To characterize the extracellular fungal proteins associated with the silver nanoparticles, SDS-PAGE was used. Cell filtrate (CF) was isolated by centrifugation from mycelial mat slurry. Protein profiles of cell filtrate clearly showed the presence of several bands of molecular weights between 50 and over 116 kDa (Figure 7, lane 2). Some of these proteins may be responsible for synthesis as well as stability of the silver nanoparticles. Treatment of silver nanoparticles with 1% SDS in boiling water bath for 10 min resulted in

detachment of the capping protein(s) from the nanoparticles. When analyzed by SDS-PAGE, the boiled sample showed an intense band of 85 kDa (Figure 7, lane 4) which was not seen when the nanoparticles were not boiled with sample buffer (Figure 7, lane 3). This band is similar to the protein band present in Protein Tyrosine Kinase inhibitor the cell filtrate (Figure 7, lane 2). It is likely that this 85-kDa protein acts as a capping material and confers stability to the silver nanoparticles. Detection of extracellular proteins responsible for MLN4924 cost synthesis and stability

of silver nanoparticles were also reported from a few other literatures [14, 36]. The presence of natural capping proteins eliminates the postproduction steps of capping which is necessary for most of applications of nanoparticles in the field of medicine. Figure 7 SDS-PAGE analysis of capping protein around the silver nanoparticles. Lane 1, molecular size marker; lane 2, extracellular proteins in the cell filtrate; lane 3, nanoparticles loaded without boiling show no protein band; and lane 4, nanoparticles after boiling with 1% SDS loading buffer show a major 85-kDa capping protein. Genotoxic effect of silver nanoparticles against plasmid DNA Agarose gel electrophoresis

of plasmid pZPY112 treated Fenbendazole with different concentrations of silver nanoparticles showed a dose-dependent induction of DNA strand break, characterized by increased degradation of supercoiled form to relaxed circle to linear forms with increase in concentration of nanoparticles used (Figure 8). DNA strand scission induced by silver nanoparticle leads to gradual degradation in the amount of both linear and supercoiled DNA and appearance of extra bands lower in the gel which are the resultant fragmented DNA (Figure 8). Besides their antimicrobial activity, silver nanoparticles have been shown to be potentially genotoxic by in vivo and in vitro assays [37]. In the present study, the buy GS-1101 genotoxicity exhibited by silver nanoparticles was demonstrated by degradation of plasmid posttreatment even with low concentrations of the nanoparticles. Such genotoxic activities of nanoparticles were reported earlier in case of carbon nanotubes [38] where degree of DNA degradation was directly proportional to the concentration of nanoparticles. A proposed mechanism of DNA damage is through generation of singlet oxygen as reported in the case of copper nanoparticles [30].

In this study, the MLST protocol was modified in two ways; firstly, the primers targeting internal fragments

of each gene were extended from 450–500 to 500–700 bp and secondly, although MLST protocols generally only use five to seven genes, in this study, eight housekeeping genes were used to analyse the population structure of L. lactis. The eight housekeeping gene fragments (carB, groEL, murC, pheS, pyrG, recA, rpoB, uvrC) were amplified from chromosomal DNA from each isolate using amplification and sequencing primers (Table  2). The PCR procedure for the pyrG, carB, murC and pheS genes was done under the following conditions: 94°C for 5 sec, 30 cycles of amplification which included 95°C for 60 sec, 50°C for 45 sec, 72°C for 60 sec and then annealing at 72°C for 10 min. PCR for the remaining genes followed the same experimental conditions except for the annealing temperature which was 54°C. PCR reactions were Ro-3306 in vitro made in a 10 μl reaction mixture containing 0.08 μl Taq polymerase (5 U/μl, Takara, Tokyo), 1 μl 10 × PCR Buffer (Mg2+ free), 0.8 μl dNTPs (2.5 mM each), 0.8 μl MgCl2 (25 mM), 0.4 μl forward primer (10 μM), 0.4 μl reverse primer (10 μM), 1 μl genomic DNA (10–50 ng/μL), and 5.52 μl dH2O. The PCR products were separated by electrophoresis on a 1.2% agarose gel and then visualised using ethidium bromide staining. Sequencing of the PCR products was done by the Shanghai Sangni Biosciences Tucidinostat mw Corporation (Shanghai, China) and the sequences

