biology

Invasive candidiasis

Invasive candidiasis is a biology topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Invasive candidiasis rather than just read about it. In short: Invasive candidiasis is an infection (candidiasis) that can be caused by various species of Candida yeast. Unlike Candida infections of the mouth and throat (oral candidiasis) or vagina (Candidal vulvovaginitis), invasive candidiasis is a serious, progressive, and potentially fatal infection that can affect the blood (fungemia), heart, brain, eyes, bones, and other parts of the body.

Key takeaways

Invasive candidiasis belongs to biology; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Invasive candidiasis to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Invasive candidiasis from memory before moving on to harder problems.

Reference excerpt

Invasive candidiasis is an infection (candidiasis) that can be caused by various species of Candida yeast. Unlike Candida infections of the mouth and throat (oral candidiasis) or vagina (Candidal vulvovaginitis), invasive candidiasis is a serious, progressive, and potentially fatal infection that can affect the blood (fungemia), heart, brain, eyes, bones, and other parts of the body.

Signs and symptoms Symptoms of invasive candidiasis can be confused with other medical conditions, however, the most common symptoms are fever and chills that do not improve with antibiotic treatment. Other symptoms develop as the infection spreads, depending on which parts of the body are involved.

Presentation Invasive candidiasis can manifest as serious diseases including as fungemia, endocarditis, endophthalmitis, osteomyelitis, and central nervous system infections.

Cause Invasive candidiasis is caused by 15 of the more than 150 known species of Candida. These species, all confirmed by isolation from patients, are: C. albicans, C. glabrata, C. tropicalis, C. parapsilosis, C. krusei, C. guilliermondii, C. lusitaniae, C. dubliniensis, C. pelliculosa, C. kefyr, C. lipolytica, C. famata, C. inconspicua, C. rugosa, and C. norvegensis. Over the last 20–30 years, C. albicans has been responsible for 95% of infections, with, C. glabrata, C. parapsilosis, C. tropicalis, and C. krusei causing the majority of the remaining cases. Recently, C. auris, a species first reported in 2009, has been found to cause invasive candidiasis. C. auris has attracted attention because it can be resistant to the antifungal medications used to treat candidiasis.

Resistance Resistance to antifungal treatment can arise from species with intrinsic resistance that experience selection pressure or spontaneous induction of resistance in isolates from normally susceptible species. For Candida, the most common is the former, as seen by the emergence of resistant C. glabrata following the introduction of fluconazole and of C. parapsilosis where there was increased use of echinocandins. Insufficient dosing of azoles has also led to the emergence of resistance. Observed rates of echinocandin resistance for C. glabrata are between 2 and 12%. Acquired echinocandin resistance has also been reported for C. albicans, C. tropicalis, C. krusei, C. kefyr, C. lusitaniae, and C. dubliniensis.

Emergent species Candida auris is an emerging multidrug-resistant yeast that can cause invasive candidiasis and is associated with high mortality. It was first described in 2009. Since then, C. auris infections, specifically fungemia, have been reported from South Korea, India, South Africa, Kuwait, Colombia, Venezuela, Pakistan, the United Kingdom and the United States. The strains isolated in each region are genetically distinct, indicating that this species is emerging in different locations. The reason for this pattern is unknown.

Risk factors Patients with the following conditions, treatments or situations are at increased risk for invasive candidiasis.

Critical illness Long-term intensive care unit stay Abdominal surgery (aggravated by anastomotic leakage or repeat laparotomies) Immunosuppressive diseases Acute necrotizing pancreatitis Malignant hematologic disease Solid-organ transplantation Hematopoietic stem cell transplantation Solid-organ tumors Neonates (especially low birth weight and preterm infants) Broad-spectrum antibiotic treatment Central venous catheter Internal prosthetic device Total parenteral nutrition Hemodialysis Glucocorticoid use Chemotherapy Noninvasive Candida colonization (particularly if multifocal)

Transmission Invasive candidiasis is a nosocomial infection with the majority of cases associated with hospital stays.

Diagnosis Because many Candida species are part of the human microbiota, their presence in the mouth, the vagina, sputum, urine, stool, or skin is not definitive evidence for invasive candidiasis. Positive culture of Candida species from normally sterile sites, such as blood, cerebrospinal fluid, pericardium, pericardial fluid, or biopsied tissue, is definitive evidence of invasive candidiasis. Diagnosis by culturing allows subsequent susceptibility testing of causative species. Sensitivity of blood culture is far from ideal, with a sensitivity reported to be between 21 and 71%. Additionally, whereas blood culture can establish a diagnosis during fungemia, the blood may test negative for deep-seated infections because candida may have been successfully cleared from the blood. Diagnosis of invasive candidiasis is supported by histopathologic evidence (for example, yeast cells or hyphae) observed in specimens of affected tissues. Additionally, elevated serum β-glucan can demonstrate invasive candidiasis while a negative test suggests a low likelihood of systemic infection. The emergence of multidrug-resistant C. auris as a cause of invasive candidiasis has necessitated additional testing in some settings. C. auris-caused invasive candidiasis is associated with high mortality. Many C. auris isolates have been found to be resistant to one or more of the three major antifungal classes (azoles, echinocandins, and polyenes) with some resistant to all three classes – severely limiting treatment options. Biochemical-based tests currently used in many laboratories to identify fungi, including API 20C AUX and VITEK-2, cannot differentiate C. auris from related species (for example, C. auris can be identified as C. haemulonii). Therefore, the Centers for Disease Control and Prevention recommends using a diagnostic method based on matrix-assisted laser desorption/ionization-time of flight mass spectrometry or a molecular method based on sequencing the D1-D2 region of the 28s rDNA to identify C. auris in settings where it may be present.

Prevention Preventive antifungal treatment is supported by studies, but only for specific high-risk groups in intensive care units with conditions that put them at high risk for the disease. For example, one group would be patients recovering from abdominal surgery that may have gastrointestinal perforations or anastomotic leakage. Antifungal prophylaxis can reduce the incidence of fungemia by approximately 50%, but has not been shown to improve survival. A major challenge limiting the number of patients receiving prophylaxis to only those that can potentially benefit, thereby avoiding the creation of selective pressure that can lead to the emergence of resistance.

… excerpt ends here. Continue reading the full article.

Worked examples

Example 1 — a first encounter with Invasive candidiasis

Start with the simplest possible case. Write down what Invasive candidiasis claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In biology, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Invasive candidiasis before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Invasive candidiasis ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Invasive candidiasis

In research: Invasive candidiasis appears in biology research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Invasive candidiasis in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Invasive candidiasis is common in secondary-school and first-year university syllabi. It links to neighbouring topics Animal fungal diseases, Sepsis, so understanding it makes those chapters shorter.
In everyday life: Look for Invasive candidiasis outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Invasive candidiasis in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Invasive candidiasis means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Invasive candidiasis out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Invasive candidiasis in simple terms?

Why does Invasive candidiasis matter?

Because it connects several biology ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Invasive candidiasis?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Invasive candidiasis.