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Macrolide Resistance (macrolide + resistance)
Selected AbstractsHelicobacter pylori antimicrobial resistance in the United Kingdom: the effect of age, sex and socio-economic statusALIMENTARY PHARMACOLOGY & THERAPEUTICS, Issue 9 2001H. K. Parsons Background: Helicobacter pylori antimicrobial resistance is the most common reason for eradication failure. Small studies have shown metronidazole resistance to be more prevalent in certain population groups. Aim: To determine the resistance rates in a large cohort of patients from a single centre in the UK, and to evaluate resistance patterns over time, according to age, sex and socio-economic status. Methods: Consecutive patients with H. pylori -positive antral gastric biopsy samples were studied from 1994 to 1999. Susceptibility testing was performed to metronidazole, tetracycline, macrolide and amoxicillin by the modified disk diffusion method. The Jarman under-privileged area score was used as a measure of socio-economic status. Results: A total of 1064 patients were studied. Overall metronidazole resistance was 40.3%, decreasing with age (P < 0.0001, odds ratio for patients over 60 years 0.63, 95% CI: 0.48,0.80). Women were more likely to have metronidazole resistant strains (P=0.003, odds ratio 1.5, 95% CI: 1.15,1.91), but there was no association with Jarman score. Macrolide resistance was associated with metronidazole resistance (P=0.03, odds ratio 2.14, 95% CI: 1.07,4.28). Conclusions: Metronidazole resistance in H. pylori is highly prevalent and more common in women and the young, but does not appear to be related to socio-economic status. [source] Macrolide resistance in group A beta haemolytic Streptococcus isolated from outpatient children in LatviaAPMIS, Issue 5 2010DACE ZAVADSKA Zavadska D, B,rzinža D, Drukalžska L, Puga,ova Nž, Mikla,evi,s E, Gardovska D. Macrolide resistance in group A beta haemolytic Streptococcus isolated from outpatient children in Latvia. APMIS 2010; 118: 366,70. Group A streptococci (GAS) are responsible for up to 30% of cases of pharyngitis in children, and such children do not benefit from treatment with antibiotics. During the last decade, increased resistance to macrolides has emerged as a critical issue in the treatment of GAS pharyngitis. The objective of this study was to determine the antimicrobial resistance of group A beta haemolytic Streptococcus isolated from outpatient children. From 2002 to 2006, 96 GAS strains were obtained from the pharynx of outpatients having symptoms of acute pharyngitis. Antibiotic resistance was determined by disc susceptibility tests according to CLSI standards. The presence of ermA, ermB and mefA was established by the amplification of streptococcal DNA with specific primers. Antimicrobial susceptibility tests revealed that all the strains tested were sensitive to vancomycin, linezolid, penicillin and ceftriaxone. Simultaneously, high levels of resistance to macrolides were evident; 78% of the isolates were resistant to clindamycin and erythromycin. No significant change in the yearly or seasonal incidence of resistance was observed. We describe high antimicrobial resistance of GAS to macrolides in outpatient children (78%), which can be explained by the frequent use of macrolides in the treatment of such individuals. Therefore, macrolides should not be the first drug of choice. [source] Molecular characterisation and clonal analysis of group A streptococci causing pharyngitis among paediatric patients in Palermo, ItalyCLINICAL MICROBIOLOGY AND INFECTION, Issue 2 2006G. Lorino Abstract Group A streptococci (n = 123), isolated consecutively from paediatric patients with pharyngitis from Palermo, Italy, were analysed. The emm and sof genes were sequenced, the presence of the speA and speC genes was investigated, and the macrolide resistance phenotypes and genotypes were determined. A limited number of emm/sof genotypes was found, and the most prevalent types were different from those found in a previous study from Rome. Macrolide resistance was found in the most prevalent clones, suggesting that the spread of mobile antibiotic resistance genes among the fittest clones in the community was the main mechanism influencing macrolide resistance rates in different emm types. [source] Activity