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In recent decades, infants' gut microbiota has aroused constant scientific interest, primarily due to early‐ and long‐term repercussions on the host health. In this context, nutritional challenges such as those found in less developed countries can influence infants' gut microbiota development, thus generating potentially critical health outcomes. However, comprehensive investigations regarding species‐level differences in the infant gut microbiota's composition between urbanized and rural countries are still missing. In this study, 16S rRNA and Shallow Shotgun metagenomics sequencing were exploited to dissect the microbial community's species‐level composition of 11 faecal samples collected from infants living in a semi‐urban area of Sub‐Saharan Africa, i.e. Côte d'Ivoire. Moreover, the generated data were coupled with those retrieved from public available metagenomic repositories, including two rural communities and 13 urban communities of industrialized countries. The meta‐analysis led to the identification of Infant Species Community States Type (ISCSTs) and microbial species covariances, which were exploited to reveal key signatures of infants living in rural and semi‐urban societies. Remarkably, analysis of rural and semi‐urban datasets revealed shifts from ISCSTs prevalent in urbanized populations with putative health implications. Thus, indicating the need for population‐wide investigations aimed to define the factors determining such potentially harmful gut microbial communities' signatures.

Pneumocystis jirovecii is an opportunistic fungus predominantly reported in immunocompromised individuals, who develop severe interstitial pneumonia (PcP). However, it is known that asymptomatic or mild pulmonary infections, defined as colonization, are widely observed in the general adult population. So far, genetic and epidemiological data of P. jirovecii infections in Italy are rather scarce and limited to defined geographical regions, mainly regarding isolates from HIV-infected patients. The aim of this study was to evaluate the polymorphisms at the mtLSU-rRNA and the DHPS loci by the screening and genotyping of a cohort of patients from two major hospitals in Rome (Italy). The study included 263 patients divided into two groups, all enrolled consecutively from January 2006 to December 2010: (i) 38 immunocompromised subjects including 25 HIV-infected; (ii) 225 immunocompetent patients. Sixty-seven out of 263 patients (25.5%) were found positive after PCR amplification of the mtLSU-rRNA gene. Overall, genotyping at mtLSU-rRNA locus revealed that the genotype 2 was the most frequent. Sequences of the DHPS gene were obtained from 21 patients, 9 from immunocompromised patients (6 from HIV infected individuals), 12 from immunocompetent ones. Considering the most common DHPS mutations usually detected at amino acid positions 55 and 57 and potentially related to drug resistance, all samples analyzed showed the wild-type signatures. These are the first data in Italy on prevalence and genotypes of P. jirovecii regarding colonized immunocompetent adults. Further multicenter analyses on P. jirovecii infection will be necessary to better define the specific epidemiology of the disease in the Italian populations.

Human parechoviruses (HPeV) circulate worldwide, causing a broad variety of symptoms, preferentially in early childhood. We report here the nearly complete genome sequence of a novel HPeV type, consisting of 7,062 nucleotides and encoding 2,179 amino acids. M36/CI/2014 was taxonomically classified as HPeV-17 by the picornavirus study group.

Introduction: Literature data provide little information about protozoa infections and gut microbiota compositional shifts in humans. This preliminary study aimed to describe the fecal bacterial community composition of people from Cote d’Ivoire harboring Giardia duodenalis , Entamoeba spp., and Blastocystis hominis , in trying to discover possible alterations in their fecal microbiota structure related to the presence of such parasites. Methodology: Twenty fecal samples were collected from people inhabiting three different localities of Cote d’Ivoire for copromicroscopic analysis and molecular identification of G. duodenalis, Entamoeba spp., and B. hominis . Temporal temperature gradient gel electrophoresis (TTGE) was used to obtain a fingerprint of the overall bacterial community; quantitative polymerase chain reaction (qPCR) was used to define the relative abundances of selected bacterial species/group, and multivariate statistical analyses were employed to correlate all data. Results: Cluster analysis revealed a significant separation of TTGE profiles into four clusters (p < 0.0001), with a marked difference for G. duodenalis -positive samples in relation to the others (p = 5.4×10 -6 ). Interestingly, qPCR data showed how G. duodenalis -positive samples were related to a dysbiotic condition that favors potentially harmful species (such as Escherichia coli ), while Entamoeba spp./ B. hominis -positive subjects were linked to a eubiotic condition, as shown by a significantly higher Faecalibacterium prausnitzii - Escherichia coli ratio. Conclusions: This preliminary investigation demonstrates a differential fecal microbiota structure in subjects infected with G. duodenalis or Entamoeba spp./ B. hominis , paving the way for using further next-generation DNA technologies to better understand host-parasite-bacteria interactions, aimed at identifying potential indicators of microbiota changes.

