| is the fourth most common cause of
bloodborne infection in the United States, accounting for 10%
to 15% of all hospital-acquired septicemia cases. | Candida albicans |
| Yeast fungi can be classified into one of two groups | yeasts
and yeastlike fungi |
| Isolates that reproduce sexually, by forming
either ascospores or basidiospores, | True yeast |
| Most isolates
that are not capable of sexual reproduction or whose sexual state
has not yet been discovered are correctly termed | yeastlike fungi |
| Color of a yeast colony | ranges from white to cream or tan, with a few species forming
pink- to salmon-colored colonies |
| -are darkly pigmented because of melanin
in their cell walls
-are associated with several
species of the polymorphic fungi | phaeoid yeasts |
| -are the most notorious agents of yeast infection
-most important group of opportunistic fungal pathogens | Candida |
| is the premier cause of yeast infection
in the world. It is recovered as normal biota from a variety of
sites, including skin, the oral mucosa, the digestive tract, and the
vagina | Candida albicans |
| In individuals
with an intact immune system, infections are | localized and limited |
| One of the most widely recognized manifestations of C. albicans
infection is | thrush (oropharyngeal candidiasis), |
| also recognized as an indicator of
immunosuppression. Among individuals infected with human
immunodeficiency virus (HIV) and those receiving prolonged
antibacterial therapy or other chemotherapeutic agents, it
manifests itself as a serious infection capable of dissemination | Thrush |
| -is also a common Candida species that causes
disease and may account for 21% of all urinary yeast isolates
-difficult to treat | C. glabrata |
| This organism has different
sugar assimilation patterns, notably (blank)
from those of C. albicans and therefore can be easily differentiated | rapid assimilation of trehalose, |
| has emerged as a multidrug-resistant yeast
linked to high mortality rates associated with hospital-acquired
infections worldwide. | C. auris |
| Candida spp. produce pseudohyphae except | C. glabrata |
| special agar for Candida
More specific than sabouraud dextrose agar (SDA)
They are chromogenitc substrates included the agar produces different color products based on specific species specific enzyme | Chrom agar |
| inhibit the presence of bacteria | CHLORAMPHENICOLE |
| Candida is examine after how many hours of incubation | 48 |
| Appearance of C.albicans in Chrom agar | Light Green Colonies |
| Appearance of C.dubliniensis in Chrom agar | Dark Green |
| Appearance of C.auris in Chrom agar | Pink, Purple (Multiple color) |
| Appearance of C.krusel in Chrom agar | Fuzzy Pale Pink |
| Appearance of C.tropicalis in Chrom agar | Metallic/ Dull-Blue/ Grayish Blue |
| Appearance of .kefyr in Chrom agar | Pink to Purple/ Pink-Lavender |
| (white stuff/white cottage-cheese like patches on the mouth) | Oral moniliasis: THRUSH |
| Vulvovaginitis | Vaginal moniliasis: |
| fungal infection of the nails | Onychomycosis and Paronychomycosis |
| hyphae-like extensions of young yeast cells showing
parallel sides, aseptate and will not constrict at their point of origin | Germ tube |
| look like germ tubes but are septate and constricted at their point of origin | PSEUDOHYPHAE |
| can be misidentified as several other yeast species.
