Methodology and transport medium for collection of Helicobacter pylori on a string test in remote locations.
BACKGROUND
Helicobacter pylori can be isolated from patients using the string test but contaminating oral and nasopharyngeal microflora need to be suppressed by rapid plating out onto selective culture media. Recently, use of this diagnostic method was enhanced by using a novel transport medium to collect specimens from subjects in a remote Australian clinic over 1300 km from the laboratory.


METHODS
Retrieved string tests were transported to the laboratory in chilled polystyrene boxes in 5 ml screw-cap bottles with 3 ml of a brain heart infusion broth plus antibiotics. These were 20 g/ml vancomycin, 10 g/ml trimethoprim, 10 g/ml cefsulodin, and 10 g/ml amphotericin B. A comparison was made between subjects who gargled with a chlorhexidine mouthwash before swallowing the string test and those who did not.


RESULTS
Forty-five urea breath test-positive subjects were tested and H. pylori was isolated from 34 of them. Successful culture was achieved from string tests that were in transit for up to 29 hours and where the maximum temperature in the transport box was 14 degrees C. The additional use of a mouthwash had a marked effect on the isolation rate. H. pylori was cultured from 75% of subjects who gargled but only from 39% who did not.


CONCLUSIONS
This methodology and transport medium can broaden the use of the string test to more remote geographic areas where endoscopy is not feasible so that H. pylori isolates may still be obtained for diagnostic and epidemiologic studies. The value of this promising methodology of collection and transport should be assessed in a controlled study.
Windsor
Helen M
HM
NHMRC Helicobacter Research Laboratory, Microbiology, University of Western Australia, Perth, Australia.
Abioye-Kuteyi
Emmanuel A
EA
Marshall
Barry J
BJ
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000554:Ambulatory Care Facilities; D001315:Australia; D001431:Bacteriological Techniques; D002648:Child; D003470:Culture Media; D005260:Female; D016481:Helicobacter Infections / Q000175:diagnosis* / Q000382:microbiology; D016480:Helicobacter pylori / Q000302:isolation & purification*; D006801:Humans; D008297:Male; D008875:Middle Aged; D013048:Specimen Handling / Q000379:methods*
D003470:Culture Media