Focus: Antimicrobial Resistance: The Status of Carbapenem Resistance in Cystic Fibrosis: A Systematic Review and Meta-Analysis

Background: Antibiotic resistance in cystic fibrosis (CF) is a well-known phenomenon. However, the comprehensive epidemiological impact of antibiotic resistance in CF is not clearly documented. So, this meta-analysis evaluated the proportion rates of carbapenem resistance (imipenem, meropenem, and doripenem) in CF based on publication date (1979-2000, 2001-2010, and 2011-2021), continents, pathogens, and antimicrobial susceptibility testing (AST). Methods: We searched studies in PubMed, Scopus, and Web of Science (until April 2021). Statistical analyses were conducted using STATA software (version 14.0). Results: The 110 studies included in the analysis were performed in 25 countries and investigated 13,324 pathogens associated with CF. The overall proportion of imipenem, meropenem, and doripenem resistance in CF were 43% (95% CI 36-49), 48% (95% CI 40-57), 28% (95% CI 23-33), and 45% (95% CI 32-59), respectively. Our meta-analysis showed that trends of imipenem, meropenem, and doripenem-resistance had gradual decreases over time (1979-2021). This could be due to the limited clinical effectiveness of these antibiotics to treat CF cases over time. Among the opportunistic pathogens associated with CF, the highest carbapenem resistance rates were shown in Stenotrophomonas maltophilia, Burkholderia spp., Pseudomonas aeruginosa, and Staphylococcus aureus. The highest and lowest carbapenem resistance rates among P. aeruginosa in CF patients were shown against meropenem (23%) and doripenem (39%). Conclusions: We showed that trends of carbapenem resistance had decreased over time (1979-2021). This could be due to the limited clinical effectiveness of these antibiotics to treat CF cases over time. Plans should be directed to fight biofilm-associated infections and prevent the emergence of mutational resistance. Systematic surveillance for carbapenemase-producing pathogens in CF by molecular surveillance is necessitated.     

A non-rotational, computer-controlled suspension bioreactor for expansion of umbilical cord blood mononuclear cells

The proliferation and differentiation characteristics of umbilical cord blood mononuclear cells were examined in a non-rotational suspension bioreactor with a fishtail mixer. The system consisted of a glass vessel, a mixer that moved vertically, a data acquisition and control system to continuously monitor pH, temperature and dissolved O₂. The bioreactor provided superior expansion of total HSCs and not total cell number, as well as expression of stemness-related genes which followed with increasing in number of colony-forming cells during 14 days of culture compared to T -lask culture. Vertical agitation thus reduces the total cell number, which may be related to increased shear stress, but has no effect on HSC function.     

Autophagy regulation and its role in normal and malignant hematopoiesis

Autophagy, the molecular machinery of self-eating, plays a dual role of a tumor promoter and tumor suppressor. This mechanism affects different clinical responses in cancer cells. Autophagy is targeted for treating patients resistant to chemotherapy or radiation. Limited reports investigate the significance of autophagy in cancer therapy, the regulation of hematopoietic and leukemic stem cells and leukemia formation. In the current review, the role of autophagy is discussed in various stages of hematopoiesis including quiescence, self-renewal, and differentiation.     

Effects of dietary Ergosan on cutaneous mucosal immune response in rainbow trout (Oncorhynchus mykiss)

The effects of dietary Ergosan on the growth performance and mucosal immunity in rainbow trout skin were investigated. 60 rainbow trout (100-110 g) were randomly assigned to 2 groups in triplicates and fed one of the experimental diet formulated with 5 g kg⁻¹ Ergosan or control diet for 50 days. Results showed that on the 45th day of feeding trial, Ergosan supplementation significantly enhanced the growth performance compared to control group. Various enzyme activities, namely lysozyme, protease, alkaline phosphatase and esterase in treatment group were also enhanced on the 45th and 50th day. Skin mucus in Ergosan-fed fish showed the agglutination of erythrocytes while in control group, no visible agglutination was shown. In addition, skin mucus in treatment group showed strong antibacterial activity against Yersinia ruckeri. In conclusion, the major immune components of rainbow trout mucus that are involved in the non-specific immunity were enhanced by administration of Ergosan in 5 g kg⁻¹.     

