Growth response and acquired resistance of Nile tilapia ...
Growth Response and Acquired Resistance of Nile Tilapia Oreochromis niloticus Following Infection or Vaccination with Streptococcus iniae
Craig A. Shoemaker*, Chhorn Lim, Mediha Yildirim-Aksoy, Thomas L. Welker, Phillip H. Klesius and Joyce J. Evans
United States Department of Agriculture-Agricultural Research Service, Aquatic Animal Health Research Unit, P.O. Box 0952, Auburn, Alabama, 36831, USA
Email: cshoemaker@ars.
Key words: Streptococcus iniae, tilapia, growth performance, acquired resistance
Abstract
Growth performance and acquired resistance of Nile tilapia, Oreochromis niloticus (L.) that survived Streptococcus iniae infection was determined. Tilapia were challenged with three doses of S. iniae (8.8 x 103, 8.8 x 104 and 8.8 x 105 CFU fish-1 for low, medium and high challenges, respectively). Groups of non-injected and tryptic soy broth-injected fish were maintained as controls. Significantly (P < 0.05) higher mortality (45.0 %) occurred in the high challenge treatment than in the low challenge treatment group (29.6 %). The medium challenge group had mortality (36.3 %) that did not differ significantly from the high or low treatment. Few fish died in the non-injected and broth-injected treatments (3.4 and 0.8 %, respectively). The tilapia that survived S. iniae infection and used to assess growth performance were selected from survivors without gross clinical signs of disease. These fish were randomly stocked at a rate of 30 fish into each 57-L aquarium in triplicate and fed to apparent satiation twice daily for 8 weeks. No significant differences were detected in weight gain, feed intake, feed efficiency ratio or survival between S. iniae-survived tilapia and the control treatments following the 8-week growth performance trial. After the 8-week feeding study, tilapia were challenged with 1 x 106 CFU fish-1 of S. iniae to assess acquired immunity. Mean cumulative mortality was significantly higher (P < 0.05) in the control treatments (41.7 % for the non-injected and 43.3 % for the broth-injected fish) than in the low, medium and high challenge treatments (7.4, 3.3 and 8.3 %, respectively). Serum protein was significantly (P < 0.05) elevated in S. iniae-survived tilapia that were subsequently challenged when compared to controls challenged for the first time. Agglutinating antibody titer was significantly higher in the fish in the medium and high challenge treatments, compared to the control fish challenged for the first time. Tilapia surviving S. iniae challenge without showing overt disease signs performed as well as non-infected tilapia and gained acquired resistance to homologous S. iniae challenge.
Streptococcus iniae is an important Gram-positive bacterial pathogen of tilapia and other cultured fish species world wide (Eldar et al. 1997; Perera et al. 1997; Bowser et al. 1998; Zlotkin et al. 1998; Shoemaker et al. 2001; Colorni et al. 2002; Nguyen et al. 2002). Tilapia producers suggest fish infected with S. iniae do not perform well and the poor performance results in lost profits. Some suggestion has also been made that decreased growth in tilapia occurred following intraperitoneal (i.p. injection) vaccination; however, little work has been conducted to address this potential problem. Immune-induced growth suppression has been suggested (Klasing et al. 1987) in other animal species. Cook (1999) estimated more than $500 million U.S. is lost due to stimulation of the immune system either via vaccination or through exposure to natural microbes in terrestrial animals that result in decreased performance. The presence of overt disease in a population nullifies the lost performance following vaccination (Chamberlee et al. 1992). Recent work in channel catfish (Ictalurus punctatus) administered a modified live Edwardsiella ictaluri vaccine has shown an improved profit to farmers by as much as $700/ha over non-vaccinated catfish due to improved growth of the vaccinated catfish (Intervet, Inc., Technical Bulletin AQ-ESC-PKA 12/04, Millsboro, DE). Edwardsiella ictaluri is known to be present in the aquatic environment and has been reported to be a problem for 70% of commercial catfish operations (Wagner et al. 2002).
Most growth performance studies to date in fish have involved diet manipulation and/or prebiotic or probiotic supplementation with subsequent challenge of fish to assess disease resistance (Whittington et al. 2003; Peres et al. 2004; Li and Gatlin 2004). Mixed results have been obtained with regard to the addition of nutrients and/or probiotics with respect to increasing growth and/or resistance of tilapia to streptococcal disease. Lara-Flores et al. (2003) reported that the growth response of Nile tilapia (Oreochromis niloticus) was improved following feeding of two bacterial (S. faecium and Lactobacillus acidophilus) and one yeast (Saccharomyces cerivisiae) probiotic for 9 weeks. The fish in their study (Lara-Flores et al. 2003) were not challenged following feeding. In contrast, Shelby et al. (In Press) found that supplementation of tilapia fry diets with probiotics (3 bacteria and one yeast) did not improve growth performance or disease resistance in tilapia fry weighing 12-29 mg. These authors did show that the probiotic bacteria persisted for at least 48 h in the digestive tract after feeding. Limited published information is available on the growth response of tilapia following infection or vaccination with S. iniae. This manuscript will describe recent studies conducted by our group on growth performance and acquired resistance of Nile tilapia following infection or vaccination with S. iniae.
