Query: the amount of vibrio harveyi in water quality

title: Distribution profile of Vibrio harveyi in Panulirus homarus
abstract: Microbiological studies in lobster culture rearing system at Kovalam laboratory, Chennai was carried out for a period of 150 days. The infected tissues, gills, gut and the exoskeleton of the diseased animal were subjected to various microbial analysis to study the distribution profile of luminous bacterial. The total heterotrophic bacteria in the water, sediment and animal samples were also determined. The total heterotrophic bacterial counts ranged from 1.6 x 10 3 to 26.3 x 10 3 cfu/ml in water, 2.4 x 10 5 24.2 x 10 5 cfu/ml in sediment and 3.4 x 10 6 to 4.2 x 10 6 cfu/ml in infected animals. The Vibrio harveyi population density varied between 0.8 x 10 3 to 9.6 x 10 3 LCFU/ml in water, 1.8 x 10 5 to 12.5 x 10 5 LCFU/ml in sediment and 1.3 x 10 6 to 2.2 x 10 6 LCFU/ml in animal. The high amount of luminescent bacteria accounted to the outbreak of tail fan

title: Assimilable Organic Carbon (AOC) in Soil Water Extracts Using Vibrio harveyi BB721 and Its Implication for Microbial Biomass
abstract: Assimilable organic carbon (AOC) is commonly used to measure the growth potential of microorganisms in water, but has not yet been investigated for measuring microbial growth potential in soils. In this study, a simple, rapid, and non growth based assay to determine AOC in soil was developed using a naturally occurring luminous strain Vibrio harveyi BB721 to determine the fraction of low molecular weight organic carbon in soil water extract. Calibration of the assay was achieved by measuring the luminescence intensity of starved V. harveyi BB721 cells in the late exponential phase with a concentration range from 0 to 800 ug l 1 glucose (equivalent to 0 16.0 mg glucose C kg 1 soil) with the detection limit of 10 ug l 1 equivalent to 0.20 mg glucose C kg 1 soil. Results showed that bioluminescence was proportional to the concentration of glucose added to soil. The luminescence intensity of the cells was highly pH dependent and the optimal pH was about 7.0. The average AOC concentration in 32 soils tested was 2.9+ 2.2 mg glucose C kg 1. Our data showed that AOC levels in soil water extracts were significantly correlated (P<0.05) with microbial biomass determined as microbial biomass carbon, indicating that the AOC concentrations determined by the method developed might be a good indicator of soil microbial biomass. Our findings provide a new approach that may be used to determine AOC in environmental samples using a non growth bioluminescence based assay. Understanding the levels of AOC in soil water extract provides new insights into our ability to estimate the most available carbon pool to bacteria in soil that may be easily assimilated into cells for many metabolic processes and suggest possible the links between AOC, microbial regrowth potential, and microbial biomass in soils.

title: Studies on the chemical control of luminous bacteria Vibrio harveyi and V. splendidus isolated from diseased Penaeus monodon larvae and rearing water
abstract: The minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) of 24 drugs for luminous bacteria Vibrio harveyi and V. splendidus were determined. Only chloramphenicol, sodium nifurstyrenate and the nitrofurans (furazolidone, nitrofurazone, nitrofurantoin and Prefuran) showed relatively low MICs and MBCs 25 pg ml l) The bacteria showed varied responses to chloramphenicol and Prefuran, and low sensitivity to oxytetracycline. Chloramphenicol, oxytetracycline and Prefuran are commonly used in shrimp hatcheries. Shrimp larvae showed high survival rates and active swimming movement after 24 h exposure to in vivo bactericidal doses of chloramphenicol, Furacin, nitrofurantoin (protozoea only) oxytetracycline (nauplius only) Prefuran (mysis only) and sodium nifurstyrenate, but the drugs caused deformities in the carapace, rostrum, and setae. Chemical control of luminous vibriosis among shrimp larvae appears limited, based on the efficacy of existing and readily available drugs, because of the possible development of resistant strains of bacteria and the limited tolerance of the shrimp larvae to the drugs.

