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Sample records for pylori isolates obtained

  1. Quasispecies development of Helicobacter pylori observed in paired isolates obtained years apart from the same host.

    PubMed

    Kuipers, E J; Israel, D A; Kusters, J G; Gerrits, M M; Weel, J; van Der Ende, A; van Der Hulst, R W; Wirth, H P; Höök-Nikanne, J; Thompson, S A; Blaser, M J

    2000-01-01

    Helicobacter pylori isolates show greater genetic diversity than other bacterial species studied, but the basis for this phenomenon is unknown. Whether detectable genomic mutation appears within an H. pylori population during persistent colonization was investigated. Paired H. pylori populations obtained across 7- to 10-year intervals from 13 patients were characterized by use of methods including polymerase chain reaction (PCR) genotyping for cagA, vacA, iceA, recA, and IS605; random arbitrarily primed DNA (RAPD)-PCR and amplified fragment length polymorphism (AFLP) analysis; and ELISA, to determine Lewis phenotypes. Genotyping, including recA sequence analysis, revealed that initial and follow-up populations represented the same population in 11 patients (85%). Nevertheless, distinct dissimilarities were shown within each of these 11 pairs by both RAPD-PCR and AFLP analyses. During follow-up, Lewis-y levels, but not Lewis-x levels, decreased significantly. The changes detected by RAPD-PCR and AFLP indicate that genetic drift occurs within H. pylori populations over the course of years of colonization of a single host.

  2. Increasing metronidazole and rifampicin resistance of Helicobacter pylori isolates obtained from children and adolescents between 2002 and 2015 in southwest Germany.

    PubMed

    Regnath, Thomas; Raecke, Olaf; Enninger, Axel; Ignatius, Ralf

    2017-02-01

    Increasing antibiotic resistance has been reported for Helicobacter pylori, but data on the prevalence of antibiotic resistance of H. pylori in pediatric patients and the development of resistance over time are sparse. Data for 610 H. pylori isolates obtained between 2002 and 2015 from gastric biopsies of 582 (mainly treatment-naïve) pediatric patients from southwest Germany were analyzed retrospectively regarding the antibiotic susceptibility determined by Etest and patients' characteristics. Overall resistance to metronidazole, clarithromycin, and rifampicin was 28.7%, 23.2%, and 13.3%, respectively, while resistance to amoxicillin was rare (0.8%). Simultaneous resistance to metronidazole and clarithromycin was observed for 7.7% of the isolates, and 2.3% were resistant to metronidazole, clarithromycin, and rifampicin. Differences between primary vs secondary resistance existed for metronidazole (24.7% vs 38.8%, P=.01) and clarithromycin (17.2% vs 54.1%, P=.0001). From 2002-2008 to 2009-2015, resistance to metronidazole increased from 20.8% to 34.4% (P=.003) and to rifampicin from 3.9% to 18.8% (P=.0001); this was not associated with increased numbers of patients previously treated for H. pylori infection in the second study period. In contrast, resistance to clarithromycin did not change significantly over time. Resistance was not associated with age, sex, or family origin in Europe. The considerable antibiotic resistance of H. pylori isolates argues for standard antibiotic susceptibility testing of H. pylori in pediatric patients prior to the initiation of antibiotic therapy. © 2016 John Wiley & Sons Ltd.

  3. Phylogenomics of Colombian Helicobacter pylori isolates.

    PubMed

    Gutiérrez-Escobar, Andrés Julián; Trujillo, Esperanza; Acevedo, Orlando; Bravo, María Mercedes

    2017-01-01

    During the Spanish colonisation of South America, African slaves and Europeans arrived in the continent with their corresponding load of pathogens, including Helicobacter pylori. Colombian strains have been clustered with the hpEurope population and with the hspWestAfrica subpopulation in multilocus sequence typing (MLST) studies. However, ancestry studies have revealed the presence of population components specific to H. pylori in Colombia. The aim of this study was to perform a thorough phylogenomic analysis to describe the evolution of the Colombian urban H. pylori isolates. A total of 115 genomes of H. pylori were sequenced with Illumina technology from H. pylori isolates obtained in Colombia in a region of high risk for gastric cancer. The genomes were assembled, annotated and underwent phylogenomic analysis with 36 reference strains. Additionally, population differentiation analyses were performed for two bacterial genes. The phylogenetic tree revealed clustering of the Colombian strains with hspWestAfrica and hpEurope, along with three clades formed exclusively by Colombian strains, suggesting the presence of independent evolutionary lines for Colombia. Additionally, the nucleotide diversity of horB and vacA genes from Colombian isolates was lower than in the reference strains and showed a significant genetic differentiation supporting the hypothesis of independent clades with recent evolution. The presence of specific lineages suggest the existence of an hspColombia subtype that emerged from a small and relatively isolated ancestral population that accompanied crossbreeding of human population in Colombia.

  4. Emerging trends of antimicrobial resistance in Helicobacter pylori isolates obtained from Pakistani patients: The need for consideration of amoxicillin and clarithromycin.

    PubMed

    Siddiqui, Taranum Ruba; Ahmed, Waquaruddin; Arif, Ambreen; Bibi, Safia; Khan, Adnan

    2016-06-01

    To present antimicrobial susceptibility profile of helicobacter pylori isolated from gastric biopsies of dyspeptic patients. The cross-sectional study was conducted from March 2008 to May 2013 at the Jinnah Postgraduate Medical Centre (JPMC), Karachi, and comprised patients with suspected peptic ulcer disease who underwent upper gastrointestinal endoscopy. Multiple gastric antral biopsies were taken. One sample was imbedded in the Campylobacter-like organism test, while other biopsies were processed for culture and confirmed on polymerase chain reaction. Isolates were subjected to antimicrobial susceptibility testing and minimum inhibitory concentrations of antimicrobial agents were estimated by Epsilometer test. SPSS 21 was used for statistical analysis. Of the 889 samples available, 254(28.6%) were positive after campylo-like organism test, of them, 92(36.2%) isolates were cultured. Susceptibility test showed 90(97.8%) resistance to metronidazole, 25(30.1%) ofloxacin, 6(16.2%) levofloxacin, 14(15.2%) furazolidone, 5(5.4%) clarithromycin, 4(4.3%) tetracycline and 2(2.2%) isolates showed resistance to amoxicillin. Resistance to more than one drug was observed in 37(40.2%) isolates. Low clarithromycin resistance was surprising since Pakistan is considered a hot bed of drug-resistant bacteria.

  5. Levofloxacin resistance of Helicobacter pylori strains isolated from patients in southern Poland, between 2006-2012.

    PubMed

    Karczewska, Elzbieta; Klesiewicz, Karolina; Wojtas-Bonior, Izabela; Skiba, Iwona; Sito, Edward; Czajecki, Krzysztof; Zwolińska-Wcisło, Małgorzata; Budak, Alicja

    2014-01-01

    An increasing resistance of Helicobacter pylori (H. pylori) to antimicrobial agents leads to the need of regional monitoring of the prevalence resistant strains (according to the Maastricht/Florence consensus report, 2012). The aim of the study was to assess the resistance to levofloxacin of H. pylori strains isolated from adult patients of Małopolska region in Poland. Bioptates taken from gastric mucosa during gastroscopy constituted the material for the study. Two hundred ten H. pylori strains were isolated from 811 patients. A majority of strains (171) came from patients before the treatment of H. pylori infections while the remaining 39 strains were isolated from patients after the failed therapy. Susceptibility of H. pylori to levofloxacin was determined by strips impregnated with antibiotic gradient (E-test, bioMerieux). The obtained minimum inhibitory concentration (MIC) values ranged from 0.002 mg/L to 32 mg/L. The percentage of strains resistant to levofloxacin amounted to 8.10% (17/210). Among the group of strains isolated from patients before the treatment, 5.85% (10/171) of H. pylori strains were resistant to levofloxacin. In the group of strains isolated from patients after the treatment 17.95% (7/39) of strains were resistant. The difference in the frequency of H. pylori strains resistant to levofloxacin in patients before and after the treatment of the infection due to H. pylori was statistically significant (p = 0.0297). The low percentage of H. pylori strains resistant to levofloxacin justify that the introduction of a triple therapy with levofloxacin is a good alternative in the treatment of H. pylori infections, especially in regions with high prevalence of H. pylori strains resistant to clarithromycin (> 20%).

  6. New urea biosensor based on urease enzyme obtained from Helycobacter pylori.

    PubMed

    Dindar, Bahar; Karakuş, Emine; Abasıyanık, Fatih

    2011-11-01

    The urease enzyme of Helicobacter pylori was isolated from biopsy sample obtained from antrum big curvature cell extracts. A new urea biosensor was prepared by immobilizing urease enzyme isolated from Helicobacter pylori on poly(vinylchloride) (PVC) ammonium membrane electrode by using nonactine as an ammonium ionophore. The effect of pH, buffer concentration, and temperature for the biosensor prepared with urease from H. pylori were obtained as 6.0, 5 mM, and 25 °C, respectively. We also investigated urease concentration, stirring rate, and enzyme immobilization procedures in response to urea of the enzyme electrode. The linear working range of the biosensor extends from 1 × 10(-5) to 1 × 10(-2) M and they showed an apparent Nernstian response within this range. Urea enzyme electrodes prepared with urease enzymes obtained from H. pylori and Jack bean based on PVC membrane ammonium-selective electrode showed very good analytical parameters: high sensitivity, dynamic stability over 2 months with less decrease of sensitivity, response time 1-2 min. The analytical characteristics were investigated and were compared those of the urea biosensor prepared with urease enzyme isolated from Jack bean prepared at the same conditions. It was observed that rapid determinations of human serum urea amounts were also made possible with both biosensors.

  7. Inhibition of Helicobacter pylori and Its Associate Urease by Labdane Diterpenoids Isolated from Andrographis paniculata.

    PubMed

    Shaikh, Rafik U; Dawane, Ashwini A; Pawar, Rajendra P; Gond, Dhananjay S; Meshram, Rohan J; Gacche, Rajesh N

    2016-03-01

    The present study was carried out to evaluate anti-Helicobacter pylori and its associated urease activity of labdane diterpenoids isolated from Andrographis paniculata. A molecular docking analysis was performed by using ArgusLab 4.0.1 software. The results obtained indicate that compound A possesses strong inhibition to H. pylori, 28 ± 2.98 (minimum inhibitory concentration, 9 µg/mL), and its urease, 85.54 ± 2.62% (IC50 , 20.2 µg/mL). Compounds B, C, and D also showed moderate inhibition to H. pylori and its urease. The obtained results were in agreement with the molecular docking analysis of compounds. The phytochemicals under investigation were found to be promising antibacterial agents. Moreover, the isolated compounds can be considered as a resource for searching novel anti-H. pylori agents possessing urease inhibition.

  8. Antibiotic resistance among Helicobacter pylori clinical isolates in Lima, Peru

    PubMed Central

    Boehnke, Kevin F; Valdivieso, Manuel; Bussalleu, Alejandro; Sexton, Rachael; Thompson, Kathryn C; Osorio, Soledad; Reyes, Italo Novoa; Crowley, John J; Baker, Laurence H; Xi, Chuanwu

    2017-01-01

    Objectives Gastric carcinoma is the most common cancer and cause of cancer mortality in Peru. Helicobacter pylori, a bacterium that colonizes the human stomach, is a Group 1 carcinogen due to its causal relationship to gastric carcinoma. While eradication of H. pylori can help prevent gastric cancer, characterizing regional antibiotic resistance patterns is necessary to determine targeted treatment for each region. Thus, we examined primary antibiotic resistance in clinical isolates of H. pylori in Lima, Peru. Materials and methods H. pylori strains were isolated from gastric biopsies of patients with histologically proven H. pylori infection. Primary antibiotic resistance among isolates was examined using E-test strips. Isolates were examined for the presence of the cagA pathogenicity island and the vacA m1/m2 alleles via polymerase chain reaction. Results Seventy-six isolates were recovered from gastric biopsies. Clinical isolates showed evidence of antibiotic resistance to 1 (27.6%, n=21/76), 2 (28.9%, n=22/76), or ≥3 antibiotics (40.8%). Of 76 isolates, eight (10.5%) were resistant to amoxicillin and clarithromycin, which are part of the standard triple therapy for H. pylori infection. No trends were seen between the presence of cagA, vacA m1, or vacA m2 and antibiotic resistance. Conclusion The rate of antibiotic resistance among H. pylori isolates in Lima, Peru, is higher than expected and presents cause for concern. To develop more targeted eradication therapies for H. pylori in Peru, more research is needed to better characterize antibiotic resistance among a larger number of clinical isolates prospectively. PMID:28331349

  9. Prevalence of resistant Helicobacter pylori isolates in Bulgarian children.

    PubMed

    Boyanova, Lyudmila; Koumanova, Radka; Gergova, Galina; Popova, Maria; Mitov, Ivan; Kovacheva, Youlia; Derejian, Sirigan; Katsarov, Nikolai; Nikolov, Rossen; Krastev, Zacharii

    2002-09-01

    The aim of this study was to assess the primary and combined resistances of Helicobacter pylori isolates obtained from paediatric patients in 2000-2001 to seven antimicrobial agents. Resistance rates of pre-treatment isolates from 115 children were investigated by the limited agar dilution method alone and by the E-test. The cut-off concentrations for resistance were: metronidazole >8 mg/L, clarithromycin and azithromycin >1 mg/L, clindamycin >4 mg/L, amoxicillin >0.5 mg/L, tetracycline >4 mg/L and ciprofloxacin >1 mg/L. Primary resistance rates were: metronidazole 15.8%, clarithromycin 12.4%, azithromycin 14.6%, clindamycin 20.0%, amoxicillin 0%, metronidazole + clarithromycin 4.5%, ciprofloxacin 6.0%, metronidazole + clarithromycin + ciprofloxacin 1.2%, tetracycline 3.1% and metronidazole + ciprofloxacin 1.2%. There were no significant age (1-9 years versus 10-18 years) or gender differences. Prevalence of both macrolide-resistant and intermediately susceptible strains was 21.9% for azithromycin and 15.9% for clarithromycin. Of 18 metronidazole-resistant isolates, 77.8% exhibited a metronidazole MIC > or = 32 mg/L. H. pylori resistance rates to metronidazole, clarithromycin and both agents were relatively low in Bulgarian children. However, resistance was found to all drugs tested except for amoxicillin. The consumption of newer macrolides and tetracyclines could be related to the prevalence of resistance to the corresponding agents. There were no significant differences in primary resistance rates of H. pylori to antimicrobial agents between children and adults except for metronidazole. Multi-drug resistance to newer macrolides, metronidazole and ciprofloxacin in association with a slightly elevated amoxicillin MIC (0.38 mg/L) was detected in one strain.

  10. Characterization and presumptive identification of Helicobacter pylori isolates from rhesus monkeys.

    PubMed Central

    Drazek, E S; Dubois, A; Holmes, R K

    1994-01-01

    We characterized 38 Helicobacter isolates, including 22 from gastric biopsy samples obtained from 14 rhesus monkeys and single isolates from 16 monkeys in a different colony. Biochemical profiles of these isolates were nearly identical to that of Helicobacter pylori ATCC 43504. Restriction fragment length polymorphism (RFLP) analysis indicated that each infected monkey harbored one to four strains. The 17 RFLP types found among these 22 isolates differed from all seven RFLPs found among the other 16 isolates. Thus, monkeys within a given colony are more likely to be infected by Helicobacter isolates with the same or a similar RFLP than are monkeys from different colonies. A 16S rRNA gene was amplified by PCR and cloned from the Helicobacter isolate from rhesus monkey 85D08. Ribotyping with this probe demonstrated less diversity among isolates from rhesus monkeys than was reported among isolates of H. pylori from humans, as did RFLP analysis of a PCR fragment of the ureA-ureB gene cluster. The DNA sequence of the cloned 16S rRNA gene was determined and compared with sequences reported for H. pylori and other Helicobacter species. Our analysis of 127 nucleotides (corresponding with residues 1240 to 1366 of the Escherichia coli 16S rRNA gene) indicated that the Helicobacter isolate from monkey 85D08 was 99.2 to 100% homologous to isolates of H. pylori from humans but only 83.5 to 96.9% homologous with other Helicobacter species in this region of the 16S rRNA gene. These data provide strong support for the presumptive identification of these isolates as H. pylori. Images PMID:7523441

  11. Indicator medium for isolation of Campylobacter pylori.

    PubMed Central

    Queiroz, D M; Mendes, E N; Rocha, G A

    1987-01-01

    The use of a new indicator culture medium, Belo Horizonte medium, is proposed for better colony recognition and a presumptive identification of Campylobacter pylori. This medium, containing brain heart infusion sheep blood agar, was supplemented with 40 mg of 2,3,5-triphenyltetrazolium chloride per liter in addition to vancomycin, nalidixic acid, and amphotericin B. On Belo Horizonte medium, Campylobacter pylori present unique golden colonies. PMID:3429628

  12. Draft Genome Sequences of 13 Colombian Helicobacter pylori Strains Isolated from Pacific Coast and Andean Residents.

    PubMed

    Pazos, Alvaro; Kodaman, Nuri; Piazuelo, M Blanca; Romero-Gallo, Judith; Sobota, Rafal S; Israel, Dawn A; Bravo, Luis E; Morgan, Douglas R; Wilson, Keith T; Correa, Pelayo; Peek, Richard M; Williams, Scott M; Schneider, Barbara G

    2017-04-13

    We present here the draft genomes of 13 Helicobacter pylori strains isolated from Colombian residents on the Pacific coast (n = 6) and in the Andes mountains (n = 7), locations that differ in gastric cancer risk. These 13 strains were obtained from individuals with diagnosed gastric lesions. Copyright © 2017 Pazos et al.

  13. An improvement in isolation and preservation of clinical strains of Helicobacter pylori.

    PubMed

    Farshad, Shohreh; Japoni, Aziz; Shahidi, Maneli Amin; Hosseini, Marziyeh; Alborzi, Abdolvahab

    2011-01-01

    Isolation of H. pylori from gastric mucosal biopsy specimens is a prerequisite for further studies addressing drug susceptibility testing, analysis and characterization of virulence factors, molecular epidemiology studying or other comparative studies. In this study, we used a modified enriched culture medium with short incubation time to improve the isolation rate of H. pylori from the clinical specimens. Between October 2008 and October 2009, 266 dyspeptic patients attending the endoscopy ward of Motahhary Clinic of Shiraz University of Medical Sciences, were investigated. The biopsy samples were cultured on two selective media called M1, which we used in our previous studies, and a modified medium called M2. The cultures were kept in a microaerophilic atmosphere at 37 degrees C. The plates were inspected first on day 1, and then on daily basis for a total of 10 days. The isolates were confirmed as H. pylori by colony morphology and positive oxidase, catalase and rapid urease tests. We used the same media and culture conditions to subculture the isolates for several times. Specimens were considered to be H. pylori positive if either the culture or two of the three diagnostic methods yielded positive results. The isolation rate of H. pylori strains from the samples was significantly higher on M2 in comparison with M1 medium (p<0.05). The bacterial growth on M2 was observed after a significantly shorter time (p<0.05), i.e., after incubation for about 24 hrs. Following these procedures, the preservation time could be extended beyond 6 months without a significant loss of viability. The modified culture technique enabled a shorter incubation time and a higher isolation rate for H.pylori obtained from clinical samples.

  14. [Isolation of Helicobacter pylori from dental plaque].

    PubMed

    Mattana, C M; Vega, A E; Flores, G; de Domeniconi, A G; de Centorbi, O N

    1998-01-01

    It has been suggested that oral dissemination might be the major transmission vehicle for Helicobacter pylori, and that dental plaque might act as its reservoir. The presence of H. pylori was investigated in 62 odontological male and female patients (average age: 35 years old). Samples were taken from supragingival plaque, placed in 0.3 ml of thioglycolate broth, cultured within 12 h in Mueller-Hinton agar with the addition of 5-7% of sheep blood and antibiotic supplement, and incubated at 37 degrees C in microaerophilia for 5-7 days. Typical colonies were identified by gram, urease, oxidase and catalase. H. pylori was detected in a 15 year-old patient suffering from gastric acidity (1.61% positivity index). The medium used facilitated recovery of the agent from a sample abundant in germs. H. pylori was not recovered from the same patient 12 months later, suggesting that there might have been a transitory passage by gastric reflux or that the bacterium was acquired from an exogenous source.

  15. Isolation of Abscisic Acid from Korean Acacia Honey with Anti-Helicobacter pylori Activity.

    PubMed

    Kim, SeGun; Hong, InPyo; Woo, SoonOk; Jang, HyeRi; Pak, SokCheon; Han, SangMi

    2017-07-01

    Helicobacter pylori (H. pylori) is linked to the development of the majority of peptic ulcers and some types of gastric cancers, and its antibiotic resistance is currently found worldwide. This study is aimed at evaluating the anti-H. pylori activity of Korean acacia honey and isolating the related active components using organic solvents. The crude acacia honey was extracted with n-hexane, dichloromethane, ethyl acetate (EtOAc), and n-butanol. The EtOAc extract was subjected to octadecyl-silica chromatography. The extracts and fractions were then examined for anti-H. pylori activity using the agar well diffusion method. The antimicrobial activity of abscisic acid against H. pylori was investigated by determining the minimum inhibitory concentrations (MICs), minimum bactericidal concentrations (MBCs), and by performing a time-kill assay. Abscisic acid related to the botanical origins of acacia honey from Korea has been analyzed using ultra-performance liquid chromatography. The MICs and MBCs of abscisic acid were 2.7 ± 1.3 and 6.9 ± 1.9 μg/mL, respectively. The bactericidal activity of abscisic acid (at 10.8 μg/mL corresponding to 4 × MIC) killed the organism within 36-72 h. These results suggest that abscisic acid isolated from Korean acacia honey has antibacterial activity against H. pylori. Abscisic acid isolated from Korean acacia honey can be therapeutic and may be further exploited as a potential lead candidate for the development of treatments for H. pylori-induced infections. The crude acacia honey was extracted with n-hexane, dichloromethane, EtOAc, and n-butanolThe EtOAc extract yielded eight fractions and four subfractions were subsequently obtained chromatographicallyAbscisic acid was isolated from one subfractionAll the solvent extracts and fractions showed antibacterial activity against H. pyloriAbscisic acid exhibited antibacterial activity against H. pylori. Abbreviations used: MeOH: Methanol; EtOAc: Ethyl acetate; TSB: Trypticase soy broth

  16. Molecular Basis of Pathogenicity in Helicobacter pylori Clinical Isolates

    PubMed Central

    Ramis, Ivy Bastos; Fonseca, Tesiê Leopoldo; Moraes, Ernani Pinho de; Fernandes, Márcia Silveira; Mendoza-Sassi, Raul; Rodrigues, Obirajara; Juliano, Carlos Renan Varela; Scaini, Carlos James; Almeida da Silva, Pedro Eduardo

    2010-01-01

    This study identified pathogenicity genes in 40 Helicobacter pylori clinical isolates. The cagA, vacA, and iceA genes were detected in 65%, 97.5%, and 97.5% of the isolates, respectively. The cagA, iceA1, and vacAs1a/m1 genes were related to erosive gastritis, whereas the vacAs2/m2 and iceA2 genes were associated with enanthematous gastritis. PMID:20686086

  17. Isolation and diagnosis of Helicobacter pylori by a new method: microcapillary culture.

    PubMed

    Allahverdiyev, Adil M; Bagirova, Melahat; Caliskan, Reyhan; Tokman, Hrisi Bahar; Aliyeva, Hayat; Unal, Gokce; Oztel, Olga Nehir; Abamor, Emrah Sefik; Toptas, Hilal; Yuksel, Pelin; Kalayci, Fatma; Aslan, Mustafa; Erzin, Yusuf; Bal, Kadir; Kocazeybek, Bekir S

    2015-03-07

    To investigate the performance of the microcapillary culture method (MCM) in Helicobacter pylori (H. pylori) isolation and diagnosis. Microcapillary culture (MC), classical culture (CC), rapid urease (CLO) test, and histopathologic examination (HE) were performed with biopsy samples. Homogenized biopsy samples were loaded into capillary tubes and incubated for 48 h at 37 °C without providing a microaerophilic environment. Additionally, three or four loops of the homogenized sample were inoculated in a ready-to-use selective medium (Becton Dickinson, Helicobacter Agar, Modified) specific for the isolation of H. pylori and incubated at 37 °C in a microaerophilic atmosphere provided by CampyGen (Becton Dickinson, GasPack). Bacteria reproducing in microcapillary tubes were evaluated in an inverted microscope and also were evaluated after performing a CC with the content. Results obtained by CC, CLO test, and HE were compared with those of MC. The diagnostic performances of the methods used in this study were evaluated for specificity, sensitivity, positive predictive value (PPV), negative predictive value (NPV), and CI. H. pylori was found positive by CLO test + HE and/or CC culture in 26 patient antrum and corpus biopsy samples. In 25 (25/26) patient biopsy samples, H. pylori was isolated by MCM, whereas in only 14 (14/26) patient biopsy samples, H. pylori was isolated by CC. CLO test and HE were found positive in 17 (17/26) patient biopsy samples. Comparing the results of the isolation of H. pylori by MCM, CC, CLO test, and HE, the sensitivity of the MCM was found as 96%, the specificity as 80%, the PPV as 83%, the NPV as 95%, and the 95%CI as 0.76 (χ (2) = 31.51, P < 0.01) whereas the sensitivity of the CC was found as 54% (χ (2) = 19.15, P < 0.01), and the sensitivity of the CLO test and HE were found as 65% (χ (2) = 25.26, P < 0.01). This new microcapillary cultivation method for H. pylori has high diagnostic sensitivity compared with CC, HE, and CLO

  18. Isolation and diagnosis of Helicobacter pylori by a new method: Microcapillary culture

    PubMed Central

    Allahverdiyev, Adil M; Bagirova, Melahat; Caliskan, Reyhan; Tokman, Hrisi Bahar; Aliyeva, Hayat; Unal, Gokce; Oztel, Olga Nehir; Abamor, Emrah Sefik; Toptas, Hilal; Yuksel, Pelin; Kalayci, Fatma; Aslan, Mustafa; Erzin, Yusuf; Bal, Kadir; Kocazeybek, Bekir S

    2015-01-01

    AIM: To investigate the performance of the microcapillary culture method (MCM) in Helicobacter pylori (H. pylori) isolation and diagnosis. METHODS: Microcapillary culture (MC), classical culture (CC), rapid urease (CLO) test, and histopathologic examination (HE) were performed with biopsy samples. Homogenized biopsy samples were loaded into capillary tubes and incubated for 48 h at 37 °C without providing a microaerophilic environment. Additionally, three or four loops of the homogenized sample were inoculated in a ready-to-use selective medium (Becton Dickinson, Helicobacter Agar, Modified) specific for the isolation of H. pylori and incubated at 37 °C in a microaerophilic atmosphere provided by CampyGen (Becton Dickinson, GasPack). Bacteria reproducing in microcapillary tubes were evaluated in an inverted microscope and also were evaluated after performing a CC with the content. Results obtained by CC, CLO test, and HE were compared with those of MC. The diagnostic performances of the methods used in this study were evaluated for specificity, sensitivity, positive predictive value (PPV), negative predictive value (NPV), and CI. RESULTS: H. pylori was found positive by CLO test + HE and/or CC culture in 26 patient antrum and corpus biopsy samples. In 25 (25/26) patient biopsy samples, H. pylori was isolated by MCM, whereas in only 14 (14/26) patient biopsy samples, H. pylori was isolated by CC. CLO test and HE were found positive in 17 (17/26) patient biopsy samples. Comparing the results of the isolation of H. pylori by MCM, CC, CLO test, and HE, the sensitivity of the MCM was found as 96%, the specificity as 80%, the PPV as 83%, the NPV as 95%, and the 95%CI as 0.76 (χ2 = 31.51, P < 0.01) whereas the sensitivity of the CC was found as 54% (χ2 = 19.15, P < 0.01), and the sensitivity of the CLO test and HE were found as 65% (χ2 = 25.26, P < 0.01). CONCLUSION: This new microcapillary cultivation method for H. pylori has high diagnostic sensitivity compared

  19. Primary Antibiotic Resistance to Helicobacter pylori Strains Isolated From Children in Northern Iran: A Single Center Study

    PubMed Central

    Maleknejad, Shohreh; Mojtahedi, Ali; Safaei-Asl, Afshin; Taghavi, Zeinab; Kazemnejad, Ehsan

    2015-01-01

    Background: Initial resistance to antibiotics is the main reason for the failure of Helicobacter pylori (H. pylori) eradication in children. Objectives: As we commonly face high antibiotic resistance rates in children, we aimed to determine the susceptibility of H. pylori to common antibiotics. Patients and Methods: In this cross-sectional in vitro study, 169 children younger than 14 years with clinical diagnosis of peptic ulcer underwent upper gastrointestinal endoscopy. Biopsy specimens from stomach and duodenum were cultured. In isolated colonies, tests of catalase, urease, and oxidase as well as gram staining were performed. After confirming the colonies as H. pylori, the antibiogram was obtained using disk diffusion method. Results: Culture for H. pylori was positive in 12.3% of the specimens, urease test in 21.3%, serological test in 18.9% and stool antigen test was positive in 21.9%. We could show high specificity but moderate sensitivity of both histological and H. pylori stool antigen tests to detect H. pylori. The overall susceptibility to metronidazole was 42.9%, amoxicillin 95.2%, clarithromycin 85.7%, furazolidone 61.9%, azithromycin 81.0%, and tetracycline 76.2% with the highest resistance to metronidazole and the lowest to clarithromycin. Conclusions: In our region, there is high resistance of H. pylori to some antibiotics including metronidazole and furazolidone among affected children. To reduce the prevalence of this antibiotic resistance, more controlled use of antibiotics should be considered in children. PMID:26635938

  20. Isolation and characterisation of putative adhesins from Helicobacter pylori with affinity for heparan sulphate proteoglycan.

    PubMed

    Ruiz-Bustos, E; Ochoa, J L; Wadström, T; Ascencio, F

    2001-03-01

    A pool of heparan sulphate-binding proteins (HSBPs) from Helicobacter pylori culture supernates was obtained by sequential ammonium sulphate precipitation and affinity chromatography on heparin-Sepharose. The chromatographic procedure yielded one major fraction that contained proteins with heparan sulphate affinity as revealed by inhibition studies of heparan sulphate binding to H. pylori cells. Preparative iso-electric focusing, SDS-PAGE and blotting experiments, with peroxidase(POD)-labelled heparan sulphate as a probe, indicated the presence of two major extracellular proteins with POD-heparan sulphate affinity. One protein had a molecular mass of 66.2 kDa and a pI of 5.4, whilst the second protein had a molecular mass of 71.5 kDa and a pI of 5.0. The N-terminal amino acid sequence of the 71.5-kDa HSBP did not show homology to any other heparin-binding protein, nor to known proteins of H. pylori, whereas the 66.2-kDa HSBP showed a high homology to an Escherichia coli chaperon protein and equine haemoglobin. A third HSBP was isolated from an outer-membrane protein (OMP) fraction of H. pylori cells with a molecular mass of 47.2 kDa. The amino acid sequence of an internal peptide of the OMP-HSBP did not show homology to the extracellular HSBP of H. pylori, or to another microbial HSBP.

  1. Optimal combination of media for primary isolation of Helicobacter pylori from gastric biopsy specimens.

    PubMed Central

    Piccolomini, R; Di Bonaventura, G; Festi, D; Catamo, G; Laterza, F; Neri, M

    1997-01-01

    The aim of the present study was to compare eight media, four nonselective and four selective media, to determine the best combination of media for the primary isolation of Helicobacter pylori. Over a period of 5 months, mucosal antral biopsy specimens were obtained from 222 consecutive dyspeptic patients undergoing endoscopy. Biopsy samples were plated in parallel on all eight media. Egg yolk emulsion agar (EYE), Skirrow's medium, Dent's medium, and modified Thayer-Martin medium were used as selective media; modified chocolate agar (MCHOC), Triptycase soy agar (TSA), brucella agar, and brain heart infusion agar were used as nonselective media. Overall, by using these eight media, H. pylori was recovered from biopsy specimens from 114 of 222 patients, yielding an isolation rate of 51%. Comparison of all possible combinations of the eight media showed that the highest rate of isolation of H. pylori was 100% (114 of 114) with EYE-MCHOC, followed by 96.5% (110 of 114) when EYE-TSA was used. Conversely, it was found that none of the media used alone yielded a 100% rate of recovery (the maximum recovery rate was 95%, which was achieved with EYE). These results indicate that the association of EYE and MCHOC yielded the maximum recovery of H. pylori from gastric biopsy specimens. Therefore, the use of selective and nonselective media in parallel offers optimal recovery rates with only a slight increase in costs. PMID:9163478

  2. [Isolation of Helicobacter pylori in gastric mucosa, dental plaque and saliva in a population from the Venezuelan Andes].

    PubMed

    De Sousa, Lilibeth; Vásquez, Libia; Velasco, Judith; Parlapiano, Donatella

    2006-06-01

    Helicobacter pylori infection is common in people. However, the existence of extra gastric reservoirs and transmission routes remain controversial in the field. Because the oral cavity has been proposed as a reservoir for H. pylori, a study was carried out to determine the presence of H. pylori in dental plaque and saliva. The results were asociated with those obtained in the gastric biopsy. Ninety-seven dyspeptic and fifty asymptomatic patients were studied and samples taken for biopsy, dental plaque and saliva. The gastric biopsies were evaluated using microbiology and histology methods. Cultures and urease tests were carried out on the oral cavity samples and included pretreatment methods using urea and HCl. The frequency of H. pylori for all the patients evaluated was 75.5%. H. pylori was not isolated in saliva or dental plaque in any of the two groups studied with or without sample pretreatment. The urease test in dental plaque was positive in 99.3% of the patients and 89.8% in saliva. There was no statistically significant difference between the infection prevalence by H. pylori in dyspeptic or not dyspeptic patients. The obtained results suggest that the methodology used for the detection of H. pylori is not sufficiently sensitive for the determination of the microorganism in the oral cavity.

  3. Analysis of Genomic Diversity among Helicobacter pylori Strains Isolated from Iranian Children by Pulsed Field Gel Electrophoresis

    PubMed Central

    Falsafi, Tahereh; Sotoudeh, Nazli; Feizabadi, Mohammad-Mehdi; Mahjoub, Fatemeh

    2014-01-01

    Objective: Presence of genomic diversity among Helicobacter pylori (H. pylori) strains have been suggested by numerous investigators. Little is known about diversity of H. pylori strains isolated from Iranian children and their association with virulence of the strains. Our purpose was to assess the degree of genomic diversity among H. pylori strains isolated from Iranian-children, on the basis of vacA genotype, cagA status of the strains, sex, age as well as the pathological status of the patients. Methods: Genomic DNA from 44 unrelated H. pylori strains isolated during 1997–2009, was examined by pulse-field gel electrophoresis (PFGE). Pathological status of the patients was performed according to the modified Sydney-system and genotype/status of vacA/cagA genes was determined by PCR. PFGE was performed using XbaI restriction-endonuclease and the field inversion-gel electrophoresis system. Findings: No significant relationship was observed between the patterns of PFGE and the cagA/vacA status/genotype. Also no relationship was observed between age, sex, and pathological status of the children and the PFGE patterns of their isolates. Similar conclusion was obtained by Total Lab software. However, more relationship was observed between the strains isolated in the close period (1997–2009, 2001–2003, 2005–2007, and 2007–2009) and more difference was observed among those obtained in the distant periods (1997 and 2009). Conclusion: H. pylori strains isolated from children in Iran are extremely diverse and this diversity is not related to their virulence characteristics. Occurrence of this extreme diversity may be related to adaptation of H. pylori strains to variable living conditions during transmission between various host individuals. PMID:26019775

  4. Anti-Helicobacter pylori activity of bioactive components isolated from Hericium erinaceus.

    PubMed

    Liu, Jian-Hui; Li, Liang; Shang, Xiao-Dong; Zhang, Jun-Ling; Tan, Qi

    2016-05-13

    The fungus Hericium erinaceus (Bull.) Pers is used in Chinese traditional medicine to treat symptoms related to gastric ulcers. Different extracts from the fungus were assessed for anti-Helicobacter pylori activity to investigate the antibacterial activity of the ethanol extracts from H. erinaceus and verify the traditional indication of use. The fruiting bodies of H. erinaceus were concentrated with ethanol by HPD-100 macroporous resin and the whole extract was partitioned by petroleum ether and chloroform to afford fractions with using a silica gel column. Several pure compounds of petroleum ether extracts were obtained and analyzed using nuclear magnetic resonance (NMR). The activity of the extracts and fractions towards H. pylori was assessed by the microdilution assay and by the disk diffusion assay in vitro. From the most active fraction, two pure compounds were isolated and identified as the main components with anti-H. pylori activity from the fungus H. erinaceus. The cytotoxicity of these two compounds against the human erythroleu-kemia cell line K562 was also evaluated. The crude ethanol extracts from the fungus H. erinaceus were inhibitory to H. pylori. The petroleum ether extracts (PE1s, PE2s) and the chloroform extracts (TEs) demonstrated strong inhibition to H. pylori. The inhibition of H. pylori was observed through an agar dilution test with minimal inhibition concentration (MIC) values from 400μg/mL to 12.5µg/mL. Two pure compounds, 1-(5-chloro-2-hydroxyphenyl)-3-methyl-1-butanone and 2,5-bis(methoxycarbonyl)terephthalic acid were isolated from the petroleum ether fractions and identified using (1)H NMR and (13)C NMR spectra analysis. The MIC value for 1-(5-chloro-2-hydroxyphenyl)-3-methyl-1-butanone was 12.5-50µg/mL and the MIC value for 2,5-bis(methoxycarbonyl)terephthalic acid was 6.25-25µg/mL. Both two compounds showed weak cytotoxicity against K562 with IC50<200mM. This study revealed that the extracts from petroleum ether contribute to

  5. Diversity of Helicobacter pylori isolates in expression of antigens and induction of antibodies

    PubMed Central

    Tang, Ren-Xian; Luo, Dong-Jiao; Sun, Ai-Hua; Yan, Jie

    2008-01-01

    AIM: To obtain evidence for selection of antigens used in genetically engineered vaccine against Helicobacter pylori (H pylori). METHODS: Enzyme linked immunoabsorbent assay (ELISA) was established on the basis of recombinant protein antigens rUreB, rHpaA, rVacA, rCagA1, rNapA, rFlaA and rFlaB of H pylori to detect expression rates of the antigens in bacterial isolates as well as positive rates of the antibodies in sera from H pylori-infected patients. PCR was applied to the detection of carrying rates of the genes encoding antigens in the isolates. RESULTS: The outputs of rUreB, rHpaA, rVacA, rCagA1, rNapA, rFlaA and rFlaB were approximately 35%, 32%, 15%, 23%, 56%, 25% and 20% of the total bacterial proteins, respectively. One hundred and fifty-one strains of H pylori were isolated from 347 biopsy specimens of chronic gastritis, peptic ulcer or gastric adenocarcinoma, with a positive rate of 43.5%. All of the isolates expressed UreB, HpaA, FlaA and FlaB while 52.3%, 92.1% and 93.4% of the isolates expressed VacA, CagA and NapA, respectively. In the sera of 151 H pylori-infected patients, the positive rates of IgG antibodies against UreB, HpaA, VacA, CagA, NapA, FlaA and FlaB were 100%, 87.4%, 43%, 71.5%, 89.4%, 84.8% and 79.5%, respectively. Furthermore, the expression frequencies of VacA and NapA were found to be relative to the severity of gastric diseases (P = 0.016 and P < 0.0001, respectively). CONCLUSION: UreB antigen is the top option of developing genetically engineered vaccine against H pylori followed by NapA or HpaA. PMID:18720546

  6. Isolation of Helicobacter pylori in gastric mucosa and susceptibility to five antimicrobial drugs in Southern chile

    PubMed Central

    Otth, Laura; Wilson, Myra; Fernández, Heriberto; Otth, Carola; Toledo, Claudio; Cárcamo, Victoria; Rivera, Paula; Ruiz, Luis

    2011-01-01

    Helicobacter pylori colonizes more than 50% of the world population thus, it is considered an important cause of gastric cancer. The aim of this study was to determine the isolation frequency of H. pylori in Southern Chile from patients with symptomatology compatible with gastritis or gastric ulcer and to correlate these findings with demographic parameters of infected patients and the susceptibility profiles of the isolated strains to the antimicrobial drugs used in the eradication treatments. A total of 240 patients were enrolled in the study. Each gastric biopsy was homogenized and seeded onto blood agar plates containing a selective antibiotics mixture (DENT supplement). Plates were incubated at 37° C in a microaerophilic environment for five days. The susceptibility profiles to amoxicillin, ciprofloxacin, clarithromycin, tetracycline and metronidazole were determined using the E-test method. H. pylori was isolated from 99 patients (41.3%) with slightly higher frequency in female (42% positive cultures) than male (40.2% positive cultures). With regard to age and educational level, the highest isolation frequencies were obtained in patients between 21–30 (55%) and 41–50 (52.6%) years old, and patients with secondary (43.9%) and university (46.2%) educational levels. Nineteen (21.6%) strains showed resistance to at least one antimicrobial drug. Tetracycline was the most active antimicrobial in vitro, whereas metronidazole was the less active. One strain (5.3%) showed resistance to amoxicillin, clarithomycin and metronidazole, simultaneously. PMID:24031652

  7. Isolation of Helicobacter pylori in gastric mucosa and susceptibility to five antimicrobial drugs in Southern chile.

    PubMed

    Otth, Laura; Wilson, Myra; Fernández, Heriberto; Otth, Carola; Toledo, Claudio; Cárcamo, Victoria; Rivera, Paula; Ruiz, Luis

    2011-04-01

    Helicobacter pylori colonizes more than 50% of the world population thus, it is considered an important cause of gastric cancer. The aim of this study was to determine the isolation frequency of H. pylori in Southern Chile from patients with symptomatology compatible with gastritis or gastric ulcer and to correlate these findings with demographic parameters of infected patients and the susceptibility profiles of the isolated strains to the antimicrobial drugs used in the eradication treatments. A total of 240 patients were enrolled in the study. Each gastric biopsy was homogenized and seeded onto blood agar plates containing a selective antibiotics mixture (DENT supplement). Plates were incubated at 37° C in a microaerophilic environment for five days. The susceptibility profiles to amoxicillin, ciprofloxacin, clarithromycin, tetracycline and metronidazole were determined using the E-test method. H. pylori was isolated from 99 patients (41.3%) with slightly higher frequency in female (42% positive cultures) than male (40.2% positive cultures). With regard to age and educational level, the highest isolation frequencies were obtained in patients between 21-30 (55%) and 41-50 (52.6%) years old, and patients with secondary (43.9%) and university (46.2%) educational levels. Nineteen (21.6%) strains showed resistance to at least one antimicrobial drug. Tetracycline was the most active antimicrobial in vitro, whereas metronidazole was the less active. One strain (5.3%) showed resistance to amoxicillin, clarithomycin and metronidazole, simultaneously.

  8. Antimicrobial activity of curcumin against Helicobacter pylori isolates from India and during infections in mice.

    PubMed

    De, Ronita; Kundu, Parag; Swarnakar, Snehasikta; Ramamurthy, T; Chowdhury, Abhijit; Nair, G Balakrish; Mukhopadhyay, Asish K

    2009-04-01

    Treatment failure is a major cause of concern for the Helicobacter pylori-related gastroduodenal diseases like gastritis, peptic ulcer, and gastric cancer. Curcumin, diferuloylmethane from turmeric, has recently been shown to arrest H. pylori growth. The antibacterial activity of curcumin against 65 clinical isolates of H. pylori in vitro and during protection against H. pylori infection in vivo was examined. The MIC of curcumin ranges from 5 microg/ml to 50 microg/ml, showing its effectiveness in inhibiting H. pylori growth in vitro irrespective of the genetic makeup of the strains. The nucleotide sequences of the aroE genes, encoding shikimate dehydrogenase, against which curcumin seems to act as a noncompetitive inhibitor, from H. pylori strains presenting differential curcumin MICs showed that curcumin-mediated growth inhibition of Indian H. pylori strains may not be always dependent on the shikimate pathway. The antimicrobial effect of curcumin in H. pylori-infected C57BL/6 mice and its efficacy in reducing the gastric damage due to infection were examined histologically. Curcumin showed immense therapeutic potential against H. pylori infection as it was highly effective in eradication of H. pylori from infected mice as well as in restoration of H. pylori-induced gastric damage. This study provides novel insights into the therapeutic effect of curcumin against H. pylori infection, suggesting its potential as an alternative therapy, and opens the way for further studies on identification of novel antimicrobial targets of curcumin.

  9. Antimicrobial Activity of Curcumin against Helicobacter pylori Isolates from India and during Infections in Mice▿

    PubMed Central

    De, Ronita; Kundu, Parag; Swarnakar, Snehasikta; Ramamurthy, T.; Chowdhury, Abhijit; Nair, G. Balakrish; Mukhopadhyay, Asish K.

    2009-01-01

    Treatment failure is a major cause of concern for the Helicobacter pylori-related gastroduodenal diseases like gastritis, peptic ulcer, and gastric cancer. Curcumin, diferuloylmethane from turmeric, has recently been shown to arrest H. pylori growth. The antibacterial activity of curcumin against 65 clinical isolates of H. pylori in vitro and during protection against H. pylori infection in vivo was examined. The MIC of curcumin ranges from 5 μg/ml to 50 μg/ml, showing its effectiveness in inhibiting H. pylori growth in vitro irrespective of the genetic makeup of the strains. The nucleotide sequences of the aroE genes, encoding shikimate dehydrogenase, against which curcumin seems to act as a noncompetitive inhibitor, from H. pylori strains presenting differential curcumin MICs showed that curcumin-mediated growth inhibition of Indian H. pylori strains may not be always dependent on the shikimate pathway. The antimicrobial effect of curcumin in H. pylori-infected C57BL/6 mice and its efficacy in reducing the gastric damage due to infection were examined histologically. Curcumin showed immense therapeutic potential against H. pylori infection as it was highly effective in eradication of H. pylori from infected mice as well as in restoration of H. pylori-induced gastric damage. This study provides novel insights into the therapeutic effect of curcumin against H. pylori infection, suggesting its potential as an alternative therapy, and opens the way for further studies on identification of novel antimicrobial targets of curcumin. PMID:19204190

  10. Comparative genomics of Helicobacter pylori isolates recovered from ulcer disease patients in England

    PubMed Central

    Kauser, Farhana; Hussain, M Abid; Ahmed, Irshad; Srinivas, Sriramula; Devi, S Manjulata; Majeed, Ahmed A; Rao, K Rajender; Khan, Aleem A; Sechi, Leonardo A; Ahmed, Niyaz

    2005-01-01

    Background Genomic diversity of H. pylori from many different human populations is largely unknown. We compared genomes of 65 H. pylori strains from Nottingham, England. Molecular analysis was carried out to identify rearrangements within and outside the cag-pathogenicity-island (cag PAI) and DNA sequence divergence in candidate genes. Phylogenetic analysis was carried out based on various high-resolution genotyping techniques. Results Analyses of virulence genes (cagT, cagE, cagA, vacA, iceA, oipA and babB) revealed that H. pylori strains from England are genetically distinct from strains obtained from other countries. The toxigenic vacA s1m1 genotype was found to be less common and the plasticity region cluster was found to be disrupted in all the isolates. English isolates showed a predominance of iceA1 alleles and a functional proinflammatory oipA gene. The English H. pylori gene pool revealed several Asian/oriental features. This included the predominance of cagA – glr (cagA right junction) motif types III and II (up to 42%), presence of vacA m1c alleles and phylogenetic affinity towards East Asian / Amerindian gene pools based on fluorescent amplified fragment length polymorphism (FAFLP) analysis and glmM sequence analysis. Conclusion Overall, our results demonstrated genetic affinities of H. pylori in England with both European and the Asian gene pools and some distinctive genetic features of virulence genes that may have evolved in this important European population. PMID:15916705

  11. Universal high-level primary metronidazole resistance in Helicobacter pylori isolated from children in Egypt.

    PubMed

    Sherif, May; Mohran, Zaynab; Fathy, Hanan; Rockabrand, David M; Rozmajzl, Patrick J; Frenck, Robert W

    2004-10-01

    Antimicrobial susceptibility testing was performed on 48 isolates of Helicobacter pylori recovered from Egyptian children undergoing routine endoscopies. The isolates were universally highly resistant to metronidazole, but resistance to other tested antimicrobial agents was rare (4% for clarithromycin, erythromycin, and azithromycin resistance versus 2% for ciprofloxacin and ampicillin resistance). Use of metronidazole for the treatment of H. pylori in Egypt should be avoided.

  12. Genome Sequence of a Helicobacter pylori Strain Isolated from a Mexican Patient with Intestinal Gastric Cancer

    PubMed Central

    Larios-Serrato, Violeta; Olguín-Ruiz, Gabriela Edith; Sánchez-Vallejo, Carlos Javier; Torres-López, Roberto Carlos; Avilés-Jiménez, Francisco; Camorlinga-Ponce, Margarita

    2014-01-01

    Helicobacter pylori strains are the major risk factor for gastric cancer. Strains vary in their content of disease-associated genes, so genome-wide analysis of cancer-isolated strains will help elucidate their pathogenesis and genetic diversity. We present the draft genome sequence of H. pylori isolated from a Mexican patient with intestinal gastric cancer. PMID:24459275

  13. Study of Biofilm Formation in C57Bl/6J Mice by Clinical Isolates of Helicobacter pylori

    PubMed Central

    Attaran, Bahareh; Falsafi, Tahereh; Moghaddam, Ali N.

    2016-01-01

    Background/Aim: Despite the significant number of studies on H. pylori pathogenesis, not much data has been published concerning its ability to form biofilm in the host stomach. This study aims to evaluate the potential of clinical isolates of H. pylori to form biofilm in C57BL/6J mice model. Materials and Methods: Two strains of H. pylori were selected from a collection of clinical isolates; one (19B), an efficient biofilm producer and the other (4B), with weak biofilm-forming ability. Mice infected through gastric avages were examined after one and two weeks. Colonization was determined by CFU and urease activity; the anti-H. pylori IgA was measured by ELISA, and chronic infections were evaluated by histopathology. Bacterial communities within mucosal sections were studied by immunofluorescence and scanning electron microscopy (SEM). Results: Successful infection was obtained by both test strains. Strain 19B with higher ability to form biofilm in vitro also showed a higher colonization rate in the mice stomach one week after infection. Difference (P < 0.05) in IgA titers was observed between the infected mice and the controls as well as between 19B and 4B infected mice, two weeks after the last challenge. Immunofluorescence and SEM results showed tightly colonizing H. pylori in stomach mucosal sections and in squamous and glandular epithelium. Conclusion: H. pylori is able to form biofilm in the mouse stomach and induce IgA production, reflecting the same potential as in humans. Firm attachment of coccoid form bacteria to host cells suggests the importance of this state in biofilm formation by H. pylori. Occurrence of biofilm in squamous and glandular epithelium of the mouse stomach proposes that H. pylori can all parts of the upper gastrointestinal tract. PMID:26997224

  14. Primary antibiotic resistance of Helicobacter pylori strains isolated from patients with dyspeptic symptoms in Beijing: A prospective serial study

    PubMed Central

    Zhang, Yue-Xi; Zhou, Li-Ya; Song, Zhi-Qiang; Zhang, Jian-Zhong; He, Li-Hua; Ding, Yu

    2015-01-01

    AIM: To determine the resistance patterns of Helicobacter pylori (H. pylori) strains isolated from patients in Beijing and monitor the change of antibiotic resistance over time. METHODS: In this prospective, serial and cross-sectional study, H. pylori cultures were successfully obtained from 371 and 950 patients (never receiving eradication) during 2009-2010 and 2013-2014, respectively. Resistance to amoxicillin, clarithromycin, metronidazole, levofloxacin, tetracycline, and rifampicin was determined by Epsilometer test. RESULTS: The resistance rates of isolates obtained during 2009-2010 were 66.8%, 39.9%, 34.5%, 15.4%, 6.7%, and 4.9% to metronidazole, clarithromycin, levofloxacin, rifampicin, amoxicillin and tetracycline, respectively; and the corresponding rates for isolates during 2013-2014 were 63.4%, 52.6%, 54.8%, 18.2%, 4.4% and 7.3%, respectively. The resistance rates to clarithromycin and levofloxacin were significantly increased after four years. In 2009-2010, 14.6% of H. pylori isolates were susceptible to all tested antibiotics, with mono (33.7%), double (28.3%), triple (16.7%), quadruple (6.2%), quintuple (0.3%) and sextuple resistance (0.3%) also being detected. In 2013-2014, 9.4% were susceptible to all tested antibiotics, and mono (27.6%), double (28.4%), triple (24.9%), quadruple (7.3%), quintuple (2.3%) and sextuple resistance (0.1%) was also observed. More multiple resistant H. pylori isolates were found during 2013-2014. Gender (to levofloxacin and metronidazole), age (to levofloxacin) and endoscopic findings (to clarithromycin) were independent factors influencing antibiotic resistance. CONCLUSION: H. pylori resistance to commonly used antibiotics in Beijing is high with increased multiple antibiotic resistance. PMID:25759550

  15. Enzyme biotypes of Helicobacter pylori isolated from Penang, Peninsular Malaysia.

    PubMed

    Uyub, A M; Azlan, A A

    2000-12-01

    A total of 52 clinical strains of Helicobacter pylori were characterized on the basis of preformed enzyme production with API ZYM kits. Using the biotyping schemes as defined by Reina and Alomar (1989), Kung et al (1989) and Matsumoto et al (1996), 15.3% (8/52), 13.5% (7/52) and 11.5% (6/52) of the isolates were not biotypable, respectively. Two enzymes, valine arylamidase and cystine arylamidase could be additionally used to differentiate between isolates. Our isolates were either negative or positive for both the enzymes or positive only for cystine arylamidase. We propose the incorporation of these two enzymes into the Matsumoto et al (1996) biotyping scheme to biotype strains into additional enzyme biotypes.

  16. [Genomic diversity and population structure of Helicobacter pylori isolates in China].

    PubMed

    You, Y H; He, L H; Peng, X H; Sun, L; Zhang, J Z

    2016-10-10

    Objective: To learn about the overall genomic characteristics and population structure of Helicobacter pylori isolated in China. Methods: In this study, we used 10 public available genome sequences of H. pylori strains isolated in China, combined with other H. pylori sequences from GenBank, to analyzed the overall genomic characteristics of H. pylori isolated in China. Core genes and strain specific genes were determined for a further function definition. Results: A total of 1 203 core genes were found among all sequenced China H. pylori isolates. The number of strain specific genes ranged from 19 to 32. These genes mainly encodes hypothetical proteins which might play an important role in adaption to different hosts. Genomic variation regions were mainly in genes encoding type four secretion systems and restriction modification systems. All the China isolates belong to hpEastAsia group, hspEAsia subgroup. Prophages sequences were found in three China H. pylori strains, carrying key elements required for phage assembly. Conclusion: China H. pylori isolates belong to hpEastAsia group, hspEAsia subgroup, and some isolates contain prophages.

  17. Comparison of antimicrobial activity of zinc chloride and bismuth subsalicylate against clinical isolates of Helicobacter pylori.

    PubMed

    Yakoob, Javed; Abbas, Zaigham; Usman, Muhammad Waqas; Awan, Safia; Naz, Shagufta; Jafri, Fatima; Hamid, Saeed; Jafri, Wasim

    2014-08-01

    We determined the in vitro susceptibility of clinical isolates of Helicobacter pylori to ZnCl, compared its sensitivity to bismuth subsalicylate (BSS) and clarithromycin (CLR) that are used for the treatment of H. pylori infection and its activity at different gastric pH. One hundred sixteen clinical isolates of H. pylori strains were chosen. Agar gel dilution method was used to determine the susceptibility of H. pylori isolates to ZnCl 40 μg/ml, BSS 20 μg/ml, and CLR 2 μg/ml. Suspension of 10(9) bacteria/μl was streaked on the blood agar plate. The control consisted of H. pylori incubated without ZnCl, BSS, and CLR. One hundred ten H. pylori strains (95%) were susceptible to ZnCl 40 μg/ml compared to 114 (98%) to BSS 20 μg/ml (p=0.002) and 92 (79%) to CLR 2 μg/ml (p=0.602). H. pylori isolates from patients with nonulcer dyspepsia and from peptic ulcer were equally susceptible to ZnCl 40 μg/ml (90/96 vs. 26/26, p=0.208). H. pylori associated with chronic gastritis and chronic active gastritis were equally susceptible to ZnCl. H. pylori demonstrated susceptibility to ZnCl in vitro. H. pylori susceptibility to ZnCl 40 μg/ml was greater than BSS and comparable to CLR. ZnCl may be used in the treatment of H. pylori infection.

  18. Interaction of legionella pneumophila and helicobacter pylori with bacterial species isolated from drinking water biofilms

    PubMed Central

    2011-01-01

    Background It is well established that Legionella pneumophila is a waterborne pathogen; by contrast, the mode of Helicobacter pylori transmission remains unknown but water seems to play an important role. This work aims to study the influence of five microorganisms isolated from drinking water biofilms on the survival and integration of both of these pathogens into biofilms. Results Firstly, both pathogens were studied for auto- and co-aggregation with the species isolated from drinking water; subsequently the formation of mono and dual-species biofilms by L. pneumophila or H. pylori with the same microorganisms was investigated. Neither auto- nor co-aggregation was observed between the microorganisms tested. For biofilm studies, sessile cells were quantified in terms of total cells by SYTO 9 staining, viable L. pneumophila or H. pylori cells were quantified using 16 S rRNA-specific peptide nucleic acid (PNA) probes and cultivable cells by standard culture techniques. Acidovorax sp. and Sphingomonas sp. appeared to have an antagonistic effect on L. pneumophila cultivability but not on the viability (as assessed by rRNA content using the PNA probe), possibly leading to the formation of viable but noncultivable (VBNC) cells, whereas Mycobacterium chelonae increased the cultivability of this pathogen. The results obtained for H. pylori showed that M. chelonae and Sphingomonas sp. help this pathogen to maintain cultivability for at least 24 hours. Conclusions It appears that M. chelonae may have an important role in the survival of both pathogens in drinking water. This work also suggests that the presence of some microorganisms can decrease the cultivability of L. pneumophila but not the viability which indicates that the presence of autochthonous microorganisms can lead to misleading results when the safety of water is assessed by cultivable methods alone. PMID:21418578

  19. Interaction of Legionella pneumophila and Helicobacter pylori with bacterial species isolated from drinking water biofilms.

    PubMed

    Gião, Maria S; Azevedo, Nuno F; Wilks, Sandra A; Vieira, Maria J; Keevil, Charles W

    2011-03-18

    It is well established that Legionella pneumophila is a waterborne pathogen; by contrast, the mode of Helicobacter pylori transmission remains unknown but water seems to play an important role. This work aims to study the influence of five microorganisms isolated from drinking water biofilms on the survival and integration of both of these pathogens into biofilms. Firstly, both pathogens were studied for auto- and co-aggregation with the species isolated from drinking water; subsequently the formation of mono and dual-species biofilms by L. pneumophila or H. pylori with the same microorganisms was investigated. Neither auto- nor co-aggregation was observed between the microorganisms tested. For biofilm studies, sessile cells were quantified in terms of total cells by SYTO 9 staining, viable L. pneumophila or H. pylori cells were quantified using 16 S rRNA-specific peptide nucleic acid (PNA) probes and cultivable cells by standard culture techniques. Acidovorax sp. and Sphingomonas sp. appeared to have an antagonistic effect on L. pneumophila cultivability but not on the viability (as assessed by rRNA content using the PNA probe), possibly leading to the formation of viable but noncultivable (VBNC) cells, whereas Mycobacterium chelonae increased the cultivability of this pathogen. The results obtained for H. pylori showed that M. chelonae and Sphingomonas sp. help this pathogen to maintain cultivability for at least 24 hours. It appears that M. chelonae may have an important role in the survival of both pathogens in drinking water. This work also suggests that the presence of some microorganisms can decrease the cultivability of L. pneumophila but not the viability which indicates that the presence of autochthonous microorganisms can lead to misleading results when the safety of water is assessed by cultivable methods alone.

  20. Antimicrobial susceptibility profiles of Helicobacter pylori isolated from patients in North India.

    PubMed

    Gehlot, Valentina; Mahant, Shweta; Mukhopadhyay, Asish Kumar; Das, Kunal; De, Ronita; Kar, Premashis; Das, Rajashree

    2016-06-01

    Helicobacter pylori-related gastroduodenal diseases are very common in India. Antibiotic resistance to commonly used antibiotics against H. pylori is increasing very rapidly. The aim of this study was to determine the antimicrobial susceptibility patterns of H. pylori strains from India against commonly used antibiotics in H. pylori treatment. Helicobacter pylori were cultured from 68 patients suffering from various gastroduodenal diseases in North India. Minimum inhibitory concentrations (MICs) to different antibiotics were determined by agar dilution. The clinical diagnosis of the 68 patients who were H. pylori culture-positive were gastro-oesophageal reflux disease (GERD) (n=23), non-erosive reflux disease (NERD) (n=22), non-ulcer dyspepsia (NUD) (n=13), antral gastritis (n=3), duodenal ulcer (n=2) and others (n=5). Of the 68 H. pylori isolates, 20 (29.4%) showed no resistance. The prevalence of drug resistance was 70.6%, including resistance to metronidazole (48.5%), furazolidone (22.1%), amoxicillin (17.6%), tetracycline (16.2%) and clarithromycin (11.8%). Dual and multiple drug resistance were found in 26.5% and 8.8% of cases, respectively. In conclusion, more than two-thirds of the isolated H. pylori strains showed resistance to at least one of the antibiotics for H. pylori treatment. Metronidazole resistance was most prevalent amongst the isolates tested. Emergence of dual and multidrug resistance is of great concern and there is an urgent need for regular antibiotic resistance surveillance studies. Amoxicillin- and clarithromycin-based anti-H. pylori regimens commonly prescribed for triple therapy in India show least resistance and hence are appropriate for anti-H. pylori management in India. Copyright © 2015 International Society for Chemotherapy of Infection and Cancer. Published by Elsevier Ltd. All rights reserved.

  1. [Antimicrobial susceptibility of Helicobacter pylori strains isolated from gastric lesions].

    PubMed

    Pereyra, Laura Del V; Gorordo Ipiña, Rosa C; Berruezo, Fabiana A; Amieva, Cristian A; García, Maria E; Bottiglieri, Marina T

    Antimicrobial susceptibility was evaluated by two diffusion methods: E-test strips to determine minimum inhibitory concentration (MIC) and disk diffusion for amoxicillin, clarithromycin, metronidazole and ciprofloxacin in 30 Helicobacter pylori strains isolated from gastric biopsies. No strains were resistant to amoxicillin, 17% (5/30) were resistant to clarithromycin, 20% (6/30) ciprofloxacin by both methods, and 37% (11/30) to metronidazole by the E-test. Although the number of strains studied was reduced, there was a single mismatch in interpreting susceptibility when both methods were compared; the same mismatch was observed for metronidazole, being categorized as sensitive by the E-test and as intermediate by disk diffusion. No association between the histological type of lesion and the resistance pattern found could be determined. Copyright © 2017 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.

  2. High primary antibiotic resistance of Helicobacter Pylori strains isolated from dyspeptic patients: A prevalence cross-sectional study in Spain.

    PubMed

    Macías-García, Fernando; Llovo-Taboada, José; Díaz-López, Mario; Bastón-Rey, Iria; Domínguez-Muñoz, Juan Enrique

    2017-09-15

    The rate of H. pylori resistance to different antibiotics is increasing and determines the selection of eradication therapy. The aim of this study was to determine the resistance patterns of H. pylori strains in our area. Biopsies from gastric corpus for microbiological culture and antibiotic resistance were obtained in patients undergoing upper gastrointestinal endoscopy for dyspepsia. Selective Agar Pylori for isolation of the bacteria and Agar Mueller-Hinton supplemented with blood to test the sensitivity to antibiotics were used. Presence of H. pylori was confirmed using direct observation with phase-contrast microscopy and/or smears stained with acridine orange. In vitro bacterial susceptibility to amoxicillin, clarithromycin, rifampicin, tetracycline, metronidazole, and levofloxacin was tested using diffusion MIC test strips. Minimum inhibitory concentration values were determined based on the 6th version of the EUCAST (European Committee on Antimicrobial Susceptibility Testing) Clinical Breakpoint (2016). Two hundred and seventeen patients were included (58.1% female, median age 64 years, range 25-92). H. pylori was identified in 108 patients (49.8%); culture and antibiogram were completed in 77 of them (71.3% of H. pylori-positive patients). The resistance rates were as follows: levofloxacin 38.7%, rifampicin 33.3%, metronidazole 27% and clarithromycin 22.4%. No case of amoxicillin or tetracycline resistance was identified. Dual clarithromycin-metronidazole resistance was observed in 10% of strains, whereas multiple drug-resistant was observed in 14.2%. Resistance rate of H. pylori to antibiotics is high in the northwest of Spain. The high resistance to levofloxacin and clarithromycin advises against their wide empirical use of these antibiotics in eradication regimens. © 2017 John Wiley & Sons Ltd.

  3. Complete Genome Sequence of Helicobacter pylori Strain 29CaP Isolated from a Mexican Patient with Gastric Cancer

    PubMed Central

    Mucito-Varela, Eduardo; Castillo-Rojas, Gonzalo; Cevallos, Miguel A.; Lozano, Luis; Merino, Enrique; López-Leal, Gamaliel

    2016-01-01

    Helicobacter pylori infection is a risk factor for the development of gastric cancer and other gastroduodenal diseases. We report here the complete genome sequence of H. pylori strain 29CaP, isolated from a Mexican patient with gastric cancer. The genomic data analysis revealed a cag-negative H. pylori strain that contains a prophage sequence. PMID:26769924

  4. Complete Genome Sequence of Helicobacter pylori Strain 29CaP Isolated from a Mexican Patient with Gastric Cancer.

    PubMed

    Mucito-Varela, Eduardo; Castillo-Rojas, Gonzalo; Cevallos, Miguel A; Lozano, Luis; Merino, Enrique; López-Leal, Gamaliel; López-Vidal, Yolanda

    2016-01-14

    Helicobacter pylori infection is a risk factor for the development of gastric cancer and other gastroduodenal diseases. We report here the complete genome sequence of H. pylori strain 29CaP, isolated from a Mexican patient with gastric cancer. The genomic data analysis revealed a cag-negative H. pylori strain that contains a prophage sequence.

  5. Molecular characterization and susceptibility testing of Helicobacter pylori strains isolated in western Argentina.

    PubMed

    Vega, Alba Edith; Cortiñas, Teresa Inés; Puig, Olga Nélida; Silva, Humberto Jesús

    2010-09-01

    To characterize Helicobacter pylori isolates from western Argentina using virulence markers and antimicrobial susceptibility patterns in order to assess the association between virulent genotypes, antimicrobial resistance, and disease. DNA fingerprinting was also evaluated for the segregation of virulent or resistant strain clusters. Genotyping of 299 H. pylori isolates was performed by PCR using specific primers for the cagA, vacA and iceA genes. Random amplification of polymorphic DNA (RAPD)-PCR and rep-PCR genetic clustering were assessed using five random primers and BOXA1R and ERIC primers, respectively. Resistance to clarithromycin (Cla) and metronidazole (Mtz) was assessed by the agar dilution method. It was observed that 40.8% of the genotypes were cagA-positive; 66.9% were vacA s1m1 genotype and the iceA1 allele was found in 40.8%. A significant correlation (p=0.0000) was observed between cagA positivity and vacA s1m1/iceA1 genotypes. Triple virulent genotypes were statistically associated with peptic ulcer (PU) (p=0.0001) and Cla resistance (p=0.0000). RAPD fingerprints obtained with AO2 primers identified clusters that were strongly associated with PU, virulence markers, and resistance to Cla and Mtz. The H. pylori isolates that harbored two or three virulence markers were more resistant to Cla and Mtz. Combined analysis of virulent genotypes and resistance patterns may permit identification of high-risk patients to prevent PU later in life or to avoid antimicrobial treatment failure. Copyright © 2010 International Society for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

  6. Genotypic and phenotypic variation of Lewis antigen expression in geographically diverse Helicobacter pylori isolates

    PubMed Central

    Pohl, Mary Ann; Zhang, William; Shah, Sunny; Sanabria-Valentín, Edgardo L.; Perez-Perez, Guillermo I.; Blaser, Martin J.

    2011-01-01

    Background Helicobacter pylori is a persistent colonizer of the human gastric mucosa, which can lead to the development peptic ulcer disease and gastric adenocarcinomas. However, H. pylori can asymptomatically colonize a host for years. One factor that has been hypothesized to contribute to such persistence is the production of Lewis (Le) antigens in the lipopolysaccharide layer of the bacterial outer membrane as a form of molecular mimicry, since humans also express these antigens on their gastric mucosa. Humans and H. pylori both are polymorphic for Le expression, which is driven in H. pylori by variation at the Le synthesis loci. In this report we sought to characterize Le genotypic and phenotypic variation in geographically diverse H. pylori isolates. Materials and Methods From patients undergoing endoscopy in 29 countries, we determined Le phenotypes of 78 H. pylori strains, and performed genotyping of the galT and β-(1,3)galT loci in 113 H. pylori strains. Results Le antigen phenotyping revealed a significant (p <0.0001) association between type 1 (Lea and Leb) expression and strains of East-Asian origin. Genotyping revealed a significant correlation between strain origin and the size of the promoter region upstream of the Le synthesis gene, galT (p <0.0001). Conclusion These results indicate that the heterogeneity of human Le phenotypes are reflected in their H. pylori colonizing strains, and suggest new loci that can be studied to assess variation of Le expression. PMID:22059399

  7. Genomic variability of Helicobacter pylori isolates of gastric regions from two Colombian populations.

    PubMed

    Matta, Andrés Jenuer; Pazos, Alvaro Jairo; Bustamante-Rengifo, Javier Andrés; Bravo, Luis Eduardo

    2017-02-07

    To compare the genomic variability and the multiple colonization of Helicobacter pylori (H. pylori) in patients with chronic gastritis from two Colombian populations with contrast in the risk of developing gastric cancer (GC): Túquerres-Nariño (High risk) and Tumaco-Nariño (Low risk). Four hundred and nine patients from both genders with dyspeptic symptoms were studied. Seventy-two patients were included in whom H. pylori was isolated from three anatomic regions of the gastric mucosa, (31/206) of the high risk population of GC (Túquerres) and (41/203) of the low risk population of GC (Tumaco). The isolates were genotyped by PCR-RAPD. Genetic diversity between the isolates was evaluated by conglomerates analysis and multiple correspondence analyses. The proportion of virulent genotypes of H. pylori was 99% in Túquerres and 94% in Tumaco. The coefficient of similarity of Nei-Li showed greater genetic diversity among isolates of Túquerres (0.13) than those of Tumaco (0.07). After adjusting by age, gender and type of gastritis, the multiple colonization was 1.7 times more frequent in Túquerres than in Tumaco (P = 0.05). In Túquerres, high risk of GC there was a greater probability of multiple colonization by H. pylori. From the analysis of the results of the PCR-RAPD, it was found higher genetic variability in the isolates of H. pylori in the population of high risk for the development of GC.

  8. Genomic variability of Helicobacter pylori isolates of gastric regions from two Colombian populations

    PubMed Central

    Matta, Andrés Jenuer; Pazos, Alvaro Jairo; Bustamante-Rengifo, Javier Andrés; Bravo, Luis Eduardo

    2017-01-01

    AIM To compare the genomic variability and the multiple colonization of Helicobacter pylori (H. pylori) in patients with chronic gastritis from two Colombian populations with contrast in the risk of developing gastric cancer (GC): Túquerres-Nariño (High risk) and Tumaco-Nariño (Low risk). METHODS Four hundred and nine patients from both genders with dyspeptic symptoms were studied. Seventy-two patients were included in whom H. pylori was isolated from three anatomic regions of the gastric mucosa, (31/206) of the high risk population of GC (Túquerres) and (41/203) of the low risk population of GC (Tumaco). The isolates were genotyped by PCR-RAPD. Genetic diversity between the isolates was evaluated by conglomerates analysis and multiple correspondence analyses. RESULTS The proportion of virulent genotypes of H. pylori was 99% in Túquerres and 94% in Tumaco. The coefficient of similarity of Nei-Li showed greater genetic diversity among isolates of Túquerres (0.13) than those of Tumaco (0.07). After adjusting by age, gender and type of gastritis, the multiple colonization was 1.7 times more frequent in Túquerres than in Tumaco (P = 0.05). CONCLUSION In Túquerres, high risk of GC there was a greater probability of multiple colonization by H. pylori. From the analysis of the results of the PCR-RAPD, it was found higher genetic variability in the isolates of H. pylori in the population of high risk for the development of GC. PMID:28223724

  9. Alaska sentinel surveillance study of Helicobacter pylori isolates from Alaska Native persons from 2000 to 2008.

    PubMed

    Tveit, Adrienne H; Bruce, Michael G; Bruden, Dana L; Morris, Julie; Reasonover, Alisa; Hurlburt, Debby A; Hennessy, Thomas W; McMahon, Brian

    2011-10-01

    Helicobacter pylori infection is more common in Alaska Native persons than in the general U.S. population, with seroprevalence to H. pylori approaching 75%. Previous studies in Alaska have demonstrated elevated proportions of antimicrobial resistance among H. pylori isolates. We analyzed H. pylori data from the Centers for Disease Control and Prevention's sentinel surveillance in Alaska from January 2000 to December 2008 to determine the proportion of culture-positive biopsy specimens with antimicrobial resistance from Alaska Native persons undergoing endoscopy. The aim of the present study was to monitor antimicrobial resistance of H. pylori isolates over time and by region in Alaska Native persons. Susceptibility testing of H. pylori isolates to metronidazole, clarithromycin, amoxicillin, and tetracycline was performed using agar dilution. Susceptibility testing for levofloxacin was performed by Etest. Overall, 45% (532/1,181) of persons undergoing upper endoscopy were culture positive for H. pylori. Metronidazole resistance was demonstrated in isolates from 222/531 (42%) persons, clarithromycin resistance in 159/531 (30%) persons, amoxicillin resistance in 10/531 (2%) persons, and levofloxacin resistance in 30/155 (19%) persons; no tetracycline resistance was documented. The prevalence of metronidazole, clarithromycin, and levofloxacin resistance varied by region. Female patients were more likely than male patients to demonstrate metronidazole (P < 0.05) and clarithromycin (P < 0.05) resistance. No substantial change in the proportion of persons with resistant isolates was observed over time. Resistance to metronidazole, clarithromycin, and levofloxacin is more common among H. pylori isolates from Alaska Native persons than those from elsewhere in the United States.

  10. Clonality Analysis of Helicobacter pylori in Patients Isolated from Several Biopsy Specimens and Gastric Juice in a Japanese Urban Population by Random Amplified Polymorphic DNA Fingerprinting

    PubMed Central

    Toita, Nariaki; Fujii, Nobuhiro; Konno, Mutsuko

    2013-01-01

    Background. The number of Helicobacter pylori clones infecting a single host has been discussed in numerous reports. The number has been suggested to vary depending on the regions in the world. Aim. The purpose of this study was to examine the number of clones infecting a single host in a Japanese urban population. Materials and Methods. Thirty-one Japanese patients undergoing upper gastrointestinal endoscopy were enrolled in this study. H. pylori isolates (total 104 strains) were obtained from biopsy specimens (antrum, corpus, and duodenum) and gastric juice. Clonal diversity was examined by the random amplified polymorphic DNA (RAPD) fingerprinting method. Results. The RAPD fingerprinting patterns of isolates from each patient were identical or very similar. And the isolates obtained from several patients with 5- to 9-year intervals showed identical or very similar RAPD patterns. Conclusion. Each Japanese individual of an urban population is predominantly infected with a single H. pylori clone. PMID:24348543

  11. Pretreatment with Urea-Hydrochloric Acid Enhances the Isolation of Helicobacter pylori from Contaminated Specimens

    PubMed Central

    Song, Qunsheng; Zirnstein, Gerald W.; Swaminathan, Bala; Gold, Benjamin D.

    2001-01-01

    Human saliva seeded with H. pylori was incubated in urea-HCl and then cultured on nonselective media. Pretreatment with 0.06 N HCl–0.08 M urea for 5 min at 37°C resulted in reproducible isolation of H. pylori, even at low inocula (≤102 CFU/ml of saliva), despite the presence of large numbers of contaminating organisms. PMID:11326024

  12. Mixed Infections of Helicobacter pylori Isolated from Patients with Gastrointestinal Diseases in Taiwan

    PubMed Central

    Huang, Ju-Chun; Chiang-Ni, Chuan; Li, Ju-Pi; Wu, Lii-Tzu; Wu, Hua-Shan; Sun, Yu-Chen; Lin, Mei-Ling; Lee, Ju-Fang

    2016-01-01

    Background. Persistent Helicobacter pylori infection may induce several upper gastrointestinal diseases. Two major virulence factors of H. pylori, vacuolating cytotoxin A (VacA) and cytotoxin-associated gene A (CagA), are thought to be associated with the severity of disease progression. The distribution of vacA and cag-pathogenicity island (cag-PAI) alleles varies in H. pylori isolated from patients in different geographic regions. Aim. To assess the association between mixed infection of H. pylori clinical isolates from Taiwanese patients and the severity of gastrointestinal diseases. Methods. A total of 70 patients were enrolled in this study. Six distinct and well-separated colonies were isolated from each patient and 420 colonies were analyzed to determine the genotypes of virulence genes. Results. The prevalence of mixed infections of all H. pylori-infected patients was 28.6% (20/70). The rate of mixed infections in patients with duodenal ulcer (47.6%) was much higher than that with other gastrointestinal diseases (P < 0.05). Conclusions. H. pylori mixed infections show high genetic diversity that may enhance bacterial adaptation to the hostile environment of the stomach and contribute to disease development. PMID:27738429

  13. A highly specific and sensitive DNA probe derived from chromosomal DNA of Helicobacter pylori is useful for typing H. pylori isolates.

