Differences in virulence markers between Helicobacter pylori strains from the Brazilian Amazon region

Introduction This study compares virulence markers of Helicobacter pylori isolated from patients in 2 cities in the Brazilian Amazon. Methods The study analyzed 168 patients with chronic gastritis from Belém and 151 from Bragança, State of Pará, Brazil. Levels of bacterial DNA associated with cagA and vacA alleles were checked by PCR, and hematoxylin-eosin staining was used for histologic diagnosis. Results In Bragança 87% of patients were genotype s1m1 cagA-positive (s1m1 cagA+), compared with 76% in Belém. In samples from patients in both cities, there was an association between s1m1 cagA+ strains and gastric mucosal damage. Conclusions Both cities have a high frequency of s1m1 cagA+ strains of H. pylori. .

Aspectos imunopatogênicos da sífilis materno-fetal: revisão deliteratura / Immunopathogenic characteristics of maternal-fetal syphilis: review of literature

Objetivo: revisar os aspectos imunopatogênicos da sífilis materno-fetal. Método: uma pesquisabibliográfica foi realizada utilizando-se as palavras-chave: sífilis congênita + imunopatogenia, sífilis materna+ imunopatogenia, sífilis + interface materno-fetal. As bases de dados pesquisadas foram a Medline (MedicalLiterature Analysis and Retrieval System Online) da National Library of Medicine (EUA) e a LILACS(Literatura Latino-Americana e do Caribe em Ciências da Saúde). Considerações finais: a infecção peloTreponema pallidum e o desenvolvimento das características clínicas deletérias deve-se ao êxito dosmecanismos de invasão, evasão e da resposta imunológica do hospedeiro. Na gestação ocorrem mudançashormonais, imunológicas e nutricionais necessárias ao bom desenvolvimento fetal que, porém, modulam asuscetibilidade materno-fetal à infecção. Nesse contexto, o perfil de citocinas na placenta tende a proteger ofeto de ser expulso, ao inibir a resposta celular citotóxica, dificultando, no entanto, a eliminação dotreponema da interface materno-fetal. Por outro lado, a resposta imunológica do feto ainda é imatura até a10ª - 20ª semana de gestação, permitindo que o patógeno invada, dissemine e escape. Assim, o diagnósticoprecoce para instituição do tratamento no recém-nascido é mandatório para prevenção das seqüelas e, comoainda não existe um exame laboratorial disponível na rede pública que permita esse diagnóstico em tempohábil, fica claro que um maior conhecimento da fisiopatogenia da doença é prioritário no sentido decontribuir para o avanço nas pesquisas clínicas

Objective: the objective of this study was to revise the immunopathogenic aspects of maternalfetalsyphilis. Methods: a detailed literature search of the Medline (Medical Literature Analysisand Online Retrieval System) of the American National Library of Medicine and the LILACS(Latin American and Caribbean Health Sciences) databases was conducted using the key wordscongenital syphilis + immunopathogeny, maternal syphilis + immunopathogeny, and syphilis +maternal-fetal interface. Final Considerations: the success of infection by T. pallidum and thedevelopment of deleterious clinical symptoms is due to the effectiveness of the mechanisms ofinvasion a, evasion and immunological response of the host. The hormonal, immunological, andnutritional changes that occur during pregnancy and are necessary for the successfuldevelopment of the fetus also modulate the susceptibility of the fetus to infection. In thiscontext, the cytokine profile of the placenta protects the fetus from expulsion by inhibiting thecytotoxic cell response, although this also hampers the elimination of the treponema from thematernal-fetal interface. However, the immunological response of the fetus is immature up untilthe 10-10th week of gestation, allowing the pathogen to invade, spread, and escape. Thus, theearly diagnosis for the treatment of the neonate is essential for the prevention of sequels, but asthe public health service does not provide clinical exams for the timely for the diagnosis of thiscondition, there is a clear need for a better understanding of the physiopathogeny of the diseasewith the specific objective of contributing to the advance of clinical research into the problem

Hepatitis B and C virus infection among Brazilian Amazon riparians / Infecção pelo virus da hepatite B e C em ribeirinhos da Amazônia brasileira

