Biomonitoring of the Physicochemical Variables, Vibrio and Salmonella Pathogens from Raw Shrimp in Selected Rivers in Southern Region Nigeria

Abstract

This study was designed to reveal the physicochemical and microbial
variables of raw shrimps and their habitat. Water and raw shrimp
samples were obtained from different surface water bodies in Delta,
Bayelsa, and Rivers States Nigeria from June 2016 to May 2017 and
analysed using standard analytical and culture-based methods for their
physicochemical and microbial diversity respectively. Analytical
Profile Index (API 20NE) was used to secure the identity of Vibrio and
Salmonella isolates. The mean physicochemical variables values range
as follows: pH (7.73±0.47 - 7.82±0.53), turbidity (179.66±9.07 -
181.79±5.92 NTU) and COD (83.66±6.75 - 86.63±6.61 mgL-1
). The
mean population cell density from the surface water range as follows:
total heterotrophic population (6.3×109±21.83 - 7.5×109±48.86
CFU/mL), Vibrio species (2.0×103±6.02 - 2.1×103±13.00 CFU/mL),
Salmonella species (1.8×104±5.60 - 3.8×104±27.02 CFU/mL), total
coliform count (1.0×104±4.54 - 2.5×104±10.44 CFU/mL). The mean
population cell density from the raw shrimp range as follows: total
heterotrophic population (3.3×10
6±12.11 - 8.1×106±31.49 CFU/mL),
Vibrio species (1.4×102±7.72 - 2.7×102±15.91 CFU/mL), Salmonella
species (1.7×103±7.73 - 4.6×103±33.98 CFU/mL), total coliform count
(9.8×102±3.52 - 1.1×103±5.36 CFU/mL). Significant correlation of the
physicochemical variables on the population cell density of the bacteria
isolated from both the water bodies and the raw shrimps were observed
both at 0.05 and 0.01 levels in Delta, Bayelsa and Rivers State. The
findings demonstrated that the shrimps associated with coliforms,
vibrios and Salmonella give an insight on the sanitary condition of the
harvesting period, thus call for public and environmental health control
measures