Can cheese mites, maggots and molds enhance bioactivity? Peptidomic investigation of functional peptides in four traditional cheeses.

Aside from their amino acid content, dairy proteins are valuable for their ability to carry encrypted bioactive peptides whose activities are latent until released by digestive enzymes or endogenous enzymes within the food. Peptides can possess a wide variety of functionalities, such as antibacterial, antihypertensive, and antioxidative properties, as demonstrated by in vitro and in vivo studies. This phenomenon raises the question as to what impact various traditional cheese-making processes have on the formation of bioactive peptides in the resulting products. In this study, we have profiled the naturally-occurring peptides in two hard and two soft traditional cheeses and have identified their known bioactive sequences. While past studies have typically identified fewer than 100 peptide sequences in a single cheese, we have used modern instrumentation to identify between 2900 and 4700 sequences per cheese, an increase by a factor of about 50. We demonstrated substantial variations in proteolysis and peptide formation between the interior and rind of each cheese, which we ascribed to the differences in microbial composition between these regions. We identified a total of 111 bioactive sequences among the four cheeses, with the greatest number of sequences, 89, originating from Mimolette. The most common bioactivities identified were antimicrobial and inhibition of the angiotensin-converting enzyme. This work revealed that cheese proteolysis and the resulting peptidomes are more complex than originally thought in terms of the number of peptides released, variation in peptidome across sites within a single cheese, and variation in bioactive peptides among cheese-making techniques.

Artisan fresh cheese from raw cow's milk as a possible route of transmission in a toxoplasmosis outbreak, in Brazil.

BACKGROUND: The objective of this study was to report an outbreak of human toxoplasmosis occurring in the municipality of Montes Claros de Goiás, Goiás, Brazil, from December 2015 to August 2016. Seven acute cases in June 2016 triggered the subsequent search. METHODS: A total of 251 individuals were selected through an active search, of which 114 (45.4%) agreed to participate in the research and blood collection. For serological diagnosis were used enzyme-linked immunosorbent assay (ELISA) for IgG and IgM and avidity tests. RESULTS: Of the 114 serum samples evaluated, 12.3% (14/114) showed antibodies against Toxoplasma gondii, with a profile indicative of acute infection. Samples of artisan fresh cheese, public water, vegetables and irrigation water were collected. Toxoplasma gondii DNA fragments were amplified using the polymerase chain reaction from two samples of artisan fresh cheese and a sample of irrigation water from the vegetable garden. A control case study was carried out, and the variable cow's artisan fresh cheese consumption was statistically significant (p = .01). CONCLUSIONS: The results showed that cheese analysed and/or irrigated water of vegetable represented an important route of transmission for the disease. This is the first reported outbreak possibly caused by cow's artisan fresh cheese. It is difficult to prove that these routes were the cause of the outbreak; however, the findings allow us to infer that the individuals involved in the outbreak were in contact with these risk factors.

Detection and survival of Toxoplasma gondii in milk and cheese from experimentally infected goats.

The consumption of unpasteurized goat cheese and goat's milk has been suggested as a risk factor for toxoplasmosis in humans. In the present study, detection and survival of Toxoplasma gondii in milk and cheese was studied by bioassay in mice (milk) and in cats (cheese). Eight goats were inoculated orally with 300 to 10,000 oocysts of T. gondii strain TgGoatUS26. Milk samples were collected daily up to 30 days postinoculation and bioassayed in mice and cats. For mouse bioassay, 50 ml of milk samples were centrifuged, and the sediment was inoculated subcutaneously into mice. Mice were tested for T. gondii infection by seroconversion and by the demonstration of parasites. By mouse bioassay, T. gondii was detected in milk from all eight goats. The T. gondii excretion in milk was intermittent. For cat bioassay, 400 ml (100 ml or more from each goat) of milk from four goats from 6 to 27 days postinoculation were pooled daily, and cheese was made using rennin. Ten grams of cheese was fed daily to four cats, and cat feces were examined for oocyst shedding. One cat fed cheese shed oocysts 7 to 11 days after consuming cheese. Attempts were made to detect T. gondii DNA in milk of four goats; T. gondii was detected by PCR more consistently, but there was no correlation between detection of viable T. gondii by bioassay in mice and T. gondii DNA by PCR. Results indicate that T. gondii can be excreted in goat's milk and can survive in fresh cheese made by cold-enzyme treatment. To prevent transmission to humans or animals, milk should not be consumed raw. Raw fresh goat cheese made by cold-enzyme treatment of unpasteurized milk also should not be consumed.

