Molecular characterization and pathogenicity of Streptococcus agalactiae serotypes Ia ST7 and III ST283 isolated from cultured red hybrid tilapia in Malaysia

Isolation and molecular characterization of streptococcal species recovered from clinical infections in farmed Nile tilapia (Oreochromis niloticus) in the Philippines

“…The data presented showed that S. agalactiae was the more prevalent and geographically widespread aetiological agent, while S. iniae appeared to be confined to a specific area. While we acknowledge the limited sample sizes, these findings are in agreement with reports from neighbouring South‐East Asia (SEA) countries (Anshary, Kurniawan, Sriwulan, Ramil, & Baxa, 2014; Barkham et al., 2019; Jantrakajorn, Maisak, & Wongtavatchai, 2014; Kayansamruaj et al., 2019; Syuhada et al., 2020) and in China (Li et al., 2014; Su et al., 2019) where S. agalactiae is the primary streptococci species associated with fish disease. This observed prevalence of S. agalactiae over S. iniae is similar to reports worldwide, especially in the major tilapia‐producing regions in Asia and Latin America (Liu et al., 2016).…”

“…Serotyping of S. agalactiae isolates is important when considering vaccine development as cross‐protection between the different bio/serotypes does not occur in fish (Munang'andu, Paul, & Evensen, 2016). The results from the Philippines are in agreement with data from surrounding SEA countries and China which all reported S. agalactiae serotype Ia as the most prevalent and widespread cause of streptococcosis in freshwater tilapia aquaculture (Kannika et al., 2017; Kayansamruaj et al., 2019; Lusiastuti, Textor, Seeger, Akineden, & Zschock, 2014; Su et al., 2019; Syuhada et al., 2020). In this study, cps gene serotyping was applied which is used widely by others as a reliable way to serotype S. agalactiae (Kannika et al., 2017).…”

Prevalence and Antimicrobial Resistance of Escherichia coli, Salmonella and Vibrio Derived from Farm-Raised Red Hybrid Tilapia (Oreochromis spp.) and Asian Sea Bass (Lates calcarifer, Bloch 1970) on the West Coast of Peninsular Malaysia

“…In Malaysia, bacterial diseases are a major burden in tilapia production; infection with Streptococcus sp. in general, and co-infection of S. agalactiae with tilapia lake virus (TiLV) are responsible for high mortality rate [ 68 , 69 , 70 , 71 ], leading to a decrease in tilapia production between 2012–2018 [ 72 ]. According to [ 73 ], erythromycin is commonly used for the treatment of streptococcal diseases in fish and is considered a drug of choice that can effectively curb streptococcal infection [ 74 ].…”

Haemato-immunological responses and effectiveness of feed-based bivalent vaccine against Streptococcus iniae and Aeromonas hydrophila infections in hybrid red tilapia (Oreochromis mossambicus × O. niloticus)

“…Amongst different important bacterial diseases of tilapia, Streptococcosis and Motile Aeromonad Septicaemia (MAS) are the major obstruction to the sustainable development of tilapia farming mainly in Asia [8,9]. Streptococcosis due to Streptococcus iniae and S. agalactiae is considered one of the key tilapia disease with high morbidity and mortality throughout the world including Malaysia [10]. It was calculated globally that the yearly economic loss due to Streptococcosis outbreaks was as high as $150 million [11].…”