Plantation hardwood resource specifications required for planning small log sawing infrastructure investment in Queensland.

Improved information on the product quality of the plantation resource is needed to allow businesses to consider investing in the development of value-adding processing facilities. These facilities are likely to require customised design that optimises the utilisation of future small diameter plantation hardwood logs. This log resource will become available as wood supply in Queensland transitions from native forests to 100% from sustainable plantations. This resource will be controlled by plantations established prior to 2000. A survey of the three main growers (former Forest Enterprises Australia Pty Ltd, former Forestry Corporation of New South Wales, Hancock Queensland Plantation Pty Ltd) revealed that C. citriodora subsp.variegata – CCV (28.0%), Eucalyptus dunnii (27.5%), E. pilularis (23.0%), E. grandis (11.3%) and E. cloeziana –GMS (7.1%) were the most widely planted species in the southern Queensland and northern New South Wales subtropical hardwood estate and would potentially dominate the supply of plantation hardwoods to sawmill processing facilities.

Biological control of prickly acacia: Current research and future prospects

Prickly acacia, Vachellia nilotica subsp. indica (syn. Acacia nilotica subsp. indica) (Fabaceae), a major weed in the natural grasslands of western Queensland, has been a target of biological control since the 1980s with limited success to date. Surveys in India, based on genetic and climate matching, identified five insects and two rust pathogens as potential agents. Host-specificity tests were conducted for the insects in India and under quarantine conditions in Australia, and for the rust pathogens under quarantine conditions at CABI in the UK. In no-choice tests, the brown leaf-webber, Phycita sp. A, (Lepidoptera: Pyralidae) completed development on 17 non-target plant species. Though the moth showed a clear preference for prickly acacia in oviposition choice trials screening of additional test-plant species was terminated in view of the potential non-target risk. The scale insect Anomalococcus indicus (Hemiptera: Lecanodiaspididae) developed into mature gravid females on 13 out of 58 non-target plant species tested. In the majority of cases very few female scales matured but development was comparable to that on prickly acacia on four of the non-target species. In multiple choice tests, the scale insect showed a significant preference for the target weed over non-target species tested. In a paired-choice trial under field conditions in India, crawler establishment occurred only on prickly acacia and not on the non-target species tested. Further choice trials are to be conducted under natural field conditions in India. A colony of the green leaf-webber Phycita sp. B has been established in quarantine facilities in Australia and host-specificity testing has commenced. The gall-rust Ravenelia acaciae-arabicae and the leaf-rust Ravenelia evansii (Puccineales: Raveneliaceae) both infected and produced viable urediniospores on Vachellia sutherlandii (Fabaceae), a non-target Australian native plant species. Hence, no further testing with the two rust species was pursued. Inoculation trials using the gall mite Aceria liopeltus (Acari: Eriophyidae) from V. nilotica subsp. kraussiana in South Africa resulted in no gall induction on V. nilotica subsp. indica. Future research will focus on the leaf-weevil Dereodus denticollis (Coleoptera: Curculionidae) and the leaf-beetle Pachnephorus sp. (Coleoptera: Chrysomelidae) under quarantine conditions in Australia. Native range surveys for additional potential biological control agents will also be pursued in northern and western Africa.

Life cycle and host range of Phycitasp. rejected for biological control of prickly acacia in Australia

Prickly acacia (Vachellia nilotica subsp. indica), a native of the Indian subcontinent, is a serious weed of the grazing areas of northern Australia and is a target for classical biological control. Native range surveys in India identified a leaf webber, Phycita sp. (Lepidoptera: Pyralidae) as a prospective biological control agent for prickly acacia. In this study, we report the life cycle and host-specificity test results Phycita sp. and highlight the contradictory results between the no-choice tests in India and Australia and the field host range in India. In no-choice tests in India and Australia, Phycita sp. completed development on two of 11 and 16 of 27 non-target test plant species, respectively. Although Phycita sp. fed and completed development on two non-target test plant species (Vachellia planifrons and V. leucophloea) in no-choice tests in India, there was no evidence of the insect on the two non-target test plant species in the field. Our contention is that oviposition behaviour could be the key mechanism in host selection of Phycita sp., resulting in its incidence only on prickly acacia in India. This is supported by paired oviposition choice tests involving three test plant species (Acacia baileyana, A. mearnsii and A. deanei) in quarantine in Australia, where eggs were laid only on prickly acacia. However, in paired oviposition choice trials, only few eggs were laid, making the results unreliable. Although oviposition choice tests suggest that prickly acacia is the most preferred and natural host, difficulties in conducting choice oviposition tests with fully grown trees under quarantine conditions in Australia and the logistic difficulties of conducting open-field tests with fully grown native Australian plants in India have led to rejection of Phycita sp. as a potential biological control agent for prickly acacia in Australia.

