micro respi skin infect 1 and 2 revised1

8/4/2019 Micro Respi Skin Infect 1 and 2 Revised1

1/18

***Note: Mukha lng pong mahaba kasi table form at saka ung pictures hahaha. Pero maiksi lng yan, promise! Hahaha =] pls take note yung mga

nakabold at underlined kasi un ang usually inemphasized ni Dra. Padla :3

Systemic Mycosis

Are inherently virulent Orginate primarily in the lungs; can spread to different body organs Caused by dimorphic fungi Broad distribution, however, is confined in the body and the absence of animal-to human horizontal transmission typifies this.

A. Endemic Respiratory Mycoses Have restricted geographical locations Exhibit thermal dimorphism (2 forms: mold and yeast; depends on temperature) Acquired through inhalation ofconidia (asexual spores) from the soil Portal of entry: Respiratory tract Lungs are the main focus of infection Usually asymptomatic or of very short duration Accompanied by a high degree of specific resistance to reinfection Affect otherwise healthy individuals At rm temp, molds persist, but at 37OC, molds transforms into yeast.

Disease Characteristics Geographical

Distribution/Transmision

Clinical Disease Laboratory Diagnosis Identification/Lab

Test

Treatment

and

prevention

Histoplasmosis Aka darlings dse;cavers dse,

spelunkers dse, N.

American

histoplasmosis;

Caused by

Endemic to North

America, Locally

distributed

Habitat: Grow in soil

contaminated with bat

Asymptomaticinfection (90-95%)

[self limiting flu-like

illness;

Pulmonary infection-inhaled

microconidia taken

GMS/Giemsa/PAS show small

round to oval

intracellular and

extracellular

yeast cell

KOH not

Exoantigen test;

nucleic acid probe

Skin test

Serology (cf test);

Antigen (Ag)

detection

Usually not

required,

Lungs:

Itraconazole,

ketoconazole,

fluconazole


2/18

histoplasma

capsulatum

An ascomycte withtelemorphic(ajellomyces

capsulatus = sexual

state)

Thermallydimorphic;

facultative

intracellular

Infectious particle:

Microconidia

Tissue form:

intracellular yeast cell

and bird excreta

Transmission: soil

infections, bat, avian

habitat; can be controlled

by occupational exposure

Not transmissible from

human to human or

animal to human.

up by alveolar

macrophage;

mimics PTB

(acute/chronic);

Disseminatedinfection (includes

RES and

mucocutaneous;

skin lesions);

primary sign is

splenomegaly

(assoc w.

immunosuppressio)

Primary cutaneousis rare

Mimics PulmonaryTuberculosis (PTB)

because

homogenous

appearance at the

hilar

H. capsulate varduboisii is large,

thick walled yeast

causing a variant

form ofhistoplasmosis

prevalent in Africans

that preferentially

involves the skin,

subcutaneous

tissues, lymphatics

and bones

applicable

Rm TempCulture: fine

septate hyphae,

large tuberculatemacroconidia

and small

microcondia

(therefore highly

infectious)

Tuberculatemacroconidia dx of the

organism

Invitro/Cuture atBHIA: 37

OC:

appear single

budding yeast

cell

Systemic:

Amphotherici

n B

Others:

Surgical

debridement

Prevention:

Wearing

protecting

clothing,

mask, soil

decontaminati

on with 3-5%formalin


3/18

Blastomycosis

B for Broad

Based Bud!

Aka N. Americanblastomycosis;

Chicago dse,

gilchrist;s dse;

suppurative

granulomatous

mycosis of the lungs,

skin and

subcutaneous tissue

caused byblastomyces

dermatitidis

ascomycyte, thermally dimorphic

inhabits decayingwood, soil

saprophyte


conidia

Tissue form:broad

based yeast cells

found in N. America,

Africa, Asia

outbreaks associated

with activities with moist

soil enriched with organic

debris and rotting wood

Natural disease that is

common in cats and dogs

and therefore not

transmissible from these

animals.

