OPT2222 Exam 2 Flashcards
(157 cards)
1
Q
How many species of bacteria on hands?
A
150 unique species
2
Q
Do males or females have more diversity in species on hands?
A
Females
3
Q
What are you most likely to be infected by?
A
Own flora
hands
4
Q
What are the 4 groups of pathogenic microbes?
A
bacteria
viruses
fungi
protozoa
5
Q
What are bacteria?
A
Prokaryotic (no nucleus) unicellular microscropic organisms that reproduce by binary fission (grow too big and then divide into 2 cells) Oldest organisms on earth Smaller than eukaryotes Complex
6
Q
What are viruses?
A
Acellular infectious particles
Not living - piece of genetic code only
Oldest things on earth - older than bacteria
Most common infections are caused by viruses
7
Q
What are fungi?
A
Eukaryotic
Yeast and Molds
Difficult to kill since cells share same characteristics as our cells (toxic)
8
Q
What are protozoans?
A
Eukaryotic Unicellular Microscopic No cell wall Helminths
9
Q
What are the differences between prokaryotes and eukaryotes?
A
DNA, RNA and protein synthesis (both cells have but differences: chromosomes 1 vs. 46)
Cell wall (only prokaryotes)
Metabolism (all cells have)
Nucleus (only eukaryotes have)
10
Q
Do all bacteria have cell walls containing peptidoglycan?
A
No, mycoplasma do not
11
Q
What do antibiotics target?
A
bacterial cell walls
12
Q
Who invented antibiotics?
A
prokaryotes create them
13
Q
What bacteria are round spheres? What are two round spheres? What are a chain of round spheres?
A
Cocci
Diplococci
Streptococci
14
Q
What is the most common organism causing infection?
A
Staphylococcus
15
Q
What is a biofilm?
A
Bacteria produce a capsular glycocalyx biofilm of layers which attach to host cells
Interacts and adapts to environment
Are difficult to treat with antibiotics
Resists hosts immune system
16
Q
What coccus grows in clusters?
A
Staphylococci
17
Q
Which bacteria is gram positive, grows in irregular clusters of spherical cells, contains 31 species?
A
Staphylococci
18
Q
What bacteria grow at 37 degrees Celsius, are facultative anaerobes, are the most common skin flora, produce virulence factors and the most common ocular infection?
A
Staphylococcus Aureus
19
Q
What are staph virulence factors?
A
Produce coagulase (coagulate plasma and blood)
hyaluronidase (digest ground substance of connective tissue)
DNAse (hydrolyze DNA)
Lipases (break down oils in skin)
Penicillinase (inactivates penicillin)
Staph toxins
20
Q
What are the staph toxins?
A
Hemolysins - lyse RBCs
Leukocidin - lyse neutrophils and macrophages
21
Q
What does Staph infiltrate?
A
Meibomian glands
22
Q
What is folliculitis?
A
Staph disease - Inflammation of hair follicle
23
Q
What is a furuncle?
A
Staph disease - a boil - progresses into abscess or pustule
24
Q
What is a carbuncle?
A
Staph disease - a larger, deeper lesion
25
What is impetigo?
Staph disease - Bubble-like swellings that break and peel away from skin
26
What is eyelid margin disease?
Staph disease
Blepharitis
epidemiology 20-60% carriage rate for healthy adults
27
What is MRSA?
methicillin resistant staph aureus
most dangerous staphylococcus
resistant to beta lactams, penicillin, ampicillin, oxacillins, and even vancomycin
28
How to prevent staph infection?
Wash hands!
29
What are gram positive spherical cocci that grow in long chains?
streptococci
30
What bacteria are gram positive, with slime layers and capsules, facultative anaerobes, but not a common ocular pathogen?
streptococci
31
What is the most common and serious strep pathogen?
strep pyogenes
32
What is impetigo (pyoderma)?
Superficial lesions that form hightly contagious crust
| Epidemic in school children
33
What is Erysipelas?
Enters through a break in the skin, spreads to dermis and subcutaneous tissues
34
What is Streptococcal Pharyngitis?
strep throat
35
What are Group D Enterococci?
Found in large intestine
| Causes opportunistic UTI, wound and skin infections
36
What bacteria are gram negative bean-shaped diplococci, grow in mucous membrane, have pili
Neisseriaceae
37
What is neisseria gonorrhoeae?
STD gonorrhea
2nd most common reportable disease
causes ophthalmia neonatorum
38
What prevents blindness in infants immediately after birth from ophthalmia neonatorum?
Crede prophylaxis
39
What bacteria are rod shaped?
Bacilli
40
What bacteria is rod shaped, gram positive, found in soil, frequent cause of soft tissue infection, causes gas gangrene, releases exotoxins
Clostridium Perfringens
41
What is a clostridium tentai
Tetanus infection
42
What is a gram positive rod, common resident in pilosebaceous glands, causes acne and best treated with benzoyl peroxide?
