Description of Aporcella daklakensis sp. n. (Nematoda: Dorylaimida: Aporcelaimidae), associated with coffee plantations in Central Highland of Vietnam.

A new species of the genus Aporcella, collected in replanted coffee orchards in Central Highland of Vietnam, is described and illustrated. Aporcella daklakensis sp. n. is characterized by its 1.63-1.98 mm long body, lip region offset by weak constriction and 14-15 µm broad, odontostyle 13-15 µm long or equal to lip region diameter, neck 400-565 µm long, pharyngeal expansion 205-335 µm long and occupying 51-60% of the total neck length, female genital system diovarian with very poorly developed genital tract and transverse vulva (V = 53-59), tail conical with rounded terminus (31-39 µm, c = 43-57, c' = 1.0-1.4), visibly subdigitate and bearing cuticular irregularities at its ventral side, and male absent. The new species is compared with its closest Aporcella representatives.

Detection of Escherichia coli in ready-to-eat fresh vegetables using broad-host-range recombinant phages.

AIM: To construct a simple method to detect Escherichia coli in ready-to-eat fresh vegetables using broad-host-range recombinant phages. METHODS AND RESULTS: Firstly, a gene encoding cytochrome c peroxidase (CCP) chromogenic enzyme was inserted into genomes of wild-type phages IP008 and IP052 to produce recombinant phages IP008BK and IP052BK. They were then used in the production of the chromogenic enzyme (CCP) through infection into E. coli. The method was then examined in the colorimetric detection of E. coli K12 in broth, and its appearance was confirmed by a significant change in absorbance after a few minutes of the enzyme assay. Secondly, the protocol using the recombinant phages for the detection of E. coli in vegetables, that is, lettuce and mustard greens, was investigated. A low E. coli concentration at 4 CFU per g vegetable was detected within 16·5 h that is of a shorter duration than agar plate methods and in some commonly known phage-based methods. CONCLUSION: The existence of E. coli as a faecal contamination indicator in two types of ready-to-eat fresh vegetables, that is, lettuce and mustard greens, can be identified by the broad-host-range recombinant phages. SIGNIFICANCE AND IMPACT OF STUDY: The method is simple and convenient since it enables the detection of E. coli without expensive apparatus. It is applicable to other types of food samples.