Detection of Pseudomonas aeruginosa pus wound isolate using a polymerase chain reaction targeting 16S rRNA and gyrB genes: A case from Indonesia

Infectious wounds on the skin surface are easily colonized by bacteria from pyogenic group that manifest as inflammation, such as Pseudomonas aeruginosa. P. aeruginosa is a Gram-negative bacterium and an opportunistic pathogen known for causing invasive state in critically ill and immunocompromised patients. The aim of this study was to detect the 16S rRNA and gyrB genes in P. aeruginosa using polymerase chain reaction (PCR) method. The sample in this study was pus isolate from a 5-year-old boy with leg wounds. The bacteria were isolated on brain heart infusion broth (BHIB) media and identified with molecular identification. Sequencing and BLAST analysis were carried out to determine the similarity of gene identity by comparing sample sequence with other isolate sequences on the Gene Bank. The results of molecular identification showed amplification DNA band of around 934 base pairs (bp) for 16S rRNA and 225 bp for gyrB gene. The BLAST program demonstrated that the sample had 99.89% similarity with P. aeruginosa strain XC4 (accession code ON795960.1) for the 16S rRNA gene. Meanwhile, the gyrB gene exhibited 99.10% similarity with the P. aeruginosa strain PSA-1.2 (accession code KP172300.1)

Bmi1 is expressed in vivo in intestinal stem cells

Bmi1 plays an essential part in the self-renewal of hematopoietic and neural stem cells. To investigate its role in other adult stem cell populations, we generated a mouse expressing a tamoxifen-inducible Cre from the Bmi1 locus. We found that Bmi1 is expressed in discrete cells located near the bottom of crypts in the small intestine, predominantly four cells above the base of the crypt (+4 position). Over time, these cells proliferate, expand, self-renew and give rise to all the differentiated cell lineages of the small intestine epithelium. The induction of a stable form of beta-catenin in these cells was sufficient to rapidly generate adenomas. Moreover, ablation of Bmi1(+) cells using a Rosa26 conditional allele, expressing diphtheria toxin, led to crypt loss. These experiments identify Bmi1 as an intestinal stem cell marker in vivo. Unexpectedly, the distribution of Bmi1-expressing stem cells along the length of the small intestine suggested that mammals use more than one molecularly distinguishable adult stem cell subpopulation to maintain organ homeostasis

Diverse epigenetic strategies interact to control epidermal differentiation

It is becoming clear that interconnected functional gene networks, rather than individual genes, govern stem cell self-renewal and differentiation. To identify epigenetic factors that impact on human epidermal stem cells we performed siRNA-based genetic screens for 332 chromatin modifiers. We developed a Bayesian mixture model to predict putative functional interactions between epigenetic modifiers that regulate differentiation. We discovered a network of genetic interactions involving EZH2, UHRF1 (both known to regulate epidermal self-renewal), ING5 (a MORF complex component), BPTF and SMARCA5 (NURF complex components). Genome-wide localization and global mRNA expression analysis revealed that these factors impact two distinct but functionally related gene sets, including integrin extracellular matrix receptors that mediate anchorage of epidermal stem cells to their niche. Using a competitive epidermal reconstitution assay we confirmed that ING5, BPTF, SMARCA5, EZH2 and UHRF1 control differentiation under physiological conditions. Thus, regulation of distinct gene expression programs through the interplay between diverse epigenetic strategies protects epidermal stem cells from differentiation