INFLUENCE OF OROPHARYNGEAL FLORA AND SPECIMEN PRETREATMENT ON THE RECOVERY OF HELICOBACTER-PYLORI

The recovery of Helicobacter pylori was studied in vitro in the presen ce of different concentrations of oropharyngeal flora. The effect on t he bacterial yield of Helicobacter pylori and oropharyngeal flora of w ashing biopsies once, twice or thrice before culture was then studied in biopsies taken from 35 patients, A low rate of recovery of low Heli cobacter pylori concentrations (less than or equal to 10(3) cfu/ml) wa s related to the presence of relatively high oropharyngeal flora conce ntrations (greater than or equal to 10(4) cfu/ml), After three washing s a decrease in oropharyngeal flora between 10-fold and 100-fold cfu/b iopsy was observed in seven patient samples. In another three specimen s a more than 100-fold reduction in cfu/biopsy was observed, In the ca se of Helicobacter pylori, a 60-fold decrease in log cfu/biopsy was ob served in only one patient, Pretreatment of the specimens by washing o f the biopsies improved the recovery of small amounts of Helicobacter pylori in 10 of 28 patients, For optimal detection of Helicobacter pyl ori in gastric mucosal biopsies, washing of the specimens in addition to the use of selective media is recommended.