UAMS P2 - PCol 2 Exam 4 SG

Gram-Positive Bacteria:

Stains:

Peptidoglycan Layer:

Outer Membrane:

Lipopolysaccharides:

Porin Proteins:

Stains: Purple

Peptidoglycan Layer: Thick

Outer Membrane: Absent

Lipopolysaccharides: Absent

Porin Proteins: Absent

Gram-Negative Bacteria:

Stains:

Peptidoglycan Layer:

Outer Membrane:

Lipopolysaccharides:

Porin Proteins:

Stains: Reddish Pink

Peptidoglycan Layer: Thin

Outer Membrane: Present

Lipopolysaccharides: Present

Porin Proteins: Present

T/F: Anaerobe Bacteria can be either Gram + or Gram -

True

Staphylococcus are catalase _____________

positive

Streptococcus are catalase _____________

Negative

Enterococcus are catalase _____________

Negative

Gram-Positive Cocci

Staphylococcus, Streptococcus, Enterococcus

Coagulase Positive Staphylococcus

Staph. Aureus:

- MSSA

- MRSA

- VISA

- VRSA

coagulase Negative Staphyllococcus

Staph. epidermidis:

- MSSE

- MRSE

Staph. saprophyticus,

Staph. lugdunensis,

Staph. schleiferi,

Staph. hominis,

Staph. capitis,

Staph. warneri,

Staph. haemolyticus

Which Staph aureus is sensitive to antistaphylococcal PCNs?

MSSA (Rest are almost always resistant)

VISA has MIC

4-8

VRSA has MIC

>= 16

Staph. aureus can cause

Cellulitis,

abscesses,

endocarditis,

osteomyelitis,

food poisoning,

toxic shock syndrome,

hospital-acquired infections

Staph. epidermidis can cause

endocarditis, line infections

Staph. saprophyticus can cause

UTI

Streptococcus Hemolysis Classes

alpha

- partial lysis

beta

- complete lysis

gamma

- no lysis

Streptococcus alpha hemolytic:

strep. pneumoniae, Viridans Strep

Streptococcus beta hemolytic:

Group A: S. pyogenes

Group B: S. agalactiae

Group D: S. bovis

Streptococcus gamma hemolytic:

Enterococcus (faecalis, faecium)

Strep pneumoniae can cause

Pneumonia, meningitis, acute sinusitis

Strep pyogenes can cause

soft tissue infections (cellulitis), pharyngitis, rheumatic fever

Viridans Streptococcus can cause

endocarditis

Strep. agalactiae can cause

neonatal meningitis

Enterococcus faecalis is vacomycin _________________

sensitive

Enterococcus faecium is vacomycin _________________

resistant

Enterococcus species can cause

Endocarditis,

UTI,

Hospital-acquired (nosocomial) infections

Gram + bacilli

Listeria, Bacillus,

Gram + bacilli listeria can cause

meningitis, food poisoning

Gram + bacilli bacillus can cause

anthrax

Gram - Cocci

Neisseria (gonorrhoeae, meningitidis)

Neisseria gonorrhoeae can cause

gonorrhea, neonatal conjunctivitis

Neisseria meningitidis can cause

meningitis

Gram - Coccobacillus

Haemophilus (influenze, ducreyi, aphrophilus, parainfluenzae)

Morexella (catharrhalis, nonliquefaciens)

Haemophilus influenzae can cause

meningitis otitis media pneumonia sinusitis

Haemophilus ducreyi can cause

STD (chancroid)

Haemophilus aphrophilus and parainfluenzae can cause

Endocarditis

Moxrella catarrhalis can cause

sinusitis, otitis media, bronchitis, pneumonia

moraxella nonliquefaciens can cause

blepharitis

Gram - Bacilli Enterobacterales (from the gut)

Yersinia

Escherichia

Serratia

Proteus

Enterobacter

Citrobacter

Klebsiella

Salmonella

Shigella

(YES PECKSS + morganella and providencia)

E. Coli can cause

UTI, sepsis, traveler's diarrhea, neonatal meningitis

Proteus can cause

UTI, sepsis

Klebsiella pneumoniae can cause

UTI, pneumonia, sepsis

Serratia can cause

UTI, hospital-acquired pneumonia

Enterobacter can cause

UTI, hospital-acquired pneumonia

Salmonella typhi can cause

typhoid fever

salmonella enteritidis can cause

entercolitis, sepsis

Shigella can cause

entercolitis

Yersina pestis can cause

plague (black death)

Gram - Bacilli (these are Non-Fermenters, HIGHLY antibiotic resistant)

Pseudomonas aeruginosa,

Burkholderia species,

Strenotrophomonas maltophilia,

Acinetobacter baumannii

Pseudomonas aeruginosa can cause

Lower respiratory tract infection,

Nosocomial pneumonia,

Endocarditis,

ear infection,

UTI,

"Hot tub" folliculitis,

Burn wound sepsis

Burkholderia cepacia can cause

Lower respiratory tract infection,

catheter-associated infections,

IV line infections

Burkholderia pseudomallei

Melioidosis

Stenotrophomonas maltophilia can cause

Lower respiratory tract infection,

Bacteremia,

Endocarditis,

cather-associated bacteruria,

Nosocomial pneumonia (hospital acquired)

Acintobacter baumannii can cause

Nosocomial pneumonia,

bacteremia,

meningitis,

nosocomial UTI,

endocarditis

Atypical Organisms

(neither gram + or -, no stains, colorless)

