How skin wards off infection. Name and describe two layers of skin.
Epidermis—compact layer of cells on top Dermis- the inner layer, relatively thick portion of skin, composed mainly of connective tissue. The hair follicles, sweat glands, ducts, and oil gland ducts provide passageways for microorganisms to enter the skin and penetrate deeper tissues
Which bacteria cause folliculities? What are different forms of the disease?
A. Staphlococcus aureus/ folliculitis is an infection of a hair follicle. Ex:sty (eye)/ furuncle (small bump)/ carbuncle (big bump)
B. 1. MRSA 2. Scalded Skin Syndrome 3. Impetigo 4. Toxic Shock Syndrome
List and describe the mode of action of virulence factors possessed by staph and strep.
• Capsule—inhibits phagocytosis
• Coagulase—may impede progress of leukocytes by producing clots in capillaries
• Exfoliatin—separates epidermis, causing scabbed skin syndrome
• Leukocidin—kills WBC
• Lipase—breaks down fat
• Proteases—degrades collagen and proteins
• Protein A—precipitates antibody so it cannot bind to target bacteria
• Toxic Shock Syndrome Toxin—causes rash, diarrhea, and shock (can be caused by strep and staph)
What makes staph and strep resist phagocytosis? Name other bacteria resistant to phagocytosis
Capsule—contains hyaluronic acid which inhibits phagocytosis by camoflauge/ Streptococcus pyogenes
Name the antibiotic used to treat staph infections. Why resistance to this drug is an issue
Penicillin/ resistance causes an issue because it can quickly lead to an endemic that cannot be treated or cured with antibiotic
Compare and contrast impetigo and erysipelas
Impetigo—caused by strep and staph/ itchy pus-filled vessicles
Erysipelas—caused by strep/ large red patches when spread to lymph nodes
Compare staph and strep: common diseases, common virulence factors, resistance to penicillin based on antibiotics
A. Streptococcus pyogenes
I. G+ cocci in chains; Beta hemolytic colonies; cell wall contains group A polysaccharide and M protein.
II. Hemolysins: streptolysins O and S; streptokinase, DNase, hyaluronidase, and others
III. Causes impetigo, strept throat, wound infections, scarlet fever, puerperal fever, toxic shock, and flesh eating, fascitis. Complications: glomerulanephritis, rhuematic fever, and cholera.
B. Staphylococcus aureus
I. G+ cocci in clusters; cream-colored colonies; cell walls contain protein A.
II. Hemolysins, leukocidin, hyaluronidase, nuclease, protease, penicillinase, and others
III. Caueses boils, scalded skin syndrome, wound infections, abcesses, impetigo, food poisoning, and toxic shock syndrome
What is the role of hyaluronidase in pathogenicity of streptococci?
dissolves human tissue so bacteria could spread
Which genus of organisms is the most infectious to human?
Name diseases caused by strep pyogenes. Name virulence factors possessed by this organism.
Pharyngitis (strep throat)
M protein—interferes with phagocytosis
Hemolysin—destroys red blood cells
Streptolysin—kills human cells(WBC, RBC...)
Hyaluronidase—dissolves human tissue so bacteria could spread
What are the characteristics of the disease called necrotizing fasciitis?
Intense pain and swelling, caused by s. pyogenes, quick growth and spread, BP drops, toxic shock, easily killed by penicillin, can die
Describe how acne bacteria damages the skin
The propionibacterium acnes clog pores and thrives in the anaerobic environment causing pimples to occur
What is the most important characteristic of Pseudomonas aeruginosa?
Occurs in burn victims
Name and describe skin infections caused by viruses. Mode of transmission? Any treatment for them? Is there any vaccine available for them? Name common childhood rashes caused by viruses
Measles—kopliks shots diagnostic/ respiratory tract/ MMR vaccine
Rubella—rash, swollen lymph nodes/ respiratory tract/ MMR vaccine
Chicken Pox(childhood)/shingles—varicella-zoster, rash/respiratory tract/ attenvated vaccine
Herpes—skin lesions, recurrence after latency/skin-contact/chemotherapeutic drugs treat (acyclovir)
Smallpox—1st human disease eradicated, 1.papules2.vesicles3.pustules/inhalation/vaccine
What is the difference between chickenpox and shingles? What is meant by recurrent infections?
