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A gene is best defined as
a sequence of nucleotides in DNA that codes for a functional product such as a protein.
What is a holoenzyme?
a combination of a protein and 1+ cofactors.
Which genus of Apicomplexan Protozoa can cause malaria?
C always binds to G
Which is a fungus that can cause meningitis?
Which item is from the patient in a direct ELISA test?
The best definition of antibody is.
a protein (immunoglobulin) made in response to an antigen that can combine with that antigen.
Meningoencephalitis can be caused by
N. fowleria and acanthamoeba.
DNA is constructed of...
2 DNA strands running antiparallel.
Immunity due to injection of an antigen is an example of
Artificially acquired active immunity.
Listeria monocytogenes is a
Gram + coccobacilli.
Which of the following is a scientific name?
Which test is used to confirm if a person is HIV +
Measles and Rubella are examples of
Maculopapular rash diseases.
Lesions that contain fluid are often termed
Rubella is of concern to pregnant women because...
It can cross the placenta and cause fetal damage.
Pregnant women should not empty litter boxes because...
they can get toxoplasmosis.
TSEs are caused by...
Which is a slow, progressive, zoonotic disease characterized by fatal encephalitis?
Which of the following inhibits nucleic acid synthesis?
Which of the following interacts with the membrane phospholipids, distorts the cell surface, and causes leakage of protein and nitrogenous bases?
Hemolytic disease of the newborn can result from...
An Rh- mother and an Rh+ fetus.
Which type of transplant is least compatible?
Which of the following is a test to determine the presence of soluble antigens in patients' saliva?
The most abundant class of antibodies in serum is.....
Antibodies that can bind to large parasites are...
The antibody that is produced 1st following an infection is...
The antibody found in secretions is....
Newborns' immunity due to the transfer of antibodies across the placenta is an example of....
Naturally acquired passive immunity.
The term used to describe the amount of antibody in a person's blood serum is...
Which type of hypersensitivity reactions are mast cells and basophils involved?
Which hypersensitivity reactions are considered delayed hypersensitivity types of reactions?
The type of testing that involves in vetro testing of serum is often referred to as...
Dry heat will sterilize by...
Glycolysis is the breakdown of glucose to...
The most common healthcare associated infections are found in the...
The total NRG yeild from glycolysis is...
2ATP + 2NADH.
Which of the following inhibits cell wall synthesis?
Which of the following inhibits essential metabolite synthesis?
Which of the following pHs is considered alkaline?
Which scientist made and used simple microscopes?
Which concentration of ethyl alcohol is the most effective bacteriocide?
Primers are needed in DNA replication because...
They direct DNA polymerase to bind and begin copying DNA.
An enzyme that covalently bonds nucleotide sequences in DNA is...
An enzyme that copies DNA to make a molecule of RNA is...
Who was the 1st person to use the word "cell" after looking at cork?
The term hydrophilic refers to....
proteins, lipids, or carbohydrates that love water.
A parasitic worm may be referred to as...
Archaea differ from bacteria in that Archaea...
do not have peptidoglycan.
What are the building blocks or proteins?
DNA contains the sugar....
What is the correct order when classifying organisms from largest to smallest?
- Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species
What is the size of ribosomes in eukaryotes?
An organism that grows best at 37 degrees C?
What are the 3 domains?
- Bacteria, Eukarya, Archaea
Which way does H2O move in a hypotonic solution?
It moves into the cell.
What is the purpose of the mordant in the Gram Stain?
To complex with or hold the C.V.
Why are acidic stains seldom used when performing a simple stain?
They have a net - charge.
What is the total magnification of a chloroplast viewed with a 10x ocular and 40x objective lens?
Which of the following best describes what happens when a bacteria cell is placed in a solution containing 5% NaCl (hypertonic)?
It moves out of the cell.
By which of the following mechanisms can a cell transport a substance from a low to high concentration?
When a cell has a tuft of flagella @ 1 and of the cell, this arrangement is called....
are used primarily for attachment.
The maximum rate of cell division occurs during the _______________ phase.
both organisms benefit.
What is endocarditis?
Inflammation of the endocardium (inner lining of the heart); most affects valves.
What causes acute endocarditis?
bacterial colonization of heart valves.
What are the 3 main bacteria that cause acute endocarditis?