[A view of mites infestation on cheese and stored foods in terms of public health]. / Depo gidalarini ve peynirleri enfeste eden akarlara halk sagligi açisindan bakis

Mites are small live organism that may result in a large number of allergenic diseases such as atopic dermatitis, allergic rhinitis and asthma that may cause individuals' physical, social and mental health, adversely affects quality of life. Mites that can be found everywhere where people live are found in various foodstuffs. The purpose of this review is to examine the types of mites and possible illness result from mites can be found in stored foods especially cheese in terms of public health assessment. Finding mite in the stored foods except for some local cheeses is not desirable because of it's health risks. However, especially in cheese which is maturing in the open always to be the case of mite enfestation. In particular, this risk is much higher in some enterprises where have not taken measures enough in terms of food safety. Besides the lack of standarts related to cheese, fighting against mite in quality assurance systems have generally not been taken into consideration. Whereas mites in cheese consumed by individuals at any age, there is always a possibility of the potential cause of the allergic reactions seen in the consumer. Prevention of possible infestations in cheese, potential presence of storage mite and cheese mite in various stored foods and local cheese of Turkey should be investigated more comprehensive and protective measures should be developed in order to protect public health against mites.

Identification of cheese mite species inoculated on Mimolette and Milbenkase cheese through cryogenic scanning electron microscopy.

Samples of Mimolette (France) and Milbenkase (Germany) cheeses traditionally ripened by mites were analyzed to determine the mite species present on each sample. Scientific literature was reviewed to understand which mite species most commonly infest cheese. Morphological features possessed by mites were then studied to understand what unique characteristics are required to ensure accurate identification. After identification and compilation of a detailed key of stored food mites (subclass Acari, order Astigmata) and their delineating features, the mites were viewed through a cryogenic scanning electron microscope. It was determined that Mimolette cheese is inoculated with Acarus siro L. The features studied to identify this mite species included idiosomal length and shape, setae length and arrangement, leg size, placement of anus and genitals, and solenidia shape. The Milbenkase cheese is inoculated with Tyrolichus casei Oudemans, which was evident after viewing the same features used to identify A. siro and the supracoxal seta shape. With this knowledge, further research can be conducted on the 2 cheese varieties to understand what chemical, physical, and microbial changes occur within the cheeses because of mites. It is important to identify the mite species present on each cheese variety to improve our understanding of their role in creating the distinctive characteristics that set these cheeses apart from others.

Caracterización de cepas de listeria monocytogenes realizados a partir de queso fresco proveniente de diferentes zonas productoras costarricenses / Characterization of listeria monocytogenes isolates obtained from raw cheese samples acquired from different Costa Rican producer zones

En Costa Rica, cerca del 25 por ciento de la producción de leche nacional es utilizada en la elaboración de queso tierno no pasteurizado, y el consumo de este producto es aproximadamente de 4 a 5 kg anuales per cápita. Este alimento ha sido involucrado en brotes debidos a Listeria monocytogenes. Dado lo anterior, se aisló e identificó esta bacteria a partir de muestras de queso blanco no pasteurizado provenientes de dos zonas tradicionalmente productoras y expendedoras de dicho producto. Se recolectaron 110 muestras de queso a partir de las cuales se aislaron 27 cepas de L. monocytogenes. Las cepas fueron caracterizadas mediante pruebas bioquímicas y serológicas, además se les realizaron pruebas de susceptibilidad a los antibióticos, hemólisis en tubo e invasión en células Hela. El 85 por ciento de las cepas evaluadas fueron sensibles a todos los antibióticos analizados, no obstante, cuatro cepas (15 por ciento) presentaron patrones de resistencia a diversos agentes, incluyendo estreptomicina, kanamicina, cefalotina y tetraciclina. También, se encontraron patrones de resistencia múltiple. El 88,9 por ciento de los aislamientos estudiados fueron positivos para la prueba de hemólisis en tubo, y el 22,2 por ciento presentaron porcentajes de invasión iguales o superiores a la cepa de origen clínico usada como control. Cabe destacar que todas las cepas con capacidad de invasión fueron también susceptibles a todos los antibióticos usados. Los resultados encontrados ponen de manifiesto la presencia de L. monocytogenes en queso blanco de origen costarricense. También se evidencia un alto porcentaje de susceptibilidad a los antibióticos de uso común para los casos de listeriosis. Por otro lado, pone de manifiesto que el queso blanco puede ser transmisor de cepas con capacidad de invasión y por ende, potencialmente patógenas al hombre.

