Orientador: Tomomasa Yano / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-08T05:27:19Z (GMT). No. of bitstreams: 1 Ananias_Marcelo_M.pdf: 2055583 bytes, checksum: 5fd8a44119cef5e936f452b0c65edb49 (MD5) Previous issue date: 2006 / Resumo: A patogenicidade de Escherichia coli em infecções extra-intestinais (ExPEC) depende das propriedades de virulência bacterianas. Estas, geneticamente, distribuem-se por diversas ilhas associadas a patogenicidade ¿ blocos gênicos contíguos ¿ responsáveis por expressar fatores que permitem às bactérias colonizarem, sobreviverem e assim, agredirem a integridade do hospedeiro. Para setenta e três (73) amostras de E. coli oriundas de pacientes septicêmicos isoladas por hemocultura foram detectadas a sorogrupagem (antígeno O), produção de hemolisinas, produção de enzimas e letalidade em camundongos, assim como o estudo molecular pela PCR de genes dos principais FV relacionados a ExPEC: adesinas ¿ fímbria tipo 1 (fimH), fímbria S (sfaD/E) e fímbria P (papC), além dos alelos 1, 2 e 3 da adesina fimbrial P (papG), adesina afimbrial (afaB/C); cápsula K1/K5 (kpsMTII); sideróforos - aerobactina (iucD), yersiniabactina (fyuA) e salmoquelina (iroN); toxinas ¿ hemolisina (hlyA), fator necrozante citotóxico do tipo 1 (cnf1) e toxina autotransportadora secretada (sat); miscelâneos ¿ invasão do endotélio microvascular cerebral (ibeA), resistência sérica (traT), colicina V (cvaC) e proteína uropatogênica específica (usp). Nenhuma amostra demonstrou atividade proteolítica. A produção de hemolisina foi detectada em 20,5% das amostras. Os sorogrupos O associados a UPEC prevaleceram em 52,1% das amostras contra 13,7% de outros sorotipos. Rugosas e não-tipáveis totalizaram 34,2%. Os resultados da PCR identificaram prevalência acima de 70% para os genes fimH, fyuA, kpsMTII e iucD. Entre 30% e 70% estiveram prevalentes os genes papC e papG, sat, iroN, usp e traT. Os genes sfaD/E, hlyA, cnf1, cvaC, ibeA e afaB/C estiveram presentes em no máximo 20% das amostras. O alelo de maior incidência para papG foi o 2; contudo, o alelo 3 apresentou maiores índices de associação com os outros fatores de virulência e o alelo 1 não foi detectado. A alta prevalência de amostras encapsuladas (74,0%) e hábeis em seqüestrar ferro (75,3%) condiz com a origem septicêmicas das amostras em estudo, que necessariamente devem driblar o sistema imunológico do hospedeiro e seqüestrar ferro. Todavia, os genes com baixa prevalência parecem desempenhar significativa função na ausência dos genes com maior prevalência neste estudo / Abstract: The pathogenicity of Escherichia coli in extraintestinal infections (ExPEC) depends to virulence properties bacterial. This, genetically, spread by several pathogenicity associated islands ¿ genic blocks contiguous ¿ responsible to express factors that allow to bacteria colonize, survive and thus, hurt the host integrity. Seventh tree strains of E. coli isolated from septicemic patients by means of hemoculture, it was detected antigen O sorogroup, production of hemolysins, enzymes e mouse lethality, plus the molecular study by PCR of the main genes associated of virulence factors in ExPEC: adhesins ¿ type 1 fimbriae (fumH), S fimbriae (sfaD/E) and fimbriae P (papC), and the alleles 1, 2 and 3 of adhesin P fimbrial, afimbrial adhesin (afaB/C); capsule K1/K5 (kpsMTII); siderophores ¿ aerobactin (iucD), yersiniabactin (fyuA) and salmochelin (ironN); toxins ¿ hemolysin (hlyA), necrotizing cytotoxic factor type 1 (cnf1) and toxin autotransporter secreted (sat); miscellaneous ¿ brain microvascular endothelial cells invasion (ibeA), seric resistance (traT), colicin V (cvcA) and specific uropathogenic protein (usp). No strain showed proteolytic activity. Hemolysin production was detected in 20,5% of strains. The O sorogroups associated to UPEC prevalent in 52,1% of strains against 13,7% of others sorogroups. Wrinkled and no-type totalized 34,2%. The results of the PCR identified prevalence above 70% for the genes fimH, fyuA, kpsMTII and iucD. Between 30-70% are prevalent the genes papC and papG, sat, iron, usp and traT. The genes sfaD/E, hlyA, cnf1, cvaC, ibeA and afaB/C bave been presents in the maxim 10% of strains. The allele with higher prevalence to papG was 2; but, the allele 3 presented higher numbers of association with others virulence factors. The high prevalence of encapsulated strains (74,0%) and able to uptake iron (75,3%) is according to the origin septicemic of strains studied, that necessarily may escape of the immunological system of host and uptake iron. Howerver, the genes with low prevalence seems to display an important function in the lack of the genes prevalent in this study / Mestrado / Microbiologia / Mestre em Genética e Biologia Molecular

