Das grampositive Bakterium Staphylococcus epidermidis ist ein wesentlicher Bestandteil der kommensalen Flora der Haut und der Schleimhäute des Menschen. Jedoch stellen diese Bakterien eine häufige Ursache nosokomialer Katheter-assozierter Infektionen bei immunsupprimierten Patienten dar. Dies liegt zum einen an der Fähigkeit von S. epidermidis, Biofilm zu bilden. Diese physikalische Barriere schützt die Bakterien vor dem Immunsystem sowie vor Antibiotika. Dabei zählen sie zu den häufigsten Erregern von Infektionen an implantierten Fremdkörpern mit Plastikoberflächen, wie z. B. Venenkathetern, künstlichen Herzklappen oder Gefäßprothesen. Zum anderen stellt die Antibiotikaresistenzentwicklung unter S. epidermidis ein zunehmendes Problem dar. Vor allem die late-onset Sepsis, die durch S. epidermidis als Erreger verursacht werden kann, stellt für Frühgeborene eine Gefahr dar. Ziel der vorliegenden Arbeit war, für S. epidermidis als häufigsten und klinisch bedeutsamen KoNS zu eruieren, ob die zunehmende Dauer des stationären Krankenhausaufenthaltes von sehr kleinen Frühgeborenen mit einer höheren Rate an ica-Präsenz, Biofilmbildung und Antibiotikaresistenz assoziiert ist, sowie die Verbreitungswege und das Reservoir für diese S. epidermidis-Stämme zu identifizieren. Hierzu wurden sequenzielle Isolate von S. epidermidis bei Müttern, Kindern und vom Krankenhauspersonal gewonnen und mittels MLST (Multilocus-Sequence-Typing) klonal typisiert. Sie wurden auf Antibiotikaresistenzen, Biofilmbildung und Präsenz des icaA-Gens, das eine Rolle bei der Biofilmbildung spielt, sowie des mecA-Gens untersucht und mit Isolaten, die aus Blutkulturen oder Venenkatheter des Kindes isoliert wurden, verglichen. Es fiel auf, dass die Isolate der sehr kleinen Frühgeborenen deutlich mehr Virulenzfaktoren, wie z.B. Biofilmbildung, hohe Antibiotikaresistenzraten sowie die Präsenz des mecA- und des icaA- Gens, als die maternalen Stämme besaßen. Im Vergleich mit den Ergebnissen der untersuchten Personalstämme liegt der Verdacht nahe, dass oftmals auch das Personal als Transmitter, vor allem von Klonen mit mehreren Virulenzfaktoren, dient. Das Krankenhaus-Milieu scheint dabei ein ideales Reservoir für die Ausbreitung solcher gefährlichen S. epidermidis-Stämme zu sein. / Staphylococcus epidermidis is usually a commensal inhabitant of the human skin and mucosa. However, they are a common cause of nosocomial infections, especially in context with medical devices and catheters in immunocompromised patients. This is due to the ability of Staphylococcus epidermidis to form biofilms on inert surfaces of medical devices, like intravenous catheters or artificial arthroplastics. Furthermore the development of antibiotic resistances among Staphylococcus epidermidis is another problem. Especially the late-onset-sepsis is a danger for very low birth weight premature infants. The aim of the study was to identify for S. epidermidis isolates in very preterm infants, if a longer stay in the hospital is associated with a higher carriage of the ica-operon, a higher antibiotic resistance and the ability to form biofilms. The reservoir and the means of distribution of these nosocomial isolates should be idendified. Therefore sequential isolates were taken from mothers, their children and from the hospital staff. They were clonally typified by MLST (Multilocus-Sequence-Typing) and tested for antibiotic resistances, biofilm formation and the presence of the icaA- and mecA gene. Then they were compared with isolates from blood cultures or venous catheters from the preterm infants. Herby it was remarkable that the isolates of the very premature infants had more virulence factors, e.g. formation of biofilm, antibiotic resistances and the presence of the icaA- and mecA gene, as the maternal isolates. Compared to the results of the isolates from the medical staff it could be suggested that the staff transmits these opportunistic pathogens. The hospital environment seems to be an ideal reservoir for these dangerous S. epidermidis isolates.

