<i>Streptococcus py o genes</i>Isolated in Portugal: Macrolide Resistance Phenotypes and Correlation with T Types

Melo‐Cristino, José; Fernandes, M L

doi:10.1089/mdr.1999.5.219

Cited by 42 publications

(33 citation statements)

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“…In Portugal, where penicillin V is not available, macrolides and lincosamides have the additional advantage of being a therapeutic option with an oral route of administration. High macrolide resistance in GAS was previously identified in Portugal (13) in line with other European countries (1,4,6) but in contrast to others (14,16). The aims of this study were to determine the prevalence of macrolide resistance phenotypes and its temporal trends and to evaluate the correlation with T and emm-types.…”

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confidence: 57%

Rapid Inversion of the Prevalences of Macrolide Resistance Phenotypes Paralleled by a Diversification of T and emm Types among Streptococcus pyogenes in Portugal

Silva-Costa¹,

Ramírez²,

Melo‐Cristino³

2005

Antimicrob Agents Chemother

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In Portugal erythromycin resistance of 26.6% (n ‫؍‬ 352) remained constant during 1998 to 2003, however in 1998 the MLS B phenotype dominated (85%), whereas in 2003 the M phenotype prevailed (77%). A decline in T12/emm22 MLS B isolates could partially explain the drop in this phenotype, but the rise of the M phenotype was not due to clonal expansion.Although penicillin remains the antibiotic of choice in the treatment of Lancefield group A streptococci (GAS) infections, macrolides and lincosamides are recommended as suitable alternatives for patients allergic to penicillin (5). Newer macrolides, such as azithromycin, may be given once a day, making this an attractive option for the treatment of pharyngitis due to Streptococcus pyogenes. In Portugal, where penicillin V is not available, macrolides and lincosamides have the additional advantage of being a therapeutic option with an oral route of administration. High macrolide resistance in GAS was previously identified in Portugal (13) in line with other European countries (1, 4, 6) but in contrast to others (14,16). The aims of this study were to determine the prevalence of macrolide resistance phenotypes and its temporal trends and to evaluate the correlation with T and emm-types.A total of 1,321 GAS from clinical infections were collected from 30 laboratories, geographically distributed throughout Portugal, from January 1998 to December 2003. The isolates were distributed in the study period as follows: 153 in 1998, 240 in 1999, 213 in 2000, 216 in 2001, 270 in 2002, and 229 in 2003. The laboratories were asked to submit all nonduplicate GAS isolated from outpatients during the study period. Antimicrobial susceptibility testing, T-typing, and macrolide resistance phenotype and genotype were determined as previously described (7, 13). Strains were emm typed according to the recommendations of the Centers for Disease Control and Prevention (CDC) (http://www.cdc.gov/ncidod/biotech/strep/protocols .htm). The sequences of representatives of each restriction profile were searched against GenBank as well as the emm CDC database (http://www.cdc.gov/ncidod/biotech/strep /strepindex.htm). An isolate was considered to be of a given emm type if it had Ͼ95% identity over the 160 bases considered (3).Among this collection, 352 isolates (26.6%) were erythromycin resistant. Although there was a higher prevalence of resistant isolates recovered in 1998 (34.6%), the variation of the overall prevalence in the following years (19.6% in 1999, 27.7% in 2000, 25.5% in 2001, 23.7% in 2002, and 20.5% in 2003) was not significant ( 2 test, P ϭ 0.22) (Fig. 1). Only the 325 erythromycin-resistant isolates recovered from throat swabs associated with a diagnosis of pharyngitis were characterized further.Resistance to tetracycline was expressed by 38.7% (n ϭ 126) of the isolates (MIC 90 ϭ 96 g/ml, MIC range, 12 to 512 g/ml). The distribution of tetracycline-resistant isolates among the study years was as follows: 84.9% of the isolates recovered in 1998, 70.2% in 1999, 28.8% in 2000, 30.9...

