Antibiotic Resistance and Water Quality: Land Application of Swine Lagoon Effluent as a Potential Source of Antibiotic Resistant Genes in Surface Water

Show simple item record

dc.contributor.advisor Dr. Alexandria K. Graves, Committee Chair en_US
dc.contributor.advisor Dr. Daniel W. Israel, Committee Member en_US
dc.contributor.advisor Dr. Eric van Heugten, Committee Member en_US Liwimbi, Lloyd Chipiliro Siyani en_US 2010-04-02T17:57:29Z 2010-04-02T17:57:29Z 2009-12-01 en_US
dc.identifier.other etd-08112009-000641 en_US
dc.description.abstract The use of antibiotics in animals is suspected to be a major route for transfer of antibiotic resistance genes (ARGs) to human pathogens, although different antibiotics are used in animals than in humans. North Carolina has the second largest swine production industry in the USA which is concentrated in a small geographical area in the southeastern area of the state. This may increase the risk of antibiotic resistant bacteria reaching nearby surface waters. The goals of this study were 1) to identify and quantify ARGs in Escherichia coli isolates from swine feces, lagoon effluent, cattle, wildlife and ground and surface waters 2) to develop a data base for antibiotic resistance patterns for E. coli isolated from these sources 3) to evaluate the possible use of this database in tracking movement of fecal bacteria from confined swine operations to a nearby stream 4) to determine the relationship between antibiotic resistance genes found in E. coli strains from manure and water with the actual phenotypic expression of the resistance to their corresponding antibiotics. Escherichia coli isolates were recovered from manure and water samples by basic microbiological culture and IDEXX Colilert methods, respectively. Antibiotic resistance genes were identified from the isolates using the polymerase chain reaction (PCR) method. On average, E.coli counts in the surface water were 272.1 CFU/100 mL, 10 fold higher than that in ground water (21.1 CFU/100 mL). A total of 1,208 E. coli isolates from swine feces, lagoon effluent, cattle, deer, dog, bird and nearby ground and surface waters (n=238, 234, 192, 48, 48, 48, 200, and 200, respectively) were evaluated for ARGs. A total of 5909 E. coli isolates were evaluated for phenotypic expression of resistance to various concentrations of the following antibiotics: erythromycin, neomycin, oxytetracycline, streptomycin, tetracycline, cephalothin, apramycin, trimethoprim, and rifampicin. About 96% of the isolates displayed multiple antibiotic resistances. Genotypic evaluation indicated the presence of aadA, strA, strB, tetA, tetB, tetC, sul1, sul2, sul3, and Aac(3)IV ARGs in all the sources of isolates. Resistance genes that code for resistance to spectinomycin (aadA), low level streptomycin (str), tetracycline (tetA) and sulfonamide (sul1) were present in highest frequency. The database developed from antibiotic resistance patterns (ARP) and antibiotic resistant genes (ARGs) of E. coli isolates from the known sources were able to associate fecal bacteria in ground and surface water to lagoon effluent and to livestock respectively. The results clearly show that the presence of ARGs does not always result in phenotypic expression of the resistance and vice versa. The results will increase awareness on the widespread of antibiotic resistance in both agricultural systems and environmental pools within confined swine farms. Even though good management practices for swine waste management (anaerobic lagoon systems) are effectively mitigating fecal pollution, there is a need for prudent and responsible use of antibiotics especially with those prone to induce resistance. en_US
dc.rights I hereby certify that, if appropriate, I have obtained and attached hereto a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dis sertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to NC State University or its agents the non-exclusive license to archive and make accessible, under the conditions specified below, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report. en_US
dc.subject Soil en_US
dc.subject Animal Waste en_US
dc.subject Fecal Indicator Bacteria en_US
dc.subject Microbial Source Tracking en_US
dc.title Antibiotic Resistance and Water Quality: Land Application of Swine Lagoon Effluent as a Potential Source of Antibiotic Resistant Genes in Surface Water en_US MS en_US thesis en_US Soil Science en_US

Files in this item

Files Size Format View
etd.pdf 834.0Kb PDF View/Open

This item appears in the following Collection(s)

Show simple item record