Staphylococcus aureus and Mesophilic Aerobic Bacteria Quantification in Hygienization Process of Milking Equipment

Abstract

Background:Milk’s composition is an excellent substrate for microorganism’s multiplication. Presence of Staphylococcus aureus and aerobic mesophilic bacteria are one of the most common problems in dairy farms. On dairy industry’s and milk farms Clean in Place (CIP) system higyenization are commonly used, then the cleaning occurs as a closed process, for better results sanitizans are applied, in order to obtain a safety food. This project aim to evaluate Staphylococcus aureus and aerobic mesophilic bacteria reduction after two milking higyenization process. Materials, Methods & Results:This research was done on a Rio Grande do Sul North Milk farm, with mechanized milking and Clean in Place system for cleaning. For liners and CIP tubes higyenization commercial products as Sodium Hipoclorite 3% and phosphoric acid 11.3% are used for detergency, and peracetic acid 5% for sanitization. Milk bunk tank are higyenized with sodium hypoclorite 3.8% alcalin detergent. After higyenization steps liners, CIP’s water process, bulk milk tank and milk set were collected. At process 1, liners and CIP water were collected after milking, detergency and sanitization that occurred immediately at the detergency’s finish, while process 2 the sanitization was realized 8 h after detergency, before following milking. Cooling milk bulk tank was collected before and after detergency, and milk set after milkings Convencional microbiology were used to count and results in log10 UFC.cm-2. In CIP water’s after process 1 was 3.81 log10 reduction to aerobic mesophilic bacteria (P > 0.05) and reducing 4.51 log10 (P = 0.03). Meanwhile there was no significant reduction for mesophilic aerobic bacteria and S. aureus on the others samples (liners, bulk milk tank and milk set).Discussion: This results show the maintenance of milking machine contamination, and that even bacterial load reduced among hygienization steps this was not significant, suggesting that deteriorate and pathogenic microorganisms can remain on milk produced. Highlights are teat taps of milking machine as the major cause of contamination among cows. The results are worrying because Staphylococcus aureus contamination, once this bacteria causes alimentar diseases, even after higyenization process, which can damage public health that can reflect milk chain economically. Since amount of this microorganism found in milk is already sufficient to synthesize enterotoxins. In addition, resistance to disinfectants is another concern, as it may result in resistance to antimicrobial agents. So reduction of bacteria level among cleaning steps there was no significance, once the products and equipments on dairy and farms act as a constant elimination point of deteriorate and pathogenic microorganisms for the final product, milk. With this studies aim to aprimorate hygienization process on milk chain, in order to obtain a hygienic sanitary good product.