In Costa Rica, almost 25 percent of the national milk production is used for the elaboration of non pasteurized soft cheese, and the annual intake of this product is around 4-5 kg per capita. This product has been identified as the source of food borne outbreaks due to Listeria monocytogenes. Given that, the isolation and identification of this bacterium from non pasteurized soft cheese samples coming from two producer zones of Costa Rica was performed. 110 cheese samples were collected, from which 27 L. monocytogenes strains were isolated. These were characterized using biochemical and serological tests, also, susceptibility to common used antibiotics, test tube hemolysis and invasion in Hela cells trials were performed. 85 percent of the strains evaluated were sensible to all the antibiotics analyzed, nevertheless, four strains presented resistance to different agents, including streptomycin, kanamycin, cephalotin and tetracycline. Also, multiple resistance patterns were found. 88,9 percent of the studied isolates were positive for the test tube hemolysis trial; 22,2 percent presented invasion percentages higher than the clinical origin strain used as control. It is important to point out that all the invasive strains were completely susceptible to the antibiotics tested. The results found demonstrate the presence of L. monocytogenes in Costa Rican soft cheese samples. Also, demonstrate its high percent of susceptibility to common use antibiotics. Same time, invasion trials show that soft cheese may be a source of invasive and potentially pathogenic strains for human being.

Evaluation of low humidity treatments to control Acarus farris (Acari: Acaridae) in Cabrales cheese.

Laboratory experiments were conducted to establish the best combination of relative humidity (r.h.) and time of exposure to be applied on Cabrales cheeses infested with Acarus farris. Laboratory assays revealed that less than 30 h were required to obtain 90% mortality of mites at 50% and 60% r.h. Males were more susceptible than females to low relative humidity, since their lethal period values (LP) were lower than those obtained for females at the same relative humidity. Moreover, the response within sexes to low moisture treatments changed as exposure time increased, since the LP50 obtained for each sex at 50 and 60% r.h. were statistically different whereas the LP90 showed no significant differences within sexes. Accordingly, two modifications of the traditional maturing process were established to assess the efficacy of low moisture treatments to control A. farris on infested cheeses. The first modification consisted of one single exposure of 48 h at 50% r.h. and the second one consisted of two exposures of 48 h at 50% r.h. separated by a time interval of 15 days. No significant differences in final population density were observed for both low moisture treatments compared to control cheeses. Therefore, low humidity treatments are not effective to control A. farris in Cabrales cheese, despite the good results obtained in laboratory assays.

Determinación de Listeria spp. en quesos y embutidos comercializados en Cuba / Determination of Listeria spp in cheese and sausages sold in Cuba

La Listeria monocytogenes es un patógeno emergente causante de una enfermedad transmitida a través de los alimentos conocida como listeriosis, que cursa de forma grave y generalmente deja secuelas en las personas que la sobreviven. La detección de la L. monocytogenes en los alimentos de mayor riesgo, como son los listos para el consumo reviste gran importancia. En el presente trabajo se determinó la incidencia de la Listeria en 54 muestras de quesos y 98 de embutidos y ahumados, comercializados en Cuba. Se aplicó un método tradicional para la detección cualitativa y cuantitativa de la L. monocytogenes según la Norma UNE-EN ISO 11290-1 (1997) y el Draft International Standard ISO/DIS 11290-2 (1995), además se realizaron pruebas bioquímicas adicionales para la identificación de otras especies de Listeria. Para la detección cualitativa de la Listeria también se aplicó una prueba de diagnóstico rápido. La L. monocytogenes se aisló en queso azul, en salchichón y mortadela; la L. innocua: en queso frescal y queso cubanito, en chorizo, longaniza magro y morcilla y la L. welshimeri: en salchichas. Las dos especies halladas en salchichón se encontraron asociadas a una misma muestra. En otras tres muestras (pollo ahumado, chorizo, mortadela) se detectó la Listeria por la prueba rápida, sin lograr el aislamiento por el método tradicional, lo cual se debe a la mayor sensibilidad del primer método. La enumeración resultó < 102 UFC/g de alimento en todos los casos. La utilización de la técnica cualitativa permitió demostrar la presencia de la L. monocytogenes en tres de las muestras analizadas lo cual limita estos productos para su comercialización y consumo(AU)

A new versatile and robust mite trap for detection and monitoring of storage mites in the cereal and allied industries.

