Module 2 - ID, Cancer, Hema, Fluids

infection

The process in which an organism has a parasitic relationship with a host

Prions

Corrupted proteins that are folded abnormally

What happens when prions and normal proteins come in contact?

Normal folded proteins (PrPc), prion causes a chain reaction of abnormally folded proteins (PrPsc).

Abnormal folded chain of proteins leads to dysfunction

What do Prions cause?

Transmissible Spongiform Encephalopathies

Transmissible Spongiform Encephalopathies

Uncurable, fatal chronic degenerative disease of brain

Examples of Transmissible Spongiform Encephalopathies

Cruetzfeldt-Jakob Disease and Kuru

How are prions transmitted

Coming into contact with infected tissue

What would be examples of infected tissue causing prions?

Ingesting animal brain, blood products, or contaminated surgical instruments

Are viruses living or non-living?

Non-living

Viruses characteristics

Subcellular, made of only nucleic acids and proteins, and they are obligate intracellular parasites (can only replicate in a host)

Viruses spread

Inject the contents through the tails. Causing infection and dysfunction.

What is this a picture of?

Virus

What is this a picture of?

Virus

What is this a picture of?

Virus

What is this a picture of?

Virus

Do we typically use traditional antibiotics for a virus? If not, what do we use?

No, we use anti-virals

Bacteria characteristics

Single celled, cell wall, grow independently (most of the time), grown on a culture medium (most), contain both RNA and DNA. They have no nucleus.

Bacteria is classified by

Morphology - shapes

Colony types

Gram staining (+/-) - be able to see with stain

Aerobic/anaerobic

Facultative - anaerobic without oxygen

Obligate - harmed by oxygen

Shape of bacilli

Long, oblong, look like Cheeto puffs

What is this a picture of?

Bacilli

What is this an image of?

Bacilli

What is this an image of?

Bacilli

Shape of spirochetes

Spiral-like or worm

What is this an image of?

Spirochetes

What is this an image of?

Spirochetes

What is this an image of?

Spirochetes

Shape of cocci

Sphere or circle

Colonization

The grouping together

Streptococci

In strings/strands

Associated with strep

Staphylococci

clumps

Associated with staph infections

What is this an image on?

Cocci

What is this an image of?

Streptococci

What is this an image of?

Staphylococci

Mycoplasma Characteristics

No cell wall, Grow on culture medium, smaller, DNA and RNA, Creates ATP and proteins independently

What does mycoplasma cause?

Atypical pneumonia or STI

Rickettsiae Characteristics

Obligate intracellular parasites - unstable cell membrane, and cannot be grown on traditional culture media

Insect and animal vectors

Cell wall

DNA and RNA

Create ATP and Protein Independency

What does Rickettsiae cause?

Rocky Mountain spotted fever and typhus

Chlamydia Characteristics

Obligate intracellular parasites - can't make ATP by itself

Cell wall

Create Protein independency

Need Host for ATP

DNA and RNA

What does Chlamydia cause?

STI and pneumonia

Fungi Characteristics

Cell wall

Nuclear membranes

Yeast vs. molds

What does fungi cause?

infections in skin, GI, GU tracts

Protozoa Characteristics

Motile, Single celled organisms, Nucleus

What does protozoa cause in the US?

Giardia and trichomonas

What does protozoa cause in developing countries?

Malaria, sleeping sickness, amebiasis, leishmaniasis

Bacteria Pathophysiology

Invasion of tissue, Release Exotoxins and Endotoxins

Exotoxins

Poisonous substances secreted by bacteria

What do exotoxins do?

Cell lysis, degradation of extracellular matrix, cell dysfunction

Endotoxins?

Inflammatory/immune response, Cellular and tissue destruction

Viruses pathophysiology direct pathway

Produces a protein that damages the cell membrane

Virus pathophysiology indirect pathway

Produces a protein that is incorporated into the cell membrane, Immune system mounts a response to this protein

True or False: Sepsis is a syndrome associated with severe infection?

True

Is sepsis a systemic response to infection?

Yes, it enters the bloodstream

How is sepsis caused?

The release of bacterial endotoxins and/or exotoxins

Sepsis triggers the activation of what?

Inflammation cascade, coagulation cascade, complement system

Sepsis cycle

Infection, Bacteremia, Sepsis, Septic Shock, Multi-organ failure

What is the bacteremia stage?

