Unit 2 Microbiology

Front 1

Transduction

Back 1

A virus enters another cell via a bacteriophage andteria's RNA polymerase for transcription. The cell filles with new phages and lyses. What is the genetic transferreplication mechanism just described?

Front 2

Transformation

Back 2

A recipient bacterium takes up naked DNA fragments from its recently lysed neighbor and incorporates the fragments into its own genome. What is the genetic transfer mechanism just described?

Front 3

Transduction (Generalized or temperate - viral waits dormant)

Back 3

A bacteriophage injects DNA into a cell and after it hijacks the host cell RNA polymerase and replications, it accidently incorporates some of the host cell DNA into its own viral g

Front 4

Conjugation

Back 4

One bacterium has an F+ plasmid, uses a sex plius to transfer genetic material to an F- cell, making it F+. What genetic transfer mechanism is this?

Front 5

Catalase Test; testing for gram positive cocci

Mainly test for staphylococcus. Staph make catalase because they have more "staff."

Back 5

You perform a test in which you rub a wire loop across a colony of cocci and mix it on a slide with H202. If bubbles appear, this indicates that H202 is being broken down into oxygen and bubblbes. What is the significance of this test and what type of bacteria is it testing for?

Front 6

S. aureus is coagulase positive (of the 3 pathogenic staph species, ONLY s. aureus is coagulase posiive!); this pathogen elaborates the enzyme coagulase which activates prothrombin, causing blood to clot.

Back 6

You perform a coagulase test to differentiate between staphylococcus aureus and epidermidis. What is the likely outcome?

Front 7

S. epidermidis

Back 7

A patient who has recently undergone surgey AND has a prosthetic leg begins to show symptoms of osteomyelitis in the good leg. You perform a catalase test that comes back positive and a coagulase test that comes back negative. What is the most likely causative orgainsm?

Front 8

Hematogenously (via the blood/circulation)

Back 8

A 12 year old patient presents osteomyelitis symptoms including local warmth and swollen tissue over the bone as well as systemic fever and shakes. Labs return gram positive cocci that are catalase and coagluse positive. By what mechanism did this bacteria spread to the bone?

Front 9

The organism is likely methicillin resistant staphylococcus aureus (MRSA). It has a the mecA gene which inhibits the ring like structure of penicillin like antibiotics from attacking the transpeptidases in the cell wall.

Back 9

During a hospital stay, a patient develops a gram positive bacterial infection. Use of broad spectrum antibiotics and penicillin fails to halt the infection. As a last resort, you throw methiciillin at the infection, which also fails. Genetically, how is the bacteria resisting your pharmacological interventions?

Front 10

Optochin sensitivity test; a disc impregnanted with optochin is placed on an agar dish, where s. pneumoniae is optochin sensitive, s. viridians will continue to grow.

"VRPS"

"Pneumococcus is to Parents what group B streptococcus is to Babies"

Back 10

An adult patient presents with severe bacterial pneumonia and meningitis. Under the microscope you see "strips" of gram positive cocci in chains. What test can you perform to determine whether this is caused by s. pneumoniae or s. viridians, considering both are alpha-hemolytic?

Front 11

Bacitracin;

B-BRAS
Bacitracin - group B strep are Resistant; group A strep are Sensitive

Back 11

You suspect a meningitis and pneumonia streptococci infection in a baby. You know that Group B streptococci commonly infect neonates during delivery but you want to make SURE you're not dealing with group A strep (s. pyogenes). What test do you perform?

Front 12

The metaphysis is commonest site of osteomyelitis, because-

· Is highly vascular

· Has a hair pin like arrangement of capillaries

· Has sluggish blood flow

· has relatively fewer phagocytic cells than the physis or diaphysis, allowing infection to occur more easily in this area

· thin cortex

Back 12

You determine that a patient has osteomyelitis at the metaphysis of the femur. Why is this location more susceptible to hematogenous bactermic infection than other locations?

Front 13

Histoplasma capsulatum

"Fungi pilot fires a rocket that HITS the Mississippi river"

Back 13

A patient inhales fungal spores which takes root in the lung and results with pneumonia (inflammation of the lung) that may disseminate into the bones or joints. This patient has lived in the Mississippi and Ohio river valleys their whole life. What is the likely infective agent?

Front 14

Coccidioides immitis

"San Joaquin Phoenix COCKS his pistol in the old SOUTHWEST"

Back 14

A patient inhales fungal spores which takes root in the lung and results with pneumonia (inflammation of the lung) that may be at risk for disseminating into the bones or joints. This patient loves everything Southwest and has lived in Arizona, New Mexico, and Southern California before finally settling down in El Paso. What is the likely infective agent?

