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ABSTRACT Background: Helicobacter pylori is an etiologic agent of gastroduodenal diseases. The microorganism, considered a type I carcinogen, affects about 50% of the global population. H. pylori virulence factors are determinant for the clinical outcome of the infection. The outer inflammatory protein A (oipA) gene encodes an outer membrane adhesin and is related to severe gastropathies, such as gastric cancer. Objective: The aim of this study was to evaluate the association of the oipA gene with the severity of gastroduodenal diseases in dyspeptic patients in region Central Brazil. Methods: The polymerase chain reaction (PCR) was used to determine the presence of H. pylori. Samples positives were used for molecular screening of the oipA gene. Gastropathies were categorized as non-severe and severe diseases. Results: Approximately 68% of patients had H. pylori and 36% were infected with H. pylori oipA+ strains. Infection was significantly associated in patients aged over 44 years (P=0.004). However, there was no association between oipA and patients' age (P=0.89). Approximately 46% of patients infected with oipA+ strains had some severe illness. Gastric adenocarcinoma was the most frequent severe gastropathy. The H. pylori oipA genotype was inversely associated with the severity of gastroduodenal diseases (OR=0.247, 95%CI: 0.0804-0.7149 and P=0.007). Conclusion: The characterization of possible molecular markers will contribute to personalized medicine, impacting the prognosis of patients.

RESUMO Contexto: Helicobacter pylori é um agente etiológico de doenças gastroduodenais. O microrganismo, considerado cancerígeno tipo I, afeta cerca de 50% da população mundial. Os fatores de virulência do H. pylori são determinantes para o desfecho clínico da infecção. O gene da proteína inflamatória externa A (oipA) codifica uma adesina da membrana externa e está relacionado a gastropatias severas, como o câncer gástrico. Objetivo: O objetivo deste estudo foi avaliar a associação do gene oipA com a gravidade das doenças gastroduodenais em pacientes dispépticos na região Brasil Central. Métodos: A reação em cadeia da polimerase (PCR) foi utilizada para determinar a presença de H. pylori. Amostras positivas foram utilizadas para triagem molecular do gene oipA. As gastropatias foram categorizadas como doenças não severas e severas. Resultados: Aproximadamente 68% dos pacientes apresentaram H. pylori e 36% estavam infectados com cepas H. pylori oipA+. A infecção foi significativamente associada em pacientes com idade superior a 44 anos (P=0,004). No entanto, não houve associação entre oipA e a idade dos pacientes (P=0,89). Aproximadamente 46% dos pacientes infectados com cepas oipA+ tiveram alguma doença severa. O adenocarcinoma gástrico foi a gastropatia severa mais frequente. O genótipo oipA de H. pylori foi inversamente associado à gravidade das doenças gastroduodenais (OR=0,247, IC95%: 0,0804-0,7149 P=0,007). Conclusão: A caracterização de possíveis marcadores moleculares contribuirá para a medicina personalizada, impactando no prognóstico dos pacientes.

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The isolation of multidrug-resistant Klebsiella pneumoniae in hospitals is a major public health threat, increasing patient hospitalization costs, morbidity and mortality. Therefore, this work investigated the resistance mechanisms that produced different carbapenems susceptibility profiles in two isogenic strains of K. pneumoniae isolated from the same patient in a public hospital in Recife, Pernambuco. The genes that encode the main porins in K. pneumoniae, ompK35 and ompK36, and several beta-lactamase genes were analyzed. The expression of these genes was evaluated by quantitative real time PCR (polymerase chain reaction) with reverse transcriptase (RT-qPCR). SDS-PAGE (sodium dodecyl sulphate­polyacrylamide gel electrophoresis) was performed to analyze the outer membrane proteins. The analysis of the ompK36 genetic environment disclosed an IS903 insertion sequence disrupting this gene in the ertapenem resistant isolate (KPN133). The blaKPC-2 gene showed down-regulated expression in both isolates. Our findings show that changes in porins, especially OmpK36, are more determinant to carbapenems susceptibility profile of bacterial isolates than variations in blaKPC gene expression.

O isolamento de Klebsiella pneumoniae multirresistente em hospitais é uma grande ameaça à saúde pública, aumentando os custos de internação, morbidade e mortalidade dos pacientes. Portanto, este trabalho investigou os mecanismos de resistência que produziram diferentes perfis de suscetibilidade aos carbapenêmicos em duas cepas isogênicas de K. pneumoniae isoladas do mesmo paciente em um hospital público em Recife, Pernambuco. Foram analisados ​​os genes que codificam as principais porinas em K. pneumoniae, ompK35 e ompK36, e diversos genes de beta-lactamases. A expressão desses genes foi avaliada por PCR (reação em cadeia da polimerase quantitativa em tempo real) com transcriptase reversa (RT-qPCR). SDS-PAGE (dodecil sulfato de sódio-poliacrilamida gel eletroforese) foi realizada para analisar as proteínas da membrana externa. A análise do ambiente genético ompK36 revelou uma sequência de inserção IS903 interrompendo este gene no isolado resistente ao ertapenem (KPN133). O gene blaKPC-2 apresentou expressão negativamente regulada em ambos os isolados. Nossos achados mostram que alterações nas porinas, especialmente OmpK36, são mais determinantes no perfil de suscetibilidade aos carbapenêmicos de isolados bacterianos do que variações na expressão do gene blaKPC.

