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P1761 Extraction, purification and detoxification of Brucella abortus lipopolysaccharide and biological activity evaluation
S500 prostatitis patients by high production of specific anti-CT IgA and iperproduction of IL-8 which positively correlated with the IgA response. The continuous inflammatory reaction leads to persistent tissue damages, fibrosis and pelvic pains in these patients. In conclusion IL-8 and sIgA to CT antigens are the best immunological markers of chronic CT prostatitis. P1759 Host defence control in children with chronic sinusitis: recolonisation of nasal microflora I. Kuznecovs, I. Joksta, K. Jegina (Riga, LV) Objective: Staphylococcus aureus (SA) enterotoxins are associated with host defences mechanism disturbances by elevated specific IgE production in nasal polyps (NP). It is the main cause of disbacteriosis in upper airways. Certain alpha-streptococci have been shown to have growth inhibitory activity against common pathogens in the upper respiratory tract in vitro (K. Roos, 2000). The role of normal flora of upper respiratory tract and its interference with SA in host defences in children with chronic sinusitis (CS) and NP was the aim of present study. Methods: Nasopharyngeal swabs and nasal tissue samples were taken from 120 patients with NP and CS. Antibiotic resistance of the strains was determined with the disc diffusion method. Recolonisation with selected alpha-streptococcal strains was used in 58 patients with nasal polyposis. Method of Nonlinear diagnostic was used for demonstration Results: The rates of nasal carriage of SA were found to be 15% in control group and 89% in patients with NP and 58% with CS. A lower number of alpha-streptococci have been found in patients with NP and CS, compared to control. Colonisation rates of alpha-streptococci strains were 90% in control and 10% in patients with nasal polyposis. MRSA was found in 2% in control and in 51% in patients with NP and 74% with CS. It was demonstrated that nasal carriage of MRSA in patients recolonised with alpha-streptococci was lower (8%) than in nontreated patients with NP and CS. Conclusions: The results, obtained in this investigation can be used in chronic staphylococcal sinusitis treatment in children by recolonisation of nasal microflora with selected alpha-streptococcal strains. It was shown that patients recolonised with alpha streptococci with interfering activity against Staphylococcus aureus, get less recurrences of NP and CS symptoms than nonrecolonised persons. Recolonisation of microflora is a new effective method for host defence control in children with chronic sinusitis. P1760 Immune evasion mechanisms of Aspergillus sp. in cerebral aspergillosis G. Rambach, I. Mohsenipour, M. Dierich, C. Speth (Innsbruck, AT) Objectives: Cerebral aspergillosis is the most dangerous complication of human Aspergillus infections with a death rate of more than 90%. The central nervous system (CNS) is separated from the periphery by the blood-brain-barrier, leaving the local innate immunity with its main components complement, cytokines/chemokines and resident immune cells (microglia, astrocytes) the only defence system. We examined putative evasion strategies of Aspergillus against these weapons: reduction of antigen presentation, inhibition of phagocytosis and degradation of complement proteins. Methods: Immune cells were incubated with fungal secretory factors. Antigen presentation was analysed by quantification of subsequent Tcell activation. Phagocytosis was measured microscopically. Complement degradation was investigated by incubation of purified complement proteins with cerebrospinal fluid (CSF) wherein Aspergillus was grown. Results: The fungal factor patulin significantly reduced the capacity of cells to efficiently present antigens and thus to stimulate immune cells. Furthermore, the presence of different fungal toxins resulted in diminished phagocytosis by brain-resident astrocytes. The growth of Aspergillus sp in CSF resulted in secretion of proteolytic factors which degraded various complement factors. The extent of the proteolysis was dependent of the time period of fungal growth and the used Aspergillus
17th ECCMID / 25th ICC, Posters species. A. fumigatus, the predominant cause of cerebral aspergillosis, showed a rather quick and strong degradation, whereas the proteolysis by A. terreus was weaker and rather slow. Conclusion: These data indicate a broad spectrum of immune evasion mechanisms executed by Aspergillus species. These processes may significantly contribute to the pathogenesis of cerebral aspergillosis. Diminished antigen presentation, attenuation of phagocytosis and probably of further immunological activities of resident defence cells as well as the degradation of complement proteins act as striking weapons against the local immunity of the CNS. On the one hand, these facts in addition to other known escape mechanisms explain the high fatality of this fungal disease, otherwise this plurality shows new optional therapeutical targets to support the established antifungal treatments. Neuroprotective substances