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M1073 Fourth-Line Rescue Therapy in Patients with Three H. pylori Eradication Failures
permeability of the outer membrane of H. pylori to antimicrobials, and increased endocellular concentrations of antimicrobials probably by altering the OMP expression. M1072
AGA Abstracts
A Novel Bactericidal Strategy for Helicobacter pylori Based On Alteration of Its TCA Cycle Enzymatic Activity Which Determines the Helical or a Coccoid Form of Existence of This Bacterium Hitoshi Tsugawa, Hidekazu Suzuki, Izumi Nakagawa, Toshihiro Nishizawa, Yoshimasa Saito, Makoto Suematsu, Toshifumi Hibi Helicobacter pylori is now recognized as one of the main causes of gastritis and peptic ulcer disease in humans. Although H. pylori is known to exist in its helical form in the gastric mucosa, various environmental conditions, such as aerobiosis, extended incubation and antibiotic treatment, transform the bacteria to the coccoid form. The metabolic characteristics of the coccoid form of H. pylori are not yet fully understood, although it has been suggested that it is the form of the bacterium that is involved in the transmission and pathogenicity of H. pylori. In the TCA cycle of H. pylori, CoA transferase (CoAT) catalyzes the conversion of succinyl CoA to succinate, and alpha-ketoglutarate oxidoreductase (KOR) catalyzes the conversion of alpha-ketoglutarate to succinate. The present study was designed to examine the metabolic characteristics of the coccoid form of H. pylori, and to develop a potent bactericidal modality that would prevent the induction of the coccoid form. Methods. H. pylori strain ATCC 43504 was used throughout the study. Conversion to the coccoid form during culture was induced by aerobiosis or exposure to 15 µg/mL tetracycline (Tet). Separation of the helical and coccoid forms was performed as previously described (Clin. Diagn. Lab. Immunol., 4:285, 1997). The morphology of the helical and coccoid forms was examined by scanning electron microscopy. The activities of CoAT and KOR in the bacterial lysate was measured. The viability of the bacteria was evaluated by the Alamar Blue dyestaining method. Results. CoAT activity was reduced, while the KOR activity was increased in the coccoid form of H. pylori (table 1). When CoAT activity was inhibited by NaI (a CoAT inhibitor), the KOR activity was found to increase by 2.3-fold (p<0.01), with no influence on the growth, in the helical form of H. pylori. When the KOR activity was inhibited by NaNO2 (a KOR inhibitor), however, the growth of the helical form was inhibited and the cell viability was markedly reduced (<10%). Inactivation of KOR could be potentially bactericidal, since it did not induce conversion to the coccoid form, one of the viable forms of H. pylori with a reduced metabolism. It is expected that inactivation of the KOR activity will potentially kill H. pylori and prevent the emergence of drug-resistant strains. Conclusion. Inactivation of KOR activity exerts a potent bactericidal action on H. pylori, without induction of the coccoid form. Table 1. Effect of morphological change on the CoAT and KOR activity.
CONSORT flow diaphragm of the subject's progress through the phases of the study. ITT, intention-to-treat; PP, per-protocol. M1070 7-Day Retreatment with Furazolidone, Levofloxacin and Lansoprazole for the Eradication of Helicobacter pylori in Sao Paulo, Brazil Jaime N. Eisig, Fernando M. Silva, Ricardo C. Barbuti, Tomas Navarro-Rodriguez, Schlioma Zaterka, Joaquim P. Moraes-Filho Background/Aims: Treatment failure with first-line therapy for Helicobacter pylori (Hp) is observed in 5 to 20% of the patients in developed countries. However, in developing countries such as Brazil, this figure is usually higher: 15-30%. The reasons for treatment failure include low patient compliance and bacterial resistance to antimicrobial agents. Therefore, there is a real need for searching retreatment regimens with high efficacy and good adherence rates. Our aim was to evaluate the efficacy, safety and tolerability of a triple therapy with furazolidone and levofloxacin associated with lansoprazole in patients with peptic ulcer, who had previously been treated unsuccessfully with one or more eradications regimens for Hp. Methods: This is an open prospective clinical trial and 48 patients were included at year 2007 with peptic ulcer and presence of infection of Hp confirmed by rapid urease test, histopathology and C14-urea breath test. The patients received levofloxacin 250mg, furazolidone 200mg and lansoprazole 30mg, BID, for one week. Two months after finished therapy a quantitative C14 urea breath test was done. Results: The intention to treat analysis showed an eradication rate of 87, 5% (42/48), 95% CI, 88% - 92%. The per protocol analysis obtained eradication of 89.4% (42/47) 95% CI, 89%-99%. Forty one patients reported mild and moderate adverse effects. The most frequent were headache (22%), diarrhea (20%), nausea (14%), dizziness (12%) and vomit (6%). One case of severe adverse effect had to interrupt the treatment in the second day. The eradication rates had a correlation with the number of treatments previously done, p=.004 (100% for one, 84% for 2 and 57% for 3 ore more). Conclusion: The triple regimen furazolidone+levofloxacin+lansoprazole for the retreatment of Hp infection was well tolerated, good adherence, with rates per protocol of eradication close to 90%. It is a good alternative which should be considered in these cases.
