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).

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 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.

scholarly journals Molecular Typing and Macrolide Resistance Analyses ofTreponema pallidumin Heterosexuals and Men Who Have Sex with Men in Japan, 2017

2018 ◽  
Vol 57 (1) ◽  
Author(s):  
Mizue Kanai ◽  
Yuzo Arima ◽  
Shingo Nishiki ◽  
Ken Shimuta ◽  
Ichiro Itoda ◽  
...  
Keyword(s):  
Molecular Typing ◽  
Treponema Pallidum ◽  
Macrolide Resistance ◽  
23S Rrna ◽  
Rrna Gene ◽  
Content Type ◽  
Heterosexual Women ◽  
23S Rrna Gene ◽  
Strain Type ◽  
Sex With Men

ABSTRACTIn recent years, syphilis notifications have increased dramatically in Japan. We carried out molecular typing and macrolide resistance analyses ofTreponema pallidumsubsp.pallidumsamples collected from patients at four clinics and a hospital in Tokyo and Osaka prefectures in 2017. The macrolide resistant strain type 14d/f (SS14-like clade) was found in significantly more cases of syphilis among heterosexuals than in those among men who have sex with men (MSM); i.e., 79% (31/39) of the strains from heterosexuals were 14d/f compared to 37% (7/19) of those from MSM (odds ratio [OR], 6.6; 95% confidence interval [CI], 1.7 to 26.7;P = 0.002). In addition, 83% (50/60) of the strains were identified as macrolide resistant with an A2058G mutation in the 23S rRNA gene; 90% (35/39) of the strains from heterosexuals were macrolide resistant compared to 58% (11/19) of those from MSM. The odds of having the resistant mutation were considerably higher in the former (OR, 6.4; 95% CI, 1.3 to 33.5;P = 0.02). Heterosexual women and heterosexual men showed similar distributions, and the association remained the same when restricted to men. The strain type distribution and the prevalence of macrolide resistance differed substantially between syphilis strains from heterosexual cases and from MSM cases, suggesting distinct epidemiologic profiles for the two communities and providing important insight into the dynamics of syphilis in Japan.

scholarly journals Molecular Typing ofMycoplasma pneumoniaeStrains in Sweden from 1996 to 2017 and the Emergence of a New P1 Cytadhesin Gene, Variant 2e

2019 ◽  
Vol 57 (6) ◽  
Author(s):  
Karolina Gullsby ◽  
Björn Olsen ◽  
Kåre Bondeson
Keyword(s):  
Macrolide Resistance ◽  
23S Rrna ◽  
Clinical Samples ◽  
Rrna Gene ◽  
Content Type ◽  
New Variant ◽  
Epidemic Period ◽  
Antigenic Properties

ABSTRACTMycoplasma pneumoniaecauses respiratory infections, such as community-acquired pneumonia (CAP), with epidemics recurring every 3 to 7 years. In 2010 and 2011, many countries experienced an extraordinary epidemic peak. The cause of these recurring epidemics is not understood, but decreasing herd immunity and shifts in the strains’ antigenic properties have been suggested as contributing factors.M. pneumoniaePCR-positive samples were collected between 1996 and 2017 from four neighboring counties inhabited by 12% of Sweden’s population. A total of 578 isolates were characterized directly from 624 clinical samples using P1 typing by sequencing and multilocus variable number tandem repeat analysis (MLVA). A fluorescence resonance energy transfer (FRET)-PCR approach was also used to detect mutations associated with macrolide resistance in the 23S rRNA gene. Through P1 typing, the strains were classified into type 1 and type 2, as well as variants 2a, 2b, 2c, and a new variant found in nine of the strains, denoted variant 2e. Twelve MLVA types were distinguished, and 3-5-6-2 (42.4%), 4-5-7-2 (37.4%), and 3-6-6-2 (14.9%) predominated. Several P1 and MLVA types cocirculated each year, but type 2/variant 2 strains and MLVA types 3-5-6-2 and 4-5-7-2 predominated during the epidemic period comprising the peak of 2010 and 2011. In 2016 and 2017, type 1 became more common, and MLVA type 4-5-7-2 predominated. We also found that 0.2% (1/578) of the strains carried a macrolide resistance-associated mutation, indicating a very low prevalence of macrolide resistance in this region of Sweden.