- 1. Staph. aureus2. Strep. pyogenes
- 3. Strep. pneumoniae
What causes subacute endocarditis?
- bacteria with low pathogenicity.
- occurs from dental procedures, vigorous brushing, minor custs and lacerations.
What bacteria cause subacute endocarditis?
- Alpha-hemolytic streptococci:
- S. sanguis, S. oralis, S. mutans.
What is septicemia?
When organisms are actively multiplying in the blood.
What are the signs of septicemia?
- 1. fever, shaking, chills, GI symptoms.
- 2. increased breathing rate (respiratory alkalosis)
- 3. decreased BP caused by inflammatory response leading to loss of fluids from vasculature.
What is lyme disease?
It is nonfatal and mimics neuromuscular and rheumatoid arthritis.
What is erythma migrans?
A rash at the site of a tick bite that looks like a bulls-eye with a raised ring.
What is the cause of Lyme Disease?
Borrelia burgdorferi (can only be grown on an artificial medium with difficulty)
What causes septicemia?
Gram - and Gram + bacteria which is why broad spectrum antibiotics should be used when the cause is unknown.
What stimulates the massive inflammatory response in septicemia?
The release of large amounts of endotoxin.
What is Mononucleosis?
a disease of the lymphatic system; "kissing disease"
What virus caused Mononucleosis?
Epsein-Barr Virus (EBV) (a member of the herpesvirus family - will have forever).
How is mononucleosis transmitted?
- by direct oral contact and contamination with saliva.
- (infx during teen years - results in disease)
- (infx. b4 or after teen years usu. asymptomatic.)
What is Brucellosis?
- Non hemorrhagic (fever) disease, aka undulant fever.
- on list of possible bioterror agents
- "petting zoo" animals carry it
- cardinal manifestation: up and down fever.
What organism causes brucellosis?
Brucella - lives in phagocytic cells; carries bacteria to bloodstream.
What is septic shock?
cascading immune responses to septicemia, resulting in decreased BP.
Why is the cardiovascular system highly protected from microbial infx?
because bloodstream infxs are systemic (they affect multiple organ systems).
What microbiota are found in the cardiovascular and lymphatic systems?
Cardiovascular and lymphatic systems have NO NML MICROBIOTA! If present, it is septicemia.
Why are systemic infx. difficult to diagnose?
because they affect multiple organ systems.
What are 2 main systemic infxs?
Malaria and HIV.
What causes Malaria?
What are the 2 phases of malaria?
- Asexual - carried out in humans.
- Sexual - carried out in mosquitos.
What is the life cycle of malaria?
- 1. sporozite goes through bloodstream & is stored in the liver.
- 2. as it matures in the liver, it goes back into the bloodstream and transforms in a RBC.
- 3. it starts to replicate, the RBC lyses, RBC count decreases. The malaria gametes are produced and picked up by mosquitos.
What is the treatment for malaria?
Why do 1% of people remain AIDS free?
because of functioning immunity.
What is a nonprogressor?
a person who is healthy despite HIV infx because they lack cytokine receptors that HIV requires for entry.
What are HIV vaccine problems?
- 1. HIV is latent (hard to get to)
- 2. its surface antigens mutate rapidly.
What is the cause of HIV?
a retrovirus, genus lentivirus.
What does the HIV virus produce?
Reverse transcriptase (RT)
What does reverse transcriptase (RT) do?
It makes DNA from RNA and inserts DNA into human T cells.
What is the primary mode of transmission for HIV?
When does the HIV virus become full blown AIDS?
When the number of T cells falls below 200. As the T cell #s decrease, the virus is released and the level of the virus increases.
What does HIV testing test for?
- 1. Levels of the virus in the blood.
- 2. Levels of T cells.
What types of HIV tests are there?
- 1. Indirect ELISA - tests for antibodies (older test)
- 2. Latex agglutination
- 3. Western Blot (rules out false +)
- 4. Rapid antibody
What are the signs of HIV infection?
- sore throat caused by thrush (candida albicans)
- diarrhea, weight loss, rash, muscle wasting
How is HIV transmitted?
- sex, blood transfusion, pregnancy and childbirth, breastfeeding.
- It is NOT transmitted through saliva!
- Increased rates in adolescents and young women.
What is the 1st line of defense of the respiratory tract?
