Coliform bacteria from aquatic sources in Fiji

Area of Science:

• Environmental microbiology
• Water quality assessment
• Bacteriology

Background:

• Coliform bacteria are indicators of fecal contamination in aquatic environments.
• Bivalve molluscs can accumulate bacteria from surrounding waters.
• Fiji's coastal and riverine ecosystems may be impacted by pollution.

Purpose of the Study:

• To assess the prevalence and survival of coliform bacteria in Fiji's aquatic environments.
• To investigate coliform levels in river water, coastal areas, and bivalve molluscs.
• To understand the growth dynamics of coliform bacteria in different water types.

Main Methods:

• Sampling of river water, coastal water, and bivalve molluscs.
• Quantification of coliform bacteria.
• Survival and growth experiments in river water, seawater, and nutrient broth.
• Bacterial identification using the API 20E system.

Main Results:

• Coliform bacteria were abundant in rivers and bivalve molluscs, less so in coastal areas.
• Rivers receiving treated sewage showed high levels of pollution.
• Coliform concentrations increased notably in bivalve molluscs.
• Coliforms survived and grew in river and seawater over 5 days.
• Rapid coliform growth was observed in nutrient broth under laboratory conditions.

Conclusions:

• Coliform bacteria pose a significant contamination risk in Fiji's aquatic ecosystems, particularly in rivers and associated bivalve molluscs.
• Treated sewage effluent is a major source of coliform pollution.
• Coliforms exhibit resilience and growth potential in natural and laboratory settings, highlighting the need for effective water management strategies.