New Antimicrobial Approaches: Reuse of Old Drugs.

The global situation of antibiotic resistance and the reduction of investments in antibiotics research by the pharmaceutical industry suggest the need for specific cost-effective approaches in order to identify drugs for the therapy of many microbial infections. Among the viable alternative anti-infective compounds, drug repurposing, i.e.

Recent updates and perspectives on leishmaniasis.

Leishmaniasis is a neglected vector-borne tropical infection considered to be a disease of the poor. Concentrated in poverty-stricken countries within Southeast Asia, East Africa, and Latin America, it is also endemic in several Mediterranean countries. The management of the heterogeneous syndromes determined by parasites belonging to the genus Leishmania is particularly difficult in developed, non-endemic countries owing to the unfamiliarity of physicians with clinical symptoms, diagnostic possibilities, and available treatment options.

New perspectives in the management of Pseudomonas aeruginosa infections.

Infections with Pseudomonas aeruginosa are a major health problem, especially for immune-compromised and cystic fibrosis patients, owing to the particular drug resistance of the microorganism. The aim of this review is to provide recent insights into strategies under investigation for prevention and therapy of these infections. In this survey, the approach directed against bacterial biofilm formation and quorum-sensing systems was focused, along with the evaluation of the treatment with bacteriophages.

Novel approaches for the design and discovery of quorum-sensing inhibitors.

Introduction: The spread of antibiotic resistance, together with the lack of antibiotics based on novel molecular scaffolds, marks the so-called 'post-antibiotic era'. Interference with bacterial virulence has emerged as an attractive approach among the current potential strategies for developing new anti-infective drugs. Furthermore, the discovery that virulence gene expression is mostly regulated by quorum sensing (QS) has raised a lot of interest and prompted a lot of research aimed at finding inhibitors of this mechanism.

A strange gingival swelling in an Italian child: a case of oral myiasis.

Oral myiasis is a condition in which tissues of the oral cavity are invaded by the larvae of flies. It is a rare disease in humans, often associated with very poor dental and oral hygiene. In children the main predisposing factors are incompetent lips, thumb sucking habits and continuous mouth breathing.

Novel avenues for Clostridium difficile infection drug discovery.

Introduction: Clostridium difficile is the etiologic agent of nosocomial and community-acquired diarrhea associated with exposure to antibiotics that disrupt the normal colonic flora. As antibacterials currently used for primary C. difficile infections favor recurrences, new agents able to neutralize the bacterium without affecting the gut microbiota are badly needed.

Plant-derived antimicrobial compounds: alternatives to antibiotics.

The increasing incidence of drug-resistant pathogens has drawn the attention of the pharmaceutical and scientific communities towards studies on the potential antimicrobial activity of plant-derived substances, an untapped source of antimicrobial chemotypes, which are used in traditional medicine in different countries. The aim of this review is to provide recent insights regarding the possibilities of the most important natural antimicrobial compounds derived from plant sources containing a wide variety of secondary metabolites, which are useful as alternative strategies to control infectious diseases. This review will focus on natural plant products as a useful source of antimicrobial molecules, active in particular, on bacteria and fungi.

Current developments in the therapy of protozoan infections.

Protozoan parasites cause serious human and zoonotic infections, including life-threatening diseases such as malaria, African and American trypanosomiasis, and leishmaniasis. These diseases are no more common in the developed world, but together they still threaten about 40% of the world population (WHO estimates). Mortality and morbidity are high in developing countries, and the lack of vaccines makes chemotherapy the only suitable option.

Analysis of Escherichia coli isolated from patients affected by Crohn's disease.

The etiopathogenesis of Crohn's disease (CD) is still controversial: several genetic, immunologic, and environmental factors, including some bacteria, have been implicated. This study has been devised to assess the involvement of Escherichia coli in CD. Seven E.

Surveillance of methicillin-resistant Staphylococcus aureus isolated in Torino (northwest Italy).

Nosocomial infections by methicillin-resistant Staphylococcus aureus (MRSA) are an increasing cause of morbidity and mortality. Recently, a worldwide increase of community-acquired MRSA infections has also been recorded. The purpose of this study was to assess the frequency of MRSA isolation from in- and outpatients admitted to an academic teaching hospital near Torino (northwest Italy) in 1 year and to characterize 90 clinical isolates of MRSA collected in the same period.

In vitro activity of dermaseptin S1 derivatives against genital pathogens.