- Nasal hairs
- ciliary escalator (moves things up and out of the lungs)
What is the 2nd line of defense of the respiratory tract?
What is the 3rd line of defense of the respiratory tract?
What are the NML biota of the respiratory tract?
- Gram + bacteria (streptococci, staphylococci)
- candida albicans (yeast) colonizes oral mucosa.
What causes pharyngitis?
What are the symptoms of pharyngitis?
inflammation of the throat, swollen tonsils, foul smelling breath, white pockets on throat walls.
What is Streptococcus pyogenes?
a Gram + coccus; grows in chains, forms capsules & slime layers, catalase -.
What does Streptococcus pyogenes cause?
It causes scarlet and rheumatic fever.
How does Streptococcus pyogenes cause scarlet fever?
by erythrogenic toxic production.
What does erythrogenic toxin do?
causes the rash and fever associated with scarlet fever.
How does S. pyogenes cause rheumatic fever?
because of the reaction between streptococcal M protein & the heart muscle.
What is the extracellular toxins of Streptococcus pyogenes?
Streptolysin O (SLO) and Streptolysin S (SLS) for hemolysis.
What is the prevention for Streptococcus pyogenes?
No vaccine, handwashing, penicillin.
What is Rhinitis?
The common cold.
Why don't antibiotics work on the common cold?
because antibiotics don't work on viruses.
What is sinusitis?
Inflammation and infx. of the sinus cavities.
How do you treat sinusitis?
- Broad spectrum antibiotic treat bacterial infx.
- Antifungals treat fungal infx.
What is Acute Otitis Media?
What causes acute otitis media?
A mixed infection of bacteria and viruses. (Strep. pneumoniae, Haemophilus influenzae)
What causes Diphtheria?
Conrynebacterium diphtheria (non-spore forming, gram + club shaped).
What is the virulence factor of Diphtheria?
It produces diphtheria exotoxin that is encoded by a bacteriophage.
What is prevention of Diphtheria?
Diphtheria toxoid vaccine (DTaP)
What is the primary site of Diphtheria?
Primary site is the throat but it can move to the skin.
What is antigenic drift?
- Mutation of glycoprotein H & N genes:
- glycoprotein spikes - hemagglutinin (H)
- neuraminidase (N)
- reduced host immune response to virus
- produces most seasonal influenza
What is antigenic shift?
- an RNA exchange between different viruses.
- occurs during coinfectin of a host cell
- more likely to produce pandemic strains.
What are Lower Respiratory Tract Infxs?
What are the signs of influenza?
- begins in upper respiratory tract, can progress to lower respiratory tract
- headache, chills, dry cough, body aches, fever, stuffy nose, sore throat
- secondary infxs.
What causes influenza?
Influenza A, B, and C viruses.
What causes the inflammation in the lungs during an influenza infection?
a "cytokine storm"
How do H and N glycoproteins affect the virulence of influenza?
- Hemagglutinin (H) - binds to host cell receptors.
- Neuraminidase (N) - breaks down mucous of the respiratory tract, assists in viral budding of the disease (method of the virus getting out).
What is another name for pertussis?
What is the causative agent for pertussis?
How is Pertussis transmitted?
What are the 3 stages of Pertussis?
- 1. Catarrhal
- 2. Paroxysmal
- 3. Recovery
What is the catarrhal stage of pertussis?
Catarrhal stage - characterized by runny nose, 1 - 2 weeks.
What is the paroxysmal stage of pertussis?
Paroxysmal stage - bouts of severe coughing (paroxysm).
What is the recovery phase of pertussis?
phase during which the person is susceptible to other respiratory infxs.
What is RSV disease?
The most prevalent cause of respiratory infx. in newborns.
What is the causative agent of RSV disease?
Respiratory syncitial virus (RSV)
How is RSV transmitted?
Droplet and indirect contact via fomites (peak incidence in winter and early spring)
What is the virulence factor of RSV disease?
"giant cell" (syncitia) formation (keeps baby from getting enough oxygen.
What are the signs of Tuberculosis (TB)?
It is 85% contained in the lungs, 15% cutaneous.
What are the 3 clinical TB forms?
What are the features of Primary TB?
- minimum ID (infx. dose) is ~ 10 bacterial cells.
- bacteria multiply inside macrophages.
