Comparative study of bactericidal activities of antibiotics and plant-based nanoparticles on fish pathogens
| dc.contributor.author | Asonye, Chinemerem Miracle | |
| dc.date.accessioned | 2025-07-03T13:19:17Z | |
| dc.date.available | 2025-07-03T13:19:17Z | |
| dc.date.issued | 2025-04 | |
| dc.description | This thesis is for the award of Master of Science (MSc.) in Environmental Microbiology | |
| dc.description.abstract | Bacterial fish pathogens cause diseases which result in a considerable economic impact on the aquaculture industry, necessitating the use of antibiotics for their control. However, intensive and indiscriminate use of antibiotics has led to increased occurrence of drug resistance in pathogenic bacteria as well as normal flora. This present study was conducted to determine the most prevalent bacterial fish pathogens, synthesize and characterize plant-based Silver and Zinc oxide nanoparticles extracted from Azadirachta indica (Neem leaves) and Hibiscus rosa sinensis (Hibiscus leaves), assess and compare the antibacterial activities of antibiotics and the plant-based nanoparticles on the most prevalent bacterial fish pathogens. The most prevalent bacterial fish pathogens namely, Salmonella sp., Shigella sp., Enterobacter sp., Vibrio sp. and Bacillus sp. were bacteriologically isolated from the liver, gills and intestines of fish samples gotten from three different fisheries in and around Owerri Metropolis which include Johnny Fish Farm, Umuodu Mbieri, Mbaitoli L.G.A., Chucky Fish Farm, 18 Norbert Nworieji Lane, New Owerri and an unnamed fish farm in Ohaji/Egbema, Imo State. The synthesized nanoparticles were characterized using techniques such as Fourier Transform Infra-Red (FTIR) Analysis, Scanning Electron Microscopy, UV-Visible Spectroscopy and Energy Dispersive X-Ray Spectroscopy. The isolated bacteria were identified by their colonial morphologies, Gram-Staining and different Biochemical reactions. Bacteria were mostly prevalent in the gills of the various fish samples. The mean heterotrophic bacteria had counts ranging from 1.15×106 to 970×106 cfu/g while the mean Vibrio sp. had counts ranging from 0.087×106 to 5.42×106 cfu/g. Disc diffusion method was employed to determine and compare the antibacterial activities of both the antibiotics and the different plantbased nanoparticles. In this study, it was observed that all the bacterial fish pathogens were resistant to most of the antibiotics (especially Tetracycline and Chloramphenicol) but were all susceptible to Gentamicin. It was also observed that the silver and zinc oxide nanoparticles synthesized from the plant leaves at different sizes and concentrations had inhibitory effects against the bacterial fish pathogens, mostly with the ones of higher concentrations having more inhibitory ability than the ones of lower concentrations although their efficacy did not surpass that of gentamicin which served as the control. The analysis has shown that farmed fish harbor potentially pathogenic bacteria which are resistant to some common antibiotics. This study also highlights the important benefits of using plant-based nanoparticles as potential antibacterial agents against bacterial fish pathogens to combat antibiotic resistance in aquaculture and maintain sustainable and hygienic aquatic environments. | |
| dc.identifier.citation | Asonye, C. M. (2025). Comparative study of bactericidal activities of antibiotics and plant-based nanoparticles on fish pathogens (Unpublished Master's Thesis). Federal University of Technology, Owerri, Nigeria | |
| dc.identifier.uri | https://repository.futo.edu.ng/handle/20.500.14562/2091 | |
| dc.language.iso | en | |
| dc.publisher | Federal University of Technology, Owerri | |
| dc.rights | Attribution-NonCommercial-ShareAlike 4.0 International | en |
| dc.rights.uri | http://creativecommons.org/licenses/by-nc-sa/4.0/ | |
| dc.subject | Bacterial fish pathogens | |
| dc.subject | antibiotics | |
| dc.subject | antibiotic resistance | |
| dc.subject | neem leaves | |
| dc.subject | hibiscus leaves | |
| dc.subject | silver nanoparticles | |
| dc.subject | zinc oxide nanoparticles | |
| dc.subject | antibacterial activities | |
| dc.subject | Department of Microbiology | |
| dc.title | Comparative study of bactericidal activities of antibiotics and plant-based nanoparticles on fish pathogens | |
| dc.type | Master’s Thesis |