INTRODUCTION: Viral hepatitis is a major public health concern in Brazil. There are few past studies on this issue, especially among riparian communities. This study aims at determining the seroprevalence of viral hepatitis B and C in the riparian community of Pacuí Island, within the Cametá municipality of Pará State, Brazil. Moreover, this study aims to investigate the principal risk factors that this community is exposed to. METHODS: The current study has accessed blood samples from 181 volunteers who have answered an epidemiological questionnaire. Analyses on serological markers have been tested with commercial ELISA kits for detecting HBsAg, total anti-HBc, anti-HBs, and anti-HCV. Within seroreactive patients for HCV, RT-PCR and line probe assay have been performed to identify the viral genotype. RESULTS: In the serological marker analysis for hepatitis B, no reactivity for HBsAg, rate of 1.1 percent for total anti-HBc, and rate of 19.3 percent for anti-HBs have been observed. On hepatitis C, 8.8 percent seroprevalence has been found, in which 62.5 percent have gotten viral RNA. Among the risk factors studied, the following have been highlighted: non-use of condoms, sharing of cutting instruments, use of illicit drugs, and reports of family disease with HBV or HCV. CONCLUSIONS: The vaccination coverage against HBV is low, and the high prevalence of HCV within this community has been observed.

INTRODUÇÃO: As hepatites virais constituem um importante problema de saúde pública no mundo. No Brasil existem poucos estudos sobre esta questão, especialmente entre as comunidades ribeirinhas. O objetivo deste estudo foi determinar a soroprevalência das hepatites B e C virais na comunidade ribeirinha da Ilha do Pacuí, no Estado do Pará, Brasil, e investigar os principais fatores de risco principal a que está comunidade está exposta. MÉTODOS: O presente estudo avaliou amostras de sangue de 181 voluntários que responderam a um questionário epidemiológico. Análises de marcadores sorológicos foram testados com kits comerciais de ELISA para detecção de HBsAg, anti-HBc total, anti-HBs e anti-VHC. Nos pacientes reagentes para VHC, RT-PCR e um line probe assay foi realizado para identificar o genótipo viral. RESULTADOS: Na análise dos marcadores sorológicos para hepatite B, observou-se taxas de 1,1 por cento para anti-HBc total e 19,3 por cento para anti-HBs, o marcador sorológico HBsAg não foi encontrado nesta população. Para a hepatite C foi encontrada um soroprevalência de 8,8 por cento, destes 62,5 por cento tinham RNA viral. Entre os fatores de risco estudados se destacaram: a não-utilização de preservativos, o compartilhamento de instrumentos cortantes, uso de drogas ilícitas e relatos de doença na família com VHB ou VHC. CONCLUSÕES: Observamos que a cobertura de vacinação contra o VHB é baixa e uma alta prevalência da hepatite C nesta comunidade.

Molecular detection of Treponema pallidum sp. pallidum in blood samples of VDRL-seroreactive women with lethal pregnancy outcomes: a retrospective observational study in northern Brazil / Detecção molecular do Treponema pallidum sp. pallidum em amostras de sangue de mulheres sororeativas ao VDRL com resultado letal da gravidez: um estudo observacional retrospectivo no norte do Brasil

INTRODUCTION: Although control measures of maternal and congenital syphilis are available in Brazil, difficulties exist within the healthcare network in providing a laboratory diagnosis of the infection during the prenatal period. The objective of this study was to confirm the presence of Treponema pallidum by PCR in women with positive VDRL serology and lethal pregnancy outcomes, i.e., abortion, stillbirth and neonatal death. METHODS: A retrospective study was conducted on VDRLseroreactive women with lethal pregnancy outcomes admitted to the Fundação Santa Casa de Misericórdia do Pará (FSCM-PA) between January and July 2004. Serum samples and DNA from whole blood were obtained at the time of screening by the VDRL test. These samples were analyzed by IgG ELISA, IgM FTA-Abs and simple PCR (polA). RESULTS: During the study period, 0.7% (36/4,912) of women with lethal pregnancy outcomes presented a positive VDRL test. The polAgene was amplified in 72.7% (24/33) of these women, with 55.6% (20/36) and 94.4% (34/36) presenting IgM and IgG antibodies against T. pallidum, respectively. Comparison of these results showed a significant difference, with agreement between the PCR and IgM FTA-Abs results, suggesting that maternal syphilis was an active infection. No basic cause of death of the conceptus was reported in 97.2% (35/36) of cases. Among women who were submitted to the VDRL test during the prenatal period, only four of the nine seroreactive patients underwent treatment. CONCLUSIONS: The high frequency of syphilis in the group studied indicates the fragility of the service of infection diagnosis, treatment and monitoring, compromising epidemiological control.

