Heterogeneity of cag genotypes of Helicobacter pylori in the esophageal mucosa of dyspeptic patients and its relation to histopathological outcomes

Contreras, Mónica; Abrante, Ligia; Salazar, Víctor; Reyes, Nelson; García-Amado, Maria Alexandra; Fernández-Delgado, Milagro; Romero, Roberto; Rojas, Héctor; Michelangeli, Fabián A.

doi:10.1016/j.ijid.2014.03.1387

Cited by 8 publications

(10 citation statements)

References 30 publications

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“…Subjects were selected from those having matching H. pylori-positive cultures of biopsies of both gastric and esophageal mucosae from a previous study (8 out of 80 dyspeptic patients) taken at the gastroenterology unit of the Oncology Service Hospital of Instituto Venezolano de los Seguros Sociales (IVSS). 5,6 All volunteers signed an informed consent form in accordance with the bioethics committees of Instituto Venezolano de Investigaciones Científicas (IVIC) and IVSS. During endoscopy procedure, antral and esophageal biopsy specimens were collected and submitted for H. pylori culture as previously described.…”

Section: Methodsmentioning

confidence: 99%

“…2,3 In Venezuela, high prevalence of H. pylori in the esophagus (86%) and a heterogenous distribution of cag-pathogenicity island (cag-PAI) genotypes have been demonstrated, indicating the coexistence of different strains in a single host. 4,5 Reports provided by our research group demonstrated multiple H. pylori colonization in the esophageal mucosa by studying cag-PAI genotypes and antibiotic resistance profiles. Helicobacter pylori in the esophageal mucosa was characterized by a partial cag-PAI island and low antibiotic resistance, whereas a higher antibiotic resistance and a complete island were found in the gastric mucosa.…”

Section: Introductionmentioning

confidence: 99%

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Point Mutations at gyrA and gyrB Genes of Levofloxacin-Resistant Helicobacter pylori Isolates in the Esophageal Mucosa from a Venezuelan Population

López-Gasca

Peña

García-Amado

et al. 2018

The American Journal of Tropical Medicine and Hygiene

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The treatment of infection is complicated by antibiotic resistance. A high levofloxacin (LVX) resistance rate was previously demonstrated in isolates from gastric mucosa (40%) and esophagus (19%) in individual hosts of a Venezuelan population. We aimed to assess the molecular mechanisms of LVX resistance and susceptibility in isolates from the gastroesophageal mucosa, by studying point mutations in the quinolone resistance-determining region of and genes. Sequencing of and genes ( = 120) helped to identify point mutations in 60 isolates (30 from antrum and 30 from esophagus) of five dyspeptic patients. Double (Asn87Thr and Asp91Asn) and single (Asn87Ile or Asn87Thr) mutations in the gene were identified in the esophageal mucosa. These mutations have been commonly found in the stomach. Occurrence of a single (Asn87Ile) mutation was associated with high resistance (minimum inhibitory concentration ≥ 32 μg/mL) to LVX. Only a single (Ser479Gly) mutation was found in the gene in both mucosae. One patient presented isolates with no mutations in the two genes studied. Isolates with the same mutation pattern in individual hosts revealed identical genetic profiles for these genes, confirming that isolates identified in the esophageal mucosa come from isolates colonizing the stomach. resistance to LVX in the esophagus is related to double- and single-point mutations in and genes, such as those found in the stomach. Levofloxacin should be applied with caution, because its antibiotic effect on is decreasing in Latin America, perhaps owing to high prescription rates.

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Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Point Mutations at gyrA and gyrB Genes of Levofloxacin-Resistant Helicobacter pylori Isolates in the Esophageal Mucosa from a Venezuelan Population

López-Gasca

Peña

García-Amado

et al. 2018

The American Journal of Tropical Medicine and Hygiene

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“…H. pylori has a variable antimicrobial sensitivity pattern, depending on the geographical area and the occurrence of H. pylori resistance that reduces the success of first line treatment. Many studies have been reported on H. pylori isolates from different parts of the worlds, including Germany [ 14 ], India [ 15 ], Brazil [ 16 , 17 ], Venezuela [ 18 ], Chile [ 19 ], Colombia [ 20 ], Iran [ 21 ], Indonesia [ 22 ], and Pakistan [ 23 ]. In Arabian isolates, limited reports have been published on the antimicrobial resistance and virulence factors of H. pylori in UAE [ 24 ] and Kuwait [ 25 , 26 ].…”

Section: Introductionmentioning

confidence: 99%

Prevalence of CagA and antimicrobial sensitivity of H. pylori isolates of patients with gastric cancer in Egypt

