Presented by Sarah E. Johnston

Presented by Sarah E. Johnston
HIV effects on immune system
potential fungal pathogens of HIV patients
Pneumonocystis jirovecii and the disease PCP
Cryptococcus neoformans and fungal
• Summary
• Questions
Severely debilitates the
human immune system
by :
Defecting Macrophage’s ability to
properly process and present
foreign particles to immune system
Debilitate and deplete CD4+ T
lymphocytes needed for cytokine
production and assisting B cells to
produce antibodies
Debilitated cytokine production
effect neutrophil count and
Rhizopus oryzae
Pneumonocystis jirovecii
Candida albicans
Aspergillus fumigatus
Cryptococcus neoformans
Pneumonocystis jirovecii
•Was formerly known as
Pneumonocystis carinii and
thought to be a protozoan.
•Life cycle has both sexual
and asexual components
Interesting fact: % 80 U.S.
population has antibodies
to this organism
Pneumonocystis carinii pneumonia
• The trophozoite form attaches
to lung epithelial cells after
• P. jiroveci replicates
extracellularly and impairs
oxygen diffusion
• Inflammation causes host cell
to lysis.
• Damage to the lung basement
membrane generates a
characteristic foamy exudate
and interstitial leukemic
infiltration in the alveoli,
resulting in a decrease in
alveolar capillary permeability.
How it is diagnosed
• Diagnosis use to be based
on stained respiratory
tissues using Giemsa and
techniques, staining
sputum, branchoalveolar
fluid or lung tissue.
• Due to inability to
properly visualize
trophozoite form PCR is
the standard technique
used to identify this
How HIV contributes to risk
• HIV individuals who have
progressed to full blown
AIDS have a very low
CD4+ T cell count. This
contributes to decreased
ability to produce super
oxygen radicals used by
alveolar macrophages to
kill foreign invaders that
they take up via
• Fortunately due to the
use HAART (highly active
antiretroviral therapy)
PCP cases in HIV patients
has decreased
Cryptococcus neoformans
• Encapsulated Yeastlike fungus that
belongs to the
• Transmission occurs
via inhalation of
basidiospores into
the lungs.
• Replication occurs
via budding
Fungal Meningitis
• Is the inflammation of
the membrane that
surrounds the brain and
spinal cord.
• C. neoformans
infections usually start
in the lungs
(pneumonia) and in HIV
patients dissemination
occurs to other areas. In
this case to the CNS.
Secondary infections
• HIV patients with fungal
meningitis usually develop
a secondary infection site of
the skin, prostate, and eye.
• Secondary infection of the
prostate can contribute to
acting as a reservoir in AIDs
patients and contributing to
relapse in previoulsy treated
Different media used to culture C.
• India ink is used in
CSF to visualize
capsule and creates
characteristic halo
effect around capsule
• Bird seed agar- C.
neoformans is brown
in color due to
uptake of brown
pigment I media
• Colonies are mucoid
and cream colored
on SAB
Diagnosis of C. neoformans infection
• can be made by microscopic examination
and/or culture of tissue or body fluids such as
blood, cerebrospinal fluid, and sputum.
• cryptococcal antigen test can rapidly test
blood and/or cerebrospinal fluid to make the
• A fungal culture is essential to differentiate
between the different species of Cryptococcus
- C. neoformans and C. gatti
• HIV critically impairs immune system and leaves it
vulnerable to opportunistic fungal pathogens.
• Pneumocystis jirovecii causes Pneumocycstic
carinii pneumonia (PCP) in AIDs patients and use
to be a common indicator of HIV
• Crypotococcus neoformans is the leading cause
of fungal meningitis and is one of the most
common opportunistic infections in individuals
with AIDs
Shors, Teri.(2013). Understanding Viruses. 2nd edition, Chapter16 Human Immunodeficiency Virus (HIV) (pp.484-523).Burlington, MA: Jones and
Bartlett Learning.
NIH. (April 03, 2012).NIH HIV/AIDS Overview. Retrieved from
Ayyavoo, V., et al.(1997).HIV-1 Vpr suppresses immune activation and apoptosis through regulation of nuclear factor κB.Natural Medicine.3.11171123.
Wagner, E. K., M. J. Hewlett. (2004). Basic Virology 2nd edition, Chapter 20 Retroviruses:Converting RNA to DNA (pp. 356-376). Malden, MA:
Blackwell Science Ltd.
Orenstein, J. M., Fox, C., and S. M. Wahl.(1997, June).Macrophages as a Source of HIV During Opportunistic Infections.Science.276.1857-1861.
CDC.( May 6, 2013). CDC. C. neoformans cryptococcosis. Retreived from
Phair, J., et al.(1990). The Risk Of PNEUMOCYSTIS CARINII PNEUMONIA Among Men with Human Immunodefifiency Virus Type 1. The New England
Journal of Medicine. 322.161-165.
Wilkin, A. and J. Feinberg.(1999, October). Pneumocystis carinii Pneumonia: A Clinical Review.American Family Physician.60.1699-1708.
Sepkowitz, K.(2002, April). Opportunistic Infections in Patients with and Patients without Acquired Immunodeficiency Syndrome.
Immunocompromised Hosts.34.1098-1107.
Murray, P. R., Rosenthal, K. S., and M. A. Pfaller. (2009). Medical Microbiology 6th edition, Chapter 74 Opportunistic Mycoses(pp. 751-773).
Philadelphia, PA: Mosbey Elsevier.
Kendrick, B.(1992). The Fifth Kingdom 3rd edition, Chapter 23 Medical Mycology(pp.327-333).Newburyport, MA. Focus Publishing.
Mitchell. T. G., and J. R. Perfect.(1995).Cryptococcosis in the Era of AIDS-100 years after the Discovery of Cryptococcus neoformans.Clinical
Microbiology Reviews.8.515-548.
Maurya, V., et al.(2013).Oropharyngeal candidiasis and Candida colonization in HIV positive patients in northern India.Journal of Infectious Diseases
in Developing Countries.7.608-613.
Latge, J.P.(1999). Aspergillus fumigates and Aspergillosis.Clinical Microbiology Reviews.12.310-350.
The University of Adeliade.(November 11 2013).Mycology Online : Zygomycetes. Retrieved from
LSU.(April 26 2004). Mucology at LSU: Phycomycosis. Retreived from
Van den Berk, G, et al.(2006). A fatal pseudo-tumour: disseminated basidiobolomycosis .BMC infectious diseases.6.140.