Predominance of small dense Low Density Lipoprotein (LDL) is associated with a two to threefold increase in risk for Coronary Heart Disease (CVD). Small, dense HDL (High Density Lipoprotein) particles protect small dense LDL from oxidative stress. Technological advancements have introduced an array of techniques for measuring diameters of LDL and HDL as well as estimating overall particle heterogeneity. However, there is lack of comparative studies between these techniques, and, hence, no conclusive evidence to establish the merits of one method relative to others. The primary purpose of this study was to compare Nondenaturing Gradient Gel Electrophoresis (NDGGE) and Dynamic Laser Light Scattering (DLLS) methods in determining LDL and HDL particle diameter. Our comparison entailed: 1) Evaluating the two methods in terms of their reproducibility 2) Correlating the two methods(in future studies method selection would be driven by time and cost considerations if the two methods correlate), and 3) Evaluating the two methods in terms of their ability to identify bi-modal samples. A secondary purpose of this research was to investigate the effect of refrigerated plasma storage on particle diameter. Reproducibility was measured as Coefficient of Variance (CV). Within and between runs, CV for LDL and HDL for NDGGE were <6% and <15%, respectively and for DLLS, CV within runs were <3% and <5.5%, respectively. No correlation was observed between LDL diameter from the two methods. NDGGE showed two bands for 157 HDL samples of which only 24 samples showed bimodal peaks in DLLS. In order to study the effect of storage, three sample sets of LDL and two sample sets of HDL were used. NDGGE showed a significant difference between mean diameter of fresh and stored LDL and HDL sample for all sets, whereas DLLS showed a significant difference in only one LDL sample set and none for HDL sample sets. We conclude that DLLS may be a better method for measuring LDL diameter because NDGGE overestimated LDL diameter. However, NDGGE was able to resolve subpopulation better in an HDL sample than DLLS. Thus, NDGGE may be a better choice for measuring HDL diameter than DLLS.

The relationship between hyperlipidemia and pancreatitis remains obscure in dogs. The aim of the present study was to investigate any possible association between hyperlipidemia and pancreatitis in dogs. In the first part of the study, Miniature Schnauzers with hypertriglyceridemia were found to have significantly higher serum cPLI concentrations than Miniature Schnauzers with normal serum triglyceride concentrations (P=0.0001). Also, Miniature Schnauzers with severe hypertriglyceridemia (>862 mg/dL) had 4.5 times higher odds (P=0.0343) for having a serum cPLI concentration consistent with pancreatitis. In the second part of the study, 17 Miniature Schnauzers prospectively enrolled with a history of pancreatitis were significantly more likely to have hypertriglyceridemia (71 percent) after resolution of pancreatitis than 34 age-matched Miniature Schnauzers without a history of pancreatitis (33 percent; odds ratio=5.02; P=0.0163). For the third part of the study, assessment of the feasibility and usefulness of a novel density gradient ultracentrifugation method using NaBiEDTA for lipoprotein profiling in dogs was attempted. Density gradient ultracentrifugation using NaBiEDTA was found to be useful for the study of lipoprotein profiles in dogs. Significant differences were detected in the lipoprotein profiles (mainly involving TRL and specific LDL fractions) among healthy Miniature Schnauzers, dogs of various other breeds, and hypertriglyceridemic Miniature Schnauzers. In the fourth part of the study, the effect of a commercially available low-fat diet on serum lipid and pancreas-specific lipase (Spec cPL) concentrations and lipoprotein profiles in Miniature Schnauzers with primary hypertriglyceridemia was evaluated. The study diet was found to be effective in significantly reducing serum triglyceride and cholesterol concentrations and changing the lipoprotein profiles of the dogs studied within 2 months. However, there was no significant effect of the study diet on serum Spec cPL concentrations. In the last part of the study, serum triglyceride and cholesterol concentrations and lipoprotein profiles were compared between dogs with naturally occurring pancreatitis and healthy dogs. The majority of dogs with naturally occurring pancreatitis had normal serum triglyceride and cholesterol concentrations. Important differences were identified in lipoprotein profiles between dogs with pancreatitis (higher LDL2, LDL3, and LDL4 fractions and lower TRL, HDL2a, and HDL3c fractions) and healthy control dogs.

