Yeung Heung-fun. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1987. / Includes bibliographical references.

by Yip Chi Wai. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1992. / Includes bibliographical references (leaves 70-87). / ABSTRACT --- p.i / ACKNOWLEDGEMENT --- p.iv / TABLE OF CONTENTS --- p.v / LIST OF TABLES --- p.ix / LIST OF FIGURES --- p.xiii / INTRODUCTION --- p.1 / LITERATURE REVIEW --- p.3 / Chapter I. --- Mycobacterial Infections --- p.3 / Chapter A. --- Mycobacterium tuberculosis --- p.3 / Chapter B. --- Atypical mycobacteria --- p.3 / Chapter II. --- Identification of Mycobacteria --- p.5 / Chapter A. --- Conventional methods --- p.6 / Chapter 1. --- Mycobacterium tuberculosis --- p.6 / Chapter 2. --- Atypical mycobacteria --- p.7 / Chapter B. --- Rapid identification methods --- p.8 / Chapter 1. --- Identification by fatty acid analysis --- p.8 / Chapter 2. --- Identification by mycolic acid analysis --- p.9 / Chapter III. --- In vitro Susceptibility Testing of Mycobacteria --- p.11 / Chapter A. --- Mycobacterium tuberculosis --- p.11 / Chapter 1. --- Principle --- p.12 / Chapter 2. --- Methods of susceptibility testing --- p.13 / Chapter a. --- The absolute concentration method --- p.13 / Chapter b. --- The resistance ratio method --- p.15 / Chapter c. --- The 1% proportion method --- p.16 / Chapter d. --- Radiometric method --- p.18 / Chapter e. --- Other methods --- p.19 / Chapter B. --- Atypical mycobacteria --- p.20 / Chapter IV. --- Plasmid Analysis in Mycobacteria --- p.22 / Chapter A. --- Discovery of plasmids in mycobacteria --- p.22 / Chapter B. --- Methodologies in the studies of mycobacterial plasmids --- p.23 / Chapter C. --- Possible roles of plasmid in epidemiology of mycobacteria --- p.24 / MATERIALS AND METHODS --- p.26 / Chapter I. --- Bacterial Strains and Strain Maintenance --- p.26 / Chapter A. --- Strains collection --- p.26 / Chapter B. --- Strains maintenance --- p.26 / Chapter II. --- Culture Media and Culture Conditions --- p.26 / Chapter III. --- Identification of Mycobacteria --- p.26 / Chapter A. --- Conventional methods --- p.26 / Chapter B. --- Fatty acid profile analysis --- p.27 / Chapter 1. --- Bacterial isolates --- p.27 / Chapter 2. --- Standards and reagents --- p.27 / Chapter 3. --- Preparation of methyl ester for GC/GC-MS --- p.28 / Chapter 4. --- Instrumentation --- p.28 / Chapter a. --- Gas chromatography-mass spectrometry (GC-MS) --- p.28 / Chapter b. --- Gas liquid chromatography (GLC) --- p.28 / Chapter 5. --- Fatty acid profile analysis --- p.29 / Chapter a. --- Calibration --- p.30 / Chapter b. --- Identification of mycobacterial fatty acids --- p.30 / Chapter c. --- Construction of mycobacterial fatty acid profiles --- p.30 / Chapter 6. --- Discriminant analysis --- p.31 / Chapter IV. --- In Vitro Drug Susceptibility Test --- p.31 / Chapter A. --- Test strains --- p.31 / Chapter B. --- Preparation of drug-containing media --- p.32 / Chapter C. --- Minmum inhibition concentration (MIC) determination --- p.32 / Chapter V. --- Heavy Metal Tolerance Test --- p.33 / Chapter A. --- Bacterial strains --- p.33 / Chapter B. --- Reagent and media preparation --- p.34 / Chapter 1. --- Heavy metal stock solution preparation --- p.34 / Chapter 2. --- Media preparation --- p.34 / Chapter C. --- Minimum inhibition concentration (MIC) determination --- p.34 / Chapter VI. --- Plasmid Analysis of Mycobacteria --- p.35 / Chapter A. --- Bacterial strains --- p.35 / Chapter B. --- Extraction procedures --- p.35 / Chapter 1. --- Modified Kado & Liu method --- p.35 / Chapter 2. --- French press procedure --- p.36 / Chapter 3. --- Spheroplasts preparation procedure --- p.37 / Chapter C. --- Electrophoresis procedure --- p.37 / Chapter D. --- Statistical analysis for correlation between plasmid and drug resistance or heavy metal tolerance --- p.38 / RESULTS --- p.39 / Chapter I. --- Identification of Mycobacteria --- p.39 / Chapter A. --- General