Asymptomatic (50%) Pulmonary infection

(50%) TB like

Disseminatedinfection

Chronic cutaneousinfection

(verrucous/ulcerative

crusty, elevated

lesions with

microabscesses that

weeps)

Primary cutaneous(rare)

KOH shows thick

walled yeast cells

with single broad

based bud

At Rm temperature:

White, cottony

Mycelia form,

Pyriform conidia

borne singly on

septate hyphae

Culture at 37C:

Double walled yeast

cells with single

broad based budattached to a parent

by a wide base

which are

pathognomic of

blastomycosis

Exoantigen test;

nucleic acid probe

Others:

Skin test

Serology

Immunofluorescence

(IF)

Ag detection

Ketoconazole,

itraconazole,

fluconaole

Disseminated:

Ampho b

Exicision for

skin lesion

Coccidiomycosis Aka Posadas dse,San Joaquin Valley

Fever, Desert

Rheumatism

Caused by

Endemic in western

hemisphere; desert; Dust

storm; Soil tillage;

California; Sonoran

desert

Highly infectious, acute,

self limited nd usually

benign respiratory

disease

KOH shows thick

walled spherules

filled with non-

budding small

endospores

Exoantigen; nucleic

acid probe,

demonstration of

spherule production

in animals

Acute Respi

Disease not

necessary to

treat


4/18


5/18

Paracoccidiomyc

osis

P for Pulmonary

dse!!!

Aka pulmonary dse;

South American

Blastomycosis; Lutz-

Splendore-Almeidas

Dse

Caused byParacoccidiooides

braziliensis

Deuteromycete Thermally

dimorphic


Conidia

Habitat: unknown but

found to reside in humid

soil rich in proteins;

cultivated in fruit bats

and armadillos

Higher incidence ratio in

Males because estrogen

inhibits conversion of

mycelium to yeast.

Asymptomaticinfection

Pulmonary infection Dissemination infect

(oral/nasal mucosa)

- ChronicGranulomatous

lesions formed by

stimulation of alpha-

glucan [cell wall

polysaccharide]

- Mulberry Lesions @GIT mucosa

- Facial skin mostcommon site of

infection

- Triad of sxs inendemic areas:

Pulmonary lesions,

edentulous mouth,

cervicallymphadenopathy

Clinical specimens:

sputum, pus, crusts

from lesions

KOH shows yeast

cells with multiple

narrow based buds

(blasto kasi is broad

based)

KOH shows mariners

wheel appearance

Culture rm temp:

septate hyphae with

no typical patternofsporulation

Cutlture at 37OC

- Thick Yeast cellswith ships or

mariners

steering wheel

appearance

- Cells are large,spherical topyriform and

with thick walls

Exoantigen

Dna proble

ID:

Skin test

Serology

Itraconazole,

ketoconazole,

ampothericin

B, sulfa drugs

Others:

surgical

excision of

localized

lesion

Penicilosis caused byPenicilloisis

marneffei

Only Penicillumspecies that is

Bamboo rat (reservoir);

endemic in SEA;

Portal of entry: lungs

Affects both healthy and

immunosuppressed

individuals who have

traveled or lived in

endemic areas

KOH shows small

yeast cells with

transverse septum

Culture at RT:

Exoantigen test

Conversion to yeast

forms

Itraconazole

and

ketoconazole

For serious


6/18

thermally dimorphic

Produces redpigments around

the colony (kasi

other penicillium

produces yellow)

Reproduce:transverse

fission/schizogony


Conidia

Indicator of HIV infection

in endemic areas

Pulmonary infection Disseminated

infection

-similar to histoplasmosis;

affects many internal

organs; exhibits as skin

lesion such as those seen

in AIDS patients

Conidiophore branch

into metullae which

support the phialides

that bear chains of

conidia (brush like or

finger like)

Colonies produce

diffusible red

pigment around the

colony (very

characteristics)

Culture @ 37OC:

Round to oval yeast

cell with cross walls

infection:

Ampho B

B. Opportunistic Mycoses Portal of entry: respiratory, mucocutaneous (for Candidiasis) Infectious particle: conidia, mycelia Widely distributed as saprophytes or as members of normal flora (in comparison with endemic na restricted and distribution) Invade only in the presence of underlying predisposition Invade mainly those who are immunosuppressed