OBJECTIVE In humans, it is unclear if insulin resistance at the monocyte level is associated with atherosclerosis in vivo. Here we have studied first-degree relatives of patients with type 2 diabetes to investigate whether a reduction in components of the insulin signal transduction pathways, such as the insulin receptor (InsR) or InsR substrate 1 or 2 (IRS1 or IRS2), or a reduction in genetic modifiers of insulin action, such as the TIMP3/ADAM17 (tissue inhibitor of metalloproteinase 3/A disintegrin and metalloprotease domain 17) pathway, is associated with evidence of atherosclerosis. RESEARCH DESIGN AND METHODS Insulin sensitivity was analyzed through euglycemic-hyperinsulinemic clamp, and subclinical atherosclerosis was analyzed through intimal medial thickness. Monocytes were isolated through magnetic cell sorting, and mRNA and proteins were extracted and analyzed by quantitative PCR and pathscan enzyme-linked immunosorbent assays, respectively. RESULTS In monocyte cells from human subjects with increased risk for diabetes and atherosclerosis, we found that gene expression, protein levels, and tyrosine phosphorylation of IRS2, but not InsR or IRS1, were decreased. TIMP3 was also reduced, along with insulin resistance, resulting in increased ectodomain shedding activity of the metalloprotease ADAM17. CONCLUSIONS Systemic insulin resistance and subclinical atherosclerosis are associated with decreased IRS2 and TIMP3 expression in circulating monocytes.

Free-living amoebae (FLA) are protozoa ubiquitous in Nature, isolated from a variety of environments worldwide. In addition to their natural distribution, some species have been found to be pathogenic to humans. In the present study a survey was conducted in order to evaluate the presence and to characterize at molecular level the isolates of amoebic organisms collected from different water sources in Italy. A total of 160 water samples were analyzed by culture and microscopic examination. FLA were found in 46 (28.7%) of the investigated water samples. Groundwater, well waters, and ornamental fountain waters were the sources with higher prevalence rates (85.7%, 50.0%, and 45.9%, respectively). Identification of FLA species/genotypes, based on the 18S rDNA regions, allowed to identify 18 (39.1%) Acanthamoeba isolates (genotypes T4 and T15) and 21 (45.6%) Vermamoeba vermiformis isolates. Other FLA species, including Vahlkampfia sp. and Naegleria spp., previously reported in Italy, were not recovered. The occurrence of potentially pathogenic free-living amoebae in habitats related to human population, as reported in the present study, supports the relevance of FLA as a potential health threat to humans.

The Arg(972) insulin receptor substrate-1 (IRS-1) variant has been hypothesized to play a role in pancreatic beta-cell stimulus-coupled insulin secretion and survival. We analyzed the relations between type 1 diabetes and the Arg(972) IRS-1 variant. The frequency of the IRS-1 Arg(972) variant was investigated in two independent sets of unrelated patients: a case-control study and a collection of type 1 diabetes simplex families. In the former group, frequency of the IRS-1 Arg(972) variant was significantly increased in the patients (P = 0.0008), conferring an OR of 2.5. Transmission disequilibrium analysis of data obtained from the family set revealed that the Arg(972) IRS-1 variant was transmitted from heterozygous parents to affected probands at a frequency of 70.2% (P < 0.02). Arg(972) IRS-1 frequency showed no significant correlation with HLA genotypic risk for type 1 diabetes. Arg(972) IRS-1 type 1 diabetic patients also had lower fasting plasma concentrations of C-peptide at the time of diagnosis with respect to patients carrying the wild-type IRS-1 (0.49 +/- 0.058, n = 34, and 0.76 +/- 0.066, n = 134, respectively [means +/- SE]; P = 0.051). Our findings suggest a role for Arg(972) IRS-1 in conferring risk for the development of type 1 diabetes.

