Monitoring bovine tick fever on a dairy farm: An economic proposal for rational use of medications.

In this study, we evaluated the monitoring of tick fever (TF) in a Brazilian dairy farm in the Minas Gerais state, Brazil, from July 10 to August 4, 2018. We aimed to identify diagnostic and treatment flaws in the protocol adopted by the farm, and to establish a novel and accurate TF monitoring protocol based on precision dairy farming and rational use of antimicrobials and antiparasitic drugs, while evaluating the economic benefits of the proposed strategy. We monitored TF in 395 heifer calves aged between 3 and 14 mo. According to the farm's standard protocol, all calves with an increase of 0.5°C in rectal temperature compared with the previous week's measurement were treated for Anaplasma spp. and Babesia spp. Blood smears were collected from the tail tip of the treated calves. During the last week of the study, we prepared blood smears of all calves regardless of treatment indication. Economic analysis was performed. The results indicated that at least 56.86% (261/459) of the calves did not require treatment for TF, whereas only 23.09% (106/459) had treatment indications. Negative blood smears (45.97%; 211/459) indicated the possibility of calves being affected by another disease or a condition that was not being adequately treated or those not necessarily sick. These results demonstrate the excessive use of medications, representing a direct economic loss, in addition to potentially favoring the occurrence of resistance to antimicrobials. In contrast, 9.42% (26/276) of calves had no treatment indication based on rectal temperature but had treatment indications based on blood smears. Only 5.73% (42/735) of blood smears had co-infection with hemopathogens, and none had triple co-infection. Therefore, we proposed the monitoring of TF using rectal temperature and microscopic analysis. If implemented, this strategy would result in a direct annual savings of approximately $22,638.96 (77.99%) related to medication for the treatment of TF. Therefore, implementing the proposed protocol would be cheaper than treatment based only on rectal temperatures. The currently implemented TF protocols overestimate the occurrence of TF, resulting in overtreatment. Thus, implementing a TF monitoring protocol based on a microscopy tool is justified, with benefits including rational use of medication, potential to generate savings, and reduced morbidity and mortality rates, in addition to enabling other diagnoses.

Viability of Staphylococcus aureus and expression of its toxins (SEC and TSST-1) in cheeses using Lactobacillus rhamnosus D1 or Weissella paramesenteroides GIR16L4 or both as starter cultures.

Staphylococcus aureus is one of the main causative agents of food poisoning. This bacterium is an important component of cheese microbiota and plays an important role in foodborne diseases. Another important component of the microbiota is the lactic acid bacterium, which actively participates in processes that define the physicochemical, sensorial, and microbiological features of cheese. Of the various microbiological interactions in cheese, the interaction between lactic acid bacteria and Staph. aureus is most relevant. To this end, we evaluated the viability of Staph. aureus strains and the expression of their enterotoxins in cheeses produced experimentally, using Weissella paramesenteroides GIR16L4 or Lactobacillus rhamnosus D1 or both as starter cultures. Over 7 d, we observed that the presence of lactic acid bacteria did not impair Staph. aureus growth. However, via qPCR we observed a change in the gene expression of staphylococcal enterotoxins, suggesting that molecular communication exists between Staph. aureus strains and lactic acid bacteria in cheese.

Microbiological and physical-chemical characteristics of fermented milk beverages / Características microbiológicas e físico-químicas de bebidas lácteas fermentadas

This study aimed to evaluate some microbiological and physical-chemical characteristics of fermented milk beverages collected at the main supermarkets in Belo Horizonte (MG). 40 samples of the products corresponding to five distinct brands were collected. They were submitted to the following analyses: Most Probable Number (MPN) of total (30ºC) and thermal tolerant coliforms (45ºC), Salmonella spp., coagulase positive Staphylococcus, molds and yeasts, lactic acid bacteria, pH, titratable acidity and contents of moisture, total solids, protein and fat. The analyses were carried out during the last week of shelf life. The microbiological quality of the samples was good and the counts of lactic bacteria were above the minimum established by the official legislation. Streptococcus and Lactobacillus were isolated and identified from the products and Lactobacillus delbrueckii was molecularly identified in three samples. The mean values for the contents of fat and protein, titratable acidity, pH, moisture and total solids ranged from 1.24 to 1.98%; 1.88 to 2.22%; 0.54 to 0.66%; 3.91 to 4.16; 81.18 to 83.25% and 16.75 to 18.82%, respectively. All samples had protein content in agreement with the official legislation.

