A survey of soft cheeses in Greek retail outlets highlights a low prevalence of Listeria spp.

Recently, the European Food Safety Authority proposed that each EU member state should conduct a survey of Listeria monocytogenes in soft cheeses for sale in retail outlets. Hence, retail samples of soft cheeses in Greece (n = 137) were analyzed qualitatively and quantitatively for both L. monocytogenes and other Listeria spp., as well as for pH and a (w). None of the cheeses analyzed were found positive for L. monocytogenes (0%; 95% confidence interval (CI) = 0.0-2.2%). Three samples (2.2%; 95% CI = 0.5-6.3%) were positive for other Listeria spp., with populations ranging from < 5 to 4.5 x 10(2) CFU g(-1). Although soft cheeses are regarded as foods that permit the proliferation of L. monocytogenes, 15.4% of the whey cheeses tested had pH values a parts per thousand currency sign4.4 and 29% of the interior mold-ripened cheeses had a (w) values a parts per thousand currency sign0.92. Such low pH values for whey cheeses are unexpected, based on their manufacturing technology, and are associated with lower quality and reduced shelf life. Nonetheless, in the present survey, the percentage of whey cheeses in the Greek retail market exhibiting unusually low pH values or testing positive for Listeria spp. was much lower compared to the respective percentages reported from studies conducted in the 1990s. The absence of L. monocytogenes in the tested cheeses undoubtedly constitutes an encouraging result with respect to the safety of soft cheeses in the Greek retail market. However, the presence of other Listeria spp. in three of the tested samples implies that L. monocytogenes would, most likely, also be present in the food-processing or retail-handling environments of these products. Therefore, cheese manufacturers and retail handlers should continue or even intensify the application of all necessary measures with the aim of preventing food contamination

Cave Cyanobacteria showing antibacterial activity

Cave Cyanobacteria - thriving in an ‘extreme’ environment with interesting species biodiversity - are supposed to be a potential source of bioactive compounds. Lipid extracts from pure cultures of two recently established Cyanobacteria from Greek caves, Toxopsis calypsus and Phormidium melanochroun, were used for antibacterial screening against human pathogenic bacteria (reference and clinical isolates). Antimicrobial Susceptibility testing for both taxa was carried out using the disc-diffusion (Kirby Bauer) method, while preliminary data applying the standard broth microdilution method for the determination of the Minimal Inhibitory Concentration (MIC) are given only for T. calypsus. Antibacterial activity was demonstrated against the Gram-positive clinical and reference bacteria, mostly pronounced in enterococci; no activity was observed against the Gram-negative bacteria. The above screening is the first record of antibacterial activity from lipid extracts of cave Cyanobacteria enhancing the importance of cave microbiota and the necessity for cave conservation

Cave Cyanobacteria showing antibacterial activity

Cave Cyanobacteria - thriving in an ‘extreme’ environment with interesting species biodiversity - are supposed to be a potential source of bioactive compounds. Lipid extracts from pure cultures of two recently established Cyanobacteria from Greek caves, Toxopsis calypsus and Phormidium melanochroun, were used for antibacterial screening against human pathogenic bacteria (reference and clinical isolates). Antimicrobial Susceptibility testing for both taxa was carried out using the disc-diffusion (Kirby Bauer) method, while preliminary data applying the standard broth microdilution method for the determination of the Minimal Inhibitory Concentration (MIC) are given only for T. calypsus. Antibacterial activity was demonstrated against the Gram-positive clinical and reference bacteria, mostly pronounced in enterococci; no activity was observed against the Gram-negative bacteria. The above screening is the first record of antibacterial activity from lipid extracts of cave Cyanobacteria enhancing the importance of cave microbiota and the necessity for cave conservation