Haemorrhagic septicaemia in the hybrid surubim (Pseudoplatystoma corruscans×Pseudoplatystoma fasciatum) caused by Aeromonas hydrophila

Multilocus sequence typing revealed a clonal lineage of Aeromonas hydrophila caused motile Aeromonas septicemia outbreaks in pond-cultured cyprinid fish in an epidemic area in central China

“…Thus, the 3084-bp concatenated sequences of the six alleles in the MLST loci were identical, whereas the control strain isolated from fish with stigmatosis showed different STs and alleles with MAS outbreak isolates ( Table 2). A. hydrophila is prevalent in aquatic habitats with cosmopolitan distribution, and has resulted in heavy mortalities in farmed and feral fishes worldwide (da Silva et al, 2012;Harikrishnan and Balasundaram, 2005;Janda and Abbott, 1998). Vaccines are being developed against A. hydrophila, unfortunately, these are not yet commercially available (Yin et al, 2009).…”

“…Aeromonas hydrophila and other motile aeromonads are among the most common bacteria in freshwater habitats, and these bacteria frequently cause diseases among cultured and feral fishes worldwide (Akinbowale et al, 2007;Cipriano, 2001;da Silva et al, 2012;Gopalakannan and Arul, 2006;Nielsen et al, 2001). During the past 30 years, the aquaculture industry in China has evolved dramatically, and the capital-intensive production has become the main culture mode (Hishamunda and Subasinghe, 2003;Nielsen et al, 2001;Zhang and Jostein, 2004).…”

“…With the rapid development of the aquaculture industry, motile aeromonad infections caused by A. hydrophila have become an increasingly prominent problem (Xiao et al, 2011;Nielsen et al, 2001;Xu et al, 1993). Based on different clinical symptoms, A. hydrophila can cause several diseases in fish, which include motile Aeromonas septicemia (MAS) or hemorrhagic septicemia (da Silva et al, 2012;Nielsen et al, 2001;Xu et al, 1993), hemolytic ascitesosis (Sun et al, 1991), intussusception (Liu et al, 2008), tail or fin rot (Liu et al, 1993;Rahman et al, 2001), stigmatosis (Xu et al, 1980), and epizootic ulcerative syndrome (Austin and Adams, 1996;Roberts, 1997). MAS is the most serious disease and has frequently caused huge economic losses in the cyprinid fish industry throughout China since 1989 (Lu, 1992;Nielsen et al, 2001;Qian et al, 1997).…”

“…All these studies revealed a high intra-specific genetic diversity within A. hydrophila, and no dominant clones were found. As an etiological agent in fish and shellfish diseases, A. hydrophila is widely identified and characterized at the species level (da Silva et al, 2012;Nielsen et al, 2001;Xu et al, 1993). However, studies concerning the genetic diversity of this widespread fish pathogen are scarce.…”

Probiotic supplementation in diet and vaccination of hybrid surubim (Pseudoplatystoma reticulatum♀ x P. corruscans♂)

“…The clinical signs of septicemia caused by Aeromonas hydrophila were described previously by CAMPOS (2004) and further, strains of A. hydrophila were isolated and characterized by SILVA et al (2012) as the main surubim hybrid pathogen. Aiming bacterial control, many producers use antibiotics in fish farming, however the use of these antibiotics leads to the selection of resistant bacteria (SASAN et al, 2011 as vaccine and probiotics have been developed and have been shown to be promising tools for fighting fish bacterial diseases (MOURIÑO et al, 2012).…”