Multifactorial analysis of unstable non-acid milk occurrence in dairy production/ Análise multifatorial da ocorrência de leite instável não ácido em propriedades leiteiras

The aim was to analyze the Unstable Non-Acid Milk (UNAM) phenomenon through the association of zootechnical characteristics of the farms relating them to their occurrence. The data collection was carried out in 12 dairy farms which received a technical visit to learn the production system: handling, feeding, mineralization and milking procedures. The milk samples were analyzed for fat, protein, lactose, solids not fat, standard plate count, somatic cell count, pH, titratable acidity and ethanol test stability. Milk data were submitted to analysis of variance; association between zootechnical characteristics and UNAM were determined by logistic regression; and multivariate analysis of principal components was carried out. The occurrence of UNAM was verified in 25% of the evaluated farms. In UNAM herds 27% to 33% of the cows were classified as UNAM. The animals with UNAM milk was different between farms classified as Stable or UNAM, being 12% and 30% of cows, respectively. The detection of UNAM was possible when in the herd there are at least 23% of the animals producing UNAM milk. The three principal components identified covered the main areas of influence on the occurrence of UNAM: Quality and interaction with part of the solids; Production and relationship with lactose; Nutrition and correlations with part of the components. The classification of milk in the expansion tank as UNAM can only be identified when more than 23% of the animals were in this condition. The multivariate analysis identified that the nutritional balance of each cow was determining factor for UNAM presence

Determinação de características produtivas e a influência da assistência técnica no pagamento por qualidade do leite / Determination of productive characteristics and influence of technical assistance on milk quality payment

A pecuária leiteira é uma das atividades mais representativas na agricultura familiar. A crescente exigência do mercado consumidor por produtos mais saudáveis e de melhor qualidade aumenta a necessidade de maior engajamento de pequenos produtores na produção de leite, proporcionando qualidade e lucratividade. Instruções Normativas (INs) foram instituídas pelo Ministério da Agricultura, Pecuária e Abastecimento (MAPA), objetivando a padronização da produção de leite. Um dos pilares para vencer os desafios da atividade é a transferência de conhecimentos e tecnologias pela assistência técnica rural. Sendo assim, os objetivos deste trabalho foram avaliar a qualidade do leite de tanque de refrigeração de pequenos produtores familiares antes e depois da assistência técnica, identificando as características de produção que influenciam na qualidade do leite e simulando o impacto dos programas de penalização na renda do produtor, para promover a melhoria da qualidade do leite. Vinte produtores leiteiros de agricultura familiar foram monitorados por dois anos. Analisaram-se os aspectos de qualidade do leite de tanque de resfriamento (composição, Contagem de Células Somáticas (CCS) e contagem padrão em placas (CPP)), e caracterização dos sistemas de produção por meio de questionários. Observou-se que o maior desafio para os produtores se adequarem as INs está relacionado à CPP e CCS. As condições higiênico-sanitárias e o conforto animal foram os fatores que mais influenciaram os índices de CPP. Apesar de não ter apresentado melhora significativa na qualidade do leite antes e depois da assistência técnica, é fundamental que o produtor receba orientações desses profissionais para garantir a consolidação e a manutenção do conhecimento de boas práticas de higiene e saúde do rebanho. Os índices de CCS, CPP e simulação de renda podem auxiliar a assistência técnica na conscientização dos produtores sobre a importância da adequação às INs, visando uma melhor qualidade do produto e aumento da renda familiar.

Use of bacteriocin and cationic lipid nano-fragments against resistant Staphylococcus spp. isolated from bovine mastitis.