Disease Characteristics Geographical

Distribution/

Transmission

Clinical Disease Laboratory

Diagnosis

Identification/Lab

Test

Treatment and

Prevention

Candidiasis Caused byCandida spp

Mostly C.albicans

Normal flora

Endogenously

acquired

Normally found

in Normal flora

of skin, mouth,

Most common

systemic/opportunistic

fungal infection

worldwide; clinical

spectrum: extremely

diverse

Gramstain/KOH

shows small

budding yeast

cell and

pseudohyphae

(meaning no true

Germ Tube Test

(GTT) (+) for C.

albicans

Other test:

Assimilation

Cutaneous:

Topical

Nystatin,

ketoconazole,

fluconazole


7/18

of GIT

Ascomycete Dimorphic

[lang! not

thermally]

Exist aspseudohypha

e or hyphjae

Reproduce bybudding

Infectious/tissue

form: yeast cell

and

pseudohyphae

vagina, mucous

membranes,

stool

Major

colonizing

habitat: GIT

Leading fungal infection

patients with HIV-AIDS

Cutaneous andSubcutaneous

Systemic/disseminated/invasive

- Candidemia(catheter related)

- Acute chronicdisseminated

- Deep organcandidiasis (pulmo

candidiasis)

Predisposing factors: Physiological

(pregnancy and age)

Trauma (burn,infection)

Hematological(neutropenia, cellular

immunodeficiency)

Endocrinological (DM,Hypothyroidism,

Addisons dse) Iatrogenic

(chemotherapeutics,

corticosteroids, oral

contraceptives,

catheters, etc)

Others: IV drugaddiction,

malnutrition

septation)

Culture at RT and

37:

-Pseudophyae

with clusters of

round

blastoconida

- Chlamydospore,

yeast cells and

pseudohyphae

produced on

chlamydospore

on cornmeal agar

test

Biotyping IF Immunohisto-

chemistry

DNA probes,PCR

Mannanantigen

detection

(RIA, ELISA,

LAT)

Systemic:

Ketoconazole,

fluconazole,

itraconazole,

flucytosine,

ampho B

Prevention:

Avoid

disturbing the

normal balance

of microbial

flora and intact

host defense


8/18

Aspergillosis

A for ABPA!

A for Acute

Angle!

Caused byAspergillus spp

( commonlyfumigates and

flavus)

Ascomycte; Ubiquitous; freq lab

contaminants


Asexual spore:

conidia

Tissue form:

hyphae

Natural

reservoir: soil

and air

frequent

laboratory

contaminants

Transmission:

inhalation of

conidia

Allergic form:Allergic

Bronchopulmonary

Aspergillosis (ABPA)

may give rise toasthma or hay

fever

colonizingform/pulmonary

aspergilloma orfungus ball

Invasive ordisseminated (for

immunocompromised)

Mycotoxicosis(ingestion of food

products with toxin)

KOH show

1. wide septatedichotomousl

y branching

hpyhae

(45deg or

acute angle);

2. condialheads

supports

swollen

vesicle with

rows of

phialides

bering radial

chains ofconidia.

***so take note

niyo to ung diff

kasi

zygomycomycete

kamuka nia***

Serology

Immunohisto-

chemistry

Galactomannan

antigen detection

in serum

Allergic form:

itraconazole;

corticosterioid

Aspergilloma:

Surgery &

ampho B

Diseminated:

Itraconazole,

fluconazole,

ampho B

Prevention:

Avoid or

minimizeexposure to

conidia;

prophylactic

low-dose

ampho B or

itraconazole

Cryptococcosis

[has 3 biotypes]

[singit ko dito

ang virulence

factors ah?