We investigated the significance of Gly1057Asp and Leu647Val insulin receptor substrate (IRS)-2 polymorphisms in two Italian cohorts comprising 186 glucose-tolerant subjects and 240 subjects with type 2 diabetes from the Lazio region (i.e. representative of central Italy), and 123 glucose-tolerant subjects from the Sicily region (i.e. representative of south Italy). The allelic frequency of Gly1057Asp variant did not differ between diabetics (32.9%) and nondiabetic subjects, whatever their ethnicity was (35.8% and 33.7% from Lazio and Sicily, respectively). As compared with Gly/Gly subjects within each group, Asp/Asp individuals showed no differences in quantitative traits, including fasting insulin and C-peptide, and several indices of insulin sensitivity and secretion. Only one of the diabetic patients was heterozygous for the Leu647Val variant, and none of the control subjects carried this variant. This patient had three children who were also heterozygous for this variant. They were glucose tolerant, and their insulin sensitivity and insulin secretion indices were within the range of age-matched controls. We also analyzed IRS-2 function in fibroblasts from carriers of Gly1057Asp or Leu647Val variant. No defects in IRS-2 expression, insulin-stimulated phosphorylation, or binding to the p85 subunit of phosphatidylinositol 3-kinase were observed. These results strongly argue against a major role of IRS-2 polymorphisms in the pathogenesis of type 2 diabetes.

The insulin receptor substrate-1 (IRS-1) gene has been considered a candidate for insulin resistance, type 2 diabetes, and coronary artery disease. To investigate the relationship between the common Gly(972)Arg IRS-1 variant and the presence of cardiovascular risk factors, 153 glucose-tolerant, unrelated offspring of type 2 diabetic patients were studied. There were no differences between Arg(972) IRS-1 carriers and noncarriers in age, gender, body mass index, waist/hip ratio, body composition, fasting glucose and insulin levels, and glucose or insulin levels during the oral glucose tolerance test. Insulin sensitivity, assessed by hyperinsulinemic-euglycemic clamp, was significantly reduced in carriers of Arg(972) IRS-1 (P < 0.03). Carriers of Arg(972) IRS-1 displayed many features of the insulin resistance syndrome, including higher values for serum triglycerides (P < 0.01), total/high density lipoprotein cholesterol ratio (P < 0.01), free fatty acid levels (P < 0.04), systolic blood pressure (P < 0.04), microalbuminuria (P < 0.003), and intima-media thickness (P < 0.02). These results suggest that the Arg(972) IRS-1 variant could contribute to the risk for atherosclerotic cardiovascular diseases associated with type 2 diabetes by producing a cluster of insulin resistance-related metabolic abnormalities.

Insulin-receptor internalization and processing are defective in insulin-resistant subjects. To assess the reversibility of these defects, we cultured Epstein-Barr virus-transformed-lymphoblasts from six normal, six obese, and six non-insulin-dependent diabetic (NIDDM) subjects in media containing low (5 mmol/l) or high (25 mmol/l) glucose concentrations, and studied the insulin-receptor internalization and processing in vitro. In cells from normal, obese, and NIDDM subjects cultured in low glucose concentrations, exposure to 100 nmol/l insulin for 30 min at 37 degrees C reduced cell-surface 125I-insulin binding to a similar extent (82 +/- 2, 77 +/- 5, and 82 +/- 5% of initial values, respectively). The same results were obtained with cells cultured in high glucose concentrations. In cells cultured under both glucose conditions, and exposed to 100 nmol/l insulin for 30 min at 37 degrees C, a complete recovery of the initial 125I-insulin binding was observed in normal but not in obese and NIDDM subjects. Release of intracellular insulin and its degradation in vitro was determined by incubating cells with 600 pmol/l of 125I-insulin for 60 min at 37 degrees C, acid washing cells, and re-incubating in insulin-free buffer at 37 degrees C. The radioactivity released by cells was characterized by trichloroacetic acid precipitability, Sephadex G-50 column chromatography, and re-binding to fresh cells. Rates of release of internalized radioactivity were reduced in obese and NIDDM subjects (t1/2 = 61 +/- 9 min, p0.02; 58 +/- 10 min, p0.05; and 38 +/- 4 min in obese, NIDDM, and normal subjects, respectively). The percentage of intact insulin released from cells was significantly higher in obese and NIDDM subjects than in the normal subjects. The t1/2 of intracellular dissociation of insulin-receptor complexes measured by a polyethylene glycol assay was lower in normal (6 +/- 1 min) than in obese (12 +/- 2 min, p0.03) and NIDDM subjects (14 +/- 3 min, p0.02). The results suggest that in insulin-resistant subjects a primary defect in intracellular dissociation of insulin is responsible for alterations of receptor recycling and insulin processing.