The aim of this study was to evaluate the biological activity of nine dermaseptin-S1 (DRS-S1) derivatives (synthesized by solid-phase methods and purified) against different pathogens causing genital infections (Trichomonas vaginalis, Herpes simplex virus, Papillomavirus). The in vitro activity on T. vaginalis was determined by counting the protozoon in a hemocytometer after vital staining with trypan blue; antiviral activity of the compounds was tested on monolayers of Vero cells for Herpes simplex virus-1 (GFP) and on 293TT cells for human papillomavirus (HPV-16) pseudovirions (GFP).

The post-antibiotic era: promising developments in the therapy of infectious diseases.

An overview of investigational antibiotics highlights that antimicrobial drug development is slower than the emergence and spread of resistant strains. In the last three decades only two antibiotics belonging to truly new classes have been introduced into the market, i.e.

Achromobacter xylosoxidans respiratory tract infections in cystic fibrosis patients.

Achromobacter xylosoxidans is a ubiquitous Gram-negative non-fermenting rod, recently characterized as an emerging pathogen in cystic fibrosis (CF) patients. Its pathogenic potential and prevalent transmission routes are still unclear. This study investigated the PFGE genetic pattern and antimicrobial resistance profile of 42 A.

Synthesis and antimicrobial activity of dermaseptin S1 analogues.

Dermaseptins are peptides found in the skin secretions of Phyllomedusinae frogs. These peptides exert lytic action on some microorganisms without substantial haemolysis. In an attempt to understand the antimicrobial activity of these peptides we designed several dermaseptin S1 (ALWKTMLKKLGTMALHAGKAALGAAADTISQGTQ) (DS1) analogues.

Clinical and environmental Burkholderia strains: biofilm production and intracellular survival.

Bacteria belonging to the Burkholderia species are important pulmonary pathogens in cystic fibrosis (CF) patients. Their ability to establish chronic and sometimes fatal infections seems linked to the quorum sensing-regulated expression of virulence factors. We examined 23 Burkholderia isolates, 19 obtained from CF patients and 4 from the environment, to evaluate their ability to form biofilm and to penetrate and replicate inside J774 macrophagic cells.

Activity of an engineered synthetic killer peptide on Leishmania major and Leishmania infantum promastigotes.

This study was undertaken to analyze the effect of an engineered, killer decapeptide (KP) on Leishmania major and Leishmania infantum promastigotes. The KP was synthesized on the basis of the sequence of a recombinant, single-chain anti-idiotypic antibody acting as a functional internal image of a yeast killer toxin. The evaluation of in vitro inhibitory activity of KP on L.

Survey of phenotypic and genetic features of streptococcus pyogenes strains isolated in Northwest Italy.

Streptococcus pyogenes (group A Streptococcus [GAS]) is an important pathogen whose virulence is related to the production of exotoxins and the presence of particular surface components. One hundred eighty-two GAS strains were collected in northwestern Italy between 1994 and 2002 and analyzed for phenotypic characteristics (opacity factor, proteolyic activity, and antimicrobial susceptibility) and by polymerase chain reaction for the presence of genes responsible for the production of exotoxins implicated in pathogenesis speA and speF and of prtF(1) (encoding fibronectin-binding protein F1). All strains were speF positive and 19.

Antileishmanial activity of HIV protease inhibitors.

The proteasomes of some protozoa are possible targets for chemotherapy. Leishmaniasis is a major health problem in human immunodeficiency virus (HIV) co-infected subjects. Two HIV protease inhibitors (PI), indinavir and saquinavir, have been shown to block proteasome functions; we therefore investigated their effects on the growth of two Leishmania spp.

Antimicrobial activity of euplotin C, the sesquiterpene taxonomic marker from the marine ciliate Euplotes crassus.

Strains of the marine ciliate protist Euplotes crassus produce exclusive terpenoids called euplotins that play an ecological role. Among these derivatives, euplotin C is the main of four secondary metabolites isolated from cultures of this protozoon and represents the sesquiterpene taxonomic marker from E. crassus.

In vitro leishmanicidal activity of a monoclonal antibody mimicking a yeast killer toxin.

The microbicidal effect of a monoclonal antiidiotypic antibody, mimicking the activity of a yeast killer toxin, characterized by a wide antimicrobial spectrum, has been evaluated in vitro against two relevant species of protozoan parasites, Leishmania major and Leishmania infantum. The antiidiotypic antibody exerted a significant and dose-dependent antileishmanial activity against parasite promastigotes in comparison to an irrelevant isotype-matched monoclonal antibody. This is the first demonstration that an antibody, which had been already shown to be fungicidal and bactericidal, may also exert a direct microbicidal activity against protozoa.