Chicken pox—children, The varicella virus that causes chickenpox can remain dormant in the body for years after someone has had chickenpox. When a person is under stress or ill, the virus can recur as shingles (herpes zoster).
Shingles—adults, occurs The rash from shingles is contagious--fluid in the blisters contains the varicella zoster virus and can cause chickenpox for those who have never had chickenpox or the vaccine.
List different types of skin infections caused by fungi? Define mycosis.
Cutaneous Mycosis—hair and nail infection/ dermatophytoses-causes underlying tissue damage
Subcutaneous Mycosis—dermis, subcutaneous tissues, muscle, and fascia. These infections are chronic and can be initiated by piercing trauma to the skin
Name and describe two skin infections caused by parasites.
-Leishmaniasis Viceral—spread by sand fly, affects aids patients
-Scabies—itching rash, scabiei (mite), spread through sex
What is TSS? Which bacteria causes TSS?
- Toxic Shock Syndrome
- originally became known as a result of staphylococcal growth associated with use of a new type of highly absorbent vaginal tampon and leaving the tampon in for too long of an extended period of time.
- caused by toxic shock syndrome toxin 1 and is formed at the growth site and circulates in the bloodstream.
- Today minority of the cases of TSS are associated with menstruation.
Non menstruation TSS occurs from staphylococcal infections that follow nasal surgery in which absorbent packing is used, after surgical incisions, and in women who have just given birth
Define conjunctivitis and trachoma?
Conjunctivitis— is inflammation of the conjunctiva/ viral infection
Trachoma—leading cause of non-traumatic blindness, cause: Chlamydia trachomatis, happens at birth
What are the importance features of herpes virus? Compare HSV-1 and HSV-2? Which other viruses belong to the family of herpes viruses?
Goes into latency, Acyclovir is a commonly used chemotherapeutic drug to control but not cure the disease// HSV-1: cold sore; found primarily in the oral and facial areas. It is the most prevalent type and can become latent in sensory root ganglia. HSV-2: genital warts: found primarily in the genitals and is sexually transmitted. Recurrent infections are common but they are milder than the primary infection because of partial immunity. Recurrence may be due to stress, hormones, excessive sunlight, etc. Type 2 causes lesions on the genitals and is associated with cancer of the cervix, so frequent pap smears are recommended.
Name two infections caused by anthrax bacteria.
1. Cutaneous Anthrax-skin, black skin lesion
2. Bacillus Anthrax—pulmonary, inhale spores
What are the components of CNS? Name the normal flora of CNS. Name two diseases associated with CNS. How active is the immune system in CNS?
Brain and spinal cord, no normal flora, two diseases: Bacterial Meningitis & leprosy, the immune system is extremely active; blood-brain barrier, which inhibits particles from entering the CNS, called meninges
What is blood brain barrier?
The blood-brain barrier is a protective barrier of the CNS, it covers the brain and spinal cord, and inhibits particles from entering the CNS
What are arboviral diseases? What is the difference between meningitis and encephalitis?
Meningitis—affects immunocompromized individuals/ inflamed cranial and spinal meninges, high fever, brain infection, causes encephalitis, affects behavior
Encephalitis—rarely affects humans, affects behavior, vaccines available for horses
Compare viral meningitis? What are the signs and symptoms of meningitis?
