RESUMO
Streptococcus dysgalactiae subsp. equisimilis (SDSE) has virulence factors similar to those of Streptococcus pyogenes. Therefore, it causes pharyngitis and severe infections indistinguishable from those caused by the classic pathogen. The objectives of this study were: to know the prevalence of SDSE invasive infections in Argentina, to study the genetic diversity, to determine the presence of virulence genes, to study antibiotic susceptibility and to detect antibiotic resistance genes. Conventional methods of identification were used. Antibiotic susceptibility was determined by the disk diffusion and the agar dilution methods and the E-test. Twenty eight centers from 16 Argentinean cities participated in the study. Twenty three isolates (16 group G and 7 group C) were obtained between July 1 2011 and June 30 2012. Two adult patients died (8.7%). Most of the isolates were recovered from blood (60.9%). All isolates carried speJ and ssa genes. stG62647, stG653 and stG840 were the most frequent emm types. Nineteen different PFGE patterns were detected. All isolates were susceptible to penicillin and levofloxacin, 6 (26.1%) showed resistance or reduced susceptibility to erythromycin --#91;1 mef(A), 3 erm(TR), 1 mef(A) + erm(TR) and 1 erm(TR) + erm(B)--#93; and 7 (30.4%) were resistant or exhibited reduced susceptibility to tetracycline --#91;2 tet(M), 5 tet(M) + tet(O)--#93;. The prevalence in Argentina was of at least 23 invasive infections by SDSE. A wide genetic diversity was observed. All isolates carried speJ and ssa genes. Similarly to other studies, macrolide resistance (26.1%) was mainly associated to the MLS B phenotype.
Streptococcus dysgalactiae subsp. equisimilis (SDSE) posee factores de virulencia similares a Streptococcus pyogenes y, en consecuencia, produce faringitis e infecciones graves indistinguibles de las generadas por este patógeno clásico. Los objetivos del estudio fueron conocer la prevalencia de SDSE en infecciones invasivas en Argentina, estudiar su diversidad genética, determinar la presencia de genes de virulencia, ensayar su sensibilidad a los antibióticos y conocer los genes de resistencia. Se emplearon métodos convencionales de identificación. La sensibilidad se determinó por difusión, Etest y dilución en agar. Participaron 28 centros de 16 ciudades argentinas. Se obtuvieron 23 aislamientos (16 del grupo G y 7 del grupo C) desde el 1-7-2011 hasta el 30-6-2012. Se registraron 2 muertes en adultos (8,7%). La mayoría de los aislamientos fueron obtenidos de sangre (60,9%). Todos eran portadores de los genes speJ y ssa. Los genotipos más frecuentes fueron stG62647, stG653 y stG840. Se detectaron 19 pulsotipos distintos. Todos los aislamientos fueron sensibles a penicilina y levofloxacina, 6 (26,1%) presentaron resistencia o sensibilidad disminuida a eritromicina (1 mef--#91;A--#93;, 3 erm--#91;TR--#93;, 1 mef--#91;A--#93; + erm--#91;TR--#93; y 1 erm--#91;TR--#93; + erm--#91;B--#93;) y 7 (30,4%) fueron resistentes o tuvieron sensibilidad disminuida a tetraciclina (2 tet--#91;M--#93;, 5 tet--#91;M--#93; + tet--#91;O--#93;). La prevalencia anual en la Argentina fue de al menos 23 infecciones invasivas por SDSE y se observó una amplia diversidad genética. Todos los aislamientos presentaron los genes ssa y speJ. Como en otros estudios, la resistencia a macrólidos (26,1%) estuvo asociada, principalmente, al fenotipo MLS B.
Assuntos
Humanos , Masculino , Feminino , Infecções Estreptocócicas/classificação , Streptococcus/isolamento & purificação , Streptococcus/patogenicidade , Argentina , Streptococcus/genética , Resistência Microbiana a Medicamentos , Estudos Transversais/métodosRESUMO
Streptococcus dysgalactiae subsp. equisimilis (SDSE) has virulence factors similar to those of Streptococcus pyogenes. Therefore, it causes pharyngitis and severe infections indistinguishable from those caused by the classic pathogen. The objectives of this study were: to know the prevalence of SDSE invasive infections in Argentina, to study the genetic diversity, to determine the presence of virulence genes, to study antibiotic susceptibility and to detect antibiotic resistance genes. Conventional methods of identification were used. Antibiotic susceptibility was determined by the disk diffusion and the agar dilution methods and the E-test. Twenty eight centers from 16 Argentinean cities participated in the study. Twenty three isolates (16 group G and 7 group C) were obtained between July 1 2011 and June 30 2012. Two adult patients died (8.7%). Most of the isolates were recovered from blood (60.9%). All isolates carried speJ and ssa genes. stG62647, stG653 and stG840 were the most frequent emm types. Nineteen different PFGE patterns were detected. All isolates were susceptible to penicillin and levofloxacin, 6 (26.1%) showed resistance or reduced susceptibility to erythromycin [1 mef(A), 3 erm(TR), 1 mef(A)+erm(TR) and 1 erm(TR)+erm(B)] and 7 (30.4%) were resistant or exhibited reduced susceptibility to tetracycline [2 tet(M), 5 tet(M)+tet(O)]. The prevalence in Argentina was of at least 23 invasive infections by SDSE. A wide genetic diversity was observed. All isolates carried speJ and ssa genes. Similarly to other studies, macrolide resistance (26.1%) was mainly associated to the MLSB phenotype.
