Data for the properties of Listeria strains (a review)

It seems that taxonomy of listeriae is in a fluid stage. Between beta-haemolytic property and virulence of these bacteria a strong relationship has been demonstrated. These characters are coded by hlyA gene which seems to belong to a monocistronic unit. Virulent Listeria strains possess specific surface antigens and can enter as well as multiply in host cells. Their exact human virulence is not known. Listeriae can grow from around 0 to 42 degrees C and can survive either the effect of frost or of temperature of 48 degrees C. They may form biofilm on different surfaces. Their growth kinetics, persistance and heat resistance can be influenced by many factors (type of growth environment, pH, acidulants, salts, chemicals, antibiotics, plant substances, enzymes, humidity, atmosphere, temperature, prior temperature-effects, microbial competition and the length of influences). Radiation sensitivity of Listeria is usual. Plasmid mediated antibiotic resistant mutant of Listeria monocytogenes is verified.