23S rRNA Gene Mutations Contributing to Macrolide Resistance inCampylobacter jejuniandCampylobacter coli

2009 ◽  
Vol 6 (1) ◽  
pp. 91-98 ◽  
Author(s):  
Scott R. Ladely ◽  
Richard J. Meinersmann ◽  
Mark D. Englen ◽  
Paula J. Fedorka-Cray ◽  
Mark A. Harrison
Keyword(s):  
Gene Mutations ◽  
Macrolide Resistance ◽  
23S Rrna ◽  
Rrna Gene ◽  
23S Rrna Gene

scholarly journals Utility of Sequencing theerm(41) Gene in Isolates of Mycobacterium abscessus subsp. abscessus with Low and Intermediate Clarithromycin MICs

2015 ◽  
Vol 53 (4) ◽  
pp. 1211-1215 ◽  
Author(s):  
Barbara A. Brown-Elliott ◽  
Sruthi Vasireddy ◽  
Ravikiran Vasireddy ◽  
Elena Iakhiaeva ◽  
Susan T. Howard ◽  
...  
Keyword(s):  
Nucleotide Substitution ◽  
Gene Mutations ◽  
Mycobacterium Abscessus ◽  
Macrolide Resistance ◽  
23S Rrna ◽  
Rrna Gene ◽  
Content Type ◽  
23S Rrna Gene ◽  
Content Sequencing

Theerm(41) gene confers inducible macrolide resistance inMycobacterium abscessussubsp.abscessus, calling into question the usefulness of macrolides for treatingM. abscessussubsp.abscessusinfections. With an extended incubation (14 days), isolates with MICs of ≥8 μg/ml are considered macrolide resistant by current CLSI guidelines. Our goals were to determine the incidence of macrolide susceptibility in U.S. isolates, the validity of currently accepted MIC breakpoints, and theerm(41) sequences associated with susceptibility. Of 349 isolates (excluding those with 23S rRNA gene mutations), 85 (24%) had clarithromycin MICs of ≤8 μg/ml. Sequencing of theerm(41) genes from these isolates, as well as from isolates with MICs of ≥16 μg/ml, including ATCC 19977T, revealed 10 sequevars. The sequence in ATCC 19977Twas designated sequevar (type) 1; most macrolide-resistant isolates were of this type. Seven sequevars contained isolates with MICs of >16 μg/ml. The T28C substitution inerm(41), previously associated with macrolide susceptibility, was identified in 62 isolates (18%) comprising three sequevars, with MICs of ≤2 (80%), 4 (10%), and 8 (10%) μg/ml. No other nucleotide substitution was associated with macrolide susceptibility. We recommend that clarithromycin susceptibility breakpoints forM. abscessussubsp.abscessusbe changed from ≤2 to ≤4 μg/ml and that isolates with an MIC of 8 μg/ml have repeat MIC testing orermsequencing performed. Our studies suggest that macrolides are useful for treating approximately 20% of U.S. isolates ofM. abscessussubsp.abscessus. Sequencing of theermgene ofM. abscessussubsp.abscessuswill predict inducible macrolide susceptibility.

scholarly journals Differences in the Frequency of 23S rRNA Gene Mutations in Mycoplasma pneumoniae between Children and Adults with Community-Acquired Pneumonia: Clinical Impact of Mutations Conferring Macrolide Resistance

2012 ◽  
Vol 56 (12) ◽  
pp. 6393-6396 ◽  
Author(s):  
Soo Jin Yoo ◽  
Hyo-Bin Kim ◽  
Sang-Ho Choi ◽  
Sang-Oh Lee ◽  
Sung-Han Kim ◽  
...  
Keyword(s):  
Mycoplasma Pneumoniae ◽  
Pediatric Patients ◽  
Gene Mutations ◽  
Community Acquired Pneumonia ◽  
Clinical Impact ◽  
Macrolide Resistance ◽  
23S Rrna ◽  
Rrna Gene ◽  
Content Type ◽  
23S Rrna Gene

