates in Nepal

2017 ◽  
Vol 61 (12) ◽  
Author(s):  
Basudha Shrestha ◽  
Tatsuya Tada ◽  
Kayo Shimada ◽  
Shovita Shrestha ◽  
Hiroshi Ohara ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
16S Rrna ◽  
Clinical Isolates ◽  
Content Type ◽  
Carbapenem Resistant ◽  
Methylase Gene ◽  
16S Rrna Methylase

ABSTRACT Of 250 clinical isolates of Escherichia coli obtained in Nepal, 38 were carbapenem resistant, with MICs of imipenem or meropenem of ≥4 μg/ml. All 38 isolates harbored the following bla NDMs: bla NDM-1, bla NDM-3, bla NDM-4, bla NDM-5, bla NDM-7, bla NDM-12, and bla NDM-13. Most of these isolates also harbored the 16S rRNA methylase gene(s) armA, rmtB, and/or rmtC.

scholarly journals Association Between 16S rRNA Gene Mutations and Susceptibility to Amikacin in Mycobacterium avium Complex and Mycobacterium Abscessus Clinical Isolates

2020 ◽  
Author(s):  
Su-Young Kim ◽  
Dae Hun Kim ◽  
Seong Mi Moon ◽  
Ju Yeun Song ◽  
Hee Jae Huh ◽  
...  
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Mycobacterium Avium ◽  
Inhibitory Concentration ◽  
Gene Mutations ◽  
Mycobacterium Abscessus ◽  
Clinical Isolates ◽  
Rrna Gene ◽  
Novel Mutations ◽  
Culture Conversion

Abstract We evaluated the association between 16S rRNA gene (rrs) mutations and susceptibility in amikacin-resistant nontuberculous mycobacterial (NTM) clinical isolates in NTM- pulmonary disease (PD) patients. Susceptibility was retested for 134 amikacin-resistant isolates (minimum inhibitory concentration [MIC] ≥64 µg/ml) from 86 patients. Amikacin resistance was reconfirmed in 102 NTM isolates from 62 patients with either Mycobacterium avium complex-PD (MAC-PD) (n=54) or M. abscessus-PD (n=8). MIC and rrs mutations were evaluated for 318 single colonies from these isolates. For the 54 MAC-PD patients, rrs mutations were present in all isolates (obtained from 31 patients) with an amikacin MIC ≥128 µg/ml, but only in a few isolates (from three of 23 patients) with an MIC=64 µg/ml. For the eight M. abscessus-PD patients, all amikacin-resistant isolates (MIC ≥64 µg/ml) had rrs mutations. Of amikacin resistance isolates, A1408G mutation (n=29) was most common. Two novel mutations, C1496T and T1498A, were also identified. The culture conversion rate did not differ by amikacin MIC (20% for MIC=64µg/ml vs. 7% for MIC ≥128 µg/ml, p=0.468). In conclusion, all amikacin-resistant M. abscessus isolates had rrs mutations, but in MAC isolates showing relatively low resistance (MIC=64µg/ml), rrs mutations were infrequently identified.

scholarly journals Trends towards Lower Antimicrobial Susceptibility and Characterization of Acquired Resistance among Clinical Isolates of Brachyspira hyodysenteriae in Spain

2011 ◽  
Vol 55 (7) ◽  
pp. 3330-3337 ◽  
Author(s):  
Álvaro Hidalgo ◽  
Ana Carvajal ◽  
Birte Vester ◽  
Märit Pringle ◽  
Germán Naharro ◽  
...  
Keyword(s):  
Antimicrobial Susceptibility ◽  
Molecular Mechanisms ◽  
Tandem Repeats ◽  
Point Mutations ◽  
Clinical Isolates ◽  
23S Rrna ◽  
Rrna Gene ◽  
Content Type ◽  
Brachyspira Hyodysenteriae ◽  
23S Rrna Gene

ABSTRACTThe antimicrobial susceptibility of clinical isolates ofBrachyspira hyodysenteriaein Spain was monitored, and the underlying molecular mechanisms of resistance were investigated. MICs of tylosin, tiamulin, valnemulin, lincomycin, and tylvalosin were determined for 87B. hyodysenteriaeisolates recovered from 2008 to 2009 by broth dilution. Domain V of the 23S rRNA gene and the ribosomal protein L3 gene were sequenced in 20 isolates for which the tiamulin MIC was ≥4 μg/ml, presenting decreased susceptibility, and in 18 tiamulin-susceptible isolates (MIC ≤ 0.125 μg/ml), and all isolates were typed by multiple-locus variable-number tandem repeats analysis. A comparison with antimicrobial susceptibility data from 2000 to 2007 showed an increase in pleuromutilin resistance over time, doubling the number of isolates with decreased susceptibility to tiamulin. No alteration in susceptibility was detected for lincomycin, and the MIC of tylosin remained high (MIC50> 128 μg/ml). The decreased susceptibility to tylosin and lincomycin can be explained by mutations at position A2058 of the 23S rRNA gene (Escherichia colinumbering). A2058T was the predominant mutation, but A2058G also was found together with a change of the neighboring base pair at positions 2057 to 2611. The role of additional point mutations in the vicinity of the peptidyl transferase center and mutations in the L3 at amino acids 148 and 149 and their possible involvement in antimicrobial susceptibility are considered. An association between G2032A and high levels of tiamulin and lincomycin MICs was found, suggesting an increasing importance of this mutation in antimicrobial resistance of clinical isolates ofB. hyodysenteriae.