Viral Meningitis is the most common form of meningitis, typically a milder disease than bacterial or fungal, passes through the nervous system (neurotropic), caused by Enterovirus, which attack cells in the intestinal tract
Bacterial Meningitis is the most severe, it's an inflammatory bacterial infection of the meninges,
-inflamed cranial meninges: severe headache, vomiting, pain
-inflamed spinal meninges: stiff neck, altered muscle control
-brain infection: encephalitis, behavioral changes, coma, death
Treated with antimicrobial drugs, vaccines
Cause: foods, undercooked meat; streptococcus pneumonia (adults), Neisseria meningitides (children), haemophilus influenza (teens), listeria monocytuaenes (fetuses, immunocompromized individuals)
How tetanus and botulinum toxin affect human body. Whish microbe produces these toxins?
-Botulism is caused by intoxication rather than infection, clostridium botulinum, obligate anaerobe, produces endospores, three forms:
food-botulinum- progressive paralysis of all voluntary muscles
infant-botulinum-bacteria gros in the intestines, producing non-specific symptoms
wound-botulinum- symptoms like those of food-botulinum
treatment: antimicrobial drugs, destroying endospores through canning techniques
-Tetanus caused by clostridium spreads through lymph system, systemic, two components neurotoxin and the other a hemolysin
Name several bacterial and viral diseases of nervous system
Bacterial: Bacterial Meningitis, Leprosy, Botulism,
Viral: Viral Meningitis, Polio, Rabies, Arboviral Encephalitis, Cryptococcal Meningitis, Prion Diseases
What are the important characteristics of rabies and polio infections
-Rabies: cause- rabies virus, zoonotic, entry- bite or scratch from infected animal, pain or itching, incubation-1-2 months, treatment- post exposure vaccine (PEP) or immune glogin antibody that neutralizes virus, travels through nervous system, once symptoms show its too late and you die, raccoons & skunks
-Polio: (poliomyelitis) poliovirus is the causative agent, fecal-oral route, transmitted by drinking contaminated water, 4 conditions can result: asymptomatic infections, minor non-specific symptoms, nonparlytic muscle spasms, paraytic polio-produces paralysis small percentage, exists in Africa & asia, 2 vaccines
What are the most important features of arboviruses?
Arboviruses are Arthropod-Borne, transmitted between hosts and blood-sucking arthropods (mosquitoes), zoonotic, symptoms: mild, cold-like symptoms, if crosses blood-barrier border can cause encephalitis with similar symptoms to meningitis, supportive treatment, vaccines EEE, WEE, VEE, WNV
What are prions. How do they cause diseases? Name diseases caused by prions.
Prions are infectious proteins that can cause disease, abnormally folded prion proteins can act to cause normally folded proteins to adopt to the abnormal formation, unclear reason, triggered from transplants, contaminated surgical instruments, injections
Ex. mad cow disease, scrapie, Creutzfeld-Jacob Disease, variant(spelt wrong)
Define and give several examples of Zoonotic diseases
Zoonotic—transmitted through animals
Lyme disease—borrelia bacteria/ tick borne/ bulls-eye rash
Toxoplasmosis—toxoplasma gondii/ cats feces
Rabies—virus/ pain and nuerological manifestations
Define arthropod-borne disease. Give examples and indicate which insect is involved in each case
Leishmaniasis Viceral—spread by sand fly
Relapsing fever-louse and tick
What is meant by food poisoning? Which bacteria cause food poisoning?
- known as staphylococcal food poisoning
- staphylococcal intoxication
- caused by S. aureus
What is the causative agent of meningococcal meningitis and pneumococcal pneumonia??
Meningococcal meningitis: Neisseria meningitidis. -Pneumococcal pneumonia: S. Pneumoniae
What causes whooping cough?
- infection of the bacterium Bordetella pertussis results in this
- B. Pertussis is a small, obligately aerobic, gram negative coccobacilus
- the virulent strains possess a capsule
- the bacteria attach to ciliated cells in the trachea, first impeding their ciliary action and then progressively destroying the cells
- this prevents the ciliary escalator system from moving mucus (stops motility of cilia)
- B. Pertussis creates several toxins
- tracheal cytotoxin: a fixed cell wall fraction of the bacterium, is responsible for damage to the ciliated cells, and pertussis toxins enter the bloodstream and is associated with systemic symptoms of the disease.
