Candida parapsilosis
1. Description and significance
Candida parapsilosis is a fungal species that is responsible for several diseases states in humans [1]. Among the many microbes found on human hands, C. parapsilosis is amidst the most prevalent fungal species [2]. This species is known to cause sepsis in those with compromised immune systems, neonates, intensive care patients, individuals with implanted devices, and individuals who have just recently undergone gastrointestinal surgery [2]. Researchers have found that as much as eight to fifteen percent of all infections procured by patients in hospitals have been attributed to C. parapsilosis [1]. Because of the lack of understanding about this taxon’s virulence mechanisms, treatment is difficult and not always effective [3]. It is therefore crucial for future research to focus on understanding the signaling pathways involved in infection and how these pathways are regulated since they are not well understood.
2. Classification
a. Higher order taxa
C. parapsilosis is a fungus belonging to the phylum Ascomycota [4]. C. parapsilosis is a member of the class Saccharomycetes and the order Saccharomycetales which are most commonly known as budding yeasts, meaning they can reproduce asexually through the process of mitosis when nutrients are abundant and sexually through production of haploid cells in meiosis when nutrients are not abundant [4][5]. C. parapsilosis is a member of the family Debaryomycetaceae, which are commonly associated with the yeast’s use of pseudohyphae to grow [4][6]. C. parapsilosis is a part of the genus Candida, which is most well known for its ability to cause disease in humans [7]. C. parapsilosis is also a member of the CTG clade, along with C. albicans, meaning that their CTG codon encodes for serine and not leucine [7].
3. Genome structure
Describe the size and content of the genome. How many chromosomes? Circular or linear? Other interesting features? What is known about its sequence?
4. Cell structure
Interesting features of cell structure. Can be combined with “metabolic processes”
5. Metabolic processes
Describe important sources of energy, electrons, and carbon (i.e. trophy) for the organism/organisms you are focusing on, as well as important molecules it/they synthesize(s).
6. Ecology
Habitat; symbiosis; contributions to the environment.
7. Pathology
C. parapsilosis is a pathogenic fungus that is easily spread within susceptible populations of humans and animals. The fungus causes sepsis, endocarditis, endophthalmitis, fungemia, peritonitis, and arthritis in humans. It is most commonly found on prosthetic devices, catheters, and other medical tools that are touched by healthcare workers [10]. The virulence of C. parapsilosis is increased by the its ability to form biofilms on these medical devices and grow from prolonged attachment [1]. Furthermore, the fungus can easily spread from healthcare worker to patient if thorough hand-washing is not performed prior to contact [10]. In the body, C. parapsilosis colonizes around the implanted device and attaches to mucosal surfaces nearby. Biofilm production serves as protection and makes the microbe resistant to antifungal medications [10]. This makes it difficult for natural immune cells to fight off the fungus since they are unable to attach onto the slippery surface of the biofilm. Thus, C. parapsilosis is ultimately responsible for causing post-surgical complications and premature death in susceptible populations. The most at-risk population of contracting an infection are neonatal patients, intensive care patients, and immunocompromised patients [1]. Unlike other Candida species, such as C. albicans, C. parapsilosis is not an obligate pathogen and only causes candidiasis in these specific populations [7]. C. parapsilosis can also affect the immune systems of animals in a similar manner. Animals can ingest the pathogen from soil, insects, and other environmental sources, leading to infection and death [10]. In addition to C. parapsilosis’ ability to defend itself against the immune response and antifungal medication, it is also able to hide from detection [11]. Histopathology signatures for C. parapsilosis are useful in identifying the fungus’ infectious pathway. However, they are not always detected upon screening [11]. In one study, blood and lung cultures of neonates who died from a C. parapsilosis infection were analyzed for any histopathological signatures. Upon autopsy and immunostaining, 61% of the population was found to have significant fungal presence, but only 14 out of the 187 neonates were initially diagnosed with a C. parapsilosis induced infection [11]. The overwhelming prevalence of C. parapsilosis in the majority of the studied population went undetected by normal screening methods, showing that C. parapsilosis infections often go underdiagnosed.
8. Current Research
Include information about how this microbe (or related microbes) are currently being studied and for what purpose
9. References
It is required that you add at least five primary research articles (in same format as the sample reference below) that corresponds to the info that you added to this page. [Sample reference] Faller, A., and Schleifer, K. "Modified Oxidase and Benzidine Tests for Separation of Staphylococci from Micrococci". Journal of Clinical Microbiology. 1981. Volume 13. p. 1031-1035.