    PubMed Central

    Li, C; Ferguson, D A; Ha, T; Chi, D S; Thomas, E

    1993-01-01

    HindIII-digested DNA fragments derived from an EcoRI-digested 6.5-kb fragment of chromosomal DNA prepared from Helicobacter pylori ATCC 43629 (type strain) were cloned into the pUC19 vector. A 0.86-kb insert was identified as a potential chromosomal DNA probe. The specificity of the probe was evaluated by testing 166 non-H. pylori bacterial strains representing 38 genera and 91 species which included aerobic, anaerobic, and microaerophilic flora of the upper and lower gastrointestinal tracts. None of the 166 non-H. pylori strains hybridized with this probe (100% specificity), and the sensitivity of this probe was also 100% when H. pylori isolates from 72 patients with gastritis and with the homologous ATCC type strain were tested by dot blot hybridization. The capability of this probe for differentiating between strains of H. pylori was evaluated by Southern blot hybridization of HaeIII-digested chromosomal DNA from 68 clinical isolates and the homologous ATCC type strain of H. pylori. Fifty-one unique hybridization patterns were seen among the 69 strains tested, demonstrating considerable genotypic variation among H. pylori clinical isolates. We propose that this probe would be of significant value for conducting epidemiologic studies. Images PMID:8370744

  14. Evaluation of antimicrobial susceptibility and integron carriage in Helicobacter pylori isolates from patients

    PubMed Central

    Goudarzi, Mehdi; Heidary, Mohsen; Azad, Mehdi; Fazeli, Maryam; Goudarzi, Hossein

    2016-01-01

    Aim: The purpose of this study was to determine the antibiotic susceptibility pattern and distribution of integron in H. pylori isolates collected from patients referred to private health care centers in Tehran, Iran. Background: Antibiotic resistance is the main reason for failure of Helicobacter pylori therapy. Integrons as genetic reservoirs play main roles in the dissemination of antimicrobial resistance gene. Methods: During a 12-month cross-sectional study period, 65 H. pylori isolates were recovered from 124 biopsy specimens. Isolates were subjected to susceptibility testing using by Epsilometer test according to the European Committee on Antimicrobial Susceptibility Testing (EUCAST) guideline. PCR was used to detect different types of integrons. Results: Antimicrobial susceptibility testing revealed that 73.8% of isolates were resistant to metronidazole, 43.1% to clarithromycin, 29.2% to tetracycline, 27.7% to amoxicillin, 23.1% to rifampicin and 13.4% to levofloxacin. Frequency of multidrug resistance among H. pylori isolates was 26.1%. The most predominant resistance profiles among our isolates were included resistance to clarithromycin and metronidazole (20%). Class 1 and 2 integrons were detected in 8 (12.3%) and 15 (23.1%) of the isolates, respectively. Conclusions: The high prevalence of multidrug resistance and frequency of class 2 integron in this survey can be a warning for clinicians. Continuous surveillance is necessary for the development of new treatment protocols to prevent the treatment failures and also further spread of resistant isolates. PMID:28224028

  15. The mutation of the rdxA gene in metronidazole-resistant Helicobacter pylori clinical isolates.

    PubMed

    Mirzaei, Nasrin; Poursina, Farkhondeh; Moghim, Sharareh; Rahimi, Ebrahim; Safaei, Hajieh Ghasemian

    2014-01-01

    Antibiotic resistance is an increasing problem throughout the developed world, and knowledge about different resistance mechanisms is consequential for efficient treatment of bacterial infections. Although metronidazole has been frequently used in treatment regimens for H. pylori infection, but antibiotic resistance is now a major contributing factor in treatment failure. Nevertheless metronidazole has been greatly used as a critical component of combination therapies for H. pylori infection. This study is trying to describe the mutational mechanisms of metronidazole resistance in H. pylori in our clinical isolates in Isfahanian patients, Iran and compare with the findings of previous studies in world. MIC values of metronidazole for H. pylori strains were determined by E- test. Both rdxA and glmM genes used for confirmation of isolates as H. pylori and then amplification of another rdxA oligonucleotide pair was done. Finally, the six resistant strains were sent to sequencing for other processing and further analysis was done by software. The result of six clinical isolates in comparison with 26695, J99 and 69A as a sensitive and resistant reference strains showed plenty of mutations. No frame shift and nonsense mutation was seen in our clinical isolates. An interesting finding in metronidazole-resistant strains in our study was the detection of one mutation not previously described in the literature in the rdxA gene and this W(209)R substitution presumably plays a role in inducing metronidazole resistance.

  16. The mutation of the rdxA gene in metronidazole-resistant Helicobacter pylori clinical isolates

    PubMed Central

    Mirzaei, Nasrin; Poursina, Farkhondeh; Moghim, Sharareh; Rahimi, Ebrahim; Safaei, Hajieh Ghasemian

    2014-01-01

    Backgrounds: Antibiotic resistance is an increasing problem throughout the developed world, and knowledge about different resistance mechanisms is consequential for efficient treatment of bacterial infections. Although metronidazole has been frequently used in treatment regimens for H. pylori infection, but antibiotic resistance is now a major contributing factor in treatment failure. Nevertheless metronidazole has been greatly used as a critical component of combination therapies for H. pylori infection. Objective: This study is trying to describe the mutational mechanisms of metronidazole resistance in H. pylori in our clinical isolates in Isfahanian patients, Iran and compare with the findings of previous studies in world. Materials and Methods: MIC values of metronidazole for H. pylori strains were determined by E- test. Both rdxA and glmM genes used for confirmation of isolates as H. pylori and then amplification of another rdxA oligonucleotide pair was done. Finally, the six resistant strains were sent to sequencing for other processing and further analysis was done by software. Results: The result of six clinical isolates in comparison with 26695, J99 and 69A as a sensitive and resistant reference strains showed plenty of mutations. No frame shift and nonsense mutation was seen in our clinical isolates. Conclusion: An interesting finding in metronidazole-resistant strains in our study was the detection of one mutation not previously described in the literature in the rdxA gene and this W(209)R substitution presumably plays a role in inducing metronidazole resistance. PMID:24761398

  17. Multiple infection and microdiversity among Helicobacter pylori isolates in a single host in India.

    PubMed

    Patra, Rajashree; Chattopadhyay, Santanu; De, Ronita; Ghosh, Prachetash; Ganguly, Mou; Chowdhury, Abhijit; Ramamurthy, T; Nair, G B; Mukhopadhyay, Asish K

    2012-01-01

    Helicobacter pylori is one of the most diverse bacterial species that chronically infects more than 70% of Indian population. Interestingly, data showing microdiversity of the H. pylori strains within a particular gastric niche remained scarce. To understand the extent of genetic diversity among H. pylori strains within a given host, 30 patients with gastro-duodenal problems were subjected to endoscopy and from each patient 10 single colonies were isolated. Characterization of each of these 10 single colonies by DNA fingerprinting as well as genotyping of several important genetic markers viz. cagA, vacA, iceA, vapD, cag PAI empty site, IS605, RFLP and two other genetic segments within cag PAI revealed that all of the 30 patients were infected with more than one strain and sometimes strains with 5 to 6 types of genetic variants. Analyses of certain genetic loci showed the microdiversity among the colonies from single patient, which may be due to the recombination events during long-term carriage of the pathogen. These results suggest that most of the patients have acquired H. pylori due to repeated exposure to this pathogen with different genetic make-up, which may increase the possibility of super infections. Genetic exchanges between these unrelated H. pylori strains may support certain H. pylori variant to grow better in a given host than the parental strain and thereby increasing the possibility for the severity of the infection.

  18. Frequency of infection with Helicobacter pylori isolates of different antimicrobial profiles in children and adolescents: A preliminary study.

    PubMed

    Gościniak, Grażyna; Biernat, Monika M; Bińkowska, Aldona; Kus, Agnieszka; Iwańczak, Barbara

    2017-01-01

    Helicobacter pylori (H. pylori) infection can occur as a mixed infection caused by several strains of H. pylori. The aim of the study was to determine the frequency of colonization of the gastric mucosa by strains of H. pylori with different susceptibility to antimicrobial agents. The study was carried out on gastric biopsies taken from 54 previously untreated Polish children and adolescents. Of the 15 positive cultures, from each primary medium, 6 single H. pylori colonies were isolated, making a total of 90 isolates, and the susceptibility to metronidazole (MZ), amoxicillin (AC) and clarithromycin (CH) was determined by E-test method. The presence of the cagA gene and vacA alleles (s1, s2, m1, m2) was determined by PCR. Positive culture for H. pylori was noted in 15/54 (27.7%) of patients. All H. pylori isolates were susceptible to AC, 27.8% were resistant to MZ and 38.9% to CH. The results showed 7/15 (46.7%) of children were infected with H. pylori strains with antibiotic heteroresistance, resistant to CH (5/15, 33.3%) and to MZ (2/15, 13.3%). The cagA + vacA s1/m2 combination was predominant genotype among detected H. pylori strains. The isolates possessing different antimicrobial susceptibility profiles in the same patient were identified. Microbiological analyses confirmed the presence of isolates possessing different antimicrobial susceptibility profiles in 47% of examined children with H. pylori infection. Different antimicrobial susceptibility profiles of H. pylori isolates detected in the same patient may influence the success of eradication therapy.

  19. Identification of new enzyme biotypes of Helicobacter pylori isolated in Japan.

    PubMed

    Matsumoto, Y; Yamada, M; Fujii, Y; Kawai, T; Nishizato, Y; Uchida, Y; Hamashima, H; Sasatsu, M; Arai, T

    1996-01-01

    The enzyme biotype of 86.5% of strains of Helicobacter pylori isolated in Japan could not be determined by the method used for the identification of the biotypes defined by Reina and Alomar (1989). A modified system for naming of biotypes is proposed.

  20. [Antibiotic resistance rates of Helicobacter pylori isolates and the comparison of E-test and fluorescent in situ hybridization methods for the detection of clarithromycin resistant strains].

    PubMed

    Bakir Ozbey, Saliha; Ozakin, Cüneyt; Keskin, Murat

    2009-04-01

    Helicobacter pylori which is one of the commonly seen chronic bacterial infections in the world, has been demonstrated to have a relationship with chronic gastritis, peptic ulcer disease and gastric cancer. Current management of H. pylori infection involves the use of a proton pump inhibitor (PPI) and any two of amoxicillin, clarithromycin and metronidazole in combination. Antibiotic resistance which is in an increasing trend in H. pylori since the recent years, is the main cause of treatment failure. This study was conducted to determine the susceptibility of 31 H. pylori strains to several antibiotics by using E-test method (AB Biodisk, Sweden) and also to detect clarithromycin resistance by fluorescent in situ hybridization (FISH; SeaFAST, Hungary). The strains were isolated from the gastric biopsy specimens of patients who were admitted to Uludağ University Hospital, Bursa, Turkey with dyspeptic complaints. Clarithromycin, amoxycillin, metronidazole, tetracycline and ciprofloxacin resistance rates were as 41.9%, 3.2%, 41.9%, 3.2% and 45.2%, respectively. Resistance to single antibiotic was detected in 32.2% of the isolates whereas multiresistance was seen in 45.2%. For the hybridization process one probe specific for 16S rRNA and labeled with a fluorescein dye and the other probe specific for the mutations in 23S rRNA and labeled with Cy3 stain were used. Green signalling denoted presence of H. pylori in the specimen and red signalling was associated with clarithromycin resistance. All of the isolates yielded green signalling and the 13 isolates found to be resistant to clarithromycin by E-test, gave red signalling. No difference was detected between the two methods in terms of clarithromycin resistance determination. This was a preliminary study reporting the H. pylori resistance rates in our region, however, further larger scale studies are required for obtaining countrywide data.

  1. Resistance to amoxicillin, clarithromycin and ciprofloxacin of Helicobacter pylori isolated from Southern Brazil patients.

    PubMed

    Picoli, Simone Ulrich; Mazzoleni, Luiz Edmundo; Fernández, Heriberto; De Bona, Laura Renata; Neuhauss, Erli; Longo, Larisse; Prolla, João Carlos

    2014-01-01

    Helicobacter pylori is a bacteria which infects half the world population and is an important cause of gastric cancer. The eradication therapy is not always effective because resistance to antimicrobials may occur. The aim of this study was to determine the susceptibility profile of H. pylori to amoxicillin, clarithromycin and ciprofloxacin in the population of Southern Brazil. Fifty four samples of H. pylori were evaluated. The antibiotics susceptibility was determined according to the guidelines of the British Society for Antimicrobial Chemotherapy and the Comité de l'Antibiogramme de la Société Française de Microbiologie. Six (11.1%) H. pylori isolates were resistant to clarithromycin, one (1.9%) to amoxicillin and three (5.5%) to ciprofloxacin. These indices of resistance are considered satisfactory and show that all of these antibiotics can be used in the empirical therapy. The antibiotics amoxicillin and clarithromycin are still a good option for first line anti-H. pylori treatment in the population of Southern Brazil.

  2. RESISTANCE TO AMOXICILLIN, CLARITHROMYCIN AND CIPROFLOXACIN OF Helicobacter pylori ISOLATED FROM SOUTHERN BRAZIL PATIENTS

    PubMed Central

    Picoli, Simone Ulrich; Mazzoleni, Luiz Edmundo; Fernández, Heriberto; De Bona, Laura Renata; Neuhauss, Erli; Longo, Larisse; Prolla, João Carlos

    2014-01-01

    Introduction: Helicobacter pylori is a bacteria which infects half the world population and is an important cause of gastric cancer. The eradication therapy is not always effective because resistance to antimicrobials may occur. The aim of this study was to determine the susceptibility profile of H. pylori to amoxicillin, clarithromycin and ciprofloxacin in the population of Southern Brazil. Material and methods: Fifty four samples of H. pylori were evaluated. The antibiotics susceptibility was determined according to the guidelines of the British Society for Antimicrobial Chemotherapy and the Comité de l'Antibiogramme de la Société Française de Microbiologie. Results: Six (11.1%) H. pylori isolates were resistant to clarithromycin, one (1.9%) to amoxicillin and three (5.5%) to ciprofloxacin. These indices of resistance are considered satisfactory and show that all of these antibiotics can be used in the empirical therapy. Conclusion: The antibiotics amoxicillin and clarithromycin are still a good option for first line anti-H. pylori treatment in the population of Southern Brazil. PMID:24878996

  3. Cytotoxic isolates of Helicobacter pylori from Peptic Ulcer Diseases decrease K+-dependent ATPase Activity in HeLa cells

    PubMed Central

    Shanjana, Awasthi; Archana, Ayyagari

    2003-01-01

    Background Helicobacter pylori is a Gram negative bacterium that plays a central role in the etiology of chronic gastritis and peptic ulcer diseases. However, not all H. pylori positive cases develop advanced disease. This discriminatory behavior has been attributed to the difference in virulence of the bacteria. Among all virulence factors, cytotoxin released by H. pylori is the most important factor. In this work, we studied variation in H. pylori isolates from Indian dyspeptic patients on the basis of cytotoxin production and associated changes in K+-dependent ATPase (one of its targets) enzyme activity in HeLa cells. Methods The patients were retrospectively grouped on the basis of endoscopic and histopathological observation as having gastritis or peptic ulcer. The HeLa cells were incubated with the broth culture filtrates (BCFs) of H. pylori isolates from patients of both groups and observed for the cytopathic effects: morphological changes and viability. In addition, the K+-dependent ATPase activity was measured in HeLa cells extracts. Results The cytotoxin production was observed in 3/7 (gastritis) and 4/4 (peptic ulcer) H. pylori isolates. The BCFs of cytotoxin producing H. pylori strains reduced the ATPase activity of HeLa cells to 40% of that measured with non-cytotoxin producing H. pylori strains (1.33 μmole Pi/mg protein and 3.36 μmole Pi/mg protein, respectively, p < 0.05). The decreased activity of ATPase enzyme or the release of cytotoxin also correlated with the increased pathogenicity indices of the patients. Conclusions Our results suggest that the isolation of cytotoxic H. pylori is more common in severe form of acid peptic diseases (peptic ulcer) than in gastritis patients from India. Also the cytotoxin released by H. pylori impairs the ion-transporting ATPase and is a measure of cytotoxicity. PMID:14604441

  4. Population Genetic Structure and Isolation by Distance of Helicobacter pylori in Senegal and Madagascar

    PubMed Central

    Linz, Bodo; Vololonantenainab, Clairette Romaine Raharisolo; Seck, Abdoulaye; Carod, Jean-François; Dia, Daouda; Garin, Benoit; Ramanampamonjy, Rado Manitrala; Thiberge, Jean-Michel; Raymond, Josette; Breurec, Sebastien

    2014-01-01

    Helicobacter pylori has probably infected the human stomach since our origins and subsequently diversified in parallel with their human hosts. The genetic population history of H. pylori can therefore be used as a marker for human migration. We analysed seven housekeeping gene sequences of H. pylori strains isolated from 78 Senegalese and 24 Malagasy patients and compared them with the sequences of strains from other geographical locations. H. pylori from Senegal and Madagascar can be placed in the previously described HpAfrica1 genetic population, subpopulations hspWAfrica and hspSAfrica, respectively. These 2 subpopulations correspond to the distribution of Niger-Congo speakers in West and most of subequatorial Africa (due to Bantu migrations), respectively. H. pylori appears as a single population in Senegal, indicating a long common history between ethnicities as well as frequent local admixtures. The lack of differentiation between these isolates and an increasing genetic differentiation with geographical distance between sampling locations in Africa was evidence for genetic isolation by distance. The Austronesian expansion that started from Taiwan 5000 years ago dispersed one of the 10 subgroups of the Austronesian language family via insular Southeast Asia into the Pacific and Madagascar, and hspMaori is a marker for the entire Austronesian expansion. Strain competition and replacement of hspMaori by hpAfrica1 strains from Bantu migrants are the probable reasons for the presence of hspSAfrica strains in Malagasy of Southeast Asian descent. hpAfrica1 strains appear to be generalist strains that have the necessary genetic diversity to efficiently colonise a wide host spectrum. PMID:24498084

  5. Population genetic structure and isolation by distance of Helicobacter pylori in Senegal and Madagascar.

    PubMed

    Linz, Bodo; Vololonantenainab, Clairette Romaine Raharisolo; Seck, Abdoulaye; Carod, Jean-François; Dia, Daouda; Garin, Benoit; Ramanampamonjy, Rado Manitrala; Thiberge, Jean-Michel; Raymond, Josette; Breurec, Sebastien

    2014-01-01

    Helicobacter pylori has probably infected the human stomach since our origins and subsequently diversified in parallel with their human hosts. The genetic population history of H. pylori can therefore be used as a marker for human migration. We analysed seven housekeeping gene sequences of H. pylori strains isolated from 78 Senegalese and 24 Malagasy patients and compared them with the sequences of strains from other geographical locations. H. pylori from Senegal and Madagascar can be placed in the previously described HpAfrica1 genetic population, subpopulations hspWAfrica and hspSAfrica, respectively. These 2 subpopulations correspond to the distribution of Niger-Congo speakers in West and most of subequatorial Africa (due to Bantu migrations), respectively. H. pylori appears as a single population in Senegal, indicating a long common history between ethnicities as well as frequent local admixtures. The lack of differentiation between these isolates and an increasing genetic differentiation with geographical distance between sampling locations in Africa was evidence for genetic isolation by distance. The Austronesian expansion that started from Taiwan 5000 years ago dispersed one of the 10 subgroups of the Austronesian language family via insular Southeast Asia into the Pacific and Madagascar, and hspMaori is a marker for the entire Austronesian expansion. Strain competition and replacement of hspMaori by hpAfrica1 strains from Bantu migrants are the probable reasons for the presence of hspSAfrica strains in Malagasy of Southeast Asian descent. hpAfrica1 strains appear to be generalist strains that have the necessary genetic diversity to efficiently colonise a wide host spectrum.

  6. [Cloning, expression and identification of hpaA gene from a clinical isolate of Helicobacter pylori].

    PubMed

    Mao, Ya-Fei; Yan, Jie; Li, Li-Wei

    2003-02-01

    To clone Helicobacter pylori adhesin (hpaA) gene,to construct the expression vector of the gene and to identify immunogenicity of the fusion protein. The hpaA gene from a clinical isolate Y06 of H.pylori was amplified by high fidelity PCR. The nucleotide sequence of the target DNA amplification fragment was sequenced after T-A cloning. The expression vector pET32a with inserted hpaA gene was constructed. hpaA fusion protein was expressed in E.coli strain BL21DE3 induced by IPTG at different dosages. Western blot using antibody against whole cell of H.pylori as well as immunodiffusion assay using antiserum of rabbit against the fusion protein was applied to determine immunogenicity of the fusion protein. In comparison with the reported corresponding sequences, the homology of nucleotide sequence of the cloned hpaA gene was from 94.25% approximate, equals 97.32%, while the homology of its putative amino acid sequence was as high as 95.38% approximate, equals 98.46%. The expression output of HpaA fusion protein in pET32a-hpaA-BL21DE3 system was approximately 40% of the total bacterial proteins. HpaA fusion protein was able to combine with antibody against whole cell of H.pylori and induce rabbit to preduce high titer antibody after the animal was immunized with the protein. An expression system with high efficiency of H.pylori hpaA gene has been established successfully. The expressed HpaA fusion protein with satisfactory immunogenicity and immunoreactivity can be used as antigen in H.pylori vaccine.

  7. Anti-bacterial effects of enzymatically-isolated sialic acid from glycomacropeptide in a Helicobacter pylori-infected murine model

    PubMed Central

    Noh, Hye-Ji; Koh, Hong Bum; Kim, Hee-Kyoung; Cho, Hyang Hyun

    2017-01-01

    BACKGROUND/OBJECTIVES Helicobacter pylori (H. pylori) colonization of the stomach mucosa and duodenum is the major cause of acute and chronic gastroduodenal pathology in humans. Efforts to find effective anti-bacterial strategies against H. pylori for the non-antibiotic control of H. pylori infection are urgently required. In this study, we used whey to prepare glycomacropeptide (GMP), from which sialic acid (G-SA) was enzymatically isolated. We investigated the anti-bacterial effects of G-SA against H. pylori in vitro and in an H. pylori-infected murine model. MATERIALS/METHODS The anti-bacterial activity of G-SA was measured in vitro using the macrodilution method, and interleukin-8 (IL-8) production was measured in H. pylori and AGS cell co-cultures by ELISA. For in vivo study, G-SA 5 g/kg body weight (bw)/day and H. pylori were administered to mice three times over one week. After one week, G-SA 5 g/kg bw/day alone was administered every day for one week. Tumor necrosis factor-α (TNF-α), IL-1β, IL-6, and IL-10 levels were measured by ELISA to determine the anti-inflammatory effects of G-SA. In addition, real-time PCR was performed to measure the genetic expression of cytotoxin-associated gene A (cagA). RESULTS G-SA inhibited the growth of H. pylori and suppressed IL-8 production in H. pylori and in AGS cell co-cultures in vitro. In the in vivo assay, administration of G-SA reduced levels of IL-1β and IL-6 pro-inflammatory cytokines whereas IL-10 level increased. Also, G-SA suppressed the expression of cagA in the stomach of H. pylori-infected mice. CONCLUSION G-SA possesses anti-H. pylori activity as well as an anti-H. pylori-induced gastric inflammatory effect in an experimental H. pylori-infected murine model. G-SA has potential as an alternative to antibiotics for the prevention of H. pylori infection and H. pylori-induced gastric disease prevention. PMID:28194260

  8. Antimicrobial susceptibility of Canadian isolates of Helicobacter pylori in Northeastern Ontario

    PubMed Central

    Eng, Nelson F; Ybazeta, Gustavo; Chapman, Katrina; Fraleigh, Nya L; Letto, Rebecca; Altman, Eleonora; Diaz-Mitoma, Francisco

    2015-01-01

    BACKGROUND: Helicobacter pylori plays a significant role in gastritis and ulcers. It is a carcinogen as defined by the WHO, and infection can result in adenocarcinomas and mucosa-associated lymphoid tissue lymphomas. In Canada, rates of antimicrobial resistance are relatively unknown, with very few studies conducted in the past 15 years. OBJECTIVE: To examine rates of resistance in Sudbury, Ontario, compare antimicrobial susceptibility methods and attempt to determine the molecular basis of antibiotic resistance. METHODS: Patients attending scheduled visits at Health Sciences North (Sudbury, Ontario) provided gastric biopsy samples on a volunteer basis. In total, 20 H pylori isolates were collected, and antimicrobial susceptibility testing (on amoxicillin, tetracycline, metronidazole, ciprofloxacin, levofloxacin and clarithromycin) was conducted using disk diffusion and E-test methods. Subsequently, genomic DNA from these isolates was sequenced to detect mutations associated with antimicrobial resistance. RESULTS: Sixty-five percent of the isolates were found to be resistant to at least one of the listed antibiotics according to E-test. Three isolates were found to be resistant to ≥3 of the above-mentioned antibiotics. Notably, 25% of the isolates were found to be resistant to both metronidazole and clarithromycin, two antibiotics that are normally prescribed as part of first-line regimens in the treatment of H pylori infections in Canada and most of the world. Among the resistant strains, the sequences of 23S ribosomal RNA and gyrA, which are linked to clarithromycin and ciprofloxacin/levofloxacin resistance, respectively, revealed the presence of known point mutations associated with antimicrobial resistance. CONCLUSIONS: In general, resistance to metronidazole, ciprofloxacin/levofloxacin and clarithromycin has increased since the studies in the early 2000s. These results suggest that surveillance programs of H pylori antibiotic resistance may need to be

  9. The Helicobacter pylori L-form: formation and isolation in the human bile cultures in vitro and in the gallbladders of patients with biliary diseases.

    PubMed

    Wang, Dan N; Ding, Wen J; Pan, Yao Z; Tang, Ke L; Wang, Tao; She, Xiao L; Wang, He

    2015-04-01

    The Helicobacter pylori is considered the important causative agent causing biliary diseases, but the H. pylori can be isolated from very few gallbladder specimens with diseases. We studied the formation of H. pylori L-forms in bile in vitro and isolated the H. pylori L-forms from gallbladder of patients with biliary diseases. We inoculated the H. pylori into the human bile to induce the L-form in vitro. The gallbladder specimens were collected from patients with biliary diseases to isolate the bacterial L-forms by the nonhigh osmotic isolation technique, and the H. pylori L-forms in the L-form isolates were identified by the gene assay for the H. pylori-specific genes 16S rRNA and UreA. The H. Pylori cannot be isolated from the bile-induced cultures, but the H. pylori L-form can be isolated from the H. pylori-negative bile-induced cultures. The L-form isolates of bile-induced cultures showed a positive reaction of the H. pylori-specific genes by PCR, and the coincidence ratio of the nucleotide sequences between the L-forms and the H. pylori is 99%. The isolation rate of bacteria L-form is 93.2% in the gallbladder specimens with bacteria-negative isolation culture by the nonhigh osmotic isolation technique, and the positive rate of the H. pylori-specific genes in the L-form isolates is 7.1% in the bacterial L-form-positive isolation cultures by the PCR. H. pylori can be rapidly induced into the L-form in the human bile; the L-form, as the latent bacteria, can live in the host gallbladder for a long times, and they made the host became a latent carrier of the H. pylori L-form. The H. pylori L-form can be isolated by the nonhigh osmotic isolation technique, and the variant can be identified by the gene assay for the H. pylori-specific genes 16S rRNA and reA. © 2014 John Wiley & Sons Ltd.

  10. High rate of A2142G point mutation associated with clarithromycin resistance among Iranian Helicobacter pylori clinical isolates.

    PubMed

    Khashei, Reza; Dara, Mahintaj; Bazargani, Abdollah; Bagheri Lankarani, Kamran; Taghavi, Alireza; Moeini, Maryam; Dehghani, Behzad; Sohrabi, Maryam

    2016-09-01

    This study aimed to investigate the clarithromycin resistance and its associated molecular mechanisms among Helicobacter pylori isolates from dyspeptic patients in Shiraz, Iran. From January to May 2014, 100 H. pylori strains were isolated from patients with gastroduodenal disorders. The resistance to clarithromycin was quantitatively evaluated, using Epsilometer (E-test) method. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was performed on all the isolates to detect A2143G and A2142G mutations in 23S rRNA gene. The H. pylori isolation rate was found to be 31.4%. E-test showed that 20% of isolates were resistant to clarithromycin (MIC ≥ 1 mg/L). MIC of clarithromycin ranged between 0.016 and 24 mg/L. Findings of PCR-RFLP showed that the A2142G was the most (90%) frequently point mutation, followed by the A2143G (10%). No statistically significant difference was found between H. pylori clarithromycin resistance point mutations and patients' gender or age. To the best of our knowledge, this is the first report of high frequency of A2142G point mutation in Iran and probably in other regions of the world. Considering the increasing trend of H. pylori resistance to clarithromycin due to these mutations, it is crucial to investigate the new therapeutic approaches against H. pylori infection.

  11. Differences in Surface-Exposed Antigen Expression between Helicobacter pylori Strains Isolated from Duodenal Ulcer Patients and from Asymptomatic Subjects

    PubMed Central

    Thoreson, Ann-Catrin E.; Hamlet, Annika; Çelik, Janet; Byström, Mona; Nyström, Susanne; Olbe, Lars; Svennerholm, Ann-Mari

    2000-01-01

    We have analyzed possible qualitative and quantitative differences in antigen expression between Helicobacter pylori strains isolated from the antrum and different locations in the duodenum of 21 duodenal ulcer (DU) patients and 20 asymptomatic subjects (AS) by enzyme-linked immunosorbent assay (ELISA) and inhibition ELISA. Almost all antral and duodenal strains grown in vitro expressed the N-acetyl-neuroaminyllactose-binding hemagglutinin, flagellins (subunits FlaA and FlaB), urease, a 26-kDa protein, and a neutrophil-activating protein. In 75% of both the DU patients and the AS, antral H. pylori strains expressed either the blood group antigen Lewis y (Ley) alone or together with the Lex antigen. However, duodenal H. pylori strains of DU patients expressed Ley antigen more frequently than corresponding strains of AS (P < 0.05). Presence of Ley on H. pylori was related to the degree of active duodenitis (P < 0.05). Duodenal H. pylori strains isolated from AS were significantly more often Lewis nontypeable than duodenal strains of DU patients (P < 0.01). Presence of H. pylori blood group antigen-binding adhesin (BabA) was significantly higher on both antral and duodenal strains isolated from DU patients than on corresponding strains isolated from AS (P < 0.05). BabA-positive duodenal H. pylori strains isolated from DU patients were associated with active duodenitis more frequently than corresponding strains isolated from AS (P < 0.01). Infection with H. pylori strains positive for Ley and BabA in the duodenum is associated with development of duodenal ulcer formation. PMID:10970397

  12. Geographical difference in antimicrobial resistance pattern of Helicobacter pylori clinical isolates from Indian patients: Multicentric study.

    PubMed

    Thyagarajan, S P; Ray, Pallab; Das, Bimal Kumar; Ayyagari, Archana; Khan, Aleem Ahmed; Dharmalingam, S; Rao, Usha Anand; Rajasambandam, P; Ramathilagam, B; Bhasin, Deepak; Sharma, M P; Naik, S R; Habibullah, C M

    2003-12-01

    To assess the pattern of antimicrobial resistance of Helicobacter pylori isolates from peptic ulcer disease patients of Chandigarh, Delhi, Lucknow, Hyderabad and Chennai in India, and to recommend an updated anti-H. pylori treatment regimen to be used in these areas. Two hundred and fifty-nine H. pylori isolates from patients with peptic ulcer disease reporting for clinical management to the Post Graduate Institute of Medical Education and Research, Chandigarh; All India Institute of Medical Sciences, New Delhi; Sanjay Gandhi Post Graduate Institute of Medical Sciences, Lucknow; Deccan College of Medical Sciences and Allied Hospitals, Hyderabad; and hospitals in Chennai in collaboration with the Dr ALM Post Graduate Institute of Basic Medical Sciences were analyzed for their levels of antibiotic susceptibility to metronidazole, clarithromycin, amoxycillin, ciprofloxacin and tetracycline. The Epsilometer test (E-test), a quantitative disc diffusion antibiotic susceptibility testing method, was adopted in all the centers. The pattern of single and multiple resistance at the respective centers and at the national level were analyzed. Overall H. pylori resistance rate was 77.9% to metronidazole, 44.7% to clarithromycin and 32.8% to amoxycillin. Multiple resistance was seen in 112/259 isolates (43.2%) and these were two/three and four drug resistance pattern to metronidazole, clarithromycin, amoxycillin observed (13.2, 32 and 2.56%, respectively). Metronidazole resistance was high in Lucknow, Chennai and Hyderabad (68, 88.2 and 100%, respectively) and moderate in Delhi (37.5%) and Chandigarh (38.2%). Ciprofloxacin and tetracycline resistance was the least, ranging from 1.0 to 4%. In the Indian population, the prevalence of resistance of H. pylori is very high to metronidazole, moderate to clarithromycin and amoxycillin and low to ciprofloxacin and tetracycline. The rate of resistance was higher in southern India than in northern India. The E-test emerges as a reliable

  13. Virulence attributes of Helicobacter pylori isolates & their association with gastroduodenal disease

    PubMed Central

    Saxena, A.; Shukla, S.; Prasad, K.N.; Ghoshal, U.C.

    2011-01-01

    Background & objectives Certain genotype(s) of Helicobacter pylori strains may play important role in the development of gastric cancer (GC) and peptic ulcer disease (PUD). This study was undertaken to investigate the association of cagA, cagA3/ region subtypes, babA2 and vacA genotypes of H. pylori with GC, PUD and non-ulcer dyspepsia (NUD) as there are no such studies from India. Methods A total of 348 consecutive adult patients (NUD 241, PUD 45, GC 62) undergoing upper gastrointestinal endoscopy between September 2002 and May 2007 in a tertiary referral centre at Lucknow, north India, were enrolled. H. pylori infection was diagnosed by rapid urease test, culture, histopathology and PCR. Genotyping for cagA, cagA3/ subtypes, babA2 and vacA was performed by PCR using sequence specific primers. Results H. pylori infection was higher in patients with PUD than with GC (80 vs. 56.5%, P < 0.01) and NUD (80 vs. 55.2%, P= 0.002). cagA positive H. pylori isolates were detected in 80 per cent in GC, 83.3 per cent in PUD and 76.7 per cent in NUD with no significant difference among them. Only A subtype of cagA3/ was detected and its distribution in GC, PUD and NUD was 68.8, 69.4 and 52.6 per cent respectively. Presence of babA2 genotype was 31.4 per cent and it had significant association with PUD when compared with NUD (52.8 vs. 26.3%, P<0.003). On univariate regression analysis, s1a allele was associated with GC (P<0.050) and s1a/m2 vacA genotype with both GC (P=0.014) and PUD (P=0.016). Interpretation & conclusions H. pylori infection was strongly associated with PUD with a very high proportion of patients with GC have s1a allele and s1a/m2 vacA genotype. Both s1a/m2 vacA genotype and babA2 are associated with PUD. The study shows that different virulence attributes of H. pylori are involved in different gastroduodenal disorders. PMID:21623037

  14. Virulence attributes of Helicobacter pylori isolates & their association with gastroduodenal disease.

    PubMed

    Saxena, A; Shukla, S; Prasad, K N; Ghoshal, U C

    2011-05-01

    Certain genotype(s) of Helicobacter pylori strains may play important role in the development of gastric cancer (GC) and peptic ulcer disease (PUD). This study was undertaken to investigate the association of cagA, cagA3/ region subtypes, babA2 and vacA genotypes of H. pylori with GC, PUD and non-ulcer dyspepsia (NUD) as there are no such studies from India. A total of 348 consecutive adult patients (NUD 241, PUD 45, GC 62) undergoing upper gastrointestinal endoscopy between September 2002 and May 2007 in a tertiary referral centre at Lucknow, north India, were enrolled. H. pylori infection was diagnosed by rapid urease test, culture, histopathology and PCR. Genotyping for cagA, cagA3/ subtypes, babA2 and vacA was performed by PCR using sequence specific primers. H. pylori infection was higher in patients with PUD than with GC (80 vs. 56.5%, P < 0.01) and NUD (80 vs. 55.2%, P= 0.002). cagA positive H. pylori isolates were detected in 80 per cent in GC, 83.3 per cent in PUD and 76.7 per cent in NUD with no significant difference among them. Only A subtype of cagA3/ was detected and its distribution in GC, PUD and NUD was 68.8, 69.4 and 52.6 per cent respectively. Presence of babA2 genotype was 31.4 per cent and it had significant association with PUD when compared with NUD (52.8 vs. 26.3%, P<0.003). On univariate regression analysis, s1a allele was associated with GC (P<0.050) and s1a/m2 vacA genotype with both GC (P=0.014) and PUD (P=0.016). H. pylori infection was strongly associated with PUD with a very high proportion of patients with GC have s1a allele and s1a/m2 vacA genotype. Both s1a/m2 vacA genotype and babA2 are associated with PUD. The study shows that different virulence attributes of H. pylori are involved in different gastroduodenal disorders.

  15. Complete Genome Sequence of Helicobacter pylori Strain 7C Isolated from a Mexican Patient with Chronic Gastritis

    PubMed Central

    Mucito-Varela, Eduardo; Castillo-Rojas, Gonzalo; Cevallos, Miguel A.; Lozano, Luis; Merino, Enrique; López-Leal, Gamaliel

    2016-01-01

    Helicobacter pylori-induced gastritis is a risk factor for developing gastric pathologies. Here, we report the complete genome sequence of a multidrug-resistant H. pylori strain isolated from a chronic gastritis patient in Mexico City, Mexico. Nonvirulent VacA and cag-pathogenicity island (PAI) genotypes were found, but the presence of a potential mobilizable plasmid carrying an IS605 element is of outstanding interest. PMID:26744372

  16. Detection of the glmM Gene in Helicobacter pylori Isolates with a Novel Primer by PCR▿

    PubMed Central

    Córdova Espinoza, Maria Guadalupe; González Vazquez, Rosa; Morales Mendez, Iyari; Ruelas Vargas, Consuelo; Giono Cerezo, Silvia

    2011-01-01

    A novel reverse primer (GLM MR1) was designed for detection of the glmM gene in Helicobacter pylori by PCR. The percentage of amplification in clinical isolates using GLM MR1 was 100% for detection of the glmM gene and 86.36% for the ureA gene. The primer designed is useful for the identification of H. pylori. PMID:21289140

  17. Construction of hpaA gene from a clinical isolate of Helicobacter pylori and identification of fusion protein.

    PubMed

    Mao, Ya-Fei; Yan, Jie; Li, Li-Wei; Li, Shu-Ping

    2003-07-01

    To clone hpaA gene from a clinical strain of Helicobacter pylori and to construct the expression vector of the gene and to identify immunity of the fusion protein. The hpaA gene from a clinical isolate Y06 of H.pylori was amplified by high fidelity PCR. The nucleotide sequence of the target DNA amplification fragment was sequenced after T-A cloning. The recombinant expression vector inserted with hpaA gene was constructed. The expression of HpaA fusion protein in E.coli BL21DE3 induced by IPTG at different dosages was examined by SDS-PAGE. Western blot with commercial antibody against whole cell of H.pylori as well as immunodiffusion assay with self-prepared rabbit antiserum against HpaA fusion protein were applied to determine immunity of the fusion protein. ELISA was used to detect the antibody against HpaA in sera of 125 patients infected with H.pylori and to examine HpaA expression of 109 clinical isolates of H.pylori. In comparison with the reported corresponding sequences, the homologies of nucleotide and putative amino acid sequences of the cloned hpaA gene were from 94.25-97.32 % and 95.38-98.46 %, respectively. The output of HpaA fusion protein in its expression system of pET32a-hpaA-BL21DE3 was approximately 40 % of the total bacterial proteins. HpaA fusion protein was able to combine with the commercial antibody against whole cell of H.pylori and to induce rabbit producing specific antiserum with 1:4 immunodiffusion titer after the animal was immunized with the fusion protein. 81.6 % of the serum samples from 125 patients infected with H.pylori (102/125) were positive for HpaA antibody and all of the tested isolates of H.pylori (109/109) were detectable for HpaA. A prokaryotic expression system with high efficiency of H.pylori hpaA gene was successfully established. The HpaA expressing fusion protein showed satisfactory immunoreactivity and antigenicity. High frequencies of HpaA expression in different H.pylori clinical strains and specific antibody

  18. Construction of hpaA gene from a clinical isolate of Helicobacter pylori and identification of fusion protein

    PubMed Central

    Mao, Ya-Fei; Yan, Jie; Li, Li-Wei; Li, Shu-Ping

    2003-01-01

    AIM: To clone hpaA gene from a clinical strain of Helicobacter pylori and to construct the expression vector of the gene and to identify immunity of the fusion protein. METHODS: The hpaA gene from a clinical isolate Y06 of H. pylori was amplified by high fidelity PCR. The nucleotide sequence of the target DNA amplification fragment was sequenced after T-A cloning. The recombinant expression vector inserted with hpaA gene was constructed. The expression of HpaA fusion protein in E.coli BL21(DE3) induced by IPTG at different dosages was examined by SDS-PAGE. Western blot with commercial antibody against whole cell of H. pylori as well as immunodiffusion assay with self-prepared rabbit antiserum against HpaA fusion protein were applied to determine immunity of the fusion protein. ELISA was used to detect the antibody against HpaA in sera of 125 patients infected with H. pylori and to examine HpaA expression of 109 clinical isolates of H. pylori. RESULTS: In comparison with the reported corresponding sequences, the homologies of nucleotide and putative amino acid sequences of the cloned hpaA gene were from 94.25%-97.32% and 95.38%-98.46%, respectively. The output of HpaA fusion protein in its expression system of pET32a-hpaA-BL21(DE3) was approximately 40% of the total bacterial proteins. HpaA fusion protein was able to combine with the commercial antibody against whole cell of H. pylori and to induce rabbit producing specific antiserum with 1:4 immunodiffusion titer after the animal was immunized with the fusion protein. 81.6% of the serum samples from 125 patients infected with H. pylori (102/125) were positive for HpaA antibody and all of the tested isolates of H. pylori (109/109) were detectable for HpaA. CONCLUSION: A prokaryotic expression system with high efficiency of H. pylori hpaA gene was successfully established. The HpaA expressing fusion protein showed satisfactory immunoreactivity and antigenicity. High frequencies of HpaA expression in different H

  19. Multiple cag genotypes of Helicobacter pylori isolates colonize the oesophagus in individual hosts in a Venezuelan population.

    PubMed

    Peña, Jessy; Rojas, Héctor; Reyes, Nelson; Fernández-Delgado, Milagro; García-Amado, María-Alexandra; Michelangeli, Fabián; Contreras, Monica

    2017-03-01

    Multiple Helicobacter pylori strains colonize and coexist in the stomach of one single patient, carrying heterogeneous distributions of cag genotypes. The oesophagus provides a niche for H. pylori colonization; however, little is known about its adaptive role. Using PCR for cagA, cagE and virB11 genes from cag-pathogenicity island (PAI) and Etest for antimicrobial susceptibility test, we determined cag-PAI genotypes associated with H. pylori virulence, when positive cultures were matching in both the stomach and the oesophagus (96 isolates; 8 out of 80 dyspeptic patients). The stomach showed complete cag-PAI islands in 77 % of the isolates, whereas the oesophagus showed complete cag-PAI islands only in 44 % of the isolates. Expression of CagA and interleukin 8 correlated with inflammatory processes and histopathological changes in the stomach, but not in the oesophagus. Different cag-PAI profiles were found in both mucosae of an individual host, and at least one oesophagus profile corresponded to one profile identified in stomach. The antibiotic resistance profiles showed variability in the colonization by single or mixed H. pylori isolates in the gastric and oesophageal mucosa both intra- and inter-individuals. These results demonstrate colonization with multiple H. pylori isolates in the oesophageal mucosa, like those found in the stomach of individual hosts. H. pylori was characterized by a dominant partial island, low interleukin 8 induction with lower histopathological damage and lower antibiotic resistance, suggesting that the microenvironmental changes in individual hosts select less virulent isolates in the oesophagus than in the stomach. New approaches to ensure effective eradication therapy in multi-resistant H. pylori strains must be developed.

  20. Analysis of virulence factors of Helicobacter pylori isolated from a Vietnamese population

    PubMed Central

    2009-01-01

    Background The incidence of gastric cancer differs among countries in Asia, and it has been suggested that virulence factors associated with Helicobacter pylori are partly responsible. The aim of this study was to investigate several genetic factors regarded as virulence or molecular epidemiologic markers in H. pylori isolates from Vietnamese subjects. Results The cagA, vacA and cag right-end junction genotypes of 103 H. pylori strains from Vietnam (54 from Hanoi and 49 from Ho Chi Minh) were determined by PCR and sequencing. Three types of deletion in the region located upstream of the cagA Glu-Pro-Ile-Tyr-Ala (EPIYA) repeat region were identified: the 39-bp deletion type, the 18-bp deletion type, and the no-deletion type. The majority of strains studied (77%; 80/103) had the 18-bp deletion irrespective of geographical location in the country or clinical outcome. All of the 39-bp and 18-bp deletion-type strains possessed the East Asian type cagA repeat region. The type II cag right-end junction genotype was predominant (84%). The vacA m1 genotype was significantly more common in strains isolated in Hanoi, where the incidence of gastric cancer is higher, than in strains from Ho Chi Minh. Conclusion Pre-EPIYA-region typing of the cagA gene could provide a new genetic marker of H. pylori genomic diversity. Our data support the hypothesis that vacA m1 is closely associated with gastric carcinogenesis. PMID:19698173

  1. Anti-Helicobacter pylori activity of crude N-acetylneuraminic acid isolated from glycomacropeptide of whey

    PubMed Central

    Kim, Dong-Jae; Kang, Min-Jung; Choi, Jin-A; Na, Dae-Seung; Kim, Jin-Beom; Na, Chun-Soo

    2016-01-01

    Helicobacter pylori colonizes the gastric mucosa of about half of the world's population, causing chronic gastritis and gastric cancer. An increasing emergence of antibiotic-resistant H. pylori arouses demand on alternative non-antibiotic-based therapies. In this study, we freshly prepared crude N-acetylneuraminic acid obtained from glycomacropeptide (G-NANA) of whey through a neuraminidase-mediated reaction and evaluated its antibacterial ability against H. pylori and H. felis. Overnight cultures of the H. pylori were diluted with fresh media and different concentrations (1-150 mg/mL) of crude G-NANA were added directly to the culture tube. Bacterial growth was evaluated by measuring the optical density of the culture medium and the number of viable bacteria was determined by a direct count of the colony forming units (CFU) on agar plates. For the in vivo study, mice were orally infected with 100 µL (5×108 cfu/mL) of H. felis four times at a day's interval, accompanied by a daily administration of crude G-NANA or vehicle. A day after the last infection, the mice were daily administered the crude G-NANA (0, 75, and 300 mg/mL) for 10 days and euthanized. Their stomachs were collected and bacterial colonization was determined by quantitative real-time PCR. Crude G-NANA inhibited H. pylori's growth and reduced the number of viable bacteria in a dose-dependent manner. Furthermore, crude G-NANA inhibited bacterial colonization in the mice. These results showed that crude G-NANA has antibacterial activity against Helicobacter and demonstrated its therapeutic potential for the prevention of chronic gastritis and gastric carcinogenesis induced by Helicobacter infection in humans. PMID:27382378

  2. Helicobacter pylori bab Paralog Distribution and Association with cagA, vacA, and homA/B Genotypes in American and South Korean Clinical Isolates.

    PubMed

    Kim, Aeryun; Servetas, Stephanie L; Kang, Jieun; Kim, Jinmoon; Jang, Sungil; Cha, Ho Jin; Lee, Wan Jin; Kim, June; Romero-Gallo, Judith; Peek, Richard M; Merrell, D Scott; Cha, Jeong-Heon

    2015-01-01

    Helicobacter pylori genetic variation is a crucial component of colonization and persistence within the inhospitable niche of the gastric mucosa. As such, numerous H. pylori genes have been shown to vary in terms of presence and genomic location within this pathogen. Among the variable factors, the Bab family of outer membrane proteins (OMPs) has been shown to differ within subsets of strains. To better understand genetic variation among the bab genes and to determine whether this variation differed among isolates obtained from different geographic locations, we characterized the distribution of the Bab family members in 80 American H. pylori clinical isolates (AH) and 80 South Korean H. pylori clinical isolates (KH). Overall, we identified 23 different bab genotypes (19 in AH and 11 in KH), but only 5 occurred in greater than 5 isolates. Regardless of strain origin, a strain in which locus A and locus B were both occupied by a bab gene was the most common (85%); locus C was only occupied in those isolates that carried bab paralog at locus A and B. While the babA/babB/- genotype predominated in the KH (78.8%), no single genotype could account for greater than 40% in the AH collection. In addition to basic genotyping, we also identified associations between bab genotype and well known virulence factors cagA and vacA. Specifically, significant associations between babA at locus A and the cagA EPIYA-ABD motif (P<0.0001) and the vacA s1/i1/m1 allele (P<0.0001) were identified. Log-linear modeling further revealed a three-way association between bab carried at locus A, vacA, and number of OMPs from the HOM family (P<0.002). En masse this study provides a detailed characterization of the bab genotypes from two distinct populations. Our analysis suggests greater variability in the AH, perhaps due to adaptation to a more diverse host population. Furthermore, when considering the presence or absence of both the bab and homA/B paralogs at their given loci and the vac

  3. Helicobacter pylori bab Paralog Distribution and Association with cagA, vacA, and homA/B Genotypes in American and South Korean Clinical Isolates

    PubMed Central

    Kang, Jieun; Kim, Jinmoon; Jang, Sungil; Cha, Ho Jin; Lee, Wan Jin; Kim, June; Romero-Gallo, Judith; Peek, Richard M.; Merrell, D. Scott; Cha, Jeong-Heon

    2015-01-01

    Helicobacter pylori genetic variation is a crucial component of colonization and persistence within the inhospitable niche of the gastric mucosa. As such, numerous H. pylori genes have been shown to vary in terms of presence and genomic location within this pathogen. Among the variable factors, the Bab family of outer membrane proteins (OMPs) has been shown to differ within subsets of strains. To better understand genetic variation among the bab genes and to determine whether this variation differed among isolates obtained from different geographic locations, we characterized the distribution of the Bab family members in 80 American H. pylori clinical isolates (AH) and 80 South Korean H. pylori clinical isolates (KH). Overall, we identified 23 different bab genotypes (19 in AH and 11 in KH), but only 5 occurred in greater than 5 isolates. Regardless of strain origin, a strain in which locus A and locus B were both occupied by a bab gene was the most common (85%); locus C was only occupied in those isolates that carried bab paralog at locus A and B. While the babA/babB/- genotype predominated in the KH (78.8%), no single genotype could account for greater than 40% in the AH collection. In addition to basic genotyping, we also identified associations between bab genotype and well known virulence factors cagA and vacA. Specifically, significant associations between babA at locus A and the cagA EPIYA-ABD motif (P<0.0001) and the vacA s1/i1/m1 allele (P<0.0001) were identified. Log-linear modeling further revealed a three-way association between bab carried at locus A, vacA, and number of OMPs from the HOM family (P<0.002). En masse this study provides a detailed characterization of the bab genotypes from two distinct populations. Our analysis suggests greater variability in the AH, perhaps due to adaptation to a more diverse host population. Furthermore, when considering the presence or absence of both the bab and homA/B paralogs at their given loci and the vac

  4. Plasticity Region Genes jhp0940, jhp0945, jhp0947, and jhp0949 of Helicobacter pylori in Isolates from Mexican Children.

    PubMed

    Romo-González, Carolina; Consuelo-Sánchez, Alejandra; Camorlinga-Ponce, Margarita; Velázquez-Guadarrama, Norma; García-Zúñiga, Magdalena; Burgueño-Ferreira, Juan; Coria-Jiménez, Rafael

    2015-06-01

    The genes jhp0940, jhp0945, jhp0947, and jhp0949 belong to the plasticity region of the Helicobacter pylori genome. Due to their prevalence in isolates from patients with gastritis, duodenal ulcer, and gastric cancer, they have been proposed as markers of gastroduodenal diseases. These genes are associated with pro-inflammatory cytokine induction through the NF-κB activation pathway. Nevertheless, the status of these genes is unknown in H. pylori isolates from children. The aim of the present work was to determine the frequency of the jhp0940-jhp0945-jhp0947-jhp0949 genes in H. pylori isolates from children. We identified the jhp0940, jhp0945, jhp0947, and jhp0949 genes and the relationship of each with the virulence factors cagA, cagPAI, and dupA by PCR in 49 isolates of H. pylori from children. The results were corroborated using dot blots. In addition, we compared the prevalence of these genes with the prevalence in adults. The prevalence of jhp0940 (53.1%), jhp0945 (44.9%), jhp0947 (77.6%), and jhp0949 (83.7%) was determined in the isolates from children, as was the prevalence of the virulence genes cagA (63.3%), cagPAI (71.4%), and dupA (37.5%). No association was found between the four genes of the plasticity region and the virulence genes. The presence of the intact locus integrated by jhp0940-jhp0945-jhp0947-jhp0949 was very common among the isolates from children. The genes jhp0940, jhp0947, and jhp0949 were present in more than 50% of the H. pylori isolates, and the joint presence of jhp0940-jhp0945-jhp0947-jhp0949 was very frequent. The frequency of these genes in isolates from children could contribute to the virulence of H. pylori and the evolution of the infection. © 2015 John Wiley & Sons Ltd.

  5. Surveillance of Levofloxacin Resistance in Helicobacter pylori Isolates in Bogotá-Colombia (2009-2014).

    PubMed

    Trespalacios-Rangél, Alba A; Otero, William; Arévalo-Galvis, Azucena; Poutou-Piñales, Raúl A; Rimbara, Emiko; Graham, David Y

    2016-01-01

    Increased resistance of Helicobacter pylori to clarithromycin and metronidazole has resulted in recommendation to substitute fluoroquinolones for eradication therapy. The aims of the study were to determine the prevalence and changes in primary levofloxacin resistance related to H. pylori gyrA sequences. The study utilized H. pylori strains isolated from patients undergoing gastroscopy in Bogotá, Colombia from 2009 to 2014. Levofloxacin susceptibility was assessed by agar dilution. Mutations in gyrA sequences affecting the quinolone resistance-determining region (QRDR) were evaluated by direct sequencing. Overall, the mean prevalence of primary levofloxacin resistance was 18.2% (80 of 439 samples). Resistance increased from 11.8% (12/102) in 2009 to 27.3% (21/77) in 2014 (p = 0.001). gyrA mutations in levofloxacin resistant strains were present in QRDR positions 87 and 91. The most common mutation was N87I (43.8%, 35/80) followed by D91N (28.8%, 23/80) and N87K (11.3%, 9/80). Levofloxacin resistance increased markedly in Colombia during the six-year study period. Primary levofloxacin resistance was most often mediated by point mutations in gyrA, with N87I being the most common QRDR mutation related to levofloxacin resistance.

  6. Surveillance of Levofloxacin Resistance in Helicobacter pylori Isolates in Bogotá-Colombia (2009-2014)

    PubMed Central

    Trespalacios-Rangél, Alba A.; Otero, William; Arévalo-Galvis, Azucena; Poutou-Piñales, Raúl A.; Rimbara, Emiko; Graham, David Y.

    2016-01-01

    Increased resistance of Helicobacter pylori to clarithromycin and metronidazole has resulted in recommendation to substitute fluoroquinolones for eradication therapy. The aims of the study were to determine the prevalence and changes in primary levofloxacin resistance related to H. pylori gyrA sequences. The study utilized H. pylori strains isolated from patients undergoing gastroscopy in Bogotá, Colombia from 2009 to 2014. Levofloxacin susceptibility was assessed by agar dilution. Mutations in gyrA sequences affecting the quinolone resistance-determining region (QRDR) were evaluated by direct sequencing. Overall, the mean prevalence of primary levofloxacin resistance was 18.2% (80 of 439 samples). Resistance increased from 11.8% (12/102) in 2009 to 27.3% (21/77) in 2014 (p = 0.001). gyrA mutations in levofloxacin resistant strains were present in QRDR positions 87 and 91. The most common mutation was N87I (43.8%, 35/80) followed by D91N (28.8%, 23/80) and N87K (11.3%, 9/80). Levofloxacin resistance increased markedly in Colombia during the six-year study period. Primary levofloxacin resistance was most often mediated by point mutations in gyrA, with N87I being the most common QRDR mutation related to levofloxacin resistance. PMID:27454429

  7. Antimicrobial susceptibility of Helicobacter pylori and mechanisms of clarithromycin resistance in strains isolated from patients in Uruguay.

    PubMed

    Torres-Debat, M E; Pérez-Pérez, G; Olivares, A; Fernández, L; Raisler, K; González, N; Stein, S; Bazet, M C; Alallón, W; Cohen, H

    2009-11-01

    The prevalence and mechanisms of antibiotic resistance of Helicobacter pylori have not yet been investigated in Uruguay. The objective of this study was to assess the susceptibility of H. pylori to the most frequently used antibiotics and to determine the mechanism of resistance to clarithromycin. Seventy-nine isolates were obtained from gastric biopsies of 50 adult patients during two periods, 2001 and 2006. The former group enrolled the general population (GP), the latter group Afro-descendant (AD) subjects. The minimum inhibitory concentrations of clarithromycin, amoxicillin, tetracycline, metronidazole, and levofloxacin were determined using the E-test technique. Amplification was achieved through PCR and nucleic acid sequencing to detect mutations in the site of action of clarithromycin in the rRNA gene 23S. No amoxicillin or tetracycline-resistant strains were found. Clarithromycin resistance was found in 12% of the patients overall: 19.4% resistance in AD patients and no resistance in the GP group. This difference was statistically significant. The highest resistance was seen with metronidazole (36%), present in similar proportions in the two groups: 36.8% (GP) and 35.5% (AD). One GP patient and one AD patient had levofloxacin-resistant strains. Sequencing analysis of gene 23S rRNA showed that only mutation in position 2143 was presented in all clarithromycin-resistant strains.

  8. Identification of H. pylori strain specific DNA sequences between two clinical isolates from NUD and gastric ulcer by SSH.

    PubMed

    Han, Feng-Chan; Gong, Min; Ng, Han-Chong; Ho, Bow

    2003-08-01

    The genomes of Helicobacter pylori (H. pylori) from different individuals are different. This project was to identify the strain specific DNA sequences between two clinical H. pylori isolates by suppression subtractive hybridization (SSH). Two clinical H. pylori isolates, one from gastric ulcer (GU, tester) and the other from non-ulcer dyspepsia (NUD, driver), were cultured and the genomic DNA was prepared and submitted to Alu I digestion. Then two different adaptors were ligated respectively to the 5'-end of two aliquots of the tester DNA fragments and SSH was made between the tester and driver DNA. The un-hybridized tester DNA sequences were amplified by two sequential PCR and cloned into pGEM-T-Easy Vector. The tester strain specific inserts were screened and disease related DNA sequences were identified by dot blotting. Among the 240 colonies randomly chosen, 50 contained the tester strain specific DNA sequences. Twenty three inserts were sequenced and the sizes ranged from 261 bp to 1 036 bp. Fifteen inserts belonged to the H.pylori plasmid pHPO100 that is about 3.5 kb and codes a replication protein A. Other inserts had patches of homologous to the genes of H.pylori in GenBank. Various patterns of dot blots were given and no GU strain unique DNA sequences were found when 4 inserts were used as probes to screen the genomic DNA from 27 clinical isolates, 8 from GU, 12 from duodenum ulcer (DU), 4 from GU-DU, 2 from NUD and 1 from gastric cancer (GC). But a 670 bp DNA fragment (GU198) that was a bit homologous to the 3'-end of the gene of thymidylate kinase was positive in 7 GU strains (7/8), 3 GU-DU strains (3/4) and 3 DU strains (3/12). A 384 bp fragment (GU79) of the replication gene A (repA) was positive only in 4 H.pylori isolates, 2 from GU and 2 from GU-DU. Differences exist in the genes of different H.pylori isolates. SSH is very effective to screen H.pylori strain specific DNA sequences between two clinical isolates, and some of these sequences may have

  9. Identification of H. pylori strain specific DNA sequences between two clinical isolates from NUD and gastric ulcer by SSH

    PubMed Central

    Han, Feng-Chan; Gong, Min; Ng, Han-Chong; Ho, Bow

    2003-01-01

    AIM: The genomes of Helicobacter pylori (H. pylori) from different individuals are different. This project was to identify the strain specific DNA sequences between two clinical H. pylori isolates by suppression subtractive hybridization (SSH). METHODS: Two clinical H. pylori isolates, one from gastric ulcer (GU, tester) and the other from non-ulcer dyspepsia (NUD, driver), were cultured and the genomic DNA was prepared and submitted to Alu I digestion. Then two different adaptors were ligated respectively to the 5’-end of two aliquots of the tester DNA fragments and SSH was made between the tester and driver DNA. The un-hybridized tester DNA sequences were amplified by two sequential PCR and cloned into pGEM-T-Easy Vector. The tester strain specific inserts were screened and disease related DNA sequences were identified by dot blotting. RESULTS: Among the 240 colonies randomly chosen, 50 contained the tester strain specific DNA sequences. Twenty three inserts were sequenced and the sizes ranged from 261 bp to 1036 bp. Fifteen inserts belonged to the H.pylori plasmid pHPO100 that is about 3.5 kb and codes a replication protein A. Other inserts had patches of homologous to the genes of H.pylori in GenBank. Various patterns of dot blots were given and no GU strain unique DNA sequences were found when 4 inserts were used as probes to screen the genomic DNA from 27 clinical isolates, 8 from GU, 12 from duodenum ulcer (DU), 4 from GU-DU, 2 from NUD and 1 from gastric cancer (GC). But a 670 bp DNA fragment (GU198) that was a bit homologous to the 3’-end of the gene of thymidylate kinase was positive in 7 GU strains (7/8), 3 GU-DU strains (3/4) and 3 DU strains (3/12). A 384 bp fragment (GU79) of the replication gene A (repA) was positive only in 4 H.pylori isolates, 2 from GU and 2 from GU-DU. CONCLUSION: Differences exist in the genes of different H.pylori isolates. SSH is very effective to screen H.pylori strain specific DNA sequences between two clinical isolates

  10. Relationship between histopathological status of the Helicobacter pylori infected patients and proteases of H. pylori in isolates carrying diverse virulence genotypes.

    PubMed

    Gharibi, Somayyeh; Falsafi, Tahereh; Alebouyeh, Masoud; Farzi, Nastaran; Vaziri, Farzam; Zali, Mohamad Reza

    2017-09-01

    Helicobacter pylori is the main cause of several gastroduodenal diseases in Humans. Among various virulence factors of H. pylori, proteases may also be involved in its pathogenicity. In this study, relationship between proteolytic activity of H. pylori strains and histopathological changes of the stomach was investigated in the patients infected with strains carrying diverse virulence factors. H. pylori strains were isolated from the biopsies of 116 patients who referred to hospital for their gastroduodenal disorders, in Tehran, Iran. Biopsies were sent to microbiology and pathology laboratories for further analysis. All the suspected grown colonies were characterized by both biochemical tests and polymerase chain reaction (PCR). Presence of seven protease genes, htrA, clpP, hp0169, hp1012, hp0382, hp1350 and hp1435, and distinct allelic variants of H. pylori virulence factors, cagA, vacA, iceA, babA2 and sabA, were analyzed in each strain. Protease activity of the strains was assessed using spectrophotometric assay. Furthermore, association between diversity in protease genes and virulence genes, protease activity, as well as pathological changes was estimated statistically. Proteases genes, htrA, clpP, hp0169, hp1012, hp0382, hp1350, hp1435, were detected among 100%, 100%, 98%, 98%, 98%, 98%, and 8% of fifty H. pylori strains isolated from the patients, respectively. Status of cagA, vacA s1, vacA s2, vacA m1, vacA m2, iceA1, iceA2, babA2 and sabA genes in isolates were 64%, 68%, 30%, 26%, 74%, 48%, 52%, 100%, and 96%, respectively. Predominant (84%) combined status for protease genes was: htrA/clpP/hp0169/hp1012/hp0382/hP1350/hp1435, while the prevalent combined status (16%) for virulence genes was: cagA+/vacA s1m2/iceA1(+)/sabA(+)/babA2(+). Although most of the strains (91.4%) presented moderate protease activity in vitro, lowest activity was measured in strains isolated from the patients with chronic gastritis (4.25%). Present study provide the new data

  11. Helicobacter pylori.

    PubMed Central

    Dunn, B E; Cohen, H; Blaser, M J

    1997-01-01

    Helicobacter pylori is a gram-negative bacterium which causes chronic gastritis and plays important roles in peptic ulcer disease, gastric carcinoma, and gastric lymphoma. H. pylori has been found in the stomachs of humans in all parts of the world. In developing countries, 70 to 90% of the population carries H. pylori. In developed countries, the prevalence of infection is lower. There appears to be no substantial reservoir of H. pylori aside from the human stomach. Transmission can occur by iatrogenic, fecal-oral, and oral-oral routes. H. pylori is able to colonize and persist in a unique biological niche within the gastric lumen. All fresh isolates of H. pylori express significant urease activity, which appears essential to the survival and pathogenesis of the bacterium. A variety of tests to diagnose H. pylori infection are now available. Histological examination of gastric tissue, culture, rapid urease testing, DNA probes, and PCR analysis, when used to test gastric tissue, all require endoscopy. In contrast, breath tests, serology, gastric juice PCR, and urinary excretion of [15N]ammonia are noninvasive tests that do not require endoscopy. In this review, we highlight advances in the detection of the presence of the organism and methods of differentiating among types of H. pylori, and we provide a background for appropriate chemotherapy of the infection. PMID:9336670

  12. Patterns of Adherence of Helicobacter pylori Clinical Isolates to Epithelial Cells, and its Association with Disease and with Virulence Factors.

    PubMed

    Vázquez-Jiménez, Flor Elizabeth; Torres, Javier; Flores-Luna, Lourdes; Cerezo, Silvia Giono; Camorlinga-Ponce, Margarita

    2016-02-01

    Adherence to the gastric epithelium is one of the most important steps of Helicobacter pylori to remain and cause disease. The aim of this study was to analyze whether H. pylori isolates from patients with different gastroduodenal diseases present differences in the pattern of adherence to gastric epithelial cells (AGS), in the ability to induce IL-8, and in the presence of virulence genes. We tested 75 H. pylori strains isolated from nonatrophic gastritis, gastric cancer, and duodenal ulcer patients. The adhesion pattern and IL-8 induction were determined in AGS cells, and invasion of AGS cells was studied using a gentamicin protection assay. The IL-8 levels induced were determined by ELISA. Helicobacter pylori strains presented diffuse adherence (DA) and localized (LA) adherence patterns, similar to those described for enteropathogenic E. coli (EPEC), were observed in AGS cells. A DA pattern was observed in 57% and LA in 43% of the strains, and DA was more frequent in isolates from patients with gastric cancer (p = 0.044). Strains with a LA pattern induced higher levels of IL-8 (p = 0.042) in AGS cells. The adherence pattern was not associated with neither invasiveness nor with the presence of virulence genes. Our study shows that H. pylori strains present adherence patterns to AGS cells resembling those observed in EPEC and that these patterns may be associated with disease and with activity on AGS cells. © 2015 John Wiley & Sons Ltd.

  13. Identification of Markers for Helicobacter pylori Strains Isolated from Children with Peptic Ulcer Disease by Suppressive Subtractive Hybridization

    PubMed Central

    Oleastro, Mónica; Monteiro, Lurdes; Lehours, Philippe; Mégraud, Francis; Ménard, Armelle

    2006-01-01

    Peptic ulcer disease (PUD) occurs after a long-term Helicobacter pylori infection. However, the disease can develop earlier, and rare cases have been observed in children, suggesting that these H. pylori strains may be more virulent. We used suppressive subtractive hybridization for comparative genomics between H. pylori strains isolated from a 5-year-old child with duodenal ulcer and from a sex- and age-matched child with gastritis only. The prevalence of the 30 tester-specific subtracted sequences was determined on a collection of H. pylori strains from children (15 ulcers and 30 gastritis) and from adults (46 ulcers and 44 gastritis). Two of these sequences, jhp0562 (80.0% versus 33.3%, P = 0.008) and jhp0870 (80.0% versus 36.7%, P = 0.015), were highly associated with PUD in children and a third sequence, jhp0828, was less associated (40.0% versus 10.0%, P = 0.048). Among adult strains, none of the 30 sequences was associated with PUD. However, both jhp0562 and jhp0870 were less prevalent in adenocarcinoma strains than in PUD strains from children and adults, the difference being statistically significant for jhp0870. In conclusion, two H. pylori genes were identified as being strongly associated with PUD in children, and their putative roles as an outer membrane protein for jhp0870 and in lipopolysaccharide biosynthesis for jhp0562, suggest that they may be novel virulence factors of H. pylori. PMID:16790780

  14. Identification of markers for Helicobacter pylori strains isolated from children with peptic ulcer disease by suppressive subtractive hybridization.

    PubMed

    Oleastro, Mónica; Monteiro, Lurdes; Lehours, Philippe; Mégraud, Francis; Ménard, Armelle

    2006-07-01

    Peptic ulcer disease (PUD) occurs after a long-term Helicobacter pylori infection. However, the disease can develop earlier, and rare cases have been observed in children, suggesting that these H. pylori strains may be more virulent. We used suppressive subtractive hybridization for comparative genomics between H. pylori strains isolated from a 5-year-old child with duodenal ulcer and from a sex- and age-matched child with gastritis only. The prevalence of the 30 tester-specific subtracted sequences was determined on a collection of H. pylori strains from children (15 ulcers and 30 gastritis) and from adults (46 ulcers and 44 gastritis). Two of these sequences, jhp0562 (80.0% versus 33.3%, P = 0.008) and jhp0870 (80.0% versus 36.7%, P = 0.015), were highly associated with PUD in children and a third sequence, jhp0828, was less associated (40.0% versus 10.0%, P = 0.048). Among adult strains, none of the 30 sequences was associated with PUD. However, both jhp0562 and jhp0870 were less prevalent in adenocarcinoma strains than in PUD strains from children and adults, the difference being statistically significant for jhp0870. In conclusion, two H. pylori genes were identified as being strongly associated with PUD in children, and their putative roles as an outer membrane protein for jhp0870 and in lipopolysaccharide biosynthesis for jhp0562, suggest that they may be novel virulence factors of H. pylori.

  15. Virulence factors and antibiotic resistance of Helicobacter pylori isolated from raw milk and unpasteurized dairy products in Iran.

    PubMed

    Mousavi, Soolmaz; Dehkordi, Farhad Safarpoor; Rahimi, Ebrahim

    2014-01-01

    Despite the high importance of Helicobacter pylori, the origin and transmission of this bacterium has not been clearly determined. According to controversial theories and results of previous studies, animal source foods - especially milk - play an important role in the transmission of H. pylori to humans. The aim of the present study was to determine the distribution of vacA, cagA, iceA and oipA virulence factors in H. pylori strains isolated from milk and dairy products and study their antimicrobial resistance properties. A total of 520 raw milk and 400 traditional dairy product samples were cultured and tested. Those that were H. pylori-positive were analyzed for the presence of vacA, cagA, iceA and oipA virulence factors. Antimicrobial susceptibility testing was performed by the disk diffusion method. One hundred and three out of 520 milk samples (19.8%) and 77 out of 400 dairy products samples (19.2%) were contaminated with H. pylori. The most frequently contaminated samples were ovine milk (35%) and traditional cheese (30%). Total prevalence of vacA, cagA, iceA and oipA factors were 75%, 76.6%, 41.6% and 25%, respectively. H. pylori strains of milk and dairy products harbored high levels of resistance to ampicillin (84.4%), tetracycline (76.6%), erythromycin (70.5%) and metronidazole (70%). High presence of antibiotic-resistant strains of H. pylori suggest that milk and dairy samples may be the sources of bacteria that can cause severe infection. Our findings should raise awareness about antibiotic resistance in H. pylori strains in Iran.

  16. Helicobacter pylori vacA s1a and s1b alleles from clinical isolates from different regions of Chile show a distinct geographic distribution

    PubMed Central

    Díaz, MI; Valdivia, A; Martínez, P; Palacios, JL; Harris, P; Novales, J; Garrido, E; Valderrama, D; Shilling, C; Kirberg, A; Hebel, E; Fierro, J; Bravo, R; Siegel, F; Leon, G; Klapp, G; Venegas, A

    2005-01-01

    AIM: To establish the most common vacA alleles in Helicobacter pylori (H pylori) strains isolated from Chilean patients and its relationship with gastritis and gastroduodenal ulcers. METHODS: Two hundred and forty five H pylori clinical isolates were obtained from 79 biopsies from Chilean infected patients suffering from gastrointestinal diseases. An average of 2-3 strains per patient was isolated and the vacA genotype was analyzed by PCR and 3% agarose electrophoresis. Some genotypes were checked by DNA sequencing. RESULTS: The most prevalent vacA genotype in Chilean patients was s1b m1 (76%), followed by s1a m1 (21%). In contrast, the s2 m2 genotype was scarcely represented (3%). The s1b m1 genotype was found most frequently linked to gastropathies (P<0.05) rather than ulcers. Ulcers were found more commonly in male and older patients. Curiously, patients living in cities located North and far South of Santiago, the capital and largest Chilean city, carried almost exclusively strains with the s1b m1 genotype. In contrast, patients from Santiago and cities located South of Santiago carried strains with either one or both s1a m1 and s1b m1 genotypes. Regarding the s2 m2 genotype, comparison with GenBank sequences revealed that Chilean s2 sequence was identical to those of Australian, American, and Colombian strains but quite different from those of Alaska and India. CONCLUSION: Differences in geographic distribution of the s and m vacA alleles in Chile and a relationship of s1b m1 genotype with gastritis were found. Sequence data in part support a hispanic origin for the vacA genotype. Asymmetric distribution of genotypes s1b m1 and s2 m2 recedes H Pylori strain distribution in Spain and Portugal. PMID:16419167

  17. Susceptibility of clinical isolates of Campylobacter pylori to 24 antimicrobial and anti-ulcer agents.

    PubMed

    Glupczynski, Y; Delmee, M; Bruck, C; Labbe, M; Avesani, V; Burette, A

    1988-06-01

    Forty-nine isolates of Campylobacter pylori were tested for their susceptibility to twenty antibiotics and four anti-ulcer agents by an agar dilution technique. Penicillin and amoxycillin were the most active drugs (MIC90, 0.06 microgram/ml); erythromycin, cefazolin, minocycline, ciprofloxacin, ofloxacin and gentamicin were slightly less active (MIC90, less than or equal to 1 microgram/ml). Moderate activity was found for doxycyclin, rifampin, nitrofurantoin, norfloxacin, pefloxacin, enoxacin, paromomycin, metronidazole and tinidazole. All strains were resistant to trimethoprim (MIC greater than 512 micrograms/ml). Nalidixic acid (MIC90, greater than 256 micrograms/ml) and colistin (MIC90, greater than 64 micrograms/ml) had little to no activity. Of four anti-ulcer drugs, only bismuth subcitrate showed activity (MIC90, 64 micrograms/ml). Strains resistant to all 4-quinolones were found in patients who had previously received ofloxacin as part of a clinical trial aimed at eradication of C. pylori. These isolates remained susceptible to amoxycillin, tetracyclines and to other classes of antibiotics.

  18. Effect of biofilm formation by clinical isolates of Helicobacter pylori on the efflux-mediated resistance to commonly used antibiotics

    PubMed Central

    Attaran, Bahareh; Falsafi, Tahereh; Ghorbanmehr, Nassim

    2017-01-01

    AIM To evaluate the role of biofilm formation on the resistance of Helicobacter pylori (H. pylori) to commonly prescribed antibiotics, the expression rates of resistance genes in biofilm-forming and planktonic cells were compared. METHODS A collection of 33 H. pylori isolates from children and adult patients with chronic infection were taken for the present study. The isolates were screened for biofilm formation ability, as well as for polymerase chain reaction (PCR) reaction with HP1165 and hp1165 efflux pump genes. Susceptibilities of the selected strains to antibiotic and differences between susceptibilities of planktonic and biofilm-forming cell populations were determined. Quantitative real-time PCR (qPCR) analysis was performed using 16S rRNA gene as a H. pylori-specific primer, and two efflux pumps-specific primers, hp1165 and hefA. RESULTS The strains were resistant to amoxicillin, metronidazole, and erythromycin, except for one strain, but they were all susceptible to tetracycline. Minimum bactericidal concentrations of antibiotics in the biofilm-forming cells were significantly higher than those of planktonic cells. qPCR demonstrated that the expression of efflux pump genes was significantly higher in the biofilm-forming cells as compared to the planktonic ones. CONCLUSION The present work demonstrated an association between H. pylori biofilm formation and decreased susceptibility to all the antibiotics tested. This decreased susceptibility to antibiotics was associated with enhanced functional activity of two efflux pumps: hp1165 and hefA. PMID:28275296

  19. Antimicrobial Susceptibility and Mutations Involved in Clarithromycin Resistance in Helicobacter pylori Isolates from Patients in the Western Central Region of Colombia ▿

    PubMed Central

    Álvarez, Adalucy; Moncayo, José Ignacio; Santacruz, Jorge Javier; Santacoloma, Mario; Corredor, Luisa Fernanda; Reinosa, Elizabeth

    2009-01-01

    Resistance to metronidazole, clarithromycin, and amoxicillin (amoxicilline) was found in 82, 3.8, and 1.9% of 106 Helicobacter pylori isolates, respectively. No tetracycline-resistant isolates were found. In all of the clarithromycin-resistant isolates, only one point mutation was present, either A2143G or A2142G. Our results indicate that metronidazole should not be included in the empirical treatment of H. pylori infection in this region. PMID:19546360

  20. Chickpea protein isolates obtained by wet extraction as emulsifying agents.

    PubMed

    Papalamprou, Evdoxia M; Doxastakis, Georgios I; Kiosseoglou, Vassilios

    2010-01-30

    Wet extraction of protein from defatted chickpea (variety Thiva (T), Greece) flour, at alkaline or slightly acidic pH, followed by isoelectric precipitation (pI) or ultrafiltration (UF) to recover the protein, was employed to obtain a number of chickpea protein isolates, enriched either in protein constituents belonging to the globulin (TpI, TUF, TUFG) or to the albumin fraction (TUFA). The interfacial activity and film-forming ability of the isolate protein constituents as well as their emulsifying properties were evaluated. The method applied for chickpea protein isolate preparation influenced to an appreciable extent their composition, adsorption behaviour to oil-water interfaces and emulsion formation and stabilization characteristics, especially with respect to oil droplet flocculation and coalescence. The isolates also differed in their ability to stabilize emulsions subjected to thermal processing or following storage under freezing conditions. The results are discussed in terms of compositional and, possibly, structural differences existing between the protein constituents of the chickpea isolates that may influence their functional behaviour in emulsion systems. The method applied for isolate preparation influenced to an appreciable extent the ability of proteins to adsorb to the oil-water interface and stabilize emulsions during long-time ageing or following heat treatment or freezing. (c) 2009 Society of Chemical Industry.

  1. Isolation and characterization of a family of porin proteins from Helicobacter pylori.

    PubMed Central

    Exner, M M; Doig, P; Trust, T J; Hancock, R E

    1995-01-01

    Two-dimensional gel electrophoresis was used to identify heat-modifiable outer membrane proteins, which were candidates for porins, from Helicobacter pylori membrane preparations. Four such proteins with apparent molecular masses of 48, 49, 50, and 67 kDa were isolated. The four proteins copurified together after selective detergent solubilizations followed by anion-exchange chromatography, and each protein was ultimately purified to homogeneity by gel purification. These proteins were then tested for pore-forming ability with a planar lipid bilayer model membrane system. All four proteins appeared to be present as monomers, and they formed pores with low single-channel conductances in 1.0 M KCl of 0.36, 0.36, 0.30, and 0.25 nS, respectively, for the 48-, 49-, 50-, and 67-kDa proteins which we propose to designate HopA, HopB, HopC, and HopD. N-terminal amino acid sequence analyses showed a high degree of homology among all four proteins, and it appears that these proteins constitute a family of related porins in H. pylori. PMID:7534278

  2. Determination of Helicobacter pylori virulence by analysis of the cag pathogenicity island isolated from Iranian population

    PubMed Central

    Baghaei, Kaveh; Shokrzadeh, Leila; Jafari, Fereshteh; Dabiri, Hossein; Yamaoka, Yoshio; Bolfion, Mehdi; Zojaji, Homayon; Aslani, Mehdi; Zali, Mohammad Reza

    2009-01-01

    Background The cag pathogenicity island (PAI), which can divide into two parts: cagI and cagII, is the most well-known virulence factor of Helicobacter pylori. Aims We investigated the association between genetic variations within the cag PAI (cagA and cagE in the cagI and cagT in the cagII) and clinical outcomes in Iranian population. Subjects A total of 231 patients including 182 patients with gastritis, 41 with peptic ulcer and 8 with gastric cancer. Methods The presences of the cagA, cagE and cagT genes were measured by polymerase chain reaction and the results were compared with clinical outcomes and gastric histology. Results The cagA, cagE and cagT genes were found in 154 (66.7%), 90 (39.0%) and 70 (30.3%) of clinical isolates. At least 144 (62.3%) strains possessed partially deleted cag PAI (e.g., 69 [29.9%] strains were cagA-positive, but cagE and cagT-negative). Conclusion The simple gene as well as the combination of the genes in the cag PAI appeared not to be useful markers to predict H. pylori-related diseases in Iranian population. The genomic sequences of the cag PAI in Iranian strains might be considerably different from those in other geographic locations. PMID:19261552

  3. Analysis of clinical isolates of Helicobacter pylori in Pakistan reveals high degrees of pathogenicity and high frequencies of antibiotic resistance.

