The protective effect of Bdellovibrio-and-like organisms (BALO) on tilapia fish fillets against Salmonella enterica ssp. enterica serovar Typhimurium.
OBJECTIVE
To characterize freshwater Bdellovibrio-and-like organisms (BALO) isolated in China and examine their potential in controlling growth of Salmonella enterica ssp. enterica serovar Typhimurium on tilapia fillets.


RESULTS
Four BALO isolates were recovered from a pond in Yanzhou of Shandong province, China, with Salm. Typhimurium as prey using double-layer agar method. Partial 16S rDNA sequencing analysis identified BD2GL, BD5GL and BDXGL as Bdellovibrio bacteriovorus and BD2GS as a Peredibacter sp. Lysis experiments on 32 potentially pathogenic strains revealed that BALO lysis rates are in the range of 56.3-65.6%. On the five Salmonella strains tested, only BD2GS achieved 100% lysis rate. When applied on tilapia fillets against Salm. Typhimurium, BD2GS showed its growth control potential. Cell increments of Salm. Typhimurium were significantly lower (P < 0.05) in two BD2GS-treated groups compared to control and low-dose group (BD2GS to prey ratio, 1 : 1) was more effective than high-dose group (BD2GS to prey ratio, 10 : 1) in controlling Salm. Typhimurium growth.


CONCLUSIONS
Results of this study indicated that BD2GS could control Salm. Typhimurium growth on tilapia fillets.


CONCLUSIONS
BALO could be used as a live protective culture in controlling bacterial growth and ensure food safety.
Lu
F
F
School of Biosciences and Bioengineering, South China University of Technology, University City, Panyu, Guangzhou, China.
Cai
J
J
D000818:Animals; D000898:Antibiosis; D001501:Bdellovibrio / Q000145:classification / Q000235:genetics / Q000254:growth & development*; D002681:China; D004269:DNA, Bacterial / Q000235:genetics; D005506:Food Contamination / Q000517:prevention & control*; D005516:Food Microbiology; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012486:Salmonella typhimurium / Q000254:growth & development* / Q000302:isolation & purification; D017747:Seafood / Q000382:microbiology*; D017422:Sequence Analysis, DNA; D017210:Tilapia / Q000382:microbiology
D004269:DNA, Bacterial; D012336:RNA, Ribosomal, 16S