question
What relationship is beneficial to both host & bacteria?
answer
Mutualistic or co-dependent
question
What relationship is beneficial to one organism, neutral to other?
answer
Commensal
question
What relationship is beneficial to one, damaging to other?
answer
Parasitic
question
What term is used to describe colonization for a short period of time?
answer
Transient Colonization
question
Term used for microbes that cause disease?
answer
Pathogens
question
Term used for the process by which microbe causes disease?
answer
Pathogenesis
question
Term used for microbes that always cause disease?
answer
Strict pathogens (plasmodium)
question
Term used for microbes that only cause diseases when something is out of the ordinary?
answer
Opportunistic Pathogens
question
What situations do we see opportunistic pathogens?
answer
In normally sterile environments (post-op)
Microbiota disrupted (antibiotics)
immunocompromised (AIDS, CF)
Microbiota disrupted (antibiotics)
immunocompromised (AIDS, CF)
question
Long term antibiotic use associated especially with what bug?
answer
Clostridium difficile
question
What are the steps in the infectious cycle?
answer
Adhesion
Colonization
Invasion
Dissemination/Replication
Transmission
Colonization
Invasion
Dissemination/Replication
Transmission
question
Why are adhesins good drug targets?
answer
They are exposed surface molecules
question
What are 3 examples of processes/products that aid a pathogen in dissemination/systemic infection?
answer
Tissue/Cell Invasion, Degradative Enzymes, Toxins
question
How do bacteria get inside of cells?
answer
endocytosis or phagocytosis
question
What type of bacteria may invade host cells but can replicate outside?
answer
Facultative intracellular
(N. Gonorrhea)
(N. Gonorrhea)
question
What type of bacteria must replicate inside host cells?
answer
Obligate Intracellular Pathogens
(Trypanasoma Cruzi)
(Trypanasoma Cruzi)
question
What type of bacteria always remain outside host cells?
answer
Extracellular Pathogens
(Acinetobacter, Trypanosoma brucei)
(Acinetobacter, Trypanosoma brucei)
question
What is the first and last step of the infectious cycle through a particular host?
answer
Transmission
question
What type of transmission travels from parent to offspring?
answer
Vertical Transmission
question
What are the 4 types of vertical transmission?
answer
Germline (DNA - retroviruses)
Prenatal (transplacental - CMV)
Perinatal (during birth - HepB)
Postnatal (through milk/contact)
Prenatal (transplacental - CMV)
Perinatal (during birth - HepB)
Postnatal (through milk/contact)
question
What is the most common direction of transmission?
answer
Horizontal Transmission
question
What are some common sources of horizontal transmission?
answer
Respiratory, GI, UG, Oropharynx, Blood, arthropods, zoonoses (birds & other mammals), Environment
question
What is the most common method of respiratory transmission?
answer
Cough/Sneeze
question
What is the term used to describe horizontal transmission through an inanimate object?
answer
Fomite
(ex. doorknob)
(ex. doorknob)
question
What is the difference b/w biological and mechanical vectors?
answer
biological when replication occurs inside vector (tick, flea lice)
mechanical when passive (just on the bug)
mechanical when passive (just on the bug)
question
What are some outcomes of infection?
answer
Resolution & Recovery
Persistence (HSV)
Autoimmune
Progression (necrotizing fascitis)
Persistence (HSV)
Autoimmune
Progression (necrotizing fascitis)
question
What is the term used to describe the minimum amount of organisms to cause disease in half of an exposed population?
answer
ID50
(Infectious Dose)
(Infectious Dose)
question
How are disease severity & prevalance related to ID50?
answer
trick question...
not related
not related
question
What % of dry weight are microbes?
answer
10%
question
Bacteria produce what beneficial products?
answer
Folic acid, Vit K, constant low-level stimulation of immune system (anti-cancer benefit?)
question
How does the natural flora physically prevent establishment of other microbes?
answer
Occupy binding sites and receptors (prevent adhesion)
Keep nutrients low
Produce waste the discourage other bacteria
Maintain an acid pH
Keep nutrients low
Produce waste the discourage other bacteria
Maintain an acid pH
question
Skin is a hostile environment; what tends to live here?
answer
Osmotolerant organisms, mostly Gram-positive
(Staph, Strep, Coryne, Priopionibacterium, Micrococcus)
(non gram(+): candida, malassezia, acinetobacter)
C. Perfringes on 20% of people
(Staph, Strep, Coryne, Priopionibacterium, Micrococcus)
(non gram(+): candida, malassezia, acinetobacter)
C. Perfringes on 20% of people
question
What is often found at moist sites on skin?
answer
Candida and Malassezia
(fungi)
(fungi)
question
What bacteria colonize the surface of the eye?
