Discrepancies in HLA typing: use of different methods to confirm doubtful or inconclusive results / Discrepâncias na tipagem HLA: diferentes métodos para confirmar resultados duvidosos ou inconclusivos

The major histocompatibility complex (MHC) is a set of genes found on the short arm of chromosome 6. MHC molecules in human beings are known as human leukocyte antigens (HLA). HLA polymorphism can be determined by serological and molecular typing methods, which may yield discordant results. The present analysis performed HLA typing of samples with discordant results by PCR-SSP and PCR-SSO, so that typing discrepancies could be clarified. The cross-sectional study analyzed 33 samples from individuals included in an HLA-disease association study. Discrepant alleles were observed in 6 of 33 samples. Discordant samples were retyped using One Lambda Micro SSP™, Dynal RELI™ SSO and Luminex™ SSO assays for HLA class I (HLA-A, HLA-B) and class II (HLA-DRB1) molecules. The three methods produced concordant results after HLA retyping. Human error occurred in interpreting the initial results, which led to discrepancies in the results obtained. The participation of experienced professionals and the availability of at least two different methods to confirm doubtful or inconclusive results are mandatory for effective HLA typing.

O complexo principal de histocompatibilidade (MHC) é um conjunto de genes encontrados no braço curto do cromossomo 6. Em humanos, as moléculas de MHC são conhecidas como antígenos leucocitários humanos (HLA). Polimorfismo HLA pode ser determinado por métodos de tipagem sorológica e molecular que são susceptíveis de produzir resultados discordantes. Este estudo teve como objetivo realizar a tipagem HLA de amostras com resultados discordantes por PCR-SSP e-SSO e para esclarecer discrepâncias de digitação. Este estudo transversal analisou 33 amostras de indivíduos incluídos em um estudo de associação HLA-doença. Alelos discrepantes foram observados em seis das 33 amostras. Amostras discordantes foram retyped usando One Lambda Micro SSP™, Dynal RELI™ SSO Luminex e ensaios ™ SSO para HLA de classe I (HLA-A, HLA-B) e classe II (HLA-DRB1) moléculas. Todos os três métodos apresentaram resultados concordantes após HLA redigitação. Houve erro humano na interpretação dos resultados iniciais o que levou a uma discrepância entre os resultados obtidos. Concluiu-se que a participação de profissionais experientes e com a disponibilidade de pelo menos dois métodos diferentes para confirmar os resultados duvidosos ou inconclusivos são essenciais para a tipagem de HLA eficaz.

Carriage frequency, phenotypic and genotypic characteristics of Staphylococcus aureus isolated from dialysis and kidney tranplant patients at a hosptial in northern Paraná

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.

Infecção hospitalar na perspectiva dos profissionais de enfermagem: um estudo bibliográfico / Hospital-acquired infections from the perspective of nursing professionals: a bibliographical study / Infección hospitalar en la perspectiva de los profesionales de enfermería: un estudio bibliográfico

Estudo bibliográfico teve por objetivo identificar, na produção científica nacional, a forma como o profissional de enfermagem tem abordado o tema infecção hospitalar. Foram analisadas 15 publicações do período de dez anos - 1999 a 2009 - na base de dados SciELO; a busca foi feita no mês de março de 2010 e os dados analisados por meio da análise de conteúdo. Foram encontradas cinco categorias temáticas: o conceito de infecção hospitalar; a compreensão dos profissionais sobre infecção hospitalar e Comissão de Controle de Infecção Hospitalar; responsabilidade dos profissionais no controle de infecção hospitalar; a prevenção e controle da Infecção Hospitalar; e necessidade de formação adequada durante a graduação. Conclui-se que o tema deveria ser mais pesquisado, principalmente no que tange à Enfermagem e ao cuidado ao paciente; o presente estudo serve de subsídio para instigar discussões sobre o tema...

This bibliographical study of Brazilian research output aimed to identify the way in which nursing professionals have approached the theme of hospital-acquired infections. Fifteen publications from the ten-year period 1999- 2009 from the SciELO database were analyzed; the search was carried out in March 2010 and the data analyzed by content analysis. Five thematic categories were found: the concept of hospital-acquired infections; healthcare professionals' understanding of hospital-acquired infections and the Hospital-Acquired Infection Control Commission; healthcare professionals' responsibility in the control of hospital-acquired infections; the prevention and control of hospital-acquired infections; and the necessity for appropriate training during the undergraduate course. It is concluded that more research is needed, principally where nursing and patient care are affected. This study should serve as a base for discussion on the matter...

Estudio bibliográfico cuyor objetivo fue identificar, en la producción científica nacional, la forma como el profesional de enfermería viene abordando el tema infección hospitalar. Fueron analizadas 15 publicaciones del periodo de diez años - 1999 a 2009 - en la base de datos SciELO; la búsqueda fue hecha en el mes de marzo de 2010 y los datos fueron analizados por medio del análisis de contenido. Surgieron cinco categorías temáticas: el concepto de infección hospitalar; la comprensión de los profesionales sobre infección hospitalar y Comisión de Control de Infección Hospitalar; responsabilidad de los profesionales en control de infección hospitalar; la prevención y control de Infección Hospitalar; y necesidad de formación adecuada durante la graduación. Se concluye que el tema debería ser más investigado, principalmente en lo que se refiere a la enfermería y al cuidado al paciente; el presente estudio sirve de subsidio para instigar discusiones sobre el tema...

HLA molecules and nasal carriage of Staphylococcus aureus isolated from dialysis and kidney transplant patients at a hospital in Southern Brazil.

BACKGROUND: Healthy 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. RESULTS: The 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). CONCLUSIONS: Our 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.

Carriage frequency, phenotypic and genotypic characteristics of Staphylococcus aureus isolated from dialysis and kidney tranplant patients at a hosptial in northern paraná.

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.

Infections in patients with chronic renal failure and kidney transplant recipients in Brazil.

Patients with chronic renal failure who are undergoing dialysis and kidney transplant recipients are susceptible to infection for several reasons. In this study, the profile of infections in patients with chronic renal failure and kidney transplant recipients treated at a hospital in northern Paraná, Brazil, from 2007 to 2009 was examined. The study involved 187 patients: 59 kidney transplant recipients and 128 patients undergoing dialysis. The frequency of infection was 25% (32/128) in dialysis patients and 8% (5/59) in transplant recipients (P = .008). Staphylococcus aureus was the most prevalent infectious agent, cultured from 27% (13/48) of samples, followed by Escherichia coli at 17% (8/48). All isolates of S aureus were sensitive to vancomycin and resistant to penicillin, and 43% were resistant to oxacillin. Most S aureus samples (43%) were isolated from cultures of blood samples. As for the E coli, 75% were resistant to cephalothin and 38% were resistant to sulfamethoxazole/trimethoprim. Most isolates of E coli (62%) were cultured from specimens of patients with suspected urinary tract infection.