Final Exam Flashcards
What does mucus contain to help control bacterial growth?
Sliminess - traps microbes
Lysozyme- breaks cell walls
Lactoferrin- binds iron that microbes need to grow
Decensins - poke holes in cell walls
Respiratory defenses:
First line- nasal hairs, cilia, mucus
Second- macrophages
Third- pathogen specific, secretory igA
Is normal biota gram positive or negative?
Gram positive- protects our environment
Examples of biota in respiratory tract?
S.pyogenes, H.influenzae, S. pneumonia, N.meningitidis, S.aureus
What is pharyngitis caused by?
Virus - when caused by bacteria it’s S.pyogenes (strepthroat)
If scarlet fever is left untreated what will happen?
The bacteria can access the blood (becoming systemic) and cause rheumatic fever (inflammation of joints and muscles)
Treatment for strep and scarlet fever?
Penicillin
What tests would u use for diagnosis of strep/scarlet fever?
Beta hemolytic, camp, catalase, bacatracians
What is epiglottis caused by?
Normal flora- H.influenza, S.pneumonia
What is the nickname for epiglottis?
“Strangler” disease - can’t breathe
What is diphtheria caused by?
Corynebacterium diphtheria (club shape bacteria) NOT AN ENDOSPORE
What is translation?
Making chain of proteins
What do the toxins prevent in diphtheria?
They prevent translation by ribosomes.
Complications of diphtheria?
Suffocation, nerve destruction, heart arrhythmia (strangler disease) inflamed threat, forms polyps
How to treat diphtheria?
Penicillin and antitoxin
Otis externa
External - outside eardrum
Otis media
Middle - inside eardrum
What causes Acute Otitis media?
Mixed infection of viruses and bacteria (S.pneumonaie, H.influenzae)
How to treat Otis media?
Antibiotics, tympanic membrane tubes, watchful waiting
Vaccine for acute otitis media?
Prevnar, Hib
Swimmers ear is?
Otis externa - too much moisture breaks down membranes
Symptoms of Otis externa?
Itching and pain
What caused Sinusitis?
Viruses, bacteria, fungi, allergies
Treatment for sinusitis?
Broad-spectrum antibiotics for bacterial infection, antifungals or surgery for fungal infection
What causes the common cold?
Rhinovirus - airborne transmission, direct contact
Why no cure for the common cold?
Because there’s 200 different virus strains can cause common colds. Can’t take 200 vaccines.
What other virus can cause a cold
Adenovirus infections
lower respiratory tract diseases:
Influenza, pertussis, RSV Disease
What two spikes does the Flue contain?
Hemaggluetin helps the virus attach and penetrate host cells (H)
Neauraminidase helps release virus from the host cell after replication and assembly (N)
H1N1
Signs and symptoms of the flu:
Begin in upper respiratory tract Lower tract Headache Chills Dry cough Body aches Fever Stuffy nose Sore throat Extreme fatigue Secondary infections
Types of flu:
Influenza A, B, C
A - most common, every year, circulates in animals
B- less common but still every year, only in humans, found in vaccine
C- causes a mild respiratory illness but not epidemic
What is antigenic drift?
Slowing moving away from immune recognition
Produces most seasonal flu strains
Mutations of glycoproteins H, N genes
What is antigenic shift?
RNA exchange between diff viruses
Occurs during co-infection of a host cell
More likely to produce pandemic strains
How to diagnose influenza?
Symptoms, culture tests to identify virus subtype causing infections, rapid flu tests(Elisa)
How to prevent flu?
Vaccination
Inactivated seasonal (70-90% effective, pregnant people get this & people over 6 mos) or live attenuated seasonal (98-99% effective, age 5-49 can get this)
Cause of pertussis (whooping cough)
Bordatella pertussis - spread by respiratory droplets (gram -)
What do the toxins in pertussis do?
Paralyze ciliates cells in the respiratory tract = no mucus movement can lead to pneumonia
How to prevent pertussis?
DTaP vaccine, antibiotic tx, supportive measures
Stages of pertussis?
Catarrhal stage - runny nose, 1-2 weeks
Paroxysmal stage - severe coughing
Recovery phase - susceptible to other respiratory infections
What is the respiratory syncytial virus caused by?
