Micro Final Exam

exam 1 and part of exam 2 chs. 25 & 26

Gastroenteritis

inflammation of stomach and intestine

Dysentary

severe diarrhea w blood and/or mucous. If bacteria invade bloodstream fever results.

Temperature abuse

allowing food to remain at a temp that’s not hot enough to kill the microbes and not cold enough th inhibit growth

Infection

S&S require bacteria to multiply in host; onset is 12hrs to several days

Example of a microbial disease that’s an infection

whooping cough (pertussis)

Example of a microbial disease that’s an intoxication

food poisoning caused by B. cereus

Intoxication

S&S caused by pre-formed toxins; onset is a few hours —> wait until food gets into intestines and infection starts

Describe the pathogenesis of tooth decay

S. mutans metabolizes sucrose to dextran and dextran forms biofilm sheltering many bacteria. Bacteria produces lactic acid and acid eats away at tooth enamel. 

Bacillary dysentery causitive organism

gram - rods; enterobacteriaceae Shigella spp.

bacillary dysentery means of transmission and reservoir

fecal oral transmission; humans majority and sometimes monkeys (b)

Salmonellosis causative organism

Salmonella enterica serotypes; gram - bacilli rods

Salmonellosis transmission

zoonotic; usually doesn’t spread by blood

Salmonellosis reservoir

poultry and reptiles

Typhoid fever causative organism

salmonella typhi and enterobacteriae

typhod fever gram reaction

gram - bacilli —> rods

typhoid fever resevoir

human to human

typhoid fever transmission

fecal-oral; eating/drinking contaminated food/water tf

cholera gram reaction

gram - comma shaped rod

cholera causative organism

vibrio cholerae

cholera transmission

fecal-oral; eating/drinking contaminated food/water (ct)

cholera reservoir

humans and water c

E. coli gastroenteritis gram reaction

gram - bacilli rods

e. coli gastroenteritis causative organisms

enterobactericae and e. coli

e. coli gastroenteritis reservoir

human and animal intestines

e. coli gastroenteritis transmission

foodborne illness; fecally contaminated food or water

Peptic ulcer disease gram reaction

gram - spiral shaped rods

Peptic ulcer disease causative organism

Helicobacter pylori

Peptic ulcer disease transmission

person to person w direct contact to vomit saliva or stool

Peptic ulcer disease reservoir

oral cavity (dental plaque, saliva, tongue, tonsil tissue, root canals, oral mucosa) as well as the human stomach

Viral hepatitis A (HAV) causative organism

picornavirus single stranded RNA genome; no envelope

Viral hepatitis A (HAV) transmission

fecal-oral

Reservoir for all hepatitis

humans

Hepatitis B (HBV) causative organism

picornavirus double stranded DNA genome; enveloped

Hepatitis B (HBV) transmission

blood, saliva, semen, breast milk

T or F: HBV and HCV can both chronic and acute

true

Hepatitis C (HCV) causative organism

picornavirus single stranded RNA genome; enveloped

Hepatitis C (HCV) transmission

blood, sexual contact

Acute viral gastroenteritis causative organisms

rotavirus, norovirus

Acute viral gastroenteritis S&S

low grade fever, diarrhea, vomiting

Acute viral gastroenteritis transmission

fecal-oral, person-to-person contact, contaminated objects (fomite)

Acute viral gastroenteritis reservoir

humans

Giardiasis causative organims

Giardia lamblia; protozoa

Giardiasis transmission

fecal-oral via contaminated water (g)

Giardiasis S&S

diarrhea, cramping, gas, bad breath, weakness, and weight loss

Cryptosporidiosis causative organisms

Cryptospridium spp; protozoa

Cryptosporidiosis transmission

fecal-oral; person-person, animal-person

Cryptosporidiosis S&S

watery diarrhea lasting ~2wks

Amoebic dysentary causative organism

Entamoeba histolytica; protozoa

Amoebic dysentary transmission

fecal-oral

Amoebic dysentary S&S

asypmtomatic or bloody diarrhea (dysentary)

Hep A genome and virus

Single stranded RNA; not enveloped

Hep B genome and virus

double stranded DNA; enveloped

Hep C genome and virus

single stranded RNA; enveloped

Is Hep A chronic or acute

Subclinical or acute never chronic

Is Hep B chronic or acute

Subclinical, acute or chronic (~10%)

Is Hep C chronic or acute

subclinic or chronic (~85%)

Recall the bacterial species that is the most common cause of urinary tract infections

E. coli

Urethritis

inflammation of the urethra

Cystitis

inflammation/infection of the bladder that almost always is secondary to a bacterial infection in the urine

Pyelonephritis

bacterial infection causing inflammation in the kidneys; could result in permanent damage if not treated

