ABSTRACT
The antibacterial activities of NE-2001 were tested against 24 clinical isolates of
Helicobacter pylori
and compared with those of amoxicillin, clarithromycin, metronidazole, and furazolidone. The MIC
50
and MIC
90
of this synthetic compound on the isolates were 8 and 16 μg/ml, respectively. This action was highly selective against
Helicobacter pylori
; there was a >4-fold difference between the concentration of NE-2001 required to inhibit the growth of
Helicobacter pylori
and that required to inhibit the growth of common aerobic and anaerobic bacteria. Exposure of
Helicobacter pylori
(ATCC43504) to NE-2001 at the MIC (4 μg/ml), or at a greater concentration, resulted in an extensive loss of viability. The phenomenon was also observed at pH levels between 3.0 and 7.0. When two clinical
Helicobacter pylori
strains were successively cultured at subinhibitory concentrations of NE-2001, no significant changes in the bactericidal effects were found. The morphological alterations of
Helicobacter pylori
cells (ATCC43504), exposed to NE-2001 at various concentrations for 6 h, were observed using transmission electron microcopy. The bacterium displayed features such as swelling, vacuole-like structures in the cytoplasm, and cell destruction following exposure to NE-2001. The efficacy of NE-2001 was maintained when evaluated in eight clinical isolates resistant to metronidazole and five isolates resistant to both metronidazole and clarithromycin (MIC ranging between 4 and 16 μg/ml). The above-described results suggest that NE-2001 may have the potential to be developed as a candidate agent for the treatment of
Helicobacter pylori
infection.