- tubercle formation in lungs.
- neutrophils release enzymes causing necrotic caseous lesions that heal by calcification.
What are the features of Secondary B?
- live bacteria can remain dormant, than reactivate
- chronic TB: tubercles expand
What is the causative agent of TB?
Mycobacterium* tuberculosis - acid-fast bacillus, strict aerobe, mycolic acids, waxes in cell wall, resistant to drying and disinfectants.
*all mycobacterium have a waxy coat of mycolic acid.
What is the pathogenesis of TB?
- The waxy cell wall enhances survival in environment and within macrophages.
- It stimulates strong cell-mediated immune response enhancing damage.
What is the treatment for latent TB?
- isoniazid for 9 months
- rifampin plus pyrazinamide for 2 months.
What is the treatment for activeTB?
- 9 months of isoniazid plus rifampin (12 months for extrapulmonary TB infx.)
- pyrazinamide taken for the 1st 2 months.
What happens in Pneumonia?
inflammation leads to fluid-filled alveoli.
What is the most common cause of pneumococcal pneumonia?
What is the cause of atypical pneumonia?
Mycoplasma pneumoniae (rigid cell wall)
How is atypical pneumonia transmitted?
by aerosol droplets in close living quarters.
Where did the name "walking pneumonia" come from.
It came from a lack of acute illness.
What is a frequent opportunistic pneumonia infection in AIDS patients?
Pneumocystis Pneumonia (PCP)
What is nosocomial Pneumonia?
- occurs in 1% of hospitalized people.
- 2nd most common nosocomial infx.
What causes nosocomial Pneumonia?
polymicrobial infection (strep. pneumoniae, klebsiella pneumoniae, anaerobic bacteria, coliform bacteria.
What are the defenses of the GI tract?
Saliva, stomach fluid, and bile
How does saliva defend the GI tract?
It contains lysozyme and lactoferrin.
How does stomach fluid defend the GI tract?
It is antimicrobial due to its high acidity.
How does bile defend the GI tract?
it is antimicrobial.
What is an enteric bacteria?
rod-shaped Gram-negative bacteria; most occur normally or pathogenically in intestines of humans and other animals.
Which genus of Salmonella bacteria is of interest?
How are enteric bacteria named and designated?
by H, K, and O.
What does H designate?
H: flagellar antigen.
What does K designate?
K: capsular antigen.
What does O designate?
o: cell wall antigen; the polysaccharide portion of lipopolysaccharide implicated in endotoxic shock.
Which antigen do all enteric bacteria carry?
Not all enteric bacteria carry the H and K antigens. All have O.
What are the characteristics of Shigella?
gram - rods, non-motile, non-spore forming.
What are the signs of Shigella?
frequent, watery stools, fever, intense abdominal pain, nausea & vomiting. In Shigella, stools often contain obvious blood and even more often found to have occult blood and mucus from the GI tract.
What is occult blood?
Blood in stool that is not visible to the naked eye.
What is dysentery?
diarrhea containing blood
What is the pathogenesis of Shigella dysenteriae?
Shigella dysenteriae produces the shiga toxin which may be responsible for more serious damage to the intestine and also causes systemic effects, including nerve damage.
Which is the most virulent enterohemorrhagic E. Cole strain?
What is the most common bacterial cause of diarrhea in the U.S.?
Campylobacter. causes more diarrhea than Salmonella and Shigella combined.
What precedes an infection with Guillain-Barre Syndrome?
Campylobacter infection (20 - 40% of GBS cases are preceded by an infection with Campylobacter.
What is Guillain-Barre Syndrome (GBS)?
GBS is the leading cause of acute paralysis since the eradication of polio.
What brings on an infection with Clostridium difficile (C. diff)?
- therapy with broad-spectrum antibiotics (kill nml biota in the intestine, cause overgrowth).
- *major cause of diarrhea in hospitals!
What can predispose people to an infection with Clostridium difficile?
Use of gastric acid inhibitors.
What condition does C. diff cause?
What are treatments for C. difficile?
- Vancomycin and fidaxomicin (Dificid)
- future: vaccination with C. difficile toxoid, ingestion of a mixed culture of lactobacilli and yeasts.
What causes Cholera?
When do cholera outbreaks occur?
- After natural disasters
- large refugee movements, esp. in underdeveloped parts of the world.
