RESUMO
Numerous host and environmental factors contribute to persistent and intermittent nasal Staphylococcus aureus carriage in humans. The effects of worsening glycemia on the odds of S. aureus intermittent and persistent nasal carriage was established in two cohorts from an adult Mexican American population living in Starr County, Texas. The anterior nares were sampled at two time points and the presence of S. aureus determined by laboratory culture and spa-typing. Persistent carriers were defined by the presence of S. aureus of the same spa-type at both time points, intermittent carriers were S. aureus-positive for 1 of 2 swabs, and noncarriers were negative for S. aureus at both time points. Diabetes status was obtained through personal interview and physical examination that included a blood draw for the determination of percent glycated hemoglobin A1c (%HbA1c), fasting plasma glucose, and other blood chemistry values. Using logistic regression and general estimating equations, the odds of persistent and intermittent nasal carriage compared to noncarriers across the glycemic spectrum was determined controlling for covariates. Increasing fasting plasma glucose and %HbA1c in the primary and replication cohort, respectively, were significantly associated with increasing odds of S. aureus intermittent, but not persistent nasal carriage. These data suggest that increasing dysglycemia is a risk factor for intermittent S. aureus nasal carriage potentially placing those with poorly controlled diabetes at an increased risk of acquiring an S. aureus infection. IMPORTANCE Factors affecting nasal S. aureus colonization have been studied primarily in the context of persistent carriage. In contrast, few studies have examined factors affecting intermittent nasal carriage with this pathogen. This study demonstrates that the odds of intermittent but not persistent nasal carriage of S. aureus significantly increases with worsening measures of dysglycemia. This is important in the context of poorly controlled diabetes since the risk of becoming colonized with one of the primary organisms associated with diabetic foot infections can lead to increased morbidity and mortality.
Assuntos
Infecções Estafilocócicas , Staphylococcus aureus , Adulto , Glicemia , Portador Sadio/epidemiologia , Hemoglobinas Glicadas , Humanos , Americanos Mexicanos , Infecções Estafilocócicas/diagnóstico , Infecções Estafilocócicas/epidemiologia , Staphylococcus aureus/genéticaRESUMO
Selection pressures exerted on Staphylococcus aureus by host factors may lead to the emergence of mutants better adapted to the evolving conditions at the infection site. This study was aimed at identifying the changes that occur in S. aureus exposed to the host defense mechanisms during chronic osteomyelitis and evaluating whether these changes affect the virulence of the organism. Genome assessment of two S. aureus isolates collected 13 months apart (HU-85a and HU-85c) from a host with chronic osteomyelitis was made by whole genome sequencing. Agr functionality was assessed by qRT-PCR. Isolates were tested in a rat model of osteomyelitis and the bacterial load (CFU/tibia) and the morphometric osteomyelitic index (OI) were determined. The ability of the isolates to trigger the release of proinflammatory cytokines was determined on macrophages in culture. Persistence of S. aureus within the host resulted in an agrC frameshift mutation that likely led to the observed phenotype. The capacity to cause bone tissue damage and trigger proinflammatory cytokines by macrophages of the agr-deficient, unencapsulated derivative (HU-85c) was decreased when compared with those of the isogenic CP8-capsulated parental strain (HU-85a). By comparison, no significant differences were found in the bacterial load or the OI from rats challenged with isogenic Reynolds strains [CP5, CP8, and non-typeable (NT)], indicating that lack of CP expression alone was not likely responsible for the reduced capacity to cause tissue damage in HU-85c compared with HU-85a. The production of biofilm was significantly increased in the isogenic derivative HU-85c. Lack of agr-dependent factors makes S. aureus less virulent during chronic osteomyelitis and alteration of the agr functionality seems to permit better adaptation of S. aureus to the chronically infected host.
