Majallah-i ̒Ilmī-i Shīlāt-i Īrān (Jan 2018)
In vitro evaluation of the susceptibility of Streptococcus iniae, etiological agent of streptococcusis in rainbow trout Oncorhynchus mykiss to florfenicol and nano-florfenicol
Abstract
In vitro studies were conducted to assess the sensitivity of Streptococcus iniae, theetiological agentof streptococcusis of rainbow trout (Oncorhynchus mykiss) to the antibacterial drugs florfenicol (FFC) and nano florfenicol (NFFC). The isolates originated from rainbow trout (Oncorhynchus mykiss) infected with Streptococcus iniae through natural outbreaks of streptococcusis. The minimum inhibitory concentration (MIC), the minimum bactericidal concentration (MBC) and Kirby- Bauer zones of inhibition (in mm) for FFC and NFFC against S. iniae were determined. The results showed that the MIC for NFFC and FFC tested with S. iniae were 0.078µg/ml and 0.312µg/ml respectively. The MBC for NFFC were 0.156μg/ml and for FFC 0.312μg/ml. There were statistically significant difference in the MIC and the MBC between NFFC and FFC (p0.05). It is concluded that these drugs, especially nano-florfenicol, have a high potential for controlling Streptococcus iniae. Therefore, nano-florfenicol can be considered as the basis for antibiotic-resistant bacteria.
