Development of a Proficiency Test Specimen for Enumerating Escherichia coli in Molluscan Bivalve Shellfish

Abstract

This study was conducted to develop a proficiency test (PT) specimen for the enumeration of Escherichia coli, a sanitary indicative bacterium, in molluscan bivalve shellfish. The common mussel Mytilus edulis was chosen as a matrix for the PT specimen. Mussels were artificially bioaccumulated for approximately 3 h with E. coli culture. After determining the homogeneity of samples, samples were distributed to 17 participants involved in the proficiency testing program. The enumeration of E. coli was performed by the most probable number method of the American Public Health Association. Statistical evaluations of the results obtained from inter-and intra-laboratory variation indicated no significant differences in the accuracy of these techniques between participants, indicating z-scores of ≤±2 and suggesting that preparation of the PT specimen for enumerating E coli in shellfish was successful.

Effectiveness of depuration of Pacific Oyster (Crassostrea gigas): removal of bioaccumulated Vibrio vulnificus by UV-treatment

“…Thus, V. vulnificus is successfully bioaccumulated inside the oyster, and the cell population tends to be maintained thereafter. These results were consistent with the previous reports that bacterial cells were accumulated in shellfish by the bioaccumulation process (Correa et al, 2007 ; Kwon et al, 2011 ). Dore et al ( 1995 ) also reported that the initial bacterial population rapidly increased and was continuously maintained without employing the relaying or depuration process.…”

Simultaneous isolation and enumeration of virulent Vibrio cholerae and Vibrio vulnificus using an advanced MPN-PCR method

“…Furthermore, to check the e ciency of the depuration, several studies showed the arti cial bioaccumulation of the shell sh with the microbial pathogen followed by its enumeration of the cells during the process of depuration (Croci et al, 2002;Marino et al, 2005;Schneider et al, 2009). Martins et al (2006) and Kwon et al (2011) reported a clam Thylacodes decussatus and a mussel Mytilus edulis bioaccumulated by Escherichia coli. In this study, we selected paci c oysters for the bioaccumulation of V. cholerae and V. vulni cus, respectively (detail procedure described in Materials and Methods).…”

Simultaneous Isolation and Enumeration of Virulent Vibrio Cholerae and Vibrio Vulnificus using an Advanced MPN-PCR Method

“…Furthermore, to check the e ciency of the depuration, several studies showed the arti cial bioaccumulation of the shell sh with the microbial pathogen followed by its enumeration of the cells during the process of depuration (Croci et al, 2002;Marino et al, 2005;Schneider et al, 2009). Martins et al (2006) and Kwon et al (2011) reported a clam Thylacodes decussatus and a mussel Mytilus edulis bioaccumulated by Escherichia coli. In this study, we selected paci c oysters for the bioaccumulation of V. cholerae and V. vulni cus, respectively (detail procedure described in Materials and Methods).…”