Draft genome sequence of a prodigiosin-hyperproducing Serratia marcescens strain isolated from Cairo, Egypt

Serratia marcescens is a Gram-negative bacterium with both environmental and host-associated strains. Pigmentation is reportedly inversely correlated with infection frequency, and prodigiosin is one of Serratia pigments that has medical and industrial applications. Here, we report the draft genome sequence of prodigiosin-hyperproducing Serratia marcescens strain N2, isolated from Cairo, Egypt. The sequence is assembled into 142 contigs, with a combined size of 5,570,793 bp. The assembled genome carries typical S. marcescens genes, with potential prodigiosin-biosynthesizing genes detected.

A potential role of mesenchymal stem cells derived from human umbilical cord blood in ameliorating psoriasis-like skin lesion in the rats

BACKGROUND

Psoriasis is a common autoimmune inflammatory skin disease, with no clear cause, treated with topical agents and phototherapy to conventional immunosuppressant drugs and biologic agents. Stem cell therapy has showed significant interest in regenerative medicine. The aim of this study was to use mesenchymal stem cell (MSC) therapy compared to the topical application of the standard conventional corticosteroid cream.

MATERIALS AND METHODS

40 male adult albino rats were used, divided into 4 groups, 10 rats each. Group I (control), Group II (Psoriasis-like lesions induced by usage of Aldara cream), Group III (treated with Betamethasone) and Group IV (treated with mesenchymal stem cells). Specimens were stained with Hematoxylin & Eosin, Masson's trichrome, immune-histochemical technique for CD4, CD8 and CD31. Ultra-sections were prepared for transmission electron microscope examination.

RESULTS

MSCs demonstrated efficacy in reduction of disease severity in the form of uniform epidermal thickness covered by a very thin keratin layer. Normally- arranged layers of epidermal layers, with a clear border demarcation was seen between the epidermis and the dermis with apparently intact basement membrane. TEM showed absence of gaps between the tightly connected cells of the basal layer and the resting basement membrane.

CONCLUSIONS

application of MSCs raises hope for developing a new, safe and effective therapy for psoriatic patients, avoiding the side effects of betamethasone.

Investigating the antimicrobial, antioxidant and cytotoxic activities of the biological synthesized glutathione selenium nano-incorporation

Aqueous glutathione selenium nano-incorporation (GSH-SeN-Inco) was prepared by gamma radiation in presence of microbial glutathione (GSH) and selenium dioxide. The novel prepared GSH-SeN-Inco are validated by UV-vis spectroscopy, TEM (17.5 nm), DLS, XRD, EDX and FTIR spectrum reveals the presence of GSH moiety that coating the selenium nanoparticles (SeNPs) forming GSH-SeN-Inco. The XRD analysis verified the presence of metallic SeNPs. The nucleation and radiolysis mechanism of GSH-SeN-Inco formation are also discussed. The size GSH-SeN-Inco (17.5 nm) is affected by certain factors such as concentration of GSH, selenium dioxide, and absorbed dose of gamma radiation. The present study explored the positive role of GSH-SeN-Inco as an antitumor activity against HepG-2 and MCF-7, with IC₅₀ at a concentration of 1.00 and 0.9 mM, respectively. The GSH-SeN-Inco show significant scavenging activity at 33%. The GSH-SeN-Inco shows antimicrobial potential against Gram-negative and Gram-positive bacteria with significant MIC especially Escherichia coli ATCC 25922 at 5.20 µg/ml.

Complete genome sequence and comparative analysis of two potential probiotics Bacillus subtilis isolated from honey and honeybee microbiomes

BACKGROUND

We have previously isolated Bacillus subtilis HMNig-2 and MENO2 strains, from honey and the honeybee gut microbiome respectively, and demonstrated these strains to produce levansucrase with potential probiotics characteristics. Here we report their complete genome sequence and comparative analysis with other and other B. subtilis strains.

RESULTS

The complete genome sequences of Bacillus subtilis HMNig-2 and MENO2 were de novo assembled from MiSeq paired-end sequence reads and annotated using the RAST tool. Whole-genome alignments were performed to identify functional differences associated with their potential use as probiotics.

CONCLUSIONS

The comparative analysis and the availability of the genome sequence of these two strains will provide comprehensive analysis about the diversity of these valuable Bacillus strains and the possible impact of the environment on bacterial evolution.

SIGNIFICANCE AND IMPACT OF STUDY

We introduce complete genome sequence of two new B. subtilis strains HMNig-2 and MENO2 with probiotic potential and as cell factories for the production of levan and other valuable components for pharmaceutical and industrial applications.

Comparative Structural Analysis of Different Mycobacteriophage-Derived Mycolylarabinogalactan Esterases (Lysin B)

Mycobacteriophage endolysins have emerged as a potential alternative to the current antimycobacterial agents. This study focuses on mycolylarabinogalactan hydrolase (LysB) enzymes of the α/β-hydrolase family, which disrupt the unique mycolic acid layer of mycobacterium cell wall. Multiple sequence alignment and structural analysis studies showed LysB-D29, the only enzyme with a solved three-dimensional structure, to share several common features with esterases (lacking lid domain) and lipases (acting on long chain lipids). Sequence and structural comparisons of 30 LysB homology models showed great variation in domain organizations and total protein length with major differences in the loop-5 motif harboring the catalytic histidine residue. Docking of different p-nitrophenyl ligands (C4-C18) to LysB-3D models revealed that the differences in length and residues of loop-5 contributed towards wide diversity of active site conformations (long tunnels, deep and superficial funnels, shallow bowls, and a narrow buried cave) resembling that of lipases, cutinases, and esterases. A set of seven LysB enzymes were recombinantly produced; their activity against p-nitrophenyl esters could be related to their active site conformation and acyl binding site. LysB-D29 (long tunnel) showed the highest activity with long chain p-nitrophenyl palmitate followed by LysB-Omega (shallow bowl) and LysB-Saal (deep funnel).

Emergence of colistin resistance in multidrug-resistant Klebsiella pneumoniae and Escherichia coli strains isolated from cancer patients

BACKGROUND

Colistin resistance is mainly driven by alterations in the Gram-negative outer membrane lipopolysaccharides and is caused, in most cases, by mutations in mgrB gene. However, the recent emergence of plasmid-encoded colistin resistance among Enterobacteriaceae strains represents a serious threat to global public health. In this paper we have investigated the rates of colistin resistance and the underlying mechanisms in 450 Klebsiella pneumoniae and Escherichia coli isolates obtained from cancer patients in Egypt.

METHODS

Colistin susceptibility and minimum inhibitory concentrations were determined according to the European Committee on Antimicrobial Susceptibility Testing, by broth microdilution, and by E-test. The mcr-1, mcr-2 and mgrB genes were detected by PCR and then sequenced. Clonal diversity in colistin-resistant K. pneumoniae was evaluated by multilocus sequence typing.

RESULTS

Forty (8.8%) colistin-resistant isolates, including 22 K. pneumoniae and 18 E. coli, were isolated over 18 months. Of these, 50% were carbapenem-resistant, out of which nine were blaOXA-48 and seven blaNDM-1 positive. The mechanisms of colistin resistance could be revealed only in three of the 40 resistant strains, being represented by mcr-1 in one blaNDM-1-positive E. coli strain and in one K. pneumoniae ST11 and by mgrB mutations, detected in one K. pneumoniae isolate. None of the studied isolates harbored mcr-2.