Wala ng box eh

:P ]

Aka busse-buschke dse;Torulosis

Caused byFilobasidella

neoformans

Sexual phase:Basidiomycete

(the spores are

produced

Widespread in

nature; soilsaprophyte and

abundanct in

avian habitats

Transmission:

Inhalation of

non-

encapsulated

Primary site of infection:

Lungs

One of the most life

threatening infection with

AIDS

Pulmo (acute/chronic) usually

asymptomatic; mx:

KOH/India ink

shows yeast cellswith wide

capsule

Culture 37OC:

-Creamy, mucoid

yeast colonies

-Brown to blkack

colonies on

Biochemical test:

(+) Urease Test:fuschia pink in

color

(+) caffeic acid

test due to

phenoloxidase

production

Others:

Ampho B;

ampho B 5 FCcombination;

fluconazole

prophylaxis ff

primary

treatment (for

AIDS patients)


9/18

Virulence

factors:

1)Capusule:

-wide

-Antiphagocytic

-Serotype

A,B,C,D and AD

2.Production of

phenoloxidase

convert

phenoilic

compounds to

melanin;

survival

mechanismwithin

phagocytes

externally, on

the end of

specialized

cells called

basidia.)

SpecificallyCryptococcus

neoformans

and C. gattii

Encapsulatedyeast

Replicate bybudding

0nly fungalspecies with

well-defined

virulence

factor

Infectious

particle: non-

encapsulated

yeast (at 27 and

37 C);

basidiospore

Or minimally

encapsulated

yeast cells

soilatary pulmo

nodulein the

mediastinum

mimicking a carcinoma

Disseminated Predilection for

the CNS

Meningitis: mostfrequent

diagnosed form

[difference ke

cocciodiomycosis

naman cause of

death]

Neutropismrelated tophenoloxidase

activity

Cutaneous (rare) mx:

nodule in the lungs

niger/bird seed

agar due to

phenoloxidase

Direct IF Ag detection

test

DifferentialGrowth on L-

canavarine

glycine

bromtymol

blue

- appear in cobalt

blue for C. Gatti

(blue)

- Yellow on C.

neofromans

C Neoformans

var neoformans

[1st

biotype]

Serotype D

Virulence factor:

Capsule + 37 +

phenoloxidase

production

Found in soil

contaminated

with pigeon

droppings (rich

nitrogen and

alkaline pH of

the droppings

favors survival

Affects

immunocompromised


10/18

of the yeast)

Globally

distributed

(predominantly

in N. Europe

and N. America

C neoformans

var gattii

[2nd

biotype]

Serotype Band C

Telemorphicname of

filbasidiella

bacillispora

Infectiousparticle:

basidiospores

***B = more

prevalent and

pathogenic

Found ineucalyptus

tree

specifically:

caladunensis

(river red

gum tree,

and

teretucornics (forest red

gum tree),

decaying

wood

forming

hollows in

living trees;

Worldwidedistribution;Common on

tropical/sub

trop

climates;

(predomi-

nantly in

SEA, S.

California,

Affects

immunocompetent

Clinica Mx: Pneumonia


11/18

Australia,

Africa

C neoformans

var grubii

[3rd biotype]

Serotype A Biological,

ecological and

epidemiological

characteristics

not yet clearly

defined;

Zygomycosis Akamucormycosis

/phycomycosis

Caused byfilamentous

fungi namely:

rhizopus,

mucor, absidia

Order:mucorales,

Class:

zygomycetes

Non-septate Asexual form:

sporangispore

Sexual form:zygospore

Acquired by

exposure to

sporangiospores

Natural

reservoir: soil

air and water

Ubiquitous;

frequently

encountered as

contaminants

(e.g bread

mold)

Primary Site of Infection:

Lungs

Rhinocerebral Most common;

cotton like fungus

Pulmonary Cutaneous GIT Disseminated

-aggresive angio-

invaised and

predominantly

infarctive.

