Micro Lecture Exam 2 Flashcards
skin Diseases
Broad spectrum antibiotic
effective against more than 1 group of bacteria
Penicillin
treats gram + cocci & some gram- bacteria
Narrow spectrum antibiotic
target a specific group of bacteria (ex. vancomycin targets MRSA)
Bactericidal antibiotics
kill the bacteria
Antibiotic resistance
resistance to a drug by a bacteria that was previously sensitive to
What does MRSA stand for
Methicillin-resistant Staphylococcus aureus
What is MRSA?
Common cause of skin lesions in non-hospitalized people
What virus causes MRSA?
S. auerus
What are the signs and symptoms of MRSA?
- Raised, red, tender, localized lesions
- Features pus and feels hot to the touch
- Occur easily in breaks in the skin and may localize around a hair follicle
- Fever is common
How is MRSA transmitted?
Contaminant of all kinds of surfaces
What is the virulence factor of MRSA?
Enzyme that coagulates plasma
PCR
polymerase chain reaction that detects bacterial DNA quickly by nasal swab
Maculopapular
Skin eruptions by a variety of microbes and are flat to slightly colored bumps
Examples of Maculopapular rash viral diseases
Measles & Rubella
Pathogenesis virulence factors of Measles
- Virus implants on respiratory mucosa and infects the tracheal and bronchial cells
- It travels to the lymphatic system where it multiplies and enters the bloodstream (viremia) which carries the virus to the skin and various organs
Transmission of mealses
- Transmitted by respiratory droplets from only humans
- person is infectious during the periods of incubation, prodrome and skin rash
Incubation period
the time between when a person is exposed to an infectious agent and when they begin to develop symptoms
Prodromal stage
the period after incubation and before the characteristic symptoms of infection occur
Convalescence
The final stage of infection; symptoms resolve, and a person can return to their normal functions
Sgns and symptoms of measles
- Sore throat
- Dry cough
- Headache
- Conjunctivitis
- Lymphadenitis (inflammation of lymph node gland)
- Fever
- Oral lesions called Koplik’s spots (white spots can be seen before skin rash)
- Red, maculopapular rash that erupts on the head and progresses to the trunk and extremities
Sequelae
sequel; whats the aftermath
Sequelae and complications of measles
Pneumonia, encephalitis, may result in permanent brain damage or epilepsy
ELISA
Enzyme-linked immunosorbent assay to test for quantifying the presence of specific molecules, such as proteins, antibodies, hormones, or antigens, in a sample
MMR Vaccine
(Measles, Mumps, Rubella) contains live, attenuated measles virus that confers protection for up to 20 years
Best way to treat measles?
Replace lost fluids, reduce fever, suppress cough
Rubella : German Measles
Can be pre and postnatal, is a milder version of measles and adult rubella is characterized
How is rubella characterized in adults?
by joint inflammation and joint pain rather than a rash
How long does postnatal rubella take to advance and resolve?
3 days
Congenital Rubella
teratogenic and is transmitted from mother even if mother is asymptomatic
Teratogenic
causes harm to fetus
Common defects in congenital rubella
Deafness, ocular lesions, retardation, anemia, hepatitis, bone infection
Transmission or rubella
respiratory secretions and occasionally urine
Rubella transmission
Close living conditions are required for it to shed, and is in prodromdal stage for up to a week
How to test Rubella
Latex agglutination or ELISA
Impetigo
Superficial bacterial infection that causes the skin to flake or peel
What virus is Impetigo caused by
Can be caused by either S. aureus (older children) or S. pyogenes (newborns), or may be caused by a mixture of the two
Cellulitis
inflammation of subcutaneous connective tissue
Lymphangitis
red lineson the body leading away from the area are visible, the result of microbes and inflammatory products being carried by the lymphatic system
Causative agents of cellulitis
- In healthy individuals: S.. pyogenes and S. auerus
- Immunocompromised: almost any bacterium and some fungi
- Infants: Streptococci
What has to be done if there is extensive tissue damage from cellulitis?
