Escherichia coli and Klebsiella pneumoniae isolates were obtained from the Canadian Ward Surveillance Study (CANWARD) and underwent in vitro susceptibility testing to determine prevalence and antimicrobial resistance patterns. The prevalence was found to be relatively stable over the years although there was an increase in prevalence among the K. pneumoniae isolates; 1.1% to 1.3% to 2.5% to 2.6% in 2007, 2008, 2009, and 2010, respectively. Genotypic characterization was conducted on ESBL, AmpC, carbapenemase genes, and outer membrane porins. The highest proportion of isolates were found to produce CTX-M-15 β-lactamase. Only 1 of each KPC-producing E. coli and K. pneumoniae was found. Porin alteration was found to be a factor leading to carbapenem reduced susceptibility among isolates. Genetic relatedness of CRS/CIR E. coli and K. pneumoniae was determined using pulsed-field gel electrophoresis. The spread of these organisms was mainly due to polyclonal spread rather than one specific clone.

Escherichia coli and Klebsiella pneumoniae isolates were obtained from the Canadian Ward Surveillance Study (CANWARD) and underwent in vitro susceptibility testing to determine prevalence and antimicrobial resistance patterns. The prevalence was found to be relatively stable over the years although there was an increase in prevalence among the K. pneumoniae isolates; 1.1% to 1.3% to 2.5% to 2.6% in 2007, 2008, 2009, and 2010, respectively. Genotypic characterization was conducted on ESBL, AmpC, carbapenemase genes, and outer membrane porins. The highest proportion of isolates were found to produce CTX-M-15 β-lactamase. Only 1 of each KPC-producing E. coli and K. pneumoniae was found. Porin alteration was found to be a factor leading to carbapenem reduced susceptibility among isolates. Genetic relatedness of CRS/CIR E. coli and K. pneumoniae was determined using pulsed-field gel electrophoresis. The spread of these organisms was mainly due to polyclonal spread rather than one specific clone.

A.baumannii é um importante patógeno em infecções nosocomiais principalmente por sua capacidade de se tornar resistente aos antimicrobianos. Surtos de A.baumannii resistente aos carbapenêmicos (ABRC) têm sido descritos em todo mundo. Devido à emergência de resistência aos antimicrobianos e ausência de novas opções de tratamento, as polimixinas reemergiram como opção de terapia contra infecções causadas por A.baumannii. O uso de polimixina é associado a maior mortalidade e menor eficácia comparada a outros antimicrobianos. Alguns estudos in vitro têm avaliado a combinação de polimixina com outros antimicrobianos a fim de aumentar a eficácia dos tratamentos. O objetivo deste estudo foi avaliar o sinergismo entre a polimixina B com outros antimicrobianos em isolados de ABRC, pelo método de Curvas Tempo-Morte bacteriana (Time- Kill Curves). Os isolados foram provenientes de banco de amostras e foram avaliadas as combinações de polimixina B com carbapenêmicos (imipenem e meropenem), tigeciclina, rifampicina, amicacina e ceftazidima. As combinações foram testadas nos tempo 0, 30’, 1,4,12 e 24 h. Sinergismo entre polimixina B foi demonstrado contra todos antimicrobianos para ambos isolados, exceto para ceftazidima e imipenem no isolado 1. Nosso estudo mostrou que tigeciclina, amicacina e rifampicina são agentes mais ativos combinados com polimixina B, sendo assim estes agentes podem apresentar efeito benéfico em combinação com a polimixina no tratamento de ABRC. / A.baumannii is an important pathogen in nosocomial infections primarily for its ability to become resistant to antimicrobials. Outbreaks carbapenem- resistant A.baumannii (CRAB) has been described worldwide. Due to the emergence of antimicrobial resistance and the absence of new treatment options, the polymyxins reemerged as an option therapy against infections caused by A.baumannii. The use of polymyxin is associated with higher mortality and lower effectiveness compared to other antimicrobials. In vitro studies have evaluated the combination of polymyxin with other antimicrobial agents to enhance the effectiveness of the treatments. This study was to evaluate the synergy between polymyxin B with other antimicrobials in isolates from ABRC, by Time-Kill Curves. The isolates were from stool samples and were evaluated combinations of polymyxin B with carbapenems (imipenem and meropenem), tigecycline, rifampin, amikacin and ceftazidime. The combinations were tested at time 0, 30 ', 1,4,12 and 24 h. Synergism between polymyxin B was demonstrated against all antimicrobials for both isolates, except for ceftazidime and imipenem in isolated 2. Our study showed that tigecycline, amikacin and rifampicin more active agents are combined with polymyxin B, and thus these agents may have a beneficial effect in combination with a polymyxin in treating CRAB.

