Epidemiological Link Between Wastewater and Human Vancomycin-Resistant <Emphasis Type="Italic">Enterococcus faecium</Emphasis> Isolates

We investigated the prevalence of vancomycin-resistant enterococci (VRE) isolated from wastewater (n = 593) and clinical (n = 450) samples, and the genetic linkage between the isolates was compared. Out of the total samples, 38 Enterococcus faecium (3.6%) from sewage (n = 19) and clinical (n = 19) isolates were found to be highly resistant to vancomycin. The majority of the VRE isolates from the two sources showed distinct phenotyping and genotyping patterns. At the same time, one common pulsed-field gel electrophoresis pattern was found among the VRE obtained from wastewater and human clinical isolates, suggestive of an epidemiological link.     

Molecular Structure and Transferability of Tn1546-Like Elements in Enterococcus faecium Isolates from Clinical, Sewage, and Surface Water Samples in Iran

The molecular structure and transferability of Tn1546 in 143 vancomycin-resistant Enterococcus faecium (VREF) isolates obtained from patients (n = 49), surface water (n = 28), and urban and hospital sewage (n = 66) in Tehran, Iran, were investigated. Molecular characterization of Tn1546 elements in vanA VREF was performed using a combination of restriction fragment length polymorphism analysis and DNA sequencing of the internal PCR fragments of vanA transposons. Long-PCR amplification showed that the molecular size of Tn1546 elements varied from 10.8 to 12.8 kb. The molecular analysis of Tn1546 showed that 45 isolates (31.5%) harbored a deletion/mutation upstream from nucleotide 170. No horizontal transfer of Tn1546 was observed following filter-mating conjugation with these isolates. Nevertheless, the rates of transferability for other isolates were 10⁻⁵ to 10⁻⁶ per donor. Insertion sequences IS1216V and IS1542 were present in 103 (72%) and 138 (96.5%) of the isolates, respectively. The molecular analysis of Tn1546 elements resulted in three genomic organizations. The genomic organization lineage 1 was dominated by the isolates from clinical samples (3.4%), lineage 2 was dominated mostly by sewage isolates (24.5%), and lineage 3 contained isolates obtained from all sources (72.1%). The genetic diversity determined using pulsed-field gel electrophoresis (PFGE) revealed a single E. faecium clone, designated 44, which was common to the samples obtained from clinical specimens and hospital and municipal sewage. Furthermore, the results suggest that lineage 3 Tn1546 was highly disseminated among our enterococcal isolates in different PFGE patterns.     

Demography of greenbug,Schizaphis graminum (Rondani) (Hemiptera: Aphididae) on six barley cultivars

The greenbugs, Schizaphis graminum (Rondani) were collected from the barley fields in Isfahan region of Iran. The aphid colonies were maintained on each of six barley cultivars including Karoon, Kavir, Zarjoo, Nosrat, Afzal and Rihane. All the experiments were done on the mentioned barley varieties at 26 ± 1°C, 60 ± 5% relative humidity (RH) and at a photoperiod of 16:8 (L:D) h. The shortest and longest developmental times were obtained on Nosrat 6.35 ± 0.11 and Rihane 6.75 ± 0.07 days, respectively. The survivorship of immature stages varied from 71.95% on Nosrat to 82.14% on Zarjoo. The total number of offsprings were 71.05 and 63.22 nymphs per female on Kavir and Karoon. The highest and lowest r _m values were observed on Kavir (0.336 ± 0.005) and Rihane (0.299 ± 0.008), respectively. The statistical analysis of jackknife did not show a significant influence of the tested barley varieties for the mean generation time and a similar procedure of difference for λ and r _m was estimated.     

Estimation of effective connectivity using multi-layer perceptron artificial neural network

Studies on interactions between brain regions estimate effective connectivity, (usually) based on the causality inferences made on the basis of temporal precedence. In this study, the causal relationship is modeled by a multi-layer perceptron feed-forward artificial neural network, because of the ANN’s ability to generate appropriate input–output mapping and to learn from training examples without the need of detailed knowledge of the underlying system. At any time instant, the past samples of data are placed in the network input, and the subsequent values are predicted at its output. To estimate the strength of interactions, the measure of “Causality coefficient” is defined based on the network structure, the connecting weights and the parameters of hidden layer activation function. Simulation analysis demonstrates that the method, called “CREANN” (Causal Relationship Estimation by Artificial Neural Network), can estimate time-invariant and time-varying effective connectivity in terms of MVAR coefficients. The method shows robustness with respect to noise level of data. Furthermore, the estimations are not significantly influenced by the model order (considered time-lag), and the different initial conditions (initial random weights and parameters of the network). CREANN is also applied to EEG data collected during a memory recognition task. The results implicate that it can show changes in the information flow between brain regions, involving in the episodic memory retrieval process. These convincing results emphasize that CREANN can be used as an appropriate method to estimate the causal relationship among brain signals.     

