Oxidative stress,ceruloplasmin and neopterin biomarkers in dromedary camels with clinical endometritis

The purpose of this study is to investigate the role of some oxidative stress (OS), ceruloplasmin (Cp), and neopterin (NPT) as diagnostic biomarkers for dromedary camels endometritis as well as to explore the impact of ceftiofur treatment on endometritis. Camels were categorized into two groups; healthy control group (n = 20) and endometritis group (n = 60). She-camels with clinical signs of endometritis (CE) received 6.6 mg/kg BW of ceftiofur (i/m). On days 7, and 14, she-camels were evaluated and clinical cure or failure to cure was determined. The comparison of the groups for OS demonstrated that endometritis caused an increase in serum malondialdehyde (sMDA), Cp, and NPT levels (P<0.05), but decreased serum levels of superoxide dismutase (SOD), catalase (CAT), and glutathione (GSH) (P<0.05). The most prevalent pathogens involved in the etiology of CE are Arcanobacterium pyogenes, Streptococcus pyogenes, and Staphylococcus aureus. All examined biomarkers demonstrated a high degree of recognition between CE camel and healthy controls (the area under the curve (AUC) was 95.9 for NPT). A higher proportion of camels with CE that were treated with ceftiofur (90%, P<0.0001) showed clinical cure by the first dose, while 10% required a second dose. In conclusion, CE causes increased oxidative reactions and decreased antioxidant defense competence. Subsequently, the alteration in that balance that was represented by the biomarkers of OS could be beneficial for clinical practice and basic clinical research. Additionally, all trials demonstrated the efficacy of ceftiofur for the treatment of CE in she-camel.     

Isolation,Classification and Antagonistic Properties of Alkalitolerant Actinobacteria from Algerian Saharan Soils

Abstract

The Sahara, one of the most extreme environments on Earth, constitutes an unexplored source of alkalitolerant actinobacteria. In this work, we studied the diversity of alkalitolerant actinobacteria in various soils collected from different regions of the Algerian Sahara. A total of 29 alkalitolerant actinobacterial strains were isolated by using a complex agar medium. The diversity of these actinobacteria was evaluated using a polyphasic approach, which included morphological, chemotaxonomic, physiological (numerical taxonomy) and 16S rRNA gene analyses. The isolates which were assigned to the genus Nocardiopsis, shared relatively low 16S rRNA gene sequences similarities compared to closely related species suggesting that they belonged to putatively new species. All of the strains were tested for antibiotic activity against a broad range of microorganisms and screened for genes encoding polyketide synthases and non-ribosomal peptide synthetases and found to have the potential to produce secondary metabolites. Consequently, the study supports the view that extreme environments contain many novel actinobacteria, which represent an unexplored source for the discovery of biologically active compounds.     

Prokaryotic diversity of a Tunisian multipond solar saltern

16S rRNA gene clone libraries were separately constructed from three ponds with different salt concentrations, M2 (15%), TS38 (25%) and S5 (32%), located within a multipond solar saltern of Sfax. The 16S rRNA genes from 216 bacterial clones and 156 archaeal clones were sequenced and phylogenetically analyzed. 44 operational taxonomic units (OTUs) were generated for Bacteria and 67 for Archaea. Phylogenetic groups within the bacterial domain were restricted to Bacteroidetes and Proteobacteria, with the exception that one cyanobacterial OTU was found in the TS38 pond. 85.7, 26.6 and 25.0% of the bacterial OTUs from M2, TS38 and S5 ponds, respectively, are novel. All archaeal 16S rRNA gene sequences were exclusively affiliated with Euryarchaeota. 75.0, 60.0 and 66.7% of the OTUs from, respectively, M2, TS38 and S5 ponds are novel. The result showed that the Tunisian multipond solar saltern harbored novel prokaryotic diversity that has never been reported before for solar salterns. In addition, diversity measurement indicated a decrease of bacterial diversity and an increase of archaeal diversity with rising salinity gradient, which was in agreement with the previous observation for thalassohaline systems. Comparative analysis showed that prokaryotic diversity of Tunisian saltern was higher than that of other salterns previously studied. A. Sghir and E. Ammar have equally contributed to this work.     

