Microbio test 5

Defense mechanisms of the lower respiratory tract

-blocked by the mucociliary escalator

-little to no normal flora

-alveolar macrophages

bronchitis

Mucus accumulation

• Marked by a cough and

wheezing

• Usually viral and clears on

its own

Pleuritis (Pleurisy)

Smooth pleural lining gets

inflamed and rubs together

• Sharp pain, coughing

makes it worse

• Can hear “rubbing” with

stethoscope

Pneumonia (bacterial vs viral)

-Infection and swelling of lung

tissue

• Fluid may collect

• Difficulty breathing

• Bacterial is usually more

serious due to pus

• Viral usually clears on its own

what is a sputum culture

thick mucus coughed up from lungs

• Healthy people don’t make it

diagnosis of pnemonea

what is a good quality specimen for sputum

Less than 10 squamous epithelial

cells

• Greater than 25 WBC per low

power field (40X) on Gram stain

Whooping cough (Pertussis)

• Bordetella pertussis

• Gram-negative coccobacillus

• Spread by respiratory droplets

• Very contagious (R0 = 17)

• Outbreaks in schools & on college

campuses

• Also called the “100-day cough”

• Reportable disease

stages of whooping cough

1) Catarrhal stage = cold-like/fever

2) Paroxysmal stage = cough-whoop

3) Convalescent stage = lasts for months

pertussis virulence factors

A-B toxins

• Pertussis toxin: causes systemic symptoms; halts

phagocytosis; increases mucus production

• Tracheal toxin: damages ciliary cells

Adhesins

• Filamentous hemagglutinin: attaches to ciliated

epithelial cells and impedes ciliary action

Capsule

end result of musculatory escalator

1) Stops Mucociliary escalator

2) Allows entry to lower respiratory tract

what is main characteristic of pertusis

whoop cough

prevention for pertusis

DTaP vaccine

what is the bacteria and alternative name for primary pnemoneia

Streptococcus pneumoniae

• Also called pneumococcal

pneumonia

what is the prevention and treatment for primary pnemonia

prevention- Vaccines:

• PNEUMOVAX (for elderly)

• PCV 13 (for kids)

treatment: antibiotics

atypical or walking pnemonia

milder form of pnemonia

what are the 3 causes of walking pnemonia

a) Mycoplasma pneumoniae

b) Chlamydophila pneumoniae

c) Legionella pneumophila

identifier of Mycoplasma pneumoniae

bacteria have no cell wall

key part of Chlamydophila pneumoniae

intracellular life cycle

Legionella pneumophila (alternate name and where does it come from)

Inhalation of bacteria – from contaminated water, assosiated with outbrakes

“Legionnaires disease”

legionnaires considerations

Test water temps to ensure bacteria can’t grow

describe the bacteria for tuberculoses

Mycobacterium tuberculosis

• Waxy cell wall, rod shaped

• Intracellular bacteria

what happens in TB diesease

• Immune cells form a wall around infection, called a tubercle

• This allows TB to go “latent”

• A disruption of the wall will cause

  bacteria to spread, and disease is

  “reactivated”

Extrapulmonary or Miliary TB

-Infects other organs

– Granulomas in other organs, bone, blood

– Associated with immunocompromised patient

– This is deadly!

main symptom of active tuberculosis

greenish or bloody sputum

epidemiology of TB

increasing drug resistance, serious problem with AIDS

diagnosis of TB

Tuberculin skin test (TST) or Purified

Protein Derivative (PPD)

What can give you a positive PPD or TST?

- Active TB

- Latent TB (tubercles)

- Extrapulmonary TB

- BCG vaccine

- Past exposure

- Cured TB

diagnosis of TB if symptomatic

AFB Smear with pink/red results

treatment of TB

prolonged course of 6 months with a concern of lack of compliance

who is Respiratory Syncytial Virus (RSV) dangerous for

infants (especially premature) and elderly

what and who is RSV prevention for

pregnant mothers and the elderly

most popular influenza and whats special about it

influenza A and it is seasonal so only oct-may

how to test for the flu

Can test via lateral flow for antigens

what does it mean to be antigenetically different

when an antigen is not recognized by the

same antibody anymore

antigenic drift

• genomes mutate over time

• Minor mutations where subtype

  remains the same

antigenic shift

• large changes over short periods of time

• Influenza can swap RNA segments with other influenza viruses

• Often the source of epidemics

• zoonotic mixing occurs

what happens to vaccine effectiveness as antigenic shift continues

Vaccines become less effective

over time

flu vaccine (what does it contain and how long to make it)

