ALGAS E LEVEDURAS ISOLADAS DE MASTITE BOVINA: IDENTIFICAÇÃO E PERFIL DE SENSIBILIDADE A ANTISSÉPTICOS E ANTIMICROBIANOS

A mastite bovina é uma das doenças mais prevalentes e impactantes na pecuária leiteira. Diferentes microrganismos estão envolvidos em sua etiologia, sendo classificados como contagiosos, quando adaptados ao interior da glândula mamária, ou ambientais, presentes normalmente no ambiente de criação dos animais. Entre os agentes ambientais, as algas e as leveduras são agentes incomuns, mas considerados emergentes. Neste trabalho, 149 cepas de leveduras e 62 de algas isoladas de casos de mastite em rebanhos bovinos de São Paulo, Minas Gerais e Paraná foram avaliadas quanto aos perfis de suscetibilidade a antimicrobianos e antissépticos, utilizando-se a técnica de concentração inibitória mínima (CIM). Adicionalmente, os isolados de leveduras foram caracterizados por meio da técnica de MALDI-TOF. Por teste de concentração inibitória mínima (CIM) não houve crescimento das algas na concentração de 4% da gentamicina, 16% amicacina e 8% polimixina B.Foram encontrados diferentes índices de inibição de crescimento das algas aos antissépticos: para o triclosano 0,25%, amônio quaternário <0,01%, peroxido de hidrogênio <0,002%, iodo 0,015, ácido peracético 0,25%, hipoclorito de sódio 0,125% e clorexina <0,018%, houve crescimento das algas nas maiores concentrações de ácido láctico e glutaraldeido. Os resultados de CIM para as leveduras foram: <0,0015% para triclosano, amônio quaternário <0,02%, peróxido de hidrogênio <0,007%, iodo 0,125%, ácido peracético 0,125%, clorexidina <0,0018 e hipoclorito de sódio na concentração de 0,125%. Estes resultados permitem confirmar a eficácia destes agentes como mecanismo de assepsia em fazendas leiterias. Houve crescimento das leveduras nas maiores concentrações do ácido láctico e o glutaraldeido. Com a técnica de identificação proteica foi traçado o perfil dos isolados identificando 6 espécies de leveduras predominando a Issatchenkia orientalis, se tratando de rebanho houve a identificação de mais de um isolado mas com predominância de espécie. Testes in vivo devem ser realizados para a comprovação da sensibilidade dos isolados aos antibióticos testados, de acordo com este estudo os resultados endossam a utilização dos antissépticos para a antissepsia de tetos (pré e pós-dipping), visando o controle e prevenção da mastite causada por estes agentes ambientais da mastite bovina. As espécies de leveduras identificadas neste estudo se assemelha a espécies já identificadas na literatura.

Bovine mastitis is one of the most prevalent and impacting diseases in dairy cattle. Different microorganisms are involved in their etiology, being classified as contagious, when adapted to the interior of the mammary gland, or environmental, normally present in the environment of animal husbandry. Among environmental agents, algae and yeasts are unusual agents, but considered emerging. In the present study, 149 yeast strains and 62 strains of algae isolated from cases of mastitis in bovine herds of São Paulo, Minas Gerais and Paraná were evaluated for the antimicrobial and antiseptic susceptibility profile, using the minimum inhibitory concentration. In addition, isolated yeasts were characterized by the MALDI-TOF technique. A minimum inhibitory concentration (MIC) test did not show growth of algae at the concentration of 4% gentamicin, 16% amikacin and 8% polymyxin B. Different rates of algae growth inhibition were observed for antiseptics: for triclosan 0.25%, quaternary ammonia <0.01%, hydrogen peroxide <0.002%, iodine 0.015, peracetic acid 0.25%, sodium hypochlorite 0.125% and chlorhexine <0.018%, there was growth of algae at the highest acid concentrations lactic acid and glutaraldehyde. The MIC results for yeast were: <0.0015% for triclosan, quaternary ammonia <0.02%, hydrogen peroxide <0.007%, iodine 0.125%, peracetic acid 0.125%, chlorhexidine <0.0018 and sodium hypochlorite in concentration of 0.125%. These results confirm the efficacy of these agents as an asepsis mechanism in dairy farms. There was growth of yeasts in the highest concentrations of lactic acid and glutaraldehyde. With the protein identification technique, the profile of the isolates was traced, identifying 6 yeast species with predominance of Issatchenkia orientalis, if in a herd there was identification of more than one isolate, but with a predominance of species. In vivo tests should be performed to confirm the sensitivity of the isolates to the antibiotics tested. According to this study, the results endorse the use of antiseptics for roof antisepsis (pre and post-immersion), aiming at the control and prevention of mastitis caused by these environmental agents of bovine mastitis. The yeast species identified in this study resemble species already identified in the literature.

