Diversity and Antimicrobial Activity of Actinomycetes Isolated from Lut Desert: The Extremely Arid Climatic Zones of Iran

Lut desert is situated in one of the extremely arid climatic zones of Iran and is one of the hottest deserts in our plant with the extreme fluctuation of temperature over a day. The main objective of this study is to characterize the diversity of the culturable actinomycetes and preliminary evaluation of their extracts as antimicrobial components on drug resistant pathogens. Twenty-four soil samples were collected, successively diluted and inoculated into the different culture media to support the growth of most culturable bacteria including actinomycetes. Phenotypic and molecular methods were used for accurate identification of recovered isolates particularly actinomycetes at the genus and species levels. The isolates were also evaluated for their inhibitory activities against drug resistant Acinetobacter baumannii, Enterococcus faecium, Klebsiella pneumoniae and Staphylococcus aureus. A total of 56 isolates recovered from the samples. Based on phenotypic tests, 41 isolates were identified as actinomycetes, amongst them 8 isolates were active against drug resistant pathogens. Our study revealed Lut desert, as one of the hottest deserts in the world, is the habitat to diverse taxa of bacteria particularly actinomycetes which have potential novel antimicrobial components.

     

The Chemical Diversity of Lantana camara: Analyses of Essential Oil Samples from Cuba,Nepal, and Yemen

The aerial parts of Lantana camara L. were collected from three different geographical locations: Artemisa (Cuba), Biratnagar (Nepal), and Sana'a (Yemen). The essential oils were obtained by hydrodistillation and analyzed by gas chromatography/mass spectrometry. A cluster analysis of 39 L. camara essential oil compositions revealed eight major chemotypes: β‐caryophyllene, germacrene D, ar‐curcumene/zingiberene, γ‐curcumen‐15‐al/epi‐β‐bisabolol, (E)‐nerolidol, davanone, eugenol/alloaromadendrene, and carvone. The sample from Cuba falls into the group dominated by (E)‐nerolidol, the sample from Nepal is a davanone chemotype, and the sample from Yemen belongs to the β‐caryophyllene chemotype. The chemical composition of L. camara oil plays a role in the biological activity; the β‐caryophyllene and (E)‐nerolidol chemotypes showed antimicrobial and cytotoxic activities.     

Identification of the New Pathogen (Stemphylium lycopersici) Causing Leaf Spot on Pepino (Solanum muricatum)

Pepino (Solanum muricatum var. pepino) plants were found affected by an extensive leaf spot caused by plant pathogenic fungi during a survey in the Cameron highlands, Pahang state, Malaysia. Symptomatic leaf samples were collected from infected pepino plants and cultivated on PDA medium, and the pathogen was isolated and purified; then, consequently, all isolates were identified as Stemphylium lycopersici on the basis of their cultural and morphological characteristics and combined sequences of the internal transcribed spacer (ITS) and glyceraldehyde‐3‐phosphate dehydrogenase (gpd) regions. A pathogenicity assay on detached leaves further confirmed that S. lycopersici causes leaf spot disease. To the best of our knowledge, this is the first report of S. lycopersici causing leaf spot on pepino in Malaysia and worldwide.     

Optimisation of a microwave-assisted method for extracting withaferin A from Withania somnifera Dunal. using central composite design

