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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Colonização por Staphylococcus aureus em indivíduos com HIV/aids internados em um hospital escola do interior paulista / Staphylococcus aureus colonization in individuals with HIV/AIDS hospitalized in a teaching hospital in the city of Ribeirão Preto, state of São Paulo

Reinato, Lilian Andreia Fleck 18 December 2012 (has links)
Introdução: a colonização de indivíduos com HIV/aids por microrganismos patogênicos tem sido associada a maior risco de morbidade e mortalidade, principalmente quando esse microrganismo é o Staphylococcus aureus. Identificar precocemente esta condição permite implementar medidas preventivas do adoecimento a ele relacionado, em nível individual e coletivo. Objetivo: avaliar a prevalência de colonização por Staphylococcus aureus em indivíduos com HIV/aids internados em um hospital escola. Metodologia: estudo de corte transversal, tendo como sujeito pessoas vivendo com HIV/aids, internadas em duas unidades especializadas em HIV/aids de um Hospital Escola do município de Ribeirão Preto- SP. Todos os preceitos éticos foram criteriosamente respeitados. No período de Agosto/2011 a Julho/2012, todos os indivíduos internados foram abordados e para aqueles que aceitaram participar, procedeu-se a coleta de amostra de saliva e secreção nasal, além da coleta de dados sociodemográficos, clínicos e imunológicos, obtidos por meio do prontuário e entrevista individual. As amostras foram encaminhadas e processadas pelo Laboratório de Microbiologia e Sorologia da instituição em estudo. Foram semeadas em meios de cultura ágar sangue e manitol, e após, transferidas para o sistema automatizado Vitek® 2 (BioMérieux(TM)), por meio dos cartões GP Test Kit Vitek® 2, para bactérias gram-positivas. Foram empregados cartões AST-P585 para avaliar a sensibilidade dos Staphylococcus aureus meticilina resistente (MRSA) aos antibióticos. Os dados foram armazenados em planilhas do Microsoft Office Excel 2011 for Mac e organizados por meio do software Statistical Package for the Social Sciences (SPSS), versão 17.0 for Windows. Resultados: De 229 indivíduos com HIV/aids internados nas unidades, 169 constituíram os sujeitos desta pesquisa, dos quais 57,4% eram do sexo masculino, 39,6% apresentaram idade de 40 a 49 anos e 45% tinham o primeiro grau completo. Foram obtidas 338 amostras (169 de secreção nasal e 169 de saliva). A prevalência de colonização por Staphylococcus aureus foi identificada em 20,4% das amostras, com 21,7% de resistência à oxacilina, sendo em secreção nasal 66,7% e em saliva 33,3%. Apresentaram contagem de linfócitos T CD4 abaixo de 200 células/mm3 60,0% dos indivíduos com MRSA nasal e 80,0% estavam em uso de antimicrobianos. Em 40,0% dos indivíduos com MRSA na saliva carga viral foi igual ou superior a 500.001 cópias/mL, e 80,0% destes também usavam antimicrobianos, MRSA nasal e saliva foi identificado em 60,0% dos indivíduos que não estavam em uso de antirretroviral. Conclusão: a prevalência de colonização por Staphylococcus aureus em indivíduos com HIV/aids foi predominante em secreção nasal, com baixa contagem de linfócitos T CD4, com história de internação prévia, uso de antimicrobiano e ausência do uso de antirretroviral, podendo representar importante fonte de infecção. / Introduction: colonization by pathogenic microorganisms in individuals with HIV/AIDS has been associated with increased risk of morbidity and mortality, especially when that organism is Staphylococcus aureus. Early identification of this condition allows implementing preventive measures of illness related to it, both individually and collectively. Objective: to evaluate the prevalence of Staphylococcus aureus colonization in individuals with HIV/AIDS in a teaching hospital. Method: cross-sectional study; the subjects were people living with HIV/AIDS and hospitalized in two specialized HIV/AIDS care units of a Teaching Hospital in the city of Ribeirão Preto. All ethical principles were carefully observed. In the period from August 2011 to July 2012, all subjects hospitalized were approached and, for those who agreed to participate, the collection of saliva and nasal discharge sample was performed, in addition to collecting sociodemographic, clinical and immunological data, obtained through medical record and individual interviews. The samples were forwarded and processed by the Laboratory of Microbiology and Sorology of the institution. They were seeded in blood agar and mannitol-salt-agar culture medium, and thereafter, transferred to the automated system Vitek® 2 (BioMérieux(TM)) through Vitek® 2 Test Cards for Gram-positive bacteria. AST-P585 cards were used to assess the sensitivity of methicillin-resistant Staphylococcus aureus (MRSA) to the antibiotic. Data were stored in spreadsheets of Microsoft Office Excel 2011 for Mac and organized by the Statistical Package for the Social Sciences (SPSS) version 17.0 for Windows. Results: of the 229 individuals with HIV/AIDS hospitalized in the units, 169 were the subjects in this study, of whom 57.4% were male, 39.6% were aged from 40 to 49 years, and 45% had completed elementary school. 338 samples were collected (169 of nasal discharge and 169 of saliva). The prevalence of Staphylococcus aureus colonization was identified in 20.4% of samples, with 21.7% of oxacillin resistance, being 66.7% in nasal discharge and 33.3% in saliva. 60.0% of individuals with MRSA in nasal had lymphocytes T CD4 count below 200 cells/mm3 , and 80.0% were taking antimicrobials. In 40.0% of the individuals with MRSA in saliva, the viral load was equal or higher than 500.001 copies/mL, and 80.0% of these also used antimicrobials; MRSA in nasal and in saliva were detected in 60.0% of individuals who were not taking antiretroviral. Conclusion: the prevalence of Staphylococcus aureus colonization in individuals with HIV/AIDS was prevalent in nasal discharge, had lymphocytes T CD4 low count, with a history of previous hospitalization, antimicrobial use and the absence of antiretroviral use, and it may represent an important source of infection.
22

