RESUMO
Abstract Yellow pigmented, filamentous, Gram-negative bacteria belonging to genus Flavobacterium are commonly associated with infections in stressed fish. In this study, inter-species diversity of Flavobacterium was studied in apparently healthy freshwater farmed fishes. For this, ninety one yellow pigmented bacteria were isolated from skin and gill samples (n = 38) of three farmed fish species i.e. Labeo rohita, Catla catla and Cyprinus carpio. Among them, only twelve bacterial isolates (13.18%) were identified as Flavobacterium spp. on the basis of morphological, biochemical tests, partial 16S rDNA gene sequencing and phylogenetic analysis. On the basis of 16S rDNA gene sequencing, all the 12 isolates were 97.6-100% similar to six different formally described species of genus Flavobacterium. The 16S rDNA based phylogenetic analysis grouped these strains into six different clades. Of the 12 isolates, six strains (Fl9S1-6) grouped with F. suncheonense, two strains (Fl6I2, Fl6I3) with F. indicum and the rest four strains (Fl1A1, Fl2G1, Fl3H1 and Fl10T1) clustered with F. aquaticum, F. granuli, F. hercynium and F. terrae, respectively. None of these species except, F. hercynium were previously reported from fish. All the isolated Flavobacterium species possessed the ability of adhesion and biofilm formation to colonize the external surface of healthy fish. The present study is the first record of tropical freshwater farmed fishes as hosts to five environmentally associated species of the Flavobacterium.
Assuntos
Animais/classificação , Animais/genética , Animais/isolamento & purificação , Animais/microbiologia , Animais/fisiologia , Animais/veterinária , DNA Bacteriano/classificação , DNA Bacteriano/genética , DNA Bacteriano/isolamento & purificação , DNA Bacteriano/microbiologia , DNA Bacteriano/fisiologia , DNA Bacteriano/veterinária , DNA Ribossômico/classificação , DNA Ribossômico/genética , DNA Ribossômico/isolamento & purificação , DNA Ribossômico/microbiologia , DNA Ribossômico/fisiologia , DNA Ribossômico/veterinária , Doenças dos Peixes/classificação , Doenças dos Peixes/genética , Doenças dos Peixes/isolamento & purificação , Doenças dos Peixes/microbiologia , Doenças dos Peixes/fisiologia , Doenças dos Peixes/veterinária , Peixes/classificação , Peixes/genética , Peixes/isolamento & purificação , Peixes/microbiologia , Peixes/fisiologia , Peixes/veterinária , Infecções por Flavobacteriaceae/classificação , Infecções por Flavobacteriaceae/genética , Infecções por Flavobacteriaceae/isolamento & purificação , Infecções por Flavobacteriaceae/microbiologia , Infecções por Flavobacteriaceae/fisiologia , Infecções por Flavobacteriaceae/veterinária , Flavobacterium/classificação , Flavobacterium/genética , Flavobacterium/isolamento & purificação , Flavobacterium/microbiologia , Flavobacterium/fisiologia , Flavobacterium/veterinária , Água Doce/classificação , Água Doce/genética , Água Doce/isolamento & purificação , Água Doce/microbiologia , Água Doce/fisiologia , Água Doce/veterinária , Índia/classificação , Índia/genética , Índia/isolamento & purificação , Índia/microbiologia , Índia/fisiologia , Índia/veterinária , Dados de Sequência Molecular/classificação , Dados de Sequência Molecular/genética , Dados de Sequência Molecular/isolamento & purificação , Dados de Sequência Molecular/microbiologia , Dados de Sequência Molecular/fisiologia , Dados de Sequência Molecular/veterinária , Filogenia/classificação , Filogenia/genética , Filogenia/isolamento & purificação , Filogenia/microbiologia , Filogenia/fisiologia , Filogenia/veterinária , /classificação , /genética , /isolamento & purificação , /microbiologia , /fisiologia , /veterináriaRESUMO
No abstract available.
Assuntos
Humanos , Masculino , Pessoa de Meia-Idade , Povo Asiático , Infecções por Flavobacteriaceae , Flavobacterium/genética , Cirrose Hepática Alcoólica/sangue , RNA Ribossômico 16S/química , República da Coreia , Análise de Sequência de DNARESUMO
Bacterial cold water disease, enteric red mouth disease and frunculosis are the common bacterial diseases of fish worldwide. The etiologic agents of these diseases are Flavobacterium (F.) psychrophilum, Yersinia (Y.) ruckeri and Aeromonas (A.) salmonicida subsp. salmonicida, respectively. In this study, a multiplex polymerase chain reaction (m-PCR) method with YER8/10-Fer3/4-FP1/3 primer pairs which can identify these fish pathogens simultaneously was developed and optimized. In optimized conditions, neither false specific nor nonspecific amplification occurred. The detection limits of the m-PCR method using DNA extracts from dilutions of pure cultures of bacteria were 35 pg for Y. ruckeri and F. psychrophilum and 70 pg for A. salmonicida subsp. salmonicida. It was determined that 15 CFU Y. ruckeri and F. psychrophilum and 30 CFU A. salmonicida subsp. salmonicida could be detected by m-PCR developed using genomic DNA extracted from dilutions of the suspensions. The detection limits in the presence of tissue debris were 125 CFU for Y. ruckeri and F. psychrophilum and 250 CFU for A. salmonicida subsp. salmonicida. In conclusion, we submit that the m-PCR method developed and optimized in this study can be used for accurate and rapid identification of these bacteria.
Assuntos
Animais , Aeromonas salmonicida/genética , Primers do DNA/genética , Doenças dos Peixes/diagnóstico , Peixes , Flavobacterium/genética , Infecções por Bactérias Gram-Negativas/diagnóstico , Reação em Cadeia da Polimerase/métodos , Yersinia ruckeri/genéticaRESUMO
In order to evaluate the genetic variability of the causative agent of cold water disease (CWD), plasmid profiling was used to characterize Flavobacterium (F.) psychrophilum isolates (n = 169). Size analysis of plasmids in F. psychrophilum isolates (n = 128) from several fish species demonstrated that six kinds of plasmids were harbored, and ayu isolates had different profiles compared to other isolates. Moreover, multiple isolates (n = 41) from CWD outbreaks in 2002 to 2003 at a single ayu farm were examined to determine differences between isolates from successive outbreaks and showed different profiles by the sources of seedlings.
Assuntos
Animais , DNA Bacteriano/genética , Surtos de Doenças/veterinária , Eletroforese em Gel de Ágar/veterinária , Doenças dos Peixes/genética , Infecções por Flavobacteriaceae/microbiologia , Flavobacterium/genética , Variação Genética/genética , Japão , Osmeriformes , Plasmídeos/genéticaRESUMO
Plasmid borne organophosphorus pesticide degrading (opd) gene of Flavobacterium balustinum has been amplified using polymerase chain reaction (PCR) and the resulting PCR product (1.25 Kb) was cloned in pUC18. Further, a detailed restriction map was determined to PCR product and subcloned as overlapping restriction fragments. The nucleotide sequence was determined for all subclones to obtain complete sequence of PCR amplified fragment. The sequence showed 98% similarity to opd genes cloned from other soil bacteria isolated from diversified geographical regions. The protein sequence predicted from the nucleotide sequence was almost identical to parathion hydrolase, a triesterase involved in hydrolysis of triester bond found in variety of op-pesticides. The signal sequence of parathion hydrolase contained recently discovered twin arginine transport (tat) motif. It appears that tat motif plays a critical role in membrane targeting of parathion hydrolase.