Molecular and phenotypic characterization of atypical enteropathogenic Escherichia coli serotypes isolated from children with and without diarrhea

BackgroundWe characterized 36 atypical enteropathogenic Escherichia coli (EPEC) serotypes isolated from children with and without diarrhea in Iran. Because the identification of atypical EPEC based on biochemical features is rather difficult and time consuming, we used a combination of three approaches, including a polymerase chain reaction-based method, culture adherence assay, and the restriction analysis of fliC gene (fliC-restriction fragment length polymorphism), to identify E coli serotypes.MethodsTo distinguish typical and atypical EPEC strains, the presence of EPEC attaching effacing A gene (eaeA) gene and EPEC-attaching factor (EAF) plasmid were analyzed. All E coli strains were identified based on the detection of the eaeA+, bundle-forming pili A gene (bfpA−), EAF− or eaeA−, bfpA+, EAF− profiles and the absence of stx (encoded for shiga toxin) gene as atypical EPEC.ResultsAll strains studied belonged to 5 atypical EPEC serogroups and 15 serotypes based on the virulence profiles. Of 36 atypical EPEC serotypes, 22 (61.2%) and 14 (38.8%) strains isolated from diarrheal and healthy cases, respectively. O142:H48 (19.5%) and O111:H21 (11.1%) serotypes were the most prevalent isolates, followed by serotypes O111: H− and O86:H48 (5.6% each).ConclusionsThe characteristics of the atypical EPEC serotypes from children with diarrhea were significantly different from those without diarrhea. The compilation of data on atypical EPEC strains presented here indicates the importance of a combined approach of conventional and molecular tests to study the virulence and epidemiology of EPEC serotypes in human subjects

Gender Differential in the Association of Body Mass Index and Abdominal Obesity with Prehypertension and Hypertension in Iranian Adults

*Objective:* The aim of this study was to determine the gender differential in the relationship of body mass index (BMI) and abdominal obesity with blood pressure (BP) and prevalence of hypertension (HTN) and prehypertension (Pre-HTN) among the adult population of Iran.

*Design:* A nationwide cross-sectional survey was conducted from December 2004 to February 2005. The selection was conducted by stratified probability cluster sampling through household family members in Iran.

*Subjects and Measurements:* Weight, height, waist circumference (WC), and systolic and diastolic BP of 45,082 men and 44,322 women aged 15-65 (mean 39.2) were measured. 

*Results:* The prevalence of HTN was 25.2% in men and 24.8% in women; and 50.1% of men and 39.1% of women were pre-hypertensive. WC and BMI were strongly associated with BP in both genders. Multivariate analysis revealed that both WC and BMI had the stronger association with HTN and Pre-HTN in men than women. Compared to men and women with normal weight, the multivariate-adjusted odds ratio (OR) (95% confidence interval) of HTN was 5.75 (5.13, 6.44) for men and 4.29 (3.95, 4.66) for women with BMI ≥ 30. The multivariate OR of prevalence HTN in men with abdominal obesity compared with men without was 3.76 (3.41, 4.22) and in women, 2.92 (2.73, 3.13).

*Conclusion:* These data indicate that both BMI and WC had the stronger association with HTN and Pre-HTN in men than women. 
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Isolation, characterization and tolerance survey of bacterial strains to cadmium in soils receiving Hamadan industrial parks wastewater treatment plant effluent

Background and Aims: Biosorption is a relatively new clean up method used for the removal of heavy metals from the environment. Entry of heavy metals into the environment may result in change in population structure and further alteration of resistance mechanism(s) in exposed microorganisms. The first question inthis study sought to determine the threshold of bacterial resistance to cadmium (Cd). The second question was to identify indigenous bacterial species capable of removing the Cd from the soil and consequently to achieve a more efficient biological treatment for industrial effluents.Materials and Methods: Natural topsoil samples were obtained from three industrial parks in Hamadan, Iran. The concentration of Cd in soil samples was measured and thence the bacterial cultures were prepared. Following the screening process, the minimum inhibitory concentration [MIC] and minimum bactericidal concentration [MBC] were determined in order to find the threshold of bacterial tolerance. Indeed, theadsorption capacity of bacterial strains came down in favor of the identification of resistant bacteria.Results: Respectively, 42, 4 and 4 bacterial strains were identified for cultures having average cadmium concentrations of 0.78, 500 and 750 mg/L. This experiment did also detect that Tcd2 and Tcd4 showed the highest MIC with 1250 mg Cd/L. Moreover, TCd2, belonging to the family of Enterobacteriaceae and Enterobacter genus, demonstrated the maximum cadmium removal efficiency (30.2%).Conclusion: The test was successful as it was able to identify the indigenous cadmium tolerant bacteria with high adsorption capacity. This finding has important implications for developing special biological wastewater treatment such as a biofilter in the cadmium-releasing industries.Key words: Cadmium, Hamadan, Industrial park, Resistant bacteria, Soi

A Low-Cost Method for Optical Tomography

INTRODUCTION: In this study, arrangement of a low-cost optical tomography device compared to other methods such as frequency domain diffuse tomography or time domain diffuse tomography is reported. This low-cost diffuse optical imaging technique is based on the detection of light after propagation in tissue. These detected signals are applied to predict the location of in-homogeneities inside phantoms. The device is assessed for phantoms representing homogenous healthy breast tissues as well as those representing healthy breast tissues with a lesion inside.METHODS: A diode laser at 780nm and 50 mW is used as the light source. The scattered light is then collected from the outer surface of the phantom by a detector. Both laser and detector are fiber coupled. The detector fiber may turn around the phantom to collect light scattered at different angles. Phantoms made of intralipid as the scattering medium and ink as the absorbing medium are used as samples. Light is collected after propagation in the phantoms and the capability of the device in collecting data and detecting lesions inside the phantoms is assessed. The fact that the detection fiber orbits around the sample and detects light from various angles has eliminated the need to use several detectors and optical fibers. The results obtained from experiments are compared with the results obtained from a finite element method (FEM) solution of diffusion equation in cylindrical geometry written in FORTRAN.RESULTS: The graphs obtained experimentally and numerically are in good accordance with each other. The device has been able to detect lesions up to 13 mm inside the biological phantom.CONCLUSION: The data achieved by the optical tomography device is compared with the data achieved via a FEM code written in FORTRAN. The results indicate that the presented device is capable of providing the correct pattern of diffusely backscattered and transmitted light. The data achieved from the device is in excellent correlation with the numerical solution of the diffusion equation. Therefore, results indicate the applicability of the reported device. This device may be used as a base for an optical imaging. It is also capable of detecting lesions inside the phantom

Antimicrobial Photodynamic Therapy: An Effective Alternative Approach to Control Bacterial Infections

Introduction: The purpose of this review was to evaluate the available literature for in vitro and in vivo effectiveness of antimicrobial Photodynamic therapy (aPDT) in the field of bacteriology.Methods: A review of the relevant articles carried out in PubMed and Scopus to determine the efficiency of aPDT used in the reduction of microbial infection. Thirty-one relevant documents retrieved from PubMed, Scopus by inserting “antimicrobial photodynamic therapy” and “bacterial infection” and “photodynamic therapy” keywords.Results: According to different results, aPDT can be used as an adjuvant for the treatment of infectious diseases. The use of photosensitizer methylene blue, toluidine blue O (TBO), indocyanine green with light diode laser centered at (630±10 nm) and (650±10 nm) wavelengths have been shown to have significant results for the treatment of infectious diseases and bactericidal propertiesConclusion: These findings suggest that, aPDT can be an efficient method in the treatment of localized and superficial infections