Microbiology Exam test 1 chapters 1&3 review

Fungal Distribution in the Body
- Normal fungi are consistently present but are generally outcompeted by bacteria.
- The highest concentrations of fungi in the human body are found on the bottom of the feet and the hands.
- Fungi are typically not found residing on the eye, the hair, or the tongue.
- Yeast (a type of fungus) is present on the teeth; this was previously confirmed through negative staining techniques.
Microbial Competition and Antibiotics
- Fungal overgrowth occurs when the bacterial population is destroyed, typically by antibiotic treatment.
- Common results of bacterial destruction include:
  - Vaginal yeast infections.
  - Fungal overgrowth of the intestines (observed in patients treated for long periods with antibiotics for C. diff/CDP seal).
Pathogenicity of Fungi
- Fungi are generally not considered highly pathogenic or virulent in their own right.
- Illness resulting from fungi usually stems from:
  - Toxins released by the fungi.
  - Allergic reactions (e.g., redness or scalding sensations in skin folds).
  - Opportunistic infections in immunocompromised individuals (e.g., cancer patients or those on heavy antibiotics).
- If a patient presents with a significant fungal infection, clinicians must investigate the underlying cause, as healthy immune systems usually keep fungal growth in check.

Definition and Function of Antibiotics
- By definition, antibiotics are substances produced by fungi and bacteria to inhibit the growth of other bacteria and fungi.
- Antibiotics are biological tools used by microbes to maintain their own niche (milieu).
- Antibiotics are notably ineffective against protozoa because protozoa do not typically compete with bacteria or fungi for resources in a way that requires that biological response.
Misleading Information in Medical Media
- There is a significant misconception regarding the treatment of Cryptosporidiosis (a protozoan disease).
- News reports and even some physician-targeted applications (such as Open Evidence) may incorrectly suggest that antibiotics treat protozoan infections.
- Proper treatment requires an anti-protozoal medication, which is distinct from an antibiotic.

Virulent E. coli
- Escherichia coli O157:H7 is identified as a virulent, emergent disease implicated in many deaths.
- The nomenclature "O157:H7" refers to specific markers:
  - O157: Refers to the cell wall polysaccharide index.
  - H7: Refers to the flagella type.
Prions
- Prions are the causative agents of Mad Cow Disease (Boviform Spongiform Encephalopathy).
- Prions are not bacteria. If they were bacteria, they would be significantly easier to treat.
Historical Microbiology
- Robert Koch did not use E. coli to establish his postulates.
- Koch utilized Anthrax because it was the "domestic dollar" issue of the era, causing significant mortality in livestock.

Serous vs. Mucous Membranes
- Serous Membranes: These must always be sterile. Any laboratory report showing microbial growth on a serous membrane is indicative of a serious infection.
- Mucous Membranes: These are not sterile and naturally host normal flora. Examples include the throat, nose, ear, and eye.

Microbial Scale
- $1\,\mu m$ (one micron or micrometer) is equivalent to $10^{-6}\,m$ .
- Organisms/structures approximately one micron in size include typical bacteria and mitochondria.
- Viruses are significantly smaller than one micron ( $10^{-9}\,m$ range).
Mathematical Operations in Measurement
- When multiplying exponents, the values are added.
- Example: A micron ( $10^{-6}$ ) times a micron ( $10^{-6}$ ) equals $10^{-12}$ .
- A nanometer is defined as $10^{-9}\,m$ .
Biotechnology
- While many consider biotechnology to encompass all uses of microorganisms for products, its most specific definition is the development of recombinant DNA.
- Bioremediation is a sub-field, exemplified by the use of oil-degrading bacteria to clean up oil spills.

Protozoa Characteristics
- Classification: Eukaryotic, unicellular, and highly diverse.
- Locomotion: They move via pseudopods, flagella, or cilia.
- Cell Structure: They lack rigid cell walls, which allows for their motility.
- Genetics: They contain eukaryotic structures but may have specific circular DNA elements in organelles.
Archaea
- Archaea represent their own evolutionary line and are not derived from bacteria.
- They are known for existing in extreme environments and have remained relatively unchanged.

Syphilis Staging
- Primary: Formation of a chancre.
- Secondary: (General progression).
- Tertiary: Neurological complications.
Lyme Disease Staging
- Primary: Bull's-eye rash (Erythema migrans).
- Secondary: General rash.
- Tertiary: Neurological complications.

Vaccines are primarily developed to target toxins and viruses.
There are currently very few or no vaccines effectively used against fungi and protozoa in standard clinical practice.

Institutional Requirements
- Nursing students are often required to pass calculation tests every semester.
- Failure to pass these tests (often allowing three attempts per semester) can result in being withdrawn from the program due to the high risk of medication errors.
The Sydney Farber Case Study (Case of Dosage Error)
- A significant medical error occurred at the Sydney Farber Cancer Institute involving a patient who was a writer for the Boston Globe.
- The patient was accidentally administered a dose that was $10^{6}$ (one million) times the intended amount of a chemotherapeutic agent.
- The error persisted for approximately three weeks.
- Systemic Failure: The error was written incorrectly, filled incorrectly by the pharmacist at a million times the dose, and administered by 12 different nurses over those weeks.
- Outcome: The patient died, and all 12 nurses involved had their licenses suspended and were required to undergo remediation.
- Critical Lesson: Distinguishing between a microgram and a milligram is a life-or-death calculation.