Bacterial Physiology, Human Disease, and Antibiotics Flashcards Preview

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Flashcards in Bacterial Physiology, Human Disease, and Antibiotics Deck (79)
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The patient In case 5 was an 18 year old. How would that be different today?

Majority of patients with menstrual TSS will be in the 11-13 y.o. range


What were the major presenting symptoms of the patient in case 5? (5)

Progressively Increasing fever
Dizziness (hypotension)
Macular erythroderma on abdomen and face


By 13 y.o. 80% of people will have antibodies to TSST1 and 20% won't. Who is suceptible to the menstrual TSS, people with or without the antibody? Is there a way to help these people?

People without the antibody developed
IVIG when infected, or monthly IM injections of antigen


Why do tampons make women more succeptible to menstrual TSS?

The vagina is usually anaerobic, tampons trap oxygen, and the TSS1 toxin requires oxygen to be made


What is the significance of the vaginal yellow discharge in case 5?

Indicates that the colonizing bacteria was likely staph aureus


Menstrual TSS is associated with what 5 cardinal signs?

Fever (Over 102)
Hypotension (less than 90/X)
Red rash (resembles sunburn)
Peeling skin (palms and soles)
Abnormal multiorgan changes (e.g. liver, platelets, mucous membranes)


What were the 2 drugs used to treat the patient in case 5? What 2 drugs would be used currently?

Nafcillin and Clindamyacin
Now, Use Vanco and Rifampin


What were the 2 candidate diagnoses in case 5?

Staphylococcus aureus toxic shock syndrome (TSS)
Group A streptococcal (Streptococcus pyogenes) TSS


Regarding the lab results, what chemistry values were elevated in case 5? What was low?

ALT AST CPK Creatinine BUN


What was the infecting organism in case 5 that caused the menstrual TSS?

MSSA staph aureus producing superantigen TSS1


What is the significance of a left shift of WBCs?

Shows that the bone marrow was producing new WBCs, and some immature cells were being pushed out


What are the 2 organisms that can cause menstrual TSS? What is a major distinction between the 2?

Staph aureus and strep pyogenes (group A strep)
Staph A menstrual TSS will show staph limited to the throat and vagina, while Strep will most likely invade the bloodstream


What are band neutrophils and when would you expect to see them elevated?

Immature neutrophils, elevated during infection


What are some CNS findings associated with menstrual TSS?

Confusion and combativeness, without any focal neurological findings


Regarding drug treatment, what does it mean that the cultured organisms was MSSA? What is the antibiotic of choice for staphyloccocal TSS?

You can treat with penicillins and cephalosporins


Why is renal failure especially bad in menstrual TSS?

Because the toxin TSST-1 is cleared by the kidneys


Why is clindamycin a good drug for the treatment of TSS?

Clindamycin is a protein synthesis inhibitor, and can prevent the manufacture of toxin even at concentrations below its antimicrobial range


While removal of The tampon (and trapped O2) helped in this case of menstrual TSS, in what case of menstrual TSS would removing the tampon not have helped?

If the causative agent was streptococcus pyogenes (group A strep), it would not have helped. Strep is an aerotolerant anaerobe


Regarding bacterial growth, what is the lag phase? log phase? stationary phase? Death phase?

Lag - enzymes being made to prepare for growth
Log - Exponential growth phase
Stationary - Nutrients used up, no more growth
Death - Bacteria are dying because of their toxic waste


What are The 2 significant types of bacteria regarding the death phase and how are they different?

Obligate fermenters die fast (hours) due to the presence of ROS, acid and H2O2 in the medium
Aerobes / oxidative bacteria can live for longer because of their metabolic enzymes


What phase of bacterial growth is associated with toxin production? How does this happen?

The post exponential phase, bacteria signal a quorum are present, initiating the production of exotoxin


Where is the lag phase longer, in people or in culture media?

In media, people have defense systems bacteria need to over come


What is an obligate aerobe? What enzymes does it have? What is the significance of these enzymes? What are the 2 examples provided?

Requires O2 to grow
SOD and catalase - convert superoxide amd acid eventually to water and oxygen
Bacillus and mycobacterium


What is a facultative anaerobe? What 2 enzymes do they have? What are the 2 examples provided?

Can grow in the presence (oxidative) or absence (fermentative) of oxygen
SOD and catalase
Staphylococcus and Escherichia


What is an aerotolerant anaerobe? What enzyme(s) do they have? What is the example provided?

Can grow in the presence of O2, but will still ferment
SOD (no catalase)


What is an obligate anaerobe? What are the 2 examples provided?

Can only grow in the absence of O2
No catalase or SOD
Clostridium. Tetani


What are microaerophiles?

Aerobes that prefer a small amount of oxygen
Neisseria and Borella


What is a major anaerobic component of gut bacteria that that causes disease? Under what conditions will it cause disease?

If the barrier is compromised


A bacteria described as gram positive cocci, clusters, catalase and coagulase positive is likely _

Staph aureus


A bacteria described as gram positive cocci, chains, SOD positive but no catalase is likely _