Three new species of Tilletia on Eriachne from north-western Australia

Three new species of Tilletia are described from species of Eriachne (Poaceae) in the arid tropics of north-western Australia. In Western Australia, T. mactaggartii sp. nov. infects E. burkittii, and T. geeringii sp. nov. infects E. festucacea. Tilletia marjaniae sp. nov. infects E. pulchella subsp. dominii in Western Australia and the Northern Territory. These species are the first records of Tilletia on Eriachne. Phylogenetic relationships of these species were inferred from internal transcribed spacer of ribosomal RNA region and large subunit ribosomal RNA gene sequences.

Biomass for aviation fuel production in the Fitzroy Basin, Queensland: a preliminary assessment of native and plantation forest potential

SummaryThis scoping study assesses the contribution that woody biomass could make to feedstock supply for an aviation biofuel industry in Queensland. The inland 600?900 mm rainfall zone, including the Fitzroy Basin region, is identified as an area that is particularly worthy of closer study as it has potential for supply of woody biomass from existing native regrowth (brigalow and other species) as well as from new plantings. New analyses carried out for this study of Corymbia citriodora subsp. variegata trials suggest biomass plantings could produce harvestable yield of aboveground dry mass of about 85 t ha?1 over a 10-year rotation at relatively low-rainfall (600?750 mm mean annual precipitation) sites and about 115 t ha?1 at medium-rainfall (750?900 mm) sites. Estimates of productivity for native regrowth suggest potential productivity should be around 40 t ha?1 during the initial decade after clearing when systems are managed for bioenergy rather than grazing. In this paper, potential production systems are described, and sustainability issues are briefly considered. It is concluded that more detailed studies focused particularly on biomass production would be worthwhile, and further research requirements are briefly discussed.

Green and brown bridges between weeds and crops reveal novel Diaporthe species in Australia

Diaporthe (syn. Phomopsis) species are well-known saprobes, endophytes or pathogens on a range of plants. Several species have wide host ranges and multiple species may sometimes colonise the same host species. This study describes eight novel Diaporthe species isolated from live and/or dead tissue from the broad acre crops lupin, maize, mungbean, soybean and sunflower, and associated weed species in Queensland and New South Wales, as well as the environmental weed bitou bush (Chrysanthemoides monilifera subsp. rotundata) in eastern Australia. The new taxa are differentiated on the basis of morphology and DNA sequence analyses based on the nuclear ribosomal internal transcribed spacer region, and part of the translation elongation factor-1α and ß-tubulin genes. The possible agricultural significance of live weeds and crop residues ('green bridges') as well as dead weeds and crop residues ('brown bridges') in aiding survival of the newly described Diaporthe species is discussed.