    PubMed

    Rasheed, Faisal; Campbell, Barry James; Alfizah, Hanafiah; Varro, Andrea; Zahra, Rabaab; Yamaoka, Yoshio; Pritchard, David Mark

    2014-10-01

    Antibiotic resistance in Helicobacter pylori contributes to failure in eradicating the infection and is most often due to point and missense mutations in a few key genes. The antibiotic susceptibility profiles of H. pylori isolates from 46 Pakistani patients were determined by Etest. Resistance and pathogenicity genes were amplified, and sequences were analyzed to determine the presence of mutations. A high percentage of isolates (73.9%) were resistant to metronidazole (MTZ), with considerable resistance to clarithromycin (CLR; 47.8%) and amoxicillin (AML; 54.3%) also observed. Relatively few isolates were resistant to tetracycline (TET; 4.3%) or to ciprofloxacin (CIP; 13%). However, most isolates (n = 43) exhibited resistance to one or more antibiotics. MTZ-resistant isolates contained missense mutations in oxygen-independent NADPH nitroreductase (RdxA; 8 mutations found) and NADH flavin oxidoreductase (FrxA; 4 mutations found). In the 23S rRNA gene, responsible for CLR resistance, a new point mutation (A2181G) and 4 previously reported mutations were identified. Pathogenicity genes cagA, dupA, and vacA s1a/m1 were detected frequently in isolates which were also found to be resistant to MTZ, CLR, and AML. A high percentage of CagA and VacA seropositivity was also observed in these patients. Phylogenetic analysis of partial sequences showed uniform distribution of the 3' region of cagA throughout the tree. We have identified H. pylori isolates in Pakistan which harbor pathogenicity genes and worrying antibiotic resistance profiles as a result of having acquired multiple point and missense mutations. H. pylori eradication regimens should therefore be reevaluated in this setting. © 2014 John Wiley & Sons Ltd.

  4. Analysis of Clinical Isolates of Helicobacter pylori in Pakistan Reveals High Degrees of Pathogenicity and High Frequencies of Antibiotic Resistance

    PubMed Central

    Rasheed, Faisal; Campbell, Barry James; Alfizah, Hanafiah; Varro, Andrea; Zahra, Rabaab; Yamaoka, Yoshio; Pritchard, David Mark

    2014-01-01

    Background Antibiotic resistance in Helicobacter pylori contributes to failure in eradicating the infection and is most often due to point and missense mutations in a few key genes. Methods The antibiotic susceptibility profiles of H. pylori isolates from 46 Pakistani patients were determined by Etest. Resistance and pathogenicity genes were amplified, and sequences were analyzed to determine the presence of mutations. Results A high percentage of isolates (73.9%) were resistant to metronidazole (MTZ), with considerable resistance to clarithromycin (CLR; 47.8%) and amoxicillin (AML; 54.3%) also observed. Relatively few isolates were resistant to tetracycline (TET; 4.3%) or to ciprofloxacin (CIP; 13%). However, most isolates (n = 43) exhibited resistance to one or more antibiotics. MTZ-resistant isolates contained missense mutations in oxygen-independent NADPH nitroreductase (RdxA; 8 mutations found) and NADH flavin oxidoreductase (FrxA; 4 mutations found). In the 23S rRNA gene, responsible for CLR resistance, a new point mutation (A2181G) and 4 previously reported mutations were identified. Pathogenicity genes cagA, dupA, and vacA s1a/m1 were detected frequently in isolates which were also found to be resistant to MTZ, CLR, and AML. A high percentage of CagA and VacA seropositivity was also observed in these patients. Phylogenetic analysis of partial sequences showed uniform distribution of the 3′ region of cagA throughout the tree. Conclusions We have identified H. pylori isolates in Pakistan which harbor pathogenicity genes and worrying antibiotic resistance profiles as a result of having acquired multiple point and missense mutations. H. pylori eradication regimens should therefore be reevaluated in this setting. PMID:24827414

  5. [Susceptibility of 36 Helicobacter pylori clinical isolates to four first-line antibiotics and virulence factors].

    PubMed

    Díaz-Reganon, J; Alarcón, T; Domingo, D; López-Brea, M

    2006-03-01

    Helicobacter pylori possess various virulence factors, including cagA and vacA genes, that are associated with more aggressive symptoms such as bleed-ing ulcer and gastric cancer. Although there are different treatment regimens, there is still a failure rate of up to 20% due to antibiotic resistance, among other causes. In our country resistance to metronidazole and clarithromycin is increasing, especially in children, although they are still susceptible to amoxicillin and tetracycline. In order to determine the susceptibility pattern to these antibiotics 36 H. pylori clinical isolates were studied. MIC was determined by agar diffusion and agar dilution, and vacA and cagA genes were detected by conventional PCR. All isolates were susceptible to amoxicillin and tetracycline. Resistance to metronidazole by diffusion or dilution tests was 35.7% and 36.1%, respectively, and to clarithromycin, 21.4% and 22.3%, respectively. There was one strain that showed intermediate resistance to clarithromycin (MIC 0.38 mg/l), using agar diffusion, and that was included among the resistant strains. Three discrepancies were observed between the diffusion and dilution methods. The vacA s1 allele was detected in 17.2% of the strains, and vacA s2 in 82.8%; 51.7% of the total were cagA+. In conclusion, all strains tested in our study were susceptible to amoxicillin and tetracycline, allowing them to be considered as first-line antibiotics, while clarithromycin and metronidazole maintain a slight increase in their resistance level. The cagA+ strains were detected in expected quantities, while the s1 allele of the vacA gene was detected in lower quantities.

  6. Draft Genome Sequence of a Helicobacter pylori Strain Isolated from a Patient with Diffuse Gastritis from a Region of High Cancer Risk in Colombia

    PubMed Central

    Bayona Rojas, Martin; Barragán Vidal, Carlos; Trujillo, Clara Esperanza; Bravo, María Mercedes

    2015-01-01

    The draft genome sequence of one Colombian Helicobacter pylori strain is presented. This strain was isolated from a patient with diffuse gastritis from Tibaná, Boyacá, a region with high gastric cancer risk. PMID:25858838

  7. The Bioinformatics Report of Mutation Outcome on NADPH Flavin Oxidoreductase Protein Sequence in Clinical Isolates of H. pylori.

    PubMed

    Mirzaei, Nasrin; Poursina, Farkhondeh; Moghim, Sharareh; Ghaempanah, Abdol Majid; Safaei, Hajieh Ghasemian

    2016-05-01

    frxA gene has been implicated in the metronidazole nitro reduction by H. pylori. Alternatively, frxA is expected to contribute to the protection of urease and to the in vivo survival of H. pylori. The aim of present study is to report the mutation effects on the frxA protein sequence in clinical isolates of H. pylori in our community. Metronidazole resistance was proven in 27 of 48 isolates. glmM and frxA genes were used for molecular confirmation of H. pylori isolates. The primer set for detection of whole sequence of frxA gene for the effect of mutation on protein sequence was used. DNA and protein sequence evaluation and analysis were done by blast, Clustal Omega, and T COFFEE programs. Then, FrxA protein sequences from six metronidazole-resistant clinical isolates were analyzed by web-based bioinformatics tools. The result of six metronidazole-resistant clinical isolates in comparison with strain 26695 showed ten missense mutations. The result with the STRING program revealed that no change was seen after alterations in these sequences. According to consensus data involving four methods, residue substitutions at 40, 13, and 141 increase the stability of protein sequence after mutation, while other alterations decrease. Residue substitutions at 40, 43, 141, 138, 169, and 179 are deleterious, while, V7I, Q10R, V34I, and V96I alterations are neutral. As FrxA contribute to survival of bacterium and in regard to the effect of mutations on protein function, it might affect the survival and bacterium phenotype and it need to be studied more. Also, none of the stability prediction tool is perfect; iStable is the best predictor method among all methods.

  8. Prevalence of vacA, cagA and babA2 genes in Cuban Helicobacter pylori isolates

    PubMed Central

    Torres, Lino E; Melián, Karelia; Moreno, Arlenis; Alonso, Jordis; Sabatier, Carlos A; Hernández, Mayrín; Bermúdez, Ludisleydis; Rodríguez, Boris L

    2009-01-01

    AIM: To investigate the prevalence of vacuolating cytotoxin (vacA), cytotoxin associated gene A (cagA) and blood adhesion binding antigen (babA2) genotypes of Helicobacter pylori (H pylori) isolates from Cuban dyspeptic patients. METHODS: DNA was extracted from H pylori-positive cultures taken from 130 dyspeptic patients. Genotyping was performed by PCR, using specific primers for vacA (s1, s2, m1, m2), cagA and babA2 genes. Endoscopic observations and histological examinations were used to determine patient pathologies. RESULTS: vacA alleles s1, s2, m1 and m2 were detected in 96 (73.8%), 34 (26.2%), 75 (57.7%) and 52 isolates (40%), respectively, while the cagA gene was detected in 95 isolates (73.2%). One hundred and seven isolates (82.3%) were babA2-positive. A significant correlation was observed between vacAs1m1 and cagA and between vacAs1m1 and babA2 genotypes (P < 0.001 and P < 0.05, respectively) and between babA2 genotype and cagA status (P < 0.05); but, no correlation was observed between vacAs1 and babA2 genotypes. Eighty five (65.4%) and 73 (56.2%) strains were type 1 (vacAs1-cagA-positive) and “triple-positive” (vacAs1-cagA-babA2-positive), respectively, and their presence was significantly associated with duodenal ulcer (P < 0.01 and P < 0.001, respectively). CONCLUSION: The distribution of the main virulence factors in the Cuban strains in this study resembled that of the Western-type strains, and the more virulent H pylori isolates were significantly associated with duodenal ulcer, ulcer disease being the worst pathology observed in the group studied. PMID:19132771

  9. Ulcerogenic Helicobacter pylori Strains Isolated from Children: A Contribution to Get Insight into the Virulence of the Bacteria

    PubMed Central

    Vitoriano, Inês; Saraiva-Pava, Kathy D.; Rocha-Gonçalves, Alexandra; Santos, Andrea; Lopes, Ana I.; Oleastro, Mónica; Roxo-Rosa, Mónica

    2011-01-01

    Infection with Helicobacter pylori is the major cause for the development of peptic ulcer disease (PUD). In children, with no other etiology for the disease, this rare event occurs shortly after infection. In these young patients, habits of smoking, diet, consumption of alcohol and non-steroid anti-inflammatory drugs and stress, in addition to the genetic susceptibility of the patient, represent a minor influence. Accordingly, the virulence of the implicated H. pylori strain should play a crucial role in the development of PUD. Corroborating this, our in vitro infection assays comparing a pool of five H. pylori strains isolated from children with PUD to a pool of five other pediatric clinical isolates associated with non-ulcer dyspepsia (NUD) showed the greater ability of PUD strains to induce a marked decrease in the viability of gastric cells and to cause severe damage in the cells cytoskeleton as well as an impairment in the production/secretion of mucins. To uncover virulence features, we compared the proteome of these two groups of H. pylori strains. Two-dimensional gel electrophoresis followed by mass-spectrometry allowed us to detect 27 differentially expressed proteins between them. In addition to the presence of genes encoding well established virulence factors, namely cagA, vacAs1, oipA “on” status, homB and jhp562 genes, the pediatric ulcerogenic strains shared a proteome profile characterized by changes in the abundance of: motility-associated proteins, accounting for higher motility; antioxidant proteins, which may confer increased resistance to inflammation; and enzymes involved in key steps in the metabolism of glucose, amino acids and urea, which may be advantageous to face fluctuations of nutrients. In conclusion, the enhanced virulence of the pediatric ulcerogenic H. pylori strains may result from a synergy between their natural ability to better adapt to the hostile human stomach and the expression of the established virulence factors. PMID

  10. Differences among Helicobacter pylori strains isolated from three different populations and demonstrated by restriction enzyme analysis of an internal fragment of the conserved gene hpaA.

    PubMed

    Evans, D G; Queiroz, D M; Mendes, E N; Svennerholm, A M; Evans, D J

    1999-06-01

    Our goal was to test the idea that Helicobacter pylori genotypes vary from one population to another. Analysis of Sau3A and HinfI restriction fragment-length polymorphism (RFLP) in a 375-bp polymerase chain reaction amplicon of hpaA was used to compare 31 H. pylori isolates from a relatively small and genetically homogeneous population (Goteborg, Sweden) with those of large, genetically heterogeneous populations located in two different countries (50 isolates from Houston, TX, and 69 isolates from Minas Gerais, a state in the southeastern region of Brazil). Five different Sau3A and three different HinfI restriction patterns were found; different combinations of these comprise 10 different RFLP types, I through X. The RFLP types found in the United States and Brazil collections were very similar, except for two Brazil isolates belonging to type VIII and five Brazil isolates belonging to type X, neither type found in the United States. The overall profile of H. pylori isolates from Sweden was remarkably different, with 18 of 31 (58%) having a new Sau3A restriction pattern, termed gS; 10 of these 18 isolates had HinfI restriction pattern E (RFLP type VIII), and 8 had HinfI restriction pattern F (RFLP type IX). No isolates from Sweden belonged to RFLP type III or type X. RFLP typing of a 375-bp polymerase chain reaction-amplified DNA fragment of H. pylori hpaA revealed that H. pylori genotypes can and do vary from one population to another. We conclude that the unique RFLP profile shown by the group of H. pylori isolates from Goteborg is the result of a cohort effect in this relatively small, stable, genetically homogeneous population. Also, the overall similarity between RFLP profiles of the H. pylori isolates from Texas and Minas Gerais coincides with the fact that although geographically distanced, these populations are similar in being large, dynamic, and genetically heterogeneous.

  11. In vitro effect of bergamot (Citrus bergamia) juice against cagA-positive and-negative clinical isolates of Helicobacter pylori.

    PubMed

    Filocamo, Angela; Bisignano, Carlo; Ferlazzo, Nadia; Cirmi, Santa; Mandalari, Giuseppina; Navarra, Michele

    2015-07-30

    Helicobacter pylori infection has been associated with chronic gastritis, peptic ulcer and gastric carcinoma as over half of the world's population is colonized with this gram-negative bacterium. Due to the increasing antibiotic resistance, its eradication rates fails in a great portion of patients. A number of studies showed that molecules largely distributed in commonly consumed fruits and vegetables may have antimicrobial activity. The aim of the present study was to investigate the effect of bergamot juice (BJ) against Helicobacter pylori in vitro. The potential therapeutic combination between BJ and the antibiotics amoxicillin (AMX), clarithromycin (CLA) and metronidazole (MTZ) has also been evaluated. The minimum inhibitory concentration (MIC) of BJ, AMX, CLA and MTZ against 2 ATCC and 32 clinical isolates of H. pylori was assayed according to CLSI. The checkerboard method was used to determine the efficacy of the association BJ with the three reference antibiotics. Killing curves were performed on the two cagA-positive ATCC strains of H. pylori (ATCC 43504 and ATCC 49503), on the clinical isolate cagA-positive HP6 strain of H. pylori and on the clinical isolate cagA-negative HP61 strain of H. pylori. BJ (2.5%, v/v) inhibited the growth of 50% of the H. pylori clinical isolates, whereas 5% (v/v) inhibited 90%. AMX was the most effective antibiotic against the reference strains and the clinical isolates, followed by CLA and MTZ. In the combination assays, synergism was observed between BJ and AMX and between BJ and MTZ against both the reference strains and the clinical isolates. Indifference was observed between BJ and CLA. BJ was effective in vitro against H. pylori and the genotype status of the clinical strains may have an impact on its susceptibility. The synergistic combination of BJ and antibiotics could be used to prevent or treat resistance.

  12. Evaluation of Clarithromycin Resistance Among Iranian Helicobacter pylori Isolates by E-Test and Real-Time Polymerase Chain Reaction Methods.

    PubMed

    Hakemi Vala, Mojdeh; Eyvazi, Shirin; Goudarzi, Hossein; Sarie, Hamid Reza; Gholami, Mehrdad

    2016-05-01

    Helicobacter pylori is an important pathogen of human gastric mucosa. Antibiotic resistance, especially resistance to clarithromycin is a major factor for treatment failure of H. pylori infections. The main mechanism of clarithromycin resistance in these bacteria is related to point mutations in three different locations of 23S rRNA gene. The aims of this study were to evaluate the resistance rate to clarithromycin among local H. pylori isolates by the E-test method and to determine the profile of point mutation in 23S rRNA by real-time polymerase chain reaction (PCR) method. Eighty biopsy samples were collected from dyspeptic patients by endoscopy during 2011 - 2012. All samples were homogenized immediately and cultured on supplemented brucella blood agar and incubated under microaerophilic conditions. Further biochemical tests and ureC gene PCR was done for H. pylori confirmation. The H. pylori OC1096 strain was used as the control strain, simultaneously. Frequency of clarithromycin resistance was determined by the E-test method based on the clinical and laboratory standard institute (CLSI) standards. Point mutation profile was determined by real-time PCR and further analysis of melting curve, amplicon sequencing was done continuously. From 80 biopsy samples, 20 positive H. pylori isolates were detected and confirmed by biochemical tests and PCR method. Overall, 21.7% of the H. pylori isolates, showed clarithromycin resistance phenotype by use of the E-test. Also, the minimal inhibitory concentration of clarithromycin was determined as ≥ 0.5 mg/L by the E-test method. Only point mutation in the location of A2143G with melting temperature of 54.7°C was observed in all resistant isolates. This study showed that the frequency of H. pylori clarithromycin resistance in Iran is relatively high. Since clarithromycin is not commonly used in Iran for H. pylori eradication, the high rate of resistance could be related to cross-reactivity between other macrolides

  13. Evaluation of Clarithromycin Resistance Among Iranian Helicobacter pylori Isolates by E-Test and Real-Time Polymerase Chain Reaction Methods

    PubMed Central

    Hakemi Vala, Mojdeh; Eyvazi, Shirin; Goudarzi, Hossein; Sarie, Hamid Reza; Gholami, Mehrdad

    2016-01-01

    Background Helicobacter pylori is an important pathogen of human gastric mucosa. Antibiotic resistance, especially resistance to clarithromycin is a major factor for treatment failure of H. pylori infections. The main mechanism of clarithromycin resistance in these bacteria is related to point mutations in three different locations of 23S rRNA gene. Objectives The aims of this study were to evaluate the resistance rate to clarithromycin among local H. pylori isolates by the E-test method and to determine the profile of point mutation in 23S rRNA by real-time polymerase chain reaction (PCR) method. Patients and Methods Eighty biopsy samples were collected from dyspeptic patients by endoscopy during 2011 - 2012. All samples were homogenized immediately and cultured on supplemented brucella blood agar and incubated under microaerophilic conditions. Further biochemical tests and ureC gene PCR was done for H. pylori confirmation. The H. pylori OC1096 strain was used as the control strain, simultaneously. Frequency of clarithromycin resistance was determined by the E-test method based on the clinical and laboratory standard institute (CLSI) standards. Point mutation profile was determined by real-time PCR and further analysis of melting curve, amplicon sequencing was done continuously. Results From 80 biopsy samples, 20 positive H. pylori isolates were detected and confirmed by biochemical tests and PCR method. Overall, 21.7% of the H. pylori isolates, showed clarithromycin resistance phenotype by use of the E-test. Also, the minimal inhibitory concentration of clarithromycin was determined as ≥ 0.5 mg/L by the E-test method. Only point mutation in the location of A2143G with melting temperature of 54.7°C was observed in all resistant isolates. Conclusions This study showed that the frequency of H. pylori clarithromycin resistance in Iran is relatively high. Since clarithromycin is not commonly used in Iran for H. pylori eradication, the high rate of resistance could

  14. Prospective multi-region study on primary antibiotic resistance of Helicobacter pylori strains isolated from Chinese patients.

    PubMed

    Song, Zhiqiang; Zhang, Jianzhong; He, Lihua; Chen, Minhu; Hou, Xiaohua; Li, Zhaoshen; Zhou, Liya

    2014-12-01

    Large-scale multi-region studies are urgently needed to provide comprehensive and up-to-date information on the antibiotic resistance of Helicobacter pylori that is critical for selecting the most optimal eradication regimens. To determine the resistance patterns of Helicobacter pylori strains isolated from dyspeptic patients. This is a prospective, multicentre, cross-sectional, observational study. Helicobacter pylori cultures were successful in 600 patients (never receiving eradication therapy) from Northern, Eastern, Middle, and Southern regions between 2008 and 2012. Resistance to amoxicillin, clarithromycin, metronidazole, levofloxacin, tetracycline, and rifampicin was determined by Epsilometer test. The overall resistance rate was highest for metronidazole (403, 67.2%), followed by clarithromycin (225, 37.5%), levofloxacin (201, 33.5%), rifampicin (85, 14.2%), amoxicillin (41, 6.8%), and tetracycline (21, 3.5%). There were 16.3% isolates susceptible to all tested antibiotics, followed by mono-resistance (34.2%), double resistance (27.0%), triple resistance (16.8%), quadruple resistance (4.7%), quintuple resistance (0.7%) and sextuple resistance (0.3%). Independent factors influencing antibiotic resistance were gender (to levofloxacin), age (to levofloxacin), and endoscopic finding (to clarithromycin, metronidazole, and levofloxacin). Among the clarithromycin-resistant isolates, 75.6% and 48.0% were also resistant to metronidazole and levofloxacin, respectively. Helicobacter pylori resistance to commonly used antibiotics in China is a very serious issue, due to the high resistance rate and general multiple resistance. Copyright © 2014 Editrice Gastroenterologica Italiana S.r.l. Published by Elsevier Ltd. All rights reserved.

  15. Secondary antibiotic resistance of Helicobacter pylori isolates in Israeli children and adults.

    PubMed

    Khoury, Johad; Geffen, Yuval; Shaul, Ron; Sholy, Hisham; Chowers, Yehuda; Saadi, Tarek

    2017-09-01

    Failure of standard therapy for Helicobacter pylori infections results primarily from increasing antibiotic resistance. Patients in Israel are referred for H. pylori culture after failure of at least two therapeutic regimens. To estimate the prevalence of secondary antimicrobial resistance of H. pylori in Israel. We retrospectively collected results of H. pylori cultures performed by gastric biopsies at Rambam Health Care Campus, Haifa, Israel, between the years 2012-2015. Antimicrobial susceptibility to five drugs was tested by gradient-diffusion. 107 patients, 46 adults and 61 children, were referred for performance of H. pylori cultures. Cultures were positive in 64 samples (63.7%). In adults, 23 (50%) patients had positive H. pylori cultures; 8.69% showed resistance to amoxicillin (AM), 39.1% to clarithromycin (CH), 61.9% to metronidazole (MZ), 8.69% to tetracycline (TC), and 21.7% to levofloxacin (LEV). In children, 41 (67%) patients had positive H. pylori cultures; 5.1% showed resistance to AM, 42.5% to CH, 46.66% to MZ, 2.5% to TC and 0% to LEV. In children, 94.9% of H. pylori strains were susceptible to both AM and LEV. In adults, 82.6% of the strains were susceptible to both AM and TC. 28.6% of adults and 24.1% children were resistant to both MZ and CH. The sensitivity of H. pylori culture was low. Resistance of H. pylori to MZ and CH was very high after failure of two therapeutic regimens in both adults and children. No LEV resistance was detected in children. AM resistance was higher in adults than in children. Copyright © 2017. Published by Elsevier Ltd.

  16. Identification of a Latin American-specific BabA adhesin variant through whole genome sequencing of Helicobacter pylori patient isolates from Nicaragua

    SciTech Connect

    Thorell, Kaisa; Hosseini, Shaghayegh; Palacios Gonzales, Reyna Victoria Palacios; Chaotham, Chatchai; Graham, David Y.; Paszat, Lawrence; Rabeneck, Linda; Lundin, Samuel B.; Nookaew, Intawat; Sjoling, Asa

    2016-02-29

    In this study, Helicobacter pylori (H. pylori) is one of the most common bacterial infections in humans and this infection can lead to gastric ulcers and gastric cancer. H. pylori is one of the most genetically variable human pathogens and the ability of the bacterium to bind to the host epithelium as well as the presence of different virulence factors and genetic variants within these genes have been associated with disease severity. Nicaragua has particularly high gastric cancer incidence and we therefore studied Nicaraguan clinical H. pylori isolates for factors that could contribute to cancer risk. The complete genomes of fifty-two Nicaraguan H. pylorii isolates were sequenced and assembled de novo, and phylogenetic and virulence factor analyses were performed. The Nicaraguan isolates showed phylogenetic relationship with West African isolates in whole-genome sequence comparisons and with Western and urban South-and Central American isolates using MLSA (Multi-locus sequence analysis). A majority, 77 % of the isolates carried the cancer-associated virulence gene cagA and also the s1/i1/m1 vacuolating cytotoxin, vacA allele combination, which is linked to increased severity of disease. Specifically, we also found that Nicaraguan isolates have a blood group-binding adhesin (BabA) variant highly similar to previously reported BabA sequences from Latin America, including from isolates belonging to other phylogenetic groups. These BabA sequences were found to be under positive selection at several amino acid positions that differed from the global collection of isolates. In conclusion, the discovery of a Latin American BabA variant, independent of overall phylogenetic background, suggests hitherto unknown host or environmental factors within the Latin American population giving H. pylori isolates carrying this adhesin variant a selective advantage, which could affect pathogenesis and risk for sequelae through specific adherence

  17. [Molecular characterization of Echinococcus granulosus isolates obtained from different hosts].

    PubMed

    Erdoğan, Emrah; Özkan, Bora; Mutlu, Fatih; Karaca, Serkan; Şahin, İzzet

    2017-01-01

    Echinococcus granulosus is a parasite that can be seen throughout the world. So far, five species of genus Echinococcus have been identified as parasite in people: E.granulosus, E.multilocularis, E.vogeli, E.oligarthrus, E.shiquicus. Larval (metacestod) form of parasite settles in internal organs of hoofed animals (cattle, goats, pigs, horses, sheep, etc.) and human; the adult form is found in small intestine of final host, canine. Disease caused by parasite called as "Cystic echinococcosis" (CE) is an important health problem and causes economic losses in many countries including our country that livestock is common. Infective eggs cause infections in intermediate hosts by taking oral way and rarely inhalation. Received egg opens in the stomach and intestines of intermediate host and oncosphere is released. Oncosphere quickly reaches the lamina propria of the villus epithelium by its histolytic enzymes and hooks. It usually transported from here to the liver and lungs, less frequently, muscle, brain, spleen, kidney and to other organs through the veins. By molecular studies, five species have been validated taxonomically and 10 different variants or strains of E.granulosus have been identified. Host and developmental differences between strains may negatively affect control studies and fight against the parasite. This study aimed to determinate E.granulosus strains obtained from cyst material of different intermediate hosts from different regions of Turkey by molecular methods. In the study, 25 human, 8 cattle, 6 sheep and 2 goat cysts material has been collected. Total genomic DNA was isolated from protoscoleces in cyst fluid and analyzed by PCR with COX-1 (L) and COX-1 (S) genes specific primers. DNA sequence analysis for each PCR product has been made. DNA sequence analysis results evaluated phylogenetically by MEGA analyze and BLAST software. As a result of this study, all isolates were identified as E.granulosus sensu stricto (G1) by DNA sequence analysis. CE

  18. Tyrosine Phosphorylation of CagA from Chinese Helicobacter pylori Isolates in AGS Gastric Epithelial Cells

    PubMed Central

    Zhang, Youli; Argent, Richard H.; Letley, Darren P.; Thomas, Rachael J.; Atherton, John C.

    2005-01-01

    Helicobacter pylori strains possessing the cag pathogenicity island (PaI) are associated with the development of gastroduodenal diseases, including gastric cancer. cag PaI products induce the secretion of interleukin-8 (IL-8) from epithelial cells and facilitate the translocation of CagA into the cell cytosol. In East Asia, where the incidence of gastric cancer is high, most strains possess the cag PaI. To date, however, no cag PaI phenotypic data have been provided for strains isolated in mainland China. Here we used 31 Chinese strains to determine the genotypic and phenotypic status of the cag PaI. All strains possessed cagA and cagE, and we observed a variation in the length of cagA variable regions. Nucleotide sequencing of the cagA variable region revealed that CagA was of two types, a short “Western” form with two tyrosine phosphorylation sites and a longer “East Asian” form with three tyrosine phosphorylation sites. Coculture of strains with AGS epithelial cells showed that strains could induce IL-8 secretion from the cells and that CagA with three phosphorylation sites became more phosphorylated than that with two and could induce significantly (P < 0.001) more cells to elongate. We hypothesize that the preponderance of the more active East Asian form of cagA may underlie the high rate of gastric cancer in China. PMID:15695680

  19. Bactericidal activity of Pistacia lentiscus mastic gum against Helicobacter pylori.

    PubMed

    Marone, P; Bono, L; Leone, E; Bona, S; Carretto, E; Perversi, L

    2001-12-01

    In this study we evaluated the antibacterial activity of mastic gum, a resin obtained from the Pistacia lentiscus tree, against clinical isolates of Helicobacter pylori. The minimal bactericidal concentrations (MBCs) were obtained by a microdilution assay. Mastic gum killed 50% of the strains tested at a concentration of 125 microg/ml and 90% at a concentration of 500 microg/ml. The influence of sub-MBCs of mastic gum on the morphologies of H. pylori was evaluated by transmission electron microscopy. The lentiscus resin induced blebbing, morphological abnormalities and cellular fragmentation in H. pylori cells.

  20. Genetic Manipulation of a Naturally Competent Bacterium, Helicobacter pylori

    PubMed Central

    Noto, Jennifer M.; Peek, Richard M.

    2013-01-01

    Genetic manipulation of Helicobacter pylori facilitates characterization and functional analysis of individual H. pylori genes. This chapter discusses the methods involved in H. pylori chromosomal DNA isolation, mutagenesis of individual genes, and natural transformation. PMID:23015491

  1. High Frequency of vacA s1m2 Genotypes Among Helicobacter pylori Isolates From Patients With Gastroduodenal Disorders in Kermanshah, Iran

    PubMed Central

    Pajavand, Hamid; Alvandi, Amirhooshang; Mohajeri, Parviz; Bakhtyari, Somaye; Bashiri, Homayoon; Kalali, Behnam; Gerhard, Markus; Najafi, Farid; Abiri, Ramin

    2015-01-01

    Background: Helicobacter pylori infection and related diseases outcome are mediated by a complex interplay between bacterial, host and environmental factors. Several distinct virulence factors of H. pylori have been shown to be associated with different clinical outcomes. Here we focused on vacA and cagA genotypes of H. pylori strains isolated from patients with gastric disorder. Objectives: The aim of this study was to determine the frequency of two toxins and genotypes of VacA toxin in patients referred to a central hospital in the west of Iran (Imam Reza hospital, Kermanshah) during 2011 - 2012. Patients and Methods: Samples were collected from patients infected with H. pylori. Gastric biopsy specimens from the stomach antrum and corpus were cultured. PCR analysis was performed for genotyping H. pylori vacA and cagA genes. Results: Helicobacter pylori was isolated from 48% (96/200) of patients with gastroduodenal disorders. In 81/96 (84%) cases, the cagA gene was present. Among different genotypes of vacA, two s1m2 and s2m2 genotypes were dominant with frequency of 39.5% and 50%, respectively. The frequency of the s1m1 genotype was 7.2% (7/96), which is much lower than elsewhere. H. pylori isolates with positive results for cagA gene and vacA s1m2 genotypes showed statistically significant correlation with peptic ulcer (s1m2 13/34 [38.2%] P = 0.003). However, isolates of H. pylori infection with cagA gene and vacA s2m2 genotypes were significantly associated with development of gastritis (s2m2 41/42 [97.6%] P = 0.000). Conclusions: About 90% of H. pylori strains potentially contained vacA s2m2 and s1m2 genotypes. Infection with H. pylori strain containing the cagA gene or the vacA s1m1 and s1m2 genotypes was associated with increased incidence of peptic ulcer disease (PUD). PMID:26862378

  2. Antimicrobial susceptibility of 6 antimicrobial agents in Helicobacter pylori clinical isolates by using EUCAST breakpoints compared with previously used breakpoints.

    PubMed

    Alarcón, Teresa; Urruzuno, Pedro; Martínez, Maria Josefa; Domingo, Diego; Llorca, Laura; Correa, Ana; López-Brea, Manuel

    2017-05-01

    The aim of this study was to determine the differences in percentage resistance in H. pylori clinical isolates using EUCAST breakpoints compared with previously used breakpoints. MIC value distribution in H. pylori clinical isolates was also studied. Susceptibility to amoxicillin, tetracycline, metronidazole, clarithromycin, rifampicin and levofloxacin was performed by E-test in 824 H. pylori clinical isolates. EUCAST and previous breakpoints defined resistance as follows: MIC >0.12mg/L and ≥2mg/L for amoxicillin, >8mg/L and ≥8mg/L for metronidazole, >0.5mg/L and ≥1mg/L for clarithromycin, >1mg/L and ≥32mg/L for rifampicin, and >1mg/L and ≥4mg/L for tetracycline and >1mg/L levofloxacin. Overall resistance rate by EUCAST and by previous breakpoints was 8.5% and 3.2% for amoxicillin, 0.6% and 0.1% for tetracycline, 39.2% and 39.7% for metronidazole, 51.2% and 51.2% for clarithromycin, 32% and 3.1% for rifampicin, and 6.7% and 6.7% for levofloxacin. When using the different breakpoints for antimicrobial susceptibility testing, similar results were found with most antibiotics tested (tetracycline, metronidazole, clarithromycin, and levofloxacin), except for amoxicillin and rifampicin. Copyright © 2016 Elsevier España, S.L.U. and Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica. All rights reserved.

  3. Identification of a Latin American-specific BabA adhesin variant through whole genome sequencing of Helicobacter pylori patient isolates from Nicaragua

    DOE PAGES

    Thorell, Kaisa; Hosseini, Shaghayegh; Palacios Gonzales, Reyna Victoria Palacios; ...

    2016-02-29

    In this study, Helicobacter pylori (H. pylori) is one of the most common bacterial infections in humans and this infection can lead to gastric ulcers and gastric cancer. H. pylori is one of the most genetically variable human pathogens and the ability of the bacterium to bind to the host epithelium as well as the presence of different virulence factors and genetic variants within these genes have been associated with disease severity. Nicaragua has particularly high gastric cancer incidence and we therefore studied Nicaraguan clinical H. pylori isolates for factors that could contribute to cancer risk. The complete genomes ofmore » fifty-two Nicaraguan H. pylorii isolates were sequenced and assembled de novo, and phylogenetic and virulence factor analyses were performed. The Nicaraguan isolates showed phylogenetic relationship with West African isolates in whole-genome sequence comparisons and with Western and urban South-and Central American isolates using MLSA (Multi-locus sequence analysis). A majority, 77 % of the isolates carried the cancer-associated virulence gene cagA and also the s1/i1/m1 vacuolating cytotoxin, vacA allele combination, which is linked to increased severity of disease. Specifically, we also found that Nicaraguan isolates have a blood group-binding adhesin (BabA) variant highly similar to previously reported BabA sequences from Latin America, including from isolates belonging to other phylogenetic groups. These BabA sequences were found to be under positive selection at several amino acid positions that differed from the global collection of isolates. In conclusion, the discovery of a Latin American BabA variant, independent of overall phylogenetic background, suggests hitherto unknown host or environmental factors within the Latin American population giving H. pylori isolates carrying this adhesin variant a selective advantage, which could affect pathogenesis and risk for sequelae through specific adherence properties.« less

  4. Impact of Helicobacter pylori on multiple sclerosis-related clinically isolated syndrome.

    PubMed

    Deretzi, G; Gavalas, E; Boziki, M; Tsiptsios, D; Polyzos, S A; Venizelos, I; Zavos, C; Koutlas, E; Tsiptsios, I; Katsinelos, P; Kountouras, J

    2016-04-01

    There are no data regarding the relationship between Helicobacter pylori infection (Hp-I) and clinically isolated syndrome (CIS) suggestive of multiple sclerosis. The purpose of this pilot study was to investigate the association between active Hp-I, confirmed by histology, and CIS and to evaluate the impact of Hp eradication on the CIS clinical course. We conducted a study on 48 patients with CIS and 20 matched controls. At baseline, apart from histology, serum anti-Hp-specific IgG titer, inflammatory mediators, and HLA-A, HLA-B, HLA-DR genetic polymorphisms were estimated. Hp-positive patients received standard triple eradication regimen, and all patients were followed up for 2 years. The prevalence of Hp-I was significantly higher in patients with CIS (43/48, 89.6%) than in control (10/20, 50%) (P < 0.001, OR: 8.6, 95% CI: 2.4-30.8). When compared with controls, patients with CIS also showed significantly higher serum anti-Hp IgG titer and HLA-A26, HLA-A30, and HLA-B57 frequencies. Hp-positive patients also showed higher serum concentrations of inflammatory cytokines and homocysteine. At 2-year clinical endpoint, in the subgroup of CIS patients with successful Hp eradication, the number of patients who presented with a second episode was significantly lower accompanied by significant improvement in mean Expanded Disability Status Scale score. Hp-I seems more frequent in a Greek CIS cohort and its eradication might delay CIS progression, suggesting a possible link between Hp-I and CIS. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  5. Composition and gene expression of the cag pathogenicity island in Helicobacter pylori strains isolated from gastric carcinoma and gastritis patients in Costa Rica.

    PubMed

    Occhialini, A; Marais, A; Urdaci, M; Sierra, R; Muñoz, N; Covacci, A; Mégraud, F

    2001-03-01

    The composition and in vitro expression of the cag pathogenicity island genes in a group of Helicobacter pylori strains obtained from patients suffering from chronic gastritis-associated dyspepsia (n = 26) or gastric carcinoma (n = 17) were analyzed. No significant difference in the distribution of the 10 studied regions was found between the cases and the controls. Nine strains did not harbor any of the selected regions: eight (30.8%) isolated from patients with gastritis only and one (5.9%) from a patient with gastric carcinoma. No association was found between the number of repeated sequences at the 3' end of the cagA gene or the presence of tyrosine phosphorylation motifs and the clinical origin of the strains. The virB10 homolog gene was the sole gene studied to be significantly expressed more often in cancer strains than in gastritis strains (P = 0.03).

  6. Composition and Gene Expression of the cag Pathogenicity Island in Helicobacter pylori Strains Isolated from Gastric Carcinoma and Gastritis Patients in Costa Rica

    PubMed Central

    Occhialini, Alessandra; Marais, Armelle; Urdaci, Maria; Sierra, Rafaela; Muñoz, Nubia; Covacci, Antonello; Mégraud, Francis

    2001-01-01

    The composition and in vitro expression of the cag pathogenicity island genes in a group of Helicobacter pylori strains obtained from patients suffering from chronic gastritis-associated dyspepsia (n = 26) or gastric carcinoma (n = 17) were analyzed. No significant difference in the distribution of the 10 studied regions was found between the cases and the controls. Nine strains did not harbor any of the selected regions: eight (30.8%) isolated from patients with gastritis only and one (5.9%) from a patient with gastric carcinoma. No association was found between the number of repeated sequences at the 3′ end of the cagA gene or the presence of tyrosine phosphorylation motifs and the clinical origin of the strains. The virB10 homolog gene was the sole gene studied to be significantly expressed more often in cancer strains than in gastritis strains (P = 0.03). PMID:11179371

  7. Antibiotic susceptibility of Helicobacter pylori strains isolated from Iranian children: High frequency of A2143G point mutation associated with clarithromycin resistance.

    PubMed

    Mahmoudi, Shima; Mamishi, Setareh; Banar, Maryam; Keshavarz Valian, Sepideh; Bahador, Abbas; Najafi, Mehri; Farahmand, Fatemeh; Pourakbari, Babak

    2017-09-01

    Increasing antibiotic resistance in Helicobacter pylori is a global concern and is associated with treatment failure. The aim of this study was to evaluate antibiotic resistance of H. pylori to different antibiotics including amoxicillin, erythromycin, ciprofloxacin, furazolidone, tetracycline, metronidazole and clarithromycin. In addition, ​detection of A2143G mutation in clarithromycin resistant isolates was performed using real-time PCR technique. Ninety patients with upper gastrointestinal symptoms were enrolled in this study. H. pylori were isolated from 32 specimens and the resistance rate of these strains to amoxicillin, erythromycin, ciprofloxacin, furazolidone, and tetracycline was tested by disc agar diffusion method. The resistance level to metronidazole and clarithromycin was determined by agar dilution method. The presence of A2143G point mutation in clarithromycin resistant isolates was determined using real-time PCR technique. The resistance rates to amoxicillin, erythromycin, ciprofloxacin, furazolidone, tetracycline, metronidazole and clarithromycin were 53%, 50%, 37.5%, 62.5%, 25%, 62.5% and 22%, respectively. The A2143G point mutation was detected in 71% of clarithromycin resistant strains (5 out of 7). The prevalence of H. pylori resistance to metronidazole, ciprofloxacin, erythromycin, amoxicillin and furazolidone in Iran is high. Determination of antibiotic susceptibility plays an important role in selecting of the appropriate anti H. pylori regimen. Copyright © 2017 International Society for Chemotherapy of Infection and Cancer. Published by Elsevier Ltd. All rights reserved.

  8. Differentiation of Metronidazole-Sensitive and -Resistant Clinical Isolates of Helicobacter pylori by Immunoblotting with Antisera to the RdxA Protein

    PubMed Central

    Latham, Stephanie R.; Owen, Robert J.; Elviss, Nicola C.; Labigne, Agnès; Jenks, Peter J.

    2001-01-01

    Antimicrobial resistance in Helicobacter pylori is a serious and increasing problem, and the development of rapid, reliable methods for detecting resistance would greatly improve the selection of antibiotics used to treat gastric infection with this organism. We assessed whether detection of the RdxA protein could provide the basis for determining the susceptibility of H. pylori to metronidazole. In order to raise polyclonal antisera to RdxA, we cloned the rdxA gene from H. pylori strain 26695 into the commercial expression vector pMAL-c2, purified the resultant fusion protein by affinity chromatography, and used this recombinant RdxA preparation to immunize rabbits. We then used this specific anti-RdxA antibody to perform immunoblotting on whole bacterial cell lysates of 17 metronidazole-sensitive and 27 metronidazole-resistant clinical isolates of H. pylori. While a 24-kDa immunoreactive band corresponding to the RdxA protein was observed in all metronidazole-sensitive strains, this band was absent in 25 of 27 resistant isolates. Our results indicate that testing for the absence of the RdxA protein would identify the majority of clinical isolates that will respond poorly to metronidazole-containing eradication regimens and have implications for the development of assays capable of detecting metronidazole resistance in H. pylori. PMID:11526127

  9. Implications of Molecular Genotyping of Helicobacter pylori Isolates from Different Human Populations by Genomic Fingerprinting of Enterobacterial Repetitive Intergenic Consensus Regions for Strain Identification and Geographic Evolution

    PubMed Central

    Hussain, M. Abid; Kauser, Farhana; Khan, Aleem A.; Tiwari, Santosh; Habibullah, Chittoor M.; Ahmed, Niyaz

    2004-01-01

    Biogeographic partitioning of the genome is typical of the gastric pathogen Helicobacter pylori. Such population-specific evolution could serve as a model for understanding host-pathogen interaction and the impact of genetic drift and recombination on insular populations. With a total of 320 isolates from six geographic regions (Japan, India, England, Spain, Ireland, Africa, and Peru) analyzed by enterobacterial repetitive intergenic consensus (ERIC)-based genotyping, we examined genetic affinities among various H. pylori populations in the world. Several strain-specific and region-specific differences were observed by ERIC-based typing. Polymorphic ERIC patterns indicated that the ERIC sequences are in fact dispersed in the H. pylori chromosome at different locations separated by various distances. Phylogenetic analysis of 61 representative isolates revealed three distinct genetic clusters populated by isolates with shared ERIC types independent of the cag right-junction motif type and vacA allele status. Among the notable genetic relationships were the genotypic similarities between Irish and Japanese and between Peruvian and Japanese isolates. Insular genotypic characteristics of Irish isolates amid genetic similarity to East Asian, as well as North European, strains have been once again proved in this study. Peruvian genotypes were more similar to those of Japanese isolates than to those of Iberian or European isolates. Given the current debate on the origin and age of present-day H. pylori, this is a significant finding that supports the possibility of ancient colonization of Amerindians with East Asian strains. Genotypic data presented here will be additionally helpful in realizing the importance of H. pylori geographical genomics in the development of gastroduodenal pathology. PMID:15184407

  10. Detection of Helicobacter pylori and the genotypes of resistance to clarithromycin and the heterogeneous genotype to this antibiotic in biopsies obtained from symptomatic children.

    PubMed

    Aguilera-Correa, John Jairo; Urruzuno, Pedro; Barrio, Josefa; Martinez, María José; Agudo, Sonia; Somodevilla, Angela; Llorca, Laura; Alarcón, Teresa

    2017-02-01

    The aim of this study was to use a commercially available kit (GenoType® HelicoDR; Hain Life Science, Germany) to detect Helicobacter pylori infection and clarithromycin resistance genotype in biopsies obtained from symptomatic children. 111 out of 136 (81.6%) biopsies were H. pylori positive by genotype: 47 (42.3%) showed wild-type genotype, 53 resistant genotype (47.7%) and 11 heterogeneous genotype (9.9%). Culture was negative in 27 out of the 111 genotyped biopsies. Mutation A2143G (87.5%), followed by A2142G (7.5%) and double mutant A2142C-A2143G (5%) were found. The 11 heterogeneous genotype biopsies showed wild-type plus A2143G in 9 and plus A2142G in 2. This kit is a rapid, culture-independent method for routine application in biopsies from the pediatric population that allows detection of clarithromycin resistance and heterogeneous genotypes. It is important to know the clinical impact of infection with this type of strains as well as the role in treatment success. Copyright © 2015 Elsevier Inc. All rights reserved.

  11. Helicobacter pylori

    MedlinePlus

    ... illnesses. H. pylori , which used to be called Campylobacter pylori , also can cause peptic ulcers (commonly known ... H. Pylori Antigen Food Safety for Your Family Campylobacter Infections Pyloric Stenosis Peptic Ulcers Digestive System Vomiting ...

  12. Centralized isolation of Helicobacter pylori from multiple centers and transport condition influences

    PubMed Central

    Gong, Ya-Nan; Li, You-Ming; Yang, Ning-Min; Li, Hong-Zhang; Guo, Feng; Lin, Lang; Wang, Qun-Ying; Zhang, Jia-Kun; Ji, Zi-Zhong; Mao, Ji-Bo; Mao, Jun-Liang; Shi, Zheng-Chao; Tang, Wu-Heng; Zhu, Xin-Jian; Shao, Wei; Zhang, Xiao-Feng; Wang, Xing-Hua; Tong, Yue-Feng; Jiang, Mi-Zu; Chen, Guang-Lan; Wang, Zhi-Yong; Tu, Hui-Min; Jiang, Guo-Fa; Wu, Jian-Sheng; Chen, Xu-Peng; Ding, Qiu-Long; Ouyang, Hong; Jin, Feng-Zhe; Xu, Yan-Li; Zhang, Jian-Zhong

    2015-01-01

    AIM: To evaluate the efficacy of centralized culture and possible influencing factors. METHODS: From January 2010 to July 2012, 66452 patients with suspected Helicobacter pylori (H. pylori) infection from 26 hospitals in Zhejiang and Jiangsu Provinces in China underwent gastrointestinal endoscopy. Gastric mucosal biopsies were taken from the antrum for culture. These biopsies were transported under natural environmental temperature to the central laboratory in Hangzhou city and divided into three groups based on their transport time: 5, 24 and 48 h. The culture results were reported after 72 h and the positive culture rates were analyzed by a χ2 test. An additional 5736 biopsies from H. pylori-positive patients (5646 rapid urease test-positive and 90 14C-urease breath test-positive) were also cultured for quality control in the central laboratory setting. RESULTS: The positive culture rate was 31.66% (21036/66452) for the patient samples and 71.72% (4114/5736) for the H. pylori-positive quality control specimens. In the 5 h transport group, the positive culture rate was 30.99% (3865/12471), and 32.84% (14960/45553) in the 24 h transport group. In contrast, the positive culture rate declined significantly in the 48 h transport group (26.25%; P < 0.001). During transportation, the average natural temperature increased from 4.67 to 29.14 °C, while the positive culture rate declined from 36.67% (1462/3987) to 24.12% (1799/7459). When the temperature exceeded 24 °C, the positive culture rate decreased significantly, especially in the 48 h transport group (23.17%). CONCLUSION: Transportation of specimens within 24 h and below 24 °C is reasonable and acceptable for centralized culture of multicenter H. pylori samples. PMID:25624729

  13. Comparison of E-test and disk diffusion assay to evaluate resistance of Helicobacter pylori isolates to amoxicillin, clarithromycin, metronidazole and tetracycline in Costa Rica.

    PubMed

    Lang, Lore; García, Fernando

    2004-12-01

    MIC distribution and susceptibility to four antimicrobial agents were determined by E-test for 94 Helicobacter pylori isolates from Costa Rica. Disk diffusion was evaluated as an alternative method to determine susceptibility and compared with the E-test results by linear regression analysis and an error-rate bounded method. Thirty-eight (40.4%) of the isolates were resistant to metronidazole, 5.3% to clarithromycin and 5.3% to amoxicillin. No isolate was resistant to tetracycline. Multiple resistance was found in 4.3% of the isolates. H. pylori isolates were categorised as resistant to amoxicillin, clarithromycin and tetracycline when inhibition diameters were less than 25, 21 and 25 mm, respectively, in the disk diffusion assay. A breakpoint diameter for metronidazole with disk diffusion could not be firmly established.

  14. Evidence of the gastroprotective and anti- Helicobacter pylori activities of β-mangostin isolated from Cratoxylum arborescens (vahl) blume

    PubMed Central

    Sidahmed, Heyam Mohamed Ali; Hashim, Najihah Mohd; Mohan, Syam; Abdelwahab, Siddig Ibrahim; Taha, Manal Mohamed Elhassan; Dehghan, Firouzeh; Yahayu, Maizatulakmal; Ee, Gwendoline Cheng Lian; Loke, Mun Fai; Vadivelu, Jamuna

    2016-01-01

    Purpose β-Mangostin (BM) from Cratoxylum arborescens demonstrated various pharmacological activities such as anticancer and anti-inflammatory. In this study, we aimed to investigate its antiulcer activity against ethanol ulcer model in rats. Materials and methods BM was isolated from C. arborescens. Gastric acid output, ulcer index, gross evaluation, mucus production, histological evaluation using hematoxylin and eosin and periodic acid–Schiff staining and immunohistochemical localization for heat shock protein 70 (HSP70) and Bax proteins were investigated. Possible involvement of reduced glutathione, lipid peroxidation, prostaglandin E2, antioxidant enzymes, superoxide dismutase and catalase enzymes, radical scavenging, nonprotein sulfhydryl compounds, and anti-Helicobacter pylori were investigated. Results BM showed antisecretory activity against the pylorus ligature model. The pretreatment with BM protect gastric mucosa from ethanol damaging effect as seen by the improved gross and histological appearance. BM significantly reduced the ulcer area formation, the submucosal edema, and the leukocytes infiltration compared to the ulcer control. The compound showed intense periodic acid–Schiff staining to the gastric mucus layer and marked amount of alcian blue binding to free gastric mucus. BM significantly increased the gastric homogenate content of prostaglandin E2 glutathione, superoxide dismutase, catalase, and nonprotein sulfhydryl compounds. The compound inhibited the lipid peroxidation revealed by the reduced gastric content of malondialdehyde. Moreover, BM upregulate HSP70 expression and downregulate Bax expression. Furthermore, the compound showed interesting anti-H. pylori activity. Conclusion Thus, it could be concluded that BM possesses gastroprotective activity, which could be attributed to the antisecretory, mucus production, antioxidant, HSP70, antiapoptotic, and anti-H. pylori mechanisms. PMID:26834460

  15. Evidence of the gastroprotective and anti- Helicobacter pylori activities of β-mangostin isolated from Cratoxylum arborescens (vahl) blume.

    PubMed

    Sidahmed, Heyam Mohamed Ali; Hashim, Najihah Mohd; Mohan, Syam; Abdelwahab, Siddig Ibrahim; Taha, Manal Mohamed Elhassan; Dehghan, Firouzeh; Yahayu, Maizatulakmal; Ee, Gwendoline Cheng Lian; Loke, Mun Fai; Vadivelu, Jamuna

    2016-01-01

    β-Mangostin (BM) from Cratoxylum arborescens demonstrated various pharmacological activities such as anticancer and anti-inflammatory. In this study, we aimed to investigate its antiulcer activity against ethanol ulcer model in rats. BM was isolated from C. arborescens. Gastric acid output, ulcer index, gross evaluation, mucus production, histological evaluation using hematoxylin and eosin and periodic acid-Schiff staining and immunohistochemical localization for heat shock protein 70 (HSP70) and Bax proteins were investigated. Possible involvement of reduced glutathione, lipid peroxidation, prostaglandin E2, antioxidant enzymes, superoxide dismutase and catalase enzymes, radical scavenging, nonprotein sulfhydryl compounds, and anti-Helicobacter pylori were investigated. BM showed antisecretory activity against the pylorus ligature model. The pretreatment with BM protect gastric mucosa from ethanol damaging effect as seen by the improved gross and histological appearance. BM significantly reduced the ulcer area formation, the submucosal edema, and the leukocytes infiltration compared to the ulcer control. The compound showed intense periodic acid-Schiff staining to the gastric mucus layer and marked amount of alcian blue binding to free gastric mucus. BM significantly increased the gastric homogenate content of prostaglandin E2 glutathione, superoxide dismutase, catalase, and nonprotein sulfhydryl compounds. The compound inhibited the lipid peroxidation revealed by the reduced gastric content of malondialdehyde. Moreover, BM upregulate HSP70 expression and downregulate Bax expression. Furthermore, the compound showed interesting anti-H. pylori activity. Thus, it could be concluded that BM possesses gastroprotective activity, which could be attributed to the antisecretory, mucus production, antioxidant, HSP70, antiapoptotic, and anti-H. pylori mechanisms.

  16. Draft Genome Sequence of a Helicobacter pylori Strain Isolated from a Patient with Diffuse Gastritis from a Region of High Cancer Risk in Colombia.

    PubMed

    Gutiérrez-Escobar, Andrés J; Bayona Rojas, Martin; Barragán Vidal, Carlos; Trujillo, Clara Esperanza; Bravo, María Mercedes

    2015-04-09

    The draft genome sequence of one Colombian Helicobacter pylori strain is presented. This strain was isolated from a patient with diffuse gastritis from Tibaná, Boyacá, a region with high gastric cancer risk. Copyright © 2015 Gutiérrez-Escobar et al.

  17. Macrolide and fluoroquinolone resistance in Helicobacter pylori isolates: an experience at a tertiary care centre in Pakistan.

    PubMed

    Rajper, Sana; Khan, Erum; Ahmad, Zubair; Alam, Syed Muhammad Zaheer; Akbar, Adil; Hasan, Rumina

    2012-11-01

    To assess fluoroquinolone and clarithromycin susceptibility pattern along with the types of genomic mutations involved in the resistance of Helicobacter pylori isolates. The cross-sectional study was conducted at the Department of Pathology and Microbiology, Aga Khan University Hospital, Karachi, from June 2009 to July 2010, and comprised 162 gastric biopsy samples which were tested with GenoTypeHelicoDR (Hain Lifescience GmbH, Germany), a reverse hybridisation multiplex polymerase chain reaction (PCR) line probe assay (LiPA). Also, 23S rRNA (ribosomal ribonucleic acid) gene was analysed with three-point mutations at A2146G, A2146C and A2147G for clarithromycin, and gyrA gene was analyzed at two codon positions 87 and 91 for fluoroquinolone susceptibility testing. SPSS 19 was used for statistical analyses. Clarithromycin resistance was seen in 60 (37.0%) of the isolates mainly involving mutation at A2147G (85%) followed by A2146G (n=35; 21.6%) and A2146C (n=19; 11.6%). Fluoroquinolone resistance was noted in 101(62.3%) isolates, while gyrA mutations at codon 87 was seen in 64 (39.6%) and at codon 91 in 66 (40.6%). Isolates showing combined resistance to both antibiotics were 44 (26.9%). High rate of resistance to fluoroquinolones was seen despite the fact that the drug was not part of the first-line anti-helicobacter therapy. There was moderate increase of clarithromycin resistance beyond the cutoff rates where empirical use of this antibiotic is abandoned. The findings warrant the need for pre-treatment susceptibility testing in Helicobacter pylori infections, especially in Pakistan where burden of disease is high and very limited data is available, to improve patient care by providing targeted therapy.

  18. Antibiotic susceptibility of Helicobacter pylori in Iceland.

    PubMed

    Gunnarsdottir, Anna Ingibjorg; Gudjonsson, Hallgrimur; Hardardottir, Hjordis; Jonsdottir, Karen Drofn; Bjornsson, Einar Stefan

    2017-09-01

    Increasing resistance of Helicobacter pylori (H. pylori) to antibiotics calls for constant re-evaluation of multidrug regimens that have been used to eradicate the infection. The aim of this study was to evaluate the current antibiotic susceptibility of H. pylori in an Icelandic cohort. Patients referred for gastroscopy were recruited prospectively. Those found to have a positive rapid urease test were included in the study. Susceptibility testing was conducted by the Epsilometer test (E-test) method for ampicillin, clarithromycin, levofloxacin, metronidazole and tetracycline. Results were obtained after three days of incubation in microaerophilic conditions at 37 °C, except for the metronidazole were the first 24 hours were anaerobic. Of the 613 patients who underwent gastroscopy, 138 (23%) had a positive rapid urease test. H. pylori was successfully cultured from 105 (76%) of the urease test positive patients and the isolates were tested for antibiotic susceptibility. Five patients had prior H. pylori eradication. Antibiotic resistance for ampicillin, clarithromycin, levofloxacin, metronidazole and tetracycline was 0%, 9%, 4%, 1% and 0%, respectively. If those who had previously undergone eradication treatment were excluded, the resistance was 0%, 6%, 3%, 1% and 0%, respectively. Clarithromycin resistance was higher amongst women than men, 13% vs. 5%, however, not significantly. Clarithromycin resistance was 60% amongst those who had previously received eradication treatment compared to 6% of those who had not (p < .0001). Clarithromycin resistance amongst the H. pylori isolates can be considered relatively low. Therefore, in the current cohort, standard triple-drug clarithromycin-containing regimen should remain the first-line treatment against H. pylori.

  19. Isolation and characterization of a conserved porin protein from Helicobacter pylori.

    PubMed Central

    Doig, P; Exner, M M; Hancock, R E; Trust, T J

    1995-01-01

    Helicobacter pylori is a causative agent of gastritis in humans and is correlated with gastric ulcer formation. Infections with this bacterium have proven difficult to treat with antimicrobial agents. To better understand how this bacterium transports compounds such as antimicrobial agents across its outer membrane, identification of porin proteins is important. We have recently identified a family of H. pylori porins (HopA to HopD) (M. M. Exner, P. Doig, T. J. Trust, and R. E. W. Hancock, Infect. Immun. 63:1567-1572, 1995). Here, we report on an unrelated porin species (HopE) from this bacterium. This protein had a apparent molecular mass of 31 kDa and was seen to form 50- and 90-kDa aggregates that were designated putative dimeric and trimeric forms, respectively. The protein was purified to homogeneity and, with a model planar lipid membrane system, was shown to act as a nonselective pore with a single channel conductance in 1.0 M KCl of 1.5 nS, similarly to other bacterial nonspecific porins. An internal peptide sequence of HopE shared homology with the P2 porin of Haemophilus influenzae. HopE was also shown to be antigenic in vivo as assessed by sera taken from H. pylori-infected individuals and was immunologically conserved with both patient sera and specific monoclonal antibodies. From these data, it appears that HopE is a major nonselective porin of H. pylori. The implications of these findings are discussed. PMID:7559328

  20. Differences in Genome Content among Helicobacter pylori Isolates from Patients with Gastritis, Duodenal Ulcer, or Gastric Cancer Reveal Novel Disease-Associated Genes▿ †

    PubMed Central

    Romo-González, Carolina; Salama, Nina R.; Burgeño-Ferreira, Juan; Ponce-Castañeda, Veronica; Lazcano-Ponce, Eduardo; Camorlinga-Ponce, Margarita; Torres, Javier

    2009-01-01

    Helicobacter pylori establishes a chronic infection in the human stomach, causing gastritis, peptic ulcer, or gastric cancer, and more severe diseases are associated with virulence genes such as the cag pathogenicity island (PAI). The aim of this work was to study gene content differences among H. pylori strains isolated from patients with different gastroduodenal diseases in a Mexican-Mestizo patient population. H. pylori isolates from 10 patients with nonatrophic gastritis, 10 patients with duodenal ulcer, and 9 patients with gastric cancer were studied. Multiple isolates from the same patient were analyzed by randomly amplified polymorphic DNA analysis, and strains with unique patterns were tested using whole-genome microarray-based comparative genomic hybridization (aCGH). We studied 42 isolates and found 1,319 genes present in all isolates, while 341 (20.5%) were variable genes. Among the variable genes, 127 (37%) were distributed within plasticity zones (PZs). The overall number of variable genes present in a given isolate was significantly lower for gastric cancer isolates. Thirty genes were significantly associated with nonatrophic gastritis, duodenal ulcer, or gastric cancer, 14 (46.6%) of which were within PZs and the cag PAI. Two genes (HP0674 and JHP0940) were absent in all gastric cancer isolates. Many of the disease-associated genes outside the PZs formed clusters, and some of these genes are regulated in response to acid or other environmental conditions. Validation of candidate genes identified by aCGH in a second patient cohort allowed the identification of novel H. pylori genes associated with gastric cancer or duodenal ulcer. These disease-associated genes may serve as biomarkers of the risk for severe gastroduodenal diseases. PMID:19237517

  1. Differences in genome content among Helicobacter pylori isolates from patients with gastritis, duodenal ulcer, or gastric cancer reveal novel disease-associated genes.

    PubMed

    Romo-González, Carolina; Salama, Nina R; Burgeño-Ferreira, Juan; Ponce-Castañeda, Veronica; Lazcano-Ponce, Eduardo; Camorlinga-Ponce, Margarita; Torres, Javier

    2009-05-01

    Helicobacter pylori establishes a chronic infection in the human stomach, causing gastritis, peptic ulcer, or gastric cancer, and more severe diseases are associated with virulence genes such as the cag pathogenicity island (PAI). The aim of this work was to study gene content differences among H. pylori strains isolated from patients with different gastroduodenal diseases in a Mexican-Mestizo patient population. H. pylori isolates from 10 patients with nonatrophic gastritis, 10 patients with duodenal ulcer, and 9 patients with gastric cancer were studied. Multiple isolates from the same patient were analyzed by randomly amplified polymorphic DNA analysis, and strains with unique patterns were tested using whole-genome microarray-based comparative genomic hybridization (aCGH). We studied 42 isolates and found 1,319 genes present in all isolates, while 341 (20.5%) were variable genes. Among the variable genes, 127 (37%) were distributed within plasticity zones (PZs). The overall number of variable genes present in a given isolate was significantly lower for gastric cancer isolates. Thirty genes were significantly associated with nonatrophic gastritis, duodenal ulcer, or gastric cancer, 14 (46.6%) of which were within PZs and the cag PAI. Two genes (HP0674 and JHP0940) were absent in all gastric cancer isolates. Many of the disease-associated genes outside the PZs formed clusters, and some of these genes are regulated in response to acid or other environmental conditions. Validation of candidate genes identified by aCGH in a second patient cohort allowed the identification of novel H. pylori genes associated with gastric cancer or duodenal ulcer. These disease-associated genes may serve as biomarkers of the risk for severe gastroduodenal diseases.

  2. Comparative Genomics of a Helicobacter pylori Isolate from a Chinese Yunnan Naxi Ethnic Aborigine Suggests High Genetic Divergence and Phage Insertion

    PubMed Central

    You, Yuanhai; He, Lihua; Zhang, Maojun; Zhang, Jianzhong

    2015-01-01

    Helicobacter pylori is a common pathogen correlated with several severe digestive diseases. It has been reported that isolates associated with different geographic areas, different diseases and different individuals might have variable genomic features. Here, we describe draft genomic sequences of H. pylori strains YN4-84 and YN1-91 isolated from patients with gastritis from the Naxi and Han populations of Yunnan, China, respectively. The draft sequences were compared to 45 other publically available genomes, and a total of 1059 core genes were identified. Genes involved in restriction modification systems, type four secretion system three (TFS3) and type four secretion system four (TFS4), were identified as highly divergent. Both YN4-84 and YN1-91 harbor intact cag pathogenicity island (cagPAI) and have EPIYA-A/B/D type at the carboxyl terminal of cagA. The vacA gene type is s1m2i1. Another major finding was a 32.5-kb prophage integrated in the YN4-84 genome. The prophage shares most of its genes (30/33) with Helicobacter pylori prophage KHP30. Moreover, a 1,886 bp transposable sequence (IS605) was found in the prophage. Our results imply that the Naxi ethnic minority isolate YN4-84 and Han isolate YN1-91 belong to the hspEAsia subgroup and have diverse genome structure. The genome has been extensively modified in several regions involved in horizontal DNA transfer. The important roles played by phages in the ecology and microevolution of H. pylori were further emphasized. The current data will provide valuable information regarding the H. pylori genome based on historic human migrations and population structure. PMID:25799515

  3. Consensus and Variable Region PCR Analysis of Helicobacter pylori 3′ Region of cagA Gene in Isolates from Individuals with or without Peptic Ulcer

    PubMed Central

    Rota, Cláudia Augustin; Pereira-Lima, Júlio C.; Blaya, Carolina; Nardi, Nance Beyer

    2001-01-01

    The clinical outcome of Helicobacter pylori infection may be associated with the cagA bacterial genotype. To investigate the cagA status of H. pylori-infected patients and the relationship between cagA and peptic ulcer disease, gastric biopsy specimens from 103 Caucasian patients in Brazil were analyzed by PCR. Since allelic variation in cagA exists and distinct H. pylori subgenotypes may circulate in different regions, PCR using primers for a variable 3′ region of the cagA gene according to a Japanese methodology and for a consensus cagA 3′ region used in Western methods was used for cagA detection. cagA was present in 53 (71%) of 75 H. pylori-positive cases when analyzed by the consensus region method and was associated with duodenal ulcer disease (P = 0.02), but not with gastric ulcer (P = 0.26), when compared to patients with duodenitis or gastritis. The variable region PCR method was able to detect 43 (57%) cagA-positive cases within the same group of H. pylori-positive patients and showed three subtypes of cagA (A, B/D, and C) that were not associated with clinical outcome. However, in 8 (18%) of the cases, more than one subtype was present, and an association between patients with multiple subtypes and disease outcome was observed when compared to patients with isolated subtypes (P = 0.048). cagA was a marker of H. pylori strains for duodenal ulcer disease in our population, and in spite of the differences in the 3′ region of the cagA gene, the Japanese methodology was able to detect the cagA status in most cases. The presence of multiple subgenotypes of cagA was associated with gastric ulcer. PMID:11158115

  4. Regional Differences in Metronidazole Resistance and Increasing Clarithromycin Resistance among Helicobacter pylori Isolates from Japan

    PubMed Central

    Kato, Mototsugu; Yamaoka, Yoshio; Kim, Jae J.; Reddy, Rita; Asaka, Masahiro; Kashima, Kei; Osato, Michael S.; El-Zaatari, Fouad A. K.; Graham, David Y.; Kwon, Dong H.

    2000-01-01

    The patterns of antibiotic resistance in Helicobacter pylori were assessed in two different regions in Japan. Overall, prevalences of resistance to metronidazole and clarithromycin were 12.4 and 12.9%, respectively. While there was no difference in clarithromycin resistance, the prevalence of metronidazole resistance was significantly higher in Kyoto (23.8%) than in Sapporo (8.1%). From 1996 to 1999, the prevalence of metronidazole resistance did not change but the prevalence of clarithromycin resistance doubled (from 9.1 to 18.7%). PMID:10898707

  5. Antibiotic susceptibility of Helicobacter pylori clinical isolates: comparative evaluation of disk-diffusion and E-test methods.

    PubMed

    Mishra, K K; Srivastava, S; Garg, A; Ayyagari, A

    2006-10-01

    Antimicrobial susceptibility of 25 Helicobacter pylori strains isolated from patients with acid peptic diseases were tested for in vitro sensitivity to commonly used antibiotics using disk-diffusion and E-test, methods. All strains tested were susceptible to tetracycline by E-test, with the minimum inhibitory concentration (MIC) values being <0.125 microg/ml for all strains except for 6 (<0.023 microg/ml). However 1 strain was resistant by disk-diffusion method. One strain was resistant to clarithromycin both by disk diffusion and E-test (MIC <48 microg/ml), and 1 strain was resistant only by disk diffusion. Only one strain was resistant to amoxicillin by disk diffusion and E-test (MIC >256 microg/ml). For ciprofloxacin, three strains were resistant by disk diffusion and two by E-test (MIC <32 microg/ml). Sixteen strains were resistant to metronidazole by disk diffusion and E-test (MIC >or= 8 microg/ml), and 1 was resistant only by E-test (MIC <48 microg/ml). Overall, 64% of the strains were resistant to metronidazole. The MIC for metronidazole was also tested by agar-dilution method, and metronidazole resistant strains had an, MIC >8 microg/ml. The disk-diffusion method showed excellent correlation with E-test results; there was 100% agreement for amoxicillin a other antibiotics showed 90% to 95% accuracy. Disk diffusion is cheaper than E-test (approximately 2.6 cents vs. 2.60 US dollars), is easy to perform, and is a reliable method for testing H. pylori susceptibility to antimicrobial agents in the clinical microbiology laboratory.

  6. Multiple in vivo passages enhance the ability of a clinical Helicobacter pylori isolate to colonize the stomach of Mongolian gerbils and to induce gastritis.

    PubMed

    Bleich, A; Köhn, I; Glage, S; Beil, W; Wagner, S; Mähler, M

    2005-04-01

    The Mongolian gerbil is an excellent animal model for Helicobacter pylori-induced gastritis in humans. In this study, initially low colonization rates of the H. pylori strains ATCC 43504, SS1, or HP87 inoculated into gerbils caused difficulties in establishing this model. In order to increase the colonization ability and pathogenicity, the clinical HP87 isolate was selected for adaptation to the gerbil stomach by multiple in vivo passages through gerbils. Development of gastritis was examined histologically at 4-52 weeks after infection. The proportion of gerbils which tested positive for H. pylori by culture at four weeks after inoculation gradually increased from 11.1% of gerbils inoculated with HP87 without prior in vivo passage (P0) to 100% of gerbils inoculated with HP87 with seven in vivo passages (P7). In addition, adaptation of HP87 resulted in more severe histopathological changes. Gerbils infected with adapted HP87 (P7) exhibited severe infiltration by monomorphonuclear and polymorphonuclear leukocytes in the mucosa, submucosa, and subserosa of the gastric antrum, as well as epithelial changes consisting of hyperplasia, erosion, and ulceration. Histopathological changes increased in severity from four to 52 weeks after infection. Adaptation of HP87 during its passages through gerbils could be due to genetic changes in bacterial colonization factors. Identification of these changes might be useful to understand the underlying mechanism of gastric adaptation and pathogenesis of H. pylori.

  7. Serum antibody responses to the N-acetylneuraminyllactose-binding hemagglutinin of Campylobacter pylori.

    PubMed Central

    Evans, D J; Evans, D G; Smith, K E; Graham, D Y

    1989-01-01

    We recently reported that Campylobacter pylori possesses a surface-associated fibrillar hemagglutinin which has an affinity for N-acetylneuraminyllactose; this hemagglutinin may function as a colonization factor for attachment to the gastric epithelium. In the present study we examined serum samples obtained from 65 C. pylori-infected individuals with gastric ulcers, duodenal ulcers, or both and from 121 asymptomatic volunteers, including 62 who were infected with C. pylori, for immunoglobulin G (IgG) specific for the C. pylori neuramin-lactose-binding hemagglutinin (NLBH). The NLBH purified from a single isolate was used as the antigen in an enzyme-linked immunosorbent assay. A positive result was obtained with serum from 81.5% (53 of 65) of the individuals with ulcers, 67.7% (42 of 62) of the C. pylori-infected volunteers, and 1.7% (1 of 59) of the C. pylori-negative volunteers. This result confirms that NLBH is produced in vivo. There are several possible explanations for the fact that only 75% of 127 C. pylori-infected individuals were positive for anti-NLBH IgG in serum. We favor the hypothesis that there are probably several antigenically distinct C. pylori NLBHs, i.e., NLBHs which would stimulate antibody that was undetectable by the antigen used in the enzyme-linked immunosorbent assay described here. PMID:2917777

  8. Helicobacter pylori infection in Japan

    PubMed Central

    Shiota, Seiji; Murakawi, Kazunari; Suzuki, Rumiko; Fujioka, Toshio; Yamaoka, Yoshio

    2013-01-01

    The prevalence of Helicobacter pylori infection is gradually decreasing in Japan. On the main island of Japan, nearly all H. pylori isolates possess cagA and vacA with strong virulence. However, less virulent H. pylori strains are frequently found in Okinawa where cases of gastric cancer are the lowest in Japan. Eradication therapy for peptic ulcer, idiopathic thrombocytopenic purpura, gastric mucosa-associated lymphoid tissue lymphoma and early gastric cancer after endoscopic resection has been approved by the Japanese national health insurance system. However, the Japanese Society for Helicobacter Research recently stated that all ‘H. pylori infection’ was considered as the indication for eradication irrespective of the background diseases. To eliminate H. pylori in Japan, the Japanese health insurance system should approve the eradication of all H. pylori infections. PMID:23265147

  9. Helicobacter pylori infection in Japan.

    PubMed

    Shiota, Seiji; Murakawi, Kazunari; Suzuki, Rumiko; Fujioka, Toshio; Yamaoka, Yoshio

    2013-01-01

    The prevalence of Helicobacter pylori infection is gradually decreasing in Japan. On the main island of Japan, nearly all H. pylori isolates possess cagA and vacA with strong virulence. However, less virulent H. pylori strains are frequently found in Okinawa where cases of gastric cancer are the lowest in Japan. Eradication therapy for peptic ulcer, idiopathic thrombocytopenic purpura, gastric mucosa-associated lymphoid tissue lymphoma and early gastric cancer after endoscopic resection has been approved by the Japanese national health insurance system. However, the Japanese Society for Helicobacter Research recently stated that all 'H. pylori infection' was considered as the indication for eradication irrespective of the background diseases. To eliminate H. pylori in Japan, the Japanese health insurance system should approve the eradication of all H. pylori infections.

  10. Free recombination within Helicobacter pylori

    PubMed Central

    Suerbaum, Sebastian; Smith, John Maynard; Bapumia, Khairun; Morelli, Giovanna; Smith, Noel H.; Kunstmann, Erdmute; Dyrek, Isabelle; Achtman, Mark

    1998-01-01

    Sequences of three gene fragments (flaA, flaB, and vacA) from Helicobacter pylori strains isolated from patients in Germany, Canada, and South Africa were analyzed for diversity and for linkage equilibrium by using the Homoplasy Test and compatibility matrices. Horizontal genetic exchange in H. pylori is so frequent that different loci and polymorphisms within each locus are all at linkage equilibrium. These results indicate that H. pylori is panmictic. Comparisons with sequences from Escherichia coli, Neisseria meningitidis, and Drosophila melanogaster showed that recombination in H. pylori was much more frequent than in other species. In contrast, when multiple family members infected with H. pylori were investigated, some strains were indistinguishable at all three loci. Thus, H. pylori is clonal over short time periods after natural transmission. PMID:9770535

  11. Helicobacter pylori cultivation from gastric biopsies and susceptibility to antibiotics used in empirical therapy.

    PubMed

    Ilie, Mădălina; Popa, Marcela; Chifiriuc, Mariana Carmen; Baltac, Alina; Constantinescu, Gabriel; Tănăsescu, Coman

    2011-01-01

    Helicobacter pylori is one of the most common among the numerous bacterial species of the stomach. It is classified as a class 1 carcinogen because of its causal relationship to gastric adenocarcinoma. The epidemiology of H. pylori infection is characterized by a marked difference between developing and developed countries. Treatment of H. pylori still remains a challenge due to the high rate of antibiotic resistance. The aim of this study was to investigate the susceptibility of H. pylori strains isolated from gastric biopsies to different antibiotics currently used in the H. pylori infection treatment schemes. Upper gastrointestinal GI endoscopy was performed, followed by the rapid urease test on gastric biopsies. The positive samples were cultivated on specific media under microaerophilic conditions and the antibiotic susceptibility assay was performed on the isolated strains. A positivity rate of 70% was obtained for cultures performed from the biopsy samples positive for the urease test. The resistance rates for the antibiotics used in the classic triple therapy proved to be high, i.e. 92.8% for metronidazole, 50% for amoxicillin and 32% for clarithromycin. The isolated strains proved to be sensitive to ciprofloxacin and levofloxacin. The role of gastric microbiota and its contribution to the H. pylori associated pathology need to be established. The problem of antibiotic treatment failure in case of resistant H. pylori strains can be surpassed by routine culture and antibiotic susceptibility testings.

  12. Antimicrobial resistance among Campylobacter isolates obtained from retail chicken meat and offal products in Japan.

    PubMed

    Hidano, Arata; Yamamoto, Takehisa; Hayama, Yoko; Muroga, Norihiko; Kobayashi, Sota; Nishida, Takeshi; Tsutsui, Toshiyuki

    2014-01-01

    A rapid increase in antimicrobial resistance in Campylobacter has been posing a serious concern for human health. In this study, we aimed to demonstrate the overall trend in antimicrobial resistance among Campylobacter isolates obtained from chicken meat and offal products collected from a wide geographic area throughout Japan. Resistance to Enrofloxacin was most frequently observed, with significantly higher rate of resistance among isolates obtained from offal (55.6%) than from meat (27.3%) samples (p = 0.05). These results highlight need for a better understanding of the characteristics of Campylobacter isolates obtained from chicken meat and offal products.

  13. Draft Genome Sequences of Four Pseudomonas aeruginosa Isolates Obtained from Patients with Chronic Obstructive Pulmonary Disease.

    PubMed

    Lira, Felipe; García-León, Guillermo; Oliver, Antonio; Martínez, José L

    2017-06-15

    Patients suffering chronic obstructive pulmonary disease are frequently infected by Pseudomonas aeruginosa Nevertheless, the number of sequenced isolates causing this type of infection is low. Here, we present the draft genomes of four P. aeruginosa isolates obtained from patients presenting chronic obstructive pulmonary disease. Copyright © 2017 Lira et al.