Hospital and meat associated <em>Staphylococcus aureus</em> and Their Biofilm Characteristics

Wienclaw, Trevor Michael 01 April 2018 (has links)
Biofilm phenotypes were studied in 32 Staphylococcus aureus strains isolated from store-bought meats and 22 from diseased patients in hospitals. Of the meat-associated strains, 21 were methicillin-resistant Staphylococcus aureus (MRSA) and 11 were methicillin-susceptible Staphylococcus aureus (MSSA). The hospital-associated strains included 15 MRSAs and 7 MSSAs. We studied the robustness and composition of the biofilms produced by these strains. We found that on average hospital-associated strains form more robust biofilms than meat associated strains. The model often used to describe S. aureus biofilm composition includes two biofilm types defined by the presence or absence of polysaccharide intercellular adhesin (PIA), PIA-dependent and PIA-independent respectively. In this model, PIA-independent biofilms are structurally reliant on proteins and extracellular DNA (eDNA) and PIA-dependent are structurally reliant on polysaccharides. Enzymatic degradation of the extracellular matrix can reveal which compounds are essential for the structural integrity of the biofilm, and by this model PIA-independent biofilms should be susceptible to both DNase and proteinase K. We found that hospital-associated strains are, on average, more susceptible to degradation by proteinase K. Interestingly, hospital-associated strains are less susceptible to degradation by DNase than meat-associated strains. Finding that proteinase K and DNase susceptibility for these strains are not linked gives evidence to support the idea that S. aureus biofilm composition can vary greatly from strain to strain and that the PIA-dependent and PIA-independent dichotomy of the standard model may be insufficient to describe the variety of S. aureus biofilm composition and may only apply to the extremes of the spectrum. Additionally, we saw no relationship between MRSA or MSSA strains and biofilm robustness, proteinase K degradation, or DNase degradation. Differences in biofilm characteristics between hospital-associated and meat-associated strains reinforce previous findings that these populations are genetically distinct.
23

Wundheilungsraten nach Roboter-assistierter minimalinvasiver Pedikelschraubenosteosynthese im Vergleich zu konventioneller fluoroskopisch-gestützter Instrumentierung bei pyogener Spondylodiszitis. / Robot guidance for percutaneous minimally invasive placement of pedicle screws for pyogenic spondylodiscitis is associated with lower rates of wound breakdown compared to conventional fluoroscopy-guided instrumentation

Alaid, Awad 30 July 2019 (has links)
No description available.
24

Kunskaper om Methicillin Resistent Staphylococcus Aureus (MRSA) och hygienrutiner hos sjuksköterskestuderande i termin sex.