of telithromycin compared with seven other agents against 1039 Streptococcus pyogenes pediatric isolates from ten centers in central and eastern EuropeCLINICAL MICROBIOLOGY AND INFECTION, Issue 7 2003B. Bozdogan In total, 1039 pediatric Streptococcus pyogenes isolates from Bulgaria, Croatia, the Czech Republic, Hungary, Latvia, Lithuania, Poland, Romania, Slovakia and Slovenia were studied. All strains were susceptible to penicillin G, levofloxacin, and quinupristin,dalfopristin, 91,100% to telithromycin, and 82,100% to erythromycin, azithromycin, and clarithromycin, and 90,100% to clindamycin. Macrolide resistance occurred mainly in Slovakia (25%), the Czech Republic (17.3%), and Croatia (15.8%). Overall, 9.7% of S. pyogenes isolates were erythromycin resistant due to erm(B) - or erm(A) -encoded methylases (72.3%) or to a mef(A) -encoded efflux pump (25.7%). One strain had alterations of both 23S rRNA (A2058G Escherichia coli numbering) and ribosomal protein L22 (G95D). [source] Mutations in 23S rRNA and ribosomal protein L4 account for resistance in Chlamydia trachomatis strains selected in vitro by macrolide passageANDROLOGIA, Issue 4 2010H. Zhu Summary Thirteen strains of Chlamydia trachomatis were exposed to subinhibitory concentrations of erythromycin (0.5 ,g ml,1), azithromycin (0.5 ,g ml,1) and josamycin (0.04 ,g ml,1) to select macrolide-resistant mutants with serial passages. The C. trachomatis mutants presented with low-level resistance to erythromycin, azithromycin and josamycin for which a 16-fold increase, a 16-fold increase and an 8-fold increase respectively in the minimal inhibitory concentration (MICs) for the mutant strains compared with the MIC for the susceptible strains were found. The results of chemosensitivity showed that josamycin had the highest susceptibility rate compared with erythromycin and azithromycin in the treatment of C. trachomatis. The ribosomal protein L4 and 23S rRNA genes of the susceptible and resistant strains of C. trachomatis were partially sequenced. A double mutation was found in ribosomal protein L4 of the mutants, leading to Pro109(CCG),Leu(CTG), and Pro151(CCG),Ala(GCC) (Escherichia coli numbering) in the corresponding protein, but these mutations were also found in parent strains. An investigation into the sequences of 23S rRNAs in the mutants revealed point mutations of A2057G, A2059G and T2611C (E. coli numbering). These results suggest that point mutations located in 23S rRNA were associated with macrolide resistance in C. trachomatis. [source] Prevalence and mechanisms of macrolide resistance among Staphylococcus epidermidis isolates from neutropenic patients in TunisiaCLINICAL MICROBIOLOGY AND INFECTION, Issue 1 2007O. Bouchami Abstract The prevalence of macrolide,lincosamide,streptogramin (MLS) resistance phenotypes was determined among erythromycin-resistant Staphylococcus epidermidis isolates collected at the Bone Marrow Transplant Centre, Tunisia during 2002. The erm(A), erm(B), erm(C), msrA, mefA and icaA genes were detected by PCR. The vga, vgb and vat genes were amplified from pristinamycin-resistant isolates. The icaA gene was detected in 76.5% of 34 isolates examined in detail. The erm(C) (53%) and erm(A) (32%) genes predominated because of clonal dissemination, followed by msrA (15%). Gene distribution was related to the methicillin resistance pattern. The vga gene was present in combination with erm(A) in three isolates. [source] Changes in macrolide resistance among respiratory pathogens after decreased erythromycin consumption in TaiwanCLINICAL MICROBIOLOGY AND INFECTION, Issue 3 2006P.-R. Hsueh Abstract Measures to alleviate the growing problem of macrolide resistance in Taiwan resulted in a decrease in macrolide consumption, from 0.629 defined daily doses/1000 inhabitants per day (DIDs) in 1999 to 0.301 DIDs in 2003 (a reduction of 52%). A linear relationship was observed between the decline in erythromycin consumption and the decline in erythromycin resistance in Streptococcus pyogenes (46% in 1999 vs. 17% in 2003; p < 0.001) and azithromycin resistance in Haemophilus influenzae (31% in 2000 vs. 0% in 2003; p < 0.001). However, the rate of erythromycin resistance in Streptococcus pneumoniae showed a continued increase, from 80.2% in 1999 to 92% in 2003. [source] | ||||||||||