or antagonists might neutralise or decrease the harmful effects of mycotoxins; specific protease inhibitors could strengthen the attack of complement against the fungal pathogens. P1761 Extraction, purification and detoxification of Brucella abortus lipopolysaccharide and biological activity evaluation I. Pakzad, A. Rezaee, M. Rasaee, A. Hosseini, A. Kasemnejad, T. Bahman, R. Saied (Ilam, IR) Lipopolysaccharide (LPS) of Brucella abortus is important in brucellosis diagnosis and as one of the components for developing a subunit vaccine against brucellosis. Biological evaluation of B. abortus LPS and it’s protection have been considered as the goal of this research. Brucella abortus LPS was extracted by n-butanol, then it was purified by ultracentrifugation and it was detoxified by alkaline treatment. Toxicity of LPS and detoxified LPS (D-LPS) by LAL (Limulus Amoebocyte Lysate) method, and pyrogenicity in Rabbit was compared. Immunological evaluation in animal model was carried out. Purified LPS from B. abortus by butanol extraction was shown to have <2% (wt/wt) contamination by protein and <1% (wt/wt) contamination by nucleic acids. Pyrogenicity test of B. abortus LPS (10 mg/mL) and E. coli LPS (0.5 mg/mL) was positive, but for D-LPS (10, 50 mg/mL) it was negative. In LAL test, 10 ng/mL of D-LPS was negative, but 0.04 ng/mL of B. abortus LPS was positive and endotoxin unit of B. abortus LPS was less than E. coli LPS. Antibody titer of LPS group was higher than that of D-LPS group. The difference of protection among LPS group, DLPS group comparing with negative control was significant (p0.05), In addition, the difference of protection ratio between LPS and D-LPS groups was not significant. Results show that D-LPS toxicity is severely decreased; we can use several as many as B. abortus LPS for stimulating immune system. Besides, ability of B. abortus LPS is likely much less than the LPS from E. coli to evoke endotoxic shock, and it can be used directly as immunogen. In addition, protection of LPS and D-LPS probably is due to humoral important role in secondary infection of brucellosis.
17th ECCMID / 25th ICC, Posters species. A. fumigatus, the predominant cause of cerebral aspergillosis, showed a rather quick and strong degradation, whereas the proteolysis by A. terreus was weaker and rather slow. Conclusion: These data indicate a broad spectrum of immune evasion mechanisms executed by Aspergillus species. These processes may significantly contribute to the pathogenesis of cerebral aspergillosis. Diminished antigen presentation, attenuation of phagocytosis and probably of further immunological activities of resident defence cells as well as the degradation of complement proteins act as striking weapons against the local immunity of the CNS. On the one hand, these facts in addition to other known escape mechanisms explain the high fatality of this fungal disease, otherwise this plurality shows new optional therapeutical targets to support the established antifungal treatments. Neuroprotective substances or antagonists might neutralise or decrease the harmful effects of mycotoxins; specific protease inhibitors could strengthen the attack of complement against the fungal pathogens. P1761 Extraction, purification and detoxification of Brucella abortus lipopolysaccharide and biological activity evaluation I. Pakzad, A. Rezaee, M. Rasaee, A. Hosseini, A. Kasemnejad, T. Bahman, R. Saied (Ilam, IR) Lipopolysaccharide (LPS) of Brucella abortus is important in brucellosis diagnosis and as one of the components for developing a subunit vaccine against brucellosis. Biological evaluation of B. abortus LPS and it’s protection have been considered as the goal of this research. Brucella abortus LPS was extracted by n-butanol, then it was purified by ultracentrifugation and it was detoxified by alkaline treatment. Toxicity of LPS and detoxified LPS (D-LPS) by LAL (Limulus Amoebocyte Lysate) method, and pyrogenicity in Rabbit was compared. Immunological evaluation in animal model was carried out. Purified LPS from B. abortus by butanol extraction was shown to have <2% (wt/wt) contamination by protein and <1% (wt/wt) contamination by nucleic acids. Pyrogenicity test of B. abortus LPS (10 mg/mL) and E. coli LPS (0.5 mg/mL) was positive, but for D-LPS (10, 50 mg/mL) it was negative. In LAL test, 10 ng/mL of D-LPS was negative, but 0.04 ng/mL of B. abortus LPS was positive and endotoxin unit of B. abortus LPS was less than E. coli LPS. Antibody titer of LPS group was higher than that of D-LPS group. The difference of protection among LPS group, DLPS group comparing with negative control was significant (p0.05), In addition, the difference of protection ratio between LPS and D-LPS groups was not significant. Results show that D-LPS toxicity is severely decreased; we can use several as many as B. abortus LPS for stimulating immune system. Besides, ability of B. abortus LPS is likely much less than the LPS from E. coli to evoke endotoxic shock, and it can be used directly as immunogen. In addition, protection of LPS and D-LPS probably is due to humoral important role in secondary infection of brucellosis.