Vängborg, Helena, Östergrens, Carina January 2008 (has links)
<p>The purpose of this study was to describe the level of knowledge that nurse students in term 6 have about Methicillin-Resistant Staphylococcus aureus (MRSA) and basic hygiene routines. The data collection was carried out by questionnaires. The questionnaire contained questions about knowledge regarding MRSA and basic hygiene routines. The questionnaires were handed out at an obligatory tuition occasion and all of the nurse students who were present (n=57) were asked to take part. The sample consisted of 45 women and 12 men. The youngest participant was 22 years old and the oldest participant was 52 years old. The main results showed a large variation regarding the participants knowledge on the subjects. Regarding questions about basic hygiene routines the majority had given the right answers. The number of right answers in the survey on questions about the participants knowledge of MRSA was lower. Only 12 % had given the right answer to the question about common symptoms of MRSA infection. Regarding the question about whether the nurse students considered themselves knowledgeable enough about MRSA for their future occupation, 32% had answered "to a high degree".</p> / <p>Syftet med studien var att beskriva vilka kunskaper sjuksköterskestuderande i termin 6 har om Methicillinresistenta Staphylococcus aureus (MRSA) och basala hygienrutiner. Datainsamlingen genomfördes med enkäter. Enkäten innehöll frågor om kunskaper gällande MRSA samt basala hygienrutiner. Enkäterna delades ut vid ett obligatoriskt undervisningstillfälle och samtliga, vid undervisningstillfället närvarade sjuksköterskestudenter (n =57) tillfrågades om deltagande. Undersökningsgruppen bestod av 45 kvinnor och 12 män. Yngsta deltagaren var 22 år och den äldsta deltagaren var 52 år. Huvudresultatet visade en stor variation gällande deltagarnas kunskaper i ämnena. På frågor angående basala hygienrutiner hade majoriteten svarat rätt. På de frågor som berörde deltagarnas kunskaper om MRSA var antalet rätta svar i undersökningen lägre. Endast 12 % hade svarat rätt på frågan om symtom som är vanliga vid MRSA infektion. På frågan om sjuksköterskestudenterna ansåg att de hade tillräckliga kunskaper om MRSA för sitt kommande yrke som sjuksköterskor svarade 32 % ”i hög grad”.</p>
25

Kunskaper om Methicillin Resistent Staphylococcus Aureus (MRSA) och hygienrutiner hos sjuksköterskestuderande i termin sex.

Vängborg, Helena, Östergrens, Carina January 2008 (has links)
The purpose of this study was to describe the level of knowledge that nurse students in term 6 have about Methicillin-Resistant Staphylococcus aureus (MRSA) and basic hygiene routines. The data collection was carried out by questionnaires. The questionnaire contained questions about knowledge regarding MRSA and basic hygiene routines. The questionnaires were handed out at an obligatory tuition occasion and all of the nurse students who were present (n=57) were asked to take part. The sample consisted of 45 women and 12 men. The youngest participant was 22 years old and the oldest participant was 52 years old. The main results showed a large variation regarding the participants knowledge on the subjects. Regarding questions about basic hygiene routines the majority had given the right answers. The number of right answers in the survey on questions about the participants knowledge of MRSA was lower. Only 12 % had given the right answer to the question about common symptoms of MRSA infection. Regarding the question about whether the nurse students considered themselves knowledgeable enough about MRSA for their future occupation, 32% had answered "to a high degree". / Syftet med studien var att beskriva vilka kunskaper sjuksköterskestuderande i termin 6 har om Methicillinresistenta Staphylococcus aureus (MRSA) och basala hygienrutiner. Datainsamlingen genomfördes med enkäter. Enkäten innehöll frågor om kunskaper gällande MRSA samt basala hygienrutiner. Enkäterna delades ut vid ett obligatoriskt undervisningstillfälle och samtliga, vid undervisningstillfället närvarade sjuksköterskestudenter (n =57) tillfrågades om deltagande. Undersökningsgruppen bestod av 45 kvinnor och 12 män. Yngsta deltagaren var 22 år och den äldsta deltagaren var 52 år. Huvudresultatet visade en stor variation gällande deltagarnas kunskaper i ämnena. På frågor angående basala hygienrutiner hade majoriteten svarat rätt. På de frågor som berörde deltagarnas kunskaper om MRSA var antalet rätta svar i undersökningen lägre. Endast 12 % hade svarat rätt på frågan om symtom som är vanliga vid MRSA infektion. På frågan om sjuksköterskestudenterna ansåg att de hade tillräckliga kunskaper om MRSA för sitt kommande yrke som sjuksköterskor svarade 32 % ”i hög grad”.
26

