A Case of Pasteurellosis in Rainbow Trout (Oncorhynchus mykiss) Cultured in Black Sea

Er A.

2nd International Conference on Scientific and Academic Research, Konya, Turkey, 14 - 16 March 2023, pp.562

  • Publication Type: Conference Paper / Summary Text
  • City: Konya
  • Country: Turkey
  • Page Numbers: pp.562
  • Recep Tayyip Erdoğan University Affiliated: Yes


Fish are very susceptible to diseases caused by a wide variety of bacterial pathogens. One of the

pathogenic bacteria is Pasteurella sp. (Photobacterium sp.), non-motile, Gram-negative coccobacilli often

exhibiting bipolar staining. oxidase-positive, bacterium that causes the disease Pasteurellosis. Many marine

fish have reportedly died from the sickness, which has been known to infect them. In this study, 10 days

following the transfer period, illness signs were seen in rainbow trout (Oncorhynchus mykiss) transferred

for marine rearing, and daily death rates of 1 to 2 percent were noted. There were blackberry-like nodule in

the spleen tissue, as well as petechial bleeding in the skin, liver, intestine, and kidney. bacteria grew as very

small colonies on TSA medium. The bacteria were gram negative, bipolar cocci-bacil, oxidase positive,

catalase positive and non-motile. bacteria were identified using API 20 E and API 20 NE test kits.

According to API test, Pasteurella sp. and Photobacterium damsela were identified with 22.1% and 72.3%

of ratio for API 20 NE (0500004) and API 20 E (200100407), respectively. The bacteria isolated from the

sick fish were found to be sensitive to enrofloxacin. Antibiotics were administered 5 days after the outbreak

of symptoms on the fish. After the antibiotics were administered, mortality continued for up to 3 days, after

which no mortality was observed.