What are the signs of cholera (Vibrio cholerae)?
- Incubation period of a few hours to a few days.
- Abrupt symptoms of vomiting followed by copious, watery feces called secretory diarrhea (contains mucous and is described as "rice water stool")
- Fluid losses of 1 liter/hour have been reported.
- In severe cases, an untreated patient can loses up to 50% of their body weight during the course of the disease.
What is the virulence factor of Vibrio cholerae?
- They adhere to microvilli of epithelia at junction of the duodenum and jejunum using flagella.
- They never enter host cells or invade mucosa
- virulence due entirely to cholera toxin (CT) that disrupts the normal physiology of intestinal cells and cause cells to shed large amounts of electrolytes into the intestine accompanied by profuse water loss.
When is food poisoning suspected?
- When a patient presents with severe nausea and frequent vomiting accompanied by diarrhea.
- When people who shared the meal have the same symptoms.
- when the onset is within the last 1 - 6 hours of a meal.
What is Giardia lamblia?
- a pathogenic flagellated protozoan first discovered by Antonie van Leeuwenhoek in his own feces.
- considered a harmless or weak pathogen for 200 years.
- only recognized as a cause of diarrhea since the 1950s.
- most common flagellate isolated in clinical specimens.
What is the appearance of Giardia lamblia?
- unique symmetrical heart shape
- organelles positioned in such a way that it resembles a face
- four pairs of flagella emerge from a ventral surface
- ventral surface is concave and acts like a suction cup.
- Giardia cysts are small, compace, and contain 4 nuclei.
What is the prevention against Giardia lamblia?
- No vaccine for humans, vaccine available for animals, including dogs.
- Avoid drinking from freshwater sources.
What is the treatment for Giardia lamblia?
tinidazole or metranidazole.
What are entamoebas?
- Amoebas are widely distributed in aqueous habitats and are frequent parasites of animals.
- Only a few have the necessary virulence factors to invade tissues and cause serious pathology.
What is Entamoeba histolytica?
- Entamoeba histolytica is one of the most significant pathogenic amoebas.
- It can actually engulf RBCs
What can result in the breakdown of hard tooth structure due to the production of acids in the mouth?
What is the most common infectious disease of human beings?
Dental carries (tooth decay).
What is tooth decay?
the dissolution of solid tooth surface due to the metabolic action of bacteria.
What causes a toothache?
Infection in the soft tissue inside the tooth (pulp).
What causes dental carries (tooth decay)?
Streptococcus mutans (oral, alpha-hemolytic streptococcus)
How common is periodontal disease?
So common that 97% - 100% of the population has some manifestation by age 45.
What is gingivitis?
Gingivitis is the initial stage of periodontal disease.
When does periodontitis occur?
Periodontitis occurs if gingivitis persists.
What does periodontitis do?
- Periodontitis increases the size of pockets in the gum.
- It can cause bone resorption severe enough to loosen the tooth in its socket.
What is Mumps?
Mumps is a mildly epidemic illness associated with painful swelling at the angle of the jaw.
What are the signs of Mumps?
- incubation period of 2-3 weeks.
- fever, nasal discharge, muscle pain, and malaise.
- may be followed by inflammation of the parotid salivary glands, producing gopherlike swelling of the cheeks.
What causes gastritis and gastric ulcers?
What are the characteristics of Helicobacter pylori?
curved gram - rods, closely related to Campylobacter.
Who first detected Helicobacter pylori?
J. Robin Warren and Barry J. Marshall in 1979.
What is the virulence factor of Helicobacter pylori?
- Once the bacterium passes in to the GI tract it bores through the outermost mucus layer that lines the stomach epithelium.
- Then it attaches itself to specific binding sites on the cells and entrenches itself.
What is the treatment for Helicobacter pylori?
antibiotics + acid suppressors.
What is hepatitis?
an inflammatory disease marked by necrosis of hepatocytes (liver cells).
What is jaundice?
a yellow tinge in the skin and eyes caused by bilirubin accumulation in the blood and tissues.
What do pathologic changes in the liver do?
They interfere with the liver's excretion of bile pigments such as bilirubin into the intestine.
What is the treatment for Hepatitis?
There is a hepatitis vaccine HAV/HBV.
