scholarly journals Molecular characterization of macrolide resistance mechanisms among Streptococcus pneumoniae and Streptococcus pyogenes isolated from the PROTEKT 1999-2000 study

2002 ◽  
Vol 50 (suppl 2) ◽  
pp. 39-47 ◽  
Author(s):  
D. J. Farrell ◽  
I. Morrissey ◽  
S. Bakker ◽  
D. Felmingham
Keyword(s):  
Streptococcus Pneumoniae ◽  
Molecular Characterization ◽  
Streptococcus Pyogenes ◽  
Resistance Mechanisms ◽  
Macrolide Resistance

scholarly journals Antistreptococcal Activity of Telithromycin Compared with Seven Other Drugs in Relation to Macrolide Resistance Mechanisms in Russia

2002 ◽  
Vol 46 (9) ◽  
pp. 2963-2968 ◽  
Author(s):  
Roman S. Kozlov ◽  
Tatiana M. Bogdanovitch ◽  
Peter C. Appelbaum ◽  
Lois Ednie ◽  
Leonid S. Stratchounski ◽  
...  
Keyword(s):  
Streptococcus Pneumoniae ◽  
Ribosomal Protein ◽  
Streptococcus Pyogenes ◽  
Prevalence Rate ◽  
Resistance Mechanism ◽  
Resistance Mechanisms ◽  
Macrolide Resistance ◽  
Penicillin G ◽  
23S Rrna

ABSTRACT The susceptibilities of 468 recent Russian clinical Streptococcus pneumoniae isolates and 600 Streptococcus pyogenes isolates, from 14 centers in Russia, to telithromycin, erythromycin, azithromycin, clarithromycin, clindamycin, levofloxacin, quinupristin-dalfopristin, and penicillin G were tested. Penicillin-nonsusceptible S. pneumoniae strains were rare except in Siberia, where their prevalence rate was 13.5%: most were penicillin intermediate, but for three strains (two from Smolensk and one from Novosibirsk) the MICs of penicillin G were 4 or 8 μg/ml. Overall, 2.5% of S. pneumoniae isolates were resistant to erythromycin. Efflux was the prevalent resistance mechanism (five strains; 41.7%), followed by ribosomal methylation encoded by constitutive erm(B), which was found in four isolates. Ribosomal mutation was the mechanism of macrolide resistance in three isolates; one erythromycin-resistant S. pneumoniae isolate had an A2059G mutation in 23S rRNA, and two isolates had substitution of GTG by TPS at positions 69 to 71 in ribosomal protein L4. All S. pyogenes isolates were susceptible to penicillin, and 11% were erythromycin resistant. Ribosomal methylation was the most common resistance mechanism for S. pyogenes (89.4%). These methylases were encoded by erm(A) [subclass erm(TR)] genes, and their expression was inducible in 96.6% of isolates. The rest of the erythromycin-resistant Russian S. pyogenes isolates (7.6%) had an efflux resistance mechanism. Telithromycin was active against 100% of pneumococci and 99.2% of S. pyogenes, and levofloxacin and quinupristin-dalfopristin were active against all isolates of both species.

scholarly journals Molecular Characterization of Increasing Fluoroquinolone Resistance in Streptococcus pneumoniae Isolates in Canada, 1997 to 2005

2006 ◽  
Vol 51 (1) ◽  
pp. 198-207 ◽  
Author(s):  
Heather J. Adam ◽  
Kristen N. Schurek ◽  
Kimberly A. Nichol ◽  
Chris J. Hoban ◽  
Trish J. Baudry ◽  
...  
Keyword(s):  
Streptococcus Pneumoniae ◽  
Early Detection ◽  
Molecular Characterization ◽  
Gel Electrophoresis ◽  
Resistance Mechanisms ◽  
Pulsed Field Gel Electrophoresis ◽  
Fluoroquinolone Resistance ◽  
Pulsed Field ◽  
Ciprofloxacin Resistance

ABSTRACT Molecular characterization of fluoroquinolone-resistant Streptococcus pneumoniae in Canada was conducted from 1997 to 2005. Over the course of the study, 205 ciprofloxacin-resistant isolates were evaluated for ParC and GyrA quinolone resistance-determining region (QRDR) substitutions, substitutions in the full genes of ParC, ParE, and GyrA, reserpine sensitivity, and serotype and by pulsed-field gel electrophoresis. Rates of ciprofloxacin resistance of S. pneumoniae increased significantly, from less than 1% in 1997 to 4.2% in 2005. Ciprofloxacin resistance was greatest in people >64 years of age and least in those <16 years of age. Significant increases were also noted in rates of resistance to gatifloxacin, gemifloxacin, levofloxacin, and moxifloxacin, to the current rates of 1.6%, 1.0%, 1.1%, and 1.0%, respectively. The most common genotype observed consisted of QRDR substitutions in GyrA (Ser81Phe) and ParC (Ser79Phe). Substitutions outside the QRDR of GyrA, ParC, and ParE were not associated with fluoroquinolone resistance in this study. Overall, 21% of isolates were reserpine-sensitive and were thus assumed to be efflux positive. The ciprofloxacin-resistant isolates belonged to 35 different serotypes, but 10 (19F, 11A, 23F, 6B, 22F, 12F, 6A, 14, 9V, and 19A) accounted for 72% of all isolates. The majority of the isolates were found to be genetically unrelated by pulsed-field gel electrophoresis. Within the observed clusters, there was considerable genetic heterogeneity with regard to fluoroquinolone resistance mechanisms and serotypes. Continued surveillance and molecular analysis of fluoroquinolone-resistant S. pneumoniae in Canada are essential for appropriate empirical treatment of infections and early detection of novel resistance mechanisms.

scholarly journals Phenotypic and Molecular Characterization of Optochin-Resistant Streptococcus pneumoniae Isolates from Brazil, with Description of Five Novel Mutations in the atpC Gene

2013 ◽  
Vol 51 (10) ◽  
pp. 3242-3249 ◽  
Author(s):  
T. C. A. Pinto ◽  
A. R. V. Souza ◽  
S. E. C. M. de Pina ◽  
N. S. Costa ◽  
A. A. Borges Neto ◽  
...  
Keyword(s):  
Streptococcus Pneumoniae ◽  
Molecular Characterization ◽  
Novel Mutations

Molecular Characterization of Streptococcus pyogenes Causing Invasive Disease in Pediatric Population in Spain A 12-year Study

2019 ◽  
Vol 38 (12) ◽  
pp. 1168-1172
Author(s):  
Viviana Sánchez-Encinales ◽  
Guillermo Ludwig ◽  
Esther Tamayo ◽  
Jose Maria García-Arenzana ◽  
Carmen Muñoz-Almagro ◽  
...  
Keyword(s):  
Molecular Characterization ◽  
Streptococcus Pyogenes ◽  
Pediatric Population ◽  
Invasive Disease
Sign in / Sign up

Export Citation Format

Share Document