"Cara inchada" of cattle, an infectious, apparently soil antibiotics-dependant periodontitis in Brazil

The objective of this review on the investigation of "cara inchada" in cattle (CI), pursued over the last 30 years, was to elucidate the pathogenicity of the disease and come to proper conclusions on its etiology. CI has been widely considered to be of nutritional origin, caused primarily by mineral deficiency or imbalance. However, the disease consists of a rapidly progressive periodontitis, affecting the periodontal tissues at the level of the premolars and molars during the period of tooth eruption generally starting in young calves. The disease led to great economic losses for farmers in central-western Brazil, after the occupation of new land for cattle raising in the 1960s and 1970s. The lateral enlargement of the maxillary bones of affected calves gave the disease the popular name of "cara inchada", i.e., swollen or enlarged face. The enlargement was found to be due to a chronic ossifying periostitis resulting from the purulent alveolitis of CI. Black-pigmented non-saccharolytic Bacteroides melaninogenicus, always together with Actinomyces (Corynebacterium) pyogenes, were isolated in large numbers from the periodontal lesions. B. melaninogenicus could be isolated in small numbers also from the marginal gingiva of a few healthy calves maintained on CI-free farms. "In vitro"-assays showed that streptomycin and actinomycin, as well as the supernatants of cultivates of actinomycetes from soils of CI-prone farms, applied in subinhibitory concentrations to the bacteria tested, enhanced significantly (up to 10 times) the adherence of the black-pigmented B.melaninogenicus to epithelial cells of the bovine gingiva. The antibiotics are apparently produced in large quantities by the increased number of soil actinomycetes, including the genus Streptomyces, that develop when soil microflora are modified by cultivating virgin forest or "Cerrado" (tree-savanna) for the first time for cattle grazing. The epidemiology of CI now provides strong evidence that the ingestion with the forage of such antibiotics could possibly be an important determinant factor for the onset and development of this infectious periodontitis. The antibiotic enhanced adherence of B.melaninogenicus to the sulcus-epithelium of the marginal gingiva, is thought to allow it to colonize, form a plaque and become pathogenic. There is experimental evidence that this determinant factor for the development of the periodontitis is present also in the milk of the mothers of CI-diseased calves. It has been shown that the bacteria isolated from the periodontal CI-lesions produce enzymes and endotoxins capable of destroying the periodontal tissues. The epidemiology of CI, with its decline in incidence and its disappearance after several years, could be explained by the fact that the former equilibrium of the microflora of the once undisturbed virgin soil has been reached again and that the number of antibiotic producing actinomycetes has been anew reduced. By this reasoning and all the data available, CI should be considered as a multifactorial infectious disease, caused primarily by the anaerobic black-pigmented non-saccharolytic Bacteroides melaninogenicus, always together with the micro-anaerobic Actinomyces pyogenes. Accordingly, the onset and development of the infectious periodontitis is apparently determined by ingestion with the forage of subinhibitory concentrations of antibiotics produced in recently cultivated virgin soils. This hypothesis is supported by the recent observation of renewed outbreaks of CI-periodontitis in former CI-prone areas, following fresh cultivation after many years. The infectious nature of CI is confirmed by trials in which virginiamycin was used efficiently for the oral treatment of CI-diseased cattle. Previously it has been shown, that spiramycin and virginiamycin, used as additives in mineral supplements, prevented CI-periodontitis.

Crystal-associated cholangiopathy in sheep grazing Brachiaria decumbens containing the saponin protodioscin

An outbreak of hepatogenous photosensitization is reported in a flock of 28 sheep grazing Brachiaria decumbens in Mato Grosso do Sul State, Central-Western Brazil. Seven lambs and an adult sheep were affected and 6 of them died. Two surviving affected lambs and one lamb without clinical signs had increased serum values of gamma glutamyltransferase, bilirubin, and cholesterol. In two adult unaffected sheep those parameters were within normal values. An adult sheep submitted to necropsy presented moderate body condition, unilateral corneal opacity, drying of the muzzle, moderate jaundice, increased lobular pattern of the liver, and a distended gallbladder. Histological lesions were epithelial degeneration, necrosis, and hyperplasia of small bile ducts. Mild amounts of foamy macrophages were observed, mainly in the centroacinar zone. Diffuse swelling and vacuolation were observed in hepatocytes. Crystal negative images were found within bile ducts, foamy macrophages, and the lumen of some renal tubules. The heart showed multifocal areas of degeneration and necrosis of the muscle fibers. Pasture samples (Brachiaria decumbens) contained 2.36% of protodioscin. No Pithomyces chartarum spores were found in the pasture. Samples from a similar neighboring B. decumbens pasture grazed by cattle without photosensitization contained 1.63% of protodioscin isomers. Outbreaks of photosensitization caused by Brachiaria spp. are common in cattle in the Brazilian Cerrado (savanna) with about 51 million hectares of Brachiaria spp pastures. Sheep farming has been recently developed in this region, and the number of sheep is increasing significantly. Because sheep are more susceptible than cattle to lithogenic saponins, poisoning by Brachiaria should be an important limiting factor for the sheep industry.

