scholarly journals Molecular Basis of Intrinsic Macrolide Resistance in the Mycobacterium tuberculosis Complex

2004 ◽  
Vol 48 (1) ◽  
pp. 143-150 ◽  
Author(s):  
Karolína Buriánková ◽  
Florence Doucet-Populaire ◽  
Olivier Dorson ◽  
Anne Gondran ◽  
Jean-Claude Ghnassia ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Macrolide Resistance ◽  
Saccharopolyspora Erythraea ◽  
23S Rrna ◽  
Type I ◽  
Intrinsic Resistance ◽  
Streptomyces Ambofaciens ◽  
Resistance Patterns ◽  
Sequence Encoding ◽  
Mycobacterial Cell Wall

ABSTRACT The intrinsic resistance of the Mycobacterium tuberculosis complex (MTC) to most antibiotics, including macrolides, is generally attributed to the low permeability of the mycobacterial cell wall. However, nontuberculous mycobacteria (NTM) are much more sensitive to macrolides than members of the MTC. A search for macrolide resistance determinants within the genome of M. tuberculosis revealed the presence of a sequence encoding a putative rRNA methyltransferase. The deduced protein is similar to Erm methyltransferases, which confer macrolide-lincosamide-streptogramin (MLS) resistance by methylation of 23S rRNA, and was named ErmMT. The corresponding gene, ermMT (erm37), is present in all members of the MTC but is absent in NTM species. Part of ermMT is deleted in some vaccine strains of Mycobacterium bovis BCG, such as the Pasteur strain, which lack the RD2 region. The Pasteur strain was susceptible to MLS antibiotics, whereas MTC species harboring the RD2 region were resistant to them. The expression of ermMT in the macrolide-sensitive Mycobacterium smegmatis and BCG Pasteur conferred MLS resistance. The resistance patterns and ribosomal affinity for erythromycin of Mycobacterium host strains expressing ermMT, srmA (monomethyltransferase from Streptomyces ambofaciens), and ermE (dimethyltransferase from Saccharopolyspora erythraea) were compared, and the ones conferred by ErmMT were similar to those conferred by SrmA, corresponding to the MLS type I phenotype. These results suggest that ermMT plays a major role in the intrinsic macrolide resistance of members of the MTC and could be the first example of a gene conferring resistance by target modification in mycobacteria.

scholarly journals Functional Complementation of the Essential Gene fabG1 of Mycobacterium tuberculosis by Mycobacterium smegmatis fabG but Not Escherichia coli fabG

2007 ◽  
Vol 189 (10) ◽  
pp. 3721-3728 ◽  
Author(s):  
Tanya Parish ◽  
Gretta Roberts ◽  
Francoise Laval ◽  
Merrill Schaeffer ◽  
Mamadou Daffé ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Cell Wall ◽  
Mycobacterium Tuberculosis ◽  
Mycobacterium Smegmatis ◽  
Essential Gene ◽  
Permeability Barrier ◽  
Type I ◽  
Type Ii ◽  
Mycolic Acids ◽  
Mycobacterial Cell Wall

ABSTRACT Mycolic acids are a key component of the mycobacterial cell wall, providing structure and forming a major permeability barrier. In Mycobacterium tuberculosis mycolic acids are synthesized by type I and type II fatty acid synthases. One of the enzymes of the type II system is encoded by fabG1. We demonstrate here that this gene can be deleted from the M. tuberculosis chromosome only when another functional copy is provided elsewhere, showing that under normal culture conditions fabG1 is essential. FabG1 activity can be replaced by the corresponding enzyme from the closely related species Mycobacterium smegmatis but not by the enzyme from Escherichia coli. M. tuberculosis carrying FabG from M. smegmatis showed no phenotypic changes, and both the mycolic acids and cell wall permeability were unchanged. Thus, M. tuberculosis and M. smegmatis enzymes are interchangeable and do not control the lengths and types of mycolic acids synthesized.

scholarly journals Prevalence, genotyping and macrolide resistance of Mycoplasma pneumoniae among isolates of patients with respiratory tract infections, Central Slovenia, 2006 to 2014

2015 ◽  
Vol 20 (37) ◽  
Author(s):  
Rok Kogoj ◽  
Tatjana Mrvic ◽  
Marina Praprotnik ◽  
Darja Kese
Keyword(s):  
Respiratory Tract ◽  
Mycoplasma Pneumoniae ◽  
Respiratory Tract Infections ◽  
Geographic Area ◽  
Macrolide Resistance ◽  
23S Rrna ◽  
Rrna Gene ◽  
Type I ◽  
Type Ii ◽  
Tract Infections