ABSTRACTWe investigated the frequency and clinical significance of macrolide resistance in adult and pediatric patients with community-acquired pneumonia from aMycoplasma pneumoniaeinfection. The frequency of the A2063G mutation in the 23S rRNA gene was significantly higher in children than in adults (61.3% [19/31] and 13.3% [8/60], respectively;P< 0.001). Patients with macrolide-resistantM. pneumoniaeinfections showed a longer duration of fever (P= 0.021) and required a longer duration of antibiotic treatment (P= 0.007).

scholarly journals Molecular Basis of Macrolide Resistance inCampylobacterStrains Isolated from Poultry in South Korea

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Bai Wei ◽  
Min Kang
Keyword(s):  
Molecular Mechanisms ◽  
Macrolide Resistance ◽  
23S Rrna ◽  
Rrna Gene ◽  
Campylobacter Coli ◽  
Erythromycin Resistance ◽  
23S Rrna Gene ◽  
Ribosomal Protein L22 ◽  
Resistant Strains ◽  
Azithromycin Resistance

We investigated the molecular mechanisms underlying macrolide resistance in 38 strains ofCampylobacterisolated from poultry. Twenty-seven strains were resistant to azithromycin and erythromycin, five showed intermediate azithromycin resistance and erythromycin susceptibility, and six showed azithromycin resistance and erythromycin susceptibility. FourCampylobacter jejuniand sixCampylobacter colistrains had azithromycin MICs which were 8–16 and 2–8-fold greater than those of erythromycin, respectively. The A2075G mutation in the 23S rRNA gene was detected in 11 resistant strains with MICs ranging from 64 to ≥ 512μg/mL. Mutations including V137A, V137S, and a six-amino acid insertion (114-VAKKAP-115) in ribosomal protein L22 were detected in theC. jejunistrains. Erythromycin ribosome methylase B-erm(B) was not detected in any strain. All strains except three showed increased susceptibility to erythromycin with twofold to 256-fold MIC change in the presence of phenylalanine arginine ß-naphthylamide (PAßN); the effects of PAßN on azithromycin MICs were limited in comparison to those on erythromycin MICs, and 13 strains showed no azithromycin MIC change in the presence of PAßN. Differences between azithromycin and erythromycin resistance and macrolide resistance phenotypes and genotypes were observed even in highly resistant strains. Further studies are required to better understand macrolide resistance inCampylobacter.

scholarly journals Effect of 23S rRNA gene mutations in Mycoplasma pneumoniae on severity of community-­acquired pneumonia in young adult patients treated at the Smolensk military hospital

2020 ◽  
Vol 22 (4) ◽  
pp. 306-312
Author(s):  
O.V. Ivanova ◽  
Inna A. Edelstein ◽  
O.I. Romashov ◽  
Roman S. Kozlov
Keyword(s):  
Young Adult ◽  
Mycoplasma Pneumoniae ◽  
Gene Mutations ◽  
Community Acquired Pneumonia ◽  
Adult Patients ◽  
23S Rrna ◽  
Military Hospital ◽  
Rrna Gene ◽  
Resistant Genotype ◽  
23S Rrna Gene

Objective. To evaluate effect of 23S rRNA gene mutations in Mycoplasma pneumoniae on severity of community-acquired pneumonia (CAP) in young adult patients. Materials and Methods. A total of 42 case histories of young adult patients with CAP treated at the Smolensk military hospital over the period of 25 October 2017 to 25 December 2019 were reviewed. «AmpliSens® Mycoplasma pneumoniae/Chlamydophila pneumoniae-FL» real-time PCR kit was used to detect M. pneumoniae from nasopharyngeal swabs collected prior to antimicrobial therapy. Testing for 23S rRNA gene mutations conferring macrolide resistance was performed by real-time PCR melt curve analysis (patent no. 2646123) and confirmed by DNA sequencing. Results. All patients had a clinical picture of non-severe CAP on hospital admission. All patients were treated with standard doses of azithromycin or clarithromycin. No respiratory failure or any other complications were observed. Macrolide-resistant genotype of M. pneumoniae was detected in 4 (9.5%) patients. Clinical, laboratory and radiological resolution of pneumonia in all cases occurred on day 10– 16, regardless of the presence of macrolide-resistant genotype. Conclusions. There were no differences in clinical course of severity between CAP caused by M. pneumoniae with 23S rRNA gene mutation and CAP caused by wild-type M. pneumoniae The presence of mutations in the 23S rRNA gene of M. pneumoniae did not worsen the clinical course of CAP.