Time-kill study and synergistic activity of cell-wall inhibitor antibiotics in combination with gentamicin against Enterococcus faecalis and Enterococcus faecium

The synergy between gentamicin and vancomycin, teicoplanin, ampicillin and linezolid was studied by time-kill method. Two clinical vancomycin resistant enterococci (VRE) and two vancomycin susceptible enterococci (VSE) isolates were used. Different concentrations of antibiotics were combined. Two VSE strains and the control strain exhibited synergism with the combination of gentamicin, vancomycin, teicoplanin, ampicillin and linezolid. Two VRE strains exhibited synergism with the combination of gentamicin and ampicillin. Synergy between gentamicin and vancomycin, teicoplanin and linezolid was not observed against these isolates. The VRE isolates were positive for vanA, aac (6')-Ie aph (2") and aph (3')-IIIa genes and their vancomycin, teicoplanin and gentamicin MICs were 512 μg/ml, 512 μg/ml and >4000 μg/ml, respectively. In order to treat serious enterococcal infections, further clinical evaluation is needed to examine the in vitro combined effects of gentamicin and vancomycin, teicoplanin and linezolid.     

Modification of phytochemical production and antioxidant activity of Dracocephalum kotschyi cells by exposure to static magnetic field and magnetite nanoparticles

Plant Cell, Tissue and Organ Culture (PCTOC) - Dracocephlum kotschyi Boiss is a genus in Lamiaceae family and a medicinal herb native to Iran. The cell suspension cultures were treated by static...     

Cytogenetic study on some Fritillaria species of Iran

Five species (14 ecotypes) belonging to three subgenera of ornamental-medicinal Iranian Fritillaria plant were chromosomally and karyotypically assessed, using squash technique and 1 % (w/v) aceto-orcein stain. All species were diploid (2n = 2x = 24) having mean chromosome length of 16.8 μm (14.2–18.6 μm). The satellites varied in number (1–4 pairs) and in size (1.27–3.01 μm): mostly locating on long arms. Four chromosome types (“m”, “sm”, “st”, “T”) formed 11 different karyotypic formulas: the latter is being reported for the first time in some ecotypes in either S1 or S4. Nine chromosomal parameters were calculated. ANOVA verified intra- and inter-specific chromosomal variation in examined Iranian Fritillaria species. Twelve different methods were used to assess the degree of karyotype asymmetry. Among those, one qualitative (Stebbins classification) and seven quantitative (TF %, CV_TL, DI, AsK %, A2, Rec, CG %) parameters verified that S2 and S5 species were recognized as having the most asymmetrical and symmetrical karyotypes, respectively.     

Features of free software packages in flow cytometry: a comparison between four non-commercial software sources

Flow cytometers designed to analyze large particles are enabling new applications in biology. Data analysis is a critical component of the process FCM. In this article we compare features of four free software packages including WinMDI, Cyflogic, Flowing software, and Cytobank.     

Protective effects of Ephedra pachyclada extract on mouse models of carbon tetrachloride- induced chronic and acute liver failure

Inflammation and oxidation are two important factors in the pathogenesis of liver. Ephedra pachyclada (EP) is a traditional medical herb that has anti-inflammatory and anti-oxidant activities. During this study, anti-oxidant activities of the EP extract was measured in vitro by 2,2′- diphenyl-1-picrylhydrazyl (DPPH) and β-Carotene bleaching assays. Then, we examined possible in vivo hepatoprotective effects of EP extract on mouse models of carbon tetrachloride (CCl₄)-induced chronic and acute liver failure. To produce mouse models of chronic and acute liver injuries, male SW1 mice were interaperitoneally injected with 1 ml/kg body weight (bw) CCl₄ biweekly for 42 days and a single dose of 2 ml/kg bw, respectively. In the experimental groups, mouse models were treated with low (140 mg/kg bw) and high (1400 mg/kg bw) doses of the EP extract. Olive oil and water treated mice were considered as controls during model derivation and EP extract treatment respectively. The results showed the antioxidant activity of EP extract and a significant reduction of all parameters of CCl₄-induced liver injury such as relative liver weight, necrosis, fibrosis, inflammation, and serum aspartate transaminase (AST) and alanine aminotransferase (ALT) in mouse models of acute and chronic liver injury treated with EP extract. Therefore, EP induces its hepatoprotective effects probably by suppressing oxidative stress and inhibit inflammation in the liver and is able to protect the liver against CCl₄-induced acute and chronic injuries.