Diversity and characterisation of coagulasenegative staphylococci isolated from healthy individuals in Portugal

In the past few years the interest in coagulase-negative staphylococci (CoNS) has significantly increased in human medicine. CoNS are common commensal colonisers of the human skin, although now also recognised as major nosocomial pathogens. Over the last decades, several studies have been carried out in order to understand the pathogenicity mechanisms of CoNS. The well known determinants in the pathogenesis of CoNS infections are their ability to form biofilms and an exceptional resistance to several antibiotics. Nevertheless, there is a lack of studies regarding the commensal lifestyle of these microorganisms. Additionally, it is now hypothesised that commensal bacteria might be a reservoir of pathogenic determinants. Therefore, the work described throughout this thesis was aimed to perform a phenotypic and genotypic characterisation of different CoNS species isolated from healthy Portuguese individuals. A total of 61 CoNS isolates, comprising 7 different species, were obtained and characterised at the level of biofilm formation and antibiotic susceptibility profiles. According to the results, biofilm formation ability and presence of biofilm-associated genes were commonly found features, highlighting their pivotal role in the colonising lifestyle of CoNS. This study also addressed the correlation between phenotypic and genotypic characteristics of biofilm formation, corroborating and raising questions about the importance of some genes in this process. Moreover, it was observed a great proportion of isolates with decreased susceptibility and multiple resistances to some important antibiotics. A significant association between antibiotic resistance and biofilm formation was also demonstrated, and some hypotheses about the nature of such association were provided. Lastly, the expression patterns of two biofilm-associated genes at two distinct biofilm developmental stages were determined, confirming their importance in the accumulative stage of biofilm formation. Overall, the results presented in this thesis indicate that staphylococcal skin flora might be an important reservoir of potentially pathogenic bacteria and, simultaneously, bring to light new perceptions about the molecular basis of staphylococcal biofilm formation, and the nature of the association between antibiotic resistance and biofilm formation.

Uso de medidas de comorbidades para predição de risco de óbito em pacientes brasileiros hospitalizados

OBJETIVO: Avaliar o uso de medidas de comorbidade para predizer o risco de óbito em pacientes brasileiros. MÉTODOS: Foram utilizados dados de internações obtidos do Sistema de Informações Hospitalares do Sistema Único de Saúde, que permite o registro de somente um diagnóstico secundário. Foram selecionadas 1.607.697 internações ocorridas no Brasil em 2003 e 2004, cujos diagnósticos principais foram doença isquêmica do coração, insuficiência cardíaca congestiva, doenças cérebro-vasculares e pneumonia. O Índice de Charlson e as comorbidades de Elixhauser foram as medidas de comorbidade utilizadas; o simples registro de algum diagnóstico secundário foi também empregado. A regressão logística foi aplicada para avaliar o impacto das medidas de comorbidade na estimava da chance de óbito. O modelo de base incluiu as seguintes variáveis: idade, sexo e diagnóstico principal. Os modelos de predição de óbitos foram avaliados com base na estatística C e no teste de Hosmer-Lemeshow. RESULTADOS: A taxa de mortalidade hospitalar foi 10,4% e o tempo médio de permanência foi 5,7 dias. A maioria (52%) das internações ocorreu em homens e a idade média foi 62,6 anos. Do total de internações, 5,4% apresentava um diagnóstico secundário registrado, mas o odds ratio entre óbito e presença de comorbidade foi de 1,93. O modelo de base apresentou uma capacidade de discriminação (estatística C) de 0,685. A melhoria nos modelos atribuída à introdução dos índices de comorbidade foi fraca - equivaleu a zero quando se considerou a estatística C com somente dois dígitos. CONCLUSÕES: Embora a introdução das três medidas de comorbidade nos distintos modelos de predição de óbito tenha melhorado a capacidade preditiva do modelo de base, os valores obtidos ainda são considerados insuficientes. A precisão desse tipo de medida é influenciada pela completitude da fonte de informação. Nesse sentido, o alto sub-registro de diagnóstico secundário, aliado à conhecida insuficiência de espaço para anotação desse tipo de informação no Sistema de Informações Hospitalares, são os principais elementos explicativos dos resultados encontrados.

