——————————————————————– Non-fermenting Gram-negative bacilli ——————————————————————– [cannot catabolize glucose and therefore are not able to ferment. Non-spore forming.] >Acinetobacter baumannii >Achromobacter xylosoxidans >Bordetella pertussis >Burkholderia species: 1] Burkholderia cepacia (also known as Pseudomonas cepacia) – important pathogen of pulmonary infections in people with cystic fibrosis. 2] Burkholderia pseudomallei (also known as Pseudomonas pseudomallei) >Elizabethkingia meningoseptica (Previously Chryseobacterium meningosepticum) >Moraxella catarrhalis (formerly known as Branhamella catarrhalis) >Pseudomonas aeruginosa >Stenotrophomonas maltophilia (Initially classified as Pseudomonas maltophilia)
-Increasingly important as a hospital derived (nosocomial) infection .
-A. baumannii is part of the ACB complex which are difficult to speciate (A. baumannii, A. calcoaceticus, and Acinetobacter genomic species 13TU).
-Has been identified as an ESKAPE pathogen which have a high rate of antibiotic resistance and are responsible for the majority of nosocomial infections: (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species).
Therapy:
Important considerations: The choice of an agent should be based on local antimicrobial sensitivities, site of infection, cost, and comorbid conditions. Generally, the most common agents/regimens are listed first. Listed dosages may need to be adjusted for renal dysfunction.
Imipenem500mg IV every 6 hours [Range: 250-1000 mg q6-8h]
Meropenem 0.5 – 1 gram IV q8h (life-threatening infection -unlabeled use: 2 grams IV q8h)
Carbapenemase producing strains –
Colistimethate (colistin base): 2.5 – 5mg/kg/day in 2-4 divided doses. Max 5 mg/kg/day PLUS [ Meropenem 1 gram IV q8h OR Imipenem500mg IV every 6 hours [Range: 250-1000 mg q6-8h]
Antibiotics used in combination with agents listed above for resistant infections or severe disease:
Gentamicin or Tobramycin 1 to 2.5 mg/kg IV q8-12h or consider high-dose extended-interval dosing: 5 to 7 mg/kg q24-48h. Adjust dosing frequency based on estimated clearance.
Amikacin 5 to 7.5 mg/kg IV q8h or consider high-dose extended-interval dosing: 15-20 mg/kg q24-48h. Adjust dosing frequency based on estimated clearance.
