RESUMO
Skin and soft tissue infections (SSTIs) due to Staphylococcus aureus have become increasingly common in the outpatient setting; however, risk factors for differentiating methicillin-resistant S. aureus (MRSA) and methicillin-susceptible S. aureus (MSSA) SSTIs are needed to better inform antibiotic treatment decisions. We performed a case-case-control study within 14 primary-care clinics in South Texas from 2007 to 2015. Overall, 325 patients [S. aureus SSTI cases (case group 1, n = 175); MRSA SSTI cases (case group 2, n = 115); MSSA SSTI cases (case group 3, n = 60); uninfected control group (control, n = 150)] were evaluated. Each case group was compared to the control group, and then qualitatively contrasted to identify unique risk factors associated with S. aureus, MRSA, and MSSA SSTIs. Overall, prior SSTIs [adjusted odds ratio (aOR) 7·60, 95% confidence interval (CI) 3·31-17·45], male gender (aOR 1·74, 95% CI 1·06-2·85), and absence of healthcare occupation status (aOR 0·14, 95% CI 0·03-0·68) were independently associated with S. aureus SSTIs. The only unique risk factor for community-associated (CA)-MRSA SSTIs was a high body weight (⩾110 kg) (aOR 2·03, 95% CI 1·01-4·09).
Assuntos
Infecções Comunitárias Adquiridas/epidemiologia , Infecções dos Tecidos Moles/epidemiologia , Infecções Estafilocócicas/epidemiologia , Staphylococcus aureus/fisiologia , Adulto , Idoso , Estudos de Casos e Controles , Infecções Comunitárias Adquiridas/microbiologia , Feminino , Humanos , Masculino , Staphylococcus aureus Resistente à Meticilina/fisiologia , Pessoa de Meia-Idade , Atenção Primária à Saúde , Fatores de Risco , Infecções dos Tecidos Moles/microbiologia , Infecções Estafilocócicas/microbiologia , Infecções Cutâneas Estafilocócicas/epidemiologia , Infecções Cutâneas Estafilocócicas/microbiologia , Texas/epidemiologia , Adulto JovemRESUMO
The immune response of experimentally infected hamsters and human patients to Mycoplasma pneumoniae was examined by radioimmunoprecipation in conjunction with gel electrophoresis and fluorography. Both intrinsically and extrinsically labeled mycoplasma proteins were coincubated with acute and convalescent sera in a radioimmunoprecipitation assay. Two M. pneumoniae proteins were selectively precipitated by convalescent sera. These predominant immunogens were trypsin-sensitive, antibody-accessible surface proteins that co-migrate on polyacrylamide gels with proteins P1 and P2, which were previously implicated by us as mediators of cytadsorption. Anti-M. pneumoniae antiserum did not precipitate radiolabeled antigens derived from Mycoplasma orale or Mycoplasma salivarium. These data indicate that M. pneumoniae infection stimulates a specific and highly targeted host antibody response to key proteinaceous immunogens.
Assuntos
Antígenos de Bactérias/análise , Proteínas de Bactérias/imunologia , Pneumonia por Mycoplasma/imunologia , Doença Aguda , Animais , Anticorpos Antibacterianos/biossíntese , Proteínas de Bactérias/análise , Precipitação Química , Cricetinae , Humanos , Mycoplasma pneumoniae/efeitos dos fármacos , Mycoplasma pneumoniae/imunologia , Tripsina/farmacologiaRESUMO
A genomic library of Mycoplasma pneumoniae was generated by using bacteriophage lambda EMBL3 as the vector. Screening of the library for the expression of M. pneumoniae protein antigens with adsorbed anti-M. pneumoniae serum revealed strong reactivity from a third of those clones which contained mycoplasma DNA inserts. Three of the most highly reactive clones were analyzed in detail and found to synthesize discrete mycoplasma proteins. Two carried overlapping fragments of mycoplasma DNA which encoded a protein that was readily detected in Escherichia coli after infection with recombinant bacteriophage. The third clone contained a novel mycoplasma DNA fragment which directed the synthesis of two additional mycoplasma proteins. Further screening of the library with antiserum raised against the major M. pneumoniae adhesin protein P1 (165 kilodaltons [kDa]) yielded one clone which produced an immunologically reactive protein of 140 kDa. Adsorption of anti-P1 serum by this clone selected a population of antibodies that were reactive with M. pneumoniae adhesin P1 (165 kDa). These results demonstrate that immunologically active M. pneumoniae proteins are synthesized in E. coli.
Assuntos
Antígenos de Bactérias/genética , Proteínas de Bactérias/genética , Mycoplasma pneumoniae/genética , Adesividade , Clonagem Molecular , DNA Bacteriano/genética , Eletroforese em Gel de Poliacrilamida , Escherichia coli/genética , Genes , Genes Bacterianos , Técnicas de Imunoadsorção , Proteínas de Membrana/genética , Peso MolecularRESUMO
Cytadsorption by Mycoplasma pneumoniae requires dense clustering of the surface membrane protein, P1, at the extreme end of the mycoplasma tip-like organelle. M. pneumoniae mutants incapable of cytadsorption either lack P1 or cannot mobilize and cluster P1 at the terminus. Specific cytadsorption-associated proteins in addition to P1 have been shown by mutant and revertant analysis to be essential for cytadsorption. Using monoclonal antibody probes and surface iodination techniques, additional chemical differences were observed between wild-type and mutant M. pneumoniae. M. genitalium, the recently identified new species, possesses structural and antigenic properties that appear similar to M. pneumoniae. Studies were initiated to establish the relatedness between M. pneumoniae and M. genitalium in terms of cytadsorption and membrane proteins.