Hospitalization rates for pneumococcal disease in Brazil, 2004 - 2006

OBJECTIVE: To estimate hospitalization rates for pneumococcal disease based on the Brazilian Hospital Information System (SIH). METHODS: Descriptive study based on the Hospital Information System of Brazilian National Health System data from January 2004 to December 2006: number of hospitalizations and deaths for pneumococcal meningitis, pneumococcal sepsis, pneumococcal pneumonia and Streptococcus pneumoniae as the cause of diseases reported in Brazil. Data from the 2003 Brazilian National Household Survey were used to estimate events in the private sector. Pneumococcal meningitis cases and deaths reported to the Notifiable Diseases Information System during the study period were also analyzed. RESULTS: Pneumococcal disease accounted for 34,217 hospitalizations in the Brazilian National Health System (0.1% of all hospitalizations in the public sector). Pneumococcal pneumonia accounted for 64.8% of these hospitalizations. The age distribution of the estimated hospitalization rates for pneumococcal disease showed a "U"-shape curve with the highest rates seen in children under one (110 to 136.9 per 100,000 children annually). The highest hospital case-fatality rates were seen among the elderly, and for sepsis and meningitis. CONCLUSIONS: PD is a major public health problem in Brazil. The analysis based on the SIH can provide an important input to pneumococcal disease surveillance and the impact assessment of immunization programs.

Rastreamento de resultados adversos nas internações do Sistema Único de Saúde

OBJETIVO: Descrever a frequência de rastreadores de potenciais resultados adversos em internações no Sistema Único de Saúde. MÉTODOS: Estudo retrospectivo, incluindo as internações de adultos na clínica médica (n = 3.565.811) e clínica cirúrgica (n = 2.614.048) no Brasil em 2007. O Sistema de Informações Hospitalares foi utilizado como fonte de informação. A mensuração dos resultados adversos baseou-se no rastreamento de 11 condições clínicas, definidas em estudos internacionais anteriores, registradas no campo diagnóstico secundário. Foram realizadas análises bivariada e multivariada, no intuito de associar resultado adverso, óbito (variável dependente) e outras variáveis como idade, utilização de unidade de terapia intensiva e realização de cirurgia. RESULTADOS: A frequência obtida foi 3,6 potenciais resultados adversos por 1.000 internações para ambas as clínicas, superior na clínica médica (5,3 por 1.000) em relação à clínica cirúrgica (1,3 por 1.000). Houve diferenças no perfil das internações: na clínica médica predominaram idosos, maior tempo médio de permanência, maior taxa de mortalidade e menor custo total de internação. O rastreador de resultado adverso mais frequente foi pneumonia hospitalar. Choque/parada cardíaca apresentou maior risco de óbito (OR = 5,76) em relação aos demais resultados adversos. Os maiores gastos com internações estiveram relacionados à sepse hospitalar. Os rastreadores de potencial resultado adverso apresentaram altas chances de óbito, mesmo com a introdução de variáveis como uso de terapia intensiva e realização de cirurgia. CONCLUSÕES: A alta frequência de resultados adversos em internações indica a necessidade de desenvolver estratégias de monitoramento e melhorias dirigidas para a segurança do paciente.