Magister Pharmaceuticae - MPharm / Cardiovascular diseases (CVDs) such as ischaemic heart diseases, heart failure and stroke remain a major cause of death globally. Various deep-rooted factors influence CVD development; these include but are not limited to elevated blood lipids, high blood pressure, obesity and diabetes. A considerable number of proteins are involved directly and indirectly in the transport, maintenance and elimination of plasma lipids, including high and low-density lipoprotein cholesterol (HDL-C and LDL-C). There are several mechanisms involved in the removal of LDL particles from systemic circulation. One such mechanism is associated with the gene that encodes proprotein convertase subtilisin/kexin type 9 (PCSK9), which has become an exciting therapeutic target for the reduction of residual risk of CVDs. Currently, statins are the mainstay treatment to reduce LDL-C, and a need exists to further develop more effective LDL-C-lowering drugs that might supplement statins.

The Drosophila Lipoprotein particles bear lipid-linked morphogens on their surface and are required for long-range signaling activity of Wingless and Hedgehog. They also bind a wide variety of gpi-linked proteins. Whether any of these proteins affect morphogen signaling is unknown. Here, I show that the gpi-linked heparan sulfate proteoglycan Dally is released from cell membranes and binds to lipoprotein particles both with and without its lipid anchor. Hedgehog signaling efficiency is reduced in Dally mutant discs, but can be rescued non-autonomously by expression of non-gpi-modified Dally. This Dally isoform colocalizes with Hedgehog, Patched and Lipophorin in endosomes and increases Hedgehog signaling efficiency without affecting Hedgehog distribution. These data show that Hedgehog signaling activity can be influenced by other Lipophorin-associated proteins, and suggest Lipoproteins provide a platform for regulation of morphogen signaling.

Background Elevated concentrations of low-density lipoprotein cholesterol (LDL-c) are a major risk factor for the development of coronary artery disease (CAD) because of their role in the progression of atherosclerosis. The black South African population is known to have had historically low LDL-c and in the past there was almost no CAD in the population. However, as this population moves through the nutrition transition, LDL-c levels are increasing. LDL-c levels are regulated by the LDL receptors, which is the major protein involved with transporting cholesterol across cell membranes in humans. Proprotein convertase subtilisinlike/kexin type 9 (PCSK9) is another protein involved with the regulation of LDL-c through its role in assisting with the degradation of the LDL receptor. Variants in both genes can cause elevated or lowered LDL-c levels. Very little information is available on the frequency or presence of variants in the low-density lipoprotein receptor (LDLR) and PCSK9 gene in the black South African population and on how these variants associate with LDL-c. The main aim of the study was thus to determine novel and existing genetic variants in these two genes and to describe the manner in which they associate with plasma LDL-c levels in a black South African population undergoing an epidemiological transition. Methods The 2005 baseline data from the Prospective Urban and Rural (PURE) study population were used in this study. The study population consisted of apparently healthy black volunteers form the North West province of South Africa, aged 35 to 60 years. Thirty individuals were randomly chosen from the 1860 volunteers to determine the presence of known and novel variants in these genes by automated bidirectional sequencing. The promoter region, exons and flanking regions were sequenced and variants were identified utilising CLC DNA Workbench. Deoxyribonucleic acid (DNA) samples for 1500 individuals of the PURE study population were genotyped by means of a Golden Gate Genotyping Assay. Analyses of covariance (ANCOVA) were used to test for associations between the different genotypes in both the LDLR and PCSK9 genes and LDL-c levels. Haplotypes were generated by using the confidence intervals on the software programme, HaploView. A genetic risk score (GRS) was determined by including variants which associated significantly with LDL-c. The GRS, the haplotypes and the variants that associated significantly with LDL-c were used in separate linear regression models with variants which correlated with LDL-c to determine how all these variables contribute to the differences in LDL-c levels. Results and discussion Novel and known variants were identified in both the genes and in total 52 variants were genotyped. Rare variants