Biologia floral de Vochysia cinnamomea Pohl (Vochysiaceae) em cerrados do Triângulo Mineiro, MG

(Biologia floral de Vochysia cinnamomea Pohl (Vochysiaceae) em cerrados do Triângulo Mineiro, MG). Vochysia cinnamomea é uma arvoreta de cerrado comum na região do triângulo mineiro. Apresenta flores zigomorfas com pétalas amarelas e cálice gamossépalo com um dos lobos maior e calcarado. As flores abrem pela manhã e duram apenas um dia. Apresentam um estame que se desprende durante a antese, depositando o pólen no estilete, o que representa um tipo de apresentação secundária de pólen. As flores são visitadas principalmente por abelhas do gênero Epicharis e outras Anthophoridae, que são os polinizadores primários, mas beija-flores e esfingídeos diurnos também foram observados. A planta é parcialmente autocompatível, sendo os frutos formados por autopolinização pouco mais que um quarto dos formados por polinizações cruzadas, um índice de auto-incompatibilidade (ISI) de 0,26. Tubos polínicos de autopolinização cessam o crescimento no meio do estilete na maioria dos pistilos, indicando um mecanismo de incompatibilidade semelhante ao de outras espécies de vochysia. Os sistemas de polinização e reprodução de V. cinnamomea são, de maneira geral, similares aos de outras espécies brasileiras de vochysia, apesar da maioria ser claramente autoincompatível. A autocompatibilidade parcial na espécie estudada pode explicar a existência de espécies de Vochysia totalmente compatíveis encontradas em Costa Rica.

Estudo fenológico de Stryphnodendron adstringens (Mart.) Coville no cerrado sensu stricto da Fazenda Água Limpa no Distrito Federal, Brasil

Stryphnodendron adstringens, conhecida como barbatimão, é uma espécie de distribuição geográfica ampla no bioma cerrado, ocorrendo desde o Pará, pelo planalto central, até Minas Gerais e São Paulo. Sua casca e frutos contêm tanino e apresentam propriedades medicinais. É uma espécie de baixa exigência nutricional e não acumuladora de alumínio. É hermafrodita e polinizada por pequenos insetos, especialmente abelhas. Está entre as principais espécies lenhosas encontradas na área de estudo. O objetivo deste estudo foi avaliar os eventos fenológicos desta espécie, numa área de cerrado sensu stricto na Fazenda Água Limpa (15°56'S e 47°46'W), durante cinco anos (1987-1991). Dez árvores foram selecionadas e observadas de 18/01/1987 até 07/11/1991 a intervalos quinzenais. A estacionalidade pluvial do clima foi bem definida durante o período de observação. Os padrões fenológicos foram analisados graficamente, pelo teste de Kruskall-Wallis a 5% e pelo coeficiente de correlação de Spearman. Todos os indivíduos floriram anualmente exceto dois que não floriram em 1990, provavelmente como conseqüência da queimada em 1989. A floração ocorreu entre julho e novembro, sendo que os picos variaram entre os anos. Todos os indivíduos frutificaram até 1989 quando os frutos foram abortados pela queimada. Nenhuma frutificação foi observada no ano seguinte e em 1991 a produção de frutos atingiu apenas a metade daquela observada nos dois primeiros anos. A espécie apresenta modelo fenológico anual com floração, frutificação, dispersão de sementes e picos de senescência e de emissão de folhas novas, todos na estação seca. Seus frutos requerem um longo período de maturação, cerca de 12 meses, alcançando a maturidade na época seca do ano seguinte. Queimadas ocasionais afetaram, de maneira acentuada, as atividades reprodutivas, especialmente a frutificação.