AlEraky

Helmy

Ragab

et al. 2018

Infect Agents Cancer

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BackgroundHelicobacter pylori (H. pylori) infection has been recognized as a significant threat for gastric cancer. However, studies that investigated the oncogenic factors and antimicrobial resistance of H. pylori in Egyptian isolates with gastric cancer are rare. The current study aimed to examine: (1) The pattern of antimicrobial resistance of H. pylori isolates of Egyptian gastric cancer patients, and (2) the prevalence of Cytotoxin-associated gene A (CagA).MethodsSamples were collected from patients with gastric cancer. Isolation of H. pylori was performed using Columbia blood agar supplemented with 10% horse blood, and selective supplement of H. pylori for 3 to 5 days at 37 °C under microaerophilic condition. Isolates were identified by biochemical traits of H. pylori: oxidase, urease and catalase tests. Antimicrobial susceptibility of H. pylori isolates was examined against five antimicrobial agents using disc diffusion method. After that, extraction of DNA and Polymerase Chain Reaction (PCR) were performed to amplify the target genes.ResultsTwelve samples were collected from six males and six females Egyptian patients with cancer with an age range from 22 to 65 years. These cases are scarce and samples were collected over a period of almost eleven months. All isolates were confirmed as positive H. pylori through colony morphology and biochemical tests. The most effective antibiotic found was ciprofloxacin whereas all isolates showed resistance to metronidazole and erythromycin. The target CagA oncogene gene with expected product size was reported and seven (out of twelve) isolates (58%) were identified as CagA positive.ConclusionThe current study is unique in two main aspects. First, it reported the pattern of antimicrobial susceptibility and prevalence of CagA gene in H. pylori from Egyptian patients. Second, it exclusively recruited isolates from gastric cancer patients which were confirmed by clinical and laparoscopic examination. The moderately high prevalence of CagA gene in Egyptian cancer patients calls for more vigilance against that oncogene.

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“…pylori possess many virulence genes; one of them is cag pathogenicity island (cagPAI) (1). CagPAI is since its discovery the most analysed base pairs region of H. pylori chromosome and contains around 30 genes divided into region I and II.…”

mentioning

confidence: 99%

“…Some authors correlate intact cagPAI with severe gastroduodenal diseases, with higher grade of chronic gastritis and premalignant lesions of gastric mucosa. (1,(3)(4), while partially deleated and deleated cagPAI are associated with milder forms of gastroduodenal disease and lower grade of pathological alternations of gastric mucosa (5-6). On the contrary, some of the authors did not find correlation between cagPAI and gastroduodenal disease (7).…”

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Detection of virulence gene belonging to cag pathogenicity island in Helicobacter pylori isolates after multiple unsuccessful eradication therapy in Northwest Croatia

et al. 2016

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Background: Some of the genes belonging to cag pathogenicity island (cagPAI) in Helicobacter pylori were found to be associated with an increased severity of gastric mucosal inflammation that might lead to the development of gastroduodenal disease. Aim: The aim of our study was to define a group of patients based on the frequency of virulence genes of cagPAI island and comparison with pathohistological alterations of gastric mucosa who need to be subjected to further eradication therapy after previous unsuccessful eradication therapy and in spite of benign endoscopic findings.Material and methods: In total 103 H. pylori isolates were analysed. Genes encoding virulence factors were detected by PCR with primers for 10 loci in cagPAI: Apcag (cagA promotor region), cagA1, cagA2, cagA3, cagM, cagT, cagE, LEC, tnpA and tnpB. The patients who provided isolates were classified into three clinical categories: non-ulcer dyspepsia (n=69), erosio/ulcus ventriculi (n=22) and erosio/ulcus duodeni (n=12 (5)(6). On the contrary, some of the authors did not find correlation between cagPAI and gastroduodenal disease (7). CagPAI encodes multiple structural components of bacterial type IV secretion system (T4SS). T4SS translocates cagA protein directly to the cytosol of the gastric epitelium where it gets tyrosin phosphorylated by Src-family kinases and becomes able to alter the host cell functions leading to malignant transformation (2). CagA gene is located in the region I of cagPAI and is considered to be the marker of this region. CagA positive isolates are associated with more severe clinical features in many studies. However, there are contradictory results in the references regarding these studies.CagE is also located in the region I and is necessary to induce production of interleukin IL-8. Some authors consider cagE gene to be better marker of cagPAI region compared to cagA and more useful in monitoring the progress of H. pylori induced gastric disease. CagT gene is a marker of cagII region and some studies connect it with more severe clinical disease (8). LEC (left terminal end of cagII) is not necessary for translocation of cagA into the host cell or induction of interleukin IL8. It is associated with peptic ulcer and adenocarcinoma. Some of the study found connection of tnpA gene with peptic ulcer (9).There are no published studies on the presence of H. pylori virulence genes in Croatia. Considering quite large number of patients with multiple unsuccessful eradication therapy, in spite of lack of clinical symptoms and benign endoscopic result, there is a question to pose whether to insist on eradication or not.The aim of our study was to detect virulence genes of H. pylori just in these patients as a possible predictors of future severe gastroduodenal diseases, by comparing it with clinical and pathohistological results. MATERIAL AND METHODS PatientsThe study analysed gastroscopic test results and bioptic specimens of gastric mucosa with positive H. pylori culture in 103 patients examined during routine, clini...

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Heterogeneity of cag genotypes of Helicobacter pylori in the esophageal mucosa of dyspeptic patients and its relation to histopathological outcomes

Cited by 8 publications

References 30 publications

Point Mutations at gyrA and gyrB Genes of Levofloxacin-Resistant Helicobacter pylori Isolates in the Esophageal Mucosa from a Venezuelan Population

Point Mutations at gyrA and gyrB Genes of Levofloxacin-Resistant Helicobacter pylori Isolates in the Esophageal Mucosa from a Venezuelan Population

Prevalence of CagA and antimicrobial sensitivity of H. pylori isolates of patients with gastric cancer in Egypt

Detection of virulence gene belonging to cag pathogenicity island in Helicobacter pylori isolates after multiple unsuccessful eradication therapy in Northwest Croatia

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