CONCLUSIONS

Our results demonstrate a high frequency of colistin resistance in enterobacterial strains isolated from cancer patients, but a low prevalence of the most well known resistance mechanisms.

A Validation Study of the Limulus Amebocyte Lysate Test as an End-Product Endotoxin Test for Polyvalent Horse Snake Antivenom

The only definitive management of snake envenoming is the use of snake antivenom. Endotoxin contamination is a serious threat to the safe use of parenteral drugs. A greater understanding of the nature of limulus amebocyte lysate (LAL) test interference and use of permissible dilutions has minimized enhancement problems. Common interference issues include suboptimal pH, enzyme or protein modification, and nonspecific LAL activation. This study aimed at determining the interference factors associated with validating the antivenom sera preparations to avoid false-positive results when testing snake antivenom serum samples by the LAL method. Phase I (preliminary screening/interference assay) was performed to determine a compatible test dilution, which was then used in Phase II (inhibition-enhancement/validation study). The best approach to resolve interference issues was dilution by 1:80 (maximum valid dilution) plus a specific treatment as heat-activation at 70°C-80°C for 10 min with rehydration of LAL reagent with endotoxin-specific buffer solution.LAY ABSTRACT: Snake antivenom sera are produced by immunizing horses with repeated nonlethal doses of snake venom. Bacterial endotoxins constitute one of the major problems in the formulation of pharmaceutical products. One such method for detecting endotoxin levels is the bacterial endotoxin test (BET). However, some substances show strong interfering action with the BET that cannot be avoided by simply diluting the sample solution. In this work, the test for interfering factors was performed as two identical series of product dilutions-one spiked with 2λ and one left unspiked. The result of the interference test revealed the noninterfering dilution (NID) of the product, which was used for the actual validation. Our results showed that after treating the samples using different procedures, such as heat activation at 70-80°C for 10 min followed by centrifugation at 2000 rpm for 10 min and dilution of samples in BD100 (biodispersing agent), inhibition and enhancement up to 1:100 maximum valid dilution (MVD) were observed. Finally, to resolve this inhibition/enhancement problem, the activated sample was heated at 70-80°C for 10 min with rehydration of the Endosafe LAL reagent in an endotoxin-specific buffer solution (BG120) to block β-d-glucans and limulus amebocyte lysate (LAL) reactive material (LAL-RM).

Hospital Microbiome Variations As Analyzed by High-Throughput Sequencing

Hospital-acquired infections remain a serious threat to human life and are becoming a top public health issue. As the latest advances in sequencing technologies have allowed the unbiased identification of bacterial communities, we aimed to implement emerging omics technologies to characterize a hospital's microbiome at the center of Cairo, Egypt. To this end, we screened surfaces and inanimate objects in the hospital, focusing on bed sheets and door knobs, with additional screening for resistant microbes and resistance genes. While bacterial load and community composition were not dramatically different between door knobs of hospital units with different hygiene levels, the bacterial communities on door knob samples were richer and more diverse than those detected on bed sheets. Bacteria detected on door knobs were a mix of those associated with dust/particulate matter/debris (e.g., Bacillus, Geobacillus, Aeribacillus) and skin-associated bacteria (e.g., Staphylococcus, Corynebacterium). The latter were among the core genera shared by all analyzed samples. Conversely, bacteria that were more abundant in bed sheets were not associated with a particular source (e.g., Pseudomonas and Nitrobacter). Resistance screening indicated an expansion of a mobile beta-lactamase-encoding gene (bla_TEM), reflecting its current global spread. This study is a first step toward more comprehensive screening of hospital surfaces and correlating their microbiome with hospital outbreaks or chronic infections. We conclude that, as hospitals are unique built environments, these findings can inform future infection control strategies in hospitals and health care-related built environments, and attest to the importance of the emerging hospital microbiome research field.

Polymorphisms of base-excision repair genes and the hepatocarcinogenesis

AIM

To determine the possible association between polymorphisms of DNA repair genes, including XRCC1 Arg194Tryp, Arg280His, and Arg399Glu, APE1 Asp148Glu, and NEIL2 Arg257Leu, and the risk of developing hepatitis C virus (HCV)-related hepatocellular carcinoma (HCC).

METHODS

A total of 264 subjects were recruited in this retrospective case-control study and were categorized into four groups: 88 control subjects (CR), 53 chronic hepatitis C patients (CHC), 36 liver cirrhotic patients (LC), and 87 HCC patients. The XRCC1 Arg194Tryp, Arg280His, and Arg399Glu polymorphisms were detected using PCR-RFLP, while real-time PCR was used to genotype APE1 Asp148Glu and NEIL2 Arg257Leu.

RESULTS

Our data revealed that, compared with the healthy controls, for those subjects with the XRCC1 Arg194Trp genotype, the risk of developing CHC, LC, and HCC was increased by 6.66- (odds ratio (OR) = 6.667; 95% confidence interval (CI) = 3.244-13.701; P > 0.01), 3.85- (OR = 3.852; 95% CI = 1.797-8.256; P > 0.01), and 2.14-fold (OR = 2.14; 95% CI = 1.13-4.06; P > 0.05), respectively. There was no association between the risk of HCC development and the XRCC1 Arg280His or XRCC1 Arg399Gln genotypes. Moreover, the analysis showed a lack of association between APE1 Asp148Glu and the risk of HCC development. The analysis of clinicopathological parameters showed that the HCC patients with the XRCC1 Arg280His polymorphism were 2.9 fold more likely to have hepatic lesions in both hepatic lobes (OR: 2.9; 95% CI: 1.15-7.29). Notably, in the HCC patients, the prevalence of the APE1 polymorphism in the males was four times higher than that in the females (OR = 4; 95% CI = 1.129-14.175; P > 0.05).

CONCLUSION

Our results indicate that the XRCC1 Arg194Trp polymorphism could be a risk factor for HCV-related HCC development in Egypt.

Optimization and enhancement of textile reactive Remazol black B decolorization and detoxification by environmentally isolated pH tolerant Pseudomonas aeruginosa KY284155

Azo dyes are complex derivatives of diazene used in food and textile manufacture. They are highly recalcitrant compounds, and account for severe environmental and health problems. Different strains of Pseudomonas species were isolated from textile wastewater effluents. The bioconversion of Remazol black B (a commonly used water soluble dye) by Pseudomonas aeruginosa was observed in static conditions. The bio-decolorization process was optimized by a multi factorial Plackett–Burman experimental design. Decolorization of 200 mg L⁻¹ reached 100% in 32 h. Interestingly, the presence of yeast extract, magnesium and iron in the culture media, highly accelerated the rate of decolorization. Moreover, one of our isolates, P. aeruginosa KY284155, was kept high degradation rates at high pH (pH = 9), which represents the pH of most textile wastewater effluents, and was able to tolerate high concentration of dye up to 500 mg L⁻¹. In bacteria, azo-dye degradation is often initiated by reductive azo compound cleavage catalyzed by azo-reductases. Three genes encoding azo-reductases, paazoR1, paazoR2 and paazoR3, could be identified in the genome of the isolated P. aeruginosa stain (B1). Bioinformatics analyses of the paazoR1, paazoR2 and paazoR3 genes reveal their prevalence and conservation in other P. aeruginosa strains. Chemical oxygen demand dramatically decreased and phyto-detoxification of the azo dye was accomplished by photocatalytic post treatment of the biodegradation products. We suggest applying combined biological photocatalytic post treatment for azo dyes on large scale, for effective, cheap decolorization and detoxification of azo-dyes, rendering them safe enough to be discharged in the environment.

