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Evaluación de la utilidad de diferentes métodos para el diagnóstico de Helicobacter pylori Evaluation of the usefulness of different methods for diagnosis of Helicobacter pylori  [cached]
Jordi Alonso Soto,Boris Luis Rodríguez González,Arlenis Moreno Guerra,Lissette Chao González
Revista Cubana de Investigaciones Biom??dicas , 2013,
Abstract: Con el propósito de evaluar la utilidad de la serología, reacción a la cadena de la polimerasa e histología para el diagnóstico de Helicobacter pylori utilizando como prueba de oro el cultivo se realizó un estudio descriptivo prospectivo en pacientes mayores de 18 a os de edad que acudieron al servicio de Gastroenterología del Centro de Investigaciones Médico-Quirúrgica (CIMEQ) con indicación de endoscopia digestiva superior durante el período comprendido entre julio y diciembre del 2010. La muestra quedó constituida por 89 pacientes que cumplieron todos los criterios de inclusión, de ellos 52 pertenecían al sexo masculino y 37 al femenino, el promedio de edad fue de 49,6 ± 18.0 a os. El 60,7 % fueron casos positivos para la bacteria; la serología fue el método más sensible y la reacción a la cadena de la polimerasa el más especifico para el diagnóstico del Helicobacter pylori. In order to evaluate the usefulness of serology, reaction to polymerase chain and histology for the diagnosis of Helicobacter pylori using as a gold farming was conducted a prospective study of patients over 18 years of age who presented serving Gastroenterology Research Center Medical Surgical (CIMEQ) with indication of upper gastrointestinal endoscopy during the period between July and December 2010. The sample was composed of 89 patients who fulfilled all inclusion criteria, of whom 52 were male and 37 were female, average age was 49.6 ± 18.0 years, these patients underwent upper gastrointestinal endoscopy and sampling for detection of Helicobacter pylori. 60.7 % were positive for bacteria cases, serology was the most sensitive reaction to polymerase chain the most specific for diagnosis of Helicobacter pylori.
DIAGNOSIS OF HELICOBACTER PYLORI INFECTION  [cached]
Vladan N. Petrovi?
Acta Facultatis Medicae Naissensis , 2003,
Abstract: Helicobacter pylori is the most widen infection on the World. It is importrant factor in the genesis of ulcer disease, gastric carcinoma, gastric lymphoma, as a numerous extragastric disease. Diagnosis is made by invasive and non-invasive tests. Maastricht Consensus Report (2000) and First Consensus of Yugoslav Gastroenterologic Association recommend group of patients and methods for detection of Helicobacter pylori infection.
DIAGNOSIS OF HELICOBACTER PYLORI INFECTION  [PDF]
Tatjana Babi?,Branislava Koci?,Biljana Miljkovi?-Selimovi?,Predrag Stojanovi?
Acta Facultatis Medicae Naissensis , 2009,
Abstract: Helicobacter pylori induces persistent inflammation in the human stomach, yet only a minority of colonized persons develop peptic ulcer disease or gastric malignancy. Results from recent investigations have demonstrated that H. pylori isolates possess substantial phenotypic and genotypic diversity which leads to different host inflammatory responses that influence clinical outcome. Numerous studies are being published on diagnostic tests for H. pylori. The tendency is to favor noninvasive tests. The urea breath and stool antigen tests using monoclonal antibodies are applied in different types of patients, while serology is still a subject of interest. Invasive tests were the first to be applied to H. pylori detection and still remain the “gold standard”. In patients having underwent upper endoscopy, in order to obtain gastric biopsy specimens, diagnosis of H. pylori infection is achieved using histological and cultivation methods and urease tests. In order to get insight into virulence factors and macrolide susceptibility, the molecular methods (realtime PCR) have been developed. Knowing the mechanisms of H. pylori pathogenesis and specific interaction between pathogen and the host, which are dependent upon strain-specific bacterial factors and induced host effectors, helps to define colonized persons bearing the highest risk for disease, and enable physicians to use the most appropriate diagnostic testing and eradication therapy.
