New chemotherapeutic strategies against malaria, leishmaniasis and trypanosomiases.

Due to the persistent lack of suitable vaccines, chemotherapy remains the only option for the treatment of patients infected by protozoan parasites. However, most available antiparasitic drugs have serious disadvantages, ranging from high cost and poor compliance to high toxicity and rapid induction of resistance. In recent decades basic research laboratories identified a considerable number of promising new molecules, but their development has not been pursued in depth by pharmaceutical firms because of poor prospects of economic return. The establishment of adequately funded public-private partnerships is currently reversing the trend. This review deals with new drugs against Plasmodium, Leishmania and Trypanosoma parasites, focusing on the molecules that are in the most advanced stage of development. The purpose of this article is to provide the reader with a panoramic view of the updated literature on the challenges and strategies of contemporary antiprotozoal drug research, paying the due attention to the already published reviews.

New antimicrobial frontiers.

New antimicrobials able to counteract bacterial resistance are needed to maintain the control of infectious diseases. The last 40 years have seen the systematic tailoring and refinement of previously identified antibiotics, to produce a multitude of semi-synthetic derivatives that share their mechanism of action with the original molecules. The major limit of this approach is the emergence of multi- and cross-resistant bacterial strains, favoured by the selective pressure inherent to the targeting of specific enzymes. The most promising new strategies aim to the development of molecules that, targeting essential bacterial structures instead of specific enzymatic activities, achieve infection control without enforcing a selective pressure on bacteria. This review, based on the consultation of the up-to-date literature, deals with antimicrobial peptides and some antivirulence factors.

Improvement of clinical response in allergic rhinitis patients treated with an oral immunostimulating bacterial lysate: in vivo immunological effects.

Allergic rhinitis is known to be one of the most common chronic diseases in the industrialized world. According to the concept that allergic rhinitis patients generally suffer from an immune deficit, in order to stimulate specifically or aspecifically their immune system, immunomodulating agents from various sources, such as synthetic compounds, tissue extracts or a mixture of bacterial extracts, have been used. The aim of the present trial is to evaluate the efficacy of the treatment with an immunostimulating vaccine consisting of a polyvalent mechanical bacterial lysate (PMBL) in the prophylaxis of allergic rhinitis and subsequently to analyze its in vivo effects on immune responses. 41 allergic rhinitis patients were enrolled: 26 patients were randomly assigned to the group for PMBL sublingual treatment and 15 others to the group for placebo treatment. For all 26 patients blood samples were drawn just before (T0) and after 3 months of PMBL treatment (T3) to evaluate plasma IgE levels (total and allergen-specific) and the cytokine production involved in the allergic response (IL-4, IFN-gamma). The results of our study indicate that PMBL is effective in vivo in the reduction or in the elimination of the symptoms in rhinitis subjects during the treatment period in comparison to a non-immunostimulating treatment. A significant and clinically relevant improvement was found in 61.5%, a stationary clinical response was registered in 38.4% and no negative side effects associated with the medication or worsening were recorded. At the end of a 3-month follow up period the clinical picture remained the same as that observed at T3. PMBL treatment did not affect the serum IgE levels (either total or allergen-specific) and did not induce significant changes in IFN-gamma concentration. In contrast, PMBL therapy may be accompanied, in some patients, by a potential immunomodulating activity by decreasing IL-4 cytokine expression.

Burkholderia respiratory tract infections in Italian patients with cystic fibrosis: molecular characterization.

OBJECTIVES: To characterize by molecular techniques Burkholderia strains responsible for respiratory tract infections in cystic fibrosis (CF) patients (children and adults), to assign the Burkholderia cepacia complex (Bcc) isolates to a genomovar and to assess the presence of cblA and esmR genes in bacteria. Unique or sequential Burkholderia isolates (n=48) that had been collected from eight CF children and 17 adults over several (4-6) years were investigated; moreover 11 reference strains were analyzed. METHODS: The microorganisms were identified by using biochemical methods, genotyped by pulse field gel electrophoresis (PFGE) and random-amplified polymorphic DNA fingerprinting-PCR (RAPD-PCR), and assessed by PCR assays for the genomovar and cblA and esmR genes of Bcc. RESULTS: Among isolates 70.8% were identified as Bcc genomovar III-A; one child was infected by Burkholderia ambifaria and four adults were colonized with Burkholderia gladioli. The cblA gene was not detected in any of the isolates, while the esmR gene was detected in the 52.1% of the strains, all belonging to genomovar III-A. CONCLUSION: Molecular analysis of strains revealed in CF patients a colonization with a persistent Burkholderia flora with strains of one genotype. The prevalence of Bcc of genomovar III-A in the two categories of patients and of B. gladioli in four adults demonstrated that transmission may have occurred between subjects. Moreover the B. ambifaria infection demonstrated in a child may be environmentally derived.

Co-detection and discrimination of JCV and BKV DNA by duplex nested-PCR in renal transplant recipients.

AIM: Several studies have disclosed a correlation between human polyomavirus BK (BKV) and interstitial nephritis in renal transplant recipients. It has recently been hypothesized that some cases of nephropathy may be associated with human polyomavirus JC (JCV). METHODS: In this paper we describe the development of duplex nested-PCR assay which allows the simultaneous detection and discrimination of genomic sequences of JCV and BKV ''large T antigen'', resulting in amplicons of 150 bp and 278 bp, respectively. Thus, the presence of JCV and BKV DNA in urine and serum samples from 51 renal transplant recipients and 29 healthy controls was investigated and related to immunosuppressive regimens and renal function. RESULTS: The comparison between the incidence of the of BKV and/or JCV infections (detected by viruria and/or viraemia) in renal transplant recipients and the control group revealed a highly significant increase of the incidence of BKV infection in immunosuppressed patients vs healthy subjects (62.7% vs 27.6%; p=0.005). In particular, we found a significant increase of BKV-DNA viruria in renal transplant recipients vs healthy subjects (49% vs 17.2%; p=0.01), in agreement with the BKV urinary shedding in renal transplant recipients of the literature (5-45%). CONCLUSION: The nested-PCR technique is a valid diagnostic tool to detect viral presence in urine and its systemic diffusion. Our assay links the high sensitivity of nested amplification with the simultaneous detection and discrimination of genomic sequences of JC and BK polyomaviruses and thus provides a handy, rapid and sensitive means for DNA analysis of large numbers of samples.

Human polyoma virus BK DNA detection by nested PCR in renal transplant recipients.

Several studies report a correlation between the human polyomavirus BK (BKV) and interstitial nephritis in renal transplant recipients in whom immunosuppressive treatment is thought to allow or induce reactivation of the virus. Furthermore, it is described that nephropathy may result from the use of newly introduced immunosuppressive drugs. In the present study, we evaluated the presence of BKV DNA by nested-PCR (n-PCR) in urine and serum samples from 35 renal transplant patients related to the immunosuppressive regimens and renal function.