Kefir4All, a citizen science initiative to raise awareness of the roles that microbes play in food fermentation.

Microorganisms are ubiquitous in nature and are central to human, animal, environmental, and planetary health. They play a particularly important role in the food chain and the production of high-quality, safe, and health-promoting foods, especially fermented foods. This important role is not always apparent to members of the public. Here, we describe Kefir4All, a citizen science project designed to provide the general public with an opportunity to expand their awareness, knowledge, and practical skills relating to microbiology, introduced through the medium of producing fermented food, i.e., milk kefir or water kefir. During the course of Kefir4All, 123 citizen scientists, from second-level school and non-school settings, participated in a study to track changes in the microbial composition of kefirs, by performing and recording details of milk kefir or water kefir fermentations they performed in their homes or schools over the 21-week project. At the start of the study, the citizen scientists were provided with milk or water kefir grains to initiate the fermentations. Both types of kefir grain are semi-solid, gelatinous-like substances, composed of exopolysaccharides and proteins, containing a symbiotic community of bacteria and yeast. The experimental component of the project was complemented by a number of education and outreach events, including career talks and a site visit to our research center (Kefir Day). At the end of the study, a report was provided to each citizen scientist, in which individualized results of their fermenting activities were detailed. A number of approaches were taken to obtain feedback and other insights from the citizen scientists. Evaluations took place before and after the Kefir4All project to gauge the citizen scientist's self-reported awareness, knowledge, and interest in microbiology and fermented foods. Further insights into the level of citizen science participation were gained through assessing the number of samples returned for analysis and the level of participation of the citizen scientists throughout the project. Notably, the survey results revealed a self-reported, increased interest in, and general knowledge of, science among the Kefir4All citizen scientists after undertaking the project and a willingness to take part in further citizen science projects. Ultimately, Kefir4All represents an example of the successful integration of citizen science into existing education and research systems.

Filamentous fungi in artisanal cheeses: A problem to be avoided or a market opportunity?

The microbial diversity of artisanal cheeses has been ever more extensively explored over recent years. Many new studies have been particularly focused on the detection and identification of fungi associated with cheese rinds. This is not surprising given that the composition and abundance of fungi on the cheese surface can significantly contribute to desirable sensory qualities, while also contributing to defects, particularly during ripening, and risks associated with the production of mycotoxins. Here we critically review the impact of fungi on the quality of artisanal cheeses, as well as the risks associated with the presence of particular species or strains with specific phenotypes. Ultimately, we address the question; should fungi be predominantly considered villains when it comes to artisanal cheese safety or could their presence be better exploited by producers in order to generate innovative products with greater added value? Such discussions will be increasingly important from the perspective of the future commercialization and regulation of artisanal cheeses that frequently contain a high abundance of moulds.

Effect of kombucha intake on the gut microbiota and obesity-related comorbidities: A systematic review.

Kombucha is a fermented nonalcoholic tea-based beverage produced through a symbiotic culture of bacteria and yeasts. In vitro studies have demonstrated antimicrobial, antioxidant, antiproliferative, and anti-carcinogenic properties of kombucha. However, no systematic reviews have evaluated the effects of kombucha in vivo. Thus, we aimed to evaluate the evidence that exists so far about kombucha consumption on comorbidities associated with obesity as well as on the gut microbiota. The search was conducted in accordance with PRISMA and the protocol was registered in PROSPERO (registration number: CRD42020158917). The MEDLINE/PubMed, Web of Science, LILACS, SciELO, Scopus, and Science Direct databases were used in the search considering the following terms: "kombucha" OR "kombucha tea" OR "kombucha teas" OR "tea, kombucha" OR "teas, kombucha" NOT "review." Fifteen studies were included in this review. The results suggest that kombucha consumption attenuates oxidative stress and inflammation, improves the liver detoxification process, and reduces intestinal dysbiosis. There is evidence that kombucha consumption is beneficial for the control and treatment of obesity and associated comorbidities, as well as for the modulation of the gut microbiota in vivo.

What Is Candida Doing in My Food? A Review and Safety Alert on Its Use as Starter Cultures in Fermented Foods.

