Gen Path Chapter 2 Flashcards
List the Antibiotic Super Bugs
- Methicillin-Resistant Staphylococcus Aureus (MRSA)
- Multi-drug Resistant: Mycobacterium tuberculosis
- Vancomycin-resistant enterococci
- Fluoroquinolone-Resistant Clostridium Difficile
Infection
Some bacteria, all viruses and all parasites cause illness via infection
Bacteria Examples
Salmonella spp, listeria monocytogenes, Campylobacter, jejuni, Vibri parahaemolyticus, and Yersinia enterocolitica
Virus Examples
- Hepatits A
- Norovirus
- Rotavirus
Parasites
- Trichinella Spiralis
2. Giardia Duodenalis
Intoxication
Results when a person eats food containing toxins that cause illness
Produced by harmful microorganisms, the result of chemical contamination or a natural part of a plant or seafood. Some bacteria cause an intoxication.
Viruses and Parasites do not cause food borne intoxication T/F?
True
Intoxicating Bacteria
- Clostridium Botulinum
- Staphylococcus Aureus
- Clostridium Perfringens
- Bacillus Cereus
Signs and symptoms of disease
Systemic (fever) or Local (Pus)
What do the symptoms of a disease depend on?
Etiologic Agent - Type and virulence
- System affected
- Health of the individual
Common Systemic S&S
- Fever
- Chills
- Sweat
- Malaise
- Nausea
- Vomiting
- Change in
- Leukocyte type and/or Number
- Enlarged lymph nodes
- Possible cognitive changes in elderly
What is a pyrogen?
A substance that typically causes fever
- Bacteria
- Cytokines
Raises ‘set point’ in the hypothalamus resulting in increased temperature
Fevers that are not infectious are usually caused by
- Inflammatory Diseases
- Abnormalities of the hypothalamus
- Dehydration
- Toxic Substances - medications
- Neoplastic Diseases
- Immunologically - mediated diseases
- Pulmonary embolism
Normal Body temperature of a child and an adult
Child: 96.6-99f (36-37.2 C)
Adult: 98.6 F (37c)
Temperature of low grade fever
Up to 102 F (39C)
Temperature of high fever
101f or over for babies
over 102f
104f (40c) - Seek medical attention
Effects of Prolonged High Fever
- Seizures
- Delirium
- Disorientation
- Hallucinations
Describe inflammations caused by infections
- Local or systemic
Abscess - pus formed from leukocytes
Infectious Diseases Caused by abscesses:
Infectious GI diseases (Diverticulitis)
P.I.D (Pelvic Inflammatory Disease)
Rashes with Fevers can result from:
Infection caused by microbe that has successfully penetrated the layers of the skin and multiplied locally
Infection elsewhere in the body unrelated to local skin disease (eg Scarlet Fever from streptococci)
Common Rashes Caused by Infections:
- Maculopapular Eruptions
- Nodular Lesions
- Diffuse Erythema
- Vesiculobullous eruptions
- Petechial purpuric eruptions
What are red streaks and what are they caused by?
Local infection that is spreading into the lymphatic system (Lymphangitis, moves toward local lymph Node)
What can inflamed lymph nodes be associated with?
Many infectious diseases, not just sepsis
What regions are the lymph nodes palpated
- Cervical
- Inguinal
- Axillary
Causes of inflamed lymph nodes
- Cancer
- Rheumatoid Arthritis
- medications
Characteristics of acute swollen nodes (bacterial)
- Palpable
- Tender
- Enlarged
- Fluctuant
If red and hot with fever send to Dr.
Characteristics of Chronic swollen Nodes (Infection)
- Palpable
- Tender
- Enlarged
Not usually red/warm
Characteristics of Metastatic Cancer
- Supraclavicular & Inguinal are common areas
2. Hard, fixed, non-tender and may be rubbery
What is Sepsis caused by normally?
Secondary to infection:
- Hemolytic Streptococcus and/or staphylococcus
What lymph Nodes are the most often affected by sepsis?
- Submandibular
- Cervical
- Inguinal
- Axillary
What causes Joint effusion and what can it be a sign of?