scholarly journals Macrolide Resistance in Campylobacter jejuni and Campylobacter coli: Molecular Mechanism and Stability of the Resistance Phenotype

2005 ◽  
Vol 49 (7) ◽  
pp. 2753-2759 ◽  
Author(s):  
Amera Gibreel ◽  
Veronica N. Kos ◽  
Monika Keelan ◽  
Cathy A. Trieber ◽  
Simon Levesque ◽  
...  
Keyword(s):  
Campylobacter Jejuni ◽  
Target Gene ◽  
Macrolide Resistance ◽  
23S Rrna ◽  
Rrna Gene ◽  
Campylobacter Coli ◽  
Resistance Level ◽  
Resistance Phenotype ◽  
E Coli ◽  
23S Rrna Gene

ABSTRACT A collection of 23 macrolide-resistant Campylobacter isolates from different geographic areas was investigated to determine the mechanism and stability of macrolide resistance. The isolates were identified as Campylobacter jejuni or Campylobacter coli based on the results of the hippurate biochemical test in addition to five PCR-based genotypic methods. Three point mutations at two positions within the peptidyl transferase region in domain V of the 23S rRNA gene were identified. About 78% of the resistant isolates exhibited an A→G transition at Escherichia coli equivalent base 2059 of the 23S rRNA gene. The isolates possessing this mutation showed a wide range of erythromycin and clarithromycin MICs. Thus, this mutation may incur a greater probability of treatment failure in populations infected by resistant Campylobacter isolates. Another macrolide-associated mutation (A→C transversion), at E. coli equivalent base 2058, was detected in about 13% of the isolates. An A→G transition at a position cognate with E. coli 23S rRNA base 2058, which is homologous to the A2142G mutation commonly described in Helicobacter pylori, was also identified in one of the C. jejuni isolates examined. In the majority of C. jejuni isolates, the mutations in the 23S rRNA gene were homozygous except in two cases where the mutation was found in two of the three copies of the target gene. Natural transformation demonstrated the transfer of the macrolide resistance phenotype from a resistant Campylobacter isolate to a susceptible Campylobacter isolate. Growth rates of the resulting transformants containing A-2058→C or A-2059→G mutations were similar to that of the parental isolate. The erythromycin resistance of six of seven representative isolates was found to be stable after successive subculturing in the absence of erythromycin selection pressure regardless of the resistance level, the position of the mutation, or the number of the mutated copies of the target gene. One C. jejuni isolate showing an A-2058→G mutation, however, reverted to erythromycin and clarithromycin susceptibility after 55 subcultures on erythromycin-free medium. Investigation of ribosomal proteins L4 and L22 by sequence analysis in five representative isolates of C. jejuni and C. coli demonstrated no significant macrolide resistance-associated alterations in either the L4 or the L22 protein that might explain either macrolide resistance or enhancement of the resistance level.

scholarly journals Intrinsic Macrolide Resistance in Mycobacterium smegmatis Is Conferred by a Novel erm Gene, erm(38)

2003 ◽  
Vol 47 (10) ◽  
pp. 3053-3060 ◽  
Author(s):  
Kevin A. Nash
Keyword(s):  
Mycobacterium Smegmatis ◽  
Sequence Data ◽  
Macrolide Resistance ◽  
23S Rrna ◽  
Cross Resistance ◽  
Rrna Gene ◽  
Mycobacterium Fortuitum ◽  
Knockout Mutant ◽  
23S Rrna Gene ◽  
High Level