Isolation, Characterization and Bioactivities of an Extracellular Polysaccharide Produced from Streptomyces sp. MOE6

A Streptomyces strain was isolated from soil and the sequence of 1471 nucleotides of its 16S rDNA showed 99% identity to Streptomyces sp. HV10. This newly isolated Streptomyces strain produced an extracellular polysaccharide (EPS) composed mainly of glucose and mannose in a ratio of 1:4.1, as was characterized by Fourier transform infrared spectroscopy (FTIR), HPLC and ¹H-NMR. The antioxidant activities of the partially purified MOE6-EPS were determined by measuring the hydroxyl free radical scavenging activity and the scavenging of 2,2-diphenyl-2-picryl-hydrazyl (DPPH) radicals. In addition, the partially purified MOE6-EPS showed high ferrous ion (Fe2+) chelation activity which is another antioxidant activity. Interestingly, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays that were colorimetric assays for NAD(P)H-dependent cellular oxidoreductases and a proxy of the number of viable cells, showed that the partially purified MOE6-EPS inhibited the proliferation of the human breast cancer cells (MDA-MB-231). The scratch wound assay showed that MOE6-EPS reduced the migration of mouse breast cancer cells (4T1). This study reports the production of EPS from Streptomyces species with promising antioxidant, metal chelating and mammalian cell inhibitory activities.

Optimization of prodigiosin production by Serratia marcescens using crude glycerol and enhancing production using gamma radiation

Prodigiosin is a red pigment produced by Serratia marcescens. Prodigiosin is regarded as a promising drug owing to its reported characteristics of possessing anti-microbial, anti-cancer, and immunosuppressive activity. A factorial design was applied to generate a set of 32 experimental combinations to study the optimal conditions for pigment production using crude glycerol obtained from local biodiesel facility as carbon source for the growth of Serratia marcescens. The maximum production (870 unit/cell) was achieved at 22 °C, at pH 9 with the addition of 1% (w/v) peptone and 109 cell/ml inoculum size after 6 days of incubation. Gamma radiation at dose 200 Gy was capable of doubling the production of the pigment using the optimized conditions and manipulating production temperature. Our results indicate that we have designed an economic medium supporting enhanced Serratia marcescens MN5 prodigiosin production giving an added value for crude glycerol obtained from biodiesel industry.

Development and evaluation of a novel vaccine against prevalent invasive multi-drug resistant strains of Streptococcus pneumoniae

Streptococcus pneumoniae is a pathogen that causes serious invasive infections, such as septicemia, meningitis and pneumonia in addition to mild upper respiratory tract infections. Protection from pneumococcal diseases is thought to be mediated mainly by serotype-specific antibodies to capsular antigens. Pneumococcal conjugate vaccine consists of sugars (polysaccharides) from the capsule of the bacterium S. pneumoniae that are conjugated to a carrier protein. Three pneumococcal conjugated vaccines, each directed against a group of serotypes, are registered in Egypt; however, local vaccine production is required to cover the most prevalent serotypes. In this work, capsular polysaccharide from the most current and prevalent serotypes in Egypt were extracted, purified and conjugated to bovine serum albumin (BSA). The polysaccharide protein conjugate was purified through ultrafiltration technique and molecular size distribution was compared to an available vaccine. The immunogenicity of the prepared vaccine was examined via two methods: First, by measuring the levels of the elicited antibodies in the sera of the vaccinated mice; second, by challenging the vaccinated groups of mice with approximately 107 CFU of each specific serotype and determining the degree of protection the developled vaccine offers. Our results show that the developed conjugated capsular polysaccharide vaccine is highly immunogenic and protective in mice. This finding illustrates the importance of tracking the most recent and predominant peneumococcal serotypes to generate effective vaccines, instead of using expensive imported vaccines with large number of serotypes which might not be even present in the community.

Cancer derived peptide of vacuolar ATPase 'a2' isoform promotes neutrophil migration by autocrine secretion of IL-8

Neutrophils play significant regulatory roles within the tumor microenvironment by directly promoting tumor progression that leads to poor clinical outcomes. Identifying the tumor associated molecules that regulate neutrophil infiltration into tumors may provide new and specific therapeutic targets for cancer treatment. The a2-isoform of vacuolar ATPase (a2V) is uniquely and highly expressed on cancer cell plasma membrane. Cancer cells secrete a peptide from a2V (a2NTD) that promotes the pro-tumorigenic properties of neutrophils. This provides a2V the propensity to control neutrophil migration. Here, we report that the treatment of human neutrophils with recombinant a2NTD leads to neutrophil adherence and polarization. Moreover, a2NTD treatment activates surface adhesion receptors, as well as FAK and Src kinases that are essential regulators of the migration process in neutrophils. Functional analysis reveals that a2NTD can act as a chemo-attractant and promotes neutrophil migration. In addition, a2Neuɸ secrete high levels of IL-8 via NF-κB pathway activation. Confirmatory assays demonstrate that the promoted migration of a2Neuɸ was dependent on the autocrine secretion of IL-8 from a2Neuɸ. These findings demonstrate for the first time the direct regulatory role of cancer associated a2-isoform V-ATPase on neutrophil migration, suggesting a2V as a potential target for cancer therapy.

Breast cancer associated a2 isoform vacuolar ATPase immunomodulates neutrophils: potential role in tumor progression

In invasive breast cancer, tumor associated neutrophils (TAN) represent a significant portion of the tumor mass and are associated with increased angiogenesis and metastasis. Identifying the regulatory factors that control TAN behavior will help in developing ideal immunotherapies. Vacuolar ATPases (V-ATPases), multi-subunit proton pumps, are highly expressed in metastatic breast cancer cells. A cleaved peptide from a2 isoform V-ATPase (a2NTD) has immunomodulatory role in tumor microenvironment. Here, we report for the first time the role of V-ATPase in neutrophils modulation. In invasive breast cancer cells, a2NTD was detected and a2V was highly expressed on the surface. Immunohistochemical analysis of invasive breast cancer tissues revealed that increased neutrophil recruitment and blood vessel density correlated with increased a2NTD levels. In order to determine the direct regulatory role of a2NTD on neutrophils, recombinant a2NTD was used for the treatment of neutrophils isolated from the peripheral blood of healthy volunteers. Neutrophils treated with a2NTD (a2Neuɸ) showed increased secretion of IL-1RA, IL-10, CCL-2 and IL-6 that are important mediators in cancer related inflammation. Moreover, a2Neuɸ exhibited an increased production of protumorigenic factors including IL-8, matrix metaloprotinase-9 and vascular endothelial growth factor. Further, functional characterization of a2Neuɸ revealed that a2Neuɸ derived products induce in vitro angiogenesis as well as increase the invasiveness of breast cancer cells. This study establishes the modulatory effect of breast cancer associated a2V on neutrophils, by the action of a2NTD, which has a positive impact on tumor progression, supporting that a2V can be a potential selective target for breast cancer therapy.