Orientador: Lígia Maria Suppo Souza Rugolo / Resumo: A sepse neonatal tardia é importante causa de morbidade e mortalidade em recém-nascidos prematuros. Os sinais e sintomas são inespecíficos, o que dificulta o diagnóstico. As citocinas são potentes mediadores inflamatórios que desempenham importante papel na patogênese da infecção. Níveis séricos aumentados de citocinas são observados durante infecções. A Interleucina 8 (IL-8) tem função de atrair e ativar neutrófilos, mantendo o processo inflamatório. O objetivo deste estudo foi determinar os níveis séricos e urinários da IL-8 em recém-nascidos prematuros com sepse tardia confirmada por culturas (sangue, urina ou líquor) ou associada com meningite, e avaliar se os níveis urinários de IL-8 podem ser utilizados como teste diagnóstico da sepse neonatal tardia. Amostras de sangue e urina foram coletadas de 36 RN prematuros com suspeita clínica de sepse tardia e os exames foram repetidos após 48 horas do início do estudo. Os valores séricos e urinários da IL-8 foram determinados pelo método de ELISA e a IL-8 urinária foi ajustada pelo valor da creatinina urinária. Dois grupos foram constituídos: Grupo séptico: 19 RN com sepse confirmada por culturas ou associada a meningite, idade gestacional (IG) de 31 ± 2,5 semanas, peso de nascimento (PN) de 1350 ± 420g, idade pós-natal (IPN) de 9,7 ± 5,3 dias e Grupo não infectado: 17 RN nos quais o diagnóstico de sepse foi excluído, IG 31 ± 2,1 sem, PN 1510 ± 380g, IPN 6,9 ± 4,1 dias. A mediana dos níveis séricos da IL-8 não diferiu estatisticamente entre os grupos séptico e não infectado (929 x 624 pg/ml; p=0,079) mas os níveis urinários (IL-8 ur/cr) foram significativamente maiores no grupo séptico (249 x 41,7; p<0,001). O ponto de corte ótimo da IL-8 sérica foi de 304 pg/ml com sensibilidade de 84% (IC 95%: 60 a 95%) e especificidade de 47% (IC 95%: 23 a 72%)... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Late onset sepsis (LOS) is an important cause of morbidity and mortality in preterm infants. However, the diagnosis of LOS is difficult. Elevated serum levels of cytokines have been found during infections and this plays a critical role in the pathogenesis of infections. Interleukin 8 (IL-8) attracts and activates neutrophils which is crucial for the maintenance of the inflamatory process. The aim of this study was to determine serum and urine IL-8 levels in preterm infants with clinical LOS and positive culture (blood, urine ou cerebrospinal fluid) or meningitis and to evaluate if IL-8 levels can be a useful test for the diagnosis of LOS. Blood and urine were obtained from 36 premature babies with clinical signs of LOS and the collection of the samples were repeated after two days. Serum and urine IL-8 levels were determined by ELISA and the urine IL-8 concentration was corrected with the urine creatinine level. Nineteen preterm infants with sepsis (positive cultures or meningitis) - LOS Group: gestational age (GA) 31 ± 2.5wk, Birth Weight (BW) 1.35 ± 0.42 Kg, postnatal age(PNA) 9.7 ± 5.3 days and 17 noninfected - Control Group: GA 31 ± 2.1wk, BW 1.51 ± 0.38, PNA 6.9 ± 4.1 days, were studied. The medium serum IL-8 levels were not statistically different between groups (LOS vs Control, 929 x 624 pg/ml; p=0,079) but urine IL-8 levels were significantly higher in the LOS group when compared with the noninfected (249 x 41,7 p<0,001). The optimal cut-off point was 304pg/ml for serum IL8 with 84% sensitivity (95% CI: 60-95%) and 47% specificity (95% CI: 23-72%). The cut-off point for urine IL-8 was 89 with 100% sensitivity (95% CI: 82-100%) and 100% specificity (95%CI:81-100%). Two days after of clinical signs of LOS, urine IL-8 levels decreased in LOS group (p<0,001). The decrease in serum IL-8 levels in the LOS group was not statistically different (p=0,123)... (Complete abstract, click electronic address below) / Doutor