Introduction – Recently, there have been growing attention on the modification and optimisation of new extraction and quantification methods, caused by the lack of environmentally friendly methodologies for the extraction of phytochemicals from complex matrices. In the case of pharmaceutical compounds, not only the extraction procedure but also the analysis method should be efficient, precise, fast and easy. Objectives – The essential pharmaceutical characteristics and trace concentration of withanolides led us to modify and optimise the previously reported extraction and quantification procedure for withaferin A (WA) as a candidate for withanolides. Matrial and methods – The WA from the air‐dried aerial part of Withania somnifera Dunal. was extracted using a microwave‐assisted extraction (MAE) technique. Four variables affecting the extraction procedure were optimised using the central composite design approach. The method of high‐performance thin‐layer chromatography assay was validated and applied for the quantification of each experiment. Results – The optimum values of factors were: extraction time (150 s), extraction temperature (68°C) and 17 mL of methanol : water in the ratio 25 : 75 as extracting solvent. The solvent system consisted of ethyl acetate : toluene : formic acid : 2‐propanol (7.0 : 2.0 : 0.5 : 0.5, v/v/v/v), and densitometric scanning at 220 nm was applied for the analysis. The dynamic linear range, LOD, LOQ and recovery with the inter‐day, and intra‐day RSDs of the developed method indicated the validity of the method. Conclusion – A pressurised MAE method for extracting WA from the plant's aerial part was optimised using factorial‐based design. The net effect of time, temperature, solvent volume and its ratio suggests that the yield of WA increases until each factor reaches its optimum value, and decreases with further increase in temperature or solvent ratio. Copyright © 2010 John Wiley & Sons, Ltd.     

Association of the ACE-II genotype with the risk of nephrotic syndrome in Pakistani children

Nephrotic syndrome is a common pediatric glomerular disease associated with heavy proteinuria. Since, the angiotensin converting enzyme (ACE) gene insertion/deletion (I/D) polymorphism is a putative genetic risk factor for NS, in this study, ACE (I/D) polymorphism was analyzed in 268 NS and 223 control samples by a PCR-based method. The genotypic and allelic frequencies were determined and the association between ACE I/D polymorphism and NS was evaluated. The frequency distribution of the II, ID and DD genotypes was 82 (30.6%), 128 (47.8%) and 58 (21.6%) in the NS patients and 9 (4.0%), 171 (76.7%) and 43 (19.3%) in the control samples respectively. In the Pakistani pediatric NS population, the II genotypic and allelic frequencies were found to be significantly associated with the disease (OR = 6.755; C.I = 3-14.9). No significant association was found between this polymorphism and the response to standard steroid therapy. Thus, in contrast to reports from other parts of the world, the II genotype was found to be significantly associated with NS in the Indian and Malay populations and in the Pakistani population described here. To our knowledge, this is the first report from Pakistan describing the association of the ACE I/D polymorphism with pediatric NS. On the basis of these results, it is suggested that analysis of the ACE (I/D) polymorphism should be performed for the early diagnosis in the high risk NS patients in South Asia.     

Intravenous immunoglobulin G treatment increases live birth rate in women with recurrent miscarriage and modulates regulatory and exhausted regulatory T cells frequency and function

Exhausted T cells and regulatory T (Treg) cells have been recently proposed to be new risk factors for recurrent miscarriage (RM). Intravenous immunoglobulin G (IVIG) treatment reported to modulate various immune cells. In this study, the effects of IVIG on the frequency and function of exhausted T cells, exhausted Tregs, and Treg cells, as well as pregnancy outcome in women with unexplained RM (URM), were investigated. Ninety-four pregnant women with RM were enrolled. At the time of positive pregnancy, blood samples were drawn. Forty-four patients with URM were included as IVIG receiving treated group and received 400 mg/kg of IVIG and the rest fifty patients were considered as a control group and received no IVIG administration. IVIG was given intravenously every 4 weeks during 32 weeks of gestation. Blood samples of patients were collected after the latest administration. Exhausted T cells, exhausted Tregs, and Treg cells were evaluated pre- and posttreatment in both groups. IVIG induced a significant decrease in the frequency of exhausted Tregs population and function as well as a significant increase in Treg cells population, however, IVIG failed to affect population and the function of exhausted T cells. Pregnancy outcome was successful in IVIG treated women (86.3%) and were significantly different (P = 0.0006) in compared with the untreated URM subjects (42%). Therefore, employing of IVIG increases Treg cells and diminishes exhausted Tregs responses in RM patients with cellular immune anomalies throughout the pregnancy. Immunemodulatory effects of IVIG are probably associated with successful pregnancy outcome.