INTRODUÇÃO: Apesar das medidas de controle da sífilis materna e congênita estarem disponíveis no Brasil, existem dificuldades da rede em prover o diagnóstico laboratorial da infecção durante o pré-natal. O objetivo deste estudo foi confirmar a presença do Treponema pallidum pela PCR em mulheres com sorologia positiva ao VDRL e com resultado letal da gravidez, isto é, aborto, natimorto e neomorto. MÉTODOS: Estudo retrospectivo realizado em mulheres VDRL-sororeativas com resultado negativo da gravidez, admitidas na Fundação Santa Casa de Misericórdia do Pará FSCM-PA entre janeiro e julho de 2004. As amostras de soro e DNA de sangue total foram obtidas no mesmo período da triagem pelo VDRL. Estas amostras foram analisadas pelo ELISA IgG, FTA-Abs IgM e PCR simples (polA). RESULTADOS: Durante o período de estudo, 0,7% (36/4.912) das mulheres com resultado letal da gravidez apresentaram VDRL positivo. O genepolA foi amplificado em 72,7% (24/33) destas mulheres,com 55,6% (20/36) e 94,4% (34/36) apresentando anticorpos tipo IgG e IgM contra o T. pallidum, respectivamente. A comparação destes resultados mostrou uma diferença estatística significativa, sendo que os resultados da PCR versus FTA-Abs Ig Mmostraram-se concordantes, sugerindo que a sífilis materna era uma infecção ativa. A causa básica de morte dos conceptos não foi relatada em 97,2% (35/36) dos casos. Entre as mulheres que foram submetidas ao VDRL no pré-natal, somente quatro das nove soropositivas receberam tratamento. CONCLUSÕES: A elevada frequência de sífilis no grupo de estudo indica a fragilidade do serviço no diagnóstico, tratamento e monitoramento da infecção, comprometendo o controle epidemiológico.

Determination of strains of Helicobacter pylori and of polymorphism in the interleukin-8 gene in patients with stomach cancer / Determinação das cepas do Helicobacter pylori e do polimorfismo do gene da interleucina-8 em pacientes com câncer gástrico

CONTEXT: Gastric neoplasia is the second most common cause of death by cancer in the world and H. pylori is classified as a type I human carcinogen by the World Health Organization. However, despite the high prevalence of infection by H. pylori around the world, less than 3 percent of individuals carrying the bacteria develop gastric neoplasias. Such a fact indicates that evolution towards malignancy may be associated with bacterial factors in the host and the environment. OBJECTIVES: To investigate the association between polymorphism in the region promoting the IL-8 (-251) gene and the H. pylori genotype, based on the vacA alleles and the presence of the cagA gene, using clinical and histopathological data. METHODS: In a prospective study, a total of 102 patients with stomach cancer and 103 healthy volunteers were analysed. Polymorphism in interleukin 8 (-251) was determined by the PCR-restriction fragment length polymorphism reaction and sequencing. PCR was used for genotyping the vacA alleles and the cagA in the bacterial strains PCR. Gastric biopsies were histologically assessed. RESULTS: The H. pylori serology was positive for 101 (99 percent) of all patients analysed, and 98 (97 percent) of them were colonized by only one strain. In patients with monoinfection, 82 (84 percent) of the bacterial strains observed had the s1b/m1 genotype. The cagA gene was detected in 74 (73 percent) of patients infected by H. pylori. The presence of the cagA gene was demonstrated as associated with the presence of the s1b/m1 genotype of the vacA gene (P = 0.002). As for polymorphism in the interleukin 8 (-251) gene we observed that the AA (P = 0.026) and AT (P = 0.005) genotypes were most frequent in the group of patients with gastric adenocarcinoma. By comparing the different types of isolated bacterial strains with the interleukin -8 (-251) and the histopathological data we observed that carriers of the A allele (AT and AA) infected by virulent strains (m1s1 cagA+) demonstrated a greater risk of presenting a degree of inflammation (OR = 24.75 CI 95 percent 2.29-267.20 P = 0.004) and increased neutrophilic activity (OR = 28.71 CI 95 percent 2.62-314 P = 0.002) in the gastric mucosa. CONCLUSION: Our results demonstrate that the interaction between polymorphism in the interleukin -8 (-251) gene, particularly with carriers of the A allele and the infecting type of H. pylori strain (s1m1 cagA positive) performs an important function in development of gastric adenocarcinoma.