MICROBIOLOGICAL DIAGNOSIS OF HELICOBACTER PYLORI INFECTION  [cached]
Marica Ota?evi?,Marina Dini?,Biljana Miljkovi?-Selimovi?,Ljiljana Ota?evi?
Acta Facultatis Medicae Naissensis , 2003,
Abstract: Methods for H. pylori infection diagnosis are classified in two groups: invasive and noninvasive ones. Microbiological and histological methods, as well as urease test performed on biopsy are invasive because of preceding gastroscopy, but 13C and 14C-urea test breathing and serology are noninvasive methods. Any of these methods solely possess some advantages and disadvantages too, and choose of the most convenient one, depend on team that conduct investigation in specialized laboratories. Many conditions must be fulfilled for successfully performing of microbiological diagnosis in H. pylori infection: sampling, transport medium quality, velocity of collected material transport to laboratory, correct and urgent samples processing, selection of nutritive media and microaerophilic conditions and optimal temperature providing for growth and multiplying of H. pylori. Microbiological diagnosis is preformed by direct microscopy, culturing and by serological methods. H.pylori is slim, S shaped, sometimes spiral Gram-negative rod. Its length varies from 2,5 to 5 μm and wide from 0,5 to 1 μm. It possesses 4 - 6 monopolar flagella. Immediately after patient material arrival in laboratory, performing of smears and staining according to Gram should be done. Microscopically investigation of preparation stained according to Gram is based on recognition of typical S shaped Gram-negative rods placed singular or in groups. Smear staining is considered to be successful method for H. pylori detection in gastric tissue, but this method is never recommended as the only one. Culturing of gastric tissue bioptates is the most reliable method in establishing of H. pylori infection diagnosis. For successfully diagnosis of H. pylori, variety of basic agar media supplemnted with 5-10% sheep or horse blood are in use. Selective use of antibacterial and antifungal agents is recommended for primary isolation of H. pylori in order to inhibit growth of contaminants. Colonies of H. pylori primoculture are convex, smooth, shiny and translucent, with entire margin, 0,5 - 1 mm in diameter. In order to identify suspected colonies in primary nutrient media microscopical preparations are maid and stained according to Gram. Microscopically, curved, Gram-negative rods, S and U shaped are seen. Verification of microorganisms microscopically, directs to further investigation of biochemical properties necessary for finally identification of spiral, gastric microorganisms. Microorganisms are identified as H. pylori if urease, oxidase and catalase tests are positive. Noninvasive, serological methods
Helicobacter pylori infection in Africa: Pathology and microbiological diagnosis
NF Tanih, AM Clarke, N Mkwetshana, E Green, LM Ndip, RN Ndip
African Journal of Biotechnology , 2008,
Abstract: Helicobacter pylori is a microaerophilic motile curve rod that inhabits the gastric mucosa of the human stomach. The organism chronically infects billions of people worldwide and is one of the most genetically diverse of bacterial species. Infection with the bacterium which leads to chronic gastritis, peptic ulceration, gastric cancers and gastric MALT lymphoma has been reported to follow a pattern linked to geographic and socio-demographic factors. However; the infection rate in various populations does not parallel the incidence of morbidity caused by the infection. This has been termed by a number of authors as the ‘African enigma’ based on an apparently low incidence of gastric carcinoma and other H. pylori-associated morbidities in the continent of Africa. There are various techniques employed to detect H. pylori from specimens. These tests may be invasive or non-invasive. Endoscopy and gastric mucosal biopsy, microscopic examination of histological sections, PCR and rapid urease test are forms of invasive test that could be used. Non-invasive tests such as Urea Breath Test (UBT) make use of the ability of the organism to produce urease; enzyme linked immunosorbent Assay (ELISA), H. pylori stool antigen test, and latex agglutination tests are important non-invasive serological approaches employed to detect the presence of antibody or antigen from a specimen. H. pylori is a very fastidious bacterium. Restraint should therefore be exercised to allow for efficient performance of some of these techniques.
