Some bacterial pathogens elaborate and secrete virulence factors in response to environmental signals, others in response to a specific host product, and still others in response to no discernible cue. In this study, we have demonstrated that the synthesis of Staphylococcus aureus virulence factors is controlled by a density-sensing system that utilizes an octapeptide produced by the organism itself. The octapeptide activates expression of the agr locus, a global regulator of the virulence response. This response involves the reciprocal regulation of genes encoding surface proteins and those encoding secreted virulence factors. As cells enter the postexponential phase, surface protein genes are repressed by agr and secretory protein genes are subsequently activated. The intracellular agr effector is a regulatory RNA, RNAIII, whose transcription is activated by an agr-encoded signal transduction system for which the octapeptide is the ligand.

Cell Density Control of Staphylococcal Virulence Mediated by an Octapeptide Pheromone

Iran as a developing nation is in epidemiological transition from communicable to non-communicable diseases. Although, cancer is the third cause of death in Iran, it;s mortality are on the rise during recent decades. This mini-review was carried out to provide a general viewpoint on common cancers incidence in Iran and to explain incidental differences that may help us to establish early detection programs and investigate population risk factors. A detailed PubMed, Scopus and Google scholar search were made from 2000 to 2009. The basic inclusion criteria were all relevant studies focused on cancer epidemiological data from Iran. Overall age-standard incidence rate per 100 000 population according to primary site is 110.43 in males and 98.23 in females. The five most common cancers (except skin cancer) are stomach, esophagus, colon-rectum, bladder and leukemia in males, and in females are breast, esophagus, stomach, colon-rectum and cervix uteri. The incidence rates of gastrointestinal cancers are high in Iran (it is one of the known areas with a high incidence of GI cancers). Breast cancer mainly affects Iranian women about a decade earlier than Western countries and younger cases are affected by an increasing rate of colorectal cancer in Iran, near the Western rates.

Five common cancers in Iran.

Medline and PubMed databases were searched on epidemiology of Helicobacter pylori for the period of April 2013–March 2014. Several studies have shown that the prevalence of H. pylori is still high in most countries. In north European and North American populations, about one‐third of adults are still infected, whereas in south and east Europe, South America, and Asia, the prevalence of H. pylori is often higher than 50%. H. pylori remains highly prevalent in immigrants coming from countries with high prevalence of H. pylori. However, the lower prevalence of infection in the younger generations suggests a further decline of H. pylori prevalence in the coming decades. Low socioeconomic conditions in childhood are confirmed to be the most important risk factors for H. pylori infection. Although the way the infection is transmitted is still unclear, interpersonal transmission appears to be the main route. Finally, H. pylori recurrence after successful eradication can still occur, but seems to be an infrequent event.

Epidemiology ofHelicobacter pyloriInfection

A review of the antibacterial activity of Hypericum perforatum L.

Summary
Mitochondrial aldehyde dehydrogenase (ALDH2) is one of the most important enzymes in human alcohol metabolism. The oriental ALDH2*504Lys variant functions as a dominant negative, greatly reducing activity in heterozygotes and abolishing activity in homozygotes. This allele is associated with serious disorders such as alcohol liver disease, late onset Alzheimer disease, colorectal cancer, and esophageal cancer, and is best known for protection against alcoholism. Many hundreds of papers in various languages have been published on this variant, providing allele frequency data for many different populations. To develop a highly refined global geographic distribution of ALDH2*504Lys, we have collected new data on 4,091 individuals from 86 population samples and assembled published data on a total of 80,691 individuals from 366 population samples. The allele is essentially absent in all parts of the world except East Asia. The ALDH2*504Lys allele has its highest frequency in Southeast China, and occurs in most areas of China, Japan, Korea, Mongolia, and Indochina with frequencies gradually declining radially from Southeast China. As the indigenous populations in South China have much lower frequencies than the southern Han migrants from Central China, we conclude that ALDH2*504Lys was carried by Han Chinese as they spread throughout East Asia. Esophageal cancer, with its highest incidence in East Asia, may be associated with ALDH2*504Lys because of a toxic effect of increased acetaldehyde in the tissue where ingested ethanol has its highest concentration. While the distributions of esophageal cancer and ALDH2*504Lys do not precisely correlate, that does not disprove the hypothesis. In general the study of fine scale geographic distributions of ALDH2*504Lys and diseases may help in understanding the multiple relationships among genes, diseases, environments, and cultures.

