Nathanon Trachoo and Kanchana Chumpamee

pp. 377 - 383

Abstract

Physicochemical properties such as hydrophobicity and ability to aggregate play an important role in
the attachment of microorganisms to environmental surfaces and intestinal tissues of humans and animals
leading to gastroenteritis in hosts. The objective of this research was to determine relative hydrophobicity
and aggregation properties of major foodborne pathogens including Campylobacter jejuni, Escherichia coli
0157:H7 and Listeria monocytogenes LM18, LM32, LM msu1 and LM msu2. Relative hydrophobicity as
determined by the microbial adhesion to hydrocarbon (MATH test) of E. coli 0157:H7 was 19.30% indicating
that substances on its cell surfaces were more hydrophobic than other pathogens and thus could be extracted
more by the hydrocarbon, hexadecane. C. jejuni had relative hydrophobicity of 4.15% while the four strains
of L. monocytogenes had relative hydrophobicity ranging from 3.79% to 16.23%. Aggregation of C. jejuni,
E. coli and L. monocytogenes LM18, LM32, LM msu1 and LM msu2 were 45%, 21.25%, 12.51%, 13.09%,
31.27% and 41.22%, respectively

Keywords

• hydrophobicity
• aggregation
• biofilm