Fredun Hassani; Tahere Abyavi; Ali Taheri mirghaed; Rahim Payghan; Mojtaba Alishahi
Abstract
Extensive and long-term use of chemical compounds causes microorganisms ability to adapt with the antimicrobial agents used against them, reduced the effect of drugs, and in return make microbes resistant. Plant essential oils have been studied as antimicrobial and antifungal compounds in the pharmacology, ...
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Extensive and long-term use of chemical compounds causes microorganisms ability to adapt with the antimicrobial agents used against them, reduced the effect of drugs, and in return make microbes resistant. Plant essential oils have been studied as antimicrobial and antifungal compounds in the pharmacology, microbiology and medicine fields. In this study, the essential oils of Ziziphora cliniopodiodes, Thymus vulgaris and Salvia rosmarinus to fungal pathogens including Aspergillus fumigatus, Aspergillus niger, Aspergillus flavusus, Saprolegnia spp., Fusarium spp., and bacteria pathogens including Streptococcus mitis, Lactococcus Garvieae, Yersinia ruckeri and Aeromonas hydrophila were examined. Evaluation of antifungal and antibacterial activity by Tube dilution method used for determine the minimum growth inhibitory concentration (MIC), minimum bactericidal concentration (MBC) and fungicide (MFC). Based on the results of MIC and MFC, the highest antifungal properties were obtained for thyme essential oils to Aspergillus fumigatus (0.023 ± 0.015 and 0.046±0.03 μl/ml) and the lowest fungicidal property of rosemary essential oil against Aspergillus niger (1.66±0.72 and 3.33±1.44) were obtained and there was a significant difference with other treatments (P<0.05). According to the results of MIC and MBC, the lowest concentrations obtained against bacteria were related to the essential oil of Z. clinopodioides against Streptococcus mitis (0.016±0.005 and 0.033±0.011 μl/ml), which were obtained with essential oil of rosemary was significantly different (P<0.05). According to this study, essential oils of Z. clinopodioides, thyme and rosemary can be used to control and prevent fungal and bacterial diseases of Aquatic animals.
Fereydun Hassani; Rahim Peyghan; Mojtaba Alishahi; Masoud Ghorbanpour; Mina Ahangarzadeh
Abstract
Streptococcus iniae is a gram-positive bacterium that causes invasive infections with severe septicemia and meningitis as well as high economic losses in freshwater and sea fish. It is one of the most infectious diseases in Asian sea bass. The purpose of the present study was to investigate the role ...
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Streptococcus iniae is a gram-positive bacterium that causes invasive infections with severe septicemia and meningitis as well as high economic losses in freshwater and sea fish. It is one of the most infectious diseases in Asian sea bass. The purpose of the present study was to investigate the role of this bacterium in marine bass fish mortality in farmed cages on the northern coast of the Persian Gulf. In this study, a number of 150 cultured Asian sea bass (60 fish suspected of bacterial infection and 90 apparently healthy fish) were selected and bacterial sampling were taken from head kidneys and brain of fish from sea bass cages of Bushehr, Khuzestan and Hormozgan provinces. After isolation and purification of the bacteria, the presence of Streptococcus iniae was evaluated and confirmed via biochemical tests and molecular methods (with specific primers of lctO gene). The PCR results and sequencing of the PCR product indicate high prevalence of Streptococcus iniae in Asian sea bass cages culturing in the Persian Gulf. Therefore, effective measures should be taken to prevent Streptococcosis (especially vaccination).
