Endotoxins (chemically known as Lipopolysaccharide) from gram-negative microorganisms initiates clot formation in blood when it is accidentally encountered by horseshoe crab blood stream. This property was extensively studied by various researchers as a result Limulus Amebocyte Lysate (LAL) test was established. The LAL tests in general, 3 to 300 times more sensitive than the United States Pharmacopeial (USP) rabbit pyrogen test method. It is apparent that major differences among the LAL preparations lie in the area of sensitivity. Differences, up to 100-fold, exist in the sensitivity of the various LAL preparations to the same endotoxin. Based on the above perspective, a portable Kit (Endo sensor) was developed to detect the presence of bacterial endotoxin in liquid biological samples using Tachypleus Amebocyte Lysate (TAL) as a source. Sensitivity of the Kit was determined using various concentrations of prepared endotoxin standards and pyrogen free water samples. It was observed that Endo sensor could detect up to nano gram level of endotoxin in liquid biological samples which could be expressed in (EU/ml) and the labeled sensitivity of the lysated product was 0.125 EU/ml. The gel clotting principle method was utilized for the detection of bacterial endotoxin in liquid biological samples.
Increasing utilization of living animals in ecological and biomedical research has drawn serious concerns in terms of animal welfare and ethical practices in animal handling. Significant attention has been given to animals of higher taxonomical hierarchy especially vertebrates such as fishes, rodents, reptiles and mammals, while ethical framework on invertebrate handling and welfare is less addressed (except for cephalopods). The definition of ‘Animal’ itself by any international consortia or Animal Research Act (ARA) does not include invertebrates as an animal entity. This is due to the lack of standard ethical framework to understand the pain and other physiological stress experienced by the invertebrate test animal. One such example would be the living fossil ‘horseshoe crab’ which is extensively bled to obtain its blue blood that is used for endotoxin quantification in biological samples. The biomedical bleeding itself leads to 15-30% post bleeding mortality of crabs, while pain and stress caused by the bleeding practice is not studied. Hence, this paper discusses the technicality of establishing standard framework for invertebrate handling. The paper also highlights the shari’ah (Islamic law) principles on scientific experimentations on animal subjects, particularly the norms related to the adoption of invertebrates in environmental and biomedical practice. Comprehensive review of ethical regulations in animal experiments, especially invertebrates, would be beneficial for revising and improving existing animal ethical practices.
Microorganisms are the major cause of spoilage of most seafood products. Fishes are more perishable than other protein foods and thus more prone to bacterial contamination. Based on above perspectives, a bacterial invasion in commercially important fresh and spoiled marine (Lates calcarifer, Lutjanus sanguineus) and freshwater fish (Pangasius pangasius) were analyzed using API 20E kit. Out of 25 isolates obtained from fresh water fish, only 6 isolates were characterized as Gram-positive bacteria and the rest were Gram negative strains (19 isolates). The most dominant genera were Vibrio, Enterobacter, Serratia, and Aeromonas. All these bacteria were found in both fresh fish and spoiled fish sample while Erwinia spp. and Kluyvera spp. were identified only in fresh fish samples. Out of four (4) strains of Staphylococcus spp., S. xylosus was detected exclusively from spoiled fish. The higher number of bacterial micro flora in the spoiled fish gut indirectly indicated increased microbial degradation in the fish gut during spoilage process. Notably, almost all the isolates were lactose degraders, positive oxidizers and carbohydrate fermenters. Vibrio fluvialis, Proteus mirabilis, Proteus vulgaris, Brucella sp. and Ochrabactrum anthropi were the human pathogenic bacteria found in marine fish Lates calcarifer (Sea perch). While Vibrio fluvialis, Proteus mirabilis and Proteus vulgaris were detected in Lutjanus sanguineus (Red snapper). The study portrays that the existing postharvest handling techniques could be a vital factor for degrading hygienic conditions of fish in local fish markets. Nevertheless, a long term monitoring is an urgently needed for sustaining the quality flesh of fish towards the betterment of the consumer’s health.