LOLS10在线直播下注

九线水果小玛丽Shape 自助领取彩金Shape 12选5APP下载author yobet体育平台Shape 10bet亚洲体育appchevron 日博电竞登录cross 极速体育登录Shape 新利18体育登录Shape 尊亿老虎机平台Shape 567彩票手机版Group 金博宝体育apphamburger 尊亿娱乐登录注册home 甘肃体彩注册Group 万博体育appmagnify 旧版炸金花Shape 太阳2登陆Shape 11选5官网Shape 炸金花app官网rss 陕西体彩Shape

Necrotising Hepatopancreatitis (NHP)

What is it?

Necrotising hepatopancreatitis (NHP), also known as infection with necrotising hepatobacterium, is caused by infection with a Gram-negative, intracytoplasmic species of alphaproteobacterium that infects the hepatopancreas of prawns, also referred to as NHP bacterium.

The NHP bacterium exists in two morphological forms: a rod-shaped, nonflagellated, rickettsia-like organism; and a helical, flagellated form.

Various varieties of shrimp are known to be susceptible to the disease and mortality can be 9095 per cent within 30 days of an outbreak.

Where and When Might it Occur?

NHP outbreaks are often preceded by lengthy periods of high water temperatures (2931 C) and elevated salinity (up to 40 parts per thousand).

NHP appears to be transmitted by direct ingestion of carrier prawns (survivors of NHP bacterial infection may carry the bacteria for life) and through contaminated water.

NHP bacteria may also be shed in faeces and contribute to disease transmission.

LOLS10在线直播下注 Mortalities usually occur midway through the grow-out phase.

Diagnosis

Signs of the disease often include lethargy, emaciation, heavy protozoan or bacterial fouling and a reduced growth rate.

LOLS10在线直播下注 Gross pathological signs are:

  • soft shell
  • flaccid body
  • black gills
  • empty intestinal tract
  • degenerated or atrophied digestive gland (hepatopancreas), which appears pale to white
  • black (melanised) streaks in the hepatopancreas.

LOLS10在线直播下注Microscopic pathological signs are:

  • multifocal granulomatous lesions in hepatopancreatic tubules, with atrophy of adjacent hepatopancreatic tubule epithelial cells
  • tubular cells within the granulomatous lesions that can be hypertrophied and contain basophilic organisms within the cytoplasm
  • sloughing of tubule epithelial cells
  • severe haemocytic inflammation of the intratubular spaces.

LOLS10在线直播下注Four distinct phases of infection have been described: initial, acute, transition and chronic. Acute and transition phases are identifiable by the presence of pathognomonic lesions in the hepatopancreas. Molecular techniques are required for positive diagnosis of NHP bacterium infected individuals in the initial or chronic phase of infection.

LOLS10在线直播下注SOURCE: Australian Government, Department of Agriculture, Fisheries and Forestry