O objetivo do presente trabalho foi avaliar as características microbiológicas e físico-químicas de bebidas lácteas fermentadas. Foram coletadas 40 amostras de bebidas lácteas fermentadas pertencentes a cinco marcas distintas, em grandes redes de supermercados de Belo Horizonte. Em cada amostra, foram avaliados os seguintes parâmetros: número mais provável de coliformes totais (30ºC), número mais provável de coliformes termotolerantes (45ºC), pesquisa de Salmonella spp., contagem de Staphylococcus coagulase positiva, contagem de bolores e leveduras, contagem total de bactérias lácticas viáveis, umidade, sólidos totais, teor de proteína, teor de gordura, pH e acidez titulável. As análises foram realizadas na última semana do período de validade. As amostras apresentaram qualidade microbiológica satisfatória, bem como contagens totais de bactérias lácticas viáveis superiores ao mínimo estabelecido pela legislação. Streptococcus e Lactobacillus foram identificados em todas as marcas de bebidas lácteas fermentadas analisadas, e em três delas foi possível identificar a espécie Lactobacillus delbrueckii. Os valores médios encontrados para os teores de gordura, proteína, acidez titulável, pH, umidade e sólidos totais variaram de 1,24 a 1,98%, 1,88 a 2,22%, 0,54 a 0,66%, 3,91 a 4,16, 81,18 a 83,25% e 16,75 a 18,82%, respectivamente. Todas as marcas de bebidas lácteas fermentadas apresentaram teor médio de proteína superior ao mínimo preconizado pela legislação.

Detection of cheese whey and caseinomacropeptide in fermented milk beverages using high performance liquid chromatography / Detecção de soro lácteo e caseinomacropeptídeo por cromatografia líquida de alta eficiência em bebidas lácteas fermentadas

Cheese whey level and caseinomacropeptide (CMP) index of fermented milk beverages added with four levels of cheese whey (0, 10, 20, and 40percent) and stored at 8-10oC for 0, 7, 14 and 21 days were determined by high performance liquid chromatography-gel filtration (HPLC-GF). Additionally, the interference of the starter culture and the storage time on the detection of cheese whey and CMP were investigated. Refrigerated storage up to 21 days did not affect (P>0.05) cheese whey and CMP amounts in milk (0 percent of cheese whey) and in fermented milk beverages added with 10 and 20percent of cheese whey (P>0.05). However, cheese whey and CMP amounts were higher than expected (P<0.05) in fermented milk beverages added with 40 percent of cheese whey and stored for 21 days...

O presente trabalho teve como objetivos quantificar o teor de soro e o índice de caseinomacropeptídeo (CMP) de bebidas lácteas fermentadas preparadas em laboratório, adicionadas de diferentes concentrações de soro (0, 10, 20 e 40 por cento), fermentadas e armazenadas em refrigeração (8-10oC) por tempos distintos (zero, sete, 14 e 21 dias), por cromatografia líquida de alta eficiência-filtração em gel (CLAE-FG), bem como verificar a interferência da cultura utilizada no preparo das bebidas lácteas fermentadas e do tempo de armazenamento na detecção de soro lácteo e CMP. Quando os teores de soro lácteo e os índices de CMP obtidos por CLAE-FG de bebidas lácteas fermentadas foram analisados ao longo do tempo de armazenamento, verificou-se que não houve diferença (p>0,05) para o leite (0 por cento de soro) e as bebidas lácteas com 10 e 20 por cento de soro nos tempos de zero, sete, 14 e 21 dias de armazenamento. No entanto, para a bebida láctea fermentada adicionada de 40 por cento de soro, foi observada diferença para o tempo de armazenamento de 21 dias (p<0,05), em que o teor de soro e o índice de CMP obtidos foram maiores que os demais, que se mostraram equivalentes entre si (p>0,05) para os tempos de zero, sete e 14 dias...