Another sign of infection Result of: 1. Bacterial 2. Mycobacterial 3. Fungal 4. or Viral Usually through the blood stream, but could be innoculated as a consequence of surgery or trauma
Signs and Symptoms of joint effusion
Usually one joint
Associated with infectious Arthritis
and Suppurative infectious arthritis
Define infectious arthritis
arthritis resulting from infection of synovial tissue with pyrogenic bacteria or other agents
Define Suppurative infectious arthritis
Suppuration (pyrogenic): the formation or discharge of pus
Symptoms of Infectious Arthritis
- Acute Pain
- Stiffness
- Most common in knee
- Also in shoulder, wrist, fingers, hips, elbows
- Fever and Chills
- Heat
- Tenderness w Palp
Define Immunosenescence
Changes in immune system as we age
Effects of aging
Immunosenescence
Decreased circulation and poor wound healing
Decreased function of natural barriers
Decreased cough/gag reflexes
(decrease ability to clear secretions)
Decreased bronchiolar elasticity and mucociliary activity (increased risk of phenumonia
What causes a decrease in t-cells but an increase in memory cells?
Aging…
Slower to respond/require a strong stimulus
Increased likelihood of reactivation of dormant infections (Tb, Shingles)
effects of comorbidities
chronic disease rises with age
Medications and aging
Can mask signs and symptoms of other problems related to aging
Fever symptoms in an aging person
Serious infection with little to no fever due to impaired thermoregulatory system
or masking effects of drugs
1st symptoms of infection in elderly may be:
- Confusion
- Memory Loss
- Delirium
Define Infectious Diseases
Organism establishes parasitic relationship with host causing an invasion + Multiplication = an immune response
Thus causing damage to the host
either by microorganisms toxins, replication, or indirectly by competing for nutrients.
Or even our own immune system
Define Carriers
Someone infected with microorganisms with 0 symptoms. Can still transmit to other people and be infectious (non-symptomatic)
List the 3 Processes of infection
- Transmission
- Incubation
- Infection
Define Transmission in regards to process of infection
Depends on pathogen, ideal factors for transmission as well as state of host.
MUST have -
- Portal of entry
- Mode of transportation
- Portal of exit
Define Chain transmission and list the 6 steps
Infection begin with transmission
- A pathogenic agent
- reservoir
- Portal of exit
- Mode of transmission
- Portal of entry
- Susceptible host
This is known as the chain of transmission
define pathogen
and how the infection is caused
organism elicits a pathologic response in host Depends on: 1. Site of invasion 2. Number of pathogens and virulence 3. How well they disseminate in host 4. Immune status of host.
Define Principal Pathogens
Cause disease in people with intact immune systems
Define Opportunistic Pathogens
Pathogens that don’t cause disease in people with intact immune systems, but can cause devastating disease in hospitalized or immunocompromised people
Define Pathogenicity
Ability of organism to induce disease
Define Virulence
Refer to potency of pathogen in producing sever disease and is measure in case fatality rate
Define Nosocomial infections
Originates or takes place in hospital, acquired in hospital esp, in reference to an infection
HAI - hospital acquired infection
List the most common nosocomial infection HAI
UTI from catheters or urologic procedures, blood infections from IV catheters or surgical wounds and GI infections.
Define Reservoir
Environment in which organism can live and multiply
(Animals, Plants, Soil, Food, Organic Substances)
Humans an animal reservoirs can be symptomatic or asymptomatic
What is a portal of exit?