The use of yeasts as starter cultures was boosted with the emergence of large-scale fermentations in the 20th century. Since then, Saccharomyces cerevisiae has been the most common and widely used microorganism in the food industry. However, Candida species have also been used as an adjuvant in cheese production or as starters for coffee, cocoa, vegetable, meat, beer, and wine fermentations. A thorough screening of candidate Candida is sometimes performed to obtain the best performing strains to enhance specific features. Some commonly selected species include C. pulcherrima (teleomorph Metschnikowia pulcherrima) (wine), C. parapsilosis (teleomorph Monilia parapsilosis) (coffee), C. famata (teleomorph Debaryomyces hansenii) (cheese), and C. zeylanoides (teleomorph Kurtzmaniella zeylanoides) and C. norvegensis (teleomorph Pichia norvegensis) (cocoa). These species are associated with the production of key metabolites (food aroma formation) and different enzymes. However, safety-associated selection criteria are often neglected. It is widely known that some Candida species are opportunistic human pathogens, with important clinical relevance. Here, the physiology and metabolism of Candida species are addressed, initially emphasizing their clinical aspects and potential pathogenicity. Then, Candida species used in food fermentations and their functional roles are reported. We recommended that Candida not be used as food cultures if safety assessments are not performed. Some safety features are highlighted to help researchers choose methods and selection criteria.

Seasonal variation in the Canastra cheese mycobiota.

Canastra cheese is the most well-known artisanal cheese produced in Brazil. Although its production includes a step to remove fungi from the cheese surface, in recent years some cheesemakers have preserved the autochthonous fungi grown during ripening due to an interest in the sensory characteristics attributed to these microorganisms. In this work, the mycobiota of artisanal cheeses produced in the Canastra region was characterized based on ITS marker gene analysis. A total of 96 artisanal cheeses from 16 different farms across 9 cities were collected during two different periods (dry and wet seasons). The Canastra cheese mycobiota was significantly impacted by the season, the city of production and the farm but altitude did not affect the fungal community of the cheeses analyzed. Debaryomyces prosopidis was most abundant in the majority of samples across both seasons. During the wet season, Trichosporon asahii, Kluyveromyces lactis and Fusarium solani were the next most abundant species, followed by Torulaspora delbrueckii and Acremonium citrinum. These results highlight the importance of manufacturing practices and seasonality on the fungal composition of Canastra cheeses. These insights are particularly important in light of recent new regulation in Brazil, removing previous obstacles for surface fungi to persist on cheese. These new regulations will allow new approaches to cheese production, and ultimately, novel products.

Summer school: a warm journey through teaching microbiology to undergraduate students.

The Núcleo de Estudos em Microbiologia Agrícola (NEMA) is an academic-scientific group created by graduate students in the Post Graduate in Agricultural Microbiology in the Department of Microbiology at Universidade Federal de Viçosa, Brazil. NEMA's purposes include promoting and sharing research and knowledge on microbiology in different fields of application. Here, we will comment on our experience in organizing the Summer School on Microbiology and teaching microbiology to undergraduate students during the program. NEMA offers this annual event to disseminate and stimulate knowledge about microbiology for undergraduate students in a participatory, collaborative and interactive way.

Phylogenetic distribution of the bacteriocin repertoire of lactic acid bacteria species associated with artisanal cheese.

The microbiota contributes to artisanal cheese bioprotection and biopreservation through inter and intraspecific competition. This work aimed to investigate the phylogenetic distribution of the repertoire of bacteriocin structural genes of model lactic acid bacteria (LAB) in order to investigate its respective role in the artisanal cheeses microenvironment. A phylogenetic analysis of the rRNA 16S gene from 445 model strains of LAB was conducted using bayesian inference and the repertoire of bacteriocin genes was predicted from these strains by BAGEL software. Bacterial strains were clustered in five monophyletic clades (A, B, C, D and E) with high posterior probability values (PP > 0.99). One bacteriocin structural gene was predicted for 88.5% of the analyzed strains. The majority of the species encoded different classes of bacteriocins. Greater diversity of bacteriocin genes was found for strains included in clade A, comprising Lactococcus lactis, Streptococcus agalactiae, Streptococcus thermophilus, Streptococcus macedonicus, Enterococcus faecalis and Enterococcus faecium. In addition, Lactococcus lactis presented higher diversity of bacteriocin classes, encoding glycocins, lanthipeptides, sactipeptides, cyclic and linear azole-containing peptides, included in bacteriocins class I, besides class II and III. The results suggest that the distribution of bacteriocin structural genes is related to the phylogenetic clades of LAB species, with a higher frequency in some specific clades. Information comprised in this study contributes to comprehend the bacterial competition mechanisms in the artisanal cheese microenvironment.