Personers upplevelse av att vara bärare av MRSA : En litteraturstudie

Jonsson, Mats, Tunc, Sevgi January 2013 (has links)
Syftet med föreliggande litteraturstudie var att beskriva upplevelsen av att vara bärare av meticillin-resistensta Stafylococcus aureus (MRSA) samt att kvalitetsbedöma de valda artiklarnas urval och bortfall. Artikelsökning i databaserna Cinahl, Medline och PsycInfo resulterade i inkludering av 12 artiklar. I resultatet framkom faktorerna: Upplevelsen av att vara smittbärare, MRSA:s påverkan på det dagliga livet, Stöd eller frånvaro av stöd från familj och vänner, Information och kunskap, Bemötande från vårdpersonal samt Upplevelsen av isolering. I resultatet framkom att personer bärare av MRSA upplevde rädsla att smitta andra, framförallt sina familjemedlemmar, och avstod från fysiskt kontakt. Personerna upplevde begränsningar i arbetslivet, i dagliga livet samt begränsningar av fysisk aktivitet. Stöd från familj och vänner hade stora betydelser för personernas anpassning till livet som bärare av MRSA. Flera personer med MRSA upplevde att de hade brister i kunskap och information om MRSA, vilket påverkade dem negativt. Positivt bemötande från vårdpersonal gjorde att personerna anpassade sig lättare till sin situation. Isoleringsvård upplevdes antingen som positiv eller som diskriminerande och en begränsning till deras självständighet. Urvalsprocessen beskrevs i tio artiklar och bortfall beskrevs i elva artiklar. Slutsatsen blev att personer med MRSA upplevde adekvat information om sitt tillstånd som en påverkande faktor vid livsstilsförändring. Brister som uppstod vid kunskapsförmedling, i relationer till vänner och familj samt i bemötandet från vårdpersonal upplevdes som negativa erfarenheter. / The aim of this study was to describe the experience of being a carrier of methicillin-resistant Staphylococcus aureus (MRSA) and to evaluate the quality of the selected articles sample and dropouts. Articles were search in databases Cinahl, Medline and PsycInfo which resulted in an inclusion of 12 articles. The result showed factors: The experience of being a carrier, MRSA's impact on daily life, Support or absence of support from family and friends, Information and knowledge, Encounter from health professionals and The experience of isolation. The result showed that individuals carrying MRSA experienced fear of infecting others, especially their family members, and refrained from physical contact. Participants experienced restrictions in the workplace, in everyday life, and limitation of physical activity. Support from family and friends had great meaning for persons adjusting to life as carriers of MRSA. Several people with MRSA felt that they were deficient in knowledge and information on MRSA, which affected them adversely. Positive attitude from health workers led to a facilitated adaption to the carriers’ situation. Isolation care was either percieved as a positive experience or caused discrimination in which subjects felt that their autonomy was restricted. The sample process was described in ten articles and dropouts were described in eleven articles. The conclusion of this study was that people with MRSA felt that adequate information about their condition as an influencing factor to lifestyle change. Deficiencies in sharing of knowledge, in relationships with friends and family as well as in the encounter with health professionals were perceived as negative experiences.
27

Oral antibiotics for methicillin-resistant Staphylococcus aureus (MRSA) skin and soft tissue infections (SSTIs) in the primary care setting : incidence of treatment failure and its additional economic impact

