Identification of \u3ci\u3ebla\u3c/i\u3e\u3csub\u3eOXA-51-like\u3c/sub\u3e, \u3ci\u3ebla\u3c/i\u3e\u3csub\u3eOXA-58\u3c/sub\u3e, \u3ci\u3ebla\u3c/i\u3e\u3csub\u3eDIM-1\u3c/sub\u3e, and \u3ci\u3ebla\u3c/i\u3e\u3csub\u3eVIM\u3c/sub\u3e Carbapenemase Genes in Hospital \u3ci\u3eEnterobacteriaceae\u3c/i\u3e Isolates from Sierra Leone

We describe the results of a molecular epidemiological survey of 15 carbapenemase-encoding genes from a recent collection of clinical isolates from Mercy Hospital in Bo, Sierra Leone. The most salient findings revealed that (i) 60% of the isolates harbored multiple carbapenemase genes; (ii) the blaDIM-1 gene, which has previously only been reported in The Netherlands, is also circulating in this environment; and (iii) blaOXA-51-like and blaOXA-58 genes, which were thought to reside exclusively in Acinetobacter species, can also be found in members of the Enterobacteriaceae

Identification of AlgR-Regulated Genes in Pseudomonas aeruginosa by Use of Microarray Analysis

The Pseudomonas aeruginosa transcriptional regulator AlgR controls a variety of different processes, including alginate production, type IV pilus function, and virulence, indicating that AlgR plays a pivotal role in the regulation of gene expression. In order to characterize the AlgR regulon, Pseudomonas Affymetrix GeneChips were used to generate the transcriptional profiles of (i) P. aeruginosa PAO1 versus its algR mutant in mid-logarithmic phase, (ii) P. aeruginosa PAO1 versus its algR mutant in stationary growth phase, and (iii) PAO1 versus PAO1 harboring an algR overexpression plasmid. Expression analysis revealed that, during mid-logarithmic growth, AlgR activated the expression of 58 genes while it repressed the expression of 37 others, while during stationary phase, it activated expression of 45 genes and repression of 14 genes. Confirmatory experiments were performed on two genes found to be AlgR repressed (hcnA and PA1557) and one AlgR-activated operon (fimU-pilVWXY1Y2). An S1 nuclease protection assay demonstrated that AlgR repressed both known hcnA promoters in PAO1. Additionally, direct measurement of hydrogen cyanide (HCN) production showed that P. aeruginosa PAO1 produced threefold-less HCN than did its algR deletion strain. AlgR also repressed transcription of two promoters of the uncharacterized open reading frame PA1557. Further, the twitching motility defect of an algR mutant was complemented by the fimTU-pilVWXY1Y2E operon, thus identifying the AlgR-controlled genes responsible for this defect in an algR mutant. This study identified four new roles for AlgR: (i) AlgR can repress gene transcription, (ii) AlgR activates the fimTU-pilVWXY1Y2E operon, (iii) AlgR regulates HCN production, and (iv) AlgR controls transcription of the putative cbb(3)-type cytochrome PA1557

The utility of \u3ci\u3eShewanella japonica\u3c/i\u3e for microbial fuel cells

Shewanella-containing microbial fuel cells (MFCs) typically use the fresh water wild-type strain Shewanella oneidensis MR-1 due to its metabolic diversity and facultative oxidant tolerance. However, S. oneidensis MR-1 is not capable of metabolizing polysaccharides for extracellular electron transfer. The applicability of Shewanella japonica (an agar-lytic Shewanella strain) for power applications was analyzed using a diverse array of carbon sources for current generation from MFCs, cellular physiological responses at an electrode surface, biofilm formation, and the presence of soluble extracellular mediators for electron transfer to carbon electrodes. Critically, air-exposed S. japonica utilizes biosynthesized extracellular mediators for electron transfer to carbon electrodes with sucrose as the sole carbon source

Drug resistance and population structure of Plasmodium falciparum and Plasmodium vivax in the Peruvian Amazon

Malaria is a major health problem in Peru despite substantial progress achieved by the ongoing malaria elimination program. This study explored the population genetics of 63 Plasmodium falciparum and 170 P. vivax cases collected in the Peruvian Amazon Basin between 2015 and 2019. Microscopy and PCR were used for malaria detection and positive samples were genotyped at neutral and drug resistance-associated regions. The P. falciparum population exhibited a low nucleotide diversity (π = 0.02) whereas the P. vivax population presented a higher genetic diversity (π = 0.34). All P. falciparum samples (n = 63) carried chloroquine (CQ) resistant mutations on Pfcrt. Most P. falciparum samples (53 out of 54) carried sulfadoxine (SD) resistant mutations on Pfdhfr and Pfdhps. No evidence was found of artemisinin resistance mutations on kelch13. Population structure showed that a single cluster accounted for 93.4% of the P. falciparum samples whereas three clusters were found for P. vivax. Our study shows a low genetic diversity for both species with significant differences in genetic sub-structuring. The high prevalence of CQ-resistance mutations could be a result of indirect selection pressures driven by the P. vivax treatment scheme. These results could be useful for public health authorities to safeguard the progress that Peru has achieved towards malaria elimination

The Transcriptional Regulator AlgR Controls Cyanide Production in Pseudomonas aeruginosa

Article on the transcriptional regulator AlgR controlling cyanide production in Pseudomonas aeruginosa