Pathogen-Induced Defense Signaling and Signal Crosstalk in Arabidopsis

Erwinia carotovora subsp. carotovora is a bacterial phytopathogen that causes soft rot in various agronomically important crop plants. A genetically specified resistance to E. carotovora has not been defined, and plant resistance to this pathogen is established through nonspecific activation of basal defense responses. This, together with the broad host range, makes this pathogen a good model for studying the activation of plant defenses. Production and secretion of plant cell wall-degrading enzymes (PCWDE) are central to the virulence of E. carotovora. It also possesses the type III secretion system (TTSS) utilized by many Gram-negative bacteria to secrete virulence- promoting effector proteins to plant cells. This study elucidated the role of E. carotovora HrpN (HrpNEcc), an effector protein secreted through TTSS, and the contribution of this protein in the virulence of E. carotovora. Treatment of plants with HrpNEcc was demonstrated to induce a hypersensitive response (HR) as well as resistance to E. carotovora. Resistance induced by HrpNEcc required both salicylic acid (SA)- and jasmonate/ethylene (JA/ET)-dependent defense signaling in Arabidopsis. Simultaneous treatment of Arabidopsis with HrpNEcc and PCWDE polygalacturonase PehA elicited accelerated and enhanced induction of defense genes but also increased production of superoxide and lesion formation. This demonstrates mutual amplification of defense signaling by these two virulence factors of E. carotovora. Identification of genes that are rapidly induced in response to a pathogen can provide novel information about the early events occurring in the plant defense response. CHLOROPHYLLASE 1 (AtCLH1) and EARLY RESPONSIVE TO DEHYDRATION 15 (ERD15) are both rapidly triggered by E. carotovora in Arabidopsis. Characterization of AtCLH1 encoding chlorophyll-degrading enzyme chlorophyllase indicated that it might have a role in chlorophyll degradation during plant tissue damage. Silencing of this gene resulted in increased accumulation of reactive oxygen species (ROS) in response to pathogen infection in a light-dependent manner. This led to enhanced SA-dependent defenses and resistance to E. carotovora. Moreover, crosstalk between different defense signaling pathways was observed; JA-dependent defenses and resistance to fungal pathogen Alternaria brassicicola were impaired, indicating antagonism between SA- and JA-dependent signaling. Characterization of ERD15 suggested that it is a novel, negative regulator of abscisic acid (ABA) signaling in Arabidopsis. Overexpression of ERD15 resulted in insensitivity to ABA and reduced tolerance of the plants to dehydration stress. However, simultaneously, the resistance of the plants to E. carotovora was enhanced. Silencing of ERD15 improved freezing and drought tolerance of transgenic plants. This, together with the reducing effect of ABA on seed germination, indicated hypersensitivity to this phytohormone. ERD15 was hypothesized to act as a capacitor that controls the appropriate activation of ABA responses in Arabidopsis.

A systematic-ecological approach to Baltic Sea ice studies of algae and protists

The seasonal occurrence of sea ice that annually covers almost half the Baltic Sea area provides a unique habitat for halo- and cold temperature-tolerant extremophiles. Baltic Sea ice biology has more than 100 years of tradition that began with the floristic observation of species by the early pioneers using light microscopic techniques that were the only thing available at the time. Since the discovery of life within sea ice, more technologies have become available for taxonomy. Electron microscopy and genetic evidence have been used to identify sea ice biota revealing increased numbers of taxa. Meanwhile ecologists have used light microscopic cell enumeration in addition to the chemical and physical properties of sea ice in attempts to explain the food web structure of sea ice and its functions. Thus, during the Baltic winter, the sea ice hosts more abundant and diverse microbial communities than the water column beneath it. These communities are typically dominated by autotrophic diatoms together with a diverse assortment of dinoflagellates, auto- and heterotrophic flagellates, ciliates, metazoan rotifers and bacteria, which are mostly responsible for the recycling of nutrients. This thesis comprises ecological and systematic studies. In addition to the results of the previous studies carried out on landfast ice, the data presented here provide new insight into the spatial distribution of pelagial sea ice, which has remained largely unexplored. The studies reveal spatial heterogeneity in the pelagial sea ice of the Gulf of Bothnia. There were mismatches in chlorophyll-a concentrations and in photosynthetic efficiencies of the communities studied. The temporal succession was followed and experimental studies performed investigating the community responses towards increased or decreased light in landfast ice in the Gulf of Finland. The systematic studies carried out with established dinoflagellate cultures revealed a new resting cyst belonging to common sea ice dinoflagellate, Scrippsiella hangoei (Schiller) Larsen 1995. The cyst can be used to explain the overwintering of this species during prolonged periods of darkness. The dissimilarities and similarities in the material isolated from the sea ice called for description of a new subspecies Heterocapsa arctica ssp. frigida. The cells obtained in the cultured material were unlike those of the previously described species, necessitating description of ssp. frigida. As a result of its own unique habitus, the subspecies had been noted by Finnish taxonomists during the past three decades and thus its annual occurrence and geographical distribution in the Baltic Sea. This illustrates how combining ecology and systematics increases our understanding of organisms.