Abstract 728: Enhancement of survival and migration of neutrophils by tumor associated a2 isoform vacuolar ATPase

Tumors associated neutrophils (TAN) regulate the tumor environment by directly promoting tumor progression and represent a potential therapeutic target for cancer treatment. Identifying tumor associated factors that promote neutrophil recruitment and survival will uncover new targets for cancer therapy. In tumor cells, a secreted peptide from the N­terminal domain of a2­ isoform vacuolar ATPase (a2NTD) promotes the protumorigenic properties of neutrophils which in turn, enhance tumor progression. In order to investigate the regulatory role of a2NTD on neutrophils survival, we stimulated freshly isolated neutrophils from healthy volunteers with recombinant a2NTD. a2NTD treatment delayed apoptosis in neutrophils and led to 2.1 fold increase in the percentage survival (P < 0.001). In addition, a2NTD treated neutrophils (a2Neuφ) showed a significant decreased gene expression of caspase-3, -6, -7 and -8, that was associated with decreased activity of these caspases. Further analysis of the apoptosis related molecules revealed that a2NTD treatment upregulates the gene expression of anti-apoptotic factors; Bcl2-A1, Bcl-xL, c-FLIP, G-CSF and downregulates the gene expression of pro-apoptotic factors; BAX and Apaf-1. Since NF-kB pathway is an important regulator of apoptosis, here we showed by immunofluorescence analysis that a2NTD induces NF-kB p65 activation in neutrophils by nuclear translocation in a reactive oxygen species generation dependent manner. Additionally, treatment of a2Neuφ with specific NF-kB inhibitor; parthenolide showed a significant abrogation in neutrophil survival as well as downregulation of the gene expression of Bcl2-A1, Bcl-xL, G-CSF and upregulation of BAX. Suggesting that a2NTD enhances neutrophil survival by activating NF-kB pathway in neutrophils. Interestingly, live imaging revealed that a2NTD stimulates neutrophil polarization which was confirmed by the increased assembly of F-actin. Also, flow cytometry analysis revealed that a2NTD treatment stimulates surface expression and activation of Mac-1 integrin. Moreover, important regulators of neutrophil migration; FAK and Src Kinases were activated in a2Neuφ. Previous studies showed that IL-8; potent neutrophil chemoattractant is secreted by neutrophils. Here, we showed that a2NTD treatment led to upregulation of the gene expression and the secreted protein levels of IL-8 in a time dependent manner. This enhanced secretion of IL-8 was NF-kB dependent. Furthermore, to evaluate the influence of a2NTD on neutrophil migration we did trans-well migration assay. a2NTD stimulation caused 2.8 fold increase in neutrophil migration which decreased to 1.5 fold upon neutralizing IL-8 (P < 0.05). Together, these data demonstrate a novel role of the tumor associated a2-vacuolar ATPase on regulating neutrophil survival and migration, by the action of a2NTD.

Citation Format: Safaa A. Ibrahim, Arpita Kulshrestha, Mukesh K. Jaiswal, Gajendra K. Katara, Magdy A. Amin, Kenneth D. Beaman. Enhancement of survival and migration of neutrophils by tumor associated a2 isoform vacuolar ATPase. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 728.

T4 lysozyme fused with cellulose-binding module for antimicrobial cellulosic wound dressing materials

AIMS

Bacterial infection is a major challenge in wound care. Antimicrobial wound dressings are of great value for treating wound infections. Endolysins are evolving as a new class of antimicrobials with multiple applications. This study describes the production and evaluation of T4 lysozyme (T4Lyz), product of gene e of the T4 bacteriophage, fused with Cellulose Binding Module (CBM) for facile immobilization to cellulosic wound dressing.

METHODS AND RESULTS

Genes encoding T4Lyz-CBM and T4Lyz were cloned and expressed in Escherichia coli and the enzymes were purified by cation exchange chromatography. While the CBM tag did not alter the optimum pH and stability features of T4Lyz, the lytic activity of the fusion protein was lowered. The bactericidal activity of T4Lyz-CBM, determined by viable count plating assay after 1 h incubation with Micrococcus lysodeikticus was 97·5% with 10 μg ml(-1) , and 99·96% and 95% for E. coli and Pseudomonas mendocina, respectively, with 200 μg ml(-1) enzyme. T4Lyz-CBM was immobilized to wound dressing gauze with a capacity of 5·5 μg mg(-1) matrix, whereas the unmodified T4Lyz did not exhibit any binding. The immobilized protein retained its bactericidal activity against Gram-positive and Gram-negative bacteria. Both free and immobilized T4Lyz-CBM, after heat denaturation, retained their bactericidal activities against Gram-negative bacteria only. The immobilized enzyme exhibited higher stability than the free enzyme when stored in dry form or in the presence of polyol stabilizers.

CONCLUSION

Tagging T4Lyz with CBM provides a facile, irreversible binding to cellulosic wound dressing while retaining its activity. This approach may be suitable even for other antimicrobial enzymes and -peptides.

SIGNIFICANCE AND IMPACT OF THE STUDY

The spread of antibiotic resistance requires innovative strategies for discovery and development of effective antimicrobial alternatives. This report presents a novel strategy for producing antimicrobial wound dressing materials.

Emergence of Neoteric Serotypes Among Multidrug Resistant Strains of Streptococcus pneumoniae Prevalent in Egypt

Background

Streptococcus pneumoniae is still one of the major causes of morbidity and mortality worldwide. The prevalent serotype distribution had shown variation along different studies conducted at different time intervals. In order to efficiently assess the epidemiology of the diseases for effective preventive and treatment strategies, serotype prevalence need to be periodically reassessed.

Objectives

Conducting a reassessment of the prevalent S. pneumoniae serotypes in Egypt as an essential step in the search for a regional vaccine. In addition, monitoring the antibiotic susceptibility patterns of pneumococcal strains currently causing infections as an evaluation of therapeutic strategies applied.

Materials and Methods

A total of 100 specimens of different sources were collected in Cairo, Egypt, from 2011 to 2013, representing almost all different types of diseases caused by S. pneumoniae such as meningitis, pneumonia, otitis media and sinusitis. Conventional and molecular identification methods were performed, the antimicrobial susceptibility patterns were assessed and serotyping was done using PCR assays to identify the most prevalent types. In addition, detection of certain virulence genes for the most prevalent serotypes was carried out.

Results

Our results revealed that in Egypt, currently, the most prevalent serotypes were serogroup 6 and serotype 19F as they represented 58% of all isolates. High rates of resistance were found to different antibiotic classes. The lytA and psaA genes were found to be more sensitive for S. pneumoniae identification than ply.

Conclusions

Our study illustrates the importance of constantly monitoring the prevalent serotypes in any region in order to aid in the development of more effective vaccines.

