Analysis of potential virulence genes and competence to transformation in Haemophilus influenzae biotype aegyptius associated with Brazilian Purpuric Fever.

Brazilian Purpuric Fever (BPF) is a hemorrhagic pediatric illness caused by Haemophilus influenzae biogroup aegyptius (Hae), a bacterium that was formerly associated with self-limited purulent conjunctivitis. BPF is assumed to be eradicated. However, the virulence mechanisms inherent to Hae strains associated with BPF is still a mystery and deficient in studies.

A selected bacterial strain for the self-healing process in cementitious specimens without cell immobilization steps.

The use of microorganisms capable of mediating the bioprecipitation process can be an important application in the self-healing processes of cement specimens. Thus, the present study identified and evaluated five Bacillus strains for potential application in the protocol of self-healing via bioprecipitation. Cell growth, enzyme production, and kinetic parameters conditions were evaluated during the fermentation process.

Synthesis of silver-cerium titanate nanotubes and their surface properties and antibacterial applications.

Nano-heterostructures of titanate nanotubes were synthesized and they revealed a complex structure with the formation of TiO (anatase), CeO, AgO and metallic silver nanoparticles on the outer walls and intercalation of Ce and Ag into the interlayer spaces of the nanotubes by microwave-assisted hydrothermal process and subjected to ion exchange reactions. To the best of our knowledge, this is the first reported silver and cerium co-exchanged titanate nanotubes for bio-applications. The co-ion exchange processes preserved the original tubular structure of titanate nanotubes with significant changes of the superficial as well as interlamellar environment.

ACP-TX-I and ACP-TX-II, Two Novel Phospholipases A Isolated from Trans-Pecos Copperhead Venom: Biochemical and Functional Characterization.

This work reports the purification and biochemical and functional characterization of ACP-TX-I and ACP-TX-II, two phospholipases A (PLA) from venom. Both PLAs were highly purified by a single chromatographic step on a C reverse phase HPLC column. Various peptide sequences from these two toxins showed similarity to those of other PLA toxins from viperid snake venoms.

Draft Whole-Genome Sequences of Haemophilus influenzae Biogroup Strains Isolated from Five Brazilian Purpuric Fever Cases and One Conjunctivitis Case.

Brazilian purpuric fever is a febrile hemorrhagic pediatric disease caused by biogroup , a bacterium which was formerly associated with only self-limited purulent conjunctivitis. Here, we present draft genomes of strains from five Brazilian purpuric fever cases and one conjunctivitis case.

Preparation of Thermosensitive Gel for Controlled Release of Levofloxacin and Their Application in the Treatment of Multidrug-Resistant Bacteria.

Levofloxacin is a synthetic broad-spectrum antibacterial agent for oral or intravenous administration. Chemically, levofloxacin is the levorotatory isomer (L-isomer) of racemate ofloxacin, a fluoroquinolone antibacterial agent. Quinolone derivatives rapidly and specifically inhibit the synthesis of bacterial DNA.

Effects of hyperbaric oxygen on Pseudomonas aeruginosa susceptibility to imipenem and macrophages.

Background: The seriousness to treat burn wounds infected with Pseudomonas aeruginosa led us to examine whether the effect of the carbapenem antibiotic imipenem is enhanced by hyperbaric oxygen (HBO).

Materials & Methods: The effects of HBO (100% O2, 3 ATA, 5 h) in combination with imipenen on bacterial counts of six isolates of P. aeruginosa and bacterial ultrastructure were investigated.

Haemophilus influenzae porine ompP2 gene transfer mediated by graphene oxide nanoparticles with effects on transformation process and virulence bacterial capacity.

Background: H. influenzae is a natural competent bacterium that can uptake DNA from the environment and recombine into bacterial genome. The outbreaks of Brazilian purpuric fever, heavily polluted areas of a different H.

Inflammatory response of Haemophilus influenzae biotype aegyptius causing Brazilian Purpuric Fever.

The Brazilian Purpuric Fever (BPF) is a systemic disease with many clinical features of meningococcal sepsis and is usually preceded by purulent conjunctivitis. The illness is caused by Haemophilus influenza biogroup aegyptius, which was associated exclusively with conjunctivitis. In this work construction of the las gene, hypothetically responsible for this virulence, were fusioned with ermAM cassette in Neisseria meningitidis virulent strains and had its DNA transfer to non BPF H.

Chemical modifications of PhTX-I myotoxin from Porthidium hyoprora snake venom: effects on structural, enzymatic, and pharmacological properties.

We recently described the isolation of a basic PLA2 (PhTX-I) from Porthidium hyoprora snake venom. This toxin exhibits high catalytic activity, induces in vivo myotoxicity, moderates footpad edema, and causes in vitro neuromuscular blockade. Here, we describe the chemical modifications of specific amino acid residues (His, Tyr, Lys, and Trp), performed in PhTX-I, to study their effects on the structural, enzymatic, and pharmacological properties of this myotoxin.

Effects of multi-walled carbon nanotubes (MWCNT) under Neisseria meningitidis transformation process.

Background: This study aimed at verifying the action of multi-walled carbon nanotubes (MWCNT) under the naturally transformable Neisseria meningitidis against two different DNA obtained from isogenic mutants of this microorganism, an important pathogen implicated in the genetic horizontal transfer of DNA, causing the escape of the principal vaccination measured worldwide by the capsular switching process.

Materials And Methods: The bacterium receptor strain C2135 was cultivated and had its mutant DNA donor M2 and M6, which received a receptor strain and MWCNT at three different concentrations. The inhibition effect of DNAse on the DNA in contact with nanoparticles was evaluated.

Effect of mesoporous silica under Neisseria meningitidis transformation process: environmental effects under meningococci transformation.

Background: This study aimed the use of mesoporous silica under the naturally transformable Neisseria meningitidis, an important pathogen implicated in the genetic horizontal transfer of DNA causing a escape of the principal vaccination measures worldwide by the capsular switching process. This study verified the effects of mesoporous silica under N. meningitidis transformation specifically under the capsular replacement.

Pathogenic and opportunistic respiratory bacteria-induced apoptosis.

Several pathogenic or opportunistic bacteria have the ability to either induce or inhibit host cell apoptosis. The capacity to modulate cell pathways that result in the induction or delay of host cell apoptosis is considered to be an important bacterial virulence mechanism. These processes could be mediated by different host cell signaling pathways that are subverted by the bacteria.

An inherited mutation leading to production of only the short isoform of GATA-1 is associated with impaired erythropoiesis.

Acquired somatic mutations in exon 2 of the hematopoietic transcription factor GATA-1 have been found in individuals with Down syndrome with both transient myeloproliferative disorder and acute megakaryoblastic leukemia. These mutations prevent the synthesis of the full-length protein but allow the synthesis of its short isoform, GATA-1s. Experiments in mice suggest that GATA-1s supports normal adult megakaryopoiesis, platelet formation and erythropoiesis.