Green nanotechnology: Anticancer Activity of Silver Nanoparticles using Citrullus colocynthis aqueous extracts

Green synthesis of metal nanoparticles is a growing research area because of their potential applications in nanomedicines. The green synthesis of silver nanoparticles (SNPs) is a convenient, cheap and environmentally safe approach compared to chemical synthesis. In the present study, we synthesized SNPs from AgNO3 using aqueous extracts (AEs) of fruits, leaves, roots and seeds of Citrullus colocynthis as reducing and capping agents. The SNPs were early detected in the aqueous extracts by color change to the reddish brown, and further were confirmed by Transmission Electron Microscope (TEM) analysis. The TEM analysis of SNPs showed spherical nanoparticles with mean size between 7 to 19nm. The anticancer activity of SNPs has been assessed invitro.  MTT assay on human cancer cell lines of colon (HCT-116), breast (MCF-7), liver (Hep-G2) and intestine (Caco-2) showed good anticancer activity which was negligible for the aqueous plant extracts. Regarding to the tested cell lines the Hep-G2 cell line and HCT-116 were the most sensitive cell line towards the cytotoxic activities of the tested SNPs, while the Caco-2 was the most resistant cell line towards the cytotoxic activities. Keywords: green synthesis, silver nanoparticles, Citrullus colocynthis, anticancer

A Catalogue of the Birds in the Collection of the Bombay Natural History Society - 16. Capitonidae, Lndicatoridae and Picidae (Part)

Volume: 71Start Page: 244End Page: 26

Emergence of Klebsiella pneumoniae clinical isolates harboring Klebsiella pneumoniae carbapenemase and metallo-β-lactamase in two hospitals in Egypt

Klebsiella pneumoniae carbapenemases (KPCs) as well as metallo- β-lactamases (MBL) producing Enterobacteriaceae are associated with severe and often fatal infections in severely ill patients. This study was carried out to investigate and confirm the emergence of carbapenemase producing Enterobacteriaceae in Egyptian Hospitals. Particularly the molecular class A KPC and the molecular class B MBL namely the imipenem resistant phenotype carbapenemase (IMP) and verona integron-encoded metallo-beta-lactamase (VIM) producers. To pursue this aim, 134 non-duplicate clinical isolates belonging to Enterobacteriaceae were collected from three Hospitals in Cairo Egypt. The antimicrobial resistance patterns of all isolates included in the study were following the screening criteria of carbapenemase producing bacteria. Detection of carbapenemase producing isolates was carried out by the modified Hodge test (MHT). Phenotypic detection of KPCs and MBLs was by inhibitors combined disc tests, in MHT positive isolates, and was confirmed by detection of bla KPC, bla IMP and bla VIM. Concomitant existence of: KPCs and IMP was confirmed in clinical isolates of K. pneumoniae from inpatients hospitalized in the National Cancer Institute (NCI) Hospital and Al-Demerdash University Hospital (DUH). bla KPC and bla VIM genes were detected together in two isolates from inpatients in the NCI. bla KPC gene was detected alone in three isolates from inpatients in the NCI and two isolates from inpatients in the DUH. bla IMP gene was detected alone in two isolates from inpatients in the DUH and one from NCI Hospital. To our knowledge this was the first report on emergence of KPC-VIM and IMP–KPC producing K. pneumoniae isolates in Egyptian hospitals. We concluded that, emergence of KPC and MBL-producing Enterobacteriaceae should be investigated in other hospitals located in other geographic locations in Egypt to assess the magnitude of the problem. Also, infection control practices and antibiotic policies should be strengthened to avoid the blowout of these microbial bums in our hospitals

Phenotypic and Genotypic Features of Klebsiella pneumoniae Harboring Carbapenemases in Egypt: OXA-48-Like Carbapenemases as an Investigated Model

This study aimed at the characterization of carbapenem-resistant Klebsiella pneumoniae isolates focusing on typing of the blaOXA-48-like genes. Additionally, the correlation between the resistance pattern and biofilm formation capacity of the carbapenem-resistant K. pneumoniae isolates was studied. The collected isolates were assessed for their antimicrobial resistance and carbapenemases production by a modified Hodge test and inhibitor-based tests. The carbapenemases encoding genes (blaKPC, blaNDM, blaVIM, blaIMP, and blaOXA-48-like) were detected by PCR. Isolates harboring blaOXA-48-like genes were genotyped by Enterobacterial Repetitive Intergenic Consensus-Polymerase Chain Reaction (ERIC-PCR) and plasmid profile analysis. The discriminatory power of the three typing methods (antibiogram, ERIC-PCR, and plasmid profile analysis) was compared by calculation of Simpson’s Diversity Index (SDI). The transferability of blaOXA-48 gene was tested by chemical transformation. The biofilm formation capacity and the prevalence of the genes encoding the fimbrial adhesins (fimH-1 and mrkD) were investigated. The isolates showed remarkable resistance to β-lactams and non-β-lactams antimicrobials. The coexistence of the investigated carbapenemases encoding genes was prevalent except for only 15 isolates. The plasmid profile analysis had the highest discriminatory power (SDI = 0.98) in comparison with ERIC-PCR (SDI = 0.89) and antibiogram (SDI = 0.78). The transferability of blaOXA-48 gene was unsuccessful. All isolates were biofilm formers with the absence of a significant correlation between the biofilm formation capacity and resistance profile. The genes fimH-1 and mrkD were prevalent among the isolates. The prevalence of carbapenemases encoding genes, especially blaOXA-48-like genes in Egyptian healthcare settings, is worrisome and necessitates further strict dissemination control measures