Parasitosis and Deep fungal disease

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Parasitosis and Deep fungal disease

• Tian Dong Ping
• ???
• Dept. of Pathology
• Shantou University Medical College

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Amoebic dysentery
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Amoebic dysentery

• ?. Etiology
• Amaebiasis is also an infectious disease of
  digestive tractcaused by entamoeba histolytica.
  Two forms- trophozoites and cysts cysts are
  ingested- enter the lower part of ileum and upper
  part of the colon- transform to trophozoites

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• ?. Pathogenesis
• The trophozoites penetrate the mucosa and
  release membrane- bound cytolytic ezymes damage
  of mucosa (liquefactive necrosis) , cytotoxin-
  enterotoxin- caused diarrhea and mucosa damage

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• ?. Pathological changes
• Location- cecum, ascending colon, sigmoid and
  rectum There are stages

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• Grossly
• Solitary or multiple, 80 right lobe, 10 left
  lobe, 10 both
• The abscess contains a brown-pasty material
  (liquefactive necrosis and old blood) it appears
  ragged due to incompletely liquefied necrosis

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1. Acute lesion

• The initial lesion is located in the surface of
  intes-tinal mucosa- crypts of colonic glands
  Multiple elevated lesion with grayish- yellow
  color can be seen- necrotic- superficial
  ulceration .
• The trophozoites penetrate the muscularis mucosa
  into the submucosa- large undermined flask-
  shaped ulceration can be seen
• The trophozoites found between viable tissue and
  necrotic tissoe.

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Amebiasis of the colon with a portion of three
Entamoeba histolytica trophozoites
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• Clinically
• Abdominal pain diarrhea
• Stools contain mucus blood and necrotic tissue

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• 2. Chronic stage
• The pathological changes are very complicated
  necrosis, ulceration, granulation tissue and
  scar formation may alternate polyp formation
  fibrosis Amoebic liver abscess
• The parasite reach the liver through the
  portal vein.

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• Clinically
• Fever, abdominal pain at right upper part of
  the abdomen The liver is enlarged and tender.

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Deep fungal disease
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Deep fungal disease

• Disease caused by fungi are called mycosis
  two groups
• 1. The superficial mycosisdermatophytosis
• 2. The deep or systemic mycosis- candiasis,
  aspergillosis, cryptococcosis, mucormycosis.
• Pathogenesis of fungi may be related to the
  mechanical injury caused by proliferative the
  fungus or to the metabolic products or enzymes.

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• Factors which can reduce host resistance and
  induce mycosis are as follows
• 1.chronic debilitating disease
• 2.The growing use of wide spectrum antibi-otics,
  radiation, immunosuppressive drugs.
• 3. Treatment with steroid drugs
• 4. Iatrogenic factors

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Basic pathological change of deep fungal diseases
are as follows

• 1. Suppurative inflammation-acute suppurative
• inflammation, chronic suppurative
  inflammation, or microabscess mucormycosis,
  Aspergillosis, Actinomycosis
• 2. Granulomatous lesion- candidiasis

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3. Fungi invade vessels leading to hematogenous
spread and thrombosis. Infarction-mucomycosis,
aspergillosis 4. Some form pseudomembrane-
thrush. Some form vegetation lesion on the heart
valves. Candidiasis
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candidiasis

• candidiasis is one of the most common causes
  of human fungal disease.
• Pathological changes
• 1. There are three types basic lesions.
• (1) moncytes lymphocytes and neutrophilic
  infiltration.
• (2)  Disuse necrosis
• Granulomatous reaction (uncommon)

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• 2.Lesion of skin and mucosa
• pseudomembrane. Candidiasis of the mucous
  membrane of the mouth is known as thrush.
• 3. systemic candidiasis

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B
A
A.Severe candidiasis of the distal esophagus. B
silver stain of a section of the same lesion
reveals the dense mat of Candida
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cryptococcosis

• cryptococcosis is caused by cryptococous
  neoformans it usually infects the central nervous
  systems the lung, skin bone.
• Pathological change
• 1. It causes chronic inflammation chronic
  granulomatous reaoction.
• 2. cryptococcoal meningitis
• The meninges are thickened particularly at the
  base of the brain. The infection extends into the
  brain It produces small cysts filled with
  cryptocci granulomatous lesion.

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cryptococcosis

• Fungi invade vessels leading to hematogenous
  spread and thrombosis. Infarction- mucomycosis,

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Mucormmcosis

• Pathological change
• 1. Acute suppurative inflammation.
• The nonseptate wide fungal hyphae with marked
  right angle branching are demonstrated in the
  necrotic tissue
• 2. The fungi invade vessel- Thrombosis-
  infarction. hemo to genous spread.

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Aspergillosis

• Aspergillosis is caused by asperillus fumigates.
• Pathological change
• 1.Basic change- suppurative inflammation,
  microabscess, chronic change is granulomatous
  lesion
• 2.  Aspergillus tends to invade vessels
• (1)   Thrombosis infarction.
• (2)   Hemotogenous spread.
• 3. Aspergillosis of heart valve- vegetation

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Aspergillosis

• Some form pseudomembrane- thrush. Some form
  vegetation lesion on the heart valves.

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Aspergillus colony showing fruiting body and
septate hyphae in the nasal septum (silver stain)_
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Actinomycosis

• Actinomycosis chiefly occur in the cervico-
  cacial region about 50.
• Pathological change
• (1) chronic suppurative inflammation.
• The old lesion with fibrosis and the new
  lesions with abscess formation can be seen at the
  same time.
• (2). Abscess- sinus fistula
• (3) actinomycosis often contain other mixed
  bacterial infection.

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good bye! students