deposited in the GenBank/EMBL

databases under accession numbers KJ149820 to KJ150219. Data analysis The sequences obtained for the eight housekeeping genes in the MLST protocol from all Selleckchem PND-1186 isolates were imported into BioNumerics software (version 6.0, Applied-Maths, Sint Maartens-Latem, Belgium) and the number of unique alleles per locus obtained. In date analysis, all unique sequences were assigned an allele number and each unique combination of eight allele numbers per isolate was assigned a ST [27]. The guanine-cytosine content, d N /d S ratio (d S is the number of synonymous substitutions per synonymous site and d N is the number of non-synonymous substitutions per non-synonymous mafosfamide site) and the number of polymorphic sites and single nucleotide polymorphisms (SNPs) of the eight housekeeping genes for each isolate were calculated using LIAN-Linkage analysis [51]. The level of linkage disequilibrium between all alleles of the isolates was investigated by determining the standardised index of association (I A S) [34]. Phylogenetic trees were constructed by the neighbour-joining (N-J) method in MEGA version 5.0 software (version 5.0, http://​www.​megasoftware.​net). The relationships between MLST STs and analysis of CCs were revealed using eBURST (Based Upon Related Sequence Types) V 3.0 software ( http://​eburst.​mlst.​net). CCs are typically composed of a single predominant genotype with a number of much less common close relatives of that genotype [52]; the isolates of L.

Materials and methods Materials and chemicals The reporter peptide (CP-RP), the anchor peptide (CP-AP) and the internal standard (IS) (Table 1) were synthesized in the functional genome analysis laboratory of the German Cancer Research Centre (Heidelberg, Germany). HPLC-grade acetonitrile was purchased from Fisher Chemicals (Germany). Formic acid was purchased from Sigma (Germany). Phosphate buffered saline pH 7.4 (PBS) was purchased from PAA Laboratories. Protease buffer: 200 mol/L TrisHCl, 20 mmol/L CaCl2, pH 7.8. Iodoacetamide and trichloroacetic acid were purchased from Sigma and Fluka respectively. AZD2281 manufacturer All reagents and chemicals were at least of analytical grade.

Serum samples Whole blood specimens were Adriamycin acquired from patients with

metastatic colorectal tumors (n = 30) and patients without malignant disease but elevated acute phase protein CRP (n = 30) at the University Hospital Mannheim. Blood from healthy control individuals (n = 30) was taken from employees of the University Hospital Mannheim during routine laboratory testing at the works doctor’s office. Patient characteristics are summarized in Table 2. Blood collection was performed after we obtained institutional review board approval and patients’ written informed consent. After a 30 min clotting time at room temperature the specimens were centrifuged at 20°C for 10 min at 3000 x g. The serum was aliquoted and stored at −80°C until further use. All serum specimens were refrigerated within 6 hours after blood withdrawal. Any handling and processing of serum specimens from tumor patients and controls was performed in click here a strictly randomized and blinded manner. Measurements of C-reactive protein (CRP) and carcinoembryonic antigene (CEA) were performed on the Dimension VistaTM System (Siemens). Sample preparation Serum specimens were diluted in the ratio of 1:3 with PBS to a final volume of 100 μL. The reporter peptide (CP-RP) and the internal standard