answer
Coagulase-negative staphylococci
question
What bacteria colonize the conjunctiva?
answer
S. epi
S. aureus
S. aureus
question
What bacteria cause disease in the eye?
answer
S. Pneumoniae, S. aureus, H. influenzae, N. gonorrhea, C. trachomatis, P. aeruginosa, B. cereus
question
What does the mouth have 10x more of?
answer
10x more anaerobes
than aerobes
than aerobes
question
What bacteria causes dental caries and can enter blood after surgery and colonize heart valves, leading to infective endocarditis?
answer
Streptococcus mutans
question
In the upper respiratory tract are there more aerobes or anaerobes? Which in particular?
answer
10-100x more anaerobes
Streptococcus pyogenes, S. Pneumonia, S. aureus, N. meningitidis, H. influenza
also candida (thrush); entamoeba & trichomonas
Streptococcus pyogenes, S. Pneumonia, S. aureus, N. meningitidis, H. influenza
also candida (thrush); entamoeba & trichomonas
question
What are the usual suspects for bacterial sinusitis and otitis media in children?
answer
S. pneumonia
H. influenza
M. catarrhalis
H. influenza
M. catarrhalis
question
What are some bacterial causes of acute lower respiratory disease?
answer
S. pneumoniae
S. aureus
Enterobacteriaceae (Klebsiella)
S. aureus
Enterobacteriaceae (Klebsiella)
question
What are the normal bacteria in the ear?
answer
coagulase-negative staph
Also: S. pneumoniae, Pseudomonas aeruginosa, Enterobacteriaceae
Also: S. pneumoniae, Pseudomonas aeruginosa, Enterobacteriaceae
question
What are most esophageal infections caused by?
answer
HSV & CMV (tends to be transient locale)
question
What are some organisms found in stomach?
answer
Lactobacillus
Streptococcus
Helicobacter Pylori (G- spiral, microaerophile, indicated in gastric cancer)
Streptococcus
Helicobacter Pylori (G- spiral, microaerophile, indicated in gastric cancer)
question
What are the bacteria in the small intestine?
answer
Peptostreptococcus
Porphyromonas
Prevotella
Porphyromonas
Prevotella
question
What are some bacterial causes of gastroenteritis?
answer
Salmonella
Campylobacter
Campylobacter
question
What are the bacteria in the large intestines?
answer
Bifidobaceria
Eubacteria
Baceroides
Enterococcus (nosicomial problems)
Enterobacteria
E. coli
Eubacteria
Baceroides
Enterococcus (nosicomial problems)
Enterobacteria
E. coli
question
What is the most common anaerobe causing intra-abdominal disease?
answer
Baceroides fragilis
question
What are some opportunistic bacteria in the large intestines that can proliferate w/ antibiotic tx?
answer
Enterococcus, Pseudomonas, fungi
Clostridium difficile
Enteric pathogens such as shigella, Entameba histolytica
Clostridium difficile
Enteric pathogens such as shigella, Entameba histolytica
question
What are some normal colonizers in the urethra?
answer
Avirulent stable: Lactobacillus, Streptococcus, coagulase-negative staph
Transient: Enterococcus, Enterobacteriaceae, Candida
Transient: Enterococcus, Enterobacteriaceae, Candida
question
What are some infection causing bacteria of the urethra?
answer
N. gonorrhea, Chlamydia trachomatis
(always significant when isolated)
(always significant when isolated)
question
What are some normal vaginal bacteria?
answer
@ birth: lactobacilli
@ 6 weeks add in staph & strep & Entero
@ puberty: lactobacilli, coagulase-neg staph, strept, eterococcus, gardnerella, mycoplasma, ureaplasma, candida
@ 6 weeks add in staph & strep & Entero
@ puberty: lactobacilli, coagulase-neg staph, strept, eterococcus, gardnerella, mycoplasma, ureaplasma, candida
question
What are some causes of vaginitis?
answer
N. gonorrhoeaea
Trichomonas vaginalis
Candida albicans/glabrata
Trichomonas vaginalis
Candida albicans/glabrata
question
What causes persistent vaginal infections?
answer
HSV, HPV
question
What bacteria cause cervicitis?
answer
N. gonorrhoeaea
Clamydia trachomatis
Actinomyces
Clamydia trachomatis
Actinomyces
question
You are treating a woman w/ long-term antibiotics when she presents w/ cottage-cheese-like vaginal growth. What is the most likely causative agent of infection?
answer
Candida albicans
question
What is the primary effect of lactobacilli in adult vagina?
answer
Maintain acidic environment
question
What is the predominant species that colonizes human skin?
answer
S. epidermidis