The developmental anatomy of the subterranean system in Mandevilla illustris (Vell.) Woodson and M. velutina (Mart. ex Stadelm.) Woodson (Apocynaceae)

Two species of Mandevilla from the savanna area of São Paulo State, Brazil were studied. These species have been prescribed as folk medicine as infusions or alcoholic extracts of the underground system for treatment of venomous snake bites. To explain the morphological nature of such a system, its ontogeny was described to determine which parts are involved in its formation. In both Mandevilla species examined, the underground system consists of a xylopodium whose basal region joins a tuberous root.

Distribuição e quantificação de classes de vegetação do Pantanal através de levantamento aéreo

O método de levantamento aéreo foi adaptado e utilizado pela primeira vez para a elaboração de mapas de distribuição e quantificação de classes de vegetação no Pantanal Mato-Grossense por sub-região. Foram identificadas 16 classes, baseando-se em aspectos fitofisionômicos, sendo as principais campo (31,1%), cerradão (22,1%), cerrado (14,3%), brejos (7,4%), mata semidecídua (4,0%), mata de galeria e 2,4% de baceiro ou batume. Estas informações podem subsidiar a escolha de áreas de conservação ou preservação, bem como auxiliar o monitoramento de áreas com grande extensão e difícil acesso.

Dinâmica de foliação e perfilhamento de duas gramíneas C4 e uma C3 nativas do Cerrado

Este estudo comparou a fenologia de três gramíneas nativas do Cerrado em dois níveis estruturais: variação do número de folhas por perfilho (colmo) e do número de perfilhos por planta. As espécies C4 Axonopus marginatus (Trin.) Chase e Trachypogon marginatus (L.f.) Kuntze e a C3 Echinolaena inflexa (Poir.) Chase foram estudadas na Reserva Ecológica do IBGE em Brasília, Distrito Federal, entre novembro de 1996 e junho de 1998. A fenologia de perfilhos foi comparada em três comunidades vegetais: cerrado denso protegido de fogo por 26 anos, campo sujo protegido de fogo por 22 anos e campo sujo queimado bienalmente. A fenologia de folhas foi estudada apenas no cerrado denso. O número de folhas da espécie C3 foi sempre maior que das C4. A área foliar foi constante durante todo o período na espécie C3, mas decresceu nas espécies C4 durante a estação seca. Para as espécies A. marginatus e E. inflexa, o número de perfilhos foi maior no campo sujo protegido, seguido de cerrado denso protegido e do campo sujo queimado. O número de perfilhos de T. spicatus no campo sujo protegido foi o dobro do encontrado no campo sujo queimado; o campo sujo queimado, não diferiu do cerrado denso. As diferenças fenológicas foram mais claras no nível foliar que no de perfilhos. O fogo promoveu a simplificação da arquitetura da planta nas três espécies.

Atlantic Forest succession over calcareous soil, Parque Estadual Turístico do Alto Ribeira - PETAR, SP

The forest succession after abandonment of slash-and-burn agriculture over calcareous soil in Brazilian Atlantic Forest was assessed. This is one of the world's most threatened Biome, with only 8% remaining. The study area is located over calcareous soil inside the Alto Ribeira Touristic State Park (PETAR), southeast Brazil. The phytossociological survey showed a successional pattern dominated by species of Leguminosae, especially Piptadenia gonoacantha (Mart.) J.F. Macbr. This species occurs in calcareous soils as a substitute of Tibouchina pulchra (Cham.) Cogn. (Melastomataceae) that is the most usual dominant tree species in early succession over acidic soil, which is the most common situation in this Biome. These results are important for a better understanding of Neotropical forest biodiversity and characterize a unique genetic bank in this highly endangered Biome. They are also decisive to support actions regarding rehabilitation of degraded lands and a potential tool for Neotropical forest sustainable management, both inside and around the conservation unit.

Biologia reprodutiva de Copaifera langsdorffii Desf. (Leguminosae, Caesalpinioideae

Copaifera langsdorffii Desf. é uma espécie da família Leguminosae, subfamília Caesalpinioideae, de ampla distribuição no Brasil. O estudo da biologia reprodutiva desta espécie foi realizado numa área de cerradão aberto para pastagem da Fazenda Capim Branco, Uberlândia, MG. A espécie floresce durante o período das chuvas e dispersa suas sementes na época seca. As flores são branco-esverdeadas, com cerca de 0,5 cm de diâmetro, fracamente zigomorfas e estão reunidas em inflorescência paniculada. Apresentam um forte odor adocicado e duram apenas um dia. A antese inicia-se por volta das 5:00 h. Os recursos oferecidos aos visitantes são pólen e néctar. Produzem pouco néctar (0,2 ml) com concentração média de 49% de equivalentes de sacarose. Os visitantes mais freqüentes foram as abelhas Apis mellifera, Scaptotrigona cf. depiles e Trigona spinipes. Os resultados das polinizações manuais e o índice de incompatibilidade (ISI) indicam que a espécie é auto-incompatível e não apomítica. No entanto, foram observados tubos polínicos crescendo até o ovário e penetrando os óvulos em flores autopolinizadas, sugerindo a ocorrência de fenômenos de auto-esterilidade de ação tardia ou depressão endogâmica. A baixa produção de frutos está relacionada à pequena conversão de flores em frutos e também à predação dos frutos.