RSV - infects the bronchioles and alveoli of the lungs causing cells to fuse together into syncytia
Children under 1
What is the virulence of RSV disease?
Giant cell formation (syncitia)
How to diagnose RSV?
Direct antigen testing
Prevention for RSV?
Antibody therapy, ribavirin
What causes TB?
Mycobacterium tuberculosis
Calcified white blood cells are called:
Granulomas
Signs and symptoms of TB
Easily infected but usually resistant to disease development
Contained in the lungs
Forms of TB:
Primary- initial infection, no symptoms
Secondary- severe symptoms, fever, anorexia, violet cough, fatigue, chest pain, night sweats
Disseminated/extrapulmonary- infection outside the lungs. Regional lymph nodes, kidneys, long bones, genital tract, brain = organ failure
What causes Bronchitis?
90% by viruses ; if bacterial it’ll be your normal flora
Begins as a URT infection
Getting flu vaccine prevents bronchitis
Sign of bronchitis:
Coughing up mucus
What is pneumonia?
Fluid in the lungs, usually after bronchitis
What causes pneumonia?
Bacteria: typical- S.pneumoniae
Atypical- Legionella sp, Mycoplasma pneumonia
Viruses: mainly VIRAL, Hantavirus, emerging viruses
Fungi: histoplasma copsulatum, Pneumocystis
Typical vs atypical pneumonia
Complaints: cough, fever, chest pain
S.pneumoniae(entire lung lobe, both lungs) H.influenzae (hospital acquired) S.aureus( hospital acquired)
Atypical: symptoms- cough, fever, headache, muscle pain
M.pneumoniae(causes atypical, called walking pneumonia, have no sensitivity to penicillin because it has no cell wall)
What causes Legionnaires disease?
Legionella pneumophila
How do u get legionnaires?
Breathing in or ingesting amoebas
How do u get Hantavirus?
Deer mice, transmitted airborne dust contaminated with rodent urine, feces, or saliva
What causes Histoplasmosis?
Histoplasma capsulatum
How is histoplasmosis transmitted? (Summer flu)
By inhalation of soil contaminated with bat or bird feces. Common for hunters or farmers
Symptoms of histoplasmosis
Mild flu like symptoms
If you’re immunocompromised then it’ll be a TB like disease
What causes pneumocystis pneumonia (pcp) and what can it cause?
Caused by: pneumocystis jiroveci
Causes: lethal pneumonia
Mold grows on the lungs
What causes cavities?
S.mutans and S.sorbrinus - produce lots of acid
What is Rubulavirus?
Mumps virus - infectious parotitis.
Enlarged jaw tissues caused by swollen salivary glands
How is mumps spread?
Respiratory droplets, direct contact
What causes diarrhea?
Salmonella, shigella, ecoli, vibrio cholera, giardia
What is diarrhea?
3 or more loose stools in a 24 hour period
What causes salmonella?
Salmonella typhi (aka typhoid fever)
S. Typhi is transmitted by?
Flies, food, fingers, feces, fomites
Is salmonella acid resistant?
Yes - it passes thru the stomach to the small intestine, it causes ulcers, bleeding, pain
Characteristics of shigella?
Gram-negative Rods
Non motile
Non spore forming
What causes Shigellosis?
Shigella sonnei
How do you get shigella?
Contaminated food - eggs, veggies, shellfish, dairy
E.coli diarrheas causes various forms of:
Gastroenteritis
Transmission of e.coli?
Fecal- oral
Types of e.coli?
Enterotoxigenic E.Coli - infects GI tract and secretes a toxin that causes gastroenteritis (aka travelers diarrhea)
Enteropathogenic E.Coli - causes diarrhea in infants, where sanitation is lacking
E.Coli (EHEC) - shigella like toxin, gastroenteritis, fever, bloody diarrhea
Campylobacter- (subacute) ingested thru fecal oral, motile, fever, vomiting, headaches, watery diarrhea, abdominal pains - symptoms last longer than 2 weeks
What causes inflammation of the colon?
Clostridium difficile - extremely spore forming, mucus like diarrhea
What causes clostridium difficile?
Gram positive endospore forming rod
What causes cholera?
Vibrio cholerae- usually consumed with raw oysters and water
Symptoms of cholera?
