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Bactericidal activities of the cationic steroid CSA-13 and the cathelicidin peptide LL-37 against Helicobacter pylori in simulated gastric juice.

Leszczyńska K, Namiot A, Fein DE, Wen Q, Namiot Z, Savage PB, Diamond S, Janmey PA, Bucki R - BMC Microbiol. (2009)

Bottom Line: After incubation in simulated gastric juice (low pH with presence of pepsin) CSA-13, but not LL-37 or WLBU2, retained antibacterial activity.Compared to LL-37 and WLBU2 peptides, CSA-13 activity was also more resistant to inhibition by isolated host gastric mucins.These data indicate that cholic acid-based antimicrobial agents such as CSA-13 resist proteolytic degradation and inhibition by mucin and have potential for treatment of H. pylori infections, including those caused by the clarithromycin and/or metronidazole-resistant strains.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Diagnostic Microbiology, Medical University of Bialystok, 15-230 Bialystok, Poland. katles@onet.eu

ABSTRACT

Background: The worldwide appearance of drug-resistant strains of H. pylori motivates a search for new agents with therapeutic potential against this family of bacteria that colonizes the stomach, and is associated with adenocarcinoma development. This study was designed to assess in vitro the anti-H. pylori potential of cathelicidin LL-37 peptide, which is naturally present in gastric juice, its optimized synthetic analog WLBU2, and the non-peptide antibacterial agent ceragenin CSA-13.

Results: In agreement with previous studies, increased expression of hCAP-18/LL-37 was observed in gastric mucosa obtained from H. pylori infected subjects. MBC (minimum bactericidal concentration) values determined in nutrient-containing media range from 100-800 microg/ml for LL-37, 17.8-142 microg/ml for WLBU2 and 0.275-8.9 microg/ml for ceragenin CSA-13. These data indicate substantial, but widely differing antibacterial activities against clinical isolates of H. pylori. After incubation in simulated gastric juice (low pH with presence of pepsin) CSA-13, but not LL-37 or WLBU2, retained antibacterial activity. Compared to LL-37 and WLBU2 peptides, CSA-13 activity was also more resistant to inhibition by isolated host gastric mucins.

Conclusion: These data indicate that cholic acid-based antimicrobial agents such as CSA-13 resist proteolytic degradation and inhibition by mucin and have potential for treatment of H. pylori infections, including those caused by the clarithromycin and/or metronidazole-resistant strains.

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Bactericidal activity against H. pylori. Minimum bactericidal concentration (MBC) of LL-37 (white column), WLBU2 (gray column) and CSA-13 (black column) against H. pylori (ATCC 43504 strain and seven clinical isolates obtained from mucosal samples from different subjects) evaluated in HEPES (panel A) or Brucella Broth Bulion (panel B). MBC indicates concentrations at which compounds completely eradicate an inoculum of H. pylori.
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Figure 2: Bactericidal activity against H. pylori. Minimum bactericidal concentration (MBC) of LL-37 (white column), WLBU2 (gray column) and CSA-13 (black column) against H. pylori (ATCC 43504 strain and seven clinical isolates obtained from mucosal samples from different subjects) evaluated in HEPES (panel A) or Brucella Broth Bulion (panel B). MBC indicates concentrations at which compounds completely eradicate an inoculum of H. pylori.

Mentions: To identify resistant strains, clinical isolates of H. pylori were subjected to MIC evaluation (Table 1) with several antibiotics currently used in clinical treatment of H. pylori infection. Among seven tested isolates obtained from different subjects, strain 4 was resistant to metronidazole and strains 5, 6, 7 were resistant to both metronidazole and clarithromycin. All isolates were susceptible to amoxicillin and tetracycline. Consistent with previous reports on the effects of hBD-1, h-BD-2 and LL-37 peptides against H. pylori [10,11] all isolated strains of H. pylori were killed after 6 hours incubation with LL-37, WLBU2 and CSA-13 with average MBC (μg/ml) values 8.9 ± 4.03; 5.23 ± 2.7 and 0.31 ± 0.25 when MBC was evaluated in HEPES buffer, or 300 ± 232, 53 ± 41 and 2.98 ± 3.11 when MBC was evaluated in Brucella Broth Bullion respectively (Figure 2). Evaluation of MBC values in HEPES buffer with addition of 2 mM MgCl2 for H. pylori ATCC 43504 revealed an eight fold increase for LL-37, and a four fold increase for both WLBU2 and CSA-13 (data not show).