Composição florística de veredas no Município de Uberlândia, MG

Foram estudadas quatro comunidades vegetais de veredas no Municipio de Uberlândia, MG, durante dois anos com o objetivo de conhecer sua composição florística. As veredas foram percorridas por meio de trilhas estabelecidas, ao acaso, passando pela borda (local de solo mais seco), meio (solo medianamente úmido) e fundo (solo saturado com água). A freqüência de visitas à cada vereda foi mensal e o material botânico coletado foi incluído no Herbarium Uberlandense (HUFU). A identificação das espécies foi feita utilizando-se chaves analíticas, consultas a especialistas de várias famílias e/ou comparação com exsicatas devidamente identificadas e depositadas nos herbários HUFU, IBGE e UB. No levantamento florístico foram registradas 526 espécies, 250 gêneros e 89 famílias. As cinco famílias com maior número de espécies foram Poaceae (64), Asteraceae (63), Cyperaceae (54), Melastomataceae (27) e Fabaceae (23). Na zona de borda da vereda foram amostradas 361 espécies sendo 168 exclusivas deste ambiente. Um total de 300 espécies ocorreu na zona de meio, sendo 75 exclusivas. Na zona de fundo ocorreu a menor riqueza específica, compreendendo um total de 136 espécies com 52 exclusivas desta área. A grande riqueza florística encontrada nas veredas amostradas deve-se, possivelmente, às diferenças edáficas, especialmente aquelas relacionadas com a umidade.

Plant species and habitat structure in a sand dune field in the brazilian Caatinga: a homogeneous habitat harbouring an endemic biota

One dune habitat in the semi-arid Caatinga Biome, rich in endemisms, is described based on plant species composition, woody plant density, mean height and phenology and a multivariate analysis of the micro-habitats generated by variables associated to plants and topography. The local flora is composed mainly by typically sand-dweller species of Caatinga, suggesting the existence of a phytogeographic unity related to the sandy areas in the Caatinga biome, which seems to be corroborated by faunal distribution. Moreover, some species are probably endemic from the dunes, a pattern also found in vertebrates. The plant distribution is patchy, there is no conspicuous herbaceous layer and almost 50% of the ground represents exposed sand. Phenology is not synchronized among species, occurring leaves budding and shedding, flowers development and anthesis, fruits production and dispersion both in rainy and dry seasons. Leaf shedding is low compared to the level usually observed in Caatinga areas and about 50% of the woody individuals were producing leaves in both seasons. Spectrum of dispersal syndromes shows an unexpected higher proportion of zoochorous species among the phanerophytes, accounting for 31.3% of the species, 78.7% of the total frequency and 78.6% of the total density. The habitat of the dunes is very simple and homogeneous in structure and most of environmental variance in the area is explained by one gradient of woody plants density and another of increase of Bromelia antiacantha Bertol. (Bromeliaceae) and Tacinga inamoena (K. Schum.) N.P. Taylor & Stuppy (Cactaceae) toward valleys, which seem to determine two kinds of protected micro-habitats for the small cursorial fauna.

Lognormal abundance distribution of woody species in a cerrado fragment (São Carlos, southeastern Brazil)

The lognormal distribution model is frequently found in communities, especially those which are rich in species and influenced by many environmental factors, as those of the cerrado. We tested the hypothesis that the abundance distribution of woody plant species in a cerrado fragment fits the lognormal model. We placed 20 lines in a cerrado fragment and sampled, with the point-quarter method, 800 individuals with stem perimeter equal or larger than 3 cm. We plotted the abundance-class histogram of the species, verified its normality with the Kolmogorov-Smirnov test, and estimated the expected number of woody species for this community. Of the 63 obtained species, Anadenanthera falcata (with 185 species), Eriotheca gracilipes (43), Stryphnodendron obovatum (37), and Miconia albicans (36) were the most abundant ones. Twelve species were represented by only one individual. We did not reject the null hypotheses that the distribution of woody component species was normal and, thus, their abundances fitted the lognormal model. Therefore, with our work, we can predict that cerrado plant communities fit the lognormal model. If this pattern is maintained in other cerrado communities, there would be implications for the conservation of this vegetation type, because rare species are susceptible of extinction, and implications to their structure, because the dominant species may act as keystone species.

