Acute hepatopancreatic necrosis disease (AHPND) is one
of the most significant bacterial diseases in global shrimp
culture, causing severe economic losses. In the present study,
we carried out in vitro antimicrobial tests to investigate the
disinfection efficacy of 14 common disinfectants toward different
AHPND-causing Vibrio spp., including eight isolates
of V. parahaemolyticus, four isolates of V. campbellii, and
one isolate of V. owensii. Polyhexamethylene biguanidine hydrochloride
(PHMB) was revealed to possess the strongest
inhibitory activity. Through analyzing and evaluating the results
of antimicrobial tests and acute toxicity test, we selected
PHMB and hydrogen peroxide (H2O2) for further clinical
protection test. Clinical manifestations indicated that both
PHMB (2 mg/L and 4 mg/L) and H2O2 (12 mg/L) could effectively
protect juvenile Penaeus vannamei from the infection
of V. parahaemolyticus isolate Vp362 at 106 CFU/ml, and the
survival rate was over 80%. When the bacterial concentration
was reduced to 105 CFU/ml, 104 CFU/ml, and 103 CFU/ml,
the survival rate after treated by 1 mg/L PHMB was 64.44%,
93.33%, and 100%, respectively. According to the results,
PHMB and H2O2 showed a lower toxicity while a better protection
activity, particularly against a lower concentration of
the pathogens. Therefore, these two disinfectants are proved
to be promising disinfectants that can be applied to prevent
and control AHPND in shrimp culture. Moreover, the methods
of this study also provided valuable information for the
prevention of other important bacterial diseases and suggested
a reliable means for screening potential drugs in aquaculture.