Labreche, Matthew Jude 08 November 2012 (has links)
Our investigation sought to identify the incidence of treatment failure and its associated costs in patients with methicillin-resistant Staphylococcus aureus (MRSA) skin and soft tissue infections (SSTIs) treated in the primary care setting. Thirteen clinics participated in this multi-site, observational study. Clinicians consented patients and collected clinical information, pictures, and wound swabs; isolates were processed in the principal investigator's laboratory. Treatment failure was defined as the occurrence of one or more of the following within 90 days: (1) change in antibiotic therapy, (2) subsequent need for incision and drainage, (3) SSTI at new site, (4) SSTI at same site, (5) emergency department visit, or (6) hospitalization. Cost estimates were obtained from the Agency for Healthcare Research and Quality (AHRQ) and Centers for Medicare and Medicaid Service's National Average Drug Acquisition Costs (NADAC). Patients were considered to have “moderate or complicated” SSTIs if they had a lesion ≥ 5cm in diameter, diabetes mellitus, or both. Patients not exhibiting these characteristics were classified as having “mild or uncomplicated” infections. Ninety-eight patients were enrolled. Most patients were of Hispanic ethnicity and more than half of all patients had a body mass index (BMI) ≥ 30kg/m2. The most common treatment modality was incision and drainage (I&D) plus antibiotics (57%). Treatment failure occurred in 21% of all patients at a mean additional cost of $1,933.71. Patients with moderate or complicated SSTIs who received I&D experienced significantly more treatment failures compared mild or uncomplicated patients who received I&D (36% vs. 10%; p = 0.04). The additional cost of treatment failure in patients with moderate or complicated SSTIs was nearly twice that of patients with mild or uncomplicated SSTIs ($2,093.40 vs. $1,255.02; p = 1.0). Treatment failure occurred sooner, on average, in the moderate or complicated group compared to the mild or uncomplicated group (11.8 days vs. 38.8 days; p = 0.06). Among patients with MRSA SSTIs treated in the primary care setting, the rate of treatment failure is high (21%) and costs are considerable ($1,933.71). / text
28

Διερεύνηση των γονιδίων αντοχής και των μηχανισμών που συμβάλλουν στην παθογένεια λοιμώξεων από πηκτάση-αρνητικούς σταφυλοκόκκους

