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Recycled biowaste as a source of infection

Sahlström, Leena (2006). Recycled biowaste as a source of infection. Diss. (sammanfattning/summary) Uppsala : Sveriges lantbruksuniv., Acta Universitatis Agriculturae Sueciae, 1652-6880 ; 2006:70
ISBN 91-576-7119-2
[Doctoral thesis]

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Biowaste and sewage sludge can be used as a fertiliser and soil amendment in agriculture. However if not treated efficiently before use, such products can contain microbial pathogens that pose a health risk for humans and animals. This study investigated the pathogen content, mainly pathogenic and antimicrobial-resistant bacteria, present in sewage sludge and biowaste. It also assessed the effects of different treatment methods on various pathogens by analysis of the pathogen content of sewage sludge and biowaste substrate before and after treatment. Compared to sewage sludge, biowaste contained fewer pathogens, both in the untreated substrate and the digested residue. Frequent findings of Salmonella spp. in sewage sludge were the main reason for the difference. In addition, vancomycin resistant enterococci (VRE) were frequently isolated from sewage sludge. PFGE and PhenePlate analyses showed that both VRE and Salmonella spp. were capable of persisting for some months and up to two years, respectively, in the sewage sludge. Thus sewage sludge may act as a reservoir of Salmonella spp., VRE and other pathogens. Pasteurisation (70C, 60 minutes) proved to be an effective sanitation treatment for biowaste and in combination with anaerobic digestion it resulted in better inactivation of pathogens and indicator bacteria than the treatments currently used at Swedish wastewater treatment plants. In further studies at laboratory scale, pasteurisation effectively inactivated the majority of pathogens and indicator bacteria analysed except heat resistant (parvo-) viruses and spore-producing Clostridium perfringens. The pathogens and antimicrobial resistant bacteria found in sewage sludge and biowaste could be spread to humans and animals if these treated wastes are used in agriculture. However, it is possible to diminish the pathogen load in the wastes so that the risks to the community are minimised. It is important to be aware of the general hygiene risks associated with the biowaste and sewage sludge and to handle, treat and use these products accordingly.

Authors/Creators:Sahlström, Leena
Title:Recycled biowaste as a source of infection
Series Name/Journal:Acta Universitatis Agriculturae Sueciae
Year of publishing :August 2006
Number of Pages:47
ALLI. Sahlström, L., Aspan, A., Bagge, E., Danielsson-Tham, M-L. & Albihn, A. (2004) Bacterial pathogen incidences in sludge from Swedish sewage treatment plants. Water Research 38, 1989-1994. II. Bagge, E., Sahlström, L. & Albihn, A. (2005) The effect of hygienic treatment on the microbial flora of biowaste at biogas plants. Water Research 39, 4879-4886. III. Sahlström, L., Bagge, E., Emmoth, E., Holmqvist, A., Danielsson-Tham, M-L. & Albihn, A. (2006) A laboratory study of survival of selected microorganisms after heat treatment of biowaste used in biogas plants. Submitted. IV. Sahlström, L., De Jong, B. & Aspan, A. (2006) Salmonella isolated in sewage sludge traced back to human cases of salmonellosis. Letters in Applied Microbiology 43, 46-52. V. Sahlström, L., Albihn, A., Aspan, A., Rehbinder, V. & Bengtsson, B. (2006) Vancomycin resistant enterococci (VRE) in Swedish sewage sludge. Submitted.
Place of Publication:Uppsala
ISBN for printed version:91-576-7119-2
Publication Type:Doctoral thesis
Full Text Status:Public
Agrovoc terms:organic wastes, sewage sludge, anaerobic treatment, recycling, bacteria, salmonella, campylobacter, escherichia coli, zoonoses, sweden
Keywords:Agriculture, anaerobic digestion, antimicrobial resistant bacteria, biowaste, Campylobacter spp., E. coli O157, recycling, Salmonella spp., sewage sludge, zoonoses
Permanent URL:
ID Code:1170
Department:(VH) > Dept. of Biomedical Sciences and Veterinary Public Health
Deposited By: Leena Sahlström
Deposited On:25 Aug 2006 00:00
Metadata Last Modified:02 Dec 2014 10:10

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