RESUMO
AIMS: To investigate the distribution of the genes that encode enterotoxins and the colonization factors (CF) types as well as the antibiotic susceptibility profile of enterotoxigenic Escherichia coli (ETEC) isolated from children from the Brazilian Northeast. METHODS AND RESULTS: We conducted a 3·5-year prospective study that involved 250 children with and 150 without diarrhoea, aged 1-60 months, from low-income families in Teresina/Brazilian Northeast. All samples were assayed for E. coli, enterotoxin and CF genes and antimicrobial susceptibility by microbiological methods and PCR. ETEC strains were isolated from 9·2% children with and 4·0% without diarrhoea. Infection was more common in children aged 6-24 months in rainy months. elt⺠/CFA/IV⺠and elt⺠/CS14⺠were the most frequent genotypes. Susceptibility to nalidixic acid, ciprofloxacin and gentamicin and resistance to ampicillin, cephalothin and sulfamethoxazole-trimethoprim were common. CONCLUSIONS: elt âºisolates and ETEC strains harbouring genes encoding CFA/IV and CS/14 were the most common ETEC found in Brazilian Northeast. SIGNIFICANCE AND IMPACT OF THE STUDY: Our data, the first generated for north-eastern Brazilian children, may be important for the development of an effective vaccine and for facilitation of an empirical choice of antibiotic treatment or prophylaxis for traveller's diarrhoea in the area studied.
Assuntos
Diarreia/microbiologia , Escherichia coli Enterotoxigênica/isolamento & purificação , Infecções por Escherichia coli/microbiologia , Toxinas Bacterianas/genética , Brasil , Pré-Escolar , Diarreia/tratamento farmacológico , Diarreia Infantil/tratamento farmacológico , Diarreia Infantil/microbiologia , Escherichia coli Enterotoxigênica/efeitos dos fármacos , Escherichia coli Enterotoxigênica/genética , Escherichia coli Enterotoxigênica/patogenicidade , Infecções por Escherichia coli/tratamento farmacológico , Proteínas de Escherichia coli/genética , Feminino , Humanos , Lactente , Masculino , Estudos Prospectivos , Combinação Trimetoprima e Sulfametoxazol/uso terapêutico , Fatores de Virulência/genéticaRESUMO
AIMS: To purify and partially characterize a bacteriocin produced by a Fusobacterium nucleatum strain. METHODS AND RESULTS: Following protein precipitation the effect of different treatments on a bacteriocin produced by a F. nucleatum strain named P12.2 isolated from a patient with periodontitis was evaluated. The antagonistic activity of the intracellular fraction obtained at 80% ammonium sulphate was preserved at pH values from 6.0 to 9.0 and showed to be sensitive to high temperatures and to treatment with proteases. The fraction was submitted to sequential steps of gel filtration, ion exchange, and reverse phase chromatography, and SDS-PAGE. Data obtained by mass spectrometry revealed that the molecular mass of the protein was 27,296 Da. CONCLUSIONS: For the first time a bacteriocin produced by a F. nucleatum strain was purified and characterized. SIGNIFICANCE AND IMPACT OF THE STUDY: This is the first description on characterization of a bacteriocin produced by F. nucleatum. It is possible that the bacteriocin plays a role in the regulation of population levels of periodontopathic organisms.