Growth Response Following Infection
Tilapia were used that had survived experimental infection with S. iniae at three challenge levels: low (8.8 X 103 CFU/fish), medium (8.8 x 104 CFU/fish) and high (8.8 x 105 CFU/fish). Groups of non-injected and tryptic soy broth-injected fish were maintained as controls. Significantly (P < 0.05) higher mortality (45.0 %) occurred in the high challenge treatment than in the low challenge treatment group (29.6 %). The medium challenge group had mortality (36.3 %) that did not differ significantly from the high or low treatment. Few fish died in the non-injected and broth-injected treatments (3.4 and 0.8 %, respectively). The surviving fish were selected based on the absence of gross clinical signs of streptococcal disease (i.e., spiral swimming, cloudy eyes, or body curvature; Klesius et al. 2000). The initial stocking density of the surviving tilapia (30/tank in triplicate) was ~ 6.2 g/L. These fish were fed a commercial diet (32 % protein) twice daily to apparent satiation for 8 weeks and growth performance was assessed (Table 1). No differences were recorded in weight gain, feed intake, feed efficiency ratio or survival following the 8 week growth performance trial (Table 1).
Table 1 Average weight gain, dry matter feed intake, feed efficiency ratio (FER) and survival of Streptococcus iniae-survived tilapia following the 8-week feeding study1 (Shoemaker et al., In Press).
|Treatment |Weight gain (g) |Feed intake |FER2 |Survival3 |
| | |(g DM fish-1) | |(%) |
|Low challenge |27.0 |49.1 |0.55 |76.7 |
|Medium challenge |27.9 |47.8 |0.58 |81.1 |
|High challenge |26.3 |44.9 |0.58 |84.7 |
|Control (non-injected) |27.9 |46.0 |0.60 |88.9 |
|Control (broth-injected) |27.8 |45.2 |0.61 |95.6 |
|Pooled SEM | 1.6 | 1.8 |0.02 | 4.7 |
1Values are means of three replicates per treatment. No significant differences were determined at P > 0.05.
2FER = weight gain (g) / dry feed fed (g).
3Streptococcus iniae was not isolated from dead fish during the growth performance period.
Growth response following vaccination
Whittington et al. (2005) reported on the growth response of injection-vaccinated (primary and booster immunization) and non-vaccinated Nile tilapia (~10.5 g/L initial density) following feeding a commercial diet (32 %) supplemented with beta-glucan at 0, 50, 100 or 200 mg/kg for 14 weeks. Their experiment (Whittington et al. 2005) demonstrated after 10 weeks of feeding that vaccination, beta-glucan supplementation or a combination of vaccination and immunostimulation had no effect on weight gain or survival. Interestingly, beta-glucan supplementation above 50 mg/kg diet appeared to negatively influence the feed efficiency ratio (FER). The FER of the vaccinated and non-vaccinated fish ranged from 0.62-0.71.
Acquired resistance following infection and/or vaccination
The S. iniae-survived tilapia exhibited agglutinating antibody titers prior to and following the 8-week performance period (Table 2). Acquired resistance to homologous S. iniae challenge was also demonstrated in the S. iniae-survived tilapia challenged with 1 X 106 CFU/fish following the 8-week growth performance period (Table 2). Mean cumulative mortality was significantly higher (P < 0.05) in the control groups (i.e., challenged for the first time) than in the S. iniae-survived groups. Initial level of challenge (low, medium or high) did not influence mortality patterns following the 8-week growth performance period.
Table 2 Agglutinating antibody (Ab) titer of S. iniae-survived tilapia (prior to and following the 8-week feeding period) and mean cumulative mortality at 21 days post-challenge with S. iniae of S. iniae-survived tilapia and control fish infected for the first time (Shoemaker et al., In Press).
|Initial Treatment |Agglutinating Ab1 titer (log10)|Agglutinating Ab titer (log10)|Cumulative mortality2 |
| |(prior to 8 week feeding) |(post 8 week feeding) |(%) |
|Low challenge |1.04b |0.17a,b | 7.4a |
|Medium challenge |1.08b |0.40a | 3.3a |
|High challenge |1.78a |0.37a | 8.3a |
|Control (non-injected) |0.00c |0.00b |41.7b |
|Control (broth-injected) |0.00c |0.00b |43.3b |
|Pooled SEM |0.17 |0.1 | 6.0 |
1Agglutination antibody (Ab) titer as determined by microagglutination method according to Klesius et al. (2000).