Novel Molecular Mechanisms of Arabidopsis Disease Resistance

Plants are capable of recognizing phytopathogens through the perception of pathogen-derived molecules or plant cell-wall degradation products due to the activities of pathogen-secreted enzymes. Such elicitor recognition events trigger an array of inducible defense responses involving signal transduction networks and massive transcriptional re-programming. The outcome of a pathogen infection relies on the balance between different signaling pathways, which are integrated by regulatory proteins. This thesis characterized two key regulatory components: a damage control enzyme, chlorophyllase 1 (AtCHL1), and a transcription factor, WRKY70. Their roles in defense signaling were then investigated. The Erwinia-derived elicitors rapidly activated the expression of AtCLH1 and WRKY70 through different signaling pathways. The expression of the AtCHL1 gene was up-regulated by jasmonic acid (JA) but down-regulated by salicylic acid (SA), whereas WRKY70 was activated by SA and repressed by JA. In order to elucidate the functions of AtCLH1 and WRKY70 in plant defense, stable transgenic lines were produced where these genes were overexpressed or silenced. Additionally, independent knockout lines were also characterized. Bacterial and fungal pathogens were then used to assess the contribution of these genes to the Arabidopsis disease resistance. The transcriptional modulation of AtCLH1 by either the constitutive over-expression or RNAi silencing caused alterations in the chlorophyll-to-chlorophyllide ratio, supporting the claim that chlorophyllase 1 has a role in the chlorophyll degradation pathway. Silencing of this gene led to light-dependent over-accumulation of the reactive oxygen species (ROS) in response to infection by Erwinia carotovora subsp. carotovora SCC1. This was followed by an enhanced induction of SA-dependent defense genes and an increased resistance to this pathogen. Interestingly, little effect on the pathogen-induced SA accumulation at the early infection was observed, suggesting that action of ROS might potentiate SA signaling. In contrast, the pathogen-induced JA production was significantly reduced in the RNAi silenced plants. Moreover, JA signaling and resistance to Alternaria brassicicola were impaired. These observations provide support for the argument that the ROS generated in chloroplasts might have a negative impact on JA signaling. The over-expression of WRKY70 resulted in an enhanced resistance to E. carotovora subsp. carotovora SCC1, Pseudomonas syringae pv. tomato DC3000 and Erysiphe cichoracearum UCSC1, whilst an antisense suppression or an insertional inactivation of WRKY70 led to a compromised resistance to E. carotovora subsp. carotovora SCC1 and to E. cichoracearum UCSC1 but not to P. syringae pv. tomato DC3000. Gene expression analysis revealed that WRKY70 activated many known defense-related genes associated with the SAR response but suppressed a subset of the JA-responsive genes. In particular, I was able to show that both the basal and the induced expression of AtCLH1 was enhanced by the antisense silencing or the insertional inactivation of WRKY70, whereas a reduction in AtCLH1 expression was observed in the WRKY70 over-expressors following an MeJA application or an A. brassicicola infection. Moreover, the SA-induced suppression of AtCLH1 was relieved in wrky70 mutants. These results indicate that WRKY70 down-regulates AtCLH1. An epistasis analysis suggested that WRKY70 functions downstream of the NPR1 in an SA-dependent signaling pathway. When challenged with A. brassicicola, WRKY70 over-expressing plants exhibited a compromised disease resistance while wrky70 mutants had the opposite effect. These results confirmed the WRKY70-mediated inhibitory effects on JA signaling. Furthermore, the WRKY70-controlled suppression of A. brassicicola resistance was mainly through an NPR1-dependent mechanism. Taking all the data together, I suggest that the pathogen-responsive transcription factor WRKY70 is a common component in both SA- and JA-dependent pathways and plays a crucial role in the SA-mediated suppression of JA signaling.