Woody community dynamics in two fragments of "cerrado" stricto sensu over a seven-year period (1995-2002), MA, Brazil

This study was conducted in two fragments of "cerrado" stricto sensu in the Gerais de Balsas Colonization Project, located in southern Maranhão, Brazil. The objective was to evaluate the dynamics of the woody plant community, over seven years (1995-2002). Four transects of 160 × 20 m were monitored. All woody plants with a stem diameter > 3 cm, at 0.30 m above ground level, were recorded. In 1995, 983 and 1,177 stems were sampled in fragments 1 and 2, respectively; in 2002, 1057 and 1406 stems were sampled in the same fragments. In 1995, the Shannon diversity indices (H') were 3.07 and 3.33, in fragments 1 and 2, respectively, reaching their maximum value in 2002 of 3.11 and 3.35. The community of fragment 1 showed an increase of 7.5% in density and 4.4% in basal area between 1995 and 2002, while in fragment 2 there was an increment of 19.4% in density and 23.5% in basal area, over the same period. The annual increment in diameter was 0.13 cm year-1 and 0.17 cm year-1 in fragments 1 and 2, respectively. The mortality rate was 2.73% per year in fragment 1 and 4.88% per year in fragment 2, while the recruitment rate was 3.25% per year and 5.86% per year, respectively. The community presented high recruitment and mortality rates compared to the studies conducted in other sites, indicating a community that was highly dynamic in the period studied.

Floristic composition, diversity and structure of the "cerrado" sensu stricto on rocky soils in northern Goiás and southern Tocantins, Brazil

The "cerrado" sensu stricto is a savanna woodland physiognomy which occupies most of central Brazil, with the degree of canopy cover varying from 10% to 60% at a site with trees reaching up to seven meters high. It occurs mostly on deep and well-drained soils but can also be found on shallower ones. The diversity and structure of the "cerrado" sensu stricto on shallow and rocky Cambisols and Litosols were studied here. Sixteen 20 x 50 m² plots were sampled in a random design over patches of this vegetation in northern Goiás State and southern Tocantins. All stems from 5 cm diameter at 30 cm from the ground level were measured. Vouchers were collected and deposited at the IBGE herbarium. A total of 87 species in 65 genera and 33 families were found. Diversity index was 2.87 nats ind-1, density was 836 stems ha-1 with a basal area of 8.4374 m² ha-1. Sørensen's index indicated higher similarities between plots at the same site indicating a geographical gradient influencing the floristic composition of the "cerrado" sensu stricto on rocky soils. Czekanowski's index confirmed this trend. TWINSPAN classification final groups were defined by preferential species of more fertile soils, in opposition to those typical of dystrophic soils and to common species to gallery forests occurring on sloping terrains with gullies.

Soils associated with rock outcrops in the Brazilian mountain ranges Mantiqueira and Espinhaço

Espinhaço and Mantiqueira are two mountain ranges of great importance in Brazil. In the uppermost parts of these areas, unique ecosystems occur, generally associated with rock outcrops, they are collectively called High Altitude Rocky Complexes. These environments show distinct soil and biota characteristics in relation to the surrounding biome. The soils are generally shallow, coarse textured, with high Al3+ and varying amounts of organic matter. Entisols, Inceptsols and Histosols are dominant, directly associated with the rock outcrops, and forming a complex mosaic of soils. Some of these soils are endemic, based on peculiar conditions of parent materials, topography and vegetation, and this pedodiversity is important for detecting unique and endangered soils. In these soils, organic matter is highly humified, with a great amount of soluble forms and conspicuous presence of charcoal. Spodic horizons and dark water rivers are typically associated with quartzite and quartzite outcrops, formed by illuviation of organic compounds, being less common in granitic rocks. The very low nutrient content of these soils and other environmental limitations required the development of specific physiological and morphological plant adaptations. Most high altitude environments are unstable under current climatic conditions, and anthropic interventions may be accelerating this process. Detailed soil surveys are necessary for a better understanding of the role of these soils in ecological processes and for the development of adequate conservation policies.