Widespread occurrence of non-phosphorylating glyceraldehyde-3-phosphate dehydrogenase among gram-positive bacteria.

The non-phosphorylating glyceraldehyde 3-phosphate dehydrogenase (GAPDHN, NADP+-specific, EC 1.2.1.9) is present in green eukaryotes and some Streptococcus strains. The present report describes the results of activity and immunoblot analyses, which were used to generate the first survey of bacterial GAPDHN distribution in a number of Bacillus, Streptococcus and Clostridium strains. Putative gapN genes were identified after PCR amplification of partial 700-bp sequences using degenerate primers constructed from highly conserved protein regions. Alignment of the amino acid sequences of these fragments with those of known sequences from other eukaryotic and prokaryotic GAPDHNs, demonstrated the presence of conserved residues involved in catalytic activity that are not conserved in aldehyde dehydrogenases, a protein family closely linked to GAPDHNs. The results confirm that the basic structural features of the members of the GAPDHN family have been conserved throughout evolution and that no identity exists with phosphorylating GAPDHs. Furthermore, phylogenetic trees generated from multiple sequence alignments suggested a close relationship between plant and bacterial GAPDHN families.     

Glycerolipid analysis during desiccation and recovery of the resurrection plant Xerophyta humilis (Bak) Dur and Schinz

Xerophyta humilis is a poikilochlorophyllous monocot resurrection plant used as a model to study vegetative desiccation tolerance. Dehydration imposes tension and ultimate loss of integrity of membranes in desiccation sensitive species. We investigated the predominant molecular species of glycerolipids present in root and leaf tissues, using multiple reaction monitoring mass spectrometry, and then analysed changes therein during dehydration and subsequent rehydration of whole plants. The presence of fatty acids with long carbon chains and with odd numbers of carbons were detected and confirmed by gas chromatography. Dehydration of both leaves and roots resulted in an increase in species containing polyunsaturated fatty acids and a decrease in disaturated species. Upon rehydration, lipid saturation was reversed, with this being initiated immediately upon watering in roots but only 12–24 hr later in leaves. Relative levels of species with short‐chained odd‐numbered saturated fatty acids decreased during dehydration and increased during rehydration, whereas the reverse trend was observed for long‐chained fatty acids. X. humilis has a unique lipid composition, this report being one of the few to demonstrate the presence of odd‐numbered fatty acids in plant phosphoglycerolipids.     

Molecular Analyses of the Microbial Community Composition of an Anoxic Basin of a Municipal Wastewater Treatment Plant Reveal a Novel Lineage of Proteobacteria

A culture-independent molecular phylogenetic approach was used to study prokaryotic diversity in an anoxic activated sludge from a municipal wastewater treatment plant. Two 16S rRNA gene libraries were constructed using total genomic DNA and amplified by polymerase chain reaction using primers specific for archaeal or bacterial domains. Phylogenetic analysis of 132 and 249 almost full-length 16S rRNA genes for Archaea and Bacteria, respectively, was done using the ARB software package. Phylogenetic groups affiliated with the Archaea belong to Euryarchaeota (93.8% of the operational taxonomic units [OTUs]) and Crenarchaeota (6.2% of the OTUs). Within the bacterial library, 84.8% of the OTUs represent novel putative phylotypes never described before and affiliated with ten divisions. The Proteobacteria phylum is the most abundant and diversified phylogenetic group representing 60.4% of the OTUs, followed by Bacteroidetes (22.1%) and gram-positives (6.1%). Interestingly, we detected a novel Proteobacteria monophyletic group distinct from the five known subclasses, which we named New Lineage of Proteobacteria (NLP) lineage, and it is composed of eight clones representing 4.6% of the Proteobacteria. A new 16S rRNA-targeted hybridization probe was designed and fluorescent in situ hybridization analyses shows representatives of NLP as cocci-shaped microorganisms. The Chloroflexi, Acidobacterium, and Nitrospira phyla and TM7 candidate division are each represented by ≤3% of clone sequences. A comprehensive set of eight 16S and 23S rRNA-targeted oligonucleotide probes was used to quantify these major groups by dot blot hybridization within 12 samples. The Proteobacteria accounted for 82.5 ± 4.9%, representing the most abundant phyla. The Bacteroidetes and Planctomycetales groups accounted for 4.9 ± 1.3% and 4 ± 1.7%, respectively. Firmicutes and Actinobacteria together accounted for only 1.9 ± 0.5%. The set of probes covers 93.4 ± 14% of the total bacterial population rRNA within the anoxic basin.     