Cortisol, the principal glucocorticoid secreted from the adrenal glands, is essential for life. Healthy cortisol levels are maintained through negative feedback on the central nervous system (CNS) – pituitary stimulatory apparatus which regulates production of adrenocorticotropin (ACTH) and contains a light–entrained intrinsic CNS driven diurnal rhythm. Cortisol participates in a regulatory mechanism where inflammatory cytokines stimulate cortisol release and cortisol in turn suppresses cytokine release. The effects of cortisol in inflammatory states include elevating blood pressure and metabolic regulation. This thesis contains three exploratory studies examining circulating cortisolaemia using the best available methodologies (total and free cortisol and corticosteroid-binding globulin (CBG)) in clinical states characterized by immune activation/ inflammation and altered blood pressure. These clinical states include: (1) septic shock, (2) hypertensive disorders of pregnancy and (3) obesity-induced hypertension. Prior to the studies described here, little was know about cortisolaemia in these common pathological states. Septic shock is a life threatening condition that complicates severe infection and is characterized by systemic inflammation and refractory hypotension. High plasma total cortisol levels and attenuated responses to synthetic ACTH stimulation are associated with increased mortality. The use of corticosteroids in septic shock has been highly controversial for decades, however recent trials have reported haemodynamic and survival benefits associated with the use of physiologic steroid replacement in patients with relative adrenal insufficiency (RAI) – currently defined as a total cortisol increment of 248 nmol/L or less following ACTH (250 μg) stimulation. However, CBG and albumin levels fall by around 50% with an increase in plasma free cortisol in critical illness. Hence, total cortisol may not reflect the biologically active free (unbound) cortisol, suggesting that standard assays for plasma cortisol (which measure total plasma cortisol) underestimate HPA axis activity. In this study, we have showed that plasma free cortisol is a better guide to circulating glucocorticoid activity in systemic infection than total cortisol. We have also validated the use of Coolens’ method in estimating free cortisol in systemic infection, using plasma total cortisol and CBG measurements as plasma free cortisol is not performed in clinical laboratories. Free cortisol measurement allows better categorization of RAI and non-RAI groups with a free cortisol increment of 110 nmol/L as cut-off. Moreover, we have shown that survivors of RAI have normal adrenocortical function on follow-up testing suggesting a lack of functional adrenal reserve rather than adrenal damage during critical illness. Larger randomized controlled trials will be required to redefine RAI using free cortisol measurements and relate that to clinical outcomes and responses to corticosteroid therapy. Nitric oxide (NO) is normally produced in the endothelium by the constitutive form of the NO synthase and this physiologic production is important for blood pressure regulation and blood flow distribution. Studies have shown that an overproduction of NO by the inducible form of NO synthase (iNOS) may contribute to the hypotension, cardiodepression and vascular hyporeactivity in septic shock. Clinical studies of non-selective inhibitors of the L-arginine nitric oxide pathway showed increased mortality from cardiovascular complications. However, glucocorticoids, which improve vasopressor sensitivity, may act by partially suppressing NO synthesis through selective direct inhibition of iNOS, and suppression of inflammatory cytokine synthesis. Hence, plasma nitrate/ nitrite (NOx) levels may provide a titratable end point to individualize glucocorticoid therapy in sepsis. The NOx study in this thesis showed that cortisol (total and free), CBG and NOx correlated to illness severity. Free cortisol, and to a lesser extent total cortisol, but not NOx levels, predicted septic shock. NOx levels were characteristically stable