Evolution of metronidazole and tetracycline susceptibility pattern in Helicobacter pylori at a hospital in Saudi Arabia.

The association of Helicobacter pylori with chronic gastritis and peptic ulcer disease led to new therapeutic approaches including the use of antibiotics. Recently, resistance of H. pylori to antibiotics has emerged as the major cause of treatment failure. This retrospective analysis was aimed at investigating the development of antimicrobial susceptibility patterns amongst H. pylori strains isolated at King Fahd Hospital of the University, Al-Khobar. Susceptibility patterns obtained using isolates from a pilot study (1987-1988) were compared with those subsequently isolated (1990-1996). Metronidazole resistance was estimated to be 35.2% in the first period but more than doubled (78.5%) during the second period. Isolates from females showed a higher resistance rate to metronidazole than those from males. Only one strain was tetracycline resistant. The extremely high resistance rate to metronidazole indicates that it may not be very effective for eradication of H. pylori. Tetracycline should prove a useful component of treatment regimens in this geographical region.