Infection and childhood leukemia: review of evidence

OBJECTIVE : To analyze studies that evaluated the role of infections as well as indirect measures of exposure to infection in the risk of childhood leukemia, particularly acute lymphoblastic leukemia. METHODS : A search in Medline, Lilacs, and SciELO scientific publication databases initially using the descriptors “childhood leukemia” and “infection” and later searching for the words “childhood leukemia” and “maternal infection or disease” or “breastfeeding” or “daycare attendance” or “vaccination” resulted in 62 publications that met the following inclusion criteria: subject aged ≤ 15 years; specific analysis of cases diagnosed with acute lymphoblastic leukemia or total leukemia; exposure assessment of mothers’ or infants’ to infections (or proxy of infection), and risk of leukemia. RESULTS : Overall, 23 studies that assessed infections in children support the hypothesis that occurrence of infection during early childhood reduces the risk of leukemia, but there are disagreements within and between studies. The evaluation of exposure to infection by indirect measures showed evidence of reduced risk of leukemia associated mainly with daycare attendance. More than 50.0% of the 16 studies that assessed maternal exposure to infection observed increased risk of leukemia associated with episodes of influenza, pneumonia, chickenpox, herpes zoster, lower genital tract infection, skin disease, sexually transmitted diseases, Epstein-Barr virus, and Helicobacter pylori . CONCLUSIONS : Although no specific infectious agent has been identified, scientific evidence suggests that exposure to infections has some effect on childhood leukemia etiology.

Associação entre exposição ao material particulado e internações por doenças respiratórias em crianças

O objetivo desse estudo foi estimar a associação entre exposição a material particulado com menos de 2,5 micra de diâmetro aerodinâmico e internações por doenças respiratórias em crianças. Foi realizado estudo ecológico de séries temporais com indicadores diários de internação por doenças respiratórias, em crianças de zero a dez anos de idade, residentes em Piracicaba, SP, entre 1º de agosto de 2011 e 31 de julho de 2012. Utilizou-se modelo aditivo generalizado da regressão de Poisson. Os riscos relativos foram RR = 1,008; IC95% 1,001;1,016 para o lag 1 e RR = 1,009; IC95% 1,001;1,017 para o lag 3. O incremento de 10 μg/m 3 de material particulado com menos de 2,5 micra de diâmetro implicou aumento no risco relativo entre 7,9 e 8,6 pontos percentuais. Concluiu-se que a exposição ao material particulado com menos de 2,5 micra de diâmetro aerodinâmico esteve associada às internações por doenças respiratórias em crianças.

Intestinal cryptosporidiosis. association with Pneumocystis carinii, cytomegalovirus and Candida sp. Infections

This is a case report of intestinal cryptosporidiosis diagnosed in histological specimen collected from autopsy. The patient was a child of 5 months admitted to the hospital with severe acute diarrhea associated with Pneumocystis carinii pneumonia, cytomegalic sialadenitis, oral and dermal candidiasis. The presence of multiple opportunistic infections in this case indicated immunodeficiency state. Cryptosporidium sp is a possible etiology of acute diarrhea in both immunodeficient and immunocompetent patients and has to be searched for at autopsy when diagnosis was not possible "in vivo".

Conhecimento sobre a doença do criador de pombos entre sócios da Sociedade Columbófila de Sacavém

A Doença do Criador de Pombos (DCP) é uma pneumonia de hipersensibilidade que se desenvolve pela exposição a antigénios orgânicos existentes nas penas e principalmente nos excrementos de pombos. Em Portugal existem cerca de 784 sociedades columbófilas. Contudo, encontraram-se poucos estudos sobre esta temática na população portuguesa e não se encontraram quaisquer referências sobre o nível de conhecimento acerca do risco potencial que a columbofilia comporta. Objetivo do estudo - Realizou-se um estudo exploratório com o objetivo de analisar o conhecimento de um grupo de criadores de pombos sobre a DCP e sobre a forma de a prevenir.

