Orientador: Mara Corrêa Lelles Nogueira / Banca: Doroti de Oliveira Garcia / Banca: Fátima Pereira de Souza / Resumo: As Enterobacteriaceae constituem um importante grupo de patógenos humanos, causadores de infecções hospitalares e comunitárias. Nestas bactérias, a produção de beta-lactamases de espectro estendido (ESBL) é um dos principais mecanismos de resistência aos antibióticos, e responsável pela falha da terapia antimicrobiana. Enterobactérias resistentes a antibióticos são encontradas em águas superficiais e apresentam alta prevalência em águas servidas, inclusive pós-tratamento. Esta realidade caracteriza-se como um importante problema de saúde pública, pois estes ambientes atuam como reservatórios de patógenos humanos e de genes de resistência que se disseminam horizontalmente. Crescentes evidências mostram a relação entre a disseminação ambiental de bactérias resistentes e genes de resistência e a evolução da resistência em bactérias de importância clínica. Este estudo investigou a diversidade de enterobactérias produtoras de ESBL e a presença dos genes blaSHV, blaTEM, blaCTX-M e blaGES em amostras de água coletadas de efluentes hospitalar e comunitário em um município localizado na região noroeste do estado de São Paulo. Genes de resistência foram detectados em várias espécies de Enterobacteriaceae apresentando resistência a diversas classes de antimicrobianos. Estes dados indicam a necessidade de adoção de medidas para o controle da disseminação de bactérias resistentes a antimicrobianos e seus genes no meio ambiente. / Abstract: The Enterobacteriaceae constitutes an important group of human patogens, causing of hospital and communitarian infections. In these bacteria, the production of extended spectrum beta-lactamases (ESBL) is one of the main mechanisms of resistance the antibiotics, responsible for the imperfection of the therapy against infections for gram-negative bacilli. Enterobacteria resistant the antibiotics are found in superficial waters and present high prevalence in served waters, also post-cure. This reality is characterized as an important problem of public health, therefore these environments act as reservoirs of human patogens and genes of resistance that if spread through horizontal transmission. Increasing evidences show the relation between the ambient dissemination of resistant bacteria and genes of resistance and the evolution of the resistance in bacteria of clinical importance. This study it investigated the diversity of producing Enterobacteria of ESBL and the presence of the genes blaSHV, blaTEM, blaCTX-M and blaGES in water samples collected in the system of sewers in a city located in the region the northwest of the state of São Paulo. The respective genes of resistance had been detected in several strains producing of ESBL presenting profile of multiple resistant to the diverse antimicrobials groups, suggesting the necessity of the surveillance and the adoption of measures for the control of the dissemination of the genes of resistance in the environment. / Mestre

Made available in DSpace on 2014-06-11T19:27:21Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-10-26Bitstream added on 2014-06-13T20:35:44Z : No. of bitstreams: 1 ruiz_lgp_me_sjrp.pdf: 1611382 bytes, checksum: e9dd037c5c8d3c485f14ae8a1628ab2e (MD5) / As Enterobacteriaceae constituem um importante grupo de patógenos humanos, causadores de infecções hospitalares e comunitárias. Nestas bactérias, a produção de beta-lactamases de espectro estendido (ESBL) é um dos principais mecanismos de resistência aos antibióticos, e responsável pela falha da terapia antimicrobiana. Enterobactérias resistentes a antibióticos são encontradas em águas superficiais e apresentam alta prevalência em águas servidas, inclusive pós-tratamento. Esta realidade caracteriza-se como um importante problema de saúde pública, pois estes ambientes atuam como reservatórios de patógenos humanos e de genes de resistência que se disseminam horizontalmente. Crescentes evidências mostram a relação entre a disseminação ambiental de bactérias resistentes e genes de resistência e a evolução da resistência em bactérias de importância clínica. Este estudo investigou a diversidade de enterobactérias produtoras de ESBL e a presença dos genes blaSHV, blaTEM, blaCTX-M e blaGES em amostras de água coletadas de efluentes hospitalar e comunitário em um município localizado na região noroeste do estado de São Paulo. Genes de resistência foram detectados em várias espécies de Enterobacteriaceae apresentando resistência a diversas classes de antimicrobianos. Estes dados indicam a necessidade de adoção de medidas para o controle da disseminação de bactérias resistentes a antimicrobianos e seus genes no meio ambiente. / The Enterobacteriaceae constitutes an important group of human patogens, causing of hospital and communitarian infections. In these bacteria, the production of extended spectrum beta-lactamases (ESBL) is one of the main mechanisms of resistance the antibiotics, responsible for the imperfection of the therapy against infections for gram-negative bacilli. Enterobacteria resistant the antibiotics are found in superficial waters and present high prevalence in served waters, also post-cure. This reality is characterized as an important problem of public health, therefore these environments act as reservoirs of human patogens and genes of resistance that if spread through horizontal transmission. Increasing evidences show the relation between the ambient dissemination of resistant bacteria and genes of resistance and the evolution of the resistance in bacteria of clinical importance. This study it investigated the diversity of producing Enterobacteria of ESBL and the presence of the genes blaSHV, blaTEM, blaCTX-M and blaGES in water samples collected in the system of sewers in a city located in the region the northwest of the state of São Paulo. The respective genes of resistance had been detected in several strains producing of ESBL presenting profile of multiple resistant to the diverse antimicrobials groups, suggesting the necessity of the surveillance and the adoption of measures for the control of the dissemination of the genes of resistance in the environment.

