Imidazole and 1,2,4-Triazole-based Derivatives Gifted with Antitubercular Activity: Cytotoxicity and Computational Assessment.

BACKGROUND: Mycobacterium Tuberculosis (Mtb) is the causative pathogen of Tuberculosis (TB) and outbreaks are more common among immunosuppressed persons infected with HIV. The current treatment regimens are lengthy and toxic, yet the therapy has remained unchanged for many decades, so there is a need to find new structures with selective mechanism of action. Moreover, the increased incidence of severe disseminated infections produced by undiagnosed Multidrug-resistant (MDR), worsen clinical treatment and contribute the spread of the disease. OBJECTIVE: The aim of our study was to evaluate the potential of imidazole and triazole moieties for antimycobacterial activity, by synthesizing some 1-(1-(aryl)-2-(2,6-dichlorophenyl)hydrazono)ethyl- 1H-imidazole and 1H-1,2,4-triazole derivatives 2a-l. METHODS: The title compounds were obtained via classical organic synthesis. The antimicrobial activity was evaluated using the method of microdilution and the cytotoxicity assay was performed by MTT method. RESULTS: The results indicated that the presence of both the imidazole ring and that of the 2,6- dichlorosubstituted phenyl moiety, is more relevant for inhibitory activity against Mtb than the triazole nucleus and the unsubstituted phenyl ring. Among the series, (E)-1-(2-(5-chlorothiophen-2-yl)-2-(2- (2,6-dichlorophenyl)hydrazono)ethyl)-1H-imidazole derivative 2f and (Z)-1-(2-([1,1'-biphenyl]-4-yl)- 2-(2-(2,6-dichlorophenyl)hydrazono)ethyl]-1H-imidazole derivatives 2e exhibited a promising antimycobacterial property and the latter also displayed a safe cytotoxic profile. CONCLUSION: The synthesized compounds were studied for their antitubercular activity. Among the series, the compounds 2e and 2f appeared to be the most promising agents and, according to the docking assessment, the compounds could be CYP51 inhibitors. These evidences could be useful for the future development of new antimycobacterial derivatives targeting CYP51 with more specificity for the mycobacterial cell enzyme.

Detection of Virulence Genes and Growth Potential in Listeria monocytogenes Strains Isolated from Ricotta Salata Cheese.

Ricotta Salata is a traditional ripened and salted whey cheese made in Sardinia (Italy) from sheep's milk. This product is catalogued as ready-to-eat food (RTE) since it is not submitted to any further treatment before consumption. Thus, foodborne pathogens, such as Listeria monocytogenes, can represent a health risk for consumers. In September 2012, the FDA ordered the recall of several batches of Ricotta Salata imported from Italy linked to 22 cases of Listeriosis in the United States. This study was aimed at evaluating the presence and virulence properties of L. monocytogenes in 87 samples of Ricotta Salata produced in Sardinia. The ability of this product to support its growth under foreseen packing and storing conditions was also evaluated in 252 samples. Of the 87 samples 17.2% were positive for the presence of L. monocytogenes with an average concentration of 2.2 log10 cfu/g. All virulence-associated genes (prfA, rrn, hlyA, actA, inlA, inlB, iap, plcA, and plcB) were detected in only one isolated strain. The Ricotta Salata samples were artificially inoculated and growth potential (δ) was assessed over a period of 3 mo. The value of the growth potential was always >0.5 log10 cfu/g under foreseen packing and storing conditions. This study indicates that Ricotta Salata supports the L. monocytogenes growth to levels that may present a serious risk to public health, even while stored at refrigeration temperatures.