Assuntos
Antibacterianos/isolamento & purificação , Bacteriocinas/isolamento & purificação , Fusobacterium nucleatum/metabolismo , Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Bacteriocinas/metabolismo , Bacteriocinas/farmacologia , Cromatografia em Gel , Cromatografia de Fase Reversa , Eletroforese em Gel de Poliacrilamida , Temperatura Alta , Humanos , Concentração de Íons de Hidrogênio , Espectrometria de Massas , Peso Molecular , Boca/microbiologia , Periodontite/microbiologiaRESUMO
AIM: The purpose of this study was to investigate the effect of oxidative stress on physiological and genetic characteristics of Fusobacterium nucleatum and its interference on this microbial identification methods. METHODS AND RESULTS: Fus. nucleatum ssp. nucleatum ATCC 25586 (wt-strain) and an oxidative-stress-adapted strain derived from the wt-strain (aero-strain) were employed in the study. Cell-free crude protein extracts were obtained from both strains and differentially expressed proteins were identified by two-dimensional electrophoresis. Bacterium identification was performed by conventional biochemical tests, automated Rapid ID 32A system and specific PCR analysis. Genetic diversity between wt- and aero-strain was assessed by arbitrarily-primed (AP)-PCR. There were significant changes in the protein profile of aero-strain. The identification of the wt-strain was confirmed by all methods employed. Similar results were obtained for aero-strain when conventional biochemical tests and PCR were used. However, aero-strain was identified as Fusobacterium varium when submitted to Rapid ID 32A system. According to AP-PCR analysis, no significant genetic alteration was detected in aero-strain. CONCLUSIONS: The adaptive response of Fus. nucleatum to oxidative stress is associated with changes on its biology, which may lead to misidentification of the organism, according to the conventional identification methods. SIGNIFICANCE AND IMPACT OF THE STUDY: Oxidative stress may act as a cause of adaptive response in Fus. nucleatum with consequences to its biology, such as alterations on biochemical and physiological profile.
Assuntos
Fusobacterium nucleatum/fisiologia , Estresse Oxidativo/fisiologia , Adaptação Fisiológica , Proteínas de Bactérias/metabolismo , Técnicas de Tipagem Bacteriana/métodos , Eletroforese em Gel Bidimensional/métodos , Fusobacterium nucleatum/classificação , Fusobacterium nucleatum/genética , Variação Genética , Reação em Cadeia da Polimerase/métodosRESUMO
Data concerning the geographic distribution of iceA alleles are scarce, and information on the association of the gene with the disease is rare and still controversial. Furthermore, no such study has been developed in Brazil, where duodenal ulcer and gastric adenocarcinoma are very common. We investigated, by PCR, the frequency of iceA alleles and cagA status in Helicobacter pylori strains isolated from 142 patients (62 children and 80 adults; 66 female; mean age, 30.0 years; age range, 3 to 78 years) with gastritis, duodenal ulcer, or gastric adenocarcinoma. iceA was identified in bacterium samples obtained from all patients. Eleven (7.7%) of them were infected with multiple strains. Among the patients with nonmixed infection, iceA2 allele was detected in 118 (90.1%). iceA2 allele was associated with ulcer (P = 0.02) and with carcinoma (P = 0.001). iceA2 amplicons of 229, 334, or 549 bp were detected, but none of them was associated with the patient's disorder. iceA2 strains were more frequent in patients older than 7 years (P = 0.001). The gene was also more frequent in strains obtained from males (P = 0.02). cagA was more common in strains obtained from carcinoma (P = 0.0008) and ulcer patients (P < 0.006). cagA-positive strains were more frequent in children older than 7 years (P < 0.003). No association between cagA status and sex was found (P = 0.28). In conclusion, we think iceA should not be used as a reliable marker for predicting the clinical outcome of H. pylori infection.
Assuntos
Antígenos de Bactérias , Proteínas da Membrana Bacteriana Externa/genética , Infecções por Helicobacter/epidemiologia , Helicobacter pylori/classificação , Helicobacter pylori/genética , Adolescente , Adulto , Idoso , Proteínas de Bactérias/genética , Brasil/epidemiologia , Criança , Pré-Escolar , DNA Bacteriano/análise , Feminino , Genótipo , Infecções por Helicobacter/microbiologia , Helicobacter pylori/isolamento & purificação , Humanos , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da PolimeraseRESUMO
Although infection with a cagA-positive Helicobacter pylori strain is considered a risk factor for the development of duodenal peptic ulcer in adults, this association has not been demonstrated in children. The presence of cagA was investigated by polymerase chain reaction in H. pylori strains isolated from 27 children with duodenal ulcer and 53 without duodenal ulcer. All patients (100%) with duodenal ulcer and 33 (62.3%) without ulcer were colonized by a cagA-positive strain (P=.00007). A cagA-positive status was also associated with a more marked macroscopic gastritis, with a greater inflammatory infiltrate of both mononuclear and polymorphonuclear cells in the antral and oxyntic gastric mucosae and degenerative and regenerative changes of the gastric mucosa. Increased cagA positivity was also associated with increased age, but no association between cagA-positive status and sex was observed.