Efficiency of a cleaning protocol for the removal of enterotoxigenic Staphylococcus aureus strains in dairy plants.

Staphylococci are considered a major concern in dairy plants mainly due to the intensive production flow, automation of processing plants and increased demand in the microbiological quality of dairy products. This study aimed to identify S. aureus strains isolated from three Brazilian dairy plants, evaluate the influence of time, temperature and contact surface on the bacterial adhesion process, as well as the efficiency of simulated hygiene and sanitation protocol in removing adhered cells. For genotypic analyses, the presence of icaA and icaD in strains was evaluated. Adherence assays were performed in biofilm reactor, comparing the influence of 2 temperatures (5°C and 35°C), 2 surfaces (stainless steel and polypropylene) and 4 contact times (3, 6, 12h and post-sanitization). To evaluate the process effectiveness in removing adhered cells, neutral detergent and sanitizing agent based on sodium hypochlorite were used in order to simulate the situation observed in one of the dairy plants analyzed. The presence of icaA and icaD genes was determined in 75.3% and 77.6% of strains, respectively; 70.6% of isolates showed both genes, whereas 17.6% showed no genes. Genes for enterotoxin production were found in all samples, relating to SEG and SEH toxins. The number of cells adhered on both surfaces was about 3 and 6 log10 CFU/cm2 at temperatures of 5°C and 35°C, respectively, for most situations evaluated, with significant increase over the evaluation period. In general, the temperature of 35°C favored greater adherence of S. aureus. At 5°C, there was a considerable number of adhered cells, but in populations significantly lower than those observed at 35°C. The cleaning and sanitizing protocol was ineffective in removing adhered cells; better performance of sodium hypochlorite was observed at 5°C, which should be related to lower adherence observed at this temperature. Thus, the process was not able to reduce the number of S. aureus bacteria adhered on both surfaces to safe levels under the conditions evaluated.

Sensory quality of Camembert-type cheese: Relationship between starter cultures and ripening molds.

Starter cultures and ripening molds used in the manufacture of moldy cheese aimed at obtaining characteristic flavors and textures considerably differ among dairy industries. Thus, the study of variables inherent to the process and their influence on sensory patterns in cheese can improve the standardization and control of the production process. The aim of this work was to study the influence of three different variables on the sensory quality of Camembert-type cheese: type of lactic bacteria, type of ripener molds and inoculation method. Batches of Camembert-type cheese were produced using O or DL-type mesophilic starter culture, ripened with Penicillium camemberti or Penicillium candidum and mold inoculation was made directly into the milk or by spraying. All batches were sensorially evaluated using Quantitative Descriptive Analysis (QDA) with panelists trained for various attributes. Among the combinations analyzed, those resulting in more typical Camembert-type cheese were those using O-type mesophilic starter culture and P. candidum maturation mold directly applied into the milk or sprayed and those using DL-type mesophilic starter and P. camemberti ripener mold applied by surface spraying. These results demonstrate, therefore, that the combination of different ripener molds, inoculation methods and starter cultures directly influences the sensory quality of Camembert-type cheese, modifying significantly its texture, appearance, aroma and taste.

