فهرست مطالب زهرا هاشمی زاده

Due to the increasing rate of antibiotic resistance in bacteria and side effects of antibiotics, researchers aim at finding new herbal medicines. Several studies have proved the antibacterial effect of medicinal plants, such as Cuminum cyminum L. The present study aimed to investigate the antibacterial effect of Cuminum cyminum L. extract on some pathogenic bacteria in-vitro.
In this in-vitro study, aqueous and alcoholic extracts of Cuminum cyminum L. were prepared from seeds. Antibacterial effect of the extracts on several bacterial strains was evaluated using disk diffusion and broth micro-dilution methods to determine the Minimum Inhibitory Concentration (MIC). Then, the results were compared to the results of bacterial susceptibility to penicillin and amikacin antibiotics.
Cuminum cyminum L. aqueous and alcoholic extracts inhibited the growth of methicillin-sensitive Staphylococcus aureus (MSSA) (ATCC 25923). Diameters of zone of inhibition ranged from 10-22 and 14-22 mm for alcoholic and aqueous extracts, respectively. Considering methicillin-resistant Staphylococcus aureus (MRSA) (ATCC 700698), diameters of zone of inhibition ranged from 13-23 and 11-13 mm for alcoholic and aqueous extracts, respectively. These extracts were not effective in other tested bacteria. The alcoholic extract MIC was determined as 75±35.4 mg/mL for both MRSA and MSSA isolates.
With respect to the antibacterial effect of aqueous and alcoholic extracts of Cuminum cyminum L. on S. aureus isolates, further evaluation of the extracts for treatment of the infections caused by these bacteria is recommended.

Macrolide Streptococcus pneumoniae is generally mediated by two mechanisms: 23SrRNA methylation and efflux. The aim of this study was to assess the molecular mechanism of resistance in S.pneumoniae strains isolated from intensive care units in Shiraz. This was a cross – sectional study. 50 strains of S.pneumoniae were obtained from the patients admitted to intensive care units (ICU) of Nemazee and Shahid-Faghihi Hospitals, from 2010 to 2011. Suspected colonies were identified by phenotypical and biochemical tests. Organisms were confirmed to be Streptococcus pneumoniae on the basis of the presence of lytA gene by PCR method. Antibiotic resistance was evaluated according to Standard Clinical and Laboratory Standards Institute (CLSI). Macrolide resistance genes were identified by use of ermB and mefA specific primers. Using SPSS software, statistical analysis was performed by means of chi- square test. Resistance to erythromycin, clarithromycin and azithromycin levofloxacin were 18%, 48% and 44% respectively. In this study, 25 strains (50%) had mefA and 21 (42%) had ermB genes. Erythromycin resistance had significant relationships with mefA and ermB genes. The results of our study showed that the predominant mechanism of macrolide resistance was due to mefA gene in this area. Increased macrolide resistance calls for attention to the pattern of resistance in the therapeutic regimens.

Shigellosis is one of the acute gastrointestinal diseases. In view of outbreaks and emergence of antibiotic resistant therefore construction a live attenuated vaccine strains owing to high-cost antibiotics therapy and preparation new antibiotic urgently required. The current study was aimed at producing a live attenuated
mxiA by using  Red recombinase system in isolated shigella in Iran.

In this study, a total of 48 isolates of S. dysenteriae have been isolated from children at Children Medial Center, Milad and Firozabadi hospitals During the four-year period from 2006 until 2010 which were collected. By use of biochemical, serological and PCR tests, the species of isolated shigella were confirmed. The pKD46 plasmid electrotransformed into shigella and mutant strain was generated by a chloramphenicol cassette replacement through recombination using FLP flanking recognition target site. Precision of process was confirmed by PCR and sequencing.

Biochemical, serological and PCR tests were demonstrate 3 strain all of them (6.25%), belong to dysenteriae's species and serotype's type 1. present of mxiA gene was confirmed by PCR reaction. Sequencing results and PCR test were verified 2061 bp of mxiA gene was deleted.

use of  Red recombinase system facilitates mutant construction in more cost-effective method in comparison with the other techniques such as suicide vector.