scholarly journals Heterologous Expression and Functional Characterization of the Exogenously Acquired Aminoglycoside Resistance Methyltransferases RmtD, RmtD2, and RmtG

2015 ◽  
Vol 60 (1) ◽  
pp. 699-702 ◽  
Author(s):  
Laís L. Corrêa ◽  
Marta A. Witek ◽  
Natalia Zelinskaya ◽  
Renata C. Picão ◽  
Graeme L. Conn
Keyword(s):  
Escherichia Coli ◽  
Protein Structure ◽  
16S Rrna ◽  
Recombinant Proteins ◽  
Molecular Mechanisms ◽  
Substrate Recognition ◽  
Functional Characterization ◽  
Aminoglycoside Resistance ◽  
Content Type

ABSTRACTThe exogenously acquired 16S rRNA methyltransferases RmtD, RmtD2, and RmtG were cloned and heterologously expressed inEscherichia coli, and the recombinant proteins were purified to near homogeneity. Each methyltransferase conferred an aminoglycoside resistance profile consistent with m7G1405 modification, and this activity was confirmed byinvitro30S methylation assays. Analyses of protein structure and interaction withS-adenosyl-l-methionine suggest that the molecular mechanisms of substrate recognition and catalysis are conserved across the 16S rRNA (m7G1405) methyltransferase family.

scholarly journals Identification of New Single Nucleotide Polymorphism-Based Markers for Inter- and Intraspecies Discrimination of Obligate Bacterial Parasites (Pasteuria spp.) of Invertebrates

2011 ◽  
Vol 77 (18) ◽  
pp. 6388-6394 ◽  
Author(s):  
Tim H. Mauchline ◽  
Rachel Knox ◽  
Sharad Mohan ◽  
Stephen J. Powers ◽  
Brian R. Kerry ◽  
...  
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
The Other ◽  
Rrna Genes ◽  
Rrna Gene ◽  
Single Nucleotide ◽  
Content Type ◽  
Protein Encoding ◽  
Encoding Genes ◽  
The 16S Rrna Gene

ABSTRACTProtein-encoding and 16S rRNA genes ofPasteuria penetranspopulations from a wide range of geographic locations were examined. Most interpopulation single nucleotide polymorphisms (SNPs) were detected in the 16S rRNA gene. However, in order to fully resolve all populations, these were supplemented with SNPs from protein-encoding genes in a multilocus SNP typing approach. Examination of individual 16S rRNA gene sequences revealed the occurrence of “cryptic” SNPs which were not present in the consensus sequences of anyP. penetranspopulation. Additionally, hierarchical cluster analysis separatedP. penetrans16S rRNA gene clones into four groups, and one of which contained sequences from the most highly passaged population, demonstrating that it is possible to manipulate the population structure of this fastidious bacterium. The other groups were made from representatives of the other populations in various proportions. Comparison of sequences among threePasteuriaspecies, namely,P. penetrans,P. hartismeri, andP. ramosa, showed that the protein-encoding genes provided greater discrimination than the 16S rRNA gene. From these findings, we have developed a toolbox for the discrimination ofPasteuriaat both the inter- and intraspecies levels. We also provide a model to monitor genetic variation in other obligate hyperparasites and difficult-to-culture microorganisms.

scholarly journals Retrospective Molecular Analysis of DIM-1 Metallo-β-Lactamase Discovered in Pseudomonas stutzeri from India in 2000

2013 ◽  
Vol 58 (1) ◽  
pp. 596-598 ◽  
Author(s):  
Lalitagauri M. Deshpande ◽  
Ronald N. Jones ◽  
Leah N. Woosley ◽  
Mariana Castanheira
Keyword(s):  
Molecular Analysis ◽  
Pseudomonas Stutzeri ◽  
Clinical Isolates ◽  
Gram Negative ◽  
Content Type ◽  
Environmental Source ◽  
Lactamase Gene ◽  
Encoding Genes

ABSTRACTAmong 220 clinical isolates of Gram-negative bacilli collected in India during 2000, 22 strains showing elevated imipenem MICs were evaluated for carbapenemase production. One DIM-1-producingPseudomonas stutzeriisolate was detected, and no other carbapenemase-encoding genes were identified. This detection of a DIM-1-producingP. stutzeriisolate from India predating the finding of this gene in the index Dutch strain and the very recent detection of DIM-1 in Africa suggest an unidentified environmental source of this metallo-β-lactamase gene.

Sign in / Sign up

Export Citation Format

Share Document