Antibacterial activity of Ionic Liquids based on ampicillin against resistant bacteria

Antibacterial activity of novel Active Pharmaceutical Ingredient Ionic Liquids (API-ILs) based on ampicillin anion [Amp] have been evaluated. They showed growth inhibition and bactericidal properties on some sensitive bacteria and especially some Gram-negative resistant bacteria when compared to the [Na][Amp] and the initial bromide and chloride salts. For these studies were analysed the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBIC) against sensitive Gram-negative bacteria Escherichia coli ATCC 25922 and Klebsiella pneumonia (clinically isolated), as well as sensitive Gram positive S. Aureus ATCC 25923, Staphylococcus epidermidis and Enterococcus faecalis and completed using clinically isolated resistent strains: E. coli TEM CTX M9, E. coli CTX M2 and E. coli AmpC Mox. From the obtained MIC values of studied APIs-ILs and standard [Na][Amp] were derived RDIC values (relative decrease of inhibitory concentration). High RDIC values of [C16Pyr][Amp] especially against two resistant Gram-negative strains E. coli TEM CTX M9 (RDIC>1000) and E. coli CTX M2 (RDIC>100) point clearly to a potential promising role of APIs-ILs as antimicrobial drugs especially against resistant bacterial strains.

Respiratory complications in Brazilian patients infected with human immunodeficiency virus

PURPOSE: To determine how often and by what means an indentifiable pulmonary pathogen can be recognized in human immunodeficiency virus (HIV) infected patients with respiratory disorders in Brazil, which are the most frequently observed microorganisms and what impact specific therapy has on these agents. PATIENTS AND METHODS: Thirty-five HIV seroposiüve subjects with respiratory complaints were studied. All patients had a complete history, physical examination and blood counts. The pulmonary assessment included chest radiograms; sputum examination for bacterial and fungal pathogens; bronchoscopy with bronchoalveolar lavage and transbronchial biopsy. Patients with treatable complications received standard antimicrobial therapy. RESULTS: One or more microorganisms were found in 24 subjects and another 3 individuals showed nonspecific interstitial pneumonitis. The sputum examination identified the pulmonary pathogens in 7 cases. The bronchoalveolar lavage and the histopathologic examination were diagnostic in 14% and 83%, respectively, of the 28 individuals that were submitted to bronchoscopy. The most frequently identified microorganism was P. carinii (55%), followed by M. tuberculosis (41%) and cytomegalovirus (8%). The clinical, laboratory and radiographic findings failed to distinguish the specific pulmonary pathogens. Twenty-three individuals with P. carinii pneumonitis and/or tuberculosis received specific therapy; among the evaluable patients the therapeutic response rates were 79% for PCP and 100% for TB. CONCLUSIONS: We have determined that tuberculosis, P. carinii and cytomegalovirus pneumonitis are the most common respiratory opportunistic diseases in Brazilian patients infected with HIV. The histologic evaluation was crucial in order to identify the pulmonary pathogens. Tuberculosis in AIDS individuals displayed clinical and radiographic findings atypical for reactivation disease. However, most of the features observed in HIV infected patients had been previously described in infection of the normal host. Furthermore, the AIDS subjects showed a good therapeutic response to anti-tuberculous drugs.

Dot-enzyme-linked immunosorbent assay (Dot-ELISA) for detection of pneumococcal polysaccharide antigens in pleural fluid effusion samples.: Comparison with bacterial culture, counterimmunoelectrophoresis and latex agglutination

A dot-enzyme-linked immunosorbent assay (Dot-ELISA) for pneumococcal antigen detection was standardized in view of the need for a rapid and accurate immunodiagnosis of acute pneumococcal pneumonia. A total of 442 pleural fluid effusion samples (PFES) from children with clinical and laboratory diagnoses of acute bacterial pneumonia, plus 38 control PFES from tuberculosis patients and 20 negative control serum samples from healthy children were evaluated by Dot-ELISA. The samples were previously treated with 0.1 M EDTA pH 7.5 at 90°C for 10 min and dotted on nitrocellulose membrane. Pneumococcal omniserum diluted at 1:200 was employed in this assay for antigen detection. When compared with standard bacterial culture, counterimmunoelectrophoresis and latex agglutination techniques, the Dot-ELISA results showed relative indices of 0.940 to sensitivity, 0.830 to specificity and 0.760 to agreement. Pneumococcal omniserum proved to be an optimal polyvalent antiserum for the detection of pneumococcal antigen by Dot-ELISA. Dot-ELISA proved to be a practical alternative technique for the diagnosis of pneumococcal pneumonia.