characteristics of the chromatographic profile --- p.39 / Chapter B. --- Discriminant analysis --- p.40 / Chapter 1. --- Gas chromatography-mass spectrometry (GC-MS) --- p.40 / Chapter a. --- Slowly growing non-pigmented mycobacteria --- p.40 / Chapter b. --- Rapidly growing mycobacter-ia --- p.41 / Chapter c. --- Pigmented mycobacteria --- p.41 / Chapter 2. --- Gas liquid chromatography (GLC) --- p.41 / Chapter a. --- Slowly growing non-pigmented mycobacteria --- p.42 / Chapter b. --- Rapidly growing mycobacteria --- p.42 / Chapter c. --- Pigmented mycobacteria --- p.43 / Chapter II. --- Vitro Drug Susceptibility Test --- p.43 / Chapter A. --- Mycobacterium tuberculosis --- p.43 / Chapter B. --- Atypical mycobacteria --- p.45 / Chapter 1. --- General characteristics --- p.45 / Chapter 2. --- Sensitivity pattern of different species --- p.46 / Chapter a. --- Mycobacterium kansasii --- p.46 / Chapter b. --- Mycobacterium avium- intracellulare complex --- p.46 / Chapter c. --- Mycobacterium scrofulaceum --- p.47 / Chapter d. --- Mycobacterium terrae complex --- p.47 / Chapter e. --- Mycobacterium fortuitum --- p.47 / Chapter f. --- Mycobacterium chelonae --- p.48 / Chapter III. --- Heavy Metal Tolerance Test --- p.48 / Chapter IV. --- Plasmid in Mycobacteria --- p.48 / Chapter A. --- Mycobacterium tuberculosis --- p.48 / Chapter B. --- Atypical mycobacteria --- p.49 / Chapter 1. --- General characteristics --- p.49 / Chapter 2. --- Correlation between drug resistance and plasmid --- p.50 / Chapter 3. --- Correlation between heavy metal tolerance and plasmid --- p.50 / DISCUSSION --- p.52 / Chapter I. --- Identification of Mycobacteria --- p.52 / Chapter II. --- In Vitro Drug Susceptibility Test --- p.56 / Chapter A. --- Mycobacterium tuberculosis --- p.56 / Chapter B. --- Atypical mycobacteria --- p.60 / Chapter 1. --- Mycobacterium kansasii --- p.61 / Chapter 2. --- Mycobacterium avium- intracellulare complex --- p.61 / Chapter 3. --- Mycobacterium scrofulaceum --- p.62 / Chapter 4. --- Mycobacterium terrae complex --- p.62 / Chapter 5. --- Mycobacterium fortuitum --- p.63 / Chapter 6. --- Mycobacterium chelonae --- p.64 / Chapter III. --- Plasmid Analysis in Mycobacteria --- p.64 / Chapter A. --- Mycobacterium tuberculosis --- p.64 / Chapter B. --- Atypical mycobacteria --- p.66 / SUMMARYS AND CONCLUSIONS --- p.68 / LITERATURE CITED --- p.70 / Chapter APPENDIX - --- Tables --- p.88 / Figures --- p.144

Today three species are recognized in the genus: C. freundii, C. amalonaticus, and C, diversus. C. freundii is known to occur as three varieties: C. freundii H2S +, IND -, C. freundii H2S +, IND +, and C. freundii H2S -, IND -. The role of Citrobacter in disease has not been investigated thoroughly. The organism is a normal inhabitant of the human intestine, being as common as Escherichia coli in infants. With age, the child's intestine begins to show a greater ratio of E. coli to Citrobacter (Nahhas, personal communication). Citrobacter has been reported as a cause of urinary and respiratory tract infections, especially in children. Hodges et at (1978), however, believe that in most cases, Citrobacter is found in a commensalistic relationship with the organism(s) causing the infection. Most patients from whom Citrobacter was cultured and underlying diseases or factors predisposing them to infection. outbreaks of neonatal meningitis in hospital maternity wards and nurseries have been attributed to contamination of nurses' hands and equipment by C. diversus (Anderson et al, 1981; Enzenauer et al, 1982). Osteomyelitis, neonatal diarrhea, neonatal septicemia, and brain abscesses caused by Citrobacter have also been reported (Barton and Walentik, 1982). In January 1983, I began a study of this group with two objectives in mind: to study the biochemical and antibiogram characteristics of Citrobacter isolates from Stockton, California, and, if possible, to expand and update information on the biology of the genus.