In this retrospective study we employed real-time polymerase chain reaction (PCR) to analyse the occurrence of Mycoplasma pneumoniae among upper and lower respiratory tract infections (RTI) in the Central Region of Slovenia between January 2006 and December 2014. We also used a culture and pyrosequencing approach to genotype strains and infer their potential macrolide resistance. Of a total 9,431 tested samples from in- and out-patient with RTI, 1,255 (13%) were found to be positive by M. pneumoniae PCR. The proportion of positive samples was 19% (947/5,092) among children (?16 years-old) and 7% (308/4,339) among adults (>16 years-old). Overall, among those PCR tested, the highest proportions of M. pneumoniae infections during the study period were observed in 2010 and 2014. In these two years, 18% (218/1,237) and 25% (721/2,844) of samples were positive respectively, indicating epidemic periods. From the 1,255 M. pneumoniae PCR-positive samples, 783 (614 from paediatric and 169 from adult patients) were successfully cultured. Of these, 40% (312/783) were constituted of strains belonging to the P1 type II genomic group, while 60% (469/783) contained strains of the P1 type I group. Two isolates comprised both P1 type I and II strains. Results of a genotype analysis by year, showed that the dominant M. pneumoniae P1 type during the 2010 epidemic was P1 type II (82% of isolates; 81/99), which was replaced by P1 type I in the 2014 epidemic (75%; 384/510). This observation could indicate that the two epidemics may have been driven by a type shift phenomenon, although both types remained present in the studied population during the assessed period of time. Only 1% of strains (7/783) were found to harbour an A2063G mutation in the 23S rRNA gene, which confers macrolide resistance, suggesting that the occurrence of M. pneumoniae macrolide resistance still seems to be sporadic in our geographic area.

scholarly journals Crystal structure of ErmE - 23S rRNA methyltransferase in macrolide resistance

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Alena Stsiapanava ◽  
Maria Selmer
Keyword(s):  
Crystal Structure ◽  
Tertiary Structure ◽  
Catalytic Domain ◽  
Antibiotic Resistance Genes ◽  
Macrolide Resistance ◽  
Saccharopolyspora Erythraea ◽  
23S Rrna ◽  
Cofactor Binding ◽  
Sequence Identity ◽  
Adenosyl Methionine

Abstract Pathogens often receive antibiotic resistance genes through horizontal gene transfer from bacteria that produce natural antibiotics. ErmE is a methyltransferase (MTase) from Saccharopolyspora erythraea that dimethylates A2058 in 23S rRNA using S-adenosyl methionine (SAM) as methyl donor, protecting the ribosomes from macrolide binding. To gain insights into the mechanism of macrolide resistance, the crystal structure of ErmE was determined to 1.75 Å resolution. ErmE consists of an N-terminal Rossmann-like α/ß catalytic domain and a C-terminal helical domain. Comparison with ErmC’ that despite only 24% sequence identity has the same function, reveals highly similar catalytic domains. Accordingly, superposition with the catalytic domain of ErmC’ in complex with SAM suggests that the cofactor binding site is conserved. The two structures mainly differ in the C-terminal domain, which in ErmE contains a longer loop harboring an additional 310 helix that interacts with the catalytic domain to stabilize the tertiary structure. Notably, ErmE also differs from ErmC’ by having long disordered extensions at its N- and C-termini. A C-terminal disordered region rich in arginine and glycine is also a present in two other MTases, PikR1 and PikR2, which share about 30% sequence identity with ErmE and methylate the same nucleotide in 23S rRNA.

scholarly journals Multiplex PCR To Identify Macrolide Resistance Determinants in Mannheimia haemolytica and Pasteurella multocida

2012 ◽  
Vol 56 (7) ◽  
pp. 3664-3669 ◽  
Author(s):  
Simon Rose ◽  
Benoit Desmolaize ◽  
Puneet Jaju ◽  
Cornelia Wilhelm ◽  
Ralf Warrass ◽  
...  
Keyword(s):  
Multiplex Pcr ◽  
Pasteurella Multocida ◽  
Macrolide Resistance ◽  
Mannheimia Haemolytica ◽  
23S Rrna ◽  
Type I ◽  
Pcr Assay ◽  
Content Type ◽  
Microbiological Methods ◽  
Tract Infections