Assuntos
Adaptação Biológica/genética , Proteínas de Bactérias/genética , Interações Hospedeiro-Patógeno , Mutação , Osteomielite/microbiologia , Infecções Estafilocócicas/microbiologia , Staphylococcus aureus/fisiologia , Transativadores/genética , Animais , Carga Bacteriana , Biofilmes , Doença Crônica , Citocinas/metabolismo , Modelos Animais de Doenças , Suscetibilidade a Doenças , Humanos , Macrófagos/imunologia , Macrófagos/metabolismo , Masculino , Ratos , Adulto JovemRESUMO
Staphylococcus aureus is the number one cause of hospital-acquired infections. Understanding host pathogen interactions is paramount to the development of more effective treatment and prevention strategies. Therefore, whole exome sequence and chip-based genotype data were used to conduct rare variant and genome-wide association analyses in a Mexican-American cohort from Starr County, Texas to identify genes and variants associated with S. aureus nasal carriage. Unlike most studies of S. aureus that are based on hospitalized populations, this study used a representative community sample. Two nasal swabs were collected from participants (n = 858) 11-17 days apart between October 2009 and December 2013, screened for the presence of S. aureus, and then classified as either persistent, intermittent, or non-carriers. The chip-based and exome sequence-based single variant association analyses identified 1 genome-wide significant region (KAT2B) for intermittent and 11 regions suggestively associated with persistent or intermittent S. aureus carriage. We also report top findings from gene-based burden analyses of rare functional variation. Notably, we observed marked differences between signals associated with persistent and intermittent carriage. In single variant analyses of persistent carriage, 7 of 9 genes in suggestively associated regions and all 5 top gene-based findings are associated with cell growth or tight junction integrity or are structural constituents of the cytoskeleton, suggesting that variation in genes associated with persistent carriage impact cellular integrity and morphology.
Assuntos
Portador Sadio , Estudo de Associação Genômica Ampla , Nariz/microbiologia , Infecções Estafilocócicas/genética , Adulto , Idoso , Estudos de Coortes , Exoma , Éxons , Feminino , Variação Genética , Genótipo , Humanos , Inflamação , Masculino , Americanos Mexicanos , Pessoa de Meia-Idade , Fenótipo , Polimorfismo de Nucleotídeo Único , Análise de Regressão , Infecções Estafilocócicas/etnologia , Staphylococcus aureus , Texas , Fatores de Transcrição de p300-CBP/genéticaRESUMO
BACKGROUND: The community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) epidemic in the United States is attributed to the spread of the USA300 clone. An epidemic of CA-MRSA closely related to USA300 has occurred in northern South America (USA300 Latin-American variant, USA300-LV). Using phylogenomic analysis, we aimed to understand the relationships between these 2 epidemics. METHODS: We sequenced the genomes of 51 MRSA clinical isolates collected between 1999 and 2012 from the United States, Colombia, Venezuela, and Ecuador. Phylogenetic analysis was used to infer the relationships and times since the divergence of the major clades. RESULTS: Phylogenetic analyses revealed 2 dominant clades that segregated by geographical region, had a putative common ancestor in 1975, and originated in 1989, in North America, and in 1985, in South America. Emergence of these parallel epidemics coincides with the independent acquisition of the arginine catabolic mobile element (ACME) in North American isolates and a novel copper and mercury resistance (COMER) mobile element in South American isolates. CONCLUSIONS: Our results reveal the existence of 2 parallel USA300 epidemics that shared a recent common ancestor. The simultaneous rapid dissemination of these 2 epidemic clades suggests the presence of shared, potentially convergent adaptations that enhance fitness and ability to spread.