The objective of the work reported in this paper is one of a two-fold nature. The first objective is to develop a disk-plate sensitivity test that is more rapid than that of existing methods. The second requisite is that the materials, techniques, interpretation, and reporting of results be the sane as those required for the disk-plate method described in the Difco Manual.

Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / FundaÃÃo de Amparo a CiÃncia e Tecnologia / Coccidioidomicose à uma micose sistÃmica que acomete o homem e outros animais domÃsticos e silvestres, causada pelo fungo dimÃrfico geofÃlico Coccidioides posadasii. Nos Ãltimos anos, a melhoria dos mÃtodos de diagnÃstico micolÃgico e o aumento da ocorrÃncia de doenÃas imunossupressoras causaram grande impacto na incidÃncia das micoses profundas e oportunistas no mundo. Apesar da existÃncia de terapias antifÃngicas eficazes contra a coccidioidomicose, a busca por novas drogas para o tratamento desta doenÃa se faz necessÃria. O objetivo desse estudo foi determinar o efeito inibitÃrio, in vitro, e o mecanismo de aÃÃo dos anÃlogos quÃmicos da isoniazida, isolados e em combinaÃÃo com os antifÃngicos anfotericina B (AMB) e itraconazol (ITC), frente a cepas de Coccidioides posadasii (n=12). Para isso 12 cepas de C.posadasii, foram repicadas em Ãgar dextrose batata e utilizadas na realizaÃÃo dos testes de sensibilidade frente ao agente antituberculose isoniazida (INH) e seus anÃlogos quÃmicos. Os ensaios foram conduzidos por meio do teste de macrodiluiÃÃo em caldo ou definiÃÃo da concentraÃÃo inibitÃria mÃnima (CIM) e o sinergismo foi avaliado pelo mÃtodo do tabuleiro. Os anÃlogos quÃmicos inibiram o crescimento de todas as cepas de C. posadasii testadas isoladamente, com valores de CIM para cada composto que variaram de 100 a 400 Âg/mL, para os anÃlogos P3-[Nâ-(1- (4-methoxifeniletilideno) isonicotinohidrazida] P5- [Nâ- (1-m-tolileilidene) isonicotinohidrazida] e P6- [Nâ-(1-(4-metilfenil) etilideno) isonicotinohidrazida], de 25 a 100 Âg/mL para a PACT- Nâ- (1-feniletilideno) isonicotinohidrazida e de 0,0625 a 0,125 Âg/mL para AMB e 0,125 a 0,5 Âg/mL para ITC. Quanto a combinaÃÃo entre as drogas antifÃngicas e os anÃlogos quÃmicos da droga isoniazida, todos foram capazes de inibir o crescimento in vitro das cepas de C. posadasii. Sinergismo foi detectado em 8 combinaÃÃes nÃo sendo observado nenhum antagonismo em nenhuma delas. Os anÃlogos da isoniazida apresentaram valores de CIM de 2, 4, 8, 16, 32 vezes superior à atividade da droga antituberculose padrÃo. A extraÃÃo dos esterÃis e a permeabilidade da membrana fÃngica foram averiguadas, respectivamente, por saponificaÃÃo com aquecimento e por meio da leitura do sobrenadante da suspensÃo fÃngica em comprimento de onda de 260 e 280 nm. Todos os compostos inibiram o crescimento in vitro das cepas de C. posadasii. Foi observado que os anÃlogos da isoniazida isolados e em combinaÃÃo com antifÃngicos foram capazes de causar reduÃÃo do teor de ergosterol celular; apenas os anÃlogos P3 e P6 foram capazes de alterar a permeabilidade da membrana plasmÃtica nas condiÃÃes testadas. Em conclusÃo, os resultados mostram que os anÃlogos derivados da isoniazida possuem atividade inibitÃria frente a C. posadasii

Orientadores: Marta Cristina Teixeira Duarte, Pedro Luiz Rosalen / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-20T12:06:00Z (GMT). No. of bitstreams: 1 Bersan_SaleteMeiryFernandes_M.pdf: 6812876 bytes, checksum: a263025bff707f77c87f25c8c1f590e9 (MD5) Previous issue date: 2012 / Resumo: A cavidade oral é habitada por uma microbiota mista que, sob determinadas circunstâncias, pode superar as defesas do hospedeiro e agir como oportunista, produzindo diversas manifestações clínicas. Observa-se na literatura um interesse por produtos de origem natural como fonte de novas moléculas bioativas para o controle de afecções orais, entre estes produtos destacam-se os óleos essenciais e seus produtos secundários devido às suas propriedades antimicrobianas. A necessidade de gerar e agregar novas informações acerca da atividade antimicrobiana in vitro de óleos essenciais, impulsionou a realização deste trabalho, envolvendo vinte espécies do Banco de Germoplasmas da "Coleção de Plantas Medicinais e Aromáticas - CPMA" do CPQBA/UNICAMP. Nesse contexto, essa pesquisa teve por objetivo identificar a atividade antimicrobiana in vitro de óleos essenciais e frações de diferentes espécies de plantas medicinais e aromáticas contra os patógenos orais Candida albicans, Fusobacterium nucleatum, Porphyromonas gingivalis, Streptococcus