Acinetobacter spp. as nosocomial pathogens: Epidemiology and resistance features

The genus Acinetobacter is a major cause of nosocomial infections; it is increasingly being associated with various epidemics and has become a widespread concern in a variety of hospitals worldwide. Multi-antibiotic resistant Acinetobacter baumannii, is now recognized to be of great clinical significance. Numerous reports relay to the spread of A. baumannii in the hospital settings which leads to enhanced nosocomial outbreaks associated with high death rates. However, many other Acinetobacter spp. also can cause nosocomial infections. This review focused on the role of Acinetobacter spp. as nosocomial pathogens in addition to their persistence, antimicrobial resistance patterns and epidemiology. Keywords: Acinetobacter, Nosocomial infections, Multi-drug resistance, Epidemiology, Characteristic

Acinetobacter spp. as nosocomial pathogens: Epidemiology and resistance features

AbstractThe genus Acinetobacter is a major cause of nosocomial infections; it is increasingly being associated with various epidemics and has become a widespread concern in a variety of hospitals worldwide. Multi-antibiotic resistant Acinetobacter baumannii, is now recognized to be of great clinical significance. Numerous reports relay to the spread of A. baumannii in the hospital settings which leads to enhanced nosocomial outbreaks associated with high death rates. However, many other Acinetobacter spp. also can cause nosocomial infections. This review focused on the role of Acinetobacter spp. as nosocomial pathogens in addition to their persistence, antimicrobial resistance patterns and epidemiology

Effect of gut bacterial isolates from Apis mellifera jemenitica on Paenibacillus larvae infected bee larvae

The probiotic effects of seven newly isolated gut bacteria, from the indegenous honey bees of Saudi Arabia were investigated. In vivo bioassays were used to investigate the effects of each gut bacterium namely, Fructobacillus fructosus (T1), Proteus mirabilis (T2), Bacillus licheniformis (T3), Lactobacillus kunkeei (T4), Bacillus subtilis (T5), Enterobacter kobei (T6), and Morganella morganii (T7) on mortality percentage of honey bee larvae infected with P. larvae spores along with negative control (normal diet) and positive control (normal diet spiked with P. larvae spores). Addition of gut bacteria to the normal diet significantly reduced the mortality percentage of the treated groups. Mortality percentage in all treated groups ranged from 56.67% up to 86.67%. T6 treated group exhibited the highest mortality (86.67%), whereas T4 group showed the lowest mortality (56.67%). Among the seven gut bacterial treatments, T4 and T3 decreased the mortality 56.67% and 66.67%, respectively, whereas, for T2, T6, and T7 the mortality percentage was equal to that of the positive control (86.67%). Mortality percentages in infected larval groups treated with T1, and T5 were 78.33% and 73.33% respectively. Most of the mortality occurred in the treated larvae during days 2 and 3. Treatments T3 and T4 treatments showed positive effects and reduced mortality

Biological activity of Cymbopogon schoenanthus essential oil

Introduction: A number of plant species, including Cymbopogon schoenanthus, are traditionally used for the treatment of various diseases. C. schoenanthus is currently, traded in the Saudi markets, and thought to have medicinal value. This study aimed at investigating the biological activities of C. schoenanthus against both Gram-positive and Gram-negative bacteria and to identify its chemical ingredients. Materials and methods: The inhibitory effects of water extracts of C. schoenanthus essential oils were evaluated against ten isolates of both Gram-positive and Gram-negative bacteria using the agar well diffusion and dilution methods. The minimum inhibitory concentration (MIC) was assayed using the Broth microdilution test on five of the ten isolates. The death rates were determined by the time kill assay, done according to the Clinical Laboratory Standards Institute (CLSI) guidelines. The chemical composition of the essential oils of the plant was performed using GC/MS. Results: The C. schoenanthus essential oil was effective against Escherichia coli, Staphylococcus aureus, methicillin-sensitive (MSSA) S. aureus (MRSA) and Klebsiella pneumoniae. The essential oil was not effective against Staphylococcus saprophyticus at the highest concentration applied of >150 μg/ml. The MIC values were as follows: 9.37 μg/ml for E. coli 4.69 μg/ml for S. aureus (MRSA), 2.34 mg/ml for MSSA and 2.34 μg/ml for K. pneumoniae. The time-kill assay indicated that there was a sharp time dependent decline in K. pneumoniae counts in the presence of the oil. This is in contrast to a gradual decline in the case of S. aureus under the same conditions. The eight major components of the essential oil were: piperitone (14.6%), cyclohexanemethanol (11.6%), β-elemene (11.6%), α-eudesmol (11.5%), elemol (10.8%), β-eudesmol (8.5%), 2-naphthalenemethanol (7.1%) and γ-eudesmol (4.2%). Conclusion: The results of the present study provide a scientific validation for the traditional use of C. schoenanthus as an antibacterial agent. Future work is needed to investigate and explore its application in the environmental and medical fields. In addition, to evaluating the efficacy of the individual ingredients separately to better understand the underlying mechanism