Φωκά, Αντιγόνη 12 March 2015 (has links)
Σκοπός της παρούσας ερευνητικής εργασίας ήταν η επιδημιολογική μελέτη των σταφυλοκοκκικών λοιμώξεων από πηκτάση–αρνητικούς σταφυλοκόκκους (CNS) σε ασθενείς της Μονάδας Εντατικής Θεραπείας των πρόωρων νεογνών του Πανεπιστημιακoύ Γενικού Νοσοκομείου Πατρών (ΠΓΝΠ) μεταξύ 2002-2004. Κατά τη διάρκεια της μελέτης, συλλέχθηκαν συνολικά 287 στελέχη CNS. Τα στελέχη ελέγχθηκαν για την παραγωγή της πρωτεΐνης PBP2α και την ύπαρξη του γονιδίου mecA για τον προσδιορισμό των ανθεκτικών στη methicillin στελεχών CNS. Από το σύνολο των 287 CNS, τα 132 (46%) χαρακτηρίσθηκαν ως MRCNS. Τα MRCNS αποτελούν σοβαρό πρόβλημα για τα νοσοκομεία, γιατί αυξάνουν τον χρόνο παραμονής των ασθενών στο νοσοκομείο, άρα και το κόστος νοσηλείας και θεραπείας. Έγινε μελέτη του φαινοτύπου αντοχής των στελεχών σε αντιβιοτικά, της κλωνικής τους διασποράς και της ικανότητάς παραγωγής βιομεμβράνης σε σύγκριση με την παρουσία των γονιδίων του οπερονίου ica. Για την επιδημιολογική μελέτη των λοιμώξεων που οφείλονται σε MRCNS, μέθοδος αναφοράς είναι η PFGE, κυρίως σε συνδυασμό και με υβριδισμό του χρωμοσωμικού DNA με ειδικούς ανιχνευτές. Όλα τα στελέχη MRCNS ήταν πολυανθεκτικά και η πλειονότητά τους παρήγαγε βιομεμβράνη (89%). Μεταξύ των 115 στελεχών S. epidermidis αναδείχθηκε ένας κυριάρχος κλώνος (z) (77 στελέχη) και ακολούθησε ο κλώνος (g). Τα δέκα από τα δεκαέξι στελέχη του είδους S. haemolyticus ανήκαν στον κλώνο (y). Το οπερόνιο ica συμβάλλει στην παραγωγή της εξωκυττάριας ουσίας polysaccharide-intercellular-adhesin (ΡΙΑ) που είναι το κύριο συστατικό του biofilm. Η έκφραση των γονιδίων του οπερονίου ica επάγεται από την παρουσία του ρυθμιστικού γονιδίου sarA, ενώ καταστέλλεται από το γονίδιο icaR. Τα περισσότερα στελέχη που ήταν biofilm-θετικά (80%) έφεραν όλα τα γονίδια του οπερονίου ica και το τρανσποζόνιο IS256, ενώ τα υπόλοιπα 23 είχαν ποικίλους συνδυασμούς των γονιδίων. Η παρουσία όλων των γονιδίων του οπερονίου ica ανιχνεύθηκε σε τρία από τα δεκαπέντε biofilm-αρνητικά στελέχη. Αναδείχθηκαν ένας κύριος και δύο δευτερεύοντες biofilm-θετικοί, πολυανθεκτικοί MRCNS κλώνοι, που αποίκισαν και προξένησαν λοιμώξεις στα πρόωρα νεογνά. Μέρος της παρούσας ερευνητικής εργασίας ήταν η διερεύνηση της επίδρασης του χρόνου επώασης στη γονιδιακή έκφραση σε δεκατέσσερα αντιπροσωπευτικά στελέχη. Αυτό έγινε μέσω της ποσοτικοποίησης με αλυσιδωτή αντίδραση πολυμεράσης πραγματικού χρόνου (RT-PCR) των γονιδίων icaA και icaD τα οποία κυρίως σχετίζονται με την παραγωγή biofilm, καθώς και δύο ρυθμιστικών γονιδίων icaR και sarA σε σύγκριση με ένα συντηρημένο γονίδιο αναφοράς (23S rDNA). Ο έλεγχος έγινε σε στελέχη S. epidermidis που ήταν ανθεκτικά στη methicillin, κατατάσσονταν σε διαφορετικούς κλώνους, εμφάνιζαν διαφορετικό φαινότυπο σύνθεσης βιομεμβράνης και έφεραν ποικίλους συνδυασμούς γονίδιων. Οι αντιδράσεις απόλυτης ποσοτικοποίησης έκφρασης των γονιδίων είχαν υψηλή απόδοση (1,86 και 1,84 για την επώαση στις τέσσερις ώρες και δύο ώρες, αντίστοιχα). Η μαθηματική ανάλυση δεν έδειξε ιδιαίτερα μεγάλες διαφορές μεταξύ των αποτελεσμάτων για τα τέσσερα γονίδια και τους δύο χρόνους επώασης. Αυτό που παρατηρήθηκε ήταν οτι η έκφραση ήταν υψηλότερη στα biofilm-θετικά στελέχη. Προκειμένου να μελετηθεί η επίδραση της βακτηριακής προσκόλλησης στις διάφορες επιφάνειες τροποποιημένου και μη τροποποιημένου γυαλιού, πραγματοποιήθηκαν δυναμικά πειράματα, κάτω από δύο διαφορετικές συνθήκες ροής, σε δύο χρόνους επώασης σε τέσσερα στελέχη S. epidermidis. Η βακτηριακή προσκόλληση, η παραγωγή biofilm και ο σχηματισμός βιομεμβράνης στις τροποποιημένες επιφάνειες ήταν αυξημένα σε σχέση με τις μη τροποποιημένες. Αυτό ήταν σε συμφωνία με τα αποτελέσματα της γονιδιακής έκφρασης των γονιδίων icaA και icaD, μετά από ανάλυση της έκφρασης των γονιδίων icaA και icaD με RT-PCR, που έδειξε αυξημένες τιμές στις τροποποιημένες επιφάνειες, κυρίως στην υψηλή ροή. Επομένως, ο συνδυασμός της δράσης της χημείας της επιφάνειας και της ροής, επηρεάζουν την προσκόλληση, τον φαινότυπο και το γονότυπο των βακτηριακών στελεχών, όπως και την προσαρμογή τους στις αλλαγές του περιβάλλοντος. Η μελέτη της γονιδιακής έκφρασης μπορεί να βοηθήσει στην κατανόηση των αλληλεπιδράσεων της βακτηριακής προσκόλλησης με το βιοϋλικό. / A total of 132 methicillin-resistant coagulase-negative staphylococci (MRCNS) isolated from preterm neonates were studied for antibiotic resistance patterns, clonal distribution and biofilm formation in relation to the presence of ica operon. All MR-CNS were multi-resistant while the majority (89%) produced biofilm. Among 115 Staphylococcus epidermidis, a major clone (z) was identified (77 strains), followed by clone g. Ten out of 16 S. haemolyticus belonged to a common clone (y). Most of the biofilm-positive strains (80%) possessed all tested genes, while the remaining 23 had a variety of gene combinations. Presence of the entire ica cluster was detected in three out of 15 biofilm-negative strains. One major and two minor biofilm-positive, multi-resistant MRCNS clones were disseminated, colonizing and infecting hospitalized preterm neonates. Fourteen representative MR- S. epidermidis strains were selected and investigated for the expression of icaA and icaD genes, and two regulatory genes, icaR (repressor) and sarA (inducer), towards a housekeeping gene (23SrDNA), by Real-Time PCR (RT-PCR). These strains belonged to various clones, had different combinations of ica genes and biofilm-forming phenotypes. The experiments were performed in two incubation times, after two and four hours. Νο differences were observed at the gene expression level at the two tested times. In general, biofilm-positive strains had higher expression rates for ica operon and sarA genes and lower for the repressor of ica cluster gene (icaR). In order to investigate the interaction of bacteria with the surfaces after attachment, dynamic experiments were performed under two flow conditions. Two different surfaces were used, a modified and a non-modified glass surface. Bacterial adhesion, as well as biofilm production and biofilm formation, was much higher on the modified surface than on the non-modified one for four S. epidermidis strains. This was in agreement with icaA and icaD gene expression that showed increased expression by RT-PCR, for the bacteria adhered at the modified substrate, especially under the high shear rate. Therefore, the combined effect of surface chemistry and shear significantly influence the adhesion of interacting bacterial cells. This indicates that analysis of gene expression not only can greatly refine our knowledge of bacterial-material interactions, but also yield novel biomarkers for potential use in biocompatibility assessment.
29

