2019. Effect of carbapenem resistance on outcomes of bloodstream infection caused by Enterobacteriaceae in lowincome and middle-income countries (PANORAMA): a multinational prospective cohort study. Lancet Infectious Diseases 19 (6) , pp.

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Aim Analysing the effect of step‐wise exposure of Escherichia coli isolates to sublethal concentrations of triclosan (TCS) that is widely used as an antiseptic, preservative and disinfectant. Methods and Results Changes in the tolerance to the biocide itself and the cross‐resistance to clinically important antibiotics were analysed. The involvement of efflux mechanism was studied as well as the possible implication of modifications in cytoplasmic membrane properties including integrity, permeability, potential and depolarization in the resistance mechanisms. Most of E. coli isolates that were adapted to TCS showed increased antimicrobial resistance, lower outer and inner membrane permeability, higher membrane depolarization, more negative membrane potential and enhanced efflux activity using qRT‐PCR. Nonsignificant change in membrane integrity was found in the adapted cells. Conclusion This study suggests that the extensive use of TCS at sublethal concentrations contributed to the emergence of antibiotic resistance in E. coli clinical isolates, by inducing changes in bacterial membrane properties and enhancing the efflux system. Significance and Impact of the Study The extensive usage of TCS has a deleterious effect on the spread of antibiotic resistance, and more studies are needed to investigate the molecular mechanisms underlying the effects of TCS.

Niosomes are promising for enhanced antibacterial activity and reduced resistance to antibiotics. The later can be achieved by inhibition of biofilm formation.

Benzalkonium chloride (BAC) is widely used as a disinfectant and preservative. This study investigated the effect on antimicrobial susceptibility and the cellular changes that occurred after exposure of Klebsiella pneumoniae clinical isolates to sublethal concentrations of BAC. Minimum inhibitory concentration and minimum bactericidal concentration of BAC were determined for the collected 50 K. pneumoniae clinical isolates by broth microdilution method, and the tested isolates were adapted to increasing sublethal concentrations of BAC. The effect of adaptation on MICs of the tested 16 antimicrobial agents, the cell ultrastructure, efflux, and membrane depolarization of the tested isolates were examined. Interestingly, most K. pneumoniae isolates that adapted to BAC showed increased antimicrobial resistance, various morphological and structural changes, increased membrane depolarization, and enhanced efflux activity. The findings of this study suggest that the extensive use of BAC at sublethal concentrations could contribute to the emergence of antibiotic resistance in K. pneumoniae clinical isolates that might complicate the therapy of infections caused by this pathogen. In conclusion, the hazard associated with the prolonged exposure to sublethal concentrations of BAC represents a public health risk and therefore it should be a focus in both hospital and community sanitation practices.

A Gram-negative bacterium was isolated from river sediment which was able to grow with nitrilotriacetic acid as a combined carbon, nitrogen and energy source in the absence of molecular oxygen using nitrate as the terminal electron acceptor. Batch growth parameters and mass balances are reported for growth under both aerobic and denitrifying conditions. The strain was characterized with respect to its substrate spectrum and other physiological properties. This denitrifying isolate is serologically unrelated to the comprehensively described Gram-negative obligately aerobic NTA-degrading bacteria all of which belong to the alpha-subclass of Proteobacteria. Chemotaxonomic characterization, which revealed the presence of spermidine as the main polyamine and ubiquinone Q-8, excludes the new isolate from the phylogenetically redefined genus Pseudomonas and indicates a possible location within the gamma-subclass of Proteobacteria close to, but separate from the genus Xanthomonas.

Background: The noteworthy spread of carbapenem-resistant K. pneumoniae (CR-KP) isolates represents a significant safety threat. Objective: Determination of the carbapenemase genes incidence among CR-KP clinical isolates in Kafrelsheikh, Egypt. Methods: A total of 230 K. pneumoniae isolates were recovered from four hospitals in Kafrelsheikh, Egypt. Susceptibility testing was conducted using Kirby-Bauer method and automated-Vitek2 system. CR-KP isolates were tested using modified Hodge test (MHT) and combined disk synergy test. PCR and DNA sequencing were conducted for CR-KP isolates to rec- ognize the included carbapenemase-genes. Results: Out of 230 K. pneumoniae isolates, 50 isolates presented resistance to carbapenem (meropenem). All 50 CR-KP iso- lates were multidrug-resistant (MDR). Genes like blaNDM-1 and blaOXA-48 were the only detected genes among CR-KP with an incidence of 70.0% and 52.0%, respectively. Up to 74.0% of the tested isolates carried at least one of the two record- ed genes, among them 48.0% co-harbored both blaNDM-1 and blaOXA-48 genes. The accession-numbers of sequenced blaNDM-1 and blaOXA-48 genes were MG594615 and MG594616, respectively. Conclusion: This study reported a high incidence of MDR profile with the emergence of blaNDM-1 and blaOXA-48 genes co-existence in CR-KP isolates in Kafrelsheikh, Egypt. Hence, more restrictions should be applied against the spread of such serious pathogens. Keywords: Klebsiella pneumoniae; Egypt; carbapenem resistance; MDR; PCR; blaNDM-1; blaOXA-48; sequencing.