Loci Encoding Compounds Potentially Active against Drug-Resistant Pathogens amidst a Decreasing Pool of Novel Antibiotics.

Since the discovery of penicillin, microbes have been a source of antibiotics that inhibit the growth of pathogens. However, with the evolution of multidrug-resistant (MDR) strains, it remains unclear if there is an abundant or limited supply of natural products to be discovered that are effective against MDR isolates. To identify strains that are antagonistic to pathogens, we examined a set of 471 globally derived environmental Pseudomonas strains (env-Ps) for activity against a panel of 65 pathogens including Achromobacter spp., Burkholderia spp., Pseudomonas aeruginosa, and Stenotrophomonas spp. isolated from the lungs of cystic fibrosis (CF) patients. From more than 30,000 competitive interactions, 1,530 individual inhibitory events were observed. While strains from water habitats were not proportionate in antagonistic activity, MDR CF-derived pathogens (CF-Ps) were less susceptible to inhibition by env-Ps, suggesting that fewer natural products are effective against MDR strains. These results advocate for a directed strategy to identify unique drugs. To facilitate discovery of antibiotics against the most resistant pathogens, we developed a workflow in which phylogenetic and antagonistic data were merged to identify strains that inhibit MDR CF-Ps and subjected those env-Ps to transposon mutagenesis. Six different biosynthetic gene clusters (BGCs) were identified from four strains whose products inhibited pathogens including carbapenem-resistant P. aeruginosa BGCs were rare in databases, suggesting the production of novel antibiotics. This strategy can be utilized to facilitate the discovery of needed antibiotics that are potentially active against the most drug-resistant pathogens.IMPORTANCE Carbapenem-resistant P. aeruginosa is difficult to treat and has been deemed by the World Health Organization as a priority one pathogen for which antibiotics are most urgently needed. Although metagenomics and bioinformatic studies suggest that natural bacteria remain a source of novel compounds, the identification of genes and their products specific to activity against MDR pathogens remains problematic. Here, we examine water-derived pseudomonads and identify gene clusters whose compounds inhibit CF-derived MDR pathogens, including carbapenem-resistant P. aeruginosa.

Role of Leptin and dyslipidemia in chronic kidney disease.

Chronic kidney disease (CKD) patients are at an increased risk of cardiovascular complications and plasma leptin level is elevated in cardio renal syndrome. We wanted to explore leptin levels in patients with different stages of CKD and find its association with risk of cardiovascular disease. This cross-sectional study was conducted in Nephrology Department of Jinnah Post Graduate Medical Centre (JPMC) from January 2014 to September 2014. Group I comprised of controls (GFR=116±8.3, n = 44) acquired from general population, CKD patients were grouped as II, III and IV respectively with GFR; 85.77±9.9 (n = 42), 53.84±9.9 (n=42) and 20.22±8.4 (n = 42).CKD patients with any inflammatory disease, Diabetes Mellitus and on steroid therapy were excluded. Serum leptin, lipid profile and C reactive proteins (CRP) were measured. Leptin and CRP levels increased significantly with progression of CKD. High density lipoproteins (HDL) to low density lipoproteins (LDL) ratio was significantly high in control as compared to CKD groups (p<0.001). A positive correlation of leptin was observed with CRP and HDL/LDL ratio (r= 0.994,p<0.001 and r=-0.403 p<0.001) respectively. Hyperleptinemia observed with progression of CKD contributed to pathogenesis of cardiovascular disease by decreasing HDL/LDL ratio.