- gasping for air in between coughs causes a whooping sound, hence the name of the disease
What is meant by neurotropic and lymphotropic viruses?
Neurotropic— having an affinity for or localizing selectively in nerve tissue
Lymphotropic-- having an affinity for lymphocytes
What is DEET?
Insect repellant from ticks to prevent lyme disease
What are the important features of Lyme disease?
- A zoonotic disease
- a TICK-borne disease caused by Borrella Burgdorferi
- three phases ranging from a bull's eye to neurological symptoms to severe arthritis
- antimicrobial drugs can treat early phases but treatment of later phases is more difficult since they are caused by the immune system
Define: septicemia, bacteremia, viremia, toxemia, and lymphangitis
Septicemia- presence of microbes in the blood
Bacteremia- bacteria circulating in the blood stream
Toxemia- release of bacterial toxins into the blood stream
Lymphangitis- inflammation of the lymph vessels, caused by staph, sign that the infection is getting worse and might have entered the blood stream
What are the signs and symptoms of septicemia? What is the significance of G- septicemia?
- Septicemia is caused by infectious agents or their products circulating in the blood stream, gets worse very quickly
- signs/symptoms: chills, high fever, rapid breathing and heart rate, quickly progress to confusion, red spots on the shin and shock
G- septicemia is more dangerous because as these cells are killed by antibotics, the release the endotoxin LPS, which cause more damage to the body, causes shock, inflammation, G- is more common than G+
What are the important features of clostridium? Name diseases caused by these organisms
- Clostridium is and obligate anaerobe
- meaning deep wound infections
- G+ rods
- endspore formation
- produces neurotoxins
- cuts supply of oxygen to the tissus, antibiotics, and surgery to remove spores
- Gas ganrene, Botulism, tetanus
Name two systemic protozoan infections. What are the important features of these diseases?
-MALARIA: not zoonotic
1. caused by plasmodium species
2. spread by mosquitoes
4. rupture red blood cells
5. liver, fever, chills, recur every 2-3 days, anemia, fatigue and jaundice
7. sub-sahara Africa, s.e. asia, and Americas (south)
Exo-erythrocytic cycle- outside of red blood cells
Eythrocytic cycle- inside red blood cells
-TOXOPLASMOSIS: from cat & cat droppings
- severly affects AIDS patient, pregnant women and immunocompromized
- treatment is usually unnecessary unless your have been listed above ^^
- Protozoan disease can recur, latent,....?????
What are the normal flora of upper and lower respiratory tract?
The lower respiratory tract doesn't not contain any normal flora,
upper respiratory tract contains Staphylococcus aureus, Neisseria, Diphtheroids, and haemophilus influenza
What are the important characteristics of diseases called Legionellosis?
- Cause legionells pneumophila
- lower respiratory infection, inhalation of legionella, - caused by cooling systems (hotel case)
- typical pneumonia symptoms
- possible complications of the gastrointestinal tract, CNS, liver and kidneys
- susceptible to elderly, smokers, immuncompromized, - - - antibiotics, erythromycin is drug of choice
Name two bacterial infections of the upper respiratory tract
Strep throat, Diphtheria
-strep throat: caused by streptocci, s. pyogenes causes most human diseases, VF: M protein, hyaluronic acid, capsule, streptlysin (toxin produces by pyogenes kills everything), inhalation of droplets, sore throat, difficultly swallowing, may progress to scarlet or rheumatic fever
-Diphtheria: caused by Corhybacterium diphtheria, VF: diphtheria toxin pevents polypeptide syntheses (protein synthesis), and caises cell death, per-to-person, sore throat, oozing fluid that hardens into pseudo membrane that can obstruct airways, antibotics, immunization/vaccine
What are the viral diseases of upper respiratory tract? What is Croup?
