Abstract
ABSTRACT

A total of 100 random samples of marine fish fillet represented by Epinephelus alexandrinus fillet, Dicentrachus labrax fillet, Stingray fish fillet and Scomberomorus commerson fillet (25 of each) were collected from different fish markets in Alexandria city. The sample weight was 100 grams. Each sample was kept in a separate sterile plastic bag and transferred in an ice box to the laboratory under complete aseptic conditions without undue delay. All collected samples were subjected to bacteriological examination for isolation and identification of Enterobacteriaceae. The results revealed that the total Enterobacteriaceae count in the examined samples of marine fish fillet were varied from 1.6 x 102 to 6.3 x 104 with an average of 2.1 x 104 + 3.1 x 103 cfu/g for Epinephelus alexandrinus fillet, 2.1 x 102 to 4.3 x 104 with an average of 9.1 x 103 + 1.1 x 103 cfu/g for Dicentrachus labrax fillet, 3.1 x 102 to 6.7 x 104 with an average of 1.3 x 104 + 7.3 x 103 cfu/g for Stingray fish fillet and 2.3 x 102 to 1.1 x 105 with an average of 6.3 x 104 + 5.2 x 103 cfu/g for Scomberomorus commerson fillet, respectively. Accurately, all examined samples (100%) out of Epinephelus alexandrinus fillet, Dicentrachus labrax fillet, Stingray fish fillet and Scomberomorus commerson fillet were contaminated with Enterobacteriaceae. Also, the total coliform count in the examined samples of marine fish fillet were ranged from 1.3 x 10 to 2.1 x 103 with a mean value of 9 x 102 + 7.5 x 10 cfu/g for Epinephelus alexandrinus fillet, 3.1 x 10 to 3.2 x 103 with a mean value of 1.1 x 103 + 2.3 x 102 cfu/g for Dicentrachus labrax fillet, 1.9 x 10 to 7 x 103 with a mean value of 2.6 x 103 + 1.6 x 102 cfu/g for Stingray fish fillet and 6 x 10 to 1.3 x 104 with a mean value of 6.4 x 103 + 7.1 x 102 cfu/g for Scomberomorus commerson fillet. The enteric bacteria isolated were Enterobacter aerogenes (44 %) was the most frequent bacterial species isolated from Epinephelus alexandrinus fillet samples, followed by Proteus vulgaris (28 %), Citrobacter diversus and Shigella species (20 % of each) then Klebsiella ozanae and Provedencia spp (16 % of each).
In regard to Dicentrachus labrax fillet samples, the most frequent bacterial species isolated was Enterobacter aerogens (40 %), followed by Klebsiella peumoniae (32 %), Citrobacter diversus(28 %), Proteus vulgaris and Provedencia species (20 % of each), Citrobacter freundii (16 %) then Enterobacter cloacae, Klebsiella ozanae and Shigella species (12 % of each). Concerning Stingray fish fillet samples, Serratia liquifaciens (44 %) represented the highest rate of isolation followed by Enterobacter aerogens and Enterobacter cloacae (36 % of each), Citrobacter freundii (28 %), Citrobacter diversus and Enterobacter cloacae (24 % of each), Shigella species (20 %) and Proteus vulgaris (16 %) .
On the other hand, Citrobacter freundii (28 %), Enterobacter aerogens (24 %), Proteus vulgaris (20 %) then Klebsiella ozanae, Prot

Key words: Enterobacteriaceae marine fish fillet Epinephelus alexandrinus fillet Dicentrachus labrax fillet Stingray fish fillet Scomberomorus commerson fillet