Diarrhea, thickened blood, shock, death, losing 1L of water per hour, rice water stool, short incubation period - outbreaks occur after natural disasters, war, refugee movements
How is cholera treated?
Antibiotics and hydration
What causes cryptosporidiosis?
Cryptosporidium parvum and C.hominis - intestinal protozoan
How is crypto spread?
Contaminated water and physical contact
Symptoms of crypto?
1-2 weeks of diarrhea, watery diarrhea, headaches, sweating, vomiting, abdominal cramps
Rotavirus infections can be deadly for:
Children ( winter diarrhea)
Transmission of rotavirus?
Contaminated food and water - invade small intestine
Treatment of rotavirus?
Oral rehydration therapy, 2 vaccines
Norovirus infections are common cause of:
No bacterial gastroenteritis in adults
Transmission of norovirus?
Fecal-oral, direct contact person to person & infected objects (cruise ships)
Symptoms of norovirus?
High contagious, dehydration, fever, vomiting
Food poisoning / intoxication symptoms?
Cramps, nausea, vomiting, diarrhea, non-inflammatory, shared meals, short incubation
What causes food poisoning? (Intoxication)
S.aureus, B.cereus, C.perfringens - these toxins come from shellfish, fish, mushrooms
S.aureus food poisoning:
Toxins are consumed in protein rich foods such as meat, fish, dairy products - toxins are heat stable
Contaminated by boils or abscesses on handlers skin, thru sneezing
Clostridium perfringens food poisoning:
Contaminated by meat, poultry, fish
Bacillus cereus food poisoning:
Diarrhea, vomiting, eating contaminated grains
Chronic diarrhea:
Lasting longer than 14 days - people with AIDS suffer with chronic diarrhea
What causes chronic diarrhea?
Protozoans - spread fecal oral
What is Giardiasis caused by?
Giardia intestinalis
Transmission of Giardiasis?
Food or water contaminated with sewage containing cysts
Symptoms of Giardiasis?
Appear after about 7 days: nausea, cramps, flatulence, diarrhea
What causes Amoebiasis?
Entameoba histolytica
Symptoms of amoebiasis?
Second leading cause of death from parasitic disease, enter thru food or water contaminated with feces - ingest a cyst & emerge in the intestines, loose stool, stomach cramps and pain, fever, bloody stools
What causes Gastric ulcer?
Helicobacter pylori - contaminated food and water
Symptoms of gastritis:
Sharp, burning pain from abdomen, bloody stools, vomiting
Gastric ulcers:
Lesions in the mucosa of the stomach or in the uppermost portion of the small intestine (aka peptic ulcers) they worsen after eating a big meal
What is hepatitis?
Inflammatory disease marked by necrosis of hepatocytes and a mononuclear response that swells the liver
Symptoms of hepatitis:
Jaundice, confusion, fever
Acute- recover 3-4 months and immunity
Chronic- aggravated by drinking beer affecting your liver
Two types of Hep affecting the GI tract?
Hep A, Hep E - transmitted by contaminated food or water from fences of an infected individual
Hep A- has a vaccine, not chronic, fecal oral
Hep E- is opportunistic- not chronic, fecal oral
Bloodborne hep viruses:
Hep B - has vaccine, chronic, infected needle
Hep C - no vaccine, chronic, infected needle
What do the virions consist of with Hep B & C?
A nucleocapsid surrounded by a core antigen
An envelope containing a surface antigen
transmission of hep B & C?
Direct or indirect contact with bodily fluid
Primary reason for liver transplants in the US?
Hep C - symptomless chronic infection no vaccine available
Hep D & G are:
Cancerous types
Helminths examples:
Roundworms, tapeworms
Nematodes, trematodes, cestodes
How to diagnose parasitic worms?
Differential blood count, serological tests, history of travel
What causes Pinworm disease
Enterobius vermocularis
Symptoms of pinworm disease:
Infection of intestines leads to diarrhea and anal itching
Worms can die in a few weeks even without treatment
Tapeworms:
Survive in the human intestines
Beef and pork tapeworm are caused by?
Taenia saginata and T.solium - acquired by eating poorly cooked beef or pork
Flatworms
Do not have a respiratory or circulatory structures or a digestive tract
Schistosomiasis: liver disease
Suspected when liver is swelling
What causes schistosomiasis?
Blood flukes Schistosoma Masonic or S. japonicum
Symptoms of liver disease?
