Mm Soltan Dallal, A Rahimi Forushani, K Sharifi Yazdi, B Nikmanesh, A Rastegar Lari,, A Aminharati,
Volume 7, Issue 1 (spring[PERSIAN] 2013)
Abstract
Abstract
Background and Objectives: gasterointertidis is one of the most common forms of Salmonellosis, which is a worldwide problem. The invasive characteristic of intestinal bacteria is one of their pathogenicity Mechanisms , which can be easily investigated by cell culture technique. In this study ,the invasive characteristic of some Salmonella serogroup were investigated by using HEP-2 cell.
Methods and Material: The rectals soap were prepared from 280 diarrhea patients referred to Imam Khomeyni and children medical centres , 140 with bloody diarrhea and 140 with watery diarrhea as a comparison group. The rectal soap was taken before patients taking any antibiotics, and 140 rectal specimens were taken from healthy people as a control group. All the samples were inoculated in differential and selective media, like Hektoen enteric agar and Xylose lysine deoxycholate (XLD) agar .After incubation at 37C for 24 hours, the colonies were examined and identified by conventional biochemical and serological tests. Using HEP-2, cellular invasion characteristic of Salmonella serogroups was assessed. Moreover, the antibiotic resistance patterns were performed according to Clinical and Laboratory Standards Institute (CLSI).
Results: Of all tested samples, 35(8.3%) are Salmonella strains. The frequency of Salmonella is reported for bloody diarrhea (5.2%) , watery diarrhea ( 1.7%) and control group( 1.4%) .The most abundant serogroups with invasive characteristic, using HEP-2 cell culture, are serogroup B ( 62.9%) and D (17.2%).
Conclusion
The results obtained in this study show that the majority of Salmonella isolates are without invasive characteristic.
Key words: Salmonella, Diarrhea, Cell invasion, Cell culture
Mahmoud Alebouyeh , Zahra Abedi , Hossein Rastegar , Hasan Bagheri , Javad Vaez, Behrouz Akbari-Adergani ,
Volume 9, Issue 5 (Nov,Dec-2015 2015)
Abstract
Abstract
Background and Objective: Aluminum salts are among the most common useful additive compounds in preparation of human and animal vaccines. Aluminum phosphate and aluminum hydroxide are two additives that show good immunoadjuvant effects with many antigens. Aluminum-containing vaccines lead to a better and longer immune response compared to adjuvant-lacking vaccines. The Chromogenic methods used for determination of aluminum amounts in manufacturing centers are time-consuming and requires some experienced technicians to obtain accurate results. This study aimed to design and validate a simple polarographic method to measure aluminum in recombinant hepatitis B vaccine.
Methods: In this study, the effects of temperature, pH, potential range and potential scan rate on the polarographic method of measuring aluminum in hepatitis B vaccine was evaluated and the optimal values for each of these factors were achieved.
Results: In order to measure aluminum, temperature of 60 °C and pH of 4.5 were found as the optimal values. Implementation of polarographic method in the potential range of -0.25 to 0.1 volts had a better signal.
Conclusion: Since the polarography method is more simple, accurate and faster than the chromogenic methods, it is suitable to be used for the measurement of aluminum in hepatitis B vaccine and it is recommended to be used in quality control laboratories for biological products.
Keywords: Adjuvant, Hepatitis B Vaccine, Polarography, Aluminum.
Abdollah Ardebili , Malihe Talebi , Abdolaziz Rastegar Lari ,
Volume 10, Issue 1 (Jan,Feb 2016 2016)
Abstract
Abstract
Background and Objective: Due to the continuous increase of multidrug-resistant Acinetobacter baumannii strains around the world, decision making for an effective treatment of infections caused by this organism depends on the results of antimicrobial susceptibility tests. In this study, the validity of disk diffusion and E-test methods was assessed by their comparison with the reference method of microbroth dilution for three antibiotics of tetracycline, doxycycline and minocycline.
Methods: Total of 68 A. baumannii isolates were obtained from patients hospitalized in the burn center of Shahid Motahari Hospital in Tehran, Iran. Susceptibility of the Acinetobacter isolates was evaluated using the disk diffusion, E-test and microbroth dilution methods, according to the guidelines of Clinical and Laboratory Standards Institute.
Results: Among the isolates, 82.3% were tetracycline-resistant (with minimum inhibitory concentration 50 (MIC50) and MIC90 of 32 and more than 32 µg/ml, respectively and 41.2% were doxycycline-resistant (with MIC50 and MIC90 of 4 and more than 32 µg/ml, respectively). Minocycline, with resistance of up to 13.3% (MIC50 and MIC90 of 1 and 8 µg/ml, respectively) showed the highest antimicrobial activity against the A. baumannii isolates. Antimicrobial susceptibility of bacteria was different depending on the type of methods used. No very major error was observed in any of the methods of susceptibility testing. Overall, the level of major and minor errors in the E-test was lower than the disk diffusion method.
Conclusion: The results of this study indicate that minocycline has notably high antimicrobial activity against A. baumannii compared to other antibiotics of the tetracycline group.
Saman Shalibeik, Fereshte Ghandehari, Ali-Mohammad Ahadi, Ali-Asghar Rastegari, Mojgan Ghiasian,
Volume 16, Issue 3 (May-Jun 2022)
Abstract
Background and objectives: Bacteriocins are generally active antimicrobial peptides effective against bacteria closely related to the producer. Escherichia coli produce two bacteriocins: colicins and microcins. Microcin J25 (Mcc J25) is an antibacterial peptide that inhibits bacterial transcription by disrupting the nucleotide-uptake channel of bacterial RNA polymerase. The objective of this study was to evaluate antimicrobial activity of MccJ25 produced by the bacteriocinogenic E. coli.
Methods: In this experimental study, 120 clinical specimens were selected from private diagnostic laboratories in Isfahan (Iran) in 2020. Antagonistic activity of isolates was tested by adopting agar plug method. Total DNA was extracted from clinical specimens and polymerase chain reaction (PCR) was performed using specific primers for amplification of the complete sequence of MccJ25 gene. Accuracy of the PCR products was confirmed by direct sequencing. Homology analysis was performed by using BLAST. Data were analyzed with Chromasv2.1.1 software.
Results: Overall, 120 E. coli strains were isolated from the clinical specimens. The antibiotic activity of Mcc J25 was mainly directed at Enterobacteriaceae, including several pathogenic E. coli strains of which 25 had positive well test samples, and about 5 (20%) of the collected clinical samples that were infected with E. coli had the MccJ25 gene.
Conclusions: Based on the results, Mcc J25 has favorable antibacterial potential, which can be further exploited as an alternative to chemical antibiotics.
