• Asian Pacific Journal of Cancer Prevention
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• 제16권2호
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• pp.657-660
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• 2015

Background: A diagnosis of H. pylori infection can be made by invasive or non-invasive methods. Several noninvasive diagnostic tests based on the detection of H. pylori stool antigen (HpSA) have been developed. The Genx H. pylori stool antigen card test is a new rapid, non-invasive test that is based on monoclonal immunochromatographic assay. The aim of this study was to determine its sensitivity, specificity, and diagnostic accuracy for diagnosing H. pylori infection in adult patients. Materials and Methods: A total of 162 patients were included in the study. A gastric biopsy was collected for histopathology and rapid urease testing. Stool specimens for HpSA testing were also collected. Patients were considered H. pylori positive if two invasive tests (histological and rapid urease tests) were positive. Results: Using the reference test, 50.6% of the samples were positive for H. pylori infection. The Genx H. pylori antigen test was positive in 19.7% of patients. The sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy of the Genx H. pylori antigen test were 51.6%, 96.0%, 88.8%, 76.1%, and 79.0%, respectively. Conclusions: The Genx H. pylori stool antigen card test is a new non-invasive method that is fast and simple to perform but provides less reliable results.

• 센서학회지
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• 제20권6호
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• pp.400-405
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• 2011

This study introduced the development of a strip type disposable enzyme-linked immunosensor platform for the detection of IgG. Strips of the strip sensor were fabricated by using commercial nitrocellulose filter membranes and a housing holder for the strips was manufactured by using a standard injection molding process for a plastic material. An IgG-urease conjugate was prepared and used for the competitive immune-binding with sample IgG. From the enzymatic reaction between the conjugated urease and urea added, ammonia was generated and caused a localized alkaline pH change on the immobilized antibody band which was coated onto the sensor strips. This pH increase subsequently caused a color change of the antibody band in the presence of a pH indicator, phenol red. Used in conjunction with a competitive immunoassay format, the intensity of the color produced is directly linked with the concentration of target analyte, IgG, and specific measurement of IgG in a lateral flow immunoassay format was achieved over the range 100 ppb to 2000 ppb IgG.

• Bulletin of the Korean Chemical Society
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• 제25권10호
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• pp.1499-1502
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• 2004

An amperometric biosensor based on carbon paste electrodes (CPEs) for the determination of urea was constructed by enzyme (urease/GL-DH)-modified method. Urea was hydrolyzed to ${NH_4}^+$ by catalyzing urease onto the enzyme-modified electrode surface in sample solution. In the presence of ${\alpha}$-ketoglutarate and reduced nicotinamide adenine dinucleotide(NADH), a liberated ${NH_4}^+$ produce to L-glutamate and $NAD^+$ by Lglutamate dehydrogenase (GL-DH). After the chemical reaction was proceeded, the electrochemical reaction was occurred that an excess of the NADH was oxidized to $NAD^+$. The oxidation current of NADH was monitored at +1.10 volt vs. Ag/AgCl. An optimum conditions of biosensor were investigated: The optimum pH range for catalyzed hydrolysis reaction of urea was pH 7.0-7.4. The linear response range and detection limit were $2.0\;{\times}\;10^{-5}{\sim}2.0\;{\times}\;10^{-4}M\;and\;5.0\;{\times}\;10^{-6}M$, respectively. Another physiological species did not interfere, except L-ascorbic acid.

• Journal of Oral Medicine and Pain
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• 제37권2호
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• pp.75-79
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• 2012

위염 및 위암 등의 발생과 관련되어 있는 Helicobacter pylori(H. pylori)는 구강의 치태와 타액에서 주로 발견이 된다. 유년시절 동안 주로 감염되는 것으로 알려져 있지만 감염경로는 불분명하다. 구강이 H. pylori의 두 번째 서식지로서 전염경로 및 위장내 H. pylori의 제균 후 재감염에 중요한 영향을 끼칠 수 있는지는 논쟁이 되고 있다. 따라서 본 저자는 문헌고찰을 통하여 구강 내에 존재하는 H. pylori에 관하여 알아보고자 하였다. 위장에 존재하는 H. pylori는 위인두반사나 구토에 의해 구강 내 발현될 수도 있으나, 구강과 위의 감염은 서로 관련성이 없는 것으로 보고되고 있다. 진단방법으로는 혈청학적검사, 요소호기검사, 중합효소연쇄반응(polymerase chain reaction: PCR)방법, Urease검사, 조직검사 등이 있으나, 타액과 치태에서는 nested PCR 방법이 주로 추천되어 진다. 구강 내 감염율은 다양하게 나타나며, 치과질환과의 연관성은 없는 것으로 사료된다. 그러나 치주질환 환자의 구강 내에서 발현율은 높게 나타나므로, 주의가 요구되며 향균 구강세척제의 사용이 권유된다. 결과적으로 구강 내 H. pylori는 정상세균총으로 사료되며, 향후 구강내 H. pylori에 관한 추가적인 많은 연구가 필요하리라 사료된다.

