مقالات

Mucoid-coccoid H. pylori and antibiotic resistance

1398/6/15 23:19
مقدمه

: In this study one H. pylori isolate from gastric biopsy of a dyspeptic patient that turned into mucoid-coccoid (MC) form upon consecutive subcultures, was identified. The culturability, antibiotic resistance and lipid contents of MC were compared with those of non-mucoid (NM) spiral H. pylori

روش کار

MC and NM H. pylori were subculured on Brucella blood agar (BBA) and incubated under aerobic and microaerobic atmospheres at 37° C. Cultures were examined for colony characteristics and bacterial morphology after 1-3 days. The isolates were identified by biochemical tests and detection of H. pylori-16S rDNA. Antibiogram was performed with currently used antibiotics for H. pylori eradication. Cellular lipid contents were extracted and analyzed by gas chromatography

نتایج

Compared with pin-pointed and glistening colonies of NM H. pylori that appeared under microaerobic conditions, MC H. pylori grew well in consecutive subcultures under aerobic and microaerobic atmospheres and produced white patches of mucoid colonies. MC exhibited coccoid and NM spiral morphology. Both isolates were catalase, oxidase and urease positive and contained 16S rDNA. Compared with NM that was susceptible to almost all the antibiotics, MC was resistant to all the antibiotics. Lipid analyses showed high frequency of unsaturated fatty acids and cholesterol in MC.

نتیجه‌گیری

Coccoid forms with high fatty acid and cholesterol contents that show resistance to antibiotics might resist against other stressful conditions such as gastric acidity and immune response. Moreover, mucoid property may enhance resistance of coccoids to stresses. With mucoid-coccoid life style, H. pylori may establish a chronic infection refractory to antimicrobial therapy.