Bactriology Course Outline

# ## DEPARTMENT OF MEDICAL MICROBIOLOGY ### MBMM3311 MEDICAL BACTERIOLOGY **Pre-requisite:** Principles of Microbiology **Course Purpose:** To equip the student with knowledge and skills on bacteriology ## EXPECTED LEARNING OUTCOMES By the end of the course unit, the student should be able to: - Classify bacteria, Chlamydia, Rickettsiae and Mycoplasma - Describe pathogenesis of bacteria, Chlamydia, Rickettsiae and Mycoplasma - Identify micro-organisms using laboratory methods ## COURSE OUTLINE ### GRAM POSITIVE BACTERIA ## WEEK 1: GRAM POSITIVE COCCI ### Staphylococcus Species: - **Staphylococcus aureus** - Causes skin infections, pneumonia, septicemia, toxic shock syndrome, food poisoning - **Staphylococcus epidermidis** - Causes opportunistic infections, catheter-related infections - **Staphylococcus saprophyticus** - Causes urinary tract infections, especially in young women ### Streptococcus Species: - **Streptococcus pyogenes** (Group A Streptococcus) - Causes pharyngitis, scarlet fever, rheumatic fever, necrotizing fasciitis - **Streptococcus agalactiae** (Group B Streptococcus) - Causes neonatal meningitis and sepsis - **Streptococcus pneumoniae** - Causes pneumonia, meningitis, otitis media, sinusitis - **Enterococcus species** (Group D) - Causes urinary tract infections, endocarditis, wound infections ### PRACTICAL SESSION: Identification of Microorganisms **Culture Characteristics:** - Colony morphology on Blood agar and Mannitol salt agar - Haemolytic reactions: Alpha hemolysis (partial/green), Beta hemolysis (complete/clear), Gamma hemolysis (no hemolysis) **Biochemical Characteristics:** - **Coagulase test** - Differentiates S. aureus (positive) from other staphylococci (negative) - **Catalase test** - Differentiates staphylococci (positive) from streptococci (negative) - **Bacitracin sensitivity** - Identifies Group A Streptococcus (sensitive) - **Optochin sensitivity** - Identifies S. pneumoniae (sensitive) - **Bile solubility test** - Confirms S. pneumoniae (positive) **Staining Techniques:** - Gram staining procedure and interpretation - Acid-fast staining technique --- ## WEEK 2: GRAM POSITIVE SPORE-FORMING RODS ### Bacillus Species (Aerobic): - **Bacillus anthracis** - Causes anthrax (cutaneous, pulmonary "woolsorter's disease", gastrointestinal forms) - **Bacillus cereus** - Causes food poisoning with two syndromes: emetic (rice) and diarrheal ### Clostridium Species (Anaerobic): - **Clostridium tetani** - Causes tetanus (lockjaw) through neurotoxin production - **Clostridium botulinum** - Causes botulism (flaccid paralysis) through neurotoxin in contaminated food - **Clostridium perfringens** - Causes gas gangrene, food poisoning, necrotizing enteritis - **Clostridium difficile** - Causes pseudomembranous colitis and antibiotic-associated diarrhea ## WEEK 3: GRAM POSITIVE NON-SPORE FORMING RODS - **Corynebacterium diphtheriae** - Causes diphtheria with pseudomembrane formation in throat, produces diphtheria toxin - **Listeria monocytogenes** - Causes meningitis, septicemia in neonates and immunocompromised patients, causes spontaneous abortion in pregnant women # GRAM NEGATIVE BACTERIA ## WEEK 2: GRAM NEGATIVE COCCI ### Neisseria Species: - **Neisseria gonorrhoeae** - Causes gonorrhea (sexually transmitted infection), urethritis, cervicitis, pelvic inflammatory disease, neonatal conjunctivitis - **Neisseria meningitidis** - Causes meningococcal meningitis and meningococcemia (severe septicemia with petechial rash) ## WEEK 4: GRAM NEGATIVE RODS - ENTEROBACTERIACEAE ### Major Enteric Pathogens: - **Escherichia coli** - Causes urinary tract infections, gastroenteritis (ETEC, EPEC, EHEC, EIEC), neonatal meningitis, septicemia, travelers' diarrhea - **Salmonella typhi** - Causes typhoid fever (enteric fever) with sustained fever, rose spots, and intestinal perforation - **Salmonella enteritidis** and other non-typhoidal Salmonella - Cause gastroenteritis and food poisoning --- ## WEEK 5: GRAM NEGATIVE RODS - ENTERIC PATHOGENS ### Intestinal Pathogens: - **Shigella species** (dysenteriae, flexneri, boydii, sonnei) - Cause bacillary dysentery with bloody diarrhea, abdominal cramps, tenesmus - **Vibrio cholerae** - Causes cholera with severe watery diarrhea ("rice water stools"), leading to dehydration - **Vibrio parahaemolyticus** - Causes gastroenteritis from contaminated seafood - **Campylobacter jejuni** - Causes gastroenteritis with bloody diarrhea, associated with Guillain-Barré syndrome - **Helicobacter pylori** - Causes peptic ulcer disease, chronic gastritis, gastric carcinoma, MALT lymphoma --- ## WEEK 6: GRAM NEGATIVE RODS - OPPORTUNISTIC PATHOGENS ### Hospital-Acquired and Opportunistic Infections: - **Klebsiella pneumoniae** - Causes pneumonia (especially in alcoholics), urinary tract infections, septicemia, produces thick mucoid colonies - **Proteus mirabilis** - Causes urinary tract infections with ammonia smell, produces urease, kidney stones, wound