BackgroundHealthy individuals can host Staphylococcus aureus in the nasopharynx, body surface and vagina. Most invasive infections by this bacterium are endogenous, caused by strains spread from the nasopharynx of carriers. S. aureus is a pathogen involved in the etiology of hospital- and community-acquired infections. Transplant and dialysis patients are at risk of colonization or infection by multi-resistant S. aureus. Infection is directly linked to individual immunity, and the major histocompatibility complex (MHC) plays a crucial role in determining susceptibility to diseases. Different MHC specificities have been shown to be more frequent in individuals suffering from certain diseases. This study aimed to investigate the association between HLA class I (HLA-A and -B) and class II (HLA-DRB1) molecules and nasal carriage of S. aureus in dialysis and kidney transplant patients at a hospital in Southern Brazil.ResultsThe sample consisted of 70 dialysis and 46 kidney transplant patients, totaling 116 patients. All subjects were typed for HLA molecules using LABType® SSO (One Lambda). Nasal swab samples of S. aureus were isolated from the nasal cavity (both nostrils) of patients undergoing dialysis or kidney transplantation.In renal dialysis patients, HLA-A*02 was the most frequent allele in both carriers (25.5%) and non-carriers (21.2%) of S. aureus. Allele A*68 was not observed in the carrier group, but the allele was observed six times in the non-carrier group (p = 0.0097). Regarding HLA-B and HLA-DRB1, no allele was shown to be involved in protection against or susceptibility to carriage of S. aureus. In kidney transplant patients, allele A*03 was more frequent in the non-carrier (20.83%) than in the carrier (5.88%) group (p = 0.0486). HLA-B*15 was present in carriers (5.88%) and non-carriers (25%) (p = 0.0179). Regarding class II alleles, DRB1*03 appeared to be related to susceptibility to carriage of S. aureus (p = 0.0319).ConclusionsOur findings suggest that HLA-DRB1*03 may be involved in susceptibility to nasal carriage of S. aureus in transplant patients. In addition, HLA-A*68 (dialysis patients) and HLA-A*03 and HLA-B*15 (transplant patients) appear to be associated with increased resistance to S. aureus nasal carriage.

The objective of the present study was to determine the frequency of Staphylococcus aureus nasal carriage among dialysis and kidney transplant patients, to identify the antimicrobial resistance profile of these strains and to verify their genetic profiles with the RW3A primer. The study included 159 individuals, comprising 111 dialysis and 48 kidney transplant patients. Of the 48 transplant patients, 75% were positive for S.aureus, whereas 49% of the 111 dialysis patients were carriers. Two samples yielded conflicting results for oxacillin sensitivity between the disk diffusion and minimum inhibitory concentration (MIC) assays: both were sensitive by the disk diffusion assay and resistant by MIC (4 μg/ml). In the antibiogram by disk diffusion, ten samples were resistant to cefoxitin, among which eight were also resistant to oxacillin. The resistance of the ten samples to cefoxitin by the disk diffusion assay was confirmed by MIC. Of the ten oxacillin-resistant samples, eight harbored the mecA gene. All samples were sensitive to vancomycin, and most were resistant to penicillin and demonstrated high rates of resistance to the other antimicrobials tested.The samples from dialysis patients exhibited a more homogenous genetic profile. Among the samples with a high percent similarity, no correlation with sensitivity or resistance to oxacillin was observed. According to the results of this study, the implementation of prevention and control measures, such as increased restrictions on prescriptions for antimicrobial drugs and nasal decontamination prior to high-risk procedures, is recommended.

Introduction: Genetic polymorphisms define the cytokine production leading to susceptibility or resistance to diseases. We studied the cytokine polymorphism in the development of tegumentary leishmaniasis (TL). Methods: Genotyping of TNF-α, TGF-β1, IFN-γ, IL-6, and IL-10 were performed by polymerase chain reaction assay. Results: G and C alleles of TGF-β1 (codon 25) were the most common in controls and patients, respectively.

RESUMO:Estudo quantitativo, exploratório e analítico realizado no período de março a junho de 2010, na Unidade de Terapia Intensiva de um hospital paranaense com o objetivo de identificar o perfil genético das amostras de Staphylococcus aureus isoladas de pacientes e membros da equipe de enfermagem. A suscetibilidade à oxacilina foi avaliada pelo teste de determinação da concentração inibitória mínima e a técnica da reação em cadeia da polimerase foi empregada para a realização da genotipagem. TIPIFICACIÓN MOLECULAR DE STAPHYLOCOCCUS AUREUS AISLADOS DE PACIENTES Y MIEMBROS DEL EQUIPO DE ENFERMERÍARESUMEN: Estudio cuantitativo, exploratorio y analítico realizado en el periodo de marzo a junio de 2010, en la Unidad de Terapia Intensiva de un hospital de Paraná con el objetivo de identificar el perfil genético de muestras de Staphylococcus aureus aisladas de pacientes y miembros del equipo de Enfermería. La susceptibilidad a la oxacilina fue evaluada por el test de determinación de la concentración inhibitoria mínima y la técnica de reacción en cadena de la polimerasa fue utilizada para realizar el genotipaje. Algunas asociaciones de interés fueron verificadas utilizando test "qui-quadrado", adoptándose p ≤0,05. De las 61 muestras de 46 pacientes, 44,26% tuvieron grado de similitud superior a 80%; seis muestras, de parejas dos a dos, tuvieron 100% de similitud. De las 20 muestras de los 13 profesionales, 65% presentaron similitud superior a 80%. Se observó la existencia de cepas con perfiles genéticos idénticos, o semejantes, pero no es posible afirmar que hubo diseminación clonal en esta unidad.