Hepatomegaly, liver disease, splenomegaly
What is the main bacteria in the vagina?
Lactobacillus - produces an acid pH
How do diagnose vaginosis?
Look at epithelial cells and if they are covered with bacteria that is abnormal (clue cell)
Where is the normal micro biota in males and females?
Males- urethra
Females- urethra and vagina
Causative agents for a UTI?
Normal biota of the GI tract
- E.coli (80% of UTIs)
- S. saprophyticus
- Proteus mirabilis
What are venereal diseases?
STDs - chlamydia, gonorrhea, syphilis (3 most common)
Cause of gonorrhea?
Neisseria gonorrhoeae
Symptoms of gonorrhea?
Females- many are asymptomatic but can spread to Fallopian tubes causing; pelvic inflammatory disease, ectopic pregnancy
Males- tingling of penis, pain with urinating, penile discharge, swollen lymph nodes, painful testicles
How is gonorrhea treated?
Cefriaxone
How to diagnose gonorrhea?
Gram negative stain (appears as kidney bean shaped bacteria), Thayer Martin medium
What causes chlamydia?
Chlamydia trachomatis
Symptoms of chlamydia:
Females- usually asymptomatic, can cause inflammation in Fallopian tubes(salpingitis), PID
Males- can cause sterility, inflammation in urethra, some discharge, can infect throats and anus causing inflammation
Diagnosis and treatment for chlamydia?
Pap smear & treated with Azithromycin
C.trachomatis cannot make its own ATP so it must:
Rely on host cell for energy (intracelluar parasite)
2 phases of C. trachomatis?
- infectious elementary body phase
- Noninfectious reticulate body
Becomes infectious once the reticulate bodies become compact into elementary bodies and the cell bursts open to infect the next cell
What causes yeast infections?
Candida albicans (part of normal flora)
What is vulvovaginitis & symptoms?
Yeast infection (itching, burning, reddening, swelling, discharge)
What is oral candidiasis and symptoms?
Yeast infection in oral cavity (white curd-like growth on the mucous membranes of the mouth)
Breast fed babies can get it from the nipple of the mom
Vaginitis vs vaginosis?
Vaginitis- inflammation of vagina
Vaginosis- no inflammation
How to diagnose yeast infection?
Gram stain - if there’s fungus then it’s a yeast infection
What causes trichomoniasis?
Trichomonas vaginalis (protozoan)
Carried by prostitutes - sexual contact
Symptoms of trichomoniasis?
Females- intense itching, burning, yellow green frothy discharge
Males-asymptomatic
Ulcer diseases:
Syphilis, chancroid, genital herpes
Clinical stages of syphilis?
Primary- lesion where the bacteria entered the body
secondary- involves fever, skin rash, swollen lymph nodes
tertiary- formation of humans that can cause weakening and bursting blood vessels, degeneration of spinal cord tissue, brain damage
What causes syphilis?
Treponema palladium (turn, thread, pale)
Treatment for syphilis?
Penicillin
What is congenital syphilis?
Syphilis bacterium can pass from a pregnant woman’s circulation into the placenta and be carried throughout the fetal tissues
Inhibits fetal growth, mild defects, & miscarriage
What causes hutchinsons teeth?
Congenital syphilis (looks like molars for the central teeth)
Diagnose of syphilis?
Take blood and put it in a slide - if it glows pink then it’s syphilis
What causes chancroid?
Haemophilis ducreyi
How is chancroid transmitted?
Direct contact - sexually
Associated with prostitutes and poor hygiene
Uncircumcised men seem to be more commonly infected than circumcised men
People may be asymptomatic
What causes genital herpes?
HSV-1 and HSV-2
Cold sores are caused by?
HSV-1 ; after primary infection the virus become latent in sensory ganglia
Recurrence of cold sores occurs when viruses are deactivated and move to the epithelium
What causes genital herpes?
HSV-2
Symptoms for herpes?
Itching and throbbing in genital area, followed by blisters
Treatment for herpes?
No cure, but the antivirals can shorten and decrease the number of outbreaks
Infection of the eye with herpes is called:
Herpes keratitis - causes scarring of the cornea and blindness
What happens if the child gets herpes from mother?
Child’s mental development can be delayed, blindness and seizures can occur, should deliver C-section
Diagnoses of genital herpes?