The emergence of antibiotic resistance in nosocomial pathogens has become a great concern with rising reports of cases worldwide. Interestingly, the application of probiotics and their products for inhibition and bacterial replacement has been the focus of many investigations within the recent years. This study was performed to evaluate the antibacterial effect of L. casei & L. acidophilus against a number of known nosocomial bacteria in an attempt to introduce a replacement therapy. This study was carried out in bacteriology department of Shiraz Medical School in 2008. Lactobacilli strains were isolated from the local dairy (FARS) products and identified through routine microbiological methods using chemical (sugar) test. According to the results of a previous study, these two strains were tested for antibiotic resistance using disk diffusion method. Later, the supernatant of a 72-hour culture of each strain was tested for inhibitory affect on standard bacterial strains including S. aureus, E. coli, K. pneumonia, P. aeruginosa, and the spore- forming bacterium B. subtilis in two active and inactive forms. Review of the antibiotic results showed that both L.casei and L.acidophilus were resistant to all antibiotics used except the Tobramycin and Vancomycin which were demonstrated to have antibacterial activities against L.acidophilus. Additionally, when investigating the antibacterial activity of these two strains, it was revealed that except for B. subtilis, significant inhibition zones were found around the colonies of pathogenic bacteria both in active and inactive forms. According to the result of the present study it was demonstrated that the two strains of lactobacilli have a good resistance against the routine antibiotics although their antibacterial activity on growth of some usual nosocomial pathogens is limited in inactivated form when in conditions in which acid and H2O2 are available, they can act as good inhibitors of bacterial growth.

Acinetobacter is a gram-negative pathogenic bacterium and an important cause of nosocomial infections especially in immunocompromised patients in the intensive care units. Reports of multi-drug resistant isolates have increased during the last decade. As a result of extensive use of broad-spectrum antibiotics and high prevalence of ESBL producing bacteria especially in ICU ward, Acinetobacter infection is often difficult to treat.

To determine the antibiotic resistance in Acinetobacter and detecting the prevalence of ESBL producing strains in ICU patients of Namazi Hospital in Shiraz (Iran).

This study was carried our on 147 clinical isolates of Acinetobacter collected from ICU patients at Namazi Hospital during October to December (2008-2009). Antibiotic susceptibility test for isolated strains was performed using disk diffusion method. Also, isolation of ESBL Acinetobacter strains was accomplished using double disk synergy test.

The highest antibiotic resistance among 147 Acinetobacter baumannii strains was found against ciprofloxacin, amikacin, and gentamicin. Regarding the results of initial screening tests, 44% of total samples were demonstrated to be ESBL positive

Based on our data, the major reason for emergence of diverse ESBL strains was due to unjustified administration of broad spectrum cephalosporins. Accurate antibiotic susceptibility testing prior to administration of antibacterial agents for patients to reduce the high prevalence of ESBL strains is recommended.

Human cytomegalovirus (HCMV) infection is most often asymptomatic in immuno-competent individuals and has lifelong latency especially in leukocytes. However, CMV is a major cause of infection and death in immuno-compromised patients. Transfusion transmitted HCMV (TT-HCMV) can cause serious morbidity and mortality in certain patients who are at risk. In this study, we evaluated the risk of TT-HCMV infection in a seroprevalence survey of HCMV. In this descriptive cross-sectional study that was performed in a period of eight months, the blood samples were collected from 360 healthy blood donors referring to the Fars blood bank in Shiraz, Iran. The IgG and IgM antibodies to HCMV were measured by enzyme linked immunosorbent assay (ELISA) test. Of 360 samples, IgG was detected in 356 sera (98.9%) samples and only 16 samples (4.4%) were IgM positive. No statistically significant association was observed between seropositivitiy rate, age, sex, number of children and educational level in the studied population. The high prevalence of HCMV observed in this study confirms the necessity of diagnosis, prevention and treatment of HCMV infection in immuno- compromised blood recipients in our community.

Introduction & Cholesterol is an important compound in most of the biological reactions which the excess of it can be seen as a harmful compound of causing heart diseases. The aim of the present study was to evaluate the cholesterol removal property and also its pathway by dairy lactobacillus in in vitro condition under different bile salts concentration. After isolation of lactobacillus strains from dairy products, they were identified with chemical tests and their growths were evaluated under presence of cholesterol and bile salts. The method of action of the bacillus in cholesterol removal was assayed by spectrophotometer method. Collected data was analyzed by SPSS software. result of this study showed that any strains of the bacteria had the ability of cholesterol removal (7.82-34.69 µg/ml). L.casei had more competence for removal of cholesterol in compare to the rest of bacilli. The evaluation of cholesterol cell wall attachment revealed that most of removed cholesterols have been changed to the other products. Considering the result of this study, it can be concluded that cholesterol removal has a direct association with growth of bacteria where the L. casei with high growth rate had more capability of cholesterol removal. Whereas the Lactobacillus can remove the cholesterol with different methods, results of this study showed that dairy products, especially yogurt, can remove the harmful substances such as cholesterol using non chemical methods. The results of this study could be expanded on human use if more study and research could be carried out.