(IS) were dissolved in protease buffer to a concentration of 100 μmol/L for CP-RP and 20 μmol/L for the IS. The diluted serum (50 μL) and the mix of RP and IS (50 μL) were incubated at 37°C for 3 h, 6 h or 22 h as depicted in results. The incubation was terminated by adding 100 μL of 10% (v/v) trichloroacetic acid (TCA) and the resulting mixture was kept at 4°C for 30 min prior to Selleckchem SC75741 centrifugation for 15 min. at 4°C and 12.000 rpm in a microcentrifuge (Eppendorf). The supernatant was again centrifuged for 5 min. at 4°C and 12.000 rpm and 2 μL of the supernatant were injected onto the HPLC-column. Liquid chromatography – mass spectrometry (LC-MS) analysis LC-MS was performed using a nano HPLC system (UltiMate3000, Dionex) coupled to a linear ion trap Fourier Transform Ion Cyclotron Resonance mass spectrometer (LTQ-FTICR, Thermo Fisher Scientific) with a chip interface (TriVersa NanoMate, Advion).

The flp-tad gene cluster is constitutively Selleck GDC0068 transcribed as a single polycistronic operon in vitro [4]. Relative to its expression during in vitro growth, tadA transcripts are enriched in experimental pustules, suggesting that the flp-tad operon is upregulated in vivo [11]. CpxRA is the only obvious intact two-component signal transduction system contained in H. ducreyi. Transcription of flp1-3 and several other major virulence determinants are negatively regulated

by conditions that favor phosphorylation of CpxR [9, 12, 13]. Purified recombinant CpxR interacts with the promoter regions of the flp operon in electrophoretic mobility shift assays [13]. Deletion of cpxA leads to loss of CpxA phosphatase activity, activates CpxR, and cripples the ability of H. ducreyi to infect humans [9]. In contrast, a cpxR deletion Evofosfamide mutant has no effect on or upregulates the expression of virulence determinants and is fully virulent in human volunteers [13]. Taken together, the data suggest that the flp-tad operon Staurosporine clinical trial may be upregulated in vivo due to downregulation of CpxRA. The human inoculation experiments are limited in that we are precluded by several regulatory bodies from testing trans-complemented mutants in humans. However, complementation of 35000HPΔflp1-3 in trans restored the ability of the mutant to form microcolonies and bind to HFF cells, suggesting that the phenotype

of the mutant is due to the deletion of the flp genes. In the human inoculation experiments, we use 35000HP to examine the role of virulence factors in H. ducreyi pathogenesis. There are two classes of H. ducreyi strains, which express different immunotypes and proteomes [14, 15]. Although we were able to amplify flp1-3 alleles from six class I and three class II strains (data not shown), attempts to sequence the amplicons were unsuccessful, so we do not know if there is a difference in the flp genes in the class I and class II strains. 35000HP is a class I strain; whether the Flp proteins play a role in the virulence www.selleck.co.jp/products/Metformin-hydrochloride(Glucophage).html of class II strains is

unknown. We previously reported that a tadA mutant is attenuated for pustule formation in the human challenge model [5]. However, the tadA mutant, but not a flp1flp2 double mutant, is attenuated in the rabbit model of chancroid [4, 5]. Nika et al previously reported that both the flp1flp2 mutant and the tadA mutant demonstrate decreased abilities to attach to HFF cells and form fewer microcolonies on HFF cells [4]. These data suggested that microcolony formation by itself is not a virulence factor for H. ducreyi. Although H. ducreyi does not appear to co-localize with fibroblasts in experimental or natural chancroid [16, 17], our data indicate that adherence to HFF cells in vitro correlates with the virulence of H. ducreyi in humans. Similarly, both flp1 and tadA mutants fail to colonize or cause disease in a rat infection model with A.

