Prevalence of contagious and environmental mastitis-causing bacteria in bulk tank milk and its relationships with milking practices of dairy cattle herds in São Miguel Island (Azores)

Abstract

This study aimed to assess the degree of contamination of bulk tank milk (BTM) by Staphylococcus spp. and coliform bacteria and to identify major milking practices that help perpetuate them in dairy cattle herds in São Miguel Island. In July 2014, BTM was sampled and a survey concerning local milking practices was conducted on 100 herds. Semi quantitative multiplex polymerase chain reaction detected coagulase-negative staphylococci, Escherichia coli, Staphylococcus aureus, and other coliform bacteria (Klebsiella oxytoca, Klebsiella pneumoniae, and Serratia marcescens) in 100, 75, 59, and 35 % of BTM, respectively. According to multivariable univariate models, on herds not using hot water for cleaning the milking machine and teat liners, there was at least 3.4 more odds (P < 0.01) to have S. aureus or coliform bacteria contamination in BTM. The likelihood of finding S. aureus in BTM was higher (P < 0.001) on herds without high hygiene during milking, when milking mastitic cows at the end, on abrupt cessation of milking at dry-off, and official milk control implementation. The glove use also favored (odds ratio (OR) 5.8; P < 0.01) the detection of coliform bacteria in BTM. Poor milking practices identified in this study should be avoided in order to decrease S. aureus and coliform bacteria contamination of BTM. Other factors associated with milk quality in São Miguel Island also should be further investigated.

Screening food-borne and zoonotic pathogens associated with livestock practices in the Sumapaz region, Cundinamarca, Colombia

“…Unsanitary handling of the cow’s udder during milking is a frequent source of contamination with S. aureus , which is recognized as a microbial contaminant (Kateete et al 2013). GFP guidelines address those problems through the implementation of protocols through which livestock farmers can control environmental bacteria such as E. coli and S. aureus , which primarily tend to colonize the teat skin (Azevedo et al 2016). …”

Prevalence of bovine milk pathogens in Azorean pastures: mobile versus fixed milking machines

“…In fact, S aureus can be isolated from several utensils used during milking as well as from animal body surfaces and the hands of the milking operator (Benić and others 2012). In a recent study (Azevedo and others 2016), the authors observed, using a six-point scale, that the poor hygiene during milking is an important risk factor for Azorean herds. Unfortunately, the milking machine maintenance and their vacuum levels and even the teat’s condition of dairy cows were not assessed, and further studies were needed in order to evaluate the impact of these factors in the incidence of S aureus .…”

“…All procedures concerning the collection and preparation of samples, DNA extraction, and PCR and qPCR amplification for this study were reported by Azevedo and others (2016).…”

Detection and drug resistance profile of Escherichia coli from subclinical mastitis cows and water supply in dairy farms in Saraburi Province, Thailand

“…E. coli was found to usually infected mammary gland of cows parturition and early lactation period which could lead to local and acute mastitis (Burvenich et al, 2003). In a study in Portugal, E. coli was found to be the second most common bacteria after non-coagulative staphylococci found in bulk tank milk (Azevedo et al, 2016). In Uruguay, E. coli was second only to S. aureus in bovine subclinical mastitis cases (Gianneechini et al, 2002), whereas in China, it was one of the leading types of coliform bacteria found in milk from cows with subclinical mastitis (Memon et al, 2013; Wang et al., 2015).…”