within individuals but inter-individual differences were only partly accounted for by illness severity or renal dysfunction. NOx levels correlated weakly with cortisol, did not relate to the need for vasopressors and were not suppressed by hydrocortisone treatment. Thus, NOx is not a suitable target for glucocorticoid therapy in septic shock. Pregnancy is the only sustained physiologic state of hypercortisolism in humans. A large body of data suggests that excessive foetal and prenatal glucocorticoid exposure leads to reduced birth weight and adverse health in offspring such as elevated blood pressure and insulin resistance. Pre-eclampsia and gamete donor pregnancies are associated with immune activation, elevated inflammatory cytokines as well as elevated blood pressure. Prior to the study described in this thesis however, there was no prospective data on maternal cortisolaemia in these complicated pregnancies. My study has demonstrated for the first time that there was a substantial fall in plasma CBG levels in the last few weeks of gestation with a corresponding rise in free cortisol in normal pregnancy, a finding obscured for methodological reasons in past studies. This free cortisol elevation in late pregnancy may facilitate organ maturation in the foetus and perhaps prepare the mother for the metabolic demands of labour. In pre-eclampsia and gestational hypertension, plasma CBG, total and free cortisol levels were lower in late third trimester; and in IUGR, plasma CBG levels were suppressed from 28 weeks gestation until delivery but with no significant difference in plasma total and free cortisol. Women with assisted reproduction using donor gametes/ embryos had significantly lower plasma CBG, total and free cortisol levels even in those with normal pregnancy outcomes. Low CBG may be due to reduced synthesis or enhanced inflammation-driven degradation. Low maternal cortisol may be due to a lack of placental corticotropin-releasing hormone, or reduced maternal ACTH, driving cortisol production. This unanticipated maternal hypocortisolism in complicated pregnancies may trigger precocious activation of the foetal HPA axis and could have implications for postnatal and adult health. Speculatively, since excess prenatal GCs increase HPA axis activity, we proposed that maternal hypocortisolism may predispose to the hypocortisolaemic state characterized by fatigue, pain and stress sensitivity, in offspring. The third state of immune/ inflammatory activation associated with blood pressure dysregulation studied in this thesis is obesity. The epidemiologic relationship between obesity and hypertension is widely recognised. Central obesity in particular has been associated with exaggerated HPA responses to stimuli. Studies of severe dieting and starvation resulted in hypercortisolism and a significant decrease in CBG. The HPA axis and the renin-angiotensin-aldosterone system (RAAS) have been implicated in the pathophysiology of obesity-induced hypertension. However, there is little data on the effect of moderate weight loss (30% caloric restriction) on adrenocortical function, and the relation of adrenal hormones to altered blood pressure with weight loss. In this study, measures of HPA axis and RAAS and blood pressure monitoring were performed in twenty-five obese subjects before and after a 12-week diet program (6000kJ/day). Short-term, moderate weight loss (mean 8.5 kg) was associated with a small reduction in blood pressure (mean arterial pressure 6 mmHg) and significantly reduced levels of aldosterone and renin but not cortisol levels. These findings suggest that aldosterone may have an important role in the blood pressure reduction with weight loss via a renin mediated mechanism, perhaps involving renal sympathetic tone. In contrast to severe caloric restriction, HPA axis activation does not occur with moderate weight loss. This suggests a threshold effect of weight loss on the HPA axis where greater caloric restriction is required for HPA stimulation, or a counterbalancing of central and direct adrenal effects on HPA axis function. Overall, these three exploratory studies have provided novel data on HPA axis function in systemic infection, pregnancy and in diet-induced weight loss. Each study offers a basis for further studies of HPA axis function in these disorders. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1289330 / Thesis(Ph.D.)-- School of Medicine, 2007.

