The Effect of Sanitization Methods on Human Urine Collected From People Residing In Different Parts of Addis Ababa, Ethiopia

No Thumbnail Available

Date

2018-05-03

Journal Title

Journal ISSN

Volume Title

Publisher

Addis Ababa University

Abstract

Urine is rich in nutrients such as Nitrogen and Phosphorus which are essential for agriculture and therefore worthy of safe recovery. The aim of this study was to evaluate the effectiveness of acidification, storage and pasteurization of source-separated human urine in reducing coliform bacteria. Urine samples were collected using acetic acid-treated portable toilets and jerrycans from four sites of Addis Ababa namely; Addis Ababa University (AAU) Natural Science campus, Merkato portable toilet, Megenagna public toilet and Gelila Elementary school. Treatment of urine was conducted using Hydrochloric acid (HCl) heating to 80 ºC for pasteurization and storage in tight-sealed containers at room temperature. The urine undergoing the three sanitization methods were analyzed for their physico-chemical parameters, coliform bacteria and for the stored samples, PCR-based detection of genes resistant to tetracycine (tetB), sulfonamides (sul2) and quinolones (qnrB) were analyzed. The study showed the pH of fresh urine collected from the four sites to be slightly acidic in the range of pH 5.2 and 5.8, which increased to a maximum of 10.4 during storage for six months. Total coliforms in fresh urine collected from the four sites of Addis Ababa ranged between the highest count of 234,000 cfu/ml to 64500 cfu/ml, which decreased steadily during the storage time reaching to nil at the sixth month of storage. In all the fresh urine samples, fecal coliforms were detected with the maximum count of 1500 cfu/100 ml in samples collected from AAU. Storage for one month was efficient in reducing fecal coliform units to zero in all the samples collected from the four sites. Pasteurization was also efficient in completely removing both total and fecal coliforms. Acidification was didn‘t show any reduction in total coliform counts of urine collected from all the four sites. Regarding fecal coliforms, a slight decrease was observed resulting in 20% removal of fecal coliforms in the case of urine collected from Merkato .PCR-based detection of tetB resistance gene from the meta-DNA revealed that fresh urine collected from AAU was positive for the tetB which was absent at the sixth month of storage. Similarly, the fresh urine sample collected from Merkato was positive for qnrB which persisted in the stored sample for 4 months and finally absent at the sixth month of storage. It was concluded that storage as a sanitization process is the most effective method in reducing coliform bacteria and some of the horizontally transmitted antibiotic resistance genes, with minimal loss of Nitrogen and Phosphorus.

Description

Keywords

Urine, Coliforms, Storage, Nutrient Recovery, Antibiotic Resistance Genes

Citation