  14. Frequencies of the expression of main protein antigens from Helicobacter pylori isolates and production of specific serum antibodies in infected patients

    PubMed Central

    Yan, Jie; Mao, Ya-Fei; Shao, Zhe-Xin

    2005-01-01

    AIM: To investigate the frequencies of the expression of main protein antigens of Helicobacter pylori (H pylori) isolates, such as UreB, VacA, CagA1, HpaA, NapA, FlaA and FlaB and the production of specific antibodies in sera from H pylori-infected patients, and to understand the correlations among the different clinical types of chronic gastritis and peptic ulcer and the infection and virulence of H pylori. METHODS: H pylori strains in biopsy specimens from 157 patients with chronic gastritis and peptic ulcer were isolated and serum samples from the patients were also collected. The target recombinant proteins rUreB, rVacA, rCagA1, rHpaA, rNapA, rFlaA and rFlaB expressed by the prokaryotic expression systems constructed in our previous studies were collected through Ni-NTA affinity chromatography. Rabbit antisera against rUreB, rVacA, rCagA1, rHpaA, rNapA, rFlaA and rFlaB were prepared by using routine subcutaneous immunization. By using ultrasonic lysates of the isolates as coated antigens, and the self-prepared rabbit antisera as the first antibodies and commercial HRP-labeling sheep anti-rabbit IgG as the second antibody, expression frequencies of the seven antigens in the isolates were detected by ELISA. Another ELISA was established to detect antibodies against the seven antigens in sera of the patients by using the corresponding recombinant proteins as coated antigens, and the sera as the first antibody and HRP-labeling sheep anti-human IgG as the second antibody respectively. Correlations among the different clinical types of chronic gastritis and peptic ulcer and the infection and virulence of H pylori were statistically analysed. RESULTS: In the 125 isolates of H pylori, the positive rates of UreB, VacA, CagA1, HpaA, NapA, FlaA and FlaB were 100%, 65.6%, 92.8%, 100%, 93.6%, 100% and 99.2% respectively. In the 125 serum samples from the H pylori-infected patients, the positive rates of antibodies against recombinant UreB, VacA, CagA1, HpaA, NapA, FlaA and

  15. In vitro effect of amoxicillin and clarithromycin on the 3’ region of cagA gene in Helicobacter pylori isolates

    PubMed Central

    Bustamante-Rengifo, Javier Andrés; Matta, Andrés Januer; Pazos, Alvaro; Bravo, Luis Eduardo

    2013-01-01

    AIM: To evaluate the in vitro effect of amoxicillin and clarithromycin on the cag pathogenicity island (cag PAI). METHODS: One hundred and forty-nine clinical isolates of Helicobacter pylori (H. pylori) cultured from gastric biopsies from 206 Colombian patients with dyspeptic symptoms from a high-risk area for gastric cancer were included as study material. Antimicrobial susceptibility was determined by the agar dilution method. Resistant isolates at baseline and in amoxicillin and clarithromycin serial dilutions were subjected to genotyping (cagA, vacA alleles s and m), Glu-Pro-Ile-Tyr-Ala (EPIYA) polymerase chain reaction and random amplified polymorphic DNA (RAPD). Images of the RAPD amplicons were analyzed by Gel-Pro Analyzer 4.5 program. Cluster analyses was done using SPSS 15.0 statistical package, where each of the fingerprint bands were denoted as variables. Dendrograms were designed by following Ward’s clustering method and the estimation of distances between each pair of H. pylori isolates was calculated with the squared Euclidean distance. RESULTS: Resistance rates were 4% for amoxicillin and 2.7% for clarithromycin with 2% double resistances. Genotyping evidenced a high prevalence of the genotype cagA-positive/vacA s1m1. The 3’ region of cagA gene was successfully amplified in 92.3% (12/13) of the baseline resistant isolates and in 60% (36/60) of the resistant isolates growing in antibiotic dilutions. Upon observing the distribution of the number of EPIYA repetitions in each dilution with respect to baseline isolates, it was found that in 61.5% (8/13) of the baseline isolates, a change in the number of EPIYA repetitions lowered antibiotic pressure. The gain and loss of EPIYA motifs resulted in a diversity of H. pylori subclones after bacterial adjustment to changing conditions product of antibiotic pressure. RAPD PCR evidenced the close clonal relationship between baseline isolates and isolates growing in antibiotic dilutions. CONCLUSION: Antibiotic

  16. Influence of efflux pump inhibitors on the multidrug resistance of Helicobacter pylori

    PubMed Central

    Zhang, Zhan; Liu, Zhi-Qiang; Zheng, Peng-Yuan; Tang, Fu-Ai; Yang, Ping-Chang

    2010-01-01

    AIM: To evaluate the effect of efflux pump inhibitors (EPIs) on multidrug resistance of Helicobacter pylori (H. pylori). METHODS: H. pylori strains were isolated and cultured on Brucella agar plates with 10% sheep’s blood. The multidrug resistant (MDR) H. pylori were obtained with the inducer chloramphenicol by repeated doubling of the concentration until no colony was seen, then the susceptibilities of the MDR strains and their parents to 9 antibiotics were assessed with agar dilution tests. The present study included periods before and after the advent of the EPIs, carbonyl cyanide m-chlorophenyl hydrazone (CCCP), reserpine and pantoprazole), and the minimum inhibitory concentrations (MICs) were determined accordingly. In the same way, the effects of 5 proton pump inhibitors (PPIs), used in treatment of H. pylori infection, on MICs of antibiotics were evaluated. RESULTS: Four strains of MDR H. pylori were induced successfully, and the antibiotic susceptibilities of MDR strains were partly restored by CCCP and pantoprazole, but there was little effect of reserpine. Rabeprazole was the most effective of the 5 PPIs which could decrease the MICs of antibiotics for MDR H. pylori significantly. CONCLUSION: In vitro, some EPIs can strengthen the activities of different antibiotics which are the putative substrates of the efflux pump system in H. pylori. PMID:20222174

  17. Recent Acquisition of Helicobacter pylori by Baka Pygmies

    PubMed Central

    Montano, Valeria; Maady, Ayas; Nkwescheu, Armand; Siri, Jose; Elamin, Wael F.; Falush, Daniel; Linz, Bodo; Achtman, Mark; Moodley, Yoshan; Suerbaum, Sebastian

    2013-01-01

    Both anatomically modern humans and the gastric pathogen Helicobacter pylori originated in Africa, and both species have been associated for at least 100,000 years. Seven geographically distinct H. pylori populations exist, three of which are indigenous to Africa: hpAfrica1, hpAfrica2, and hpNEAfrica. The oldest and most divergent population, hpAfrica2, evolved within San hunter-gatherers, who represent one of the deepest branches of the human population tree. Anticipating the presence of ancient H. pylori lineages within all hunter-gatherer populations, we investigated the prevalence and population structure of H. pylori within Baka Pygmies in Cameroon. Gastric biopsies were obtained by esophagogastroduodenoscopy from 77 Baka from two geographically separated populations, and from 101 non-Baka individuals from neighboring agriculturalist populations, and subsequently cultured for H. pylori. Unexpectedly, Baka Pygmies showed a significantly lower H. pylori infection rate (20.8%) than non-Baka (80.2%). We generated multilocus haplotypes for each H. pylori isolate by DNA sequencing, but were not able to identify Baka-specific lineages, and most isolates in our sample were assigned to hpNEAfrica or hpAfrica1. The population hpNEAfrica, a marker for the expansion of the Nilo-Saharan language family, was divided into East African and Central West African subpopulations. Similarly, a new hpAfrica1 subpopulation, identified mainly among Cameroonians, supports eastern and western expansions of Bantu languages. An age-structured transmission model shows that the low H. pylori prevalence among Baka Pygmies is achievable within the timeframe of a few hundred years and suggests that demographic factors such as small population size and unusually low life expectancy can lead to the eradication of H. pylori from individual human populations. The Baka were thus either H. pylori-free or lost their ancient lineages during past demographic fluctuations. Using coalescent simulations

  18. Genetic Diversity and Pathogenicity of Cylindrocarpon destructans Isolates Obtained from Korean Panax ginseng

    PubMed Central

    Song, Jeong Young; Seo, Mun Won; Kim, Sun Ick; Nam, Myeong Hyeon; Lim, Hyoun Sub

    2014-01-01

    We analyzed the genetic diversity of Cylindrocarpon destructans isolates obtained from Korean ginseng (i.e., Panax ginseng) roots by performing virulence tests and nuclear ribosomal gene internal transcribed spacer (ITS) and mitochondrial small subunit (mt SSU) rDNA sequence analysis. The phylogenetic relationship analysis performed using ITS DNA sequences and isolates from other hosts helped confirm that all the Korean C. destructans isolates belonged to Nectria/Neonectria radicicola complex. The results of in vivo and ex vivo virulence tests showed that the C. destructans isolates could be divided into two groups according to their distinctive difference in virulence and the genetic diversity. The highly virulent Korean isolates in pathogenicity group II (PG II), together with foreign isolates from P. ginseng and P. quinquefolius, formed a single group. The weakly virulent isolates in pathogenicity group I, together with the foreign isolates from other host plants, formed another group and exhibited a greater genetic diversity than the isolates of PG II, as confirmed by the mt SSU rDNA sequence analysis. In addition, as the weakly virulent Korean isolates were genetically very similar to the foreign isolates from other hosts, they were likely to originate from hosts other than the ginseng plants. PMID:25071387

  19. Primary Antibiotic Resistance of Helicobacter pylori in China.

    PubMed

    Hu, Yi; Zhu, Yin; Lu, Nong-Hua

    2017-05-01

    Antibiotic resistance is the most important factor leading to the failure of eradication regimens; thus, it is important to obtain regional antibiotic resistance information. This review focuses on the prevalence of Helicobacter pylori primary resistance to clarithromycin, metronidazole, amoxicillin, levofloxacin, tetracycline, and furazolidone in China. We searched the PubMed, EMBASE, the China National Knowledge Infrastructure, and Chinese Biomedical databases from the earliest date of each database to October 2016. The search terms included the following: H. pylori, antibiotic (including clarithromycin, metronidazole, amoxicillin, levofloxacin, tetracycline, and furazolidone) resistance with or without China or different regions of China. The data analysis was performed using MedCalc 15.2.2. Each article was weighted according to the number of isolated H. pylori strains. A pooled proportion analysis was performed. Twenty-three studies (14 studies in English and 9 in Chinese) were included in this review. A total of 6274, 6418, 3921, 5468, 2802, and 275 H. pylori strains were included in this review to evaluate the prevalence of H. pylori primary resistance to clarithromycin, metronidazole, levofloxacin, amoxicillin, tetracycline, and furazolidone, respectively. Overall, the primary resistance rates of clarithromycin, metronidazole, levofloxacin, amoxicillin, tetracycline, and furazolidone were 28.9, 63.8, 28.0, 3.1, 3.9, and 1.7%, respectively. In China, the prevalence of H. pylori primary resistance to clarithromycin, metronidazole, and levofloxacin was high and increased over time, whereas the resistance rates to amoxicillin, tetracycline, and furazolidone were low and stable over time.

  20. PCR assay targeting virulence genes of Helicobacter pylori isolated from drinking water and clinical samples in Lahore metropolitan, Pakistan.

    PubMed

    Samra, Zahoor Qadir; Javaid, Umber; Ghafoor, Sadia; Batool, Aleeza; Dar, Nadia; Athar, Muhammad Amin

    2011-03-01

    Helicobacter pylorus is considered for chronic gastritis, gastric ulcers and adenocarcinoma and its high infection rate is observed in overcrowded and lower socioeconomic groups in developing countries. This study was designed to identify the role of drinking water in the transmission and prevalence of H. pylori (HP). Selective HP medium was developed for enrichment and presumptive identification of H. pylori by urease, catalase and species specific 16S rRNA tests. The virulence genes (vacA 's' and 'm' regions and cagA) of H. pylori in 90 out of 225 H. pylori positive drinking water samples were present (40%). Ten out of 18 biopsies (55.55%) and 15 out of 50 vomiting fluids of gastric disease patients (30%) were also positive for virulence genes. Anti-H. pylori antibodies were also detected in 31 out of 50 patients' sera. The presence of virulence genes was also directly confirmed by hybridization studies using non-radioactive DNA probes of 16S rRNA, vacA and cagA genes. The presence of H. pylori in water is due to poor sanitary conditions, improper waste disposal and lack of public health education. PCR-based analysis and colony hybridization can be used for detection of H. pylori in clinical and environmental samples.

  1. Helicobacter pylori can be induced to assume the morphology of Helicobacter heilmannii.

    PubMed

    Fawcett, P T; Gibney, K M; Vinette, K M

    1999-04-01

    Cultures of Helicobacter pylori obtained from the American Type Culture Collection (strain 43504) were grown as isolated colonies or lawns on blood agar plates and in broth culture with constant shaking. Examination of bacterial growth with Gram-stained fixed preparation and differential interference contrast microscopy on wet preparations revealed that bacteria grown on blood agar plates had a morphology consistent with that normally reported for H. pylori whereas bacteria from broth cultures had the morphologic appearance of Helicobacter heilmannii. Bacteria harvested from blood agar plates assumed an H. heilmannii-like morphology when transferred to broth cultures, and bacteria from broth cultures grew with morphology typical of H. pylori when grown on blood agar plates. Analysis by PCR of bacteria isolated from blood agar plates and broth cultures indicated that a single strain of bacteria (H. pylori) was responsible for both morphologies.

  2. In vitro synergistic effect of Hibiscus sabdariffa aqueous extract in combination with standard antibiotics against Helicobacter pylori clinical isolates.

    PubMed

    Hassan, Sherif T S; Berchová, Kateřina; Majerová, Michaela; Pokorná, Marie; Švajdlenka, Emil

    2016-09-01

    Context The increasing problem of drug-resistant strains has led to the failure of current treatment regimens of Helicobacter pylori (HP) infection. Recently, a new treatment strategy has been developed to overcome the problem by using natural products in combination with antibiotics to enhance the treatment efficacy. Objective The antimicrobial combinatory effect of the aqueous extract of Hibiscus sabdariffa L. (Malvaceae) (AEHS) with antibiotics (clarithromycin, CLA; amoxicillin, AMX; metronidazole, MTZ) has been evaluated in vitro against HP strains. Materials and methods Hibiscus calyces (35 g) were brewed in 250 mL of boiled water for 30 min, and minimum inhibitory concentrations (MICs) were determined by agar dilution method. The checkerboard assay was used to evaluate the antimicrobial combinatory effect according to the sum of fractional inhibitory concentration (∑FIC) indices. Results In this study, AEHS exerted remarkable bacteriostatic effect against all HP strains tested with MICs values ranging from 9.18 to 16.68 μg/mL. Synergy effect of AEHS with CLA or MTZ was obtained against four of seven HP strains tested with ∑FIC ranging from 0.21 to 0.39. The additive effect of AEHS with AMX was obtained against five of seven HP strains tested with ∑FIC ranging from 0.61 to 0.91. Conclusion This study presents AEHS as a potent therapeutic candidate alone, or in combination with antibiotics for the treatment of HP infection.

  3. Helicobacter pylori isolated from Iranian drinking water: vacA, cagA, iceA, oipA and babA2 genotype status and antimicrobial resistance properties.

    PubMed

    Ranjbar, Reza; Khamesipour, Faham; Jonaidi-Jafari, Nematollah; Rahimi, Ebrahim

    2016-05-01

    Despite the clinical importance of Helicobacter pylori in human gastric disorders, its exact route of transmission is still uncertain. Based on the contentious hypothesis and findings of previous investigations, water may play an important role in the transmission of H. pylori to humans. This study was carried out to investigate the vacA, cagA, oipA, iceA and babA2 genotype status and antimicrobial resistance properties of H. pylori strains isolated from the drinking water samples of four major provinces in Iran. A total of 400 drinking water samples were cultured and tested. H. pylori-positive strains were analyzed for the presence of various genotypes and antimicrobial resistance. Twelve of 400 (3%) water samples were positive for H. pylori. Samples from Isfahan province had the highest, while those from Shiraz had the lowest prevalence of H. pylori. The seasonal distribution was also determined, with the highest prevalence of bacteria in the summer season (7.36%). H. pylori strains harbored the highest levels of resistance against ampicillin (100%), erythromycin (75%), clarithromycin (75%), and trimethoprim (58.3%). The most commonly detected genotypes were vacAs1a (83.3%), vacAm1a (66.6%), vacAs2 (50%) and cagA (50%). The presence of similar genotypes in the H. pylori strains of drinking water and those of human clinical samples suggest that contaminated water maybe the sources of bacteria. Spiramycin and furazolidone are suggested for the treatment of cases of H. pylori infection.

  4. Helicobacter pylori outer membrane protein Q allele distribution is associated with distinct pathologies in Pakistan.

    PubMed

    Yakoob, Javed; Abbas, Zaigham; Khan, Rustam; Salim, Saima Azhar; Awan, Safia; Abrar, Ambar; Jafri, Wasim

    2016-01-01

    Helicobacter pylori (H. pylori) strains expressing outer membrane protein Q (HopQ) promote adherence to the gastric epithelial cell. We characterized HopQ alleles in relation to H. pylori-related disease, histology and virulence markers. Gastric biopsies were obtained at esophagogastroduodenoscopy from patients with upper gastrointestinal symptoms. H. pylori culture, histology and polymerase chain reaction (PCR) for HopQ types, cagA, cagA-promoter and vacA alleles were performed. DNA extracted was used for PCR. Sequencing of PCR products of HopQ types 1 and 2 was followed by BLAST query. We examined 241 H. pylori isolates. HopQ type 1 was positive in 70 (29%) isolates, type 2 in 60 (25%) isolates, while both type 1 and type 2 in 111 (46%) H. pylori isolates, respectively. Nonulcer dyspepsia (NUD) was associated with HopQ type 2 in 48 (41%) isolates, while gastric carcinoma (GC) in 37 (53%) (P<0.001) with type 1 isolates. Gastric ulcers (GU) were 39 (46%) (P<0.001) in H. pylori infection with multiple HopQ alleles compared to 6 (23%) in HopQ type 1. Multivariate analysis demonstrated that multiple HopQ alleles were associated with GU OR 2.9 (1.07-7.8) (P=0.03). HopQ type 1 was associated with cagA 58 (84%) (P<0.001) and cagA-promoter 58 (83%) (P<0.001) compared to 14 (23%) and 17 (28%) respectively, in type 2. VacAs1a was associated with HopQ type 1 in 59 (84%) isolates compared to HopQ type 2 in 35 (58%) (P=0.002) isolates. VacAm1 was associated with HopQ type 1 in 53 (76%) isolates compared to HopQ type 2 in 32 (53%) (P=0.004) isolates. H. pylori infection with multiple HopQ alleles was predominant. H. pylori infection with single HopQ type 1 was associated with GC in the presence of other H. pylori virulence markers. Copyright © 2015 Elsevier B.V. All rights reserved.

  5. Polyphasic characterization of Gluconacetobacter diazotrophicus isolates obtained from different sugarcane varieties

    PubMed Central

    Guedes, Helma V.; dos Santos, Samuel T.; Perin, Liamara; Teixeira, Kátia R. dos S.; Reis, Veronica M.; Baldani, José I.

    2008-01-01

    A polyphasic approach was applied to characterize 35 G. diazotrophicus isolates obtained from sugarcane varieties cultivated in Brazil. The isolates were analyzed by phenotypic (use of different carbon sources) and genotypic tests (ARDRA and RISA–RFLP techniques). Variability among the isolates was observed in relation to the carbon source use preference. Glucose and sucrose were used by all isolates in contrast to myo-inositol, galactose and ribose that were not metabolized. The results of the analysis showed the presence of two groups clustered at 68% of similarity. The genetic distance was higher when RISA-RFLP analysis was used. Analysis of 16S rDNA sequences from isolates showed that all of them belonged to the G. diazotrophicus species. Neither effect of the plant part nor sugarcane variety was observed during the cluster analysis. The observed metabolic and genetic variability will be helpful during the strain selection studies for sugarcane inoculation in association with sugarcane breeding programs. PMID:24031296

  6. TECHNICAL NOTE: Characteristics of a magneto-rheological fluid isolator obtained by permanent magnet arrangements

    NASA Astrophysics Data System (ADS)

    Oh, Hyun-Ung

    2004-06-01

    This note focuses on the characteristics of a magneto-rheological (MR) fluid isolator obtained by five permanent magnet arrangements. The basic characteristics of the isolator with various magnetic arrangements were measured from quasi-static tests, and their equivalent models were proposed. The appropriate magnet arrangement for implementing a device that can be used to prevent damage and alignment shift of on-board satellite equipment due to the shock and vibration during lift-off and, at the same time, to isolate disturbances generated by on-orbit momentum- or reaction-wheel operation was investigated.

  7. Antifungal activity of itraconazole and voriconazole against clinical isolates obtained from animals with mycoses.

    PubMed

    Okabayashi, Ken; Imaji, Mashio; Osumi, Takafumi; Murakami, Yoshihiko; Maruyama, Haruhiko; Kano, Rui; Hasegawa, Atsuhiko; Watanabe, Toshi

    2009-01-01

    Animal mycosis, particularly deep mycosis, is one of the most challenging conditions encountered by veterinarians. Pathogens causing mycotic infections in animals include fungi such as Cryptococcus neoformans, Candida spp., and Aspergillus spp. The antifungal drugs used for the treatment of deep mycoses in animals as well as humans are polyenes and azoles. However, the sensitivity of clinical isolates obtained from animals toward these drugs has rarely been assayed. In this study, the antifungal activities of itraconazole and voriconazole against clinical isolates of C. neoformans, Candida spp., and A. fumigatus isolated from animals with mycoses were examined using the broth microdilution method performed according to the guidelines provided by the Clinical and Laboratory Standards Institute. The minimum inhibitory concentrations (MICs) of itraconazole toward the C. neoformans, Candida spp., and A. fumigatus isolates were 0.125 - 1, 0.125 - 2, and 0.25 - 2 microg/ml, respectively, and those of voriconazole were 0.0625 - 0.5, < or =0.0313 - 0.0625, and 0.0625 - 1 microg/ml, respectively. The results of the MIC analyses implied that the fungal isolates obtained from infected animals exhibit an equivalent degree of susceptibility to itraconazole and voriconazole, as is observed in the case of isolates obtained from humans. The appropriate antifungal therapeutic strategy for the treatment of mycoses in animals must be selected taking into consideration the host immune status and organ function as well as the in vitro sensitivity of the pathogens to antifungal drugs.

  8. Antibacterial resistance and the success of tailored triple therapy in Helicobacter pylori strains isolated from Slovenian children.

    PubMed

    Butenko, Tita; Jeverica, Samo; Orel, Rok; Homan, Matjaž

    2017-10-01

    Primary Helicobacter pylori (H. pylori) infection occurs predominantly in childhood. Antimicrobial resistance is the leading cause for H. pylori eradication failure. The aims of this study were (i) to establish for the first time the antimicrobial resistance of H. pylori strains in infected Slovenian children not previously treated for H. pylori infection and (ii) to evaluate the effectiveness of tailored triple therapy, assuming that eradication rate with tailored triple therapy will be >90%. Data on all treatment-naive children 1-18 years old and treated for H. pylori infection according to susceptibility testing were retrospectively analyzed. All relevant clinical information and demographical information were retrospectively collected from the hospital information systems and/or patients' medical documentation. The inclusion criteria were met by 107 children (64.5% girls) with a median age of 12.0 years (range 2.0-17.6 years). Primary antimicrobial resistance rates of H. pylori were 1.0% to amoxicillin (AMO), 23.4% to clarithromycin (CLA), 20.2% to metronidazole (MET), 2.8% to levofloxacin (LEV), and 0.0% to tetracycline (TET). Dual resistances were detected to CLA and MET in 11.5% (n=12) of strains, to CLA and LEV in 2.8% (n=3), and to MET and LEV in 2.9% (n=3). Results of treatment success were available for 71 patients (66.2% girls). Eradication of H. pylori was evaluated using the 13C-urea breath test, monoclonal stool antigen test or in some cases with repeated upper GI endoscopy with histology and cultivation/molecular tests. Eradication was achieved in 61 of 71 (85.9%) patients. The primary resistance rates of H. pylori to CLA and MET in Slovenia are high. Our data strongly support the fact that in countries with high prevalence of resistant H. pylori strains susceptibility testing and tailored therapy is essential. © 2017 The Authors Helicobacter Published by John Wiley & Sons Ltd.

  9. Triazole Resistance in Aspergillus fumigatus Clinical Isolates Obtained in Nanjing, China

    PubMed Central

    Zhang, Ming; Feng, Chun-Lai; Chen, Fei; He, Qian; Su, Xin; Shi, Yi

    2017-01-01

    Background: During the past decades, the incidence of invasive aspergillosis (IA) caused by Aspergillus fumigatus has increased dramatically. The aims of this study were to investigate the susceptibility of clinical isolates of A. fumigatus to triazole and the underlying cyp51A mutations in triazole-resistant A. fumigatus. Methods: A total of 126 A. fumigatus clinical isolates from 126 patients with proven or probable IA were obtained from four large tertiary hospitals in Nanjing, China, between August 2012 and July 2015. The determination of minimal inhibitory concentrations (MICs) for itraconazole, voriconazole, and posaconazole was performed by broth microdilution according to the European Committee on Antimicrobial Susceptibility Testing reference method. Results: A total of 4 A. fumigatus isolates (3.17%) were confirmed to be itraconazole resistant, with MICs of ≥8 mg/L, and one isolate (0.8%) was confirmed to be voriconazole resistant and posaconazole resistant, with MICs of 4 mg/L and 0.5 mg/L, respectively. We found that two of the 4 isolates of triazole-resistant A. fumigatus had the L98H amino acid substitution in combination with a 34-base pair tandem repeat in the promoter region, one isolate had an M220I mutation, and another itraconazole-resistant isolate did not have a substitution in the cyp51A gene. Conclusions: This study shows that triazole-resistant A. fumigatus clinical isolates are present in Nanjing, China, which is a new challenge to the clinical management of IA. PMID:28303848

  10. Analysis of the genetic diversity of Candida isolates obtained from diabetic patients and kidney transplant recipients

    PubMed Central

    Benedetti, Volmir Pitt; Savi, Daiani Cristina; Aluizio, Rodrigo; Adamoski, Douglas; Kava-Cordeiro, Vanessa; Galli-Terasawa, Lygia V; Glienke, Chirlei

    2016-01-01

    Yeasts of the genus Candida have high genetic variability and are the most common opportunistic pathogenic fungi in humans. In this study, we evaluated the genetic diversity among 120 isolates of Candida spp. obtained from diabetic patients, kidney transplant recipients and patients without any immune deficiencies from Paraná state, Brazil. The analysis was performed using the ITS1-5.8S-ITS2 region and a partial sequence of 28S rDNA. In the phylogenetic analysis, we observed a consistent separation of the species C. albicans, C. dubliniensis, C. glabrata, C. tropicalis, C. parapsilosis, C. metapsilosis and C. orthopsilosis, however with low intraspecific variability. In the analysis of the C. albicans species, two clades were formed. Clade A included the largest number of isolates (91.2%) and the majority of isolates from GenBank (71.4%). The phylogenetic analysis showed low intraspecific genetic diversity, and the genetic polymorphisms between C. albicans isolates were similar to genetic divergence found in other studies performed with isolates from Brazil. This low genetic diversity of isolates can be explained by the geographic proximity of the patients evaluated. It was observed that yeast colonisation was highest in renal transplant recipients and diabetic patients and that C. albicans was the species most frequently isolated. PMID:27276363

  11. Analysis of the genetic diversity of Candida isolates obtained from diabetic patients and kidney transplant recipients.

    PubMed

    Benedetti, Volmir Pitt; Savi, Daiani Cristina; Aluizio, Rodrigo; Adamoski, Douglas; Kava-Cordeiro, Vanessa; Galli-Terasawa, Lygia V; Glienke, Chirlei

    2016-06-07

    Yeasts of the genus Candida have high genetic variability and are the most common opportunistic pathogenic fungi in humans. In this study, we evaluated the genetic diversity among 120 isolates of Candida spp. obtained from diabetic patients, kidney transplant recipients and patients without any immune deficiencies from Paraná state, Brazil. The analysis was performed using the ITS1-5.8S-ITS2 region and a partial sequence of 28S rDNA. In the phylogenetic analysis, we observed a consistent separation of the species C. albicans, C. dubliniensis, C. glabrata, C. tropicalis, C. parapsilosis, C. metapsilosis and C. orthopsilosis, however with low intraspecific variability. In the analysis of the C. albicans species, two clades were formed. Clade A included the largest number of isolates (91.2%) and the majority of isolates from GenBank (71.4%). The phylogenetic analysis showed low intraspecific genetic diversity, and the genetic polymorphisms between C. albicans isolates were similar to genetic divergence found in other studies performed with isolates from Brazil. This low genetic diversity of isolates can be explained by the geographic proximity of the patients evaluated. It was observed that yeast colonisation was highest in renal transplant recipients and diabetic patients and that C. albicans was the species most frequently isolated.

  12. Preparation and Respirometric Assessment of Mitochondria Isolated from Skeletal Muscle Tissue Obtained by Percutaneous Needle Biopsy

    PubMed Central

    Bharadwaj, Manish S.; Tyrrell, Daniel J.; Lyles, Mary F.; Demons, Jamehl L.; Rogers, George W.; Molina, Anthony J. A.

    2015-01-01

    Respirometric profiling of isolated mitochondria is commonly used to investigate electron transport chain function. We describe a method for obtaining samples of human Vastus lateralis, isolating mitochondria from minimal amounts of skeletal muscle tissue, and plate based respirometric profiling using an extracellular flux (XF) analyzer. Comparison of respirometric profiles obtained using 1.0, 2.5 and 5.0 μg of mitochondria indicate that 1.0 μg is sufficient to measure respiration and that 5.0 μg provides most consistent results based on comparison of standard errors. Western blot analysis of isolated mitochondria for mitochondrial marker COX IV and non-mitochondrial tissue marker GAPDH indicate that there is limited non-mitochondrial contamination using this protocol. The ability to study mitochondrial respirometry in as little as 20 mg of muscle tissue allows users to utilize individual biopsies for multiple study endpoints in clinical research projects. PMID:25741892

  13. Properties of two Lymantria dispar nuclear polyhedrosis virus isolates obtained from the microbial pesticide Gypchek

    Treesearch

    James M. Slavicek; John Podgwaite; Carita. Lanner-Herrera

    1992-01-01

    Two Lymantria dispar nuclear polyhedrosis virus isolates, 5-6 and A2-1, differing in the phenotypic characteristic of the number of viral occlusions in infected cells, were obtained from a production lot of the microbial pesticide Gypchek and several of their replication properties were investigated and compared. Budded virus titer produced in cell...

  14. Helicobacter pylori eradication therapy.

    PubMed

    Suzuki, Hidekazu; Nishizawa, Toshihiro; Hibi, Toshifumi

    2010-04-01

    Helicobacter pylori infection is the main cause of gastritis, gastroduodenal ulcers and gastric cancer. H. pylori eradication has been shown to have a prophylactic effect against gastric cancer. According to several international guidelines, the first-line therapy for treating H. pylori infection consists of a proton pump inhibitor (PPI) or ranitidine bismuth citrate, with any two antibiotics among amoxicillin, clarithromycin and metronidazole, given for 7-14 days. However, even with these recommended regimens, H. pylori eradication failure is still seen in more than 20% of patients. The failure rate for first-line therapy may be higher in actual clinical practice, owing to the indiscriminate use of antibiotics. The recommended second-line therapy is a quadruple regimen composed of tetracycline, metronidazole, a bismuth salt and a PPI. The combination of PPI-amoxicillin-levofloxacin is a good option as second-line therapy. In the case of failure of second-line therapy, the patients should be evaluated using a case-by-case approach. European guidelines recommend culture before the selection of a third-line treatment based on the microbial antibiotic sensitivity. H. pylori isolates after two eradication failures are often resistant to both metronidazole and clarithromycin. The alternative candidates for third-line therapy are quinolones, tetracycline, rifabutin and furazolidone; high-dose PPI/amoxicillin therapy might also be promising.

  15. Change in antibiotic resistance of Helicobacter pylori strains and the effect of A2143G point mutation of 23S rRNA on the eradication of H. pylori in a single center of Korea.

    PubMed

    Hwang, Tae Jun; Kim, Nayoung; Kim, Hong Bin; Lee, Byoung Hwan; Nam, Ryoung Hee; Park, Ji Hyun; Lee, Mi Kyoung; Park, Young Soo; Lee, Dong Ho; Jung, Hyun Chae; Song, In Sung

    2010-09-01

    The current prevalence of primary antibiotic resistance of H. pylori is not known in Korea. This study was done to evaluate the prevalence of primary antibiotic resistance of H. pylori, and to evaluate the effect of point mutations of 23S rRNA on the rate of eradication of H. pylori. H. pylori were isolated from gastric mucosal biopsy specimens obtained from 222 Koreans. The susceptibilities of the H. pylori isolates to amoxicillin, clarithromycin, metronidazole, tetracycline, ciprofloxacin, and levofloxacin were examined using the agar dilution method. DNA sequencing was carried out to detect H. pylori 23S rRNA mutations. The resistance to clarithromycin, tetracycline, ciprofloxacin, and levofloxacin increased during the period of 2007 to 2009 compared with 2003 to 2005 (P<0.05). However, amoxicillin and metronidazole resistance slightly decreased. The rates of eradication were 95.5% for the clarithromycin-sensitive strains, which was higher than the 67.9% for the clarithromycin-resistant strains (P=0.001). By contrast, the eradication rate was 100% in patients with amoxicillin-resistant H. pylori. Among 26 clarithromyin-resistant strains, 6 (23%) had A2143G mutations, and all of the cases in which these mutations were present were not eradicated by proton pump inhibitor-based triple therapy (P=0.0004). By contrast, none of the 26 clarithromyin-sensitive strains had A2143G mutations. The T2183C and A2223G mutations were frequently found in the sensitive strains and in the resistant strains. Clarithromycin resistance of H. pylori, which determined the efficacy of H. pylori eradication of proton pump inhibitor triple regimen, was found to be increased in a single center study. A2143G was an important 23S rRNA mutation associated with clarithromycin resistance and affected the H. pylori eradication efficacy.

  16. Pathogenicity and phenotypic sulfadiazine resistance of Toxoplasma gondii isolates obtained from livestock in northeastern Brazil.

    PubMed

    Oliveira, Claudio Bs; Meurer, Ywlliane Sr; Andrade, Joelma Ma; Costa, Maria Esm; Andrade, Milena Mc; Silva, Letícia A; Lanza, Daniel Cf; Vítor, Ricardo Wa; Andrade-Neto, Valter F

    2016-06-03

    Toxoplasma gondii is the causative protozoan agent of toxoplasmosis, which is a common infection that is widely distributed worldwide. Studies revealed stronger clonal strains in North America and Europe and genetic diversity in South American strains. Our study aimed to differentiate the pathogenicity and sulfadiazine resistance of three T. gondii isolates obtained from livestock intended for human consumption. The cytopathic effects of the T. gondii isolates were evaluated. The pathogenicity was determined by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) using a CS3 marker and in a rodent model in vivo. Phenotypic sulfadiazine resistance was measured using a kinetic curve of drug activity in Swiss mice. IgM and IgG were measured by ELISA, and the dihydropteroate synthase (DHPS) gene sequence was analysed. The cytopathic effects and the PCR-RFLP profiles from chickens indicated a different infection source. The Ck3 isolate displayed more cytopathic effects in vitro than the Ck2 and ME49 strains. Additionally, the Ck2 isolate induced a differential humoral immune response compared to ME49. The Ck3 and Pg1 isolates, but not the Ck2 isolate, showed sulfadiazine resistance in the sensitivity assay. We did not find any DHPS gene polymorphisms in the mouse samples. These atypical pathogenicity and sulfadiazine resistance profiles were not previously reported and served as a warning to local health authorities.

  17. Experimental infections with Paracoccidioides brasiliensis obtained from armadillos: comparison to clinical isolates.

    PubMed

    Nishikaku, Angela Satie; Peraçoli, Maria Terezinha S; Bagagli, Eduardo; Sugizaki, Maria Fátima; Sartori, Alexandrina

    2008-02-01

    Paracoccidioides brasiliensis causes paracoccidioidomycosis (PCM) that is one of the most prevalent systemic human mycoses in Latin America. Armadillos show a high incidence of PCM infection and could, therefore, be a natural reservoir for this fungus. In this study were compared the virulence profiles of isolates obtained from nine-banded armadillos (Dasypus novemcinctus) (PbT1 and PbT4) and isolates from PCM patients (Pb265 and Bt83). Pathogenicity was evaluated by fungal load and analysis of colony morphology. Immunity against the fungus was tested by delayed type hypersensitivity test (DTH) and antibody quantification by ELISA. The higher virulence of PbT1 and PbT4 was suggested by higher fungal load in spleen and lungs. Armadillo isolates and Bt83 presented a cotton-like surface contrasting with the cerebriform appearance of Pb265. All isolates induced cellular and humoral immune responses in infected BALB/c mice. DTH reactions were similarly induced by the four isolates, however, a great variability was observed in specific antibody levels, being the highest ones induced by Bt83 and PbT4. The present work confirms that armadillos harbor P. brasiliensis, whose multiplication and induced immunity in experimentally infected mice are heterogeneous, resembling the behavior of isolates from human PCM. This study reinforces the possibility that armadillos play an important role in the biological cycle of this pathogen.

  18. Identification of virulence genes carried by bacteriophages obtained from clinically isolated methicillin-resistant Staphylococcus aureus.

    PubMed

    Karasartova, Djursun; Cavusoglu, Zeynep Burcin; Turegun, Buse; Ozsan, Murat T; Şahin, Fikret

    2016-12-01

    Bacteriophages play an important role in the pathogenicity of Staphylococcus aureus (S. aureus) either by carrying accessory virulence factors or several superantigens. Despite their importance, there are not many studies showing the actual distribution of the virulence genes carried by the prophages obtained from the clinically isolated Staphylococcus. In this study, we investigated prophages obtained from methicillin-resistant S. aureus (MRSA) strains isolated from hospital- and community-associated (HA-CA) infections for the virulence factors. In the study, 43 phages isolated from 48 MRSA were investigated for carrying toxin genes including the sak, eta, lukF-PV, sea, selp, sek, seg, seq chp, and scn virulence genes using polymerase chain reaction (PCR) and Southern blot. Restriction fragment length polymorphism was used to analyze phage genomes to investigate the relationship between the phage profiles and the toxin genes' presence. MRSA strains isolated from HA infections tended to have higher prophage presence than the MRSA strains obtained from the CA infections (97% and 67%, respectively). The study showed that all the phages with the exception of one phage contained one or more virulence genes in their genomes with different combinations. The most common toxin genes found were sea (83%) followed by sek (77%) and seq (64%). The study indicates that prophages encode a significant proportion of MRSA virulence factors.

  19. Bacteriology of Helicobacter pylori.

    PubMed

    Owen, R J

    1995-09-01

    The discovery and first isolation of H. pylori in pure culture from gastric biopsies in 1982 provided the basis for a completely new area of microbiology. Since then, H. pylori has been an intensively pursued topic world-wide, and extensive data have been acquired on all aspects of its basic microbiology, both at the conventional phenotypic level and at the molecular level. H. pylori is a remarkable microorganism because of its ability to readily colonize a major proportion of human population worldwide and to persist successfully for long periods (probably decades) in a hostile environment. At the same time it interacts with the host immune system in such a way as to permit long-term survival. Blaser (1993) proposed a model in which both host and parasite adapt to down regulate inflammatory phenomena to promote survival. Urease production by H. pylori (an important factor in that process) is one of its most distinct features with a key role in its success as an infective agent. Another less obvious yet highly significant feature of H. pylori is the ability to achieve a high degree of interstrain diversity in genomic DNA nucleotide sequences, while maintaining overall genetic homology and phenotypic homogeneity amongst strains. The selective advantage this diversity provides the bacterium is not understood. A key objective of future microbiological studies should be to understand the population genetic structure of H. pylori. Most species of bacteria are clonal in natural population structure, yet all genomic data suggest the contrary is true for H. pylori. Furthermore, it is not clear if all strains of H. pylori are equally pathogenic, and that some subsets may possess additional pathogenicity factors that are responsible for the development of different disease pathologies. A phylogenetic framework of the genetic relationships of the clones within H. pylori would enable an examination of the total genetic diversity, with respect to ethnic or geographical

  20. Characterization of rhizobia isolates obtained from nodules of wild genotypes of common bean.

    PubMed

    Cardoso, Aline Assis; Andraus, Michel de Paula; Borba, Tereza Cristina de Oliveira; Martin-Didonet, Claudia Cristina Garcia; Ferreira, Enderson Petrônio de Brito

    This study aimed to evaluate the tolerance to salinity and temperature, the genetic diversity and the symbiotic efficiency of rhizobia isolates obtained from wild genotypes of common bean cultivated in soil samples from the States of Goiás, Minas Gerais and Paraná. The isolates were subjected to different NaCl concentrations (0%, 1%, 2%, 4% and 6%) at different temperatures (28°C, 33°C, 38°C, 43°C and 48°C). Genotypic characterization was performed based on BOX-PCR, REP-PCR markers and 16S rRNA sequencing. An evaluation of symbiotic efficiency was carried out under greenhouse conditions in autoclaved Leonard jars. Among 98 isolates about 45% of them and Rhizobium freirei PRF81 showed a high tolerance to temperature, while 24 isolates and Rhizobium tropici CIAT899 were able to use all of the carbon sources studied. Clustering analysis based on the ability to use carbon sources and on the tolerance to salinity and temperature grouped 49 isolates, R. tropici CIAT899 and R. tropici H12 with a similarity level of 76%. Based on genotypic characterization, 65% of the isolates showed an approximately 66% similarity with R. tropici CIAT899 and R. tropici H12. About 20% of the isolates showed symbiotic efficiency similar to or better than the best Rhizobium reference strain (R. tropici CIAT899). Phylogenetic analysis of the 16S rRNA revealed that two efficient isolates (ALSG5A1 and JPrG6A8) belong to the group of strains used as commercial inoculant for common bean in Brazil and must be assayed in field experiments.

  1. Nucleotide substitutions in vanC-2 gene of Enterococcus casseliflavus isolates obtained from chickens.

    PubMed Central

    Murase, T.; Mito, Y.; Otsuki, K.; Suzuki, R.; Yamai, S.

    2002-01-01

    DNA sequencing of the vanC-2 gene was partially carried out on 10 isolates of Enterococcus casseliflavus obtained from 8 samples of imported chickens in Japan between July 1999 and June 2001 to evaluate the variation in the gene. Forty nucleotide substitutions in 36 codons were identified within 345 base pairs when compared with the vanC-2 sequence of the reference strain E. casseliflavus ATCC25788. Identical nucleotide substitutions were commonly found in the isolates recovered from chickens imported from both Brazil and China. Pulsed-field gel electrophoresis (PFGE) patterns of NotI-digested chromosomal DNA of these strains were distinguished by two, or more than six, band differences. These observations suggest that sequencing of the vanC-2 gene may be helpful for epidemiological investigation in combination with the PFGE analyses of the isolates, although particular genotypes are unlikely to be restricted to each of the countries that exported chickens. PMID:12403118

  2. Bacteriocinogenic and virulence potential of Enterococcus isolates obtained from raw milk and cheese.

    PubMed

    Moraes, P M; Perin, L M; Todorov, S D; Silva, A; Franco, B D G M; Nero, L A

    2012-08-01

    To provide molecular and phenotypical characterization of Enterococcus isolates obtained from raw milk and cheese, regarding their bacteriocinogenic and virulence activity. Forty-three bacteriocinogenic enterococci isolates were identified by 16s rDNA, fingerprinted by RAPD-PCR analysis and tested by PCR for the presence of genes for lantibiotics (lanM, lanB and lanC) and enterocins (entA, entB, entP, entL50AB and entAS48) and by phenotypical methods for bacteriocin production and inhibitory spectrum. Also, the virulence of the isolates was evaluated by PCR for genes gelE, hyl, asa1, esp, cylA, efaA, ace, vanA, vanB, hdc1, hdc2, tdc and odc and by phenotypical tests for gelatinase, lipase, DNAse and α- and β-haemolysis. Most isolates (93·0%) harboured at least one lantibiotic or enterocin gene and were positive for several tested virulence genes, mainly asa1 (100%), gelE (93·0%) and efaA (83.7%). 53.5% of the isolates presented β-haemolysis [corrected]. Enterococcus spp. isolates presented an interesting potential application for food preservation because of bacteriocin production; however, virulence-related genes were identified in all RAPD profiles. The study demonstrated the contradictory characteristics of the tested Enterococcus isolates: they presented a good potential for application in food biopreservation but contained several virulence factors. © 2012 The Authors Journal of Applied Microbiology © 2012 The Society for Applied Microbiology.

  3. Pathogenicity and phenotypic sulfadiazine resistance ofToxoplasma gondii isolates obtained from livestock in northeastern Brazil

    PubMed Central

    Oliveira, Claudio BS; Meurer, Ywlliane SR; Andrade, Joelma MA; Costa, Maria ESM; Andrade, Milena MC; Silva, Letícia A; Lanza, Daniel CF; Vítor, Ricardo WA; Andrade-Neto, Valter F

    2016-01-01

    Toxoplasma gondii is the causative protozoan agent of toxoplasmosis, which is a common infection that is widely distributed worldwide. Studies revealed stronger clonal strains in North America and Europe and genetic diversity in South American strains. Our study aimed to differentiate the pathogenicity and sulfadiazine resistance of three T. gondiiisolates obtained from livestock intended for human consumption. The cytopathic effects of the T. gondii isolates were evaluated. The pathogenicity was determined by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) using a CS3 marker and in a rodent model in vivo. Phenotypic sulfadiazine resistance was measured using a kinetic curve of drug activity in Swiss mice. IgM and IgG were measured by ELISA, and the dihydropteroate synthase (DHPS) gene sequence was analysed. The cytopathic effects and the PCR-RFLP profiles from chickens indicated a different infection source. The Ck3 isolate displayed more cytopathic effects in vitro than the Ck2 and ME49 strains. Additionally, the Ck2 isolate induced a differential humoral immune response compared to ME49. The Ck3 and Pg1 isolates, but not the Ck2 isolate, showed sulfadiazine resistance in the sensitivity assay. We did not find any DHPS gene polymorphisms in the mouse samples. These atypical pathogenicity and sulfadiazine resistance profiles were not previously reported and served as a warning to local health authorities. PMID:27276184

  4. Occurrence of Mutations in the Antimicrobial Target Genes Related to Levofloxacin, Clarithromycin, and Amoxicillin Resistance in Helicobacter pylori Isolates from Buenos Aires City.

    PubMed

    Zerbetto De Palma, Gerardo; Mendiondo, Nicolas; Wonaga, Andrés; Viola, Luis; Ibarra, Daniela; Campitelli, Esteban; Salim, Nicolas; Corti, Rodolfo; Goldman, Cinthia; Catalano, Mariana

    2017-04-01

    Domain V of 23S rRNA, gyrA and gyrB Quinolones Resistance-Determining Region (QRDR), and pbp-1A gene point mutations were investigated in Helicobacter pylori-resistant isolates from three centres of Buenos Aires. Minimal inhibitory concentrations (MICs) were performed in 197 isolates from 52 H. pylori-positive naive patients by agar dilution method. Point mutations were achieved by amplification and sequencing of the target genes, and their association with resistance was determined by natural transformation assays. Resistance rates were as follows: metronidazole 28.8%, clarithromycin (CLA) 26.9%, levofloxacin (LEV) 32.7%, and amoxicillin (AMX) 7.6%. Nearly one-third of patients carried multidrug-resistant isolates. A2143G or A2142G in domain V of 23S-rRNA was found in all isolates showing high level of resistance to CLA (MIC >2 mg/L), accounting for 76.0% (38/50) of those with the resistant phenotype. The mutations A2267G or T1861C carried by 8/12 isolates with MIC 1-2 mg/L (low level) did not confer resistance by transformation. Substitutions at GyrA position 87 or 91, mainly N87K and D91G, were found in 92.8% (52/56) of the LEV-resistant isolates: 48 isolates with MIC 4-64 mg/L and 4/8 isolates with MIC 2 mg/L. The remaining four harboured K133N, also present in susceptible isolates. None of the substitutions in GyrB demonstrated to confer resistance. Transformation proved that PBP-1A N562Y and/or T556S substitutions confer the AMX resistance in our isolates, showing an additive effect. In conclusion, the usually reported mutations related to CLA, LEV, and AMX resistance were found in our isolates. However, low-level CLA resistance seems not to be due to mutations in Domain V of 23S rRNA gene.

  5. Occurrence of Mutations in the Antimicrobial Target Genes Related to Levofloxacin, Clarithromycin, and Amoxicillin Resistance in Helicobacter pylori Isolates from Buenos Aires City

    PubMed Central

    Zerbetto De Palma, Gerardo; Mendiondo, Nicolas; Wonaga, Andrés; Viola, Luis; Ibarra, Daniela; Campitelli, Esteban; Salim, Nicolas; Corti, Rodolfo; Goldman, Cinthia

    2017-01-01

    Domain V of 23S rRNA, gyrA and gyrB Quinolones Resistance-Determining Region (QRDR), and pbp-1A gene point mutations were investigated in Helicobacter pylori-resistant isolates from three centres of Buenos Aires. Minimal inhibitory concentrations (MICs) were performed in 197 isolates from 52 H. pylori-positive naive patients by agar dilution method. Point mutations were achieved by amplification and sequencing of the target genes, and their association with resistance was determined by natural transformation assays. Resistance rates were as follows: metronidazole 28.8%, clarithromycin (CLA) 26.9%, levofloxacin (LEV) 32.7%, and amoxicillin (AMX) 7.6%. Nearly one-third of patients carried multidrug-resistant isolates. A2143G or A2142G in domain V of 23S-rRNA was found in all isolates showing high level of resistance to CLA (MIC >2 mg/L), accounting for 76.0% (38/50) of those with the resistant phenotype. The mutations A2267G or T1861C carried by 8/12 isolates with MIC 1–2 mg/L (low level) did not confer resistance by transformation. Substitutions at GyrA position 87 or 91, mainly N87K and D91G, were found in 92.8% (52/56) of the LEV-resistant isolates: 48 isolates with MIC 4–64 mg/L and 4/8 isolates with MIC 2 mg/L. The remaining four harboured K133N, also present in susceptible isolates. None of the substitutions in GyrB demonstrated to confer resistance. Transformation proved that PBP-1A N562Y and/or T556S substitutions confer the AMX resistance in our isolates, showing an additive effect. In conclusion, the usually reported mutations related to CLA, LEV, and AMX resistance were found in our isolates. However, low-level CLA resistance seems not to be due to mutations in Domain V of 23S rRNA gene. PMID:27391421

  6. Resistance pattern of Helicobacter pylori strains to clarithromycin, metronidazole, and amoxicillin in Isfahan, Iran.

    PubMed

    Khademi, Farzad; Faghri, Jamshid; Poursina, Farkhondeh; Esfahani, Bahram Nasr; Moghim, Sharareh; Fazeli, Hossein; Adibi, Peyman; Mirzaei, Nasrin; Akbari, Mojtaba; Safaei, Hajieh Ghasemian

    2013-12-01

    Helicobacter pylori (H. pylori) resistance to antibiotics has become a global problem and is an important factor in determining the outcome of treatment of infected patients. The purpose of this study was to determine the H. pylori resistance to clarithromycin, metronidazole, and amoxicillin in gastrointestinal disorders patients. In this study, a total of 260 gastric antrum biopsy specimens were collected from patients with gastrointestinal disorders who referred to Endoscopy Section of the Isfahan Hospitals. The E-test and Modified Disk Diffusion Method (MDDM) were used to verify the prevalence of antibiotic resistance in 78 H. pylori isolates to the clarithromycin, metronidazole, and amoxicillin. H. pylori resistance to clarithromycin, metronidazole, and amoxicillin were 15.3, 55.1, and 6.4%, respectively. In this study, we had one multidrug resistance (MDR) isolates from patient with gastritis and peptic ulcer disease. Information on antibiotic susceptibility profile plays an important role in empiric antibiotic treatment and management of refractive cases. According to the results obtained in this study, H. pylori resistance to clarithromycin and metronidazole was relatively high. MDR strains are emerging and will have an effect on the combination therapy.

  7. Resistance pattern of Helicobacter pylori strains to clarithromycin, metronidazole, and amoxicillin in Isfahan, Iran

    PubMed Central

    Khademi, Farzad; Faghri, Jamshid; Poursina, Farkhondeh; Esfahani, Bahram Nasr; Moghim, Sharareh; Fazeli, Hossein; Adibi, Peyman; Mirzaei, Nasrin; Akbari, Mojtaba; Safaei, Hajieh Ghasemian

    2013-01-01

    Background: Helicobacter pylori (H. pylori) resistance to antibiotics has become a global problem and is an important factor in determining the outcome of treatment of infected patients. The purpose of this study was to determine the H. pylori resistance to clarithromycin, metronidazole, and amoxicillin in gastrointestinal disorders patients. Materials and Methods: In this study, a total of 260 gastric antrum biopsy specimens were collected from patients with gastrointestinal disorders who referred to Endoscopy Section of the Isfahan Hospitals. The E-test and Modified Disk Diffusion Method (MDDM) were used to verify the prevalence of antibiotic resistance in 78 H. pylori isolates to the clarithromycin, metronidazole, and amoxicillin. Results: H. pylori resistance to clarithromycin, metronidazole, and amoxicillin were 15.3, 55.1, and 6.4%, respectively. In this study, we had one multidrug resistance (MDR) isolates from patient with gastritis and peptic ulcer disease. Conclusion: Information on antibiotic susceptibility profile plays an important role in empiric antibiotic treatment and management of refractive cases. According to the results obtained in this study, H. pylori resistance to clarithromycin and metronidazole was relatively high. MDR strains are emerging and will have an effect on the combination therapy. PMID:24523796

  8. Complete Genome Sequences of Eight Helicobacter pylori Strains with Different Virulence Factor Genotypes and Methylation Profiles, Isolated from Patients with Diverse Gastrointestinal Diseases on Okinawa Island, Japan, Determined Using PacBio Single-Molecule Real-Time Technology.

    PubMed

    Satou, Kazuhito; Shiroma, Akino; Teruya, Kuniko; Shimoji, Makiko; Nakano, Kazuma; Juan, Ayaka; Tamotsu, Hinako; Terabayashi, Yasunobu; Aoyama, Misako; Teruya, Morimi; Suzuki, Rumiko; Matsuda, Miyuki; Sekine, Akihiro; Kinjo, Nagisa; Kinjo, Fukunori; Yamaoka, Yoshio; Hirano, Takashi

    2014-04-17

    We report the complete genome sequences of eight Helicobacter pylori strains isolated from patients with gastrointestinal diseases in Okinawa, Japan. Whole-genome sequencing and DNA methylation detection were performed using the PacBio platform. De novo assembly determined a single, complete contig for each strain. Furthermore, methylation analysis identified virulence factor genotype-dependent motifs.

  9. Comparison of Antimicrobial Susceptibility of Urogenital Neisseria gonorrhoeae Isolates Obtained From Women and Men.

    PubMed

    Kidd, Sarah; Moore, Page C; Kirkcaldy, Robert D; Philip, Susan S; Wiesenfeld, Harold C; Papp, John R; Kerndt, Peter R; Venkatasubramanian, Lalitha; Ghanem, Khalil G; Hook, Edward W

    2015-08-01

    The US system for gonococcal antimicrobial susceptibility surveillance monitors trends exclusively among men with urethral infection, the population from whom the yield of gonococcal culture is highest. Little is known about the susceptibility of female urogenital isolates, and it is unclear whether gonococcal susceptibility among men who report sex exclusively with women (MSW) is representative of susceptibility among women. Using isolates collected during a recent treatment trial in 5 US cities, we performed a secondary analysis to compare antimicrobial susceptibilities of Neisseria gonorrhoeae urogenital isolates obtained from women, MSW, and men who have sex with men (MSM). Pretreatment isolates were collected from trial participants; minimum inhibitory concentrations (MICs) were determined by agar dilution. Geometric mean MICs were adjusted for geographic location using general linear models. Susceptibility data for urogenital isolates from 56 women, 252 MSW, and 170 MSM were studied. The adjusted geometric mean ceftriaxone MIC was similar among women (0.0067 μg/mL; 95% confidence interval [CI], 0.0049-0.0092 μg/mL) and MSW (0.0060 μg/mL; 95% CI, 0.0053-0.0066 μg/mL). In contrast, the adjusted geometric mean ceftriaxone MIC was higher among MSM (0.0098 μg/mL; 95% CI, 0.0082-0.0119 μg/mL) than among MSW. This same pattern was observed for other antimicrobials, including cefixime and azithromycin Ceftriaxone, cefixime, and azithromycin MICs were higher among MSM than among MSW, but were similar among women and MSW. These findings suggest that gonococcal antimicrobial susceptibility surveillance based on urethral isolates from MSW may adequately represent susceptibility of urogenital N. gonorrhoeae in women.

  10. Comparison of Antimicrobial Susceptibility of Urogenital Neisseria gonorrhoeae Isolates Obtained from Women and Men

    PubMed Central

    Kidd, Sarah; Moore, Page C.; Kirkcaldy, Robert D.; Philip, Susan S.; Wiesenfeld, Harold C.; Papp, John R.; Kerndt, Peter R.; Venkatasubramanian, Lalitha; Ghanem, Khalil G.; Hook, Edward W.

    2015-01-01

    Background The United States’ (US) system for gonococcal antimicrobial susceptibility surveillance monitors trends exclusively among men with urethral infection, the population from whom the yield of gonococcal culture is highest. Little is known about the susceptibility of female urogenital isolates, and it is unclear whether gonococcal susceptibility among men who report sex exclusively with women (MSW) is representative of susceptibility among women. Methods Using isolates collected during a recent treatment trial in five US cities, we performed a secondary analysis to compare antimicrobial susceptibilities of N. gonorrhoeae urogenital isolates obtained from women, MSW, and men who have sex with men (MSM). Pre-treatment isolates were collected from trial participants; minimum inhibitory concentrations (MICs) were determined by agar dilution. Geometric mean MICs were adjusted for geographic location using general linear models. Results Susceptibility data for urogenital isolates from 56 women, 252 MSW, and 170 MSM were studied. The adjusted geometric mean ceftriaxone MIC was similar among women (0.0067 μg/ml, 95% CI 0.0049–0.0092 μg/ml) and MSW (0.0060 μg/ml, 95% CI 0.0053–0.0066 μg/ml). In contrast, the adjusted geometric mean ceftriaxone MIC was higher among MSM (0.0098 μg/ml, 95% CI 0.0082–0.0119 μg/ml) than MSW. This same pattern was observed for other antimicrobials, including cefixime and azithromycin Conclusions Ceftriaxone, cefixime, and azithromycin MICs were higher among MSM than MSW, but were similar among women and MSW. These findings suggest that gonococcal antimicrobial susceptibility surveillance based on urethral isolates from MSW may adequately represent susceptibility of urogenital N. gonorrhoeae in women. PMID:26165435

  11. HELICOBACTER PYLORI

    EPA Science Inventory

    Helicobacter pylori is a pathogenic bacteria which inhabits the human stomach and upper gastrointestinal tract. This encyclopedic entry summarizes the potential role of this organism as a waterborne pathogen. Information is provided on the physiology and morphology of this bacter...

  12. HELICOBACTER PYLORI

    EPA Science Inventory

    Helicobacter pylori is a pathogenic bacteria which inhabits the human stomach and upper gastrointestinal tract. This encyclopedic entry summarizes the potential role of this organism as a waterborne pathogen. Information is provided on the physiology and morphology of this bacter...

  13. H. pylori clinical isolates have diverse babAB genotype distributions over different topographic sites of stomach with correlation to clinical disease outcomes.

    PubMed

    Sheu, Shew-Meei; Sheu, Bor-Shyang; Chiang, Wen-Cheng; Kao, Cheng-Yen; Wu, Hsiu-Mei; Yang, Hsiao-Bai; Wu, Jiunn-Jong

    2012-05-30

    Intragenomic recombination between babA and babB mediates antigenic variations and may help H. pylori colonization. This study determined whether variable genotypes of babA and babB correlate to different clinical disease outcomes, and can distribute over the different gastric niches. This study enrolled 92 clinical strains (45 from peptic ulcer, 27 from gastritis, and 20 from gastric cancer) to detect whether the babA and babB are at locus A or B by PCR reactions using the primers designed from the upstream and variable region of the babA and babB genes. Four genotypes of babA and babB (A B, AB B, A AB, AB AB) were found. The distribution of the 4 genotypes in 92 clinical strains was significantly different among patients with different gastric diseases (p < 0.05). The isolates from gastric cancer patients had a higher rate of AB AB genotype than those from non-cancer patients (40.0% vs. 9.7%, p < 0.05). The AB AB genotype was associated with a higher intensity of intestinal metaplasia (p < 0.05), but did not correlate with a higher inflammation and colonization density in gastric histology (p > 0.05). Besides, the study enrolled 19 patients to verify whether variable genotypes of babAB existed in the different gastric niches. Among the patients infected with more than one babAB genotypes over antrum and corpus, there were higher rate of genotypes as A B or AB AB in isolates from antrum than in those from corpus (75.0 % vs. 16.7%, p < 0.05). The H. pylori isolate with the AB AB genotype correlates with an increased gastric cancer risk, and colonize in an antrum predominant manner.

  14. Amylase production potentials of bacterial isolates obtained from the gut of Oryctes rhinoceros larvae

    NASA Astrophysics Data System (ADS)

    Aryati, P. C.; Pangastuti, A.; Sari, S. L. A.

    2017-04-01

    Amylase is one of the main enzymes used in industry, such as food, detergent, textile, and pharmaceutical industry. Amylase can be produced by plants, animals, and microorganisms. However, bacterial and fungal amylases have dominated application in industries. This research was aimed to determine amylolytic activity of bacteria isolated from the gut of Oryctes rhinoceros larvae. Based on clear zone formation, 9 from 11 isolates showed amylolytic activity. Isolates with the widest clear zone, i.e Bacillus subtilis GOR1, Bacillus cereus GOR3, and Bacillus pumilus GOR2, were screened for amylolytic activity based on reduction sugar production. The result showed that Bacillus subtilis GOR1 was the most potential as amylase producer, showed by the widest clear zone 5.224 cm2 and highest reduction sugar production 0.0235 mg/ml. Highest amylase specific activity (0.1447 U/mg protein) was obtained at 60°C and pH 7. Amylase activity was stable for 3 hours at 60°C with residual activity respectively was 59.7%.

  15. Culture Method and PCR for the Detection of Helicobacter pylori in Drinking Water in Basrah Governorate Iraq.

    PubMed

    Al-Sulami, A A; Al-Edani, T A A; Al-Abdula, A A

    2012-01-01

    Helicobacter pylori is recognized by the World Health Organization to be the primary cause of peptic ulcers, chronic gastritis, and stomach cancer, though the source of human infection is not well understood. One of the problems in understanding the source of human contamination is the difficulty in isolating the organism from the environment. However, the combination of PCR results with those of culturing of 471 drinking water samples can provide a more accurate picture of H. pylori detection. In this method 78 presumptive H. pylori colonies out of 266 tap water samples were obtained in the preliminary detection on modified Columbia agar (MCUA) slant relying on urease positivity with a rate of 29.3%. However, only 11 out of them were confirmed by Gram staining and biochemical tests reducing the rate to 4.13% whereas only 3 (1.46%) from 205 reverse osmosis (RO) water samples. Furthermore, only 6 (54.5%) out of the 11 isolates from tap water and 1 (33.3%) of the 3 RO isolates were confirmed by 16SrRNA PCR. Thus PCR confirmation reduced the rate to 2.2%. In addition, only 4 (4%) of 100 tap water samples negative for H. pylori by culture method were H. pylori positive by 16SrRNA. Water samples were collected from 24 districts of Basrah Governorate from February-December 2009. The direct recovery of H. pylori from drinking water is both alarming and scientifically exciting in terms of the investigation of its epidemiology.

  16. Optimization of the isoelectric precipitation method to obtain protein isolates from amaranth (Amaranthus cruentus) seeds.

    PubMed

    Salcedo-Chávez, Beatriz; Osuna-Castro, Juan A; Guevara-Lara, Fidel; Domínguez-Domínguez, Jorge; Paredes-López, Octavio

    2002-10-23

    This research was conducted to evaluate the effect of extraction pH (7.8-9.2) and precipitation pH (4.3-5.7) on four selected quality attributes of protein isolates from amaranth seeds (Amaranthus cruentus) such as protein content (PC), whiteness index (WI), enthalpy of transition (EN), and denaturation temperature (DT). Ten different treatments involving extraction and precipitation pH combinations were analyzed by a central composite design; the experimental data were fitted by a second-order model using a least-squares method for each one of the four dependent variables. Response surface methodology was used for the optimization process; in addition, a common optimum value for the four dependent variables was obtained utilizing the desirability method. A confirmatory test showed that the generated regression equations could adequately predict performance of this isoelectric precipitation method. The results indicate that extraction pH and precipitation pH showed an important effect on PC, WI, and EN. However, the different combinations did not significantly affect the DT. Values of 9.2 and 8.0 for extraction pH and 5.7 for precipitation pH produced the best overall result for all responses. Finally, the results have shown that it is possible to obtain protein isolates from A. cruentus seeds at optimized values of extraction pH and precipitation pH, which presented a high protein content and good physicochemical properties.

  17. Characterization of bovine viral diarrhea virus isolates resistant to a novel antiviral compound obtained from persistently infected calves

    USDA-ARS?s Scientific Manuscript database

    The objective of this research was to characterize isolates resistant to a novel antiviral compound (DB772) isolated from persistently infected (PI) calves treated with the compound. Viral isolates were obtained from four Angus-cross beef calves (A,B,C,D) persistently infected with BVDV type 1 or 2 ...

  18. Whole genome sequencing of Mycobacterium bovis to obtain molecular fingerprints in human and cattle isolates from Baja California, Mexico.

    PubMed

    Sandoval-Azuara, Sarai Estrella; Muñiz-Salazar, Raquel; Perea-Jacobo, Ricardo; Robbe-Austerman, Suelee; Perera-Ortiz, Alejandro; López-Valencia, Gilberto; Bravo, Doris M; Sanchez-Flores, Alejandro; Miranda-Guzmán, Daniela; Flores-López, Carlos Alberto; Zenteno-Cuevas, Roberto; Laniado-Laborín, Rafael; de la Cruz, Fabiola Lafarga; Stuber, Tod P

    2017-10-01

    To determine genetic diversity by comparing the whole genome sequences of cattle and human Mycobacterium bovis isolates from Baja California. A whole genome sequencing strategy was used to obtain the molecular fingerprints of 172 isolates of M. bovis obtained from Baja California, Mexico; 155 isolates were from cattle and 17 isolates were from humans. Spoligotypes were characterized in silico and single nucleotide polymorphism (SNP) differences between the isolates were evaluated. A total of 12 M. bovis spoligotype patterns were identified in cattle and humans. Two predominant spoligotypes patterns were seen in both cattle and humans: SB0145 and SB1040. The SB0145 spoligotype represented 59% of cattle isolates (n=91) and 65% of human isolates (n=11), while the SB1040 spoligotype represented 30% of cattle isolates (n=47) and 30% of human isolates (n=5). When evaluating SNP differences, the human isolates were intimately intertwined with the cattle isolates. All isolates from humans had spoligotype patterns that matched those observed in the cattle isolates, and all human isolates shared common ancestors with cattle in Baja California based on SNP analysis. This suggests that most human tuberculosis caused by M. bovis in Baja California is derived from M. bovis circulating in Baja California cattle. These results reinforce the importance of bovine tuberculosis surveillance and control in this region. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  19. Ethnicity association of Helicobacter pylori virulence genotype and metronidazole susceptibility

    PubMed Central

    Alfizah, Hanafiah; Rukman, Awang Hamat; Norazah, Ahmad; Hamizah, Razlan; Ramelah, Mohamed

    2013-01-01

    AIM: To characterise the cag pathogenicity island in Helicobacter pylori (H. pylori) isolates by analysing the strains’ vacA alleles and metronidazole susceptibilities in light of patient ethnicity and clinical outcome. METHODS: Ninety-five H. pylori clinical isolates obtained from patients with dyspepsia living in Malaysia were analysed in this study. Six genes in the cagPAI region (cagE, cagM, cagT, cag13, cag10 and cag67) and vacA alleles of the H. pylori isolates were identified by polymerase chain reaction. The isolates’ metronidazole susceptibility was also determined using the E-test method, and the resistant gene was characterised by sequencing. RESULTS: More than 90% of the tested isolates had at least one gene in the cagPAI region, and cag67 was predominantly detected in the strains isolated from the Chinese patients, compared with the Malay and Indian patients (P < 0.0001). The majority of the isolates (88%) exhibited partial deletion (rearrangement) in the cagPAI region, with nineteen different patterns observed. Strains with intact or deleted cagPAI regions were detected in 3.2% and 8.4% of isolates, respectively. The prevalence of vacA s1m1 was significantly higher in the Malay and Indian isolates, whereas the isolates from the Chinese patients were predominantly genotyped as vacA s1m2 (P = 0.018). Additionally, the isolates from the Chinese patients were more sensitive to metronidazole than the isolates from the Malay and Indian patients (P = 0.047). Although we attempted to relate the cagPAI genotypes, vacA alleles and metronidazole susceptibilities to disease outcome, no association was observed. The vacA alleles were distributed evenly among the strains with intact, partially deleted or deleted cagPAI regions. Interestingly, the strains exhibiting an intact cagPAI region were sensitive to metronidazole, whereas the strains with a deleted cagPAI were more resistant. CONCLUSION: Successful colonisation by different H. pylori genotypes is

  20. Pathogenesis of Helicobacter pylori infection

    PubMed Central

    Sgouras, Dionyssios N.; Trang, Tran Thi Huyen; Yamaoka, Yoshio

    2015-01-01

    Three decades have passed since Warren and Marshall described the successful isolation and culture of Helicobacter pylori, the Gram-negative bacterium that colonizes the stomach of half the human population worldwide. Although it is documented that H. pylori infection is implicated in a range of disorders of the upper gastrointestinal tract, as well as associated organs, many aspects relating to host colonization, successful persistence and the pathophysiological mechanisms of this bacteria still remain controversial and are constantly being explored. Unceasing efforts to decipher the pathophysiology of H. pylori infection have illuminated the crucially important contribution of multifarious bacterial factors for H. pylori pathogenesis, in particular the cag pathogenicity island (PAI), the effector protein CagA and the vacuolating cytotoxin VacA. In addition, recent studies have provided insight into the importance of the gastrointestinal microbiota on the cumulative pathophysiology associated with H. pylori infections. This review focuses on the key findings of publications related to the pathogenesis of H. pylori infection published during the last year, with an emphasis on factors affecting colonization efficiency, cag PAI, CagA, VacA and gastrointestinal microbiota. PMID:26372819

  1. Pathogenesis of Helicobacter pylori Infection.

    PubMed

    Sgouras, Dionyssios N; Trang, Tran Thi Huyen; Yamaoka, Yoshio

    2015-09-01

    Three decades have passed since Warren and Marshall described the successful isolation and culture of Helicobacter pylori, the Gram-negative bacterium that colonizes the stomach of half the human population worldwide. Although it is documented that H. pylori infection is implicated in a range of disorders of the upper gastrointestinal tract, as well as associated organs, many aspects relating to host colonization, successful persistence, and the pathophysiological mechanisms of this bacteria still remain controversial and are constantly being explored. Unceasing efforts to decipher the pathophysiology of H. pylori infection have illuminated the crucially important contribution of multifarious bacterial factors for H. pylori pathogenesis, in particular the cag pathogenicity island (PAI), the effector protein CagA, and the vacuolating cytotoxin VacA. In addition, recent studies have provided insight into the importance of the gastrointestinal microbiota on the cumulative pathophysiology associated with H. pylori infection. This review focuses on the key findings of publications related to the pathogenesis of H. pylori infection published during the last year, with an emphasis on factors affecting colonization efficiency, cagPAI, CagA, VacA, and gastrointestinal microbiota. © 2015 John Wiley & Sons Ltd.

  2. Genotypic Profile of the Outer Membrane Proteins BabA and BabB in Clinical Isolates of Helicobacter pylori

    PubMed Central

    Colbeck, Jeffrey C.; Hansen, Lori M.; Fong, Julie M.; Solnick, Jay V.

    2006-01-01

    Helicobacter pylori BabA is the ABO blood group antigen binding adhesin, which has a closely related paralogue (BabB) whose function is unknown. PCR and DNA sequence analysis showed extensive genotypic diversity in babA and babB across different strains, as well as within a strain colonizing an individual patient. We hypothesize that diverse profiles of babA and babB reflect selective pressures for adhesion, which may differ across different hosts and within an individual over time. PMID:16790815

  3. Construction of a Helicobacter pylori-Escherichia coli shuttle vector for gene transfer in Helicobacter pylori.

    PubMed Central

    Lee, W K; An, Y S; Kim, K H; Kim, S H; Song, J Y; Ryu, B D; Choi, Y J; Yoon, Y H; Baik, S C; Rhee, K H; Cho, M J

    1997-01-01

    In this study, a Helicobacter pylori-Escherichia coli shuttle vector was constructed for transferring DNA into H. pylori. The smallest cryptic plasmid (1.2 kb), pHP489, among those harbored by 77 H. pylori isolates was selected as a base replicon for constructing vectors. HindIII-digested pHP489 was ligated with a kanamycin resistance gene [aph(3')-III], which originated from Campylobacter jejuni, to produce the recombinant plasmid pHP489K. pHP489K was efficiently transformed into and stably maintained in H. pylori strains. The shuttle vector pBHP489K (3.6 kb) was constructed by the recombination of pHP489, ColE1, and aph(3')-III sequences. pBHP489K was reciprocally transformed into and maintained in both H. pylori and E. coli. Introduction of the shuttle vector clone DNA (pBHP489K/AB; 6.7 kb), containing the ureA and ureB genes of H. pylori, into urease-negative mutants of H. pylori led to the restoration of their urease activity. The transformants were confirmed to contain the incoming plasmid DNA. pBHP489K satisfied the requirements for an H. pylori-E. coli shuttle vector, implying that it might be a useful vector for investigating pathogenicity and restriction-modification systems of H. pylori. PMID:9406406

  4. Helicobacter pylori Test

    MedlinePlus

    ... urease test (RUT) for H. pylori Formal name: Helicobacter pylori Related tests: Gastrin At a Glance Test ... else I should know? How is it used? Helicobacter pylori testing is used to diagnose an infection ...

  5. Helicobacter Pylori Infections

    MedlinePlus

    ... Issues Listen Español Text Size Email Print Share Helicobacter Pylori Infections Page Content Article Body Most people, ... always) caused by bacteria—specifically, an organism called Helicobacter pylori. H pylori infections occur at a low ...

  6. Involvement of the CD95 (APO-1/Fas) receptor and ligand system in Helicobacter pylori-induced gastric epithelial apoptosis.

    PubMed Central

    Rudi, J; Kuck, D; Strand, S; von Herbay, A; Mariani, S M; Krammer, P H; Galle, P R; Stremmel, W

    1998-01-01

    Helicobacter pylori infection is associated with chronic gastritis, peptic ulceration, and gastric carcinoma. The potential role of CD95-mediated apoptosis was investigated in a panel of gastric biopsies obtained from patients with H. pylori-associated chronic gastritis (n = 29) and with noninfected normal mucosa (n = 10). Immunohistochemistry revealed increased CD95 receptor expression in epithelial and lamina propria cells in chronic gastritis. By in situ hybridization, CD95 ligand mRNA was absent or low in normal mucosa but expressed at high levels in lamina propria lymphocytes and, unexpectedly, in epithelial cells in chronic gastritis. Apoptotic cells were rare in normal mucosa but were observed regularly in chronic gastritis in close proximity to CD95 ligand mRNA expression throughout the epithelial and lamina propria cells. In a functional analysis gastric epithelial cell lines were incubated with supernatants of H. pylori. Treatment with the cytotoxic isolate H. pylori 60190 but not with the noncytotoxic isolate Tx30a upregulated CD95 in up to 50% of gastric epithelial cells and induced apoptosis in these cells. H. pylori-induced apoptosis was partially prevented by blocking CD95, demonstrating the functional role of the CD95 system. These findings suggest that H. pylori-associated chronic gastritis involves apoptosis of gastric epithelial cells by activation of the CD95 receptor and ligand system. PMID:9788963

  7. VacA, cagA, iceA and oipA genotypes status and antimicrobial resistance properties of Helicobacter pylori isolated from various types of ready to eat foods.

    PubMed

    Hemmatinezhad, Behsan; Momtaz, Hassan; Rahimi, Ebrahim

    2016-01-20

    Despite the high clinical standing of Helicobacter pylori, its exact routes of transmission and origin have not been determined. Based on the contentious hypothesis, foods play an important roles in the transmission of H. pylori to humans. The present study was carried out to investigate the vacA, cagA, oipA and iceA genotypes status of H. pylori isolated from the various types of ready to eat foods. A total of 550 ready to eat food samples were cultured and tested. H. pylori-positive strains were analyzed for the presence of various genotypes and antimicrobial resistance pattern. Seventy four out of 550 (13.45 %) samples were positive for H. pylori. Olvie salad (36 %), restaurant salad (30 %), fruit salad (28 %) and soup (22 %) were the most commonly contaminated. H. pylori strains harbored the highest levels of resistance against amoxicillin (94.59 %), ampicillin (93.24 %), metronidazole (89.18 %) and tetracycline (72.97 %). The most commonly detected genotypes were vacA s1a (78.37 %), vacA m2 (75.67 %), vacA m1a (51.35 %) and cagA (41.89 %). The prevalence of iceA1, iceA2 and oipA genotypes were 13.51, 4.05 and 18.91 %, respectively. S1am2 (70.27 %), s1am1a (39.18 %) and m1am2 (31.08 %) were the most commonly detected combined genotypes. Of 40 different genotypic combinations, s1a/cagA+/iceA1/oipA- (12.16 %), s1a/cagA+/iceA1/oipA+ (10.81 %) and s1a/cagA-/iceA1/oipA+ (10.81 %) were the most prevalent. The present investigation showed that some types of ready to eat food samples maybe the sources of resistant and virulent strains of H. pylori. Warily use of antibiotics with respect to the results of disk diffusion method and careful health monitoring on food and staffs of food producing companies maybe reduce the risk of H. pylori in foods.

  8. Demonstration of an Optical Isolator with a Semiconductor Guiding Layer that was Obtained by Use of a Nonreciprocal Phase Shift.

    PubMed

    Yokoi, H; Mizumoto, T; Shinjo, N; Futakuchi, N; Nakano, Y

    2000-11-20

    We present the experimental study of an optical isolator with a semiconductor guiding layer that was obtained by use of a nonreciprocal phase shift. The isolator is equipped with an optical interferometer composed of tapered couplers, nonreciprocal phase shifters, and a reciprocal phase shifter. The nonreciprocal phase shifter was constructed by wafer direct bonding between the semiconductor guiding layer and the magneto-optic cladding layer. The isolator, designed for the 1.55-mum wavelength, was fabricated to investigate the characteristics of each component. By applying an external magnetic field to the nonreciprocal phase shifter, we achieved an isolation ratio of approximately 4.9 dB in the interferometric isolator.

  9. Assessment of Risk and Sero-Prevalence of Helicobacter pylori Colonization among Remote Orang Asli Tribes in Peninsula Malaysia.

    PubMed

    Thevakumar, Kavitha; Chandren, Josephine Rebecca; Perez-Perez, Guillermo Ignacio; Chua, Eng Guan; Teh, Lay Kek; Salleh, Mohd Zaki; Tan, Jin Ai Mary Anne; Leow, Alex Hwong Ruey; Goh, Khean Lee; Tay, Alfred Chin Yen; Marshall, Barry J; Vadivelu, Jamuna; Loke, Mun Fai; Wong, Li Ping

    2016-01-01

    The epidemiology of Helicobacter pylori (H. pylori) infection is related to human poverty with marked differences between developing and developed countries. Socioeconomic factors and living standards are the main determinants of the age-dependent acquisition rate of H. pylori, and consequently its prevalence. The aim of this study was to assess the risk and sero-prevalence of H. pylori colonization among Orang Asli in Peninsula Malaysia. This cross-sectional study was conducted on Orang Asli subjects in seven isolated settlements spanning across all three major tribes (Negrito, Proto Malay and Senoi) in Malaysia. Socio-demographic characteristics of the subjects were obtained through interview. Subjects were tested for H. pylori colonization based on CagA and whole cell (WC) antigen serological assays. A total of 275 subjects participated in this study. Among these subjects, 115 (44.7%) were H. pylori sero-positive with highest sero-prevalence among Negrito (65.7%). Among subjects who were H. pylori sero-positive, CagA sero positivity was also significantly higher among Negrito. The highest proportion of respondents reported to be H. pylori sero-positive was from age group 30 years old and below (57.9%), males (56.2%), Negrito (48.6%) and live in bamboo house (92.3%). The highest proportion of respondents reported to be CagA sero-positive was from age group 30 years old and below (41.4%), males (35.6%) and Negrito (48.6%). The results of this study demonstrate that H. pylori colonization can be related to age, gender, tribes and house materials and CagA sero-positive stain closely associated with age, gender and tribes.