Potencial probiótico in vitro de bactérias ácido-láticas isoladas de queijo-de-minas artesanal da Serra da Canastra, MG / Probiotic potential of lactic acid bacteria isolated from minas artisanal cheese from Serra da Canastra, MG

O potencial probiótico in vitro de 12 amostras de bactérias ácido-láticas (11 Lactobacillus spp. e uma Weissella paramesenteroides), isoladas de queijo-de-minas artesanal da Serra da Canastra, foi investigado. Essas amostras foram caracterizadas in vitro quanto à susceptibilidade a antimicrobianos, antagonismo contra microrganismos de referência patogênicos e não patogênicos e sensibilidade a pH gástrico e sais biliares. Apenas L. rhamnosus B4, W. paramesenteroides C10 e L. rhamnosus D1 apresentaram resistência a menor número de antimicrobianos (ceftazidima, oxacilina, estreptomicina e vancomicina). Todas as amostras apresentaram atividade antagonista frente a todas as bactérias patogênicas testadas e não inibiram as bactérias não patogênicas. Todas as amostras foram resistentes ao pH gástrico (2.0). Alguns microrganismos mostraram pouca inibição do crescimento em presença de sais biliares, enquanto outros foram moderadamente ou altamente inibidos. L. rhamnosus B4, W. paramesenteroides C10 e L.rhamnosus D1 apresentaram o melhor potencial probiótico de acordo com os testes in vitro realizados.

The in vitro probiotic potential of twelve samples of lactic acid bacteria (eleven Lactobacillus spp. and one Weissella paramesenteroides) isolated from Minas artisanal cheese from Serra da Canastra was evaluated for their antimicrobial susceptibility, antagonistic activity against pathogenic and lactic acid bacteria, as well as for their tolerance to gastric pH and biliary salts. Only L. rhamnosus B4, W. paramesenteroides C10, and L. rhamnosus D1 showed resistance to tested antimicrobials (ceftazidime, oxacillin, streptomycin, and vancomycin). All samples showed antagonism against all pathogenic bacteria tested and did not inhibit the growth of nonpathogenic samples. Regarding gastric pH tolerance, all samples showed low inhibition at pH 2. The tolerance to biliary salts varied from low to great among tested samples. L. rhamnosus B4, W. paramesenteroides C10, and L. rhamnosus D1 showed the best probiotic potential revealed by their in vitro test results.

Queijo de minas artesanal da Serra da Canastra: influência da altitude das queijarias nas populações de bactérias acidolácticas / Influence of altitute on lactic acid bacteria population of minas artisanal cheese from Serra da Canastra

Amostras de queijo de minas artesanal foram coletadas em 18 queijarias localizadas em propriedades rurais da região da Serra da Canastra, Minas Gerais, com o objetivo de avaliar a influência da altitude sobre a população de bactérias acidolácticas. As queijarias estavam distribuídas nas altitudes de 600 a 900m, 900 a 1000m e mais de 1000m. Observaram-se populações mais elevadas de bactérias acidolácticas nas amostras de queijo da altitude de 600 a 900m. Lactobacillus rhamnosus, Lactobacillus casei e Lactobacillus plantarum foram os principais microrganismos isolados e identificados por PCR ARDRA 16S-23S rDNA, além de Enterococcus spp., Lactococcus spp. e outras espécies de Lactobacillus. Sugere-se que estas espécies estejam adaptadas ao ambiente de produção do queijo de minas artesanal produzido na região, o que resultaria em características sensoriais próprias do produto.

Samples of minas artisanal cheese were collected in 18 small-scale producer properties located in the rural region of Serra da Canastra, Minas Gerais state, aiming to evaluate the influence of three altitudes, from 600 to 900m, 900 to 1000m, and higher than 1000m, on the lactic acid bacteria (LAB) population. High populations of LAB were observed in the cheese samples, mainly in the lowest altitude. Lactobacillus rhamnosus, Lactobacillus casei, and Lactobacillus plantarum were the major LAB isolated from the cheese samples and identified according to PCR ARDRA 16S-23S rDNA. Enterococcus spp., Lactococcus spp., and other species of Lactobacillus genus were also found. It is suggested that these microorganisms are adapted to the production environment of the minas artisanal cheese which result in the unique sensorial properties of the product.