Propionibacterium acnes
43
What is the spore forming anaerobe that inhabits soil and water, is the most powerful neurotoxin ever discovered?
Clostridium botulinum
44
What is the likely contaminate in poorly preserved food?
botulism
45
What leads to flaccid paralysis of muscle by blocking the release of the neurotransmitter acetylcholine at the neuromuscular junction
Botulism
46
What bacteria are aerobic, gram negative, have lipopolysaccharide endotoxin outer membrane cell wall
Gram negative bacilli
47
What bacteria are small gram negative rods, live in soil and water, about 10% of people have as normal inhabitant of colon, are resistant to disinfectants, drugs, and drying, are opportunistic pathogens and contaminates ventilators, IV equipment, anesthesia equipment or soap containers?
Pseudomonas Aeruginosa
48
What bacteria has a grape-like odor, greenish-blue pigment, is multidrug resistant and opportunistic?
Pseudomonas aeruginosa
49
What bacteria has a bright red pigment, is opportunistic, can infect burn victims, wounds, meningitis?
Serratia marcescens
50
What is gram negative rods, can lead to periorbital cellulitis and is the leading cause of acute bacterial meningitis in children?
Haemophilus Influenzae B
51
What is caused by haemophilus aegyptius?
conjunctivitis
52
What are the gram negative corkscrews that are free living saprobes, commensal, and have endoflagella?
Spirochete
53
What bacteria are thin, regular, coiled cells that live in oral cavity, intestinal tract and perigenital regions?
Treponema
54
What spirochete is fastidious, sensitive, cannot survive long outside of host so transmitted sexually or transplacental
Treponema Pallidum
55
What pathogenic spirochete binds to epithelium, multiplies and penetrates capillaries, moves into circulation and multiplies, causes a chancre and is called the great pox?
Syphilis
56
What bacteria causes lyme disease?
Borrelia burgdorferi
57
What bacteria are obligate intracellular parasites, have a gram negative cell wall, are transmitted host to host, and grows within host cell vacuoles?
Chlamydiaceae
58
What attacks mucous membranes of the eye, causes severe inflammation and scarring, and is the leading cause of blindness worldwide?
Chlamydia Trachomatis
59
What is the most prevalent sexually transmitted disease?
Chlamydia
60
What are eukaryotic organisms that produce spores and are natural decomposers?
fungi
61
What live in warm, dark, moist environments and eat dead matter?
Fungi
62
What fungi is endemic in northeast, lives in soil, and if inhaled, the conidia produce primary pulmonary infection
Histoplasmosis
63
What is found in sand in desert, alters cellular immunity, infects skin and mucosa, and can cause pneumonia, septicemia, or endocarditis
Candidiasis
64
How are fungal infections treated?
Amphotericin B (IV)
Flucytosine
Azoles
Nystatin (topical)
65
What parasites are heterotrophic, without cell walls or chloroplasts, solitary, unicellular, live in water and feed on other microbes and organic matter?
Protozoa
66
What pathogenic protozoa is an infective amoeba, causes amebic dysentery?
Entamoeba histolytica
67
What pathogenic protozoa inhabits standing water, infiltrates sinuses through nasal contact, causes primary acute meningoencephalitis
Acanthameoba Keratitis
68
What pathogenic protozoa is transmitted by kissing bug feces and can cause Chagas Disease?
Trypanosoma cruzi
69
What intracellular apicomplexan parasite lives in GI tract of cats and transmitted to humans by ingesting raw meat or contamination of cat feces by not washing hands after cleaning litter box?
Toxoplasmosis
| causes huge retinal scars
70
What causes 20% of all infectious disease?
parasites
71
What are insects that feed on blood of host, are ectoparasites and transmit infectious microbes called?
Arthropod vector
72
What insect parasites can infect eyelids because they can cling to eyelashes and cause blepharitis?
Pubic lice
73
How do you acquire helminthes?
Through ingestion of larvae or eggs in food, soil or water (fecal-oral route)
74
Ability to kill helminthes is limited. Why?
Eukaryotic
| Eosinophilia
75
What is an infection from ingestion of larvae of dog or cat roundworm?
Toxocara canis or
Toxocara catis
Causes scarring in retinal tissue similar to toxoplasmosis
76
Helminthes like what kind of tissue?
Neural tissue
| therefore it likes the eye
77
What helminth is transmitted by biting female black flies? What is the disease it can cause?
```
Onchocerca volvulus
River blindness (Onchocerciasis)
```
78
Which nematodes are elongated, spread by biting arthropods, complete life cycle in blood, lymph or skin?
