misc. gram negative bacilli and coccobacilli

• gram negative organisms

  • bacilli
  • pseudomonas aeruginosa
  • stenotrophomonas maltophilia
  • coccobacilli
  • acinetobacter baumanii
  • haemophilus (para) influenza
  • moraxella catarrhalis
• pseudomonas aeruginosa

  • non-lactose fermenting GNR
  • ubiquitous in soil, vegetation, water, and moist environmental hospital site (sinks, toilets, mechanical ventilation, dialysis equipment)
  • primarily opportunistic pathogen
• pseudomonas infections

  • largely associated w/ hospital acquired infections
  • hospital acquired or ventilator acquired pneumonia
  • risk factors: mechanical ventilation, prolonged hospitalization, CF
  • catheter related infections (bacteremia, complicated UTIs)
  • surgical site infections (especially diabetic and burn wounds)
• multiple antibiotic resistance mechanisms

  • efflux pumps upregulation --> decreased susceptibility to multiple antibiotics
  • downregulation of porin OprD --> decreases susceptibility to carbapenems
  • inducible AmpC beta lactamases --> decreased susceptibility to cephalosporins
  • extended spectrum beta lactamases (ESBL)
• stenotrophomonas maltophilia

  • non-lactose fermenting GNR
  • ubiquitous in nature and opportunistic hospital acquired pathogen
  • most commonly associated w/ ventilator associated pneumonia
  • laboratory diagnosis: culture
  • treatment challenging d/t resistance to many antibiotics
  • drug of choice: sulfamethoxazole/trimethoprim
• acinetobacter baumanii

  • non-lactose fermenting gram negative coccobacilli
  • ubiquitous in nature and opportunistic pathogen
  • hospital and healthcare associated infections
  • HAP/VAP
  • catheter assocaited infections (bacteremia, UTIs)
  • laboratory diagnosis: culture
  • treatment can be challenging d/t resistance to many antibiotics
• haemophilus influenzae and parainfluenzae

  • gram negative coccobacilli
  • opportunistic pathogens (non-encapsulated strains colonize resp tract)
  • community acquired respiratory infections
  • sinusitis, bronchitis, lower resp tract infections
  • laboratory diagnosis: culture
• moraxella catarrhalis

  • gram negative coccobacilli or diplococcus
  • community acquired respiratory infections
  • CAP
  • COPD
  • otitis media (children)
  • lab diagnosis: culture