The application of uniplex, duplex, and multiplex PCR for the absence of specified microorganism testing of pharmaceutical excipients and drug products

Notable progress has been made in methods that encourage the use of polymerase chain reaction (PCR) as a rapid and accurate tool in microbiological testing of pharmaceuticals. In this study, the detection of the four main specified microorganisms according to the pharmacopeial recommendations, Salmonella spp, Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus, was optimized in different pharmaceutical dosage forms and raw materials. Uniplex PCR was performed for the detection of each microorganism individually targeting the conserved region in each bacterial genome. Further optimizations were done to perform duplex and multiplex PCR assays considering relative concentrations of competitor primers used in the reaction. The uniplex PCR amplicons were successfully sequenced, confirming the conservation of used primers. Other validation parameters such as specificity, sensitivity, and robustness were examined closely. The method provides a high-throughput screening method to test different pharmaceutical preparations for specified microorganisms for the detection of microbiological contamination.

LAY ABSTRACT

Strict regulations govern the production of pharmaceutical products whether they are sterile or nonsterile. Certain official tests are carried out in microbiology testing laboratory in any pharmaceutical production facility to ensure the pharmaceuticals microbiological quality according to the standard pharmacopeial recommendations. Nonsterile products must be free of specified microorganisms that are used as a check for their quality. Topical preparations must be free of Pseudomonas aeruginosa and Staphylococcus aureus, and oral preparations must be free of Salmonella spp and Escherichia coli. Conventional microbiological methods are time-consuming, labor-intensive, and require long incubation times, resulting in delaying the release of the products. In this study, we tested and validated a polymerase chain reaction identification approach to detect indicator bacteria in pharmaceutical preparations. The method depends on amplification of certain conserved genes located in the four specified bacteria. The method is optimized to be carried out individually or collectively to detect all indicator bacteria in a single reaction in different forms of pharmaceutical products.

Immunoinformatics Identifies a Lactoferrin Binding Protein A Peptide as a Promising Vaccine With a Global Protective Prospective Against Moraxella catarrhalis

BACKGROUND

Moraxella catarrhalis is an established pathogen that is causing substantial infections to both children and adults. However, so far there is no effective vaccine to halt the spread of these infections.

METHODS

Immunoinformatics tools were used to predict M. catarrhalis epitopes that could offer immunoprotection among major proportions of human populations worldwide. Mice were immunized with the best 3 peptides and then challenged with M. catarrhalis in the pulmonary clearance model. Finally, antibodies against these epitopes were detected in humans.

RESULTS

Immunoinformatics analyses identified 44 epitopes that are predicted to be good major histocompatibility complex class II binders and at the same time show high population coverage worldwide. After intraperitoneal immunization of mice with the best 3 peptides, peptide A, derived from lactoferrin-binding protein A, showed superior activity in immunogenicity and in clearing M. catarrhalis from mouse lungs. Higher clearance was obtained by combining intraperitoneal and intranasal immunization. In the serum samples from children with otitis media infected with M. catarrhalis, antibody levels against peptide A were significantly lower than in samples from children without otitis media.

CONCLUSIONS

Peptide A is the first promising peptide-based vaccine against M. catarrhalis Immunoinformatics predicts that it should have a global protection around the world.

Development of safe, effective and immunogenic vaccine candidate for diarrheagenic Escherichia coli main pathotypes in a mouse model

Background

Enteric and diarrheal diseases are important causes of childhood death in the developing world. These diseases are responsible for more than 750 thousand deaths in children under 5 years old worldwide, ranking second cause of death, after lower respiratory diseases, in this age group. Among the major causative agents of diarrhea is Escherichia coli. There are several vaccine trials for diarrheagenic E. coli. However, diarrheagenic E. coli has seven pathotypes and vaccines are directed for one or two of the five main pathotypes-causing diarrhea. Currently, there are no combined vaccines available in the market for all five diarrheagenic E. coli pathotypes. Therefore, we aimed to develop a low-cost vaccine candidate combining the five main diarrheagenic E. coli to offer wide-spectrum protection. We formulated a formalin-killed whole-cell mixture of enteroaggregative, enteropathogenic, enteroinvasive, enterohemorrhagic, and enterotoxigenic E. coli pathotypes as a combined vaccine candidate.

Results

We immunized Balb/C mice subcutaneously with 10⁹ CFU of combined vaccine candidate and found a significant increase in survival rate post challenge compared to unimmunized controls (100 % survival). Next we aimed to determine the immunological response of mice to the combined vaccine candidate compared to each pathotype immunization. To do so, we immunized mice groups with combined vaccine candidate and monitored biomarkers levels over 6 weeks as well as measured responses post challenge with relevant living E. coli. We found significant increase in specific systemic antibodies (IgG), interferon gamma (IFNγ) and interleukin 6 (IL-6) levels elicited by combined vaccine candidate especially in the first 2 weeks after mice immunization compared to controls (p < 0.05). We also evaluated alum and cholera toxin B subunit (CTB) as potential adjuvant systems for our candidate vaccine. We found that CTB-adjuvanted combined vaccine candidate showed significantly higher IgG and IFNγ levels than alum.

Conclusions

Overall, our combined vaccine candidate offered protection against the five main diarrheagenic E. coli pathotypes in a single vaccine using mouse model. To the best of our knowledge, this is the first combined vaccine against the five main diarrheagenic E. coli pathotypes that is cost-effective with promise for further testing in humans.

Electronic supplementary material

The online version of this article (doi:10.1186/s13104-016-1891-z) contains supplementary material, which is available to authorized users.

Direct Detection of Burkholderia cepacia in Susceptible Pharmaceutical Products Using Semi-Nested PCR

Burkholderia cepaciahas recently received a considerable attention as one of the major risks in susceptible pharmaceutical products. This microorganism can easily propagate and cause vast and severe contamination, especially to the water supplies for pharmaceutical companies. Moreover, it proliferates within the products and can cause severe infections for humans. Therefore, fast and sensitive detection of these bacteria is of a great demand. The present study introduces improved application of a polymerase chain reaction assay with relatively high sensitivity and specificity for the direct detection ofB. cepaciafrom the aqueous pharmaceutical products. A semi-nested polymerase chain reaction approach using the primer set BCR1/BCR2 followed by BCR1/Mr yielding a 465 bp fragment of the recA gene was applied and tested using both crude lysate from isolated colonies and DNA directly extracted from artificially prepared and spiked reference syrup. The polymerase chain reaction assay showed no interference with other bacterial reference and environmental strains tested, includingStaphylococcus aureusATCC® 6538,Pseudomonas aeruginosaATCC® 9027,Escherichia coliATCC® 8739,Salmonella abonyNCTC® 6017,Bacillus subtilisATCC® 6633,Micrococcus luteus, Staphylococcus warneri, Pseudomonas fluorescens, Pseudomonas putida, andRalstonia pickettii Moreover, this semi-nested assay showed a detection limit of around 10 colony-forming units per sample and could detectB. cepaciastrains isolated from a municipal pre-treated potable water tank. Comparing the results for detection ofB. cepaciain 100 randomly collected commercial syrup preparations using both conventional standard method and polymerase chain reaction assay revealed thatB. cepaciawas detected in two samples using polymerase chain reaction assay while all samples showed negative results by conventional culturing and biochemical methods. These results highlight the advantage of using this polymerase chain reaction assay to detectB. cepaciain contaminated pharmaceutical products and even water for pharmaceutical purposes, without the need of culturing or pre-enrichment, where it may give false-negative results and may be misidentified when biochemically tested.

