A patient who has sepsis and renal impairment, secondary to intraabdominal collections has them drained, the early microbiology report is given below
Proteus mirabilis has been identified from the intra-abdominal pus sample. Antibiotic sensitivities as follows [Full report to follow]
|
Antibiotic |
Sensitivity |
|
Penicillin |
R |
|
Oxacillin |
R |
|
Cefotaxime |
S |
|
Ceftriaxone |
S |
|
Gentamicin |
S |
|
Vancomycin |
R |
What antibiotic would you choose to cover this organism?)
Third generation cephalosporins although sensitive in vitro often will become resistant in vivo early – so should be avoided
Although not reported the empiric antibiotics of choice are (any of the following):
Quinilone
Pipercacillin / Tazobactam Ticarcillin and Clavulanate Imipenem / Meropenem
Gentamicin may worsen renal impairment, consider avoiding it. A single dose is acceptable
Proteus vulgaris (the indole-positive Proteus species) and probably also Proteus mirabilis fall into the group of ESCAPPM organisms:
These bugs easily induce chromosomal cephalosporinases, and treatment with a cephalosporin will rapidly become ineffective.
ESCAPPM and HACEK bacteria are discussed elsewhere in the Required Reading section.
The college opts to avoid gentamicin in the renal impairment patient, but notes that a single dose is probably ok.
The first choices are combinations of extended spectrum β-lactam and β-lactamase inhibitor. Carbapenems and fluoroquinolones are mentioned.
The Stanford Guide recommends Tazocin, meropenem or ciprofloxacin. They permit the use of early generation cephalosporins, provided the infection is not lifethreatening.
O'Hara, Caroline Mohr, Frances W. Brenner, and J. Michael Miller. "Classification, identification, and clinical significance of Proteus, Providencia, and Morganella." Clinical microbiology reviews 13.4 (2000): 534-546.
Gram-negative Survey: 2004 Antimicrobial Susceptibility Report. Australian Group on Antimicrobial Resistance, 2006.