Isolation of Helicobacter pylori in gastric mucosa and susceptibility to five antimicrobial drugs in Southern Chile

Abstract

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.

Low co-existence rates of Lactobacillus spp. and Helicobacter pylori detected in gastric biopsies from patients with gastrointestinal symptoms

“…Our results are based on culturing recoverable bacteria, which is the recommended test when antibiotic resistant pattern of clinical isolates should be determined, even though this method is less sensitive for detecting infected individuals than serology (24). The 42.6% of prevalence informed by us is similar with the results published by Otth et al (25) for a Chilean cohort (41.3%). Thus, short-term infection among Chilean patients is rather scarce.…”

Histological changes in refractory Helicobacter pylori infection and its relationship with increased levels of resistance to antibiotics and therapeutic regimens: one‐year follow‐up

“…We determined MIC 50 value of 0.5 mg/L at first phase of the study. This was higher than those were reported from previous studies in Asia, and Latin America (MIC 50 of < 0.016 and 0.06, respectively (15,23), but lower than those presented by Boyanova et al in Bulgaria (14). Secondary resistance to clarithromycin and other antibiotics in patients who have taken previous incomplete or inappropriate treatments was reported by Selgrad et al (24).…”

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

“…On the other hand, in Chile, despite of rates of resistance to AMO being low (2.3%) strains with expressive level of resistance were found with MIC greater than 256 µg/mL 23 .…”

“…Currently, the world rates of resistance to this antibacterial have been low and, for this reason, the same has been frequently utilized in the combined first line therapy. In countries of Latin America, rates of resistance to AMO were reported as less than 4%, being 3.8% in Colombia 29 , 2.2% in Paraguay 10 and 2.3% in Chile 23 . There was no resistance to this antibiotic in Venezuela 30 , São Paulo/Brazil 9 and in any other Colombian work 2 .…”