This document discusses fungal infections. It begins by listing the characteristics of fungi and describing the differences between molds and yeasts. The major classifications of human mycoses are described including superficial infections like tinea capitis and tinea versicolor. Deeper infections like sporotrichosis, mycetoma, and systemic mycoses caused by dimorphic fungi such as coccidiomycosis and histoplasmosis are also outlined. Opportunistic fungal infections in immunocompromised individuals that are described include Pneumocystis jiroveci pneumonia, oral and vaginal candidiasis, and cryptococcosis. Common treatment regimens for several of the infections are also provided.

1. unit 6
Characteristics of fungi
Types of mycoses
Opportunistic infections
Parasitic infections

2. Learning Objectives
• At the end of these lessons the learner will be able to:
- List characteristics of fungi
- List and explain the classes of human mycoses (fungal infections)
- List some organisms that cause fungal infections and the
conditions they cause
- State and explain manifestations of common OIs ( fungal
opportunistic infections)
- Describe and outline life cycles of selected parasitic infections
- Discuss preventive measures of selected parasitic infections

3. Terms and definitions
•Diagnosis- the act or process of identifying or
determining the nature and cause of a disease or injury
through evaluation of patient history, examination, and
review of laboratory data.OR
• the process of determining by examination the nature
and circumstances of a diseased condition
•Treatment- The use of an agent, procedure, or regimen,
such as a drug or surgery, in an attempt to cure or
mitigate a disease, condition, or injury.

4. Terms and definitions
• Dimorphic fungi - fungi that exist either in yeast form or as
mold (mycelial form) depending on environmental
conditions, physiological conditions of the fungus or the
genetic characteristics.
• E.g Histoplasma capsulatum and Sporothrix schenkii are
thermally dimorphic (yeast form at 37Oc and switches to
mold at 20oc-25oc)
• Saprophyte –an organism, especially a fungus or
bacterium, that lives on and gets its nourishment from
dead organisms or decaying organic material.

5. TERMS AND DEFINITIONS
•Hypha -(plural-hyphae), a long, branching filamentous
structure of a fungus. Observed during fragmentation
•Fragmentation-A type of asexual reproduction where an
organism upon maturation breaks down into fragments (or
pieces) and each fragment grows into a new organism.
•Mycelium- a group of hyphae
•Fungal spores (conidia)- microscopic biological particles
that allow fungi to be reproduced, serving a similar
purpose to that of seeds in the plant world

6. INTRODUCTION-characteristics of fungi
•Primarily distributed in terrestrial areas
•Many are pathogenic and infect both plants and
animals
•Exists as yeasts and molds
•Multicellular fungi are molds, unicellular fungi are
yeasts
•They can be decomposers, they degrade complex
organic material to simple inorganic molecules
•They are the major cause of plant diseases

7. Characteristics of fungi
•Eukaryotic
•Fungi reproduce asexually by fragmentation, budding, or
producing spores
•Typically not motile.
•Cell wall similar in structure to plants but differ in
chemical composition, theirs is made of chitin, plants’ is
made of cellulose
•Not dependent on light
•Can occupy dark habitats

8. Characteristics (end)
•They spoil food, fabrics, leather, paper etc as
long as the environment has growth
requirements
•They are useful in some industrial processes
•They are used in biological research
processes

9. Fungi as mold

10. Multicellular filamentous molds(end)

11. Fungi as yeast
BUDS

12. Differences-molds & yeasts(end)
CHARACTERISTIC MOLDS YEAST
REPRODUCTION spores Budding
USES Useful in biodegradation and food
production (cheese)
Bread production, wine brewing,
industrial ethanol production, food
additives or flavors
HABITAT Typically found in damp, dark or
steam filled areas
Very common: can be found on fruit
and berries, in the stomach of
mammals and on the skin
SHAPE Filamentous form, threadlike Round or oval in shape
CELL multicellular unicellular
EXAMPLES Alternaria, Aspergillus, Penicillium,
Trichophyton
Cryptococcus neoformans,
Sacharomyces cerevisiae