ABSTRACTThe bacterial pathogensMannheimia haemolyticaandPasteurella multocidaare major etiological agents in respiratory tract infections of cattle. Although these infections can generally be successfully treated with veterinary macrolide antibiotics, a few recent isolates have shown resistance to these drugs. Macrolide resistance in members of the familyPasteurellaceaeis conferred by combinations of at least three genes:erm(42), which encodes a monomethyltransferase and confers a type I MLSB(macrolide, lincosamide, and streptogramin B) phenotype;msr(E), which encodes a macrolide efflux pump; andmph(E), which encodes a macrolide-inactivating phosphotransferase. Here, we describe a multiplex PCR assay that detects the presence oferm(42),msr(E), andmph(E) and differentiates between these genes. In addition, the assay distinguishesP. multocidafromM. haemolyticaby amplifying distinctive fragments of the 23S rRNA (rrl) genes. Onerrlfragment acts as a general indicator of gammaproteobacterial species and confirms whether the PCR assay has functioned as intended on strains that are negative forerm(42),msr(E), andmph(E). The multiplex system has been tested on more than 40 selected isolates ofP. multocidaandM. haemolyticaand correlated with MICs for the veterinary macrolides tulathromycin and tilmicosin, and the newer compounds gamithromycin and tildipirosin. The multiplex PCR system gives a rapid and robustly accurate determination of macrolide resistance genotypes and bacterial genus, matching results from microbiological methods and whole-genome sequencing.

scholarly journals Intrinsic Macrolide Resistance of the Mycobacterium tuberculosis Complex Is Inducible

2006 ◽  
Vol 50 (7) ◽  
pp. 2560-2562 ◽  
Author(s):  
Nadya Andini ◽  
Kevin A. Nash
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Mycobacterium Tuberculosis Complex ◽  
Macrolide Resistance ◽  
Mrna Levels ◽  
Intrinsic Resistance ◽  
Tuberculosis Complex

ABSTRACT Mycobacterium tuberculosis is intrinsically resistant to macrolides, a characteristic associated with expression of the erm(37) gene. This intrinsic resistance was found to be inducible with clarithromycin and the ketolide HMR3004. Furthermore, underlying the phenotypic induction was an increase in erm(37) mRNA levels.

scholarly journals Genomic Variations in Drug Resistant Mycobacterium tuberculosis Strains Collected from Patients with Different Localization of Infection

Antibiotics ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 27
Author(s):  
Ekaterina Chernyaeva ◽  
Mikhail Rotkevich ◽  
Ksenia Krasheninnikova ◽  
Alla Lapidus ◽  
Dmitrii E. Polev ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Mycobacterium Tuberculosis ◽  
Pulmonary Tuberculosis ◽  
Central Asia ◽  
Phylogenetic Analyses ◽  
Treatment Success ◽  
Point Mutations ◽  
Whole Genome Sequence ◽  
Public Health Importance ◽  
Resistance Patterns

Mycobacterium tuberculosis is a highly studied pathogen due to public health importance. Despite this, problems like early drug resistance, diagnostics and treatment success prediction are still not fully resolved. Here, we analyze the incidence of point mutations widely used for drug resistance detection in laboratory practice and conduct comparative analysis of whole-genome sequence (WGS) for clinical M. tuberculosis strains collected from patients with pulmonary tuberculosis (PTB) and extra-pulmonary tuberculosis (XPTB) localization. A total of 72 pulmonary and 73 extrapulmonary microbiologically characterized M. tuberculosis isolates were collected from patients from 2007 to 2014 in Russia. Genomic DNA was used for WGS and obtained data allowed identifying major mutations known to be associated with drug resistance to first-line and second-line antituberculous drugs. In some cases previously described mutations were not identified. Using genome-based phylogenetic analysis we identified M. tuberculosis substrains associated with distinctions in the occurrence in PTB vs. XPTB cases. Phylogenetic analyses did reveal M. tuberculosis genetic substrains associated with TB localization. XPTB was associated with Beijing sublineages Central Asia (Beijing CAO), Central Asia Clade A (Beijing A) and 4.8 groups, while PTB localization was associated with group LAM (4.3). Further, the XPTB strain in some cases showed elevated drug resistance patterns relative to PTB isolates. HIV was significantly associated with the development of XPTB in the Beijing B0/W148 group and among unclustered Beijing isolates.

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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