Croup is a common respiratory problem in young children(<5 yrs. Its main symptom is a harsh, barking cough. Croup causes swelling and narrowing in the voice box, windpipe, and breathing tubes that lead to the lungs. This can make it hard for your child to breathe. An attack of croup can be scary, but it is rarely serious. Children usually get better in several days with rest and care at home.
What causes TB? What are the important features of TB? What are the treatment options for TB?
Mycobacterium tuberculosis, cell wall contain mycoloc acid which contains lots of lipids heat can kill them, acid-fast tests, numerous kinds of TB, can be systemic, mjor areas associated with TB have a high immigrant population, worldwide, no VF presence is enough, intracellular pathogen, macrophazia ->kills phagocytic cells, immunocompromized individuals are most at risk (leading killer of those with HIV), heat kills isonizaide typical antibiotic treatment, mutli drug therapy(MDT) , prevention include PPD (purified protein derivative) and vaccines
What is pneumonia? Which organisms cause pneumonia? What are different types of pneumonia?
Bacterial, pneumococcal, primary atypical
Pneumonia is inflammation of the lungs accompanied by fluid-filled aleveoli and bronchioles, characterized by affected region and organism causing the disease
-bacterial: most serious, lobar pneumonia, involoves entire lobes of the lungs, Nosomical pneumonia- acquired in a health care setting, mycoplasmal- caused by the bacterium mycobacterium
- Pneumococcal pneumonia- streptococcus pneumonia, VF: adhensions, capsule, pneumolysin, inhalation, fever, chills, congestion, cough, chest pain, short rapid breathing, 1-3 days, immunocompromized & young children, penicillin treats, vaccine,
-primary atypical (mycoplasmal) pneumonia: mycoplasma pneumonia, VF: adhesion protein, enters through nasal secretions among individuals in close contact, atypical symptoms, fever, malaise, sore throat, excessive sweating, high school and college students (teens), antibiotics (tetracycline and erythromycin) , difficult to prevent because individuals can be infective despite lack of symptoms, NO cell wall
What are the important characteristics of pneumococcal pneumonia?
Pneumococcal pneumonia- streptococcus pneumonia, VF: adhensions, capsule, pneumolysin, inhalation, fever, chills, congestion, cough, chest pain, short rapid breathing, 1-3 days, immunocompromized & young children, penicillin treats, vaccine
What are the target cells for flu virus? What is the significance of the two surface proteins for flu virus, for attachment of flu virus to the host tissue, for vaccine development? Why unlike some other diseases, we have to receive a new vaccine ever year? What is meant by antigenic shift, antigenic drift? Name drugs used to treat flu. What is their mechanism of action?
feature of the influenza virus is a layer of spikes projecting from its surface. There are two different types of spikes: one is the protein hemagglutinin (HA), which allows the virus to "stick" to a cell and initiate infection, the other is a protein called neuraminidase (NA), which enables newly formed viruses to exit the host cell.
The virus is constantly changing due to mutations, therefore changing and the antibody no longer recognizes the virus, antigenic shift is a major change in the H&N segments, vaccine does not work, antigenic drift is minor changes in the proteins
Amantadine, rimantadine, oseitamiuir, zanamiuir approved drugs
Name a fungal and a parasitic disease of lower respiratory tract.
Most common fungal infection of the lungs in humans, histoplasmosis capsulatiom, inhalation, geography, systemic, dry cough with blood, endemic to eastern us, esp Africa and central & south America, children & thise exposed to soil, diagnosis presence of budding, yeast in macrophages, treatment Amphotericin B, minimize exposure to soil
-Pneumocystis pheumonia (PCP)
Cause pneumocystis liroveci, inhalation, AIDS patients and immunocrompromized
What are the examples of bacterial infection of GI tract?
Cholera, travelers diarrhea, shigellosis, salmonellosis, typhoid fever, bacterial food poisoning, and clostridium difficile?
What are the important features of Streptococcus mutans, dental carries, and gum disease?