Assuntos
Antígenos de Bactérias , Proteínas de Bactérias/metabolismo , Infecções por Helicobacter/complicações , Infecções por Helicobacter/microbiologia , Helicobacter pylori/patogenicidade , Adolescente , Proteínas de Bactérias/genética , Criança , Pré-Escolar , DNA Bacteriano/análise , Úlcera Duodenal/complicações , Úlcera Duodenal/microbiologia , Feminino , Mucosa Gástrica/imunologia , Mucosa Gástrica/patologia , Helicobacter pylori/genética , Helicobacter pylori/isolamento & purificação , Humanos , Masculino , Reação em Cadeia da Polimerase , Fatores de RiscoRESUMO
This article was originated by a request of some professors of the Masters Course in Nursing. The theme "bath", as an act of care, was developed, initially, on the meaning of moves. The esthetic of body movement, to the sound of music, was represented graphically, allowing to reach constructs as: relationship, physical contact, sharing, pleasure, satisfaction, cleanliness, reaproximation. The concept of "bath", understood through research in different bibliography and idioms, was translated as "purification". The meaning of "purification" was studied with an anthropological view. Many practices and rituals were perceived through history and human experience and bring with them tools that may help Nursing to create and recreate the experience and concept of human care. These elements and some contributions to comprehend care are shown in this study.
Assuntos
Banhos , Cuidados de Enfermagem , Humanos , MúsicaRESUMO
Helicobacter spp. have been the focus of considerable research because of the role of this genus in gastrointestinal diseases. We infected NIH germ-free mice with Helicobacter trogontum, a recently described intestinal bacterium of rats, in order to study the distribution of this bacterium in the gastrointestinal tract and the histopathological changes it can induce in this host. Sixteen mice were challenged with a single dose of H. trogontum (test group) and killed one and six weeks after inoculation (eight animals at each point). Eight animals were challenged with 0.85% saline alone (control group) and killed at the same time points (four at each point). Fragments from the gastric and intestinal mucosa were obtained for microbiological and histological examination. H. trogontum was isolated from the cecum and colon of all test mice and also from the gastric mucosa of several of them. All infected animals presented histological changes in at least one region of the bowel. Alterations in the gastric mucosa were also observed mainly in the six-week-infected group. The predominant histological change observed was a moderate diffuse inflammatory infiltrate of mononuclear cells in the lamina propria, often accompanied by a mild infiltration of polymorphonuclear cells. Two animals presented focal infiltration of inflammatory cells in the liver, although no bacteria were found in the liver of any animal. H. trogontum is an intestinal species that is able to elicit inflammatory responses in other regions of the gastrointestinal tract such as the gastric mucosa and the liver of gnotobiotic mice.
Assuntos
Sistema Digestório/microbiologia , Gastroenteropatias/microbiologia , Infecções por Helicobacter/microbiologia , Helicobacter/isolamento & purificação , Animais , Sistema Digestório/patologia , Feminino , Mucosa Gástrica/microbiologia , Mucosa Gástrica/patologia , Gastroenteropatias/patologia , Vida Livre de Germes , Infecções por Helicobacter/patologia , Mucosa Intestinal/microbiologia , Mucosa Intestinal/patologia , Intestino Grosso/microbiologia , Intestino Grosso/patologia , Intestino Delgado/microbiologia , Intestino Delgado/patologia , Fígado/patologia , Camundongos , Ratos , Baço/patologia , Estômago/microbiologia , Estômago/patologiaRESUMO
BACKGROUND: Although enzyme-linked immunosorbent assay (ELISA) is highly sensitive and specific for the diagnosis of Helicobacter pylori infection in adults, their performance in children is still controversial. METHODS: A second-generation ELISA was used to evaluate the IgG response to H. pylori in the serum of 130 consecutive children who underwent upper gastrointestinal endoscopy. The presence of H. pylori was determined in antral biopsy specimens by culture, urease test, and histologic analysis. RESULTS: Sixty-eight children (all of the 20 who had duodenal ulcer) were H. pylori positive by microbiologic test. Immunoglobulin G antibodies to H. pylori were detected in 79.4% of the infected children and in 8.1% of the noninfected ones. The sensitivity of the test was higher in patients with duodenal ulcer (100%) than in those without (70.8%). When used in children of different ages the test also presented differences in sensitivity: 44.4% in children 2 to 6 years old; 76.7% in children 7 to 11 years old, and 93.1% in children 12 to 16 years old (p = 0.006). The serum immunoglobulin G concentration was significantly higher (p = 0.0003) in children with duodenal ulcer than in those without and was higher in older children than in younger ones without duodenal ulcer (p = 0.05). CONCLUSIONS: The accuracy of the test in children with duodenal ulcer and in children more than 12 years old was good; however, in children up to 12 years of age without duodenal ulcer, the sensitivity of the test was too low to be used for screening purposes or to rule out the presence of infection.
