Jurnal Biologi Tropis
Vol. 26 No. 3 (2026): in Progress

Case Study of Pseudomonas sp. in Giant Gourami (Osphronemus goramy) via Anatomical Pathology, Histopathology, and Microbiological Examinations, and Tetracycline Sensitivity Testing

Rahmaniar, Reina Puspita (Unknown)
Rahmawati, Indra (Unknown)
Nussa, Olan Rahayu Puji Astuti (Unknown)
Firmansyah, Muhammad Irwan (Unknown)



Article Info

Publish Date
03 Aug 2026

Abstract

Pseudomonas sp. is an opportunistic bacterial pathogen causing systemic infections in cultured fish, resulting in economic losses and increasing concerns regarding antimicrobial resistance. However, comprehensive pathological and microbiological confirmation remains limited. This study aimed to evaluate Pseudomonas sp. infection in giant gourami (Osphronemus goramy) through pathological examination, bacterial identification, and antibiotic susceptibility testing. A descriptive case study was conducted on one naturally infected fish (code F-11). Clinical observation, necropsy, histopathological examination of the liver and gills using hematoxylin-eosin staining, bacterial isolation on MacConkey agar, Gram staining, biochemical characterization, and Kirby-Bauer disk diffusion testing with 30 μg tetracycline were performed. Data were analyzed descriptively by integrating pathological and microbiological findings. Gross examination revealed ecchymotic hemorrhages in the gills, labyrinth organ, and liver, hepatic nodules, and jejunal petechiae. Histopathology demonstrated congestion, inflammatory cell infiltration, hemorrhage, focal hepatic necrosis, epithelial desquamation, and lamellar necrosis in the gills. The isolate produced transparent non-lactose-fermenting colonies, consisted of Gram-negative rods, and exhibited biochemical characteristics consistent with Pseudomonas sp. The isolate remained susceptible to tetracycline, producing a 28-mm inhibition zone. These findings confirm Pseudomonas sp. infection and highlight the importance of integrated pathological and microbiological diagnosis to support appropriate antimicrobial therapy and antimicrobial resistance surveillance in aquaculture.

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Journal Info

Abbrev

JBT

Publisher

Subject

Agriculture, Biological Sciences & Forestry Biochemistry, Genetics & Molecular Biology Immunology & microbiology

Description

Jurnal Biologi Tropis (ISSN Cetak 1411-9587 dan ISSN Online 2549-7863) diterbitkan mulai tahun 2000 dengan frekuensi 2 kali setahun oleh Program Studi Pendidikan Biologi PMIPA FKIP Universitas Mataram, berisi hasil penelitian dan ulasan Ilmiah dalam bidang Biologi ...