Gonorrhea gram reaction

gram - fastidious diplococcus

Gonorrhea causative organism

Neisseria gonorrhoeae

S&S of gonorrhea in men

• inflammation of the urethra, painful urination

• discharge of pus

• Rectal infections → pain + pus, or just itching

possible complication of gonorrhea in men

epididymitis

S&S of gonorrhea in women

• asymptomatic

• vague abdominal pain

• arthritis

• rectal infections → pain + pus or just itching

possible complication of gonorrhea in women

pelvic inflammatory disease

The possible consequences for babies whose mothers are infected w gonorrhea

eye infections that can lead to blindness

T or F: anyone can get eye, throat, and bloodstream infections if they have gonorrhea

true

Chlamydiasis gram reaction

gram - → obligately-intracellular bacillus; culture like a virus

Chlamydiasis causative organism

Chlamydia trachomatis often co-infects with N. gonorrhoeae

S&S of chlamydiasis in men

• urethral discharge (mild)

• can cause non-sexually transmitted eye infections

S&S of chlamydiasis in women

usually asymptomatic

Common complication of chlamydiasis in women

pelvic inflammatory disease

The possible consequences for babies whose mothers are infected with chlamydiasis

• pneumonia

• eye infections

The type of non-sexually transmitted infection caused by Chlamydiasis

pelvic inflammatory disease

syphilis bacterium

spirochete bacteria

syphilis causative organism

Treponema pallidum

Primary stage of syphilis

• chancre: small painless ulcer w firm edges

• chancre contains lots of T. pallidum bacteria

Secondary stage of syphilis

• widespread skin rash, possible malaise, hair loss, mild fever

• fluid from rash contains lots of T. pallidum

Latency stage of syphilis

no symptoms after 2-4yrs a person is considred non-infectious

Teriary stage of syphilis

• affects ~25% of the population

• would occur 10-30yrs after infection began

• gummas, weakened aorta, vision problems, gait problems, dementia

The possible consequences to babies whose mothers are infected w syphilis during primary/secondary stages

miscarriage/stillbirth more likely

The possible consequences to babies whose mothers are infected w syphilis during latent stage

• miscarriage/stillbirth less likely

• possible health problems for surviving babies: malformation of teeth/bones, blindness, deafness, developmental delays, seizures, anemia, enlarged liver/spleen

Explain what a retrovirus is, and why it is different from other viruses

Type of virus that is able to convert its RNA genome into DNA and integrate it into the host cell’s genome. It has an enzyme called reverse transcriptase which isn’t found in other types of viruses. 

genital herpes causative organism

HSV-1 or HSV-2

genital herpes S&S

• asymptomatic

• cluster of small, painful burning blisters

herpes ability to remain latent in the body and periodically reactivate

• lifelong latency w periodic reactivations

• transmission poisslbe even w no blisters

transmission of herpes across the placenta

• most likely during intial infection (mom has no antibodies)

• 40% mortalilty rate for fetus

transmission of herpes during delivery

• most likely during initial infection

• most likely during active outbreak

types of infection from herpes in babies

• eye/skin/mucous membranes → treatable, good prognosis

• CNS infectio → developmental delays, vision/hearing loss, epilepsy, death

human papilloma virus S&S of infection (by some strains)

• “cauliflower” vs flat lesions

• strains 6 and 11 cause obvious visible warts

possible complication of infection by some strains of human papilloma virus

• strains 16,18,45 can cause an increased risk for cancer

• cervical, penile, anal, oropharyngeal cancers

Canadidiasis causative organisms

Candida albicans; fungus

Canadidiasis S&S

• Smell yeasty or none

• white curdy discharge that varies

• dry, red vaginal mucosa with a pH <4

Bacterial vaginosis causative organisms

Gardnerella vaginalis; gram + → rod shaped

Bacterial vaginosis S&S

• fishy smell, gray white color

• copious amts of thin and frothy discharge

• pink vaginal mucousa; pH >4.5

Trichomoniasis causative organism

Trichomonas vaginalis → protozoan

Trichomoniasis S&S

• foul smelling; greenish-yellow color

• copious amts of frothy discharge

• tender, red vaginal mucousa; pH 5-6

A man experiences a mild pus-filled discharge from the urethra.  No pathogens grow when a urethral swab is used to inoculate an agar plate, but a special staining technique reveals tiny gram-negative bacilli inside urethral epithelial cells.  The most likely cause of his symptoms is:

A. Chlamydia trachomatis

            B. Herpes Simplex Virus

            C. Neisseria gonorrhoeae

            D. Treponema pallidum

Chlamydia trachomatis

Genital warts are caused by:

A. Candida albicans

            B. Chlamydia trachomatis

            C. Herpes Simplex Virus

            D. Human Papilloma Virus

            E. Trichomonas vaginalis

human papilloma virus