Qualidade de leites fermentados funcionais elaborados a partir de bactérias ácido-lácticas isoladas de queijo de coalho / Quality of functional fermented milks produced by the use of lactic acid bacteria isolated from coalho cheese

Leites fermentados foram elaborados a partir de bactérias ácido-lácticas com propriedades funcionais, isoladas de queijo de coalho com e sem a adição de concentrado proteico de soro (CPS). Características físico-químicas, microbiológicas e sensoriais dos produtos elaborados foram analisadas durante 40 dias de estocagem sob refrigeração a 8-10ºC. Todos os leites fermentados elaborados, independentemente da adição de CPS e da cultura utilizada, apresentaram contagens adequadas de bactérias (>10(8)UFC/mL) durante todo o período de avaliação, o que garantiria seu possível potencial funcional. Leites fermentados por Lactobacillus acidophilus apresentaram melhor aceitação (P<0,05) pelos provadores aos 10 dias de estocagem; enquanto, aos 40 dias, o leite fermentado por Weissella confusa sem CPS resultou em pior aceitação (P<0,05). A associação de Lactobacillus acidophilus e Weissella confusa ou somente Lactobacillus acidophilus, independentemente da adição de CPS, seriam recomendados para elaboração industrial de novos leites fermentados potencialmente funcionais a partir de culturas lácticas brasileiras.

Fermented milks were produced using whey protein concentrate (WPC) and potentially functional lactic acid bacteria, which were isolated from coalho cheese produced in. Physical-chemical, microbiological, and sensorial characteristics of the fermented milks were analyzed during 40 days under refrigeration at 8-10ºC. All products, irrespectively of WPC adding or culture used, showed appropriated bacterial counts (>10(8)CFU/mL) throughout the evaluation time, which would guarantee their functional potential. Lactobacillus acidophilus fermented milks presented better sensorial approval (P<0.05) when evaluated at 10-day storage; while Weissella confusa fermented milks presented lower acceptance (P<0.05) at 40-day storage. The association of Lactobacillus acidophilus and Weissella confusa or Lactobacillus acidophilus isolatedly, irrespectively of WPC adding, should be recommended for the industrial elaboration of novel functional fermented milks using Brazilian lactic cultures as starters.

Eficiência dos testes COPAN (Microplate e Single) na detecção de resíduos de antimicrobianos no leite / Efficacy of COPAN (Microplate and Single kits) in detection of antimicrobials residues in milk

Avaliou-se a eficiência dos testes microbiológicos COPAN (Microplate e Single) para detecção de resíduos de 13 antimicrobianos inoculados em leite isento de resíduos. Foram utilizadas quatro concentrações, sendo a primeira equivalente à metade do limite de detecção declarado pelo fabricante (C1); a segunda equivalente ao limite máximo de resíduos (LMR) estabelecido pela legislação brasileira (C2); a terceira equivalente ao limite de detecção declarado pelo fabricante (C3); e a quarta equivalente ao dobro do limite de detecção declarado pelo fabricante (C4). Os testes apresentaram 100 por cento de sensibilidade na detecção de amoxicilina, ampicilina, cloxacilina, penicilina, tilosina, sulfadiazina, sulfametoxazol, e 96,7 por cento na detecção de oxacilina para as concentrações informadas pelo fabricante como limite de detecção. Em relação às concentrações estabelecidas pela legislação brasileira, verificou-se que os testes foram capazes de detectá-las para a maioria dos antimicrobianos avaliados. Os testes não se mostraram eficientes na detecção das concentrações estabelecidas pela legislação para eritromicina, oxitetraciclina, tetraciclina, trimetoprim e gentamicina (Microplate).

The efficacy of the microbiological kits COPAN (Microplate and Single) for detection of antimicrobials residues was tested. Thirteen drugs were inoculated into milk without residues at four concentration levels: C1 - half of the detection threshold declared by the manufacturer, C2 - the maximum residues threshold established by the Brazilian legislation, C3 - the detection threshold declared by the manufacturer, and C4 - two fold the detection threshold declared by the manufacturer. The tests showed 100 percent efficient in detection of amoxicillin, cloxacillin, penicillin, tilosin, sulfadiazine, and sulfa methoxazol; and 96.7 percent for oxacillin considering the concentration stated by the manufacturer as threshold level. Regarding the concentrations established by the Brazilian legislation, all tested kits were able to detect most of the evaluated antimicrobials. The kits were not efficient in detection of the concentration levels established by the Brazilian legislation for erythromycin, oxytetracyclin, tetracyclin, trimetoprim, and gentamycin (Microplate).