Made available in DSpace on 2014-06-11T19:33:27Z (GMT). No. of bitstreams: 0 Previous issue date: 2003Bitstream added on 2014-06-13T19:04:16Z : No. of bitstreams: 1 bentlin_mr_dr_botfm.pdf: 810873 bytes, checksum: 830e8baa1a9b44778883a83210feaf9d (MD5) / A sepse neonatal tardia é importante causa de morbidade e mortalidade em recém-nascidos prematuros. Os sinais e sintomas são inespecíficos, o que dificulta o diagnóstico. As citocinas são potentes mediadores inflamatórios que desempenham importante papel na patogênese da infecção. Níveis séricos aumentados de citocinas são observados durante infecções. A Interleucina 8 (IL-8) tem função de atrair e ativar neutrófilos, mantendo o processo inflamatório. O objetivo deste estudo foi determinar os níveis séricos e urinários da IL-8 em recém-nascidos prematuros com sepse tardia confirmada por culturas (sangue, urina ou líquor) ou associada com meningite, e avaliar se os níveis urinários de IL-8 podem ser utilizados como teste diagnóstico da sepse neonatal tardia. Amostras de sangue e urina foram coletadas de 36 RN prematuros com suspeita clínica de sepse tardia e os exames foram repetidos após 48 horas do início do estudo. Os valores séricos e urinários da IL-8 foram determinados pelo método de ELISA e a IL-8 urinária foi ajustada pelo valor da creatinina urinária. Dois grupos foram constituídos: Grupo séptico: 19 RN com sepse confirmada por culturas ou associada a meningite, idade gestacional (IG) de 31 ± 2,5 semanas, peso de nascimento (PN) de 1350 ± 420g, idade pós-natal (IPN) de 9,7 ± 5,3 dias e Grupo não infectado: 17 RN nos quais o diagnóstico de sepse foi excluído, IG 31 ± 2,1 sem, PN 1510 ± 380g, IPN 6,9 ± 4,1 dias. A mediana dos níveis séricos da IL-8 não diferiu estatisticamente entre os grupos séptico e não infectado (929 x 624 pg/ml; p=0,079) mas os níveis urinários (IL-8 ur/cr) foram significativamente maiores no grupo séptico (249 x 41,7; p<0,001). O ponto de corte ótimo da IL-8 sérica foi de 304 pg/ml com sensibilidade de 84% (IC 95%: 60 a 95%) e especificidade de 47% (IC 95%: 23 a 72%)... / Late onset sepsis (LOS) is an important cause of morbidity and mortality in preterm infants. However, the diagnosis of LOS is difficult. Elevated serum levels of cytokines have been found during infections and this plays a critical role in the pathogenesis of infections. Interleukin 8 (IL-8) attracts and activates neutrophils which is crucial for the maintenance of the inflamatory process. The aim of this study was to determine serum and urine IL-8 levels in preterm infants with clinical LOS and positive culture (blood, urine ou cerebrospinal fluid) or meningitis and to evaluate if IL-8 levels can be a useful test for the diagnosis of LOS. Blood and urine were obtained from 36 premature babies with clinical signs of LOS and the collection of the samples were repeated after two days. Serum and urine IL-8 levels were determined by ELISA and the urine IL-8 concentration was corrected with the urine creatinine level. Nineteen preterm infants with sepsis (positive cultures or meningitis) - LOS Group: gestational age (GA) 31 ± 2.5wk, Birth Weight (BW) 1.35 ± 0.42 