Thesis (Ph.D.)--University of Texas at Arlington, 2009.

Made available in DSpace on 2014-07-29T15:26:25Z (GMT). No. of bitstreams: 1 tese Luiz Rocha.pdf: 212153 bytes, checksum: 62272961dc1eef42f0cc10bf2761b7b3 (MD5) Previous issue date: 2010-02-23 / The high biodiversity of fungi pathogenic to invertebrates and their potential to control pests until today not well known emphasize the importance to look for new effective species and strains. The Cerrado is considered one of the hotspots of biodiversity and little is known about the occurrence and the potential of fungi pathogenic to invertebrates found in this biome. In the present study a survey of fungi was carried out in different areas of the Cerrado of Goiás. Samples of soil, slurry, water and moribund or dead insects were collected for isolation of fungi. Vectors of medical importance such as triatomines (Triatoma infestans and Rhodnius neglectus), mosquitoes (Aedes aegypti and Culex quinquefasciatus), ticks (Riphicephalus (Boophilus) microplus) and snails (Biomphalaria glabrata) were used as baits for isolation of fungi. After isolation fungi were morphologically identified and included in the collection ofInstitute of Tropical Pathology and Public Health, Federal University of Goiás. Some isolates of Evlachovaea and Metarhizium were molecularly characterized and activity tested against T. infestans. A total of 561 samples of soil (440), slurry (106) and water (15) was collected in different areas of Goiás State. Concerning samples collected at Fazenda Santa Branca, 68 isolates of pathogenic fungi were obtained and identified as belonging to the genera Aspergillus, Beauveria, Cladosporium, Evlachovaea, Fusarium, Gliocladium, Isaria,Lecanicillium, Metarhizium, Paecilomyces, Pochonia and Trichoderma. An total of 106 isolates of Metarhizium spp. and 6 of Evlachovaea spp. were sampled in other areas, being 65isolates of Metarhizium and 1 of Evlachovaea from the Ema National Park, 33 and 1 from the Northern portion of Goiás state, and 8 and 4 from the Silvânia National Forest, respectively.Most fungi were isolated from soils using triatomines as baits. Fungi from genera Aschersonia, Batkoa, Beauveria, Cordyceps, Evlachovaea, Fusarium, Lecanicillium, Pandora and Torrubiella were isolated from mycosed cadavers. All tested isolates of Metarhizium spp. and Evlachovaea spp. induced high mortality of T. infestans in relative humidity (RH) close to saturation. The lowest values for lethal time of 90% were 6.6 d (6.3 7.1 d; M. robertsii IP 34)and 7.1 d (6.7 7.8 d; Evlachovaea IP 141), after treatment of T. infestans and exposure to RH> 98%. The lethal concentration to obtain 50% mortality (LC50) of IP 34 was 2.8x103 (C.I. 4.4x102-4.6x103) and the LC90 was 7.2x103 (C.I. 4.4x103-6.4x105) CFU/cm2 at 10 d p.i. In RH 75% mortality of triatomines did not exceed 20%. Morphological studies and sequencing of the ITS and TEF region of Evlachovaea isolates showed that genus Evlachovaea must be synonymized with Isaria, and that the largest group of isolates previously identified as Evlachovaea are I. cateniannulata, whereas the smaller group is probably a new species of Isaria. The sequencing of the TEF and ITS regions showed that Metarhizium isolates belong to species M. anisopliae, M. robertsii, M. flavoviride var. pemphigi, and the largest group of Metarhizium isolates can be a new species of Metarhizium or a M. anisopliae variety. The results confirmed that in the Cerrado a high diversity of fungi is present and some of them, in special M. robertsii (IP 34) and Evlachovaea (IP 141) have potential for biological control of T. infestans / A grande biodiversidade de fungos patogênicos para invertebrados e o potencial desses patógenos para controle de pragas até hoje pouco conhecido ressaltam a importância de se procurar por novas espécies e linhagens eficazes. O Cerrado é considerado um dos hotspots de biodiversidade e pouco se sabe sobre a ocorrência e a atividade de fungos patogênicos para invertebrados encontrados neste bioma. No presente trabalho foi realizado levantamento de fungos em diferentes áreas do Cerrado de Goiás. Foram coletadas amostras de substrato, sedimento, água e insetos moribundos ou mortos para o isolamento de fungo. Vetores de importância médica como triatomíneos (Triatoma infestans e Rhodnius neglectus), mosquitos (Aedes aegypti e Culex uinquefasciatus), carrapato (Riphicephalus (Boophilus) microplus) e caramujo (Biomphalaria glabrata), foram usados como isca para isolamento de fungos. Após o isolamento de fungos eles foram identificados morfologicamente e incluídos na coleção do Instituto de Patologia Tropical e Saúde Pública, Universidade Federal de Goiás. Para alguns isolados de Evlachovaea e Metarhizium foram realizados uma caracterização molecular e teste de atividade contra T. infestans. Um total de 561 amostras de solo (440), sedimento (106) e água (15) foi coletado em diferentes áreas do Estado de Goiás. Das amostras coletadas na Fazenda