scholarly journals Antimicrobial Susceptibility of Mycoplasma bovis and Analyses of Domain V in 23S Ribosomal RNA of Macrolide-Resistant Strains

2011 ◽  
Vol 64 (1) ◽  
pp. 45-49 ◽  
Author(s):  
Shinpei KOIKE ◽  
Yoshihide USAMI
Keyword(s):  
Ribosomal Rna ◽  
Antimicrobial Susceptibility ◽  
Mycoplasma Bovis ◽  
Resistant Strains ◽  
Domain V ◽  
23S Ribosomal Rna

scholarly journals Antimicrobial Susceptibility of Canadian Isolates ofHelicobacter pyloriin Northeastern Ontario

2015 ◽  
Vol 26 (3) ◽  
pp. 137-144 ◽  
Author(s):  
Nelson F Eng ◽  
Gustavo Ybazeta ◽  
Katrina Chapman ◽  
Nya L Fraleigh ◽  
Rebecca Letto ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Antimicrobial Resistance ◽  
Ribosomal Rna ◽  
Antimicrobial Susceptibility ◽  
Point Mutations ◽  
Test Methods ◽  
Surveillance Programs ◽  
Resistant Strains ◽  
H Pylori ◽  
23S Ribosomal Rna

BACKGROUND:Helicobacter pyloriplays a significant role in gastritis and ulcers. It is a carcinogen as defined by the WHO, and infection can result in adenocarcinomas and mucosa-associated lymphoid tissue lymphomas. In Canada, rates of antimicrobial resistance are relatively unknown, with very few studies conducted in the past 15 years.OBJECTIVE: To examine rates of resistance in Sudbury, Ontario, compare antimicrobial susceptibility methods and attempt to determine the molecular basis of antibiotic resistance.METHODS: Patients attending scheduled visits at Health Sciences North (Sudbury, Ontario) provided gastric biopsy samples on a volunteer basis. In total, 20H pyloriisolates were collected, and antimicrobial susceptibility testing (on amoxicillin, tetracycline, metronidazole, ciprofloxacin, levofloxacin and clarithromycin) was conducted using disk diffusion and E-test methods. Subsequently, genomic DNA from these isolates was sequenced to detect mutations associated with antimicrobial resistance.RESULTS: Sixty-five percent of the isolates were found to be resistant to at least one of the listed antibiotics according to E-test. Three isolates were found to be resistant to ≥3 of the above-mentioned antibiotics. Notably, 25% of the isolates were found to be resistant to both metronidazole and clarithromycin, two antibiotics that are normally prescribed as part of first-line regimens in the treatment ofH pyloriinfections in Canada and most of the world. Among the resistant strains, the sequences of 23S ribosomal RNA andgyrA, which are linked to clarithromycin and ciprofloxacin/levofloxacin resistance, respectively, revealed the presence of known point mutations associated with antimicrobial resistance.CONCLUSIONS: In general, resistance to metronidazole, ciprofloxacin/levofloxacin and clarithromycin has increased since the studies in the early 2000s. These results suggest that surveillance programs ofH pyloriantibiotic resistance may need to be revisited or improved to prevent antimicrobial therapy failure.

scholarly journals Mutations in domain V of Mycoplasma pneumoniae 23S rRNA and clinical characteristics of pediatric M. pneumoniae pneumonia in Nanjing, China

2021 ◽  
Vol 49 (6) ◽  
pp. 030006052110163
Author(s):  
Changdi Xu ◽  
Huan Deng ◽  
Jiamin Zhang ◽  
Yifan Zhu ◽  
Qiangquan Rong ◽  
...  
Keyword(s):  
Hospital Stay ◽  
Mycoplasma Pneumoniae ◽  
Ribosomal Rna ◽  
Clinical Characteristics ◽  
Laboratory Data ◽  
Pulmonary Complications ◽  
23S Rrna ◽  
High Prevalence ◽  
Domain V ◽  
23S Ribosomal Rna