Detecção de Staphylococcus aureus e Staphylococcus aureus resistentes à meticilina em profissionais da saúde lotados no Instituto Lauro de Souza Lima, Bauru-SP / Detection of Staphylococcus aureus and methicillin-resistant Staphylococcus aureus in health care workers packed the Instituto Lauro de Souza Lima, Bauru-SP

O Staphylococcus aureus (S. aureus) é um patógeno comumente isolado de amostras biológicas humanas. É encontrado com freqüência na pele e fossas nasais de indivíduos saudáveis, podendo provocar desde simples infecções ate graves enfermidades. Cerca de 40% da população adulta saudável é portadora nasal de S. aureus e esta taxa pode ser ainda maior em ambientes hospitalares, especialmente entre os pacientes internados e equipe médica. O surgimento da resistência à meticilina, uma penicilina sintética, pelo S. aureus e sua disseminação tornaram as medidas de controle epidemiológico ainda mais importantes no que diz respeito à prevenção de infecções hospitalares e, mais recentemente, comunitárias. Profissionais da área de saúde que são portadores nasais de S. aureus e Staphylococcus aureus resistentes a meticilina (MRSA) são considerados importantes fontes de disseminação do patógeno e estão intimamente envolvidos na epidemiologia dos mesmos. Investigação constante e adoção de medidas de controle na admissão dos pacientes em áreas de alta endemicidade para MRSA, tais com CTIs e centros de dermatologia, são consideradas estratégias efetivas em termos de custo-benefício contra as ionfecções hospitalares, bem como o estudo da prevalência de MRSA em profissionais de saúde que atuam nos referidos lugares. O objetivo do estudo foi verificar a colonização por S. aureus e MRSA nas fossas nasais de profissionais das equipes médicas de enfermagem e dos laborat´rios em um hospital de dermatologia de nível terciário - Instituto Lauro de Souza Lima - Bauru/SP...

Pesquisa de Salmonella e das condições sanitárias em frangos e lingüiças comercializados na cidade de Botucatu / Research of Salmonella and sanitary conditions in poultry and sausages retailed in Botucatu

O objetivo do trabalho foi avaliar as condições sanitárias de frango e diversos tipos de lingüiças comercializados na cidade de Botucatu,São Paulo, pela determinação do número mais provável de coliformes a 45ºC/g além da pesquisa de Salmonella pela metodologia tradicional e pela PCR. Foram coletadas 50 amostras de carcaça de frango e 75 de lingüiças frescais, procedentes de nove estabelecimentos diferentes da cidade, no período de abril a novembro de 2006. Das 50 amostras de frango, 35 (70%) estavam fora dos parâmetros microbiológicos, segundo a RDC n°12 da Anvisa (>104 coliformes a 45ºC/g). Embora nessa Resolução, a pesquisa de Salmonella não seja exigida, 4 amostras(8%) apresentaram o patógeno pela metodologia tradicional. Essa presença foi confirmada pela PCR, que também foi positiva para mais 23 amostras, num total de 27 positivas (54%). Dentre as 75 amostras de lingüiças, 30 (40%) estavam fora dos limites permitidos, com 7 amostras positivas para Salmonella, pela metodologia tradicional. Entretanto, se considerar-se a pesquisa pela PCR, o número de amostras positivas aumenta para 42 (56%). Somando-se a taxa de freqüência de Salmonella aos limites microbiológicos para coliformes a 45ºC, 86,7% das lingüiças analisadas estavam impróprias para o Consumo.

In the present investigation were evaluated the sanitary conditions of poultry and several types of sausages retailed in Botucatu, São Paulo, Brazil for the determination of the most probable number of coliforms at 45ºC/g besides the research of Salmonella using traditional methodology and PCR. In order to do so, 50 samples of poultry and 75 of sausages were collected from nine different establishments in the city, in the period of April to November of 2006. Of the 50 samples of chicken meat, 35 (70%) were out of the microbiologic parameters, according to Brazilian Sanitary Resolution RDC n°12 of Anvisa (>104 coliforms at 45ºC/g). In this Resolution, the research of Salmonella is not demanded, but 4 samples (8%) presented the pathogen using the traditional methodology. That presence was confirmed by PCR, which was also positive in another 23, in a total of 27 positive samples (54%). Among 75 samples of sausages, 30 (40%)were out of the allowed limits, with 7 positive samples for Salmonella,using traditional methodology. However, if we consider PCR test, the number of positive samples increases to 42 (56%). Adding this number to coliforms microbiological limits, 86.7% of the analyzed sausages were inappropriate for the consumption.