Suchergebnisse

This study aimed to determine the frequency of Pseudomonas fluorescens, P. putida, and P. aeruginosa in refrigerated raw milk; their proteolytic potential; and your association with the aprX gene. Of the 173 isolates confirmed as belonging to Pseudomonas spp., 37% were P. fluorescens, 25.4% P. putida, and none belongs to P. aeruginosa. The aprX gene was distributed proportionally between P. putida (68%) and P. fluorescens (75%), but it was not associated with low or high proteolytic potential in both species. P. putida (16) and P. fluorescens (14) isolates with no aprX gene identified also had proteolytic potential. Considering the synthesis of proteases other than AprX by the isolates under study, we concluded that P. fluorescens and P. putida represented 62.4% of the Pseudomonas genus, with high probability of having the aprX gene and proteolytic potential. However, there was no association between the deteriorating potential with the presence of the aprX gene.

Em uma indústria beneficiadora, foram observados em produtos lácteos fermentados defeitos como redução acelerada do pH durante a fermentação, perda de coloração e viscosidade, sabor amargo e formação de gás. A partir das contagens de bactérias láticas não iniciadoras (NSLAB) e de bactérias fermentadoras de citrato, decidiu-se por avaliar os protocolos de higienização (CIP-clean in place) dos equipamentos no setor de produtos lácteos fermentados. Para comparação da eficiência dos CIPs intermediário e completo, três pontos da produção foram avaliados através do monitoramento do pH: pasteurizador de base láctea (A); tanque de fermentação antes (B1) e após (B2) a adição da cultura láctea. Amostras foram coletadas após a realização das CIPs intermediário (amostra I) e completo (amostra II). Em seguida, as amostras foram coletadas após 12 horas de produção dos lácteos fermentados e antes do CIP completo (amostra III) e intermediário (amostra IV). Estas amostras, dos pontos A e B1, mostraram redução do pH em 1 escala em 8h e 6h depois do CIP intermediário e 9 h e 8h depois do CIP, respectivamente. Apesar do CIP completo ter se mostrado mais eficaz, sua eficiência não apresentou a duração necessária determinada pelo controle interno da indústria. Foi proposta uma alteração no processo de limpeza no ponto A, mantendo apenas o CIP completo a cada 10 horas e solução de limpeza alcalina em maior concentração (2,0 a 2,5%), o que acarretou adequação no tempo de fermentação dos produtos e ausência dos defeitos observados.
Palavras-chave: Higienização. Biofilme. Bactérias Ácido Lácticas. Defeitos Tecnológicos. pH.
AbstractIn a milk-processing industry, defects such as accelerated pH reduction during fermentation, loss of color and viscosity, bitter taste and gas formation were observed in fermented dairy products. Observing non-starter lactic acid bacteria (NSLAB) and citrate fermenting bacteria counts, it was decided to evaluate the hygiene protocols (CIP-clean in place) of the equipment in the fermented dairy products sector. To compare the efficiency of intermediate and complete CIPs, three checking points of fermented dairy products production were evaluated by monitoring the pH: milk pasteurizer (A), and fermentation tank before (B1) and after (B2) the addition of the dairy culture. Samples were collected after performing the intermediate (sample I) and complete (sample II) CIPs. Then, samples were collected after 12 hours of fermented dairy products production and before the complete (sample III) and intermediate (sample IV). These samples from point A and point B1, showed a reduction of 1 pH scale in a period of 8h and 6h after the intermediate CIP, and 9 h and 8h after the complete CIP, respectively. Although the full CIP proved to be more effective, its efficiency did not show the required duration determined by the internal control of the industry. A change was proposed in the cleaning process at point A, keeping only the complete CIP every 10 hours and using alkaline cleaning solution in higher concentration (2.0 to 2.5%), which led to the adequacy in the fermentation time of the products and in the absence of the observed defects.
Keywords: Hygiene. Biofilm. Lactic Acid Bacteria. Technological Defects. pH.

The objective of the work was to evaluate the multiplication capacity and proteolytic activity of different Pseudomonas spp. cell counts inoculated in milk and storaged under different temperature. Strains isolated from refrigerated raw milk (RRM) were confirmed at genus level by Polymerase Chain Reaction (PCR). The Pseudomonas spp. was cultured in cephalothin-sodium fusidate-cetrimide (CFC) agar-base (30?C for 48 h) until it reached 2 log and 6 log CFU mL-1. Three of eight strains confirmed as Pseudomonas spp were inoculated in sterile reconstituted whole milk powder and incubated at 2°C, 4°C, and 8°C for 96 h. Primary proteolysis indices was determined by the Kjeldahl method. When taking into account the effect of storage time in Pseudomonas spp. population, it was found that the initial population (2 log CFU mL-1) showed significant difference in growth rates only from 0 h to 24 h, keeping at the same levels along 96 h. When a higher initial population was incubated (6 log CFU mL-1), it was not observed a significant difference for times tested. Related to the effect of storage time in proteolysis index, it was not observed a significant difference in samples inoculated with 2 and 6 log CFU mL-1 Pseudomonas spp. When we analyzed the influence of storage temperature on the bacterial multiplication, there was a significant difference in the Pseudomonas spp. population only between 2°C and 8°C after 96 h of milk storage with 2 log CFU/mL of initial inoculum. If we consider the temperature effect in the primary proteolysis index, there were significant differences at the inoculum of 2 log CFU mL-1 where the primary proteolysis at 24 h was lower at 2°C than at 8ºC. Low temperatures or short storage time had no influence on Pseudomonas spp. enumeration or in the primary proteolysis index when high initial contaminations are observed. At lower Pseudomonas spp. initial population, the smaller storage time tested influenced the population control, and linked with the reduction in the storage temperature, lower proteolysis index were observed.

