Identification of Vibrio campbellii isolated from diseased farm-shrimps from south India and establishment of its pathogenic potential in an Artemia model.
Shrimp diseases are frequently reported to be caused by closely related vibrios, and in many cases they are tentatively but inaccurately identified as Vibrio harveyi and related vibrios. In the present study, 28 biochemically identified V. harveyi-related strains isolated from diseased shrimps were randomly selected for further characterization by molecular tools. Twenty-six strains were identified as Vibrio campbellii and two as V. harveyi by sequence analysis of 16S rRNA and uridylate kinase genes. Haemolysin-gene-based species-specific multiplex PCR also confirmed these results. Experimental challenge studies using Artemia as a model showed that eight isolates were highly pathogenic, three were moderately pathogenic and the remaining 17 were non-pathogenic. Ribotyping with BglI clearly distinguished V. campbellii from V. harveyi, but it failed to separate pathogenic and non-pathogenic clusters. Artemia nauplii challenged with a fluorescently labelled highly pathogenic strain (IPEY54) showed patches in the digestive tract. However, no patches were observed for a non-pathogenic strain (IPEY41). Direct bacterial counts also supported colonization potential for the highly pathogenic strain. To our knowledge, this is the first report on the isolation and accurate identification of large numbers of V. campbellii associated with shrimp disease in aquacultural farms. V. campbellii has long been considered to be non-pathogenic and classified with V. harveyi-related bacteria. However, we show that this species may be an emerging aquaculture pathogen. This study will help to formulate suitable strategies to combat this newly identified pathogen.
Haldar
Soumya
S
Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Osaka, Japan.
Chatterjee
Shruti
S
Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Osaka, Japan.
Sugimoto
Norihiko
N
Research and Development Centre, Fuso Pharmaceutical Industries Ltd, Osaka, Japan.|Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Osaka, Japan.
Das
Surajit
S
CAS in Marine Biology, Annamalai University, Tamilnadu, India.
Chowdhury
Nityananda
N
Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Osaka, Japan.
Hinenoya
Atsushi
A
Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Osaka, Japan.
Asakura
Masahiro
M
Research and Development Centre, Fuso Pharmaceutical Industries Ltd, Osaka, Japan.|Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Osaka, Japan.
Yamasaki
Shinji
S
Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Osaka, Japan.
D000818:Animals; D017756:Aquaculture; D001156:Artemia / Q000382:microbiology*; D015373:Bacterial Typing Techniques; D016000:Cluster Analysis; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D004195:Disease Models, Animal; D006460:Hemolysin Proteins / Q000235:genetics; D007194:India; D008969:Molecular Sequence Data; D009703:Nucleoside-Phosphate Kinase / Q000235:genetics; D033561:Penaeidae / Q000382:microbiology*; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D021521:Ribotyping; D017422:Sequence Analysis, DNA; D014733:Vibrio / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification* / Q000472:pathogenicity
D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D006460:Hemolysin Proteins; D012336:RNA, Ribosomal, 16S; C023276:uridine monophosphate kinase; D009703:Nucleoside-Phosphate Kinase