The insulin receptor exists in two isoforms differing by the absence (HIR-A) or presence (HIR-B) of 12 amino acids in the COOH-terminus of the alpha-subunit as a consequence of alternative splicing of exon 11. In this study, we developed a radioimmunoassay for the two isoforms employing antibodies raised against two peptides, one (Pep-12) corresponding to residues encoded by exon 11, and the other (Pep-13) corresponding to a COOH-terminal domain of the alpha-subunit which is common to both HIR-A and HIR-B isoforms. These peptides were iodinated and used as both ligands and standards. The assay is specific, highly reproducible, and sensitive with a detection limit of 10 fmol of receptor. One mole of purified insulin receptor, measured by Scatchard analysis, is read as one mole of receptor in the radioimmunoassay with either Pep-12 or Pep-13 as standards. The radioimmunoassay is applicable to the measurement of total content and relative abundance of the two isoforms in extracts from various tissues. We applied the radioimmunoassay to measure the relative abundance of the two isoforms in fat and muscle from normal, obese non-diabetic and non-insulin-dependent diabetic (NIDDM) subjects. Results demonstrate that expression of the low-affinity HIR-B form is significantly increased in obese and NIDDM subjects compared with control subjects. In addition, the increased expression of the HIR-B isoform was significantly correlated with both body mass index (r = 0.52; p = 0.006) and fasting glucose levels (r = 0.59; p = 0.001).

Two insulin receptor mRNA species are expressed in human tissues as a result of alternative splicing of exon 11. This event is regulated in a tissue-specific manner. To date, there is little information about the relative abundance of the two receptor protein isoforms on the cell surface. The aim of the present investigation was to assess whether the tissue-specific expression of the two insulin receptor mRNA species is paralleled by a similar pattern of expression of the two receptor protein isoforms. To this end, we assessed the relative distribution of the two receptor variants in various human tissues at the mRNA and protein levels. A PCR-based technique was used to measure the relative abundance of the two mRNA species, and two immunological assays were used to measure the relative steady-state expression of the two receptor protein isoforms. The expression of the two insulin receptor protein isoforms followed the tissue-specific pattern of expression of the two mRNA species.

Sulfonylureas may stimulate glucose metabolism by protein kinase C (PKC) activation. Because interaction of insulin receptors with PKC plays an important role in controlling the intracellular sorting of the insulin-receptor complex, we investigated the possibility that the sulfonylurea glimepiride may influence intracellular routing of insulin and its receptor through a mechanism involving PKC, and that changes in these processes may be associated with improved insulin action. Using human hepatoma Hep-G2 cells, we found that glimepiride did not affect insulin binding, insulin receptor isoform expression, and insulin-induced receptor internalization. By contrast, glimepiride significantly increased intracellular dissociation of the insulin-receptor complex, degradation of insulin, recycling of internalized insulin receptors, release of internalized radioactivity, and prevented insulin-induced receptor down-regulation. Association of PKC-betaII and -epsilon with insulin receptors was increased in glimepiride-treated cells. Selective depletion of cellular PKC-betaII and -epsilon by exposure to 12-O-tetradecanoylphorbol-13-acetate (TPA) or treatment of cells with PKC-betaII inhibitor G06976 reversed the effect of glimepiride on intracellular insulin-receptor processing. Glimepiride increased the effects of insulin on glucose incorporation into glycogen by enhancing both sensitivity and maximal efficacy of insulin. Exposing cells to TPA or G06976 inhibitor reversed these effects. Results indicate that glimepiride increases intracellular sorting of the insulin-receptor complex toward the degradative route, which is associated with both an increased association of the insulin receptor with PKCs and improved insulin action. These data suggest a novel mechanism of action of sulfonylurea, which may have a therapeutic impact on the treatment of type 2 diabetes.