Once again, following caffeine supplementation times to exhaustion were significantly increased. Results indicated subjects were able to cycle for 96 min during the caffeine trial, as compared to 75 min for placebo [18]. Recently McNaughton et al. [72] reported the effects of a moderate dose of caffeine (6 mg/kg) on 1-hour time trial performance. AR-13324 research buy This investigation is unique to the research because, while

continuous, the protocol also included a number of hill simulations to best represent the maximal work undertaken by a cyclist during daily training. The caffeine condition resulted in the cyclists riding significantly further during the hour-long time trial, as compared to placebo and control. In fact, time trial performance was improved 4-5% by the caffeine treatment over the other two treatments [72]. The use of caffeine in anhydrous form, as compared to a cup of caffeinated

coffee, seems to be of greater benefit for the purpose of enhancing endurance performance. In addition, a low-to-moderate dose of caffeine between 3 and 6 mg/kg appears to be sufficient for enhancing performance in a maximal sustained endurance effort. Caffeine: High-Intensity and Team Sport Exercise It is evident that caffeine supplementation provides an ergogenic response for sustained aerobic efforts in moderate-to-highly trained endurance athletes. The research is more varied, however, GSK2118436 when pertaining to bursts of high-intensity maximal efforts. Collomp et al. [46] reported results for a group of untrained subjects, who participated in only 2-3 hours per week of non-specific sport activity. In a fasted state, and in a crossover design, subjects consumed caffeine at a dose of 5 mg/kg as well as a placebo condition, and performed a 30-second BI-D1870 concentration Wingate test. Compared to a placebo, caffeine did not result selleck kinase inhibitor in any significant increase in performance for peak power or total work performed [46]. These results are in agreement with Greer and

colleagues [45], where in addition to a lack of performance enhancement with caffeine supplementation (6 mg/kg), subjects classified as non-trained experienced a decline in power, as compared to placebo, during the last two of four Wingate bouts [45]. As previously stated, Crowe et al. [47] reported significantly slower times to reach peak power in the second of two bouts of 60-s maximal cycling. Subjects in that study were untrained in a specific sport and consumed caffeine at a dose of 6 mg/kg [47]. Finally, Lorino et al. [47] examined the effects of caffeine at 6 mg/kg on athletic agility and the Wingate test. Results were conclusive in that non-trained males did not significantly perform better for either the pro-agility run or 30-s Wingate test [73]. In contrast, a study published by Woolf et al.

Median survival among patients with “”active”" treatment did not show significant this website differences (log rank test: P > 0.05). Overall median survival was 15.1 months. Median survival rates of the group receiving long-acting

octreotide [Sandostatin LAR], TACE, multimodal therapy and palliative care were 22.4, 22.0, 35.5 and 2.9 months, respectively (Table 2). Survival rates of patients with “”active”" treatment (long-acting octreotide [Sandostatin LAR], TACE or multimodal therapy) were significantly higher than of patients who received palliative care only (log rank test: P = 0.00043, P = 0.00151, P = 0.00005). Median survival among patients with various “”active”" treatment forms did not show significant differences (log rank test: Selleckchem SBI-0206965 P > 0.05). The 1 year survival rate in the long-acting octreotide [Sandostatin LAR] group was 64% and in patients who received multimodal therapy, TACE, and palliative care 90%, 78% and 23%, respectively. The 2 year survival rate in the long-acting octreotide [Sandostatin

LAR] group was 36% and in patients who received multimodal therapy, TACE, and palliative care 80%, 34% and 5%, respectively. Discussion In the present paper we studied Ferrostatin-1 clinical trial retrospectively the influence of octreotide monotherapy (long-acting octreotide [Sandostatin LAR]) on survival of patients with hepatocellular carcinoma and compared it to BCLC stage-matched patients who received either TACE, multimodal therapy or palliative care only. Our data showed that survival rates of Selleck Rucaparib patients with BCLC stage B and any “”active”" treatment (long-acting octreotide [Sandostatin LAR], TACE or multimodal therapy) were significantly higher as compared to patients who received palliative care only. Although survival