The purpose of this research study was to improve the nursing care of intravenous catheters by providing evidence on the effects of prolonged duration of intravenous administration set use. Intravenous therapy is a vital part of modern health care. However, its invasive nature can result in infection, with high associated morbidity and mortality. The highest infection rates are displayed in intensive care patients with central venous catheters. The duration of intravenous administration set use may have an impact on infection rates,however the current practice usage and the optimum duration of use is unknown. Previous studies of central venous catheters have reported equal infection rates with 1 to 4 days of administration set use; however few patients have been evaluated with administration sets used beyond this time. Previous research has been limited by the inadequacy of available definitions for Catheter-Related Infection. A prospective, randomised, controlled clinical trial was performed to assess the infection risk of using administration sets for prolonged periods. In the developmental phase prior to the clinical trial; definitions of Catheter-Related Bloodstream Infection (CRBSI) were developed; a nursing practice survey was undertaken to establish the current duration of administration set use; and laboratory experiments were executed to assess the impact of prolonged use on administration set physical integrity and performance. Central venous catheters were randomised to have their administration sets used for 4 days (n = 203) or 7 days (n = 201). Percutaneous central venous catheters were enrolled into the study from two adult intensive care units at a metropolitan, tertiary-referral, teaching hospital. Catheters were multiple-lumen, chlorhexidine-gluconate and silver-sulphadiazine coated lines, both inserted and removed in the intensive care unit. Catheters were cultured for microbial colonisation on removal using the Maki roll-plate technique. Patients were assessed for CRBSI using the developed definitions consisting of categories: definite, probable (type I and II), possible and absent. Prior to the clinical trial, a practice survey questionnaire was administered, and laboratory experimentation was performed. Normality of distribution for continuous variables was assessed using the Kolmogorov- Smirnov statistic. The distribution between groups of variables considered risk factors for Catheter-Related Infection were tested to assess for bias using Chi-square and T-test. Logistic regression modelling was performed to analyse the influence of potentially confounding variables. The incidence of catheter colonisation and CRBSI was tested between groups using Kaplan-Meier survival curve with Log-rank test. Paired T-tests were performed to test for difference in programmed and delivered volumes of administration sets. A general linear model (ANOVA)± a Scheffe post hoc test to isolate difference was fitted to the standardised values of delivered volumes to determine the effects of day of measurement and volume delivery rate on the accuracy of volume delivery. There were 10 colonised tips in the intervention group and 19 in the control group. This difference was not statistically significant (Kaplan Meier survival analysis, Log Rank = 0.87, df = 1, p = 0.35). There were 3 cases of CRBSI per group and the difference in survival from CRBSI was not statistically significant (Kaplan Meier with Log Rank test, p = 0.86). The pre-clinical trial phases of the research programme established that current clinical practice was 3 to 7-day use of administration sets; that administration sets were physically intact and delivered clinically accurate volumes after 7 days of use; and developed useful definitions of CRBSI. Prolonged intravenous administration set use of 7 days was found to have no significant impact on patient infection indicators or physical performance of the sets. This finding is congruent with previous research and trends in current clinical practice. In conclusion, the research findings support the use of intravenous administration sets for 7 days.

Cortisol, the principal glucocorticoid secreted from the adrenal glands, is essential for life. Healthy cortisol levels are maintained through negative feedback on the central nervous system (CNS) – pituitary stimulatory apparatus which regulates production of adrenocorticotropin (ACTH) and contains a light–entrained intrinsic CNS driven diurnal rhythm. Cortisol participates in a regulatory mechanism where inflammatory cytokines stimulate cortisol release and cortisol in turn suppresses cytokine release. The effects of cortisol in inflammatory states include elevating blood pressure and metabolic regulation. This thesis contains three exploratory studies examining circulating cortisolaemia using the best available methodologies (total and free cortisol and corticosteroid-binding globulin (CBG)) in clinical states characterized by immune activation/ inflammation and altered blood pressure. These clinical states include: (1) septic shock, (2) hypertensive disorders of pregnancy and (3) obesity-induced hypertension. Prior to the studies described here, little was know about cortisolaemia in these common pathological states. Septic shock is a life threatening condition that complicates severe infection and is characterized by systemic inflammation and refractory hypotension. High plasma total cortisol levels and attenuated responses to synthetic ACTH stimulation are associated with increased mortality. The use of corticosteroids in septic shock has been highly controversial for decades, however recent trials have reported haemodynamic and survival benefits associated with the use of physiologic steroid replacement in patients with relative adrenal insufficiency (RAI) – currently defined as a total cortisol increment of 248 nmol/L or less following ACTH (250 μg) stimulation. However, CBG and albumin levels fall by around 50% with an increase in plasma free cortisol in critical illness. Hence, total cortisol may not reflect the biologically active free (unbound) cortisol, suggesting that standard assays for plasma cortisol (which measure total plasma cortisol) underestimate HPA axis activity. In this study, we have showed that plasma free cortisol is a better guide to circulating glucocorticoid