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MSK- MICRO
Musculoskeletal Bacterial Infections
59
Microbiology
Professional
03/05/2012

Additional Microbiology Flashcards

 


 

Cards

Term
Can you name 6 ways that bacteria establish resistance to antibiotics?
Definition
Inhibit uptake, inactivate drug, efflux pump, alter target site, overproduce target site, alter metabolism
Term
How do bacteria avoid the action of Beta Lactams?
Definition
1- Alteration of target sites- as in PRSP- penicillin resistant strep pneumo
2- Alter the drugs access to the target
3- Inactivate the drug
Term
Why do bacteria sometimes overproduce PBP?
Definition
To soak up the drug- there is still enough target site left to do its job
Term
How is resistance established by changing the nature of the PBP?
Definition
Picking up a new form of PBP
The new form has a much lower affinity PBP (drug binding site)
Term
A catalase +, coag +, gram + cocci is most likely?
Definition
Staph Aureus
Term
How do we treat MRSA?
Definition
Vanco
Term
How do we treat MSSA?
Definition
Nafcillin and Oxacillin
Term
What type of bacteria have the ability to restrict access to PBP? Why?
Definition
Gram NEGATIVE RODS- They have an outer membrane that gram + don't have that includes porin proteins that can be made smaller to keep out Beta Lactams
Term
What type of bacteria have porins, why are they special, and what is the role of porins in resistance?
Definition
Gram - Rods
They allow nutrients and drugs into the cell
The cell can make the porins smaller to keep Beta Lactams out
Term
What enzyme inactivates Beta Lactams?
Definition
Beta Lactamase (there are different kinds)
Term
How do we overcome Beta Lactamases?
Definition
Use CLAVALONIC ACID, which inhibits Beta Lactamases and allows the Beta Lactam to do its job
Term
What are 2 outcomes for resistance in gram + bugs?
Definition
Bacteria which drug fails to bind to
Bacteria which acquire Beta Lactamase
Term
What are 3 outcomes for resistance in gram - bugs?
Definition
Altered PBP
Enzymes to inactivate
EXCLUDING DRUG BY SHRINKING PORINS
Term
What gene codes for resistance in MRSA?
Definition
MEC A- makes a different, lower affinity PBP
Term
How does Vanco work?
Definition
It doesn't work on PBP but it DOES inhibit cell wall synthesis
-binds to the D-Ala to prevent cross-linking
Term
How does VAN A work in resistance to Vanco?
Definition
Makes a different NAM using D-Ala AND D-Lactate- Vanco cannot bind to this
Term
What two strains are resistant to Vanco?
Definition
VRE- Vanco Resistant Enterococci
VRSA- Vanco Resistant Staph Aureus
Term
What are 3 sources of infection in osteomyelitis?
Definition
Hematogenous, contiguous, and Trauma/Frax/Surgery
Term
What bug is the primary cause of hematogenous osteomyelitis?
Definition
Staph Aureus
Term
What are you likely to find in a contiguous osteomyelitis infection?
Definition
Gram+ cocci, Gram- rods, anaerobes
MIXED INFECTION
Term
What bug is likely to cause osteomyelitis from fracture, trauma, or surgery?
Definition
Staph Aureus
Term
What are two signs on blood tests that suggest infection/osteomyelitis?
Definition
CBC- Increased WBCs
ESR- Increased Sed Rate
Term
What are 4 options for treatment of osteomyelitis?
Definition
Drainage, Debridement, Surgery, Long Term Antibiotics
MUST TREAT THE SOURCE!!!
Term
What bug is the MOST COMMON cause of osteomyelitis?
Definition
Staph Aureus- gram+ cocci, Grape-like cluster, CATALASE+, COAG+
Term
What bug is the major cause of nosocomial infections, device related infections, and postsurgical complication?
Definition
STAPH AUREUS
Term
What bug is Gram+ cocci found in CHAINS and CATALASE NEGATIVE?
Definition
Strep
Term
What bug contributes greatly to/makes biofilm, and what encases the biofilm?
Definition
Staph Aureus; exopolysaccharide matrix
Term
What do we have to do to treat biofilm?
Definition
PHYSICALLY REMOVE- the sugars in exopolysaccharide make a sticky gel-like substance that drugs and the immune system cannot penetrate
Term
What bug is responsible for osteomyelits and osteochondritis, is highly resistant to antibiotics, makes a biofilm, and is found most often in puncture wounds?
Definition
Pseudomonas Aeruginosa
Term
What bug produces GREEN pigment in wound drainage, has a grapelike odor, and grows on MACCONKEY AGAR?
