To study the drug resistance phenotype, drug resistance gene, and virulence gene of Helicobacter pylori(Hp) in patients with failed eradication therapy, and to provide reference for remedial therapy.
Hp was isolated and cultured from gastric mucosa of patients with failed eradication therapy. Drug sensitivity test was used to detect the resistance of isolated strains to Metronidazole (MTZ), Clarithromycin (CLA), Levofloxacin (LEV), Amoxicillin (AMX), Tetracycline (TET),and Furazolidone (FZ). CLA and LEV resistance genes 23S rRNA, gyrA and virulence genes cagA, vacA, iceA, oipA were amplified by PCR, to further explore the relationship between drug resistance phenotype and drug resistance and virulence genes.
In total 40 strains of Hp were isolated from 58 patients (69.0%). The resistance rates to MTZ, CLA, LEV, AMX, TET, and FZ were 100.0%, 82.5%, 72.5%, 0%, 0%, and 0%, respectively. The most common mutations of 23S rRNA and gyrA genes were T2182C (78.6%) and N87K (32.0%), respectively, and new C2165T and A2219G mutations were found in CLA resistant strains. In addition, the positive rates of virulence genes cagA, vacA s1, vacA s2, vacA m1, vacA m2, iceA1, iceA2, and oipA were 97.1%, 100.0%, 0%, 42.9%, 57.1%, 62.9%, 11.4%, and 68.6%, respectively, and the difference was statistically significant.
The resistance of Hp isolates to MTZ, CLA and LEV in patients with failed eradication therapy in this area is serious, and AMX, TET and FZ are recommended for remedial therapy. The relationship between CLA resistance and C2165T and A2219G mutation and LEV resistance and vacA m2 warrants further investigation.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |