Isolation Procedure for CP E. coli from Caeca Samples under Review Towards an Increased Sensitivity

Due to the increasing reports of carbapenemase-producing Enterobacteriaceae (CPE) from livestock in recent years, the European Reference Laboratory for Antimicrobial Resistances (EURL-AR) provided a protocol for their recovery from caecum and meat samples. This procedure exhibited limitations for the detection of CPE with low carbapenem MIC values. Therefore, it was modified by a second, selective enrichment in lysogeny broth with cefotaxime (CTX 1 mg/L) and with meropenem (MEM 0.125 mg/L) at 37 °C under microaerophilic conditions. By Real-time PCR, these enrichments are pre-screened for the most common carbapenemase genes. Another adaptation was the use of in-house prepared MacConkey agar with MEM and MEM+CTX instead of commercial selective agar. According to the EURL-method, we achieved 100% sensitivity and specificity using the in-house media instead of commercial agar, which decreased the sensitivity to ~75%. Comparing the method with and without the second enrichment, no substantial influence on sensitivity and specificity was detected. Nevertheless, this enrichment has simplified the CPE-isolation regarding the accompanying microbiota and the separation of putative colonies. In conclusion, the sensitivity of the method can be increased with slight modifications.

The Biological Role of Glycerol in Yeast Cells. Yeast as Glycerol Producers

This review contains information about the physiological role of glycerol as an osmoprotective and cryoprotective factor in the vital activity of yeast cells. The significance of the glycerol biosynthesis in yeast when cultured under anaerobic and microaerophilic conditions is shown. The dependence of the glycerol production by yeast on the cultivation conditions and the composition of nutrient media is discussed. The publications on glycerol production by various taxonomic yeast groups have been analyzed. Based on the studied literature material, prospects of using yeast organisms as producers of glycerol by fermentation are predicted. glycerol, yeast, hyperosmotic stress, fermentation

Novel Antibacterial Resin-Based Filling Material Containing Nanoparticles for the Potential One-Step Treatment of Caries

The aim of this work was to study the application of resin filling containing nanomaterials for the potential treatment of caries. Zinc nanoparticles (ZnO@NP, 50 nm) were chosen for their antimicrobial capacity against aerobic bacteria, and here, they have proved to be bactericidal against anaerobic bacterial strains (Streptococcus mutans, Streptococcus mitis, and Lactobacillus spp.). Potential mechanism of action is proposed based on microbiological assays and seems to be independent of oxidative stress because the nanoparticles are effective in microaerophilic conditions. The loading of nanoparticles on the demineralized dental surface and their infiltration power were significantly improved when ZnO@NP were carried by the resin. Overall, this material seems to have a high potential to become a one-step treatment for caries lesions.

Draft Genome Sequences of Marinobacter Strains Recovered from Utica Shale-Produced Fluids

ABSTRACT The genomes of three Marinobacter strains, isolated from saline fluids produced from a Utica-Point Pleasant shale well, have been sequenced. These genomes provide novel information on the degradation of petroleum distillates and virulence mechanisms under microaerophilic conditions in fractured shale.