such as rs17249141 and rs28362286 were detected in the study population and are associated with low levels of LDL-c. The variants identified in the LDLR gene were situated largely in regulatory regions such as the promoter, intron and 3‟untranslated regions. Haplotypes in the LDLR gene with the highest frequency associated with lower LDL-c levels, which could contribute to the study population‟s low mean LDL-c level. Haplotypes identified in the PCSK9 gene had a weaker association with LDL-c levels. The minor allele frequencies of many of the variants differed from those of the European population and therefore the importance of population-specific research cannot be sufficiently emphasised. The GRS, haplotypes and variants used in the regression models to determine whether they contributed to predicting the variance in LDL-c in the study population made a small contribution to explaining this. BMI best explained the variance in LDL-c levels. Older women with a body mass index (BMI)>25kg/m2 were identified as being at greater risk of developing elevated LDL-c levels than the rest of the study population. Heterozygote carriers of variant, rs28362286, had 0.787 mmol/L lower LDL-c than carriers of the wild type and this is associated with a reduced risk of developing CAD. Conclusion and recommendation When considering the results mentioned above, adding genetic analysis to explaining the variance in LDL-c levels seems to have its limitations, but the study included only two of many genes that play a role in the metabolism and regulation of LDL-c levels. Incorporating more genes and more variants into analyses and prediction models will add greater value to defining LDL-c levels. Rarer variants with a large impact on protein function, such as rs28362286, have a greater effect on LDL-c levels and could predict the variance better than the common variants. Risk factors such as BMI can also still be trusted to indicate which individuals or groups are at risk of developing elevated LDL-c levels. Health advice should be given to appropriate target groups such as older women with a BMI >25kg/m2 in order to prevent CAD from becoming a burden in this population. / PhD (Dietetics), North-West University, Potchefstroom Campus, 2014

Background Elevated concentrations of low-density lipoprotein cholesterol (LDL-c) are a major risk factor for the development of coronary artery disease (CAD) because of their role in the progression of atherosclerosis. The black South African population is known to have had historically low LDL-c and in the past there was almost no CAD in the population. However, as this population moves through the nutrition transition, LDL-c levels are increasing. LDL-c levels are regulated by the LDL receptors, which is the major protein involved with transporting cholesterol across cell membranes in humans. Proprotein convertase subtilisinlike/kexin type 9 (PCSK9) is another protein involved with the regulation of LDL-c through its role in assisting with the degradation of the LDL receptor. Variants in both genes can cause elevated or lowered LDL-c levels. Very little information is available on the frequency or presence of variants in the low-density lipoprotein receptor (LDLR) and PCSK9 gene in the black South African population and on how these variants associate with LDL-c. The main aim of the study was thus to determine novel and existing genetic variants in these two genes and to describe the manner in which they associate with plasma LDL-c levels in a black South African population undergoing an epidemiological transition. Methods The 2005 baseline data from the Prospective Urban and Rural (PURE) study population were used in this study. The study population consisted of apparently healthy black volunteers form the North West province of South Africa, aged 35 to 60 years. Thirty individuals were randomly chosen from the 1860 volunteers to determine the presence of known and novel variants in these genes by automated bidirectional sequencing. The promoter region, exons and flanking regions were sequenced and variants were identified utilising CLC DNA Workbench. Deoxyribonucleic acid (DNA) samples for 1500 individuals of the PURE study population were genotyped by means of a Golden Gate Genotyping Assay. Analyses of covariance (ANCOVA) were used to test for associations between the different genotypes in both the LDLR and PCSK9 genes and LDL-c levels. Haplotypes were generated by using the confidence intervals on the software programme, HaploView. A genetic risk score (GRS) was determined by including variants which associated significantly with LDL-c. The GRS, the haplotypes and the variants that associated significantly with LDL-c were