Multiplexed integrating plasmids for engineering of the erythromycin gene cluster for expression in Streptomyces spp. and combinatorial biosynthesis

Bacteria in the genus Streptomyces and its close relatives are prolific producers of secondary metabolites with antibiotic activity. Genome sequencing of these bacteria has revealed a rich source of potentially new antibiotic pathways, whose products have never been observed. Moreover, these new pathways can provide novel genes that could be used in combinatorial biosynthesis approaches to generate unnatural analogues of existing antibiotics. We explore here the use of multiple orthologous integrating plasmid systems, based on the int/attP loci from phages TG1, SV1, and ϕBT1, to express the polyketide synthase (PKS) for erythromycin in a heterologous Streptomyces host. Streptomyces strains containing the three polyketide synthase genes eryAI, eryAII, and eryAIII expressed from three different integrated plasmids produced the aglycone intermediate, 6-deoxyerythronolide B (6-dEB). A further pair of integrating plasmids, both derived from the ϕC31 int/attP locus, were constructed carrying a gene cassette for glycosylation of the aglycone intermediates, with or without the tailoring gene, eryF, required for the synthesis of erythronolide B (EB). Liquid chromatography-mass spectrometry of the metabolites indicated the production of angolosaminyl-6-dEB and angolosaminyl-EB. The advantages of using multiplexed integrating plasmids for engineering expression and for combinatorial biosynthesis were demonstrated.

Quality Control Testing for Tracking Endotoxin-Producing Gram-Negative Bacteria during the Preparation of Polyvalent Snake Antivenom Immunoglobulin

Snake bites represent a serious public health problem, particularly in rural areas worldwide. Antitoxic sera preparations are antibodies from immunized animals and are considered to be the only treatment option. The purification of antivenom antibodies should aim at obtaining products of consistent quality, safety, efficacy, and adherence to good manufacturing practice principles. Endotoxins are an integral component of the outer cell surface of Gram-negative bacteria. They are common contaminates of the raw materials and processing equipment used in the manufacturing of antivenoms. In this work, and as a part of quality control testing, we establish and examine an environmental monitoring program for identification of potential sources of endotoxin-producing Gram-negative bacteria throughout the whole steps of antivenom preparation. In addition, we follow all the steps of preparation starting from crude plasma till finished product using a validated sterility and endotoxin testing.Samples from air, surface, and personnel were collected and examined through various stages of manufacturing for the potential presence of Gram-negative bacteria. A validated sterility and endotoxin test was carried out in parallel at the different production steps. The results showed that air contributed to the majority of bacterial isolates detected (48.43%), followed by surfaces (37.5%) and then personnel (14%). The most common bacterial isolates detected were Achromobacter xylosoxidans, Ochrobactrum anthropi, and Pseudomonas aeruginosa, which together with Burkholderia cepacia were both also detected in cleaning water and certain equipment parts. A heavy bacterial growth with no fungal contamination was observed in all stages of antivenom manufacturing excluding the formulation stage. All samples were positive for endotoxin including the finished product.Implementation and continued evaluation of quality assurance and quality improvement programs in aseptic preparation is essential in ensuring the safety and quality of these products.

LAY ABSTRACT

Antitoxic sera preparations are the only treatment option for snake bites worldwide. They are prepared by immunizing animals, usually horses, with snake venom and collecting horse plasma, which is then subjected to several purification steps in order to finally prepare the purified immunoglobulins. Components of the bacterial cell wall known as endotoxins can constitute a potential hazardous contamination known as pyrogen in antisera, which can lead to fever and many other adverse reactions to the person subjected to it.In this work, we monitored the environment associated with the different steps of production and purification of snake antivenom prepared from immunized horses. We examined the air quality, surface, and personnel for possible sources of contamination, particularly the presence of Gram-negative bacteria, which is the major source of endotoxin presence. We also monitored all stages of preparation by sterility and endotoxin testing. Our results showed that air contributed to the majority of bacterial isolates. Sterility testing revealed the presence of bacterial contamination in all the intermediate steps, as only the final preparation after filtration was sterile. Endotoxin was present in all tested samples and the final product. Good manufacturing practice procedures are essential in any facility involved in antisera production.

Laccase production by Pleurotus ostreatus and its application in synthesis of gold nanoparticles

In this work, the production of fungal laccase was optimized from local isolate of Pleurotus ostreatus using solid state fermentation. Factorial design was used to study the effect of several nutrients on enzyme production. Purification and characterization of the enzyme and the effect of temperature, pH and gamma radiation on fungal growth and enzyme production was investigated.

Optimization of production conditions yielded an enzyme with activity over 32,450 IU/g of fermented substrate. Factorial design was capable of establishing the conditions that multiplied the activity of the enzyme several folds, consequently, reducing the cost of production. The enzyme was capable of decolorizing several dyes with over 80% reduction in color confirming the aromatic degrading capability of laccase. The enzyme was also used in the synthesis of gold nanoparticles, proving that laccase from Pleurotus ostreatus has a strong potential in several industrial applications.

Site selectivity in reactions of hydrazonoyl halides with heterocycles containing amino and thione groups leading to fused heterocycles of potential antimicrobial activity

Reaction of hydrazonoyl halides with 6-(benzylidenamino)-2-thioxo-2,3-dihydro-1H-pyrimidin-4-one and 2,3-diaminoquinazolin-4-one site-selectively afforded 3-substituted-7-(benzylidenamino)-1-phenyl-[1,2,4]triazolo[4,3-a]-pyrimidin-5(1H)-ones, [1,2,4,5]tetrazino[6,1-b]quinazolin-6(4H)-one, and 3-methyl-2-(4-substituted-phenylhydrazo)-[1,2,4]triazino[3,2-b]quinazolin-10-ones in good yields. The structures of the newly synthesized compounds were elucidated by chemical evidence and their IR, 1H, 13C NMR, and MS spectra. Furthermore, some of the products were screened against different strains of bacteria and fungi.

Precipitating factor of seizure in epilepsy: experience in a tertiary care hospital

Patients with epilepsy experience recurrent, unprovoked seizures. In most of the cases seizure occurs spontaneously, but there may be association with various triggers. These triggers may act as seizure precipitating factors (SPFs). This study was done to find out the most common SPFs and their relationship to different types epileptic patients attending a tertiary care hospital in Bangladesh. This cross sectional study was carried out in specialized epilepsy weekly outdoor clinic and Medicine outpatient department (OPD) of Dhaka Medical College Hospital from January 2008 to July 2011, which included 1168 epilepsy patients. All patients attending the clinic were included in the study. Epilepsy syndromes were broadly classified into four categories using the classification system of international league against epilepsy (ILAE) namely, generalized epilepsy (GE), localization related epilepsy (LRE), symptomatic and unclassified. Each patient was evaluated and classified by consultant neurologist. All participants were interviewed through a predesigned close ended questionnaire that included a long list of 30 precipitating factors. Among all the patients 71.5% were male, with most common age group 11-20 years (36.8%). About 62% could indentify at least one precipitator. Excitation (25.2%) was the most common SPF reported by patients followed by emotional stress in 17.7%. Fever precipitated seizure in 16.4% of the subjects. A good number of them (15.5%) noticed that whenever there was sleep deprivation, they had an attack of epilepsy. However, drug withdrawal, playing outside and head trauma were also common among the patients, about 11.7%, 11.3% and 8.4% respectively. Most of the patients can identify their seizure precipitant and clustering of many SPFs suggests a common patho-physiologic mechanism for these triggers. Excitation, sleep deprivation, fever, watching television and head trauma showed a strong association with generalized epilepsy. Patients with seizure disorder should be evaluated for presence of SPFs, because identification of these might help in proper management of epilepsy.