Bacteria in the bloodstream

What is the sepsis stage?

2 or more of:

Temp>100 degrees, <96 degrees

HR>90

RR>20

WBC >12k, <4k

septic shock stage

Hypotension, Perfusion abnormalities, Altered mental status

multi-organ failure stage?

Failure of the kidneys, lungs, heart, liver, clotting, and CNS

What are the treatments for sepsis?

Treat primary infection, Fluid resuscitation, Medications to vasoconstrict, improve heart function, Treat organ failure, Immune modulators

Pathogen

The parasite or microorganism responsible for arousing a pathologic response

Infectivity

Pathogen's ability to invade and replicate in a host; how likely is the pathogen to infect someone

Pathogenicity

Ability of organism to cause disease; certain conditions or some disease can happen at any time.

Virulence

Potency of pathogen and producing severe disease; how bad it will be

Antigenicity?

The pathogen's ability to stimulate an immune response

What is are the sequences of infection?

Transmission, Contact, Airborne, Enteric, Vector-borne

contact transmission

Host is in direct/indirect contact with infection

Airborne transmission

Pathogen is inhaled in through contaminated droplets

Enteric transmission

Fecal/oral route

Vector-borne transmission

Indirect, intermediate, insects transmit the disease

Sequence of infection

Inoculation/portal of entry, Incubation, Prodromal period, Clinical disease, Convalescence, Recovery

Inoculation/portal of entry period

Pathogen fights past 1st line of defense

Incubation period

The period of time from when the pathogen enters until symptoms occur

Replication

Host may/not be contagious

Prodromal period

Mild non-specific symptoms

Clinical disease period

Body's response - immune, inflammation

true symptoms

Convalescence period

Resolution - body defeats pathogen

Recovery

No longer having the pathogen

Symptoms of infection

Fever, chills, sweating, malaise (general fatigue and feeling ill), nausea, vomiting

Symptoms in elderly for infection

Confusion, memory loss, difficulty concentrating

Signs of infection

Fever, rash, lymphadenopathy (swelling of lymph), and lymphangitis

What is this a picture of?

Lymphangitis

What is this picture of?

Lymphangitis

What is the ancillary testing for infection?

Direct visualization of the organism, Culture and sensitivity, Detection of microbial antigen or antibody, Clues that infection may be present, Detection of specific microbial nucleotide sequences

Direct visualization of the organism?

Gram staining - finding certain bacteria, Used by sputum or urinalysis

What is the difference between culture and sensitivity?

Culture is different because each bacteria grow differently. Cultures are 24 hours. Sensitivity is 48 hours. Sensitivity is different by seeing how long infected tissue grows, antibiotics are treatments.

What does the detection of microbial antigen or antibody help do?

Identify viral rapid strep test

What clues that infection may be present?

X-ray and WBC in urinalysis

What is the detection of specific microbial nucleotide sequences?

Viral and bacterial infections

How do we treat infection?

Local methods: Heat, incision and drain

Antibiotics - bacterial

Antivirals - viruses

Antifungals - fungals

What are the antibiotic mechanisms?

Destroy the cell wall

Inhibit protein synthesis

Inhibit DNA synthesis

Inhibit RNA synthesis

What does inhibiting the protein synthesis do?

Bacteria can't replicate

What does inhibiting DNA and RNA synthesis do?

Prevent function and replicate

Antiviral medications do what for the body?

Inhibit viral replication

Frequent resistance

Often use multiple medications

What are the preventions for infection?

Handwashing

Disinfecting tables/equipment

Personal protective equipment (PPE)

Vaccinate healthcare workers

Follow isolation procedures

If ill, avoid treating high-risk patients

Staphylococcus aureus

The most common staphylococcal infections

Normally on the skin, Break in skin or mucous membrane, Suppurative - form abscesses/ pus-filled

What can staphylococcus aureus cause?

Cellulitis, folliculitis, furuncles, carbuncles in skin

How does staphylococcus aureus spread?

Through hematogenous spreading (blood)

Bone, joint, and heart valves

How to control staphylococcus aureus?

Proper handwashing

What does MRSA stand for?

Methicillin-resistant staphylococcus aureus

How is hospital vs community acquired MRSA different?

Hospital MRSA is severe and hard to treat

Community acquired is mild and needs an antibiotic to treat