Orientador: Carlos Magno Castelo Branco Fortaleza / Resumo: Atualmente, estamos diante de uma notável presença de isolados de enterobactérias resistentes aos carbapenêmicos em um hospital público do município de Bauru-SP desde outubro de 2012. No entanto, não estão disponíveis estudos relacionando a epidemiologia e os fatores associados à aquisição de tais isolados. Este estudo teve como objetivo identificar fatores de risco para aquisição de Enterobactérias Resistentes aos Carbapenêmicos (CRE) em pacientes internados no Hospital Estadual Bauru, os fatores associados ao desenvolvimento de quadro infeccioso em uma coorte de pacientes colonizados por CRE e os fatores preditores de óbito. Foram incluídos pacientes do local de estudo que apresentaram colonização do trato digestório por CRE, de outubro de 2012 a dezembro de 2016, dos quais foram levantados dados clínicos e demográficos. Os isolados foram identificados por métodos fenotípicos e foram testadas as suscetibilidades por concentração inibitória mínima (MIC). Realizamos um estudo de caso-controle que incluiu 427 casos e igual número de controles. Os fatores de risco observados foram queimadura (HR 3,91; IC95% 2,36-6,46; p=<0,001), índice de Charlson (HR 1,12; IC95% 1,05-1,20; p=<0,001), uso prévio de esteróides (HR 2,79; IC95% 1,94-4,02; p=<0,001) e antimicrobianos como as penicilinas/inibidores de beta-lactamases (HR 2,01; IC95% 1,43-2,82; p=<0,001), cefalosporinas de 3ª. e 4ª. gerações (HR 2,45; IC95% 1,75-3,44; p=<0,001), quinolonas (HR 1,70; IC95% 1,75-2,45; p=0,003) e anaero... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Currently, we are facing a remarkable presence of isolates of carbapenem-resistant enterobacteriacea in Bauru city public hospital, São Paulo state, Brazil, since october 2012. However no studies are available relating the epidemiology and the factors associated with acquisition of such isolates. The purpose this study was to identify risk factors for acquisition of Carbapenem Resistant Enterobacteriaceae in patients hospitalized at the Bauru State Hospital, factors associated with the development of infectious disease in a cohort of patients colonized by CLP and factors predicting death. We included patients from the study site who presented colonization of the digestive tract by CRE, from October 2012 to December 2016, from which clinical and demographic data were collected. Isolates were identified by phenotypic methods and susceptibilities were tested by minimum inhibitory concentration (MIC). We performed a case-control study that included 427 cases and an equal number of controls. The risk factors observed were burn (HR 3.91, 95% CI 2.36-6.46, p = 0.001), Charlson index (HR 1.12, 95% CI 1.05-1.20, p = <0.001), previous use of steroids (HR 2.79, 95% CI 1.94-4.02, p = <0.001) and antimicrobials such as penicillins / beta-lactamase inhibitors (HR 2.01, 95% CI, 43-2.82, p = <0.001), cephalosporins of 3rd. and 4ª. (HR 2.45, IC 95% 1.75-3.44, p = 0.001), quinolones (HR 1.70, IC 95% 1.75-2.45, p = 0.003) and anaerobicides (HR 1, 63, 95% CI 1.04-2.56, p = 0.03). The cohort stud... (Complete abstract click electronic access below) / Doutor