Cytisus villosus from Northeastern Algeria is nodulated by genetically diverse Bradyrhizobium strains

Fifty-one rhizobial strains isolated from root nodules of Cytisus villosus growing in Northeastern Algeria were characterized by genomic and phenotypic analyses. Isolates were grouped into sixteen different patterns by PCR-RAPD. The phylogenetic status of one representative isolate from each pattern was examined by multilocus sequence analyses of four housekeeping genes (16S rRNA, glnII, recA, and atpD) and one symbiotic gene (nodC). Analysis of 16S rRNA gene sequences showed that all the isolates belonged to the genus Bradyrhizobium. Phylogenetic analyses based on individual or concatenated genes glnII, recA, and atpD indicated that strains cluster in three distinct groups. Ten out of the sixteen strains grouped together with Bradyrhizobium japonicum, while a second group of four clustered with Bradyrhizobium canariense. The third group, represented by isolates CTS8 and CTS57, differed significantly from all other bradyrhizobia known to nodulate members of the Genisteae tribe. In contrast with core genes, sequences of the nodC symbiotic gene from all the examined strains form a homogeneous group within the genistearum symbiovar of Bradyrhizobium. All strains tested nodulated Lupinus angustifolius, Lupinus luteus, and Spartium junceum but not Glycine max. From these results, it is concluded that C. villosus CTS8 and CTS57 strains represent a new lineage within the Bradyrhizobium genus.     

Detection of WWE2-related Lentisphaerae by 16S rRNA gene sequencing and fluorescence in situ hybridization in landfill leachate

We collected samples of anaerobic landfill leachate from municipal solid waste landfill (Vert-le-Grand, France) and constructed 16S rRNA clone libraries using primers targeting Planctomycetes and relatives (Pla46F and 1390R). Analyses of 16S rRNA gene sequences resulted in the abundant representation of WWE2-related Lentisphaerae, members of the phylum Lentisphaerae, in the clone library (98% of the retrieved sequences). Although the sequences that are phylogenetically affiliated with the cultured isolate Victivallis vadensis were identified (WWE2 subgroup II), the majority of the sequences were affiliated with an uncultured Lentisphaerae lineage (WWE2 subgroup I). We designed oligonucleotides probes targeting the specific 16S rRNA gene regions of those 2 subgroups. Fluorescence in situ hybridization confirmed the abundance of the uncultivated WWE2 subgroup I in our leachate samples.     

Discrimination of neutral oligosaccharides through a nanopore

The detection of oligosaccharides at the single-molecule level was investigated using a protein nanopore device. Neutral oligosaccharides of various molecular weights were translocated through a single α-hemolysin nanopore and their nano-transit recorded at the single-molecule level. The translocation of maltose and dextran oligosaccharides featured by 1 → 4 and 1 → 6 glycosidic bonds respectively was studied in an attempt to discriminate oligosaccharides according to their polymerization degree and glycosidic linkages. Oligosaccharides were translocated through a free diffusion regime indicating that they adopted an extended conformation during their translocation in the nanopore. The dwell time increased with molecular mass, suggesting the usefulness of nanopore as a molecular sizing device.