Bactericidal activities of the cationic steroid CSA-13 and the cathelicidin peptide LL-37 against Helicobacter pylori in simulated gastric juice.

Leszczyńska K, Namiot A, Fein DE, Wen Q, Namiot Z, Savage PB, Diamond S, Janmey PA, Bucki R - BMC Microbiol. (2009)

Bactericidal activity against H. pylori. Minimum bactericidal concentration (MBC) of LL-37 (white column), WLBU2 (gray column) and CSA-13 (black column) against H. pylori (ATCC 43504 strain and seven clinical isolates obtained from mucosal samples from different subjects) evaluated in HEPES (panel A) or Brucella Broth Bulion (panel B). MBC indicates concentrations at which compounds completely eradicate an inoculum of H. pylori.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2748089&req=5

Figure 2: Bactericidal activity against H. pylori. Minimum bactericidal concentration (MBC) of LL-37 (white column), WLBU2 (gray column) and CSA-13 (black column) against H. pylori (ATCC 43504 strain and seven clinical isolates obtained from mucosal samples from different subjects) evaluated in HEPES (panel A) or Brucella Broth Bulion (panel B). MBC indicates concentrations at which compounds completely eradicate an inoculum of H. pylori.
Mentions: To identify resistant strains, clinical isolates of H. pylori were subjected to MIC evaluation (Table 1) with several antibiotics currently used in clinical treatment of H. pylori infection. Among seven tested isolates obtained from different subjects, strain 4 was resistant to metronidazole and strains 5, 6, 7 were resistant to both metronidazole and clarithromycin. All isolates were susceptible to amoxicillin and tetracycline. Consistent with previous reports on the effects of hBD-1, h-BD-2 and LL-37 peptides against H. pylori [10,11] all isolated strains of H. pylori were killed after 6 hours incubation with LL-37, WLBU2 and CSA-13 with average MBC (μg/ml) values 8.9 ± 4.03; 5.23 ± 2.7 and 0.31 ± 0.25 when MBC was evaluated in HEPES buffer, or 300 ± 232, 53 ± 41 and 2.98 ± 3.11 when MBC was evaluated in Brucella Broth Bullion respectively (Figure 2). Evaluation of MBC values in HEPES buffer with addition of 2 mM MgCl2 for H. pylori ATCC 43504 revealed an eight fold increase for LL-37, and a four fold increase for both WLBU2 and CSA-13 (data not show).

Bottom Line: After incubation in simulated gastric juice (low pH with presence of pepsin) CSA-13, but not LL-37 or WLBU2, retained antibacterial activity.Compared to LL-37 and WLBU2 peptides, CSA-13 activity was also more resistant to inhibition by isolated host gastric mucins.These data indicate that cholic acid-based antimicrobial agents such as CSA-13 resist proteolytic degradation and inhibition by mucin and have potential for treatment of H. pylori infections, including those caused by the clarithromycin and/or metronidazole-resistant strains.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Diagnostic Microbiology, Medical University of Bialystok, 15-230 Bialystok, Poland. katles@onet.eu

ABSTRACT

Background: The worldwide appearance of drug-resistant strains of H. pylori motivates a search for new agents with therapeutic potential against this family of bacteria that colonizes the stomach, and is associated with adenocarcinoma development. This study was designed to assess in vitro the anti-H. pylori potential of cathelicidin LL-37 peptide, which is naturally present in gastric juice, its optimized synthetic analog WLBU2, and the non-peptide antibacterial agent ceragenin CSA-13.

Results: In agreement with previous studies, increased expression of hCAP-18/LL-37 was observed in gastric mucosa obtained from H. pylori infected subjects. MBC (minimum bactericidal concentration) values determined in nutrient-containing media range from 100-800 microg/ml for LL-37, 17.8-142 microg/ml for WLBU2 and 0.275-8.9 microg/ml for ceragenin CSA-13. These data indicate substantial, but widely differing antibacterial activities against clinical isolates of H. pylori. After incubation in simulated gastric juice (low pH with presence of pepsin) CSA-13, but not LL-37 or WLBU2, retained antibacterial activity. Compared to LL-37 and WLBU2 peptides, CSA-13 activity was also more resistant to inhibition by isolated host gastric mucins.

Conclusion: These data indicate that cholic acid-based antimicrobial agents such as CSA-13 resist proteolytic degradation and inhibition by mucin and have potential for treatment of H. pylori infections, including those caused by the clarithromycin and/or metronidazole-resistant strains.

Show MeSH
Related in: MedlinePlus