A.baumannii é um importante patógeno em infecções nosocomiais principalmente por sua capacidade de se tornar resistente aos antimicrobianos. Surtos de A.baumannii resistente aos carbapenêmicos (ABRC) têm sido descritos em todo mundo. Devido à emergência de resistência aos antimicrobianos e ausência de novas opções de tratamento, as polimixinas reemergiram como opção de terapia contra infecções causadas por A.baumannii. O uso de polimixina é associado a maior mortalidade e menor eficácia comparada a outros antimicrobianos. Alguns estudos in vitro têm avaliado a combinação de polimixina com outros antimicrobianos a fim de aumentar a eficácia dos tratamentos. O objetivo deste estudo foi avaliar o sinergismo entre a polimixina B com outros antimicrobianos em isolados de ABRC, pelo método de Curvas Tempo-Morte bacteriana (Time- Kill Curves). Os isolados foram provenientes de banco de amostras e foram avaliadas as combinações de polimixina B com carbapenêmicos (imipenem e meropenem), tigeciclina, rifampicina, amicacina e ceftazidima. As combinações foram testadas nos tempo 0, 30’, 1,4,12 e 24 h. Sinergismo entre polimixina B foi demonstrado contra todos antimicrobianos para ambos isolados, exceto para ceftazidima e imipenem no isolado 1. Nosso estudo mostrou que tigeciclina, amicacina e rifampicina são agentes mais ativos combinados com polimixina B, sendo assim estes agentes podem apresentar efeito benéfico em combinação com a polimixina no tratamento de ABRC. / A.baumannii is an important pathogen in nosocomial infections primarily for its ability to become resistant to antimicrobials. Outbreaks carbapenem- resistant A.baumannii (CRAB) has been described worldwide. Due to the emergence of antimicrobial resistance and the absence of new treatment options, the polymyxins reemerged as an option therapy against infections caused by A.baumannii. The use of polymyxin is associated with higher mortality and lower effectiveness compared to other antimicrobials. In vitro studies have evaluated the combination of polymyxin with other antimicrobial agents to enhance the effectiveness of the treatments. This study was to evaluate the synergy between polymyxin B with other antimicrobials in isolates from ABRC, by Time-Kill Curves. The isolates were from stool samples and were evaluated combinations of polymyxin B with carbapenems (imipenem and meropenem), tigecycline, rifampin, amikacin and ceftazidime. The combinations were tested at time 0, 30 ', 1,4,12 and 24 h. Synergism between polymyxin B was demonstrated against all antimicrobials for both isolates, except for ceftazidime and imipenem in isolated 2. Our study showed that tigecycline, amikacin and rifampicin more active agents are combined with polymyxin B, and thus these agents may have a beneficial effect in combination with a polymyxin in treating CRAB.

A.baumannii é um importante patógeno em infecções nosocomiais principalmente por sua capacidade de se tornar resistente aos antimicrobianos. Surtos de A.baumannii resistente aos carbapenêmicos (ABRC) têm sido descritos em todo mundo. Devido à emergência de resistência aos antimicrobianos e ausência de novas opções de tratamento, as polimixinas reemergiram como opção de terapia contra infecções causadas por A.baumannii. O uso de polimixina é associado a maior mortalidade e menor eficácia comparada a outros antimicrobianos. Alguns estudos in vitro têm avaliado a combinação de polimixina com outros antimicrobianos a fim de aumentar a eficácia dos tratamentos. O objetivo deste estudo foi avaliar o sinergismo entre a polimixina B com outros antimicrobianos em isolados de ABRC, pelo método de Curvas Tempo-Morte bacteriana (Time- Kill Curves). Os isolados foram provenientes de banco de amostras e foram avaliadas as combinações de polimixina B com carbapenêmicos (imipenem e meropenem), tigeciclina, rifampicina, amicacina e ceftazidima. As combinações foram testadas nos tempo 0, 30’, 1,4,12 e 24 h. Sinergismo entre polimixina B foi demonstrado contra todos antimicrobianos para ambos isolados, exceto para ceftazidima e imipenem no isolado 1. Nosso estudo mostrou que tigeciclina, amicacina e rifampicina são agentes mais ativos combinados com polimixina B, sendo assim estes agentes podem apresentar efeito benéfico em combinação com a polimixina no tratamento de ABRC. / A.baumannii is an important pathogen in nosocomial infections primarily for its ability to become resistant to antimicrobials. Outbreaks carbapenem- resistant A.baumannii (CRAB) has been described worldwide. Due to the emergence of antimicrobial resistance and the absence of new treatment options, the polymyxins reemerged as an option therapy against infections caused by A.baumannii. The use of polymyxin is associated with higher mortality and lower effectiveness compared to other antimicrobials. In vitro studies have evaluated the combination of polymyxin with other antimicrobial agents to enhance the effectiveness of the treatments. This study was to evaluate the synergy between polymyxin B with other antimicrobials in isolates from ABRC, by Time-Kill Curves. The isolates were from stool samples and were evaluated combinations of polymyxin B with carbapenems (imipenem and meropenem), tigecycline, rifampin, amikacin and ceftazidime. The combinations were tested at time 0, 30 ', 1,4,12 and 24 h. Synergism between polymyxin B was demonstrated against all antimicrobials for both isolates, except for ceftazidime and imipenem in isolated 2. Our study showed that tigecycline, amikacin and rifampicin more active agents are combined with polymyxin B, and thus these agents may have a beneficial effect in combination with a polymyxin in treating CRAB.

