Pathological and mortality findings associated withAeromonas hydrophilafrom frog eggs in Al‐Ahsa region of Saudi Arabia

A virulent strain of Aeromonas hydrophila (PRE-1) has been identified as the primary pathogen responsible for severe disease outbreaks among indigenous marsh frogs (Pelophylax ridibundus) in Al-Ahsa Oasis, Saudi Arabia. This bacterium, confirmed through 16S rRNA gene sequencing with a 99.92% identity match and robust phylogenetic clustering (99% bootstrap support), is linked to pathological signs such as egg discoloration, jelly coat disintegration, developmental defects, and adult frog symptoms including hyperaemia, lethargy, peripheral oedema, subcutaneous haemorrhage, and cutaneous ulcerations. The study employed light microscopy, scanning electron microscopy, and dissecting microscopy to document these findings, alongside bacterial isolation and phenotypic characterization. The discovery underscores the urgent need for monitoring emerging amphibian diseases in Al-Ahsa Oasisto mitigate ecological losses, given amphibians' critical role in ecosystem health.

Khalifa, A. Y. Z., AlMalki, M. A., & Bekhet, G. M. (2020). Pathological and mortality findings associated withAeromonas hydrophilafrom frog eggs in Al‐Ahsa region of Saudi Arabia. Aquaculture Research, 52(3), 1227–1236. Portico. https://doi.org/10.1111/are.14981