Asefeh Dahmardeh Ghalehno, Maryam Ghavidel-Aliabadi, Zeinab Shahmohamadi, Maliheh Mehrshad, Mohammad Ali Amoozegar, Abolghasem Danesh,
Volume 20, Issue 12 (3-2018)
Abstract
Abstract
Background: Today, discovery and production of new antimicrobial drugs has been emphasized due to the growing of antimicrobial resistance. The purpose of this study was to screen out antimicrobial producing bacteria among halophilic or halotolerant Gram-positive endospore-forming bacteria isolated from different areas of Iran.
Materials and Methods: 62 strains were isolated from salin lakes of Iran, endospore-forming ability was evaluated and further identification of strains was done using 16S rRNA gene sequencing. Screening test was performed using two-layer agar diffusion method in which the indicator strains, Bacillus cereus (ATCC 14579) and Escherichia coli, (PTCC 1330) were inoculated in the seed layer. Finally, the production of antimicrobial active agent during a period of 7 days was studied followed by evaluating the effect of base-layer agar concentration on the dissemination of antibacterial metabolite.
Results: Isolates WT6, R4A19 produced an agent(s) which inhibited the growth of both B.cereuse and E.Coli. The inhibition zone against only E.Coli was observed when R4A20 strain had been cultured in the base layer, while four non-bacillus strains (R4S2, LbS2, RF1 and WT19) could inhibit the growth of B.cereuse. The antibacterial compound production of WT6 against Bacillus cereuse and E.Coli reached to its optimumm leved after 3 and 4 days respectively, while R4A20 produced the active substance, optimally, after 5 days. No significant difference effect on diameter of zone inhibition was observed among various base-layer agar concentrations.
Conclusion: Halophile or halotolerant endospore-forming bacteria isolated from different areas of Iran possess a potential to be considered as interesting microorganisms for further antimicrobial research studies.
Mitra Rahimzadeh, Noushin Ghavidel, Behrooz Kavehie,
Volume 28, Issue 5 (12-2025)
Abstract
Introduction: The age structure of the population has changed due to a decrease in mortality rates. With the increase in the number of elderly individuals, addressing their physical, mental, and social needs has become essential. It is necessary to have a reliable and valid tool for assessing the health status of this group for developing future policies and planning health interventions. This study aimed to evaluate the psychometric properties of Lali’s Healthy Lifestyle Questionnaire using Item Response Theory (IRT) among the elderly in Karaj City.
Methods: Data collection was done through the distribution of questionnaires and interviews with patients in the health centers of Karaj city. In addition to demographic information, Lali's Healthy Lifestyle Questionnaire (2012) was used to collect data.
Results: The mean (standard deviation) age of the participants in the study was 66.82 (6.59) years. Based on the Akaike Information Criterion (AIC), the Nominal Response Model (NRM) demonstrated a better fit to the data among the common IRT models for Likert-scale questionnaires. Based on this model, out of the 54 items used, 6 items did not meet the acceptable criteria for the discrimination parameter and were excluded from the questionnaire. Based on the total information function, the questionnaire can appropriately differentiate individuals within the ability range of -1.5 to 2.5.
Conclusions: Using Item Response Theory in questionnaire psychometrics helps to reduce the number of unrelated items and increase the accuracy of the measurement tools.