Pap smear - cell is multi-nucleated
What two STIs cause wart like growth?
Human papilloma virus and malluscum contagiosum
What causes genital warts?
Human papilloma virus infection
Symptoms of warts?
Outgrowth of tissue on the genitals
In females: occur on the vulva and in/around the vagina
In males: occurs on the penis and scrotum
In both sexes: warts can appear on the anus and the skin around the groin
Can cause cancer 10-15 years to develop
Group B streptococcus “colonization” causes:
Neonatal disease
How do u prevent the spread of group B strep from mother to fetus?
At 35-37 weeks should be treated with penicillin or ampicillin unless bacterium is found to be resistant in which erythromycin may be used
Important properties of synthetic agents, antibiotics and semisynthetic drugs?
Synthetic agents are made in a pharmaceutical lab
Antibiotics are products of living microbes & found in nature
Semisynthetic drugs include synthetic and antibiotic elements
What are broad spectrum drugs?
Affect many taxonomic groups
Ex) tetracycline
What are narrow spectrum drugs?
Affect only a few pathogens
Ex) polymyxin
Chemotherapeutic drug
Any chemical used in the treatment, relief of a disease
Prophylaxis
Use of a drug to prevent imminent infection of a person at risk
Antimicrobial chemotherapy
The use of chemotherapeutic drugs to control infection
Before antimicrobial therapy can begin what 3 factors need to be determined?
The nature of the microbe causing the infection
The degree of the microbes susceptibility to various drugs
The overall medical condition of the patient
How to identify the agent?
Collect specimens from the patient (body fluids, sputum, stool)
Gram stain
What technique do u use for testing drug susceptibility?
Kirby-Bauer technique
- surface of an agar plate is spread with bacteria
- small discs containing a prepared amount of antibiotic are placed on the plate
- zone of inhibition surrounding the discs is measured and compared with a standard for each drug
- antibiogram provides data for drug selection
- this method is less effective for anaerobic, fastidious, or slow growing bacteria
What is minimum inhibitory concentration?
The smallest concentration (highest dilution) of drug that visibly inhibits growth
Chemotherapeutic index:
The toxic (how much do I need to make it toxic to u) and therapeutic (how much do I need to kill the bacteria) doses are used to formulate it
Antibiotics that work on Cell wall synthesis?
Penicillin - active against many gram positive and some gram negative bacteria
-they interfere with cell wall synthesis causing the cell to burst
What antibiotic do u use for cell membrane?
Polymyxins -increase membrane permeability of gram negative rods, the resulting water uptake leads to cell death
Ex) neosporin
What antibiotic affects protein synthesis?
Chloramphenicol- used against a wide variety of bacteria and some rickettsial and fungi
Infections like meningitis, cholera, typhoid, Rocky Mountain spotted fever
What antibiotic affects protein synthesis?
Tetracycline - broad spectrum antibiotic that target the attatchment of tRNA to the 30S subunit
- they have a benzene ring formation
- they can destroy intestinal microbiota and cause staining of the teeth
What antibiotic affects nucleus acid synthesis?
Rifampin - interferes with RNA synthesis
Effective against TB, leprosy, meningitis
Cause liver damage
Body secretions turn red/orange
What antibiotic is affective against metabolism?
Sulfonamides - out compete folic acid components for binding sites in a bacterial enzyme
-acts as competitive inhibitor
What antifungal is effective for cell wall?
Caspofungin
What antifungal is effective for nucleic acid synthesis?
Flucytosine
What antifungal inhibits mitosis?
Griseofulvin -used against ring worm and athletes foot
What’s the goal of antiprotozoal agents?
Eradicate the parasite
What are aminoquinolines?
Antimalarial drugs that accumulate in parasitized red blood cells -they interfere with the parasites ability to break down and digest hemoglobin
What is sulfonamides?
Antiprotozoal- block folic acid synthesis
What is nitroimidazoles?
Antiprotozoal - interfere with DNA synthesis, they are used to treat amebiasis, Giardiasis, and trichomoniasis
4 ways bacteria can resist
- Alter metabolic pathway
- Antibiotic modification- destroy antibiotic
- Target modification - change the transport
- Target modification - change the make up of certain parts of the bacteria so the antibiotic won’t work