used in separate linear regression models with variants which correlated with LDL-c to determine how all these variables contribute to the differences in LDL-c levels. Results and discussion Novel and known variants were identified in both the genes and in total 52 variants were genotyped. Rare variants such as rs17249141 and rs28362286 were detected in the study population and are associated with low levels of LDL-c. The variants identified in the LDLR gene were situated largely in regulatory regions such as the promoter, intron and 3‟untranslated regions. Haplotypes in the LDLR gene with the highest frequency associated with lower LDL-c levels, which could contribute to the study population‟s low mean LDL-c level. Haplotypes identified in the PCSK9 gene had a weaker association with LDL-c levels. The minor allele frequencies of many of the variants differed from those of the European population and therefore the importance of population-specific research cannot be sufficiently emphasised. The GRS, haplotypes and variants used in the regression models to determine whether they contributed to predicting the variance in LDL-c in the study population made a small contribution to explaining this. BMI best explained the variance in LDL-c levels. Older women with a body mass index (BMI)>25kg/m2 were identified as being at greater risk of developing elevated LDL-c levels than the rest of the study population. Heterozygote carriers of variant, rs28362286, had 0.787 mmol/L lower LDL-c than carriers of the wild type and this is associated with a reduced risk of developing CAD. Conclusion and recommendation When considering the results mentioned above, adding genetic analysis to explaining the variance in LDL-c levels seems to have its limitations, but the study included only two of many genes that play a role in the metabolism and regulation of LDL-c levels. Incorporating more genes and more variants into analyses and prediction models will add greater value to defining LDL-c levels. Rarer variants with a large impact on protein function, such as rs28362286, have a greater effect on LDL-c levels and could predict the variance better than the common variants. Risk factors such as BMI can also still be trusted to indicate which individuals or groups are at risk of developing elevated LDL-c levels. Health advice should be given to appropriate target groups such as older women with a BMI >25kg/m2 in order to prevent CAD from becoming a burden in this population. / PhD (Dietetics), North-West University, Potchefstroom Campus, 2014

The apoC-III proteoform containing two sialic acid residues (apoC-III2) has different in vitro effects on lipid metabolism compared with asialylated (apoC-III0) or the most abundant monosialylated (apoC-III1) proteoforms. Cross-sectional and longitudinal associations between plasma apoC-III proteoforms (by mass spectrometric immunoassay) and plasma lipids were tested in two randomized clinical trials: ACT NOW, a study of pioglitazone in subjects with impaired glucose tolerance (n = 531), and RACED (n = 296), a study of intensive glycemic control and atherosclerosis in type 2 diabetes patients. At baseline, higher relative apoC-(I)II2 and apoC-III2/apoC-III1 ratios were associated with lower triglycerides and total cholesterol in both cohorts, and with lower small dense LDL in the RACED. Longitudinally, changes in apoC-III2/apoC-III1 were inversely associated with changes in triglycerides in both cohorts, and with total and small dense LDL in the RACED. apoC-III2/apoC-III1 was also higher in patients treated with PPAR-gamma agonists and was associated with reduced cardiovascular events in the RACED control group. Ex vivo studies of apoC-III complexes with higher apoC-III2/apoC-III1 showed attenuated inhibition of VLDL uptake by HepG2 cells and LPL-mediated lipolysis, providing possible functional explanations for the inverse association between a higher apoC-III2/apoC-III1 and hypertriglyceridemia, proatherogenic plasma lipid profiles, and cardiovascular risk.