Molecular markers for discriminating Streptococcus pyogenes and S.dysgalactiae subspecies equisimilis

Given the increasing aetiological importance of Streptococcus dysgalactiae subspecies equisimilis in diseases which are primarily attributed to S. pyogenes, molecular markers are essential to distinguish these species and delineate their epidemiology more precisely. Many clinical microbiology laboratories rely on agglutination reactivity and biochemical tests to distinguish them. These methods have limitations which are particularly exacerbated when isolates with mixed properties are encountered. In order to provide additional distinguishing parameters that could be used to unequivocally discriminate these two common pathogens, we assess here three molecular targets: the speB gene, intergenic region upstream of the scpG gene (IRSG) and virPCR. Of these, the former two respectively gave positive and negative results for S. pyogenes, and negative and positive results for S. dysgalactiae subsp. equisimilis. Thus,a concerted use of these nucleic acid-based methods is particularly helpful in epidemiological surveillance to accurately assess the relative contribution of these species to streptococcal infections and diseases.

Climate change and crop yields in the Indian Cardamom Hills, 1978-2007 CE

In this study we analyzed climate and crop yields data from Indian cardamom hills for the period 1978-2007 to investigate whether there were significant changes in weather elements, and if such changes have had significant impact on the production of spices and plantation crops. Spatial and temporal variations in air temperatures (maximum and minimum), rainfall and relative humidity are evident across stations. The mean air temperature increased significantly during the last 30 years; the greatest increase and the largest significant upward trend was observed in the daily temperature. The highest increase in minimum temperature was registered for June (0.37A degrees C/18 years) at the Myladumpara station. December and January showed greater warming across the stations. Rainfall during the main monsoon months (June-September) showed a downward trend. Relative humidity showed increasing and decreasing trends, respectively, at the cardamom and tea growing tracts. The warming trend coupled with frequent wet and dry spells during the summer is likely to have a favorable effect on insect pests and disease causing organisms thereby pesticide consumption can go up both during excess rainfall and drought years. The incidence of many minor pest insects and disease pathogens has increased in the recent years of our study along with warming. Significant and slight increases in the yield of small cardamom (Elettaria cardamomum M.) and coffee (Coffea arabica), respectively, were noticed in the recent years.; however the improvement of yield in tea (Thea sinensis) and black pepper (Piper nigrum L.) has not been seen in our analysis.

Evaluación del riesgo fitosanitario en la importación de semillas de cucurbitáceas para siembra procedente de Estados Unidos de Norteamérica

De marzo 1999 a Mayo 2000 se realizó el presente estudio, en Managua, el cual se basó en la recopilación de información sobre las plagas asociadas a las semillas de cucurbitáceas. El objetivo del estudio fue proporcionar elementos técnicos a Cuarentena Vegetal para la toma de decisiones y aplicación de medidas fitosanitarias en la importación de semillas de cucurbitáceas para siembra procedente de Estados Unidos. La información fue obtenida de Bases de Datos Internacionales de Plagas, Centros de Documentación, Organismos internacionales, consultas a especialistas en foto protección, listado de plagas presentes en los cultivos de Nicaragua y búsqueda en Internet. Para el ordenamiento de la información se realizaron fichas técnicas para cada plaga. De un listado inicial de 1O plagas, solamente 8 plagas fueron sujetas a evaluación y análisis para el manejo del riesgo, después de pasar por las tres etapas de Evaluación de un Análisis de Riesgo de Plagas según la Norma Centroamericana del OIRSA. A las plagas consideradas como cuarentenarias para Nicaragua y que pueden causar grandes daños al país si se llegan a introducir, se les evaluó el riesgo de introducción, establecimiento y dispersión, además se determinaron las medidas de manejo del riesgo de plagas. De las plagas analizadas el hongo Fusarium oxysporum f. sp niveum, el virus Cucumber Green Mottle Mosaic Virus, el virus Melón Necrotic Spot Carmovirus, la bacteria Acidovorax avenae subsp.citrulli y el virus Cucumber Mosaic Cucumovirus, son las especies que presentan mayor riesgo fitosanitario.