Elevated BMI-associated Characteristics of Patients with Invasive MRSA Infection in the Atlanta, Georgia Metro Area, 2005-2008

Lorentzson, Lauren R 15 December 2010 (has links)
INTRODUCTION: National obesity rates are leading to higher rates of Type 2 Diabetes, increasing the number of people at risk of invasive infections with Methicillin Resistant Staphylococcus aureus (iMRSA) upon onset of ESRD and hemodialysis. However, an association between adiposity and risk of iMRSA has not been researched. AIM: The purpose of this study is to describe the epidemiological characteristics of an iMRSA cohort in the Atlanta metro area between 2005-2008; to examine BMI-related health outcomes within the cohort; and to compare proportions of BMI categories in this cohort to BRFSS data. METHODS: Surveillance data collected by the CDC EIP program on iMRSA in Atlanta, Georgia was used. BMI was calculated for each eligible case. Statistical analysis was carried out in SPSS. Univariate and multivariate binary logistic regression analysis was performed on select variables. A p-value of < 0.05 and a 95% confidence interval (CI) were used to determine significance. BRFSS BMI data for Georgia was compared to the study population. RESULTS: Overweight and obese cases were more likely to be diagnosed with diabetes by regression analysis. Cases with diabetes were at greater odds of having undergone dialysis within the previous year (univariate OR=2.3, p=0.000; multivariate OR=2.5, p=0.000). The proportion of iMRSA patients with diabetes is much greater (42.8%) than in the general population of the United States (7.8-10.7%). DISCUSSION: The results indicate that there may be a higher risk for iMRSA in overweight and obese individuals, particularly if other adiposity-related health problems are present.
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Concentração inibitória mínima de vancomicina para staphylococcus sp. coagulase negativa resistente à meticilina : comparação entre os métodos de microdiluição em caldo e etest e correlação com falha terapêutica em pacientes com bacteremia / Vancomycin MIC for methicillin-resistant coagulase-negative staphylococcus sp.: comparison of broth microdilution and etest methods and correlation to therapeutic failure among patients with bacteremia