13. Classifications of fungal infections
•Superficial: these are fungal infections of the skin,
hair and nails
•TINEA CAPITIS
•RINGWORM OF THE SCALP
•Cause: Trichophyton tonsurans, Microsporum canis
•Predisposing factors: Oily skin, too much sweating
or a weakened immune system

14. TRANSMISSION
•Highly contagious!!
•by direct contact skin to skin with infected
person,
•sharing of combs,
•Sharing of hats or even clothing
•Can also be transmitted by pets-zoonotic

15. SIGNS & SYMPTOMS
•Round scaly lesions on the scalp
•Alopecia(loss of hair)

16. TINEA CAPITIS

17. DIAGNOSIS & TREATMENT(end)
Diagnosis
•Skin lesion biopsy to reveal the dermatophytes
Treatment options
•Griseofulvin
•Terbinafine, itraconazole, fluconazole

18. TINEA VERSICOLOR
•Fungal infection that normally affects trunk
and proximal extrimities
•Cause: Malassezia furfur

19. SIGNS & SYMPTOMS
•Patches that may be white, pink, red, or brown
and can be lighter or darker than the skin around
them.
•Spots that do not tan the way the rest of your skin
does.
•Spots that may occur anywhere on the body but
are most commonly seen on the neck, chest, back,
and arms.

20. Tinea versicolor

21. Diagnosis (end)
•Scrape skin and scales-observe under
microscope
TREATMENT
•Creams, Lotions or Shampoos containing:
Clotrimazole , miconazole or terbinafine

22. Other types (end)
•Other types of tinea infections that can occur
include
•tinea corporis (on the body),
•tinea cruris ('jock itch' in the groin area),
•tinea barbae (beard),
•or tinea pedis ('athletes' foot).

23. Classifications of fungal infections
• Subcutaneous: Infection affects nails and deeper layers of the
skin
• They are characterized by inflammation, fibrosis and scarring
• Examples of these are mycetomas which are deeply penetrating
infections of the subcutaneous tissue characterized by the above
as well as production of pus from openings in the skin
• Sporotrichosis is one subcutaneous condition caused by
Sporothrix schenckii

24. Sporotrichosis- rose handler’s disease
•It affects people handling thorny plants, garden
roses or hay.
•Starts with painless red, pink or purple bump
resembling an insect bite on the finger or hand.
•It then opens and becomes like a boil. Many of
them can spread and become ulcerated
•Nicknamed ‘rose handlers disease’

25. Cont’d
•Treatment: Potassium iodide taken orally or a
new drug called itraconazole (sporanox) which
has not be experimented much
•Prevention: Wear gloves when handling such
things as the above

26. Sporotrichosis

27. Sporotrichosis-rose gardener’s disease

28. Severe sporotrichosis(end)

29. Mycetoma
•Cause- Madurella mycetomitis, Exophial jeanselmei
•A chronic specific granulomatous (granuloma – collection
of macrophages filled with bacteria or fungus) infection.
•It is characterized by swelling, granuloma formation,
purulent exudate. It affects the feet
•Treatment: surgery, ketoconazole, voriconazole,
itraconazole, amputation
•Prevention: Wearing of PEP when walking in terrestrial
areas and endemic areas

30. Eumycetoma condition

31. Eumycetoma condition(end)

32. Deep/Systemic mycoses
-Caused by dimorphic fungi ( those fungi that exist in
two forms – as parasitic yeast and saprophytic mold
or mycelia)
-Infection is thru. inhalation of spores from soil in
which free living fungi live
-Infection can begin as lung lesion, becomes chronic
and disseminate via blood stream to other organs
-Examples are Coccidiomycosis, Histoplasmosis and
Blastomycosis

33. Coccidiomycosis
• Also known as ‘valley fever’
• Cause- Coccidiodes immitis
•Found in soil contaminated with bird droppings or bat
excrements
• Transmission- inhalation of coccidiodes spores
• it affects liver, brain, bones, meninges, and heart.
• Symptoms –
•Fatigue (tiredness),cough, fever, shortness of breath, night
sweats, muscle aches or joint pain.