ABSTRACT High-level, acquired macrolide resistance in mycobacteria is conferred by mutation within the 23S rRNA gene. However, several mycobacteria are naturally resistant to macrolides, including the Mycobacterium smegmatis group and Mycobacterium tuberculosis complex. Thus, the aim of this study was to characterize this resistance. Intrinsic macrolide resistance in M. smegmatis was inducible and showed cross-resistance to lincosamides but not to streptogramin B (i.e., ML resistance). A similar phenotype was found with Mycobacterium microti and macrolide-resistant Mycobacterium fortuitum. A search of the DNA sequence data for M. smegmatis strain mc2155 identified a novel erm gene, erm(38), and expression analysis showed that erm(38) RNA levels increased >10-fold after a 2-h incubation with macrolide. Inducible ML resistance was not expressed by an erm(38) knockout mutant, and complementation of this mutant with intact erm(38) in trans resulted in high-level ML resistance (e.g., clarithromycin MIC of >512 μg/ml). Thus, the results indicate that erm(38) confers the intrinsic ML resistance of M. smegmatis. Southern blot analysis with an erm(38)-specific probe indicated that a similar gene may be present in macrolide-resistant M. fortuitum. This finding, with the presence of the erm(37) gene (Rv1988) in the M. tuberculosis complex, suggests that such genes are widespread in mycobacteria with intrinsic macrolide resistance.

Antimicrobial susceptibility and mechanisms of high-level macrolide resistance in clinical isolates of Moraxella nonliquefaciens

2014 ◽  
Vol 63 (2) ◽  
pp. 242-247 ◽  
Author(s):  
Shotaro Nonaka ◽  
Kosuke Matsuzaki ◽  
Tomoya Kazama ◽  
Hiroyuki Nishiyama ◽  
Yoko Ida ◽  
...  
Keyword(s):  
Antimicrobial Susceptibility ◽  
Ribosomal Proteins ◽  
Macrolide Resistance ◽  
Clinical Isolates ◽  
23S Rrna ◽  
Rrna Gene ◽  
Efflux System ◽  
Strong Activity ◽  
23S Rrna Gene ◽  
High Level

We investigated antimicrobial susceptibility and the molecular mechanism involved in conferring high-level macrolide resistance in 47 clinical isolates of Moraxella nonliquefaciens from Japan. Antimicrobial susceptibility was determined using Etest and agar dilution methods. Thirty-two erythromycin-non-susceptible strains were evaluated for the possibility of clonal spreading, using PFGE. To analyse the mechanism related to macrolide resistance, mutations in the 23S rRNA gene and the ribosomal proteins, and the presence of methylase genes were investigated by PCR and sequencing. The efflux system was examined using appropriate inhibitors. Penicillin, ampicillin, amoxicillin, cefixime, levofloxacin and antimicrobials containing β-lactamase inhibitors showed strong activity against 47 M. nonliquefaciens isolates. Thirty-two (68.1 %) of the 47 isolates showed high-level MICs to macrolides (MIC ≥128 mg l−1) and shared the A2058T mutation in the 23S rRNA gene. The geometric mean MIC to macrolides of A2058T-mutated strains was significantly higher than that of WT strains (P<0.0001). Thirty-two isolates with high-level macrolide MICs clustered into 30 patterns on the basis of the PFGE dendrogram, indicating that the macrolide-resistant strains were not clonal. In contrast, no common mutations of the ribosomal proteins or methylase genes, or overproduction of the efflux system were observed in A2058T-mutated strains. Moreover, of the 47 M. nonliquefaciens strains, 43 (91.5 %) were bro-1 and 4 (8.5 %) were bro-2 positive. Our results suggest that most M. nonliquefaciens clinical isolates show high-level macrolide resistance conferred by the A2058T mutation in the 23S rRNA gene. This study represents the first characterization of M. nonliquefaciens.

scholarly journals The reduced prevalence of macrolide resistance in Mycoplasma pneumoniae clinical isolates from pediatric patients in Beijing in 2016