scholarly journals Mutational and Transcriptomic Changes Involved in the Development of Macrolide Resistance in Campylobacter jejuni

2012 ◽  
Vol 57 (3) ◽  
pp. 1369-1378 ◽  
Author(s):  
Haihong Hao ◽  
Zonghui Yuan ◽  
Zhangqi Shen ◽  
Jing Han ◽  
Orhan Sahin ◽  
...  
Keyword(s):  
Campylobacter Jejuni ◽  
Dna Microarray ◽  
Ribosomal Proteins ◽  
Macrolide Resistance ◽  
23S Rrna ◽  
Rrna Gene ◽  
Content Type ◽  
23S Rrna Gene ◽  
Resistant Mutants ◽  
Antibiotic Efflux

ABSTRACTMacrolide antibiotics are important for clinical treatment of infections caused byCampylobacter jejuni. Development of resistance to this class of antibiotics inCampylobacteris a complex process, and the dynamic molecular changes involved in this process remain poorly defined. Multiple lineages of macrolide-resistant mutants were selected by stepwise exposure ofC. jejunito escalating doses of erythromycin or tylosin. Mutations in target genes were determined by DNA sequencing, and the dynamic changes in the expression of antibiotic efflux transporters and the transcriptome ofC. jejuniwere examined by real-time reverse transcription-PCR, immunoblotting, and DNA microarray analysis. Multiple types of mutations in ribosomal proteins L4 and L22 occurred early during stepwise selection. On the contrary, the mutations in the 23S rRNA gene, mediating high resistance to macrolides, were observed only in the late-stage mutants. Upregulation of antibiotic efflux genes was observed in the intermediately resistant mutants, and the magnitude of upregulation declined with the occurrence of mutations in the 23S rRNA gene. DNA microarray analysis revealed the differential expression of 265 genes, most of which occurred in the intermediate mutant, including the upregulation of genes encoding ribosomal proteins and the downregulation of genes involved in energy metabolism and motility. These results indicate (i) that mutations in L4 and L22 along with temporal overexpression of antibiotic efflux genes precede and may facilitate the development of high-level macrolide resistance and (ii) that the development of macrolide resistance affects the pathways important for physiology and metabolism inC. jejuni, providing an explanation for the reduced fitness of macrolide-resistantCampylobacter.

scholarly journals Ribosomal Mutations as the Main Cause of Macrolide Resistance in Campylobacter jejuni and Campylobacter coli

2011 ◽  
Vol 55 (12) ◽  
pp. 5939-5941 ◽  
Author(s):  
Mirva Lehtopolku ◽  
Pirkko Kotilainen ◽  
Marjo Haanperä-Heikkinen ◽  
Ulla-Maija Nakari ◽  
Marja-Liisa Hänninen ◽  
...  
Keyword(s):  
Macrolide Resistance ◽  
23S Rrna ◽  
Rrna Gene ◽  
Campylobacter Coli ◽  
Resistance Mutations ◽  
Content Type ◽  
Amino Acid Insertion ◽  
23S Rrna Gene ◽  
Ribosomal Protein L22 ◽  
Resistant Strains

ABSTRACTThe aim of this study was to examine macrolide resistance mutations inCampylobacterspecies. In 76 strains studied, point mutation A to G at position 2059 of the 23S rRNA gene was detected in 30 of the 33 erythromycin-resistant strains. An amino acid insertion in the ribosomal protein L22 was found in one resistant strain without a 23S rRNA mutation. The A2059G mutation is the main cause of macrolide resistance inCampylobacterspecies.

scholarly journals Clinical Characteristics and Treatment Outcomes of Patients with Acquired Macrolide-Resistant Mycobacterium abscessus Lung Disease