Assuntos
Infecções Comunitárias Adquiridas/epidemiologia , Infecções Comunitárias Adquiridas/microbiologia , Epidemias , Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Infecções Estafilocócicas/epidemiologia , Infecções Estafilocócicas/microbiologia , Monitoramento Epidemiológico , Genoma Bacteriano , Genótipo , Humanos , Epidemiologia Molecular , Tipagem Molecular , América do Norte/epidemiologia , Filogeografia , Análise de Sequência de DNA , América do Sul/epidemiologiaRESUMO
The molecular fingerprinting of a collection of 94 Staphylococcus aureus isolates from patients with osteomyelitis in Argentina was performed. Twenty-three SmaI pulsed-field gel electrophoresis (PFGE) types and 37 spa types were identified. The isolates were assigned to 23 sequence types (STs). The proportion of methicillin-resistant S. aureus (MRSA) isolates was significantly higher among cap5 S. aureus (35/61) compared with cap8 S. aureus (8/33) isolates (p = 0.0025). Twenty-four of the 94 isolates carried the lukS-PV/lukF-PV genes, which were significantly associated to cap5 [(23/38) compared with cap8 S. aureus isolates (1/32) (p = 0.0001)]. Forty of the 94 isolates carried genes of the egc locus (seg/sei). The distribution of seg/sei genes among isolates was related to certain clones. Isolates of the four agr types were found in the S. aureus collection. Whereas agr I isolates were evenly distributed among cap5 and cap8 S. aureus isolates (32/61 and 14/33, respectively), the agr II group was composed of 29 cap5 S. aureus isolates and agr III was composed of 16 cap8 S. aureus isolates. Two clones originally associated to animals (ST 188, 7 isolates and ST 1796, 5 isolates) were associated with chronic osteomyelitis and lack of capsular polysaccharide (CP) production. Loss of CP production remains the single factor among those investigated that is associated with chronic osteomyelitis.
Assuntos
Proteínas de Bactérias/genética , Osteomielite/microbiologia , Polissacarídeos Bacterianos/genética , Staphylococcus aureus/isolamento & purificação , Fatores de Virulência/genética , Argentina/epidemiologia , Técnicas de Tipagem Bacteriana , Eletroforese em Gel de Campo Pulsado , Enterotoxinas/genética , Genes Bacterianos , Loci Gênicos , Humanos , Proteínas de Ligação às Penicilinas , Prevalência , Infecções Estafilocócicas/epidemiologia , Infecções Estafilocócicas/microbiologia , Staphylococcus aureus/classificação , Staphylococcus aureus/genética , Superantígenos/genética , Transativadores/genéticaRESUMO
OBJECTIVE: To assess the adequacy of the process of informed consent for surgical patients at the University Hospital of the West Indies. METHOD: The study is a prospective, cross-sectional, descriptive study. 210 patients at the University Hospital of the West Indies were interviewed using a standardised investigator-administered questionnaire, developed by the authors, after obtaining witnessed, informed consent for participation in the study. Data were analysed using SPSS V.12 for Windows. RESULTS: Of the patients, 39.4% were male. Of the surgical procedures, 68.6% were scheduled, 7.6% urgent and 23.8% emergency, 35.2% were minor and 64.8% major. Information imparted/received was acceptable in 40% of cases, good in 24% and inadequate (unacceptable) in 36% of cases. Almost all (97.6%) patients stated that they understood why an operation was planned and 93.3% thought that they had given informed consent. Most (95.2%) thought that they had free choice and made up their own mind. A quarter (25.2%) of all patients were told that it was mandatory for them to sign the form. There was a discussion of possible side effects and complications in 56.7% of patients. CONCLUSIONS: This study clearly indicates that surgical patients at the University Hospital of the West Indies feel that they have given informed consent. However, it also suggests that more information should be given to patients for consent to be truly informed.
