Bacteria, ABX Master Study Flashcards
What are bacteria and how big are they?
Prokaryotes, no nucleous, no organelles, infectious, may have toxins, .5 - 5 microns.
What are Protazoa?
Eukaryote, nucleated with organelles, infectious no toxins, 15 - 30 microns. Ex: malaria
What are fungi?
Eukaryote, nucleated with organelles, infectious but might have toxins, 5 - 10 microns. Ex: yeast
What are viruses?
Not in a kingdom, have no cells, a parasite of living cells.015-.1 microns. Ex: smallpox
Relative size of bacteria & viruses?
Limit of vision is 40 - 50 microns. WBC ~ 12-14 microns. RBC ~ 8 microns. Bacteria ~ 1 micron. Limit of light microsope magnification = .2 microns. Virus ~ .015 - .1 microns.
An AIDS patient develops extensive pneumonia and dies a week later. A sample of the lung fluid reveals 5-8 micron cells with a nucleus. The appearance of these cells means the organism is?
an unidentified eukaryote
The urine from a patient with pain under the ribs on the right and mild jaundice (yellow skin and eyes) reveals many long thin coiled cells, without a nucleus. These cells are _____, and he has leptospirosis
spirochetes
The sputum from a patient with difficulty breathing, a fever, fluid in the lungs seen on chest X-ray, and chest pain, reveals many round purple cells in pairs. The bacteria is a
Strep pneumoniae
A vaginal swab from a patient complaining of vaginal burning, itching, and a creamy discharge reveals many large (8-10 micron) oval cells with obvious nuclei. So you know
It can’t be bacteria, it could be yeast, it’s not HIV.
The swab of the throat of a college student with moderate swelling of obviously red tonsils, and many red spots on the soft tissue at the roof of the mouth, and little white abscesses on the tonsils, reveals many round purple cells in chains. A reasonable cause of this might be:
Streptococcus pyogenes
A 50 year old chain-smoking, alcoholic, diabetic, obese male develops an acute pneumonia. The cultures of sputum grow colonies of bacilli and the cells stain pink. They could be
Could be E.coli, klebsiella, Hemophilus, and Leginella
The Gram stained CSF from a [premature] neonatal patient with meningitis reveals small round purple cells in chains. The same bacteria was cultured from the cerebral-spinal fluid.
A reasonable cause of this infection might be
Group B Streptococcus
The amniotic fluid from a pregnant patient who just delivered a still-born infant reveals purple rods. You know it can’t be
Group B Streptococcus
The cervical swab of an 18 year old college student reveals round pink cells in groups of two. A reasonable cause of this might be _____, and she’s wrong when she asks ““it’s just a UTI, right?
Neisseria gonorrhea
The fluid draining from the ruptured eardrum of a 4 year old child reveals small, unpaired, oval-ish
pink cells. Being neither rods, nor spheres, they’re best described as
G- coccobacillus
An college student is seen in the clinic for a 2-month cough, weight loss, and night sweats. The sputum is thick, and sometimes tinged with blood. His sputum is stained a variety of ways, and one is designated ““AFB+””. What disease does he have (probably). ?
tuberculosis
The large blackened ulcer on the forearm of a soldier serving in Bloatedgoatistan reveals large, purple, square-ended rods in chains. The Gram’s stain is consistent with
Bacillus anthracis
A teenager complains of very stiff neck, fever, photosensitivity, vomiting and severe headache.
The CSF reveals a small number of white blood cells, but no other obvious cells.
Assume any cellular infectious agents would be visible. Which of these is incorrect?
the infection is probably due to bacteria less that .2 µM in size
An elderly patient with a post-surgical infection develops pus around the wound site and inflammation. The culture reveals round, G+ cocci in clusters. Which of these is correct?
he has a staph infection
The urine from a female complaining of burning, cloudy urine reveals pink rods. It’s likely to be
E. coli
The genital ulcer of a young adult is Gram stained, but no bacteria are visible. A silver stain reveals
numerous spirochetes, and a fluorescent antibody stain for Treponema is positive. She has?
syphilis
A college-aged female develops persistent vaginal irritation, and a greenish vaginal discharge.
Microscopic examination of a swabbed sample reveals pear shaped cells ~7x10 uM with a nucleus
and Trichomonas protozoa are presumptively identified . Which of the following is incorrect?
the infection could be treated with penicillin
A spherical bacteria that occur in clusters of 4 [and there are many G+ skin bacteria like this),
could be called which of these? (the names are fake!)