As antibiotic resistant bacterial strains are becoming more prevalent in healthcare settings, it is necessary to find alternative methods of detecting and treating these infections. One of the antibiotic resistant strains of interest is the carbapenem-resistant Enterobacteriaceae (CRE). CREs have the ability to evade some of the most potent antibiotics currently in use and employ carbapenemases to negate the effect of antibiotics. The three most common carbapenemase genes, found in carbapenem-resistant Enterobacteriaceae along with a gene found only in Escherichia coli were chosen to create a qPCR assay for rapid detection of resistant infections. The carbapenemase genes are KPC, VIM and NDM and the E. coli gene is uidA, a β-glucuronidase gene. Consensus sequences were obtained from each of the genes to account for the many variants of each gene. We were able to triplex the assay and test it against a library for twenty isolates varying by which gene they contain. Additional research has been conducted on the library of carbapenem-resistant Enterobacteriaceae using bacteriophages or phage. The Phage Hunters class isolated and identified twenty phage that infect K. pneumoniae. Out of the twenty phage, seven phage were able to effectively infect carbapenem-resistant K. pneumoniae.

No description available.

Magister Pharmaceuticae - MPharm / Antimicrobial resistance is a global concern associated with increased morbidity and mortality. It has been estimated that, by 2050, the continuous escalation of antimicrobial resistance, globally, will result in more deaths per year, compared to cancer and diabetes. The direct and indirect impact of ineffective antibiotics, and therefore, antimicrobial resistance, will be hardest felt by low and middle-income countries, as the financial burden will be too great to manage. Carbapenems are considered the last line of antimicrobials to treat multidrug-resistant bacterial infections. They are the preferred choice to treat infections, presenting with extended-spectrum beta-lactamases (ESBL) producing Enterobacteriacea. Various strains of bacteria that have become resistant, due to the selective pressure, as a result of carbapenem over use, are referred to as Carbapenem-resistant Enterobacteriaceae (CRE). / 2022

Bacteriophages (phages) are the smallest biological entity on the planet. They provide vast amounts of valuable knowledge to biologists. Phage genomes are relatively simple compared to the organisms they infect (prokaryotes) and yet continually point to the complexity surrounding molecular- and microbiological mechanisms of life. By studying phages we can learn of the systems of gene expression, protein interaction and DNA organization. Phages are useful not only from an academic perspective, but may also have useful clinical applications. In the face of the rise of antibiotic-resistant bacterial “super pathogens”, scientists and researchers turn to phages as alternative treatments to these types of infections. Phages are capable of infecting and killing even the deadliest of bacterial pathogens, such as carbapenem-resistant Enterobacteriaceae (CRE) or Bacillus anthracis, and may prove increasingly useful in the future for combatting harmful pathogens. This thesis looks at several aspects of phage biology—from the underlying genetics contributing to phage virulence, to the clinical application of phage therapy to treat infections. First, a look at CRE-Klebsiella pneumoniae isolates and phages capable of infecting some strains may reveal a potential therapeutic approach in the future. Additionally, genomic analysis reveals interesting features that may explain aspects of phage virulence and evolutionary history. Then, a collection of genetically diverse phages is used in infection assays on pathogenic strains of Bacillus anthracis to establish the first-reported phages capable of infecting these strains. Finally, the process of preparing phage samples for therapeutic application is explored in-depth to conclude with discussion of clinical application. During the course of these projects over 25 phages were isolated, as many phage genomes were assembled and annotated, resulting in the preparation of two genome announcements and near-completion of two publishable first-author papers (chapters II and III). In addition, participation in a variety of collaborative efforts may lead to a handful of co-author papers and on various topics, including phage biology and application.