[Comparison on resistance of bacteriophages to sodium dichloroisocyanurate in laboratory].
OBJECTIVE
To scan the most resistable bacteriophage as an indicator in disinfection tests, and to study the resistance of bacteriophage T4, Phichi 174D, and f2 to the sodium dichloroisocyanurate (NaDCC) in laboratory.


METHODS
The virucidal activity of NaDCC against bacteriophage T4, Phichi 174D, and f2 were assessed by suspension test. The neutralizer was selected and be appraised by test of neutralizer. Bacteriophage T4, Phichi 174D, and f2 were detected and enumerated by the double-agar-layer plaque technique.


RESULTS
(1) With 150 mg/L of available chlorine of NaDCC solution, within a contact time of 40 minutes, or 300 mg/L, 5 minutes, the reductions of bacteriophage T4 achieved the "disinfection" level [log(10) inactivation value or log(10) reduction value of bacteriophage T4 (log(10)No-log(10)Nt) > or = 4.00 log(10)]. (2) With 300 mg/L of available chlorine of NaDCC solution, within a contact time of 5 minutes, or 400 mg/L, 3 minutes, the reductions of bacteriophage Phichi 174D achieved the "disinfection" level. (3) With 2000 mg/L of available chlorine of NaDCC solution, within a contact time of 20 minutes, or 4000 mg/L, 5 minutes, the reductions of bacteriophage f2 might achieve the "disinfection" level.


CONCLUSIONS
The order of resistance of the above three bacteriophages to NaDCC from greatest to smallest is as follows: bacteriophage f2 > bacteriophage T4 > bacteriophage Phichi 174D.
Chen
Zhao-bin
ZB
Department of Medical Laboratory Technology, West China School of Public Health, Sichuan University, Chengdu 610041, China.
Zhang
Chao-wu
CW
Xu
Xin
X
Zhu
Min
M
Wang
Guo-qing
GQ
D017122:Bacteriophage T4 / Q000187:drug effects; D010584:Bacteriophage phi X 174 / Q000187:drug effects; D001435:Bacteriophages / Q000187:drug effects*; D004202:Disinfectants / Q000494:pharmacology*; D024882:Drug Resistance, Viral; D012973:Sodium Hypochlorite / Q000494:pharmacology*
D004202:Disinfectants; D012973:Sodium Hypochlorite