sanguis e Streptococcus mitis, organizados nas formas livre e em biofilme. A atividade antimicrobiana dos óleos e frações foi avaliada através da determinação da Concentração Inibitória Mínima (CIM) e Concentração Bactericida e Fungicida Mínima (CBM/CFM), pelo método da microdiluição. Foram identificadas as classes de substâncias químicas presentes nos óleos essenciais e frações de melhor atividade por CG-EM. Além disso, os óleos essenciais e frações selecionadas foram submetidos à avaliação quanto à possível alteração morfológica causada no biofilme, através de análise por microscopias eletrônica de varredura (MEV). A maioria dos óleos essenciais apresentou atividade antimicrobiana moderada a forte sobre os microrganismos orais, com valores de CIM entre 0,007 a 1,00 mg/mL. Melhores atividades sobre células planctônicas foram exibidas pelas espécies Aloysia gratissima, Coriandrum sativum, Cyperus articulatus, Lippia sidoides e Mikania glomerata, cujos óleos foram fracionados e submetidos a estudos de ação sobre a formação de biofilme pelos microrganismos. Coriandrum sativum se destacou por apresentar os mais baixos valores de CIM em relação às células planctônicas de 0,007 a 0,125. As inibições de aderência variaram de 1.00 % para óleo de Mikania glomerata sobre S. mitis a 63,96 % para o óleo bruto de C. articulatus sobre S. sanguis. Através da análise das imagens obtidas por MEV não foi possível observar alterações na morfologia celular dos microrganismos orais. Porém, houve redução e alterações na organização da estrutura dos biofilmes. A análise da composição química do C. sativum mostrou a presença de compostos majoritários derivados de álcoois e aldeídos, enquanto C. articulatus e A. gratissima apresentaram compostos mono e sesquiterpenos. Em conclusão, o óleo essencial de C. articulatus mostrou o maior percentual de inibição sobre os microrganismos estudados, enquanto o óleo de A. gratissima inibiu a aderência do biofilme de S. mitis / Abstract: The oral cavity is inhabited by a mixed microbial flora which, under determined circumstances, can overcome the host's defenses producing some of clinical pathological manifestations. Considerable interest has been found in the literature concerning natural products as sources new bioactive molecules for oral diseases control and the essential oils and their secondary products stand out with these products due to their antimicrobial properties. In order to produce and aggregate new information relating to in vitro antimicrobial activity of essential oils, this work was designed involving twenty species from the Germplasm Bank of the "Medicinal and Aromatic Plant Collection - CPMA" of CPQBA/UNICAMP, Brazil. Thus the objective of the present research was to identify the in vitro antimicrobial activity of essential oils and fractions of the different species of medicinal and aromatic plants against the oral pathogens Candida albicans, Fusobacterium nucleatum, Porphyromonas gingivalis, Streptococcus sanguis and Streptococcus mitis, organized in the free form and in biofilms. The antimicrobial activity of the oils and fractions was evaluated by determining the Minimum Inhibitory Concentration (MIC) and the Minimum Bactericidal and Fungicidal Concentrations (MBC/MFC) using the micro-dilution method. The classes of bioactive chemical substances present in the essential oils and fractions showing the best activity were identified by GC-MS. In addition the selected essential oils and fractions were submitted to an evaluation to detect any possible morphological alterations caused in the biofilm by way of scanning electronic microscopy (SEM). The majority of the essential oils showed moderate to strong antimicrobial activity against the oral microorganisms, with MIC values between 0.007 and 1.00 mg/mL. Better activities against planktonic cells were shown by the species Aloysia gratissima, Coriandrum sativum, Cyperus articulatus, Lippia sidoides and Mikania glomerata, whose oils were fractionated and submitted to studies of their action against biofilms formation by microorganisms. The essential oil of C. sativum stood out, since it inhibited all investigated species with MIC lowest values, varieting from 0.007 to 0.250 mg/mL, and for MBC from 0.015 to 0.500 mg/mL. The inhibition of biofilm formation varied from 1.00% for Mikania glomerata oil against S. mitis to 63.96% for the crude C. articulatus oil against S. sanguis. No alterations in cell morphology of the oral microorganisms could be observed from an analysis of the SEM images, but there were reductions and alterations in the organization of the biofilm structure. An analysis of the chemical composition of C. sativum showed the presence of alcohol and aldehyde derivatives as major compounds, whereas C. articulatus and A. gratissima showed mono and sesquiterpenes. In conclusion, the essential oil of C. articulatus showed the best results percentage inhibition on the microorganisms under study, whereas the A. gratissima oil inhibited of the S. mitis biofilm formation / Mestrado / Farmacologia, Anestesiologia e Terapeutica / Mestre em Odontologia