**p<0.01, *p<0.05 M1073 Fourth-Line Rescue Therapy in Patients with Three H. pylori Eradication Failures Javier P. Gisbert, Manuel Castro-Fernandez, Eloisa Lamas, Angeles Perez-Aisa, Jose Luis Cabriada, Luis Rodrigo, Luis Miguel Benito, Jose Luis Gisbert, Eusebio Marcos
M1071 Mechanisms of Aspirin Increasing the Susceptibility of Helicobacter pylori to Antimicrobials Xiaoping Zhang, Weihong Wang, Yu Tian, Wen Gao
AIM: In some cases, H. pylori infection persists even after the administration of 3 consecutive eradication treatments. It is unknown whether a 4th eradication regimen may be effective and safe in this difficult scenario. Our aim was to evaluate the efficacy and tolerability of a forth-line rescue regimen (with rifabutin or with levofloxacin) in patients with 3 consecutive H. pylori eradication failures. METHODS: Forty patients in whom 3 consecutive H. pylori eradication treatments had failed were prospectively studied. In all cases, a first treatment with PPI-clarithromycin-amoxicillin and a second with a quadruple therapy (PPI-bismuthtetracycline-metronidazole) or with ranitidine bismuth citrate-tetracycline-metronidazole had been administered. In 13 patients, a 3rd eradication regimen with PPI-amoxicillin-rifabutin had been prescribed, and therefore a 4th eradication regimen with PPI, amoxicillin (1 g b.i.d.) and levofloxacin (500 mg b.i.d.) was prescribed for 10 days. In the remaining 27 patients, a 3rd eradication regimen with PPI-amoxicillin-levofloxacin had been prescribed, and therefore a 4th eradication regimen with PPI, amoxicillin (1 g b.i.d.) and rifabutin (150 mg b.i.d.) was prescribed for 10 days. Antibiotic susceptibility was unknown and, therefore, rescue regimens were chosen empirically. Eradication was confirmed with 13C-urea breath test 4-8 weeks after therapy. RESULTS: Thirteen patients received a 4th treatment with levofloxacin, and 27 with rifabutin. All patients but three (all receiving rifabutin) completed the follow-up. Compliance in the levofloxacin group was 100%, whereas 3 patients receiving rifabutin did not take correctly the medication (due to adverse effects: fever, myalgia, abdominal pain and diarrhea in one case, and vomiting in two cases). Overall incidence of adverse effects with the 4th rescue treatment was 37% (none of them were severe): 33% in those treated with rifabutin (including leucopenia in one patient, and thrombopenia in another one), and 54% in those treated with levofloxacin (mainly myalgias). Per-protocol and intention-to-treat eradication rates with the 4th rescue treatment were, respectively, 53% (95% CI, 37-67%) and 50% (95% CI, 35-65%). Corresponding intention-to-treat cure rates for levofloxacin and rifabutin 4th line regimens were, respectively, 77% and 37%. CONCLUSION: Even after 3 previous H. pylori eradication failures, an empirical fourth-line rescue treatment (with levofloxacin or with rifabutin) may be effective to eradicate the infection in approximately 50% of the cases.