Determinación de la relación sólidos solubles/acidez total en muestras de frutos de cuatro especies de cítricos

Este trabajo fue realizado en el laboratorio químico de la Estación Experimental Agropecuaria La Calera en la terminación del año de 1964 y principios de 1965 con las especies: naraja dulce (Citrus sinensis); grape fruit (Citrus paradisi); mandarina (Citrus reticulata) y limón agrio (Citrus limonum). El objeto del trabajo fue el investigar la relación sólidos totales solubles sobre acidez total en base a un tamaño promedio del fruto (los cuales están especificados para cada especie en el cuadro V) y comparar estos resultados con los encontrados en otros países que consideran a esta relación como indice para la cosecha en la industrialización de los cítricos. Se utilizaron tras arboles de naranja dulce criolla, identificados en este trabajo como : No. 28, 29 y 30; dos variedades de grape fruit: DUNCAN y FOSTER, dos variedades de mandarina; variedad carazo, cascara roja y variedad criolla, cascara amarilla y dos variedades de limón agrio: Criollo y Bear's Seedless. Los valores obtenidos de la relación sólidos totales solubles sobre acidez total son: naranja dulce del 9.2:1 a 9.3:1 (cuadro No. I), para la grape fruit FOSTER fue de 3.78:1, para la DUNCAN 6.6:1 (cuadro No. II); para la mandarina se obtuvo una relación de 21.1:1 a 18.6:1 (cuadro No. III) y para el limón ácido un porcentaje de ácido cítrico de 6.81 a 6.89 (cuadro No. IV). Estos resultados coinciden con los encontrados por Chandler (2) haciendo mención que en la naranja dulce, la relación sólidos/ácidos de este ensayo es mayor que la relación 8:1 encontrada en los Estados Unidos, debido quizás al mayor periodo cálido en que se desarrollan nuestros cítricos. Con respecto a la mandarina, la relación mencionada es mayor en la variedad Carazo, de color de cascara mas intenso. Este resultado coincide con el encontrado por Chandler (2). Esta relación no se encontró con la grape fruit. Con respecto al limon agrio, el porcentaje de ácido cítrico fue menor que el promedio de los resultados de FELIU (4), pudiendo deberse la diferencia al factor climático, tal como se explico con la naranja dulce. Finalmente se recomienda que estos resultados sean acompañados con un estudio de la palatabilidad de las frutas.

Detection of specific bacteria in water: implications of survival strategy

It is widely recognised that conventional culture techniques may underestimate true viable bacterial numbers by several orders of magnitude. The basis of this discrepancy is that a culture in or on media of high nutrient concentration is highly selective (either through ”nutrient shock” or failure to provide vital co-factors) and decreases apparent diversity; thus it is unrepresentative of the natural community. In addition, the non-culturable but viable state (NCBV) is a strategy adopted by some bacteria as a response to environmental stress. The basis for the non-culturable state is that cells placed in conditions present in the environment cannot be recultured but can be shown to maintain their viability. Consequently, these cells would not be detected by standard water quality techniques that are based on culture. In the case of pathogens, it may explain outbreaks of disease in populations that have not come into contact with the pathogen. However, the NCBV state is difficult to attribute, due to the failure to distinguish between NCBV and non-viable cells. This article will describe experiences with the fish pathogen Aeromonas salmonicida subsp. salmonicida and the application of molecular techniques for its detection and physiological analysis.

Papel das hemaglutininas 67-72p de Corynebacterium diphtheriae na ligação a proteínas plasmáticas, superfícies celulares, invasão e indução de apoptose