Οικογενής Υπερχοληστερολαιμία (FH) είναι η επικρατής αυτοσωμική νόσος, κατά την οποία τα επίπεδα χοληστερόλης στο αίμα είναι αυξημένα, εμφανίζονται ξανθώματα και ένα αυτοσωμικό επικρατές χαρακτηριστικό για στεφανιαία αρτηριακή νόσος (CAD). Η FH προκαλείται από ανωμαλία στο γονίδιο LDL-R και κάποιες φορές και στο γονίδιο APOB (apolipoprotein B-100). Η ετεροζυγία του LDLR συναντάται σε αναλογία πληθυσμού 1:500. Πρόσφατα παρατηρήθηκε ότι και το γονίδιο PCSK9 (proprotein convertase subtilisin/kexin type 9) προκαλεί FH. Τα γονίδια APOB και PCSK9 αποκλείστηκαν από τη συγκεκριμένη έρευνα. Στόχοι της διατριβής ήταν (α) η καταγραφή των μεταλλάξεων του γονιδίου LDLR (Low Density Lipoprotein Receptor) σε 21 πληθυσμούς, (β) ο υπολογισμός της συχνότητας αυτών των μεταλλάξεων και (γ) η προσθήκη αυτών των δεδομένων σε μία γενετική βάση δεδομένων, την FINDbase, η οποία δίνει πληροφορίες για τη συχνότητα μιας μετάλλαξης σε κάθε χώρα καθώς και το φαρμακευτικό δείκτη της. Από τους 21 πληθυσμούς, οι 14 προέρχονταν από Ευρωπαϊκές χώρες (Ελλάδα, Γερμανία,Πορτογαλία, Τσεχία, Ολλανδία, Ισπανία, Βρετανία, Ιταλία, Πολωνία, Σουηδία, Γαλλία, Αυστρία, Βέλγιο και Δανία) και οι υπόλοιποι από την Κίνα, την Ιαπωνία, την Μαλαισία, το Λίβανο, τις Φιλιππίνες, την Ταϊβάν και το Καναδά. Τα δεδομένα των μεταλλάξεων σε κάθε πληθυσμό αντλήθηκαν από άρθρα (papers) μέσω της Βάσης Δεδομένων Pubmed και της μηχανής αναζήτησης Google. Τα άρθρα επιλέχθηκαν με βάση (1) το μέγεθος του δείγματος και (2) τη χρονολογία πραγματοποίησης της έρευνας στο συγκεκριμένο πληθυσμό. Η συχνότητα υπολογίστηκε σε σύνολο χρωμοσωμάτων, δηλαδή στο διπλάσιο του μεγέθους του δείγματος. Ως ιδανικό μέγεθος δείγματος θεωρήθηκε ένα σύνολο τουλάχιστον 100 χρωμοσωμάτων, δηλ. 50 άτομα. Η καταγραφή των δεδομένων έγινε σε λογιστικό φύλλο Excel. Τα αποτελέσματα έδειξαν ότι υπάρχει μεγάλη ανομοιογένεια σε επίπεδο μεταλλάξεων ανάμεσα στους 21 πληθυσμούς. / Familial hypercholesterolaemia (FH), defined as the heritable occurence of severe hypercholesterolaemia with cholesterol deposits in tendons and premature heart disease, is caused by at least four genes in sterol and lipoprotein pathways and displays varying gene-dose effects. The genes are the low-density lipoprotein (LDL) receptor, apolipoprotein (apo) B, proprotein convertase subtilisin/kexin 9, and the autosomal recessive hypercholesterolaemia (ARH) adaptor protein. The world-wide prevalence of FH is about 1 in 500 people. In this assessment, the genes apoB, PCSK9 and ARH have been excluded. The aim of this study was the recording of LDLR mutations in 21 populations, the calculation of the mutations’ frequencies in each population and the introduction of these data in the National Ethnic Mutation DataBase (NEΜDB), FINDbase, which gives information about a mutation’s frequency in each country and also about its pharmacogenomic marker. Among 21 populations, 14 were of European origin (Greece, Germany, Portugal, Czech Republic, Netherlands, Spain, Great Britain, Italy, Poland, Sweden, France, Austria, Belgium and Denmark) and the remainders from China, Japan, Malaysia, Lebanon, Philippines, Taiwan and Canada. The mutation data in each population were derived from papers through the database of references, PubMed and the search engine, Google. The selection of papers was based on (1) the size of patient group and (2) the date of paper publication. The calculation of mutation frequency was based on the total number of chromosomes, which was the double size of the patient group. An ideal size of sample was at least 100 chromosomes, which means 50 index patients. The data were inserted in an excel file. The results showed that there is a great ανομοιογένεια in mutation level among 21 populations.

Any lipoproteins and cells present in the inflammatory environment of atherosclerotic plaques are likely to be exposed to high levels of oxidative stress. As 7,8-dihydroneopterin (7,8-NP) is synthesized by interferon-γ (IFN-γ)-activated macrophages, this pteridine is also thought to exist at sites of inflammation. 7,8-NP s in vivo role remains controversial, but numerous in vitro studies have identified a radical scavenging activity. The possibility of 7,8-NP protecting against oxidative damage in inflammatory environments like plaque was investigated in this thesis. Both human monocyte-derived macrophages (HMDMs) and low density lipoprotein (LDL) were used as substrates. The extent of protein hydroperoxide formation in each model, and 7,8-NP s effect on this process, were specifically studied since most previous research has focussed on lipid rather than protein peroxidation. For the first time, neopterin (including oxidized 7,8-NP) was also directly detected by high performance liquid chromatography in the inflammatory environments of 19 pus and two atherosclerotic plaque samples. Peak concentrations even reached the low micromolar range. The positive correlation identified in the pus between neopterin and a well known antioxidant, vitamin E, further hinted at a potential antioxidant function. However, no significant association was noted between neopterin and markers of protein or lipid oxidation. Exposure of HMDMs to the AAPH peroxyl radical generator resulted in significant quantities of lipid hydroperoxides but not protein hydroperoxides, as detected by the FOX assays. This is likely due to the large accumulation of polyunsaturated fatty acidrich lipid in the