Citrobacter freundii

ALSO KNOWN AS: Opportunistic Septicemia

Citrobacter freundii is a Gram-negative, facultatively anaerobic bacterium found in freshwater environments. It is an opportunistic pathogen that can cause hemorrhagic septicemia, ulcers, and systemic infections in fish, often triggered by stress or poor water quality. Infected fish may exhibit lethargy, skin lesions, and abnormal swimming behavior.

Distribution: Worldwide in freshwater environments.

Hosts: Various freshwater fish species.

Detection Methods: Bacterial culture – TSA (tryptic soy agar).

Target Tissue: Blood and internal organs.