  10. Assessment of Risk and Sero-Prevalence of Helicobacter pylori Colonization among Remote Orang Asli Tribes in Peninsula Malaysia

    PubMed Central

    Thevakumar, Kavitha; Chandren, Josephine Rebecca; Perez-Perez, Guillermo Ignacio; Chua, Eng Guan; Teh, Lay Kek; Salleh, Mohd Zaki; Tan, Jin Ai Mary Anne; Leow, Alex Hwong Ruey; Goh, Khean Lee; Tay, Alfred Chin Yen; Marshall, Barry J.; Vadivelu, Jamuna; Loke, Mun Fai; Wong, Li Ping

    2016-01-01

    The epidemiology of Helicobacter pylori (H. pylori) infection is related to human poverty with marked differences between developing and developed countries. Socioeconomic factors and living standards are the main determinants of the age-dependent acquisition rate of H. pylori, and consequently its prevalence. The aim of this study was to assess the risk and sero-prevalence of H. pylori colonization among Orang Asli in Peninsula Malaysia. This cross-sectional study was conducted on Orang Asli subjects in seven isolated settlements spanning across all three major tribes (Negrito, Proto Malay and Senoi) in Malaysia. Socio-demographic characteristics of the subjects were obtained through interview. Subjects were tested for H. pylori colonization based on CagA and whole cell (WC) antigen serological assays. A total of 275 subjects participated in this study. Among these subjects, 115 (44.7%) were H. pylori sero-positive with highest sero-prevalence among Negrito (65.7%). Among subjects who were H. pylori sero-positive, CagA sero positivity was also significantly higher among Negrito. The highest proportion of respondents reported to be H. pylori sero-positive was from age group 30 years old and below (57.9%), males (56.2%), Negrito (48.6%) and live in bamboo house (92.3%). The highest proportion of respondents reported to be CagA sero-positive was from age group 30 years old and below (41.4%), males (35.6%) and Negrito (48.6%). The results of this study demonstrate that H. pylori colonization can be related to age, gender, tribes and house materials and CagA sero-positive stain closely associated with age, gender and tribes. PMID:27441568

  11. Mutations affecting domain V of the 23S rRNA gene in Helicobacter pylori from Cairo, Egypt.

    PubMed

    Ghaith, Doaa; Elzahry, Mohammad; Mostafa, Gehan; Mostafa, Sally; Elsherif, Rasha; Ramzy, Iman

    2016-10-01

    Clarithromycin is a main component of the recommended first-line triple therapy for Helicobacter pylori in Egypt. We aimed in our study to investigate the prevalence of clarithromycin-resistant H. pylori strains due to the point mutations at domain V of the H. pylori 23S rRNA among the Egyptian population using the polymerase chain reaction/restricted fragment length polymorphism (PCR/RFLP) assay. Gastric biopsies obtained from 100 dyspeptic patients who consecutively attended at Cairo University Hospital during the period from January to November 2013 were subjected to PCR/RFLP in order to detect the point mutations at domain V of the H. pylori 23S rRNA associated with clarithromycin resistance. The PCR amplicon of the 23S H. pylori rRNA is restricted with MboII for detection of A2142G mutation and with BsaI for A2143G mutation. The prevalence of H. pylori infection among 100 patients was 70%; clarithromycin resistance was detected in 39/70 (57.7%) of positive H. pylori isolates. Occurrence of 23S rRNA A2142G mutations resulted in two DNA fragments (418 and 350 bp) by PCR-RFLP; on the other hand, no A2143G mutations were detected. The high prevalence of clarithromycin resistance (57.7%) caused by A2142G mutations at domain V of the H. pylori 23S rRNA may mandate changing of the standard clarithromycin-containing triple therapy. The PCR/RFLP assay was a rapid and accurate method for molecular detection of H. pylori infection in addition to determination of different nucleotide mutations causing clarithromycin resistance.

  12. [Establishment of optimun conditions in order to obtain a protein isolate from Chilean Hazelnut].

    PubMed

    Villarroel, Mario; Zapata, Constanza; Pino, Leonardo; Rubilar, Mónica

    2012-03-01

    An alternative to solve the problem of the overall deficit of proteins has been the use ofdefatted cakes generated by the extraction of oil from vegetable sources such as rapeseed, soybean, lupin, etc. This process at the same time increases the protein content, making this feasible to be used to enrich some types of food. This is the case of the chilean hazelnut (Gevuina avellana, Mol), monotypic species characterized by their high percentage of oil (50%) and whose defatted cake isolated protein could be used to obtain an isolated protein. For this purpose optimized conditions of extraction of protein were carried out using the surface response methodology (SRM) and a central composite design with three independent variables: time of contact of the cake with the solvent, sample/solvent ratio and pH was used. All variables were controlled at five different levels. The data were subjected to an analysis of regression and ANOVA, the first to determine the polynomial equation and the second to select the control factors with significant effect on the extraction of the protein. The best combination of factors turned out to be: time between 30 and 40 minutes, pH between 9 and 9.5 and a relationship sample/solvent between 1/15 to 1/16 with a final yield of 76%. The physical characteristics were: density 0,504 g/cm3, compaction 43, 34% apparent and pale yellow. Proximal analysis showed a concentration of protein of 76%, 13%, raw fiber carbohydrate 0.68% and oil 1.29%. With regard to the functional properties emphasized water absorption (320 g/100 g), absorption of oil (410 g/100 g) and foaming capacity (221%).

  13. Rapid Ovary Mass-Isolation (ROMi) to Obtain Large Quantities of Drosophila Egg Chambers for Fluorescent In Situ Hybridization.

    PubMed

    Jambor, Helena; Mejstrik, Pavel; Tomancak, Pavel

    2016-01-01

    Isolation of large quantities of tissue from organisms is essential for many techniques such as genome-wide screens and biochemistry. However, obtaining large quantities of tissues or cells is often the rate-limiting step when working in vivo. Here, we present a rapid method that allows the isolation of intact, single egg chambers at various developmental stages from ovaries of adult female Drosophila flies. The isolated egg chambers are amenable for a variety of procedures such as fluorescent in situ hybridization, RNA isolation, extract preparation, or immunostaining. Isolation of egg chambers from adult flies can be completed in 5 min and results, depending on the input amount of flies, in several milliliters of material. The isolated egg chambers are then further processed depending on the exact requirements of the subsequent application. We describe high-throughput in situ hybridization in 96-well plates as example application for the mass-isolated egg chambers.

  14. PCR-Based Restriction Pattern Typing of the vacA Gene Provides Evidence for a Homogeneous Group among Helicobacter pylori Strains Associated with Peptic Ulcer Disease

    PubMed Central

    Donati, Manuela; Storni, Elisa; D’Apote, Lucia; Moreno, Sandra; Tucci, Antonio; Poli, Loris; Cevenini, Roberto

    1999-01-01

    The results of PCR-based molecular typing of Helicobacter pylori strains by restriction fragment length polymorphism analysis of a 1,161-bp nucleotide sequence of the midregion of the vacA gene are reported. A total of 48 H. pylori strains isolated from gastric biopsy specimens obtained from 18 patients with peptic ulcer dyspepsia, 15 patients with nonulcer dyspepsia, and 15 asymptomatic H. pylori-infected subjects were studied. Highly heterogeneous restriction patterns were obtained by digestion of PCR products with SauII, BglII, and HhaI, whereas HaeIII digestion resulted in a strictly homogeneous profile for H. pylori strains isolated from 14 of 18 (77.7%) patients with peptic ulcer dyspepsia, but a strictly homogeneous profile was found for strains from only 8 of 15 (53.3%) patients with nonulcer dyspepsia (P = 0.163) and 5 of 15 (33.3%) asymptomatic H. pylori-infected subjects (P = 0.014). A potentially important aspect of the results obtained is the clinical relevance, since a single restriction pattern seems to be able to identify the majority of H. pylori strains associated with peptic ulcer disease. PMID:10074500

  15. Draft Genome Sequence of Thermus sp. Isolate 2.9, Obtained from a Hot Water Spring Located in Salta, Argentina

    PubMed Central

    Berretta, Marcelo F.; Ortiz, Elio M.; Benintende, Graciela B.; Amadio, Ariel F.; Zandomeni, Rubén O.

    2015-01-01

    Thermus sp. isolate 2.9 was obtained from a hot water spring in Salta, Argentina. Here, we report the draft genome sequence (2,485,434 bp) of this isolate, which consists of 11 scaffolds of >10 kbp and 2,719 protein-coding sequences. PMID:25593256

  16. Prevalence of Helicobacter pylori in United States Navy submarine crews.

    PubMed

    Jackman, R P; Schlichting, C; Carr, W; Dubois, A

    2006-06-01

    Helicobacter pylori prevalence is elevated in German submarine crews and in United States Navy (USN) surface fleet personnel, but H. pylori prevalence in USN submariners was unknown. The goal of the study was to determine the prevalence of H. pylori in the crews of USN nuclear submarines compared to other military personnel and to the general US population. The presence of H. pylori IgG antibodies was determined in serum samples using a commercial ELISA. Only 47 out of 451 submariners (9.4%) were H. pylori positive, which is similar to that of the US general population with a similar level of education. In contrast, H. pylori prevalence is significantly higher in US Army recruits (26%), USN surface fleet personnel (25%), and German diesel submariners (38%). These data demonstrate that submarine service (and by inference activity requiring isolation and close contact, per se) is not a risk factor for H. pylori infection.

  17. Genetic diversity of Japanese encephalitis virus isolates obtained from the Indonesian archipelago between 1974 and 1987.

    PubMed

    Schuh, Amy J; Guzman, Hilda; Tesh, Robert B; Barrett, Alan D T

    2013-07-01

    Five genotypes (GI-V) of Japanese encephalitis virus (JEV) have been identified, all of which have distinct geographical distributions and epidemiologies. It is thought that JEV originated in the Indonesia-Malaysia region from an ancestral virus. From that ancestral virus GV diverged, followed by GIV, GIII, GII, and GI. Genotype IV appears to be confined to the Indonesia-Malaysia region, as GIV has been isolated in Indonesia from mosquitoes only, while GV has been isolated on three occasions only from a human in Malaysia and mosquitoes in China and South Korea. In contrast, GI-III viruses have been isolated throughout Asia and Australasia from a variety of hosts. Prior to this study only 13 JEV isolates collected from the Indonesian archipelago had been studied genetically. Therefore the sequences of the envelope (E) gene of 24 additional Indonesian JEV isolates, collected throughout the archipelago between 1974 and 1987, were determined and a series of molecular adaptation analyses were performed. Phylogenetic analysis indicated that over a 14-year time span three genotypes of JEV circulated throughout Indonesia, and a statistically significant association between the year of virus collection and genotype was revealed: isolates collected between 1974 and 1980 belonged to GII, isolates collected between 1980 and 1981 belonged to GIV, and isolates collected in 1987 belonged to GIII. Interestingly, three of the GII Indonesian isolates grouped with an isolate that was collected during the JE outbreak that occurred in Australia in 1995, two of the GIII Indonesian isolates were closely related to a Japanese isolate collected 40 years previously, and two Javanese GIV isolates possessed six amino acid substitutions within the E protein when compared to a previously sequenced GIV isolate collected in Flores. Several amino acids within the E protein of the Indonesian isolates were found to be under directional evolution and/or co-evolution. Conceivably, the tropical climate

  18. Genetic Diversity of Japanese Encephalitis Virus Isolates Obtained from the Indonesian Archipelago Between 1974 and 1987

    PubMed Central

    Schuh, Amy J.; Guzman, Hilda; Tesh, Robert B.

    2013-01-01

    Abstract Five genotypes (GI–V) of Japanese encephalitis virus (JEV) have been identified, all of which have distinct geographical distributions and epidemiologies. It is thought that JEV originated in the Indonesia-Malaysia region from an ancestral virus. From that ancestral virus GV diverged, followed by GIV, GIII, GII, and GI. Genotype IV appears to be confined to the Indonesia-Malaysia region, as GIV has been isolated in Indonesia from mosquitoes only, while GV has been isolated on three occasions only from a human in Malaysia and mosquitoes in China and South Korea. In contrast, GI–III viruses have been isolated throughout Asia and Australasia from a variety of hosts. Prior to this study only 13 JEV isolates collected from the Indonesian archipelago had been studied genetically. Therefore the sequences of the envelope (E) gene of 24 additional Indonesian JEV isolates, collected throughout the archipelago between 1974 and 1987, were determined and a series of molecular adaptation analyses were performed. Phylogenetic analysis indicated that over a 14-year time span three genotypes of JEV circulated throughout Indonesia, and a statistically significant association between the year of virus collection and genotype was revealed: isolates collected between 1974 and 1980 belonged to GII, isolates collected between 1980 and 1981 belonged to GIV, and isolates collected in 1987 belonged to GIII. Interestingly, three of the GII Indonesian isolates grouped with an isolate that was collected during the JE outbreak that occurred in Australia in 1995, two of the GIII Indonesian isolates were closely related to a Japanese isolate collected 40 years previously, and two Javanese GIV isolates possessed six amino acid substitutions within the E protein when compared to a previously sequenced GIV isolate collected in Flores. Several amino acids within the E protein of the Indonesian isolates were found to be under directional evolution and/or co-evolution. Conceivably, the

  19. Extended-Spectrum Beta-Lactamases among Enterobacter Isolates Obtained in Tel Aviv, Israel

    PubMed Central

    Schlesinger, Jacob; Navon-Venezia, Shiri; Chmelnitsky, Inna; Hammer-Münz, Orly; Leavitt, Azita; Gold, Howard S.; Schwaber, Mitchell J.; Carmeli, Yehuda

    2005-01-01

    The extended-spectrum beta-lactamase (ESBL)-producing phenotype is frequent among Enterobacter isolates at the Tel Aviv Sourasky Medical Center, Tel Aviv, Israel. We examined the clonal relatedness and characterized the ESBLs of a collection of these strains. Clonal relatedness was determined by pulsed-field gel electrophoresis. Isoelectric focusing (IEF) and transconjugation experiments were performed. ESBL gene families were screened by colony hybridization and PCR for blaTEM, blaSHV, blaCTX-M, blaIBC, blaPER, blaOXA, blaVEB, and blaSFO; and the PCR products were sequenced. The 17 Enterobacter isolates studied comprised 15 distinct genotypes. All isolates showed at least one IEF band (range, one to five bands) whose appearance was suppressed by addition of clavulanate; pIs ranged from 5.4 to ≥8.2. Colony hybridization identified at least one family of beta-lactamase genes in 11 isolates: 10 harbored blaTEM and 9 harbored blaSHV. PCR screening and sequence analysis of the PCR products for blaTEM, blaSHV, and blaCTX-M identified TEM-1 in 11 isolates, SHV-12 in 7 isolates, SHV-1 in 1 isolate, a CTX-M-2-like gene in 2 isolates, and CTX-M-26 in 1 isolate. In transconjugation experiments with four isolates harboring blaTEM-1 and blaSHV-12, both genes were simultaneously transferred to the recipient strain Escherichia coli HB101. Plasmid mapping, PCR, and Southern analysis with TEM- and SHV-specific probes demonstrated that a single transferred plasmid carried both the TEM-1 and the SHV-12 genes. The widespread presence of ESBLs among Enterobacter isolates in Tel Aviv is likely due not to clonal spread but, rather, to plasmid-mediated transfer, at times simultaneously, of genes encoding several types of enzymes. The dominant ESBL identified was SHV-12. PMID:15728917

  20. The diversity of oomycetes on crayfish: morphological vs. molecular identification of cultures obtained while isolating the crayfish plague pathogen.

    PubMed

    Kozubíková-Balcarová, Eva; Koukol, Ondřej; Martín, María P; Svoboda, Jiří; Petrusek, Adam; Diéguez-Uribeondo, Javier

    2013-10-01

    Numerous oomycetes colonise the crayfish cuticle, the best known being the crayfish plague pathogen Aphanomyces astaci. Although other oomycetes associated with crayfish complicate the isolation and molecular detection of A. astaci, their diversity is little known. To improve this knowledge, we analysed 95 oomycete isolates obtained during attempts to isolate A. astaci from crayfish presumably infected by this pathogen. We characterized the isolates morphologically and by sequencing of the nuclear internal transcribed spacer (ITS) region. We identified 13 taxa by molecular analysis. Ten of them were assigned to five genera; the remaining three were affiliated with the order Saprolegniales but could not be reliably assigned to any genus. Morphological identification to species level was only possible for 15 % of isolates; all corresponded to Saprolegnia ferax, which was confirmed by ITS sequencing. The most frequently isolated species were S. ferax and Saprolegnia australis. Only seven isolates of A. astaci were obtained, all from one disease outbreak. We show that oomycete cultures obtained as by-products of parasite isolation are valuable for oomycete diversity studies, but morphological identification may uncover only a fraction of their diversity. Further, we show that crayfish may be frequently associated with potentially serious parasites of other organisms.

  1. Molecular characterization of Pasteurella multocida isolates obtained from poultry, ruminant, cats and dogs using RAPD and REP-PCR analysis

    PubMed Central

    Shirzad-Aski, Hesamaddin; Tabatabaei, Mohammad

    2016-01-01

    In the present study, Randomly Amplified Polymorphic DNA (RAPD) and Repetitive Extragenic Palindromic sequence-based Polymerase Chain Reaction (REP- PCR) were used to characterize 131 isolates of Pasteurella multocida, originating from different healthy and diseased animal species obtained from several geographical regions of Iran. The RAPD and REP-PCR generated amplified products in the range of 300 to 3400 bp and 200 to 2850 bp, respectively. Among all of the P. multocida isolates, cluster analysis revealed that 63 clusters and nine untypable isolates and 81 clusters and six untypable isolates were produced with RAPD and REP-PCR methods, respectively. The results indicated that the REP-PCR method showed a slightly higher level of discrimination power in differentiating of P. multocida isolates as compared with RAPD. The results showed that a considerable level of genetic diversity exists among P. multocida isolates even in the isolates with the same animal or geographical origins. There was no host- and region-specific pattern. In addition, the isolates obtained from the healthy and diseased animal did not reveal any correlation genotypic profiles, which could be supported by the hypothesis that P. multocida is a strictly opportunistic pathogen. In conclusion, because of a large amount of genetic heterogeneity in the P. multocida isolates, Pasteurellosis may be caused by different clones in the same herd or animal. PMID:28097166

  2. Assignment of serotype to Salmonella enterica isolates obtained from poultry and their environment in Southern Brazil.

    USDA-ARS?s Scientific Manuscript database

    To assess diversity of Salmonella enterica serotypes present in poultry and their environment from Southern Brazil, the Kauffman-White-LeMinor (KWL) scheme was used to serotype a total of 155 isolates. Isolates were then re-examined with nested PCR and sequencing of the dkgB-linked Intergenic Sequ...

  3. Identification, characterization and antibiotic resistance of bacterial isolates obtained from waterpipe device hoses.

    PubMed

    Masadeh, Majed M; Hussein, Emad I; Alzoubi, Karem H; Khabour, Omar; Shakhatreh, Muhamad Ali K; Gharaibeh, Mahmoud

    2015-05-13

    The general lack of knowledge about the health effects of waterpipe smoking is among the reasons for its global spread. In this study, bacterial contamination of waterpipe hoses was investigated. Twenty hoses were collected from waterpipe cafés and screened for bacterial pathogens using standard culture and isolation techniques. Additionally, resistance of isolated bacteria to common antibiotics was determined by identifying the minimum inhibitory concentration (MIC) of each isolate. Forty eight bacterial isolates were detected. Isolates included both Gram-positive and Gram-negative pathogens from species that included Micrococcus (12), Corynebacterium (13) and Bacillus (9). In addition, some of the detected pathogens were found to be resistant to aztreonam (79%), cefixime (79%), norfloxacin, amoxicillin (47%), clarithromycin (46%) and enrofloxacin (38%). In conclusion, the hose of the waterpipe device is a good environment for the growth of bacterial pathogens, which can then be transmitted to users.

  4. Identification, Characterization and Antibiotic Resistance of Bacterial Isolates Obtained from Waterpipe Device Hoses

    PubMed Central

    Masadeh, Majed M.; Hussein, Emad I.; Alzoubi, Karem H.; Khabour, Omar; Shakhatreh, Muhamad Ali K.; Gharaibeh, Mahmoud

    2015-01-01

    The general lack of knowledge about the health effects of waterpipe smoking is among the reasons for its global spread. In this study, bacterial contamination of waterpipe hoses was investigated. Twenty hoses were collected from waterpipe cafés and screened for bacterial pathogens using standard culture and isolation techniques. Additionally, resistance of isolated bacteria to common antibiotics was determined by identifying the minimum inhibitory concentration (MIC) of each isolate. Forty eight bacterial isolates were detected. Isolates included both Gram-positive and Gram-negative pathogens from species that included Micrococcus (12), Corynebacterium (13) and Bacillus (9). In addition, some of the detected pathogens were found to be resistant to aztreonam (79%), cefixime (79%), norfloxacin, amoxicillin (47%), clarithromycin (46%) and enrofloxacin (38%). In conclusion, the hose of the waterpipe device is a good environment for the growth of bacterial pathogens, which can then be transmitted to users. PMID:25985311

  5. Gastroprotective effect of desmosdumotin C isolated from Mitrella kentii against ethanol-induced gastric mucosal hemorrhage in rats: possible involvement of glutathione, heat-shock protein-70, sulfhydryl compounds, nitric oxide, and anti-Helicobacter pylori activity.

    PubMed

    Sidahmed, Heyam Mohamed Ali; Azizan, Ainnul Hamidah Syahadah; Mohan, Syam; Abdulla, Mahmood Ameen; Abdelwahab, Siddig Ibrahim; Taha, Manal Mohamed Elhassan; Hadi, A Hamid A; Ketuly, Kamal Aziz; Hashim, Najihah Mohd; Loke, Mun Fai; Vadivelu, Jamuna

    2013-07-19

    Mitrella kentii (M. kentii) (Bl.) Miq, is a tree-climbing liana that belongs to the family Annonaceae. The plant is rich with isoquinoline alkaloids, terpenylated dihydrochalcones and benzoic acids and has been reported to possess anti-inflammatory activity. The purpose of this study is to assess the gastroprotective effects of desmosdumotin C (DES), a new isolated bioactive compound from M. kentii, on gastric ulcer models in rats. DES was isolated from the bark of M. kentii. Experimental rats were orally pretreated with 5, 10 and 20 mg/kg of the isolated compound and were subsequently subjected to absolute ethanol-induced acute gastric ulcer. Gross evaluation, mucus content, gastric acidity and histological gastric lesions were assessed in vivo. The effects of DES on the anti-oxidant system, non-protein sulfhydryl (NP-SH) content, nitric oxide (NO)level, cyclooxygenase-2 (COX-2) enzyme activity, bcl-2-associated X (Bax) protein expression and Helicabacter pylori (H pylori) were also investigated. DES pre-treatment at the administered doses significantly attenuated ethanol-induced gastric ulcer; this was observed by decreased gastric ulcer area, reduced or absence of edema and leucocytes infiltration compared to the ulcer control group. It was found that DES maintained glutathione (GSH) level, decreased malondialdehyde (MDA) level, increased NP-SH content and NO level and inhibited COX-2 activity. The compound up regulated heat shock protein-70 (HSP-70) and down regulated Bax protein expression in the ulcerated tissue. DES showed interesting anti-H pylori effects. The efficacy of DES was accomplished safely without any signs of toxicity. The current study reveals that DES demonstrated gastroprotective effects which could be attributed to its antioxidant effect, activation of HSP-70 protein, intervention with COX-2 inflammatory pathway and potent anti H pylori effect.

  6. Gastroprotective effect of desmosdumotin C isolated from Mitrella kentii against ethanol-induced gastric mucosal hemorrhage in rats: possible involvement of glutathione, heat-shock protein-70, sulfhydryl compounds, nitric oxide, and anti-Helicobacter pylori activity

    PubMed Central

    2013-01-01

    Background Mitrella kentii (M. kentii) (Bl.) Miq, is a tree-climbing liana that belongs to the family Annonaceae. The plant is rich with isoquinoline alkaloids, terpenylated dihydrochalcones and benzoic acids and has been reported to possess anti-inflammatory activity. The purpose of this study is to assess the gastroprotective effects of desmosdumotin C (DES), a new isolated bioactive compound from M. kentii, on gastric ulcer models in rats. Methods DES was isolated from the bark of M. kentii. Experimental rats were orally pretreated with 5, 10 and 20 mg/kg of the isolated compound and were subsequently subjected to absolute ethanol-induced acute gastric ulcer. Gross evaluation, mucus content, gastric acidity and histological gastric lesions were assessed in vivo. The effects of DES on the anti-oxidant system, non-protein sulfhydryl (NP-SH) content, nitric oxide (NO)level, cyclooxygenase-2 (COX-2) enzyme activity, bcl-2-associated X (Bax) protein expression and Helicabacter pylori (H pylori) were also investigated. Results DES pre-treatment at the administered doses significantly attenuated ethanol-induced gastric ulcer; this was observed by decreased gastric ulcer area, reduced or absence of edema and leucocytes infiltration compared to the ulcer control group. It was found that DES maintained glutathione (GSH) level, decreased malondialdehyde (MDA) level, increased NP-SH content and NO level and inhibited COX-2 activity. The compound up regulated heat shock protein-70 (HSP-70) and down regulated Bax protein expression in the ulcerated tissue. DES showed interesting anti-H pylori effects. The efficacy of DES was accomplished safely without any signs of toxicity. Conclusions The current study reveals that DES demonstrated gastroprotective effects which could be attributed to its antioxidant effect, activation of HSP-70 protein, intervention with COX-2 inflammatory pathway and potent anti H pylori effect. PMID:23866830

  7. Morphological and molecular characterization of Calothrix isolates obtained from diverse environments in India.

    PubMed

    Singh, S; Dhar, D W; Gupta, R K

    2011-01-01

    Abstract-Thirty cyanobacterial strains of Calothrix (family Rivulariaceae) isolated from diverse geographical regions of India were analyzed using morphological and molecular approaches. Most of the isolates were planktonic while some grew benthically. Significant differences were observed with regard to the shape and size of the vegetative cells, heterocysts, and akinetes. Analyses of molecular polymorphisms using Restriction Fragment Length Polymorphisms (RFLP) of 16S rRNA genes with the reference strain led to unambiguous differentiation of the isolates as well as understanding of their genetic relationships.

  8. Resistance to diclazuril in field isolates of Eimeria species obtained from commercial broiler flocks in Brazil.

    PubMed

    Kawazoe, U; Fabio, J D

    1994-06-01

    The efficacy of the anticoccidial drug diclazuril against field isolates of Eimeria spp. collected from broiler farms in four different sites of the South and Southeastern regions of Brazil were investigated. The effect of the drug was measured by an assessment of weight gain, lesion score and oocyst production. Two reference laboratory strains not previously exposed to diclazuril were sensitive to the drug. Two field isolates were judged to be sensitive to diclazuril, four were partly resistant and six were resistant to the drug. The response of the isolates to diclazuril varied depending upon the extent of exposure and type of drug programme in use at the farms.

  9. Antimicrobial resistance trends among Salmonella isolates obtained from horses in the northeastern United States (2001-2013).

    PubMed

    Cummings, Kevin J; Perkins, Gillian A; Khatibzadeh, Sarah M; Warnick, Lorin D; Aprea, Victor A; Altier, Craig

    2016-05-01

    OBJECTIVE To describe the antimicrobial resistance patterns of Salmonella isolates obtained from horses in the northeastern United States and to identify trends in resistance to select antimicrobials over time. SAMPLE 462 Salmonella isolates from horses. PROCEDURES Retrospective data were collected for all Salmonella isolates obtained from equine specimens that were submitted to the Cornell University Animal Health Diagnostic Center between January 1, 2001, and December 31, 2013. Temporal trends in the prevalence of resistant Salmonella isolates were investigated for each of 13 antimicrobials by use of the Cochran-Armitage trend test. RESULTS The prevalence of resistant isolates varied among antimicrobials and ranged from 0% (imipenem) to 51.5% (chloramphenicol). During the observation period, the prevalence of resistant isolates decreased significantly for amoxicillin-clavulanic acid, ampicillin, cefazolin, cefoxitin, ceftiofur, chloramphenicol, and tetracycline and remained negligible for amikacin and enrofloxacin. Of the 337 isolates for which the susceptibility to all 13 antimicrobials was determined, 138 (40.9%) were pansusceptible and 192 (57.0%) were multidrug resistant (resistant to ≥ 3 antimicrobial classes). The most common serovar isolated was Salmonella Newport, and although the annual prevalence of that serovar decreased significantly over time, that decrease had only a minimal effect on the observed antimicrobial resistance trends. CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that current antimicrobial use in horses is not promoting the emergence and dissemination of antimicrobial-resistant Salmonella strains in the region served by the laboratory.

  10. Identification of xanthans isolated from sugarcane juices obtained from scalded plants infected by Xanthomonas albilineans.

    PubMed

    Fontaniella, Blanca; Rodríguez, C W; Piñón, Dolores; Vicente, C; Legaz, María-Estrella

    2002-04-25

    The exudate gum produced by Xanthomonas albilineans, a specific sugarcane pathogen, has been isolated from juices of diseased sugarcane stalks, hydrolyzed with hydrochloric acid, and the hydrolysate analyzed by capillary electrophoresis. Sucrose. cellobiose, mannose, glucose, glucose-1-P and glucuronic acid were identified as the major components of the polysaccharide isolated from diseased stalks. Juices from healthy stalks contained maltose instead of cellobiose. The chemical nature of this polysaccharide is discussed.

  11. Genetic characterisation of Helicobacter pylori isolates from an Argentinean adult population based on cag pathogenicity island right-end motifs, lspA-glmM polymorphism and iceA and vacA genotypes.

    PubMed

    Leanza, A G; Matteo, M J; Crespo, O; Antelo, P; Olmos, J; Catalano, M

    2004-09-01

    Isolates of Helicobacter pylori from 88 patients were characterised by cagA status, cagA pathogenicity island (PAI) right-end motifs, iceA, vacA and lspA-glmM genotypes, primarily by PCR-based analysis, to investigate whether Argentinean isolates differed from those recovered in southern Europe or other Latin American countries. PCR-based analysis of vacA alleles was confirmed by reverse hybridisation in 56 cases, while sequence analysis was performed either when iceA and vacA genotypes could not be determined by PCR, or to investigate PCR and reverse hybridisation vacA genotyping discordance. Typing by lspA-glmM restriction fragment length polymorphism was performed with HhaI and AluI. The pattern of cag PAI right-end motifs and the prevalence of type Ia were similar to those in isolates from southern European countries, with cagA(+)/iceA1/vacA-s1 m1 being the commonest genotype. Reverse hybridisation identified a vacA-s1a/s1b recombinant allele, confirmed by sequencing analysis. Analysis of lspA-glmM genotypes identified at least 73 unrelated strains. Few mixed infections were identified, but in one case, isolates from a single biopsy exhibiting two vacA alleles were shown by lspA-glmM fingerprints to be two unrelated strains. No associated effect on ulcer disease risk was demonstrated by analysis of cagA, vacA and iceA status. Overall, the isolates of H. pylori from Argentina were similar to isolates from southern Europe or Latin American countries, and infections were associated mainly with single H. pylori strains.

  12. Nationwide survey of Helicobacter pylori antibiotic resistance in Thailand.

    PubMed

    Vilaichone, Ratha-Korn; Gumnarai, Pornpen; Ratanachu-Ek, Thawee; Mahachai, Varocha

    2013-12-01

    The objectives of this study are to survey the antibiotic-resistant pattern of Helicobacter pylori infection in different geographical locations in Thailand and to determine factors associated with antibiotic resistance. Dyspeptic patients undergoing upper gastrointestinal endoscopy from the Northern, Northeastern, Central, and Southern regions of Thailand between January 2004 and December 2012 were enrolled in this study. Two antral gastric biopsies were obtained for culture; susceptibility tests were performed using E-test. A total of 3964 were enrolled, and 1350 patients (34.1%) were infected with H. pylori as identified by rapid urease test. Cultures were positive in 619 isolates. E-test for amoxicillin, clarithromycin, metronidazole, and tetracycline were successful in 400 isolates and for levofloxacin and ciprofloxacin in 208 isolates. Antibiotic resistance was present in 50.3% including amoxicillin 5.2%, tetracycline 1.7%, clarithromycin 3.7%, metronidazole 36%, ciprofloxacin 7.7%, levofloxacin 7.2%, and multi-drugs in 4.2%. Clarithromycin resistance was significantly more common in those older than 40 years (i.e., 100% versus 0%; P = 0.04). The prevalence of metronidazole resistant in Southern Thailand was significantly higher than in the Northeastern region (66.7% versus 33.3% P = 0.04). Metronidazole resistance remains the most common antibiotic resistant type of H. pylori in Thailand. The pattern of H. pylori antibiotic resistance over 9 years demonstrated a fall in clarithromycin resistance such that currently age >40 years is a predictor for clarithromycin resistance in Thailand. Quinolone resistance is a growing problem. © 2013.

  13. Germfree status of mice obtained by embryo transfer in an isolator environment.

    PubMed

    Inzunza, José; Midtvedt, Tore; Fartoo, Mona; Norin, Elisabeth; Osterlund, Ewa; Persson, Anna-Karin; Ahrlund-Richter, Lars

    2005-10-01

    The technique of embryo transfer has been evaluated for the purpose of changing the mouse stocks to a germfree (GF) status. Our results show reproducible and quality-assured conversion of animals to those which are negative for the presence of microorganisms. Rapid and easy access to GF mice is advantageous for studies of selected microflora and their cross-talks with the host, when applying, e.g. genomic, proteomic and metabolic methodology. The study involved embryo transfer in an isolator environment, thereby allowing implantation of cleansed embryos into GF recipients under well-controlled conditions. The recipient females gave birth normally and took care of the offspring as if they were their own pups, thus enhancing the survival rate. Access to full technical resources required to maintain GF isolators are, however, a prerequisite. In this study, we used stainless steel isolators designed by Gustafsson (1959), on which a stereomicroscope was mounted to facilitate embryo transfer inside the isolator. The use of embryo transfer and isolator techniques will facilitate the availability of various mouse mutant models under different gnotobiotic conditions, GF, monoxenic or polyxenic animals, to enable comparison with conventional animals for physiological and pathophysiological studies.

  14. Virulence profiles of ten Paracoccidioides brasiliensis isolates obtained from armadillos (Dasypus novemcinctus).

    PubMed

    Hebeler-Barbosa, F; Montenegro, M R; Bagagli, E

    2003-04-01

    Paracoccidioides brasiliensis is the etiologic agent of paracoccidioidomycosis (PCM), the most important systemic mycosis in Latin America. The armadillo, Dasypus novemcinctus, has been confirmed as the primary natural reservoir of this fungus. Its geographic distribution is similar to that of human PCM. In this study, virulence profiles of 10 P. brasiliensis isolates from different armadillos and of two clinical isolates were tested in an experimental hamster model. Pathogenicity was evaluated by counting cfu and performing histopathological analysis in the testis, liver, spleen and lung. Circulating specific antibodies were measured using enzyme-linked immunosorbent assay (ELISA). All isolates from armadillos were virulent in the model, with dissemination to many organs. The clinical isolates, which had long been stored in cultured collections, were less virulent. The isolates were classified into four virulence categories according to number of cfu per gram of tissue: very high, high, intermediate and low. This study confirms that armadillos harbor pathogenic genotypes of P. brasiliensis, probably the same ones that infect humans.

  15. Susceptibilities to antimicrobials and disinfectants in Salmonella isolates obtained from poultry and swine in Thailand.

    PubMed

    Chuanchuen, Rungtip; Pathanasophon, Pornpen; Khemtong, Sirintip; Wannaprasat, Wechsiri; Padungtod, Pawin

    2008-06-01

    Salmonella enterica isolates from poultry (n=125) and swine (n=132) in Thailand were investigated for antibiotic resistance, susceptibility to disinfectants (benzalkonium chloride (BKC), chlorhexidine digluconate (CHX), zinc chloride and copper sulfate) and cyclohexane tolerance. Forty-two percent were of multiple resistance to antibiotics. The minimum inhibitory concentrations (MICs) of all antibiotics against isolates from swine were higher than that against the isolates from poultry. There were generally few variations in MICs to all disinfectants, indicating that the isolates had either no or only a limited degree of developed resistance to the disinfectants tested. Only 5 isolates (1.9%) were tolerant to cyclohexane. The proton-dependent efflux systems did not play a major role in the reduced susceptibility to BKC and CHX, since susceptibility was not restored when an efflux inhibitor, carbonyl cyanide m-chlorophenylhydrazone (CCCP) was present. Successive exposure to subinhibitory concentrations of BKC and CHX generated mutants resistant to BKC and CHX. A spontaneous BKC-resistant derivative expressed cross-resistance to antibiotics, chloramphenicol and erythromycin. The mechanism responsible for cross-resistance between BKC and antibiotics was not driven by the proton motif force (PMF).

  16. Virulence characteristics of Escherichia coli isolates obtained from broiler breeders with salpingitis.

    PubMed

    Monroy, Maria A R; Knöbl, Terezinha; Bottino, José A; Ferreira, Claudete S Astolfi; Ferreira, Antonio J Piantino

    2005-01-01

    Thirty isolates of Escherichia coli from broiler breeders with salpingitis were studied. Using the slide agglutination test, the isolates were found to belong to serogroups O1, O2, O5, O36, O45, O53 and O78. Pathogenicity for day-old chicks was determined by air sac inoculation and isolates were categorized as having high, intermediate or low virulence. Growth on iron starvation medium was observed together with aerobactin production. Based on the results of in vitro adherence tests, attachment to oviduct epithelium from old birds was found to be superior to that observed using corresponding material from young birds. DNA hybridization testing for type 1, P, and S fimbriae revealed predominant expression of type 1, correlating with mannose-sensitive hemagglutination using guinea-pig erythrocytes. In this study, P and S fimbriae were not considered to be important adherence factors. Study findings would suggest that, as far as salpingitis is concerned, type 1 fimbriae can play an important role in E. coli infection in breeders. An interesting result to emerge from the study was the observation that E. coli isolates were completely resistant to serum from young breeders, whereas they were completely sensitive using serum from older breeders. Based on serogroups involved, pathogenicity for day-old chicks and virulence indicators, the salpingitis isolates were similar to those from cases of chronic respiratory disease.

  17. Extreme spore UV resistance of Bacillus pumilus isolates obtained from an ultraclean Spacecraft Assembly Facility.

    PubMed

    Link, L; Sawyer, J; Venkateswaran, K; Nicholson, W

    2004-02-01

    Recent environmental microbial sampling of the ultraclean Spacecraft Assembly Facility at NASA Jet Propulsion Laboratory (JPL-SAF) identified spores of Bacillus pumilus as major culturable bacterial contaminants found on and around spacecraft. As part of an effort to assess the efficacy of various spacecraft sterilants, purified spores of 10 JPL-SAF B. pumilus isolates were subjected to 254-nm UV and their UV resistance was compared to spores of standard B. subtilis biodosimetry strains. Spores of six of the 10 JPL-SAF isolates were significantly more resistant to UV than the B. subtilis biodosimetry strain, and one of the JPL-SAF isolates, B. pumilus SAFR-032, exhibited the highest degree of spore UV resistance observed by any Bacillus spp. encountered to date. Copyright 2004 Springer-Verlag

  18. Early Molecular Events in Murine Gastric Epithelial Cells Mediated by Helicobacter pylori CagA.

    PubMed

    Banerjee, Aditi; Basu, Malini; Blanchard, Thomas G; Chintalacharuvu, Subba R; Guang, Wei; Lillehoj, Erik P; Czinn, Steven J

    2016-10-01

    Murine models of Helicobacter pylori infection are used to study host-pathogen interactions, but lack of severe gastritis in this model has limited its usefulness in studying pathogenesis. We compared the murine gastric epithelial cell line GSM06 to the human gastric epithelial AGS cell line to determine whether similar events occur when cultured with H. pylori. The lysates of cells infected with H. pylori isolates or an isogenic cagA-deficient mutant were assessed for translocation and phosphorylation of CagA and for activation of stress pathway kinases by immunoblot. Phosphorylated CagA was detected in both cell lines within 60 minutes. Phospho-ERK 1/2 was present within several minutes and distinctly present in GSM06 cells at 60 minutes. Similar results were obtained for phospho-JNK, although the 54 kDa phosphoprotein signal was dominant in AGS, whereas the lower molecular weight band was dominant in GSM06 cells. These results demonstrate that early events in H. pylori pathogenesis occur within mouse epithelial cells similar to human cells and therefore support the use of the mouse model for the study of acute CagA-associated host cell responses. These results also indicate that reduced disease in H. pylori-infected mice may be due to lack of the Cag PAI, or by differences in the mouse response downstream of the initial activation events. © 2016 John Wiley & Sons Ltd.

  19. High Helicobacter pylori resistance to metronidazole and clarithromycin in Brazilian children and adolescents.

    PubMed

    Ogata, Silvio K; Godoy, Anita P Ortiz; da Silva Patricio, Francy R; Kawakami, Elisabete

    2013-06-01

    The aim of the present study was to assess the primary and secondary resistance of Helicobacter pylori strains to clarithromycin, amoxicillin, furazolidone, tetracycline, and metronidazole, the conventional antibiotics presently used in Brazilian children and adolescents. Seventy-seven consecutive H pylori strains, 71 of 77 strains obtained from patients without previous eradication treatment for H pylori infection, and 6 strains from patients in whom previous eradication treatment had failed. Global rate of resistance was 49.3% (38/77): 40% of strains were resistant to metronidazole, 19.5% to clarithromycin, and 10.4% to amoxicillin. All of the tested H pylori strains were susceptible to furazolidone and tetracycline. Multiple resistance were detected in 18.2% (14/77 patients) of the strains: 6 of 14 (43%) simultaneously resistant to clarithromycin and metronidazole; 5 of 14 (36%) to amoxicillin and metronidazole; 2 of 14 (14%) to amoxicillin, clarithromycin, and metronidazole; and 1 of 14 (7%) to clarithromycin and amoxicillin. The high resistance rate to metronidazole and clarithromycin observed in clinical H pylori isolates can exclude these antimicrobials in empirical eradication treatment in Brazil. Otherwise, furazolidone and tetracycline presented no resistance. Properly assessing the risks and benefits, these 2 antimicrobials and their derivatives could be used in empirical eradication schedules, both associated with amoxicillin, which showed a low resistance rate despite its wide use in pediatric patients.

  20. Helicobacter pylori: treatment with combinations of pivampicillin and tripotassium dicitrato bismuthate.

    PubMed

    Weil, J; Bell, G D; Powell, K; Morden, A; Harrison, G; Gant, P W; Trowell, J E; Burridge, S

    1991-10-01

    Fifty Helicobacter pylori- (H. pylori) positive patients entered an open study and were assigned to one of four treatment regimens comprising: pivampicillin (500 mg b.d.) for 2 weeks +/- tripotassium dicitrato bismuthate (tablet or liquid form) for one month. The 14C-urea breath test was used to evaluate clearance (negative at the end of treatment) and eradication (negative at 1 month post-treatment) of H. pylori. Clearance rates were 20% (2/10) after pivampicillin alone, 86% (12/14) after tripotassium dicitrato bismuthate tablets (240 mg b.d.) plus pivampicillin, 67% (6/9) after tripotassium dicitrato bismuthate tablets (120 mg q.d.s.) plus pivampicillin, and 100% (13/13) after tripotassium dicitrato bismuthate liquid (120 mg in 5 ml q.d.s) plus pivampicillin. The eradication rates were 0% (0/10), 13% (2/15), 0% (0/11) and 54% (7/13), respectively. Combination of the results from the 2 tripotassium dicitrato bismuthate tablet/pivampicillin groups gave an eradication rate of 7.7% (2/26) which was significantly lower than the 53.9% (7/13) obtained with tripotassium dicitrato bismuthate liquid/pivampicillin (P less than 0.02). In conclusion, a liquid tripotassium dicitrato bismuthate pivampicillin combination may be of special use in the treatment of H. pylori-positive patients when triple therapy is contraindicated (e.g. patient sensitivity/allergy to metronidazole) or when the H. pylori isolate is resistant to metronidazole.

  1. The Changing Profile of Helicobacter pylori Antibiotic Resistance in Singapore: A 15-Year Study.

    PubMed

    Ang, Tiing Leong; Fock, Kwong Ming; Ang, Daphne; Kwek, Andrew Boon Eu; Teo, Eng Kiong; Dhamodaran, Subbiah

    2016-08-01

    Antibiotic resistance is an important cause of H. pylori treatment failure. This study aimed to examine the change in H. pylori antibiotic resistance profile in Singapore over the course of 15 years. The study period was from 2000 to 2014. Gastric mucosal biopsies obtained from H. pylori-positive patients were cultured. Antibiotic susceptibility to metronidazole, clarithromycin, levofloxacin, tetracycline, and amoxicillin was tested. The change in resistance rates over time was analyzed. A total of 708 H. pylori isolates were cultured. There was a significant increase in resistance rates for metronidazole (2000-2002: 24.8%; 2012-2014: 48.2%; p < .001), clarithromycin (2000-2002: 7.9%; 2012-2014: 17.1%; p = .022), and levofloxacin (2000-2002: 5%; 2012-2014: 14.7%; p = .007). The resistance rates for tetracycline (2000-2002: 5%; 2012-2014: 7.6%) and amoxicillin (2000-2002: 3%; 2012-2014: 4.4%) remained stable. Increase in dual (2000-2002: 6.9%; 2012-2014: 9.4%; p = .479) and triple antibiotic resistance rates (2000-2002: 0; 2012-2014: 7.6%; p < .001) were observed. Overall, the most common dual and triple resistance patterns were metronidazole/clarithromycin (4.4%) and metronidazole/clarithromycin/levofloxacin (1.8%), respectively. Over 15 years, H. pylori resistance rates to metronidazole, clarithromycin and levofloxacin had increased. There was increased resistance to multiple antibiotics. © 2016 John Wiley & Sons Ltd.

  2. Role of Helicobacter pylori plasticity region genes in development of gastroduodenal diseases.

    PubMed

    Sugimoto, Mitsushige; Watada, Masahide; Jung, Sung Woo; Graham, David Y; Yamaoka, Yoshio

    2012-02-01

    The plasticity region of Helicobacter pylori is a large chromosomal segment including isolate-specific open reading frames with characteristics of pathogenicity islands. It remains unclear whether genes in the plasticity region play a role in the pathogenesis of gastric mucosal inflammation and gastroduodenal disease. Our aim was to assess the role of selected genes in the plasticity region in relation to risk of H. pylori-related disease and the severity of gastric mucosal damage. We used PCR to study the relation of disease outcome and mucosal damage with four genes in the H. pylori plasticity region (jhp0940, jhp0945, jhp0947, and jhp0949) from isolates obtained from both Western (n = 296) and East Asian (n = 217) patients. The prevalence of jhp0945, jhp0947, and jhp0949 differed significantly between Western and East Asian isolates. In Western isolates, the presence of jhp0945 was significantly associated with gastric ulcer, duodenal ulcer, and gastric cancer (odds ratios [95% confidence intervals]: 2.27 [1.04 to 4.98], 1.86 [1.03 to 3.34], and 1.92 [1.03 to 3.56], respectively). jhp0940-positive Western isolates were significantly associated with absence of gastric ulcer or duodenal ulcer (0.21 [0.05 to 0.94] and 0.31 [0.12 to 0.78], respectively). No significant difference was observed between inflammatory cell infiltration or atrophy and the presence or absence of plasticity region genes. The outcome of H. pylori infections varies widely geographically. These data suggest a possible role for difference in the prevalence of plasticity region genes in the geographic variation in H. pylori-related diseases.

  3. Evaluation of antimicrobial resistance of Helicobacter pylori in the last 15 years in West Poland.

    PubMed

    Karpiński, Tomasz M; Andrzejewska, Ewa; Eder, Piotr; Linke, Krzysztof; Szkaradkiewicz, Andrzej

    2015-09-01

    Increasing resistance to drugs represents a serious problem in treatment of infections with Helicobacter pylori, providing cause of frequent therapeutic failures. Present study aimed at analysis of changes in resistance of H. pylori to antibiotics in West Poland within the recent 15 years. 108 strains of H. pylori were analysed, isolated from gastric mucosa of adult patients. Group 1 involved 66 strains isolated in years of 1998/1999. Group 2 comprised 42 isolates obtained in years of 2013/2014. Susceptibility to amoxicillin (AMX), clarithromycin (CL), tetracycline (TC) and metronidazole (MTZ) was determined by E-test (AB Biodisc). All strains on both studied groups were susceptible to AMX. In group 1 all strains proved to be susceptible to TC, while 9% and 36% of tested strains were resistant to CL and MTZ, respectively. By contrast, in group 2, 31% and 83% of strains were resistant to CL and MTZ, respectively. In parallel, 14% strains were found to be resistant to TC (according to EUCAST interpretations). In West Poland, within recent 15 years a dramatic increase was noted in H. pylori strains resistant to metronidazole. In parallel, a significant increase was noted in proportion of strains resistant to clarithromycin.

  4. Biofilm Formation by Drug Resistant Enterococci Isolates Obtained from Chronic Periodontitis Patients

    PubMed Central

    Mehta, Manjula; Sood, Shaveta; Sharma, Jyoti

    2017-01-01

    Introduction Enterococci are an important cause of opportunistic nosocomial infections and several multidrug resistant strains have emerged. The severity of periodontal diseases is managed by reduction in the pathogenic bacteria. There is a need to assess the prevalence and antibiotic susceptibility of enterococci colonizing the periodontal pocket and correlate its biofilm formation ability because oral biofilms provide a protective environment and are a reservoir of bacterial colonization of the gingival crevice. Aim To investigate possible association between antibiotic susceptibility and biofilm formation in enterococci isolates from chronic periodontitis patients. Materials and Methods This retrospective study was conducted at Dr. Harvansh Singh Judge Institute of Dental Sciences and Hospital, Punjab University, Chandigarh from January 2015 to October 2015. Sterile paper points were inserted in the periodontal pocket of 100 subjects and put in a transport media. Forty -six isolates were identified as enterococci. The isolates were further examined for their ability to form biofilm by microtitre plate assay and antimicrobial susceptibility testing was done by disc diffusion method for clinically relevant antibiotics. Results Significant relationship (p<0.001) was found between biofilm production with antibiotic resistance to Vancomycin, Erythromycin, Ciprofloxacin, Tiecoplanin, Amoxycillin and Gentamycin. Conclusion The study demonstrates a high propensity among the isolates of Enterococci to form biofilm and a significant association of biofilm with multiple drug resistance. PMID:28273964

  5. Genome Sequences of 12 Bacterial Isolates Obtained from the Urine of Pregnant Women

    PubMed Central

    Weimer, Cory M.; Deitzler, Grace E.; Robinson, Lloyd S.; Park, SoEun; Hallsworth-Pepin, Kymberlie; Wollam, Aye; Mitreva, Makedonka

    2016-01-01

    The presence of bacteria in urine can pose significant risks during pregnancy. However, there are few reference genome strains for many common urinary bacteria. We isolated 12 urinary strains of Streptococcus, Staphylococcus, Citrobacter, Gardnerella, and Lactobacillus. These strains and their genomes are now available to the research community. PMID:27688327

  6. Helicobacter pylori infection in Finland.

    PubMed

    Rautelin, Hilpi; Kosunen, Timo U

    2004-01-01

    Helicobacter pylori causes chronic gastritis worldwide and it is the most important single factor in peptic ulcer disease. Up to half of H. pylori infected individuals develop atrophic gastritis over years and decades. H. pylori infection has also been classified as a class I carcinogen in human gastric cancer. Most infections are obtained in childhood, in Finland mainly before the age of 7 years but the exact transmission routes are not known. The infection shows an age-dependent pattern, the infection being rare among children but gradually becoming more prevalent among older age groups. As new infections are few in adults and the infection only rarely disappears without effective anti-microbial therapy, the occurrence of the infection in the old actually reflects the prevalence of the infection in their childhood. In developed countries, such as Finland, a rapid decline of H. pylori prevalence rate has been demonstrated. In order to speed up this natural decline of the infection, a unique population based 'screen and treat' project was started in Vammala, a semiurban south-western community in Finland. In this survey, young inhabitants were offered diagnosis and treatment for H. pylori.

  7. Serotyping, antibiotic susceptibility, and virulence genes screening of Escherichia coli isolates obtained from diarrheic buffalo calves in Egyptian farms.

    PubMed

    Hakim, Ashraf S; Omara, Shimaa T; Syame, Sohier M; Fouad, Ehab A

    2017-07-01

    In Egypt as in many other countries, river water buffalo (Bubalus bubalis) is considered an important source of high-quality milk and meat supply. The objective of this study was to investigate serotypes, virulence genes, and antibiotic resistance determinants profiles of Escherichia coli isolated from buffalo at some places in Egypt; noticibly, this issue was not discussed in the country yet. A number of 58 rectal samples were collected from diarrheic buffalo calves in different regions in Egypt, and bacteriological investigated for E. coli existence. The E. coli isolates were biochemically, serologicaly identified, tested for antibiotic susceptibility, and polymerase chain reaction (PCR) analyzed for the presence of antibiotic resistance determinants and virulence genes. Overall 14 isolates typed as E. coli (24.1%); 6 were belonged to serogroup O78 (10.3%), followed by O125 (4 isolates, 6.9%), then O158 (3 isolates, 5.2%) and one isolate O8 (1.7%), among them, there were 5 E. coli isolates showed a picture of hemolysis (35.7%). The isolates exhibited a high resistance to β lactams over 60%, followed by sulfa (50%) and aminoglucoside (42.8%) group, in the same time the isolates were sensitive to quinolone, trimethoprim-sulfamethoxazole, tetracycline (100%), and cephalosporine groups (71.4%). A multiplex PCR was applied to the 14 E. coli isolates revealed that all were carrying at least one gene, as 10 carried blaTEM (71.4%), 8 Sul1 (57.1%), and 6 aadB (42.8%), and 9 isolates could be considered multidrug resistant (MDR) by an incidence of 64.3%. A PCR survey was stratified for the most important E. coli virulence genes, and showed the presence of Shiga toxins in 9 isolates carried either one or the two Stx genes (64.3%), 5 isolates carried hylA gene (35.7%), and eae in 2 isolates only (14.3%), all isolates carried at least one virulence gene except two (85.7%). The obtained data displayed that in Egypt, buffalo as well as other ruminants could be a potential

  8. Electrochemical and genomic analysis of novel electroactive isolates obtained via potentiostatic enrichment from tropical sediment

    NASA Astrophysics Data System (ADS)

    Doyle, Lucinda E.; Yung, Pui Yi; Mitra, Sumitra D.; Wuertz, Stefan; Williams, Rohan B. H.; Lauro, Federico M.; Marsili, Enrico

    2017-07-01

    Enrichment of electrochemically-active microorganisms (EAM) to date has mostly relied on microbial fuel cells fed with wastewater. This study aims to enrich novel EAM by exposing tropical sediment, not frequently reported in the literature, to sustained anodic potentials. Voltamperometric techniques and electrochemical impedance spectroscopy, performed over a wide range of potentials, characterise extracellular electron transfer (EET) over time. Applied potential is found to affect biofilm electrochemical signature. Geobacter metallireducens is heavily enriched on the electrodes, as determined by metagenomic and metatranscriptomic analysis, in the first report of the species in a lactate-fed system. Two novel isolates are grown in pure culture from the enrichment, identified by 16S rRNA gene sequencing as Aeromonas and Enterobacter, respectively. The names proposed are Aeromonas sp. CL-1 and Enterobacter sp. EA-1. Both isolates are capable of EET on carbon felt and screen-printed carbon electrodes without the addition of exogenous redox mediators. Enterobacter sp. EA-1 can also perform mediated electron transfer using the soluble redox mediator 2-hydroxy-1,4-naphthoquinone (HNQ). Both isolates are able to use acetate and lactate as electron donors. This work outlines a comprehensive methodology for characterising novel EAM from unconventional inocula.

  9. Non-human reservoirs of Helicobacter pylori.

    PubMed

    Fox, J G

    1995-01-01

    Early attempts to identify non-human reservoirs for Helicobacter pylori were largely unrewarding. The one exception being old-world macaques, which were found to be colonized with H. pylori; however, it is doubtful whether this species provides an important reservoir for human infection. The possibility of other animal reservoirs and zoonotic transmission of H. pylori has been discussed, but until recently has not received serious study. Enthusiasm to initiate extensive studies in this area were further dampened by the inability to experimentally infect several different species of mammals with the organism. Reports using whole-cell enzyme-linked immunoabsorbent assay (ELISA) sonicate to monitor infection serologically, have cited a high incidence of H. pylori infection in abattoir workers. These results have been criticized because of potential antigenic cross-reactivity in workers' sera due to the constant exposure of these personnel to other gastrointestinal flora of animals. The large spiral gastric Helicobacter-like organisms (GHLOs) commonly noted in dogs and cats are associated with approximately 0.08-1% of gastritis in humans. These GHLOs often infect patients who own pets, suggesting a zoonotic link. Thus, the recent isolation of H. pylori from the inflamed gastric mucosa of commercially reared cats, and the ability to experimentally infect cats with H. pylori, raises the possibility of zoonotic H. pylori transmission from infected animals who have close human contact. Water and raw vegetables have been linked with H. pylori transmission in a few epidemiologically-based studies in developing populations. The recent isolation of H. pylori from the faeces of adults and children implicates a faecal-oral transmission pathway and supports the theory that both food and water (via faecal contamination) could be a source of H. pylori. Providing conclusive evidence that H. pylori has the ability to exist in the environment as a viable, non-culturable coccoid form

  10. Role of dupA in virulence of Helicobacter pylori.

    PubMed

    Talebi Bezmin Abadi, Amin; Perez-Perez, Guillermo

    2016-12-14

    Helicobacter pylori (H. pylori) is a gastric human pathogen associated with acute and chronic gastritis, 70% of all gastric ulcers, 85% of all duodenal ulcers, and both forms of stomach cancer, mucosal-associated lymphoid tissue (MALT) lymphoma and adenocarcinoma. Recently, attention has focused on possible relationship between presence of certain virulence factor and H. pylori-associated diseases. Some contradictory data between this bacterium and related disorders has been observed since not all the colonized individuals develop to severe disease. The reported diseases plausibility related to H. pylori specific virulence factors became an interesting story about this organism. Although a number of putative virulence factors have been identified including cytotoxin-associated gene a (cagA) and vacA, there are conflicting data about their actual participation as specific risk factor for H. pylori-related diseases. Duodenal ulcer promoting gene a (dupA) is a virulence factor of H. pylori that is highly associated with duodenal ulcer development and reduced risk of gastric cancer. The prevalence of dupA in H. pylori strains isolated from western countries is relatively higher than in H. pylori strains from Asian countries. Current confusing epidemiological reports will continue unless future sophisticated and molecular studies provide data on functional and complete dupA cluster in H. pylori infected individuals. This paper elucidates available knowledge concerning role of dupA in virulence of H. pylori after a decade of its discovery.

  11. Role of dupA in virulence of Helicobacter pylori

    PubMed Central

    Talebi Bezmin Abadi, Amin; Perez-Perez, Guillermo

    2016-01-01

    Helicobacter pylori (H. pylori) is a gastric human pathogen associated with acute and chronic gastritis, 70% of all gastric ulcers, 85% of all duodenal ulcers, and both forms of stomach cancer, mucosal-associated lymphoid tissue (MALT) lymphoma and adenocarcinoma. Recently, attention has focused on possible relationship between presence of certain virulence factor and H. pylori-associated diseases. Some contradictory data between this bacterium and related disorders has been observed since not all the colonized individuals develop to severe disease. The reported diseases plausibility related to H. pylori specific virulence factors became an interesting story about this organism. Although a number of putative virulence factors have been identified including cytotoxin-associated gene a (cagA) and vacA, there are conflicting data about their actual participation as specific risk factor for H. pylori-related diseases. Duodenal ulcer promoting gene a (dupA) is a virulence factor of H. pylori that is highly associated with duodenal ulcer development and reduced risk of gastric cancer. The prevalence of dupA in H. pylori strains isolated from western countries is relatively higher than in H. pylori strains from Asian countries. Current confusing epidemiological reports will continue unless future sophisticated and molecular studies provide data on functional and complete dupA cluster in H. pylori infected individuals. This paper elucidates available knowledge concerning role of dupA in virulence of H. pylori after a decade of its discovery. PMID:28028359

  12. Prevalence of multiple drug-resistant Helicobacter pylori strains among patients with different gastric disorders in Iran.

    PubMed

    Shokrzadeh, Leila; Alebouyeh, Masoud; Mirzaei, Tabassom; Farzi, Nastaran; Zali, Mohammad Reza

    2015-02-01

    Emergence of multidrug-resistant (MDR) strains of Helicobacter pylori is a global health concern. This study was aimed to determine the frequency of MDR H. pylori strains in Iran. H. pylori isolates were obtained from cultured gastric biopsy samples on selective culture media after their characterization by PCR and conventional biochemical methods. The minimal inhibitory concentrations of rifampicin, ciprofloxacin, levofloxacin, ampicillin, clarithromycin, erythromycin, metronidazole, and tetracycline were determined for 111 strains that were isolated from 197 dyspeptic patients by the agar dilution method. The primary resistance rates were 61.3% (68/111) for metronidazole, 15.3% (17/111) for ampicillin, and 14.4% (16/111) for rifampicin. Resistance rates for other antimicrobials were as follows: macrolides (erythromycin or clarithromycin) 32.4% (36/111) and quinolones (levofloxacin or ciprofloxacin) 30.6% (34/111). Among the resistant strains, the rates of double and multiple drug resistance phenotypes were 22.6% (19/84) and 34.5% (29/84), respectively. The quadruple drug resistance phenotype encompasses 37.9% of the MDR strains, of which 90% of them was resistant to metronidazole. In conclusion, these results showed a high frequency of MDR phenotypes among the studied H. pylori strains in Iran. The eradication of the H. pylori strains presenting high resistance rates to macrolides, fluoroquinolones, or metronidazole could be achieved by approved tetracycline- or amoxicillin-containing regimens as alternative regimens to standard triple therapy.

  13. Biocide and antibiotic susceptibility of Salmonella isolates obtained before and after cleaning at six Danish pig slaughterhouses.

    PubMed

    Gantzhorn, Mette Rørbæk; Pedersen, Karl; Olsen, John Elmerdahl; Thomsen, Line Elnif

    2014-07-02

    Salmonella sp. continues to be one of the most important foodborne pathogens. Control measures in terms of cleaning and disinfection on food production plants are very important for limiting the risk of contaminated food products to reach the consumer. In the last decade concern has arisen that bacteria exposed to disinfectants can develop resistance toward disinfectants and can have a higher risk of developing antibiotic resistance. The objectives of this study were to examine the prevalence of biocide resistant Salmonella sp. in Danish pig slaughterhouses, to evaluate if there was a correlation between susceptibilities to biocides and antibiotics, and to examine if cleaning and disinfection select isolates with changed susceptibility toward biocides or antibiotics. Salmonella sp. was isolated from the environment in Danish pig slaughterhouses before and after cleaning and disinfection. The susceptibility toward three different biocides, triclosan and two commercial disinfection products: Desinfect Maxi, a quaternary ammonium compound, and Incimaxx DES, an acetic compound, was determined. We found no resistance toward the biocides tested, but we did find that isolates obtained after cleaning had higher minimum inhibitory concentration (MIC) values toward one of the disinfectants (Incimaxx DES) compared to isolates obtained before cleaning and disinfection. This could indicate selection of strains that are more tolerant, due to the cleaning and disinfection. Furthermore, we found that there was a weak statistical correlation between MICs toward the biocides and some antibiotics, but no difference in log(MIC)s toward antibiotics between isolates obtained before and after cleaning, nor did we find any difference in the number of resistances of isolates obtained before and after cleaning and disinfection.

  14. Assignment of serotype to Salmonella enterica isolates obtained from poultry and their environment in southern Brazil

    PubMed Central

    Pulido-Landínez, M; Sánchez-Ingunza, R; Guard, J; do Nascimento, V Pinheiro

    2013-01-01

    To assess diversity of Salmonella enterica serotypes present in poultry and their environment from southern Brazil, the Kauffmann–White–Le Minor (KWL) scheme was used to serotype a total of 155 isolates. Isolates were then re-examined with nested PCR and sequencing of the dkgB-linked intergenic sequence ribotyping (ISR) region that assesses single nucleotide polymorphisms occurring around a 5S ribosomal gene. Serotypes identified were Heidelberg (40·6%), Enteritidis (34·2%), Hadar (8·4%), Typhimurium (3·9%), Gallinarum (3·2%), Agona (1·3%), Cerro (1·3%), Livingstone (1·3%), Infantis (0·6%), Isangi (0·6%), Mbandaka (0·6%), Montevideo (0·6%) and Senftenberg (0·6%). Three unique ISRs were detected from four strains. Day old chicks yielded only S. Enteritidis, whereas S. Heidelberg was most often associated with poultry carcasses. Overall agreement between KWL and ISR was 85·2%, with disagreement possibly due to the ability of ISR to detect mixtures of serotypes in culture. Overall, ISR provided more information than did KWL about the ecology of Salm. enterica on-farm. The O-antigen group D Salm. enterica serovars such as Pullorum, Gallinarum and Enteritidis appear susceptible to overgrowth by other serotypes. Significance and Impact of the Study Single nucleotide polymorphisms found in a group of poultry-associated Salmonella isolates from southern Brazil provided evidence of mixtures of serovar group D serotypes on-farm and in single samples from birds. This finding suggests that co-infection and interserotype competition of Salmonella enterica in poultry could impact the incidence of disease in animals or humans. In addition, unique serotypes were identified on-farm that escaped characterization by antibody typing. Application of cost-efficient and highly discriminatory genomic methods for assigning serotype may alter concepts about the epidemiology of Salm. enterica on-farm and in foods. PMID:23734786

  15. Virulence attenuation and phenotypic variation of Paracoccidioides brasiliensis isolates obtained from armadillos and patients.

    PubMed

    Macoris, S A G; Sugizaki, M F; Peraçoli, M T S; Bosco, S M G; Hebeler-Barbosa, F; Simões, L B; Theodoro, R C; Trinca, L A; Bagagli, E

    2006-05-01

    Paracoccidioides brasiliensis is the etiological agent of paracoccidioidomycosis, the most important systemic mycosis in Latin America. The virulence profiles of five isolates of P. brasiliensis were studied in two different moments and correlated with some colonial phenotypic aspects. We observed a significant decrease in the virulence and an intense phenotypic variation in the mycelial colony. The recognition of all ranges of phenotypic and virulence variation of P. brasiliensis, as well as its physiological and genetic basis, will be important for a better comprehension of its pathogenic and epidemiological features.

  16. Isolation and Partial Characterization of an Immunogenic Moiety Obtained from Salmonella typhimurium

    PubMed Central

    Venneman, Martin R.; Bigley, Nancy J.

    1969-01-01

    Ribosomal preparations obtained from Salmonella typhimurium by differential centrifugation and sodium dodecyl sulfate (SDS) treatment of the bacillary lysate were found to be immunogenic in F1 hybrid (C3H/HeJ × DBA/2J) and albino Swiss mice, as determined by progressive host survival. The immunity obtained was independent of the need for adjuvant and dependent on the dosage of immunogen given. Immunizations with the ribosomal preparations induced an immune response comparable to that obtained by vaccination with living organisms and significantly greater than that obtained by immunization with heat-killed salmonellae, purified lipopolysaccharide, or crude and SDS-treated endotoxin preparations. No effect on the immunogenicity of the ribosomal fraction was observed by enzymatic treatment with trypsin, Pronase, deoxyribonuclease, and pancreatic ribonuclease. Linear sucrose density gradient resolution of the preparations showed that the immunogenicity of the ribosomal fraction was not unique to any one of its subcomponents. Ethyl alcohol-precipitated, crude ribonucleic acid preparations obtained from the ribosomal and sucrose density-resolved ribosomal preparations were found to induce an immune response comparable to that obtained by immunization with the entire ribosomal fraction. Dialysis in doubly distilled demineralized water slightly reduced the immunogenicity of the preparation; however, comparable dialysis in 10−4m MgCl2-phosphate buffer did not. Chemical assays of the preparations found to be immunogenic were performed. PMID:4898982

  17. Apoptotic depletion of infiltrating mucosal lymphocytes associated with Fas ligand expression by Helicobacter pylori-infected gastric mucosal epithelium: human glandular stomach as a site of immune privilege.

    PubMed

    Koyama, S

    2000-04-01

    H. pylori infection almost invariably results in chronic gastritis, but only a proportion of patients develops severe destruction of epithelial glandular structure or peptic ulcer. To confirm the recent data obtained in testis and eye, showing that Fas ligand is involved in the phenomenon of "immune privilege," expression of Fas receptor and its ligand of the stomach was investigated in a panel of gastric biopsies obtained from patients H. pylori-positive (N = 42) and with H. pylori-negative (N = 18) by two-color flow cytometry. The results show that membrane-bound Fas ligand protein is constitutively expressed on freshly isolated human gastric mucosal epithelium coupled with infiltrating lymphocytes. There was significant overexpression of Fas receptor and its ligand, and a higher frequency of apoptotic cell death detected by TUNEL in epithelium and infiltrating lymphocytes in H. pylori-infected patients. These findings suggest that involvement of Fas receptor and its ligand system contributes to some extent to mucosal damage in H. pylori-associated gastritis. However, the more specific findings are apoptotic depletion of invading mucosal lymphocytes associated with Fas ligand expression by gastric epithelium. These provide the first direct quantitative evidence to support Fas receptor counterattack and/or paracrine fratricide as a mechanism of immune privilege in vivo in the H. pylori-infected glandular stomach.

  18. Helicobacter Pylori Bacteremia: An Unusual Finding

    PubMed Central

    De Luca, Concetta; Mancin, Annalisa; Calabrò, Maria; Daleno, Cristina; Ferrario, Antonella; Renzulli, Raffaella; Scuderi, Cristina; Casari, Erminia

    2016-01-01

    We report a case of Helicobacter pylori transient bacteremia in a woman with ulcerated antral gastric cancer. The patient was hospitalized for laparoscopy and subtotal gastrectomy. After surgery she developed fever (39°C) and was empirically treated with levofloxacin. Blood cultures, collected and sent immediately to Laboratory, were positive for a spiral Gram-negative bacterium. This isolate was identified as H. pylori and the specific susceptibility test was performed. One day after the fever was decreased but antibiotic treatment with levofloxacin was continued and it was maintained until discharge. In summary, H. pylori transient bacteremia may occur as a rare complication after stomach surgery. Further studies are necessary to elucidate the potential role of Helicobacter pylori presence in blood.

  19. Helicobacter pylori genome evolution during human infection

    PubMed Central

    Kennemann, Lynn; Didelot, Xavier; Aebischer, Toni; Kuhn, Stefanie; Drescher, Bernd; Droege, Marcus; Reinhardt, Richard; Correa, Pelayo; Meyer, Thomas F.; Josenhans, Christine; Suerbaum, Sebastian

    2011-01-01

    High genetic diversity is a hallmark of the gastric pathogen Helicobacter pylori. We used 454 sequencing technology to perform whole-genome comparisons for five sets of H. pylori strains that had been sequentially cultured from four chronically infected Colombians (isolation intervals = 3–16 y) and one human volunteer experimentally infected with H. pylori as part of a vaccine trial. The four sets of genomes from Colombian H. pylori differed by 27–232 isolated SNPs and 16–441 imported clusters of polymorphisms resulting from recombination. Imports (mean length = 394 bp) were distributed nonrandomly over the chromosome and frequently occurred in groups, suggesting that H. pylori first takes up long DNA fragments, which subsequently become partially integrated in multiple shorter pieces. Imports were present at significantly increased frequency in members of the hop family of outer membrane gene paralogues, some of which are involved in bacterial adhesion, suggesting diversifying selection. No evidence of recombination and few other differences were identified in the strain pair from an infected volunteer, indicating that the H. pylori genome is stable in the absence of mixed infection. Among these few differences was an OFF/ON switch in the phase-variable adhesin gene hopZ, suggesting strong in vivo selection for this putative adhesin during early colonization. PMID:21383187

  20. mRNA levels of TLR4 and TLR5 are independent of H pylori

    PubMed Central

    Garza-González, Elvira; Bocanegra-García, Virgilio; Bosques-Padilla, Francisco Javier; Flores-Gutiérrez, Juan Pablo; Moreno, Francisco; Perez-Perez, Guillermo Ignacio

    2008-01-01

    AIM: To determine if the presence H pylori or its virulence affect toll-like receptor 4 (TLR4) and TLR5 mRNA expression levels. METHODS: For the in vivo assays, gastric biopsies were obtained from 40 patients and H pylori status was determined. For the in vitro assays, human gastric adenocarcinoma mucosal cells (AGS) were cultured in the presence or absence of twelve selected H pylori strains. H pylori strains isolated from culture-positive patients and selected strains were genotyped for cagA and vacA. The cDNA was obtained from mRNA extracted from biopsies and from infected AGS cells. TLR4 and TLR5 mRNA levels were examined by real-time PCR. RESULTS: The presence of H pylori did not affect the mRNA levels of TLR4 or TLR5 in gastric biopsies. The mRNA levels of both receptors were not influenced by the vacA status (P > 0.05 for both receptors) and there were no differences in TLR4 or TLR5 mRNA levels among the different clinical presentations/histological findings (P > 0.05). In the in vitro assay, the mRNA levels of TLR4 or TLR5 in AGS cells were not influenced by the vacAs1 status or the clinical condition associated with the strains (P > 0.05 for both TLR4 and TLR5). CONCLUSION: The results of this study show that the mRNA levels of TLR4 and TLR5 in gastric cells, both in vivo and in vitro, are independent of H pylori colonization and suggest that vacA may not be a significant player in the first step of innate immune recognition mediated by TLR4 or TLR5. PMID:18785283

  1. Effect of treatment failure on the CagA EPIYA motif in Helicobacter pylori strains from Colombian subjects.

    PubMed

    Bustamante-Rengifo, Javier Andres; Matta, Andres Jenuer; Pazos, Alvaro Jairo; Bravo, Luis Eduardo

    2017-03-21

    To evaluate effect of treatment failure on cagA and vacA genotypes in Helicobacter pylori (H. pylori) isolates from Colombia. One hundred and seventy-six participants infected with H. pylori from Colombia were treated during 14 d with the triple-standard therapy. Six weeks later, eradication was evaluated by (13)C-Urea breath test. Patients with treatment failure were subjected to endoscopy control; biopsies obtained were used for histopathology and culture. DNA from H. pylori isolates was amplified using primers specific for cagA and vacA genes. The phylogenetic relationships among isolates obtained before and after treatment were established by conglomerate analysis based on random amplified polymorphic DNA (RAPD) fingerprinting. Treatment effectiveness was at 74.6%. Of the participants with treatment failure, 25 accepted subjected to a second endoscopy. Prevalence of post-treatment infection was 64% (16/25) and 40% (10/25) by histology and culture, respectively. Upon comparing the cagA and vacA genotypes found before and after therapy, multiple cagA genotypes (cagA-positive and cagA-negative) were found before treatment; in contrast, cagA-negative genotypes decreased after treatment. vacA s1m1 genotype was highly prevalent in patients before and after therapy. The 3'cagA region was successfully amplified in 95.5% (21/22) of the isolates obtained before and in 81.8% (18/22) of the isolates obtained after treatment. In the isolates obtained from patients with treatment failure, it was found that 72.7% (16/22) presented alterations in the number of EPIYA motifs, compared to isolates found before treatment. Unsuccessful treatment limits colonization by low-virulence strains resulting in partial and selective eradication in mixed infections, and acts on the cagA-positive strains inducing genetic rearrangements in cagA variable region that produces a loss or gain of EPIYA repetitions.

  2. [Isolation, identification and serotyping of yeasts obtained from the vaginal fluid in patients with clinical vaginitis].

    PubMed

    Mendoza, M; González, I; Bellorin, E J; Salazar, W; Mendoza, L; Zambrano, E A; de Albornoz, M C

    1999-03-01

    A study was carried out to determine the presence of Candida in 105 patients with clinical vaginitis who consulted in the Infectious Disease Unit of the Vargas Hospital after referral from Gynecology Service. Yeasts were detected in 23 cases (24%), and identified as C. albicans (12), C. tropicalis (5), C. guilliermondii (3), C. glabrata (2) and C. parapsilosis (1). The presence of hyphae was observed in 50% of the direct examinations, in which the isolated species was C. albicans. These structures were not observed in infections with other species of Candida. In this study, there was relatively little difference between the percentages of serotypes A and B, 58 % and 42, respectively. This is in contrast with previous studies reported in clinical material from Venezuela and other countries, in which serotype A presented a greater incidence than serotype B. Our observations suggest an increase in serotype B C. albicans in vaginal candidiasis.

  3. In vitro inflammatory responses elicited by isolates of Alloiococcus otitidis obtained from children with otitis media with effusion.

    PubMed

    Ashhurst-Smith, Christopher; Hall, Sharron T; Burns, Christine J; Stuart, John; Blackwell, C Caroline

    2014-04-01

    Alloiococcus otitidis is usually detected in children with otitis media (OM) by PCR as it is not often detected by routine culture. Our improved method for its isolation obtained A. otitidis from nearly 50% of 78 children with OM with effusion. The role of A. otitidis in pathogenesis of OM is unclear. This study tested two hypothesis: (1) that fresh isolates of A. otitidis would elicit pro-inflammatory cytokines from THP-1 monocytic cells equivalent to those induced by Streptococcus pneumoniae; (2) priming THP-1 cells with interferon-gamma (IFN-γ) a surrogate for virus infection, would enhance pro-inflammatory responses. Recent clinical isolates of A. otitidis, S. pneumoniae (ATCC 49619) and a blood culture isolate of S. pneumoniae (SP2) were used in the assays. Cytokines were quantified by BioRad bead assay and Luminex 200. IFN-γ priming enhanced cytokine responses. S. pneumoniae ATCC 49619 induced lower responses than SP2 for IL-1β, IL-6, TNF-α. A. otitidis LW 27 elicited higher IL-1β and TNF-α responses than either pneumococcal isolate. Small green colony types of A. otitidis induced higher responses than large white colony types for IL-8 and IL-1β. The hypothesis that A. otitidis elicits cytokines observed in middle ear effusions was supported; the need to use recent clinical isolates in studies of pathogenesis was highlighted.