Storage mites are important primary pests but present methods for trapping them are either rudimentary or have several limitations. These prevent effective early detection or reliable monitoring of mites in the food, animal feed and associated industries. The BT Trap is the first trap designed specifically for the detection and monitoring of mite infestation. This trap is made up of a mixed food base lure held in a robust adjustable housing. It is user friendly, requires an exposure period of only 4 days and can be used in a dusty environment. The performance of the BT Trap was evaluated in the laboratory and the mean minimal capture rate of mites was 62%. In a comparative field trial, this trap detected significantly more mites than the bait bag or the fishmeal trap. The trap's performance was also assessed in four different types of premises. These were premises engaged in the production of cereal based dry pet food, specialist animal feed, traditional cheese, and in the finished cereal section of a large transit storage warehouse. A total of 17 genera or species of storage and predatory mites was detected in these four premises, with at least seven species detected in each of these premises. This study confirms that the BT Trap was able to function under the rigours of use in the field. It has demonstrated its potential as a useful tool for early detection and monitoring of mites in production premises. It also provided information that was vital for improving existing mite control measures and in implementing effective management strategies.

Cheese mites and other delicacies: the introduction of test objects into microscopy.

In the 1820s, certain minute objects began to be used regularly as tests for microscopes. Scales of insects, animal hairs and tiny leaves served as convenient means to assess their optical performance. It was a peculiar conjunction of optics, astronomy and natural history that formed the intellectual background for the emergence of the tests; and their establishment was greatly facilitated by the culture of conversation and competition in which microscopical practice was embedded. The introduction of the tests soon gave rise to a peculiar and highly productive interaction: the application of test objects incited instrument makers to aspire after technical improvements. These pursuits led, in turn, to a differentiation and refinement of the tests themselves, which then again suggested specific kinds of improvements. Historians have paid only scant attention to these issues. But the early history of test objects deserves thorough investigation. In fact, it provides a key to the understanding of the intellectual and social contexts and the dynamics of microscopy in early 19th-century Britain.

Infectivity of cysts of the ME-49 Toxoplasma gondii strain in bovine milk and homemade cheese.

OBJECTIVE: Analyze the infectivity and storage resistance of cysts of the ME-49 strain of Toxoplasma gondii in artificially infected bovine milk and homemade fresh cheese. METHODS: Pasteurized bovine milk was infected with 10 cysts/ml of the ME-49 strain of T.gondii and inoculated in different groups of mice, immediately or after storage at 4 degrees C for 5, 10 and 20 days. Homemade fresh cheese was prepared with artificially infected milk, and also tested in groups of mice, using the same storage process. Infection was identified by the presence of cysts in the brain or serological testing in challenged mice after 5 weeks, confirmed by Western Blot and histology. RESULTS: The infectivity of cysts of the ME-49 strain of T.gondii was maintained in the milk even after storage for 20 days at refrigerator temperatures. Cysts were also able to survive the production process of homemade fresh cheese and storage for a period of 10 days in the same conditions. CONCLUSIONS: These data demonstrated that milk and dairy products could be an important source of T.gondii in human contamination, reinforcing the importance of milk pasteurization before any processing or ingestion.

Aspectos microbiológicos do queijo tipo "coalho" comercializado em Fortaleza - Ceará / Microbiological aspects of \"coalho\" type cheese commercialized in Fortaleza - Ceará

Avaliou-se a qualidade microbiológica de cinquenta e seis amostras de queijo tipo "coalho" provenientes de diferentes pontos comerciais de Fortaleza - Ceará. Foram quantificadas as bactérias mesófilas, Staphylococcus aureus, coliformes totais e fecais, bolores e leveduras. Verificou-se que em relaçäo às contagens de coliformes fecais e Staphylococcus aureus, 67,9 por cento e 62,5 por cento das amostras respectivamente, näo atenderam aos estabelecidos pela legislaçäo brasileira em vigor

Occupational allergy to mites in salty ham, chorizo and cheese.

We present three cases of occupational allergy caused by the manipulation of food: cheese, chorizo (typical Spanish salami) and salty ham. A IgE-mediated sensitization is demonstrated by skin tests, RAST and positive challenge tests to Acarus siro and Blomia kulagini of the cheese rind, Euroglyphus maynei of the "chorizo" and Tyrophagus putrescentiae of the salty ham.