title: ADHERENCE AND PATHOGENICITY ASSAY OF VIBRIO HARVEYI IN TIGER SHRIMP (PENAEUS MONODON) LARVAE FOR SCREENING BIOCONTROL AGENT
abstract: Rifampicin resistant marker was employed as a reporter to detect the adherence and colonization of V. harveyi in shrimp larvae. Vibrio harveyi P1B and YA32.2 were isolated from dead shrimp larvae in Besuki, Northern Coast of East Java, while V. harveyi HB3, was isolated from pristine sea water in Pacitan, Southern Coast of East Java. Vibrio metschnikovii used as biocontrol agent was isolated from healthy shrimp larvae in Serang, West Java. Spontaneous mutation was conducted to generate V. harveyi P1B, YA32.2 and HB3 resistant to rifampicin. These mutants exhibited similar survival ability to their parental (wild type) strains. Significant larval mortality was observed in shrimp larvae inoculated with YA32.2 than that of larvae inoculated with P1B. Larvae inoculated with HB3 showed the lowest mortality. Bacterial cell count of Vibrio Rf* in dead larvae were 103 104 cells/larvae. Isolates of Vibrio metschnikovii Z and M as biocontrol candidates effectively reduced the growth and adherence ability of YA32.2 to shrimp larvae. Larval mortality in rearing water inoculated simultaneously with YA32.2 and V. metschnikovii was lower than the one inoculated with YA32.2 alone. Therefore, Vibrio metschnikovii Z or M could be developed as an effective probiotic or biocontrol agent for V. harveyi in shrimp hatcheries.  Biological control/Vibrio metschnikovii/shrimp \arvae/Penaeus mwu<<fon

title: Rapid multiplex polymerase chain reaction for simultaneous detection of Vibrio harveyi, V. parahaemolyticus, and V. vulnificus in pacific white shrimp (Litopenaeus vannamei)
abstract: A comparatively small number of species, e.g. Vibrio parahaemolyticus and V. vulnificus, cause disease in both aquatic animals and humans. V. harveyi is marine animal pathogen and rarely causes infections in humans; however, it might become a reservoir of antibiotic resistant bacteria forms and virulence genes.  1) to develop rapid multiplex polymerase chain reaction (PCR) assay for the simultaneous detection of V. harveyi, V. parahaemolyticus, and V. vulnificus by using vhhP2, tl, and rpoS genes as the respective target genes and 2) to evaluate specificity and determined detection of multiplex PCR technique.  The multiplex PCR assay was developed and evaluated for specificity on 36 isolates of V. harveyi, 30 isolates of V. parahaemolyticus, and 14 isolates of V. vulnificus, along with other species of Vibrio and non Vibrio bacterial isolates. Sensitivity of test was described as detection limit of pathogens in lowest amount of sample (CFU/mL or CFU/g) was determined by diluted DNA extracts of the pure cultures and spiked pacific white shrimp (Litopenaeus vannamei) samples  This developed multiplex PCR was proved as an accurate method, which was specific for three Vibrio species. The detection limits of V. harveyi, V. parahaemolyticus, and V. vulnificus in pure cultures and spiked shrimp samples ranged 1.05 4.8 x 103 CFU/mL and 1.9 7 x 104 CFU/g, respectively.  This rapid multiplex PCR assay can decrease amount and process of sample preparation, which was time consuming, and had preferable accuracy. This developed technique will be suitable and useful for food borne pathogen detection in shrimp and horizontal gene transfer study among different Vibrio species in aquatic animals.

