Microbiological Hygiene Quality of Thermal Muds
Microbiological Hygiene Quality of Thermal Muds: A Pilot Study in Pelotherapy Facilities of the Euganean Thermal District (NE Italy)
Abstract
Evaluation of hygienic aspects of thermal mud microbiology is still neglected. This study evaluates the microbiological hygiene quality of thermal muds, providing a comprehensive assessment of the whole mud cultivation chain. Maturing mud, peloid and used mud samples were collected twice in a year from 30 SPAs of the Euganean Thermal District, NE Italy. Samples were processed with an ad hoc laboratory method. The following indicator parameters were assessed: Total Count at 22, 37 and 55 °C; total coliforms; Escherichia coli; enterococci; Staphylococcus aureus; Pseudomonas aeruginosa; sulfite-reducing clostridia; dermatophytes. Statistical significance of differences between the two sampling campaigns and correlation between temperature and indicator parameters were evaluated. One-hundred eighty samples were analyzed. Widespread presence of environmental species was found, as well as hints of possible microorganism transfer from the patient’s skin to the mud. Proper setting of thermal water temperature resulted critical, in terms of hygienic quality. Although optimal maturation should be granted (thermal water at 30–42 °C), a pasteurization step at 60–65 °C is strongly recommended to sanitize peloids before pelotherapy. Facilities re-using thermal muds should also implement a regeneration step at ≥65 °C. Core evaluation of thermal mud hygienic quality could encompass the following guidelines: absence (i.e., 0 colony forming units (CFU)/g) of E. coli, P. aeruginosa, S. aureus and dermatophytes.
Credits: Creative Commons licence
Conclusions
Microbial hygienic quality of TMs was thoroughly assessed after the validation of an ad hoc laboratory method. Analysis of TM samples (i.e., maturing mud, peloids and used mud) highlighted how presence of undesired microorganisms can either result from environmental contamination or transfer from patients’ skin. A core set of suitable indicator parameters for evaluating the microbiological hygiene quality of TMs could encompass Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus and dermatophytes. Absence (0 CFU/g) of such indicators is recommended. Proper management of thermal water temperatures throughout the diverse phases of the mud cultivation process represents a critical issue. If, on the one hand, maturation of virgin mud must ensure the achievement of the best therapeutic properties, on the other a pasteurization step of TMs with thermal water ≥ 60 °C should be compulsory just before treatment, so as to grant its hygienic quality as well.
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