The first record of acute hepatopancreatic necrosis disease in the Philippines

Abstract

A new and emerging disease is threatening the shrimp industry, a bacterial disease which contains a highly pathogenic plasmid, creating a deadly toxin that causes high mortality in shrimps. The disease has been identified as acute hepatopancreatic necrosis disease (AHPND) or commonly known as early mortality syndrome (EMS). To help the efforts of sustaining the shrimp industry, the study focused on detecting Vibrio parahaemolyticus causing AHPND/EMS affecting Penaeus vannamei (Boone, 1931) (Pacific white shrimp) and Penaeus monodon (Fabricius 1798) (Black Tiger shrimp) in different locations in the Philippines. The presence of the disease was determined by microbiological methods and polymerase chain reaction (PCR) and was confirmed by the histopathology of the hepatopancreas of infected shrimp. Results show that the prevalence of the pathogenic strain of V. parahaemolyticus from the shrimps collected were 33% in Luzon, 21% in Visayas and 5% in Mindanao. The study presents the first record of AHPND/EMS in the country. The detection of this newly emerging disease in the shrimp industry is very crucial as it is the first step in identifying affected sites towards strategizing ways to combat the disease.

Prophylactic properties of biofloc- or Nile tilapia-conditioned water against Vibrio parahaemolyticus infection of whiteleg shrimp (Penaeus vannamei)

“…Moreover, the observations are in line with other reports that demonstrate biofloc to be beneficial against shrimp pathogens, possibly through probiotic or immunostimulatory effects as distinct from simply reducing the probability of exposure to pathogens through operating a very low-water exchange system (Crab et al, 2010;Haslun et al, 2012;Moss et al, 2012;Zhao et al, 2012, Dash et al, 2017. Excessive biofloc concentrations might exert detrimental effects on shrimp health, e.g.…”

“…In this present study, NTC water prepared at 10 ppt increased shrimp survival significantly during 96 h post-challenge with VpAHPND compared to the 10 ppt CW control, thus confirming a protective effect of the NTC water against VpAPHND. The protection afforded by the NTC water at 10 ppt could be due to the microbial community in this milieu, as microorganisms with anti-Vibrio effects have been isolated from tilapia skin and gut mucus and from NTC water shrimp ponds (Lio-Po et al, 2005;Dash et al, 2017).…”

“…Since 2009 this infection, known as acute hepatopancreatic necrosis disease (AHPND), has resulted in collective losses exceeding an estimated US$ 43 bn across Asia (China, Malaysia, Thailand, Vietnam) and in Mexico (Flegel, 2012;Tran et al, 2013;Chonsin et al, 2016;Pakingking et al, 2016; Office International des Epizooties [OIE], 2017;Shinn et al, in press b). AHPND infections, however, are also known in India (Ananda Raja et al, 2017), the Philippines (Dabu et al, 2015;de la Peña et al, 2015), Costa Rica and Honduras (Jun et al, 2016), while mortalities of P. monodon attributed to an AHPND-like condition have been reported from Cambodian ponds (Lang and Sothea, 2016). In Thailand, AHPND caused whiteleg shrimp production to reduce from ca.…”

“…Since 1996, tilapiaconditioned water with a high Chlorella content has been used in shrimp farming to prevent Vibrio spp. infections (Dash et al, 2017). Meanwhile, bacteria isolated from tilapia skin and mucus from the gut and skin have demonstrated potent anti-Vibrio spp.…”

Diagnostic approaches and contribution of next-generation sequencing technologies in genomic investigation of Vibrio parahaemolyticus that caused acute hepatopancreatic necrosis disease (AHPND)

“…This has raised concern as PCR methods based on AP1, AP2 and TUMSAT-Vp3 for the VP AHPND detection only target the plasmid sequences, and this could lead to false positive results. Thus, the AP3-PCR and duplex PCR methods that there were designed to detect both the pirA vp and pirB vp genes, respectively, are recommended for specific detection of VP AHPND (Devadas et al 2019).…”