Pseudomonas spp.: contamination sources in bulk tanks of dairy farms

Abstract

RESUMO.-[Pseudomonas spp.: fontes de contaminação em tanques de expansão em fazendas leiteiras.] Este estudo se propôs a isolar Pseudomonas spp. durante o processo de ordenha em dez fazendas com sistemas manuais e mecanizados, durante as estações seca e chuvosa, além de avaliar a homologia do DNA e seus padrões de distribuição entre os isolados, a fim de se determinar as principais fontes de contaminação do leite. Cento e sessenta e sete isolados de Pseudomonas spp. foram obtidos a partir de amostras de água, mãos de ordenhadores, tetos, teteiras, tanques de resfriamento e leite cru armazenado, sendo 85 e 82 pontos de amostragem em fazendas com sistemas de ordenha manual e mecânico, respectivamente. Diferença estatisticamente significativa foi encontrada entre os isolados observados entre a superfície dos tetos antes e após o pré-dipping (p=0,02), mas nenhuma diferença foi encontrada entre sistemas de ordenha ou estações (p>0,05 This study focused on isolating Pseudomonas spp. during milking process in ten dairy farms with manual and mechanical milking systems during dry and rainy seasons, and evaluating DNA homology and patterns of distribution between isolates, in order to identify main sources of milk contamination by Pseudomonas spp. A total of 167 isolates of Pseudomonas spp. were obtained from water, milkers' hands, cows' teats, teat cups, cooling tanks and raw milk. Bacteria of Pseudomonas spp. genus were isolated from 85 and 82 sampling points in dairy farms with manual and mechanical milking system, respectively. A significant difference (p=0.02) on Pseudomonas spp. isolation was observed among samples of surface of cows' teats before and after pre-dipping, but no significant difference (p>0.05) was observed among milking systems or seasons. The possibility of the same Pseudomonas spp. patterns are distributed in different farms and seasons using Amplified Fragment Length Polymorphism (AFLP) technique was demonstrated. Milkers' hands, surface of cows' teats, teat cups and cooling tanks were associated with raw milk contamination with Pseudomonas spp. on farms with manual and mechanical milking system, showing that regardless of the type of milking system and season, proper hygiene procedures of equipment, utensils and workers' hands are essential to avoid contamination of the milk and, therefore, improve milk quality.

Antimicrobial and Antibiofilm Capacity of Chitosan Nanoparticles against Wild Type Strain of Pseudomonas sp. Isolated from Milk of Cows Diagnosed with Bovine Mastitis

“…Pseudomonas sp. is widespread in the environment of dairy cows where the major sources in farms are multiple water supplies, soil, contaminated teat dips and infusion equipment [ 13 ]. The antibiotic recalcitrance associated with Pseudomonas can be mainly attributed to the formation of biofilms in different surfaces [ 14 , 15 ].…”

Microrganismos Psicrotróficos Em Leites Submetidos À Ultra Alta Temperatura Adquiridos Em Curitiba, Paraná

“…Tais resultados podem ser atingidos por qualquer indústria de laticínios por meio da adoção de boas práticas de ordenha e refrigeração adequada do leite cru. Sabe-se que a presença de bactérias psicrotróficas, como a Pseudomonas spp., pode afetar negativamente o processamento térmico de derivados lácteos, portanto, boas práticas higiênicas podem contribuir diretamente para a melhoria da qualidade desses produtos (VIDAL et al, 2017). VIDAL et al (2017), procurando as principais fontes de contaminação por bactérias psicrotróficas em tanques de expansão de dez fazendas leiteiras, verificaram que a má higienização da mão de ordenhadores, da superfície dos tetos das vacas, das teteiras e dos tanques de resfriamento são as principais causas da presença das bactérias no leite cru.…”

Proteolytic and lipolytic potential of Pseudomonas spp. from goat and bovine raw milk

“…Milkers' hands, surface of cows' teats, teat cups and cooling tanks were associated with raw milk contamination with Pseudomonas spp. on farms with manual and mechanical milking system, showing that regardless of the type of milking system and season, proper hygiene procedures of equipment, utensils and workers' hands are essential to avoid contamination of raw milk (Vidal et al 2017).…”