Aerobic bacteria, Chlamydia trachomatis, Pneumocystis carinii and Cytomegalovirus as agents of severe peneumonia in small infants

The authors studied 58 infants hospitalized for pneumonia in a semi-intensive care unit. Age ranged from 1 complete to 6 incomplete months. The infants were sent from another hospital in 20 cases and from home in a further 38. Pulmonary involvement, which was alveolar in 46 cases and interstitial in 12, was bilateral in 31 children. The investigation was carried out prospectively on the etiological agents associated with respiratory infection to look for evidence of aerobic bacteria (blood cultures), Chlamydia trachomatis and Cytomegalovirus (serology), and Pneumocystis carinii (direct microscopy of tracheal aspirated material). The following infectious agents were diagnosed in 21 children (36.2%): Aerobic bacteria (8), Chlamydia trachomatis (5), Pneumocystis carinii (3), Cytomegalovirus (3), Cytomegalovirus and Chlamydia trachomatis (1), Aerobic bacteria and Cytomegalovirus (1). Seven cases of infection by Chlamydia trachomatis and/or Cytomegalovirus were diagnosed out of the 12 cases with pulmonary interstitial involvement.

The role of Public Health Laboratory in the problem os salmonellosis in São Paulo, Brazil

From 1950 to 1990 a total of 45,862 strains (31,517 isolates from human sources, and 14,345 of non-human origin) were identified at Instituto Adolfo Lutz. No prevalence of any serovars was seen during the period 1950-66 among human sources isolates. Important changing pattern was seen in 1968, when S. Typhimurim surprisingly increased becoming the prevalent serovar in the following decades. During the period of 1970-76, S. Typhimurium represented 77.7% of all serovars of human origin. Significant rise in S. Agona isolation as well as in the number of different serovars among human sources strains were seen in the late 70' and the 80's. More than one hundred different serovars were identified among non-human origin strains. Among serovars isolated from human sources, 74.9%, 15.5%, and 3.7% were recovered from stool, blood, and cerebrospinal fluid cultures, respectively. The outbreak of meningitis by S. Grumpensis in the 60's, emphasizes the concept that any Salmonella serovars can be a cause of epidemics, mainly of the nosocomial origin. This evaluation covering a long period shows the important role of the Public Health Laboratory in the surveillance of salmonellosis, one of the most frequent zoonosis in the world.

Resistance of Streptococcus pneumoniae to antimicrobials in São Paulo, Brazil: clinical features and serotypes

To study resistance to antimicrobials, serotypes and clinical features of S. pneumoniae in S. Paulo, Brazil, 50 patients with a positive culture were evaluated: 7 were considered carriers and 43 had pneumococcal infections. Pneumonia and meningitis were the most commom infections. Mortality was 34% and underlying diseases were present in 70%. Relative resistance to penicillin occurred in 24% and complete resistance was not detected. Resistance to tetracycline was 32% and to sulfamethoxazole/trimethoprim 32%; one strain had intermediate susceptibility to erythromycin; no resistance was present for chloramphenicol, rifampin or vancomycin. Resistance to at least one of the drugs tested occurred in 62%. Results by the E-test for penicillin were similar to those by the agar dilution method. There were 24 different serotypes and 74% of the strains belonged to the 23-valent vaccine including all the penicillin-resistant strains. In this study S. pneumoniae caused severe infections and presented a high resistance rate to commonly used antimicrobials. Routine surveillance of resistance and the use of vaccination, as well as the restriction of inappropriate use of antimicrobials, are recommended in São Paulo, Brazil.

Studies on resistance and response to vancomycin in Enterococcus faecalis: a last resort antibiotic

Dissertation presented to obtain a Ph.D. degree in Biochemistry by Instituto de Tecnologia Química e Biológica Universidade Nova de Lisboa.