- Streptococcus mutans is a frequent cause of dential carriers, uses dextron which uses sucrose to soften tooth animal, enters through normal microbiota, creates hole or pits in the teeth accompanied with sensitivity, also breaks down gum tissue, proper tooth care (brushing, flossing and use of fluoridated toothpaste; a gram + occurs that is thought to be capable of metabolizing a wider range of carbohydrates that any other gram+ organism
- It is cariogenic meaning "caries causing"
- dental carries- accumulation of microorganisms is called dental plaque
- oral bacteria convert sucrose and other carbs into lactic acid, which in turn attacks the tooth enamel. The initiation of caries depends on the attachment of S. mutans or other streptoccoci to the tooth. Bacteria do not attach to a clean tooth, but attaches to the pellicle (thin film of proteins from the saliva). The bacteria produce a gummy polysaccharide of glucose molecules called dextran. Accumulations of bacteria and dextran adhering to the teeth make up dental plaque.
What are the characteristics of Helicobacter pylori?
- spiral shaped microaerophilic bacterium;
- main cause of peptic ulcer disease
- the syndrome includes gastric and duodenal ulcers
- it is a carcinogenic bacterium
What type of infection is Cholera? What virulence factor is responsible for damage to the host?
gram negative rod with a single polar flagellum
- they grow in the small intestine and produce an exotoxin. This exotoxin causes host cells to secrete water and electrocytes, especially potassium. The result is watery stools containing masses of intestinal mucus and epithelial cells called "rice water stools" from their appearance. Loss fluid can be 12v to 20 liters a day which causes shock, collapse, and often death
Which bacteria cause Traveler's diarrhea? Name the toxin produced by these bacteria?
- caused by one of the strains of E. Coli
- strains of E. coli that can cause travelers diarrhea: Enterotoxigenic coli, enteroaggregative coli, and enteroinvasive coli
- 1. not invasive but produces an interotoxin that causes watery diarrhea that resembles a mild case of cholera
2. bacteria adhere to ech other in a stacked - brick configuration
3. invade the intestinal wall, resulting in inflammation, fever, and sometimes shigella-like dysentery
- Travelers diarrhea can also be caused by gastrointestinal pathogens such as salmonela and camplyobacteria
What are the important features of diseases caused by Salmonella?
A. Salmonella are G- facultative rods, motile w/ peritrichous flaagella and placed in serological groups based on O(Somatic) and H(Flagella) antigens. Transmission is by ingestion of food and water contaminated by feces. Sometimes it is contracted through eggs from infected hens.
What is meant by food poisoning? Which bacteria cause food poisoning?
- known as staphylococcal food poisoning
- caused by s. aureus
- food poisoning is a staphylococcal intoxication
What is CDAD? What diseases it causes? What type of virulence factors does it produces? What kind of damages it causes? What is its relationship to use of antibiotics?
- clostridium difficle- associated diarrhea
- the bacterium produces exotoxins that cause inflammation accompanied by increased fluid secretion and permeability of the intestinal mucosa
- the condition CDAD is caused by the extended use of broad - spectrum antibiotics
Name and describe important features of different types of Hepatitis
Type A- the hepatitis A virus is the causative agent of hepatitis A, virus contains single stranded RNA and lacks an envelope, and its main entrance route is via the oral route and multiplies in the epithelial lining of the intestinal tract. Viremia occurs spreading it to multiple organs of the body and it is detected in the blood and urine.
Type B- HBV is larger than HAV (hepatitis A virus), HBV is a unique DNA virus because instead of replicating its DNA directly, it passes through an intermediate RNA stage resembling retrovirus. HBV has often been transmitted by blood transfusion.
- The serum from patients with Hepatitis B contains thre distinct particles which are 1. dane particles 2. spherical particles 3. filamentous particles
- 1. the complete virion, it is infectious and capable of replicating
2. smaller particles, about half the size of a dane particle
3. tubular particles similar in diameter to the spherical particels but about ten times as long
- 2 and 3 are unassembled components of dane particles without nuceilc acids
- see chart on page 724
What are the important features of Giardia, Amoeba, and Cryptosporidia?