Corynebacterium diphtheriae pode ser isolado tanto de quadros de difteria clássica, quanto de infecções sistêmicas, como endocardite. O fibrinogênio (Fbn) e a fibronectina (Fn) são glicoproteínas presentes na matriz extracelular de tecidos conjuntivos. A influência destas proteínas na patogênese das infecções locais e invasivas causadas por C. diphtheriae é objeto de estudo devido ao fato do bacilo diftérico poder ser encontrado em lesões nas quais o Fbn e a Fn são predominantes, incluindo a pseudomembrana diftérica e vegetações cardíacas presentes na endocardite infecciosa. São crescentes as evidências de que o C. diphtheriae pode, além de aderir, ser internalizado por células em cultura. No presente estudo, investigou-se a participação de C. diphtheriae e das proteínas de superfície 67-72p na aderência à Fn e ao Fbn de plasma humano e a eritrócitos. A aderência às células HEp-2 e internalização também foram analisadas. A participação de 67-72p nos mecanismos de morte celular foi avaliada através das colorações por Azul de Tripan e 46-diamidino-2-fenil indol (DAPI), pelo ensaio de redução utilizando dimetil-tiazol-difenil tetrazólio (MTT) e por citometria de fluxo. As 67-72p foram extraídas da superfície da amostra toxigênica C. diphtheriae subsp. mitis CDC-E8392 através de processos mecânicos e precipitação com sulfato de amônio saturado. Análises por SDS-PAGE e immunoblotting detectaram a presença das bandas protéicas de 67 e 72kDa nas amostras toxinogênicas e atoxinogênicas analisadas, as quais pertenciam aos biotipos fermentador e não fermentador de sacarose. C. diphtheriae foi capazes não só de formar agregados na presença de plasma de coelho, mas também de converter Fbn em fibrina independentemente da presença do gene tox. No entanto, a amostra atoxinogênica ATCC 27010 (tox-) foi menos aderente ao Fbn do que a homóloga ATCC 27012 (tox+). A interação bacteriana com eritrócitos foi inibida somente pela Fn. Ligações entre Fn e/ou Fbn com 67-72p foram demonstradas por dot blotting, ELISA e/ou ensaios utilizando fluorescência. As 67-72p foram capazes de inibir as interações bacterianas com o Fbn, indicando que 67-72p podem participar do processo de aderência do patógeno aos tecidos do hospedeiro. Através da microscopia óptica, demonstrou-se a ligação de 67-72p adsorvidas em microesferas de látex com células HEp-2. Anticorpos de coelho do tipo IgG anti 67-72p interferiram somente com a expressão do padrão de aderência do tipo difuso, normalmente apresentado pela amostra CDC-E8392. A Microscopia Eletrônica de Transmissão (MET) e a inibição da internalização bacteriana pela IgG anti 67-72p ou por 67-72p indicaram o papel de 67-72p como invasina. Alterações do citoesqueleto de células HEp-2 com acumulação de actina polimerizada, induzida por microesferas sensibilizadas com 67-72p, foi observada pelo fluorescent actin staining (FAS) test. Foi visualizado um aumento no número de bactérias viáveis no compartimento intracelular após tratamento de células HEp-2 ou dos microrganismos com Fn. A presença de partículas de látex adsorvidas com 67-72p no interior de vacúolos frouxos em células HEp-2 sugeriu que estas proteínas podem causar efeito citotóxico. A avaliação através das colorações com Azul de Tripan, DAPI e os ensaios de redução utilizando MTT demonstraram um decréscimo na viabilidade de células tratadas com 67-72p. As mudanças morfológicas observadas 3 horas após o início do tratamento com 67-72p incluíram vacuolização, fragmentação nuclear e formação de corpúsculos apoptóticos. A citometria de fluxo revelou um decréscimo de 15,13% no volume/tamanho de células tratadas com 67-72p. Além disso, o ensaio utilizando Iodeto de Propídio (IP) e Anexina V (AV)-FITIC demonstrou que havia 66,1% de células vivas (IP-/AV-), 16,6% de células em apoptose inicial (IP-/AV+) e 13,8% de células em apoptose tardia ou necrose secundária. Em conclusão, as 67-72p estão diretamente envolvidas na interação com Fn e Fbn. As proteínas não fimbriais 67-72p são hemaglutininas implicadas na aderência a células respiratórias e na internalização. Além disso, estas proteínas podem atuar como fatores de virulência em potencial para induzir apoptose de células epiteliais nos estágios iniciais da difteria e nas infecções invasivas causadas pelo C. diphtheriae