Efficacy of the Immobilized Kocuria flava Lipase on Fe3O4/Cellulose Nanocomposite for Biodiesel Production from Cooking Oil Wastes

The increasing global demand for petroleum oils has led to a significant increase in their cost and has led to the search for renewable alternative waste resources for biodiesel synthesis and production using novel environmentally sound and acceptable methods. In the current study, Kocuria flava lipase was immobilized on Fe3O4/cellulose nanocomposite; and used as a biocatalyst for the conversion of cooking oil wastes into biodiesel through the transesterification/esterification process. The characterization of Fe3O4/cellulose nanocomposite revealed several functional groups including carboxyl (C=O) and epoxy (C-O-C) groups that act as multipoint covalent binding sites between the lipase and the Fe3O4/cellulose nanocomposite and consequently increasing lipase immobility and stability. The immobilized lipase showed a high thermo-stability as it retained about 70% of its activity at 80 °C after 30 min. The kinetics of immobilized lipase revealed that the Km and Vmax values were 0.02 mM and 32.47 U/mg protein, respectively. Moreover, the immobilized lipase showed high stability and reusability for transesterification/esterification reactions for up to four cycles with a slight decline in the enzyme activity. Furthermore, the produced biodiesel characteristics were compatible with the standards, indicating that the biodiesel obtained is doable and may be utilized in our daily life as a diesel fuel

Efficacy of the Immobilized <i>Kocuria flava</i> Lipase on Fe₃O₄/Cellulose Nanocomposite for Biodiesel Production from Cooking Oil Wastes

The increasing global demand for petroleum oils has led to a significant increase in their cost and has led to the search for renewable alternative waste resources for biodiesel synthesis and production using novel environmentally sound and acceptable methods. In the current study, Kocuria flava lipase was immobilized on Fe3O4/cellulose nanocomposite; and used as a biocatalyst for the conversion of cooking oil wastes into biodiesel through the transesterification/esterification process. The characterization of Fe3O4/cellulose nanocomposite revealed several functional groups including carboxyl (C=O) and epoxy (C-O-C) groups that act as multipoint covalent binding sites between the lipase and the Fe3O4/cellulose nanocomposite and consequently increasing lipase immobility and stability. The immobilized lipase showed a high thermo-stability as it retained about 70% of its activity at 80 °C after 30 min. The kinetics of immobilized lipase revealed that the Km and Vmax values were 0.02 mM and 32.47 U/mg protein, respectively. Moreover, the immobilized lipase showed high stability and reusability for transesterification/esterification reactions for up to four cycles with a slight decline in the enzyme activity. Furthermore, the produced biodiesel characteristics were compatible with the standards, indicating that the biodiesel obtained is doable and may be utilized in our daily life as a diesel fuel