No description available.

Kolistin är ett gammalt polypeptidantibiotikum och används som sista utväg för behandling av allvarliga infektioner orsakad av multiresistenta gramnegativa bakterier. Nya studier har påvisat kolistinresistensgener, mcr (mobil colistin resistance), hos extended spectrum beta-lactamase (ESBL)-producerande Enterobacteriaceae. Mcr-genen ligger i plasmider som kan överföras mellan bakterier, vilket innebär att det är mycket svårare att behandla människor och djur vid infektion orsakad av patogen som erhållit denna resistens. Syfte med detta projekt var att utveckla en PCR-baserad metod för detektion av mcr-1 och mcr-3 gener. I denna studie optimerades en PCR-metod och sedan screenades 60 ESBL-isolat från Kristianstads vattenrike. Därefter undersöktes PCR-produkt med hjälp av agarosgelselektrofores. Resultatet visade att 51oC är den optimala annealingtemperaturen vid multiplex-PCR för detektion av mcr-1 och mcr-3. Ingen av mcr-generna kunde detekteras i de 60 ESBL-isolaten. Positiva kontrollstammar med specifika primers kunde detekteras i PCR-analyser som genomfördes i denna studie, vilket tyder på att den optimerade PCR metoden kan vara pålitlig för detektion av mcr-1 och mcr-3 generna.

The increasing number of Extended Spectrum Beta-Lactamase (ESBL) producing Escherichia coli (E. coli) associated with sepsis in China is the reason for designing the current study. During 2014-2016, thirty hospitals representing 10 different provinces in China was involved in collecting E. coli isolates causing blood stream infections. Early treatment with suitable antibiotics have been found to be of lifesaving importance in the case of care for septic patients. Thorough understanding of the pathogens involved is therefore crucial. Using antimicrobial susceptibility testing, PCR and Multi Locus Sequence Typing (MLST), the molecular characteristics of ESBL producing E. coli isolates could be determined. This study can report that the most common ESBL producing genes found were CTX-M-14 (51 isolates, 45,5%), CTX-M-55 (23 isolates, 20,5%) CTX-M-15 (22 isolates, 19,6%). In addition, 2 isolates (1,8%) were found to be SHV-11 positive which is another ESBL producing gene. As a side finding, 5 isolates harbored Metallo-beta-lactamase (MBL) encoding genes such as NDM-5 and NDM-1 which were found to coexist with CTX-M-55 and CTX-M-14 respectively. An MLST analysis resulted in the finding of 25 different and 17 previously unknown (16,2 %) sequence types. The most common sequence types were ST131 (18 isolates, 17,1 %) as reported previously.  No significant differences in antimicrobial susceptibility were identified whether ESBL producing genes such as SHV and CTX-M was present or not. This study indicates that there could be novel resistance mechanisms present among those isolates not encoding the genes of interest. However, this finding requires further research before it can be confirmed.