AIMS: Aspirin increased the susceptibility of H. pylori to clarithromycin, metronidazol and amoxicillin. The aim is to investigate the mechanisms of aspirin increasing the susceptibility of H. pylori to clarithromycin and metronidazol. METHODS: H. pylori 26695, strains of H. pylori converted from clarithromycin/metronidazol resistant to susceptible when treated with aspirin (1mM) were included. Strains were incubated with or without aspirin (1mM) under microaerobic condition for 48h. The genomic DNA was prepared with silicon dioxicide method. Mutations in V function domain of 23SrRNA gene were identified by PCR and analyzed by BsaI. The complete rdxA gene was amplified by PCR and sequenced. H. pylori 26695 treated with and without aspirin (1mM) were incubated with [7-3H]tetracycline. The radioactivity was analyzed by a scintillation counter. The OMP profiles were analyzed by SDS-PAGE. The mRNA of strains were extracted and the expression of the porins ( hopA, B, C, D, E) and the putative RND efflux system (hefABC) were analyzed using Taqmanbased real-time PCR. RESULTS: 1. Position 2144 A-G mutations did not change in V function domain of 23SrRNA gene for clarithromycin resistant strains treated with aspirin, indicating that aspirin increased the susceptibility of H. pylori to clarithromycin not by changing the effective position of H. pylori to clarithromycin. 2. Sequence analysis revealed that the homology of the nucleotides of metronidazole resistant strain and the corresponding susceptible strain converted in the presence of aspirin was over 99.5%. No difference was found for the corresponding amino acids sequences. This indicated that aspirin did not change the rdxA gene of H. pylori. 3. The radioactivities of H. pylori cells treated with aspirin were higher than that in control at different time, indicating that more [7-3H] tetracycline entered the H. pylori cells in the presence of aspirin. This suggested that aspirin could enhance the permeability of the outer membrane of H. pylori. 4. The OMP profiles of H. pylori treated with aspirin were similar to that in control. However, the expression of an 80KD protein was higher in the presence of aspirin. 5. Irrespective of the presence of aspirin, the expression of mRNA levels of hopA, B, C, D, E, and hefA, B, C did not change. CONCLUSIONS: Although aspirin could increase the susceptibility of H. pylori to clarithromycin and metronidazole, it had no effect on the 23SrRNA gene and the rdxA gene. However, aspirin increased the
AGA Abstracts
A-332
AGA Abstracts
A Novel Bactericidal Strategy for Helicobacter pylori Based On Alteration of Its TCA Cycle Enzymatic Activity Which Determines the Helical or a Coccoid Form of Existence of This Bacterium Hitoshi Tsugawa, Hidekazu Suzuki, Izumi Nakagawa, Toshihiro Nishizawa, Yoshimasa Saito, Makoto Suematsu, Toshifumi Hibi Helicobacter pylori is now recognized as one of the main causes of gastritis and peptic ulcer disease in humans. Although H. pylori is known to exist in its helical form in the gastric mucosa, various environmental conditions, such as aerobiosis, extended incubation and antibiotic treatment, transform the bacteria to the coccoid form. The metabolic characteristics of the coccoid form of H. pylori are not yet fully understood, although it has been suggested that it is the form of the bacterium that is involved in the transmission and pathogenicity of H. pylori. In the TCA cycle of H. pylori, CoA transferase (CoAT) catalyzes the conversion of succinyl CoA to succinate, and alpha-ketoglutarate oxidoreductase (KOR) catalyzes the conversion of alpha-ketoglutarate to succinate. The present study was designed to examine the metabolic characteristics of the coccoid form of H. pylori, and to develop a potent bactericidal modality that would prevent the induction of the coccoid form. Methods. H. pylori strain ATCC 43504 was used throughout the study. Conversion to the coccoid form during culture was induced by aerobiosis or exposure to 15 µg/mL tetracycline (Tet). Separation of the helical and coccoid forms was performed as previously described (Clin. Diagn. Lab. Immunol., 4:285, 1997). The morphology of the helical and coccoid forms was examined by scanning electron microscopy. The activities of CoAT and KOR in the bacterial lysate was measured. The viability of the bacteria was evaluated by the Alamar Blue dyestaining method. Results. CoAT activity was reduced, while the KOR activity was increased in the coccoid form of H. pylori (table 1). When CoAT activity was inhibited by NaI (a CoAT inhibitor), the KOR activity was found to increase by 2.3-fold (p<0.01), with no influence on the growth, in the helical form of H. pylori. When the KOR activity was inhibited by NaNO2 (a KOR inhibitor), however, the growth of the helical form was inhibited and the cell viability was markedly reduced (<10%). Inactivation of KOR could be potentially bactericidal, since it did not induce conversion to the coccoid form, one of the viable forms of H. pylori with a reduced metabolism. It is expected that inactivation of the KOR activity will potentially kill H. pylori and prevent the emergence of drug-resistant strains. Conclusion. Inactivation of KOR activity exerts a potent bactericidal action on H. pylori, without induction of the coccoid form. Table 1. Effect of morphological change on the CoAT and KOR activity.