Each seasonal vaccine is trivalent

takes a year to make

how to SARS and MERS start and then what do they develope into

Disease starts like influenza, but

becomes severe

• Pneumonia, hypoxia, respiratory failure

what is hostoplasmosis, whats it confusion with, how does it spread, who is at risk

• Infects macrophages (survives and multiplies)

• Can be confused with TB, granulomas form in lung

• spread from droppings of birds and bats

• AIDS at risk

Coccidioidomycosis (Valley Fever)

• spores spread from soil and wind

• AIDS at risk

• TB like

the four fungal diseases of the lower respiratory tract

1. Histoplasmosis

2. Coccidiomycosis

3. Aspergillosis

4. Pneumocystis pneumonia

aspergillosis

• Causes granulomas in the

lung, called “fungus balls”

• Produces aflatoxins which are

carcinogens

Pneumocystis Pneumonia

• forms cysts

• Must be treated

• Pneumonia occurs in infected

infants & immunosuppressed

individuals (AIDS)

Paragonimiasis

• Lung flukes (Paragonimus sp.)

• parasitic infection that starts from undercooked crabs/crayfish then goes to the lungs

defenses in the mouth

• saliva

• gram positive normal flora

  • makes biofilm

defenses of the stomach and small intestine

few normal flora

what defenses does the large intestine contain

lots of normal flora

what is dysentary

diarrhea plus mucus, blood, and/or

inflammation

gastroenteritis

inflammation of stomach and intestinal mucosa

enterocolitis

inflammation in the small and large intestines at the same time

most common normal flora in stool

Facultative Gram-negative rods (coliforms- Lactose-fermentors)

• e.coli

  and

• Gram-positive cocci

  • Enterococci

what is HE (Hektoen-Enteric) selective for

Selects against Gram

+

Grows Gram (-) rods

what is HE (Hektoen-Enteric) differential for (the colors)

Lac (+) =yellow/orange

Lac(-) =pale green

• Shig = pale green

• Salm= pale green w/ black centers

organisms for HE

Pathogen are non- lactose ferm

Lac + is normal flora (except EHEC)

what is maconkey (lac) selective for

Selects against Gram +

Grows Gram (-) rods

what is the differential for maconkey

Lac (+) =magenta

Lac(-) =pale pink

organisms for maconkey

Pathogen are non- lactose ferm

Normal flora- lactose ferm.

what does campylobacter agar do

Grow at 45oC only Campy

grows, antibiotics only

MacConkey Sorbitol selective for waht

Selects against Gram+

Grows Gram (-) rods

sorbital differentials

Sorb (+) =magenta

Sorb(-) =pale pink

orginisms that sorbital differentiates

Differentiates NF E.coli (sorb. +)

from EHEC (sorb. -)

food intoxication vs food infection

Food intoxication: symptoms caused by toxin

• Quick onset (3-6 hrs)

Food infection: symptoms caused by organism

• 24-48 hours until onset

main cause of cavities

Viridans/oral streptococci

• Streptococcus mutans

• Streptococcus sobrinus

what is gingivitis

inflammation of the gums, usually caused by anaerobes

peridontis

chronic issues qith gingivitis

Acute necrotizing ulcerative gingivitis

“Trench mouth”

• Anaerobes

6 food intoxications

a) Staphylococcus aureus

b) Clostridioides difficile

c) Bacillus cereus

d) Clostridium perfringens

e) Vibrio cholerae

f) Shigella dysenteriae

Staphylococcus aureus

• could be enterotoxin

• superantigen: strong immune response

• onset: 3-6 hours

what is staphylococcal food poisening

Bacteria on food handler: hands, nasal, skin to food

Bacteria grow,

• produce toxin that is heat

stable(resists boiling 30 min.)

what is Clostridioides difficile and what is associated with

• Opportunistic pathogen

  • Can have in normal flora in low numbers

• Antibiotic-associated diarrhea (AAD)

  • Superinfection following broad-spectrum antibiotic use

complications of clostridioides

pseudomembranous colitis

• Toxins kill cells of the colon

• Thick, yellow scabs cover the damaged area

Epidemiology of C diff

nosocomial

2 toxins responsible for Bacillus cereus

2 toxins responsible:

• Diarrheal toxin – found on meats and vegetables

• Nausea and vomiting toxin – on rice

what is Clostridium perfringens caused by

Spores contaminate meat, canned goods

• Toxin is made during the sporulation process

what does Vibrio cholerae produce and where does it come from

from crustaceons/seafood

cholera toxin

• Makes cells secrete water

Shigella dysenteriae

Severe, bloody diarrhea

• Uncommon in U.S.