34. Coccidiomycosis(end)
Treatment
•Antifungal medication- fluconazole (Diflucan)
and itraconazole (Sporanox)
•Amphotericin B for severe cases

35. Histoplasmosis
• a disease of the reticulo endothelial system.
• It is caused by Histoplasma capsulatum
• Habitat - same as for C. immitis
Symptoms
• coughing, fever, joint pains. Lesions may appear in the lungs.
• Affects meninges, heart & adrenal glands.
Treatment
• It is treated with amphotericin B or ketoconazole

36. Blastomycosis (end)
•Cause- Blastomyces dermatitidis
•fungus is found in moist soil of rotting plants or
wood.
•Transmission- spore inhalation
•Affects bones, joints and central nervous system
•Symptoms-same as coccidio…confusion
•Treatment-itraconazole and amphotericin B

37. OPPORTUNISTIC FUNGAL
INFECTIONS

38. Opportunistic fungal infections ( OIs)
•An opportunistic organism: harmless in its
environment but can become pathogenic in
a compromised host.
•Malnutrition, alcoholism, cancer, diabetes,
leukemia can all compromise the immune
system

39. Pneumocystis jiroveci pneumonia
(PJP)
•condition of the lower resp tract
•A yeast like fungus called Pneumocystis jiroveci
•Presents with cough, dyspnea, abnormal Xrays
•Organism causes inflammation and fluid build up in the
lungs
•Treatment- Trimethoprim/sulfamethoxazole (TMP/SMX)
commonly known as cotrimoxazole or Bactrim or septra

40. Oral candidiasis (thrush)
• Cause: Candida albicans- a normal flora in the GI tract,
mouth, vaginal area, resp tract.
• Condition also common in newborns and in HIV
patients.
• Signs and symptoms: Presents as white patches on
the tongue and in the mouth, can go down the
oesophagus if severe and cause difficulty swallowing

41. Vaginal candidiadis
• Affects the vaginal area when the normal flora is decreased.
• Symptoms: itchiness, redness, dysuria, yellowish curds-like
vaginal discharge.
• Predisposing factors
•Antibiotics, which decrease the amount of Lactobacillus
(“good bacteria”) in the vagina.
•Pregnancy, uncontrolled diabetes, weak immune system,
poor eating habits, including a lot of sugary foods,
hormonal imbalance near the menstrual cycle, stress, lack
of sleep.

42. Cont’d
•Can be transmitted to males to cause
balanitis, especially in uncircumcised
individuals, which presents as itching,
burning white patches around the penis
•Treatment: miconazole, ketoconazole and
trichomycin

43. Prevention
•Wear breathable underwear. ...
•Keep things loose. ...
•Don't douche. ...
•Skip the scent in feminine products. ...
•Avoid hot tubs and extra hot baths. ...

44. Oral candidiasis

45. end

46. Cryptococcosis
•A type of systemic mycoses
•An O.I caused by Cryptococcus neoformans, a large
budding encapsulated yeast
•found in aged dried droppings of pigeons which are
the source of infection.
•Infection is thru inhalation of the yeast & spreads to
other organs
•Can cause cryptococcal meningits if it reaches the CNS

47. END
• Aspergillosis: caused by Aspergellosus fumigatus ,whose
main of entry is thru inhalation. Spores can be inhaled and
these can cause an allergic response that presents like an
asthma attack
• Treatment- Voriconazole or Amphotericin B
• Tuberculosis: an OI caused by the bacteria Mycobacterium
tuberculosis and when it is pulmonary it presents with
coughing, night sweats, loss of weight, loss of appetite,
abnormal Xrays.
• Treatment-isoniazid with a combination of
rifampin, pyrazinamide and ethambutol.