Staphylococcus spp. é uma das principais causas da mastite bovina, onde o uso de antimicrobianos tem sido comprometido por mecanismos de resistência bacteriana e geração de resíduos que alteram a qualidade e segurança alimentar do leite e derivados. Foi avaliada a atividade in vitro da nisina (NS), do brometo de dioctadecildimetilamônio (DDA) e do complexo NS/DDA contra Staphylococcus spp. resistentes isolados de mastite bovina. A CBM50 da nisina e DDA foi 50 e 4μg/mL, respectivamente, enquanto que a CBM50 do complexo NS/DDA foi 3/2μg/mL, com efeito parcialmente sinérgico. O estudo de time-kill revelou redução de 3 log10 UFC/mL após uma hora de interação entre NS/DDA e a bactéria. A microscopia de fluorescência confirmou uma perda da viabilidade após 6 horas de interação. A interação NS/DDA resultou na formação de nanopartículas (148,5 nm) catiônicas (+8,84 mV) cuja interação com a superfície bacteriana negativa (-27,32 mV) resultou em ação bactericida. NS/DDA pode ser uma alternativa promissora contra Staphylococcus spp. resistentes isolados de mastite bovina.Staphylococcus spp. is a major cause of bovine mastitis, where the use of antimicrobials has been compromised by bacterial resistance mechanisms and waste generation that change the food quality and safety of milk and dairy products. The in vitro activity antibacterial was evaluated of the nisin (NS), of the dioctadecyldimethylammonium bromide (DDA) and of the NS/DDA complex against drug-resistant Staphylococcus spp. isolated from bovine mastitis. The CBM50 of nisin and DDA were 50 and 4μg/ml, respectively, while the CBM50 NS/DDA complex was 3/2mg/mL, with partially synergistic effect. The time-kill study showed reduction of 3log10 CFU/mL after an hour of interaction between NS/DDA and bacteria. Fluorescence microscopy confirmed a loss of viability after 6h of interaction. NS/DDA interaction resulted in formation of nanoparticles (148.5 nm) cationic (+8.84 mV) which interact with negative bacterial surface (-27.32 mV) resulted in bactericidal activity. NS/DDA may be a promising alternative against drug-resistant Staphylococcus spp. isolated from bovine mastitis

Perfil microbiológico do leite produzido em uma fazenda do Estado de São Paulo

O artigo não apresenta resumo em português

Perfil microbiológico do leite produzido em uma fazenda do Estado de São Paulo

O artigo não apresenta resumo em português

Milk microbiological profile produced in a dairy farm from São Paulo State

Milk is considered one of the finest food because its composition presents several important elements for human nutrition, but problems with animal health, such as mastitis, leads to the decrease in its production and quality. Mastitis is a bovine udder disease that has been the cause of low productivity and offers potential risk to the animal’s health. Therefore, attention to the sanitary control of animals is very important. This study aimed to evaluate the milk microbiological quality of cows from a herd which is-composed of breed mixed /Jersey. Milk samples were collected fortnight in February and March of 2011, in 15 lactating cows that exhibited a herd’s profile. Each collection totaled 60 samples and a total of 240 samples were obtained in the period. The samples were collected individually in sterile test tubes, previously identified with animal’s name and number and mammary quarter. The teats were individually washed with water, dried with disposable paper and then dipped within antiseptic solution of iodine alcohol. The material was packed in insulated box material provided with ice cubes and taken to the laboratory for bacterial isolation and identification. The isolation and identification of strains were performed at Laboratory of the Milk Quality, in Instituto de Zootecnia. From 240 milk samples, 101 (42.08%) were infected and the microorganisms found and its prevalence are on table 1. The most prevalent organism was S. aureus, which one is quite worrying, because of its pathogenicity causing large variations in milk composition and somatics cells counts (SCC), reducing the functionality of the infected udder and being very contagious, leading to early disposal or death of the animal. Besides, toxins produced by S. aureus in milk foods may be responsible for causing food intoxication in humans. The second most frequent was Streptococcus spp., that is an important pathogen of contagious mastitis. The results showed presence of large population of bacteria such as S. aureus, Streptococcus, Corynebacterium spp. and indicated inadequate sanitary conditions of dairy cows; thus reinforcing the need for microbiological examination of milk samples, targeting specific measures that enable mastitis control in the herd

Antimicrobial sensitivity profile of Staphylococcus spp. Isolated from clinical mastitis

