Isolation and identification of bacteria from marine market fish Scomberomorus guttatus (Bloch and Schneider, 1801) from Madurai district, Tamil Nadu, India
Abstract The present study was conducted to evaluate the hygienic quality and freshness of fish Indo-pacific King Mackerel “Scomberomorus guttatus” through the investigation of the occurrence of bacteria which is an indicator for fish quality. Fishes were collected every fortnight from Madurai fish market on monthly twice of January 2014 to March 2014. Skin surface of the fish was examined. Escherichia coli, Proteus vulgaris, Bacillus subtilis, Klebsiella pneumonia, Pseudomonas aeruginosa and Staphylococcus aureus were identified by Biochemical tests (IMViC Tests). Among the six bacterial species E. coli and K. pneumonia were found in all the collected samples where as other bacterial species were not found. The result of this study revealed that raw fish sold in Madurai fish market has high contamination so the presence of the bacterial species has strongly suggested the urgent need to improve the quality control systems in Madurai fish market.
Isolation of Enterobacteriaceae and Pseudomonas spp. from raw fish sold in fish market in Khartoum state
Enterobacteriaceae were isolated from gills, skin, muscles and the intestine of 83 out of 150 (55%) randomly collected fishes, the most dominants isolates were E. coli, Citrobacter spp, Enteriobacter spp and Klebsiella spp. This together with the highly pathogenic Enterobacteriaceae including Salmonella spp and Shigella spp.Proteus spp, and Alklegens spp. Potential pathogenic organisms were also among the isolates. On the other hand Pseudomonas spp was isolated from 62% of randomly collected fishes. The number and percentages of the isolated bacteria were compared according to seasons. The total bacterial count, coliform count and E. coli count were estimated from all parts of collected samples. The negative impacts of the presence of Enterobacteriaceae and Pseudomonas spp in fishes were discussed based on their potential pathogenic effect toward public health and their role to enhance rapid spoilage of fishes. 
 
   
 
 Key words: Enterobacteriaceae, fisheries, public health, Pseudomonas.
Methods of determining the desired frequency characteristics of the automatic control systems
Considered the methods of determining the desired frequency characteristics of the automatic control systems while the synthesis of their corrective devices.