ECU BIOL 2110 Exam 3

When do infections likely occur in Streptococcal Diseases?

When immune system is weakened or when bacteria enters through cuts, the throat, or respiratory tract.

In Streptococcal Diseases how does transmission occur?

Through droplets or direct contact

Which strains are more pathogenic in a Streptococcal Disease?

S. pyogenes

Most virulent types are ______-hemolytic, which means what?

beta

Streptococcus pyogenes causative agent?

Strep Throat

Streptococcus pneumoniae causative agent?

pneumonia

Is there a vaccine for Streptococcus pyogenes?

Currently none

Is there a vaccine for Streptococcus pneumoniae?

Yes. Polysaccharide or conjugate vaccine

Diphtheria causative agent?

Corynebacterium diphtheriae

What population is Diphtheria mostly found in?

Unvaccinated children under 15 years old and adults without boosters

Diphtheria vaccine

• “D” in DTap vaccine (for kids), Tdap booster (for teens and adults)

• Is a toxoid vaccine

Signs/symptoms of Diphtheria

sore throat, swollen neck (“bull neck”), fever, and airway obstruction

What role does Lysogenic bacteriophage play?

It encodes diphtheria toxin

What is the most important aspect of treatment for Diphtheria?

Diphtheria antitoxin

Pertussis (Whooping cough) causative agent?

Bordetella pertussis

What is population is mostly affected in Pertussis?

Most severe in infants younger than 1 and unvaccinated children

Vaccine for Pertussis

• Acellular subunit vaccine

• “P” in Dtap

Since when has there been an upward in trend infections in pertussis? What is likely the cause?

• Since the 1980s

• The cause would be lower vaccination rates, and post COVID effects.

Tetanus causative agent

Clostridium tetani

Where is tetanus commonly found?

• soil

• dust

• animal feces

Tetanus symptoms observed

• stiffness (“lockjaw”)

• difficulty swallowing

• rigid neck

What are Tetanus symptoms caused by?

caused by a neurotoxin (tetanospasmin)

What vaccine is used to prevent tetanus?

Toxoid vaccine

• DTap (kids)

• Tdap/Td (teens and adults)

Are boosters needed for tetanus?

Yes, every 10 years

Dtap

• original vaccine

• mostly approved for children

Tdap

• booster shot

• lower dose than Dtap

• mostly approved for older children and adults

Tuberculosis causative agent?

Mycobacterium tuberculosis

Where is tuberculosis found in the world?

It’s worldwide and common in:

• high risk HIV positive patients

• areas in crowded living conditions

• higher risk in immunocompromised populations

Tuberculosis is transmitted by?

• respiratory droplets (airborne)

• spread if someone infected coughs or sneezes

Primary infection

• first time infection

• usually asymptomatic

• becomes latent

• not contagious

Post-Primary infection

• reactivation of latent infection

• highly contagious

• Is an active disease: persistent cough, fever, night sweats, weight loss, hemoptysis (blood in sputum)

Treatment: single or multi-drug therapy in tuberculosis?

• multi-drug therapy

• long treatment (6 months long)

What type of resistance is developing leading to an increase in incidence in tuberculosis?

• Antibiotic resistance

• multi-drug resistance TB (MDR-TB)

Are there any vaccines available for tuberculosis? And if so what type?

• Yes

• BCG vaccine (live attenuated vaccine)

• Protects mostly children (less effective in adults)

What is a common diagnostic test in TB?

Tuberculin skin test (Mantoux)

Hansen’s disease (Leprosy) causative agent?

Mycobacterium leprae

How is leprosy transmitted?

• through respiratory droplets (close contact)

• not easily spread

Leprosy relationship with macrophages?

• bacteria lives inside macrophages

• helps them hide from the immune system

Leprosy’s relationship to the nervous system?

• invades peripheral nerves

• causes: loss of sensation, muscle weakness, nerve damage

What host(s) exist besides humans in Leprosy?

Armadillos (major animal reservoir) or some rodents

Is leprosy more or less contagious than TB?

It’s less contagious

Is leprosy a long or short incubation period?

• long incubation period

• can take years to show symptoms

How is leprosy made noncontagious?

• multidrug antibiotic therapy

• patients become noninfectious within days of treatment

Tuberculoid leprosy?

more localized, few skin lesions, and a strong immune response

Lepromatous leprosy?

progressive, widespread nodules, and severe nerve damage

Meningitis is an inflammation of what?

meninges

What is meningitis caused by?

many microbes like viruses, bacteria, fungi, and protists

For meningitis what is the specific causative agent for the severe bacterial form?

Neisseria meningitidis (meningococcus)

What are the symptoms and what are they caused by in meningitis?

• sudden fever

• headache

• stiff neck

• vomiting

• sensitivity to light

• ocnfusion

Caused of symptoms are usually inflammation of the meninges

How rapid and likely is death in meningitis?

Death occurs usually in a few hours

• Without treatment: mortality rates 80%

• With Treatment: mortality rate 9-12%

What groups of individuals are more likely to be victims in meningitis breakouts?

• college students (dorms) and military (housing)

• affects infants, adolescents, elderly, and immunocompromised individuals

What are two common causative agent species for staphylococcus

• Staphylococcus epidermis

• Staphylococcus aureus

Name 3 virulence factors associated with staphylococcus infections?