• Journal of Microbiology and Biotechnology
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• 제13권3호
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• pp.373-377
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• 2003

Various groups of industrial and agricultural pollutants (heavy metal ions, cyanides, and pesticides) can be detected by enzymes. Since heavy metal ions inhibit urease, cyanides inhibit peroxidase, organophosphorus and carbamate pesticides inhibit butyrylcholinesterase, these enzymes were co-immobilized into a bovine serum albumin gel on the surface of an ion-sensitive field effect transistor to create a bioprobe that is sensitive to the compounds mentioned above. The sensitivity of the present sensor towards KCN corresponded to $1\;\mu\textrm{M}$ with 1 min of incubation time. The detection limits for Hg(II) ions and the pesticide carbofuran were 0.1 and $0.5\;\mu\textrm{M}$, respectively, when a 10 min sensor incubation time in contaminated samples was chosen. The total time for determining the concentrations of all species mentioned did not exceed 20 min.

• Asian Pacific Journal of Cancer Prevention
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• 제17권12호
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• pp.5265-5272
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• 2016

Objective: The present study was conducted to evaluate invasive and noninvasive diagnostic methods for detection of Helicobacter pylori (H. pylori) in patients admitted with dyspeptic complaints and to compare sensitivities and specificities. Method: Sets of four gastric biopsy specimens were obtained from a total of 126 patients included in the study. The presence of H. pylori was determined by invasive tests including culture, rapid urease test, polymerase chain reaction (PCR) and histopathology. Among noninvasive tests, urea breath test, serological tests and enzyme-linked immunosorbent assay (ELISA) were performed. Results: H. pylori was isolated in 79 (62.7%) gastric biopsy cultures, whereas positivity was concluded for 105 (83.3%) patients by rapid urease test, for 106 (84.1%) by PCR, for 110 (87.3%) by histopathology, for 119 (94.4%) by urea breath test, and for 107 (84.9%) by ELISA. In the present study, the culture findings and histopathological examination findings were accepted as gold standard. According to the gold standard, urea breath test had the highest sensitivity (96.5%) and the lowest specificity (30%), whereas culture and histopathology had the highest specificities (100%). Conclusion: The use of PCR invasively with gastric biopsy samples yielded parallel results with the gold standard. PCR can be recommended for routine use in the diagnosis of H. pylori.

• Fisheries and Aquatic Sciences
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• 제6권3호
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• pp.105-109
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• 2003

Fifty four strains of pathogenic vibrios were isolated from the Gwangan Beach from May to October, 2002. The isolated vibrios were composed of 7 different species: Vibrio parahaemolyticus, V. cholerae non-O1, V. alginolyticus, V. vulnificus, V. hollisae, V. fluvialis, ane V. mimicus. In the detection rate, V. parahaemolyticus was most predominant as $46\%$(25/54). From the isolated strains, only 25 strains have hemolytic activity or 25 strains only proteolytic activity on agar plates. Eleven strains showed both hemolytic and proteolytic activity. No strains showed urease activity. All strains of V parahaemolyticus did not show hemolytic activity, while V. cholerae non-O1 strains showed $\beta$ hemolytic activity. Kanagawa phenomena of pathogenic vibrios did not accord with hemolytic activity of the culture supernatant at the late log phase. Some strains showed high hemolytic activity despite having proteolytic activity, but some weak hemolytic activities despite having no proteolytic activity.

