Background and Aim: The emergence of colistin-resistant strains is considered a great threat for patients with severe infections. Here, we investigate the prevalence and some possible mechanisms of colistin resistance among multidrug-resistant (MDR) and extensively drug-resistant (XDR) Pseudomonas aeruginosa (P. aeruginosa). Methods: Antimicrobial susceptibility was performed using disc diffusion methods while colistin resistance was detected by agar dilution method. Possible mechanisms for colistin resistance were studied by detection of mcr-1 and mcr-2 genes by conventional PCR, detection of efflux mechanisms using Carbonyl Cyanide 3-Chlorophenylhydrazone (CCCP), studying outer membrane protein profile and Lipopolysaccharide (LPS) profile of resistant isolates. Results: It was found that MDR and XDR represented 96% and 87% of the isolated P. aeruginosa, respectively, and colistin resistance represented 21.3%. No isolates were positive for mcr-2 gene while 50% of colistin-resistant isolates were positive for mcr-1. Efflux mechanisms were detected in 3 isolates. Protein profile showed the presence of a band of 21.4 KDa in the resistant strains which may represent OprH while LPS profile showed differences among colistin-resistant mcr-1 negative strains, colistin-resistant mcr-1 positive strains and susceptible strains. Conclusion: The current study reports a high prevalence of colistin resistance and mcr-1 gene in P. aeruginosa strains isolated from Egypt that may result in untreatable infections. Our finding makes it urgent to avoid unnecessary clinical use of colistin.

We aimed to isolate Acinetobacter baumannii (A. baumannii) from wound infections, determine their resistance and virulence profile, and assess the impact of Silver nanoparticles (AgNPs) on the bacterial growth, virulence and biofilm-related gene expression. AgNPs were synthesized and characterized using TEM, XRD and FTIR spectroscopy. A. baumannii (n = 200) were isolated and identified. Resistance pattern was determined and virulence genes (afa/draBC, cnf1, cnf2, csgA, cvaC, fimH, fyuA, ibeA, iutA, kpsMT II, PAI, papC, PapG II, III, sfa/focDE and traT) were screened using PCR. Biofilm formation was evaluated using Microtiter plate method. Then, the antimicrobial activity of AgNPs was evaluated by the well-diffusion method, growth kinetics and MIC determination. Inhibition of biofilm formation and the ability to disperse biofilms in exposure to AgNPs were evaluated. The effect of AgNPs on the expression of virulence and biofilm-related genes (bap, OmpA, abaI, csuA/B, A1S_2091, A1S_1510, A1S_0690, A1S_0114) were estimated using QRT-PCR. In vitro infection model for analyzing the antibacterial activity of AgNPs was done using a co-culture infection model of A. baumannii with human fibroblast skin cell line HFF-1 or Vero cell lines. A. baumannii had high level of resistance to antibiotics. Most of the isolates harbored the fimH, afa/draBC, cnf1, csgA and cnf2, and the majority of A. baumannii produced strong biofilms. AgNPs inhibited the growth of A. baumannii efficiently with MIC ranging from 4 to 25 µg/ml. A. baumannii showed a reduced growth rate in the presence of AgNPs. The inhibitory activity and the anti-biofilm activity of AgNPs were more pronounced against the weak biofilm producers. Moreover, AgNPs decreased the expression of kpsMII , afa/draBC,bap, OmpA, and csuA/B genes. The in vitro infection model revealed a significant antibacterial activity of AgNPs against extracellular and intracellular A. baumannii. AgNPs highly interrupted bacterial multiplication and biofilm formation. AgNPs downregulated the transcription level of important virulence and biofilm-related genes. Our findings provide an additional step towards understanding the mechanisms by which sliver nanoparticles interfere with the microbial spread and persistence.

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Background and Aim: Lung Cancer (LC) is a major cancer killer worldwide, and 5-yr survival is extremely poor (≤15%), accentuating the need for more effective diagnostic and therapeutic strategies. Studies have shown cell-free microRNAs (miRNAs) circulating in the serum and plasma with specific expression in cancer, indicating the potential of using miRNAs as biomarkers for cancer diagnosis and therapy. This study aimed to identify differentially-expressed two miRNAs in the plasma of Non-Small Cell Lung Cancer (NSCLC) patients that might be a clinically useful tool for lung cancer early detection. miRNA-21 is one of the most abundant oncomirs. miRNA-23a functions as an oncogene in several human cancers, however, its clinical value has not been investigated in NSCLC. Materials and Methods: A case-control study was conducted in Assiut University Hospital, Egypt, from 2017 to 2018. Plasma samples were obtained from 45 NSCLC patients. The expression level of miR-21 and miRNA-23a was detected by qRT-PCR and compared to 40 healthy control subjects. The relation between both miRNAs and clinicopathological parameters was evaluated. Results: The expression level of miR-21 and miRNA-23a was significantly up-regulated (36.9 ± 18.7 vs. 1.12 ± 0.84 and 24.7 ± 19.09 vs. 1.16 ± 0.45) in NSCLC compared to matched controls (P<0.0001each). There was a significant difference in the level of plasma miRNA-21 and miRNA- 23a expression between the different grades of the disease (P = 0.032 and P = 0.001, respectively). The plasma miRNA-21 and miRNA-23a levels in the lung cancer patients with distant metastasis (n = 20) were significantly higher than those in the patients without metastasis (n = 25) (P<0.0001 each), the expression of miR-21 and miRNA-23a was significantly associated with tumor size (P = 0.001, P = 0.0001, respectively), but not significantly related to lymph node metastasis (P = 0.687 and 0.696, respectively). A positive correlation was observed between miRNA-21 and miRNA-23a (r = 0.784, P<0.01), There was no significant difference in the plasma miRNA-21 and miRNA-23a levels in the lung cancer patients with different histopathological types. Conclusion: miR-21 and miR-23a might play an oncogenic role in LC and is a poor prognostic factor. Switching off miRNA-21 and miRNA-23a may improve the treatment of LC. Our results must be verified by large-scale prospective studies with standardized methodology.

Background and aim: Diabetic retinopathy is a serious and common complication of diabetes that causes irreversible blindness. The aim of the present study was to assess the knowledge, attitudes, and practice regarding diabetic retinopathy among patients attending a diabetic clinic and identify the effect of an educational program about diabetic retinopathy. Patients and methods: Two hundred diabetic patients were recruited from the outpatient's diabetic clinic, Assiut University hospitals, Egypt. Quasi-experimental (pretest-posttest) research design was applied using a structured interview questionnaire; including socio-demographic data, assessment of the patients' knowledge, attitude, and practices toward diabetic retinopathy. Results: The mean score of knowledge and attitude showed significant improvement (5.3 and 15.1, respectively in pretest vs 16.7 and 16.8, respectively in posttest) among the diabetic patients (p<0.001). From multivariate linear regression model; the predictors for knowledge score were educational level, family history of diabetes and diabetic retinopathy and hypertension. Likewise, attitude score predictors were age, residence, and smoking. Predictors for practice score were hypertension, blood sugar level, and weight. Conclusion: There was a statistically significant relationship between educational level and mean knowledge score. The diabetic education program significantly helped to improve awareness of patients in relation to diabetic retinopathy.