Mycoplasma,

Chlamydia,

Legionella

Mycoplasma pneumoniae can cause

Upper respiratory tract disease and atypical pneumonia

Mycoplasma hominis can cause

Pyelonephritis, plevic inflammatory disease, postpartum fever

Mycoplasma genitalium can cause

Nongonococcal urethritis

Chlamydia pneumoniae can cause

bronchitis, sinusitis, pneumonia

Chlamydia trachomatis can cause

urogenital infections, trachoma, conjunctivitis, pneumonia

Chlamydia psittaci can cause

Pneumonia

Legionella pneumophila can cause

pneumonia

Gram + Anaerobic Rods

Clostridium (tetani, botulinum, perfringens, difficile)

C. Tetani can cause

Tetanus

C. Botulinum can cause

botulism

C. perfringens can cause

Gas gangrene or myonecrosis

C. difficile can cause

Pseudomembranous colitis

Gram - Anaerobic Rods

Bacteroides fragilis,

Bacteroides corrodens,

Prevotella melaninogenica

Gram + Anaerobic Cocci

Peptococcus, Peptostreptococcus

Bacteroides fragilis can cause

sepsis, peritonitis, abscesses

Prevotella melaninogenica can cause

aspiration pneumonia,

chronic otitis media,

chronic sinusitis,

abscesses around the oral cavity,

brain abscesses,

human bites

Resistant Pathogens

Enterococcus faecium,

Staph. aureus,

Klebsiella pneumoniae,

Acinetobacter baumanii,

Pseudomonas aeruginosa,

Enterobacter species

Types of Bacteria Resistance

change in binding site,

enzymatic degradation,

porin channels,

efflux pumps

3 Common Aminoglycosides

Tobramycin, Amikacin, Gentamicin (TAG)

Aminoglycosides inhibit protein synthesis with _____________ and mostly used against ________________.

30s ribosomal function; gram - bacilli

Spectrum of activity of Aminoglycosides

Anaerobes: Not Active,

Atypicals: Not active (Mycoplasma, Legionella, Chlamodyphila),

Active against mycobacteria

- Streptomycin, tobramycin, and amikacin

Active against Entamoeba histolytica

- Paromomycin

Resistance of Aminoglycosides

Enzymes:

- Acetylation

- Adenylation

- Phosphorylation

Decreased permeability,

Target alteration (methylation of ribosomal RNA in the 30s subunit)

Absorption characterisitcs of Aminoglycosides

High polar bad PO administration, rapid absorption from IM

Distribution characterisitcs of Aminoglycosides

Poor CNS and adipose distrubtion (due to polar nature),

High conc found in renal cortex and inner ear

Metabolism characterisitcs of Aminoglycosides

low metabolism

Excretion characterisitcs of Aminoglycosides

unchanged in urine,

short half-life in normal renal function,

long lasting in renal cortex (100hrs),

Requires dose adjustments based on renal function

Aminoglycosides have ______________________ killing and ______________________

concentration-dependent, post antibiotic effect

Which ratio correlates with efficacy for Aminoglycosides

PEAK/MIC > 10-12

Which Aminoglycosides are PO

Neomycin and Paromomycin

Aminoglycosides require renal adjustments... If CrCl > 60, what's the recommended frequency?

24hrs

Aminoglycosides require renal adjustments... If CrCl 40-59, what's the recommended frequency?

36hrs

Aminoglycosides require renal adjustments... If CrCl > 20-39, what's the recommended frequency?

48hrs

Inhalation of Tobramacyin and Amikacin can be used for

cystic fibrosis

ADEs of Aminoglycosides

Nephrotoxicity (Acute Tubular Necrosis),

Ototoxicity,

Acute Neuromuscular blockade and apnea

Which Aminoglycosides primarily causes Vestibular (balance) ototoxicity?

Streptomycin and Gentamicin

(Tobramycin too but also causes cochlear (hearing) ototoxicity)

Which Aminoglycosides primarily causes Cochlear (hearing) ototoxicity?

Amikacin, kanamycin, and neomycin

(Tobramycin too but also causes Vestibular (balance) ototoxicity)

Aminoglycosides From Most to least Potent cause of acute neuromuscular blockade and apnea effects

Neomycin > Kanamycin > Amikacin > Gentamicin > Tobramycin

How does Aminoglycosides cause Acute Neuromuscular Blockade and Apnea

inhibit prejunctional release of ACh and reduce postsynaptic sensitivity to the transmitter

Aminoglycosides Monitoring

Vitals (BP, HR, Temp, O2),

Labs (WBC, procalcitonin, ESR, C-reactive Protein),

Renal Function (eGFR, BUN, SCr, Urine output),

Hearing Function

Aminoglycosides Drug-Drug that increase Nephrotoxicity a Break

Vanc,

Amphotericin B,

Cisplatin,

ACEi,

NSAIDs,

Diuretics,

Radiographic Contrast Agents

Aminoglycosides can be used with what 2 Classes that are Cell Wall Active for therapy of serious infections

Beta Lactams and Glycopeptides

3 Reasons Aminoglycosides are used in combo with Cell Wall-Active Agents

expand the empiric spectrum of activity of antimicrobial regimen,

provide synergistic bacterial killing,

prevent emergence of resistance to the individual agents

Monotherapy uses of Aminoglycosides

Zoonoses:

- Tularemia

- Brucella

- Plague

UTI due to MDR organisms

What Aminoglycoside is resistant to Enzymatic modification (a common reason of resistance... HINT: It's a New Agent)?

Plazomicin (Zemdri)

Plazomicin (Zemdri) is used for

complicated urinary tract infections (not approved for blood stream infections)