• hemolysins

• coagulase

• leukocidins

Cutaneous infections

infection of the skin

Foodborne Infections

• from toxins already in food

• bacteria doesn’t need to grow in the body

Systemic infection

infections spread through the whole body

Toxin-meditated infections

bacteria grows in the body and produce toxins that cause symptoms

In order, what three antibiotics has S. aureus developed resistance to?

1. Penicillin

2. Methicillin

3. Vancomycin

For staphylococcus infections what other organism likely provided the vancomycin resistance gene?

Enterococcus

True or False: STI’s are only caused by prokaryotes?

False

Where are STI’s pathogens generally found?

• Found through se*ual contact

• genital, anal, or oral

Describe the trends in syphilis and gonorrhea that overlapped with the introduction of penicillin and birth control pills?

• After penicillin was introduced: rates of syphilis and gonorrhea decreased (effective treatment)

• After birth control pills became common: rates increased again and people likely used less protection.

Gonorrhea causative agent

Neisseria gonorrrhoeae

For gonorrhea the presence of what is needed for survival?

• requires mucous membranes

• does not survive well outside the body

How does transmission occur in gonorrhea?

• sexual contact (genital, oral, anal)

• mother → infant during childbirth

difference in gonorrhea symptoms for males vs. females

Males

• painful urination and pus discharge

Females

• mild/no symptoms

• causes pelvic inflammatory disease and infertility

Describe how infants may acquire an infection and what may be used as a preventative measure in gonorrhea?

• How infants acquire it: during birth and causes an eye infection

• Preventative measure: erythromycin ointment applied during birth

Syphilis causative agent

Treponema pallidum

What is the morphological shape of syphilis?

Spirochete: spiral shaped bacteria

How is syphilis transmitted?

• By direct contact with sores during s*x

• mother → fetus (congenital syphilis)

What is congenital syphilis?

infection passed on from pregnant mother to fetus

Four stages of syphilis

1. Primary: painless sore at infection site

2. secondary: rash, fever, swollen lymph nodes

3. Latent: symptom-free but still infectious

4. Tertiary: years later → brain, heart, or nerve damage

What antibiotic is highly effective during _____ and _____ stages of syphyilis?

• Penicillin

• Most effective during: primary and secondary stages (early stages)

Describe the Tuskegee and Guatemala experiments

Tuskegee (1932-1972):

• 600 men enrolled; 339 had syphilis; 201 were infected

• researchers were held without treatment

• Participants were misled and denied informed consent

• resulted in death, disability, and infection of family members.

Guatemala (1946-1948)

• U.S researchers were intentionally infected prisoners, soldiers, and psychiatric patients.

• Done without consent

• did not receive proper treatments

Rocky mountain spotted fever causative agent

Rickettsia spp.

Where is the rocky mountain spotted fever endemic?

In the southeastern states (Mostly NC)

Describe the signature symptoms of the rocky mountain spotted fever

• fever, headache, and muscle pain

• A rash begins on the wrists and ankles, spreads to palms, soles, and trunk

Mortality in treated vs. untreated in the rocky mountain spotted fever

• 25% untreated

• < 1% with treatment

Lyme disease causative agent and vector

• Borrelia burgdorferi

• vector: deer ticks (Ixodes species)

most prevalent _____ disease in the united states for Lyme disease

arthropod-borne

Describe the initial symptoms seen in Lyme disease. What is the most prominent disease?

• fever, fatigue, and headache

• The most prominent disease is “bull’s eye” rash (erythema migrans)

In Lyme disease when is it best to treat with antibiotics?

Doxycycline or amoxicillin early; longer therapy if disseminated

Chronic stage of Lyme disease

joint pain, nerve problems, heart complications if untreated

Anthrax causative agent

Bacillus anthracis

Virulent factor of Anthrax

Anthrax toxin (damages immune cells)

The natural reservoir is ______ and it is primarily associated with____

• natural reservoir: soil

• Primarily associated with: animal products

Is anthrax treatable? When if so.

• Yes, with antibiotics (ciprofloxacin or doxycycline)

• Must be treated early

What are the three forms of anthrax infections?

• Cutaneous: skin contact

• Inhalation: spore inhalation

• Gastrointestinal: ingestion

Is a vaccine available for anthrax?

• Yes

• Subunit vaccine for high risk individuals given to military, lab, high-risk workers

State anthrax’s relationship to use in water/terrorism

B. anthracis spores were used in 2001 U.S postal attacks → 22 cases, 5 deaths

Plague causative agent

Yersinia pestis

What are the intermediate hosts/vectors which spread plague between mammalian hosts?

• Main vector: flea

• They spread bacteria between rodents and other mammals

What are the main forms of plagues?

• Bubonic: flea bite

• Septicemic: blood infection

• Pneumonic: inhalation

When can plague be treated? What does it reduce the mortality to?

• Plague can be treated if rapidly diagnosed

• mortality reduces to <5% of those infected

Transparent water may still be contaminated with potentially pathogenic

microorganism. So water is routinely tested for _____ as indicator organisms

Coliform bacteria

Water quality is reported to the EPA monthly as described by_____

Safe drinking water act

Cholera causative agent

Vibrio cholerae

How is cholera transmitted?

• ingestion of contaminated water or food

• regions in lacking clean water and sanitation

• natural disasters or war

• raw or uncooked shellfish from contaminated coastal waters

Where is cholera commonly found?

• developing countries

• refugee camps

• disaster zones

• travelers to endemic regions

How can cholera be controlled?

safe water supply, sanitation, and hand hygiene