Identification ofN‐acyl homoserine lactone‐degrading bacteria isolated from rainbow trout (Oncorhynchus mykiss)

Abstract

We could isolate and identify some novel QQ bacteria including Enterobacter hormaechei, Acinetobacter radioresistens and Citrobacter gillenii. The aiiA gene was detected for the first time in these strains as well as in Stenotrophomonas maltophilia. Our QQ isolates could be used for biocontrol of bacterial infections in aquaculture.

Effect of quorum quenching bacteria on growth, virulence factors and biofilm formation of Yersinia ruckeri in vitro and an in vivo evaluation of their probiotic effect in rainbow trout

“…The presence of QQ bacteria at the portal of entry of Y. ruckeri might be considered as a defence barrier against the pathogen. Our previous findings (Torabi Delshad et al., ) indicate that the used QQ bacteria can be found in the gill, skin and intestine tissues of rainbow trout. Hence, if infection is established by immersion, there is the potential that supplemented QQ bacteria can interfere with Yersinia and probably the QQ capacity of the tested strains downregulate virulence factor important during the early stage of infection by Yersinia .…”

“…Five isolates with positive QQ activity including Bacillus cereus strain 24QT (accession number: ), B. thuringiensis strain 7QT (accession number: ), Stenotrophomonas moltiphilia strain 2QT (accession number: ), Enterobacter hormaechei subsp. hormaechei strain 5QT (accession number: ) and Citrobacter gillenii strain 10QT (accession number: ) were selected from our previous study (Torabi Delshad, Soltanian, Sharifiyazdi, Haghkhah, & Bossier, ) to evaluate their inhibitory effect on QS‐regulated processes in Y. ruckeri .…”

“…Five QQ strains including S. moltophilia , E. hormaechei , B. thuringiensis , C. gillenii and B. cereus isolated from rainbow trout in our previous study (Torabi Delshad et al., ) were tested to verify any possible pathogenicity to fish, and the 50% lethal dose (LD 50 ) was calculated before the beginning of the feeding trial. To carry out this experiment, rainbow trout (average weight: 76 ± 10 g) were randomly taken and stocked in glass aquaria (10 fish per aquarium).…”

“…Therefore, in the current work, the role of quorum sensing in the regulation of some virulence factors of Y. ruckeri was studied. It also tried to use QQ bacteria, in vitro and as well as hormaechei strain 5QT (accession number: MF687149) and Citrobacter gillenii strain 10QT (accession number: MF687152) were selected from our previous study (Torabi Delshad, Soltanian, Sharifiyazdi, Haghkhah, & Bossier, 2018) to evaluate their inhibitory effect on QS-regulated processes in Y. ruckeri.…”

Quorum Quenching Properties and Probiotic Potentials of Intestinal Associated Bacteria in Asian Sea Bass Lates calcarifer

“…However, the majority of the strains that have been tested in the past are allochthonous QQ bacteria [21,23]. Moreover, the isolation of autochthonous bacteria with QQ potential has frequently been reported from freshwater fish [19,[24][25][26], and to our knowledge, there is only one report in marine fish [27]. On the other hand, despite the high mortalities caused by marine vibriosis, QQ strategy has not been adopted against commonly occurring Vibrio pathogens in fish, particularly, L. calcarifer, a euryhaline marine fish with high economic importance that has gained much attention from researchers and farmers in the last decade.…”