Molecular epidemiology, antimicrobial susceptibilities and resistance mechanisms of Streptococcus pyogenes isolates resistant to erythromycin and tetracycline in Spain (1994–2006)

Abstract

BackgroundGroup A Streptococcus (GAS) causes human diseases ranging in severity from uncomplicated pharyngitis to life-threatening necrotizing fasciitis and shows high rates of macrolide resistance in several countries. Our goal is to identify antimicrobial resistance in Spanish GAS isolates collected between 1994 and 2006 and to determine the molecular epidemiology (emm/T typing and PFGE) and resistance mechanisms of those resistant to erythromycin and tetracycline.ResultsTwo hundred ninety-five out of 898 isolates (32.8%) were erythromycin resistant, with the predominance of emm4T4, emm75T25, and emm28T28, accounting the 67.1% of the 21 emm/T types. Spread of emm4T4, emm75T25 and emm28T28 resistant clones caused high rates of macrolide resistance. The distribution of the phenotypes was M (76.9%), cMLSB (20.3%), iMLSB (2.7%) with the involvement of the erythromycin resistance genes mef(A) (89.5%), msr(D) (81.7%), erm(B) (37.3%) and erm(A) (35.9%).Sixty-one isolates were tetracycline resistant, with the main representation of the emm77T28 among 20 emm/T types. To note, the combination of tet(M) and tet(O) tetracycline resistance genes were similar to tet(M) alone reaching values close to 40%. Resistance to both antibiotics was detected in 19 isolates of 7 emm/T types, being emm11T11 and the cMLSB phenotype the most frequent ones. erm(B) and tet(M) were present in almost all the strains, while erm(A), mef(A), msr(D) and tet(O) appeared in less than half of them.ConclusionsSpanish GAS were highly resistant to macrolides meanwhile showed minor resistance rate to tetracycline. A remarkable correlation between antimicrobial resistance and emm/T type was noticed. Clonal spread of emm4T4, emm75T25 and emm28T28 was the main responsable for macrolide resistance where as that emm77T28 clones were it to tetraclycline resistance. A wide variety of macrolide resistance genes were responsible for three macrolide resistance phenotypes.

Susceptibility of Group AStreptococcusto Antimicrobial Agents in Northern Israel: A Surveillance Study

“…A wide variability in antimicrobial susceptibility of GAS to macrolides and tetracyclines has been reported in several geographical regions. 3,4,6,10,12,16,19,23,[27][28][29]32 Recent published data from Europe indicate an increase of resistance to macrolides, which is quite a common practice in our region. A nationwide study conducted in Israel during 1996 to 1999 studied 500 GAS isolates from invasive infections.…”

Molecular epidemiology of macrolide resistant Group A streptococci from Puducherry, India

“…In the only other published report from India where such association was studied, detected that emm49 and emm56 were associated with macrolide resistance [23]. The emm28 and emm4 types were reported to be associated with macrolide resistance in Europe, Spain, Finland and Quebec whereas emm12 was found to be the main resistant emm type in Germany, Greece, Italy, Portugal and Israel [13]. In the United States, emm75 and emm12 accounted for majority of erythromycin resistant S. pyogenes [24].…”

“…All erythromycin resistant isolates were screened by a multiplex PCR for the presence of genes ermB, ermA and mefA as described previously [13], using 25µl reagent that contains 2×Taq PCR Smart Mix (Origin, Karunagappalli, Kerala, India), 10 pmol of each primers and 10 ng of sample DNA. The PCR cycling conditions were as follows: initial heating at 93°C for 3 minutes, followed by 30 cycles of denaturation at 93°C for 1 minute, annealing at 61.8°C for 1 minute, extension at 65°C for 1 minute and final extension for 3 minutes after the last cycle.…”

Detection of Streptococcus pyogenes by Use of Illumigene Group A Streptococcus Assay

“…Such resistance is higher in Europe and in Canada. It is reported to be 8.2% in Germany (17) and 32.8% in Spain (18). It is highest in China, where more than 96% of GAS isolates are resistant (19,20).…”

“…Although GAS can be treated with ␤-lactam drugs, such as penicillin and amoxicillin, because of its universal susceptibility to the class, macrolides are alternatives for patients allergic to penicillins (1). GAS resistance to macrolides varies significantly by geographic location, and it has been increasing in some areas (16)(17)(18)(19)(20). In the United States, based on a multicenter study conducted about a decade ago, erythromycin resistance of GAS ranged from 3.8% to 4.3% in different years (16).…”