Modeling the effects of Bunium persicum [Black Zira] essential oil, pH, inoculums size and temperature on the growth of Listeria monocytogenes

Listeriosis is acknowledged as a major foodborne disease throughout the world caused by Listeria monocytogenes. Different factors can affect the growth of food borne microbial pathogens. The aim of this study was to investigate the combined effects of different concentrations of Bunium persicum essential oil [EO] [0%, 0.08%, 0.16%, 0.24%], three incubation temperatures [35ºC, 25ºC, 4ºC], three levels of pH [5, 6, 7] and two inoculum sizes [103 and 105 cfu ml-1] on the growth of Listeria monocytogenes in brain heart infusion [BHI] broth. To evaluate effects of explanatory variable on time to detection [TTD] of bacterial growth, parametric survival models based on the log normal distribution were used. All explanatory variables had significant association with TTD [P<0.05]. The final model accurately predicted the growth initiation and inhibition of L. monocytogenes. Key words: Listeria monocytogenes, Black Zira essential oil, Time to detection, Modeling

[Accuracy of emergency severity index of triage in Imam Hossein hospital - Tehran, Iran [2011]]

Triage is the most important and the first stage of patient's management at the time of arrival to hospital emergency department. Emergency severity index [ESI] is a common triage system worldwide. This study was aimed to evaluate the accuracy of ESI in emergency department of Imam Hossein hospital in Tehran, Iran. In this descriptive study the result of patients' triage based on ESI were gathered for all patients referred to emergency department of Imam Hossein Hospital from January to April 2011. A questioner was filled for each patient by the nurse and a emergency specialist independently. The lamda index was applied to compare the nurse observation with the specialist clinician. The STATA-11.0 statistical software and roctab table were used to determine the validity, specificity and sensivity of triage. Data were analyzed using Chi-Square and Fisher tests. The calculated lamda for the degree of agreement of triage between nurse and clinician was 81% [95% CI: 0.79-0.83]. The sensivity of triage for step I, II, III, IV and V were 100%, 53.2%, 90.7%, 67.1% and 98% respectively. The specificity of triage for step I, II, III, IV and V were 99.8%, 97.5%, 93.7%, 98.3% and 94% respectively. There was a significant overlapping between the triage step and the patient clinical outcome. This study showed that five steps triage contain a high accuracy and estimation of patient outcomes