Definition
Pseudomonas Aeruginosa
Term
Name this bug:
Alginate capsule
Gram Negative Rod
Lactose Negative
Associated with IV drug use?
Definition
Pseudomonas Aeruginosa
Term
Pott disease is caused by:
Definition
Myco Tuberculosis
Term
What is miliary TB?
Definition
Disseminated- spread to spine- osteomyelitis
Term
What bug is acid fast, causes osteomyelitis, and disseminates to the spine?
Definition
TB
Term
Childeren with sickle cell are most likely to get osteomyelitis from what bug?
Definition
Salmonella
Term
What is the triad of symptoms in reactive arthritis?
Definition
Joint inflammation (polyarticular, KNEE)
Conjunctivitis
Urethritis/Cervicitis
Term
A patient had diarrhea 023 days ago. They present to you complaining of painful joints and burning while urinating. You immediately suspect:
Definition
Reactive arthritis (the artist formerly known as "Reiter's Syndrome")
Term
When does reactive arthritis usually present?
Definition
2-4 weeks after primary infection
Term
What are some primary infections that can cause reactive arthritis later on?
Definition
GI: Campy, Salmonella, Shigella, Yersinia
STD: Chlamydia
Term
What marker is associated with reactive arthritis? What population usually gets reactive arthritis?
Definition
HLA-B27;
White males 20-40 years old
Term
How is reactive arthritis diagnosed? What DOESN'T work?
Definition
Genital swab for chlamydia; patient history
You will NOT find bugs in the synovial fluid because the problem is autoimmune
Term
A patient presents to you with a very swollen, seemingly arthritic knee. You aspirate synovial fluid and it is CLOUDY- what does this mean?
Definition
Septic Arthritis- gonococcal OR nongonoccocal
Term
What joints are most often affected by septic arthritis?
Definition
KNEE, HIP, ankle, shoulder, elbow, wrist
Term
What are some important risk factors for septic arthritis?
Definition
History of arthritis (joint already damaged), PROSTHESIS, gonorrhea, trauma, immunosuppression, IV drug users
Term
In septic arthritis, what do we see on blood studies?
Definition
CBC: increased NEUTROPHILS
ESR and CRP are increased due to inflammation
Term
What is the most common cause of septic arthritis in young adults?
Definition
N. Gonorrhoea
Term
What is the role of pili in gonorrhea?
Definition
Attachment
Antigenic Variation
Term
Gram negative diplococci that grow on Thayer Martin Agar must be:
Definition
Gonorrhea (yeah!)
Term
A 24 year old pharmacy student, who has failed at everything else in life, presents to your practice with migratory joint pain and a pustular rash on the extremities. You aspirate and joint and culture the aspirate. What are you likely to see on gram staining?
Definition
COFFEE BEANS
gonnorrhea
Term
What are the symptoms of gonococcemia?
Definition
Fever, MIGRATORY joint pain, suppurative arthritis, pustular rash on the extremities
Term
Describe the rash associated with gonorrhea:
Definition
Pustular rash with RED RING on the EXTREMITIES- no on the head, face, or trunk
Term
What is the primary cause of prosthetic joint infections in the first 3 months after surgery?
Definition
Staph aureus
Term
What is the likely cause of prosthetic joint infections after 3-4 months?
Definition
CoNS- Coagulase Negative Staph
(often Staph Epi)
Term
What is a likely cause of septic arthritis in IV drug users?
Definition
Pseudomonas Aeruginosa
Term
Officer Dwight comes into your primary care practice complaining of joint and bone pain that comes and goes. You gram stain and find nothing. He has a characteristic rash. Did I mention the joint pain comes and goes and is in more than one joint? What do you think he has?
Definition
Lyme Disease- RECURRING POLYARTICULAR ARTHRITIS
Borrelia Burgdorferi
Term
A pharmacy student with gonorrhea has no idea what drug to use to treat it. What do you suggest?
Definition
CEFTRIAXONE
Term
How do we treat septic arthritis?
Definition
Drain the joint
Several Weeks IV of:
Ceftriaxone for Gonnorhea
Nafcillin/Oxacillin for MSSA
Vanco for MRSA
Term
How do we treat septic arthritis of a prosthetic joint?
Definition
REMOVE AND REPLACE+ 6 weeks of antibiotics
Term
If a patient has septic arthritis due to Staph Aureus, what else are they at risk for?
Definition
Toxic Shock Syndrome
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