Studies on the growth temperature ranges of bacteria isolated from fresh sardine at different primary incubation temperature

The effect of primary incubation temperature on the growth temperature range was studied with reference to 296 bacterial cultures isolated from sardine using streak plate technique. The primary incubation temperature used during bacteriological sampling caused a selection of strains according to their growth temperature requirements. Incubation at 8°C caused greater recoveries of psychrotrophs while 30°C favored mesophiles. An incubation temperature of 30°C facilitated the growth of both psychrotrophs and mesophiles

The influence of plating technique and incubation temperature on bacterial count from fish and fishery products

For bacterial sampling of raw unprocessed fish and frozen fishery products, spread plate method is preferable to pour plate method; incubation of plates at 30°C gives a higher count than incubation at 37°C. Analysis of variance of the data shows that sample variation between different types of fishes is highly significant whereas the variations between triplicate plates are not significant at 5 % level

Selection of suitable diluents for bacteriological examination of fishery products

For raw, iced and frozen samples of fish and prawn, significant difference was observed in total plate counts done with various diluents, the significance level ranging from 5% to 0.1%. For raw fish, N-saline, seawater and quarter strength Ringers' solution gave maximum total plate counts. In the case of iced-fish, n-saline yielded highest total plate counts. For frozen samples, however, peptone water and n-saline gave good recoveries. Trials with suitable combinations of diluents showed that though some of them were as good as the control, namely n-saline, none were superior in any way

Effect of incubation period on plate count of raw ices and frozen fish

The total viable counts were estimated in one hundred and sixty five samples of raw, iced and frozen fish using incubation periods of 24, 48, 72 and 96h. For raw fish, 24h and for iced and frozen fish 48h incubation of the plates were found to be adequate. Variation between samples was significant at 1% level for raw iced and frozen samples

Studies on frozen characteristics of individually quick frozen and block frozen mackerel

Studies on mackerel (Rastrelliger kanagurta) of medium (4%) and high (11%) lipid contents quick frozen individually (IQF) and as blocks (BF) and stored at -23°C showed that block frozen mackerel had higher frozen storage shelf-life than individually quick frozen samples. IQF samples of medium and high lipid contents had shelf-lives of 17 and 20 weeks whereas BF samples of both series had 23 and 24 weeks respectively based on sensory evaluation

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Not AvailableThe food borne pathogens that are naturally present in the marine or estuarine environments are members of the family Vibrionaceae, Aeromonadacae that are species Clostridium botulinum, particularly Clostridium botulinum type E. Among members of the family Vibrionaceae that are important as inherent pathogens in seafood, the genera Vibrio and Plessiomonas are significant. The role of pathogenic vibrios in food-borne gastroenteritis and also other disease manifestations have been thoroughly investigated all over the world. The important species in this group are Vibrio parahaemolyticus, V. vulnificus and to be a lesser extent V. hollisae and V. mimicus. aeromonas hydrophila, A. sobriae and Plessiomonas shigelloides, though not frequently associated with seafood borne infections, are also to be considered as human pathogens of aquatic origin. Unlike the above pathogens, Clostridium botulinum is an anaerobic, Gram positive, spore former present in the aquatic systems. It is a well- known pathogen causing severe intoxication and death in humans. Inadequately heat processed and smoked seafood are identified as the common vehicle of this organism. The distribution of these pathogens in seafood of different origins, significance as a pathogen and strategies for their removal and control are highlighted in this paper.Not Availabl

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Not AvailableThe food safety and quality control in the seafood processing industry necessitates rapid detection of pathogens. Most of the pathogens occur in the food in small numbers only so that detection becomes very difficult. Some of the pathogens like Vibrio cholerae also exist in the so called "viable but non-culturable" state in the environment so that ordinary biochemical protocol becomes unsuccessful to detect their presence. Molecular methods such as polymerase chain reaction (PCR) has the advantage over the existing biochemical detection method in detection very small numbers of stressed cells of these pathogens and that too in a relatively short time. A PCR method is described to detect Vibrio cholerae in fish by amplifying a 564 bp fragment of the CTX gene.Not Availabl

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Not AvailableHistidine decarboxylase activity of Enterobacteriaceae isolates from 104 samples of fish and shellfish samples collected from retail markets of Cochin was studied. The total Enterobacteriaceae count varied from 2.5 to 6.5 log cfu g- 1 among the different fish species. Generic level characterization of 248 enteric bacteria showed that Enterobacter Spp., and Escherichia Spp. were the dominant groups. All the isolates were checked for their ability to decarboxylase histidine and the isolates showing positive reaction from different sample sources were reported. Effect of five different incubation temperatures on the decarboxylase activity of these isolates was also evaluated.Not Availabl

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Not AvailableMotile Aeromonds ubiquitous to the aquatic environment has been frequently associated with disease of fishes and other aquatic animals. Recent studies point to its role as a causative agent for foodborne gastroenteritis. This paper reports the incidence of motile aeromonds in the fishing ground, raw marine fish and processed fishery products. The density of motile aeromonad in the samples were analyzed by direct plating and enrichment methods along with a total plate count. Typical isolates were identified upto species level. In sea water of the fishing grounds off Cochin, the aeromonad count ranged between 4.0 * 10^2 to 2.1 * 10^3 /ml in July-August. The aeromonad count in the skin with muscle of the fishes during that period were in the range of 9 * 10^2/g to 9.9 * 10^5/g corresponding to a TPC range of 6.7 * 10^4/g to 7.12 * 1066/g. In frozen fishes the aeromonad count ranged between 9.0/g to 2.0 * 10^4/g and the TPC, in the range of 4.5 * 1064/g to 9.7 * 10^5/g. Cured of salted fishes were found to be free from motile aeromonads. Random colonies picked from the plate were identified upto species level and the dominant species in water, raw fish and frozen fish were found to A. caviae which is considerd as non-toxigenic. the incidence of Aeromonas hydrophila was more in the frozen fish than fresh fish. the enterotoxigencity of the isolates were assessed on the basis of biochemical tests.Not Availabl

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