CONSORT flow diaphragm of the subject's progress through the phases of the study. ITT, intention-to-treat; PP, per-protocol. M1070 7-Day Retreatment with Furazolidone, Levofloxacin and Lansoprazole for the Eradication of Helicobacter pylori in Sao Paulo, Brazil Jaime N. Eisig, Fernando M. Silva, Ricardo C. Barbuti, Tomas Navarro-Rodriguez, Schlioma Zaterka, Joaquim P. Moraes-Filho Background/Aims: Treatment failure with first-line therapy for Helicobacter pylori (Hp) is observed in 5 to 20% of the patients in developed countries. However, in developing countries such as Brazil, this figure is usually higher: 15-30%. The reasons for treatment failure include low patient compliance and bacterial resistance to antimicrobial agents. Therefore, there is a real need for searching retreatment regimens with high efficacy and good adherence rates. Our aim was to evaluate the efficacy, safety and tolerability of a triple therapy with furazolidone and levofloxacin associated with lansoprazole in patients with peptic ulcer, who had previously been treated unsuccessfully with one or more eradications regimens for Hp. Methods: This is an open prospective clinical trial and 48 patients were included at year 2007 with peptic ulcer and presence of infection of Hp confirmed by rapid urease test, histopathology and C14-urea breath test. The patients received levofloxacin 250mg, furazolidone 200mg and lansoprazole 30mg, BID, for one week. Two months after finished therapy a quantitative C14 urea breath test was done. Results: The intention to treat analysis showed an eradication rate of 87, 5% (42/48), 95% CI, 88% - 92%. The per protocol analysis obtained eradication of 89.4% (42/47) 95% CI, 89%-99%. Forty one patients reported mild and moderate adverse effects. The most frequent were headache (22%), diarrhea (20%), nausea (14%), dizziness (12%) and vomit (6%). One case of severe adverse effect had to interrupt the treatment in the second day. The eradication rates had a correlation with the number of treatments previously done, p=.004 (100% for one, 84% for 2 and 57% for 3 ore more). Conclusion: The triple regimen furazolidone+levofloxacin+lansoprazole for the retreatment of Hp infection was well tolerated, good adherence, with rates per protocol of eradication close to 90%. It is a good alternative which should be considered in these cases.