CONTEXTO: A neoplasia gástrica é a segunda causa mais comum de morte por câncer no mundo e o H. pylori é classificado como carcinógeno humano tipo I pela Organização Mundial de Saúde. Entretanto, apesar da elevada prevalência da infecção pelo H. pylori em todo mundo, menos de 3 por cento de indivíduos portadores dessa bactéria desenvolvem neoplasias gástricas. Tal fato indica que a evolução para malignização possa estar associada a fatores bacterianos, do hospedeiro e do ambiente. OBJETIVOS: Investigou-se a associação do polimorfismo da região promotora do gene IL-8 (-251) e do genótipo do H. pylori, baseado nos alelos vacA e na presença do gene cagA, com a clínica e os dados histopatológicos. MÉTODOS: Em estudo prospectivo, 102 pacientes com câncer gástrico e 103 voluntários saudáveis foram analisados. O polimorfismo da IL-8 (-251) foi determinado pela reação de PCR-RFLP e sequenciamento. Para genotipagem dos alelos vacA e do gene cagA das cepas bacterianas foi utilizada a PCR. As biopsias gástricas foram avaliadas histologicamente. RESULTADOS: A sorologia para o H. pylori foi positiva em 101 (99 por cento) de todos os pacientes analisados, e 98 (97 por cento) deles foram colonizados por apenas uma cepa bacteriana. Em pacientes com monoinfecção, 82 (84 por cento) das cepas bacterianas observadas apresentavam o genótipo s1b/m1. O gene cagA foi detectado em 74 (73 por cento) dos pacientes infectados pelo H. pylori. A presença do gene cagA demonstrou estar associada com a presença do genótipo s1b/m1 do gene vacA (P = 0,002). Quanto ao polimorfismo do gene da IL-8 (-251), observou-se que os genótipos AA (P = 0,026) e AT (P = 0,005) foram mais frequentes no grupo de pacientes com adenocarcinoma gástrico. Comparando os diferentes tipos de cepas bacterianas isoladas, com o polimorfismo do gene da IL-8-251 e dados histopatológicos, observou-se que, portadores do alelo A (AT e AA) infectados por cepas virulentas (m1s1 cagA+), demonstraram risco aumentado de apresentar maior grau de inflamação (OR = 24,75 IC 95 por cento 2,29-267,20 P = 0,004) e aumento da atividade neutrofílica (OR = 28,71 IC 95 por cento 2.62-314 P = 0,002) na mucosa gástrica. CONCLUSÃO: Os resultados demonstram que a interação entre o polimorfismo do gene da IL-8, particularmente em portadores do alelo A, e o tipo de cepa infectante do H. pylori (s1m1 cagA positiva) desempenha importante função no desenvolvimento do câncer gástrico.

