Experimental Germ Tube Induction in : An Evaluation of the Effect of Sodium Bicarbonate on Morphogenesis and Comparison with Pooled Human Serum.

OBJECTIVE

The potential of NaHCO versus human serum to induce germ tube formation in was investigated.

SPECIMENS

A total of 100 isolates were obtained from oral swabs of patients presenting with thrush. Approval for the study was granted by the Joint Research Ethics Committee (JREC/23/08).

METHOD

Confirmed isolates by routine methods were tested for germ tube induction using 5 different concentrations of Tris-maleate buffered NaHCO and Tris-maleate buffer control. Standard control strains included were (ATCC 10231) and (ATCC 6258). Microculture was done in 20 L inoculums on microscope slides for 3 hours at 37°C. The rate of germ tube formation at 10-minute intervals was determined on 100 isolates using the optimum 20 mM Tris-maleate buffered NaHCO concentration. Parallel germ tube formation using human serum was done in test tubes.

RESULTS

The optimum concentration of NaHCO in Tris-maleate buffer for germ tube induction was 20 mM for 67% of isolates. Only 21% of isolates formed germ tubes in Tris-maleate buffer control. There was no significant difference in induction between human serum and Tris-maleate buffered NaHCO.

CONCLUSION

Tris-maleate buffered NaHCO induced germ tube formation in isolates at rates similar to human serum.