The emergence of a novel sequence type of MDR Acinetobacter baumannii from the intensive care unit of an Egyptian tertiary care hospital

Abstract Background and aim of work Acinetobacter baumannii is known for nosocomial outbreaks worldwide. In this study, we aimed to investigate the antibiotic susceptibility patterns and the clonal relationship of A. baumannii isolates from the intensive care unit (ICU) of an Egyptian hospital. Methods In the present study, 50 clinical isolates of multidrug resistant (MDR)-A. baumannii were obtained from patients admitted into the ICU from June to December 2015. All isolates were analyzed for antimicrobial susceptibilities. Multiplex PCR was performed to detect genes encoding oxacillinase genes (bla OXA-51-like, bla OXA-23-like, bla OXA-24-like, and bla OXA-58-like). Multilocus sequence typing (MLST) based on the seven-gene scheme (gltA, gyrB, gdhB, recA, cpn60, gpi, rpoD) was used to examine these isolates. Results All A. baumannii clinical isolates showed the same resistance pattern, characterized by resistance to most common antibiotics including imipenem (MIC ≥ 8μ/mL), with the only exception being colistin. Most isolates were positive for bla OXA-51-like and bla OXA-23-like (100 and 96%, respectively); however, bla OXA-24-like and bla OXA-58-like were not detected. MLST analysis identified different sequence types (ST195, ST208, ST231, ST441, ST499, and ST723) and a new sequence type (ST13929) with other sporadic strains. Conclusions MDR A. baumannii strains harboring bla OXA-23-like genes were widely circulating in this ICU. MLST was a powerful tool for identifying and epidemiologically typing our strains. Strict infection control measures must be implemented to contain the worldwide spread of MDR A. baumannii in ICUs

Biosynthesis of Copper Oxide Nanoparticles Using Streptomyces MHM38 and Its Biological Applications

Biosynthesis methods employing microorganisms have emerged as an eco-friendly, clean, and viable alternative to chemical and physical processes. The present study reports the synthesis of copper oxide nanoparticles (CuONPs) using cell-free culture supernatant of marine Streptomyces sp. MHM38. For the optimized production of CuONPs, the influence of some parameters, such as the concentration of copper sulfate (CuSO4), reaction time, filtrate to substrate ratio, and pH, was studied. 5 mM of CuSO4 was optimal for nanoparticle (NP) production. Well-defined CuONP formation occurred after 60 min of incubation when an equal volume of filtrate (cell-free supernatant) to substrate (CuSO4 solution) was added. UV-visible spectroscopy analysis of CuONPs exhibited a peak at 550 nm, which corresponds to the surface plasmon resonance of CuONPs. Most of the particles were spherical and were 1.72–13.49 nm when measured using a transmission electron microscope. The antimicrobial activity of CuONPs was determined using a well diffusion method against Enterococcus faecalis ATCC 29212, Salmonella typhimurium ATCC 14028, Pseudomonas aeruginosa ATCC 9027, Escherichia coli ATCC 8939, fungi (Rhizoctonia solani, Fusarium solani, and Aspergillus niger), and yeast (Candida albicans ATCC 10237). The highest antimicrobial activities were recorded against Candida albicans ATCC 10237, whereas Salmonella typhimurium ATCC 14028 and Escherichia coli ATCC 8939 showed the less activity. The biochemical findings of the CuONP groups were significant (p<0.05) with diminished levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), lactate dehydrogenase (LDH), total and direct bilirubin, urea, and creatinine compared with the paracetamol group. Nonenzymatic and enzymatic antioxidants of the CuONP groups were significantly elevated (p<0.05) in SOD and GSH levels, and exceptionally low nitric oxide (NO) and malondialdehyde (MAD) levels were found for the paracetamol group. The histopathological examination of the CuONP groups assured the impact of improving CuONPs against paracetamol-induced liver damage