Psychrotrophic bacteria in mrketed fish

Sixty samples (20 each of Tilapia sp., Mugil cephalus and frozenmackerel fish samples) were randomly collected from different local shopsof fish saling and fish retailers of different sanitation levels at Zagazig city.Collected samples were examined bacteriologically for determination ofthe incidence as well as the count of psychrotrohic microorganisms usingthe rapid method (25 pOCI 24 hours) following by pour plate technique.The obtained results revealed that the mean values of thepsychrotrophic count by the rapid method (25°C 124 hours) were1.3xl07±5.3xl06, 1.0xl07±2.7xl06 and 2.4xl07±8.2xl06 cfu/g. flesh ofTilapia nilotica, Mugil cephlaus and frozen mackerel respectively.The order of magnitude of psychrotrophic count was frozen mackerel >Tilapia >Mugil cephalus but such difference in counts was of nonsignificant as it is estimated through the analysis of the vanance(ANOVA).The mean Pseudomonas count was 5.7xl04±3.5xl03,1.4xl04±7.5xl03 and 3.5xl04±2.8xl03 cfu/g flesh of examined Tilapianilotica, Mugil cephalus and frozen Mackerel respectively.-3The mean count of Aeromonas was 5.7 xlO)± 3.0 x l O”, 1.0xl05±4.9xl04 and 3.3 xl05±2.7 xl04 cfu/g of examined Tilapia nilotica,Mugil cephalus and frozen Mackerel samples, respectively.The obtained results showed that Pseudomonas, flavobacterium,Alcaligenes, Acinetobacter, Moraxella, Chromobacterium, Aeromonas