• Shiga toxin

• A-B toxin

• Damages cells

• Intense inflammation

• Bleeding, ulceration,

mucous secretion

shigellosis- bacterial disease

Very contagious

• Infectious dose = 10 cells

• Non-lactose fermenting on

HE and MacConkey

• No black centers on colonies

• Antibiotic resistance

common, so perform

susceptibility testing

Salmonellosis- bacterial disease

• Salmonella enterica

• Gram-negative rod

• O:H serotyping to identify serovars

  • 12-36 hour onse

• Infection from

  • Processed meats

  • Eggs (shell is contaminated)

  • Milk

typhoid fever (what organism it is from, spread thru, what happens) bacterial disease

• Salmonella Typhi

• spread thru contaminates water and feces

• bacteria hide in cells and can shed for a year or more after an infection

disease of typhoid fever week 1 and week 2

disease:

Week 1: septicemia and fever

Week 2: diarrhea, high fever, confusion, delirium, rash

diagnosis of typhoid fever

• Non-lactose fermenting on HE and

MacConkey

• Black centers on colonies

what is Enteropathogenic E. coli (EPEC)

• infantile diahreah

• E. coli strains are lactose fermenters

  • Magenta on MacConkey

  • Gold/orange on Hektoen-Enteric

Enteroinvasive E. coli (EIEC)

acute, severe diseas, dysentary

what is Enterohemorrhagic E. coli (EHEC), what does it have and what strain is it

• an intoxication,

• Caused by strain O157:H7

• Has acquired the shiga toxin

diagnosing EHEC

O157:H7 looks like normal flora

• Lactose fermenter

• MacConkey sorbitol plate

• O157:H7 is a non-fermenter (pale pink)

what is Enterotoxogenic E. coli (ETEC)

AN INTOXICATION

Has acquired a toxin akin to cholera toxin

Campylobacteriosis (whats it known for and what can it lead to)

Most common cause of bacterial gastroenteritis in the U.S.

• can lead to Guillan-Barre syndrome

  (30-40%)

  • Autoimmune attack and temporary

  paralysis

campylobacteriosis diagnosis

Campy blood agar plate

• Blood plate with many antibiotics

• Grow at 42 degrees

• Any growth = positive for Campylobacter

Yersiniosis

• “Refrigerator food poisoning”

• Grows at 4oC

• can be misdiagnosed as appendicitis

Gastric Ulcers (what is the organism and what is special about that organism)

• Helicobacter pylori

• Can withstand stomach acid

  • Urease: breaks down urea and

  raises pH

listeriosis (where comes from, risk for who)

Listeria monocytogenes

• Foodborne

• Lunch meat

• Unpasteurized dairy products

•Grows at 4oC

Risk of fetal meningitis

• Bacteria crosses the placenta

mumps (what does it cause, prevention,

• Infects parotid glands (salivary)

  • Swelling of the cheek and jaw

• MMR vaccine

  • Used to be common in children

  • In males after puberty, can cause sterility

rotavirus

Causes viral gastroenteritis

• common in children

norovirus

• Leading cause of adult gastroenteritis

• very contagious

• can live on surfaces for up to two weeks

Hepatitis A (transmission, effects, treatment)

A = acute

• Acquired by ingestion

• can spread to liver

• there is a vaccine

Hepatitis B (transmission, effects, treatment)

Transmitted by blood, semen, vaginal fluids

• asymptomatic in most

  • chronic carriers

• treatments

  • Vaccine

  • Post-exposure treatment

    • Antibodies

Hepatitis C (what does it cause, treatment)

C = chronic

• Many asymptomatic

• If untreated, chronic hepatitis

  • 20% get liver cirrhosis or cancer

• Antivirals for treatment – can cure infection but no vaccine

hepatitis D

• D = dud

• Requires Hepatitis B

virus in order to replicate

• When present,

• Increases chances of liver

disease

• Higher mortality rate than

HBV alone

Giardiasis (type of disease, organism description, transmission)

• Parasitic Protozoa

• Flagellated

• Drinking contaminated water

  • use filtration