Lecture Notes: Bacterial Diseases

Introduction

• Bacterial diseases are discussed throughout the course, rather than at the end.
• Focus is on disease recognition, not human health and treatment.

Lower Respiratory Tract Diseases

Mycoplasma Pneumonia (Walking Pneumonia)

• Also known as atypical pneumonia.
• Caused by the smallest known bacterial pathogen, lacking a cell wall.
• Common in adolescents; symptoms may be absent.
• Treatable with antibiotics.
• Example case: Spread in high schools, personal anecdote involving a son.

Legionnaire’s Disease

• Not spread person-to-person, transmitted via aerosolized water sources.
• Found in air conditioning units, pools, hot tubs.
• Symptoms: fever, chills, GI effects; can be fatal.
• Historical outbreak: 1976 War veterans convention.
• Recent outbreak example: Hampton Beach, New Hampshire.

Bacterial STDs (Sexually Transmitted Diseases)

Gonorrhea

• Caused by Neisseria gonorrhoeae.
• Asymptomatic possibility, treatable with antibiotics.

Syphilis

• Caused by Treponema pallidum, a spirochete bacterium.
• Transmitted through saliva, can cross the placenta.
• Treatable with antibiotics.

Chlamydia

• Most common bacterial STD in the US.
• Asymptomatic possibility, affects fertility.
• Cultural reference: Joke from "Mean Girls" movie.

Bacterial Diseases of the Brain and Meninges

Meningitis

• Inflammation of central nervous system protective coverings.
• Bacterial form is serious and rapid; viral form usually not fatal.
• Caused by various bacteria, e.g., Streptococcus pneumoniae.
• Vaccination available, especially recommended for college students.
• Symptoms: headache, stiff neck, rapid progression.
• Example case: Bacterial meningitis from sinus infection.

Haemophilus Influenzae

• Most common in young children, fatal if untreated.
• Vaccination available.

Listeriosis

• Caused by Listeria monocytogenes, dangerous for unborn babies.
• Pregnant women advised to avoid unpasteurized products and deli meats.
• Associated with food recalls.

Laboratory Diagnosis

Analytical Profile Index (API)

• Diagnostic tool used in labs to identify bacteria via biochemical profiles.
• Tests metabolism types, carbohydrate sources, fermentation processes.
• API will be used in the lab at the semester's end.

Conclusion

• Discussion of bacterial diseases to continue throughout the semester.
• Reminder: This class focuses on disease recognition, not treatment.