Antimicrobial effect of different types of honey on Staphylococcus aureus

Honey exhibits antimicrobial activities against a wide range of bacteria in different milieu. This study aims to compare the effects of five types of honey (both imported and local Saudi honey) against Staphylococcus aureus. The five types of honey (Manuka Honey UMF +20, Manuka Honey UMF +16, Active +10 Manuka Honey, Sidr honey and Nigella sativa honey) were evaluated for their bactericidal/bacteriostatic activities against both methicillin resistant and sensitive S. aureus. The inhibitory effect of honey on bacterial growth was evident at concentrations of 20% and 10% (v/v). Manuka Honey showed the best results. Manuka Honey UMF +20 had a bactericidal effect on both methicillin resistant and sensitive S. aureus. However, Sidr and N. sativa honey exerted only a bacteriostatic effect. The efficacy of different types of honey against S. aureus was dependent on the type of honey and the concentration at which it was administered. Manuka Honey had the best bactericidal activity. Future experiments should be conducted to evaluate the effects of honey on bacterial resistance. Keywords: Manuka Honey, Sidr honey, Nigella sativa honey, Methicillin resistant Staphylococcus aureus (MRSA), Saudi Arabi

Antioxidant, Anti-inflammatory, and Antiulcer Potential of Manuka Honey against Gastric Ulcer in Rats

Gastric ulcers are among the most common diseases affecting humans. This study aimed at investigating the gastroprotective effects of manuka honey against ethanol-induced gastric ulcers in rats. The mechanism by which honey exerts its antiulcer potential was elucidated. Four groups of rats were used: control, ethanol (ulcer), omeprazole, and manuka honey. Stomachs were examined macroscopically for hemorrhagic lesions in the glandular mucosa, histopathological changes, and glycoprotein detection. The effects of oxidative stress were investigated using the following indicators: gastric mucosal nitric oxide (NO), reduced glutathione (GSH), lipid peroxide (MDA, measured as malondialdehyde) glutathione peroxidase (GPx), superoxide dismutase (SOD), and catalase. Plasma tumour necrosis factor-α, interleukin-1β, and IL-6 were also measured. Manuka honey significantly decreased the ulcer index, completely protected the mucosa from lesions, and preserved gastric mucosal glycoprotein. It significantly increased gastric mucosal levels of NO, GSH, GPx, and SOD. Manuka honey also decreased gastric mucosal MDA and plasma TNF-α, IL-1β, and IL-6 concentrations. In conclusion, manuka honey likely exerted its antiulcer, effect by keeping enzymatic (GPx and SOD) and nonenzymatic (GSH and NO) antioxidants as well as inflammatory cytokines (TNF-α, IL-1β, and IL-6) in a reduced form, inhibited lipid peroxidation (MDA), and preserved mucous glycoproteins levels

Manuka Honey Exerts Antioxidant and Anti-Inflammatory Activities That Promote Healing of Acetic Acid-Induced Gastric Ulcer in Rats

Gastric ulcers are a major problem worldwide with no effective treatment. The objective of this study was to evaluate the use of manuka honey in the treatment of acetic acid-induced chronic gastric ulcers in rats. Different groups of rats were treated with three different concentrations of honey. Stomachs were checked macroscopically for ulcerative lesions in the glandular mucosa and microscopically for histopathological alterations. Treatment with manuka honey significantly reduced the ulcer index and maintained the glycoprotein content. It also reduced the mucosal myeloperoxidase activity, lipid peroxidation (MDA), and the inflammatory cytokines (TNF-α, IL-1β, and IL-6) as compared to untreated control group. In addition, honey-treated groups showed significant increase in enzymatic (GPx and SOD) and nonenzymatic (GSH) antioxidants besides levels of the anti-inflammatory cytokine IL-10. Flow cytometry studies showed that treatment of animals with manuka honey has normalized cell cycle distribution and significantly lowered apoptosis in gastric mucosa. In conclusion, the results indicated that manuka honey is effective in the treatment of chronic ulcer and preservation of mucosal glycoproteins. Its effects are due to its antioxidant and anti-inflammatory properties that resulted in a significant reduction of the gastric mucosal MDA, TNF-α, IL-1β, and IL-6 and caused an elevation in IL-10 levels