THE IMPACT OF WATER HARDNESS ON THE ANTIMICROBIAL PHOTODYNAMIC EFFECT OF SYNTHETIC DYES

Sintetska bojila, metilen plavo i toluidin plavo, u medicini se koriste za bojanje histoloških preparata. Osvjetljavanje tih spojeva monokromatskom ljubičastom lampom, dolazi do pobuđivanja tih molekula i nastaju spojevi koji djeluju citotoksično. Taj proces se naziva fotodinamički učinak. Cilj ovog istraživanja bio je odrediti kako sintetska bojila, s obzirom na tvrdoću vode, djeluju na odabrani mikroorganizam, Legionella pneumophila. To je gram – negativna štapićasta bakterija koja je prisutna u podzemnim i površinskim vodama. Ljudi se inficiraju udisanjem kontaminiranog aerosola, a lakši oblik infekcije, naziva se pontijačka groznica, dok je teži oblik legionarska bolest. U vodovodnim cijevima može stvarati biofilmove, što je štiti od djelovanja različitih vanjskih uvjeta. U ovom istraživanju, djelovanje sintetskih bojila, ispitivalo se na četiri uzorka vode različite tvrdoće. Djelotvornost sintetskih spojeva, ispitivalo se određivanjem minimalne efektivne koncentracije (MEC), testom fotoinaktivacije, inhibicijom adhezije na polistiren, inhibicijom stvaranja biofilma te razbijanjem već stvorenog biofilma. Iz rezultata je vidljivo da oba sintetska spoja pokazuju antilegionela učinak i da antibiofilm učinak ne ovisi o tvrdoći vode. Prisutnost iona zamjetno pogoduje djelovanju sintetske boje toluidin plavo na planktonske legionele, dok za metilen plavo vrijedi obratno. Najveća redukcija broja bakterija je prisutna već u 10 minuta izlaganja monokromatskom ljubičastom svjetlu. Kod inhibicije adhezije, inhibicije stvaranja biofilma i razbijanja već stvorenog biofilma, postoji značajna razlika u broju bakterija uzoraka vode s ispitivanim spojevima u odnosu na kontrolu.Synthetic dyes, methylene blue and toluidine blue, are used in medicine for coloring histological preparations. Illumination of these compounds with a monochromatic purple lamp results in the excitation of these molecules and cytotoxic compounds are formed. This process is called a photodynamic effect. The aim of this study was to determine how the synthetic dyes, depending on the hardness of the water, act on the selected microorganism, Legionella pneumophila. It is a gram negative bacteria that is present in ground and surface waters. People are infected by the inhalation of contaminated aerosols, and Legionella can cause Pontifical fever, and severe systemic disease, Legionnaires disease. Legionella form biofilms in water pipes, which protects it against the effects of different external conditions. In this study, the effect of synthetic dyes was investigated on four samples of different water hardness. The efficacy of synthetic compounds was investigated by determining minimum effective concentration (MEC), photoinactivation test, inhibition of adhesion to polystyrene, inhibition of biofilm formation, and breaking the already formed biofilm. It is apparent that both synthetic compounds show an anti - Legionella effect and that the antibiophilic effect does not depend on the hardness of the water. The presence of ions is noticeably favored by the synthetic color of toluidine blue effect, while the methylene blue is vice versa. The highest bacterial reduction is present in 10 minutes of monochromatic purple light exposure. Inhibition of adhesion, inhibition of biofilm formation, and degradation of the already formed biofilm, there is a significant difference in the number of bacteria in samples of water with the tested compounds compared to the control