  4. Characterization of Helicobacter pylori urease mutants.

    PubMed Central

    Segal, E D; Shon, J; Tompkins, L S

    1992-01-01

    The association between Helicobacter pylori, gastritis, and peptic ulcer is well established, and the association of infection with gastric cancer has been noted in several developing countries. However, the pathogenic mechanism(s) leading to disease states has not been elucidated. The H. pylori urease is thought to be a determinant of pathogenicity, since the enzyme is produced by all H. pylori clinical isolates. Evidence indicates that some H. pylori strains are more cytotoxic than others, with a correlation between the activity of the urease and the presence of a vacuolating cytotoxin having been made. However, the number of cytotoxins remains unknown at this time. The relationship between the urease and cytotoxicity has previously been examined with chemical inhibitors. To examine the role of the urease and its relationship to cytotoxicity, urease-deficient mutants were produced following ethyl methanesulfonate mutagenesis of H. pylori 87A300. Two mutants (the ure1 and ure5 mutants) which were entirely deficient in urease activity (Ure-) were selected. Characterization of the isolates at the protein level showed that the urease subunits lacked the ability to complex and form the active urease enzyme. The ure1 mutant was shown to be sensitive to the effects of low pH in vitro and exhibited no cytotoxicity to eucaryotic cells, whereas the parental strain (Ure+) produced a cytotoxic effect in the presence of urea. Interaction between the H. pylori Ure+ and Ure- strains and Caco-2 cells appeared to be similar in that both bacterial types elicited pedestal formation and actin condensation. These results indicate that the H. pylori urease may have many functions, among them (i) protecting H. pylori against the acidic environment of the stomach, (ii) acting as a cytotoxin, with human gastric cells especially susceptible to its activity, and (iii) disrupting cell tight junctions in such a manner that the cells remain viable but an ionic flow between the cells occurs

  5. Identification and Characterization of Imipenem-Resistant Klebsiella pneumoniae and Susceptible Klebsiella variicola Isolates Obtained from the Same Patient.

    PubMed

    Garza-Ramos, Ulises; Moreno-Dominguez, Stephania; Hernández-Castro, Rigoberto; Silva-Sanchez, Jesús; Barrios, Humberto; Reyna-Flores, Fernando; Sanchez-Perez, Alejandro; Carrillo-Casas, Erika M; Sanchez-León, María Carmen; Moncada-Barron, David

    2016-04-01

    Klebsiella variicola, a bacterium closely genetically related to Klebsiella pneumoniae, is commonly misidentified as K. pneumoniae by biochemical tests. To distinguish between the two bacteria, phylogenetic analysis of the rpoB gene and the identification of unique genes in both bacterial species by multiplex-polymerase chain reaction (PCR) provide the means to reliably identify and genotype K. variicola. In recent years, K. variicola has been described both as the cause of an intrahospital outbreak in a pediatric hospital, which resulted in sepsis in inpatients, and as a frequent cause of bloodstream infections. In the present study, K. pneumoniae and K. variicola were isolated from a unique patient displaying different antimicrobial susceptibility phenotypes and different genotypes of virulence determinants. Eight clinical isolates were obtained at different time intervals; all during a 5-month period. The isolates were identified as K. pneumoniae by an automated identification system. The clinical (biochemical test) and molecular (multiplex-PCR and rpoB gene) characterization identified imipenem resistance in the first six K. pneumoniae ST258 isolates, which encode the SHV-12 cephalosporinase and KPC-3 carbapenemase genes. The two last remaining isolates corresponded to susceptible K. variicola. The bacterial species showed a specific profile of virulence-associated determinants, specifically the fimA, fimH, and ecpRAB fimbrial-encoding genes identified only in K. pneumoniae isolates. However, the entb (enterobactin), mrkD (fimbrial adhesin), uge (epimerase), ureA (urease), and wabG (transferase) genes were shared between both bacterial species. Recent studies attribute a higher mortality rate to K. variicola than to K. pneumonia. This work highlights the identification of K. pneumoniae and the closely related K. variicola isolated from the same patient. The value of distinguishing between these two bacterial species is in their clinical significance, their

  6. Phenotypic and Molecular Characterization of Acinetobacter Clinical Isolates Obtained from Inmates of California Correctional Facilities▿†

    PubMed Central

    Golanbar, Galarah D.; Lam, Christopher K.; Chu, Yi-Ming; Cueva, Carla; Tan, Stephanie W.; Silva, Isba; Xu, H. Howard

    2011-01-01

    Acinetobacter spp. increasingly have been wreaking havoc in hospitals and communities worldwide. Although much has been reported regarding Acinetobacter isolates responsible for nosocomial infections, little is known about these organisms in correctional facilities. In this study, we performed species identification, examined the antibiotic resistance profiles, and determined the mechanisms of resistance and clonal relationships of 123 Acinetobacter isolates obtained from inmates of 20 California correctional facilities (CCFs). We found that 57.7% of the isolates belong to A. baumannii, followed by isolates of Acinetobacter genomic species 3 (gen. sp. 3; 23.6%) and of Acinetobacter gen. sp. 13TU (10.6%). Multidrug-resistant (MDR) CCF isolates were found in only six CCFs. Additionally, DNA sequences of gyrA and parC genes were consistent with fluoroquinolone (FQ) susceptibility phenotypes. Furthermore, the presence of class 1 integrons was detected in 15 CCF isolates, all of which are MDR. Integron-associated gene cassettes encode several aminoglycoside modification enzymes, which correlate with most of the aminoglycoside-resistant phenotypes. Antimicrobial susceptibility testing in the presence of Phe-Arg-β-naphthylamide dihydrochloride and 1-(1-naphthylmethyl)-piperazine indicated the involvement of efflux pumps in the FQ resistance of only a few CCF isolates. Finally, genetic profiling showed that there was no evidence of A. baumannii outbreaks in CCFs. Instead, our analyses revealed only limited clonal dissemination of mostly non-MDR A. baumannii strains in a few facilities. This study represents the first report to characterize phenotypic and molecular features of Acinetobacter isolates in correctional facilities, which provides a baseline for monitoring the antimicrobial resistance changes and dissemination patterns of these organisms in such specialized institutions. PMID:21450955

  7. Frequency of vacA, cagA and babA2 virulence markers in Helicobacter pylori strains isolated from Mexican patients with chronic gastritis

    PubMed Central

    Paniagua, Gloria Luz; Monroy, Eric; Rodríguez, Raymundo; Arroniz, Salvador; Rodríguez, Cristina; Cortés, José Luis; Camacho, Ausencio; Negrete, Erasmo; Vaca, Sergio

    2009-01-01

    Background Helicobacter pylori has been strongly associated with chronic gastritis, peptic and duodenal ulcers, and it is a risk factor for gastric cancer. Three major virulence factors of H. pylori have been described: the vacuolating toxin (VacA), the cytotoxin-associated gene product (CagA) and the adhesion protein BabA2. Since considerable geographic diversity in the prevalence of H. pylori virulence factors has been reported, the aim of this work was to establish the H. pylori and vacA, cagA and babA2 gene status in 238 adult patients, from a marginal urban area of Mexico, with chronic gastritis. Methods H. pylori was identified in cultures of gastric biopsies by nested PCR. vacA and cagA genes were detected by multiplex PCR, whereas babA2 gene was identified by conventional PCR. Results H. pylori-positive biopsies were 143 (60.1%). All H. pylori strains were vacA+; 39.2% were cagA+; 13.3% were cagA+ babA2+ and 8.4% were babA2+. Mexican strains examined possessed the vacA s1, m1 (43.4%), s1, m2 (24.5%), s2, m1 (20.3%) and s2, m2 (11.9%) genotypes. Conclusion These results show that the Mexican patients suffering chronic gastritis we have studied had a high incidence of infection by H. pylori. Forty four percent (63/143) of the H. pylori strains analyzed in this work may be considered as highly virulent since they possessed two or three of the virulence markers analyzed: vacA s1 cagA babA2 (9.8%, 14/143), vacA s1 babA2 (4.9%, 7/143), and vacA s1 cagA (29.4%, 42/143). However, a statistically significant correlation was not observed between vacAs1, cagA and babA2 virulence markers (χ2 test; P > 0.05). PMID:19405980

  8. Frequency of vacA, cagA and babA2 virulence markers in Helicobacter pylori strains isolated from Mexican patients with chronic gastritis.

    PubMed

    Paniagua, Gloria Luz; Monroy, Eric; Rodríguez, Raymundo; Arroniz, Salvador; Rodríguez, Cristina; Cortés, José Luis; Camacho, Ausencio; Negrete, Erasmo; Vaca, Sergio

    2009-04-30

    Helicobacter pylori has been strongly associated with chronic gastritis, peptic and duodenal ulcers, and it is a risk factor for gastric cancer. Three major virulence factors of H. pylori have been described: the vacuolating toxin (VacA), the cytotoxin-associated gene product (CagA) and the adhesion protein BabA2. Since considerable geographic diversity in the prevalence of H. pylori virulence factors has been reported, the aim of this work was to establish the H. pylori and vacA, cagA and babA2 gene status in 238 adult patients, from a marginal urban area of Mexico, with chronic gastritis. H. pylori was identified in cultures of gastric biopsies by nested PCR. vacA and cagA genes were detected by multiplex PCR, whereas babA2 gene was identified by conventional PCR. H. pylori-positive biopsies were 143 (60.1%). All H. pylori strains were vacA+; 39.2% were cagA+; 13.3% were cagA+ babA2+ and 8.4% were babA2+. Mexican strains examined possessed the vacA s1, m1 (43.4%), s1, m2 (24.5%), s2, m1 (20.3%) and s2, m2 (11.9%) genotypes. These results show that the Mexican patients suffering chronic gastritis we have studied had a high incidence of infection by H. pylori. Forty four percent (63/143) of the H. pylori strains analyzed in this work may be considered as highly virulent since they possessed two or three of the virulence markers analyzed: vacA s1 cagA babA2 (9.8%, 14/143), vacA s1 babA2 (4.9%, 7/143), and vacA s1 cagA (29.4%, 42/143). However, a statistically significant correlation was not observed between vacAs1, cagA and babA2 virulence markers (chi2 test; P > 0.05).

  9. CAMP-reaction among skin isolates obtained from a dog with an acute squamous eczema.

    PubMed

    Brückler, J; Wibawan, I W; Lämmler, C

    1990-12-01

    The primary culture of a clinical specimen obtained from a dog with an acute squamous eczema revealed 3 different bacterial cultures. Two of these cultures, a beta-hemolytic Staphylococcus aureus and a group B streptococcal culture, demonstrated synergistic hemolytic activities on this primary culture plate. The group B streptococcus had the serotype surface antigens Ib/c, protein antigen c in its c beta component.

  10. Helicobacter Pylori Infections

    MedlinePlus

    Helicobacter pylori (H. pylori) is a type of bacteria that causes infection in the stomach. It is found in about two-thirds of ... or stool to see if it contains H. pylori. The best treatment is a combination of antibiotics ...

  11. Isolation and characterization of starch obtained from Brosimum alicastrum Swarts seeds.

    PubMed

    Pérez-Pacheco, E; Moo-Huchin, V M; Estrada-León, R J; Ortiz-Fernández, A; May-Hernández, L H; Ríos-Soberanis, C R; Betancur-Ancona, D

    2014-01-30

    In this paper, the Ramon starch was isolated and its chemical composition and physical and microscopic characteristics were determined. Corn starch was used as reference. In general, the proximal composition was similar between starches studied. Ramon starch granules were oval-spherical and rounded with sizes between 6.5 and 15 μm. Starch purity was high (92.57%) with amylose content of 25.36%. The gelatinization temperature was 83.05°C and transition enthalpy was 21.423 J/g. At 90°C, solubility was 20.42%, swelling power 17.64 g water/gstarch and water absorption capacity was 13 gwater/gstarch. The pH, clarity and color (Hue angle) of Ramon starch were higher to those reported for corn starch. The results achieved suggest that Ramon starch has potential for application in food systems requiring high processing temperatures and it is also a promising option for use in the manufacture of biodegradable materials.

  12. Low Helicobacter pylori primary resistance to clarithromycin in gastric biopsy specimens from dyspeptic patients of a city in the interior of São Paulo, Brazil

    PubMed Central

    2013-01-01

    Background Clarithromycin, amoxicillin, and a pump proton inhibitor are the most common drugs recommended as first-line triple therapy for H.pylori treatment, which results in eradication rates close to 80%, varying regionally, principally due to emergency cases and increases of clarithromycin resistant strains. Nucleotide substitutions at the H. pylori domain V of the 23S rRNA fraction are involved in the macrolide resistance and the A2142G and A2143G mutations are predominant in clinical isolates worldwide including in Brazil. As H. pylori culture is fastidious, we investigated the primary occurrence of H. pylori A2142G and A2143G rDNA 23S mutations using a molecular approach directly on gastric biopsies of dyspeptic patients consecutively attended at Hospital das Clinicas of Marilia, São Paulo, Brazil. Methods Biopsy specimens obtained from 1137 dyspeptic patients, were subjected to histopathology and H. pylori diagnosis by histology and PCR. PCR/RFLP assay was used to detect A2142G and A2143G point mutations at domain V of the H. pylori 23S rDNA associated with clarithromycin resistance. Through the developed assay, a 768 bp PCR amplicon corresponding to1728 to 2495 bp of the 23S H. pylori rDNA is restricted with MboII for A2142G mutation detection and with BsaI for A2143G mutation detection. Occurrence of 23S rDNA A2142G results in two DNA fragments (418 and 350 bp) and of 23S rDNA A2143G results in three DNA fragments (108, 310 and 350pb), due to a conserved BsaI restriction site. Results The PCR method used to diagnose H. pylori presented sensitivity, specificity and accuracy of 77,6%, 79,3% and 78,6%, respectively, compared to histology, the gold standard method for H. pylori diagnosis used in our routine. Prevalence of H.pylori with clarithromycin resistant genotypes was 2,46%, with predominance of A2143G 23S rDNA point mutation. Conclusions The PCR/RFLP assay was a rapid and accurate H.pylori diagnostic and clarithromycin resistance determination

  13. Characterization and molecular analysis of macrolide-resistant Mycoplasma pneumoniae clinical isolates obtained in Japan.

    PubMed

    Matsuoka, Mayumi; Narita, Mitsuo; Okazaki, Norio; Ohya, Hitomi; Yamazaki, Tsutomu; Ouchi, Kazunobu; Suzuki, Isao; Andoh, Tomoaki; Kenri, Tsuyoshi; Sasaki, Yuko; Horino, Atsuko; Shintani, Miharu; Arakawa, Yoshichika; Sasaki, Tsuguo

    2004-12-01

    In recent years, Mycoplasma pneumoniae strains that are clinically resistant to macrolide antibiotics have occasionally been encountered in Japan. Of 76 strains of M. pneumoniae isolated in three different areas in Japan during 2000 to 2003, 13 strains were erythromycin (ERY) resistant. Of these 13 strains, 12 were highly ERY resistant (MIC, > or =256 microg/ml) and 1 was weakly resistant (MIC, 8 microg/ml). Nucleotide sequencing of domains II and V of 23S rRNA and ribosomal proteins L4 and L22, which are associated with ERY resistance, showed that 10 strains had an A-to-G transition at position 2063 (corresponding to 2058 in Escherichia coli numbering), 1 strain showed A-to-C transversion at position 2063, 1 strain showed an A-to-G transition at position 2064, and the weakly ERY-resistant strain showed C-to-G transversion at position 2617 (corresponding to 2611 in E. coli numbering) of domain V. Domain II and ribosomal proteins L4 and L22 were not involved in the ERY resistance of these clinical M. pneumoniae strains. In addition, by using our established restriction fragment length polymorphism technique to detect point mutations of PCR products for domain V of the 23S rRNA gene of M. pneumoniae, we found that 23 (24%) of 94 PCR-positive oral samples taken from children with respiratory infections showed A2063G mutation. These results suggest that ERY-resistant M. pneumoniae infection is not unusual in Japan.

  14. Is duodenal biopsy appropriate in areas endemic for Helicobacter pylori?

    PubMed

    Sahin, Abdurrahman; Cihangiroglu, Gulcin; Bilgic, Yilmaz; Calhan, Turan; Cengiz, Mustafa

    2017-01-01

    The primary reason for obtaining duodenal biopsy sample is to diagnose celiac disease. Helicobacter pylori (H. pylori) and drug injury are common causes of duodenitis. The aim of this retrospective study was to explore effects of H. pylori and drugs on duodenal mucosa. Duodenal biopsy samples of patients who underwent upper gastrointestinal endoscopy (UGIE) between February 2014 and December 2014 were retrospectively examined. Clinical symptoms, referral indications, endoscopic findings, H. pylori status, and drug history were recorded. Duodenal biopsy findings were compared based on presence of H. pylori and drug history. Of 2389 patients who underwent UGIE, 206 had duodenal biopsy. Eight patients (3.9%) were diagnosed with celiac disease. After excluding cases with celiac disease, 76 patients of remaining 198 patients (36.9%) had duodenal histopathological abnormality. H. pylori was found in 95 (47.9%) patients. Drug usage was less common (42%). Of patients who had histopathological duodenitis, 59% were H. pylori-infected. Rate of duodenitis was higher in H. pylori (+) group than in H. pylori (-) group (45% vs 27.1%; odds ratio, 2.4; 95% confidence interval, 1.3-4.4; p=0.005). There was no difference between groups regarding drug use in terms of histopathological duodenitis. H. pylori is the major contributor to duodenitis in high prevalence regions. Serological testing may be more appropriate before performing duodenal biopsy in patients with suspected celiac disease.

  15. Stool Test: H. Pylori Antigen

    MedlinePlus

    ... Your 1- to 2-Year-Old Stool Test: H. Pylori Antigen KidsHealth > For Parents > Stool Test: H. Pylori Antigen A A A What's in this article? ... en español Muestra de materia fecal: antígeno de H. pylori What It Is Helicobacter pylori ( H. pylori ) bacteria ...

  16. Isolation and characterization of nicotiflorin obtained by enzymatic hydrolysis of two precursors in tea seed extract.

    PubMed

    Lee, Hyang-Bok; Kim, Eun-Ki; Park, Sang-Jae; Bang, Sang-Gu; Kim, Tae Gil; Chung, Dae-Won

    2010-04-28

    Two flavonol triglycosides, camelliaside A (CamA) and camelliaside B (CamB), of tea seed extract (TSE) were subjected to enzymatic hydrolysis. Among five kinds of glycosidases investigated, beta-galactosidase (Gal) induced selective hydrolysis of CamA. On the other hand, pectinase (Pec) and cellulase (Cel) induced hydrolysis of CamB. For Gal and Pec, only kaempferol diglycoside (nicotiflorin, NF) was produced; on the other hand, significant amounts of kaempferol monoglycoside (astragalin, AS) and kaempferol (KR) were also detected for Cel. The combination of the use of Gal and Pec in the enzymatic hydrolysis of TSE afforded NF with high specificity. Crude NF with 22% purity was recovered from the enzymatic reaction mixture by extraction with organic solvent, and pure NF with >95% purity was obtained by crystallized in water. The chemical structure of NF was confirmed by (1)H and (13)C NMR analyses.

  17. Autophagy-related genes in Helicobacter pylori infection.

    PubMed

    Tanaka, Shingo; Nagashima, Hiroyuki; Uotani, Takahiro; Graham, David Y; Yamaoka, Yoshio

    2017-06-01

    In vitro studies have shown that Helicobacter pylori (H. pylori) infection induces autophagy in gastric epithelial cells. However, prolonged exposure to H. pylori reduces autophagy by preventing maturation of the autolysosome. The alterations of the autophagy-related genes in H. pylori infection are not yet fully understood. We analyzed autophagy-related gene expression in H. pylori-infected gastric mucosa compared with uninfected gastric mucosa obtained from 136 Bhutanese volunteers with mild dyspeptic symptoms. We also studied single nucleotide polymorphisms (SNPs) of autophagy-related gene in 283 Bhutanese participants to identify the influence on susceptibility to H. pylori infection. Microarray analysis of 226 autophagy-related genes showed that 16 genes were upregulated (7%) and nine were downregulated (4%). We used quantitative reverse transcriptase polymerase chain reaction to measure mRNA levels of the downregulated genes (ATG16L1, ATG5, ATG4D, and ATG9A) that were core molecules of autophagy. ATG16L1 and ATG5 mRNA levels in H. pylori-positive specimens (n=86) were significantly less than those in H. pylori-negative specimens (n=50). ATG16L1 mRNA levels were inversely related to H. pylori density. We also compared SNPs of ATG16L1 (rs2241880) among 206 H. pylori-positive and 77 H. pylori-negative subjects. The odds ratio for the presence of H. pylori in the GG genotype was 0.40 (95% CI: 0.18-0.91) relative to the AA/AG genotypes. Autophagy-related gene expression profiling using high-throughput microarray analysis indicated that downregulation of core autophagy machinery genes may depress autophagy functions and possibly provide a better intracellular habit for H. pylori in gastric epithelial cells. © 2017 John Wiley & Sons Ltd.

  18. Relationship between Helicobacter pylori Virulence Genes and Clinical Outcomes in Saudi Patients

    PubMed Central

    2012-01-01

    Helicobacter pylori has been strongly associated with gastritis, gastric and duodenal ulcers, and it is a risk factor for gastric cancer. Two major virulence factors of H. pylori have been described: the cytotoxin-associated gene product (cagA) and the vacuolating toxin (vacA). Since considerable geographic diversity in the prevalence of H. pylori virulence factors has been reported, the aim of this work was to determine if there is a significant correlation between different H. pylori virulence genes (cagA and vacA) in 68 patients, from Saudi Arabia, and gastric clinical outcomes. H. pylor was recognized in cultures of gastric biopsies. vacA and cagA genes were detected by polymerase chain reaction (PCR). The cagA gene was obtained with 42 isolates (61.8%). The vacA s- and m- region genotypes were determined in all strains studied. Three genotypes were found: s1/m1 (28%), s1/m2 (40%) and s2/m2 (26%). The s2/m1 genotype was not found in this study. The relation of the presence of cagA and the development of cases to gastritis and ulcer was statistically significant (P < 0.05). The study showed a significant correlation between the vacA s1/m2 genotype and gastritis cases, and a significant correlation between vacA s1/m1 genotype and peptic ulcer cases. The results of this study might be used for the identification of high-risk patients who are infected by vacA s1/m1 genotype of H. pylori strains. In conclusion, H. pylori strains of vacA type s1 and the combination of s1/m1 were associated with peptic ulceration and the presence of cagA gene. PMID:22323867

  19. Binding of isolated plant lectin by rhizobia during episodes of reduced gravity obtained by parabolic flight

    NASA Technical Reports Server (NTRS)

    Henry, R. L.; Green, P. D.; Wong, P. P.; Guikema, J. A.; Spooner, B. S. (Principal Investigator)

    1990-01-01

    Development of a legume root nodule is a complex process culminating in a plant/bacterial symbiosis possessing the capacity for biological dinitrogen fixation. Formation of root nodules is initiated by the binding and stabilization of rhizobia to plant root hairs, mediated in part by a receptor/ligand recognition system composed of lectins on the plant root surface and lectin-binding sites on the rhizobial cell surface. The dinitrogen fixation activity of these root nodules may be an important feature of enclosed, space-based life support systems, and may provide an ecological method to recycle nitrogen for amino acid production. However, the effects on nodule development of varied gravitational fields, or of root nutrient delivery hardware, remain unknown. We have investigated the effects of microgravity on root nodule formation, with preliminary experiments focused upon the receptor/ligand component. Microgravity, obtained during parabolic flight aboard NASA 930, has no apparent effect on the binding of purified lectin to rhizobia, a result that will facilitate forthcoming experiments using intact root tissues.

  20. Binding of isolated plant lectin by rhizobia during episodes of reduced gravity obtained by parabolic flight

    NASA Technical Reports Server (NTRS)

    Henry, R. L.; Green, P. D.; Wong, P. P.; Guikema, J. A.; Spooner, B. S. (Principal Investigator)

    1990-01-01

    Development of a legume root nodule is a complex process culminating in a plant/bacterial symbiosis possessing the capacity for biological dinitrogen fixation. Formation of root nodules is initiated by the binding and stabilization of rhizobia to plant root hairs, mediated in part by a receptor/ligand recognition system composed of lectins on the plant root surface and lectin-binding sites on the rhizobial cell surface. The dinitrogen fixation activity of these root nodules may be an important feature of enclosed, space-based life support systems, and may provide an ecological method to recycle nitrogen for amino acid production. However, the effects on nodule development of varied gravitational fields, or of root nutrient delivery hardware, remain unknown. We have investigated the effects of microgravity on root nodule formation, with preliminary experiments focused upon the receptor/ligand component. Microgravity, obtained during parabolic flight aboard NASA 930, has no apparent effect on the binding of purified lectin to rhizobia, a result that will facilitate forthcoming experiments using intact root tissues.

  1. Equine preantral follicles obtained via the Biopsy Pick-Up method: histological evaluation and validation of a mechanical isolation technique.

    PubMed

    Haag, K T; Magalhães-Padilha, D M; Fonseca, G R; Wischral, A; Gastal, M O; King, S S; Jones, K L; Figueiredo, J R; Gastal, E L

    2013-03-15

    The aims of this study in mares were to: (1) compare preantral follicle parameters between in vitro Biopsy Pick-Up (BPU) and scalpel blade collection methods and between histological and mechanical isolation processing (experiment 1); (2) histologically evaluate preantral follicles (experiment 2); and (3) compare histological analysis with a previously established mechanical isolation technique using a tissue chopper (experiment 3) for ovarian cortical fragments obtained in vivo using a BPU instrument. In experiment 1, preantral follicles were analyzed (N = 220; 90% primordial and 10% primary). Proportions of primordial and primary follicles did not differ (P > 0.05) between tissue collection (BPU vs. scalpel blade dissection) or processing (mechanical isolation vs. histology) methods. Follicle viability and morphology rates were similar (P > 0.05) between tissue collection methods, but mechanical isolation produced more (P < 0.05) morphologically normal follicles than histology. For experiment 2, preantral follicles (N = 332) were analyzed and primordial and transitional (combined) follicles and oocytes were 36.3 ± 0.3 and 26.1 ± 0.3 μm in diameter, respectively, and primary follicles and oocytes averaged 42.9 ± 1.8 and 31.8 ± 2.1 μm. For experiment 3 (188 preantral follicles), within the same animals, the proportion of primordial versus primary follicles was higher (P < 0.03) for histological analysis (98%) compared to tissue chopper analysis (94%), and number of follicles per mg of tissue was not affected (P > 0.05) by processing methods. In conclusion, most parameters evaluated for preantral follicles were similar between histological and tissue chopper processing techniques; hence, mechanical isolation efficiently dissociated equine preantral follicles from the ovarian cortex. Therefore, the tissue chopper could be used to isolate large numbers of morphologically normal equine preantral follicles for cryopreservation and/or in vitro culture. Copyright

  2. Study of Helicobacter pylori genotype status in saliva, dental plaques, stool and gastric biopsy samples

    PubMed Central

    Momtaz, Hassan; Souod, Negar; Dabiri, Hossein; Sarshar, Meysam

    2012-01-01

    AIM: To compare genotype of Helicobacter pylori (H. pylori) isolated from saliva, dental plaques, gastric biopsy, and stool of each patient in order to evaluate the mode of transmission of H. pylori infection. METHODS: This cross-sectional descriptive study was performed on 300 antral gastric biopsy, saliva, dental plaque and stool samples which were obtained from patients undergoing upper gastrointestinal tract endoscopy referred to endoscopy centre of Hajar hospital of Shahrekord, Iran from March 2010 to February 2011. Initially, H. pylori strains were identified by rapid urease test (RUT) and polymerase chain reaction (PCR) were applied to determine the presence of H. pylori (ureC) and for genotyping of voculating cytotoxin gene A (vacA) and cytotoxin associated gene A (cagA) genes in each specimen. Finally the data were analyzed by using statistical formulas such as Chi-square and Fisher’s exact tests to find any significant relationship between these genes and patient’s diseases. P < 0.05 was considered statistically significant. RESULTS: Of 300 gastric biopsy samples, 77.66% were confirmed to be H. pylori positive by PCR assay while this bacterium were detected in 10.72% of saliva, 71.67% of stool samples. We were not able to find it in dental plaque specimens. The prevalence of H. pylori was 90.47% among patients with peptic ulcer disease (PUD), 80% among patients with gastric cancer, and 74.13% among patients with none ulcer dyspepsia (NUD) by PCR assay. The evaluation of vacA and cagA genes showed 6 differences between gastric biopsy and saliva specimens and 11 differences between gastric and stool specimens. 94.42% of H. pylori positive specimens were cagA positive and all samples had amplified band both for vacA s and m regions. There was significant relationship between vacA s1a/m1a and PUD diseases (P = 0.04), s2/m2 genotype and NUD diseases (P = 0.05). No statically significant relationship was found between cagA status with clinical outcomes and

  3. Different distribution of Helicobacter pylori EPIYA- cagA motifs and dupA genes in the upper gastrointestinal diseases and correlation with clinical outcomes in iranian patients

    PubMed Central

    Haddadi, Mohammad Hossein; Bazargani, Abdollah; Khashei, Reza; Fattahi, Mohammad Reza; Bagheri Lankarani, Kamran; Moini, Maryam; Rokni Hosseini, Seyed Mohammad Hossein

    2015-01-01

    Aim: Our aim was to determine the EPIYA-cagA Phosphorylation sites and dupA gene in H. pylori isolates among patients with upper gastrointestinal diseases. Background: Pathogenicity of the cagA-positive Helicobacter pylori is associated with EPIYA motifs and higher number of EPIYA-C segments is a risk factor of gastric cancer, while duodenal ulcer-promoting gene (dupA) is determined as a protective factor against gastric cancer. Patients and methods: A total of 280 non-repeated gastric biopsies obtained from patients undergoing endoscopy from January 2013 till July 2013. Samples were cultured on selective horse blood agar and incubated in microaerophilic atmosphere. The isolated organisms were identified as H. pylori by Gram staining and positive oxidase, catalase, and urease tests. Various motif types of cagA and the prevalence of dupA were determined by PCR method. Results: Out of 280 specimens, 128 (54.7%) isolated organisms were identified as H. pylori. Of 120 H. pylori isolates, 35.9% were dupA positive and 56.26% were cagA positive, while cagA with ABC and ABCC motifs were 55.5% and 44.5%, respectively. Fifty six percent of the isolates with the ABCC motif have had dupA genes. We also found a significant association between strains with genotypes of dupA-ABC and duodenal ulcer disease (p = 0.007). Conclusion: The results of this study showed that the prevalence of cagA-positive H. pylori in Shiraz was as high as in western countries and higher numbers of EPIYA-C segments were seen in gastric cancer patients. We may also use dupA as a prognostic and pathogenic marker for duodenal ulcer disease and cagA with the segment C for gastric cancer and gastric ulcer disease in this region. PMID:26171136

  4. The internalization of Helicobacter pylori plays a role in the failure of H. pylori eradication.

    PubMed

    Wang, You-Hua; Lv, Zhi-Fa; Zhong, Yao; Liu, Dong-Sheng; Chen, Shu-Ping; Xie, Yong

    2017-02-01

    Helicobacter pylori (H. pylori) internalization involves invasion of cells by the bacterium. Several studies have shown that H. pylori can invade human gastric epithelial cells, immune cells, and Candida yeast in vivo and in vitro. Whether bacterial invasion plays a role in eradication failure is unclear. To investigate the relationship between H. pylori invasion of GES-1 cells and H. pylori eradication failure. Forty-two clinical strains isolated from H. pylori-positive patients with different outcomes after treatment with furazolidone-based therapy were examined (17 failures and 25 successes). The H. pylori strains were shown to be susceptible to amoxicillin and furazolidone, and the patients also exhibited good compliance. Genotyping was performed for cagA and vacA (s and m). The antibiotic susceptibility of the strains to amoxicillin, furazolidone, clarithromycin, metronidazole, and levofloxacin was determined by E-tests. The levels of H. pylori invasion of GES-1 cells were detected by gentamicin colony-forming unit assays. The internalization level in the eradication success group was 5.40±5.78 × 10(-3)  cfu/cell, and the median was 6.194 × 10(-3)  cfu/cell; the internalization level in the eradication failure group was 8.98±5.40 × 10(-3)  cfu/cell, and the median was 10.28 × 10(-3)  cfu/cell. The eradication failure group showed a greater invasion level than the eradication success group (P<.05). No significant difference was observed between the susceptible strains and the resistant strains when the internalization levels were compared (P>.05). The results showed that H. pylori invasion of the gastric epithelia might play a role in eradication failure. © 2016 John Wiley & Sons Ltd.

  5. Focus on RNA isolation: obtaining RNA for microRNA (miRNA) expression profiling analyses of neural tissue

    PubMed Central

    Wang, Wang-Xia; Rajeev, Bernard W.; Baldwin, Donald A.; Isett, R. Benjamin; Ren, Na; Stromberg, Arnold; Nelson, Peter T.

    2008-01-01

    MicroRNAs (miRNAs) are present in all known plant and animal tissues and appear to be somewhat concentrated in the mammalian nervous system. Many different miRNA expression profiling platforms have been described. However, relatively little research has been published to establish the importance of ‘upstream’ variables in RNA isolation for neural miRNA expression profiling. We tested whether apparent changes in miRNA expression profiles may be associated with tissue processing, RNA isolation techniques, or different cell types in the sample. RNA isolation was performed on a single brain sample using eight different RNA isolation methods, and results were correlated using a conventional miRNA microarray and then cross-referenced to Northern blots. Differing results were seen between samples obtained using different RNA isolation techniques and between microarray and Northern blot results. Another complication of miRNA microarrays is tissue-level heterogeneity of cellular composition. To investigate this phenomenon, miRNA expression profiles were determined and compared between highly-purified primary cerebral cortical cell preparations of rat primary E15–E18 neurons versus rat primary E15–E18 astrocytes. Finally, to assess the importance of dissecting human brain gray matter from subjacent white matter in cerebral cortical studies, miRNA expression profiles were compared between gray matter and immediately contiguous white matter. The results suggest that for microarray studies, cellular composition is important, and dissecting white matter from gray matter improves the specificity of the results. Based on these data, recommendations for miRNA expression profiling in neural tissues, and considerations worthy of further study, are discussed. PMID:18316046

  6. The study of mutation in 23S rRNA resistance gene of Helicobacter pylori to clarithromycin in patients with gastrointestinal disorders in Isfahan - Iran.

    PubMed

    Khademi, Farzad; Faghri, Jamshid; Moghim, Sharareh; Esfahani, Bahram Nasr; Fazeli, Hossein; Poursina, Farkhondeh; Adibi, Peyman; Madhi, Masoumeh; Safaei, Hajieh Ghasemian

    2014-01-01

    Helicobacter pylori antimicrobial resistance is an important factor responsible for treatment failure. The purpose of this study was evaluating the prevalence of point mutations in clarithromycin-resistant clinical isolates of H. pylori in Isfahan city of Iran. Thirty isolates of H. pylori from 130 biopsy specimens were isolated by culture and confirmed by biochemical and PCR tests. The MIC of clarithromycin antibiotic for 30 clinical isolates of H. pylori was determined by E-test method. The point mutations in the 288 bp of 23S rRNA gene of H. pylori were investigated in four clarithromycin-resistant clinical isolates by PCR followed by sequencing. Among 30 isolates of H. pylori, 4 cases were resistant to clarithromycin. One point mutation was found at position T2243C in the 23S rRNA gene in all resistance isolates. In our study, H. pylori resistance to clarithromycin associated with point mutation at position 2243 (T2243C).

  7. Effect of Rebamipide, a Novel Antiulcer Agent, on Helicobacter pylori Adhesion to Gastric Epithelial Cells

    PubMed Central

    Hayashi, Shunji; Sugiyama, Toshiro; Amano, Ken-Ichi; Isogai, Hiroshi; Isogai, Emiko; Aihara, Miki; Kikuchi, Mikio; Asaka, Masahiro; Yokota, Kenji; Oguma, Keiji; Fujii, Nobuhiro; Hirai, Yoshikazu

    1998-01-01

    Helicobacter pylori is a major etiological agent in gastroduodenal disorders. The adhesion of H. pylori to human gastric epithelial cells is the initial step of H. pylori infection. Inhibition of H. pylori adhesion is thus a therapeutic target in the prevention of H. pylori infection. Experiments were performed to evaluate the effect of rebamipide, a novel antiulcer agent, on H. pylori adhesion to gastric epithelial cells. MKN-28 and MKN-45 cells, derived from human gastric carcinomas, were used as target cells. Ten H. pylori strains isolated from patients with chronic gastritis and gastric ulcer were used in the study. We evaluated the effect of rebamipide on H. pylori adhesion to MKN-28 and MKN-45 cells quantitatively using our previously established enzyme-linked immunosorbent assay. The adhesion of H. pylori to MKN-28 and MKN-45 cells was significantly inhibited by pretreatment of these cells with 100 μg of rebamipide per ml. However, the adhesion was not affected by the pretreatment of H. pylori with rebamipide. On the other hand, the viabilities of H. pylori, MKN-28 cells, and MKN-45 cells were not affected by rebamipide. Our studies suggest that rebamipide inhibits the adhesion of H. pylori to gastric epithelial cells. PMID:9687380

  8. Metronidazole susceptibility testing for Helicobacter pylori: comparison of disk, broth, and agar dilution methods and their clinical relevance.

    PubMed Central

    DeCross, A J; Marshall, B J; McCallum, R W; Hoffman, S R; Barrett, L J; Guerrant, R L

    1993-01-01

    Since the methods for metronidazole susceptibility testing of Helicobacter pylori have not been standardized or validated, we compared three methods that are used to test the metronidazole susceptibilities of 25 isolates of H. pylori. Specifically, we examined the methods of Steer's replicator agar dilution, tube broth microdilution, and modified Kirby-Bauer disk diffusion. The metronidazole disk zone sizes obtained by the disk diffusion method correlated well (r = 0.74) with the MICs obtained by the agar dilution method. Afterward, the disk diffusion method was used to characterize the metronidazole susceptibilities of 44 isolates of H. pylori. Dual therapy (bismuth and metronidazole) proved to be highly effective against metronidazole-susceptible strains (81.6% eradication rate) but fared poorly against resistant strains (16.7% eradication rate; P < 0.01). Using agar dilution testing, we validated the modified Kirby-Bauer disk diffusion method for metronidazole susceptibility testing of H. pylori and conclude that it is practical, accurate, and clinically applicable. PMID:8370723

  9. Isolation and differentiation of human mesenchymal stem cells obtained from second trimester amniotic fluid; experiments at Chang Gung Memorial Hospital.

    PubMed

    Peng, Hsiu-Huei; Wang, Tzu-Hao; Chao, An-Shine; Chang, Shuenn-Dyh

    2007-01-01

    The aims of this study were to evaluate the efficacy of current techniques for isolating mesenchymal stem cells (MSCs) from amniotic fluid obtained by second-trimester amniocentesis as well as to determine their differentiation potential. We collected 50 samples of amniotic fluid by second-trimester amniocentesis. To obtain MSCs from amniotic fluid, the fluid was cultured using the two-stage culture protocol described in previous literature. Reverse transcription-polymerase chain reaction (RT-PCR) of a stem cell-specific transcription factor, octamer-binding protein 4 (Oct-4), was used to identify the characteristics of the MSCs cultured from amniotic fluid. Osteogeneic differentiation of these MSCs was confirmed by the presence of osteocalcin (a mineral-binding protein uniquely synthesized by osteoblasts) using RT-PCR and Von Kossa staining. Adipogenic differentiation of these MSCs was displayed by RT-PCR of adipocyte lipid-binding protein (a lipid-binding protein specifically in adipocytes) and Oil Red O staining. Amniotic fluid-derived MSCs were successfully isolated and cultured from six samples. These cells could express the pluripotent stem cell-specific transcription factor Oct-4 as confirmed by RT-PCR. Under specific culture conditions, amniotic fluid-derived MSCs could be successfully induced to differentiate into adipocytes and osteocytes, based on product analysis by RT-PCR and specific staining. Based on our experiment, we estimate the efficacy of isolating mesenchymal stem cells from second-trimester amniotic fluid obtained by amniocentesis to be about 12%. Human MSCs from second-trimester amniotic fluid had the ability to differentiate in vitro into adipocytes and osteocytes under specific culture conditions. The multilineage differentiation potential of these amniotic fluid-derived MSCs may be applicable to cell transplantation and regenerative medicine.

  10. Lactobacillus pentosus strain LPS16 produces lactic acid, inhibiting multidrug-resistant Helicobacter pylori.

    PubMed

    Zheng, Po-Xing; Fang, Hsin-Yi; Yang, Hsiao-Bai; Tien, Nai-Yueh; Wang, Ming-Cheng; Wu, Jiunn-Jong

    2016-04-01

    Helicobacter pylori is a human gastric pathogen. Antibiotic resistance of H. pylori has become a problem increasing the failure of H. pylori eradication. Therefore alternative approaches are required. The aim of this study was to evaluate the anti-H. pylori activity of Lactobacillus pentosus strain LPS16 and the mechanism of its killing effect. The anti-H. pylori activity of LPS16 was determined by the disc diffusion test and time killing assay. High-performance liquid chromatography analysis was used to analyze the secreted compounds of LPS16. Sixty H. pylori strains isolated from different gastric diseases, having different antibiotic susceptibility were collected to analyze the spectrum of anti-H. pylori activity of LPS16. Adhesion ability of LPS16 to gastric epithelial cell lines was assayed by flow cytometry. The anti-H. pylori activity of LPS16 depended on the secreted component, and lactic acid mediated bactericidal activity against H. pylori. The bactericidal activity did not vary significantly among the strains isolated from different diseases having different antibiotic susceptibility. Moreover, LPS16 can adhere on gastric epithelial cell lines AKG and MKN45. L. pentosus strain LPS16 had the broad-spectrum anti-H. pylori activity, suggesting that it can be used to prevent H. pylori infection. Copyright © 2014. Published by Elsevier B.V.

  11. Lipopolysaccharide Diversity Evolving in Helicobacter pylori Communities through Genetic Modifications in Fucosyltransferases

    PubMed Central

    Nilsson, Christina; Skoglund, Anna; Moran, Anthony P.; Annuk, Heidi; Engstrand, Lars; Normark, Staffan

    2008-01-01

    Helicobacter pylori persistently colonizes the gastric mucosa of half the human population. It is one of the most genetically diverse bacterial organisms and subvariants are continuously emerging within an H. pylori population. In this study we characterized a number of single-colony isolates from H. pylori communities in various environmental settings, namely persistent human gastric infection, in vitro bacterial subcultures on agar medium, and experimental in vivo infection in mice. The lipopolysaccharide (LPS) O-antigen chain revealed considerable phenotypic diversity between individual cells in the studied bacterial communities, as demonstrated by size variable O-antigen chains and different levels of Lewis glycosylation. Absence of high-molecular-weight O-antigen chains was notable in a number of experimentally passaged isolates in vitro and in vivo. This phenotype was not evident in bacteria obtained from a human gastric biopsy, where all cells expressed high-molecular-weight O-antigen chains, which thus may be the preferred phenotype for H. pylori colonizing human gastric mucosa. Genotypic variability was monitored in the two genes encoding α1,3-fucosyltransferases, futA and futB, that are involved in Lewis antigen expression. Genetic modifications that could be attributable to recombination events within and between the two genes were commonly detected and created a diversity, which together with phase variation, contributed to divergent LPS expression. Our data suggest that the surrounding environment imposes a selective pressure on H. pylori to express certain LPS phenotypes. Thus, the milieu in a host will select for bacterial variants with particular characteristics that facilitate adaptation and survival in the gastric mucosa of that individual, and will shape the bacterial community structure. PMID:19043574

  12. Helicobacter pylori and thrombocytopenia in the pregnant hispanic population.

    PubMed

    Epstein, Aaron; Wing, Deborah A; Ouzounian, Joseph G; Miller, David A; Lee, Richard H

    2012-12-01

    An association between Helicobacter pylori (H. pylori) and thrombocytopenia has been demonstrated in the literature in a non-pregnant population. The purpose of this study was to determine whether or not there is a similar association in the third trimester of pregnancy in a Hispanic population. This is a secondary analysis of 82 pregnant Hispanic women with and without hyperemesis gravidarum who underwent serologic evaluation for H. pylori IgG. Results of complete blood counts obtained in the third trimester were analysed for thrombocytopenia. Of the 82 subjects who had H. pylori testing, 54 subjects had both serum H. pylori IgG results and third trimester platelet levels. The prevalence of thrombocytopenia was 11.1% (6/54). Thirty-six subjects were seropositive for H. pylori IgG and 18 subjects were seronegative. Of the 36 subjects who were H. pylori seropositive, four (11.1%) developed thrombocytopenia compared to three of 18 (16.7%) H. pylori seronegative subjects (P = 0.67). There was no difference between the groups in their mean platelet values (205 K/cu mm vs. 212 K/cu mm, P = 0.69). In this limited study, we found no association between H. pylori and thrombocytopenia in the pregnant Hispanic population.

  13. Mass spectrometry identification of alkyl-substituted pyrazines produced by Pseudomonas spp. isolates obtained from wine corks.

    PubMed

    Bañeras, Lluís; Trias, Rosalia; Godayol, Anna; Cerdán, Laura; Nawrath, Thorben; Schulz, Stefan; Anticó, Enriqueta

    2013-06-15

    We investigated the pyrazine production of 23 Pseudomonas isolates obtained from cork in order to assess their implications in off-flavour development. Off-flavour development in cork stoppers is a crucial process in maintaining the high quality of some wines. Pyrazine production was analyzed by headspace solid-phase-microextraction (HS-SPME) and gas chromatography coupled with mass spectrometry (GC-MS). Five out of the 23 isolates, i.e. Pseudomonas koreensis TCA20, Pseudomonas palleroniana TCA16, Pseudomonas putida TCA23 and N7, and Pseudomonas stutzeri TRA27a were able to produce branched alkyl-substituted pyrazines. For isolates N7 and TCA16, 14 compounds could be identified as pyrazines. The use of mineral media supplemented with different carbon and nitrogen sources resulted in changes in the pyrazine production capacity. In the two strains the amount of pyrazines produced was higher with glucose and decreased significantly with lactate. In all cases, 2,5-di(1-methylethyl)pyrazine was found to be dominant and independent of amino acid addition, suggesting a completely de novo synthesis. Aroma descriptions of most alkyl substituted pyrazines include mild vegetal aromas, not necessarily undesirable for the cork manufacturing industry. Methoxypyrazines, exhibiting earthy and musty aromas, could not be detected in any of the strains analysed. Copyright © 2012 Elsevier Ltd. All rights reserved.

  14. Classification of Austrian rhizobia and the Mexican isolate FL27 obtained from Phaseolus vulgaris L. as Rhizobium gallicum.

    PubMed

    Sessitsch, A; Ramírez-Saad, H; Hardarson, G; Akkermans, A D; de Vos, W M

    1997-10-01

    The phylogenetic positions of four rhizobial strains obtained from nodules of common bean plants (Phaseolus vulgaris L.) grown in an Austrian soil and of the Mexican bean isolate FL27 are described. Analysis of the 16S rRNA genes revealed sequences almost identical to that of the Rhizobium gallicum type strain, R602sp, with a maximum of two nucleotide substitutions. Comparison of the 16S rRNA gene sequences with those from other bacteria indicated highest similarity to Rhizobium sp. strain OK-50, Rhizobium leguminosarum IAM 12609, and Rhizobium etli. DNA homology determined by DNA-DNA hybridization was high among the Austrian isolates and R602spT (45 to 90%) and ranged from 21 to 65% with FL27, but hybridization analysis revealed very low homology to the recognized common bean-nodulating species, R. leguminosarum bv. phaseoli, R. etli, and Rhizobium tropici. Ribosomal gene organization was studied by Southern hybridization with the 16S rRNA gene and temperature gradient gel electrophoresis, indicating identical organizations and the presence of three identical 16S rRNA copies in the genome of this species. The six strains investigated showed different plasmid profiles based on their geographical origins. We propose that the Austrian isolates and the Mexican strain FL27 are members of the species R. gallicum.

  15. Helicobacter pylori vacA genotype is a predominant determinant of immune response to Helicobacter pylori CagA.

    PubMed

    Link, Alexander; Langner, Cosima; Schirrmeister, Wiebke; Habendorf, Wiebke; Weigt, Jochen; Venerito, Marino; Tammer, Ina; Schlüter, Dirk; Schlaermann, Philipp; Meyer, Thomas F; Wex, Thomas; Malfertheiner, Peter

    2017-07-14

    To evaluate the frequency of Helicobacter pylori (H. pylori) CagA antibodies in H. pylori infected subjects and to identify potential histopathological and bacterial factors related to H. pylori CagA-immune response. Systematic data to H. pylori isolates, blood samples, gastric biopsies for histological and molecular analyses were available from 99 prospectively recruited subjects. Serological profile (anti-H. pylori, anti-CagA) was correlated with H. pylori isolates (cagA, EPIYA, vacA s/m genotype), histology (Sydney classification) and mucosal interleukin-8 (IL-8) mRNA and protein expression. Selected H. pylori strains were assessed for H. pylori CagA protein expression and IL-8 induction in co-cultivation model with AGS cells. Thirty point three percent of microbiologically confirmed H. pylori infected patients were seropositive for CagA. Majority of H. pylori isolates were cagA gene positive (93.9%) with following vacA polymorphisms: 42.4% vacA s1m1, 23.2% s1m2 and 34.3% s2m2. Anti-CagA-IgG seropositivity was strongly associated with atrophic gastritis, increased mucosal inflammation according to the Sydney score, IL-8 and cagA mRNA expression. VacA s and m polymorphisms were the major determinants for positive (vacA s1m1) or negative (vacA s2m2) anti-CagA serological immune response, which also correlated with the in vitro inflammatory potential in AGS cells. In vitro co-cultivation of representative H. pylori strains with AGS cells confirmed functional CagA translocation, which showed only partial correlation with CagA seropositivity in patients, supporting vacA as major co-determinant of the immune response. Serological immune response to H. pylori cagA+ strain in H. pylori infected patients is strongly associated with vacA polymorphism, suggesting the crucial role of bacterial factors in immune and clinical phenotype of the infection.

  16. Prevalence of clarithromycin-resistant Helicobacter pylori in patients with chronic tonsillitis by allele-specific Scorpion real-time polymerase chain reaction assay.

    PubMed

    Naserpour Farivar, Taghi; Najafipour, Reza; Johari, Pouran

    2013-06-01

    To investigate the allelic prevalence of resistance to clarithromycin in the DNA of clinical isolates of Helicobacter pylori obtained from biopsy specimens of patients with chronic tonsillitis by Scorpion real-time polymerase chain reaction (PCR). Pathologic specimens of patients with chronic tonsillitis were used for rapid urease test, and blocks of paraffin-embedded tonsillar tissue were used for McMullen staining, rapid urease test, and Scorpion real-time PCR test. A total of 103 biopsy samples were obtained from patients with chronic tonsillitis and examined for the presence of clarithromycin resistant H. pylori. Modified McMullen staining and rapid urease test were done on the all the samples. The DNA of specimens was extracted from the pathology blocks, and Scorpion real-time PCR was performed on a final volume of 25 μL. Of 103 biopsy specimens, 22 samples were identified as infected by H. pylori, of which none were sensitive to clarithromycin. One had the A2143G genotype, and four had the A2142G genotype. Two had a mixed sensitive and the A2143G genotype, and five had a mixed sensitive and A2142G genotype. One strain had a mixed genotype of sensitive, A2143G, and A2142G. The reported rate of resistance to clarithromycin is of great variation among H. pylori strains isolated from specimens in different countries. Our study showed that the most prevalent genotypes in our H. pylori-positive specimens was A2142G followed by A2143G, which is different from reported results of allele-specific genotyping of H. pylori strains isolated from gastric biopsy and may be a result of cross-resistance to erythromycin and other macrolides. Copyright © 2013 The American Laryngological, Rhinological, and Otological Society, Inc.

  17. Bacteriology and taxonomy of Helicobacter pylori.

    PubMed

    Windsor, H M; O'Rourke, J

    2000-09-01

    As the scientific community approaches the twentieth anniversary of the first isolation of H. pylori, it appears that despite the wealth of articles published in journals throughout the world every month, there are still many unanswered questions about the microbiology of this bacterium and others in the genus Helicobacter.

  18. An Appropriate Cutoff Value for Determining the Colonization of Helicobacter pylori by the Pyrosequencing Method: Comparison with Conventional Methods.

    PubMed

    Kim, Jaeyeon; Kim, Nayoung; Jo, Hyun Jin; Park, Ji Hyun; Nam, Ryoung Hee; Seok, Yeong-Jae; Kim, Yeon-Ran; Kim, Joo Sung; Kim, Jung Mogg; Kim, Jung Min; Lee, Dong Ho; Jung, Hyun Chae

    2015-10-01

    Sequencing of 16S ribosomal RNA (rRNA) gene has improved the characterization of microbial communities. It enabled the detection of low abundance gastric Helicobacter pylori sequences even in subjects that were found to be H. pylori negative with conventional methods. The objective of this study was to obtain a cutoff value for H. pylori colonization in gastric mucosa samples by pyrosequencing method. Gastric mucosal biopsies were taken from 63 subjects whose H. pylori status was determined by a combination of serology, rapid urease test, culture, and histology. Microbial DNA from mucosal samples was amplified by PCR using universal bacterial primers. 16S rDNA amplicons were pyrosequenced. ROC curve analysis was performed to determine the cutoff value for H. pylori colonization by pyrosequencing. In addition, temporal changes in the stomach microbiota were observed in eight initially H. pylori-positive and eight H. pylori-negative subjects at a single time point 1-8 years later. Of the 63 subjects, the presence of H. pylori sequences was detected in all (28/28) conventionally H. pylori-positive samples and in 60% (21/35) of H. pylori-negative samples. The average percent of H. pylori reads in each sample was 0.67 ± 1.09% in the H. pylori-negative group. Cutoff value for clinically positive H. pylori status was approximately 1.22% based on ROC curve analysis (AUC = 0.957; p < .001). Helicobacter pylori was successfully eradicated in five of seven treated H. pylori-positive subjects (71.4%), and the percentage of H. pylori reads in these five subjects dropped from 1.3-95.18% to 0-0.16% after eradication. These results suggest that the cutoff value of H. pylori sequence percentage for H. pylori colonization by pyrosequencing could be set at approximately 1%. It might be helpful to analyze gastric microbiota related to H. pylori sequence status. © 2015 John Wiley & Sons Ltd.

  19. Structural characterization of purine nucleoside phosphorylase from human pathogen Helicobacter pylori.

    PubMed

    Štefanić, Zoran; Mikleušević, Goran; Luić, Marija; Bzowska, Agnieszka; Leščić Ašler, Ivana

    2017-08-01

    Microaerophilic bacterium Helicobacer pylori is a well known human pathogen involved in the development of many diseases. Due to the evergrowing infection rate and increase of H. pylori antibiotic resistence, it is of utmost importance to find a new way to attack and eradicate H. pylori. The purine metabolism in H. pylori is solely dependant on the salvage pathway and one of the key enzymes in this pathway is purine nucleoside phosphorylase (PNP). In this timely context, we report here the basic biochemical and structural characterization of recombinant PNP from the H. pylori clinical isolate expressed in Escherichia coli. Structure of H. pylori PNP is typical for high molecular mass PNPs. However, its activity towards adenosine is very low, thus resembling more that of low molecular mass PNPs. Understanding the molecular mechanism of this key enzyme may lead to the development of new drug strategies and help in the eradication of H. pylori. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Identification of cagA tyrosine phosphorylation DNA motifs in Helicobacter pylori isolates from peptic ulcer patients by novel PCR-restriction fragment length polymorphism and real-time fluorescence PCR assays.

    PubMed

    Owen, Robert J; Sharp, Sally I; Chisholm, Stephanie A; Rijpkema, Sjoerd

    2003-07-01

    Cag pathogenicity island-containing Helicobacter pylori (type I) induces signal transduction pathways resulting in tyrosine phosphorylation of proteins adjacent to the site of bacterial adhesion on host gastric epithelial cells. Conventional block PCR-restriction fragment length polymorphism (RFLP) and real-time LightCycler (LC) PCR hybridization assays, validated by direct sequencing, were designed to test for the presence of three nucleotide sequences corresponding to tyrosine phosphorylation motifs (TPMs) A, B, and C in 84 isolates of H. pylori type I from patients in England. Overall, the PCR assays demonstrated that one or more TPMs were present in 62 strains (75%). Motif A was common (71% of strains), whereas motifs B and C were rarer (8% of strains). Strains lacking a TPM were typically vacuolating cytotoxin genotype vacA m2. Motif A was widely distributed in relation to disease severity and was more commonly (but not significantly [P = 0.071]) associated with gastric ulcer than with duodenal ulcer (86 versus 56%). The LC hybridization assay provided a rapid means of detecting all three motifs, but RFLP analysis was more specific for TPM-A. TPMs provide novel additional strain markers for defining cagA variation, including identification of RFLP types within TPM-A. The presence of a particular TPM was not of direct diagnostic value, either singly or in combination, but the higher proportion of TPM-A strains in gastric ulcer patients merits further investigation.

  1. Identification of cagA Tyrosine Phosphorylation DNA Motifs in Helicobacter pylori Isolates from Peptic Ulcer Patients by Novel PCR-Restriction Fragment Length Polymorphism and Real-Time Fluorescence PCR Assays

    PubMed Central

    Owen, Robert J.; Sharp, Sally I.; Chisholm, Stephanie A.; Rijpkema, Sjoerd

    2003-01-01

    Cag pathogenicity island-containing Helicobacter pylori (type I) induces signal transduction pathways resulting in tyrosine phosphorylation of proteins adjacent to the site of bacterial adhesion on host gastric epithelial cells. Conventional block PCR-restriction fragment length polymorphism (RFLP) and real-time LightCycler (LC) PCR hybridization assays, validated by direct sequencing, were designed to test for the presence of three nucleotide sequences corresponding to tyrosine phosphorylation motifs (TPMs) A, B, and C in 84 isolates of H. pylori type I from patients in England. Overall, the PCR assays demonstrated that one or more TPMs were present in 62 strains (75%). Motif A was common (71% of strains), whereas motifs B and C were rarer (8% of strains). Strains lacking a TPM were typically vacuolating cytotoxin genotype vacA m2. Motif A was widely distributed in relation to disease severity and was more commonly (but not significantly [P = 0.071]) associated with gastric ulcer than with duodenal ulcer (86 versus 56%). The LC hybridization assay provided a rapid means of detecting all three motifs, but RFLP analysis was more specific for TPM-A. TPMs provide novel additional strain markers for defining cagA variation, including identification of RFLP types within TPM-A. The presence of a particular TPM was not of direct diagnostic value, either singly or in combination, but the higher proportion of TPM-A strains in gastric ulcer patients merits further investigation. PMID:12843050

  2. Standardization of disk diffusion test and its clinical significance for susceptibility testing of metronidazole against Helicobacter pylori.

    PubMed Central

    Xia, H; Keane, C T; Beattie, S; O'Morain, C A

    1994-01-01

    Susceptibilities of 121 clinical Helicobacter pylori strains to metronidazole were determined by both a 5-micrograms metronidazole disk diffusion test and a plate dilution method in duplicate and after different periods of incubation. The distribution of MICs of metronidazole against H. pylori among the strains was found to be bimodal. The diameters of inhibitory zones obtained by the disk diffusion test and the MICs obtained by the plate dilution method correlated well, especially after 4 days of incubation (r = 0.77). An inhibitory zone diameter of 20 mm was found to correspond to a MIC of 8 micrograms/ml and is recommended as a suitable zone for differentiating susceptibility and resistance with a 5-micrograms metronidazole disk. Three interpretive categories of susceptibility results were defined; strains with inhibitory zone diameters of more than 26 mm were defined as susceptible (MIC, < 4 micrograms/ml), strains with zone diameters of 20 to 26 mm were deemed intermediate (MIC, 4 to 8 micrograms/ml), and those with zone diameters of less than 20 mm were deemed resistant (MIC, > 8 micrograms/ml). Furthermore, 76 H. pylori-positive patients with duodenal ulcers or nonulcer dyspepsia were treated with a 1 week of triple therapy (colloidal bismuth subcitrate, metronidazole, and tetracycline). H. pylori strains were isolated before treatment from antral biopsies from those patients, and the metronidazole susceptibilities of the strains were determined by the disk diffusion test. H. pylori status was evaluated again 4 weeks after completion of treatment. The eradication rates for susceptible, intermediate, and resistant strains were 95.9% (47 of 49), 62.5% (5 of 8), and 52.6% (10 of 19), respectively. It is included that the 5-micrograms disk diffusion test is easy to perform and gives final results similar to those of the plate dilution method. The three interpretive categories of susceptibility may be of benefit for clinical choice of chemotherapy in eradicating

  3. What constitutes an Arabian Helicobacter pylori? Lessons from comparative genomics.

    PubMed

    Kumar, Narender; Albert, M John; Al Abkal, Hanan; Siddique, Iqbal; Ahmed, Niyaz

    2017-02-01

    Helicobacter pylori, the human gastric pathogen, causes a variety of gastric diseases ranging from mild gastritis to gastric cancer. While the studies on H. pylori are dominated by those based on either East Asian or Western strains, information regarding H. pylori strains prevalent in the Middle East remains scarce. Therefore, we carried out whole-genome sequencing and comparative analysis of three H. pylori strains isolated from three native Arab, Kuwaiti patients. H. pylori strains were sequenced using Illumina platform. The sequence reads were filtered and draft genomes were assembled and annotated. Various pathogenicity-associated regions and phages present within the genomes were identified. Phylogenetic analysis was carried out to determine the genetic relatedness of Kuwaiti strains to various lineages of H. pylori. The core genome content and virulence-related genes were analyzed to assess the pathogenic potential. The three genomes clustered along with HpEurope strains in the phylogenetic tree comprising various H. pylori lineages. A total of 1187 genes spread among various functional classes were identified in the core genome analysis. The three genomes possessed a complete cagPAI and also retained most of the known outer membrane proteins as well as virulence-related genes. The cagA gene in all three strains consisted of an AB-C type EPIYA motif. The comparative genomic analysis of Kuwaiti H. pylori strains revealed a European ancestry and a high pathogenic potential. © 2016 John Wiley & Sons Ltd.

  4. Natural maternal transmission of H pylori in Mongolian gerbils

    PubMed Central

    Lee, Jin-Uk; Kim, Okjin

    2006-01-01

    AIM: To investigate maternal H pylori infection status to determine the potential of maternal transmission. METHODS: In the present study, we examined these issues in an experimental murine model, which is a Mongolian gerbil model that has been reported as an optimal laboratory animal model to study H pylori. Pregnant Mongolian gerbils, infected experimentally with H pylori, were divided into as four groups. Following the experimental design, the stomachs of the mother and litters were isolated and assessed for transmission of H pylori at the prenatal period, parturition day, 1-wk old and 3-wk old respectively. Bacterial culture and polymerase chain reaction (PCR) were used to examine the presence of transmitted H pylori. RESULTS: All litters showed no transmission of H pylori during pregnancy and at parturition day. However, they revealed 33.3% and 69.6% at 1-wk and 3-wk of age respectively by PCR. CONCLUSION: These results suggested that vertical infection during the prenatal period or delivery procedure is unlikely as a route of mother-to-child H pylori infection. It may be that H pylori is acquired through breast-feeding, contaminated saliva and fecal-oral transmission during co-habitation. PMID:17007019

  5. High Efficacy of Finafloxacin on Helicobacter pylori Isolates at pH 5.0 Compared with That of Other Fluoroquinolones

    PubMed Central

    Lee, Jung Won; Nam, Ryoung Hee; Kim, Jung Mogg; Park, Jong Youn; Lee, Sun Min; Kim, Joo Sung; Lee, Dong Ho; Jung, Hyun Chae

    2015-01-01

    Finafloxacin is a novel fluoroquinolone with improved antimicrobial efficacy, especially in an acidic environment. The efficacy of finafloxacin for the inhibition of Helicobacter pylori infection was compared with the efficacies of levofloxacin and moxifloxacin at neutral and acidic pH. The impacts of gyrA point mutation on the efficacy of those three fluoroquinolones were also investigated. A total of 128 clinical H. pylori strains were utilized. MICs of levofloxacin, moxifloxacin, and finafloxacin were determined at pH 5.0 and pH 7.0 by the agar dilution method. The impact of gyrA point mutations that are responsible for fluoroquinolone resistance was analyzed; the results showed 50 strains with an Asn-87 point mutation, 48 strains with an Asp-91 point mutation, and the remaining 30 strains with no gyrA mutations. The use of finafloxacin led to MIC values at pH 5.0 that were lower than the values seen at pH 7.0 for 112 strains (112/128, 87.5%), and this proportion was higher than that seen with moxifloxacin (21/128, 16.4%, P < 0.001). Finafloxacin also demonstrated a rate of susceptibility (MIC, <1 μg/ml) (37.5%, 48/128) at pH 5.0 that was higher than that seen with moxifloxacin (2.3%, 3/128) (P < 0.001). The trends were similar regardless of which of the Asn-87, Asp-91, and A2143 point mutations were present. In conclusion, the superior antimicrobial efficacy of finafloxacin against H. pylori in an acidic environment suggests the possible use of finafloxacin for treatment of H. pylori infection, as has been proposed by its developer, Merlion Pharma. PMID:26416863

  6. High Efficacy of Finafloxacin on Helicobacter pylori Isolates at pH 5.0 Compared with That of Other Fluoroquinolones.

    PubMed

    Lee, Jung Won; Kim, Nayoung; Nam, Ryoung Hee; Kim, Jung Mogg; Park, Jong Youn; Lee, Sun Min; Kim, Joo Sung; Lee, Dong Ho; Jung, Hyun Chae

    2015-12-01

    Finafloxacin is a novel fluoroquinolone with improved antimicrobial efficacy, especially in an acidic environment. The efficacy of finafloxacin for the inhibition of Helicobacter pylori infection was compared with the efficacies of levofloxacin and moxifloxacin at neutral and acidic pH. The impacts of gyrA point mutation on the efficacy of those three fluoroquinolones were also investigated. A total of 128 clinical H. pylori strains were utilized. MICs of levofloxacin, moxifloxacin, and finafloxacin were determined at pH 5.0 and pH 7.0 by the agar dilution method. The impact of gyrA point mutations that are responsible for fluoroquinolone resistance was analyzed; the results showed 50 strains with an Asn-87 point mutation, 48 strains with an Asp-91 point mutation, and the remaining 30 strains with no gyrA mutations. The use of finafloxacin led to MIC values at pH 5.0 that were lower than the values seen at pH 7.0 for 112 strains (112/128, 87.5%), and this proportion was higher than that seen with moxifloxacin (21/128, 16.4%, P < 0.001). Finafloxacin also demonstrated a rate of susceptibility (MIC, <1 μg/ml) (37.5%, 48/128) at pH 5.0 that was higher than that seen with moxifloxacin (2.3%, 3/128) (P < 0.001). The trends were similar regardless of which of the Asn-87, Asp-91, and A2143 point mutations were present. In conclusion, the superior antimicrobial efficacy of finafloxacin against H. pylori in an acidic environment suggests the possible use of finafloxacin for treatment of H. pylori infection, as has been proposed by its developer, Merlion Pharma. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  7. Antimicrobial susceptibility testing for Helicobacter pylori isolates from Brazilian children and adolescents: comparing agar dilution, E-test, and disk diffusion.

    PubMed

    Ogata, Silvio Kazuo; Gales, Ana Cristina; Kawakami, Elisabete

    2014-01-01

    Antimicrobial susceptibility testing for Helicobacter pylori is increasingly important due to resistance to the most used antimicrobials agents. Only agar dilution method is approved by CLSI, but it is difficult to perform routinely. We evaluated the reliability of E-test and disk diffusion comparing to agar dilution method on Helicobacter pylori antimicrobial susceptibility testing. Susceptibility testing was performed for amoxicillin, clarithromycin, furazolidone, metronidazole and tetracycline using E-test, disk-diffusion and agar dilution method in 77 consecutive Helicobacter pylori strains from dyspeptic children and adolescents. Resistance rates were: amoxicillin - 10.4%, 9% and 68.8%; clarithromycin - 19.5%, 20.8%, 36.3%; metronidazole - 40.2%33.7%, 38.9%, respectively by agar dilution, E-test and disk diffusion method. Furazolidone and tetracycline showed no resistance rates. Metronidazole presented strong correlation to E-test (r = 0.7992, p < 0.0001) and disk diffusion method (r=-0.6962, p < 0.0001). Clarithromycin presented moderate correlation to E-test (r = 0.6369, p < 0.0001) and disk diffusion method (r=-0.5656, p < 0.0001). Amoxicillin presented weak correlation to E-test (r = 0.3565, p = 0.0015) and disk diffusion (r=-0.3565, p = 0.0015). Tetracycline presented weak correlation with E-test (r = 0.2346, p = 0.04) and furazolidone to disk diffusion (r=-0.0288, p = 0.8038). E-test presented better agreement with gold standard. It is an easy and reliable method for Helicobacter pylori susceptibility testing. Disk diffusion method presented high disagreement and high rates of major errors.

  8. In Vitro Activities of Rabeprazole, a Novel Proton Pump Inhibitor, and Its Thioether Derivative Alone and in Combination with Other Antimicrobials against Recent Clinical Isolates of Helicobacter pylori

    PubMed Central

    Kawakami, Yoshiyuki; Akahane, Takayuki; Yamaguchi, Masaru; Oana, Kozue; Takahashi, Yuko; Okimura, Yukie; Okabe, Tadashi; Gotoh, Akira; Katsuyama, Tsutomu

    2000-01-01

    The MICs of rabeprazole sodium (RPZ), a newly developed benzimidazole proton pump inhibitor (PPI), against 133 clinical Helicobacter pylori strains revealed a higher degree of activity than the another two PPIs, lansoprazole and omeprazole. Time-kill curve assays of RPZ, when combined with amoxicillin, clarithromycin, or metronidazole, disclosed that synergistic effects were demonstrated in combination with each antibiotic examined. Moreover, no apparent antagonistic effect appeared among all of the strains tested. PMID:10639386

  9. In vitro activities of rabeprazole, a novel proton pump inhibitor, and its thioether derivative alone and in combination with other antimicrobials against recent clinical isolates of Helicobacter pylori.

    PubMed

    Kawakami, Y; Akahane, T; Yamaguchi, M; Oana, K; Takahashi, Y; Okimura, Y; Okabe, T; Gotoh, A; Katsuyama, T

    2000-02-01

    The MICs of rabeprazole sodium (RPZ), a newly developed benzimidazole proton pump inhibitor (PPI), against 133 clinical Helicobacter pylori strains revealed a higher degree of activity than the another two PPIs, lansoprazole and omeprazole. Time-kill curve assays of RPZ, when combined with amoxicillin, clarithromycin, or metronidazole, disclosed that synergistic effects were demonstrated in combination with each antibiotic examined. Moreover, no apparent antagonistic effect appeared among all of the strains tested.

  10. Antimicrobial susceptibility testing for Helicobacter pylori isolates from Brazilian children and adolescents: Comparing agar dilution, E-test, and disk diffusion

    PubMed Central

    Ogata, Silvio Kazuo; Gales, Ana Cristina; Kawakami, Elisabete

    2014-01-01

    Antimicrobial susceptibility testing for Helicobacter pylori is increasingly important due to resistance to the most used antimicrobials agents. Only agar dilution method is approved by CLSI, but it is difficult to perform routinely. We evaluated the reliability of E-test and disk diffusion comparing to agar dilution method on Helicobacter pylori antimicrobial susceptibility testing. Susceptibility testing was performed for amoxicillin, clarithromycin, furazolidone, metronidazole and tetracycline using E-test, disk-diffusion and agar dilution method in 77 consecutive Helicobacter pylori strains from dyspeptic children and adolescents. Resistance rates were: amoxicillin - 10.4%, 9% and 68.8%; clarithromycin - 19.5%, 20.8%, 36.3%; metronidazole - 40.2%33.7%, 38.9%, respectively by agar dilution, E-test and disk diffusion method. Furazolidone and tetracycline showed no resistance rates. Metronidazole presented strong correlation to E-test (r = 0.7992, p < 0.0001) and disk diffusion method (r=-0.6962, p < 0.0001). Clarithromycin presented moderate correlation to E-test (r = 0.6369, p < 0.0001) and disk diffusion method (r=−0.5656, p < 0.0001). Amoxicillin presented weak correlation to E-test (r = 0.3565, p = 0.0015) and disk diffusion (r=−0.3565, p = 0.0015). Tetracycline presented weak correlation with E-test (r = 0.2346, p = 0.04) and furazolidone to disk diffusion (r=−0.0288, p = 0.8038). E-test presented better agreement with gold standard. It is an easy and reliable method for Helicobacter pylori susceptibility testing. Disk diffusion method presented high disagreement and high rates of major errors. PMID:25763052

  11. Recent "omics" advances in Helicobacter pylori.

    PubMed

    Berthenet, Elvire; Sheppard, Sam; Vale, Filipa F

    2016-09-01

    The development of high-throughput whole genome sequencing (WGS) technologies is changing the face of microbiology, facilitating the comparison of large numbers of genomes from different lineages of a same organism. Our aim was to review the main advances on Helicobacter pylori "omics" and to understand how this is improving our knowledge of the biology, diversity and pathogenesis of H. pylori. Since the first H. pylori isolate was sequenced in 1997, 510 genomes have been deposited in the NCBI archive, providing a basis for improved understanding of the epidemiology and evolution of this important pathogen. This review focuses on works published between April 2015 and March 2016. Helicobacter "omics" is already making an impact and is a growing research field. Ultimately these advances will be translated into a routine clinical laboratory setting in order to improve public health.

  12. Antitumour and apoptotic effects of a novel Tris-peptide complex obtained after isolation of Raoultella ornithinolytica extracellular metabolites.

    PubMed

    Fiołka, M J; Grzywnowicz, K; Rzymowska, J; Lewtak, K; Szewczyk, R; Mendyk, E; Keller, R

    2015-06-01

    The characterization of the antitumour activity and chemical identification of the compounds obtained after the isolation of extracellular metabolites of bacteria Raoultella ornithinolytica. The fraction with anticancer activity against the HeLa cell line, T47D and TOV-112D was obtained from the supernatants of R. ornithinolytica culture using ion-exchange chromatography, and separated by Sephadex G-50 medium gel filtration into two subfractions. The obtained compounds were analysed using Fourier Transform-Infrared Spectroscopy, Raman spectroscopy and matrix-assisted laser desorption/ionization MS/MS spectrometry. The antitumour activity of the two subfractions was analysed using 5-bromo-2-deoxy-uridine kit. The subfraction with the highest activity against HeLa cells was identified as Tris-peptide complex. The amino acid sequence of the peptide from the complex was found to be TDAPSFSDIPN and molecular weight was estimated at 1430·6576 Da. Cytotoxic, cytopathic and apoptotic effects in HeLa cells treated with the active complex were observed; however, the cytotoxic effect against normal human skin fibroblasts was minimal. The Tris-peptide complex from R. ornithinolytica showed selective antitumour activity against the HeLa cell line. The Tris-peptide complex due to the high selectivity can be used in biomedicine, and its derivatives may contribute to the development of new anticancer compounds. © 2015 The Society for Applied Microbiology.

  13. Population structure of Helicobacter pylori among ethnic groups in Malaysia: recent acquisition of the bacterium by the Malay population

    PubMed Central

    2009-01-01

    Background Helicobacter pylori is a major gastric bacterial pathogen. This pathogen has been shown to follow the routes of human migration by their geographical origin and currently the global H. pylori population has been divided into six ancestral populations, three from Africa, two from Asia and one from Europe. Malaysia is made up of three major ethnic populations, Malay, Chinese and Indian, providing a good population for studying recent H. pylori migration and admixture. Results Seventy eight H. pylori isolates, including 27 Chinese, 35 Indian and 16 Malay isolates from Malaysia were analysed by multilocus sequence typing (MLST) of seven housekeeping genes and compared with the global MLST data. STRUCTURE analysis assigned the isolates to previously identified H. pylori ancestral populations, hpEastAsia, hpAsia2 and hpEurope, and revealed a new subpopulation, hspIndia, within hpAsia2. Statistical analysis allowed us to identify population segregation sites that divide the H. pylori populations and the subpopulations. The majority of Malay isolates were found to be grouped together with Indian isolates. Conclusion The majority of the Malay and Indian H. pylori isolates share the same origin while the Malaysian Chinese H. pylori is distinctive. The Malay population, known to have a low infection rate of H. pylori, was likely to be initially H. pylori free and gained the pathogen only recently from cross infection from other populations. PMID:19538757

  14. Population structure of Helicobacter pylori among ethnic groups in Malaysia: recent acquisition of the bacterium by the Malay population.

    PubMed

    Tay, Chin Yen; Mitchell, Hazel; Dong, Quanjiang; Goh, Khean-Lee; Dawes, Ian W; Lan, Ruiting

    2009-06-19

    Helicobacter pylori is a major gastric bacterial pathogen. This pathogen has been shown to follow the routes of human migration by their geographical origin and currently the global H. pylori population has been divided into six ancestral populations, three from Africa, two from Asia and one from Europe. Malaysia is made up of three major ethnic populations, Malay, Chinese and Indian, providing a good population for studying recent H. pylori migration and admixture. Seventy eight H. pylori isolates, including 27 Chinese, 35 Indian and 16 Malay isolates from Malaysia were analysed by multilocus sequence typing (MLST) of seven housekeeping genes and compared with the global MLST data. STRUCTURE analysis assigned the isolates to previously identified H. pylori ancestral populations, hpEastAsia, hpAsia2 and hpEurope, and revealed a new subpopulation, hspIndia, within hpAsia2. Statistical analysis allowed us to identify population segregation sites that divide the H. pylori populations and the subpopulations. The majority of Malay isolates were found to be grouped together with Indian isolates. The majority of the Malay and Indian H. pylori isolates share the same origin while the Malaysian Chinese H. pylori is distinctive. The Malay population, known to have a low infection rate of H. pylori, was likely to be initially H. pylori free and gained the pathogen only recently from cross infection from other populations.

  15. Levofloxacin susceptibility testing for Helicobacter pylori in China: comparison of E-test and disk diffusion method.

    PubMed

    Yu, Chaohui; Li, Lan; Chen, Wenguo; Jiao, Yangwen; Yang, Ningmin; Yang, En; Zhang, Jianzhong; Chen, Lihua; Li, Youming

    2011-04-01

     The aims of this study were to compare disk diffusion with E-test method for levofloxacin susceptibility testing of Helicobacter pylori and standardized breakpoints for disk diffusion as a stable and reliable method for determining qualitative levofloxacin susceptibility.  We determined the levofloxacin susceptibility of 45 H. pylori strains isolated from Chinese patients by the E-test method. Disk diffusion was evaluated as an alternative method to determine susceptibility and compared with the E-test results by linear regression analysis.  The minimum inhibitory concentration (MIC) values tested by E-test method ranged from 0.047 to 32 μg/mL. Resistance to levofloxacin was detected in 16 (35.6%) isolates. The levofloxacin disk zone sizes obtained by disk diffusion method correlated well (r² = .877) with the MICs obtained by E-test method. As a consequence of regression analysis, isolates with inhibition diameters < 12 mm were considered resistant to levofloxacin. There was 100% agreement between the two methods for levofloxacin, applying the regression-based breakpoints. The disk diffusion method is equivalent to the E-test method for testing levofloxacin susceptibility of H. pylori strains; it is more practical and inexpensive, and it is suitable for the analysis of a small number of isolates compared with the E-test method. © 2011 Blackwell Publishing Ltd.

  16. Effect of replacement of corn starch by whey protein isolate in biodegradable film blends obtained by extrusion.

    PubMed

    Azevedo, Viviane Machado; Borges, Soraia Vilela; Marconcini, José Manoel; Yoshida, Maria Irene; Neto, Alfredo Rodrigues Sena; Pereira, Tamara Coelho; Pereira, Camila Ferreira Gonçalves

    2017-02-10

    The aim of this study was to evaluate the effect of replacing corn starch by whey protein isolated (WPI) in biodegradable polymer blends developed by extrusion. X-ray diffraction showed the presence of a Vh-type crystalline arrangement. The films were homogeneous, indicating strong interfacial adhesion between the protein and the thermoplastic starch matrix (TPS) as observed in scanning electron microscopy. The addition of WPI on TPS matrix promoted an increase in the thermal stability of the materials. It was observed 58.5% decrease in the water vapor permeability. The effect of corn starch substitution by WPI on mechanical properties resulted in a more resistant and less flexible film when compared the TPS film. The addition of WPI caused greenish yellow color and less transparent films. The substitution of corn starch by WPI made it possible to obtain polymer blends with improved properties and represents an innovation for application as a packaging material.