Filarial Worms
79
What filarial worm is spread by mosquitoes, blocks lymphatic circulation, migrates to eye and causes elephantiasis?
Bancroftian Filariasis
80
What is the African eye worm?
Loa loa
81
What filarial worms are temperature sensitive, spread by bite of deer fly, and like conjunctiva?
Loa loa
82
What are the most abundant microbes on earth?
viruses
83
Are viruses living?
No
84
What is the most common cause of infectious disease?
Viruses
85
What viruses are the largest?
DNA viruses
86
What are viruses?
Obligate intracellular parasites
87
Can you ever eradicate a virus?
No
88
What is course of virus?
Infects particular cell or can be born with it
Infects Tissues
Reproduces
Evokes immune response
Lytic cycle - multiplies slowly and causes little or no disease for long period
Lifetime infection
Virus enters dormant phase
then reactivates in recurrent infections (comorbidity of viruses)
89
Which viruses cause cancer?
Oncogenic ones:
| HPV (Cervical Cancer)
90
What are the enveloped DNA viruses?
Poxvirus (chicken pox, smallpox)
Herpes
HepaDNA (hepatitis)
"Envelope" constantly mutates from person to person
91
What illness is caused by highly contagious, flat papules, transmitted by direct contact, spreads easily if not treated and infects skin (common around eye)? Treatment is by freezing, electrocautery, chemical agents (but not on eyelids)
Molluscum Contagiosum
92
What viruses are very common, people are infected soon after birth from mother, shows up typically around mouth because mother kisses baby, reoccurs in immunocompromised hosts, have for life
Herpes Simplex
Cold sore (can be activated by UV light, stress, mechanical injury)
Varicella Zoster - chicken pox
93
What is a latent virus that resides in the fifth cranial nerve trigeminal ganglion, vesicles appear on scalp, face, eyebrows, lids, nose, mouth and chin, antibody levels keep in check until immune status drops then returns
Herpes Simplex I
94
What virus is caused by herpes simplex, is a neurotropic virus, has a dendritic pattern, if travels to cornea and is often misdiagnosed
Herpetic Keratitis
| Herpes of the cornea
95
What causes inflammation of the liver and the accumulation of bile and leads to jaundice
Viral hepatitis
96
Primary infection of varicella zoster, infects dorsal root ganglia, get vesicles all over body, DNA virus that enters neurons and remains for life, tranmitted by respiratory droplets
Chicken pox
97
Reactivation of varicella zoster from ganglion cell bodies, common in older adults or immunosuppressed, usu. occur along path of one nerve root, extremely painful!
Shingles
98
What are the herpes viruses?
Herpes Simplex I - above waist
Herpes Simplex II - below waist
transmitted mucus membrane to mucus membrane
Varicella Zoster (DNA virus) - chicken pox
ubiquitous
99
What is worst thing to do for someone with a herpes infection?
Suppress the immune system (via steriods, UV light)
100
What is the DNA virus that causes inflammation of the liver, accumulation of bile that leads to jaundice or icterus
Hepatitis B (viral)
101
What is yellowing of the conjunctiva/sclera?
Icterus
102
What virus causes common respiratory illness spread by autoinfecting (mucus membranes), mutates rapidly, and is transmitted easily
Adnovirus
103
What is the most common cause of pink eye?
Epidemic Keratoconjunctivitis (EKC)
104
What virus is caused by Adnovirus 8 and 19?
EKC
105
Where is the lymphatic drainage for the eye?
Preauricular node (in front of ear)
106
What non-enveloped virus causes bumps?
Papilloma viruses
107
What is bad about papilloma viruses?
They are chronic viral infections, oncogenic
108
What are eyelid warts?
Verruca vulgaris
| Papilloma virus
109
What viruses attach and multiply in respiratory tract cells and takes a piece of cell membrane as it's envelope
RNA viruses
110
What is an orthomyxovirus?
Highly contagious respiratory illness
Influenza
3 types: A, B, C
Type A is most common (seasonal flu)
111
How many people are affected by influenza each year?
5-20% of population is affected annually
40,000 people or more die
Top 10 cause of death in the US
112
What contagious RNA morbillivirus invades the respiratory tract and causes sore throat, dry cough, headache, conjunctivitis, lymphadenitis, fever, and koplik spots in throat?
Measles - Rubeola
113
What virus permanently integrates itself into host DNA, makes DNA from RNA, enters through mucous membrane, and infects T4 helper cells shutting down lymphocytes
HIV - retrovirus
114
What virus causes the common cold, is spread through respiratory droplets and direct contact?
Rhinovirus
115
Goal is to use natural or synthetic drugs developed to destroy infective agents with harming the host's cells
Antibiotic and Antimicrobial Therapy
116
What are the metabolic products of aerobic bacteria and fungi that are fighting for nutrients and space with other microbes?
