1. Pathogenicity and virulence

2. Virulence factors of bacteria

3. Virulence Microorganisms cause resulting in human diseases
Disease causing microorganisms possess virulence factors.
Virulence factors are properties of pathogens to overcome the host defenses and to establish an infection and cause disease.

4. Virulence factors 1. Adhesion factors 2. Invasiveness 3. Toxicity
Capsules, slime layers, surface carbohydrates, proteins, flagella and pili aid in attachment.
2. Invasiveness
enzymes that enhance invasiveness by enabling the microorganisms to destroy body tissue and cells. Eg. Hyluronidase, collagenase etc.
3. Toxicity
Pathogens produce toxins, that disrupt the normal functioning of the body. Classified into Endotoxins and exotoxins.
Intoxications are diseases that result from the entrance of a specific toxin into the host body.

5. Toxins
Exotoxins : Exotoxins are soluble heat-labile proteins that are released as the bacteria grow
Examples: i. Neurotoxin – Botulinum toxin
ii. Cytotoxin – Haemolysin
iii. Enterotoxin – Cholera toxin
Endotoxins:
Most Gram negative bacteria
have lipopolysaccharides (LPS) in
their outer membrane of their cell
envelope.
LPS is toxic to specific hosts.

6. Diseases Classification and Glossary
Endemic disease
Epidemic
Pandemic
Epidemiology
Zoonoses
Nosocomial infections
Types of Disease
Acute disease
Chronic

7. Disease Process Patterns of disease Stages of a disease
Signs and symptoms
Stages of a disease
Incubation
Prodromal stage
Period of illness
Period of decline
Full recovery

8. Transmission of infectious agents
Portals of Entry
Respiratory tract
Gastro intestinal tract
Genitourinary tract
Skin and wounds and paraenterel routes
Transmission is effected by
Direct contact transmission
Direct faecal – oral route
Indirect contact transmission
Portals of exit
Pathogens of gastrointestinal and genitourinary systems exit through body fluids or faeces
Pathogens of respiratory systems exit through nose, mouth fluids – during coughing, sneezing and speaking

9. Diseases of the respiratory systems
Pharyngitis or sore throat
Pneumonia
Diphtheria – Corynebacterium diphtheria
Tuberculosis – Mycobacterium tuberculosis

10. Diseases of the gastrointestinal tract
Staphylococcal food poisoning -Staph aureus
Salmonellosis-Salmonella
Shigellosis
Travelers' diarrhea
Other gastroenteritis

11. Diseases of Central Nervous System
A. Meningitis - Neisseria meningitis, Haemosphilus influenza
B. Tetanus - Clostridium tetani
C. Botulism - Clostridium botulinum

12. Diseases of the cardiovascular and lymphatic system
Septicemia or blood poisoning E.coli, Pseudomonas qeruginosa, Proteus sp etc.,
Typhoid fever – Salmonella typhi
Plague – Yersinia pestis

13. Diseases of the Urino-genital tract
Urethritis and cystitis – E.coli, Klebsiella Enterobacter, Proteus, Pseudomonas etc.,
Leptospirosis – Leptospira interrogans
Gonorrhea – Neisseria gonorrhoeae
Syphillis – Treponema palladium

14. Fungal human Diseases Diseases of the respiratory tract
Histoplarma Capsulatum, Coccidioides immitis Aspergillus
Diseases of the gastrointestinal tract
Aspergillus sp.
Diseases of Vaginal tract – by Candida
Diseases of central nervous system
Ergotism - by Claviceps purpurea
Meningitis - Cryptococcus neoformans
Diseases of the skin
Dermatomycosis - Trichophyton
Asporotrichosis - Sporothrix

15. Diseases caused by Protozoa and Parasites
Amoebiosis - Entamoeba histolytica
Vulvovaginitis - Trichomonas vaginalis
Trypanosomiaris - Trypanosoma gambiense
Malaria - Plasmodium (transmitted by mosquitoes)
Parasitic Diseases
Tapeworms, Elephantiasis, Schistosomiasis