Risk factors:

Diabetic acidosis

Immunosuppression

KOH shows wide

ribbon like

aseptate hyphae

branching of

right angle (ung

narrow or acute

angle is

aspergillus)

Culture @ RT:

Cotton candy

appearance of

colonies

Morphologic

features identify

species

Caution in

interpreting

results because

they are common

contaminants

Rhizopus:

sporangia round;

sporangiospore

unbranched and

at nodal;

Mucor: sporangiaround; branch

and at

intermodal;

columellae

round to oval;

rhizoid absent

Absidia:

Rudimentary,

collumellaeconical;branch; in

between nodes

Ampho B

Surgical

debridement

Control of

predisposing

factors


12/18

Characteristics of Species Causing Zygomycosis

Characteristics Rhizopus Mucor Absidia

Sporangia Round Round Pyriform

Sporangiospores Unbranched, nodal Branched, intermodal Branched, intermodal

Collumellae Hemi-spherical Round to oval Conical

Rhizoids Well developed Absent Rudimentary

Collarettes None remains when sporangial

wall is dissolved

Present when sporangial wall is

dissolved

===

Endemic Respiratory Mycosis

1. Histoplasmosis H. Capsulatum

GMS/giems/PAS show small round to oval intra and extracell yeast cell Culture at rm tem: fine septate hyphae, large tuberculate macroconidia and small microcondia (therefore highly infectious) Invitro/Cuture at 37: ppear single budding yeast cell


13/18

2. Blastomycosis B. dermatitidis

KOH shows thick walled yeast cells with single broad based bud (3rd pic) At Rm temperature: White, cottony Mycelia form, Pyriform conidia borne singly on septate hyphae (1st pic) Culture at 37C: Double walled yeast cells with single broad based bud attached to a parent by a wide base which are pathognomic of

blastomycosis (2nd

pic)

3. Coccidiomycosis C. immitis

Koh shows thich walled endospore spherules Culture at RT: Hyphae bearing barrel shaped atroconindia separated by dysjunctor cells (2nd pic) Culture at 37: not routinely done4. Paracoccidiomycosis P. braziliensis


14/18

KOH shows yeast cells with multiple narrow based buds (blasto kasi is broad based) [2nd pic] KOH shows mariners wheel appearance [1st pic] Culture rm temp: septate hyphae with no typical patternof sporulation Cutlture at 37

O

C: Thick Yeast cells with ships or mariners steering wheel appearance [or sometimes mickey mouse]; Cells are large,spherical to pyriform and with thick walls

5. Pencillosis P. marneffei

KOH shows small yeast cells with transverse septum (2nd pic) Culture at RT: Conidiophore branch into metullae which support the phialides that bear chains of conidia (brush like or finger like) [1st

and 3rd

pic]

Culture: Colonies produce diffusible red pigment around the colony (very characteristic ) [3rd pic] Culture at 37OC temp : Round to oval yeast cell with cross walls


15/18

Opportunistic Mycoses

1. Candidiasis C. albicans Gramstain/KOH shows small budding yeast cell and pseudohyphae (meaning no true septation) Culture at RT and 37: Pseudophyae with clusters of round blastoconida; Chlamydospore, yeast cells and pseudohyphae produced on

chlamydospore on cornmeal agar

2. Aspergillosis Aspergillus spp.

KOH show a) wide septate dichotomously branchinghpyhae (45deg or acute angle); (3rd

pic) b) condial heads supports swollen vesicle with

rows of phialides bering radial chains of conidia. (2nd

pic) ***so un ang diff this to zygo kasi magkamuka cla***


16/18

3. Cryptococcosis C. neoformans

KOH/India ink shows yeast cells with wide capsule Culture 37OC:Creamy, mucoid yeast colonies;Brown to blkack

colonies on niger/bird seed agar due to phenoloxidase

4.Zygomycosis filamentous fungi namely: Rhizopus, Mucor, Absidia


17/18

KOH shows wide ribbon like aseptate hyphae branching of right angle (ung narrow or acute angle is aspergillus) Culture @ RT: Cotton candy appearance of colonies; Morphologic features identify species Rhizopus: sporangia round; sporangiospore unbranched and at nodal (1st row); Mucor: sporangia round; branch and at intermodal; columellae round to oval; rhizoid absent (2nd row) Absidia: Rudimentary, collumellae conical;branch; in between nodes (3rd row)


18/18

Further differentiation:

Penicillium brush like, finger like

Aspergillus swollen head na may fingerlike din ang dulo

Rhizopus round sporangia, unbranched

A. RhizopusB. MucorC. Absidia

micro respi skin infect 1 and 2 revised1

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