<p class="Pa7">The aims of present study were to evaluate the effects of milk somatic cell count (SCC) and heat stress on yield and milk composition of cows in a herd for commercial production in a temperate region during the period 2008-2012. Data from the monthly milk test-day records of 161±9 Holstein, totaling 9,650 milkings, were provided by the Association of Holstein Cattle Breeders of Parana State, and analyzed by descriptive analysis, correlation, analysis of variance, and regression analysis. The average daily milk yield was 31.78 kg/cow, which decreased to 29.31% when the somatic cell score (SCS) was 9, and to 11% when the Equivalent Temperature Index (ETI) was 32 or above. Lactose content decreased from SCS 0 until 9 and fat content decreased from SCS 1 until 9, totaling decrease 7.88 and 9.23%, respectively, when the SCS was 9. An opposite effect was observed for the protein content, which increased by 3.6% at SCS 8, when compared to SCS 0. Losses were observed in the daily total solids production from the SCS 0, totaling 30.64% at SCS 9.The increase in ETI to 32 or above reduced all milk constituents as much as 3.42%, except protein. These results, combined with the losses in milk yield at that ETI level, led to a decrease of up to 12.74% of milk solids. It is concluded that since losses in milk quality and yield resulting from SCC and ETI are significant, actions to prevent infection in the mammary gland and to provide a comfortable environment for dairy cattle are needed even in temperate regions.</p>

Campilobacteriose genital bovina (CGB) e Tricomonose bovina (TB) são doenças infectocontagiosas de transmissão venérea, assintomáticas nos touros, sendo consideradas como importantes enfermidades causadoras de falha reprodutiva, morte embrionária ou abortamento, ocasionando perdas econômicas significativas em rebanhos bovinos infectados. CGB é causada pela bactéria Campylobacter fetus subsp. venerealis e Campylobacter fetus subsp. fetus, e TB pelo protozoário Tritrichomonas foetus. O estado de Mato Grosso é detentor do maior rebanho bovino do Brasil, envolve a região do Pantanal Mato-Grossense que possui grandes extensões de terra, com ciclo anual de enchentes e a reprodução dos animais realizada predominantemente por monta natural, condições estas, favoráveis a presença de CGB e TB no rebanho. Considerando a carência de informações recentes sobre a ocorrência dessas enfermidades no estado de Mato Grosso, o objetivo deste estudo foi investigar a presença de Campylobacter spp. e Tritrichomonas foetus em 100 touros provenientes dos municípios de Poconé, Santo Antônio de Leverger e Nossa Senhora do Livramento, localizados na região pantaneira do estado de Mato Grosso. Amostras de esmegma prepucial foram coletadas por meio de escarificação via swab prepucial e armazenadas em solução salina a -80ºC. Para a detecção de Campylobacter fetus subsp. venerealis, Campylobacter fetus subsp. fetus, e Tritrichomonas foetus, foi realizada a reação em cadeia pela polimerase (PCR). Apesar do questionário aplicado nas propriedades revelar condições epidemiológicas que favorecem a manutenção e disseminação desses patógenos, este estudo não identificou a presença dos referidos agentes em touros avaliados nas propriedades rurais do pantanal Mato-Grossense.

<p>The aim of this research was to identify the occurrence of pathogens causing subclinical mastitis in grade B milk farms of the Jaguapitã county, state of Paraná, Brazil. California Mastitis Test (CMT) were carried out in 400 milk samples from 100 animals and 157 teats from 55 animals (55%) were positive, showed score two or higher to CMT. When these 157 positive samples to CMT were transported for bacterial culture in blood agar, 25.48% (40/157) samples showed no bacterial growth or more than two types of bacterial colonies grew, 28.03% (44/157) were Coagulase-negative staphylococci (CNS), 8.28% (13/157) were <em>Streptococcus uberis</em>, 7.64% (12/157) were <em>Staphylococcus aureus</em>, 7.64% (12/157) were <em>Corynebacterium </em>spp, 7.01% (11/157) were <em>Staphylococcus intermedius</em>, 4.46% (7/157) were <em>Staphylococcus hyicus</em>, 3.82% (6/157) were <em>Bacillus </em>spp., 2.55% (4/157) were <em>Streptococcus dysgalacteae</em>, Enterobacteria and Yeasts. We conclude that CNS is the most relevant subclinical mastitis causative agent.</p><p><strong> </strong></p>