time of patients with BCLC stage A and “”active”" treatment (long-acting octreotide [Sandostatin LAR], TACE or multimodal therapy) were more than twice as long as of patients who received palliative care only this difference was not statistically significant. Median survival among patients with various forms of “”active”" treatment did not show significant differences (BCLC stage A and B; log rank test: P > 0.05). In particular, octreotide monotherapy showed a similar outcome compared to patients who received TACE or multimodal therapy. Kouroumalis et al [11] for the first time published a patient population with advanced liver disease (only 3.6% of the patients had Child-Pugh stage A) and HCC treated with octreotide. The treatment group had an excellent median survival of 13.0 months as compared to 4.0 months in the control group, suggesting a beneficial effect of octreotide treatment in this patient population. Similarly, Dimitroulopoulos et al [12] recently reported the results of a randomised placebo-controlled trial which showed a significantly higher survival in somatostatin receptor positive patients receiving long-acting octreotide [Sandostatin LAR] as compared to placebo.

6–7.8), in Europe (1.6–6.4), and in Canada and the United States (3.3–3.8) [1]. This type of cancer is usually characterised with high metastatic activity see more and relatively high fatality. Besides the constantly emphasised role of early recognition and prevention, surgical removal of tumour and chemotherapy constitute the standard treatment [2]. Surgical procedures and hospital treatment expose cancer patients to a high level of hospital

bacterial infections. The risk of hospital bacterial infection is substantial. According to the World Health Organization, between 5% and 10% of patients admitted to hospitals in industrial countries and more than 25% of those in developing countries acquire such infections. This means hundreds of millions of hospital infections every year and a substantial death rate [3]. “”Hospital”" strains of bacteria are the main representatives of antibiotic-resistant, often multi-drug-resistant, microorganisms. Bacteria are particularly efficient in developing resistance because of their ability to multiply very rapidly and because they can easily transfer their resistance genes (by normal replication and conjugation). Hospitals are a critical component of the antimicrobial

resistance problem worldwide. Selleckchem STA-9090 This results from the combination of highly susceptible patients, intensive and prolonged antimicrobial use, and easy cross-infection [4]. Bacteriophages, bacterial viruses unable to infect eukaryotic cells, constitute a serious alternative to antibiotic therapy of bacterial infections [5]. These viruses have been known for almost a hundred years, but renewed interest was noted as the crisis of antibiotic

resistance in bacteria became serious. Although phage therapy is limited to only a few therapeutic centres worldwide, the Farnesyltransferase available data documents its high effectiveness and safety. Complete independence from antibiotics’ antimicrobial mechanisms was also shown, i.e. bacteriophages do not follow antibiotics’ cross-resistance and can be fully effective on antibiotic-resistant bacterial strains [6–9]. The antibacterial activity of bacteriophages has been described rather well and its molecular mechanisms and qualifying agents are also well known. However, knowledge about the direct interactions of bacteriophages with mammalian organisms and their other (i.e. non-antibacterial) activities in mammalian systems is quite scarce. As bacteriophages are unable to infect mammalian cells, they are considered a neutral object characterised by their antigenic properties [10]. It must be emphasised that bacteriophages are natural S63845 in vivo parasites of bacteria, which in turn are parasites or symbionts of mammals (including humans). This implies a role of mammalian organisms as a special environment for bacteriophages’ life cycles. One should expect that bacteriophages adapt to this special “”environment”" and develop the means of interacting with it.

In contrast, treatment with the cytostatic drug cyclophosphamide prevents the recruitment of immune effector cells to the side of infection. Therefore, despite a retarded germination of find more conidia, fungal hyphae stay alive, which is well visualized by the massive increase in fungal DNA determined at the late stage of infection (Figure 2). In agreement, the bioluminescence steadily

increased under this regimen and explanted lungs show a 50 – 100 times higher light emission than observed under corticosteroid treatment. This result shows that bioluminescence measurements and DNA quantification correlate best under the cyclophophamide regimen. Although the bioluminescence readout does not correlate linearily with the fungal burden as measured by qRT-PCR, the general tendency of increasing and decreasing fungal burden as well as the impact of the inflammatory

