Microbiological monitoring of some pathogenic bacteria in common commercial molluscan shellfish in Lake Timsah, Suez Canal, Egypt

Microbiological monitoring of some pathogenic bacteria in common
commercial molluscan shellfish in Lake Timsah, Suez Canal, Egypt
Hanaa Mohamed Fadel1
and Samya Hussein Mohammad2
1
Department of Animal Hygiene and Zoonoses, Faculty of Veterinary Medicine,
Suez Canal University, Egypt
2
Department of Zoology, Faculty of Science, Suez Canal University, Egypt
*E-Mail: [email protected]
Received 7th May 2009, Accepted 30th July 2009
Abstract
Seafood is considered as an important source of protein and also it includes several important nutritive elements.
Owing to its low fat content, it is considered the most favourable food for many people. On the other hand, eating raw or
slightly cooked shellfish is one of the feeding habits that lead to infection with some diseases. This study was carried out
to evaluate the prevalence of some pathogenic bacteria in the common street seafood. A total of 114 specimens of the
gastropod Thais carinifera and 358 specimens of the bivalves; Ruditapes decussata, Venerupis aurea and Venerupis
white were collected during the period from July to December, 2008. A diverse array of bacterial species, including
several human pathogens, was isolated from these species. Aeromonas hydrophila, Salmonella spp., Staphylococcus
aureus and Escherichia coli were isolated from soft tissue of the examined gastropod and bivalve samples at the rates of
34.88% and 28%, 20.9% and 26.3%, 86% and 57.9 % and 41.9 % and 57.9 %, respectively. They were also isolated
from hand swabs collected from fishermen and shellfish sellers at the rates of 10%, 0%, 100% and 50%, respectively.
The current research showed that bivalve species have higher bacterial counts than that of the gastropod. This study
assessed that Aeromonas hydrophila was the most harmful bacteria infected bivalve species especially Venerupis aurea.
It adversely affected their growth with size. The isolation of potentially pathogenic bacteria from the examined shellfish
indicates a risk for health of people who consume or handle raw seafood.
Keywords: Shellfish, gastropod, bivalve, pathogenic bacteria, allometric growth, public health significance.