Assessment of the Antioxidant and Anti-inflammatory Properties of Aqueous Extract of Rosa sempervirens Leaves.

The antioxidant and anti-inflammatory properties of an aqueous natural extract obtained from Rosa sempervirens leaves were assessed. The ability of the extract to scavenge DPPH, •OH, and H2O2 radicals, chelate ferrous ions, reduce ferric ions, and protect ß-carotene-linoleic acid in emulsion from peroxidation was investigated in vitro. Furthermore, the anti-inflammatory activity of the extract was evaluated by measuring the stability of the membrane of human red blood cells against different hypotonic concentrations of NaCl and heat, as well as by inhibiting the denaturation of albumin. A high total phenolic content (278.38± 11.07 mg GAE/g) and flavonoid content (34.22± 0.12 mg QE /g) were found in the extract. The extract exhibited significant scavenging activity of DPPH (IC50 6.201 ± 0.126 µg/ ml), •OH (IC50 = 894.57 ± 21.18 µg/ml), and H2O2 (IC50= 107±09.58 µg/ml) radicals, and good antioxidant activity by chelating ferrous ions (IC50 = 2499.086 ± 28.267µg/ml), reducing ferric ions (IC50=141.33±2.34 µg/ml), exhibiting total antioxidant capacity (IC50 465.65 ± 9.71 µg/ml), and protecting ß-carotene-linoleic acid against peroxidation (I% = 90.05 ± 1.65% at 1000µg/ml). R. sempervirens displayed anti-inflammatory activity in aqueous extract by inhibiting heat-induced albumin denaturation and stabilizing the membrane of human red blood cells. It was suggested from the results that R. sempervirens aqueous extract could help prevent oxidative and inflammatory processes due to its good antioxidant and anti-inflammatory properties.

Evaluating the Synergistic Potency of Essential Oils and Antibiotics Against Klebsiella pneumoniae BLSE Strains.

Klebsiella pneumoniae producing extended-spectrum ß-lactamases (ESBL) continues to pose huge therapeutic challenges in the treatment of infections, primarily urinary infections, due to its multidrug resistance to antibiotics. Therefore, there is a need for research on this topic to investigate ways to reduce the spread of antibiotic resistance, identify novel therapeutic approaches to treat these infections and gain a better understanding of the mechanisms of resistance. In this context, this study aimed to analyze the chemical composition of essential oils (EOs) of Thymus algeriensis, Syzygium aromaticum, and Eucalyptus globulus and assess their activity against K. pneumoniae ESBL strains, as well as the interaction type between these EOs and antibiotics used for the treatment of K. pneumoniae ESBL infections. The composition of the EOs was determined by gas chromatography-mass spectrometry (GC-MS). The activity of EOs was tested using the disc diffusion and liquid microdilution methods. The type of interaction between EOs and antibiotics was studied using the agar disk diffusion and chessboard methods. The analysis of the EO of T. algeriensis showed that the main compounds were thymol (23.14%), linalool (18.44%), and p-cymene (16.17%). The main constituents of EO of E. globulus were eucalyptol (54.29%), α-pinene (17.32%), aromadendrene (7.02%), and pinocarveol (6.32%). As for the EO of S. aromaticum, the major constituents were eugenol (80.46%) and eugenol acetate (16.23%). Results of the activity tests showed that all three EOs were active against the tested strains, with inhibition diameters ranging from 7.39±0.44mm to 32.4±1.05mm and minimum inhibitory concentrations (MICs) varying from 2 to 441.5±5.66 mg/ml. A synergistic interaction was obtained between amoxicillin-clavulanic acid and T. algeriensis EO against two strains of K. pneumoniae ESBL. These results demonstrate the potential of our EOs to inhibit multi-resistant pathogenic ESBL strains, as well as their synergistic interaction with antibiotics used in therapy, which could be an alternative to the use of antibiotics alone in treatment to fight against these multi-resistant pathogenic bacteria.

Multidrug resistance of the extended-spectrum beta-lactamase-producing Klebsiella pneumoniae isolated in Tizi-Ouzou (Algeria).

The emergence and spread of multidrug-resistant bacteria is a major public health concern. This study sought to investigate the phenotypic and genotypic characteristics of clinical isolates of ESBL-producing Klebsiella pneumoniae, at University Hospital of Tizi-Ouzou.  Antibiotic susceptibility testing of the strains was carried out by the disc diffusion method, the ESBL production was screening by the Double Disc Synergy Test and  confirmed by the Phenotypic Confirmatory Disc Diffusion Test. Genomic DNA was extracted using the  Qiagen DNeasy Blood & Tissue Kit  mini kit (Qiagen) according to the manufacturer's instructions.PCR targeting the genes  blaCTX-M, blaTEM, blaSHV, blaVEB, blaGES, blaPER, blaBEL, blaVIM, blaIMP, blaKPC, blaNDM and blaOXA48 was performed. A CTX-M PCR-based grouping method was carried out using primers specific to the groups 1, 2 and 9. Conjugative transfer of plasmids was carried out using sodium azide-resistant recipient strain Escherichia coli K12. The phylogenetic relationship was determined by ERIC-PCR. All strains of K. pneumoniae tested shared ESBL producer's genes belonging to the CTX-M group 1. These strains showed a high level of resistance to ß-lactams, aminoglycosides, fluoroquinolones and trimethoprim/ sulfamethoxazole. Resistance to fosfomycin was also detected in one strain of K. pneumoniae. Only one carbapenem-resistant strain was isolated. Phylogenetic analysis showed 49 different genetic profiles of K. pneumoniae strains, showing the absence of clonality. This study revealed a high prevalence of ESBL belonging to the CTX-M group 1 in K. pneumoniae tested. The emergence of resistance to carbapenem and fosfomycin, could seriously limits the therapeutic choices options.