The effect of oral bacteria on Candida albicans germ-tube formation.
A total of eight bacterial isolates belonging to six species, and a select group of 12 oral Candida albicans isolates, were used to study the effect of bacteria on germ-tube formation. Briefly, each bacterial suspension (10(5-6) cells/ml) was mixed with a C. albicans suspension (10(7) cells/ml) and incubated at 37 degrees C for 90 min with bovine serum, and the percentage germ-tube-positive Candida cells was quantified using a haemocytometer, under light microscopy. In general, out of eight bacteria, Streptococcus sanguis SK21A, Streptococcus salivarius SK56, Escherichia coli ATCC 25922, and S. salivarius OBU3 suppressed germ-tube formation to varying degrees, with different C albicans isolates. Porphyromonas gingivalis Pg 50, Lactobacillus casei ATCC 7469 and Prevotella intermedia OBU4 elicited significant enhancement of germ-tube formation, whereas S. sanguis OBU 2 had no effect. E. coli ATCC 25922 was the only organism to show statistically significant suppression of germ-tube formation (p=0.0312). A significant increase in the germ tube production of C. albicans isolated from HIV-infected compared with HIV-free individuals was also noted. The current results tend to suggest that commensal and transient oral bacterial populations may selectively influence the differential expression of germ-tube-forming ability of C. albicans isolates.
Nair
R G
RG
Oral Bio-Sciences, Faculty of Dentistry, University of Hong Kong, Hong Kong.
Anil
S
S
Samaranayake
L P
LP
D002176:Candida albicans / Q000254:growth & development*; D003470:Culture Media; D004926:Escherichia coli / Q000502:physiology; D006090:Gram-Negative Bacteria / Q000502:physiology*; D006094:Gram-Positive Bacteria / Q000502:physiology*; D015658:HIV Infections / Q000382:microbiology*; D015497:HIV-1; D006801:Humans; D007780:Lacticaseibacillus casei / Q000502:physiology; D009055:Mouth / Q000382:microbiology*; D016966:Porphyromonas gingivalis / Q000502:physiology; D018713:Prevotella intermedia / Q000502:physiology; D013291:Streptococcus / Q000502:physiology; D013298:Streptococcus sanguis / Q000502:physiology
D003470:Culture Media