Fluoroquinolone resistant mechanisms in methicillin-resistant Staphylococcus aureus clinical isolates in Cairo, Egypt

INTRODUCTION

Methicillin-resistant Staphylococcus aureus (MRSA) is a persistent problem in community and health care settings. Fluoroquinolones are among the drugs of choice used to treat MRSA infections. This study aims to identify different mechanisms of fluoroquinolne resistance in local MRSA random sampling isolates in Cairo, Egypt.

METHODOLOGY

A total of 94 clinical isolates of S. aureus were collected from two major University hospitals in Cairo. Identification was confirmed by appropriate morphological, cultural, and biochemical tests. The antibiotic susceptibility pattern was determined for all isolates. The possible involvement of efflux pumps in mediating fluoroquinolone resistance as well as changes in the quinolone resistance determining region (QRDR) of gyrA and gyrB genes were investigated

RESULTS

A total of 45 isolates were found to be MRSA, among which 26 isolates were found to be fluoroquinolone-resistant. The MIC values of the tested fluoroquinolones in the presence of the efflux pump inhibitors omeprazole and piperine were reduced. Measuring the uptake of ciprofloxacin upon the addition of the efflux pump inhibitor omeprazole, an increased level of accumulation was observed. Non-synonymous and silent mutations were detected in the QRDR of gyrA and gyrB genes.

CONCLUSIONS

These results shed light on some of the resistance patterns of MRSA strains isolated from local health care settings in Cairo, Egypt. The resistance of these MRSA towards fluoroquinolones does not depend only on mutation in target genes; other mechanisms of resistance such as the permeability effect, efflux pumps and decreased availability of quinolones at the target site can also be involved.

Progress achieved in the elimination of schistosomiasis from the Jazan region of Saudi Arabia

Among the inhabitants of the Jazan region of Saudi Arabia, the prevalence and intensity of Schistosoma haematobium infection have been kept very low for several years, by sustained control efforts. The success of the interventions, which were based on case finding, the treatment of infected individuals, and the chemical and environmental control of freshwater snails, led, in mid-2002, to a strategy to eliminate human infection with S. haematobium from Jazan. The strategy, which was based on regular chemotherapy, snail control (made easier by the focality of transmission in the area) and health education, with screening at primary-healthcare centres, by mobile teams and at diagnostic units, appears to have been successful. No infected snails can now be found in the region and new cases of human infection with S. haematobium are only being detected in border villages (and are attributed to infections beyond the region, in areas where active transmission is still taking place). Total elimination appears possible if the health authorities in neighbouring areas can be persuaded to adopt a similar strategy of control.

A molecular investigative approach to an outbreak of acute hemorrhagic conjunctivitis in Egypt, October 2010

Background

During October 2010, Egypt reported an outbreak of acute hemorrhagic conjunctivitis (AHC). A total of 1831 cases were reported from three governorates; 1703 cases in El Daqahliya, 92 cases in Port Said, and 36 in Damietta. The purpose of this study was to identify and characterize the causative agent associated with this outbreak.

Methods

The U.S. Naval Medical Research Unit No.3 (NAMRU-3) was contacted by the Egyptian Ministry of Health and Population to perform diagnostic laboratory testing on eighteen conjunctival swabs from patients with conjunctivitis from El Daqahliya Governorate. Conjunctival swabs were tested by molecular methods for human adenovirus (HAdV) and enteroviruses (EV). Virus isolation was performed; the isolated virus was further characterized by molecular typing and phylogenetic analysis.

Results

The majority of the samples (17/18) were positive for enterovirus and all were negative for HAdV. Molecular typing and sequencing of the isolated virus revealed the presence of coxsackievirus A24 variant. Phylogenetic analysis based on the VP1 and 3C regions demonstrated that the Egyptian viruses belonged to Genotype IV and are closely related to coxsackievirus A24 variant, reported in a similar outbreak in China in August 2010.

Conclusions

This study strongly suggests that coxsackievirus A24 variant was associated with the acute hemorrhagic conjunctivitis outbreak reported in Egypt in October 2010. There is a possibility that the same strain of CV-A24v was implicated in the AHC outbreaks in both China and Egypt in 2010.

Antiviral activity of liquorice powder extract against varicella zoster virus isolated from Egyptian patients

BACKGROUND

Varicella-zoster virus (VZV) is the etiologic agent of two diseases, varicella (chicken pox) and zoster (shingles). Varicella is a self- limited infection, while zoster is mainly a disease of adults. The present study was conducted to isolate VZV from clinically diagnosed children using cell cultures and compare the activity of liquorice powder extract, an alternative herbal antiviral agent, with acyclovir and interferon alpha 2a (IFN-α2a) against the isolated virus.

METHODS

Forty-eight VZV specimens, 26 from vesicular aspirates and 22 from vesicular swabs, from children clinically diagnosed with varicella were isolated on the Vero cell line. Isolates were propagated and identified with specific antiserum using indirect immunofluorescence and immunodot blotting assays. The growth kinetics of the viral isolates was studied. The antiviral activity of liquorice powder extract, acyclovir (ACV) and IFN-α2a was evaluated against the isolated virus.

RESULTS

VZV was successfully isolated in 4 of the 48 specimens, all from vesicular aspirates. The growth kinetics of the viral isolates was time dependent. The inhibitory activity of liquorice powder extract (containing 125 µg/ml glycyrrhizin) when compared to ACV (250 µg/ml) and IFN-α2a is the lowest.

CONCLUSIONS

VZV isolates were successfully isolated and propagated using Vero cells. Isolates were identified using indirect immunofluorescent and immunodot blotting techniques. Growth kinetics of the isolates revealed an increase in the viral infectivity titer relative to time. Glycyrrhizin in the crude form has low antiviral activity against VZV compared with acyclovir and interferon.

High-throughput molecular identification of Staphylococcus spp. isolated from a clean room facility in an environmental monitoring program

BACKGROUND

The staphylococci are one of the most common environmental isolates found in clean room facility. Consequently, isolation followed by comprehensive and accurate identification is an essential step in any environmental monitoring program.

FINDINGS

We have used the API Staph identification kit (bioMérieux, France) which depends on the expression of metabolic activities and or morphological features to identify the Staphylococcus isolates. The API staphylococci showed low sensitivity in the identification of some species, so we performed molecular methods based on PCR based fingerprinting of glyceraldehyde-3-phosphate dehydrogenase encoding gene as useful taxonomic tool for examining Staphylococcus isolates.

CONCLUSIONS

Our results showed that PCR protocol used in this study which depends on genotypic features was relatively accurate, rapid, sensitive and superior in the identification of at least 7 species of Staphylococcus than API Staph which depends on phenotypic features.