How is passive immunity from hepatitis acquired?
from immunization with hepatitis B immune globulin (HBIG) - recommended for those with exposure via needle puncture, or neonates born to infected mothers.
What are the 3 categories of helminths?
- 1. Nematodes (roundworms)
- 2. Trematodes (flukes)
- 3. Cestodes (tapeworms)
What is Taenia solium?
a tapeworm around 5 meters long that has a scolex with hooklets and suckers to attach to the intestine.
What does urine flow encourage?
- Urine flow encourages desquamation of epithelial cells lining the urinary tract, shedding microbes with the cells.
What is the cause of UTIs?
the invasion of the urinary system by bacteria or other microorganisms.
What are the 4 defenses in urine?
- 1. acidic pH
- 2. lysozyme
- 3. lactoferrin
- 4. secretory IgA
What is lysozyme?
Lysozyme is an enzyme that breaks down peptidoglycan.
What is lactoferrin?
Lactoferrin is an iron-binding protein that inhibits bacterial growth.
What is secretory IgA?
secretory IgA is specific for previously encountered organisms.
How are the kidneys, ureters, bladder, and upper urethra kept sterile?
by urine flow and regular bladder emptying.
Why are females more prone to UTIs?
Because they have a shorter urethra (3.5 cm long) and it is in close proximity to the anus.
What are the flora of the penis?
the penis is colonized by aerobic Pseudomonas and Staphylococcus species.
What discourages the growth of many organisms in the vagina?
the acidic environment and the predominance of Lactobillus species.
What does the Lactobillus species do?
They convert sugars to acid.
What causes the acidic pH in the vagina?
after puberty, estrogen leads to glycogen release in the vagina, resulting in an acidic pH.
What is leptospirosis?
- Leptospirosis is a spirochete-caused disease transmitted by contact of broken skin or mucous membranes with contaminated animal urine.
- It is also a zoonosis associated with wild and domesticated animals.
Why is the flushing action of urine not enough to stop UTIs?
because urine is a good growth medium for many microorganisms.
What is cystitis?
cystitis is an infection o f the urinary bladder that occurs when urine flow is reduced or bacteria are accidentally introduced into the bladder.
What is pylenophritis?
pyelonephritis is an infection of the kidneys (Nephrons).
What is urethritis?
Urethritis is an infection limited to the urethra.
What microbe causes UTIs?
- normal biota Esherichia coli accounts for 80% of UTIs, and are not strains of E. coli that cause diarrhea and other digestive tract diseases.
- Staph. saprophyticus (eats off dead skin)
- Proteus mirabilis (good swimmer)
What can leptospirosis affect?
Kidneys, liver, brain, and eyes.
What is Leptospira interrogans?
The species that causes leptospirosis in humans and animals.
What is the most common mode of transmission of Leptospirosis?
contaminated soil or water. It is shed into the environment through animal urine.
What are discharge diseases?
discharge diseases are infectious agents that cause an increase in fluid discharge in the male and female reproductive tract. (e.g. trichomoniasis, gonorrhea, chlamydia)
What is the causative agent of Gonorrhea?
- Neisseria gonorrhoeae, a gram - diplococcus.
- it appears as a kidney bean-shaped bacteria with their flat sides touching.
- *In 2011, a strain of N. gonorrhoeae that is resistant to all existing antibiotics was identified in Japan.
What are the signs of Gonorrhea?
- In males: urethritis, painful urination, yellowish disharge
- * a relatively large number of cases are asymptomatic!
What is the pathogenesis of Neisseria gonorrhoeae?
- It has fimbrial genes that can rearrange themselves to put out fimbriae of different configurations and confuses the body's immune system.
- It also has IgA protease that cleaves IgA molecules stationed on mucosal surfaces.
How is Neisseria gonorrhoeae spread?
It is spread through some form of sexual contact, except for neonatal infxs.
What is the most common reportable infectious disease in the U.S.?
- +1,000,000 cases reported annually.
- overall prevalence among young adults in the U.S. is 4% (at least 2-3 times as common as gonorrhea.)
How is Chlamydia spread?
- It is transmitted vertically (through the placenta) and through sexual contact.
- adolescent women are more likely than older women to harbor the bacterium because it prefers to infect cells prevalent in the adolescent cervix.
What is vaginitis?
Vaginitis is inflammation of the vagina.