2Percent cumulative mortality was calculated following a 21-day monitoring period. All groups were challenged with 1 X 106 CFU fish-1 by intraperitoneal injection. Different superscript letters indicate significant differences at P < 0.001.
Whittington et al. (2005) also demonstrated significantly lower (P < 0.05) mortality (0.0 -7.9 %) in vaccinated tilapia compared to mortality in non-vaccinated tilapia (48.3-72.2 %) regardless of dietary supplementation with beta-glucan. Vaccinated fish in their study exhibited significantly higher (P < 0.05) agglutinating antibody titers when measured 21 days post-booster immunization. Mean agglutinating titer of vaccinated fish was 1.53 (log10) compared to 0.21 for the non-vaccinated fish. The antibody titers determined from vaccinated fish were similar to those reported from the S. iniae-survived fish (Table 2).
Management implications
Previous studies have demonstrated the importance of antibody in the acquired immune response of tilapia to S. iniae either indirectly by measuring antibody in vaccinated and protected fish (Eldar et al. 1997; Klesius et al. 1999, 2000a) or directly by passive immunization (Shelby et al. 2002). Results of the current studies suggest that vaccinated tilapia or tilapia that survive S. iniae infection seroconvert and produce a protective antibody response with little or no effect on the growth performance of 10-20 g tilapia. Densities of fish used in these studies were low (~6-20 g/L) compared to commercial recirculation aquaculture operations (30-290 g/L). Removal of tilapia showing overt signs of infection (i.e., difficulty in consuming feed) may improve overall production efficiency of water re-use systems. Removal of dead /moribund fish will also reduce disease transmission as previously suggested (Shoemaker et al. 2000). Vaccinations, albeit labor intensive and costly at present, can significantly reduce mortality and should be considered as a viable strategy to prevent streptococcal infection (Klesius et al. 2000b). Relative percent survival values as reported by Whittington et al. (2005) were 91-100 in vaccinated tilapia. Studies are presently underway to develop cost effective strategies [e.g. oral immunization (Shoemaker et al. 2006) and immersion immunization (Klesius et al. 2006, 7th ISTA)] to mass immunize young tilapia prior to introduction into grow out systems.
Literature cited
Bowser, P.R., G.A. Wooster, R.G. Getchell, and M.B. Timmons. 1998. Streptococcus iniae infection of tilapia Oreochromis niloticus in a recirculation production facility. Journal of the World Aquaculture Society 29: 335-339.
Chamberlee, T.N., J.R. Thompson, and J.P. Thaxton. 1992. Effects of day old vaccination on broiler performance. Poultry Science 71(Supplement 1): 144 (abstract).
Colorni, A., A. Diamant, A. Eldar, H. Kvitt, and A. Zlotkin. 2002. Streptococcus iniae infections in Red Sea cage-cultured and wild fishes. Diseases of Aquatic Organisms 49: 165-170.
Cook, M.E. 1999. Nutritional effects on vaccination. Pages 53-59 in R.D. Schultz editor, Advances in Veterinary Medicine Volume 41. 1999. Academic Press, San Diego.
Eldar, A., A. Horovitcz, and H. Bercovier. 1997. Development and efficacy of a vaccine against Streptococcus iniae infection in farmed rainbow trout. Veterinary Immunology and Immunopathology 56: 175-183.
Klasing, K.C., D.E. Laurin, R.K. Peng and D.M. Fry. 1987. Immunologically mediated growth depression in chicks: Influence of feed intake, corticosterone and interleukin-1. Journal of Nutrition 117: 1629-1637.
Klesius, P.H., C.A. Shoemaker and J.J. Evans. 1999. Efficacy of a killed Streptococcus iniae vaccine in tilapia (Oreochromis niloticus). Bulletin of the European Association of Fish Pathologists 19(1): 39-41.
Klesius, P.H., C.A. Shoemaker, and J.J. Evans. 2000a. Efficacy of single and combined Streptococcus iniae isolate vaccine administered by intraperitoneal and intramuscular routes in tilapia (Oreochromis niloticus). Aquaculture 188: 237-246.
Klesius, P.H., C.A. Shoemaker, and J.J. Evans. 2000b. Vaccination: A health management practice for preventing diseases caused by Streptococcus in tilapia and other cultured fish. Pages 558-559 in Tilapia Aquaculture in the 21st Century. Proceedings of the 5th International Symposium on Tilapia Aquaculture, K. Fitzsimmons and J.C. Filho, editors. Rio DeJaneiro, Brasil.
