Psychrobacter

Background

• Genus of aerobic Gram-negative coccobacillus within the family Moraxellaceae
• Tolerant of cold (i.e. psychrotrophic)
• May be phenotypically misidentified as Neisseria
• Have been identified in marine environment and isolated from food products
• May be part of normal gut flora

Clinical Manifestations

• Infection is rare, more common in immunosuppressed patients
• Wound infections after exposure to ocean or marine water
• Cases of bacteremia and meningitis

Management

• Generally susceptible to cefotaxime, ceftazidime, piperacillin, amikacin, ciprofloxacin, cephalothin, gentamicin, chloramphenicol, and erythromycin, though some cases of resistance to penicillin, aminopenicillins, and macrolides1

Further Reading

• Psychrobacter Infections in Humans-A Narrative Review of Reported Cases. Antibiotics (Basel). 2025;14(2):140. doi: 10.3390/antibiotics14020140. PMID: 40001384; PMCID: PMC11851457.