Antimicrobial drugs;
| examples are pencillium, streptomyces, bacillus, cephalosporium
117
How do antibiotic and antimicrobial drugs work? What is the action of the drug?
```
Inhibit cell wall
Break cell membrane
Inhibit Nucleic Acid Synthesis, structure or function
Inhibit protein synthesis
Block key metabolic pathways
```
118
Different antibiotics can kill different classes of bacteria
Drug spectrum
119
Effective on very small range of microbes; targets specific cell component found only in certain microbes
Narrow spectrum
120
Effective on greatest range of microbes; targets cell components common to most pathogens (ribosomes)
Broad spectrum
121
What is most effective way to kill bacteria?
Disrupt bacterial cell wall
122
What drugs are used to target phospholipids in Gram negative bacteria?
Polymyxins (polysporin, neosporin)
123
What drugs disrupt nucleic acid synthesis?
Antiparasitic (chloroquine, anti-malarial drugs)
124
What drugs inhibit DNA helicases?
Quinolones
125
Ribosomes in prokaryotes differs from eukaryotes. How?
ribosomes are different
126
What drugs block protein synthesis on 30S subunit and cause misreading of mRNA?
aminoglycosides (streptomycin,gentamicin)
127
Drugs acting on prokaryotic ribosomes, can do what?
Damage eukaryotic mitochondria
128
What drugs that inhibit protein synthesis in gram negative rods (found in soil) ?
Aminoglydosides (tobramycin)
129
What drugs block attachment of tRNA on acceptor site to stop synthesis?
Tetracyclines
130
What is problem with tetracycline?
Affects developing teeth and bones
| Don't give to children
131
What is it called when a drug competes with normal substrates for enzyme active sites?
Competitive Inhibition
132
What occurs when the effects of antibiotic combinations are greater than either alone?
Synergistic Effect
| Ex: trimethoprim and sulfamethoxazole (Septra)
133
What drugs interfere with cell wall synthesis?
Beta-lactam antimicrobials
| ex: penicillins
134
What is someone that had untreated strep susceptible of getting?
rheumatic fever (affects heart valves)
135
Who discovered penicillin?
Alexander Fleming in 1929
136
What route was natural penicillin given by?
Injection
| Mold was killed by stomach acid if taken orally
137
What were developed to make oral versions of penicillin or to make a side group less capable of being destroyed by penicillinase?
Semisynthetic penicillins
138
What are the natural penicillins?
G and V (oral)
139
What was penicillin given for?
gram positive: strep, staph and some gram negative: syphilis and meningococci
140
Some strains of bacteria are penicillin resistant and produce enzyme that deactivates it. What are some examples of penicillinase-resistant penicillins?
Methicillin
Nafcillin
Cloxacillin
Floxacillin
141
What is cephalosporin?
Another mold found in a sewer
Kills bacteria cell wall (bactericidal)
Ex: Cephalothin, Cefazolin
142
2nd generation cephalosporins?
Cefaclor
| Cefonacid
143
3rd generation cephalosporins?
Cephalexin
| Ceftriaxone
144
4th generation cephalosporins?
Cefepime
| Must be used sparingly
145
What drugs are cell wall inhibitors that are used in the eye? They are toxic (kill all gut bacteria), but when used topically on eye, are safe
Vancomycin
146
What drugs inhibit cell walls but are not taken orally because very toxic?
Bacitracin
Neomycin
Polymixin
Together are Neosporin
147
What drug inhibits DNA or RNA?
Isoniazid (INH) for TB
148
What drug binds to DNA gyrase to inactivate topoisomerase IV?
Fluoroquinolones
Ex: Nalidixic Acid
take with cranberry juice
149
What are the 5 ophthalmic fluoroquinolones?
```
Ofloxacin
Ciprofloxacin
Levofloxacin
Gatifloxacin (Zymar)
Moxifloxacin (Vigamox)
```
150
What drugs block synthesis of folic acid?
Sulfoamides
151
What drugs are good bacterial static drugs for burns?
silver sulfadiazine
152
What drugs are the most prescribed ocular antibiotics?
Fluoroquinolones
153
What drug blocks peptide bond formation and protein synthesis?
Chloramphenicol
| Not used anymore because it suppresses stem cells from producing RBCs (aplastic anemia)!
154
What drugs work against aerobic gram negative bacilli?
Aminoglycosides
155
What drugs block ribosomes and are used in combination with antiinflammatory agents, have been replaced by fluoroquinolones?
Aminoglycosides
156
What drugs attach to ribosomal 50s subunit, are broad-spectrum and low in toxicity?
Macrolides: Erythromycin
157
What drugs are effective against gram positive bacteria because interfere with assembly of cell wall, are broad-spectrum and toxic
Glycopeptides: Vancomycin (only taken by IV or injection)