How is vaginitis characterized?
- Vaginitis is characterized by some degree of vaginal itching.
- symptoms may include burning and discharge.
What is the difference between vaginitis and vaginosis (aka bacterial vaginosis)?
Vaginosis is similar to vaginitis, but it does not include significant inflammation.
What is the causative agent of vaginitis?
Candida albicans aka yeast infection.
What are the characteristics of Candida albicans?
- it is a dimorphic fungus (can be either yeast-like or mold like, depending upon environment).
- It is the normal biota in 50 - 100% of humans.
- Live in low #s on mucosal surfaces of the mouth, GI tract, vagina, etc.
What is the causative agent of vaginosis?
What is a sign of vaginosis?
a vaginal discharge with a very fishy odor is the result of metabolic by-products of anaerobic metabolism by the bacteria causing the infection.
What is Trichomonas vaginalis?
Trichomonas vaginalis is a small, pear-shaped protozoa with four anterior flagella and an undulating membrane.
What are characteristics of Trichomonas vaginalis?
- It causes asymptomatic infections in app. 50% of females and males, therefore considered asymptomatic infectious agents rather than normal biota.
- Males seldom have symptoms.
- females have a white to green frothy discharge.
What is prostatis?
- Prostatis is inflammation of the prostate gland.
- Acute and chronic prostatis is always caused by a bacterial infection.
What are 3 common genital ulcer diseases?
- Genital Herpes
What is the causative agent of syphilis?
Treponema palladium - a spirochete with a gram - cell wall.
What are the clinical stages of syphilis?
- Primary syphilis
- Secondary syphilis
- Tertiary syphilis
- Latent period (of varying duration)
What are the characteristics of Primary syphilis?
- Early indication of syphilis is the appearance of a hard chancre at the site of entry of the pathogen.
- chancre heals spontaneously without scarring in 3 - 6 weeks (at this point, spirochete has escaped into circulation and is entering a period of tremendous activity.
What is a chancre?
a painless ulcer, particularly one developing on the genitals as a result of venereal disease.
What are the characteristics of secondary syphilis?
- appears about 3 weeks - 6 months after the chancre heals.
- many systems of the body have been invaded.
- Initial symptoms: fever, headache, sore throat.
- Symptoms after initial symptoms: lymphadenopathy (disease affecting lymph nodes), red-brown rash that breaks out on all skin surfaces, including the palms of the hands and the soles of the feet.
What are the characteristics of tertiary syphilis?
30% of infxs. enter a highly varied latent period that can last 20 years or longer.
What are gummas?
- Gummas are painful, swolen syphilitic tumors that develop in tissues in the liver, skin, bone, and cartilage.
- They are usually benign and only occasionally lead to death, but can impair function.
What is the treatment for Syphilis?
What causes Genital Herpes?
Genital Herpes is caused by herpes simplex viruses HSV-1 and HSV-2. (you have it for life)
What are the signs of genital herpes?
the appearance of single or multiple vesicles (that are small and filled with clear fluid) on the genitalia, perineum, thigh, and buttocks.
How does Herpes get to the newborn?
through the reproductive tract immediately before or during birth, also from hand transmission from the mother's lesions to the baby.
What does HSV-1 normally infect?
HSV-1 normally infects the oral mucosa, resulting in "cold sores" or "fever blisters".
What does HSV-2 normally infect?
HSV-2 normally affects the genitals.
What is the treatment for genital herpes?
Acyclovir (Zorivax) and valacycovir (Valtrex) are very effective only when the virus is replcating.
What are 2 viral STIs that cause wartlike growth?
Human Papilloma Virus (HPV) and Molluscum contgiosum.
Which Strep is considered a neonatal disease?
Group B Strep
What are the effects of Group B strep?
- non pregnant women experience no ill effects from this colonization.
- colonization of pregnant women can result in preterm delivery.
When is testing done for group b strep?
Testing is done at 35 - 37 weeks of pregnancy.
How is group B strep treated?
Group B strep is treated with pencillin or ampicillin unless it is resistant, then it is treated with erythromycin.
Are the vast majority of microbes on our planet pathogenic or nonpathogenic?
The vast majority of microbes on our planet are non pathogenic.
How has human intervention in natural settings affected the planet?