Lara-Flores, M., M.A. Olvera-Novoa, B.E. Guzman-Mendez, and W. Lopez-Madrid. 2003. Use of the bacteria Streptococcus faecium and Lactobacillus acidophilus, and the yeast Saccharomyces cerevisiae as growth promoters in Nile tilapia (Oreochromis niloticus). Aquaculture 216: 193-201.
Li, P., and D.M. Gatlin. 2004. Dietary brewers yeast and the prebiotic Grobiotic™ AE influence growth performance, immune responses and resistance of hybrid striped bass (Morone chrysops X M. saxatilis) to Streptococcus iniae infection. Aquaculture 231: 445-456.
Nguyen, H.T., K. Kanai and K. Yoshikoshi. 2002. Ecological investigation of Streptococcus iniae in cultured Japanese flounder (Paralichthyes olivaceus) using selective isolation procedures. Aquaculture 205: 7-17.
Perera, R.P., S.K. Johnson and D.H. Lewis. 1997. Epizootiological aspects of Streptococcus iniae affecting tilapia in Texas. Aquaculture 152: 25-33.
Peres, H., C. Lim, and P.H. Klesius. 2004. Growth, chemical composition and resistance to Streptococcus iniae challenge of juvenile Nile tilapia (Oreochromis niloticus) fed graded levels of dietary inositol. Aquaculture 235: 423-432.
Shelby, R.A., P.H. Klesius, C.A. Shoemaker, and J.J. Evans. 2002. Passive immunization of tilapia, Oreochromis niloticus (L.), with anti-Streptococcus iniae whole sera. Journal of Fish Diseases 26: 1-6.
Shelby, R.A., C. Lim, M. Yildirim-Aksoy, and M.A. Delaney. In Press. Effects of probiotic feed supplements on disease resistance and immune response of young Nile tilapia (Oreochromis niloticus). Journal of Applied Aquaculture 18(2).
Shoemaker, C.A., J.J. Evans, and P.H. Klesius. 2000. Density and dose: factors affecting mortality of Streptococcus iniae infected tilapia (Oreochromis niloticus). Aquaculture 188: 229-235.
Shoemaker, C.A., P.H. Klesius, and J.J. Evans. 2001. Prevalence of Streptococcus iniae in tilapia, hybrid striped bass, and channel catfish on commercial fish farms in the United States. American Journal of Veterinary Research 62: 174-177.
Shoemaker, C.A., G.W. Vandenberg, A. Désormeaux, P.H. Klesius, and J.J. Evans. 2006. Efficacy of a Streptococcus iniae modified bacterin delivered using Oralject™ technology in Nile tilapia (Oreochromis niloticus). Aquaculture 255: 151-156.
Shoemaker, C.A., C. Lim, M. Yildirim-Aksoy, T.L. Welker, and P.H. Klesius. In Press. Growth response and acquired resistance of Nile tilapia, Oreochromis niloticus (L.), that survived Streptococcus iniae infection. Aquaculture Research.
Wagner, B.A., D.J. Wise, L.H. Khoo, and J.S. Terhune. 2002. The epidemiology of bacterial diseases in food-size channel catfish. Journal of Aquatic Animal Health 14: 263-272.
Whittington, R., C.A. Shoemaker, C. Lim, and P.H. Klesius. 2003. Effects of dietary β-hydroxy-β-methylbutyrate on growth and survival of Nile tilapia, Oreochromis niloticus, vaccinated against Streptococcus iniae. Journal of Applied Aquaculture 14: 25-36.
Whittington, R., C. Lim, and P.H. Klesius. 2005. Effect of dietary β-glucan levels on the growth response and efficacy of Streptococcus iniae vaccine in Nile tilapia, Oreochromis niloticus. Aquaculture 248: 217-225.
Zlotkin, A., H. Hershko, and A. Eldar. 1998. Possible transmission of Streptococcus iniae from wild fish to cultured marine fish. Applied and Environmental Microbiology 64: 4065-4076.
................
................
In order to avoid copyright disputes, this page is only a partial summary.
To fulfill the demand for quickly locating and searching documents.
It is intelligent file search solution for home and business.
Related searches
- chemical resistance of ebonite
- acquired apraxia of speech drills
- acquired dysplasia of right hip icd 10
- total resistance of a parallel circuit
- total resistance of a circuit
- finding total resistance of combination circuit
- equivalent resistance of a circuit
- total resistance of combination of resistors calculator
- resistance of pcb trace
- adult acquired apraxia of speech
- acquired apraxia of speech assessment
- calculate resistance of a parallel circuit