Characterization of 23S rRNA domain V mutations in gastric biopsy patients from the eastern Amazon

Resistance of Helicobacter pylori to clarithromycin is characterised by simple point mutations in the 23S ribosomal RNA (rRNA) gene and is responsible for the majority of cases of failure to eradicate this bacterium. In this paper, we characterised the variability of the 23S rRNA gene in biopsies of patients with gastric pathologies in the eastern Amazon (Northern Region of Brazil) using PCR and sequencing. A total of 49 sequences of H. pylori strains were analysed and of those, 75.6 percent presented nucleotide substitutions: A2142G (3.3 percent), T2182C (12.9 percent), G2224A (6.45 percent), T2215C (61.3 percent), A2192G (3.3 percent), G2204C (6.4 percent) and T2221C (6.4 percent). Of the mutations identified, four are known mutations related to cases of resistance and 16.1 percent are not yet described, revealing a high prevalence of mutations in the H. pylori 23S rRNA gene among the strains circulating in the in the eastern Amazon. The high prevalence in individuals with gastric pathologies in the Northern Region of Brazil demonstrates the need for characterising the profile of these strains to provide correct therapy for patients, considering that mutations in this gene are normally associated with resistance to the primary medication used in controlling H. pylori infection.

Article Molecular analysis of three FUT3 gene single nucleotide polymorphisms and their relationship with the lewis erythrocytary phenotype in a human population of japanese-ancestry living in Tomé Açu, a town in the Brazilian Amazon

The Lewis blood group system involves two major antigens, Leª and Le b. Their antigenic determinants are not primary gene products but are synthesized by the transfer of sugar subunits to a precursory chain by a specific enzyme which is the product of the FUT3 gene (Lewis gene). The presence of three FUT3 gene single nucleotide polymorphisms (SNPs) (59T > G; 508G > A and 1067T > A) was related to the Lewis phenotype of erythrocytes from 185 individuals of Japanese ancestry living in the town of Tomé-Açu in the Brazilian Amazon region. This relationship was detected using a serological hemagglutination test and the Dot-ELISA assay along with the molecular technique PCR-RFLP. We found that the three SNPs investigated in this study only accounted for a proportion of the Lewis-negative phenotype of the erythrocytes.

Clinical and pathological importance of vacA allele heterogeneity and cagA status in peptic ulcer disease in patients from north Brazil

We have examined the prevalence of gene cagA and vacA alleles in 129 patients, 69 with gastritis and 60 with peptic ulcer diseases from North Brazil and their relation with histopathological data. vacA and cagA genotype were determined by polymerase chain reaction. Hematoxylin-eosin staining was used for histological diagnosis. 96.6 percent of the patients were colonized by Helicobacter pylori strains harboring single vacA genotype (nont-mixed infection). Among them, 11.8 percent had subtype s1a, 67.8 percent had subtype s1b, and 17 percent subtype s2. In regard to the middle region analysis, m1 alleles were found in 75.4 percent and m2 in 21.2 percent of patients. The cagA gene was detected in 78 percent patients infected with H. pylori and was associated with the s1-m1 vacA genotype. The H. pylori strains, vacA s1b m1/cagA-positive, were associated with increased risk of peptic ulcer disease and higher amounts of lymphocytic and neutrophilic infiltrates and the presence of intestinal metaplasia. These findings show that cagA and vacA genotyping may have clinical relevance in Brazil.

Soroprevalência de anticorpos contra o antígeno CagA do Helicobacter pylori em pacientes com úlcera gástrica na regiÒo Norte do Brasil / Seroprevalence of antibodies against Helicobacter pylori CagA antigen in patients with gastric ulcer in the North region of Brazil

Helicobacter pylori is a pathogenic agent with a worldwide distribution and is involved in the development of many gastrointestinal diseases. Nowadays infection with the virulent strain CagA+ of H. pylori is considered one of the main etiological factors in the development of gastric ulcer. Based on this information, we investigated the seroprevalence of virulent strains among patients with gastric ulcer from one region, using serologic tests to detect antibodies against H. pylori and CagA protein. Infection by the virulent strain was found in 82 (40/55) of the patients, and among these, 89 (40/45) presented an increased degree of inflammation in the gastric mucosa, with a dense infiltration of leukocytes in the tissue, which probably favored the formation of gastric ulcer. We concluded that the presence of the virulent strain is related to the development of an increased inflammation in the gastric mucosa.