Paiva, Rodrigo Minuto January 2010 (has links)
Vancomicina é o antimicrobiano de escolha no tratamento de bacteremias causadas por estafilococos resistentes à meticilina. No entanto, estudos recentes têm reportado que a vancomicina apresenta atividade reduzida contra Staphylococcus aureus resistentes à meticilina com concentrações inibitórias mínimas (CIMs) próximas do limite do ponto de corte de suscetibilidade, conforme critérios do CLSI, indicando falha terapêutica. Entretanto, existem poucos estudos à respeito dos Staphylococcus sp. coagulase negativa resistentes à meticilina (SCoNRM). Ademais, para determinação da CIM, deveria ser utilizado o método de referência microdiluição em caldo (MDC), mas a maioria dos laboratórios clínicos utiliza a técnica de Etest ou sistemas automatizados. Alguns estudos com S. aureus demonstraram discrepâncias entre MDC e Etest, contudo não existem dados referentes aos SCoN. Os objetivos deste estudo foram avaliar a correlação entre as CIMs de vancomicina determinadas pelas técnicas de MDC e Etest em 130 SCoNRM isolados de hemocultura, bem como verificar a relação entre valores de CIM e falha terapêutica entre pacientes com bacteremia por SCoNRM tratados com este antimicrobiano. A maioria dos resultados de CIM por MDC (98,5%) foram ≤1,0 mg/mL, enquanto o Etest apresentou 72,3% de CIM ≥ 1,5 mg/mL. As CIMs de vancomicina obtidas por Etest foram, em geral, uma a duas diluições maiores do que as CIMs obtidas por MDC. Os resultados indicam que a técnica de Etest gera valores de CIM consistentemente maiores do que os obtidos por MDC nos SCoNRM. Apenas 37 (28,5%) dos 130 pacientes com hemocultura positiva para SCoNRM apresentaram dados clínicos compatíveis com bacteremia. A maioria dos pacientes com bacteremia comprovada (n=24) apresentaram CIMs de vancomicina ≥1,5 mg/mL, sendo que 13 pacientes (35,1%) obtiveram CIM < 1,5 mg/mL. Este estudo não observou relação estatisticamente significativa entre valores de CIM de vancomicina que pudessem ser associados com falha terapêutica em pacientes com bacteremia por SCoNRM. / Vancomycin is the first-line therapy for methicillin-resistant staphylococci bacteremia. However, recent studies have reported that vancomycin demonstrates reduced activity against methicillin-resistant Staphylococcus aureus bacteremia, with vancomycin MICs at the high end of the CLSI susceptibility range indicating treatment failure. There is, however, little data considering methicillin-resistant coagulase-negative staphylococci (MRCoNS) bacteremia. Besides, the reference method that should be used for MIC determination is the broth microdilution (BMD), but many clinical laboratories use the commercial Etest technique or automated systems. Some reports have showed a growing number of vancomycin MIC discrepancies between BMD and Etest method for S. aureus, but there are no studies about CoNS. The aims of this study were to evaluated the correlation between the vancomycin MIC determined by the Etest and the BMD method for a total of 130 MRCoNS bloodstream isolates as well as to examine the relationship between vancomycin MICs and failure among patients with MRCoNS bacteremia treated with vancomycin. The vast majority (98.5%) of MIC results by BMD were ≤1.0 mg/mL in contrast to MIC by Etest which majority (72.3%) was ≥1.5 mg/mL. The vancomycin MICs obtained by the Etest for the same isolates were, in general, one to twofold higher than those obtained by the BMD method. The results indicate that the Etest provides vancomycin MIC values consistently higher than those obtained by BMD method for MRCoNS. Only 37 (28.5%) out of the 130 patients with a positive MRCoNS bloodstream culture met the eligibility criteria to be considered bacteremic. The majority of these patients (n = 24, 64.9%) presented vancomycin MIC ≥ 1.5 mg/mL, in opposite to 13 patients (35.1%) with MIC < 1.5 mg/mL. This study did not observe any statistical significative relationship between vancomycin MIC and treatment failure.

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