Microbiology and Spoilage Trail in Nile Perch (Lates niloticus), Lake ...

4.1.2 Phase I trial 2: Sediments
The microbiological counts for sediments were between 2.5 x 10 3 -2.2 x 10 4 cfu/g of
sediment (table 13). These counts may imply that sediments from the bottom of water have
likelihood of being good reservoir for many microorganisms. There was no
Enterobacteriaceae and E. coli detected in the samples. Thus, it may be seemingly, the
Enterobacteriaceae and E. coli can not survive for long time in aquatic evnvironment
(sediments) as compared to microorganisms represented in the TVC.
Table 13: Microorganisms of sediments
PARAMETERS
41
SAMPLES (#TRAWLS)
1 2 3 4 5 RANGE
Total viable count cfu/g 3500 22000 6100 2500 2800 2.5 x10 3 -2.2x10 4
E. Coli cfu/g 0 0 0 0 0 0
Enterobacteriaceae cfu/g 0 0 20 10 0 0-20
The pathogenic Vibrios ssp. (V. cholerae, V. parahaemolyticus and V. vulnificus) as well as
Salmonella were absent in 25g of sediments (table 14).
Table 14: Pathogenic microorganisms of sediments
PARAMETERS SAMPLE SIZE NUMBER OF PRESUMPTIVE
SAMPLES SAMPLES
Vibrio cholera
Vibrio parahaemolyticus/
25g 5 0 (0%)
Vibrio vulnificus
25g
5
0 (0%)
Salmonella 25g 5 0 (0%)
4.1.3 Phase I trial 3: Whole Nile perch
All pathogenic V. cholerae, V. parahaemolyticus/ V. vulnificus were presumptively absent
in 25ml of wash diluent of whole Nile perch (table 15). However, there was presumptive
Salmonella in 25ml of wash diluent from one sample of Nile perch skin.