Giarda Lamblia- a flagellated protozoan that is able to attach firmly to a humans intestinal wall, this protozoan is the cause of giardiasis which is prolonged diarrheal disease that is characterized by malaise, nausea, weakness, weight loss, and abdominal cramps. The protozoa reproduces by binary fission and can interfere with food absorption
Cryosporidium- causes crytosporidiosis which occurs when humans ingest the crytosporidian oocysts and these oocysts release sporozoites into the small intestine. The motile sporozoites invade the epithelial cells of the intestine and undergo a cycle that eventually releases oocysts to be excreted in the feces. this disease lasts 10 to 14 days
- Amoeba- causes amoebic dysentry or amoebiasis which is spread by food or water contaminated by cysts of the protozoan amoeba entamoeba histolytica
What is PID? Which organisms cause PID. What is Salpingitis?
Pelvic Inflammatory Disease, a collective term for any extensive bacterial infection of the female pelvic organs, particularly the uterus, cervix, uterine tubes, or ovaries. It is considered to be a polymicrobial infection which means a number of different pathogens could be the cause. Two most common microbes are N. gonorrhoeae and C. trachomatis
- Salpingitis: infection of the uterine tubes and most serious form of PID
What is meant by asymptomatic infection? Name two STDs that result in asymptomatic infection
- means that the person does not report having any known symptoms
- in the latent period of syphilis the person experiences no symptoms and gonorrhea in women also appears asymptomatic. Chlamydia trachomatis is also another disease that is asymptomatic in women
What are the important features of yeast infection?
- aka Candidiasis
- the most common species is Candida albicans
- it is treated with antifungals
- C. albicans often grows on mucous membranes of the mouth, intestinal tract, and genital tract. These infections occur when competing microbiota are suppresed by antibiotics or other factors. C. albicans is the cause of oral candidiasis or thrush and is also the cause of occassional causes of NGU in men and for vulvovaginal candidiasis (the most common cause of vaginitis)
Know everything about Neisseria and Chlamydia infections
- refer to notes
- gonorrhea: pathogen is neisseria gonorrhea
- symptoms include (for men) painful urination and discharge of pus and in women there are a few symptoms that include, PID
- it is treated with cephalosporins
Nongonococcal urethritis: pathogens are chlamydia trachomatis, mycoplasma hominis, ureaplasma urealyticism
- symptoms inlcude painful urination, watery discharge, and in women PID occurs
- this is treated with doxycycline and azithromycin
Which STD presents itself in three distinct stages?
What is meant by transmission via fecal-oral-route?
- occurs when infectious particles from feces are ingested through the mouth. Although fecal oral route disease transmission is classically associated with contamination of water by human or animal waste, there are some sexual and behavioral practices that can also expose individuals to these diseases
What are the important features of Typhoid Fever?
- the most virulent serotype of Salmonella
- it is spread only in the feces of humans
- S. typhi cells multiply within phagocytic cells and spread to multiple organs especially in the spleen and the liver, and eventually S. typhi is released into the bloodstream after the phagocytic cells are lysed.
- symptoms include: a high fever, continual headache, diarrhea appears in the second or third week
- ulceration and perforation of the intestinal wall can occur in severe cases
What is WBD? Give an example.
How one must treat gangrene infection?
- typically treated with the surgical removal of necrotic tissue and amputation and when gangrene appears in the abdominal cavity, the patient can be treated using the hyperbaric chamber
Why did some mistake Chlamydia with viruses?
List general modes of transmission of Hepatitis viruses?