title: Beneficial effects of tuna hydrolysate in poultry by product meal diets on growth, immune response, intestinal health and disease resistance to Vibrio harveyi in juvenile barramundi, Lates calcarifer
abstract: This study was conducted to investigate the effects that tuna hydrolysate (TH) supplementation in poultry by product meal (PBM) diets would have on growth, immunity and resistance to Vibrio harveyi infection in juvenile barramundi, Lates calcarifer. Five isonitrogenous and isocaloric diets containing fishmeal (FM) without TH supplementation (control) and four diets with 10% TH supplementation viz. a FM protein diet (FMBD TH) a 75% PBM protein diet (LPBM TH) and two 90% PBM protein diets, either bioprocessed (BPBM TH) or unprocessed (HPBM TH) were formulated for juvenile barramundi, Lates calcarifer. The diets were fed to triplicate groups of juvenile barramundi (average pool weight 12.63 0.11 g) for 10 weeks. Significantly (P 0.05) higher final body weights and specific growth rates were noted in fish fed with FMBD TH and BPBM TH diets when compared to the control. Transmission electron microscopy observation of fish distal intestines revealed a significant enhancement of microvilli length in fish fed FMBD TH and BPBM TH whereas scanning electron microscopy analysis found no significant difference in microvilli density. A bacterial challenge with Vibrio harveyi was conducted for 14 days after the growth trial to test the immune response and survival of barramundi. In the pre challenge condition, a significant reduction in blood glucose was found in BPBM TH compared to the control, and fish in the post challenge at 24 h had higher glucose levels compared to fish in the pre and post challenge conditions at 72 h. The serum lysozyme activity was significantly higher in FMBD TH and BPBM TH compared to the control and fish at 72 h post challenge exhibited higher lysozyme activity in each treatment compared to all dietary groups in the post challenge condition at 24 h and to HPBM TH and BPBM TH in the pre challenge condition. Fish fed FMBD TH, LPBM TH and BPBM TH diets had significantly higher survival to the bacterial challenge than fish in the control and HPBM TH. These results showed that PBM supplemented with TH could successfully replace FM without compromising growth, however, bioprocessed PBM supplemented with TH (BPBM TH) may significantly improve growth performance, immune response, intestinal health and disease resistance in juvenile barramundi. HighlightsPoultry by products meal bioprocessed by Saccharomyces cerevisiae and Lactobacillus casei and supplemented with 10% tuna hydrolysate promotes growth performance and intestinal mucosal morphology of barramundi.Ten percent tuna hydrolysate supplementation in bioprocessed poultry by product meal based diet enhances the innate immunity of the barramundi against Vibrio harveyi infection.Supplementation of tuna hydrolysate is recommended for non fishmeal based barramundi diets.

title: Horizontal gene transfer contributes to virulence and antibiotic resistance of Vibrio harveyi 345 based on complete genome sequence analysis
abstract: BackgroundHorizontal gene transfer (HGT) which is affected by environmental pollution and climate change, promotes genetic communication, changing bacterial pathogenicity and drug resistance. However, few studies have been conducted on the effect of HGT on the high pathogenicity and drug resistance of the opportunistic pathogen Vibrio harveyi.ResultsV. harveyi 345 that was multidrug resistant and infected Epinephelus oanceolutus was isolated from a diseased organism in Shenzhen, Southern China, an important and contaminated aquaculture area. Analysis of the entire genome sequence predicted 5678 genes including 487 virulence genes contributing to bacterial pathogenesis and 25 antibiotic resistance genes (ARGs) contributing to antimicrobial resistance. Five ARGs (tetm, tetb, qnrs, dfra17, and sul2) and one virulence gene (CU052_28670) on the pAQU type plasmid p345 185, provided direct evidence for HGT. Comparative genome analysis of 31 V. harveyi strains indicated that 217 genes and 7 gene families, including a class C beta lactamase gene, a virulence associated protein D gene, and an OmpA family protein gene were specific to strain V. harveyi 345. These genes could contribute to HGT or be horizontally transferred from other bacteria to enhance the virulence or antibiotic resistance of 345. Mobile genetic elements in 71 genomic islands encoding virulence factors for three type III secretion proteins and 13 type VI secretion system proteins, and two incomplete prophage sequences were detected that could be HGT transfer tools. Evaluation of the complete genome of V. harveyi 345 and comparative genomics indicated genomic exchange, especially exchange of pathogenic genes and drug resistance genes by HGT contributing to pathogenicity and drug resistance. Climate change and continued environmental deterioration are expected to accelerate the HGT of V. harveyi, increasing its pathogenicity and drug resistance.ConclusionThis study provides timely information for further analysis of V. harveyi pathogenesis and antimicrobial resistance and developing pollution control measurements for coastal areas.