Orientador: Brenda Paula Figueiredo de Almeida Gomes / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-04T03:02:34Z (GMT). No. of bitstreams: 1 Pinheiro_ErickaTavares_D.pdf: 6781535 bytes, checksum: 922a6f6d42935816319b3755f08328b6 (MD5) Previous issue date: 2005 / Resumo: O presente estudo teve por objetivos: identificar a microbiota de canais radiculares de dentes com insucesso do tratamento endodôntico, e testar, in vitro, a suscetibilidade de cepas de Enterococcus faecalis a diferentes antibióticos. Sessenta dentes tratados endodonticamente com lesões periapicais persistentes foram selecionados para esse estudo. Durante o retratamento endodôntico, o material obturador foi removido e foi realizada a coleta microbiológica dos canais radiculares. Foram utilizados meios de transporte, cultura e incubação que propiciam o crescimento de bactérias anaeróbias estritas. Vinte e uma cepas de Enterococcus faecalis foram testadas quanto à suscetibilidade aos seguintes antimicrobianos: benzilpenicilina, amoxicilina, amoxicilina + ácido clavulânico, clindamicina, eritromicina, azitromicina, vancomicina, cloranfenicol, tetraciclina, doxiciclina, ciprofloxacino e moxifloxacino. As concentrações inibitórias mínimas (CIMs) dos agentes antimicrobianos foram determinadas pelo método do E-test. As cepas também foram testadas quanto à produção de beta-lactamase utilizando nitrocefin. Microrganismos foram isolados em 51 casos. A maioria dos canais apresentava somente 1 ou 2 espécies bacterianas. Do total de espécies bacterianas isoladas, 57,4% eram bactérias anaeróbias facultativas e 83,3% Gram-positivas. Enterococcus faecalis foi a espécie bacteriana mais freqüentemente isolada. Bactérias anaeróbias estritas representavam 42,6% das espécies e, entre eles, Peptostreptococcus spp. foram os mais isolados. Associações significantes foram encontradas entre dor ou história de dor e infecções anaeróbias e polimicrobianas (p<0,05). Todas as cepas de Enterococcus faecalis foram sensíveis, in vitro, às penicilinas, entretanto as CIMs de amoxicilina e amoxicilina + ácido clavulânico (CIM90= 0,75 µg/ml) foram menores do que as de benzilpenicilina (CIM90= 3.0 µg/ml). Todas as cepas também foram sensíveis a vancomicina e moxifloxacino, enquanto 95,2% foram sensíveis a cloranfenicol. Entre os isolados, 85,7% foram sensíveis a tetraciclina e doxiciclina, e 80,9% a ciprofloxacino. As CIMs de eritromicina variaram de 0,38 a >256 µg/ml, com apenas 28,5% das cepas sensíveis (CIM =0.5 µg/ml). Suscetibilidade limitada também foi verificada com azitromicina, que foi ativa contra somente 14,2% dos isolados. Nenhuma cepa produziu beta-lactamase. Concluímos que a microbiota dos canais de dentes tratados endodonticamente é composta por um número limitado de espécies microbianas, predominantemente Gram-positivas. Anaeróbios facultativos, especialmente Enterococcus faecalis, são os microrganismos mais comumente isolados, entretanto, infecções polimicrobianas e anaeróbios estritos são freqüentemente encontrados em canais de dentes tratados endodonticamente com sintomatologia clínica. As cepas de Enterococcus faecalis foram sensíveis, in vitro, a amoxicilina, amoxicilina associada ao ácido clavulânico, vancomicina e moxifloxacino. A maioria dos isolados foi sensível aos antibióticos: cloranfenicol, tetraciclina, doxiciclina, ou ciprofloxacino. Eritromicina e azitromicina foram menos eficazes / Abstract: The objectives of the present study were to identify the microbial flora within root canals of teeth with failed root canal treatment, and to test, in vitro, the susceptibility of Enterococcus faecalis isolates. Sixty root-filled teeth with persisting periapical lesions were selected for this study. During nonsurgical endodontic re-treatment, the root-filling material was removed and the canals were sampled. Microbial sampling, isolation and species determination were performed using advanced microbiologic techniques for anaerobic species. Additionally, 21 Enterococcus faecalis isolates were tested for their antibiotic