activity in systemic infection than total cortisol. We have also validated the use of Coolens’ method in estimating free cortisol in systemic infection, using plasma total cortisol and CBG measurements as plasma free cortisol is not performed in clinical laboratories. Free cortisol measurement allows better categorization of RAI and non-RAI groups with a free cortisol increment of 110 nmol/L as cut-off. Moreover, we have shown that survivors of RAI have normal adrenocortical function on follow-up testing suggesting a lack of functional adrenal reserve rather than adrenal damage during critical illness. Larger randomized controlled trials will be required to redefine RAI using free cortisol measurements and relate that to clinical outcomes and responses to corticosteroid therapy. Nitric oxide (NO) is normally produced in the endothelium by the constitutive form of the NO synthase and this physiologic production is important for blood pressure regulation and blood flow distribution. Studies have shown that an overproduction of NO by the inducible form of NO synthase (iNOS) may contribute to the hypotension, cardiodepression and vascular hyporeactivity in septic shock. Clinical studies of non-selective inhibitors of the L-arginine nitric oxide pathway showed increased mortality from cardiovascular complications. However, glucocorticoids, which improve vasopressor sensitivity, may act by partially suppressing NO synthesis through selective direct inhibition of iNOS, and suppression of inflammatory cytokine synthesis. Hence, plasma nitrate/ nitrite (NOx) levels may provide a titratable end point to individualize glucocorticoid therapy in sepsis. The NOx study in this thesis showed that cortisol (total and free), CBG and NOx correlated to illness severity. Free cortisol, and to a lesser extent total cortisol, but not NOx levels, predicted septic shock. NOx levels were characteristically stable within individuals but inter-individual differences were only partly accounted for by illness severity or renal dysfunction. NOx levels correlated weakly with cortisol, did not relate to the need for vasopressors and were not suppressed by hydrocortisone treatment. Thus, NOx is not a suitable target for glucocorticoid therapy in septic shock. Pregnancy is the only sustained physiologic state of hypercortisolism in humans. A large body of data suggests that excessive foetal and prenatal glucocorticoid exposure leads to reduced birth weight and adverse health in offspring such as elevated blood pressure and insulin resistance. Pre-eclampsia and gamete donor pregnancies are associated with immune activation, elevated inflammatory cytokines as well as elevated blood pressure. Prior to the study described in this thesis however, there was no prospective data on maternal cortisolaemia in these complicated pregnancies. My study has demonstrated for the first time that there was a substantial fall in plasma CBG levels in the last few weeks of gestation with a corresponding rise in free cortisol in normal pregnancy, a finding obscured for methodological reasons in past studies. This free cortisol elevation in late pregnancy may facilitate organ maturation in the foetus and perhaps prepare the mother for the metabolic demands of labour. In pre-eclampsia and gestational hypertension, plasma CBG, total and free cortisol levels were lower in late third trimester; and in IUGR, plasma CBG levels were suppressed from 28 weeks gestation until delivery but with no significant difference in plasma total and free cortisol. Women with assisted reproduction using donor gametes/ embryos had significantly lower plasma CBG, total and free cortisol levels even in those with normal pregnancy outcomes. Low CBG may be due to reduced synthesis or enhanced inflammation-driven degradation. Low maternal cortisol may be due to a lack of placental corticotropin-releasing hormone, or reduced maternal ACTH, driving cortisol production. This unanticipated maternal hypocortisolism in complicated pregnancies may trigger precocious activation of the foetal HPA axis and could have implications for postnatal and adult health. Speculatively, since excess prenatal GCs increase HPA axis activity, we proposed that maternal hypocortisolism may predispose to the hypocortisolaemic state characterized by fatigue, pain and stress sensitivity, in offspring. The third state of immune/ inflammatory activation associated with blood pressure dysregulation studied in this thesis is obesity. The epidemiologic relationship between obesity and hypertension is widely recognised. Central obesity in particular has been associated with exaggerated HPA responses to stimuli. Studies of severe dieting and starvation resulted in hypercortisolism and a significant decrease in CBG. The HPA axis and the renin-angiotensin-aldosterone system (RAAS) have been implicated in the pathophysiology of obesity-induced hypertension. However, there is little data on the effect of moderate weight loss (30% caloric restriction) on adrenocortical function, and the relation of adrenal hormones to altered blood pressure with weight loss. In this study, measures of HPA axis and RAAS and blood pressure monitoring were performed in twenty-five obese subjects before and after a 12-week diet program (6000kJ/day). Short-term, moderate weight loss (mean 8.5 kg) was associated with a small reduction in blood pressure (mean arterial pressure 6 mmHg) and significantly reduced levels of aldosterone and renin but not cortisol levels. These findings suggest that aldosterone may have an important role in the blood pressure reduction with weight loss via a renin mediated mechanism, perhaps involving renal sympathetic tone. In contrast to severe caloric restriction, HPA axis activation does not occur with moderate weight loss. This suggests a threshold effect of weight loss on the HPA axis where greater caloric restriction is required for HPA stimulation, or a counterbalancing of central and direct adrenal effects on HPA axis function. Overall, these three exploratory studies have provided novel data on HPA axis function in systemic infection, pregnancy and in diet-induced weight loss. Each study offers a basis for further studies of HPA axis function in these disorders. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1289330 / Thesis(Ph.D.)-- School of Medicine, 2007.