• 대한수의학회지
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• 제63권2호
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• pp.16.1-16.6
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• 2023

Salmonella spp. are pathogens involved in most salmonellosis in rabbits. This study examined Salmonella disease in rabbits raised in Thua Thien Hue, Vietnam. Two hundred and 56 rectal swabs of rabbits were taken, and a carrier rate of 33.98% was found. In addition, all the isolated Salmonella spp. strains were 100% motile; positive for H₂S, catalase, Voges Proskauer, coagulase, citrate, maltose, and dextrose; and negative for indole, methyl red, urease, oxidase, sucrose, and lactose. The Kirby-Bauer method showed that these Salmonella strains were susceptible to doxycycline (93.2%), tetracycline (84.1%), and levofloxacin (65.9%). On the other hand, they were highly resistant to streptomycin (95.5%), ampicillin (93.2%), colistin (40.9%), and gentamicin (34.1%). Furthermore, polymerase chain reaction used to screen for virulence and specific genes of Salmonella strains showed that all Salmonella strains isolated carried InvA, fimA, and Stn.

• 미생물학회지
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• 제41권3호
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• pp.177-182
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• 2005

본 연구를 수행하기 전에 H. pylori에 대한 어떠한 치료도 받지 않은 114명의 소화기 궤양 환자들을 내시경 검사를 하는 동안, 114개의 H. pylori 균주를 위 전정부로부터 분리하였다. H. pylori를 검출하기 위하여 rapid urease test, SSA와 cagA 유전자의 PCR증폭을 수행하였고, CagA 발현 검출을 위하여 Western blot을 수행하였다. H. pylori에 감염된 환자들은 omeprazole. clarithromycin (a macrolide), amoxicillin을 모두 사용하는데 3제 요법(triple therapy)으로 치료하였다. 치료가 중단되고 6주 후에 내시경 검사에서 세균 박멸률을 측정하였다. 내성률은 각각 clarithromycin이 $20.2\%$. amoxicillin이 $0.0\%$였다. Clarithromycin 내성은 H. pylori의 23S rRNA 유전자에 있는 A2142G돌연변이에 의한 것이 $87\%$이었다. A2142G돌연변이의 clarithromycin의 MIC값($32\~>256\;{\mu}g\ml$)은 A2143G돌연변이의 MIC값($4\~128\;{\mu}g/ml$)보다 더 높았다. Clarithromycin에 감수성을 가진 H. pylori는 박멸되었으나 clarithromycin내성을 가진 H. pylori는 박멸되지 않았다(P = 0.0001). 이러한 결과들은 CagA 발현에는 어떠한 영향도 받지 않았으며 H. pylori의 clarithromycin 내성은 치료 실패의 가장 중요한 이유임을 제시하였다. 우선적으로 실시되는 생검 배양에 대한 H. pylori의 항생제 감수성 시험은 감염된 환자들에 대한 3제 요법을 선택하기 이전에 필히 실시되어야 하며 국내에서 clarithromycin에 대한 1차 내성의 높은 빈도는 H. pylori의 감염증 치료에 심각한 문제점을 야기시켰다.

• Journal of Microbiology and Biotechnology
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• 제25권7호
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• pp.1146-1153
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• 2015

This study was conducted to assess the relationship between occurrence of gastric cancer and peptic ulcer, and the presence of H. pylori cagA gene and anti-CagA IgG, and to estimate the value of these antibodies in detecting infection by cagA gene-positive H. pylori strains in Saudi patients. The study included 180 patients who were subjected to upper gastrointestinal endoscopy in Taif province and Western region of Saudi Arabia (60 gastric cancer, 60 peptic ulcer, and 60 with non-ulcer dyspepsia). Gastric biopsy specimens were obtained and tested for H. pylori infection by rapid urease test and culture. PCR was performed on the isolated strains and biopsy specimens for detection of the cagA gene. Blood samples were collected and tested for CagA IgG by ELISA. H. pylori infection was detected among 72.8% of patients. The cagA gene and anti-CagA IgG were found in 63.4% and 61.8% of H. pylori-infected patients, respectively. They were significantly (p < 0.01) higher in patients with gastric cancer and peptic ulcer compared with those with non-ulcer dyspepsia. Detection of the CagA IgG was 91.6% sensitive, 89.6% specific, and 90.8% accurate compared with detection of the cagA gene. Its positive and negative predictive values were 93.8% and 86%, respectively. The study showed a significant association between the presence of the cagA gene and gastric cancer and peptic ulcer disease, and between anti-CagA IgG and the cagA gene in Saudi patients. However, a further larger study is required to confirm this finding.