title: In vitro and in vivo biocontrol of Vibrio harveyi using indigenous bacterium, Bacillus spp.
abstract: The present study was undertaken to find out the potential of indigenously isolated Bacillus spp. in controlling virulent luminous Vibrio harveyi infection in shrimp in vitro and in vivo. Luminescent bacteria were isolated from shrimp farms of east coast of India. It is biochemically and genetically identified as Vibrio harveyi. Two isolates of Vibrio harveyi obtained from infected shrimps were used for pathogenicity studies in juvenile shrimps and the LD50 values for the above isolates ranged between 3.7 x 10 6 to 8.9 x 10 7 CFU/ml. Indigenously isolated and identified Bacillus spp. exhibiting antagonism were used for controlling the Vibrio infection both in vivo and in vitro. In vivo antagonistic activity was studied with three selected Bacillus isolates. The same had reduced the mortality of Penaeus monodon juveniles when challenged with V. harveyi with an RPS of 87.5 50% This is without affecting the multiplication of the pathogen in water. Present study found that indigenously isolated antagonistic Bacillus sp. could be used as effective biocontrol agents against pathogenic luminescent V. harveyi.

title: In vitro antagonistic properties of copper nanoparticles and probiotic Bacillus subtilis against pathogenic luminescent Vibrio harveyi.
abstract: Aquaculture industry especially shrimp farming in Iran and other parts of the world has been facing various disease that among various agents, pathogenic bacteria has emerged as important because it causes large economic losses to the shrimp farming industry. This study investigated the antagonistic properties of copper nanoparticles (34 mg/L) probiotic Bacillus subtilis (10 CFU/mL) and combination of these two against with pathogenic bacteria, luminescent Vibrio harveyi in vitro condition in order to investigate possible use of probiotic B. subtilis and copper nanoparticles in the diet for growth and immunity enhancement in Litopenaeus vannamei. This study reports that in Well diffusion test and Disc diffusion test against pathogenic bacteria luminescent V. harveyi maximum inhibition showed by combination of suspension of probiotic B. subtilis and copper nanoparticles the amount of (W 22.54+ 1.72 and D 16.37+ 2.9) whereas minimum inhibition was copper nanoparticles the amount of (W D 0) Results indicated the possible synchronic use of probiotic B. subtilis and copper nanoparticles in shrimp diet.

title: Effects of stocking density of the white shrimp Litopenaeus vannamei (Boone) on immunities, antioxidant status, and resistance against Vibrio harveyi in a biofloc system
abstract: Determining optimum stocking density of the white shrimp Litopenaeus vannamei (Boone) is a big concern for shrimp farmers. However, few studies have assessed the influence of stocking density on the antioxidant status, immunology, digestive enzyme activities, and growth performance of white shrimp in biofloc systems. In this study, these parameters of white shrimp in a biofloc system were compared at three stocking densities: 300 orgs m 3 as low stocking density (LD) 400 orgs m 3 as medium stocking density (MD) and 500 orgs m 3 as high stocking density (HD) The feed conversion ratio in the LD group was significantly lower than that in the MD and HD groups (P 0.05) and the ultimate individual weight in the LD group was significantly higher than that in the other two groups (P 0.05) The antioxidant status and immunology parameters, including complement 3, complement 4, lysozyme, superoxide dismutase, glutathione peroxidase and malondialdehyde were all depressed in the HD groups. Furthermore, activities of the digestive enzymes, amylase, trypsin, and lipase were lower in the MD and HD groups than that in the LD group. The highest relative percentage survival was observed in the LD group 10 days after challenge with the pathogen Vibrio harveyi. Results of this study indicated that the immune status and welfare of white shrimp can be seriously impaired in the HD condition (i.e. =500 m 3) in biofloc systems. These findings can be used to determine suitable stocking densities in the white shrimp farming industry using the biofloc system. HighlightsHigh stocking density had effects on the culture of Litopenaeus vannamei in a biofloc based system.High stocking density stress reduced shrimp growth performance in the biofloc system.Choosing a suitable stocking density can obtain a high yield of Litopenaeus vannameiHigh stocking density had a bad influence on the shrimp immune parameters in the biofloc system.