Streptococcosis is one of the economically important diseases in the aquaculture industry particularly in rainbow trout aquaculture causing remarkable annual losses. Streptococcosis is known as a zoonotic disease causing morbidity and mortality in some consumers. In thi More
Streptococcosis is one of the economically important diseases in the aquaculture industry particularly in rainbow trout aquaculture causing remarkable annual losses. Streptococcosis is known as a zoonotic disease causing morbidity and mortality in some consumers. In this study the status of farmed rainbow trout contamination with Streptococcus iniae and Lactococcus garvieae was assessed. For this reason, during summer months, 64 apparently diseased trout were sampled from fish markets of Tehran and Karaj. Gram staining was performed on grown colonies and then gram-positive cocci were further characterized using biochemical and PCR assays. The obtained results showed that 56.23% (36 samples) of the samples were infected with the both bacterial pathogens. The prevalence of S. iniae and L. garvieae were 32.8 % (21 samples) and 23.43% (15 samples), respectively. The highest and lowest prevalence rate of S. iniae was observed in the samples of Karaj (15.62%) and Kahrizak (0%) markets, respectively. In the case of L. garvieae, the highest and lowest rates were obtained in Karaj/Kahrizak (7.81%) and Meidan-Nabi (1.56%) markets, respectively. The results revealed that in some markets, the prevalence of streptococcosis and lactococcusis in cultured rainbow were relatively high. Therefore, it is necessary to conduct further trials.
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Lactococcus garvieae (L. garvieae) is the causative agent of lactococcosis in fish. These diseases can be transmitted to humans by direct contact or consumption of infected fish meat. In this study, the susceptibility of L. garvieae to the ethanolic and aqueous extracts More
Lactococcus garvieae (L. garvieae) is the causative agent of lactococcosis in fish. These diseases can be transmitted to humans by direct contact or consumption of infected fish meat. In this study, the susceptibility of L. garvieae to the ethanolic and aqueous extracts of Juglans regia (J. regia) was evaluated. Ethanolic and aqueous extract of the J. regia was prepared and successively diluted to obtain minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) against L. garvieae bacteria by successive dilution method. Also, the inhibition of bacterial growth was measured, using disk diffusion method. The results showed that the ethanolic extract of J. regia had bactericidal effect in concentrations of 37.5 mg/ml and also the bacteriostatic effect in the concentration of 18.75 mg/ml. However, the aqueous extract of J. regia, at concentrations of 75 mg/ml showed a bacterial effect and in the concentration of 37.5 mg/ml, the bacteriostatic effect was shown against bacterial growth. Considering the proper effect of these extracts on L. garvieae, more extensive studies was needed in clinical conditions in aquaculture farms. After determining the effective concentration, non-toxicity and the mechanism of their effect, extracts can be used in the treatment and prevention of disease.
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Lactococcosis which is caused by Lactococcus garvieae is now widespread. This species is categorized in zoonosis agents and is able to cause endocarditis especially in immunosuppressed persons. This study was done to detect Lactococcus garvieae in cultured rainbow trout More
Lactococcosis which is caused by Lactococcus garvieae is now widespread. This species is categorized in zoonosis agents and is able to cause endocarditis especially in immunosuppressed persons. This study was done to detect Lactococcus garvieae in cultured rainbow trout meat collected from retail market and to evaluate the virulence of the isolates. A total of 90 fresh fish were randomly selected and were transferred to the laboratory in appropriate conditions. After collecting meat samples, the bacteria were investigated by culture on BHIA and standard biochemical tests. The results were confirmed by PCR. Presence of virulence gene in the isolates were studied and the results revealed that 4 isolates of a total of 9 collected isolates harbored cap virulence gene (44.4%). According to the results, rainbow trout meat can be contaminated with Lactococcus garvieae which is a potential danger for consumers. However, it depends on the nutritional habits and methods of reservation.
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In the past five years, The disease that suspected streptococosis was epidemic in rainbow trout farms in Ilam, In this study, 60 rainbow trout with Clinical signs such as lethargie, erratic swimming, skin darkness and exophthalmia, were collected from rainbow trout farm More
In the past five years, The disease that suspected streptococosis was epidemic in rainbow trout farms in Ilam, In this study, 60 rainbow trout with Clinical signs such as lethargie, erratic swimming, skin darkness and exophthalmia, were collected from rainbow trout farms in Ilam in southwest of Iran in January 2010, for detection agent of disease samples were collected from spleen, kidney and liver of fish then cultured on blood agar and incubated at 22 ºC for 24 h. Based on biochemical tests, Lactococcus garvieae was detected and isolates were confirmed as L. garvieae by using a m-PCR targeting lctO-gene, 16S rRNA and 16S- 23S rRNA Internal Transcribed Spacer region(ITS) sequencing that detect L .garvieae, Streptococcus iniae and S. dysgalactiae,. In the present study we observed a single band of 1100 bp for L. garvieae for most of isolates and concluded that the main agent of septicemia was L. garvieae. In conclusion, Multiplex PCR was definite method for rapid detection of L. garvieae in mixed infection in rainbow trout.
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