susceptibilities to benzylpenicillin, amoxicillin, amoxicillin-clavulanic acid, erythromycin, azithromycin, vancomycin, chloramphenicol, tetracycline, doxycycline, ciprofloxacin and moxifloxacin. Minimal inhibitory concentrations (MICs) for the antimicrobial agents were determined using the E-test System. The strains were also tested for ß-lactamase production with nitrocefin. Microorganisms were recovered from 51 teeth. In most cases, one or two strains per canal were found. Of the microbial species isolated, 57.4% were facultative anaerobic species and 83.3% Gram-positive microorganisms. Enterococcus faecalis was the bacterial species most frequently recovered. Obligate anaerobes accounted for 42.6% of the species and the most frequently isolated genera was Peptostreptococcus. Significant associations were observed between pain or history of pain and polymicrobial infections or anaerobes (p<0.05). All Enterococcus faecalis strains were susceptible to penicillins in vitro, however, the MICs of amoxicillin and amoxicillinclavulanic acid (MIC90= 0.75 µg/ml) were lower than for benzylpenicillin (MIC90= 3.0 µg/ml). All strains studied were also susceptible to vancomycin and moxifloxacin, while 95.2% were susceptible to chloramphenicol. Among the isolates, 85.7% were susceptible to tetracycline and doxycycline, and 80.9% to ciprofloxacin. The MIC of erythromycin ranged from 0.38 to >256 µg/ml; only 28.5% of the strains were susceptible (MIC =0.5 µg/ml). Limited susceptibility was also observed with azithromycin which was active against only 14.2% of isolates. No strains produced ß-lactamase. Therefore, it was concluded that the microbial flora in canals after failure of root canal treatment were limited to a small number of predominantly Gram-positive microbial species. Facultative anaerobes, especially Enterococcus faecalis, were the most commonly isolated microorganisms, however, polymicrobial infections and obligate anaerobes were frequently found in canals of symptomatic root-filled teeth. Enterococcus faecalis isolates were completely susceptible, in vitro, to amoxicillin, amoxicillin-clavulanic acid, vancomycin, and moxifloxacin. Most isolates were susceptible to chloramphenicol, tetracycline, doxycycline, or ciprofloxacin. Erythromycin and azithromycin were least effective / Doutorado / Endodontia / Doutor em Clínica Odontológica

A follow-up of traditional medicinal plants uses is an important tool in highlighting their therapeutic potentials, as they have been found to be a source of a wide range of bioactive compounds that can be used as base compounds for new pharmaceutical drugs. This study therefore focuses on assessing the anti-Listerial properties of the seeds of Garcinia kola (Heckel) plant, which is a traditional medicinal plant of west and central African origin, and was and is still used to traditionally treat several ailments. Four different solvents crude extracts of the seeds were assessed for their anti-Listerial activities in-vitro, against a panel of 42 Listeria bacteria, which included Listeria monocytogenes, Listeria ivanovii and Listeria grayi species. At 10 mg/ml concentration the aqueous extract had activity against 29% of the test isolates while the other three crude extracts namely dichloromethane, n-hexane and the methanol extracts had activity against 45% of the test bacteria. The minimum inhibitory concentration (MIC) ranges of the extracts were 0.079-0.313 mg/ml for the dichloromethane extract; 0.079-0.625 mg/ml for the n-hexane extract; 0.157-0.625 mg/ml for the methanol extract; and 10->10 mg/ml for the aqueous extract. The minimum bactericidal concentration (MBC) ranges of the extracts were 0.625–10 mg/ml for both the n-hexane and the dichloromethane extract; 5-10 mg/ml for the methanol extract; and those for the aqueous extract were above 10 mg/ml against all the susceptible Listeria isolates. The rate of kill analysis was then determined for the three most active crude extracts that is excluding the aqueous extract and it was assessed against four representative Listeria species namely L. monocytogenes (LAL 8), L. grayi (LAL 15), L. ivanovii (LEL 30) and L. ivanovii (LEL 18). All the three extracts showed a general trend of being concentration and time dependent in their rate of kill profiles such that most bacteria cells were killed at the highest test concentration of 4× MIC value after the maximum exposure time of 2 h. The n-hexane, dichloromethane and methanol extracts were bactericidal against 4, 3 and 1 isolates out of the four test Listeria isolates respectively.