Front 15

Blastomyces dermatitidis

"Blaso Buds"
"Fungi pilot fires a rocket that BLASTS everything east of the Missisippi"

Back 15

A patient inhales fungal spores which takes root in the lung and results with pneumonia (inflammation of the lung) that may be at risk for dissemination into the bone or joints. This patient has lived in states east of the Missisippi because he just loves the Atlantic ocean along the EAST COAST. What is the likely infective agent?

Front 16

Paracoccidioides Brasiliensis

"Paracoccidio Parasails with the captain's wheel all the way to Latin America"

Back 16

A patient who recently immigrated from latin America presents with a history of pneumonia and is now experiencing joint pain. You suspect a certain budding yeast with "captain's wheel" formation is the culprit.

Front 17

Fifths Disease caused by Parvovirus (Parvoviridae)

PARvovirus is the smallest icosahedral virus and has a single strand of DNA. It is the ONLY single stranded linear DNA virus.

Simple as a PAR ONE golf course at the SINGLE DOUBLE HELIX country club.

Back 17

A child presents with red, erythemous cheeks. While you initially suspect child abuse, you decide against it when you remember back to your Unit 2 Microbio flashcards. The patient also has a fever.

Front 18

Gonococcal related septic arthritis

Back 18

A young, sexually active patient presents with acute onset of fever and pain and swelling in two joints. You aspirate the synovial fluid, which is cloudy. A gram stain reveals negative diplococci WITHIN the white blood cells. This confirms your suspicions.

Front 19

Sporothrix schenkii; "rose gardeners disease"

Back 19

A patient who loves gardening presents with a local pustule and ulcer with nodules along draining lymphatics. You take a sample of the pus and view cigar shaped budding yeast visible in pus. The patient mentions they recently stuck themselves pretty bad on a rose thorn. What is the likely causative agent?

Front 20

Blastomyces dermatitis
Coccidioides immitis
Paracoccidiodes brasiliensis

TB, Lyme Disease

Back 20

What three fungal diseases can cause chronic infection arthritis? What are two other common causes of chronic infection arthritis?

Front 21

1. Grow a bacterial lawn on a plate
2. Place antibiotic loaded discs upon the lawn
3. Measure the "zone of inhibition" that is cause by the antibiotic destroying the bacteria

Larger zones of inhibition correlate with smaller MIC (because the antibiotic is very potent)

Back 21

Describe how to use the Kirby Bauer test to determine MIC

Front 22

When you stain with carbofuschin the mycolic acid binds the dye so tightly that the decolorizer can't wash it off. Thus any mycobacterium present, such as TB, shows up red on a blue background (after adding the methylene blue counterstain)

Back 22

You suspect a mycobacterium infection but want to confirm with an acid fast stain. Why is an acid fast stain useful?

Front 23

TB, Borellia, HSV, Bartolenna, Cryptosporidium, Chalmydia, Malaria, Filarasis, Trichomonas vaginalis

Back 23

What eight organisms are commonly found with flourescent labeling?

Front 24

Poliovirus; uses CD155 receptor

Icosehahderal, positive, single stranded RNA

Back 24

A patient presents with a sore throat and abdominal pain as well as LMN signs (muscle weakness, atrophy, fasciculations, hyporeflexia) in his legs. In taking a stool stample, what is the viral morphology you are expecting causing the suspected infectious myelitis?

Front 25

HTLV related tropical spastic parapesis

Host immune system mounts an antigen specific response to HTLV - Cytotoxic lymphocytes release cytokines which makes the BBB more permeable to cytokine transendothelial migration. Once cytokines are in the CNS, there is bystander cell demyelination and progressive myelopathy (pathology of the spinal cord)

Results in UMN signs

Back 25

A patient presents with spastic parapesis of the legs. He is notable for having lived in Africa and the Caribbean 20-30 years ago. What is the mechanism behind the suspected disease?

Front 26

West Nile Virus - icosahedral, enveloped single stranded RNA



Virus infects neurons in the anterior horn of the spinal cord -> can cause encephalitis, nonpoliomyelitis or meningitis.

Back 26

A patient presents with a mild flu like illness, muscle weakness and LMN signs. History is notable for a camping trip sometime in the past few weeks where the patient went fly fishing.

Front 27

Bacterial Meningitis

Back 27

A patient presents suspect for meningitis. You perform a LP and obtain cloudy CSF, with a high WBC over 1000 WBC/mm3, neutrophil predominance, increased protein to 80-500 mg/dL, and decreased glucose to <40 mg/dL. Is it viral or bacterial?

