Protective potency of clove oil and its transcriptional down-regulation of Aeromonas sobria virulence genes in African catfish (Clarias gariepinus L.).
Disease episodes of fish caused by Aeromonas species are moved to the top list of limiting problems worldwide. The present study was planned to verify the in vitro antibacterial activities as well as the in vivo potential values of clove oil and ciprofloxacin against Aeromonas sobria in African catfish (Clarias gariepinus). The in vitro phenotypic virulence activities and the successful amplification of aerolysin and hemolysin genes in the precisely identified A. sobria strain were predictive for its virulence. In the in vivo assay, virulence of A. sobria strain was fully demonstrated based on constituent mRNA expression profile of tested virulence genes and typical septicemia associated with high mortalities of infected fish. Apparent lower mortality rates were correlated well with both decrescent bacterial burden and significant down-regulated transcripts of representative genes in the treated groups with clove oil, followed by ciprofloxacin as a prophylactic use for 15 days (P < 0.0001); however, the essential oil apart from ciprofloxacin significantly enhanced different hematological parameters (P < 0.05). In addition, administration of antibiotic may be considered as a pronounced stress factor in the fish even when it used in the prophylactic dose. In conclusion, medicinal plants-derived essential oils provide a virtually safer alternative to chemotherapeutics on fish, consumers and ecosystems.
Zagazig University Department of Microbiology, Faculty of Veterinary Medicine Zagazig Egypt.
M I
MI
Abd El-Hamid
Zagazig University Department of Microbiology, Faculty of Veterinary Medicine Zagazig Egypt norhan_vet@hotmail.com.
N K
NK
Abd El-Aziz
Zagazig University Department of Biochemistry, Faculty of Veterinary Medicine Zagazig Egypt.
H A
HA
Ali
D000333:Aeromonas / Q000187:drug effects / Q000235:genetics / Q000472:pathogenicity*; D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001427:Bacterial Toxins / Q000235:genetics / Q000378:metabolism; D002397:Catfishes / Q000382:microbiology*; D045783:Clove Oil / Q000494:pharmacology* / Q000627:therapeutic use; D015536:Down-Regulation / Q000187:drug effects*; D005393:Fish Diseases / Q000097:blood / Q000382:microbiology; D005786:Gene Expression Regulation / Q000187:drug effects; D015964:Gene Expression Regulation, Bacterial / Q000187:drug effects; D005798:Genes, Bacterial; D016905:Gram-Negative Bacterial Infections / Q000097:blood / Q000382:microbiology; D008826:Microbial Sensitivity Tests; D052899:Pore Forming Cytotoxic Proteins / Q000235:genetics / Q000378:metabolism; D020011:Protective Agents / Q000494:pharmacology* / Q000627:therapeutic use; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D014158:Transcription, Genetic / Q000187:drug effects*; D014774:Virulence / Q000187:drug effects / Q000235:genetics
D000900:Anti-Bacterial Agents; D001427:Bacterial Toxins; D045783:Clove Oil; D052899:Pore Forming Cytotoxic Proteins; D020011:Protective Agents; D012333:RNA, Messenger; C032676:aerolysin