Organisms are continuously exposed to heterogeneous micro- and macro-parasitic species, hence simultaneous infections often occur in wild and farm environments. This joint project aimed to develop a co-infection model between chronic and acute infections, evaluating their impact on the fish immune system. Proliferative Kidney Disease was studied on farmed rainbow and brown trout during natural seasonal outbreaks, using a parasite gene (Tetracapsuloides bryosalmonae RPL18) as a proxy for assessment of parasite burden. In hosts with elevated susceptibility PKD pathogenesis was shaped by an anti-inflammatory phenotype, a profound B cell/antibody response and dysregulated TH cell-like activity. Pathogen-free brown trout were exposed to Viral Haemorrhagic Septicaemia Virus (comparatively using European VHSV-Ia and North American VHSV-IVb strains) or to the bacterium Yersinia ruckeri. This European native species was highly resistant to the VHSV-IVb strain, which was undetectable in internal organs despite raising a strong antiviral and mucosal immune response. Following VHS and Yersiniosis infection, haemo-lymphopoietic organs were screened by RT-qPCR to assess the specific pathogen burdens and characterise the immune responses elicited. Transcription patterns were analysed for Interferons, CXC chemokines, SOCS (potential disease resistance biomarkers) and genes of the PACAP system. Lastly, PKD-infected brown trout were co-infected with VHSV-Ia, resulting in typical lesions while showing reduced and delayed mortality. PKD+/VHS+ fish were identified by RT-qPCR and histopathology screening. Pro-inflammatory and antimicrobial peptide genes were modulated following virus co-infection when compared to fish with single infection, with an earlier activation of cellular and humoral responses, and a stronger up-regulation of TH1 and antiviral genes. Oligonucleotide microarrays were used to assess the broader immune gene transcription modulation between single- and co-infected fish. Overall, the results suggest that the immune response of brown trout might be enhanced during the PKD/VHS co-infection.

Background: Neisseria meningitidis is a gram-negative bacterium with the potential to cause invasive disease. Invasive meningococcal disease (IMD) can be fatal if delay to antibiotic therapy. There are six serogroups, which are capable of causing invasive disease in humans; A, B, C, W, X and Y. Since 2015, serogroup W and serogroup Y account for the majority of IMD cases reported in Sweden. Aim: To investigate the clinical presentations of IMD caused by Neisseria meningitidis serogroup W and Y. Method: Two databases, PubMed and Cochrane, were used to find articles that described the clinical picture of IMD. Articles with description of clinical features of the studied serogroups and with eight cases or more in every study were included. In addition, only original articles were included. Results: A total of 633 articles were found and 11 fulfilled all the inclusion criteria. Five out of seven articles found meningococcemia as the predominating presentation of serogroup W IMD. Two out of the four articles that studied serogroup Y IMD found meningitis at a higher number. Conclusion: The results of this systematic review suggest meningococcemia as a relatively common presentation of serogroup W IMD while meningitis and pneumonia might occur more frequently in serogroup Y IMD. However, these results should be interpreted carefully because the included articles were mostly retrospective studies and future prospective studies are needed to better identify clinical presentations of serogroup W and Y IMD.