Les années 2000 sont marquées par l’émergence et la diffusion de souches résistantes aux antibiotiques en particulier chez les entérobactéries. Un des principaux mécanismes de résistance concerne les bêta-lactamines, ce sont les bêta-lactamases. Certains mécanismes de résistances ont connus ou connaissent actuellement un certain succès comme les bêta-lactamase à spectre étendu (BLSE) de type CTX-M puis récemment les carbapénèmases. La transmission de plasmides porteurs de ces enzymes joue un rôle prépondérant ainsi que certaines espèces comme Klebsiella pneumoniae et Escherichia coli qui est l’entérobactérie prépondérante dans le tube digestif de l’homme et des animaux et également la principale cause d’infection. Dans ce travail, nous avons étudié le transfert par transposition qui est le mécanisme clé de cette diffusion via différents plasmides parmi les plus prépondérants chez les entérobactéries dont essentiellement E. coli et K. pneumoniae. Nous avons également recherché une éventuelle relation avec le groupe phylogénétique, les gènes de résistance, type de plasmides et systèmes d’addiction plasmidique. Ce travail montre que les plasmides IncF ayant acquis TEM-1 ont de multiples systèmes d’addiction avec une fréquence plus élevée que les souches sensibles. Ce qui contribuerait à leur maintenance dans l’hôte. Les plasmides à large spectre d’hôte sont très rares chez ces souches de manière générale. Il ne semble pas y avoir de relation entre le groupe phylogénétique et les gènes de résistances dans cette étude. Quant au phénomène de transposition, il suscite la mise au point de conditions opératoires qui le régisse. Une détermination des conditions de stress a été réalisée et il reste à tracer le phénomène à proprement dit. / The last years are characterized by the spread of antibiotics resistant strains particularly in Enterobacteriacae. Various mechanisms of resistances were acquired and transmitted by species like K. pneumoniae. Bacterial plasmids play an important role in the horizontal transfer of antimicrobial drug resistance genes like: CTX-M enzymes witch become the most prevalent family of ESBLs and recently carbapenemases. In this work, we studied the transfer by transposition, the key mechanism of resistance genes diffusion, between different plasmids. We also sought a possible relation between the genetic background and the frequency of transposition, by testing various types of plasmids among the most prevalent E. coli and K. pneumoniae. This work shows that IncF plasmids having acquired TEM-1 have multiple addiction systems with a frequency higher than the sensitive strains. It would contribute to their maintenance in the host. By the way, broad range plasmids are very rare at these strains. In addition, it does not seem to be a relation between the phylo-group and the genes of resistances in this study. For the transposition event, we start to settle the operating conditions which govern this phenomenon. A determination of the stress conditions was established and it remains to be completed.

Contexte : Les infections causées par les entérobactéries productrices de béta-lactamases à spectre étendu (EBLSE) constituent un problème de prise en charge majeur en milieu hospitalier dans le monde. Si la situation des EBLSE est de plus en plus décrite en Afrique, son ampleur reste peu documentée au Sénégal. L’objectif de cette thèse était de décrire l’épidémiologie des EBLSE et d’évaluer leur impact médico-économique en milieu hospitalier au Sénégal. Méthodes : Deux études épidémiologiques descriptives et analytiques de type cas-témoins (avec une variante cas vs cas) nichées dans la cohorte des patients hospitalisés ayant eu une EBLSE isolée des prélèvements diagnostiques ont été menées. L’une des études portait sur toutes les infections causées par une entérobactérie parmi les patients admis dans les 2 hôpitaux et l’autre portait plus spécifiquement sur les bactériémies parmi les enfants hospitalisés dans l’hôpital pédiatrique. Les cas étaient des patients avec une infection à EBLSE (EBLSE+) et des patients avec une infection à entérobactérie non BLSE (EBLSE-). Les témoins étaient des patients non infectés. Des analyses de régressions multivariées ont été réalisées pour identifier les facteurs de risque d’acquisition d’une infection à EBLSE et les facteurs de décès dans les 2 populations d’études. Par ailleurs, un modèle multi-états et une analyse économique de type « cost-of-illness » ont été menés pour estimer l’allongement de la durée de séjour attribuable aux EBLSE et le surcoût associé. Résultats : Le taux d’incidence des infections à EBLSE était de 3 cas/1 000 journées d’hospitalisation (JH) et de 1,5 cas/1000 JH pour les bactériémies en milieu pédiatrique. La présence de cathéters veineux centraux et urinaires ainsi que d’une ventilation mécanique étaient les facteurs de risque d’acquisition d’une infection à EBLSE. De plus, les nouveau-nés étaient identifiés comme un groupe de patients à risque. La production de BLSE était un facteur de risque de décès et était associée à une augmentation de la durée de séjour (+4jours) et du coût hospitalier (+100€). Conclusion : Les infections à EBLSE sont fréquentes en milieu hospitalier et ont un impact médico-économique considérable. La maîtrise de la dissémination des EBLSE, à travers la promotion des précautions standard d’hygiène et la bonne gestion des excréta est cruciale surtout en pédiatrie. Nos résultats suggèrent aussi de promouvoir le bon usage des antibiotiques, indispensable pour préserver l’efficacité des antibiotiques, en particuliers des carbapénèmes, dans les infections hospitalières. / Infections caused by Enterobacteriaceae producing extended-spectrum beta-lactamase (ESBL-E) are of major concern in clinical practice worldwide because of limited therapeutic options effective to treat them. Studies from Africa showed that ESBL are frequent in the continent, however the impact of these multidrug resistant infections is yet to be adequately determined. The aim of this thesis was to describe the epidemiological situation of ESBL-E in Senegal and to assess their clinical and economic impact. Methods : Two retrospective studies were carried out in inpatients from whom an Enterobacteriaceae strain was isolated from diagnostic samples drawn during a 6-month period (Study 1) and from blood cultures drawn within a 2-year period among pediatric patients (Study 2). Case-case-control studies were carried out to identify risk factors to acquire an ESBL-E infection. Patients infected by an ESBL-producing Enterobacteriaceae were defined as cases 1, those infected by an Enterobacteriaceae non-producer of ESBL were cases 2 and patients not infected by any bacterial strain were controls. Multivariable analyses using a stepwise logistic regression were performed to identify risk factors to acquire an ESBL-E infection and risk factors for death. Retrospective cohort analyses were performed to assess the prolonged length of stay attributable to ESBL production using a multistate model. Besides, a cost-of-illness analysis was performed to estimate the additional cost attributable to the prolonged length of stay. Results : Incidence rate of ESBL-infections was 3/1,000 patient-days (PD) and 1.5 cases/1,000 PD for bloodstream infections in children. Risk factors to acquire an ESBL infection were the presence of urinary catheter, central venous catheter and mechanical ventilation. Newborns were also identified as a patient- at risk to acquire an ESBL-E infection. ESBL production was identified as an independent risk factor for death. Besides, ESBL production was associated with an increased LOS (+4days) and cost (€100). Conclusion : Our findings show an important clinical and economic impact of ESBL infections in Senegal. Control of ESBL-E spread is an emergency especially in pediatric populations and can be achieved by the promotion of hand hygiene and proper management of excreta. Results also emphasize the need to revise current antibiotic prescriptions guidelines and to implement an antibiotic stewardship program to preserve the effectiveness of our last-resort antibiotic drugs.

