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Clostridium perfringens is widely recognised as a reliable water pollution indicator. Since several media can be employed for the membrane filtration enumeration of this microorganism, the main aim of this work was to investigate the ability of fluorocult-supplemented TSC-agar (Merck) for recovering Cl. perfringens from public springs used for direct human consumption. Cl. perfringens recovery was also performed on mCP agar (Cultimed) according to Directive 98/83 as well as on TSC-Agar (Merck), TSN-Agar (Merck) and SPS-Agar (BBL) media. Variance analysis of data obtained showed no statistically significant differences in the counts obtained among all media employed in this work. However, the Cl. perfringens recovery efficiencies with TSC and fluorogenic TSC agars were significantly greater (P = < 0.05) than the corresponding values of mCP and TSN media. On the other hand, the identification of typical and atypical colonies isolated from all media demonstrated that fluorogenic TSC agar was the most specific medium for Cl. perfringens recovery in groundwater samples (85.3% of typical colonies and 82.8% of atypical colonies confirmed). In summary, the membrane filtration technique with fluorogenic TSC agar showed the best performance characteristics of all the media tested as judged by their recovery efficiency and specificity in these water samples.

Scuticociliatosis is a severe disease in farmed flatfish. However, the causative agent is not always accurately identified. In this study, we identified two isolates of scuticociliates from an outbreak in cultured fine flounder Paralichthys adspersus. Scuticociliate identification was based on morphological data, examination of life stages and the use of molecular approaches. The isolates were compared with a strain of Philasterides dicentrachi from turbot Scophthalmus maximus and with a strain deposited in the American Type Culture Collection as Miamiensis avidus ATCC® 50180™. The use of morphological, biological and molecular methods enabled us to identify the isolates from the fine flouder as P. dicentrarchi. Comparison of P. dicentrachi isolates and M. avidus revealed some differences in the buccal apparatus. Unlike P. dicentrarchi, M. avidus has a life cycle with three forms: macrostomes (capable of feeding on P. dicentrarchi), microstomes and tomites. Additionally, we found differences in the 18S rRNA and α- and β-tubulin gene sequences, indicating that P. dicentrarchi and M. avidus are different species. We therefore reject the synonymy/conspecificity of the two taxa previously suggested. Finally, we suggest that a combination of morphological, biological, molecular (by multigene analysis) and serological techniques could improve the identification of scuticociliates parasites in fish.