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PURPOSE: In the present study, meningococcal serogroup B outer membrane vesicles (OMVs) were associated with bilayer fragments of a cationic lipid, dioctadecyldimethylammonium (DDA-BF), used as adjuvant, in an antigenic preparation tested in adult female outbred mice. This adjuvant was compared to the traditional adjuvant aluminum hydroxide. MATERIALS AND METHODS: The potential in generating humoral response was evaluated by enzyme-linked immunosorbent assay (ELISA). Individual serum was collected and immunoglobulin G (IgG), IgG1, IgG2a, and IgG2b were quantified. Analyses were carried out 15 and 60 days after immunization. Antibodies avidity index were also analyzed by ELISA. Immunoblot and dot-ELISA were carried out to evaluate specific reaction for homologous strains and cross-reactive antigens present in other meningococcal strains isolated in 2011-2012 year, in Brazil. Delayed type hypersensitivity was used as indicative of cellular immunity and compared between two experimental groups, 24 hours after homologous strain challenge. RESULTS: The OMVs of Neisseria meningitidis, and N. lactamica (related species) were characterized by electrophoretic separation of proteins in 13% polyacrylamide gel. The strains presented antigens in the range of 8 to 130 kDa, showing a heterogeneous protein migration pattern. In the group immunized with OMVs/DDA-BF, we found no significant production of total IgG 15 days after the first immunization. On the other hand, 60 days after first immunization both adjuvants act benefiting total IgG production similarly. The antibodies of the IgG isotype produced by animals immunized after one or two doses after first immunization, showed intermediate and high avidity, independent on the adjuvant used. In both experimental groups the swelling of the footpads was significantly higher than those of the controls, suggesting that only one dose was enough to stimulate the generation of cellular immunity. CONCLUSION: The use of this cationic adjuvant for N. meningitidis OMVs preparation revealed good potential for future new antigen preparation for N. meningitidis vaccine.

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Physiological conditions in living cells are strictly regulated to allow, optimize, and coordinate biological processes. The bacterial cell envelope is the compartment where the communication with the external environment takes place. This involves membrane proteins, key players in many biological processes that ensure bacterial survival. The biochemical characterization of membrane proteins, either integral, lipidated or peripheral is challenging due to their mixed protein-lipid nature, making it difficult to purify and obtain considerable amounts of samples. In contrast to integral membrane proteins, lipidated proteins are usually purified as truncated soluble versions, neglecting the impact of the membrane environment. Here we report a simple and robust protocol to characterize bacterial lipidated proteins in spheroplasts from Escherichia coli using a ß-lactamase as a model. The Metallo-ß-lactamase NDM-1 is an enzyme anchored to the inner leaflet of the outer membrane of Gram-negative bacteria. Kinetic parameters and stability of the lipidated NDM-1 and the soluble unbound version (NDM-1 C26A) were measured in spheroplasts and periplasm, respectively. These studies revealed that membrane anchoring increases the KM of the enzyme, consequently decreasing the catalytic efficiency, while not affecting its kinetic stability. This approach can be used to characterize lipidated proteins avoiding the purification step while mimicking its native environment. This approach also helps in filling the gap between in vitro and in vivo studies.

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Debido a las características particulares de la respuesta inmune en lactantes, así como a la eficacia mostrada por la vacuna cubana antimeningocóccica VA-MENGOC-BC, nos propusimos cuantificar la respuesta de la inmunoglobulina G contra los componentes inmunogénicos de los meningococos B y C presentes en la vacuna, en lactantes vacunados. Se tomó muestra por punción capilar a 109 lactantes entre 3 y 6 meses de edad antes de la vacunación a los 31,4 ± 2 días después de la primera y 32,3 ± días después de la segunda dosis vacunal. Se determinaron las concentraciones de inmunoglobulina G contra cada inmunógeno de la vacuna. Los niveles de inmunoglobulina G específica prevacunación, fueron elevadas contra el meningococo C. Se produjo un incremento estadísticamente significativo de anticuerpos para ambos inmunógenos después de la primera y segunda dosis, más marcado contra el meningococo C en la primera y para el meningococo B en la segunda, lo que apoya la presencia de memoria inmunológica.

Due to the particular characteristics of the immune response in infants and to the efficacy shown by the Cuban antimeningococcal vaccine denominated VA-MENGOC-BC, we propose ourselves to quantify the response of immunoglobulin G against the immunogenic components of the meningococci B and C present in the vaccine among the vaccinated infants. The sample was taken by capillary puncture from 109 infants between 3 and 6 months before vaccination, at 31.4±2 days after the first dose and at 32.3± days after the second one. The concentrations of immunoglobulin G against each immunogen of the vaccine were determined. The levels of prevaccination specific immunoglobulin G were elevated against meningococcus C. There was a statistically significant increase of atibodies for both immunogens after the first and second dose. It was more marked against meningococcus C in the first, and for meningococcus B in the secons one, which supports the presence of immunological memory.