ALS1 and ALS3 gene expression and biofilm formation in Candida albicans isolated from vulvovaginal candidiasis


1 Department of Mycology, Faculty of Medical Science, Isfahan University of Medical Science, Isfahan, Iran

2 Department of Parasitology and Mycology, School of Medicine, Iran University of Medical Science, Tehran, Iran

3 Department of Bacteriology, Faculty of Medical Science, Tarbiat Modares University, Tehran, Iran

4 Department of Pathobiology, Faculty of Veterinary Medicine, University of Tabriz, Tabriz, Iran

5 Department of Medical Parasitology and Mycology, School of Medicine, Isfahan University of Medical Science, Isfahan, Iran


Background: A cluster of genes are involved in the pathogenesis and adhesion of Candida albicans to mucosa and epithelial cells in the vagina, the important of which is agglutinin-like sequence (ALS) genes. As well as vaginitis is a significant health problem among women, the antifungal resistance of Candida species is continually increasing. This cross-sectional study investigates the expression of ALS1 and ALS3 genes and biofilm formation in C. albicans isolate isolated from vaginitis.
Materials and Methods: Fifty-three recognized isolates of C. albicans were collected from women with recurrent vulvovaginal candidiasis in Iran, cultured on sabouraud dextrose agar, and then examined for gene expression. Total messenger RNA (mRNA) extracted from C. albicans isolates and complementary DNA synthesized using reverse transcriptase enzyme. Reverse transcription-polymerase chain reaction (RT-PCR) using specific primer was used to evaluate the expression of ALS1 and ALS3 through housekeeping (ACT1) genes. 3-(4,5-dimethyl-2-thiazyl)-2,5-diphenyl-2H-tetrazolium bromide assay was performed to assess adherence capacity and biofilm formation in the isolated.

Results: Forty isolates (75.8%) expressed ALS1 and 41 isolates (77.7%) expressed ALS3 gene. Moreover, 39 isolates (74%) were positive for both ALS1 and ALS3 mRNA by the RT-PCR. Adherence capability in isolates with ALS1 or ALS3 genes expression was greater than the control group (with any gene expression), besides, it was significantly for the most in the isolates that expressed both ALS1 and ALS3 genes simultaneously.
Conclusion: The results attained indicated that there is an association between the expression of ALS1 and ALS3 genes and fluconazole resistance in C. albicans. A considerable percent of the isolates expressing the ALS1 and ALS3 genes may have contributed to their adherence to vagina and biofilm formation.