Kg, postnatal age(PNA) 9.7 ± 5.3 days and 17 noninfected - Control Group: GA 31 ± 2.1wk, BW 1.51 ± 0.38, PNA 6.9 ± 4.1 days, were studied. The medium serum IL-8 levels were not statistically different between groups (LOS vs Control, 929 x 624 pg/ml; p=0,079) but urine IL-8 levels were significantly higher in the LOS group when compared with the noninfected (249 x 41,7 p<0,001). The optimal cut-off point was 304pg/ml for serum IL8 with 84% sensitivity (95% CI: 60-95%) and 47% specificity (95% CI: 23-72%). The cut-off point for urine IL-8 was 89 with 100% sensitivity (95% CI: 82-100%) and 100% specificity (95%CI:81-100%). Two days after of clinical signs of LOS, urine IL-8 levels decreased in LOS group (p<0,001). The decrease in serum IL-8 levels in the LOS group was not statistically different (p=0,123)... (Complete abstract, click electronic address below)

Um die Mortalität und Morbidität von Sepsisepisoden bei Frühgeborenen zu verbessern, kommt einer frühen und sicheren Diagnosestellung besonderes Interesse entgegen. In dieser Arbeit wurde untersucht, inwiefern durch eine Analyse einfacher klinischer Symptome die Wahrscheinlichkeit einer Sepsisepisode korrekt vorausgesagt werden kann. In einer prospektiven Studie wurden in 83 Verdachtsmomenten einer Sepsis bei 67 Frühgeborenen die Basisdaten (Geburtsalter, Geburtsgewicht, etc.), die klinischen (kardiovaskuläre, pulmonale, gastrale und neurologische Symptome) und die paraklinischen (CRP, Blutkulturen, etc.) Variablen analysiert. In 39 Verdachtsmomenten konnte eine Sepsis bestätigt werden, darunter koagulase-negative Staphylokokken als häufigster Erreger. In 44 Fällen wurde keine Sepsis entdeckt. Die Studie zeigte, dass kardiovaskuläre Symptome bei Frühgeborenen frühzeitig auf eine Sepsis hinweisen können. Ein Novum stellte hierbei die Messung einer zentral-peripheren Temperaturdifferenz (cpTD) dar, deren Erhöhung mit einer deutlichen höheren Wahrscheinlichkeit für das Vorliegen einer Sepsis assoziiert war. Sie bietet eine kostengünstige, nicht-invasive und kontinuierlich messbare Methode zur verbesserten Diagnosestellung einer Neugeborenensepsis.:1. Einleitung 2. Hintergründe 3. Ableitung der Fragestellung (inklusive Hypothesen) 4. Publikation 5. Zusammenfassung der Arbeit 6. Aufnahme in die aktuellen Leitlinien 7. Literaturverzeichnis / The study investigated the association between clinical symptoms and late-onset sepsis (LOS) in preterm infants with the aim of identifying a non-invasive tool for the early detection of LOS. This was a prospective study of 83 episodes of suspected LOS in 67 preterm infants. At the time LOS was suspected, we recorded a standardized set of clinical symptoms. A diagnosis of “clinical LOS” (Clin-LOS), “culture-proven LOS” (Prov-LOS) or “LOS not present” (No-LOS) was made on the basis of C-reactive protein (CrP) and blood culture results. We examined univariable associations between clinical signs and LOS using odds ratio (OR) analysis and then adjusted the odds ratio (adOR) through binary regression analysis. Clin-LOS was diagnosed in 20/83 episodes, 19 cases were found to have Prov-LOS. Clinical signs which had a significant association with Clin-LOS were capillary refill time > 2 s (OR 2.9) and decreased responsiveness (OR 5.2), whereas there was a negative association between gastric residuals and LOS (OR 0.35). However, the most marked association was found for a greater central-peripheral temperature difference (cpTD) > 2 °C (OR 9). In Prov-LOS an increased heart rate (OR 