Bacteriological milk quality: possible hygienic factors and the role of Staphylococcus aureus in raw bovine milk in and around Gondar, Ethiopia

Betelihem Tegegne,Shimels Tesfaye

doi:10.1186/s40550-016-0046-2

Betelihem Tegegne, Shimels Tesfaye

Open Access

https://doi.org/10.1186/s40550-016-0046-2

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Abstract

BackgroundIn Ethiopia, around 97% of the annual milk production is accounted by the traditional milk processing system using on-farm traditional milk processing materials that are generally poor in processing capacity, causing high product loss and risky for public consumption. A cross-sectional study was carried out in and around Gondar town, Amhara Regional State of Ethiopia from October 2014 to may 2015 with the objective to assess the bacteriological milk quality, possible hygienic factors and status of S. aureus as contamination of bovine raw milk. The study employed questionnaire survey and raw bacteriological load analysis and cow milk samples for isolation and detection of S. aureus from raw cow milk. Sixty (60) randomly selected dairy farms were interviewed for the survey-based study of farm hygienic practices and 72 raw milk samples [60 from directly from teats and 12 from collecting tanks (buckets) were aseptically collected and tested for bacteriological load analysis and isolation of S. aureus.ResultsThe overall average total bacterial count (TBC) were 4.59 ± 0.118log10 (38,904.51 cfu/ml) and 4.77 ± 0.23log10 (58,884.37 cfu/ml) for milk samples collected directly from teat during milking and milking buckets at farm level respectively. Accordingly, the count increased by 0.18 ± 0.23 log10 or 19,979.86 cfu/ml (51.36%) increase from teat to milking buckets. Results showed very significant differences in plate counts (P < 0.05) between the two milk collection points. 73.30% of the milk samples collected directly from the teat were found (>100,000 bacteria per ml), evidence of poor milk hygiene when compared to international standards. In this study hygienic and management factors like udder cleaning, water and soap using for cleaning of udder, hand washing and water and soap using for milking vessels were significantly (P < 0.05) affects the bacteriological count of the milk. ConclusionsThe results of the current study indicated that the cow milk produced and distributed in the study area can generally be considered as substandard in quality for consumption unless pasteurized. Therefore, this risk assessment study with similar different studies reported from different regions in Ethiopia might provide a foundation for the establishment of national milk quality standards that currently do not exist in Ethiopia.

Highlights

In Ethiopia, around 97% of the annual milk production is accounted by the traditional milk processing system using on-farm traditional milk processing materials that are generally poor in processing capacity, causing high product loss and risky for public consumption
In order to protect consumers from unhygienic milk consumption and expose to microbial contamination, it was found for us very important to study bacterial load and level of pathogenic microbes such as S. aureus in the milk production and collection. Such surveillance data may provide a basis for risk assessment study as well as give a foundation for the establishment of national milk quality standards that currently do not exist in Ethiopia
73.30% of the milk samples were found high initial counts (>100,000 bacteria per ml), evidence of poor milk hygiene when compared to international standards

Summary

Introduction

In Ethiopia, around 97% of the annual milk production is accounted by the traditional milk processing system using on-farm traditional milk processing materials that are generally poor in processing capacity, causing high product loss and risky for public consumption. The study employed questionnaire survey and raw bacteriological load analysis and cow milk samples for isolation and detection of S. aureus from raw cow milk. Sixty (60) randomly selected dairy farms were interviewed for the survey-based study of farm hygienic practices and 72 raw milk samples [60 from directly from teats and 12 from collecting tanks (buckets) were aseptically collected and tested for bacteriological load analysis and isolation of S. aureus. In sub Saharan countries the traditional dairy sector, which is characterized by small herd size dominated by indigenous zebu breeds. These breeds, normally known by their low milk production with very little or no-specialized inputs, accounts 70–80% of Africa’s cattle population (Ibrahim and Olaluku 2000)

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