Molecular characterization and effects of nano-particle on resistant bacteria associated with livestock in Abia and Imo State
Date
2024-02
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Federal University of Technology, Owerri
Abstract
The unregulated practice of livestock production has endangered the public health sector through the multiplication and spread of bacteria pathogens. The study investigated the molecular characterization and compared the nano-particle and antibiotic assay of bacteria associated with livestock in Abia and Imo States. Air was sampled with passive sedimentation technique; water samples were collected randomly from the water sources in the farms while hand swabs from the farmers and feeds were collected with sterile swab sticks and container respectively. Total heterotrophic bacterial count (THBC) was performed with pour plate method; total coliform count (TCC) was determined with membrane filter technique while total potential pathogenic bacteria count (TPPBC) was examined by growing them in selective media. Rectal swabs and faecal samples; raw meat and intestine samples were obtained from cow and pigs. From poultry farm, faecal sample cloacal swab and drinking water of chickens were used for experiment. Pure isolates of E. coli and Klebsiellap neumoniae were isolated from MacConkey and eosin methylene blue (EMB) agar. Antibacterial susceptibility test was performed by adopting standard method. Extended spectrum beta lactamases (ESBLs) production was screened and confirmed phenotypically using double disc synergy assay. DNA of the ESBLs producers were extracted by boiling method and quantified using nanodrop spectrophotometer while genes sequencing were performed with polymerase chain reaction (PCR). Green synthesis of silver and zinc nanoparticles (AgNPs and ZnONPs) were done using aqueous extract of the leaves of Ocimum gratissimum plant (scent leaves), Vermonia amygadalina plant (bitter leaves), Newbouldia laevis plant (Ogirishi leaves) and Gongronema latifolium plant (utazi leaves). The biosynthesis was done by dissolving 50 mM, 100 mM, 500 mM and 1000 mM of AgNO3 and Zn-NO-.6H-O separately into 20 ml and 50 ml of each plant extract respectively. Thereafter, antibacterial activities of the nanoparticles were performed against livestock bacterial isolates using agar well diffusion assay. Among the four farms analyzed, THBC ranged from 6.13±0.6×105 to 28.43±0.3×105 CFU/ml; TPPBC ranged between 9.26±0.4×105 and 26.23±0.4×105 CFU/ml and TCC ranged from 9.03±0.3×105 to 24.06±0.4×105 CFU/ml. Of the four cities studied, Aba has the highest THBC (28.43±0.3×105 , 26.70±0.7×105 , 26.26±0.5×105 CFU/ml), TPPBC (17.47±0.5×105 and 20.02±0.5×105 CFU/ml) and TCC (24.06±0.4×105 , 17.93±0.6×105 and 22.36±0.4×105 CFU/ml) for pig, cow and poultry farms respectively while Mbaise has the least value. Escherichia coli, Staphylococcus aureus, Klebsiella pneumoniae, Salmonellaenterica, EnterobacteraerogenesVibrio spp and Shigella sp were commonly distributed in the four cities. Escherichiacoli (933) isolates were significantly higher followed by Klebsiellapneumoniae (505) while the lowest value was obtained from Shigella sp (3). In both pig and poultry farms, Staphylococcusaureus (14.6%) was quite prevalent but was isolated even more from the hands of poultry workers (53.7%). Salmonella spp, Enterobacter spp, Vibrio spp and Shigella sp were not isolated from the hands of poultry workers; Salmonella enterica and Shigella sp were not isolated cow farms. E. coli and Klebsiellapneumoniae were resistant to all the antibiotics between 70% to 88.6% except imipenem, meropenem and colistin where minimal effects were produced. However, colistin was the most active antibiotics amongst the three. ESBLs were produced by Klebsiella pneumoniae than E. coli in the four towns. AgNPs and ZnONPs produced significant zones of inhibition even more than control especially at highest concentrations of individual molarity. AgNPs exhibited higher antibacterial effects. This study indicated that Aba has the highest microbial load which could be attributed to the population and economic activities of the dwellers. The presence ESBLs producers in all the four towns are major concern as this could lead to spread of multidrug resistance (MDR). Appropriate personal and environmental cleanliness should be practiced by livestock farmers to reduce spread of pathogenic bacteria.
Description
This thesis is for the award of Doctor of Philosophy (Ph.D) in Medical Microbiology
Keywords
Bacteria, livestock, multi-drug recsitance, nano-pacticles, Department of Microbiology
Citation
Nwosu, I. L. (2024). Molecular characterization and effects of nano-particle on resistant bacteria associated with livestock in Abia and Imo State (Unpublished Doctoral Thesis). Federal University of Technology, Owerri, Nigeria