Various Candida species can cause challenging infections, with Candida albi-

species is crucial for delineating the factors controlling the process. Developing means to curtail infections resulting from this virulence phenotype is also impor­tant. This chapter focuses on Candida biolms to comprehensively understand the processes leading to biolm formation and dispersal. This chapter also provided insight into the mechanisms, transcriptional proteins, and genes controlling biolm

The major Candida spp. that cause infections include C. albicans, C. tropicalis, C. glabrata, C. parapsilosis, C. auris, and C. krusei (Malinovská etal. 2023). The

are distinct colonies of microcolonies formation. The next phase is characterized by EPS production. This is followed by bilayer formation. The bilayer is composed of yeast, germ tubes, and/or young hyphae. Maturation of biolms entails the progres­sion of a substantial extracellular polymeric substance (EPS) layer housing yeasts and hyphae, constructing a compact interconnected structure within approximately 38–72h. Subsequent to maturation, the dispersal phase ensues. In this stage, fully developed biolms release offspring cells through budding, transforming into non­adherent yeast cells available for colonization or causing infection, as indicated by Cámara etal. (2022). Notably, most researches on biolm formation have been car­ried out under controlled laboratory conditions (in vitro). An informative invivo investigation by Andes etal. (2004) observed the evolution of C. albicans biolm within a central venous catheter in rats. This study’s ndings highlighted notable distinctions compared to experiments conducted in articial environments (in vitro). For instance, the early phase of invivo biolm formation was shorter, with several layers of yeast cells and hyphae present after 8h. In contrast, invitro maturation took 38–72h. In the case of C. glabrata, matured biolm was seen after 48h in catheters in a rat subcutaneous model. There were also differences in early-phase development and cell attachment dependence on the catheter. Zuo et al. (2021) reported that C. parapsilosis had the highest biolm-forming ability among all Candida species, while C. glabrata had the least. It was also noted that non-albicans spp., including C. parapsilosis and C. glabrata, had a higher adhesion ability in catheter-related candidemia. This evidence highlights the increasing role of non­albicans in clinical infections (Govrins and Lass-Flörl 2023).

is facilitated by adhesins (proteins associated with cell walls). These adhesins facili­tate binding to epithelial cells or nonliving surfaces. The adhesins attach to amino acids or sugar residues (Gulati and Nobile 2016). Typically, adhesins belong to the glycosyl-phosphatidylinositol-cell wall proteins. This protein consists of a GPI anchor and different domains enhancing attachment to carbohydrates or peptides (Verstrepen and Klis 2006; Kumari etal. 2021). In C. albicans and other Candida spp., there are the agglutinin-like sequence proteins (Als). The Als is a subset of the GPI_CWP family. This family comprises several adhesins playing diverse roles in biolm formation. For example, deletion of Als3 results in a signicant loss of biolm- forming ability (Nobile etal. 2006). Similar ALS-like proteins are found in other Candida species. For example, similar Als have been reported in Candida spp. such as C. tropicalis, C. parapsilosis, C. lusitaniae, C. dubliniensis, and C.

Interestingly, most of these additional regulators are linked with the master regu-

So far, not much has been learned about dual-species biolms between C. albi-

cans and other microbes. Studies have explored such biolms, pairing C. albicans with bacteria frequently isolated from different human body. Some of these microbes secrete signaling molecules, directly or indirectly inuencing polymicrobial infec­tion. A recent study by Lueyar etal. (2023) provided a deep insight into Candida interaction with streptococcus species in oral biolm. The study suggests that

that it acts as a barrier, enhancing Candida cells’ resistance to drugs like amphoteri­cin B (Lucas and Silva 2023; Massey etal. 2023). Upregulation of MDR and CDR genes in C. alibicans brings about changes in the expression of genes involved in

2019). These dormant, nondividing cells display signicant resistance to antimicro-

This chapter underscores the complex processes occurring within cells that lead to the formation of Candida biolms. It has been established that the biolm forma­tion process includes adhesion, cell morphology changes, ECM formation, and bio­lm dispersal. Notably, factors that control each of these steps are species- or strain-specic in most cases. Several factors, including nutrient composition, inhibi­tors within a niche, environmental conditions, and microbiome in an environment, impact the ultimate characteristics of the biolm. Despite the existing knowledge, many aspects, particularly those related to biolm formation among non-Candida albicans cells, remain inadequately explored. Unfortunately, most non-albicans are posing major public health threats due to their frequent isolation and link to most infectious diseases. It is crucial to differentiate between biolms formed by diverse Candida spp., especially the non-albicans. It is also important to understand the biolm forms by commensal Candida populations. Understanding how this Candida population transitions to pathogens exhibiting biolm-forming propensity demands