  17. In vitro antagonistic activity of Lactobacillus casei against Helicobacter pylori

    PubMed Central

    Enany, Shymaa; Abdalla, Salah

    2015-01-01

    Helicobacter pylori is one of the most common causes of chronic infections in humans. Curing H. pylori infection is difficult because of the habitat of the organism below the mucus adherent layer of gastric mucosa. Lactobacilli are known as acid-resistant bacteria and can remain in stomach for a long time than any other organism, we aimed in this study to examine the efficacy of Lactobacillus casei as a probiotic against H. pylori in humans. Particularly, L. casei was opted as it is considered to be one of the widely used probiotics in dairy products. One hundred and seven strains of H. pylori were isolated from dyspeptic patients and were tested for their antibiotic susceptibility to metronidazole (MTZ), clarithromycin (CLR), tetracycline (TET), and amoxicillin (AMX) by the disc diffusion method. The strains were examined for their susceptibility toward L. casei - present in fermented milk products - by well diffusion method. It was found that 74.7% strains were resistant to MTZ; 1.8% to MTZ, TET, and CLR; 3.7% to MTZ and CLR; 4.6% to MTZ and TET; and 0.9% were resistant to MTZ, TET, and AMX. The antibacterial activity of L. casei against H. pylori was determined on all the tested H. pylori isolates including antibiotic resistant strains with different patterns. Our study proposed the use of probiotics for the treatment of H. pylori infection as an effective approach. PMID:26691482

  18. Helicobacter pylori-Negative Gastritis: Prevalence and Risk Factors

    PubMed Central

    Nordenstedt, Helena; Graham, David Y.; Kramer, Jennifer R.; Rugge, Massimo; Verstovsek, Gordana; Fitzgerald, Stephanie; Alsarraj, Abeer; Shaib, Yasser; Velez, Maria E.; Abraham, Neena; Anand, Bhupinderjit; Cole, Rhonda; El-Serag, Hashem B.

    2014-01-01

    OBJECTIVES Recent studies using histology alone in select patients have suggested that Helicobacter pylori-negative gastritis may be common. The objective of this study was to investigate the prevalence of H. pylori among individuals with histologic gastritis. METHODS Subjects between 40 and 80 years underwent elective esophagogastroduodenoscopy at a VA Medical Center. Gastric biopsies were mapped from seven prespecified sites (two antrum, four corpus, and one cardia) and graded by two gastrointestinal pathologists, using the Updated Sydney System. H. pylori-negative required four criteria: negative triple staining at all seven gastric sites, negative H. pylori culture, negative IgG H. pylori serology, and no previous treatment for H. pylori. Data regarding tobacco smoking, alcohol drinking, nonsteroidal anti-inflammatory drug, and proton pump inhibitor (PPI) use were obtained by questionnaire. RESULTS Of the 491 individuals enrolled, 40.7% (200) had gastritis of at least grade 2 in at least one biopsy site or grade 1 in at least two sites. Forty-one (20.5%) had H. pylori-negative gastritis; most (30 or 73.2%) had chronic gastritis, five (12.2%) had active gastritis, and six (14.6%) had both. H. pylori-negative gastritis was approximately equally distributed in the antrum, corpus, and both antrum and corpus. Past and current PPI use was more frequent in H. pylori-negative vs. H. pylori-positive gastritis (68.2% and 53.8%; P = 0.06). CONCLUSIONS We used multiple methods to define non-H. pylori gastritis and found it in 21% of patients with histologic gastritis. While PPI use is a potential risk factor, the cause or implications of this entity are not known. PMID:23147524

  19. Helicobacter pylori: A Possible Risk Factor for Bone Health

    PubMed Central

    Chung, Yun Hee; Gwak, Jong Seop; Hong, Sung Woo; Hyeon, Jung Hyeon; Lee, Cheol Min; Oh, Seung Won

    2015-01-01

    Background Helicobacter pylori (H. pylori) infection may cause systemic inflammation and increase the production of tumor necrosis factor-α, interleukin-1, and interleukin-6. Unfortunately, bone mineral density also may be affected by these cytokines. This study aimed to evaluate the association between bone mineral density and H. pylori infection. Methods A cross-sectional study evaluated 1,126 men undergoing a comprehensive health screening in a private Korean screening center. Subjects' sera were tested for H. pylori antibodies (immunoglobulin G) using an enzyme-linked immunosorbent assay, and bone mineral densities (g/cm2) of the lumbar spine, femoral neck, and total femur were obtained using dual-energy X-ray absorptiometry. To evaluate the difference in bone mineral density according to H. pylori infection status, the adjusted mean bone mineral densities at each site were compared after adjusting for potential confounders, including age, sex, body mass index, smoking, alcohol consumption, and exercise. Results H. pylori infection was associated with a significant decrease in mean lumbar bone mineral density (H. pylori-positive, 1.190 g/cm2; H. pylori-negative, 1.219 g/cm2; P=0.006), which was greatest among men who were ≥50 years old (H. pylori-positive, 1.193 g/cm2; H. pylori-negative, 1.233 g/cm2; P=0.006). However, no significant association was observed in the bone mineral densities of the total femur and femoral neck. Conclusion In men, H. pylori infection was negatively associated with lumbar bone mineral density. This association may be useful in the early detection, prevention, and management of male osteoporosis. PMID:26435815

  20. Oral and Gastric Helicobacter Pylori: Effects and Associations

    PubMed Central

    Veiga, Nélio; Pereira, Carlos; Resende, Carlos; Amaral, Odete; Ferreira, Manuela; Nelas, Paula; Chaves, Claudia; Duarte, João; Cirnes, Luis; Machado, José Carlos; Ferreira, Paula; Correia, Ilídio J.

    2015-01-01

    Introduction This study consisted in the comparison of the prevalence of Helicobacter pylori (H. pylori) present in the stomach and in saliva of a sample of Portuguese adolescents and the assessment of the association between H. pylori infection with socio-demographic variables and prevalence of dental caries. Materials and Methods A cross-sectional study was designed including a sample of 447 adolescents aged 12 to 19 years old, attending a public school in Sátão, Portugal. A questionnaire about socio-demographic variables and oral health behaviors was applied. Gastric H. pylori infection was determined using the urease breath test (UBT). Saliva collection was obtained and DNA was extracted by Polymerase Chain Reaction (PCR) in order to detect the presence of oral H. pylori. Results The prevalence of gastric H. pylori detected by UBT was 35.9%. Within the adolescents with a gastric UBT positive, only 1.9% were positive for oral H. pylori. The presence of gastric H. pylori was found to be associated with age (>15years, Odds ratio (OR)=1.64,95%CI=1.08-2.52), residence area (urban,OR=1.48,95%CI=1.03-2.29) and parents´ professional situation (unemployed,OR=1.22,95%CI=1.02-1.23). Among those with detected dental caries during the intra-oral observation, 37.4% were positive for gastric H. pylori and 40.2% negative for the same bacterial strain (p=0.3). Conclusions The oral cavity cannot be considered a reservoir for infection of H. pylori. Gastric H. pylori infection was found to be associated with socio-demographic variables such as age, residence area and socioeconomic status. PMID:26010595

  1. Helicobacter pylori's unconventional role in health and disease.

    PubMed

    Dorer, Marion S; Talarico, Sarah; Salama, Nina R

    2009-10-01

    The discovery of a bacterium, Helicobacter pylori, that is resident in the human stomach and causes chronic disease (peptic ulcer and gastric cancer) was radical on many levels. Whereas the mouth and the colon were both known to host a large number of microorganisms, collectively referred to as the microbiome, the stomach was thought to be a virtual Sahara desert for microbes because of its high acidity. We now know that H. pylori is one of many species of bacteria that live in the stomach, although H. pylori seems to dominate this community. H. pylori does not behave as a classical bacterial pathogen: disease is not solely mediated by production of toxins, although certain H. pylori genes, including those that encode exotoxins, increase the risk of disease development. Instead, disease seems to result from a complex interaction between the bacterium, the host, and the environment. Furthermore, H. pylori was the first bacterium observed to behave as a carcinogen. The innate and adaptive immune defenses of the host, combined with factors in the environment of the stomach, apparently drive a continuously high rate of genomic variation in H. pylori. Studies of this genetic diversity in strains isolated from various locations across the globe show that H. pylori has coevolved with humans throughout our history. This long association has given rise not only to disease, but also to possible protective effects, particularly with respect to diseases of the esophagus. Given this complex relationship with human health, eradication of H. pylori in nonsymptomatic individuals may not be the best course of action. The story of H. pylori teaches us to look more deeply at our resident microbiome and the complexity of its interactions, both in this complex population and within our own tissues, to gain a better understanding of health and disease.

  2. Isolation, amplification, and sequencing of human mitochondrial DNA obtained from human crab louse, Pthirus pubis (L.), blood meals.

    PubMed

    Lord, W D; DiZinno, J A; Wilson, M R; Budowle, B; Taplin, D; Meinking, T L

    1998-09-01

    The ability to identify individual human hosts based on analyses of blood recovered from the digestive tract of hematophagous arthropods has been a long-term pursuit in both medical and forensic entomology. Blood meal individualization techniques can bring important advancements to studies of vector-borne disease epidemiology. Forensically, these analyses may aid in assailant identification in violent crime cases where blood-feeding insects or their excreta are recovered from victims or at crime scenes. Successful isolation, amplification, and sequencing of human mitochondrial DNA obtained from adult human crab lice fed on human volunteers are reported. Adult lice were removed from recruited volunteers frequenting inner city health clinics. Live lice were killed by freezing and subsequently air dried at ambient temperature. A saliva sample was obtained from each volunteer and served as a DNA reference sample. Volunteers were afforded free, approved pediculosis treatment. Individual lice were subsequently processed using procedures developed for the extraction of mitochondrial DNA from human hair, teeth, and bone. The resulting DNA was amplified by the polymerase chain reaction and sequenced. Our results point to valuable avenues for future entomological research.

  3. Phylogenetic analysis of methanogenic enrichment cultures obtained from Lonar Lake in India: isolation of Methanocalculus sp. and Methanoculleus sp.

    PubMed

    Surakasi, Venkata Prasad; Wani, Aijaz Ahmad; Shouche, Yogesh S; Ranade, Dilip R

    2007-11-01

    The diversity of methanogenic archaea in enrichment cultures established from the sediments of Lonar Lake (India), a soda lake having pH approximately 10, was investigated using 16S rDNA molecular phylogenetic approach. Methanogenic enrichment cultures were developed in a medium that simulated conditions of soda lake with three different substrates viz., H(2):CO(2), sodium acetate, and trimethylamine (TMA), at alkaline pH. Archaeal 16S rRNA clone libraries were generated from enrichment cultures and 13 RFLP groups were obtained. Representative sequence analysis of each RFLP group indicated that the majority of the 16S rRNA gene sequences were phylogenetically affiliated with uncultured Archaea. Some of the groups may belong to new archaeal genera or families. Three RFLP groups were related to Methanoculleus sp, while two related to Methanocalculus sp. 16S rRNA gene sequences found in Lonar Lake were different from sequences reported from other soda lakes and more similar to those of oil reservoirs, palm oil waste treatment digesters, and paddy fields. In culture-based studies, three isolates were obtained. Two of these were related to Methanoculleus sp. IIE1 and one to Methanocalculus sp. 01F97C. These results clearly show that the Lonar Lake ecosystem harbors unexplored methanogens.

  4. Structure and antioxidant activity of soy protein isolate-dextran conjugates obtained by TiO2 photocatalysis.

    PubMed

    Jin, Bei; Zhou, Xiaosong; Li, Bing; Chen, Caiyan; Zhang, Xiaosa; Chen, Siqiao

    2015-01-01

    The aim of this study was to investigate the structural characteristics and antioxidant activities of soy protein isolate- (SPI-) dextran conjugates obtained by TiO2 photocatalysis treatment. Results revealed that the UV-vis absorption and the fluorescence intensity increased as the photocatalytic power increased (P < 0.05). Higher photocatalytic power could promote the extent of glycation and the formation of high molecular weight SPI-dextran conjugates, which were evidenced by free amino group content and sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis. The Fourier transform infrared (FT-IR) spectra suggested that the amide I, II, and III bands of SPI were altered by the glycation induced by TiO2 photocatalysis. Moreover, significant changes of secondary structure occurred in SPI-dextran conjugates. The α-helix, β-sheet, β-turns, and random coil were changed from approximately 10.6%, 37.9%, 12.9%, and 38.6% to 3.8%, 10.4%, 17.7%, and 68.8%, respectively, after treatment at photocatalytic power of 1000 W. In addition, SPI-dextran conjugates obtained by TiO2 photocatalysis treatment exhibited high hydroxyl radical scavenging activity and possessed increased reducing power. All data indicated that TiO2 photocatalysis was an efficient method for promoting protein-polysaccharide copolymerisation.

  5. Structure and Antioxidant Activity of Soy Protein Isolate-Dextran Conjugates Obtained by TiO2 Photocatalysis

    PubMed Central

    Jin, Bei; Zhou, Xiaosong; Li, Bing; Chen, Caiyan; Zhang, Xiaosa; Chen, Siqiao

    2015-01-01

    The aim of this study was to investigate the structural characteristics and antioxidant activities of soy protein isolate- (SPI-) dextran conjugates obtained by TiO2 photocatalysis treatment. Results revealed that the UV-vis absorption and the fluorescence intensity increased as the photocatalytic power increased (P < 0.05). Higher photocatalytic power could promote the extent of glycation and the formation of high molecular weight SPI-dextran conjugates, which were evidenced by free amino group content and sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis. The Fourier transform infrared (FT-IR) spectra suggested that the amide I, II, and III bands of SPI were altered by the glycation induced by TiO2 photocatalysis. Moreover, significant changes of secondary structure occurred in SPI-dextran conjugates. The α-helix, β-sheet, β-turns, and random coil were changed from approximately 10.6%, 37.9%, 12.9%, and 38.6% to 3.8%, 10.4%, 17.7%, and 68.8%, respectively, after treatment at photocatalytic power of 1000 W. In addition, SPI-dextran conjugates obtained by TiO2 photocatalysis treatment exhibited high hydroxyl radical scavenging activity and possessed increased reducing power. All data indicated that TiO2 photocatalysis was an efficient method for promoting protein-polysaccharide copolymerisation. PMID:26495283

  6. Anti-Helicobacter pylori activity of plant extracts traditionally used for the treatment of gastrointestinal disorders

    PubMed Central

    Cogo, Laura Lúcia; Monteiro, Cristina Leise Bastos; Miguel, Marilis Dallarmi; Miguel, Obdulio Gomes; Cunico, Miriam Machado; Ribeiro, Marcelo Lima; de Camargo, Eloá Ramalho; Kussen, Gislene Maria Botão; Nogueira, Keite da Silva; Costa, Libera Maria Dalla

    2010-01-01

    The antibacterial activity of plant extracts obtained from Bixa orellana L., Chamomilla recutita L., Ilex paraguariensis A. St.-Hil., Malva sylvestris L., Plantago major L. and Rheum rhaponticum L. has been evaluated against two reference strains and eleven clinical isolates of Helicobacter pylori. All the plant species chosen are used in popular Brazilian cuisine and folk medicine in the treatment of gastrointestinal disorders. Initial screening was made by the disk diffusion test and then minimum inhibitory concentration was determined by the agar dilution method. The results presented in this work demonstrated that among the plant preparations analyzed, B. orellana L., C. recutita L., I. paraguariensis A. St.-Hil. and M. sylvestris L. were capable of inhibiting the in vitro growth of H. pylori. PMID:24031496

  7. Using Macro-Arrays to Study Routes of Infection of Helicobacter pylori in Three Families

    PubMed Central

    Raymond, Josette; Thiberge, Jean-Michel; Kalach, Nicolas; Bergeret, Michel; Dupont, Christophe

    2008-01-01

    Background Analysis of the evolutionary dynamics of Helicobacter pylori allowed tracing the spread of infection through populations on different continents but transmission pathways between individual humans have not been clearly described. Materials and Methods To investigate person-to-person transmission, we studied three families each including one child with persistence of symptoms after antibiotic treatment. Ten isolates from the antrum and corpus of stomach of each family member were analyzed both by sequencing of two housekeeping genes and macroarray tests. Results A total of 134 (8.4%) out of the 1590 coding sequences (CDSs) tested, including cag PAI and insertion sequences, were present in some but not all isolates (and are therefore defined as variable CDSs). Most of the variable CDSs encoded proteins of unknown function (76/134) or were selfish DNA including that encoding restriction/modification enzymes (13/134). Isolates colonizing the stomach of one individual can vary by point mutations, as seen in hspA, or by the gain or loss of one to five CDSs. They were considered as (genetic) variants. The phylogenetic clustering of gene profiles obtained on macro-arrays allowed identifying the different strains infecting families. Two to five strains circulated within a family. Identical strains were present in at least two members of all three families supporting the accepted model of intrafamilial transmission. Surprisingly, the mother was not implicated in the transmission of H. pylori in the two French families. Sibling-to-sibling transmission and acquisition of H. pylori from outside the family appeared to be probable in the transmission pathways. Conclusion Macroarray analysis based on previously selected CDSs gives a comprehensive view of the genome diversity of a pathogen. This approach combined with information on the origin of the hspA and glmM alleles revealed that Helicobacter pylori infection may be acquired by more diverse routes than previously

  8. Validation of String Test for Diagnosis of Helicobacter pylori Infections

    PubMed Central

    Velapatiño, Billie; Balqui, Jacqueline; Gilman, Robert H.; Bussalleu, Alejandro; Quino, Willi; Finger, S. Alison; Santivañez, Livia; Herrera, Phabiola; Piscoya, Alejandro; Valdivia, Jose; Cok, Jaime; Berg, Douglas E.

    2006-01-01

    The method of recovering Helicobacter pylori DNA or viable cells absorbed on a string that a person has swallowed and that is retrieved an hour later (string test) should be a useful alternative to traditional analysis of cells or DNA obtained by endoscopy, which is invasive, uncomfortable, relatively costly, and ill-suited for community-based and pediatric studies. Here we assayed the sensitivity and validity of the string test versus conventional endoscopic biopsy for detecting and analyzing H. pylori infection. Forty-four people with gastric complaints were studied using both H. pylori culture and urease gene (ureB) PCR. H. pylori organisms cultured from strings and biopsy specimens from the same patients were fingerprinted by the randomly amplified polymorphic DNA (RAPD) method. Biopsy sections were also hematoxylin and eosin and silver stained for H. pylori detection. H. pylori was cultured from 80% of strings and detected by PCR from 91% of strings from participants whose biopsies had been H. pylori positive by culture, PCR, and/or histology. Strains recovered from strings and biopsy specimens yielded identical or closely related RAPD profiles in each of the 24 cases tested. We conclude that the string test is a useful method for H. pylori recovery and analysis when relatively noninvasive procedures are needed. PMID:16517886

  9. [Second Brazilian Consensus Conference on Helicobacter pylori infection].

    PubMed

    Coelho, Luiz Gonzaga Vaz; Zaterka, Schlioma

    2005-01-01

    Significant progress has been obtained since the First Brazilian Consensus Conference on H. pylori Infection held in 1995, in Belo Horizonte, MG, and justify a second meeting to establish updated guidelines on the current management of H. pylori infection. The Second Brazilian Consensus Conference on H. pylori Infection was organized by the Brazilian Federation of Gastroenterology and Brazilian Nucleus for the Study of Helicobacter and took place on June, 19-20, 2004 in São Paulo, SP. Thirty six delegates coming from 15 different Brazilian states including gastroenterologists, pathologists, microbiologists and pediatricians undertook the meeting. The participants were allocated in one the five main topics of the meeting: H. pylori and dyspepsia, H. pylori and NSAIDs, H. pylori and gastroesophageal reflux disease, H. pylori treatment, and H. pylori retreatment. Seventy per cent and more votes were considered as acceptance for the final statement. The results were presented during a special session on the VI Brazilian Week of Digestive System, in Recife, PE (October 2004), and this publication represents the summary of the main recommendations and conclusions emerged from the meeting.

  10. Validation of string test for diagnosis of Helicobacter pylori infections.

    PubMed

    Velapatiño, Billie; Balqui, Jacqueline; Gilman, Robert H; Bussalleu, Alejandro; Quino, Willi; Finger, S Alison; Santivañez, Livia; Herrera, Phabiola; Piscoya, Alejandro; Valdivia, Jose; Cok, Jaime; Berg, Douglas E

    2006-03-01

    The method of recovering Helicobacter pylori DNA or viable cells absorbed on a string that a person has swallowed and that is retrieved an hour later (string test) should be a useful alternative to traditional analysis of cells or DNA obtained by endoscopy, which is invasive, uncomfortable, relatively costly, and ill-suited for community-based and pediatric studies. Here we assayed the sensitivity and validity of the string test versus conventional endoscopic biopsy for detecting and analyzing H. pylori infection. Forty-four people with gastric complaints were studied using both H. pylori culture and urease gene (ureB) PCR. H. pylori organisms cultured from strings and biopsy specimens from the same patients were fingerprinted by the randomly amplified polymorphic DNA (RAPD) method. Biopsy sections were also hematoxylin and eosin and silver stained for H. pylori detection. H. pylori was cultured from 80% of strings and detected by PCR from 91% of strings from participants whose biopsies had been H. pylori positive by culture, PCR, and/or histology. Strains recovered from strings and biopsy specimens yielded identical or closely related RAPD profiles in each of the 24 cases tested. We conclude that the string test is a useful method for H. pylori recovery and analysis when relatively noninvasive procedures are needed.

  11. Isolation and Identification of Aerobic Bacteria Carrying Tetracycline and Sulfonamide Resistance Genes Obtained from a Meat Processing Plant.

    PubMed

    Li, Lili; Ye, Lei; Zhang, Sen; Meng, Hecheng

    2016-06-01

    Microbial contamination in food-processing plants can play a fundamental role in food quality and safety. The purpose of this study was to investigate aerobic bacteria carrying tetracycline and sulfonamide resistance genes from a meat processing plant as possible sources of meat contamination. One hundred swab samples from surfaces of conveyor belts, meat slicers, meat knives, benches, plastic trays, gloves, and aprons were analyzed. A total of 168 isolates belonging to 10 genera were obtained, including Pseudomonas sp. (n = 35), Acinetobacter sp. (n = 30), Aeromonas sp. (n = 20), Myroides sp. (n = 15), Serratia sp. (n = 15), Staphylococcus sp. (n = 14), Enterobacter sp. (n = 11), Escherichia coli (n = 10), Lactococcus sp. (n = 10), and Klebsiella sp. (n = 8). Of the 168 isolates investigated, 60.7% showed resistance to tetracycline and 57.7% to trimethoprim/sulfamethoxazole. The tetracycline resistance genes tetL, tetA, tetB, tetC, tetE, tetM, tetS, tetK, and tetX were found in the frequency of 7.7%, 6.0%, 4.8%, 4.8%, 3.6%, 3.6%, 3.6%, 1.2%, and 0.6%, respectively. Sulfonamide resistance genes sul1 and sul2 were observed in the frequency of 17.9% and 38.1%, respectively. The tetracycline resistance genes tetX was first found in Myroides sp. This investigation demonstrated that food contact surfaces in a meat processing plant may be sources of contamination of aerobic bacteria carrying tetracycline and sulfonamide antibiotic resistance genes. © 2016 Institute of Food Technologists®

  12. Antimicrobial susceptibility of Campylobacter jejuni and Campylobacter coli isolates obtained in Montreal, Quebec, Canada, from 2002 to 2013.

    PubMed

    Gaudreau, Christiane; Boucher, France; Gilbert, Huguette; Bekal, Sadjia

    2014-07-01

    From 2002 to 2013 in Montreal, Quebec, Canada, 38 Campylobacter coli isolates were more frequently erythromycin, tetracycline, and ciprofloxacin resistant than 440 Campylobacter jejuni subsp. jejuni isolates (18.4% versus 1.8%; P = 0.00005), of which the 148 isolates acquired abroad were more frequently erythromycin, tetracycline, and ciprofloxacin resistant than the 292 isolates acquired locally (5.4% versus 0%; P = 0.0001).

  13. Helicobacter pylori invades the gastric mucosa and translocates to the gastric lymph nodes.

    PubMed

    Ito, Takashi; Kobayashi, Daisuke; Uchida, Keisuke; Takemura, Tamiko; Nagaoka, Sakae; Kobayashi, Intetsu; Yokoyama, Tetsuji; Ishige, Ikuo; Ishige, Yuki; Ishida, Noriko; Furukawa, Asuka; Muraoka, Hiroe; Ikeda, Satoshi; Sekine, Masaki; Ando, Noboru; Suzuki, Yoshimi; Yamada, Tetsuo; Suzuki, Takashige; Eishi, Yoshinobu

    2008-06-01

    Helicobacter pylori has been considered to be non-invasive and to rarely infiltrate the gastric mucosa, even though there is an active Th1 immune response in the lamina propria of the H. pylori-infected stomach. To elucidate whether H. pylori invades the lamina propria and translocates to the gastric lymph nodes, we examined H. pylori in formalin-fixed and paraffin-embedded tissue sections of stomach and gastric lymph nodes obtained from 51 cancer patients using real-time PCR and immunohistochemistry (IHC) with a novel anti-H. pylori monoclonal antibody that recognizes lipopolysaccharides. Fresh gastric lymph nodes were used to culture for H. pylori. In 46 patients with H. pylori in the stomach, the bacterium was found in the lymph nodes from 21 patients by culture, 37 patients by PCR, and 29 patients by IHC. H. pylori captured by macrophages was found in the lamina propria of 39 patients. In the lymph nodes, the bacterium was found in many macrophages and a few interdigitating dendritic cells at the paracortical areas. H. pylori was also found in the intracellular canaliculi of parietal cells in 21 patients, but intracytoplasmic invasion into gastric epithelial cells was not identified. When compared to the commercially available anti-H. pylori antibodies, the novel antibody showed the highest sensitivity to detect H. pylori-positive macrophages, whereas no difference was found for H. pylori in the mucous layer. The H. pylori-positive macrophages in the lamina propria correlated with chronic gastritis as well as translocation of such cells to the lymph nodes. These results suggest that H. pylori-induced gastric epithelial damage allows the bacteria to invade the lamina propria and translocate to the gastric lymph nodes, which may chronically stimulate the immune system. The bacteria captured by macrophages, whether remaining alive or not, may contribute to the induction and development of H. pylori-induced chronic gastritis.

  14. Utility of normalized genome quantification of Helicobacter pylori in gastric mucosa using an in-house real-time polymerase chain reaction

    PubMed Central

    2017-01-01

    Traditional diagnostic assays for Helicobacter pylori detection have their limitations. Molecular methods can improve both diagnosis and understanding of gastric diseases. Here we describe an in-house quantitative real-time polymerase chain reaction (q-rt-PCR) for the detection of H. pylori in gastric biopsies which has been developed and has a detection limit of 10 copies, the specificity of which was tested against other gastric colonizer bacteria. In this study, 199 gastric biopsies from adults with different clinical gastric symptoms were examined. Biopsies were obtained during endoscopy and the following tests performed: rapid urease testing (RUT), culture and q-rt-PCR. H. pylori bacterial load expressed as bacterial load per 105 cells was calculated using a standard curve. H. pylori was isolated in 41% of patients, RUT was positive in 32% and bacterial genome was detected in 45% (p = 0.010). Concordance between traditional invasive microbiological methods used together and q-rt-PCR was almost 100%. Bacterial load in patients with positive RUT was significantly higher than those where it was negative (p<0.0001). There were also significant differences between bacterial load in patients with more than one positive assay versus those where only one method was positive (p = 0.006). The in-house q-PCR developed here is quick and inexpensive, and allows accurate diagnosis of H. pylori infection. It also permits normalized bacterial load quantification, which is important to differentiate between asymptomatic colonisation and infection. PMID:28575047

  15. Aspirin increases susceptibility of Helicobacter pylori to metronidazole by augmenting endocellular concentrations of antimicrobials.

    PubMed

    Zhang, Xiao-Ping; Wang, Wei-Hong; Tian, Yu; Gao, Wen; Li, Jiang

    2009-02-28

    To investigate the mechanisms of aspirin increasing the susceptibility of Helicobacter pylori (H pylori) to metronidazole. H pylori reference strain 26695 and two metronidazole-resistant isolates of H pylori were included in this study. Strains were incubated in Brucella broth with or without aspirin (1 mmol/L). The rdxA gene of H pylori was amplified by PCR and sequenced. The permeability of H pylori to antimicrobials was determined by analyzing the endocellular radioactivity of the cells after incubated with [7-(3)H]-tetracycline. The outer membrane proteins (OMPs) of H pylori 26695 were depurated and analyzed by SDS-PAGE. The expression of 5 porins (hopA, hopB, hopC, hopD and hopE) and the putative RND efflux system (hefABC) of H pylori were analyzed using real-time quantitative PCR. The mutations in rdxA gene did not change in metronidazole resistant isolates treated with aspirin. The radioactivity of H pylori increased when treated with aspirin, indicating that aspirin improved the permeability of the outer membrane of H pylori. However, the expression of two OMP bands between 55 kDa and 72 kDa altered in the presence of aspirin. The expression of the mRNA of hopA, hopB, hopC, hopD, hopE and hefA, hefB, hefC of H pylori did not change when treated with aspirin. Although aspirin increases the susceptibility of H pylori to metronidazole, it has no effect on the mutations of rdxA gene of H pylori. Aspirin increases endocellular concentrations of antimicrobials probably by altering the OMP expression.

  16. Aspirin increases susceptibility of Helicobacter pylori to metronidazole by augmenting endocellular concentrations of antimicrobials

    PubMed Central

    Zhang, Xiao-Ping; Wang, Wei-Hong; Tian, Yu; Gao, Wen; Li, Jiang

    2009-01-01

    AIM: To investigate the mechanisms of aspirin increasing the susceptibility of Helicobacter pylori (H pylori) to metronidazole. METHODS: H pylori reference strain 26 695 and two metronidazole-resistant isolates of H pylori were included in this study. Strains were incubated in Brucella broth with or without aspirin (1 mmol/L). The rdxA gene of H pylori was amplified by PCR and sequenced. The permeability of H pylori to antimicrobials was determined by analyzing the endocellular radioactivity of the cells after incubated with [7-3H]-tetracycline. The outer membrane proteins (OMPs) of H pylori 26 695 were depurated and analyzed by SDS-PAGE. The expression of 5 porins (hopA, hopB, hopC, hopD and hopE) and the putative RND efflux system (hefABC) of H pylori were analyzed using real-time quantitative PCR. RESULTS: The mutations in rdxA gene did not change in metronidazole resistant isolates treated with aspirin. The radioactivity of H pylori increased when treated with aspirin, indicating that aspirin improved the permeability of the outer membrane of H pylori. However, the expression of two OMP bands between 55 kDa and 72 kDa altered in the presence of aspirin. The expression of the mRNA of hopA, hopB, hopC, hopD, hopE and hefA, hefB, hefC of H pylori did not change when treated with aspirin. CONCLUSION: Although aspirin increases the susceptibility of H pylori to metronidazole, it has no effect on the mutations of rdxA gene of H pylori. Aspirin increases endocellular concentrations of antimicrobials probably by altering the OMP expression. PMID:19248190

  17. Genotyping of Peroxisome Proliferator-Activated Receptor gamma in Iranian Patients with Helicobacter pylori Infection.

    PubMed

    Goudarzi, Hossein; Seyedjavadi, Sima Sadat; Fazeli, Maryam; Azad, Mehdi; Goudarzi, Mehdi

    2015-01-01

    Helicobacter pylori (H. pylori) infection as a serious problem in both adults and children can induce chronic gastritis, peptic ulcer disease (PUD), and possibly gastric cancer. The aim of the current study was to survey antibiotic resistance and also to determine influence of PPARγ polymorphism in patients with H. pylori infection. During an 11-month-period, 98 H. pylori isolates were collected from 104 biopsy specimens. In vitro susceptibility of H. pylori isolates to 4 antimicrobial agents metronidazole, clarithromycin, amoxicillin and tetracycline were assessed by quantitative method according to European Committee on Antimicrobial Susceptibility Testing (EUCAST) guideline. PPARγ polymorphism was determined using polymerase chain reaction-restriction fragment length polymorphism assay. The frequency of H. pylori infection in our study was 94.2%. In vitro susceptibility data showed that highest level of resistance was related to metronidazole (66.3%), and the majority of H. pylori isolates were highly susceptible to amoxicillin and tetracycline (94.9% and 96.9%, respectively). Genotypic frequencies were 25.5% for CC (Pro12Pro), 40.8% for GC (Pro12Ala) and 33.7% for GG (Ala12Ala). In our study, CG genotype had highest distributions among infected patients with H. pylori. The study suggests that the PPAR-γ Pro12Ala polymorphism could be evaluated as a potential genetic marker for susceptibility to gastric cancer in the presence of H. pylori infection.

  18. Antimicrobial susceptibility of Helicobacter pylori to six antibiotics currently used in Spain.

    PubMed

    Cuadrado-Lavín, Antonio; Salcines-Caviedes, J Ramón; Carrascosa, Miguel F; Mellado, Purificación; Monteagudo, Idoia; Llorca, Javier; Cobo, Marta; Campos, M Rosario; Ayestarán, Blanca; Fernández-Pousa, Antonio; González-Colominas, Elena

    2012-01-01

    Antibiotic resistance is directly related to the loss of efficacy of currently accepted Helicobacter pylori therapies. Knowledge of the antibiotic susceptibility in a local area can contribute to the design of specific 'à la carte' treatments. The aim of this study was to analyse the susceptibility of H. pylori isolates to six conventional antibiotics currently used in a northern region of Spain. Seventy-one isolates were obtained from gastric biopsies of 76 consecutive adult patients suffering from peptic ulcer disease, dyspepsia or familial gastric cancer and known to be infected with H. pylori by conventional methods. Susceptibility testing was performed for amoxicillin, ciprofloxacin, levofloxacin, clarithromycin, metronidazole and tetracycline using the Etest method. The prevalence rates of resistance were as follows: amoxicillin, 1.4% [95% confidence interval (CI) 0.0-7.6]; clarithromycin, 14.7% (95% CI 7.3-25.4); ciprofloxacin, 14.3% (95% CI 7.1-24.7); levofloxacin, 14.5% (95% CI 7.2-25.0); metronidazole, 45.1% (95% CI 33.2-57.3); and tetracycline, 0% (95% CI 0.0-5.1). Our study confirms an increasing rate of resistance to levofloxacin that equals that of clarithromycin in our healthcare area. This fact may reflect a wide and indiscriminate use of the former antibiotic and could account for a loss of clinical effectiveness of levofloxacin-containing regimens. Moreover, clarithromycin resistance rates remain stable, which could allow us to maintain its use in our area.

  19. Restriction fragment length polymorphism in the adhesin gene hpaA of Helicobacter pylori.

    PubMed

    Evans, D G; Evans, D J; Lampert, H C; Graham, D Y

    1995-08-01

    To assess the degree of restriction fragment length polymorphism (RFLP) in the Helicobacter pylori adhesin gene hpaA and to determine the molecular basis of RFLP in this gene. A 375-bp, polymerase chain reaction-amplified internal sequence of hpaA, obtained from 50 different H. pylori isolates, was restricted with Sau3A and HinfI, individually. Polymerase chain reaction products representing different RFLP types were sequenced. Seven different polymorphic types were found in hpaA. Base substitutions at only four positions, two in Sau3A and two in HinfI sites, account for all of the RFLP types, including the size of the restriction fragments determined by gel electrophoresis. Most, 90%, of the base substitutions are very conservative, i.e., either do not change the encoded amino acid or substitute a homologous amino acid, and cause no detectable antigenic or functional effect on hpaA. The region of hpaA encoding the receptor-binding motif was particularly well conserved. RFLP typing of hpaA using Sau3A and HinfI provides an additional tool for comparing the genetic relatedness of H. pylori isolates collected during epidemiological and/or treatment studies.

  20. Lipopolysaccharide Structure and Biosynthesis in Helicobacter pylori.

    PubMed

    Li, Hong; Liao, Tingting; Debowski, Aleksandra W; Tang, Hong; Nilsson, Hans-Olof; Stubbs, Keith A; Marshall, Barry J; Benghezal, Mohammed

    2016-12-01

    This review covers the current knowledge and gaps in Helicobacter pylori lipopolysaccharide (LPS) structure and biosynthesis. H. pylori is a Gram-negative bacterium which colonizes the luminal surface of the human gastric epithelium. Both a constitutive alteration of the lipid A preventing TLR4 elicitation and host mimicry of the Lewis antigen decorated O-antigen of H. pylori LPS promote immune escape and chronic infection. To date, the complete structure of H. pylori LPS is not available, and the proposed model is a linear arrangement composed of the inner core defined as the hexa-saccharide (Kdo-LD-Hep-LD-Hep-DD-Hep-Gal-Glc), the outer core composed of a conserved trisaccharide (-GlcNAc-Fuc-DD-Hep-) linked to the third heptose of the inner core, the glucan, the heptan and a variable O-antigen, generally consisting of a poly-LacNAc decorated with Lewis antigens. Although the glycosyltransferases (GTs) responsible for the biosynthesis of the H. pylori O-antigen chains have been identified and characterized, there are many gaps in regard to the biosynthesis of the core LPS. These limitations warrant additional mutagenesis and structural studies to obtain the complete LPS structure and corresponding biosynthetic pathway of this important gastric bacterium. © 2016 John Wiley & Sons Ltd.

  1. Effect of protease EPg222 obtained from Penicillium chrysogenum isolated from dry-cured ham in pieces of pork loins.

    PubMed

    Benito, María J; Rodríguez, Mar; Sosa, María J; Martín, Alberto; Córdoba, Juan J

    2003-01-01

    The fungal protease EPg222 obtained from Penicillium chrysogenum Pg222 isolated from dry-cured ham, was assayed for proteolytic activity in a meat model system based on sterile pieces of pork loins for 32 days. Treated samples showed a significative reduction of total high ionic strength-soluble proteins during the incubation period, as compared with a control incubated without enzyme, both on the surface and in the depth. SDS-PAGE analysis of this protein fraction showed higher hydrolysis of the main myofibrillar proteins H-meromyosin, actin, and tropomyosin in treated samples. Non-protein and amino acidic nitrogen were detected in higher amounts in enzyme-added than in control pieces of loins, both on the surface and in the depth. Thus, addition of enzyme EPg222 to whole pieces of meat results in an increase of protein hydrolysis. The effect of this enzyme could be of great interest for stimulating proteolysis in whole dry-cured meat pieces.

  2. Retinal charge sensitivity and spatial discrimination obtainable by subretinal implants: key lessons learned from isolated chicken retina

    NASA Astrophysics Data System (ADS)

    Stett, Alfred; Mai, Andreas; Herrmann, Thoralf

    2007-03-01

    In order to obtain functional parameters relevant to the designing of a subretinal implant, we carried out electrical stimulation experiments with isolated chicken retina. The median threshold for network activation with planar disc electrodes (diameter 10 µm) was 0.5 nC (625 µC cm-2) for anodal voltage impulses and 1.6 nC (2 mC cm-2) for cathodal impulses. Above threshold, the number of spikes evoked by a single voltage impulse increased up to saturation within a range of injected charge from 0.1 nC to 1 nC for anodal impulses and from 1 nC to 10 nC for cathodal impulses. Using needle electrodes with a tip diameter of 1 µm, we determined the electrical point spread function (EPSF) for subretinal stimulation. It had a half width in the range of 100 µm, which corresponds to a visual angle of 21' and to a visual acuity of 20/417 in the human eye. It is reasonable to conclude that with subretinal implants the minimum separable will be of the same dimension.

  3. Detection of Helicobacter pylori in Oral Lesions

    PubMed Central

    Irani, Soussan; Monsef Esfahani, Alireza; Bidari Zerehpoush, Farahnaz

    2013-01-01

    Background and aims. Helicobacter pylori is a microaerophilic gram-negative spiral organism. It is recognized as the etiologic factor for peptic ulcers, gastric adenocarcinoma and gastric lymphoma. Recently, it has been isolated from dental plaque and the dorsum of the tongue. This study was designed to assess the association between H. pylori and oral lesions such as ulcerative/inflammatory lesions, squamous cell carcinoma (SCC) and primary lymphoma. Materials and methods. A total of 228 biopsies diagnosed as oral ulcerative/inflammatory lesions, oral squamous cell carcinoma (OSCC) and oral primary lymphoma were selected from the archives of the Pathology Department. Thirty-two samples that were diagnosed as being without any pathological changes were selected as the control group. All the paraffin blocks were cut for hematoxylin and eosin staining to confirm the diagnoses and then the samples were prepared for immunohistochemistry staining. Data were collected and analyzed. Results. Chi-squared test showed significant differences between the frequency of H. pylori positivity in normal tissue and the lesions were examined (P=0.000). In addition, there was a statistically significant difference between the lesions examined (P=0.042). Chi-squared test showed significant differences between H. pylori positivity and different tissue types except inside the muscle layer as follows: in epithelium and in lamina propria (P=0.000), inside the blood vessels (P=0.003), inside the salivary gland duct (P=0.036), and muscle layer (P=0.122). Conclusion. There might be a relation between the presence of H. pylori and oral lesions. Therefore, early detection and eradication of H. pylori in high-risk patients are suggested. PMID:24578822

  4. Helicobacter pylori-induced gastritis in experimentally infected conventional piglets.

    PubMed

    Poutahidis, T; Tsangaris, T; Kanakoudis, G; Vlemmas, I; Iliadis, N; Sofianou, D

    2001-11-01

    A conventional nonmutant animal that could be experimentally infected with Helicobacter pylori isolates would be a useful animal model for human H. pylori-associated gastritis. Gnotobiotic and barrier-born pigs are susceptible to H. pylori infection, but attempts to infect conventional pigs with this bacterium have been unsuccessful. In the present study, a litter of eight 20-day-old crossbreed piglets were purchased from a commercial farm. Six of them were orally challenged two to five times at different ages, between 29 and 49 days, with doses of H. pylori inoculum containing approximately 10(9) bacterial cells. Two animals served as controls. The inoculation program began 2 days postweaning when the piglets were 29 days of age. Prior to every inoculation, the piglets were fasted and pretreated with cimetidine, and prior to the first and second inoculation each piglet also was pretreated with dexamethasone. The challenged piglets were euthanasized between 36 and 76 days of age. H. pylori colonized all six inoculated piglets. The pathology of the experimentally induced gastritis was examined macroscopically and by light and electron microscopy. H. pylori induced a severe lymphocytic gastritis in the conventional piglets and reproduced the large majority of the pathologic features of the human disease. Therefore, the conventional piglet represents a promising new model for study of the various pathogenic mechanisms involved in the development of lesions of the human H. pylori-associated gastritis.

  5. Gastritis induced by Helicobacter pylori infection in experimental rats.

    PubMed

    Elseweidy, Mohamed M; Taha, Mona M; Younis, Nahla N; Ibrahim, Khadiga S; Hamouda, Hamdi A; Eldosouky, Mohamed A; Soliman, Hala

    2010-10-01

    Gastritis, an inflammation of gastric mucosa, may be due to many pathological factors and infection, such as with Helicobacter pylori. The use of experimental models of gastritis is important to evaluate the biochemical changes and study chemotherapeutic intervention. In a previous study we demonstrated an acute gastritis model induced by iodoacetamide. Our objective in this study was to evaluate a new gastritis model induced by H. pylori infection in experimental rats in terms of certain biomarkers in serum and mucosal tissues in addition to histopathological examination. Gastritis was induced in 20 albino Wistar rats by H. pylori isolated from antral biopsy taken from a 49-year-old male patient endoscopically diagnosed as having H. pylori infection. Another ten rats were used as controls. Serum gastrin, pepsinogen I activity, interleukin-6 (IL-6) and gastric mucosal myeloperoxidase (MPO) activity and prostaglandin E(2) (PGE(2)) were measured. Immunostaining for inducible nitric oxide synthase (iNOS), nitrotyrosine and DNA fragmentation were used to further evaluate H. pylori-induced gastritis. Serum gastrin, IL-6, mucosal MPO activity, and PGE(2) demonstrated significant increases joined with a decreased serum pepsinogen I activity (P < 0.001). Immunohistochemistry demonstrated positive reaction for iNOS, nitrotyrosine and DNA fragmentation. Helicobacter pylori-induced gastritis models demonstrated massive oxidative stress and pronounced injury in mucosal tissue. Since our model in rats reflected the clinical picture of H. pylori infection, it can be considered as a consistent model to study chemotherapeutic intervention for this type of gastritis.

  6. Structure, function and localization of Helicobacter pylori urease.

    PubMed Central

    Dunn, B. E.; Phadnis, S. H.

    1998-01-01

    Helicobacter pylori is the causative agent of most cases of gastritis. Once acquired, H. pylori establishes chronic persistent infection; it is this long-term infection that, is a subset of patients, leads to gastric or duodenal ulcer, gastric cancer or gastric MALT lymphoma. All fresh isolates of H. pylori express significant urease activity, which is essential to survival and pathogenesis of the bacterium. A significant fraction of urease is associated with the surface of H. pylori both in vivo and in vitro. Surface-associated urease is essential for H. pylori to resist exposure to acid in the presence of urea. The mechanism whereby urease becomes associated with the surface of H. pylori is unique. This process, which we term "altruistic autolysis," involves release of urease (and other cytoplasmic proteins) by genetically programmed autolysis with subsequent adsorption of the released urease onto the surface of neighboring intact bacteria. To our knowledge, this is the first evidence of essential communal behavior in pathogenic bacteria; such behavior is crucial to understanding the pathogenesis of H. pylori. PMID:10378351

  7. Antibiotic resistance in Helicobacter pylori strains and its effect on H. pylori eradication rates in a single center in Korea.

    PubMed

    An, Byoungrak; Moon, Byung Soo; Kim, Heejung; Lim, Hyun Chul; Lee, Yong Chan; Lee, Gyusang; Kim, Sa-Hyun; Park, Min; Kim, Jong Bae

    2013-11-01

    Clarithromycin, amoxicillin, metronidazole, tetracycline, and levofloxacin have been commonly used for the eradication of Helicobacter pylori. We compared the change in antibiotic resistance of H. pylori strains during two separate periods and investigated the effect of antibiotic resistance on H. pylori eradication. H. pylori strains were isolated from 71 patients between 2009 and 2010 and from 94 patients between 2011 and 2012. The distribution of minimal inhibitory concentration (MIC) of 5 antibiotics was assessed using the agar dilution method, and H. pylori eradication based on the antimicrobial susceptibility of the isolates was investigated retrospectively. Antibiotic resistance rate against clarithromycin, amoxicillin, tetracycline, metronidazole, and levofloxacin for the 2009-2010 isolates were 7.0% (5/71), 2.8% (2/71), 0% (0/71), 45.1% (32/71), and 26.8% (19/71), respectively, and for the 2011-2012 isolates were 16.0% (15/94), 2.1% (2/94), 0% (0/94), 56.3% (53/94), and 22.3% (21/94), respectively. Multi-drug resistance for 2 or more antibiotics increased slightly from 16.9% (12/71) in the 2009-2010 isolates to 23.4% (22/94) in the 2011-2012 isolates. In follow-up testing of 66 patients, first-line treatment successfully eradicated H. pylori in 50 patients (75.8%) and failed in 4 of 7 patients (57.1%) in a clarithromycin-resistant and amoxicillin-susceptible group. We observed an increase in resistance to clarithromycin and an overall increase in multi-drug resistance during the 2 study periods. The effectiveness of the eradication regimen was low with combinations of clarithromycin and amoxicillin, particularly in the clarithromycin-resistant group. Thus, eradication of H. pylori depends upon periodic monitoring of antimicrobial susceptibility.

  8. Molecular characterization and phylogeny of Shiga toxin-producing Escherichia coli isolates obtained from two Dutch regions using whole genome sequencing.

    PubMed

    Ferdous, M; Friedrich, A W; Grundmann, H; de Boer, R F; Croughs, P D; Islam, M A; Kluytmans-van den Bergh, M F Q; Kooistra-Smid, A M D; Rossen, J W A

    2016-07-01

    Shiga toxin-producing Escherichia coli (STEC) is one of the major causes of human gastrointestinal disease and has been implicated in sporadic cases and outbreaks of diarrhoea, haemorrhagic colitis and haemolytic uremic syndrome worldwide. In this study, we determined the molecular characteristics and phylogenetic relationship of STEC isolates, and their genetic diversity was compared to that of other E. coli populations. Whole genome sequencing was performed on 132 clinical STEC isolates obtained from the faeces of 129 Dutch patients with gastrointestinal complaints. STEC isolates of this study belonged to 44 different sequence types (STs), 42 serogenotypes and 14 stx subtype combinations. Antibiotic resistance genes were more frequently present in stx1-positive isolates compared to stx2 and stx1 + stx2-positive isolates. The iha, mchB, mchC, mchF, subA, ireA, senB, saa and sigA genes were significantly more frequently present in eae-negative than in eae-positive STEC isolates. Presence of virulence genes encoding type III secretion proteins and adhesins was associated with isolates obtained from patients with bloody diarrhoea. Core genome phylogenetic analysis showed that isolates clustered according to their ST or serogenotypes irrespective of stx subtypes. Isolates obtained from patients with bloody diarrhoea were from diverse phylogenetic backgrounds. Some STEC isolates shared common ancestors with non-STEC isolates. Whole genome sequencing is a powerful tool for clinical microbiology, allowing high-resolution molecular typing, population structure analysis and detailed molecular characterization of strains. STEC isolates of a substantial genetic diversity and of distinct phylogenetic groups were observed in this study.

  9. Persistence of Helicobacter pylori in heterotrophic drinking-water biofilms.

    PubMed

    Gião, M S; Azevedo, N F; Wilks, S A; Vieira, M J; Keevil, C W

    2008-10-01

    Although the route of transmission of Helicobacter pylori remains unknown, drinking water has been considered a possible transmission vector. It has been shown previously that, in water, biofilms are a protective niche for several pathogens, protecting them from stressful conditions, such as low carbon concentration, shear stress, and less-than-optimal temperatures. In this work, the influence of these three parameters on the persistence and cultivability of H. pylori in drinking-water biofilms was studied. Autochthonous biofilm consortia were formed in a two-stage chemostat system and then inoculated with the pathogen. Total numbers of H. pylori cells were determined by microscopy using a specific H. pylori 16S rRNA peptide nucleic acid probe, whereas cultivable cells were assessed by standard plating onto selective H. pylori medium. Cultivable H. pylori could not be detected at any time point, but the ability of H. pylori cells to incorporate, undergo morphological transformations, persist, and even agglomerate in biofilms for at least 31 days without a noticeable decrease in the total cell number (on average, the concentration was between 1.54 x 10(6) and 2.25 x 10(6) cells cm(-2)) or in the intracellular rRNA content may indicate that the loss of cultivability was due to entry into a viable but noncultivable state. Unlike previous results obtained for pure-culture H. pylori biofilms, shear stress did not negatively influence the numbers of H. pylori cells attached, suggesting that the autochthonous aquatic bacteria have an important role in retaining this pathogen in the sessile state, possibly by providing suitable microaerophilic environments or linking biomolecules to which the pathogen adheres. Therefore, biofilms appear to provide not only a safe haven for H. pylori but also a concentration mechanism so that subsequent sloughing releases a concentrated bolus of cells that might be infectious and that could escape routine grab sample microbiological

  10. Development of a Mouse Model of Helicobacter pylori Infection that Mimics Human Disease

    NASA Astrophysics Data System (ADS)

    Marchetti, Marta; Arico, Beatrice; Burroni, Daniela; Figura, Natale; Rappuoli, Rino; Ghiara, Paolo

    1995-03-01

    The human pathogen Helicobacter pylori is associated with gastritis, peptic ulcer disease, and gastric cancer. The pathogenesis of H. pylori infection in vivo was studied by adapting fresh clinical isolates of bacteria to colonize the stomachs of mice. A gastric pathology resembling human disease was observed in infections with cytotoxin-producing strains but not with noncytotoxic strains. Oral immunization with purified H. pylori antigens protected mice from bacterial infection. This mouse model will allow the development of therapeutic agents and vaccines against H. pylori infection in humans.

  11. Characterization of the Cag pathogenicity island in Helicobacter pylori from naturally infected rhesus macaques.

    PubMed

    Skoog, Emma C; Deck, Samuel L; Entwistle, Hasan D; Hansen, Lori M; Solnick, Jay V

    2016-12-01

    Helicobacter pylori commonly infects the epithelial layer of the human stomach and in some individuals causes peptic ulcers, gastric adenocarcinoma or gastric lymphoma. Helicobacter pylori is a genetically diverse species, and the most important bacterial virulence factor that increases the risk of developing disease, versus asymptomatic colonization, is the cytotoxin associated gene pathogenicity island (cagPAI). Socially housed rhesus macaques are often naturally infected with H. pylori similar to that which colonizes humans, but little is known about the cagPAI. Here we show that H. pylori strains isolated from naturally infected rhesus macaques have a cagPAI very similar to that found in human clinical isolates, and like human isolates, it encodes a functional type IV secretion system. These results provide further support for the relevance of rhesus macaques as a valid experimental model for H. pylori infection in humans. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  12. Reprint of: The diversity of oomycetes on crayfish: Morphological vs. molecular identification of cultures obtained while isolating the crayfish plague pathogen.

    PubMed

    Kozubíková-Balcarová, Eva; Koukol, Ondřej; Martín, María P; Svoboda, Jiří; Petrusek, Adam; DiÉguez-Uribeondo, Javier

    2014-07-01

    Numerous oomycetes colonise the crayfish cuticle, the best known being the crayfish plague pathogen Aphanomyces astaci. Although other oomycetes associated with crayfish complicate the isolation and molecular detection of A. astaci, their diversity is little known. To improve this knowledge, we analysed 95 oomycete isolates obtained during attempts to isolate A. astaci from crayfish presumably infected by this pathogen. We characterized the isolates morphologically and by sequencing of the nuclear internal transcribed spacer (ITS) region. We identified 13 taxa by molecular analysis. Ten of them were assigned to five genera; the remaining three were affiliated with the order Saprolegniales but could not be reliably assigned to any genus. Morphological identification to species level was only possible for 15 % of isolates; all corresponded to Saprolegnia ferax, which was confirmed by ITS sequencing. The most frequently isolated species were S. ferax and Saprolegnia australis. Only seven isolates of A. astaci were obtained, all from one disease outbreak. We show that oomycete cultures obtained as by-products of parasite isolation are valuable for oomycete diversity studies, but morphological identification may uncover only a fraction of their diversity. Further, we show that crayfish may be frequently associated with potentially serious parasites of other organisms.

  13. In vitro susceptibility of equine-obtained isolates of Corynebacterium pseudotuberculosis to gallium maltolate and 20 other antimicrobial agents.

    PubMed

    Norman, T E; Batista, M; Lawhon, S D; Zhang, S; Kuskie, K R; Swinford, A K; Bernstein, L R; Cohen, N D

    2014-07-01

    This study's objective was to determine the in vitro antimicrobial activities of gallium maltolate (GaM) and 20 other antimicrobial agents against clinical equine isolates of Corynebacterium pseudotuberculosis. The growth of cultured isolates was not inhibited by any concentration of GaM. MIC data revealed susceptibility to commonly used antimicrobials.

  14. In Vitro Susceptibility of Equine-Obtained Isolates of Corynebacterium pseudotuberculosis to Gallium Maltolate and 20 Other Antimicrobial Agents

    PubMed Central

    Batista, M.; Lawhon, S. D.; Zhang, S.; Kuskie, K. R.; Swinford, A. K.; Bernstein, L. R.; Cohen, N. D.

    2014-01-01

    This study's objective was to determine the in vitro antimicrobial activities of gallium maltolate (GaM) and 20 other antimicrobial agents against clinical equine isolates of Corynebacterium pseudotuberculosis. The growth of cultured isolates was not inhibited by any concentration of GaM. MIC data revealed susceptibility to commonly used antimicrobials. PMID:24829243

  15. Multiple-stress tolerance of ionizing radiation-resistant bacterial isolates obtained from various habitats: correlation between stresses.

    PubMed

    Shukla, Manish; Chaturvedi, Ruchi; Tamhane, Dhruti; Vyas, Pranav; Archana, G; Apte, Shree; Bandekar, J; Desai, Anjana

    2007-02-01

    Isolation of five ionizing radiation (IR)-resistant bacteria by screening of isolates from various habitats classified as common and stressed is reported. IR-resistant isolates exhibited varying degrees of resistance to gamma-radiation and were classified as highly and moderately radiation resistant. Resistance to ultraviolet (UV) radiation correlated well with gamma-radiation resistance, whereas a comparable desiccation resistance for all the highly and moderately radiation-resistant isolates was observed. However, salt tolerance failed to correlate with IR resistance, indicating a divergent evolution of the salt tolerance and radiation resistance. Characterization of isolates by the amplified rDNA restriction analysis profiling attested to the clustering of these isolates with their stress phenotype. 16S rRNA gene-based analysis of the isolates showed that the bacteria with similar-resistance physiologies clustered together and belonged to related genera. Hydrogen peroxide resistance and mitomycin survival patterns of the isolates indicated the roles of oxidative-stress tolerance in desiccation survival and recombination repair in higher radiation resistance, respectively.

  16. Genetic diversity demonstrated by pulsed field gel electrophoresis of Salmonella enterica isolates obtained from diverse sources in Mexico

    USDA-ARS?s Scientific Manuscript database

    This study was conducted to determine the genetic diversity of Salmonella isolates recovered from a variety of sources using pulsed-field gel electrophoresis (PFGE) to assess their possible relatedness. Salmonella was isolated from ca. 52% of samples from a pepper var. Bell production system. A to...

  17. Biochemical Characterization of a β-Galactosidase with a Low Temperature Optimum Obtained from an Antarctic Arthrobacter Isolate

    PubMed Central

    Coker, James A.; Sheridan, Peter P.; Loveland-Curtze, Jennifer; Gutshall, Kevin R.; Auman, Ann J.; Brenchley, Jean E.

    2003-01-01

    A psychrophilic gram-positive isolate was obtained from Antarctic Dry Valley soil. It utilized lactose, had a rod-coccus cycle, and contained lysine as the diamino acid in its cell wall. Consistent with these physiological traits, the 16S ribosomal DNA sequence showed that it was phylogenetically related to other Arthrobacter species. A gene (bgaS) encoding a family 2 β-galactosidase was cloned from this organism into an Escherichia coli host. Preliminary results showed that the enzyme was cold active (optimal activity at 18°C and 50% activity remaining at 0°C) and heat labile (inactivated within 10 min at 37°C). To enable rapid purification, vectors were constructed adding histidine residues to the BgaS enzyme and its E. coli LacZ counterpart, which was purified for comparison. The His tag additions reduced the specific activities of both β-galactosidases but did not alter the other characteristics of the enzymes. Kinetic studies using o-nitrophenyl-β-d-galactopyranoside showed that BgaS with and without a His tag had greater catalytic activity at and below 20°C than the comparable LacZ β-galactosidases. The BgaS heat lability was investigated by ultracentrifugation, where the active enzyme was a homotetramer at 4°C but dissociated into inactive monomers at 25°C. Comparisons of family 2 β-galactosidase amino acid compositions and modeling studies with the LacZ structure did not mimic suggested trends for conferring enzyme flexibility at low temperatures, consistent with the changes affecting thermal adaptation being localized and subtle. Mutation studies of the BgaS enzyme should aid our understanding of such specific, localized changes affecting enzyme thermal properties. PMID:12949099

  18. Antimicrobial resistance trends among canine Escherichia coli isolates obtained from clinical samples in the northeastern USA, 2004-2011.

    PubMed

    Cummings, Kevin J; Aprea, Victor A; Altier, Craig

    2015-04-01

    Our objectives were to describe the antimicrobial susceptibility of Escherichia coli isolates from dogs in the northeastern USA and to identify temporal trends in resistance to selected antimicrobial agents. Data were collected retrospectively for all canine E. coli isolates from clinical samples submitted to Cornell University's Animal Health Diagnostic Center between January 1, 2004 and December 31, 2011. Antimicrobial susceptibility testing was performed on 3519 canine E. coli isolates; frequency of resistance to each agent ranged from 0.4% (amikacin) to 34.3% (ampicillin). No trends were evident among urinary isolates, but cephalosporin resistance remained consistently high. Among non-urinary isolates, there was evidence of a significantly increasing trend in prevalence of resistance to several agents, including cephalosporins, enrofloxacin, and tetracycline. These data suggest that some of the most commonly used antimicrobial agents in companion animal practice are becoming less effective against canine E. coli infections outside the urinary tract.

  19. Optimizing enrichment culture conditions for detecting Helicobacter pylori in foods.

    PubMed

    Jiang, Xiuping; Doyle, Michael P

    2002-12-01

    The survival and growth of Helicobacter pylori under enrichment conditions in fresh, autoclaved and irradiated ground beef were determined. H. pylori grew in autoclaved ground beef at 37 degrees C under microaerobic conditions in brain heart infusion broth with 7% horse serum at pH 7.3 after 3 to 7 days of lag time but did not grow within 7 days in irradiated (10 kGy) ground beef under the same enrichment conditions. Adjustment of the enrichment broth to pH 5.5 enabled the growth (ca. 2 log10 CFU/ml) of H. pylori within 7 days in the presence of irradiated ground beef and the prolific growth (ca. 3 to 4 log10 CFU/ml) of H. pylori within 3 days in the presence of autoclaved beef. H. pylori in fresh ground beef could not be isolated from enrichment media with antibiotics; however. H. pylori ureA could be detected by polymerase chain reaction (PCR) in such enrichment media after 1 to 3 days of incubation at 37 degrees C. The addition of supplements, i.e., 0.3% mucin, 0.05% ferrous sulfate, and 0.05% sodium pyruvate or 0.008 M urea, or the adjustment of the enrichment broth pH to 5.5 or 4.5 enabled the detection of H. pylori ureA in enrichment media incubated for 1, 2, 3, and/or 7 days at 37 degrees C. H. pylori in sterile milk refrigerated at 4 degrees C at an initial level of 10(6) CFU/ml was inactivated to an undetectable level within 6 days; however, H. pylori was not detected either by a PCR assay or by the plating of enrichment cultures of 120 raw bovine milk samples.

  20. Characterization of reticuloendotheliosis virus isolates obtained from broiler breeders, turkeys, and prairie chickens located in various geographical regions in the United States.

    PubMed

    Mays, Jody K; Silva, Robert F; Lee, Lucy F; Fadly, Aly M

    2010-10-01

    Nine reticuloendotheliosis virus (REV) isolates obtained from broiler breeders, turkeys, and prairie chickens located in three different geographical regions in the USA, and three isolates obtained from known contaminated live-virus vaccines were characterized using polymerase chain reaction (PCR) and indirect immunofluorescence (IFA) assays. All isolates were propagated in chicken embryo fibroblasts obtained from a specific pathogen free breeder flock. PCR analysis of all 12 isolates resulted in the amplification of the 291-bp REV long-terminal repeat region (LTR); none of the isolates exhibited a different pattern or shift from the expected PCR product of REV LTR. The subtype of the REV isolates was determined by IFA using REV-specific monoclonal antibodies, 11B118.22, 11C237.8, and 11D182. Results from sub-typing indicated that all nine isolates from broiler breeders, turkeys, and prairie chickens belonged to subtype 3, and are antigenically related to the chick syncytial virus (CSV) strain of REV, the prototype of subtype 3 REV. In contrast, the three isolates from contaminated vaccines were classified as subtype 2, and were antigenically related to spleen necrosis virus (SNV) strain of REV, the prototype of subtype 2 REV. Three isolates representing REV isolated from broiler breeders, turkeys, and prairie chickens were cloned and further evaluated by DNA sequence analysis of the envelope gene. Results from DNA sequence analysis confirmed those from sub-typing and indicated that the three REV isolates representing those from broiler breeders, turkeys, and prairie chickens are closely related to CSV of REV, with an amino acid homology of 98% or greater as compared with SNV with an amino acid homology of 95% or less. Data from this study clearly indicate that subtype 3 is the most common subtype of REV circulating in three different avian species, namely broiler breeders, turkeys and prairie chickens, located in three different geographical regions in the United

  1. H. pylori Infection

    MedlinePlus

    ... pill, liquid or pudding that contains tagged carbon molecules. If you have an H. pylori infection, carbon ... uses a special device to detect the carbon molecules. Acid-suppressing drugs known as proton pump inhibitors ( ...

  2. Tests for H. pylori

    MedlinePlus

    ... special substance that has urea. Urea is a waste product the body produces as it breaks down protein. The urea used in the test has been made harmlessly radioactive. If H. pylori are present, the bacteria convert ...

  3. The antimicrobial effects and metabolomic footprinting of carboxyl-capped bismuth nanoparticles against Helicobacter pylori.

    PubMed

    Nazari, P; Dowlatabadi-Bazaz, R; Mofid, M R; Pourmand, M R; Daryani, N E; Faramarzi, M A; Sepehrizadeh, Z; Shahverdi, A R

    2014-01-01

    Organic salts of bismuth are currently used as antimicrobial agents against Helicobacter pylori. This study evaluated the antibacterial effect of elemental bismuth nanoparticles (Bi NPs) using a serial agar dilution method for the first time against different clinical isolates and a standard strain of H. pylori. The Bi NPs were biologically prepared and purified by a recently described method and subjected to further characterization by infrared spectroscopy and anti-H. pylori evaluation. Infrared spectroscopy results showed the presence of carboxyl functional groups on the surface of biogenic Bi NPs. These biogenic nanoparticles showed good antibacterial activity against all tested H. pylori strains. The resulting MICs varied between 60 and 100 μg/ml for clinical isolates of H. pylori and H. pylori (ATCC 26695). The antibacterial effect of bismuth ions was also tested against all test strains. The antimicrobial effect of Bi ions was lower than antimicrobial effect of bismuth in the form of elemental NPs. The effect of Bi NPs on metabolomic footprinting of H. pylori was further evaluated by (1)H NMR spectroscopy. Exposure of H. pylori to an inhibitory concentration of Bi NPs (100 μg/ml) led to release of some metabolites such as acetate, formic acid, glutamate, valine, glycine, and uracil from bacteria into their supernatant. These findings confirm that these nanoparticles interfere with Krebs cycle, nucleotide, and amino acid metabolism and shows anti-H. pylori activity.

  4. Characterization of feline Helicobacter pylori strains and associated gastritis in a colony of domestic cats.

    PubMed Central

    Handt, L K; Fox, J G; Stalis, I H; Rufo, R; Lee, G; Linn, J; Li, X; Kleanthous, H

    1995-01-01

    Twenty-four young adult domestic cats from a commercial vendor were found to be infected with Helicobacter pylori. Histopathologic analyses, selected electron microscopy, and urease mapping were performed on mucosal samples collected from the cardias and fundi, bodies, and antra of these cats' stomachs. H. pylori organisms were abundant in all areas of the stomach on the basis of histologic evaluation and urease mapping. H. pylori infection was associated with a moderate to severe lymphofollicular gastritis in 21 of 24 cats (88%). The gastritis was most pronounced in the antral region and consisted mainly of multifocal lymphoplasmacytic follicular infiltrates in the deep mucosa. The severity of gastritis in the antrum corresponded to high numbers of H. pylori there on the basis of the use of the urease assay as an indicator of H. pylori colonization. Ten of 24 cats (42%) also had small to moderate numbers of eosinophils in the gastric mucosa. All 24 cats had gastric lymphoid follicles, with follicles being most prevalent in the antrum. Electron microscopy of gastric tissue revealed numerous H. pylori organisms, some of which were closely adhered to the mucosal epithelium. Human H. pylori gene-specific primers to ureA and ureB amplified products of similar sizes from H. pylori cat isolates. Digestion of the products with restriction enzymes resulted in fragments characteristic of the restriction fragment length polymorphism patterns of H. pylori isolates from humans.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7494015

  5. Efflux pump gene hefA of Helicobacter pylori plays an important role in multidrug resistance

    PubMed Central

    Liu, Zhi-Qiang; Zheng, Peng-Yuan; Yang, Ping-Chang

    2008-01-01

    AIM: To determine whether efflux systems contribute to multidrug resistance of H pylori. METHODS: A chloramphenicol-induced multidrug resistance model of six susceptible H pylori strains (5 isolates and H pylori NCTC11637) was developed. Multidrug-resistant (MDR) strains were selected and the minimal inhibitory concentration (MIC) of erythromycin, metronidazole, penicillin G, tetracycline, and ciprofloxacin in multidrug resistant strains and their parent strains was determined by agar dilution tests. The level of mRNA expression of hefA was assessed by fluorescence real-time quantitative PCR. A H pylori LZ1026 knockout mutant (ΔH pylori LZ1026) for (putative) efflux protein was constructed by inserting the kanamycin resistance cassette from pEGFP-N2 into hefA, and its susceptibility profiles to 10 antibiotics were evaluated. RESULTS: The MIC of six multidrug-resistant strains (including 5 clinical isolates and H pylori NCTC11637) increased significantly (≥ 4-fold) compared with their parent strains. The expression level of hefA gene was significantly higher in the MDR strains than in their parent strains (P = 0.033). A H pylori LZ1026 mutant was successfully constructed and the ΔH pylori LZ1026 was more susceptible to four of the 10 antibiotics. All the 20 strains displayed transcripts for hefA that confirmed the in vitro expression of these genes. CONCLUSION: The efflux pump gene hefA plays an important role in multidrug resistance of H pylori. PMID:18777600

  6. Comment on "Effect of biofilm formation by clinical isolates of Helicobacter pylori on the efflux-mediated resistance to commonly used antibiotics".

    PubMed

    Kazakos, Evangelos I; Dorrell, Nick; Polyzos, Stergios A; Deretzi, Georgia; Kountouras, Jannis

    2017-09-07

    Attaran et al([1]) have recently shown that decreased susceptibility of established Helicobacter pylori (H. pylori) biofilms to specific antibiotics, was associated with the overtly enhanced transcription of two efflux pump genes, hp1165 and hefA, involved in specific resistance to tetracycline and multiple antibiotics, respectively. Apart from antibiotic exposure, secretion of multiple antimicrobial peptides, such as human β-defensins (hβDs), by the gastric epithelium upon Hp challenge, may act as early triggering events that positively impact biofilm formation and thus, antibiotic resistance. In this regard, we undertook genomic transcriptional studies using Hp 26695 strain following exposure to sublethal, similar to those present in the gastric niche, concentrations of hβDs in an attempt to provide preliminary data regarding possible mechanisms of immune evasion and selective sensitivity of Hp. Our preliminary results indicate that hβD exposure ignites a rapid response that is largely due to the activation of several, possibly interconnected transcriptional regulatory networks - origons - that ultimately coordinate cellular processes needed to maintain homeostasis and successful adaptation of the bacterium in the gastric environment. In addition, we have shown that both antibiotic and hβD resistance are mediated by dedicated periplasmic transporters, including the aforementioned efflux pump genes hp1165 and hefA, involved in active export of antibiotics from the cell membrane and/or, as recently suggested, substrate sensing and signalling. Furthermore, it appears that sublethal doses of hβDs may enhance biofilm formation by the sustained expression of, mainly, quorum sensing-related genes. In conclusion, we provide additional data regarding the role of specific innate immune molecules in antibiotic cross-resistance mechanisms that may deepen our understanding in the context of the development of novel eradication regimens.

  7. Restriction fragment length polymorphism of adhesin gene hpaA from different Helicobacter pylori strains of Chongqing, China.

    PubMed

    Hong, Yu; Mao, Xu-Hu; Zeng, Wei-Kun; Ma, Li-Ming; Jing, Shen-Rong; Zou, Quan-Ming

    2005-05-07

    To assess the variability of adhesin gene hpaA between different Helicobacter pylori (H pylori) strains with PCR-restriction fragment length polymorphism (RFLP). Twelve different H pylori strains were chosen to amplify the 710-bp segments of gene hpaA. These strains were NCTC11637, SS1; Chongqing clinical isolates CCS9801, CCS9802, CCS9803, CCS9806, CCS9809, CCS9810, CCS9813, which were gained from patients of gastritis; Mongolia gerbil adapted H pylori strains (abbreviation MG), which were gained from the following steps: gastric mucosal specimens of Mongolia gerbils infected by clinical isolate CCS9803 were cultured and detected, the positive H pylori strains were named as the first generation of Mongolia gerbil adapted H pylori strains (abbreviation MG1) and then were subcultured with healthy Mongolia gerbil to generate MG2, in turn to gain the ninth generation (abbreviation MG9). All hpaA segments, obtained from 12 different H pylori strains, were digested by HhaI and HaeIII individually and analyzed by agarose gel electrophoresis. In all 12 strains, the 710-bp PCR products were successfully amplified and products were cloned to pMD18-T vector respectively, then the recombinant plasmids were digested simultaneously with NcoI and XhoI to recover the small fragments. The objective fragments from 12 different H pylori strains digested with Hae III could be seen as 4 types of bands and 5 types with Hha I. According to the hpaA RFLP patterns, the 12 H pylori strains could be divided into 5 groups: group I, NCTC11637 and SS1; group II, CCS9809, which RFLP type digested with HaeIII was the same as strains of group I, but HhaI RFLP showed difference compared with the other groups; group III, CCS9810; group IV, CCS9803; group V: CCS9801, CCS9802, CCS9806, CCS9813, MG1, MG3 and MG9. The sequence data of 12 hpaA segments were analyzed by DNAsis software and it was observed that: (1) The homologies of base pair and amino acid sequence between strains NCTC11637, SS1, CCS

  8. Restriction fragment length polymorphism of adhesin gene hpaA from different Helicobacter pylori strains of Chongqing, China

    PubMed Central

    Hong, Yu; Mao, Xu-Hu; Zeng, Wei-Kun; Ma, Li-Ming; Jing, Shen-Rong; Zou, Quan-Ming

    2005-01-01

    AIM: To assess the variability of adhesin gene hpaA between different Helicobacter pylori (H pylori) strains with PCR-restriction fragment length polymorphism (RFLP). METHODS: Twelve different H pylori strains were chosen to amplify the 710-bp segments of gene hpaA. These strains were NCTC11637, SS1; Chongqing clinical isolates CCS9801, CCS9802, CCS9803, CCS9806, CCS9809, CCS9810, CCS9813, which were gained from patients of gastritis; Mongolia gerbil adapted H pylori strains (abbreviation MG), which were gained from the following steps: gastric mucosal specimens of Mongolia gerbils infected by clinical isolate CCS9803 were cultured and detected, the positive H pylori strains were named as the first generation of Mongolia gerbil adapted H pylori strains (abbreviation MG1) and then were subcultured with healthy Mongolia gerbil to generate MG2, in turn to gain the ninth generation (abbreviation MG9). All hpaA segments, obtained from 12 different H pylori strains, were digested by HhaI and HaeIII individually and analyzed by agarose gel electrophoresis. RESULTS: In all 12 strains, the 710-bp PCR products were successfully amplified and products were cloned to pMD18-T vector respectively, then the recombinant plasmids were digested simultaneously with NcoI and XhoI to recover the small fragments. The objective fragments from 12 different H pylori strains digested with Hae III could be seen as 4 types of bands and 5 types with Hha I. According to the hpaA RFLP patterns, the 12 H pylori strains could be divided into 5 groups: group I, NCTC11637 and SS1; group II, CCS9809, which RFLP type digested with HaeIII was the same as strains of group I, but HhaI RFLP showed difference compared with the other groups; group III, CCS9810; group IV, CCS9803; group V: CCS9801, CCS9802, CCS9806, CCS9813, MG1, MG3 and MG9. The sequence data of 12 hpaA segments were analyzed by DNAsis software and it was observed that: (1) The homologies of base pair and amino acid sequence between strains

  9. New Activities for Isolated Compounds from Convolvulus austro-aegyptiacus as Anti-ulcerogenic, Anti-Helicobacter pylori and Their Mimic Synthesis Using Bio-guided Fractionation.

    PubMed

    Awaad, Amani S; Al-Rifai, Asmaa A; El-Meligy, Reham M; Alafeefy, Ahmed M; Zain, Mohamed E

    2015-06-10

    Bio-guided fractionation of the total alcoholic extract of Convolvulus austro-aegyptiacus was screened for its anti-ulcerogenic activity, using an absolute-ethanol-induced ulcer model at 500 and 1000 mg/kg doses. Two compounds were isolated from the butanol extract of C. austro-aegyptiacus and identified by (1) H and (13) C nuclear magnetic resonance as scopoletin and scopolin. The isolated compounds (50 mg/kg) showed a remarkable anti-ulcerogenic activity because they exhibited control-ulcer protection by 16.7% and 90.8%, respectively. The acute toxicity study showed that the extract is highly safe; the median lethal dose (LD50) was more than 4000 mg/kg. Moreover, the obtained results were confirmed by the sub-chronic toxicity because the rats that have been administered 1000 mg/kg of the extract for 15 consecutive days showed no alteration in the liver and kidney functions. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

  10. New transport medium for cultural recovery of Helicobacter pylori.

    PubMed

    Cellini, Luigina; Di Campli, Emanuela; Di Bartolomeo, Soraya; Bessa, Lucinda Janete; Baffoni, Marina; Di Giulio, Mara

    2014-12-01

    We developed a new transport medium (GESA--Helicobacter pylori transport medium [publication no. WO/2014/019696, patent pending no. PCT/EP2013/002292; Liofilchem s.r.l., Roseto degli Abruzzi, Teramo, Italy]) for recovery of Helicobacter pylori from gastric biopsy samples. GESA transport medium, in a semisolid state, provides the optimal conditions for maintaining the viability of the microorganism over time. The efficacy of the transport medium was assessed through in vitro and ex vivo experiments. We were able to recover different suspensions of H. pylori ATCC 43629 and H. pylori 13 A in GESA transport medium stored at 4 °C for up to 10 days. In particular, with a starting inoculum of ∼ 10(5) CFU, after 7 days of storage, 150 ± 25 CFU and 40 ± 7 CFU of the reference and clinical strains were detected, respectively. H. pylori colonies were isolated from gastric specimens taken from both the antrum and the fundus in 68 (90.66%) of 75 urea breath test (UBT)-positive patients. Moreover, GESA transport medium allowed the recovery and isolation of H. pylori colonies from additional biopsy samples from 13 of the 75 detected subjects at up to 10 days of biopsy sample storage at 4 °C. Finally, GESA transport medium preserved its characteristics when stored at 4°C for 1 year from its preparation, thus allowing good recovery of H. pylori. GESA transport medium can be considered a standardized transport medium with high performance that optimizes the recovery rate of H. pylori grown by culture.

  11. Helicobacter pylori: enemy, commensal or, sometimes, friend?

    PubMed

    Whalen, Michael B; Massidda, Orietta

    2015-07-04

    Helicobacter pylori is a Gram-negative ε-proteobacterium that colonizes about 50% of humans. Some pertinent characteristics are that it can survive the acid of the stomach, produces urease to neutralize it and is motile due to apical flagella. Not surprisingly given its wide distribution, it has long colonized mankind and its genome encodes many features that allows this. Consequently, it frequently has a persistent lifelong association with humans and, differently from most pathogens that are transmitted horizontally, it is preferentially transmitted vertically, often from mother to child. A variety of genes and polymorphisms, both in H pylori and in humans, mediate the complex host-bacterium relationship, and can also determine if and what pathologies will be triggered by the species. H. pylori is naturally transformable, very recombinogenic and has a high mutation rate. Microbiota studies of the stomach have shown it to be an important species with a potentially regulatory role for the gastric microbial community. Likewise, epidemiological work has suggested that, while it clearly increases the risk of peptic ulcers and gastric cancer in some populations, it is also associated with lower risk of esophageal cancer and several other important pathologies. More recently, antibacterial resistant strains have been isolated, posing a problem for public health officials who called for its eradication. Hence, study of H. pylori and how it interacts with us can help revealing mutualistic or pathogenic interactions and the immune response in the digestive niche.