Die vorliegende Studie bestätigt, dass Fernreisen, insbesondere in Regionen mit hoher ESBL-Prävalenz, nach wie vor ein hohes ESBL-PE-Kolonisationsrisiko aufweisen. Am meisten betroffen sind Reisende ins südliche Asien (indischer Subkontinent) und nach Südostasien. Die spontane ESBL-Dekolonisation erfolgt in der Regel innerhalb der ersten Wochen nach Rückreise. Nach sechs Monaten ist der Großteil der kolonisierten Reisenden wieder „frei“ von ESBL-PE. Unsere Studie zeigt, dass sowohl das Alter der Reisenden, als auch die Art der Unterkunft eine wichtige Rolle bei der Kolonisation mit ESBL-PE spielt. Junge Reisende im Alter von 20-29 Jahren und Reisende, die in einem Hotel oder einer privaten Unterkunft wohnen, sind einem signifikant höheren Risiko für eine Kolonisation mit ESBL-PE ausgesetzt.

The incidence of sepsis is a growing problem worldwide with a high mortality rate.  K- capsule antigens are becoming more dangerous than before. The purpose of the study was to categorize the capsules virulence factors, as well as to find a safe and empirical antibiotic treatment for sepsis infection, and to determine if the existence of ESBL producing bacteria have increased exponentially in recent decades. A total of 101 isolates were collected for a period of 5 years, of which blood isolates (n=38) were collected at Uppsala university hospital and feces isolates from healthy mothers and their infants (n=63) at Cunghi hospital, China. Isolates were serotyped with agglutination test, using N. meningitides B / Ecoli K1 against K1 capsule antigen, and phage test, using K1, K5 and K13 bacteriophage to identify the corresponding E. coli K antigen. Results showed that K1- capsule antigen could be identified in 42% (16/38) of the blood-isolated bacterial strains, compared with 11% (7/63) in fecal-isolated bacterial strains, while K5- capsule antigen was serotyped in 5% (2/38) and 19% (12/63), respectively. In contrast, the K13 capsule antigen was not found in blood-isolated bacterial strains and was serotyped only in 4% (3/63) of the fecal-isolated bacterial strains. Overall, the investigated E.coli  K capsular antigens were identified in 47% (18/38, non -typeable n=20) of the blood-isolated cultures compared with 35% ( 22/36, non-typeable=41) in fecal-isolated cultures..

No description available.