Naglik JR, Fostira F, Ruprai J, Staab JF, Challacombe SJ, Sundstrom P. Candida albicans HWP1 gene expression and host antibody responses in colonization and disease. J Med Microbiol 2006;55:1323-7.  Back to cited text no. 1
Alves CT, Wei XQ, Silva S, Azeredo J, Henriques M, Williams DW. Candida albicans promotes invasion and colonisation of Candida glabrata in a reconstituted human vaginal epithelium. J Infect 2014;69:396-407.  Back to cited text no. 2
Brockert PJ, Lachke SA, Srikantha T, Pujol C, Galask R, Soll DR. Phenotypic switching and mating type switching of Candida glabrata at sites of colonization. Infect Immun 2003;71:7109-18.  Back to cited text no. 3
Sun JN, Solis NV, Phan QT, Bajwa JS, Kashleva H, Thompson A, et al. Host cell invasion and virulence mediated by Candida albicans. PLoS Pathog 2010;6:1-14.  Back to cited text no. 4
Gropp K, Schild L, Schindler S, Hube B, Zipfel PF, Skerka C. The yeast Candida albicans evades human complement attack by secretion of aspartic proteases. Mol Immunol 2009;47:465-75.  Back to cited text no. 5
Zhao X, Oh SH, Hoyer LL. Unequal contribution of ALS9 alleles to adhesion between Candida albicans and human vascular endothelial cells. Microbiology 2007;153(Pt 7):2342-50.  Back to cited text no. 6
Hube B, Stehr F, Bossenz M, Mazur A, Kretschmar M, Schäfer W. Secreted lipases of Candida albicans: Cloning, characterisation and expression analysis of a new gene family with at least ten members. Arch Microbiol 2000;174:362-74.  Back to cited text no. 7
Hoyer LL, Green CB, Oh SH, Zhao X. Discovering the secrets of the Candida albicans agglutinin-like sequence (ALS) gene family – A sticky pursuit. Med Mycol 2008;46:1-15.  Back to cited text no. 8
Zhao X, Oh SH, Cheng G, Green CB, Nuessen JA, Yeater K, et al. ALS3 and ALS8 represent a single locus that encodes a Candida albicans adhesin; functional comparisons between Als3p and Als1p. Microbiology 2004;150:2415-28.  Back to cited text no. 9
Du H, Guan G, Xie J, Sun Y, Tong Y, Zhang L, et al. Roles of Candida albicans Gat2, a GATA-type zinc finger transcription factor, in biofilm formation, filamentous growth and virulence. PLoS One 2012;7:e29707.  Back to cited text no. 10
Li F, Svarovsky MJ, Karlsson AJ, Wagner JP, Marchillo K, Oshel P, et al. Eap1p, an adhesin that mediates Candida albicans biofilm formation in vitro and in vivo. Eukaryot Cell 2007;6:931-9.  Back to cited text no. 11
Murciano C, Moyes DL, Runglall M, Tobouti P, Islam A, Hoyer LL, et al. Evaluation of the role of Candida albicans agglutinin-like sequence (Als) proteins in human oral epithelial cell interactions. PLoS One 2012;7:e33362.  Back to cited text no. 12
Hoyer LL, Hecht JE. The ALS5 gene of Candida albicans and analysis of the Als5p N-terminal domain. Yeast 2001;18:49-60.  Back to cited text no. 13
Liu Y, Filler SG. Candida albicans Als3, a multifunctional adhesin and invasin. Eukaryot Cell 2011;10:168-73.  Back to cited text no. 14
Schaller M, Bein M, Korting HC, Baur S, Hamm G, Monod M, et al. The secreted aspartyl proteinases Sap1 and Sap2 cause tissue damage in an in vitro model of vaginal candidiasis based on reconstituted human vaginal epithelium. Infect Immun 2003;71:3227-34.  Back to cited text no. 15
Stehr F, Felk A, Gácser A, Kretschmar M, Mähnss B, Neuber K, et al. Expression analysis of the Candida albicans lipase gene family during experimental infections and in patient samples. FEMS Yeast Res 2004;4:401-8.  Back to cited text no. 16
Roudbary M, Roudbarmohammadi SH, Bakhshi B, Farhadi Z. Relation of ALS 1 and ALS3 genes and fluconazole resistance in Candida albicans isolated from vaginal candidiasis. Inter J Mol Clin Microbiol 2012;2:170-4.  Back to cited text no. 17
Ausubel FM, Brent R, Kingston RE, More D. Current Protocols in Molecular Biology. John wiley & sons Inc; ringbou edition 2003.  Back to cited text no. 18
Kavanagh K. New Insight in Medical Mycology. Netherland: Springer; 2007.  Back to cited text no. 19
Cheng G, Wozniak K, Wallig MA, Fidel PL Jr., Trupin SR, Hoyer LL. Comparison between Candida albicans agglutinin-like sequence gene expression patterns in human clinical specimens and models of vaginal candidiasis. Infect Immun 2005;73:1656-63.  Back to cited text no. 20
Nas T, Kalkanci A, Fidan I, Hizel K, Bolat S, Yolbakan S, et al. Expression of ALS1, HWP1 and SAP4 genes in Candida albicans strains isolated from women with vaginitis. Folia Microbiol (Praha) 2008;53:179-83.  Back to cited text no. 21
Dhamgaye S, Bernard M, Lelandais G, Sismeiro O, Lemoine S, Coppée JY, et al. RNA sequencing revealed novel actors of the acquisition of drug resistance in Candida albicans. BMC Genomics 2012;13:396.  Back to cited text no. 22
García-Sánchez S, Aubert S, Iraqui I, Janbon G, Ghigo JM, d'Enfert C. Candida albicans biofilms: A developmental state associated with specific and stable gene expression patterns. Eukaryot Cell 2004;3:536-45.  Back to cited text no. 23
İnci M, Atalya MA, Ozer B, Evirgen O, Duran N, Nedretkoc A, et al. Investigations of ALS1 and HWP1 genes in clinical isolates of Candida albicans. Turk J Med Sci 2013;43:125-30.  Back to cited text no. 24
Chandra J, Kuhn DM, Mukherjee PK, Hoyer LL, McCormick T, Ghannoum MA. Biofilm formation by the fungal pathogen Candida albicans: Development, architecture, and drug resistance. J Bacteriol 2001;183:5385-94.  Back to cited text no. 25
Kumamoto CA. Candida biofilms: An update. Eukaryot Cells 2005;4: 633-638.  Back to cited text no. 26
Uwamahoro N, Qu Y, Jelicic B, Lo TL, Beaurepaire C, Bantun F, et al. The functions of Mediator in Candida albicans support a role in shaping species-specific gene expression. PLoS Genet 2012;8:e1002613.  Back to cited text no. 27
Modrzewska B, Kurnatowski P. Adherence of Candida sp. to host tissues and cells as one of its pathogenicity features. Ann Parasitol 2015;61:3-9.  Back to cited text no. 28
Argimón S, Wishart JA, Leng R, Macaskill S, Mavor A, Alexandris T, et al. Developmental regulation of an adhesin gene during cellular morphogenesis in the fungal pathogen Candida albicans. Eukaryot Cell 2007;6:682-92.  Back to cited text no. 29
Bastidas RJ, Heitman J, Cardenas ME. The protein kinase Tor1 regulates adhesin gene expression in Candida albicans. PLoS Pathog 2009;5:e1000294.  Back to cited text no. 30