Yeast diversity associated to sediments and water from two Colombian artificial lakes

In Colombia, knowledge of the yeast and yeast-like fungi community is limited because most studies have focused on species with clinical importance. Sediments and water represent important habitats for the study of yeast diversity, especially for yeast species with industrial, biotechnological, and bioremediation potential. The main purpose of this study was to identify and compare the diversity of yeast species associated with sediment and water samples from two artificial lakes in Universidad del Valle (Cali-Colombia). Yeast samplings were performed from fifteen sediment samples and ten water samples. Grouping of similar isolates was initially based on colony and cell morphology, which was then complemented by micro/mini satellite primed PCR banding pattern analysis by using GTG5 as single primer. A representative isolate for each group established was chosen for D1/D2 domain sequencing and identification. In general, the following yeast species were identified: Candida albicans, Candida diversa, Candida glabrata, Candida pseudolambica, Cryptococcus podzolicus, Cryptococcus rajasthanensis, Cryptococcus laurentii, Williopsis saturnus, Hanseniaspora thailandica, Hanseniaspora uvarum, Rhodotorula mucilaginosa, Saccharomyces cerevisiae, Torulaspora delbrueckii, Torulaspora pretoriensis, Tricosporon jirovecii, Trichosporon laibachii and Yarrowia lypolitica. Two possible new species were also found, belonging to the Issatchenkia sp. and Bullera sp. genera. In conclusion, the lakes at the Universidad del Valle campus have significant differences in yeast diversity and species composition between them.(AU)

The diversity, extracellular enzymatic activities and photoprotective compounds of yeasts isolated in Antarctica

The diversity of yeasts collected from different sites in Antarctica (Admiralty Bay, King George Island and Port Foster Bay and Deception Island) and their ability to produce extracellular enzymes and mycosporines were studied. Samples were collected during the austral summer season, between November 2006 and January 2007, from the rhizosphere of Deschampsia antarctica, ornithogenic (penguin guano) soil, soil, marine and lake sediments, marine water and freshwater from lakes. A total of 89 isolates belonging to the following genera were recovered: Bensingtonia, Candida, Cryptococcus, Debaryomyces, Dioszegia, Exophiala, Filobasidium, Issatchenkia (Pichia), Kodamaea, Leucosporidium, Leucosporidiella, Metschnikowia, Nadsonia, Pichia, Rhodotorula, and Sporidiobolus, and the yeast-like fungi Aureobasidium, Leuconeurospora and Microglossum. Cryptococcus victoriae was the most frequently identified species. Several species isolated in our study have been previously reported to be Antarctic psychophilic yeasts, including Cr. antarcticus, Cr. victoriae, Dioszegia hungarica and Leucosporidium scottii. The cosmopolitan yeast species A. pullulans, C. zeylanoides, D. hansenii, I. orientalis, K. ohmeri, P. guilliermondii, Rh. mucilaginosa, and S. salmonicolor were also isolated. Five possible new species were identified. Sixty percent of the yeasts had at least one detectable extracellular enzymatic activity. Cryptococcus antarcticus, D. aurantiaca, D. crocea, D. hungarica, Dioszegia sp., E. xenobiotica, Rh. glaciales, Rh. laryngis, Microglossum sp. 1 and Microglossum sp. 2 produced mycosporines. Of the yeast isolates, 41.7% produced pigments and/or mycosporines and could be considered adapted to survive in Antarctica. Most of the yeasts had extracellular enzymatic activities at 4ºC and 20ºC, indicating that they could be metabolically active in the sampled substrates.

Mycocinogenic yeasts isolated from Amazon soils of the Maracá Ecological Station, Roraima-Brazil

The 240 yeasts isolated from soils of the Maracá Ecological Station in the Brazilian Amazon were identified and screened for mycocin production. These strains included 82% of ascomycetous and 18% basidiomicetous affinities and the prevalent species were Candida etchellsii, Candida famata, Candida robusta, Candida rugosa, Candida valida, Debaryomyces hansenii, Cryptococcus albidus, Cryptococcus laurentii, Rhodotorula glutinis, Rhodotorula minuta and Rhodotorula mucilaginosa. Mycocins able to kill some yeasts were produced by 6 strains identified as Issatchenkia sp., Saccharomyces exiguus?, Williopsis saturnus, var. subsufficiens, and 3 W. saturnus according to 26S rDNA D1/D2 region sequence and phenotypic data.

Duzentos e quarenta linhagens de leveduras foram isoladas de amostras de solos da Estação Ecológica de Maracá, na Amazônia Brasileira, as quais representam 82% de leveduras de afinidade ascomicética e 18% basidiomicética. As especies dominantes foram Candida etchellsii, Candida famata, Candida robusta, Candida rugosa, Candida valida, Debaryomyces hansenii, Cryptococcus albidus, Cryptococcus laurentii, Rhodotorula glutinis, Rhodotorula minuta and Rhodotorula mucilaginosa. A capacidade das leveduras produzirem e excretarem toxinas letais a cepas sensíveis de leveduras, atividade micocinogênica, foi investigada. Seis linhagens foram capazes de produzir micocinas: Issatchenkia sp., Saccharomyces exiguus?, Williopsis saturnus var. subsufficiens, e 3 W. saturnus identificadas conforme os dados de taxonomia molecular baseados nas seqüências da região D1/D2 do 26S rDNA.