Where the organism leaves the reservoir and corresponds to the entry point on the next host
1. Respiratory Droplets
2. Blood
3. Vaginal Secretions
4. Semen
5. Tears
Urine and Feces as well as Open lesions and Pus
List how the organism gets from an infected host to a new host:
- Contact (Direct or Indirect)
- Aiborne - floating through air
- Droplet - diff then airborne bc drops 3ft
- Vehicle - common source Salmonella or contaminated food
- Vector - Involves insects and animals that act as intermediaries between 2 or more hosts
Define Portal of entry and list examples
Where the pathogen leaves/enters
- Ingestion
- Inhalation
- Bites
- Contact with mucous membranes
- Percutaneous
- Transplacental
List the factors of host susceptibility
- Age, sex ethnicity
- Health & Nutrition
- hormonal balance
- Co-morbidities
- Living Conditions
- Personal Behaviours (drug use, hygiene, diet, sexual practices)
- Medications
- Environment
- Use of invasive equipment - Catheters iv lines and chest tubes
- Stress
- Underlying medical disorders that specifically decrease t-cell and b-cell medicated immunity
List and explain the Process of an infection
- Incubation
- Time between entering the host, and ‘infection’
- Hours (GI Bugs) to months (lyme DZ)
- Symptoms = end of incubation
- ‘Latency = Dormant - Infection
- Clinical Symptoms
- Host-parasite interaction causes injury
- Mild -> Fatal
- Communicability: Ability to spread to another host
List the Lines of defense
1st line of defense - external barriers/secretions and microbial antagonism
2nd line of defense - inflammation
3rd Line of defense - Immune response
List the types of Organisms
- Viruses
- Mycoplasmas
- Bacteria
- Rickettsiae
- Chalmydiae
- Protozoa
- Fungi (Yeast/Mold)
- Helminths (worms)
- Mycobacteria
- Prions
How are organisms characterized?
Size, shape structure chemical composition, antigenic make up, growth requirements, produce toxins, viability under diff circumstances (sun, o2, heat, acid, etc..)
List the characteristics of Cell Walls
- Rigid Thick
- Outermost layer, surrounds cell membrane when present. Occurs in plants, bacterium and fungi
- Made of peptidoglycan in bacteria and chitin in fungi
- Metabolically inactive and non-living
- Determines cell shape and offers protection
Characteristics of cell membrane
- delicate, thin
- Outermost layer in animal cells, semipermeable
- made of lipids, proteins and carbs.
- Metabolically active and living
- protects the protoplasm and maintains homeostasis in a cell
Define Viruses
Smallest RNA or DNA covered with proteins
- antibiotics do not help
- antiviral meds only moderately effective
Entirely dependent on host
(Acyclovir decreases DNA replication)
Define mycoplasma
very small self-replicating bacteria with no cell wall, dependent on host for nutrition
Define bacteria
Single celled organisms with cell wall; independent
Replicates by growing and diving in half, they can do this in any tissue.
Classified by shapes
List the shapes that bacteria can be classified as:
Spherical-cocci, Rod-shaped - bacilli, spiral - shaped - spirochetes) Staining (gram positive/negative) motility, spores, 02, NonO2
Ex of Anaerobic bacteria
Normal gut flora
Ex of Aerobic bacteria
Staphlococcus Aureus (lungs, skin)
Compare Gram + and Gram -
Effects susceptibility to antibiotics and detergents
Gram + Destroyed by penicillin
Gram - Much more resistant
Define Rickettsiae
Small obligate intracellular parasites that are non-motile gram negative bacteria
Primarily animal pathogens that produce disease inhumans and are commonly transmitted by insect bites (tick, flea, louse, Mite)
Require host for replication
i.e. Q Fever (Coxiella); “Trench fever” Carried by lice (rochalimaea)
Define Chlamydiae
Smaller than bacteria but larger than viruses
- Obligate Intracellular - Dependent on host for replication
1. Always contains both RNA and DNA (Unlike Viruses)
2. Susceptible to antibiotics - curative
3. Most common STD - Leading cause of P.I.D.
- Leading cause of preventable blindness in neonates
Define protozoa
- SIngle cells or group of cells
- Motile, free living in moist environments
- Cell membrane, no cell wall
- Divide similar to bacteria
Ex. Giardia
Fungi
- Unicellular organism that produces hyphae (filamentous outgrowths)
- Contains Nuclei (eukaryotic)
- Cell Walls
- Yeasts or molds
- Reproduces by budding off
- Candida Albicans is an example
Define Helminths
Large multicellular organisms that are generally visible to naked eye in adult stages.
Can be either free-living or parasitic in nature.
In adult form helminths are unable to multiply in humans