(blank) can identify this species | MALDI-TOF assays |
| has become a major cause
of outbreaks of nosocomial infections. | C. parapsilosis |
| 37C: +
42C: +
45C: +
Pseudofyphae: +
True Hyphae: +
Arthroconidia: -
Cyclohexamide: Resistant
Urea: -
Nitrate: - | C. albicans |
| 37C: +
42C: -
45C: -
Pseudofyphae: +
True Hyphae: +
Arthroconidia: -
Cyclohexamide: Resistant
Urea: -
Nitrate: - | C. dubliniensis |
| 37C: +
42C: +
45C: +
Pseudofyphae: -
True Hyphae: -
Arthroconidia: -
Cyclohexamide: Susceptible
Urea: -
Nitrate: - | C. glabrata |
| 37C: +
42C: +
45C: -
Pseudofyphae: +
True Hyphae: -
Arthroconidia: -
Cyclohexamide: Resistant
Urea: -
Nitrate: - | C. guilliermondii |
| 37C: +
42C: +
45C: -
Pseudofyphae: +
True Hyphae: -
Arthroconidia: -
Cyclohexamide: Susceptible
Urea: Variable
Nitrate: - | C. krusei |
| 37C: +
42C: +
45C: +
Pseudofyphae: +
True Hyphae: -
Arthroconidia: -
Cyclohexamide: Variable
Urea: -
Nitrate: - | C. lusitaniae |
| 37C: +
42C: -
45C: -
Pseudofyphae: +
True Hyphae: -
Arthroconidia: -
Cyclohexamide: Susceptible
Urea: -
Nitrate: - | C. parapsilosis |
| 37C: +
42C: +
45C: +
Pseudofyphae: +
True Hyphae: +
Arthroconidia: -
Cyclohexamide: Susceptible
Urea: -
Nitrate: - | C. stellatoidea |
| 37C: +
42C: +
45C: +
Pseudofyphae: +
True Hyphae: -
Arthroconidia: -
Cyclohexamide: Variable
Urea: -
Nitrate: - | C. tropicalis |
| 37C: -
42C: -
45C: -
Pseudofyphae: -
True Hyphae: -
Arthroconidia: -
Cyclohexamide: Susceptible
Urea: +
Nitrate: + | C. albidus |
| 37C: +
42C: -
45C: -
Pseudofyphae: -
True Hyphae: -
Arthroconidia: -
Cyclohexamide: Susceptible
Urea: +
Nitrate: - | C. neoformans |
| 37C: +
42C: -
45C: -
Pseudofyphae: -
True Hyphae: -
Arthroconidia: -
Cyclohexamide: Resistant
Urea: +
Nitrate: - | C. gattii |
| 37C: +
42C: Variable
45C: -
Pseudofyphae: +
True Hyphae: +
Arthroconidia: +
Cyclohexamide: Resistant
Urea: +
Nitrate: - | Trichosporon spp. |
| is used primarily to examine
cerebrospinal fluid for the presence of the encapsulated yeast
Cryptococcus neoformans. | India ink |
| are important causes of meningitis, pulmonary
disease, and septicemia. | Cryptococcus spp. |
| the most notable pathogen
in this genus, is a major cause of opportunistic infection in patients
with AIDS. | C. neoformans |
| Cryptococcus neoformans is commonly found in SOIL contaminated with | pigeon droppings |
| Cryptococcus neoformans can be acquired through | Inhalation |
| (result of mucoid colony) in bird and bat droppings (pigeon droppings) | encapsulated yeast cell |
| ight halos against dark background (negative staining - presumptive test in
CSF) | India ink |
| INFECTION: Cryptococcosis (Torulosis/ Torulopsis) | Cryptococcus neoformans |
| C. neoformans produces blastoconidia at | Cornmeal agar |
| Unique from C.neoformans (positive) | Urease, Inositol, Phenol oxidase |
| C. neoformans gram stain | Starbust pattern |
| C. neoformans culture media | SDA w/o cycloheximide |
| C. neoformans in Birdseed agar | "brown black” colonies |
| Differential enrichment medium designed to isolate and preliminary identification of C.neoformans | BIRDSEED agar |
| In birdseed agar it uses ground seed of (blank) to provide the enrichment of the agar | GUIZOTIA |
| substrate in the medium that detect for the phenol oxidase activity of C.neoforman (responsible for the brown black colonies) | BIPHENYL |
| -is an emerging pathogen, particularly in the Pacifi
Northwest of the United States
-Infections caused by this species
are similar to those caused by C. neoformans, targeting primarily
immunocompromised patients. | C. gattii |
| The capsule can be detected surrounding
the budding yeast in CSF with the aid of | India ink or nigrosin |
| The use of India ink
preparation is being replaced by use of (blank) due to low sensitivity | cryptococcal antigen tests |
| an easy-to-use lateral-flow assay, are recommended for routine use in clinical microbiology laboratories, detect C. neoformans and C. gattii in CSF and serum | cryptococcal antigen
assays |
| are noted for producing blastoconidia only,
without producing true hyphae or pseudohyphae on cornmeal
agar | Cryptococcus spp |
| Production of (blank) is a feature dif
ferentiating C. neoformans from many other Cryptococcus spp. | Phenol oxidase |
| C. gatti used (blank) as a sole carbon and nitrogen source in the presence of canavanine | Glycine |
| is commercially available for this purpose and can be