response seems well reflected Fludarabine by bioluminescence imaging. Impact of immunosuppression regimens on the inflammatory response In order to correlate survival curves, weight loss, fungal burden from DNA quantification and bioluminescence with histopathological findings, additional experiments were performed, in which mice were sacrificed one day (early) and three days (late) post infection. For the clodrolip condition, this website mice were sacrificed eight days after infection to assess any later effect of treatment on mice survival. Lungs were removed, and thin sections were studied for the evaluation of the recruitment of immune effector cell lineages and fungal tissue invasion. Clodrolip treatment Lung instillation with clodrolip was expected to reduce the number of AM, which are generally denoted as the first cellular line of host innate immune defense through phagocytosis and killing of inhaled conidia. To confirm the reduction in the number

of AM, the BAL Idoxuridine fluid of non-infected mice were sampled two days after intranasal administration of clodrolip or liposomes, respectively. Flow cytometry was used to quantify the number of AM within the BAL fluid. The clodrolip treatment resulted in a numeric depletion of 60% of AM (8.30 × 104 ± 1 × 104 versus 2.03 × 105 ± 1.8 × 104) when compared to control liposome treated animals (p < 0.05). Furthermore, the viability of the residual AM subset was only 50% as evaluated by trypan blue staining. Taken together, clodrolip treatment depleted or resulted in the death of 80% of AM compared to control mice. When the cell populations in BAL were evaluated one day post-infection, we noted a 3.2-fold decrease (22 ± 11 versus 71 ± 28%) in the concentration of AM and a 2.6-fold increase (77.5 ± 10 versus 29 ± 28%) in the neutrophil concentration in clodrolip-treated mice compared to control liposome-treated mice (Figure 3A).

039 6 23 0.001   Low 11 20   23 8   Notch1 p38 MAPK signaling pathway expression               High 8 21 0.002         Low 10 21         Association of NF-κB and Notch1 expression with clinical features of ESCC The association of NF-κB expression with several

clinicopathologic factors is shown in Table 1. NF-κB expression in tumor cells was significantly correlated with lymph node metastasis (χ 2 = 32.727, P = 0.001), LVD (χ 2 = 4.312, P = 0.038), VEGF-C expression (χ 2 = 4.241, P = 0.039), https://www.selleckchem.com/products/pnd-1186-vs-4718.html podoplanin expression (χ 2 = 8.076, P = 0.004), and Notch1 expression (χ 2 = 9.675, P = 0.002). Similarly, Notch1 expression in tumor cells was significantly correlated with lymph nodes metastasis (χ 2 = 10.162, P = 0.001), LVD (χ 2 = 6.362, P = 0.010), VEGF-C expression (χ 2 = 17.176, P = 0.001), and podoplanin expression (χ 2 = 6.877, P = 0.008).

There were no associations of Notch1 or NF-κB with age, sex, GDC-0994 cell line or TNM stage of tumors. Association of NF-κB and Notch1 with lymph node metastasis in ESCC In order to observe the association of NF-κB and Notch1 expression levels with lymph nodes metastasis in greater detail, we compared the histoscores of NF-κB and Notch1 expression in the context of lymph node involvement (Figure 1). Significantly, our data suggest differences in the patterns of NF-κB and Notch1 signaling with respect to lymph node metastasis status in ESCC, demonstrating strong expression of NF-κB in ESCC tissue, but weak expression of Notch1

