Perfil de resistência de Aeromonas spp. isolada no fluxograma de produção do queijo minas frescal industrial e artesanal.

Resumo: Bactérias do gênero Aeromonas podem ser isoladas de amostras clínicas, alimentares e ambientais. Para os derivados lácteos a contaminação decorre da presença do agente na matéria prima utilizada para produção, ou devido a condições higiênicas insatisfatórias durante o processamento. Considerando a importância da Aeromonas spp. como patógeno emergente de doenças de origem alimentar, o uso indiscriminado de antimicrobianos nas patologias humanas, além do papel fundamental que o leite e seus derivados representam na alimentação humana, o presente estudo teve por objetivo verificar o comportamento dos isolados frente à ação de antimicrobianos de uso comum. Foram pesquisados produtos e pontos do fluxograma do processamento de derivados lácteos, que poderiam veicular o gênero Aeromonas e permitir sua ocorrência nos produtos finais, ou atuar como disseminadores do micro-organismo nas diferentes etapas do processamento do queijo Minas Frescal e do queijo Colonial. Os resultados demonstram altos níveis de resistência: 33,6% dos 98 isolados de Aeromonas spp. foram resistentes a todos os 15 antimicrobianos testados, correspondendo a 7,5% dos isolados do queijo Colonial e 51,7% do queijo Minas Frescal, ocorrendo, portanto, maior resistência entre as amostras coletadas na indústria. 100% dos isolados apresentaram resistência múltipla, resultado que revela um perfil preocupante para saúde pública. [Resistance profile of Aeromonas spp. Isolated in dairy products industry]. Abstract: Bacteria of the genus Aeromonas can be isolated from clinical, food and environmental samples. For dairy products contamination can be caused by the presence of the agent in the feedstock used for production or due to unsatisfactory hygienic conditions during processing. The present study aimed to assess Aeromonas isolates behavior in the presence of common antimicrobials, considering the importance of Aeromonas spp. as an emerging pathogen of foodborne diseases, the indiscriminate use of antimicrobials to treat human pathologies, in addition to the role that milk and its derivatives play in human feeding habits. The processing steps during dairy products manufacturing were studied looking for vulnerable points or products where Aeromonas could be present and, subsequently, either pass it to the final products or disseminate the micro-organism in different processing stages of Minas and Colonial cheeses. The results show high levels of resistance: 33.6% of 98 isolates of Aeromonas spp. were resistant to all 15 antibiotics tested, corresponding to 7.5% of the isolates from Colonial cheese and 51.7% from Minas cheese, thus showing greater resistance among the samples collected in the industry. Multiple antimicrobial resistance was verified in 100% of the isolates, which reveals a profile which is alarming for public health

Aeromonas no processamento de queijos tipos Minas Frescal e Colonial.

Resumo: Com o objetivo de estabelecer, durante o processamento do queijo Minas Frescal e Colonial os possíveis pontos de contaminação e a forma de disseminação de bactérias do gênero Aeromonas, foram analisados, quanto à presença do micro-organismo, diferentes produtos e pontos do fluxograma de produção. Para o Queijo Minas Frescal, Aeromonas spp. foram isoladas no leite cru, leite pasteurizado, ambiente de produção e nas mãos dos manipuladores. A. caviae foi a espécie mais frequentemente identificada, sendo também isoladas A. sobria e A. schubertii. Durante o processamento do queijo Colonial, as espécies A. hydrophila, A. caviae, A. sobria, A. veronii e A. jandaei foram isoladas a partir da água, mãos dos manipuladores, utensílios, leite cru e após tratamento térmico e de massa coagulada. Os resultados demonstram que o gênero Aeromonas encontra-se disseminado nas diferentes etapas do processamento de queijos, destacando-se o leite cru como principal fonte de contaminação para o processamento industrial e artesanal. [Aeromonas in processing line of Minas Frescal and Colonial cheeses]. Abstract: The aim of this study is to establish possible contamination points and dissemination forms of the bacteria genus Aeromonas during the processing of the Brazilian cheeses Minas Frescal and Colonial. Therefore, different products and production points of the process were analyzed to determine the presence of the microorganism. In Minas Frescal cheese, Aeromonas spp. was isolated in raw and pasteurized milk, in the environment and on the handlers? hands. A. caviae was the most frequently identified species, but A. sobria and A. schubertii were also isolated. During the processing of Colonial cheese, the species A. hydrophila, A. caviae, A. sobria, A. veronii and A. jandaei were isolated in the water, raw milk, after thermal treatment and curd, as well as on the handlers' hands and utensils. The results showed that the genus Aeromonas is disseminated throughout different stages of both cheese processes while the raw milk stands out as the main source of contamination in the industrial and handmade processing

Search for New Physics with Jets and Missing Transverse Momentum in pp collisions at sqrt(s) = 7 TeV

A search for new physics is presented based on an event signature of at least three jets accompanied by large missing transverse momentum, using a data sample corresponding to an integrated luminosity of 36 inverse picobarns collected in proton--proton collisions at sqrt(s)=7 TeV with the CMS detector at the LHC. No excess of events is observed above the expected standard model backgrounds, which are all estimated from the data. Exclusion limits are presented for the constrained minimal supersymmetric extension of the standard model. Cross section limits are also presented using simplified models with new particles decaying to an undetected particle and one or two jets

Search for anomalous t t-bar production in the highly-boosted all-hadronic final state

A search is presented for a massive particle, generically referred to as a Z', decaying into a t t-bar pair. The search focuses on Z' resonances that are sufficiently massive to produce highly Lorentz-boosted top quarks, which yield collimated decay products that are partially or fully merged into single jets. The analysis uses new methods to analyze jet substructure, providing suppression of the non-top multijet backgrounds. The analysis is based on a data sample of proton-proton collisions at a center-of-mass energy of 7 TeV, corresponding to an integrated luminosity of 5 inverse femtobarns. Upper limits in the range of 1 pb are set on the product of the production cross section and branching fraction for a topcolor Z' modeled for several widths, as well as for a Randall--Sundrum Kaluza--Klein gluon. In addition, the results constrain any enhancement in t t-bar production beyond expectations of the standard model for t t-bar invariant masses larger than 1 TeV.Comment: Submitted to the Journal of High Energy Physics; this version includes a minor typo correction that will be submitted as an erratu

Combined search for the quarks of a sequential fourth generation

Results are presented from a search for a fourth generation of quarks produced singly or in pairs in a data set corresponding to an integrated luminosity of 5 inverse femtobarns recorded by the CMS experiment at the LHC in 2011. A novel strategy has been developed for a combined search for quarks of the up and down type in decay channels with at least one isolated muon or electron. Limits on the mass of the fourth-generation quarks and the relevant Cabibbo-Kobayashi-Maskawa matrix elements are derived in the context of a simple extension of the standard model with a sequential fourth generation of fermions. The existence of mass-degenerate fourth-generation quarks with masses below 685 GeV is excluded at 95% confidence level for minimal off-diagonal mixing between the third- and the fourth-generation quarks. With a mass difference of 25 GeV between the quark masses, the obtained limit on the masses of the fourth-generation quarks shifts by about +/- 20 GeV. These results significantly reduce the allowed parameter space for a fourth generation of fermions.Comment: Replaced with published version. Added journal reference and DO