Inflammation of the mammary gland, which is also known as mastitis, occupies a prominent place among the diseases that affect dairy cattle, having a great economic importance in the dairy sector. Mastitis may have different origins, however, infectious mastitis is the most frequent and represents a risk to public health due to the propagation of microorganisms through milk. Staphylococcus spp. are considered the microorganisms that cause the greatest losses in milk production, being that Staphylococcus aureus is the pathogen of major importance because they present high resistence to antimicrobials. Empirical treatment, without prior identification of the pathogens and their resistance profile, may contribute to the emergence of multidrug-resistant strains and risk the efficiency of the antimicrobial. In that scenery, the study aimed to evaluate the resistance profile of Staphylococcus spp. against some antimicrobials used in the treatment of cows with clinical mastitis. The study was conducted on a property in the state of São Paulo from January 2011 to June 2012. We evaluated 29 lactating cows that present clinical mastitis in, at least, one mammary quarter. The diagnosis of clinical mastitis was performed by evaluating the clinical signs and also by Tamis test. Samples of milk from mammary quarters were collected aseptically in sterile tubes for microbiological evaluation. Microorganisms were isolated on sheep blood agar 5% and Sabouraud agar with chloramphenicol. The sensitivity profile of Staphylococcus spp. to the antibiotics ampicillin, cephalexin, ceftiofur, cefaclor, gentamicin, kanamycin, neomycin, penicillin G and oxacillin, was tested by disk diffusion test on Mueller-Hinton agar. From a total of 106 samples of milk analyzed, 64 (60.38%) presented microbiological growth, being observed isolation of Streptococcus spp. 29 (34.52%), Staphylococcus spp. 28 (33.33%), Corynebacterium spp. 17 (20.24%), filamentous fungi 4 (4.76%), yeast 4 (4.76%) and Gram-negative bacilli 2 (2.38%). From total of Staphylococcus spp. isolates, 67.86% were sensitive to all antibiotics tested. Resistance to penicillin G was evidenced in 25% of the strains, to ampicillin in 28.57% and 10.71% to neomycin. It was also observed that 3.57% of strains tested were resistant to all antibiotics. The isolation of multidrug-resistant strains presents risks to the health of the animal and the consumer because they can be transmitted through milk products. The identification of pathogens and the performance of antimicrobial susceptibility profile are essential for monitoring and control of multidrug-resistant strains

Perfil de sensibilidade antimicrobiana de Staphylococcus spp. isolados de mastite clínica

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Intramammary treatment with gentamicin in lactating cows with clinical and subclinical mastitis

Abstract The study evaluated the microbiological profile of milk samples collected before and after mastitis treatment with gentamicin and investigated biofilms production and antimicrobial susceptibility of Staphylococcus spp. isolated. The presence of gentamicin residues in milk after the recommended withdrawal period was also evaluated. Antimicrobial residues were analyzed by Delvotest® SP NT over a period of 12 days beginning after 24 hours the last gentamicin application. Some of Staphylococcus spp. isolates were biofilm producers (19.05%). Staphylococcus spp. showed high levels of resistance to neomycin (16.95%), penicillin G (10.17%), and ampicillin (10.17%). Multidrug resistance to all antibiotics tested was observed in 1.69% of the Staphylococcus spp. isolates. Among 1440 mammary quarter milk samples 24.95% presented gentamicin residues after the withdrawal period. Gentamicin residues were also detected in 3.8% of samples from calibrated glass recorder jar (n=383) 4.1 days after treatment. The indiscriminate use of antibiotics may lead to the emergence of multidrug-resistant strains as well as increasing the risk of presence of residues of these drugs in milk. These problems affect the milk quality and may become a public health problem

Molecular Typing of Mastitis-Causing Staphylococcus aureus Isolated from Heifers and Cows

Staphylococcus aureus is among the main etiologic agents of bovine mastitis. A total of 83 isolates of S. aureus from mammary glands of primiparous heifers were collected in the prepartum, calving and during lactation. For lactating cows, a total of 27 isolates of S. aureus from mammary glands were collected during lactation. The samples were taken in two dairy farms located in Sao Paulo State, Brazil. The highest frequency of S. aureus isolation in heifers was at the end of lactation. Strains were typified through Pulsed-field gel electrophoresis (PFGE) and grouped according to patterns of restriction enzyme SmaI. PFGE generated seven clonal profiles that were grouped into three different lineages, with the LA lineage being predominant and identified in heifers, as well as in the cows from the two regions studied. It was concluded that the cows showed a significant source of dispersion of S. aureus. At the first lactation the heifers were infected by the same clonal profiles of S. aureus which were isolated from multiparous lactating cows. The heifers were infected during milking over the months of lactation