with lymph node involvement (P < 0.05 for both). A multivariate analysis of lymph node involvement in ESCC (Table 2) indicated a positive association of NF-κB and VEGF-C expression with lymph node metastasis, independent of T stage, sex, age, and differentiation of tumor cells. Figure 1 Association of NF-κB and Notch1 expression with lymph node metastasis in ESCC. (A) Compared with samples of ESCC without lymph node involvement, the samples of ESCC with lymph node involvement showed high levels of NF-κB expression and low levels of Notch1 expression (magnification, ×200). (B) In ESCC tissue with lymph node involvement, NF-κB staining was strong (mean histoscore, 5.55 ± 0.41) and Notch1 staining was weak (mean histoscore, 3.41 ± 0.36) compared with 17-DMAG (Alvespimycin) HCl tissues without lymph node involvement (mean histoscores, 4.90 ± 0.43 and 4.27 ± 0.27 for NF-κB and Notch1, respectively; P < 0.05 for both). Table 2 Multivariate analysis of lymph node involvement in ESCC (logistic regression model) Variable β HR (95% CI) P NF-κB 1.551 4.716 (1.037-21.454) 0.045 Notch1 -0.273 0.761 (0.459-1.263) 0.291 VEGF-C 0.866 2.377 (1.257-4.494) 0.008 T stage 0.117 1.125 (0.627-2.016) 0.694 Sex -0.157 0.855 (0.160-4.566) 0.854 Age 0.030 1.030 (0.966-1.098) 0.365 Differentiation – 0.126 0.882 (0.284-2.736) 0.828 Abbreviations: HR, hazard ratio; CI, confidence interval of the estimated HR.

This complex metabolic pathway starts with acetyl-CoA and malonyl-CoA which are converted by the products of the genes PKSP (also called ALB1) and AYG1 into 1,3,6,8 tetrahydroxynaphtalene (THN). Then, by successive steps of reduction (catalyzed by the product of the gene ARP2) and dehydration (catalysed by the scytalone dehydratase and the vermelone dehydratase, encoded by the genes ARP1 and ABR1, respectively), 1,3,6,8-THN is in turn converted to 1,8-DHN, which is finally polymerised by a fungal laccase encoded

by the ABR2 gene. Strains with mutations in the PKSP/ALB1 gene were obtained by exposure to UV or by gene disruption and were shown to be less virulent XAV-939 in vivo than their parent wild-type strains in murine models of disseminated aspergillosis

[4, 5]. In vitro experiments showed that melanin protects the conidia from phagocytosis and increases their resistance to reactive oxygen species Kinase Inhibitor Library in vitro produced by phagocytic cells [4, 6]. However, deletion of the ABR2 gene in a wild-type strain did not reduce virulence in an intranasal mouse infection model [7]. Z-IETD-FMK supplier Figure 1 Biosynthetic pathway of melanin in A. fumigatus. White mutants obtained by Brakhage [5] and Kwon-Chung [4] had mutations in the ALB1 (also called PKSP) gene. Steps inhibited by commercialised DHN-melanin inhibitors are localized (Tc, tricyclazole; Pq, pyroquilon; Fx, fenoxanil). 1,3,6,8-THN, 1,3,6,8-tetrahydroxynaphthalene; 1,3,8-THN, 1,3,6,8-trihydroxynaphthalene; DHN, old dihydroxynaphthalene (adapted from Tsai

et al. [35]). Adherence of microorganisms to the host tissues is considered a crucial step in the initiation of infection. Previous studies on A. fumigatus by our group [8, 9] and others [10, 11] suggested that specific interactions involving the recognition of the extra-cellular matrix (ECM) component proteins, laminin and fibronectin, could mediate adherence. Immunofluorescence studies and scanning or transmission electron microscopy (SEM or TEM) also suggested that fungal adhesins for the ECM proteins are located on the ornamentations of the cell wall of resting conidia, the agents of infection. Therefore, as it had been shown by SEM that laboratory strains with mutations in the ALB1/PKS gene produce smooth-walled conidia, we predicted that melanin also plays an indirect role in pathogenesis, allowing correct assembly of the cell wall layers of resting conidia. In this study, three pigmentless or brownish isolates of clinical or environmental origin, from the BCCM/IHEM Collection (Scientific Institute of Public Health, Brussels, Belgium), were investigated and compared to two reference strains (Figure 2 and Table 1). After characterisation of the genetic defect of the three mutant isolates and visualisation of the conidial surface by SEM, the capaCity of their conidia to bind the ECM components laminin and fibronectin was quantified and the physical properties of the conidial surface were investigated.