Objective To investigate the prevalence of mutations in domain V of Mycoplasma pneumoniae (MP) 23S ribosomal RNA (rRNA) and the clinical characteristics of pediatric MP pneumonia (MPP) in Nanjing, China. Methods Domain V of 23S rRNA was sequenced in MP strains collected from children diagnosed with MPP in Nanjing. Clinical and laboratory data were obtained. Results Among the 276 MP strains, 255 (92.39%) harbored mutations, primarily A2063G in domain V of MP 23S rRNA. When children were stratified according to the presence or absence of mutations, no significant differences were found in sex, age, the MP DNA load at enrollment, lymphocyte counts, pulmonary complications, immunomodulator levels, fever duration, the duration of fever after macrolide therapy, and hospital stay. The prevalence of refractory MPP in the two groups was similar. Children with refractory MPP exhibited higher MP DNA loads than those with non-refractory MPP. Conclusions Despite the high prevalence of the A2063G mutation in domain V of MP 23S rRNA, mutations were not associated with the clinical characteristics of MPP. The MP DNA load significantly differed between refractory and non-refractory MPP.

Emergence of erythromycin resistance methyltransferases in Campylobacter coli strains in France

2021 ◽  
Author(s):  
Quentin Jehanne ◽  
Lucie Bénéjat ◽  
Astrid Ducournau ◽  
Chloé Domingues-Martins ◽  
Théo Cousinou ◽  
...  
Keyword(s):  
Ribosomal Rna ◽  
Multidrug Resistant ◽  
Resistance Mechanisms ◽  
Genomic Islands ◽  
Campylobacter Coli ◽  
Erythromycin Resistance ◽  
Pcr Screening ◽  
Clinical Strains ◽  
Resistant Strains ◽  
23S Ribosomal Rna

Antimicrobial resistance in Campylobacters is described worldwide. The emergence of multiresistant isolates, particularly among C. coli , is concerning. New resistance mechanisms appear frequently, and DNA-sequence-based methods such as whole genome sequencing (WGS) have become useful tools to monitor their emergence. The genomes of 51 multiresistant French Campylobacter sp. clinical strains from 2018 to 2019 were analyzed to identify associated resistance mechanisms. Analyses of erythromycin-resistant strains revealed 23S ribosomal RNA mutations among most of them and two different methyltransferases in 4 strains: Erm(B) and a novel methyltransferase, here named Erm(N). The erm(B) gene was found in multidrug-resistant genomic islands, whereas erm(N) was inserted within CRISPR arrays of the CRISPR- cas9 operon. Moreover, using PCR screening in erythromycin-resistant strains from our collection, we showed that erm(N) was already present in 3 French clinical strains 2 years before its first report in 2018 in Quebec. Bacterial transformations confirmed that insertion of erm(N) into a CRISPR- cas9 operon can confer macrolide resistance. Campylobacter species are easily able to adapt to their environment and acquire new resistance mechanisms, and the emergence of methyltransferases in Campylobacters in France is a matter of concern in the coming years.

scholarly journals Dissemination of cfr-mediated linezolid resistance among Staphylococcus species isolated from a teaching hospital in Beijing, China

2018 ◽  
Vol 46 (9) ◽  
pp. 3884-3889 ◽  
Author(s):  
Jiyong Jian ◽  
Liang Chen ◽  
Zeqiang Xie ◽  
Man Zhang
Keyword(s):  
Staphylococcus Aureus ◽  
Teaching Hospital ◽  
Ribosomal Rna ◽  
Ribosomal Proteins ◽  
Methicillin Resistant ◽  
Linezolid Resistance ◽  
Ribosomal Protein L3 ◽  
Domain V ◽  
23S Ribosomal Rna ◽  
Beijing China

Objective The aim of the present study was to report the dissemination of cfr and fexA genes mediated by linezolid resistance among Staphylococcus species. Methods Three methicillin-resistant staphylococci that were collected from a teaching hospital in Beijing were identified as linezolid-resistant. These three staphylococci were Staphylococcus aureus, S. haemolyticus, and S. cohnii. Mutations in domain V of 23S ribosomal RNA, ribosomal proteins, and the cfr, fexA, and optrA genes were analysed. Results The three isolates had no mutations of 23S ribosomal RNA, but showed mutations in the cfr and fexA genes. Mutations in the gene for ribosomal protein L3, which resulted in the amino acid exchanges Gly108Glu, Ser158Phe, and Asp159Tyr, were identified in S. cohnii X4535. Conclusions This is the first report of the cfr gene in clinical linezolid-resistant methicillin-resistant S. aureus isolated from Beijing. L3 mutations coupled with the cfr and fexA genes may act synergistically. Potential transmissibility of this agent, even without prior exposure to linezolid, may have serious epidemiological repercussions.

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