primary HMDMs during differentiation in 10% human serum and is of relevance to atherosclerotic plaque, where macrophages also become lipid-loaded. The addition of up to 200μM 7,8-NP failed to prevent AAPH-induced lipid peroxidation and was also unable to inhibit a loss of cellular thiols or viability. This lack of effect suggests the damaging peroxyl radicals are not being scavenged by 7,8-NP. The high lipid content of HMDM cells appears to cause the AAPH and/or 7,8-NP to localize to a cellular site, where they are unable to interact. Macrophage-mediated oxidation of LDL in iron(II)-supplemented Hams F10 was associated with the formation of 30-40 moles of protein hydroperoxides per mole of LDL. The close parallel between protein and lipid peroxidation supports the theory that lipid-derived radicals are involved in protein hydroperoxide formation on LDL and indicates that protein hydroperoxides are an early product of LDL oxidation. Their detection during exposure of LDL to both the THP-1 macrophage cell line and primary HMDM cells confirms that protein hydroperoxides are also a normal consequence of macrophage-mediated LDL oxidation. Incubation of LDL with micromolar 7,8-NP prevented macrophage-mediated protein hydroperoxide formation in a concentration-dependent manner. Lipid oxidation and vitamin E loss were similarly inhibited by 7,8-NP during the cell-mediated attack of LDL. Kinetic analysis revealed protection due to extension of the lag phase, with 7,8-NP depletion and initiation of the propagation phase coinciding. This supports a radical scavenging activity for 7,8-NP, resulting in protection of the entire LDL particle. By contrast, the release of nanomolar quantities of 7,8-NP by IFN-γ-stimulated THP-1 macrophages failed to prevent LDL oxidation. HMDMs activated by IFN-γ did significantly inhibit LDL oxidation, including protein hydroperoxide formation, for up to 48 hours but this antioxidant effect was not due to the de novo synthesis of 7,8-NP. These results indicate that both the prevalence of protein hydroperoxides, and the ability of 7,8-NP to act as an antioxidant, depend on the system under investigation. Neopterin exists in inflammatory environments but, considering the lack of protection against AAPH-mediated HMDM oxidation and the 7,8-NP concentration required to inhibit macrophage-mediated LDL oxidation, strong evidence for an antioxidant activity of 7,8-NP in atherosclerotic plaque is currently lacking.

Antibiotic-associated diarrhoea (AAD) and colitis, with the causative agent being the Gram-positive anaerobe, Clostridium difficile, are some of the most important hospital-acquired infections and significant burdens to healthcare services worldwide. Treatment of the infection is often ineffective and currently no vaccine is available against C. difficile infection (CDI). Research to identify novel virulence factors potentially leads to the development of new therapeutic and prophylactic drugs. As lipoproteins have been shown to play key roles in the virulence of several pathogens, the aim of this project was to investigate whether lipoproteins are involved in the virulence of C. difficile. Lipoproteins are anchored to the extracellular side of the cytoplasmic membrane in Gram-positive bacteria. Two enzymes are involved in the biosynthesis of lipoproteins: lipoprotein diacylglycerol transferase (Lgt) attaches lipoproteins to the membrane, and lipoprotein signal peptidase (Lsp) cleaves the signal peptide from the amino-terminus of lipoproteins. In order to study lipoprotein processing in C. difficile, lgt and lsp mutants of the C. difficie 630Δerm strain were generated using the ClosTron system. Antibody reactivity of 14 C. difficile lipoproteins was also investigated. It was shown in this study that lgt mutation caused changes in the lipoproteome of C. difficile. Therefore, inactivation of the lgt gene allowed investigation of the global contribution of lipoproteins to bacterial processes. The physiology and virulence of the lgt mutant was studied in vitro and in vivo. Surprisingly, many of the assayed phenotypes were not significantly affected by disruption of the lgt gene. Nevertheless, the ability of the lgt mutant to adhere to Caco-2 cells was markedly reduced. In addition, the phenotype of the lgt mutant observed in mice suggests that the faecal shedding of C. difficile is affected by Lgt inactivation. In further studies, the CD0873 lipoprotein as a potential adhesin of C. difficile was identified by in silico approach. Contribution of the CD0873 lipoprotein to the adherence of C. difficle was investigated by several different assays and the results strongly suggest that the CD0873 lipoprotein is directly involved in adhesion