Assuntos
Bacteriemia/microbiologia , Infecções Estreptocócicas/microbiologia , Streptococcus/genética , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Argentina/epidemiologia , Artrite Infecciosa/epidemiologia , Artrite Infecciosa/microbiologia , Bacteriemia/epidemiologia , Líquidos Corporais/microbiologia , Criança , Pré-Escolar , DNA Bacteriano/genética , Farmacorresistência Bacteriana Múltipla/genética , Eletroforese em Gel de Campo Pulsado , Feminino , Genes Bacterianos , Variação Genética , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Prevalência , Infecções dos Tecidos Moles/epidemiologia , Infecções dos Tecidos Moles/microbiologia , Infecções Estreptocócicas/epidemiologia , Streptococcus/efeitos dos fármacos , Streptococcus/isolamento & purificação , Streptococcus/patogenicidade , Streptococcus pyogenes/genética , Streptococcus pyogenes/isolamento & purificação , Virulência , Adulto JovemRESUMO
The beta-hemolytic group C streptococci (Lancefield's group) has been considered an emergent human pathogen, showing an important role as an opportunist agent, being responsible for nosocomial infections and outbreaks. This study is reporting the first outbreak of nosocomial infection caused by Streptococcus dysgalactiae subsp. equisimilis in Brazil. From January, 2002, to December, 2004, S. equisimilis was isolated in 67/207 (32.37%) samples from secretions of patients' infected wounds, interned at the Hospital of Sanitary Dermatology in the State of Paraná (HDSPR). The prevalence of this microorganism increased from 11/42 (26.19%) in 2002, 14/65 (21.54%) in 2003 to 42/100 (42.00%) in 2004. This increase was statistically significant (p=0.024), and this microorganism became the most frequently isolated in these patients, overtaking the rates of isolation of Pseudomonas aeruginosa. The S. equisimilis grew in pure culture, as a unique microorganism, in six samples (2.9%) out of 207. Fresh feces of 15 animals (horses and sheep) living in the proximities of the hospital were also examined and three of them positive for S. equisimilis. The biochemical profile of the strains isolated from the patients and from the animals was the same. These animals might have been the source of the dissemination of the outbreak in the hospital. New studies will be necessary to confirm the genetic relationship between the strains isolated from patients and animals.
O estreptococo beta-hemolítico do grupo C de Lancefield tem sido considerado patógeno humano emergente, mostrando importante papel como agente oportunista, implicado algumas vezes em infecções hospitalares e surtos. Este estudo está relatando o primeiro surto de infecção hospitalar causado pelos Streptococcus dysgalactiae subsp. equisimilis no Brasil. De janeiro de 2002 a dezembro de 2004, isolou-se S. equisimilis em 67/207 (32,37%) das amostras de secreções de lesões de feridas coletadas de pacientes internados no Hospital de Dermatologia Sanitária do Paraná (HDSPR). A prevalência deste microrganismo aumentou de 11/42 (26,19%) em 2002, 14/65 (21,54%) em 2003 para 42/100 (42,00%) em 2004. Este aumento foi estatisticamente significante (p=0.024), tornando este microrganismo o mais freqüentemente isolado nos pacientes, ultrapassando as taxas de isolamento de Pseudomonas aeruginosa. Em seis amostras (2,9%) entre as 207 examinadas, S. equisimilis cresceu em cultivo puro, como único microrganismo. Também foram examinadas fezes frescas de 15 animais (cavalos e ovelhas) que vivem nas proximidades do hospital, e três amostras foram positivas para S. equisimilis. O perfil bioquímico encontrado entre os isolados dos pacientes foi o mesmo encontrado entre os isolados das fezes dos animais. Acredita-se que estes animais possam ter sido a fonte de disseminação do surto no hospital. Novos estudos serão necessários para confirmar o relacionamento genético entre os isolados dos pacientes e animais.