- caused by Epstein- Barr Virus EBV or cytomegalovirus CMV
- drug and chemical toxicity can also cause acute hepatitis that is clinically identical to viral hepatitis
- HEPATITIS A: contains single strands of RNA and lacks an envelope; it can be grown in cell culture
- enters THROUGH THE ORAL ROUTE -->multiplies in the epithelial lining of the intestinal tract--> viremia occurs and the the virus spreads to the liver, kidneys and spleen--> virus is shed in the feces and can also be detected in the blood and urine
- HEPATITIS B: larger, double stranded DNA
- can be transmitted through unsterilized objects
- HEPATITIS C: transmitted hepatitis
- transmitted by sharing of razors, toothbrushes, injection equipment
List different types of pneumonia? Which type is more prevalent among younger individuals
PNEUMOCOCCAL PNEUMONIA: gram+, ovoid bacterium
1. cause of Otitis media, meningitis, and sepsis
2. the cell pairs are surrounded by a dense capsule that makes the pathogen resistant to phagocytosis. The capsules are also the basis of serological differentiation of pneumococci into 90 serotypes
3. involves both the bronchi and the alveoli
4. symptoms inlude fever, difficulty breathing, chest pain
HAEMOPHILUS INFLUENZAE PNEUMONIA: gram- coccobacillus and a gram stain of sputum will differentiate this type of pneumonia
1. susceptible to alcoholics, poor nutrition, cancer, or diabetes
MYCOPLASMAL PNEUMONIA: most common in young people
1. primary atypical and walking pneumonia
CHLAMYDIAL PNEUMONIA: transmitted from person to person by the respiratory route
A disease in which pathogens invade a susceptible host and carry out at least part of their life cycle in the host. caused by an infecting microorganism or virus.
Attributes of a microorganism or virus that promote pathogenicity.
Acute illness caused by infectious agents or their products circulating in the bloodstream.
Microorganisms or viruses living in host tissues for long terms without causing symptoms.
persisting over a long time
existing in circumscribed areas
developed during a stay at a hospital or other clinical care facility
Coagulates (clots) the fibrinogen in plasma. The clot protects that pathogen from phagocytosis and isolates it from other host defenses.
-soluble, heat-labile, proteins
-usually released into the surroundings as bacterial pathogen grows
-humans exposed to exotoxins in three main ways
-ingestion of preformed exotoxin
-bacterial colonization of a mucosal surface followed by exotoxin production
-colonization of a wound or abscess followed by local exotoxin production
-most exotoxin producers are gram-positive
-often travel from site of infection to other tissues or cells where they exert their effects
-usually synthesized by specific bacteria that have toxin genes in their plasmids or prophage DNA
-among the most lethal substances known
-are highly immunogenic
-can stimulate production of neutralizing antibodies (antitoxins)
-can be chemically inactivated to form immunogenic toxoids
e.g., tetanus toxoid
-specific host site exotoxins
-may also be an AB exotoxin
-superantigens that stimulate T cells directly to make cytokines
A. lipopolysaccharide (LPS) in gram-negative outer membrane can be toxic to specific hosts
-called endotoxin because it is bound to bacterium and released when organism lyses and some is also released during multiplication
-toxic component is the lipid portion, lipid A
-a complex array of lipid residues
-usually capable of producing general systematic effects
-bring about these effects indirectly
-endotoxin interacts with host molecules and cells, activating host systems
e.g., interaction with macrophages release of endogenous pyrogen (induces fever)
e.g., binding to LPS-binding protein release of cytokines to cause septic shock
Enzyme that breaks down hyaluronic acid, a component tissue
Protein that destroys cell membranes of phagocytes
Stimulate T cells directly to make cytokines
Filamentous structures that help attach bacteria to other bacteria or to solid surfaces.
-produced by hybridoma cells
-recognize a single epitope
-fluorescently-labeled mAbs used diagnostically
-technique has replaced use of polyclonal antisera for culture confirmation
API20E System ?
manual biochemical system
used to detect H. influenzae type B, S. pneumoniae, and N. meningitidis groups A and C.
detects HIV antibodies in saliva in 10 minutes
A sac with a distinct wall containing fluid or other material; also, a protective capsule of some protozoa.
the vegetative form of protozoa
A major genetic change in influenza viruses causing changes in H and N antigens.
A minor variation in the antigenic makeup of influenza viruses that occurs with time.