Utilidad del diagnóstico serológico de la infección por Helicobacter pylori en ni?os
Harris D,Paul; Serrano H,Carolina; González F,Carmen G;
Revista chilena de pediatría , 2005, DOI: 10.4067/S0370-41062005000300002
Abstract: helicobacter pylori (h. pylori) colonizes 50% of the world′s population. the infection is acquired during infancy; an age group of non-invasive diagnostic methods need to be urgently validated. our aim was to review the literature and evaluate the usefulness of serological diagnosis with special emphasis on the paediatric population. the relevance of these methods has been focused in epidemiological studies. in adult populations, the determination of antibodies against h. pylori exhibits a sensitivity and specificity of over 90%, being comparable to other invasive endoscopy based methods. in the paediatric population, the performance of serological testing has been less successful, with lower sensitivity and specificity. this underlies the need to establish more precise cut off values, based on local populations, where studies using antibodies as diagnostic markers of h. pylori are planned
Comparison of Different Laboratory Methods for Diagnosis of Helicobacter pylori  [PDF]
N. Sadeghifard,M.M. Aslani,A. Ghasemi
Journal of Biological Sciences , 2006,
Abstract: The aim of the present study was to compare four laboratory methods for diagnosis of Helicobacter pylori. 101 sets of four antral biopsies were collected from 101 patients, one of the biopsies in each set were tested by rapid urease test, other three biopsies were used for culture, direct staining and histopathology, respectively. By culture method in 62 cases (61.3%), Helicobacter pylori were isolated. Among several primary media that tested in this study, Brucella agar supplemented with 10% whole sheep blood supported relatively good growth of H. pylori. In present study 65 cases (64.3%) were positive by rapid urease test. Of 101 biopsy specimens in 68 cases (67.3%) were obtained positive result by histopathology method (Gimsa Staining). Sensitivity and specificity of direct staining test were 89.7 and 96.9%, respectively. We found histopathology method was the best method for diagnosis of H. pylori and it can be selected as gold standard in detection of Helicobacter pylori.
Chromoendoscopy with red phenol in the diagnosis of Helicobacter pylori infection
Hernández-Garcés,Héctor Rubén; Castellanos-González,Víctor V.; González-Fabián,Licet; Infante-Velázquez,Mirtha; Pe?a,Kevin; Andrain-Sierra,Yudit;
Revista Espa?ola de Enfermedades Digestivas , 2012, DOI: 10.4321/S1130-01082012000100002
Abstract: an analytic study to validate a diagnostic test was carried out at the institute of gastroenterology in havana, cuba in adult patients of both sexes in whom chromoendoscopy was carried out with red phenol at 0.1% over the gastric mucosa for the detection of helicobacter pylori infection between november 2008 and december 2010. the staining with red phenol at 0.1% is included in the invasive tests for the diagnosis of helicobacter pylori infection and of the reactive techniques. the sensibility of red phenol dye in the diagnosis of helicobacter pylori infection in the patients studied was of 72.6% with a confidence interval (c.i.) of 95% (64.9 to 79.2%) and a specificity of 75.5% c.i. 95% (61.9 to 85.4%). the positive predictive value was of 89.8% c.i. 95% (83.1 to 94.1%) and the negative predictive value of 48.1% c.i. 95% (37.3 to 59.0%). the proportion of false positives was of 24.5% c.i. 95% (14.6 to 38.1%) and the proportion of false negatives was of 27.4% c.i. 95% (20.8 to 35.1%). the diagnostic accuracy of the dye on the patients studied was 73.3% c.i. 95% (66.7 to 79.0%). the diagnostic odds ratio was 8.17 c.i. 95% (3.88 to 17.23), the j youden ratio of 0.5 and the kappa coefficient of 0.40 c.i. 95% (0.27 to 0.54). the staining dye with red phenol at 0.1% resulted in a useful method in the diagnosis of helicobacter pylori infection in the gastric mucosa,it can be applied in our environment and has multiple advantages (topographic localization, avoids contamination and fast and immediate reading).
