DESTRUCTION OF LACTIC ACID STREPTOCOCCUS BACTERIOPHAGE BY HYPOCHLORITE AND QUATERNARY AMMONIUM COMPOUNDS*

1951 ◽  
Vol 14 (2) ◽  
pp. 52-54 ◽  
Author(s):  
R. B. Parker ◽  
P. R. Elliker
Keyword(s):  
Lactic Acid ◽  
Sodium Hypochlorite ◽  
Quaternary Ammonium ◽  
Exposure Period ◽  
Quaternary Ammonium Compounds ◽  
Streptococcus Lactis ◽  
Streptococcus Cremoris ◽  
Quaternary Compounds ◽  
Dairy Equipment ◽  
Ammonium Compounds

A modification of the Weber and Black method was employed to compare rate of destruction of lactic streptococcus bacteriophage by sodium hypochlorite and quaternary ammonium compounds. At concentrations of 50 and 100 ppm, the hypochlorite exhibited faster destruction of phage than did the quaternary ammonium compounds. At 200 ppm both quaternaries and hypochlorites completely inactivated the phage in a 15-second exposure period. Results indicated that an active hypochlorite should be preferable to quaternary compounds for destruction of bacteriophage on dairy equipment. Different phage strains for both Streptococcus lactis and Streptococcus cremoris showed marked variations in resistance to quaternary ammonium germicides.

“INHIBITION” OF STREPTOCOCCUS LACTIS BY A QUATERNARY AMMONIUM COMPOUND IN CHEESE MILKS

1952 ◽  
Vol 15 (6) ◽  
pp. 278-299 ◽  
Author(s):  
Janet C. Curry ◽  
Franklin W. Barber
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Quaternary Ammonium ◽  
Acid Production ◽  
Lactic Acid Production ◽  
Quaternary Ammonium Compounds ◽  
Quaternary Ammonium Compound ◽  
Ammonium Compound ◽  
Streptococcus Lactis ◽  
Ammonium Compounds

The inhibition of lactic acid bacteria by quaternary ammonium compounds in milk has been shown to be an effect on acid production and not upon growth. Lactic acid production is affected by concentrations of 2.5 – 10 ppm, while growth is not affected unless the concentration is 25 – 50 ppm.

Heat Shock and Cold Shock Treatments Affect the Survival of Listeria monocytogenes and Salmonella Typhimurium Exposed to Disinfectants

2012 ◽  
Vol 75 (4) ◽  
pp. 695-700 ◽  
Author(s):  
MENG-HSUAN LIN ◽  
MING-LUN CHIANG ◽  
CHORNG-LIANG PAN ◽  
CHENG-CHUN CHOU
Keyword(s):  
Listeria Monocytogenes ◽  
Heat Shock ◽  
Salmonella Typhimurium ◽  
Chlorine Dioxide ◽  
Quaternary Ammonium ◽  
Cold Shock ◽  
Test Organism ◽  
Exposure Period ◽  
Quaternary Ammonium Compounds ◽  
Ammonium Compounds

The foodborne pathogens Listeria monocytogenes and Salmonella Typhimurium were subjected to heat shock at 48°C for 10 and 30 min, respectively, and then cold shocked at 15°C for 3 h. The effect of these shocks on the viability of test organisms exposed to chlorine dioxide and quaternary ammonium compounds was then determined. After exposure to the disinfectants, the viable population of each test organism, regardless of heat shock or cold shock treatment, decreased as the exposure period was extended. Both heat shock and cold shock treatments reduced the susceptibility of L. monocytogenes to both disinfectants at 25°C. However, for Salmonella Typhimurium, exposure to the chlorine dioxide disinfectant or quaternary ammonium compounds at 25°C significantly reduced (P < 0.05) survival of heat-shocked cells but significantly increased (P < 0.05) survival of cold-shocked cells compared with control cells. Survival of both L. monocytogenes and Salmonella Typhimurium generally was reduced after exposure to disinfectants at 40°C compared with 25°C.

STUDIES COMPARING THE SANITIZING EFFICIENCIES OF HYPOCHLORITES AND QUATERNARY AMMONIUM COMPOUNDS

1947 ◽  
Vol 25f (1) ◽  
pp. 76-91 ◽  
Author(s):  
C. K. Johns
Keyword(s):  
Quaternary Ammonium ◽  
Food Processing ◽  
Quaternary Ammonium Compounds ◽  
Glass Slide ◽  
Bacteriostatic Effect ◽  
Quaternary Compounds ◽  
Processing Plants ◽  
Glass Surfaces ◽  
Slide Technique ◽  
Ammonium Compounds

The germicidal speed of four quaternary ammonium compounds has been compared with that of two hypochlorites against Staphylococcus aureus, Bacillus panis (vegetative cells and spores), Micrococcus candidus, cheese starter organisms, Escherichia coli and Pseudomonas aeruginosa, using the glass slide technique originally devised for comparing chlorine sterilizing agents. Against the Gram-positive species, the quaternary compounds were generally more effective than the hypochlorites; against the Gram-negative species, the reverse held true. Cheese starter organisms were an exception, being killed faster by the hypochlorites. Three of the four quaternary compounds were closely comparable in efficiency, while the fourth was definitely slower. The hypochlorites responded much more readily to favourable adjustments in pH and temperature than did the quaternary compounds. Some bacteriostatic effect was observed with higher concentrations of all four quaternary compounds, but it is not believed that the results were significantly affected thereby. The glass slide technique appears to offer many advantages in the evaluation of the germicidal efficiency of products designed for sanitizing metal or glass surfaces in food processing plants.

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