Assuntos
Envelhecimento , Úlcera Duodenal/microbiologia , Ensaio de Imunoadsorção Enzimática/métodos , Infecções por Helicobacter/diagnóstico , Helicobacter pylori , Adolescente , Anticorpos Antibacterianos/sangue , Biópsia , Criança , Pré-Escolar , Úlcera Duodenal/patologia , Feminino , Mucosa Gástrica/microbiologia , Mucosa Gástrica/patologia , Gastrite/microbiologia , Gastrite/patologia , Infecções por Helicobacter/patologia , Humanos , Imunoglobulina G/sangue , Masculino , Valores de Referência , Sensibilidade e EspecificidadeRESUMO
OBJECTIVE: We aimed to determine whether cytotoxin-positive Helicobacter pylori strains are associated with gastric carcinoma. METHODS: We studied 130 patients: 57 H. pylori-positive patients with gastric carcinoma, 53 H. pylori-positive patients without gastric carcinoma, and 20 H. pylori-negative subjects. The ability of H. pylori strains to produce vacuolating cytotoxin was tested in INT-407 and HeLa cells. The presence of antibodies to cytotoxin was investigated in blood serum from all subjects by immunoblotting. Fragments of the gastric mucosa from patients without gastric carcinoma and H. pylori-negative subjects were obtained for histopathological study. RESULTS: Considering the results as a whole, 40 (70.2%) patients with and 22 (41.5%) without gastric carcinoma were colonized by cytotoxin-positive strains. Antibodies against cytotoxin were not observed in the serum from 17 (29.8%) gastric carcinoma patients and from 31 (58.5%) patients without gastric carcinoma. H. pylori strains isolated from these patients did not produce cytotoxin in vitro. In regard to cytotoxin positivity, a significant difference was observed between patients with and without gastric carcinoma (p=0.004; odds ratio [OR]: 3.3; 95% confidence interval [CI]: 1.4-7.9). Higher scores of mononuclear (p=0.0001) and polymorphonuclear (p=0.000003) cells were observed in the antral mucosa from H. pylori-positive patients without gastric carcinoma infected by cytotoxin-positive strains than in those harboring cytotoxin-negative strains. CONCLUSION: Cytotoxin-producing H. pylori strains were more frequently observed in patients with gastric carcinoma and this aspect emphasizes the role of cytotoxin in the genesis of the tumor.
Assuntos
Proteínas de Bactérias/isolamento & purificação , Infecções por Helicobacter/microbiologia , Helicobacter pylori/isolamento & purificação , Neoplasias Gástricas/microbiologia , Anticorpos Antibacterianos/análise , Proteínas de Bactérias/imunologia , Estudos de Casos e Controles , Ensaio de Imunoadsorção Enzimática , Feminino , Mucosa Gástrica/imunologia , Mucosa Gástrica/microbiologia , Infecções por Helicobacter/complicações , Infecções por Helicobacter/imunologia , Helicobacter pylori/imunologia , Helicobacter pylori/patogenicidade , Humanos , Immunoblotting , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Neoplasias Gástricas/imunologiaRESUMO
The cagA gene was detected in 100% of 16 Helicobacter pylori isolates from patients with gastric carcinoma versus 78% of 18 isolates from patients with duodenal ulcers (P = 0.344) and only 64% of 22 isolates from patients with gastritis only (P = 0.005) in Brazil. Also, there was a significant association between isolation of cagA+ s1-type vacA H. pylori in cases of stomach cancer and ulcers as opposed to cases of gastritis only (P = 0.004), but this was not true in Houston (P = 0.238), where 94% of all isolates were cagA+.