Front 28

Viral Meningitis

Back 28

A patient presents with symptoms of meningitis. You perform a LP and labs show clear CSF, a lowered WBC count (100-500), predominantly mononuclear cells, slightly elevated protein (30-100 mg/dL), and normal glucose. Is this viral or bacterial?

Front 29

Neisseria meningitidis (cocci pairs/diplococci)

Ferments

Back 29

A patient presents with the meningitis triad (nuchal rigidity, acute fever, altered mental status, vomiting). Labs return a gram negative cocci that is catalase positive, oxidase positive, and ferments maltose. What is the likely organism?

Front 30

Gram stain (-) reveals cocci
Maltose reveals a NONFERMENTER

Neisseria Gonorrhoeae (vs n. meningitidis which is a fermenter)

Back 30

A sexually promiscuous with a history of VD presents with joint pain. You suspect septic arthritis due to a certain STD. What lab algorithm can you run to distinguish/confirm this bacteria?

Front 31

Haemophilus influenzae

Generally aerobic, catalase +, oxidase +

It will grow next to s. aureus due to s. aureus production of Factor V and Factor X required for its growth. (Satellite phenomenon)

Back 31

A gram stain in a patient that presents with meningitis like symptoms shows gram negative 'coccoid' rods. What are some characteristic labs of this organism?

Front 32

s. aureus produces factor V and factor X which are required for the growth of haemophilus influezae

Back 32

You culture s. aureus and put another gram negative coccioid rod organism next to it that grows in concert - this is called the satellite phenomenon. What is happening?

Front 33

Listeria Monocytogenes

This organism can use ACTIN ROCKETS by which they move from cell to cell - only gram positive bacteria with an endotoxin.

Back 33

A patient presents with meningitis symptoms. Patient is notable for eating mad milk and cheese due to a dairy fetish. Labs reveal intracellular gram positive rods (baciill). What is the likely suspect organism?

Front 34

Arbovirus (West Nile)

Back 34

A patient from Uganda presents with nuchal rigidity, fever, vomiting, and confusion. Labs reveal ENVELOPED, icosahdral, +ssRNA. What is the likely viral causative organism?

Front 35

NO ENVELOPE, +ssRNA, icosahedral

Picorniviridae!

Back 35

A newborn presents with fever and a stiff neck. What's the morphology of the virus you expect to find in the labs?

Front 36

Enveloped, HELICAL, segmented -ssRNA

Back 36

A patient with a history of parotid swelling presents with headache, fever, vomiting and confusion. Despite the lack of nuchal rigidity, you suspect meningitis. What is the expected viral morphology from the labs?

Front 37

Encephalitis

Back 37

A patient presents with decreased mental status and meningeal signs. Diagnosis?

Front 38

Meningitis

Back 38

A patient shows signs of systemic infection (fever, vomiting) along with signs of meningeal irritation (headache, photophobia, fever, confusion, irritability, stiff neck). Diagnosis?

Front 39

Brain Abscess

Back 39

A patient MRI shows a focal cerebritis (inflammation of the brain) which has developed into a collection of pus surrounded by a vascularized capsule. Diagnosis?

Front 40

Cerebritis

Back 40

A patient MRI reveals that a bacteria has caused clear damage to an area of brain tissue. Diagnosis?

Front 41

Varicella Zoster infection

Back 41

A patient presents with meningeal symptoms and a rash. Diagnosis?

Front 42

Epstein-Barr infection

Back 42

A patient presents with pharyngitis, lymphadenopathy and splenomegaly as well as meningeal symptoms. Diagnosis?

Front 43

India Ink and Latex Agglutination for Cryptococcus Neoformans

Spherical yeast with THICK CAPSULE

Back 43

A prominent professor of ornithology presents with a chief complaint of a bad cough a few weeks prior. He has a history of AIDS (immunosuppression) and abnormal mental status. You suspect chronic meningitis. What lab should you use to identify the suspected agent?

Front 44

Borrelia burgdorferi (Lyme disease)

Back 44

A patient presents with third nerve palsy and meningeal symptoms. What is your highest suspected causative agent?

Front 45

Cryptococcus neoformans

Most common cause of fungal meningitis

Back 45

A patient presents with meningeal symptoms. The patient complains of a bad cough a few weeks prior. The patient is a avid bird watcher (lamest). You run an india ink culture with is positive for yeast with "halos" (capsule). You also run a latex agglutination test. What orgainsm are you looking at?