2018 ◽  
Author(s):  
Xiujun Tian ◽  
Ran Wei ◽  
Junyan Shao ◽  
Hong Wang ◽  
Jing Li ◽  
...  
Keyword(s):  
Mycoplasma Pneumoniae ◽  
Macrolide Resistance ◽  
23S Rrna ◽  
Cross Resistance ◽  
Rrna Gene ◽  
Older Children ◽  
Infection Susceptibility ◽  
23S Rrna Gene ◽  
Beijing China ◽  
Different Levels

Older children especially from seven to thirteen years old are more prone to develop Mycoplasma pneumoniae (MP) infection; in winter children are more susceptible to infect with MP. In Beijing, China in 2016 the rates of macrolide resistance of MP were 69.48% (in total children), 61.59% (in outpatients) and 79.28% (in hospitalized patients), respectively. All the macrolide resistant isolates harbored A2063G or A2064G mutation in the 23S rRNA gene. Seven isolates showed a mixed infection. Susceptibility results showed that 73 isolates with the A2063G mutation demonstrated different levels resistance to erythromycin (MIC=8 to>256μg/ml), azithromycin (MIC=8 to>64μg/ml) and josamycin (MIC=2 to 8μg/ml). No cross-resistance was observed in the in the antibiotics of levofloxacin and tetracycline against MP.

scholarly journals Evidence for Multidrug Resistance in NonpathogenicMycoplasmaSpecies Isolated from South African Poultry

2018 ◽  
Vol 84 (21) ◽  
Author(s):  
Amanda Beylefeld ◽  
Pamela Wambulawaye ◽  
Dauda Garba Bwala ◽  
Johannes Jacobus Gouws ◽  
Obed Mooki Lukhele ◽  
...  
Keyword(s):  
Multidrug Resistance ◽  
South African ◽  
Macrolide Resistance ◽  
Quinolone Resistance ◽  
23S Rrna ◽  
Clear Correlation ◽  
Rrna Gene ◽  
Poultry Production ◽  
Content Type ◽  
23S Rrna Gene

ABSTRACTOne hundred seventy-eight mycoplasma strains isolated from South African poultry flocks between 2003 and 2015 were identified by full-genome sequencing and phylogenetic analysis of the 16S rRNA gene and were classified as follows:Mycoplasma gallisepticum(25%),M. gallinarum(25%),M. gallinaceum, (23%),M. pullorum(14%),M. synoviae(10%), andM. iners(3%), as well as oneAcheoplasma laidlawiistrain (1%). MIC testing was performed on the axenic samples, and numerous strains of each species were resistant to either chlortetracycline or tylosin or both, with variable sensitivity to enrofloxacin. The strains of all species tested remained sensitive to tiamulin, except for oneM. gallinaceumsample that demonstrated intermediate sensitivity. The mutation of A to G at position 2059 (A2059G) in the 23S rRNA gene, which is associated with macrolide resistance, was found in the South AfricanM. gallisepticumandM. synoviaestrains, as well as a clear correlation between macrolide resistance inM. gallinarumandM. gallinaceumand mutations G354A and G748A in the L4 ribosomal protein and 23S rRNA gene, respectively. No correlation between resistance and point mutations in the genes studied could be found forM. pullorum. Only a few strains were resistant to enrofloxacin, apart from oneM. synoviaestrain with point mutation D420N, which has been associated with quinolone resistance, and no other known markers for quinolone resistance were found in this study. Proportionally more antimicrobial-resistant strains were detected inM. gallinaceum,M. gallinarum, andM. pullorumthan inM. gallisepticumandM. synoviae. Of concern, threeM. gallinaceumstrains showed multidrug resistance to chlortetracycline, tylosin, and oxytetracycline.IMPORTANCENonpathogenic poultryMycoplasmaspecies are often overlooked due to their lesser impact on poultry health and production compared to the OIE-listed pathogenic strainsM. gallisepticumandM. synoviae. The use of antimicrobials as in-feed growth promoters and for the control of mycoplasmosis is common in poultry production across the world. Here, we provide evidence that certain nonpathogenicMycoplasmaspecies are acquiring multidrug resistance traits. This would have significant implications if these species, for which no vaccines are applied, are able to transfer their antibiotic resistance genes to other mycoplasmas and bacteria that may enter the human food chain.

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