Surgical debridement (removing dead tissue from wound to prevent more bacteria growth and infection)
Pyo
pus
Gene
create
Pox
individual lesions that contain fluid
Varicella
Human herpesvirus 3 (HHV-3); an enveloped DNA virus
What is the natural host of HHV-3
Humans
What does impetigo cause?
Itchy lesions that are crusty
Vesicular rashes
small, fluid-filled blisters known as vesicles that appear on the skin (chicken pox)
Causative agents of chicen pox, small pox and shingles
HHV-3
chickenpox vs mealses
Kopliks spot - measles
Where cells go during chicken pox to cause pain in back?
Dorsal root ganglion
Centripetal
More lesions in the center of the body than in the extremities
Postherpetic neuralgia
inflammation of the ganglia and nerve pathways that cause pain and tenderness and can last for several months
Acyclovir
Antiviral
Smallpox’s causative agent
Variola virus
Monkeypox
a viral zoonosis and less severe than smallpox
Zostavax
approved by the FDA in 2006 to prevent shingles
Treatment for varicella
goes away on its own and at most be given antibiotics and acyclovir
Shingles: Herpes Zoster
virus that emerges out of the ganglia after staying there after the recovery of chickenpox
Therpetic
herpes virus
What does it mean i suffix is -vir
Its a drug to treat virus; antiviral
Macules vs papules
maculesare flat and papules are raised
Other names for ringworm
jock itch and athlete’s foot
Dermatophytes
a type of fungus that can infect the skin, hair, and nails, causing conditions.
Pathogensis and virulence factors of ringworm
Dermatophytes have the ability to digest keratin and do not invade deeper epidermal layers
Tinea-
Scientific prefix used to refer to fungal infections of the skin, hair, or nails caused by dermatophytes
How do drugs help treat ringworm?
By speeding up the loss of the outer skin layer
Virulence factors
characteristics or traits possessed by pathogens that enable them to cause disease
What salt concentrations would S. aureus need to survive?
it can withstand up to 10%
Can S. auerus be microbiotic?
Yea on 30% of people and even strains of MRSA are found on healthy people
Temerature condition for S. auerus ot sruvive
Up to 60 celsius for 60 minutes
Enzymes produced by certain strains of S. aureus
Coagulase, lipase, DNase, hyaluronidase, staphylokinase
Which of the following media is often used to isolate Staphylococcus species?
Mannitol salt and blood agar
catalase
is an enzyme that breaks down the hydrogen peroxide produced in oxidative metabolism.
treatment of MRSA
treatment with more than one antibiotic and an incision of the lesion to drain pus
Subacute sclerosing panencephalitis (SSPE)
neurological degeneration of cerebral cortex, white matter , and brain stem which results from persistence of measles years after the first episode
what is the typical age for the first dose of the MMR vaccine?
12-15 months
What causes SSPE to occur in some cases of measles?
Defective virus that cannot form a capsid
Which type of agent causes damage to the developing fetus?
teratogenic
Teratogenic agents
substances, organisms, or environmental factors that can interfere with normal fetal development, leading to structural or functional abnormalities in the fetus
Transmission of impetigo
Direct and fomites (indirect contact like touching a doorknob)
Describe impetigo lesions
small red sores that are often described as having a “honey-colored” crust or scab over the surface, flaky scabs, peeling skin
Cellulitis symptoms
pain, tenderness, swelling, inflammation, fever, and lymphangitis
Which is the sign/symptom that often differentiates postnatal rubella from adult rubella?
Mild rash
Pustular rash
small, elevated lesions filled with pus known as pustules
What are the typical sign/symptoms of chickenpox?
centripetal lesion distribution, itchy fluid-filled lesions, fever
centripetal lesion distribution
pattern in which skin lesions or rashes are moving or directed towards the center of the body
Tinea capitis
ringworm of scalp
Lymphangitis
tytpically appears as red streaks extending from the infected or inflamed area towards nearby lymph nodes
Incubation for chicken pox
10-20 days