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confidence: 57%

Rapid Inversion of the Prevalences of Macrolide Resistance Phenotypes Paralleled by a Diversification of T and emm Types among Streptococcus pyogenes in Portugal

Silva-Costa¹,

Ramírez²,

Melo‐Cristino³

2005

Antimicrob Agents Chemother

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“…The penicillin susceptibility of GAS has not altered significantly in over 50 years of use of penicillin as a treatment for GAS infection (467). Reported MIC 90 values of penicillin are a median of 0.016 mg/liter and a range of 0.0025 to 0.032 mg/liter (467)(468)(469)(470)(471). There has been only a single report of naturally occurring penicillin-tolerant GAS (472); however, this report has not been independently confirmed.…”

Section: Antibiotic Resistance Penicillin Sensitivitymentioning

confidence: 94%

Disease Manifestations and Pathogenic Mechanisms of Group A Streptococcus

et al. 2014

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SUMMARY Streptococcus pyogenes , also known as group A Streptococcus (GAS), causes mild human infections such as pharyngitis and impetigo and serious infections such as necrotizing fasciitis and streptococcal toxic shock syndrome. Furthermore, repeated GAS infections may trigger autoimmune diseases, including acute poststreptococcal glomerulonephritis, acute rheumatic fever, and rheumatic heart disease. Combined, these diseases account for over half a million deaths per year globally. Genomic and molecular analyses have now characterized a large number of GAS virulence determinants, many of which exhibit overlap and redundancy in the processes of adhesion and colonization, innate immune resistance, and the capacity to facilitate tissue barrier degradation and spread within the human host. This improved understanding of the contribution of individual virulence determinants to the disease process has led to the formulation of models of GAS disease progression, which may lead to better treatment and intervention strategies. While GAS remains sensitive to all penicillins and cephalosporins, rising resistance to other antibiotics used in disease treatment is an increasing worldwide concern. Several GAS vaccine formulations that elicit protective immunity in animal models have shown promise in nonhuman primate and early-stage human trials. The development of a safe and efficacious commercial human vaccine for the prophylaxis of GAS disease remains a high priority.

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“…Clinical and Laboratory Standards Institute (CLSI) methods and interpretation criteria were used for all antimicrobial agents (14). The macrolide resistance phenotype was determined according to a double-disk test with erythromycin and clindamycin, as previously described (43). The M phenotype corresponds to resistance to erythromycin only, while the MLS B phenotype corresponds to resistance to both antibiotics.…”

Section: Methodsmentioning

confidence: 99%

Dominance of Serotype Ia among Group B Streptococci Causing Invasive Infections in Nonpregnant Adults in Portugal

2012

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The population of group B streptococci (GBS) associated with invasive infections in nonpregnant adults from 2001 to 2008 was analyzed in isolates submitted from 24 hospital laboratories in Portugal (n ‫؍‬ 225). The isolates were characterized by antimicrobial susceptibility, pulsed-field gel electrophoresis (PFGE), multilocus sequence typing (MLST), and surface protein gene profiling. GBS invasive cases were found more frequently among men in all age groups. In addition, serotype Ia was the most frequent in our collection, whereas serotype V is dominant elsewhere. Serotype Ia was represented mainly by a single PFGE cluster defined by sequence type 23 (ST23) and surface protein gene eps and by ST24 and bca, similarly to neonatal invasive infections in Portugal, indicating that the same genetic lineages can be responsible for both vaginal colonization and invasive disease in all age groups. In contrast, the hypervirulent serotype III/ST17 neonatal lineage was responsible for a minority of infections. Serotype V isolates were distributed into two genetic lineages, one defined by ST1 and surface protein gene alp3 and macrolide resistant, and another presenting with ST2 and eps and fully susceptible to all antimicrobials tested. The erm(TR) gene was the most frequently found among erythromycin-resistant isolates, while the bovine-associated tet(O) gene was found in a minority of tetracyclineresistant isolates. Our data emphasize the importance of local identification of the genetic lineages responsible for GBS invasive infections in nonpregnant adults. The dominance of serotype Ia in invasive disease in Portugal highlights the importance of this serotype in GBS pathogenesis.

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Streptococcus py o genesIsolated in Portugal: Macrolide Resistance Phenotypes and Correlation with T Types

Cited by 42 publications

References 35 publications

Rapid Inversion of the Prevalences of Macrolide Resistance Phenotypes Paralleled by a Diversification of T and emm Types among Streptococcus pyogenes in Portugal

Rapid Inversion of the Prevalences of Macrolide Resistance Phenotypes Paralleled by a Diversification of T and emm Types among Streptococcus pyogenes in Portugal

Disease Manifestations and Pathogenic Mechanisms of Group A Streptococcus

Dominance of Serotype Ia among Group B Streptococci Causing Invasive Infections in Nonpregnant Adults in Portugal

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