title: Polymicrobial biofilm formation by Candida albicans, Actinomyces naeslundii, and Streptococcus mutans is Candida albicans strain and medium dependent.
abstract: Oral biofilms comprise of extracellular polysaccharides and polymicrobial microorganisms. The objective of this study was to determine the effect of polymicrobial interactions of Candida albicans, Actinomyces naeslundii, and Streptococcus mutans on biofilm formation with the hypotheses that biofilm biomass and metabolic activity are both C. albicans strain and growth medium dependent. To study monospecific biofilms, C. albicans, A. naeslundii, and S. mutans were inoculated into artificial saliva medium (ASM) and RPMI-1640 in separate vials, whereas to study polymicrobial biofilm formation, the inoculum containing microorganisms was prepared in the same vial prior inoculation into a 96-well plate followed by 72 hours incubation. Finally, biofilm biomass and metabolic activity were measured using crystal violet and XTT assays, respectively. Our results showed variability of monospecies and polymicrobial biofilm biomass between C. albicans strains and growth medium. Based on cut-offs, out of 32, seven RPMI-grown biofilms had high biofilm biomass (HBB), whereas, in ASM-grown biofilms, 14 out of 32 were HBB. Of the 32 biofilms grown in RPMI-1640, 21 were high metabolic activity (HMA), whereas in ASM, there was no biofilm had HMA. Significant differences were observed between ASM and RPMI-grown biofilms with respect to metabolic activity (P <01). In conclusion, biofilm biomass and metabolic activity were both C. albicans strain and growth medium dependent.
authors.affiliation: Oral Health CRC, Melbourne Dental School, The University of Melbourne, Victoria, Australia Kulliyyah of Dentistry, International Islamic University Malaysia, Kuantan, Pahang, Malaysia.
authors.forename: Mohd Hafiz
authors.initials: MH
authors.lastname: Arzmi
authors.affiliation: Oral Health CRC, Melbourne Dental School, The University of Melbourne, Victoria, Australia.
authors.forename: Ali D
authors.initials: AD
authors.lastname: Alnuaimi
authors.affiliation: Oral Health CRC, Melbourne Dental School, The University of Melbourne, Victoria, Australia.
authors.forename: Stuart
authors.initials: S
authors.lastname: Dashper
authors.affiliation: Oral Health CRC, Melbourne Dental School, The University of Melbourne, Victoria, Australia.
authors.forename: Nicola
authors.initials: N
authors.lastname: Cirillo
authors.affiliation: Oral Health CRC, Melbourne Dental School, The University of Melbourne, Victoria, Australia.
authors.forename: Eric C
authors.initials: EC
authors.lastname: Reynolds
authors.affiliation: Oral Health CRC, Melbourne Dental School, The University of Melbourne, Victoria, Australia m.mccullough@unimelb.edu.au.
authors.forename: Michael
authors.initials: M
authors.lastname: McCullough
mesh_terms: D000190:Actinomyces / Q000254:growth & development / Q000378:metabolism / Q000502:physiology*; D018441:Biofilms / Q000254:growth & development*; D002176:Candida albicans / Q000254:growth & development / Q000378:metabolism / Q000502:physiology*; D003470:Culture Media / Q000737:chemistry*; D005562:Formazans / Q000032:analysis; D005840:Gentian Violet / Q000032:analysis; D056265:Microbial Interactions; D008954:Models, Biological; D012463:Saliva / Q000382:microbiology; D013194:Staining and Labeling; D013295:Streptococcus mutans / Q000254:growth & development / Q000378:metabolism / Q000502:physiology*
chemical_list: D003470:Culture Media; D005562:Formazans; C059088:1,5-bis(2-methoxy-4-nitro-5-sulfophenyl)-3-((phenylamino)carbonyl)formazan; D005840:Gentian Violet
keywords: Polymicrobial biofilm; XTT assay; crystal violet assay