Using the PCR and Blood Agar in Diagnosis of Semen Bacterial Contamination of Fertile and Infertile Men

Background:One of the causes of male infertility is Genital tract infections (GTI). Considering the importance of GTI, widespread recognition of them seems necessary. we aimed to characterize and compare semen microbial populations in fertile and infertile men who referred to an infertility clinic in Yazd, Iran.Methods:Semen samples were collected from two groups of fertile (268) and infertile (210) men. Sperm analysis (concentration, morphology, viability and motility parameters) were performed according to the World Health Organization (WHO) 2010 guidelines laboratory manual. Bacterial isolation was performed in Sheep Blood Agar and Eosin Methylene Blue (EMB) agar plates. For PCR, samples were analyzed with genus specific primers.Results:All semen characteristics were poor in the infertile group compared to those in the fertile men (p-value< 0.05). Enterococcus spp. (18.7%, 17.1%; p= 0.814), E. coli (7.9%, 11.4%; p= 0.486), Staphylococcus aureus (6.4%, 2.9%; p= 0.398) and Proteus mirabilis (0%, 2.9%; p= 0.002) were the most common agents, respectively. Also, the results obtained from PCR were confirmed using culture-base method.Conclusion:Proteus mirabilis contamination was identified in the infertile group. While no significant association was observed between male infertility and semen microbial populations, p. mirabilis may be the leading cause of reproduction impairment in men.Key Words: Infertility, Microbial contamination, culture, PCR     

Induced in vitro differentiation of neural-like cells from human exfoliated deciduous teeth-derived stem cells

Stem cells from human exfoliated deciduous teeth (SHED) are highly proliferative, clonogenic and multipotent stem cells with a neural crest cell origin. Additionally, they can be collected with minimal invasiveness in comparison with other sources of mesenchymal stem cells (MSCs). Therefore, SHED could be a desirable option for potential therapeutic applications. In this study, SHEDs were established from enzyme-disaggregated deciduous dental pulp obtained from 6 to 9 year-old children. The cells had typical fibroblastoid morphology and expressed antigens characteristic of MSCs, STRO1, CD146, CD45, CD90, CD106 and CD166, but not the hematopoietic and endothelial markers, CD34 and CD31, as assessed by FACS analysis. Differentiation assessment revealed a strong osteogenic and adipogenic potential of SHEDs. In order to further evaluate the in vitro differentiation potential of SHED into neural cells, a simple short time growth factor-mediated induction was used. Immunofluorescence staining and flow cytometric analysis revealed that SHED rapidly expressed nestin and b-III tubulin, and later expressed intermediate neural markers. In addition, the intensity and percentages of nestin and b-III tubulin and mature neural markers (PSA-NCAM, NeuN, Tau, TH, or GFAP) increased significantly following treatment. Moreover, RT-PCR and Western blot analyses showed that the neural markers were strongly up-regulated after induction. In conclusion, these results provide evidence that SHED can differentiate into neural cells by the expression of a comprehensive set of genes and proteins that define neural-like cells in vitro. SHED cells might be considered as new candidates for the autologous transplantation of a wide variety of neurological diseases and neurotraumatic injuries.     

Dorsipes caspius n. sp. (Acari: Podapolipidae), a subelytral parasite of Pterostichus caspius (Menetries) (Coleoptera: Carabidae) with notes on host range of the genus and the distribution of the platysmae group

The ectoparasitic mite Dorsipes caspius n. sp. (Heterostigmata: Podapolipidae) belonging to the platysmae species group collected from the beneath elytra of Pterostichus (Lyrothorax) caspius (Menetries) (Coleoptera: Carabidae) in northern Iran, is described. This is the first record of species of the platysmae group from the Middle East. Keys to adult and larval female stages of world species of the platysmae group are provided. The host range of all species of the genus and the distribution of all representatives of the group are discussed.     

Detecting DNA polymorphism and genetic diversity in Lentil (Lens culinaris Medik.) germplasm: comparison of ISSR and DAMD marker

Genetic diversity and interrelationships among 31 lentil genotypes were evaluated using 10 Inter-Simple Sequence Repeat (ISSR) and 10 directed amplification of minisatellite DNA region (DAMD) primers. A total of 43 and 48 polymorphic bands were amplified by ISSR and DAMD markers, respectively. Average polymorphism information content (PIC) for ISSR and DAMD markers were 0.37 and 0.41, respectively. All 31 lentil genotypes could be distinguished by ISSR markers into three groups and by DAMD markers into two groups. Various molecular markers show a different efficiency for evaluating DNA polymorphism in lentil and indicate that the patterns of variation are clearly influenced by the genetic marker used. Comparatively, the genetic diversity of examined lentil genotypes by two different marker techniques (ISSR and DAMD) was high and indicated that ISSR and DAMD are effective and promising marker systems for fingerprinting in lentil and give useful information on its genetic relationships.