Quorum Sensing Inhibitors as an Alternate …
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(Austin and Zhang 2006). Among these, disease outbreaks caused by pathogenic
or opportunistic bacteria especially Vibrio spp., remains as a major challenging
concern in the intensive rearing of aquatic animals such as molluscs, fish, crab,
oysters and shrimp. Vibrios are Gram-negative, rod or curve shaped bacteria, pervasive in marine and estuarine ecosystems as well as aquaculture farms and encompass
one of the major microbiota of these ecosystems. In which, V. harveyi, V. splendidus, V. penaecida, V. anguillarum, V. parahaemolyticus, V. alginolyticus and V.
vulnificus are the major pathogens mostly associated with fish, shrimp and other
aquatic diseases. V. harveyi is the causative agent of luminescent vibriosis in penaeid
shrimp larval rearing systems and is responsible for mass mortality in P. monodon.
Also, V. parahaemolyticus - a halophilic bacterium scattered in temperate water,
causes the emerging and most devastating disease, early mortality syndrome (EMS)
in shrimp. EMS typically targets the shrimp post larvae between 20 and 40 days and
impose 100% mortality within a week. The syndrome is more often lethal to shrimp
than compared to other aquatic animals (de Schryver et al. 2014). This pathogen is
also responsible for the most familiar vibrio-associated seafood borne gastroenteritis,
and wound infections in humans through consumption of contaminated uncooked
seafoods (Matsumoto et al. 2000). Similarly, V. vulnificus is also well recognized
to cause gastrointestinal infections in humans by consumption of uncooked seafood
and it also causes wound or soft tissue infections in marine organisms (Bross et al.
2007). In fishes, the pathogenic vibrios causes’ intestinal necrosis, anemia, ascetic
fluid, petechial haemorrhages in the muscle wall, fluid accumulation in the air bladder,
etc. It has been described that shrimp are also prone to vibriosis and it targets the vital
organs such as gill, gut and hepatopancreas, etc. Apart from vibrios, Pseudomonas
and Aeromonas species are also considered as the major aquatic pathogens, which
cause black spot syndrome and severe necrosis in infantiles of the penaeid shrimp.
The prime mode of infection in fish involves the invasion of the host tissues mainly by
the help of chemotactic movement, followed by deployment of siderophores system,
resulting in eventual damage to the fish by means of extracellular virulent products,
which includes different types of extracellular products such as protease, chitinase
and hemolysin. After invasion, vibrios colonize the host tissue of shrimp by crossing
the epithelial cells. In human, consumption of raw or undercooked seafood, particularly shellfish with vibriosis may lead to development of acute gastroenteritis, wound
and soft-tissue infections characterized by diarrhoea, vertigo, vomiting, abdominal
pain and high fever. In 2014, vibriosis is ranked as the foremost infectious cause of
human mortality by Centre for Disease Control and Prevention revealing its important
status among bacterial pathogens.
285
(Austin and Zhang 2006). Among these, disease outbreaks caused by pathogenic
or opportunistic bacteria especially Vibrio spp., remains as a major challenging
concern in the intensive rearing of aquatic animals such as molluscs, fish, crab,
oysters and shrimp. Vibrios are Gram-negative, rod or curve shaped bacteria, pervasive in marine and estuarine ecosystems as well as aquaculture farms and encompass
one of the major microbiota of these ecosystems. In which, V. harveyi, V. splendidus, V. penaecida, V. anguillarum, V. parahaemolyticus, V. alginolyticus and V.
vulnificus are the major pathogens mostly associated with fish, shrimp and other
aquatic diseases. V. harveyi is the causative agent of luminescent vibriosis in penaeid
shrimp larval rearing systems and is responsible for mass mortality in P. monodon.
Also, V. parahaemolyticus - a halophilic bacterium scattered in temperate water,
causes the emerging and most devastating disease, early mortality syndrome (EMS)
in shrimp. EMS typically targets the shrimp post larvae between 20 and 40 days and
impose 100% mortality within a week. The syndrome is more often lethal to shrimp
than compared to other aquatic animals (de Schryver et al. 2014). This pathogen is
also responsible for the most familiar vibrio-associated seafood borne gastroenteritis,
and wound infections in humans through consumption of contaminated uncooked
seafoods (Matsumoto et al. 2000). Similarly, V. vulnificus is also well recognized
to cause gastrointestinal infections in humans by consumption of uncooked seafood
and it also causes wound or soft tissue infections in marine organisms (Bross et al.
2007). In fishes, the pathogenic vibrios causes’ intestinal necrosis, anemia, ascetic
fluid, petechial haemorrhages in the muscle wall, fluid accumulation in the air bladder,
etc. It has been described that shrimp are also prone to vibriosis and it targets the vital
organs such as gill, gut and hepatopancreas, etc. Apart from vibrios, Pseudomonas
and Aeromonas species are also considered as the major aquatic pathogens, which
cause black spot syndrome and severe necrosis in infantiles of the penaeid shrimp.
The prime mode of infection in fish involves the invasion of the host tissues mainly by
the help of chemotactic movement, followed by deployment of siderophores system,
resulting in eventual damage to the fish by means of extracellular virulent products,
which includes different types of extracellular products such as protease, chitinase
and hemolysin. After invasion, vibrios colonize the host tissue of shrimp by crossing
the epithelial cells. In human, consumption of raw or undercooked seafood, particularly shellfish with vibriosis may lead to development of acute gastroenteritis, wound
and soft-tissue infections characterized by diarrhoea, vertigo, vomiting, abdominal
pain and high fever. In 2014, vibriosis is ranked as the foremost infectious cause of
human mortality by Centre for Disease Control and Prevention revealing its important
status among bacterial pathogens.