2017 ◽  
Vol 61 (10) ◽  
Author(s):  
Hayoung Choi ◽  
Su-Young Kim ◽  
Dae Hun Kim ◽  
Hee Jae Huh ◽  
Chang-Seok Ki ◽  
...  
Keyword(s):  
Lung Disease ◽  
Treatment Outcomes ◽  
Point Mutations ◽  
Mycobacterium Abscessus ◽  
Macrolide Resistance ◽  
Clinical Isolates ◽  
23S Rrna ◽  
Molecular Characteristics ◽  
Rrna Gene ◽  
Content Type

ABSTRACT Macrolide antibiotics are mainstays in the treatment of lung disease due to the Mycobacterium abscessus complex. Although previous studies have reported development of acquired macrolide resistance in this species, limited data are available on the outcomes of lung disease due to macrolide-resistant Mycobacterium abscessus subsp. abscessus. This study evaluated the clinical features, treatment outcomes, and molecular characteristics of macrolide-resistant isolates of M. abscessus subsp. abscessus. We performed a retrospective review of medical records and genetic analysis of clinical isolates from 13 patients who had acquired macrolide-resistant M. abscessus subsp. abscessus lung disease between November 2006 and March 2016. Eleven (85%) patients had the nodular bronchiectatic form of the disease, and two (15%) patients had the fibrocavitary form. When acquired macrolide resistance was detected, 10 (77%) patients were on antibiotic therapy for M. abscessus subsp. abscessus, and three (23%) patients were on therapy for lung disease due to other nontuberculous mycobacteria. The median treatment duration after detecting resistance was 24.0 months (interquartile range, 16.0 to 43.0 months). Treatment outcomes were poor, and final sputum culture conversion was achieved in only one (8%) patient, after resectional surgery. All 13 clinical isolates demonstrated point mutations at position 2058 (n = 10) or 2059 (n = 3) of the 23S rRNA gene, which resulted in acquired macrolide resistance. This study indicates that treatment outcomes are very poor after the development of acquired macrolide resistance in patients with M. abscessus subsp. abscessus lung disease. Thus, more effective measures are needed to prevent development and effectively treat macrolide-resistant M. abscessus subsp. abscessus lung disease.

scholarly journals A 5′ Nuclease Genotyping Assay for Identification of Macrolide-Resistant Mycoplasma genitalium in Clinical Specimens

2016 ◽  
Vol 54 (6) ◽  
pp. 1593-1597 ◽  
Author(s):  
Gitte Qvist Kristiansen ◽  
Jan Gorm Lisby ◽  
Kristian Schønning
Keyword(s):  
Mycoplasma Genitalium ◽  
Antimicrobial Treatment ◽  
Macrolide Resistance ◽  
23S Rrna ◽  
Rrna Gene ◽  
Predictive Values ◽  
Content Type ◽  
Clinical Specimens ◽  
Genotyping Assay ◽  
23S Rrna Gene

Rapid and sensitive detection of macrolide resistance inMycoplasma genitaliumis required for the guidance of adequate antimicrobial treatment. Previous studies have confirmed that single-base mutations at position 2058 or 2059 in domain V of the 23S rRNA gene ofM. genitaliumresult in high-level macrolide resistance. Sequencing of PCR products remains the gold standard for the identification of mutations conferring resistance to macrolides but is laborious and time-consuming. The aim of the present study was to develop a 5′ nuclease genotyping assay to detect single nucleotide polymorphisms in the 23S rRNA gene ofMycoplasma genitaliumthat are associated with macrolide resistance by combining PCR with hydrolysis probes and subsequent endpoint genotyping analysis. The 5′ nuclease genotyping assay was used as a referral test to be used onM. genitalium-positive samples and was validated on 259 positive samples, of which 253 (97.7%) were successfully sequenced. With the newly developed assay, 237/259 (91.5%) investigatedM. genitalium-positive samples were genotyped. The positive and the negative predictive values were 100% when evaluated on successfully genotyped samples. The newly developed assay discriminated macrolide-resistantM. genitaliumin clinical specimens possessing A2058G, A2058C, A2058T, and A2059G mutations with a sensitivity of 94.4% (95% confidence interval [CI], 90.7% to 98.2%) and a specificity of 92.7% (95% CI, 87.8% to 97.6%) when evaluated on successfully sequenced samples. The assay can correctly guide antimicrobial treatment ofM. genitaliuminfections.

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.

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