**p<0.01, *p<0.05 M1073 Fourth-Line Rescue Therapy in Patients with Three H. pylori Eradication Failures Javier P. Gisbert, Manuel Castro-Fernandez, Eloisa Lamas, Angeles Perez-Aisa, Jose Luis Cabriada, Luis Rodrigo, Luis Miguel Benito, Jose Luis Gisbert, Eusebio Marcos
M1071 Mechanisms of Aspirin Increasing the Susceptibility of Helicobacter pylori to Antimicrobials Xiaoping Zhang, Weihong Wang, Yu Tian, Wen Gao
AIM: In some cases, H. pylori infection persists even after the administration of 3 consecutive eradication treatments. It is unknown whether a 4th eradication regimen may be effective and safe in this difficult scenario. Our aim was to evaluate the efficacy and tolerability of a forth-line rescue regimen (with rifabutin or with levofloxacin) in patients with 3 consecutive H. pylori eradication failures. METHODS: Forty patients in whom 3 consecutive H. pylori eradication treatments had failed were prospectively studied. In all cases, a first treatment with PPI-clarithromycin-amoxicillin and a second with a quadruple therapy (PPI-bismuthtetracycline-metronidazole) or with ranitidine bismuth citrate-tetracycline-metronidazole had been administered. In 13 patients, a 3rd eradication regimen with PPI-amoxicillin-rifabutin had been prescribed, and therefore a 4th eradication regimen with PPI, amoxicillin (1 g b.i.d.) and levofloxacin (500 mg b.i.d.) was prescribed for 10 days. In the remaining 27 patients, a 3rd eradication regimen with PPI-amoxicillin-levofloxacin had been prescribed, and therefore a 4th eradication regimen with PPI, amoxicillin (1 g b.i.d.) and rifabutin (150 mg b.i.d.) was prescribed for 10 days. Antibiotic susceptibility was unknown and, therefore, rescue regimens were chosen empirically. Eradication was confirmed with 13C-urea breath test 4-8 weeks after therapy. RESULTS: Thirteen patients received a 4th treatment with levofloxacin, and 27 with rifabutin. All patients but three (all receiving rifabutin) completed the follow-up. Compliance in the levofloxacin group was 100%, whereas 3 patients receiving rifabutin did not take correctly the medication (due to adverse effects: fever, myalgia, abdominal pain and diarrhea in one case, and vomiting in two cases). Overall incidence of adverse effects with the 4th rescue treatment was 37% (none of them were severe): 33% in those treated with rifabutin (including leucopenia in one patient, and thrombopenia in another one), and 54% in those treated with levofloxacin (mainly myalgias). Per-protocol and intention-to-treat eradication rates with the 4th rescue treatment were, respectively, 53% (95% CI, 37-67%) and 50% (95% CI, 35-65%). Corresponding intention-to-treat cure rates for levofloxacin and rifabutin 4th line regimens were, respectively, 77% and 37%. CONCLUSION: Even after 3 previous H. pylori eradication failures, an empirical fourth-line rescue treatment (with levofloxacin or with rifabutin) may be effective to eradicate the infection in approximately 50% of the cases.
AIMS: Aspirin increased the susceptibility of H. pylori to clarithromycin, metronidazol and amoxicillin. The aim is to investigate the mechanisms of aspirin increasing the susceptibility of H. pylori to clarithromycin and metronidazol. METHODS: H. pylori 26695, strains of H. pylori converted from clarithromycin/metronidazol resistant to susceptible when treated with aspirin (1mM) were included. Strains were incubated with or without aspirin (1mM) under microaerobic condition for 48h. The genomic DNA was prepared with silicon dioxicide method. Mutations in V function domain of 23SrRNA gene were identified by PCR and analyzed by BsaI. The complete rdxA gene was amplified by PCR and sequenced. H. pylori 26695 treated with and without aspirin (1mM) were incubated with [7-3H]tetracycline. The radioactivity was analyzed by a scintillation counter. The OMP profiles were analyzed by SDS-PAGE. The mRNA of strains were extracted and the expression of the porins ( hopA, B, C, D, E) and the putative RND efflux system (hefABC) were analyzed using Taqmanbased real-time PCR. RESULTS: 1. Position 2144 A-G mutations did not change in V function domain of 23SrRNA gene for clarithromycin resistant strains treated with aspirin, indicating that aspirin increased the susceptibility of H. pylori to clarithromycin not by changing the effective position of H. pylori to clarithromycin. 2. Sequence analysis revealed that the homology of the nucleotides of metronidazole resistant strain and the corresponding susceptible strain converted in the presence of aspirin was over 99.5%. No difference was found for the corresponding amino acids sequences. This indicated that aspirin did not change the rdxA gene of H. pylori. 3. The radioactivities of H. pylori cells treated with aspirin were higher than that in control at different time, indicating that more [7-3H] tetracycline entered the H. pylori cells in the presence of aspirin. This suggested that aspirin could enhance the permeability of the outer membrane of H. pylori. 4. The OMP profiles of H. pylori treated with aspirin were similar to that in control. However, the expression of an 80KD protein was higher in the presence of aspirin. 5. Irrespective of the presence of aspirin, the expression of mRNA levels of hopA, B, C, D, E, and hefA, B, C did not change. CONCLUSIONS: Although aspirin could increase the susceptibility of H. pylori to clarithromycin and metronidazole, it had no effect on the 23SrRNA gene and the rdxA gene. However, aspirin increased the
AGA Abstracts
A-332