Biological treatment of industrial wastes in a photobioreactor

An algal-bacterial consortium was tested for the treatment from a coke factory. A Chlorella vulgaris strain and a phenol-degrading Alcaligenes sp. were first isolated from the wastewater treatment plant to serve as inocula in the subsequent biodegradation tests. Batch tests were then conducted with samples from the real wastewater or using a synthetic wastewater containing 325 mg phenol/l and 500 mg NH4+/l as target pollutants. Direct biological treatment of the real wastewater was not possible due to the toxicity of organic compounds. Activated carbon adsorption and UV(A-B)-irradiation were efficient in detoxifying the effluent for subsequent biological treatment as inoculation of pretreated samples with the algal-bacterial consortium was followed by complete phenol removal and NH4+ removal of 45%. Complete phenol removal and 33% NH4+ removal were achieved during the fed-batch treatment of artificial wastewater at 6 d hydraulic retention time (HRT). Under continuous feeding at 3.6 d HRT, phenol and NH4+ removal dropped to 58 and 18%, respectively. However, complete phenol removal and 29% NH4+ removal were achieved when 8 g NaHCO3/l was added to the artificial wastewater to enhance algal growth. This study confirms the potential of solar-based industrial wastewater treatment based on solar-based UV pretreatment followed by algal-bacterial biodegradation.

Use of the buccal fat pad in the reconstruction and prosthetic rehabilitation of oncological maxillary defects

We evaluated the effectiveness of the buccal fat pad as a pedicled flap for intraoral reconstruction after partial maxillectomy for neoplastic disease in 24 patients, and subsequently, in providing support for a denture. In all patients the buccal fat pad was covered with a split-skin graft and an acrylic plate. There was complete healing of the buccal fat pad flap within 6 weeks in 18 patients with no major complications, and minimal effects on speech and eating. In six cases there was partial dehiscence of the flap, which healed spontaneously in one patient and was repaired with local flaps in two others. There were no cases of complete breakdown of the flap. Eight patients so far have been rehabilitated with small dentures. In conclusion, the buccal fat pad flap is a simple, quick, and reliable method of reconstruction of small to medium-sized posterior maxillary alveolar defects.

Congenital atresia of the orifice of the submandibular duct: a report of 2 cases and review

Two infants presented with unilateral cystic swellings in the floor of the mouth as a result of imperforate submandibular ducts. This is thought to result from a congenital failure of canalization of the terminal end of the duct. Both cases responded to simple incision and decompression of the fluid-filled duct. Early treatment is important to avoid feeding difficulties and to prevent later complications such as ranula or sialadenitis.

Fractalkine: a novel angiogenic chemokine in rheumatoid arthritis

Angiogenesis is an important aspect of the vasculoproliferation found in the rheumatoid arthritic (RA) pannus. We have previously implicated members of the CXC chemokine family as potent angiogenic mediators in RA. We investigated the possibility that the sole member of the CX(3)C chemokine family, fractalkine (fkn), induces angiogenesis and that fkn might mediate angiogenesis in RA. Recombinant human fkn significantly induced migration of human dermal microvascular endothelial cells (HMVECs), a facet of the angiogenic response, in the pmol/L range in a concentration-dependent manner (P < 0.05). Fkn also induced the formation of significantly more endothelial tubes on Matrigel than did a negative control (P < 0.05). Fkn significantly induced 2.3-fold more blood vessel growth than control in the in vivo Matrigel plug assays (P < 0.05). We identified HMVEC expression of the fkn receptor, CX(3)CR1. Next, we determined if RA synovial fluid (SF)-induced angiogenesis was fkn-dependent. SFs from six RA patients immunodepleted of soluble fkn induced 56% less migration of HMVECs than did sham-depleted RA SFs (P < 0.05). In vivo, immunodepletion of fkn from six RA SFs significantly inhibited their angiogenic activity in Matrigel plug assays (P < 0.05). Immunodepletion of fkn from five RA synovial tissue homogenates inhibited their ability to induce angiogenesis in in vivo Matrigel plug assays (P < 0.05). These results establish a new function for fkn as an angiogenic mediator and suggest that it may mediate angiogenesis in RA.

Clinical and radiological evidence to support superficial parotidectomy as the treatment of choice for chronic parotid sialadenitis: a retrospective study

We present a retrospective series of 23 consecutive parotidectomies, over a 10-year period (1989-1999) for 22 patients with chronic sialadenitis unresponsive to conservative measures. There were 10 male and 12 female patients. Mean age was 52 years (range 12-72), and mean duration of symptoms 4.5 years (range 8 months-30 years). All patients had preoperative sialography and 2 had computed tomography to exclude a neoplasm. A complete superficial parotidectomy with preservation of the main duct was done in all cases. Fifteen patients developed temporary facial nerve weakness postoperatively and 7 developed Frey's syndrome. There were no cases of permanent facial nerve palsy. Nineteen patients reported complete resolution of their symptoms and 3 patients had mild persisting symptoms that did not necessitate any further treatment. Histologically there was evidence of sialadenosis in one case and benign lymphoepithelial lesion in another; the others showed evidence of chronic sialadenitis of varying degrees of severity. Fifteen patients had postoperative sialograms, of which 11 showed evidence of some filling of residual parotid gland parenchyma and in 8 patients there was filling of a normal-looking accessory lobe. In this series, superficial parotidectomy with preservation of the main duct was safe and effective, with minimal long-term complications, for most patients with chronic parotid sialadenitis that was unresponsive to conservative measures and, in some patients, it allowed some preservation of function. The potential damage to the facial nerve and the cosmetic problems associated with a total or near-total parotidectomy were avoided.

Evidence of IL-18 as a novel angiogenic mediator

Angiogenesis, or new blood vessel growth, is a key process in the development of synovial inflammation in rheumatoid arthritis (RA). Integral to this pathologic proliferation are proinflammatory cytokines. We hypothesized a role for IL-18 as an angiogenic mediator in RA. We examined the effect of human IL-18 on human microvascular endothelial cell (HMVEC) migration. IL-18 induced HMVEC migration at 1 nM (p < 0.05). RA synovial fluids potently induced endothelial cell migration, but IL-18 immunodepletion resulted in a 68 +/- 5% decrease in HMVEC migration (p < 0.05). IL-18 appears to act on HMVECs via alpha(v)beta(3) integrin. To test whether IL-18 induced endothelial cell tube formation in vitro, we quantitated the degree of tube formation on Matrigel matrix. IL-18, 1 or 10 nM, resulted in a 77% or 87% increase in tube formation compared with control (p < 0.05). To determine whether IL-18 may be angiogenic in vivo, we implanted IL-18 in Matrigel plugs in mice, and IL-18 at 1 and 10 nM induced angiogenesis (p < 0.05). The angiogenesis observed appears to be independent of the contribution of local TNF-alpha, as evidenced by adding neutralizing anti-TNF-alpha Ab to the Matrigel plugs. In an alternative in vivo model, sponges embedded with IL-18 or control were implanted into mice. IL-18 (10 nM) induced a 4-fold increase in angiogenesis vs the control (p < 0.05). These findings support a novel function for IL-18 as an angiogenic factor in RA and may elucidate a potential therapeutic target for angiogenesis-directed diseases.