  12. Phenotypic and Molecular Antimicrobial Susceptibility of Helicobacter pylori.

    PubMed

    Chen, Derrick; Cunningham, Scott A; Cole, Nicolynn C; Kohner, Peggy C; Mandrekar, Jayawant N; Patel, Robin

    2017-04-01

    Failure to eradicate Helicobacter pylori infection is often a result of antimicrobial resistance, which for clarithromycin is typically mediated by specific point mutations in the 23S rRNA gene. The purpose of this study was to define current patterns of antimicrobial susceptibility in H. pylori isolates derived primarily from the United States and to survey them for the presence of point mutations in the 23S rRNA gene and assess the ability of these mutations to predict phenotypic clarithromycin susceptibility. Antimicrobial susceptibility testing was performed using agar dilution on 413 H. pylori isolates submitted to Mayo Medical Laboratories for susceptibility testing. For a subset of these isolates, a 150-bp segment of the 23S rRNA gene was sequenced. A total of 1,970 MICs were reported over the 4-year study period. The rate of clarithromycin resistance was high (70.4%), and elevated MICs were frequently observed for metronidazole (82.4% of isolates had an MIC of >8 μg/ml) and ciprofloxacin (53.5% of isolates had an MIC of >1 μg/ml). A total of 111 archived H. pylori isolates underwent 23S rRNA gene sequencing; we found 95% concordance between genotypes and phenotypes (P = 0.9802). Resistance to clarithromycin was most commonly due to an A2143G mutation (82%), followed by A2142G (14%) and A2142C (4%) mutations. Clinical H. pylori isolates derived primarily from the United States demonstrated a high rate of clarithromycin resistance and elevated metronidazole and ciprofloxacin MICs. The relative distribution of point mutations at positions 2143 and 2142 in the 23S rRNA gene in clarithromycin-resistant H. pylori was similar to that reported from other parts of the world; these mutations predict phenotypic resistance to clarithromycin.

  13. Genetic Relatedness of Salmonella Serovars Isolated from Catfish (Clarias gariepinus) and Tilapia (Tilapia mossambica) Obtained from Wet Markets and Ponds in Penang, Malaysia.

    PubMed

    Budiati, Titik; Rusul, Gulam; Wan-Abdullah, Wan Nadiah; Chuah, Li-Oon; Ahmad, Rosma; Thong, Kwai Lin

    2016-04-01

    A total of 43 Salmonella enterica isolates belonging to different serovars (Salmonella Albany, Salmonella Agona, Salmonella Corvallis, Salmonella Stanley, Salmonella Typhimurium, Salmonella Mikawasima, and Salmonella Bovismorbificans) were isolated from catfish (Clarias gariepinus) and tilapia (Tilapia mossambica) obtained from nine wet markets and eight ponds in Penang, Malaysia. Thirteen, 19, and 11 isolates were isolated from 9 of 32 catfish, 14 of 32 tilapia, and 11 of 44 water samples, respectively. Fish reared in ponds were fed chicken offal, spoiled eggs, and commercial fish feed. The genetic relatedness of these Salmonella isolates was determined by random amplified polymorphic DNA PCR (RAPD-PCR) using primer OPC2, repetitive extragenic palindromic PCR (REP-PCR), and pulsed-field gel electrophoresis (PFGE). Composite analysis of the RAPD-PCR, REP-PCR, and PFGE results showed that the Salmonella serovars could be differentiated into six clusters and 15 singletons. RAPD-PCR differentiated the Salmonella isolates into 11 clusters and 10 singletons, while REP-PCR differentiated them into 4 clusters and 1 singleton. PFGE differentiated the Salmonella isolates into seven clusters and seven singletons. The close genetic relationship of Salmonella isolates from catfish or tilapia obtained from different ponds, irrespective of the type of feed given, may be caused by several factors, such as the quality of the water, density of fish, and size of ponds.

  14. Isolation and Characterization of Mobile Genetic Elements from Microbial Assemblages Obtained from the Field Research Center Site

    SciTech Connect

    Patricia Sobecky; Cassie Hodges; Kerri Lafferty; Mike Humphreys; Melanie Raimondo; Kristin Tuttle; Tamar Barkay

    2004-03-17

    Considerable knowledge has been gained from the intensive study of a relatively limited group of bacterial plasmids. Recent efforts have begun to focus on the characterization of, at the molecular level, plasmid populations and associated mobile genetic elements (e.g., transposons, integrons) occurring in a wider range of aquatic and terrestrial habitats. Surprisingly, however, little information is available regarding the incidence and distribution of mobile genetic elements extant in contaminated subsurface environments. Such studies will provide greater knowledge on the ecology of plasmids and their contributions to the genetic plasticity (and adaptation) of naturally occurring subsurface microbial communities. We requested soil cores from the DOE NABIR Field Research Center (FRC) located on the Oak Ridge Reservation. The cores, received in February 2003, were sampled from four areas on the Oak Ridge Site: Area 1, Area 2, Area 3 (representing contaminated subsurface locales) and the background reference sites. The average core length (24 in) was subdivided into three profiles and soil pH and moisture content were determined. Uranium concentration was also determined in bulk samples. Replicate aliquots were fixed for total cell counts and for bacterial isolation. Four different isolation media were used to culture aerobic and facultative microbes from these four study areas. Colony forming units ranged from a minimum of 100 per gram soil to a maximum of 10,000 irrespective of media composition used. The vast majority of cultured subsurface isolates were gram-positive isolates and plasmid characterization was conducted per methods routinely used in the Sobecky laboratory. The percentage of plasmid incidence ranged from 10% to 60% of all isolates tested. This frequency appears to be somewhat higher than the incidence of plasmids we have observed in other habitats and we are increasing the number of isolates screened to confirm this observation. We are also

  15. cagA and vacA in strains of Helicobacter pylori from ulcer and non-ulcerative dyspepsia patients

    PubMed Central

    Faundez, Gustavo; Troncoso, Miriam; Figueroa, Guillermo

    2002-01-01

    Background The cytotoxin associated gene A (cagA), and the vacuolating cytotoxin gene A (vacA) of Helicobacter pylori have been associated to phenotypic characteristics of virulence. The objectives of this study were to detect the presence of cagA and to characterize the allelic variants of vacA in 63 strains of H. pylori isolated from colonized individuals with different clinical outcomes. Methods 38 strains were isolated from patients with non-ulcerative dyspepsia (NUD) and 25 were isolated from colonized individuals with peptic ulcers. The genotypic characterization was carried out utilizing PCR methodology. The presence of the cagA gene was detected using two set of primers from the middle conservative region of the cagA, and primers for the signal and middle region were used for the genotyping of vacA Results The presence of cagA showed similar rates in strains from peptic ulcers (60%) and NUD patients (55%). Also similar was the prevalence of the allelic form s1 of vacA between the strains obtained from ulcers or NUD patients. However, the combination cagA+/vacA s1m1 was found more frequently among the H. pylori strains from peptic ulcer patients (52%) than among strains isolated from NUD patients (26%), this difference was statistically significant (p = 0.035). Conclusions The presence of either cagA or the allelic variant s1 vacA alone do not have a predictive value as as a risk markers of severe gastric pathologies in the Chilean population. However, being infected by a H. pylori strain with the genotype cagA+/vacA s1m1 may be associated to an increased risk of acquiring a peptic ulcer disease. PMID:12223115

  16. Emergence of Tetracycline Resistance in Helicobacter pylori: Multiple Mutational Changes in 16S Ribosomal DNA and Other Genetic Loci

    PubMed Central

    Dailidiene, Daiva; Bertoli, M. Teresita; Miciuleviciene, Jolanta; Mukhopadhyay, Asish K.; Dailide, Giedrius; Pascasio, Mario Alberto; Kupcinskas, Limas; Berg, Douglas E.

    2002-01-01

    Tetracycline is useful in combination therapies against the gastric pathogen Helicobacter pylori. We found 6 tetracycline-resistant (Tetr) strains among 159 clinical isolates (from El Salvador, Lithuania, and India) and obtained the following four results: (i) 5 of 6 Tetr isolates contained one or two nucleotide substitutions in one part of the primary tetracycline binding site in 16S rRNA (AGA965-967 [Escherichia coli coordinates] changed to gGA, AGc, guA, or gGc [lowercase letters are used to represent the base changes]), whereas the sixth (isolate Ind75) retained AGA965-967; (ii) PCR products containing mutant 16S ribosomal DNA (rDNA) alleles transformed recipient strains to Tetr phenotypes, but transformants containing alleles with single substitutions (gGA and AGc) were less resistant than their Tetr parents; (iii) each of 10 Tetr mutants of reference strain 26695 (in which mutations were induced with metronidazole, a mutagenic anti-H. pylori agent) contained the normal AGA965-967 sequence; and (iv) transformant derivatives of Ind75 and of one of the Tetr 26695 mutants that had acquired mutant rDNA alleles were resistant to tetracycline at levels higher than those to which either parent strain was resistant. Thus, tetracycline resistance in H. pylori results from an accumulation of changes that may affect tetracycline-ribosome affinity and/or other functions (perhaps porins or efflux pumps). We suggest that the rarity of tetracycline resistance among clinical isolates reflects this need for multiple mutations and perhaps also the deleterious effects of such mutations on fitness. Formally equivalent mutations with small but additive effects are postulated to contribute importantly to traits such as host specificity and virulence and to H. pylori's great genetic diversity. PMID:12435699

  17. ESBL-producing Escherichia coli and Klebsiella pneumoniae: The most prevalent clinical isolates obtained between 2005 and 2012 in Mexico.

    PubMed

    Barrios, Humberto; Garza-Ramos, Ulises; Mejia-Miranda, Ilse; Reyna-Flores, Fernando; Sánchez-Pérez, Alejandro; Mosqueda-García, Dalila; Silva-Sanchez, Jesus

    2017-07-21

    To identify the prevalence of ESBL genes in the principal group of Enterobacteriaceae causing nosocomial infections and to identify the phylogenetic group in Escherichia coli isolates. There were collected 1084 ESBL-producing Enterobacteriaceae isolates during 2005-2012 from adult patients from 14 hospitals and corresponding to eight states and five regions (SE, S, N, W and NW) in Mexico. The CTX-M-(CTX-M-1 group), SHV-, TLA- and GES-type ESBLs genes were screened. The respective alleles were determined in the most of ESBLs genes. In E. coli isolates selected were used to identify the phylogenetic group. The ESBL-producing Escherichia coli and Klebsiella pneumoniae corresponded the most prevalent clinical isolates. CTX-M-type ESBLs genes were the most common, followed by SHV-type, GES-type and the ESBLs TLA-1 gene. The allelic frequency showed to CTX-M-15 ESBL the most prevalent, followed by the SHV-12, SHV-5 and GES-1, GES-19 in the GES family. Among ESBL-producing E. coli isolates the phylogenetic groups A and D were the most common ones. The present study showed an epidemiological change in terms of bacterial species, placing E. coli as the most frequently isolated bacteria among ESBL-producing Enterobacteriaceae in Mexico, followed by K. pneumoniae. This frequency is accompanied by a high frequency of ESBL CTX-M-15. Copyright © 2017 International Society for Chemotherapy of Infection and Cancer. Published by Elsevier Ltd. All rights reserved.

  18. Uncertainty and Sensitivity Analysis Results Obtained in the 1996 Performance Assessment for the Waste Isolation Pilot Plant

    SciTech Connect

    Bean, J.E.; Berglund, J.W.; Davis, F.J.; Economy, K.; Garner, J.W.; Helton, J.C.; Johnson, J.D.; MacKinnon, R.J.; Miller, J.; O'Brien, D.G.; Ramsey, J.L.; Schreiber, J.D.; Shinta, A.; Smith, L.N.; Stockman, C.; Stoelzel, D.M.; Vaughn, P.

    1998-09-01

    The Waste Isolation Pilot Plant (WPP) is located in southeastern New Mexico and is being developed by the U.S. Department of Energy (DOE) for the geologic (deep underground) disposal of transuranic (TRU) waste. A detailed performance assessment (PA) for the WIPP was carried out in 1996 and supports an application by the DOE to the U.S. Environmental Protection Agency (EPA) for the certification of the WIPP for the disposal of TRU waste. The 1996 WIPP PA uses a computational structure that maintains a separation between stochastic (i.e., aleatory) and subjective (i.e., epistemic) uncertainty, with stochastic uncertainty arising from the many possible disruptions that could occur over the 10,000 yr regulatory period that applies to the WIPP and subjective uncertainty arising from the imprecision with which many of the quantities required in the PA are known. Important parts of this structure are (1) the use of Latin hypercube sampling to incorporate the effects of subjective uncertainty, (2) the use of Monte Carlo (i.e., random) sampling to incorporate the effects of stochastic uncertainty, and (3) the efficient use of the necessarily limited number of mechanistic calculations that can be performed to support the analysis. The use of Latin hypercube sampling generates a mapping from imprecisely known analysis inputs to analysis outcomes of interest that provides both a display of the uncertainty in analysis outcomes (i.e., uncertainty analysis) and a basis for investigating the effects of individual inputs on these outcomes (i.e., sensitivity analysis). The sensitivity analysis procedures used in the PA include examination of scatterplots, stepwise regression analysis, and partial correlation analysis. Uncertainty and sensitivity analysis results obtained as part of the 1996 WIPP PA are presented and discussed. Specific topics considered include two phase flow in the vicinity of the repository, radionuclide release from the repository, fluid flow and radionuclide

  19. Improved method for extraction and detection of Helicobacter pylori DNA in formalin-fixed paraffin embedded gastric biopsies using laser micro-dissection

    PubMed Central

    Loayza, María Fernanda; Villavicencio, Fernando Xavier; Santander, Stephanie Carolina; Baldeón, Manuel; Ponce, Lourdes Karina; Salvador, Iván; Vivar Díaz, Nicolás

    2014-01-01

    To assess the molecular events exerted by Helicobacter pylori interacting directly with gastric epithelial cells, an improved procedure for microbial DNA isolation from stained hematoxilin-eosin gastric biopsies was developed based on laser micro-dissection (LM) [1]. Few articles have described the use of LM to select and detect H. pylori genome from formalin-fixed paraffin embedded gastric tissue [2]. To improve the yield and quality of DNA isolated from H. pylori contacting intestinal epithelial cells, the following conditions were established after modification of the QIAamp DNA Micro kit. • Use of at least 25 cut sections of 10–20 μm of diameter and 3 μm thick with more than 10 bacteria in each cut. • Lysis with 30 μL of tissue lysis buffer and 20 μL of proteinase K (PK) with the tube in an upside-down position. • The use of thin purification columns with 35 μL of elution buffer. The mean of DNA concentration obtained from 25 LM cut sections was 1.94± 0 .16 ng/μL, and it was efficiently amplified with qPCR in a Bio Rad iCycler instrument. The LM can improve the sample selection and DNA extraction for molecular analysis of H. pylori associated with human gastric epithelium. PMID:26150965

  20. Determinants of Helicobacter pylori seroprevalence in Mexican adolescents.

    PubMed

    Camargo, M Constanza; Constanza, Camargo M; Lazcano-Ponce, Eduardo; Eduardo, Lazcano-Ponce; Torres, Javier; Javier, Torres; Velasco-Mondragon, Eduardo; Eduardo, Velasco-Mondragón; Quiterio, Manuel; Manuel, Quiterio; Correa, Pelayo; Pelayo, Correa

    2004-04-01

    Helicobacter pylori infection is one of the most common human infections and is considered to play an etiologic role in several gastroduodenal diseases. In this study we determined the H. pylori seroprevalence among adolescents in Morelos, Mexico, and explored the association between seroprevalence and socioeconomic, dietary and lifestyle variables. A cross-sectional study was conducted in 5861 Mexican subjects aged 11-21 years. H. pylori infection was determined by an enzyme-linked immunosorbent assay previously validated in Mexico. A self-administered questionnaire was used to collect information on sociodemographic factors, housing, living conditions and food consumption. Multivariate logistic regression methods were used to obtain odds ratios and 95% confidence intervals. The overall H. pylori seroprevalence was 47.6%; 40.6% in preadolescents (11-14 years), 48.6% in adolescents (15-17 years), and 59.8% in young adults (18-24 years). A positive association was found between age and H. pylori seroprevalence. Inverse associations were found for availability of drinking water, sewerage, and home appliances at the time of the subject's birth, a proxy variable of socioeconomic status. Intake of milk products and total fats was positively associated with infection. This large seroprevalence study showed that H. pylori infection is frequent among adolescents in Mexico. An early acquisition of infection is indirectly suggested. Some variables denoting low socioeconomic status were inversely associated with H. pylori seroprevalence. Associations with intake of milk products and total fats suggest new hypotheses in this field of research.

  1. Long-term sequelae of Helicobacter pylori gastritis.

    PubMed

    Kuipers, E J; Uyterlinde, A M; Peña, A S; Roosendaal, R; Pals, G; Nelis, G F; Festen, H P; Meuwissen, S G

    1995-06-17

    Chronic Helicobacter pylori gastritis has been put forward as a risk factor for development of gastric mucosal atrophy and gastric cancer. The purpose of our study was to investigate the long-term effects of H pylori gastritis on the gastric mucosa. We prospectively studied 49 subjects negative for H pylori and 58 positive subjects for a mean follow-up of 11.5 years (range 10-13 years). Serum samples were obtained at the initial and follow-up visits for determination of H pylori IgG antibodies. Gastroscopies with biopsy sampling were done in all patients at both visits. Biopsy specimens were used for assessment of H pylori infection and histology. Development of atrophic gastritis and intestinal metaplasia occurred in 2 (4%) uninfected and 16 (28%) infected subjects. Regression of atrophy was noted in 4 (7%) infected subjects. Development of atrophic gastritis and intestinal metaplasia was significantly associated with H pylori infection (p = 0.0014; odds ratio 9.0, 95% CI 1.9-41.3). The proportion of atrophic gastritis in the study population showed an annual increase of 1.15% (0.5-1.8%). We conclude that H pylori infection is a significant risk factor for development of atrophic gastritis and intestinal metaplasia. Our findings support strongly the causative role of this infection in gastric carcinogenesis.

  2. Anti-Helicobacter pylori xanthones of Garcinia fusca.

    PubMed

    Nontakham, Jannarin; Charoenram, Napaporn; Upamai, Wanchalerm; Taweechotipatr, Malai; Suksamrarn, Sunit

    2014-08-01

    A new geranylated xanthone derivative, fuscaxanthone I (1), along with nine xanthones (2-9 and 11), a biphenyl (10) and three biflavonoids (12-14) were isolated from the roots of Garcinia fusca Pierre. Compounds 8, 10 and 11-14 were reported from this plant species for the first time. Their structures were elucidated by spectroscopic analyses, including 1D- and 2D-NMR and MS. The isolated compounds were evaluated for antibacterial activity against Helicobacter pylori. Cowaxanthone (5) and fukugiside (14) exhibited stronger inhibitory activity against H. pylori DMST reference strain at MICs 4.6 and 10.8 μM, respectively, than that of the control metronidazole. Isojacareubin (8) displayed the most potent activity against H. pylori HP40 clinical isolate with MIC 23.9 μM, which was approximately two times greater than that of the standard drug amoxicillin.

  3. Presence of superantigen genes and antimicrobial resistance in Staphylococcus isolates obtained from the uteri of dairy cows with clinical endometritis.

    PubMed

    Zhao, J-L; Ding, Y-X; Zhao, H-X; He, X-L; Li, P-F; Li, Z-F; Guan, H; Guo, X

    2014-10-11

    Clinical endometritis is an important disease of dairy cattle and results in decreased reproductive performance. This disease is caused by contamination of the uterus with a broad spectrum of microorganisms after calving. In this study, staphylococcal isolates from the uterus of dairy cows with clinical endometritis were tested for their distribution of superantigen (SAg) genes and antimicrobial resistance. Between the 127 staphylococcal isolates collected in this study, 10 species were identified. The predominant strain identified was Staphylococcus aureus (n=53), followed by Staphylococcus saprophyticus (n=38) and Staphylococcus chromogenes (n=22). PCR analysis demonstrated that most isolates (63.0 per cent) harboured at least one SAg gene. The most commonly observed SAg gene and genotype was selj (38.6 per cent) and sec-selj-seln (24.0 per cent), respectively. Most isolates were resistant to penicillin (79.5 per cent), ampicillin (71.7 per cent), erythromycin (56.7 per cent), and tetracycline (52.0 per cent). PCR analysis demonstrated that the antimicrobial resistance determinants ermA, ermB, ermC, tetK, tetM and blaZ were detected in 0 per cent, 44.4 per cent, 51.4 per cent, 68.2 per cent, 13.6 per cent and 86.1 per cent of the erythromycin, tetracycline and β-lactam resistant isolates, respectively. There were 22 (17.3 per cent of all isolates) coagulase-negative staphylococci shown to be methicillin resistant. In the methicillin-resistant isolates, significant resistances to ampicillin, erythromycin and penicillin were observed (P<0.01). The results of this study demonstrate that staphylococci recovered from dairy cows with clinical endometritis contain an extensive and complex prevalence of SAg genes. Significant resistances to antibiotics were also seen, highlighting the need for the rational appliance of antibiotics in veterinary medicine.

  4. Association of CagPAI integrity with severeness of Helicobacter pylori infection in patients with gastritis.

    PubMed

    Ahmadzadeh, A; Ghalehnoei, H; Farzi, N; Yadegar, A; Alebouyeh, M; Aghdaei, H A; Molaei, M; Zali, M R; Pour Hossein Gholi, M A

    2015-12-01

    The Helicobacter pylori cag pathogenicity island (cagPAI) is involved in delivery of CagA effector protein and peptidoglycan into host cells and also in IL-8 induction in the human gastric tissue. Diversity of cagPAI may affect disease status and clinical outcome of the infected patients. Our study was aimed to investigate diversity of this island and its intactness in Iranian patients to investigate possible associations between cagPAI integrity and pathological changes of the infected tissue. Out of the 75 patients, H. pylori strains were obtained from 30 patients with severe active gastritis (SAG) (n=11), moderate chronic gastritis (CG) (n=14) and intestinal metaplasia/dysplasia (IM) (n=5). Intactness of the cagPAI was determined using 12 sets of primer pairs specific for functionally important loci of cagPAI by polymerase chain reaction (PCR). The cagPAI positive strains were significantly observed in patients with SAG (52.4%) in comparison to those presenting CG (33.3%) and IM (14.3%). In addition, the presence of intact cagPAI was 87.5% in H. pylori strains isolated from patients with SAG, which was higher than those obtained from patients with CG (12.5%) or IM (0%). A significant increase in the frequency of cagα-cagY and cagW-cagT segments, as exterior proteins of the CagPAI, was illustrated in strains from SAG patients compared with those from patients with CG. Overall, these results strongly proposed an association between the severity of histopathological changes and intactness of cagPAI in the gastric tissue of patients infected with H. pylori. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  5. Composition of the essential oil of two Nepeta species and in vitro evaluation of their activity against Helicobacter pylori.

    PubMed

    Kalpoutzakis, E; Aligiannis, N; Mentis, A; Mitaku, S; Charvala, C

    2001-12-01

    The chemical composition of the essential oils obtained from the aerial parts of Nepeta camphorata and Nepeta argolica ssp. dirphya were analysed by GC-MS. A total of 52 components were identified and significant differences (qualitative and quantitative) were observed between the two samples. 1,8-Cineol and two nepetalactones were found to be the major components of the oil of N. camphorata and N. argolica ssp. dirphya respectively. The in vitro activity, of the two oils and the three above mentioned isolated compounds, against 25 clinically isolated and commercial strains of Helicobacter pylori was investigated and some activity was found.

  6. Characterization of Clostridium perfringens isolates obtained from 2010 to 2012 from chickens with necrotic enteritis in Korea.

    PubMed

    Park, Ji Young; Kim, Sara; Oh, Jae Young; Kim, Hye Ryoung; Jang, Il; Lee, Hee Soo; Kwon, Yong Kuk

    2015-06-01

    Clostridium perfringens produces diverse virulent toxins that cause necrotic enteritis in poultry, resulting in a great negative impact on the poultry industry. To study the characteristics of C. perfringens in chickens, we isolated 88 strains from chickens (1 strain per flock) with necrotic enteritis. The isolated bacterial strains were screened for toxin type and antimicrobial susceptibility. Necropsy of 17 chickens that died from necrotic enteritis revealed that their intestines were dilated with inflammatory exudates and characterized by mucosal necrosis. All the isolated strains were identified as toxin type A using multiplex PCR for toxin typing. We found that the rate of netB-positive strains isolated from dead chickens was significantly higher (8 of 17) than the rate among healthy chickens (2 of 50). We performed antimicrobial susceptibility test with 20 selected antimicrobial agents using the disk diffusion test and found that 30 tested strains were completely resistant to 5 antibiotics and partially resistant to 6 antibiotics whereas all the strains were susceptible to 9 antimicrobial agents. Using pulsed-field gel electrophoresis analysis, the 17 strains were divided into 13 genetic clusters showing high genetic diversity. In conclusion, C. perfringens strains isolated from Korean poultry showed a high resistance to antimicrobial drugs and high genetic diversity, suggesting that continuous monitoring is essential to prevent outbreaks of necrotic enteritis in chickens. © 2015 Poultry Science Association Inc.

  7. Sequence of Reston Virus Isolate AZ-1435, an Ebolavirus Isolate Obtained during the 1989-1990 Reston Virus Epizootic in the United States.

    PubMed

    Cornish, Joseph P; Diaz, Larissa; Ricklefs, Stacy M; Kanakabandi, Kishore; Sword, Jennifer; Jahrling, Peter B; Kuhn, Jens H; Porcella, Stephen F; Johnson, Reed F

    2017-01-12

    Reston virus (RESTV) was discovered in 1989-1990 during three connected epizootics of highly lethal viral hemorrhagic fever among captive macaques in primate housing facilities in the United States and Philippines. Currently, only one RESTV isolate from that outbreak (named Pennsylvania) has been sequenced. Here, we report the sequence of a second isolate, Reston virus/M.fascicularis-tc/USA/1990/Philippines89-AZ1435.

  8. Sequence of Reston Virus Isolate AZ-1435, an Ebolavirus Isolate Obtained during the 1989–1990 Reston Virus Epizootic in the United States

    PubMed Central

    Cornish, Joseph P.; Diaz, Larissa; Ricklefs, Stacy M.; Kanakabandi, Kishore; Sword, Jennifer; Porcella, Stephen F.

    2017-01-01

    ABSTRACT Reston virus (RESTV) was discovered in 1989–1990 during three connected epizootics of highly lethal viral hemorrhagic fever among captive macaques in primate housing facilities in the United States and Philippines. Currently, only one RESTV isolate from that outbreak (named Pennsylvania) has been sequenced. Here, we report the sequence of a second isolate, Reston virus/M.fascicularis-tc/USA/1990/Philippines89-AZ1435. PMID:28082493

  9. Effect of treatment failure on the CagA EPIYA motif in Helicobacter pylori strains from Colombian subjects

    PubMed Central

    Bustamante-Rengifo, Javier Andres; Matta, Andres Jenuer; Pazos, Alvaro Jairo; Bravo, Luis Eduardo

    2017-01-01

    AIM To evaluate effect of treatment failure on cagA and vacA genotypes in Helicobacter pylori (H. pylori) isolates from Colombia. METHODS One hundred and seventy-six participants infected with H. pylori from Colombia were treated during 14 d with the triple-standard therapy. Six weeks later, eradication was evaluated by 13C-Urea breath test. Patients with treatment failure were subjected to endoscopy control; biopsies obtained were used for histopathology and culture. DNA from H. pylori isolates was amplified using primers specific for cagA and vacA genes. The phylogenetic relationships among isolates obtained before and after treatment were established by conglomerate analysis based on random amplified polymorphic DNA (RAPD) fingerprinting. RESULTS Treatment effectiveness was at 74.6%. Of the participants with treatment failure, 25 accepted subjected to a second endoscopy. Prevalence of post-treatment infection was 64% (16/25) and 40% (10/25) by histology and culture, respectively. Upon comparing the cagA and vacA genotypes found before and after therapy, multiple cagA genotypes (cagA-positive and cagA-negative) were found before treatment; in contrast, cagA-negative genotypes decreased after treatment. vacA s1m1 genotype was highly prevalent in patients before and after therapy. The 3’cagA region was successfully amplified in 95.5% (21/22) of the isolates obtained before and in 81.8% (18/22) of the isolates obtained after treatment. In the isolates obtained from patients with treatment failure, it was found that 72.7% (16/22) presented alterations in the number of EPIYA motifs, compared to isolates found before treatment. CONCLUSION Unsuccessful treatment limits colonization by low-virulence strains resulting in partial and selective eradication in mixed infections, and acts on the cagA-positive strains inducing genetic rearrangements in cagA variable region that produces a loss or gain of EPIYA repetitions. PMID:28373764

  10. Genetic Diversity of Clostridium sporogenes PA 3679 Isolates Obtained from Different Sources as Resolved by Pulsed-Field Gel Electrophoresis and High-Throughput Sequencing.

    PubMed

    Schill, Kristin M; Wang, Yun; Butler, Robert R; Pombert, Jean-François; Reddy, N Rukma; Skinner, Guy E; Larkin, John W

    2015-10-30

    Clostridium sporogenes PA 3679 is a nonpathogenic, nontoxic model organism for proteolytic Clostridium botulinum used in the validation of conventional thermal food processes due to its ability to produce highly heat-resistant endospores. Because of its public safety importance, the uncertain taxonomic classification and genetic diversity of PA 3679 are concerns. Therefore, isolates of C. sporogenes PA 3679 were obtained from various sources and characterized using pulsed-field gel electrophoresis (PFGE) and whole-genome sequencing. The phylogenetic relatedness and genetic variability were assessed based on 16S rRNA gene sequencing and whole-genome single nucleotide polymorphism (SNP) analysis. All C. sporogenes PA 3679 isolates were categorized into two clades (clade I containing ATCC 7955 NCA3679 isolates 1961-2, 1990, and 2007 and clade II containing PA 3679 isolates NFL, UW, FDA, and Campbell and ATCC 7955 NCA3679 isolate 1961-4). The 16S maximum likelihood (ML) tree clustered both clades within proteolytic C. botulinum strains, with clade I forming a distinct cluster with other C. sporogenes non-PA 3679 strains. SNP analysis revealed that clade I isolates were more similar to the genomic reference PA 3679 (NCTC8594) genome (GenBank accession number AGAH00000000.1) than clade II isolates were. The genomic reference C. sporogenes PA 3679 (NCTC8594) genome and clade I C. sporogenes isolates were genetically distinct from those obtained from other sources (University of Wisconsin, National Food Laboratory, U.S. Food and Drug Administration, and Campbell's Soup Company). Thermal destruction studies revealed that clade I isolates were more sensitive to high temperature than clade II isolates were. Considering the widespread use of C. sporogenes PA 3679 and its genetic information in numerous studies, the accurate identification and genetic characterization of C. sporogenes PA 3679 are of critical importance.

  11. Genetic Diversity of Clostridium sporogenes PA 3679 Isolates Obtained from Different Sources as Resolved by Pulsed-Field Gel Electrophoresis and High-Throughput Sequencing

    PubMed Central

    Wang, Yun; Butler, Robert R.; Reddy, N. Rukma; Skinner, Guy E.; Larkin, John W.

    2015-01-01

    Clostridium sporogenes PA 3679 is a nonpathogenic, nontoxic model organism for proteolytic Clostridium botulinum used in the validation of conventional thermal food processes due to its ability to produce highly heat-resistant endospores. Because of its public safety importance, the uncertain taxonomic classification and genetic diversity of PA 3679 are concerns. Therefore, isolates of C. sporogenes PA 3679 were obtained from various sources and characterized using pulsed-field gel electrophoresis (PFGE) and whole-genome sequencing. The phylogenetic relatedness and genetic variability were assessed based on 16S rRNA gene sequencing and whole-genome single nucleotide polymorphism (SNP) analysis. All C. sporogenes PA 3679 isolates were categorized into two clades (clade I containing ATCC 7955 NCA3679 isolates 1961-2, 1990, and 2007 and clade II containing PA 3679 isolates NFL, UW, FDA, and Campbell and ATCC 7955 NCA3679 isolate 1961-4). The 16S maximum likelihood (ML) tree clustered both clades within proteolytic C. botulinum strains, with clade I forming a distinct cluster with other C. sporogenes non-PA 3679 strains. SNP analysis revealed that clade I isolates were more similar to the genomic reference PA 3679 (NCTC8594) genome (GenBank accession number AGAH00000000.1) than clade II isolates were. The genomic reference C. sporogenes PA 3679 (NCTC8594) genome and clade I C. sporogenes isolates were genetically distinct from those obtained from other sources (University of Wisconsin, National Food Laboratory, U.S. Food and Drug Administration, and Campbell's Soup Company). Thermal destruction studies revealed that clade I isolates were more sensitive to high temperature than clade II isolates were. Considering the widespread use of C. sporogenes PA 3679 and its genetic information in numerous studies, the accurate identification and genetic characterization of C. sporogenes PA 3679 are of critical importance. PMID:26519392

  12. High Diversity of vacA and cagA Helicobacter pylori Genotypes in Patients with and without Gastric Cancer

    PubMed Central

    López-Vidal, Yolanda; Ponce-de-León, Sergio; Castillo-Rojas, Gonzalo; Barreto-Zúñiga, Rafael; Torre-Delgadillo, Aldo

    2008-01-01

    Background Helicobacter pylori is associated with chronic gastritis, peptic ulcers, and gastric cancer. The aim of this study was to assess the topographical distribution of H. pylori in the stomach as well as the vacA and cagA genotypes in patients with and without gastric cancer. Methodology/Principal Findings Three gastric biopsies, from predetermined regions, were evaluated in 16 patients with gastric cancer and 14 patients with dyspeptic symptoms. From cancer patients, additional biopsy specimens were obtained from tumor centers and margins; among these samples, the presence of H. pylori vacA and cagA genotypes was evaluated. Positive H. pylori was 38% and 26% in biopsies obtained from the gastric cancer and non-cancer groups, respectively (p = 0.008), and 36% in tumor sites. In cancer patients, we found a preferential distribution of H. pylori in the fundus and corpus, whereas, in the non-cancer group, the distribution was uniform (p = 0.003). A majority of the biopsies were simultaneously cagA gene-positive and -negative. The fundus and corpus demonstrated a higher positivity rate for the cagA gene in the non-cancer group (p = 0.036). A mixture of cagA gene sizes was also significantly more frequent in this group (p = 0.003). Ninety-two percent of all the subjects showed more than one vacA gene genotype; s1b and m1 vacA genotypes were predominantly found in the gastric cancer group. The highest vacA-genotype signal-sequence diversity was found in the corpus and 5 cm from tumor margins. Conclusion/Significance High H. pylori colonization diversity, along with the cagA gene, was found predominantly in the fundus and corpus of patients with gastric cancer. The genotype diversity observed across systematic whole-organ and tumor sampling was remarkable. We find that there is insufficient evidence to support the association of one isolate with a specific disease, due to the multistrain nature of H. pylori infection shown in this work. PMID:19050763

  13. High diversity of vacA and cagA Helicobacter pylori genotypes in patients with and without gastric cancer.

    PubMed

    López-Vidal, Yolanda; Ponce-de-León, Sergio; Castillo-Rojas, Gonzalo; Barreto-Zúñiga, Rafael; Torre-Delgadillo, Aldo

    2008-01-01

    Helicobacter pylori is associated with chronic gastritis, peptic ulcers, and gastric cancer. The aim of this study was to assess the topographical distribution of H. pylori in the stomach as well as the vacA and cagA genotypes in patients with and without gastric cancer. Three gastric biopsies, from predetermined regions, were evaluated in 16 patients with gastric cancer and 14 patients with dyspeptic symptoms. From cancer patients, additional biopsy specimens were obtained from tumor centers and margins; among these samples, the presence of H. pylori vacA and cagA genotypes was evaluated. Positive H. pylori was 38% and 26% in biopsies obtained from the gastric cancer and non-cancer groups, respectively (p = 0.008), and 36% in tumor sites. In cancer patients, we found a preferential distribution of H. pylori in the fundus and corpus, whereas, in the non-cancer group, the distribution was uniform (p = 0.003). A majority of the biopsies were simultaneously cagA gene-positive and -negative. The fundus and corpus demonstrated a higher positivity rate for the cagA gene in the non-cancer group (p = 0.036). A mixture of cagA gene sizes was also significantly more frequent in this group (p = 0.003). Ninety-two percent of all the subjects showed more than one vacA gene genotype; s1b and m1 vacA genotypes were predominantly found in the gastric cancer group. The highest vacA-genotype signal-sequence diversity was found in the corpus and 5 cm from tumor margins. High H. pylori colonization diversity, along with the cagA gene, was found predominantly in the fundus and corpus of patients with gastric cancer. The genotype diversity observed across systematic whole-organ and tumor sampling was remarkable. We find that there is insufficient evidence to support the association of one isolate with a specific disease, due to the multistrain nature of H. pylori infection shown in this work.

  14. Helicobacter pylori-related diseases.

    PubMed

    Gisbert, Javier P

    2016-09-01

    This article describes the main conclusions drawn from the presentations on Helicobacter pylori infection in Digestive Diseases Week, 2016. Despite the undeniable widespread reduction in the prevalence of this infection, infection rates continue to be high in developing countries. The prevalence of clarithromycin, metronidazole and quinolone resistance is markedly high in most countries and continues to rise. The management of H. pylori infection in patients with peptic ulcers still leaves much to be desired. Although H. pylori eradication reduces the incidence of gastric adenocarcinoma, it does not completely avoid its appearance. The new rapid stool antigen tests show promising results. The efficacy of standard triple therapy is clearly inadequate and continues to decline, and cannot therefore be recommended. Vonoprazan, when associated with 2 antibiotics, is more effective than traditional proton pump inhibitors, especially in clarithromycin-resistant patients. Non-bismuth quadruple (concomitant) therapy achieves eradication rates of around 90% and has a good safety profile. Concomitant therapy is more effective and simpler than sequential therapy. Although some probiotics can increase the efficacy and tolerability of triple therapy, the utility of its association with quadruple concomitant therapy has not been established. If a first treatment with clarithromycin fails, both bismuth-containing quadruple therapy and levofloxacin-containing triple therapy achieve good-but still suboptimal-results. The combination of bismuth and levofloxacin in the same regimen increases the efficacy of rescue therapy. The management of H. pylori infection by European gastroenterologists is widely heterogeneous and the eradication rates achieved by them are generally unacceptable. In Spain, the highest first-line eradication rate is obtained with quadruple concomitant therapy in 14-day regimens and with double doses of proton pump inhibitors; in second-line therapy, the use of

  15. A study of recombinant protective H. pylori antigens

    PubMed Central

    Jiang, Zheng; Tao, Xiao-Hong; Huang, Ai-Long; Wang, Pi-Long

    2002-01-01

    AIM: To construct a recombinant vector which can express Mr26000 outer membrane protein (OMP) from Helicobacter pylori (H. pylori), and to obtain the vaccine protecting against H. pylori infection and a diagnostic reagent kit quickly detecting H. pylori infection. METHODS: The gene encoding the structural Mr26000 outer membrane protein of H. pylori was amplified from H. pylori chromosomal DNA by PCR, and inserted in the prokaryotic expression vector pET32a(+), which was transformed into the Top10 E. coli strain. Recombinant vector was selected, identified and transformed into BL-21(DE3) E. coli strain. The recombinant fusion proteins were expressed. The antigenicity of recombinant protein was studied by ELISA or immunoblotting and immunized Balb/c mice. RESULTS: The gene of Mr26000 OMP was amplified to be 594 base pairs, 1.1% of the cloned genes was mutated and 1.51% of amino acid residues was changed, but there was homogeneity between them. The recombinant fusion protein encoded objective polypeptides of 198 amino acid residues, corresponding to calculated molecular masses of Mr26000. The level of soluble expression products was about 38.96% of the total cell protein. After purification by Ni-NTA agarose resin columniation, the purity of objective protein became about 90%. The ELISA results showed that recombinant fusion protein could be recognized by patient serum infected with H. pylori and rabbit serum immunized with the recombinant protein. Furthermore, Balb/c mice immunized with the recombinant protein were protected against H. pylori infection. CONCLUSION: Mr26000 OMP may be a candidate vaccine preventing H. pylori infection. PMID:11925614

  16. Ancestral European roots of Helicobacter pylori in India

    PubMed Central

    Devi, S Manjulata; Ahmed, Irshad; Francalacci, Paolo; Hussain, M Abid; Akhter, Yusuf; Alvi, Ayesha; Sechi, Leonardo A; Mégraud, Francis; Ahmed, Niyaz

    2007-01-01

    Background The human gastric pathogen Helicobacter pylori is co-evolved with its host and therefore, origins and expansion of multiple populations and sub populations of H. pylori mirror ancient human migrations. Ancestral origins of H. pylori in the vast Indian subcontinent are debatable. It is not clear how different waves of human migrations in South Asia shaped the population structure of H. pylori. We tried to address these issues through mapping genetic origins of present day H. pylori in India and their genomic comparison with hundreds of isolates from different geographic regions. Results We attempted to dissect genetic identity of strains by multilocus sequence typing (MLST) of the 7 housekeeping genes (atpA, efp, ureI, ppa, mutY, trpC, yphC) and phylogeographic analysis of haplotypes using MEGA and NETWORK software while incorporating DNA sequences and genotyping data of whole cag pathogenicity-islands (cagPAI). The distribution of cagPAI genes within these strains was analyzed by using PCR and the geographic type of cagA phosphorylation motif EPIYA was determined by gene sequencing. All the isolates analyzed revealed European ancestry and belonged to H. pylori sub-population, hpEurope. The cagPAI harbored by Indian strains revealed European features upon PCR based analysis and whole PAI sequencing. Conclusion These observations suggest that H. pylori strains in India share ancestral origins with their European counterparts. Further, non-existence of other sub-populations such as hpAfrica and hpEastAsia, at least in our collection of isolates, suggest that the hpEurope strains enjoyed a special fitness advantage in Indian stomachs to out-compete any endogenous strains. These results also might support hypotheses related to gene flow in India through Indo-Aryans and arrival of Neolithic practices and languages from the Fertile Crescent. PMID:17584914

  17. Ancestral European roots of Helicobacter pylori in India.

    PubMed

    Devi, S Manjulata; Ahmed, Irshad; Francalacci, Paolo; Hussain, M Abid; Akhter, Yusuf; Alvi, Ayesha; Sechi, Leonardo A; Mégraud, Francis; Ahmed, Niyaz

    2007-06-20

    The human gastric pathogen Helicobacter pylori is co-evolved with its host and therefore, origins and expansion of multiple populations and sub populations of H. pylori mirror ancient human migrations. Ancestral origins of H. pylori in the vast Indian subcontinent are debatable. It is not clear how different waves of human migrations in South Asia shaped the population structure of H. pylori. We tried to address these issues through mapping genetic origins of present day H. pylori in India and their genomic comparison with hundreds of isolates from different geographic regions. We attempted to dissect genetic identity of strains by multilocus sequence typing (MLST) of the 7 housekeeping genes (atpA, efp, ureI, ppa, mutY, trpC, yphC) and phylogeographic analysis of haplotypes using MEGA and NETWORK software while incorporating DNA sequences and genotyping data of whole cag pathogenicity-islands (cagPAI). The distribution of cagPAI genes within these strains was analyzed by using PCR and the geographic type of cagA phosphorylation motif EPIYA was determined by gene sequencing. All the isolates analyzed revealed European ancestry and belonged to H. pylori sub-population, hpEurope. The cagPAI harbored by Indian strains revealed European features upon PCR based analysis and whole PAI sequencing. These observations suggest that H. pylori strains in India share ancestral origins with their European counterparts. Further, non-existence of other sub-populations such as hpAfrica and hpEastAsia, at least in our collection of isolates, suggest that the hpEurope strains enjoyed a special fitness advantage in Indian stomachs to out-compete any endogenous strains. These results also might support hypotheses related to gene flow in India through Indo-Aryans and arrival of Neolithic practices and languages from the Fertile Crescent.

  18. Complete Genome Sequence of a Multidrug-Resistant Acinetobacter baumannii Isolate Obtained from a Mexican Hospital (Sequence Type 422)

    PubMed Central

    Castro-Jaimes, Semiramis; Salgado-Camargo, Abraham David; Graña-Miraglia, Lucía; Lozano, Luis; Bocanegra-Ibarias, Paola; Volkow-Fernández, Patricia; Silva-Sanchez, Jesus; Castillo-Ramírez, Santiago

    2016-01-01

    Acinetobacter baumannii has emerged as a dangerous nosocomial pathogen, particularly for severely ill patients in intensive care units and patients with hematologic malignancies. Here, we present the complete genome sequence of a multidrug-resistant A. baumannii isolate, recovered from a Mexican hospital and classified as sequence type 422 according to the multilocus sequence typing Pasteur scheme. PMID:27340065

  19. Draft Genome Sequences of Two Clinical Isolates of Burkholderia mallei Obtained from Nasal Swabs of Glanderous Equines in India

    PubMed Central

    Malik, Praveen; Saini, Sheetal; Khurana, Sandip K.; Elschner, Mandy C.; Mertens, Katja; Barth, Stefanie A.; Tripathi, Bhupendra N.; Singh, Raj K.

    2017-01-01

    ABSTRACT Burkholderia mallei is a Gram-negative coccobacillus which causes glanders—a fatal disease of equines that may occasionally be transmitted to humans. Several cases of outbreaks have been reported from India since 2006. This paper presents draft genome sequences of two B. mallei strains isolated from equines affected by glanders in India. PMID:28385832

  20. Genetic diversity of Streptococcus suis isolated from three pig farms of China obtained by acquiring antibiotic resistance genes.

    PubMed

    Huang, Jinhu; Shang, Kexin; Kashif, Jam; Wang, Liping

    2015-05-01

    Acquiring antibiotic resistance genes may change an organism's genetic characteristics and the effect of antibiotics, resulting in a rapid transmission of microbial pathogens. The objectives of this experiment were to identify the features of Streptococcus suis (S. suis) isolated from three pig farms in China which are geographically isolated. Among the isolates, 56.52% were sequence type 7 (ST7), followed by ST1 (26.09%), indicating that ST7 prevails in China, as revealed by multi-locus sequence typing (MLST). Statistical analysis indicated an association between geography, sequence types and antibiotic resistance genotypes. 66.67% of the isolates in Sichuan province presented a (ermB(-) + mefA(-) + tetO(-) + tetM(-)) + ST7 type. The tetM(+) +ST7 type was the most prevalent in Jiangsu province, whereas the strains from Hebei province had a phenotype ermB(+) +tetO(+) +ST1 (63.64%). Pulsed-field gel electrophoresis (PGFE) pattern A2 with 100% similarity reflected the clonal dissemination between Sichuan and Jiangsu provinces. Strains carrying or not carrying antibiotic resistance genes presented different PFGE patterns in Hebei province. ST7 is widespread in many regions of China and a clonal dissemination occurred between Sichuan and Jiangsu provinces in diseased pigs. However, ST1 strains with macrolide and tetracycline resistance (ermB(+) +tetO(+) +ST1) isolated from a farm in Hebei province demonstrated that the genetic diversity was contributed by horizontal acquiring of ermB and tetO carrying elements. © 2014 Society of Chemical Industry.

  1. Involvement of Aquaporin 3 in Helicobacter pylori-Related Gastric Diseases

    PubMed Central

    Chen, Jia; Wang, Tao; Zhang, Guoxin; Shen, Lizong

    2012-01-01

    Background Gastric cancer is one of the most common and lethal malignant cancers worldwide, and numerous epidemiological studies have demonstrated that Helicobacter pylori (H. pylori) infection plays a key role in the development of gastric carcinomas. Our previous studies showed that aquaporin 3 (AQP3) is overexpressed in gastric carcinoma and promotes the migration and proliferation of human gastric carcinoma cells, suggesting that AQP3 may be a potentially important determinant of gastric carcinoma. However, the role of AQP3 in H. pylori carcinogenesis is unknown. Methods The AQP3 protein and H. pylori were detected in human gastric tissues by immunohistochemistry and modified Giemsa staining respectively. AQP3 knockdown was obtained by small interfering (si) RNA. Western blot assays and RT-PCR were used to evaluate the change of AQP3 in the human gastric cancer AGS and SGC7901 cell lines after co-culture with H. pylori. Sprague Dawley rats were orally inoculated with H. pylori to establish a rat model colonized by H. pylori. Results The present study found that AQP3 expression correlated with H. pylori infection status in gastric cancer tissues and corresponding normal mucosa, and H. pylori co-culture upregulated AQP3 expression in human gastric adenocarcinoma cells in vitro via the extracellular signal-regulated kinase signaling pathway. H. pylori infection also increased AQP3 expression in gastric mucosa colonized by H. pylori in a Sprague Dawley rat model. Conclusions These findings provide further information to understand the mechanism of H. pylori carcinogenesis and a potential strategy for the treatment of H. pylori-associated gastric carcinoma. PMID:23152856

  2. Bactericidal and anti-adhesive properties of culinary and medicinal plants against Helicobacter pylori.

    PubMed

    O'Mahony, Rachel; Al-Khtheeri, Huda; Weerasekera, Deepaka; Fernando, Neluka; Vaira, Dino; Holton, John; Basset, Christelle

    2005-12-21

    To investigate the bactericidal and anti-adhesive properties of 25 plants against Helicobacter pylori (H. pylori). Twenty-five plants were boiled in water to produce aqueous extracts that simulate the effect of cooking. The bactericidal activity of the extracts was assessed by a standard kill-curve with seven strains of H. pylori. The anti-adhesive property was assessed by the inhibition of binding of four strains of FITC-labeled H. pylori to stomach sections. Of all the plants tested, eight plants, including Bengal quince, nightshade, garlic, dill, black pepper, coriander, fenugreek and black tea, were found to have no bactericidal effect on any of the isolates. Columbo weed, long pepper, parsley, tarragon, nutmeg, yellow-berried nightshade, threadstem carpetweed, sage and cinnamon had bactericidal activities against H. pylori, but total inhibition of growth was not achieved in this study. Among the plants that killed H. pylori, turmeric was the most efficient, followed by cumin, ginger, chilli, borage, black caraway, oregano and liquorice. Moreover, extracts of turmeric, borage and parsley were able to inhibit the adhesion of H. pylori strains to the stomach sections. Several plants that were tested in our study had bactericidal and/or anti-adhesive effects on H. pylori. Ingestion of the plants with anti-adhesive properties could therefore provide a potent alternative therapy for H. pylori infection, which overcomes the problem of resistance associated with current antibiotic treatment.

  3. Bactericidal and anti-adhesive properties of culinary and medicinal plants against Helicobacter pylori

    PubMed Central

    O’Mahony, Rachel; Al-Khtheeri, Huda; Weerasekera, Deepaka; Fernando, Neluka; Vaira, Dino; Holton, John; Basset, Christelle

    2005-01-01

    AIM: To investigate the bactericidal and anti-adhesive properties of 25 plants against Helicobacter pylori (H pylori). METHODS: Twenty-five plants were boiled in water to produce aqueous extracts that simulate the effect of cooking. The bactericidal activity of the extracts was assessed by a standard kill-curve with seven strains of H pylori. The anti-adhesive property was assessed by the inhibition of binding of four strains of FITC-labeled H pylori to stomach sections. RESULTS: Of all the plants tested, eight plants, including Bengal quince, nightshade, garlic, dill, black pepper, coriander, fenugreek and black tea, were found to have no bactericidal effect on any of the isolates. Columbo weed, long pepper, parsley, tarragon, nutmeg, yellow-berried nightshade, threadstem carpetweed, sage and cinnamon had bactericidal activities against H pylori, but total inhibition of growth was not achieved in this study. Among the plants that killed H pylori, turmeric was the most efficient, followed by cumin, ginger, chilli, borage, black caraway, oregano and liquorice. Moreover, extracts of turmeric, borage and parsley were able to inhibit the adhesion of H pylori strains to the stomach sections. CONCLUSION: Several plants that were tested in our study had bactericidal and/or anti-adhesive effects on H pylori. Ingestion of the plants with anti-adhesive properties could therefore provide a potent alternative therapy for H pylori infection, which overcomes the problem of resistance associated with current antibiotic treatment. PMID:16437723

  4. High prevalence of Helicobacter pylori in saliva demonstrated by a novel PCR assay.

    PubMed Central

    Li, C; Musich, P R; Ha, T; Ferguson, D A; Patel, N R; Chi, D S; Thomas, E

    1995-01-01

    AIMS--To investigate the prevalence of Helicobacter pylori in the saliva of patients infected with this bacterium. METHODS--A novel polymerase chain reaction (PCR) assay was developed to detect H pylori in saliva and gastric biopsy specimens from patients undergoing endoscopy. RESULTS--Our PCR assay amplified a 417 base pair fragment of DNA from all 21 DNAs derived from H pylori clinical isolates but did not amplify DNA from 23 non-H pylori strains. Sixty three frozen gastric biopsy and 56 saliva specimens were tested. H pylori specific DNA was detected by PCR in all 39 culture positive biopsy specimens and was also identified from another seven biopsy specimens which were negative by culture but positive by histology. H pylori specific DNA was identified by PCR in saliva specimens from 30 (75%) of 40 patients with H pylori infection demonstrated by culture or histological examination, or both, and in three patients without H pylori infection in the stomach. CONCLUSION--The results indicate that the oral cavity harbours H pylori and may be the source of infection and transmission. Images PMID:7560176

  5. Detection of Helicobacter pylori (H.pylori) DNA in digestive systems from cadavers by real-time PCR.

    PubMed

    Nagasawa, Sayaka; Azuma, Takeshi; Motani, Hisako; Sato, Yayoi; Hayakawa, Mutsumi; Yajima, Daisuke; Kobayashi, Kazuhiro; Ootsuka, Katsura; Iwase, Hirotaro

    2009-04-01

    It is thought that there is a close relationship between regionality and DNA polymorphism of H.pylori. The application of H.pylori DNA to estimate the origin of unidentified cadavers may be possible. Previously, we detected H.pylori DNA in five stomach lesions by PCR in 50% of 100 cadavers in forensic autopsies. Furthermore, to see the localization of H.pylori in the digestive system, we tried to assay H.pylori DNA by real-time PCR. Mucous membranes at 14 points of digestive systems (5 points of the stomach, 1 point of the duodenum, 5 points of the small intestine, 3 points of the large intestine) were obtained from three cadavers whose stools were H.pylori-positive by an ImmunoCardST!HpSA detection kit. Genomic DNA was extracted using a DNA extraction kit. The 23Sr-DNA region was PCR-amplified (320 bp) by a TOYOBO Kit and the same region was assayed by real-time PCR using a Taqman probe. The PCR products were detected in 5 points of the stomach and 1 point of the duodenum in each sample. The more peripheral the intestine lesion was the weaker the band became. The quantitative PCR showed that there were more PCR products in 5 points of the stomach and 1 point of the duodenum than in the other tissues. H.pylori DNA was detected not only in the stomach but also in the duodenum and small intestine. There was a difference in the amount of H.pylori DNA detected in each organ. Further study is required for immunohistochemical staining, and to determine the relationship between a persons natural state and the H.pylori DNA polymorphism (which codes for CagA).

  6. Association of Helicobacter pylori cagA Gene with Gastric Cancer and Peptic Ulcer in Saudi Patients.

    PubMed

    Saber, Taisir; Ghonaim, Mabrouk M; Yousef, Amany R; Khalifa, Amany; Al Qurashi, Hesham; Shaqhan, Mohammad; Samaha, Mohammad

    2015-07-01

    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.

  7. Vacuolating Cytotoxin and Variants in Atg16L1 that Disrupt Autophagy Promote Helicobacter pylori Infection in Humans

    PubMed Central

    Raju, D; Hussey, S; Ang, M; Terebiznik, M.R.; Sibony, M; Galindo-Mata, E; Gupta, V; Blanke, S.R.; Delgado, A; Romero-Gallo, J; Ramjeet, M; Mascarenhas, H; Peek, R.M.; Correa, P; Streutker, C; Hold, G; Kunstmann, E; Yoshimori, T; Silverberg, M. S.; Girardin, S.E.; Philpott, D.J.; El Omar, E; Jones, N.L.

    2012-01-01

    Background & Aims The Helicobacter pylori toxin vacuolating cytotoxin (VacA) promotes gastric colonization and its presence (VacA+) is associated with more-severe disease. The exact mechanisms by which VacA contributes to infection are unclear. We previously found that limited exposure to VacA induces autophagy of gastric cells, which eliminates the toxin; we investigated whether autophagy serves as a defense mechanism against H pylori infection. Methods We investigated the effect of VacA on autophagy in human gastric epithelial cells (AGS) and primary gastric cells from mice. Expression of p62, a marker of autophagy, was also assessed in gastric tissues from patients infected with toxigenic (VacA+) or nontoxigenic strains. We analyzed the effect of VacA on autophagy in peripheral blood monocytes obtained from subjects with different genotypes of ATG16L1, which regulates autophagy. We performed genotyping for ATG16L1 in two cohorts of infected and uninfected subjects. Results Prolonged exposure of AGS and mouse gastric cells to VacA disrupted induction of autophagy in response to the toxin, because the cells lacked cathepsin-D in autophagosomes. Loss of autophagy resulted in the accumulation of p62 and reactive oxygen species. Gastric biopsies samples from patients infected with VacA+, but not nontoxigenic strains of H pylori, had increased levels of p62. Peripheral blood monocytes isolated from individuals with polymorphisms in ATG16L1 that increase susceptibility to Crohn's disease had reduced induction of autophagy in response to VacA+ compared to cells from individuals that did not have these polymorphisms. The presence of the ATG16L1 Crohn’s disease risk variant increased susceptibility to H pylori infection in 2 separate cohorts. Conclusions Autophagy protects against infection with H pylori; the toxin VacA disrupts autophagy to promote infection, which could contribute to inflammation and eventual carcinogenesis. PMID:22333951

  8. Frequency of MCR-1-mediated colistin resistance among Escherichia coli clinical isolates obtained from patients in Canadian hospitals (CANWARD 2008-2015)

    PubMed Central

    Walkty, Andrew; Karlowsky, James A.; Adam, Heather J.; Lagacé-Wiens, Philippe; Baxter, Melanie; Mulvey, Michael R.; McCracken, Melissa; Poutanen, Susan M.; Roscoe, Diane; Zhanel, George G.

    2016-01-01

    Background: Colistin is often used as an antimicrobial of last resort for the treatment of infections caused by multidrug-resistant gram-negative bacilli. In 2015, plasmid-mediated colistin resistance in Escherichia coli due to MCR-1 was described. The purpose of this study was to evaluate the frequency of colistin resistance among E. coli clinical isolates obtained from patients in Canadian hospitals as part of the Canadian Ward Surveillance Study (CANWARD) and to determine how often the mcr-1 gene is detected among the colistin-resistant subset. Methods: From January 2008 to December 2015 (excluding 2011), 10 to 15 sentinel hospitals submitted consecutive clinical isolates (1 per patient per infection site) from blood (100-240), respiratory (100-150), urine (25-100) and wound (25-100) infections. We performed susceptibility testing using Clinical and Laboratory Standards Institute broth microdilution methods. Isolates that showed resistance to colistin as defined by European Committee on Antimicrobial Susceptibility Testing breakpoints (minimum inhibitory concentration ≥ 4 µg/mL) were evaluated for the mcr-1 gene by polymerase chain reaction. Results: In total, 5571 E. coli clinical isolates were obtained over the study years. Twelve isolates (0.2%) were resistant to colistin. The proportion of colistin-resistant isolates varied from 0.0% to 0.5% depending on the study year, and there was no clear trend toward increasing resistance over time. Typically the colistin-resistant isolates remained susceptible to antimicrobials from several other classes. Two colistin-resistant isolates (0.04%) were found to harbour the mcr-1 gene. Interpretation: The results suggest that colistin resistance among E. coli human clinical isolates, including resistance mediated by the mcr-1 gene, remains rare in Canada. PMID:28018876

  9. Identification of Helicobacter pylori by immunological dot blot method based on reaction of a species-specific monoclonal antibody with a surface-exposed protein.

    PubMed Central

    Bölin, I; Lönroth, H; Svennerholm, A M

    1995-01-01

    Monoclonal antibodies (MAbs) against membrane preparations of Helicobacter pylori were produced. One MAb was found to be specific for H. pylori, because it did not react with a number of other bacterial species, including Helicobacter felis and Campylobacter jejuni. This MAb reacted with a 30-kDa protein found in outer membrane preparations of H. pylori. The protein was also detected on the cell surface on intact bacteria when analyzed by immunoelectron microscopy. To facilitate the identification of H. pylori isolates after culturing of biopsies, an immunodot blot assay based on the reaction of this MAb was developed. This assay was found to be highly specific for H. pylori. Sixty-six clinical isolates typed as H. pylori by conventional biochemical tests were found to be positive, whereas no other bacterial species tested gave a positive result. By this method, reliable and rapid identification of H. pylori could be accomplished. PMID:7714196

  10. Genome Sequencing Reveals a Phage in Helicobacter pylori

    PubMed Central

    Lehours, Philippe; Vale, Filipa F.; Bjursell, Magnus K.; Melefors, Ojar; Advani, Reza; Glavas, Steve; Guegueniat, Julia; Gontier, Etienne; Lacomme, Sabrina; Alves Matos, António; Menard, Armelle; Mégraud, Francis; Engstrand, Lars; Andersson, Anders F.

    2011-01-01

    ABSTRACT Helicobacter pylori chronically infects the gastric mucosa in more than half of the human population; in a subset of this population, its presence is associated with development of severe disease, such as gastric cancer. Genomic analysis of several strains has revealed an extensive H. pylori pan-genome, likely to grow as more genomes are sampled. Here we describe the draft genome sequence (63 contigs; 26× mean coverage) of H. pylori strain B45, isolated from a patient with gastric mucosa-associated lymphoid tissue (MALT) lymphoma. The major finding was a 24.6-kb prophage integrated in the bacterial genome. The prophage shares most of its genes (22/27) with prophage region II of Helicobacter acinonychis strain Sheeba. After UV treatment of liquid cultures, circular DNA carrying the prophage integrase gene could be detected, and intracellular tailed phage-like particles were observed in H. pylori cells by transmission electron microscopy, indicating that phage production can be induced from the prophage. PCR amplification and sequencing of the integrase gene from 341 H. pylori strains from different geographic regions revealed a high prevalence of the prophage (21.4%). Phylogenetic reconstruction showed four distinct clusters in the integrase gene, three of which tended to be specific for geographic regions. Our study implies that phages may play important roles in the ecology and evolution of H. pylori. PMID:22086490

  11. Biofilm and Helicobacter pylori: from environment to human host.

    PubMed

    García, Apolinaria; Salas-Jara, María José; Herrera, Carolina; González, Carlos

    2014-05-21

    Helicobacter pylori (H. pylori) is a Gram negative pathogen that selectively colonizes the human gastric epithelium. Over 50% of the world population is infected with H. pylori reaching up to 90% of infected individuals in developing countries. Nonetheless the increased impact upon public health care, its reservoir and the transmission pathway of the species has not been clearly established yet. Molecular studies allowed the detection of H. pylori in various aquatic environments, even forming biofilm in tap water distribution systems in several countries, suggesting a role of water as a possible reservoir of the pathogen. The persistence of human infection with H. pylori and the resistance of clinical isolates to commonly used antibiotics in eradication therapy have been related to the genetic variability of the species and its ability to develop biofilm, demonstrated both in vivo and in vitro experiments. Thus, during the last years, experimental work with this pathogen has been focused in the search for biofilm inhibitors and biofilm destabilizing agents. However, only two anti- H. pylori biofilm disrupting agents have been successfully used: Curcumin - a natural dye - and N-acetyl cysteine - a mucolytic agent used in respiratory diseases. The main goal of this review was to discuss the evidences available in the literature supporting the ability of H. pylori to form biofilm upon various surfaces in aquatic environments, both in vivo and in vitro. The results published and our own observations suggest that the ability of H. pylori to form biofilm may be important for surviving under stress conditions or in the spread of the infection among humans, mainly through natural water sources and water distribution systems.

  12. Biofilm and Helicobacter pylori: From environment to human host

    PubMed Central

    García, Apolinaria; Salas-Jara, María José; Herrera, Carolina; González, Carlos

    2014-01-01

    Helicobacter pylori (H. pylori) is a Gram negative pathogen that selectively colonizes the human gastric epithelium. Over 50% of the world population is infected with H. pylori reaching up to 90% of infected individuals in developing countries. Nonetheless the increased impact upon public health care, its reservoir and the transmission pathway of the species has not been clearly established yet. Molecular studies allowed the detection of H. pylori in various aquatic environments, even forming biofilm in tap water distribution systems in several countries, suggesting a role of water as a possible reservoir of the pathogen. The persistence of human infection with H. pylori and the resistance of clinical isolates to commonly used antibiotics in eradication therapy have been related to the genetic variability of the species and its ability to develop biofilm, demonstrated both in vivo and in vitro experiments. Thus, during the last years, experimental work with this pathogen has been focused in the search for biofilm inhibitors and biofilm destabilizing agents. However, only two anti- H. pylori biofilm disrupting agents have been successfully used: Curcumin - a natural dye - and N-acetyl cysteine - a mucolytic agent used in respiratory diseases. The main goal of this review was to discuss the evidences available in the literature supporting the ability of H. pylori to form biofilm upon various surfaces in aquatic environments, both in vivo and in vitro. The results published and our own observations suggest that the ability of H. pylori to form biofilm may be important for surviving under stress conditions or in the spread of the infection among humans, mainly through natural water sources and water distribution systems. PMID:24914322

  13. Antifungal susceptibility and molecular typing of 115 Candida albicans isolates obtained from vulvovaginal candidiasis patients in 3 Shanghai maternity hospitals.

    PubMed

    Ying, Chunmei; Zhang, Hongju; Tang, Zhenhua; Chen, Huifen; Gao, Jing; Yue, Chaoyan

    2016-05-01

    In our multicenter study, we studied the distribution of Candida species in vulvovaginal candidiasis patients and investigated antifungal susceptibility profile and genotype of Candida albicans in vaginal swab. A total of 115 Candida albicans strains were detected in 135 clinical isolates. Minimum inhibitory concentration determinations showed that 83% and 81% of the 115 Candida albicans strains were susceptible to fluconazole and voriconazole. Randomly amplified polymorphic DNA analysis (RAPD) was applied to identify clonally related isolates from different patients at the local level. All tested strains were classified into genotype A (77.4%), genotype B (18.3%), and genotype C (4.3%). Genotype A was further classified into five subtypes and genotype B into two subtypes.Candida albicans was the dominant pathogen of vulvovaginal candidiasis, the majority belonging to genotype A in this study. Exposure to azoles is a risk factor for the emergence of azole resistance among Candida albicans isolated from VVC patients. © The Author 2015. Published by Oxford University Press on behalf of The International Society for Human and Animal Mycology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  14. Characterization of Nivalenol-Producing Fusarium culmorum Isolates Obtained from the Air at a Rice Paddy Field in Korea

    PubMed Central

    Kim, Da-Woon; Kim, Gi-Yong; Kim, Hee-Kyoung; Kim, Jueun; Jeon, Sun Jeong; Lee, Chul Won; Lee, Hyang Burm; Yun, Sung-Hwan

    2016-01-01

    Together with the Fusarium graminearum species complex, F. culmorum is a major member of the causal agents of Fusarium head blight on cereals such as wheat, barley and corn. It causes significant yield and quality losses and results in the contamination of grain with mycotoxins that are harmful to humans and animals. In Korea, F. culmorum is listed as a quarantine fungal species since it has yet to be found in the country. In this paper, we report that two isolates (J1 and J2) of F. culmorum were collected from the air at a rice paddy field in Korea. Species identification was confirmed by phylogenetic analysis using multi-locus sequence data derived from five genes encoding translation elongation factor, histone H3, phosphate permease, a reductase, and an ammonia ligase and by morphological comparison with reference strains. Both diagnostic PCR and chemical analysis confirmed that these F. culmorum isolates had the capacity to produce nivalenol, the trichothecene mycotoxin, in rice substrate. In addition, both isolates were pathogenic on wheat heads and corn stalks. This is the first report on the occurrence of F. culmorum in Korea. PMID:27298593

  15. Helicobacter pylori in bottled mineral water: genotyping and antimicrobial resistance properties.

    PubMed

    Ranjbar, Reza; Khamesipour, Faham; Jonaidi-Jafari, Nematollah; Rahimi, Ebrahim

    2016-03-12

    Up to now, fecal-oral and oral-oral are the most commonly known routes for transmission of H. pylori, therefore, contaminated water can play an important role in transmission of H. pylori to humans. Genotyping using virulence markers of H. pylori is one of the best approaches to study the correlations between H. pylori isolates from different samples. The present research was carried out to study the vacA, cagA, cagE, oipA, iceA and babA2 genotyping and antimicrobial resistance properties of H. pylori isolated from the bottled mineral water samples of Iran. Of 450 samples studied, 8 samples (1.77%) were contaminated with H. pylori. Brand C of bottled mineral water had the highest prevalence of H. pylori (3.63%). The bottled mineral water samples of July month had the highest levels of H. pylori-contamination (50%). H. pylori strains had the highest levels of resistance against metronidazole (62.5%), erythromycin (62.5%), clarithromycin (62.5%), amoxicillin (62.5%) and trimethoprim (62.5%). Totally, 12.5% of strains were resistant to more than 6 antibiotics. VvacAs1a (100%), vacAm1a (87.5%), cagA (62.5%), iceA1 (62.5%), oipA (25%), babA2 (25%) and cagE (37.5%) were the most commonly detected genotypes. M1as1a (62.5%), m1as2 (37.5%), m2s2 (37.5%) and S1a/cagA+/IceA2/oipA-/babA2-/cagE- (50%) were the most commonly detected combined genotypes. Contaminated bottled mineral water maybe the sources of virulent and resistant strains H. pylori. Careful monitoring of bottled mineral water production may reduce the risk of H. pylori transmission into the human population.

  16. [Gastrointestinal giardiasis associated with Helicobacter pylori].

    PubMed

    Isaeva, G Sh; Efimova, N G

    2010-01-01

    The study involved 160 patients with chronic cholecystitis associated with chronic gastroduodenitis. Obtaining biopsy specimens of gastric mucosa and bile samples allowed to compare the microbial picture and the morphological structure of gastric mucosa in the same patient, to identify patterns of colonization of the stomach, 12 duodenal ulcer and gall bladder various microorganisms. At cytological examination was detected in the gall bladder G. lamblia in 47.5 +/- 3.95% of cases in the stomach--in 29.09 +/- 6.12% of cases. The frequency of H. pylori detection in biopsy of gastric mucosa amounted to 98.18 +/- 1.8% of cases, in 12-duodenum--93.75 +/- 1.9%, in the gall bladder--to 54.38 +/- 3.94%, in the bile duct--in 54.38 +/- 3.94%. It was found strict association between the detection of H. pylori and G. lamblia in the stomach--100% of H. pylori-infection combined with giardiasis. Morphological changes of gastric mucosa in the form of lymphoid infiltration detected mainly in the mixed-infection H. pylori and G. lamblia.

  17. Pathogenic diversity of Helicobacter pylori.

    PubMed

    Mégraud, F

    1997-04-01

    Helicobacter pylori has been shown to possess a very heterogeneous genoma despite its common phenotypic properties. Some characteristics relevant to pathogenesis have also been found to be heterogeneous. This is the case for adherence properties and the amount of urease produced, but it was not possible to relate these properties to disease entities. A vacuolating cytotoxin which alters epithelial cells has been found in about 60% of strains isolated from patients with ulcers versus 30% from those with gastritis only. The cagA gene can be used as a marker to detect the cag pathogenicity island. This DNA fragment seems to induce an increased inflammation in the gastric tissue via release of interleukin 8 by the epithelial cells. The association of this marker is strongly linked with ulcers compared with gastritis only (80% vs 55%, respectively). A number of other properties may be heterogeneous, but the low number of strains studied does not allow conclusions to be drawn.

  18. Helicobacter pylori reinfection with identical organisms: transmission by the patients' spouses.

    PubMed Central

    Schütze, K; Hentschel, E; Dragosics, B; Hirschl, A M

    1995-01-01

    Reinfection with Helicobacter pylori after eradication is responsible for the recurrence of duodenal ulcer disease. The mode of transmission has not yet been established. In this study, 18 patients with chronic duodenal ulcers in whom H pylori had been eradicated with amoxicillin and metronidazole were entered into a prospective follow up study. Control endoscopies were performed 4, 8, 14, 27, and 43 months after starting treatment and the results of direct tests were compared with the kinetics of H pylori specific IgG titres. After eradication there was a noticeable and consistent fall in anti-H pylori IgG, while reinfections were characterised by a significant increase in specific titres. Reinfection was detected in two patients after 14 and 43 months, respectively. The H pylori strains responsible for these reinfections, the corresponding pretreatment isolates, and the strains isolated from the spouses of these patients were examined by polymerase chain reaction based DNA fingerprinting. Analysis showed that reinfection had been caused by the same H pylori strain and identified the spouses of these patients as carriers of the identical strain. Considering the genomic diversity and the interpatient heterogeneity of H pylori these results suggest a person to person transmission of H pylori reinfection. By the end of the observation period reflux oesophagitis had developed in 10 of the 16 patients who had not been reinfected. This surprising finding may be explained by the changed eating habits of patients after healing of duodenal ulcer disease. Images p832-a PMID:7615268

  19. Fragmentation of CagA Reduces Hummingbird Phenotype Induction by Helicobactor pylori

    PubMed Central

    Chen, Ying-Chieh; Perng, Chin-Lin; Lin, Hwai-Jeng; Ou, Yueh-Hsing

    2016-01-01

    Infection with Helicobacter pylori (H. pylori) has been linked to various gastro-intestinal diseases; nevertheless it remains to be clarified why only a minority of infected individuals develop illness. Studies from the West have indicated that the cagA gene and the associated EPIYA genotype of H. pylori is closely linked to the development of severe gastritis and gastric carcinoma; however, as yet no consistent correlation has been found among the bacteria from East Asia. In addition to genotype variation, the CagA protein undergoes fragmentation; however, the functional significance of fragmentation with respect to H. pylori infection remains unknown. In this study, we isolated 594 H. pylori colonies from 99 patients and examined the fragmentation patterns of CagA protein using immunoblotting. By analyzing the ability of the isolates to induce the host cell morphological transition to the highly invasive hummingbird phenotype, we demonstrated that H. pylori colonies with substantial CagA fragmentation are less potent in terms of causing this morphological transition. Our results uncovered a functional role for CagA fragmentation with respect to H. pylori-induced hummingbird phenotype formation and these findings suggest the possibility that the post-translational processing of CagA may be involved in H. pylori infection pathogenesis. PMID:26934189

  20. Fragmentation of CagA Reduces Hummingbird Phenotype Induction by Helicobactor pylori.

    PubMed

    Chang, Chih-Chi; Kuo, Wein-Shung; Chen, Ying-Chieh; Perng, Chin-Lin; Lin, Hwai-Jeng; Ou, Yueh-Hsing

    2016-01-01

    Infection with Helicobacter pylori (H. pylori) has been linked to various gastro-intestinal diseases; nevertheless it remains to be clarified why only a minority of infected individuals develop illness. Studies from the West have indicated that the cagA gene and the associated EPIYA genotype of H. pylori is closely linked to the development of severe gastritis and gastric carcinoma; however, as yet no consistent correlation has been found among the bacteria from East Asia. In addition to genotype variation, the CagA protein undergoes fragmentation; however, the functional significance of fragmentation with respect to H. pylori infection remains unknown. In this study, we isolated 594 H. pylori colonies from 99 patients and examined the fragmentation patterns of CagA protein using immunoblotting. By analyzing the ability of the isolates to induce the host cell morphological transition to the highly invasive hummingbird phenotype, we demonstrated that H. pylori colonies with substantial CagA fragmentation are less potent in terms of causing this morphological transition. Our results uncovered a functional role for CagA fragmentation with respect to H. pylori-induced hummingbird phenotype formation and these findings suggest the possibility that the post-translational processing of CagA may be involved in H. pylori infection pathogenesis.

  1. Anti-inflammatory and cytoprotective effects of selected Pakistani medicinal plants in Helicobacter pylori-infected gastric epithelial cells.

    PubMed

    Zaidi, Syed Faisal; Muhammad, Jibran Sualeh; Shahryar, Saeeda; Usmanghani, Khan; Gilani, Anwarul-Hassan; Jafri, Wasim; Sugiyama, Toshiro

    2012-05-07

    Helicobacter pylori infection is associated with gastritis, peptic ulcer, and gastric cancer. Due to its high global prevalence and uprising resistance to available antibiotics, efforts are now directed to identify alternative source to treat and prevent associated disorders. In the present study, effect of selected indigenous medicinal plants of Pakistan was evaluated on the secretion of interleukin-8 (IL-8) and generation of reactive oxygen species (ROS) in a bid to rationalize their medicinal use and to examine the anti-inflammatory and cytoprotective effects in gastric epithelial cells. AGS cells and clinically isolated Helicobacter pylori strain (193C) were employed for co-culture experiments. Anti-Helicobacter pylori activity and cytotoxic effects of the selected plants were determined by serial dilution method and DNA fragmentation assay respectively. ELISA and flow cytometry were performed to evaluate the effect on IL-8 secretion and ROS generation in Helicobacter pylori-infected cells. At 100μg/ml, extracts of Alpinia galangal, Cinnamomum cassia, Cinnamomum tamala, Mentha arvensis, Myrtus communis, Oligochaeta ramose, Polygonum bistorta, Rosa damascena, Ruta graveolens, Syzygium aromaticum, Tamarix dioica, and Terminalia chebula exhibited strong inhibitory activity against IL-8 secretion. Of these, four extracts of Cinnamomum cassia, Myrtus communis, Syzygium aromaticum, and Terminalia chebula markedly inhibited IL-8 secretion at both 50 and 100μg/ml. Cinnamomum cassia was further assessed at different concentrations against Helicobacter pylori and TNF-α stimulated IL-8 secretion, which displayed significant suppression of IL-8 in a concentration-dependent-manner. Among the plants examined against ROS generation, Achillea millefolium, Berberis aristata, Coriandrum sativum, Foeniculum vulgare, Matricaria chamomilla and Prunus domestica demonstrated significant suppression of ROS from Helicobacter pylori-infected cells (p<0.01). Results of the study

  2. Identification of bacterial isolates obtained from intestinal contents associated with 12,000-year-old mastodon remains.

    PubMed

    Rhodes, A N; Urbance, J W; Youga, H; Corlew-Newman, H; Reddy, C A; Klug, M J; Tiedje, J M; Fisher, D C

    1998-02-01

    Mastodon (Mammut americanum) remains unearthed during excavation of ancient sediments usually consist only of skeletal material, due to postmortem decomposition of soft tissues by microorganisms. Two recent excavations of skeletal remains in anoxic sediments in Ohio and Michigan, however, have uncovered organic masses which appear to be remnants of the small and large intestines, respectively. Macrobotanical examinations of the composition of these masses revealed assemblages of plant material radiocarbon dated to approximately 11,500 years before the present and thought to be incompletely digested food remains from this extinct mammal. We attempted to cultivate and identify bacteria from the intestinal contents, bone-associated sediments, and sediments not in proximity to the remains using a variety of general and selective media. In all, 295 isolates were cultivated, and 38 individual taxa were identified by fatty acid-methyl ester (FAME) profiles and biochemical characteristics (API-20E). The taxonomic positions of selected ent