Quadracoccus
A rod-shaped bacteria that is multiply curved [but is not a spirochete] causes ulcers; it is?
Helicobacter
What is the cellular arrangement of Streptobacillus, the agent of ““rat-bite fever””? (a real disease)?
bacilli in chains
Bacteria isolated from a skin abscess are round, stain purple, and in clusters. It is?
Staphylococcus
A bacteria associated with an outbreak of ““food poisoning”” is rod-shaped, stains purple,
and does not form spores. Which one of these is it ? (all are associated with ““food poisoning””)
Listeria monocytogenes
Spore-forming anaerobes are found only the genus ___
Clostridium
An sample of food, associated with an outbreak of severe vomiting, grows a rod-shaped bacteria that forms spores, is aerobic, and stains purple. Which of these is it?
Bacillus cereus
A rod-shaped, pink-staining, bacteria isolated from a patient with dysentery is most likely to be…?
Shigella
Which of these is a reason that a Gram’s stain wouldn’t give a useful result?
Mycobacteria have thick waxy lipid layer
There are bacteria, called Buchnera, that grow inside the cells of some insects. They cannot grow on any agar media, and do not have cell walls. This site of growth resembles which bacteria? [Surprisingly, the aphids cannot live without them, as they supply essential amino acids to the insect].
Rickettsia
A patient with rapidly progressive paralysis is diagnosed with botulism.
What would the analysis of the suspected food reveal?
G+ rods
A patient is diagnosed with Chlamydia. What type of stain would allow the most specific
identification of the infectious agent?
flourescent Ab’s to Chlamydia
A unconscious patient with a grossly swollen lymph node in the armpit is brought to the Flagstaff hospital. He has a hemorrhagic rash and gangrenous fingers and toes. A lymph node sample obtained with a large needle biopsy reveals small G- rods. Wayson’s stain shows ““bi-polar staining””
A smear of the biopsy gives a positive result with anti-Yersina pestis fluorescent antibodies. The patient has:
bubonic plague
What is the difference between G + and G- between wall thickness?
G+ have 7-10 layer walls and G- have 1 layer.
What is the difference between G + and G- between membrane and location?
G+ have an inner membrane and G- have an outer membrane & an inner membrane
What characteristics do bacillus have?
G+ Aerobic rods with spores
What characteristics do clostridium have?
G+ Anaerobic rods with spores
Which bacteria cannot be gram stained?
Mycobacteria- too waxy outer layer, spirochetes - too thin, Rickettsia & Chlamydia obligate intracellular, and Mucoplasm Pneumonia - no cell wall.
What is the staining method for mycobacteria?
Acid Fast
What is a flourescent antibody and how specific is it?
The addition of a flourescent dye to an antibody, it is VERY specific.
What do Pilli do?
Attachement and/ or gene transfer
What do Flagella do?
Motility
What is capsule?
Protection against phagocytosis (antiphagocytic)
What are bacteial cell walls made of & what does it do?
Peptideoglycan structural integrity
What species have spores and how stable are they?
G+ aerobic and anerobic rods have spores Bacillus & Clostridium. They are very stable can withstand heat, radiation, and ehydration
Which of these bacterial structures can facilitate the penetration of the mucosal layer of the colon?
flagella
Sterilazation
Everything including the spores ae dead
Disinfectant
Almost everything except the spores are dead (even some are dead)
Sanitation
All the obvious stuff that would allow microbes to grow has been cleaned up.
What is pasteurization for & what does it kill?
Heating to 160 F does not kill spores
What is Auotoclaving, what does it kill, whats differnt from boiling?
Dry heat to 500 F, removes water so nothing can grow, kills everything sterilizes. Dry heat only works for things that wont melt wet heat can be used for food etc.
What are skin disinfectants & do they sterilize?
Iodine, alcohol, no they do not sterilize
Which of these is the common method to sterilize plastic medical supplies?
gamma radiation
Which of these is incorrect regarding bacterial cell walls?
G- cells have no cell wall - that’s why they’re ““negative””
Petri dishes that have been soaked in alcohol (prior to pouring fresh media) are:
not sterile
An autoclave is used to sterilize liquid microbiological growth media because it can
kill growing vegetative bacteria, protozoa, and fungi, inactivate non-growing cysts of protozoa and fungi spores, inactivate viruses
Which of these sanitation agents is also a very good disinfection agent?
amine detergents
The primary function of peptidoglycan is
to resist the osmotic pressure of the cytoplasm
Which of these are routinely sterilized by chlorination?
swimming pools
The ‘capsule’ of any bacteria is
a unique polysaccharide for each strain