Thesis (M.Sc. (Pharmacy))--Mahidol University, 1984.

Thesis (M.S.)--University of Michigan, 1960.

This thesis describes dip tank field trials and laboratory investigations on the acaricide Amitraz. Amitraz is a triazapenta- diene compound which is relatively unstable in fouled dip washes. The field trials were conducted on the farm Sea View according to the "Total Replacement Method" and on the farm Sea Ways according to the "Lime Stabilization Method" of dipping. The results of these trials showed that Amitraz was stable in clean dip washes, and under conditions of high pH resulting from the addition of slaked lime to the dip wash. Using mixed bacterial populations optimum conditions for degradation of Amitraz in the laboratory were determined. Bacterial cultures degraded Amitraz most efficiently in media supplemented with yeast extract or with a high content of sterile cattle faeces. Amitraz concentrations were determined by gas chromatography. A culture. efficient at degrading Amitraz was enriched from a dip tank sludge inoculum. From this culture ten bacterial isolates were identified; nine of these were of the genus Pseudomonas and one was an Achromobacter sp. Experiments with both mixed and pure cultures demonstrated that bacterial degradation of Amitraz was by the process of co-metabolism. The existence of four degradation products was shown using thin layer chromatography. Tentative identification of two of the products was made.

The problem of conatmination in culture media for Mycobacterium tuberculosis has not been solved completely, and for this reason the work herein presented was carried out. In this work experiments were made testing the effect of actidione in inhibiting certain ones of the higher fungi.

The work described in this thesis was undertaken to study the reasons why Azotobacter vinelandii ATCC 12837 after incubation in Burk's nitrogen-free liquid will not form as many colonies when plated on Difco Tryptic Soy Agar as when planted on Burk's nitrogen-free agar. The difference in growth of A. vinelandii on the two agars was established by performing viable cell-plate counts. The difference in growth was most apparent at 24-hours incubation of the Burk's liquid-media cultures. Phase contrast microscopic observations of Tryptic Soy media cultures of A. vinelandii disclosed the regular formation of fungoid cells at early stages of growth of the bacteria, 18 to 24 hours.

Bacterial populations proliferating in a pilot scale biological nutrient removal system (BNR) were studied. The objective of the research was to develop media and methods to identify bacterial populations in BNR systems. Samples were obtained from the last aerobic zone of a University of Cape Town (UCT)-type system. The most probable numbers (MPN) of bacteria in the samples were analyzed in liquid media containing volatile fatty acids as sole sources of carbon. Samples were also transferred to denitrification medium, and MPN's of denitrifiers were recorded. The growth in liquid medium was plated on solid medium. Gram-negative cultures were isolated and identified. The phosphorus-removal capacity of five isolates also was studied. The results indicated that several different genera of bacteria are involved in the removal of phosphorus in an operating BNR system. Four major groups of phosphorus storing bacteria, Aeromonas/Vibrio, coliforms, Pseudomonas spp and Acinetobacter spp, were recovered. The identification of cultures on denitrification medium also recovered Pseudomonas, Aeromonas, coliforms and Acinetobacter, indicating the overlap in the function of these genera. The phosphorus accumulations in three of the tested cultures showed accumulations in excess of 10 percent. The MPN's of bacteria in acetate and propionate media obtained using samples from the pilot scale BNR system and a full scale activated sludge system were statistically analyzed. The analyses showed significant differences between MPN in acetate and propionate medium using samples from the BNR system, whereas there were no significant differences in samples from the conventional activated sludge plant. The possibility of the application of these data in process control and modeling is proposed. / Ph. D.

Master of Science

No description available.

This study was undertaken in order to determine whether the extracts of common garden vegetables could be incorporated into simple, economical culture media which might be used for the growth and cultivation of at least some of the more commonly used microorganisms.

O presente estudo teve por objetivos estudar a ocorrência de Salmonella spp em amostras de carcaças e miúdos de frango obtidas em uma feira e um mercado municipal da zona oeste da cidade de São Paulo e fazer uma análise crítica entre a técnica convencional em meios de cultivo e reação em cadeia pela polimerase PCR. Foram utilizadas 63 carcaças de frangos e 63 conjuntos de miúdos, obtidos no período de novembro de 2006 a maio de 2007. Pesquisou-se salmonela nas amostras pela técnica convencional em meios de cultivo e pela PCR. Pela técnica convencional identificou-se Salmonella em (6/63) das amostras de carcaça e (5/63) das amostras de miúdos e, pela PCR obteve-se (20/63) das amostras de miúdos e (28/63) das amostras de carcaça. As estirpes sorotipificadas como Salmonella oriundas das amostras de carcaças foram identificadas, como S. Senftenberg; S. Kentucky; S. Enteritidis; S. Montevideo; S. Infantis, S. enterica subsp enterica (0: 6.7). S. Enteritidis; S. enterica subsp enterica; S. Infantis. As estirpes provenientes das amostras de miúdos foram identificadas como S. Enteritidis; S. enterica subsp enterica; S. Infantis. As (18/21) estirpes identificadas como Salmonella pelo estudo apresentaram resistência aos antimicrobianos testados. O método convencional é indispensável quando se necessita a obtenção da estirpe para estudos de outras naturezas, para se cumprir a legislação brasileira que se vale de padrões microbiológicos estabelecidos pelos métodos convencionais. A técnica da PCR é válida e útil desde que seja padronizada de acordo com as necessidades e condições de cada laboratório; é bastante útil na implementação de sistema APPCC; no monitoramento de agentes específicos dentro de produções de alimentos; para estudos epidemiológicos da ocorrência, dinâmica de distribuição do agente. / The aim of this study was to evaluate the presence of Salmonella spp in whole broiler carcasses and multiple-organ samples collected at a commercial retail point in the western area of the city of São Paulo and to conduct a critical analysis of the traditional culture media growth technique and polymerase chain reaction PCR. A total of 63 whole broiler carcasses and a 63 multiple-organ samples were collected between November 2006 and May 2007. The conventional technique revealed the presence of Salmonella in 6/63 whole carcasses and in 5/63 multiple-organ samples, PCR detected Salmonella in 28/63 whole carcasses and in 20/63 multiple-organ samples The following strains were identified in the whole carcasses S. Senftenberg; S. Kentucky; S. Enteritidis; S. Montevideo; S. Infantis, S. enterica subsp enterica (0: 6.7). S. Enteritidis; S. enterica subsp enterica; S. Infantis were identified in multiple organ samples. The (18/21) Salmonella strains identified in this study were resistant to the antimicrobial agents tested in this study. In conclusion, the traditional method is essential for the collection of strains for different study purposes; for the observance of the Brazilian legislation, which is based on microbiological standards that were established using traditional methods. Polymerase chain reacton is a valid and useful technique, as long as it is standardized according to the needs and conditions of each laboratory. Polymerase chain reacton is remarkably useful in the implementation of the APPCC system; in the monitorization of specific agents within the food production chain; and for epidemiological studies that evaluate the occurrence, dynamic and distribution of a specific agent.