used to differentiate between C. neoformans and C. gattii. | Canavanine glycine bromothymol
blue agar |
| Emerging important pathogens in immunocompromised patients and those with indwelling devices | Rhodotorula spp. |
| Implicated as a cause of central venous catheter infection and fungemia, ocular infections, peritonitis and meningitis | Rhodotorula spp. |
| Rhodotorula is noted for their mucoid | bright salmon-pink color |
| They resemble the cryptococci because they bear a capsule and
are urease positive | Rhodotorula spp. |
| can inhabit the lungs of many mammals. | Pneumocystis spp. |
| was originally classified with the protozoa,
but nucleic acid sequencing showed conclusively that the organism
is a fungus | Pneumocystis carinii |
| is the species most commonly
found in rats | P. carinii |
| is the species most often recovered
from humans. | P. jirovecii |
| Pneumocystis spp. infection is acquired early in life; serologic
studies have shown that most humans have antibodies or antigens
by | 2 to 4 |
| initially
was identified as the causative agent in interstitial plasma cell
pneumonia seen in malnourished or premature infants | Pneumocystis |
| one of the primary opportunistic
infections found in patients with AIDS. | Pneumonia |
| -may have nonproductive cough, difficulty breathing, and a low-grade fever
-Chest radiographs
can be normal or show a diffuse interstitial infiltrate
- | Pneumocystis |
| When the infiltrate is examined, it is found to contain cells from
the | Alveoli and plasma cells |
| -nonfilamentous fungus
-it was first considered a protozoan | Pneumocystis |
| which is 1 to 5 µm
in size and is irregularly shaped | Trophozoite |
| 5 to 8 μm; | precyst |
| which is a thick-walled sphere of about 8 μm containing up
to eight intracystic bodies | Cyst |
| Transmission of Pneumocystis is known to occur through the | respiratory route |
| Infective stage of pneumocystis | Cyst |
| The
spores or intracystic bodies are released from the cyst in the lung,
and these trophic forms multiply asexually by | Binary Fission |
| Traditional diagnosis of Pneumocystis | finding the cyst or trophozoite through open lung biopsy. |
| Specimen for Pneumocystis | bronchoalveolar lavage (BAL) fluid, transbronchial biopsy
specimens, tracheal aspirate, pleural fluid, and induced sputum |
| least productive specimen of pneumocystis | Sputum |
| Lavage and
sputum specimens are often prepared using a | Cytocentrifuge |
| Stains for Pneumocystis | Giemsa and Gomori methenamine
silver stains, |
| methenamine silver stain | the cyst
wall stains black |
| Cysts often have a punched-out ping-pong ball
appearance. | Pneumocystis |
| the organism appears round,
and the cyst wall is barely visible | Giemsa stain |
| The cyst wall does not pick up the stain, but the nuclei of all
forms stain pink, and the intracystic bodies can be demonstrated
as a circular arrangement within the cyst. | True |
| can be used to screen specimens for Pneu
mocystis
and other fungi. | Calcofluor white |
| This stain detects any organism that
contains chitin in its cell wall. | Calcoflour white |
| stains are commercially available and are
widely used. | Immunofluorescent
monoclonal antibody |
| INFECTION is acquired (blank) causes respiratory infections in immunocompromised patients | early life |
| Hallmark of pneumocystis | interstitial pneumonitis |
| cyst wall stains BLACK; "punched out ping-pong ball appearance" | GMS (Gomori methenamine silver stains) |
| cyst wall is barely visible; intracystic bodies (pink) | Giemsa- round |
| prophylactic treatment to some patients with AIDS | Aerosolized pentamidine |
| TREATMENT | 1. Trimethoprim-sulfamethoxazole
2. Pentamidine isethionate
3. Aerosolized pentamidine |
| What class of biological safety cabinet should be used to reduce exposure of
personnel to fungal elements | Class 2 |
| to eliminate the hazards of open gas flames and to contain aerosol
ized
particles emitted when loops or needles are incinerated | enclosed electric incinerator |
| The cabinets should be checked | Daily |
| Use of (Blank) in the mycology laboratory is hazardous;
screw-top tubes are recommended instead | Petri dish |
| also tend to reduce dehydration of media compared
with Petri dishes and are more easily handled and stored | Screw top tube |
| have a larger surface area for colony isolation and
are easier to manipulate when making preparations for microscopic
examination. | Petri dish |