- Human intervention has changed the earth's warming and cooling cycles (global warming)
- increased wastes in soils
- polluted water
- altered some basic relationships between microbial, animal, and plant life.
What do aerobic bacteria do?
- They initiate the digestion of organic matter in CO2 and H2O. (enriches the soil)
- they generate minerals such as phosphate (used in ATP), sulfate and nitrate are further degraded by anaerobic bacteria.
What do fungal enzymes do?
- Fungal enzymes increase the efficiency of soil decomposition
- they also hydrolyze complex natural substances such as cellulose, keratin, lignin, chitin, and paraffin.
What causes red tides?
- Red tides are produced by toxin-producing dinoflagellates (type of algae)
- These algae produce a potent muscle toxin that is concentrated in shellfish through filtration feeding.
- When humans eat clams, mussels, or oysters containing the toxin, they develop paralytic shellfish poisoning.
Where does most drinking water come from?
most drinking water comes from rivers, aquifers, and springs.
What are the three phases of water (sewage) treatment?
Primary, secondary, and tertiary.
What occurs in the primary stage of sewage treatment?
in the primary stage of sewage treatment, large matter is separated out.
What occurs in the secondary stage of sewage treatment?
- the remaining matter is reduced and some toxic substances are removed.
- a diverse community of bioremediators aerobically decomposes the remaining particles.
What occurs in the tertiary stage of sewage treatment?
In the tertiary stage of sewage treatment, the purification of the water is completed (filtration and chemical (chlorine) treatment).
What are the most prominent waterborne pathogens?
protozoa: Giardia and Cryptosporidium
bacteria: Campylobacter, Salmonella, Shigella, Vibrio, and Mycobacterium (can cause leprosy & tuberculosis)
viruses: hepatitis A and Norwalk viruses.
*some of these agents can survive in natural waters for long periods without a human host (free-living).
Is water surveyed for specific pathogens?
- No because it is time consuming. water purity assays are focused on detecting fecal contamination.
- High fecal levels can mean the water contains pathogens and is unsafe to drink.
What bacteria are used as indicator bacteria in water treatment?
Intestinal residents of birds and mammals and coliforms and enteric streptococci indicate high levels of fecal contamination.
What are coliforms?
Coliforms are gram -, lactose fermenting, gas producing bacteria (e.g. E. coli, enterobacter, and Citrobacter).
What are EPA standards for water sanitation primarily based on?
levels of coliforms (not 0!)
What 3 ways can microbes affect food?
- Microbes can affect food in a:
- beneficial: food is fermented, microbes can serve as food
detrimental: microbes cause food poisoning or food-borne illness, or spoil food.
Neutral: the presence of microbes does not cause disease or change the nature of the food.
What are some commercially mass-produced food yeasts, bacteria, and algae?
- Single cell protein (SCP) produced from waste materials such as molasses and petroleum by-products.
- Pruteen - an animal feed
- Mycoprotein - a product made from the fungus Fusarium; a likely candidate for producing meat substitutes for human consumption.
What is Spirulina?
Spirulina is a spiral-shaped cyanobacterium that is harvested from the surfaces of lakes and ponds.
What is a cyanobacterium?
a cyanobacterium is a bacteria that photosynthesizes because it has peptidoglycan in its cell walls and no nucleus.
What is pasteurization?
Pasteurization is the application of heat below 100 degrees C to destroy nonresistant bacteria and yeasts in liquids such as milk, wine, and fruit juices.
What are the 2 types of pasteurization?
- High-temperature short-time (HTST)
- Ultrahigh-temperature (UHT)
What is HTST pasteurization?
HTST pasteurization is where you expose the liquid to 72 degrees C for 15 seconds to reduce bacterial growth.
What is UHT pasteurization?
UHT pasteurization is where you steam the product until it reaches 134 degrees C for 1 second. This gives the product a shelf life of up to 3 months.
What are other forms of food preservation?
- Keep foods hot
- when in doubt, throw it out,
- UV radiation,
- Gamma or cathode ray radiation,
- high osmotic pressure produced by hypertonic levels of salt (brines, pickled foods),
- high sugar content (of candies, jellies, canned fruits),
- desiccation (removing H2O) by exposing food to warm, dry air,
- bacteriophages (recently approved by the FDA to be sprayed on ready-to-eat meat products). They are specific for Listeria