Santa Branca, foram obtidos 68 isolados de fungos patogênicos que foram identificados como pertencentes aos gêneros Aspergillus, Beauveria, Cladosporium, Evlachovaea, Fusarium, Gliocladium, Isaria, Lecanicillium, Metarhizium, Paecilomyces, Pochonia e Trichoderma. Das outras áreas de coletas foram detectados 106 isolados de Metarhizium spp. e 6 de Evlachovaea spp., sendo 65 isolados de Metarhizium e 1 de Evlachovaea do Parque Nacional das Emas, 33 e 1 da região Nordeste do Estado de Goiás, e 8 e 4 da Floresta Nacional de Silvânia, respectivamente. A maioria dos fungos foi isolada de solos utilizando triatomíneos como isca. Em insetos coletados mortos e com desenvolvimento fúngico foram identificados fungos dos gêneros Aschersonia, Batkoa, Beauveria, Cordyceps, Evlachovaea, Fusarium, Lecanicillium, Pandora e Torrubiella. Todos os isolados de Metarhizium spp. e Evlachovaea spp. testados induziram alta mortalidade em T. infestans em umidade relativa (UR) perto da saturação. O valor mais baixo de tempo letal de 90% foi de 6,6 d (6,3 7,1 (M. robertsii IP 34)) e 7,1 d (6,7 7,8 (Evlachovaea IP 141)), após tratamento de T. infestans e exposição à UR > 98%. A concentração letal de 50% (CL50) do IP 34 foi de 2,8x103 (I.C. 4,4 x102-4,6x103) e o CL90 foi de 7,2x103 (I.C. 4,4x103-6,4x105) CFU/cm2 aos 10 d após inoculação. Em UR de 75% a mortalidade dos triatomíneos não ultrapassou 20%. Estudos morfológicos e o seqüênciamento da região ITS e TEF dos isolados de Evlachovaea mostraram que o gênero Evlachovaea deve ser sinonimizado com Isaria, sendo que o maior grupo de isolados previamente identificados como Evlachovaea são I. cateniannulata e o menor grupo é provavelmente uma nova espécie de Isaria. O seqüênciamento das regiões TEF e ITS mostrou que os isolados de Metarhizium são pertencentes às espécies de M. anisopliae, M. robertsii, M. flavoviride var. pemphigi e o maior grupo de isolados podem ser uma nova espécie Metarhizium ou uma variedade de M. anisopliae. Os resultados confirmaram que nos Cerrados estão presentes uma alta diversidade de fungos e alguns deles, em especial M. robertsii (IP 34) e Evlachovaea (IP 141), têm potencial para o controle biológico de T. infestans

The National Occupational Research Agenda stresses the importance of identifying work-related musculoskeletal disorder (WMSD) risk factors, understanding their exposure dependent nature, and identifying strategies to reduce their incidence and severity. We first examined behavioral changes after exposure to a low repetition low force (LRLF) reaching task for 12 weeks in young rats. We observed increased movement reversals in LRLF - week 8, indicative of a decline in fine motor control, and a small decrease in voluntary task participation in LRLF - week 12, compared to controls. This decline was associated temporally with a low-grade increase of macrophages in peripheral nerve and distal forelimb bones that correlated with nociceptive neurochemical increases in the spinal cord. We next examined motor behavior changes in young rats exposed to either a food retrieval high repetition negligible force (HRNF) task or a lever pulling high repetition low force (HRLF) reaching task. We found that both tasks led to motor declines, with more marked declines in fine motor control in the HRNF group. Thus, repetition, rather than the difference in force magnitude between the 2 tasks, appears to be the key factor in the induction of motor declines associated with repetitive motion injuries (RMIs). Also, these findings indicate that activities involving negligible force do not necessarily pose a lower risk than activities involving low force. Factors such as fine motor coordination requirements may even pose greater risks. Also, compared to the LRLF task, the high repetition tasks resulted in more motor performance declines, thus confirming exposure-dependency in the context of RMI. We also explored the effects of HRNF and HRLF tasks on supraspinatus tendon of young adult rats in 6 and 12 weeks. We found a small but non-significant elevation of ED1+ macrophages in 6 weeks. The supraspinatus tendon does not appear to develop as many pathological changes as forelimb flexor tendons (Barbe, et al., 2003) with task performance. Lastly, we examined the effects of performing HRLF tasks in aged rats. We found that aged rats demonstrate both declines in motor performance and pathological tissue changes over the course of 12 weeks of exposure to the HRLF lever pulling task. The observed declines in grip strength in aged trained control and HRLF rats over time suggest that both age and cumulative exposure to the repetitive task are factors in the development of WMSDs. Our findings suggest that additional study of exposure-dependency and risk factors is warranted. Deeper understanding of the relative contributions of various risk factors can help inform prophylactic programs and/or interventions for individuals who are at risk for, or suffer from, WMSDs. / Physical Therapy