Assuntos
Consentimento Livre e Esclarecido/normas , Procedimentos Cirúrgicos Operatórios , Adulto , Atitude Frente a Saúde , Métodos Epidemiológicos , Feminino , Hospitais Universitários , Humanos , Consentimento Livre e Esclarecido/ética , Masculino , Satisfação do Paciente , Procedimentos Cirúrgicos Operatórios/ética , Índias OcidentaisRESUMO
The objective was to investigate the frequency of anti-cyclic citrullinated peptides (CCP) antibodies in systemic sclerosis (SSc) and primary biliary cirrhosis (PBC), utilizing a new "third generation" anti-CCP ELISA (anti-CCP3) kit and a conventional anti-CCP2 assay. Patients with PBC, SSc, RA, and normal controls were included in the study. Serum samples were screened for autoantibodies by indirect immunofluorescence (IIF), antibodies to CCP by a second- and third-generation ELISA, antibodies to "scleroderma" antigens (CENP B, Scl-70, PM/Scl and fibrillarin-Scl-34) by a line immunoassay (LIA), and IgM RF by ELISA. The frequency of anti-CCP2 antibodies in SSc and PBC samples was 14.8% (11/74) and 6.2% (5/80), respectively, and the frequency of anti-CCP3 antibodies in SSc was 13.5% (10/74) and in PBC was 3.7% (3/80). By comparison, in the RA group the frequency of anti-CCP3 and anti-CCP2 antibodies was 79.1% (38/48) and 77% (37/48), respectively. Anti-CCP3 ELISA had a sensitivity, specificity, and positive and negative likelihood ratios (LR) of 79% (95% confidence interval [CI] = 64-89%), 93% (95% CI = 88-96%), 11.8 (95% CI = 6.8-20.3), and 0.22 (95% CI = 0.12-0.38), respectively. By comparison, the anti-CCP2 assay had a sensitivity, specificity, and positive and negative LRs of 77% (95% CI = 62-87), 90% (95% CI = 85-94), 8.3 (95% CI = 5.2-13.2), and 0.25 (95% CI = 0.15-0.42), respectively. In patients with SSc, there was an association of anti-CCP2 antibodies with the presence of arthritis, but there was no association of anti-CCP2 or anti-CCP3 with anti-CENP B, anti-Scl 70, or RF. This study confirmed the high specificity and sensitivity of both anti-CCP assays for the diagnosis of RA. The presence of anti-CCP antibodies in SSc was only correlated with the presence of arthritis.
Assuntos
Artrite Reumatoide/imunologia , Autoanticorpos/análise , Cirrose Hepática Biliar/imunologia , Peptídeos Cíclicos/imunologia , Escleroderma Sistêmico/imunologia , Artrite Reumatoide/diagnóstico , Autoanticorpos/imunologia , Ensaio de Imunoadsorção Enzimática , Feminino , Técnica Indireta de Fluorescência para Anticorpo , Humanos , Cirrose Hepática Biliar/diagnóstico , Masculino , Pessoa de Meia-Idade , Escleroderma Sistêmico/diagnósticoRESUMO
The species of dermatophyte fungi causing tinea capitis vary from country to country and may also change with time. This study was done to identify the predominant organisms causing tinea capitis in the Jamaican population. It was a retrospective study looking at all fungal culture requests to the Microbiology Department at the University Hospital of the West Indies during the period January 1, 1998 to December 31, 2002. The results showed a gradual switch from the dominance of Microsporum audouinii (61.5%) in 1998 to the dominance of Trichophyton tonsurans (85%) in 2002. The mean age was 8.6. Females constituted 55.7% of positive cases and males, 44.3%.
Assuntos
Tinha do Couro Cabeludo/epidemiologia , Tinha do Couro Cabeludo/microbiologia , Adolescente , Adulto , Criança , Pré-Escolar , Feminino , Fungos/classificação , Fungos/isolamento & purificação , Humanos , Jamaica/epidemiologia , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Distribuição por Sexo , Fatores SexuaisRESUMO
The species of dermatophyte fungi causing tinea capitis vary from country to country and may also change with time. This study was done to identify the predominant organisms causing tinea capitis in the Jamaican population. It was a retrospective study looking at all fungal culture requests to the Microbiology Department at the University Hospital of the West Indies during the period January 1, 1998 to December 31, 2002. The results showed a gradual switch from the dominance of Microsporum audouinii (61.5) in 1998 to the dominance of Trichophyton tonsurans (85) in 2002. The mean age was 8.6. Females constituted 55.7of positive cases and males, 44.3.
Las especies de hongos dermatofitos que causan la tinea capitis varían de país en país, y también pueden cambiar con el tiempo. Este estudio se realizó con el propósito de identificar los organismos predominantes que causan la tinea capitis en la población jamaicana. Se trata de un estudio retrospectivo que revisó todas las solicitudes de cultivos fúngicos hechas al Departamento de Microbiología del Hospital Universitario de West Indies durante el periodo del 1ero. de enero de 1998 al 31 de diciembre de 2002. Los resultados mostraron un cambio gradual del predominio de Microsporum audoinii (61.5%) en 1998 al predominio de Trichophyton tonsurans (85%) en 2002. La edad promedio fue 8.6. Las hembras constituyeron el 55.7%, y los varones el 44.3% de los casos positivos, respectivamente.