3.1), prolonged capillary refill time (OR 3.3) and again an increased cpTD (OR 16) had a significant association with LOS, whereas gastric residuals were negatively associated (OR 0.29). Regression analysis showed that cpTD was the most striking clinical sign associated with both Clin- (adOR 6.3) and Prov-LOS (adOR 10.5). Conclusions: Prolonged capillary refill time and – more impressive – elevated cpTD were the most useful clinical symptoms for detection of LOS in preterm infants. We especially suggest using cpTD as a predictor of LOS. It is a cheap, non-invasive and readily available tool for daily routines.:1. Einleitung 2. Hintergründe 3. Ableitung der Fragestellung (inklusive Hypothesen) 4. Publikation 5. Zusammenfassung der Arbeit 6. Aufnahme in die aktuellen Leitlinien 7. Literaturverzeichnis

Background: Neonatal sepsis is one of the most important causes for elevated morbidity and mor-tality rates in neonatal intensive care units worldwide. While the clinical manifestations of a neo-natal sepsis tend to be nonspecific, its rapid development and life-threatening potential calls for reliable markers for early detection. Methods: We conducted a retrospective single center study including all neonates suspected of having developed a neonatal sepsis within 2013 - 2016. Perinatal and clinical characteristics, as well as microbiological and laboratory findings were evaluated. Neonatal sepsis was either defined as culture proven sepsis (positive blood culture) or clinical sepsis (at least one symptom and elevated C-reative protein (CRP) concentrations within 72h with nega-tive blood culture). We further differentiated between early-onset (EOS) and late-onset (LOS) sepsis. Results: Microbiological colonisation screening frequently did not detect the organism which sub-sequently caused the sepsis. Depending on the age of the newborn with sepsis (EOS or LOS), as-sociations between different anamnestic and clinical factors (prenatal or postnatal ones) were found. Especially the central-peripheral temperature difference showed a strong association to LOS. Laboratory results useful for the early detection of a neonatal sepsis included interleukin-6 (IL-6) and CRP concentrations. Conclusion: Elevated IL-6 >100 ng/l was a strong marker for neonatal sepsis. When choosing the antibiotics for treatment, data from microbiological colonisation screening should be considered, but not solely relied on. Some indicators for infection depended also on postnatal age.:Einführung 1 Definition 1 Sepsis 1 Pathophysiologie der Sepsis 2 Early-onset Sepsis vs. Late-onset Sepsis 4 Klinik und Diagnostik 6 AWMF-Leitlinie „Bakterielle Infektionen bei Neugeborenen“ 10 Mikrobiologisches Kolonisationsscreening 14 Aufgabenstellung und Zielsetzung 16 Patient:innen und Methoden 18 Datenerhebung 18 Gruppenbildung 20 Statistische Analyse 22 Ergebnisse 23 Early-onset Sepsis mit mikrobiologischem Nachweis 23 Early-onset Sepsis mit nur paraklinischem Nachweis 30 Late-onset Sepsis mit mikrobiologischem Nachweis 36 Late-onset Sepsis mit nur paraklinischem Nachweis 44 Diskussion 50 Art der Erreger in Leipzig 50 Mikrobiologisches Kolonisationsscreening 51 Anamnestische und klinische Risikofaktoren 55 Laborchemische Faktoren 60 Aussagekraft der Blutkultur 69 Grenzen der Studie 71 Weiterer Ausblick 72 Zusammenfassung 75 Literaturverzeichnis 78 Abkürzungsverzeichnis 83 Tabellenverzeichnis 85 Abbildungsverzeichnis 86 Erklärung über die eigenständige Abfassung der Arbeit 88 Curriculum vitae 89 Danksagung 91