The n-Hexane, dichloromethane, methanol and aqueous crude extracts of Garcinia kola (Heckel) seeds were screened for their anti-Vibrio activities against 50 Vibrio bacteria isolated from wastewater final effluents. The 50 isolates consisted of different Vibrio species namely V. fluvialis (14), V. vulnificus (12), V. parahaemolyticus (12), V. metschnikovii (3) and 9 others unidentified to the specie level. The n-Hexane, dichloromethane and methanol extracts had activities against 16 (32 percent) of the Vibrio isolates, while the aqueous extracts had activities against 12 (24 percent) all at a screening concentration of 10 mg/ml. The minimum inhibitory concentrations (MICs) were 0.313-0.625 mg/ml, 0.313-0.625 mg/ml, 0.313-2.5 mg/ml and 10 mg/ml for n-Hexane, dichloromethane, methanol and aqueous extracts respectively. Rate of kill studies were carried out against three different Vibrio species namely V. vulnificus (AL042), V. parahaemolyticus (AL049) and V. fluvialis ( AL040) using the n-Hexane, dichloromethane and methanol extracts at 1× to 4 × MICs and 2 hour exposure. About 96.3 percent, 82.2 percent, and 78.1 percent (V. fluvialis AL040); 92.6 percent, 87.8 percent and 68.9 percent (V. parahaemolyticus AL049); and 91.6 percent, 64.4 percent, 60 percent (V. vulnificus AL042) of the bacteria were killed by the crude n-Hexane, dichloromethane and methanol extracts respectively after 2 hour exposure time at 4× MIC. The patterns of activity were bacteriostatic, with the n-Hexane extracts being most effective in activity. We conclude that the Garcinia kola seeds have promise in the treatment and management of infections caused by Vibrio species.

El objetivo principal del estudio fue establecer el nivel de resistencia a antimicrobianos en un total de 222 cepas comensales de E. coli de origen fecal, en Perú. Las frecuencias de resistencia encontrados, frente los antimicrobianos evaluados, fueron: ampicilina (62,6%), cotrimoxazol (48,6%), tetraciclina (43,0%) y cloranfenicol (15,8%). Destacan los elevados niveles de resistencia a quinolonas: 32% al ácido nalidíxico (NAL) y 12% a ciprofloxacino (CIP). Estos elevados niveles hacia las quinolonas en cepas comensales aisladas en niños de esta franja de edad, realzan el uso extendido y el impacto de consumo de este tipo de antimicrobianos en la comunidad, mostrando el riesgo potencial de su pérdida de utilidad en el área. / The main aim of this study was to establish the resistance levels to antimicrobial agents, in 222 non-pathogenic E. Coli strains of fecal origin in Peru. The proportion of resistance found to the evaluated antimicrobials was ampicillin (62.6%), cotrimoxazole (48,6%), tetracycline (43,0%) and chloramphenicol (15,8%). We emphasize the high resistance levels found for quinolones: 32% for nalidixic acid (NAL) and 12% for ciprofloxacin (CIP). These high levels of quinoloneresistance in non-pathogenic strains isolated from children in this age group highlight the extensive use and the impact of the intake of this kind of antimicrobials in the community, showing the potential risk of the loss of their utility in the area.