Comparison of the Serological Reactivity of Lipopolysaccharides from Japanese and Western Strains of Helicobacter pylori to Sera from H. pylori-Positive Humans  [PDF]
Ken-ichi Amano,Shin-ichi Yokota,Mario A. Monteiro
ISRN Microbiology , 2012, DOI: 10.5402/2012/162816
Abstract: We compared the serological reactivity of lipopolysaccharides (LPS) isolated from Japanese and Western strains of Helicobacter pylori against anti-Lewis antigen monoclonal antibodies and H. pylori-positive Japanese sera. The two LPS from Western strains (26695 and O:2) did not react with any sera from Japanese patients, while all LPS from Japanese strains and the Sydney strain reacted with these sera. We propose that LPS of all Japanese smooth strains share either one of two epitopes, which are termed highly antigenic and weakly antigenic epitopes, present in the O-polysaccharide portion, and these epitopes are independent the Lewis antigens. The present findings indicated that the two Western strains lacked the two epitopes, which are shared by all Japanese strains. 1. Introduction Helicobacter pylori is a gram-negative and microaerophilic bacterium that is recognized as a major cause of chronic gastritis, peptic ulcer, and gastric cancer [1, 2]. The chemistry and biology of H. pylori lipopolysaccharides (LPS) have been extensively studied. Aspinall et al. [3] and Monteiro et al. [4] determined the structures of the O-polysaccharides of H. pylori LPS and found them to be the same as the Lewis X (Lex) and Lewis Y (Ley) determinants of human cell-surface glycoconjugates. Appelmelk et al. [5] suggested that the mimicry of Lewis antigens by this bacterium raised titers of autoantibodies to Lewis antigens in infected individuals. However, we find no significant titers of anti-Lewis antigen antibodies in the sera of H. pylori-positive humans [6]. On the other hand, we have observed that all H. pylori smooth-type LPS possess either one of two antigenic epitopes (the highly antigenic and the weakly antigenic epitopes) in their polysaccharide regions [7–9]. These are unlikely to be related to the structures mimicking Lewis antigens. Most H. pylori-infected individuals have high titers of antibody to one of these antigenic epitope (the highly antigenic epitope). So we proposed that an LPS possessing this antigenic epitope would be a strong candidate for an antibody diagnosis of H. pylori infection [10]. Monteiro et al. [11] compared the structures between H. pylori LPS isolated from Asian and Western patients and found that the Asian strains showed a stronger tendency to produce type 1 blood groups. In this paper, we compared the reactivity of H. pylori LPS from Japanese and Western strains to the sera of H. pylori-positive humans. 2. Materials and Methods 2.1. Bacterial Strains and Preparation of LPS Japanese H. pylori strains (GU2, DU1, CA2, CA4, and CA5) were
Comparison between Invasive and Noninvasive Tests in Diagnosis of Helicobacter pylori Infection
Saffari Mahmood,Abtahi Hamid
Pakistan Journal of Biological Sciences , 2010,
Abstract: In this study, the invasive and noninvasive diagnotic tests were compared to choose the appropriate test for diagnostice of H. pylori infection. Helicobacter pylori (H. pylori) is a human pathogen that causes chronic gastritis, has a role in gastric and duodenal ulcer, is involved in gastric carcinogenesis and is regarded as a possible important factor in at least a subset of patients with functional dyspepsia. The diagnosis of H. pylori is an essential element in the management of many common gastrointestinal pathologies. The assessment of each routine invasive and noninvasive test is important. We studied a total of 127 outpatients for the detection of H. pylori infection. The presence of H. pylori infection by invasive tests containing the Rapid Urease Test (RUT), histology (Giemsa staining) and culture in 127 patients. Patients who were positive in culture, or two tests from four tests, invasive and noninvasive, were considered to have H. pylori infection. In noninvasive tests, we evaluated anti-H. pylori IgG and anti-CagA antibodies using commercial Enzyme-Linked Immunoassay (ELISA) and Western blot in dyspeptic patients. Eighty five out of the 127 patients were positive for H. pylori. Helicobacter pylori IgG seropositivity and 35 out of the 127 patients were positive for immunoblot. RUT had sensitivity, specifity and accuracy of 96, 80 and 90.5%, respectively; for Elisa these were 85.2, 33 and 70.5%, respectively and for ELISA with immunoblotting they were 65, 45 and 58.8%, respectively. The results of this study suggest that noninvasive tests (ELISA, immunoblotting) have the lowest and RUT with histology have the highest accuracy. These earlier tests can not be used for accurate infection diagnosis.
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