The emergence of zoonotic Fusarium oxysporum infection in captive‐reared fingerlings of golden mahseer, Tor putitora (Hamilton, 1822) from the central Himalayan region of India

Abstract

Zoonotic Fusarium oxysporum infection was identified in captive‐reared fingerlings of golden mahseer, Tor putitora (Hamilton, 1822) from the central Himalayan regions, India. Initially, fingerlings of T. putitora (mean length 10.8 ± 0.002 and weight 18.58 ± 0.054 g) were observed with cottony mass like growth completely covering the dorsal and caudal fins. The infected fingerlings were showing clinical signs such as sluggish, erratic movement, gasping, flared operculum and settling at one corner of the rearing tanks. The microscopic observation of 8‐day old culture of cottony mass like growth showed the presence of septate macroconidia, randomly spread microconidia and chlamydospores in short‐chain. From sequence analysis of ITS amplified fragment, the isolate was identified as Fusarium oxysporum, TPFCF 214 (MH464266.1) and clustered with F. oxysporum, strain NRRL 43504 (EF453107.1) and F. oxysporum, strain 20736 (JX 270150.1) isolated from the human in phylogenetic tree. An experimental infection of healthy golden mahseer fingerlings with 20 µl of F. oxysporum spore suspension (2.5 × 109 spore ml−1) showed the development of lesion 6‐dpi at the site of injection. Experimental trial on EPC‐2 cell culture recorded detachment in the monolayer, clumping and shrinking of the cell line 6‐8 dpi with a spore suspension of F. oxysporum, TPFCF 214 (5.68 × 102 cell/ml). From the severity of its infection, there is a chance that F. oxysporum may emerge as pathogenically and pose a significant health risk on captive‐reared golden mahseer in other Asian countries and world. As Fusarium solani and F. oxysporum are known to cause invasive fusariosis in human especially in immunocompromised patients, localized infection in immunocompetent individuals as well as osteomyelitis, arthritis, otitis, sinusitis and brain abscess, the global fish farmers, handlers and aquaculturist need to be aware of possible health hazards caused by Fusarium spp. and should adopt proper fish health management and animal husbandry practice to control the infection of Fusarium in culture environment.

Diversity and Antimicrobial Activity of Intestinal Fungi from Three Species of Coral Reef Fish

“…The reason for this may be attributed to diverse karyotypes among isolates in the same environment [ 62 ]. As a fish pathogenic fungus, F. oxysporum has been found in many fish in recent years, and it poses a great danger to fish health [ 63 , 64 , 65 ]. Different countermeasures, such as different biological activity screening modes, and different application directions, etc., must be taken regarding different isolates.…”

Biodiversity and antimicrobial activity of intestinal fungi from three species of coral reef fishes

“…The reason for this may be attributed to diverse karyotypes among isolates in the same environment (Ayukawa et al 2018). As a sh pathogenic fungus, F. oxysporum has been found in many shes in recent years, and it poses a great danger to sh health (Huttenhower et al 2015;Kulatunga et al 2017;Mallik et al 2020). Different countermeasures must be taken in regard to different isolates.…”

Biosynthesis of Novel Tellurium Nanorods by Gayadomonas sp. TNPM15 Isolated from Mangrove Sediments and Assessment of Their Impact on Spore Germination and Ultrastructure of Phytopathogenic Fungi

“…The phytopathogen Fusarium oxysporum is a ubiquitous soilborne fungal pathogen that ranks 5th among the top 10 fungal plant pathogens, and was reported to cause devastating vascular wilt in more than 100 plant species [ 43 ]. Besides being a phytopathogen, F. oxysporum has also emerged as a human pathogen [ 44 , 45 , 46 ]. Additionally, Alternaria alternata is an important fungal pathogen that has a wide host range, causing considerable losses in the yield of many crops [ 47 , 48 , 49 , 50 ].…”