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Refined Geographic Distribution of the Oriental ALDH2 ∗ 504Lys (nee 487Lys) Variant

Epidemiology of Helicobacter pylori infection among Iranian children

The aim of this study was to evaluate effects of zinc oxide nanoparticles (ZnO-np) on initiation adhesion and agglutinin-like sequence (ALS) 1 and ALS3 gene expression, which is the first cell surface protein known to be, required for biofilm formation in 125 Candida albicans (C. albicans) from urinary tract infections (UTIs). In this descriptive-analytic study, Candida UTIs was cultured from 280 women admitted in hospital Sayad Shirazi, in Northeastern Iran in the 2018 year. 125 (44.62%) of C. albicans strains were identified by phenotypic and genotypic methods. Susceptibility testing C. albicans strains were determined by the disk diffusion method. ZnO-np with 20–40 nm diameters were prepared, there were confirmed by the X-ray diffraction and scanning electron microscope methods. 115 susceptible C. albicans and 10 fluconazole-resistant C. albicans strain from UTIs were exposed to sub-minimum inhibitory concentration (Sub-MIC) of ZnO-np (range 0.02–18.1 μg/ml). Expression of the ALS1 and ALS3 genes which are affected by adhesion was evaluated by real-time PCR. One-way ANOVA test statistical analysis was performed with SPSS 16.0. The MIC range of ZnO-np was 0.05–296 µg/ml. Sub-MIC concentration ZnO-np initial adhesion inhibition, and significantly reduced ALS1 and ALS3 gene expression was observed in all strains (P < 0.05). The finding indicated that ZnO-np is effective in reduction of ALS1 and ALS3 expression in fluconazole-resistant strains. Therefore, ZnO-np could be a candidate in the elimination of biofilm C. albicans strains from UTIs in medicine, particularly in medical instruments.

Zinc Oxide Nanoparticles Inhibition of Initial Adhesion and ALS1 and ALS3 Gene Expression in Candida albicans Strains from Urinary Tract Infections.

The chemical composition and antibacterial effect of Artemisia siberi essential oil were studied in this research. The composition of essential oil from aerial parts was analyzed by GC/MS and its antibacterial effect were determined by disc diffusion method. Artemisia ketone (48.5%), 1, 8-cineole (19.7%), selin-11-en-4-a-ol (4.6%) and lavandulon (2.8%) were the major constituents of this herbal medicine. Inhibitory zone against Pseudomonas aeroginosa, Staphylococcus aureus and Escherichia coli around discs contained 100 mg mL-1 of Artemisia siberi essential oil were 18, 13 and 12 mm, respectively. Further studies for the determination of and Pseudomonas infection in animal model are suggested. © 2007 Asian Network for Scientific Information.

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Chemical Composition and Antibacterial Activity from Essential Oil of Artemisia sieberi Besser subsp. Sieberi in North of Iran

Ethnobotany and Antibacterial Activities of Two Endemic Species of Hypericum in North-East of Iran

1 . بوركيم دشرا سانشراك ،يسانش دحاو يملاسا دازآ هاگشناد ناجيهلا ، هياپ مولع هدكشناد 2 . لگنا داتسا ناجيهلا دحاو يملاسا دازآ هاگشناد ،يسانش 3 . رايداتسا يراميب ياه ينوفع ناكدوك يكشزپ مولع هاگشناد ، ينامرد يتشادهب تامدخ و ناتسلگ 4 . سانشراك بوركيم يسانش ،ينوفع تاقيقحت زكرم ، يكشزپ مولع هاگشناد ينامرد يتشادهب تامدخ و ناتسلگ 5 . رايشناد ركيم بو يسانش ، ينوفع تاقيقحت زكرم ، يكشزپ مولع هاگشناد ينامرد يتشادهب تامدخ و ناتسلگ

Ezzatollah Ghaemi

Papers

Epidemiology of Helicobacter pylori infection among Iranian children

Zinc Oxide Nanoparticles Inhibition of Initial Adhesion and ALS1 and ALS3 Gene Expression in Candida albicans Strains from Urinary Tract Infections.

Chemical Composition and Antibacterial Activity from Essential Oil of Artemisia sieberi Besser subsp. Sieberi in North of Iran

Ethnobotany and Antibacterial Activities of Two Endemic Species of Hypericum in North-East of Iran

Frequency of methicillin resistant Staphylococcus aureus in health care