فهرست مطالب گیتا اسلامی

Backgrond:

 During the past two decades, Acinetobacter baumannii has been introduced as an important clinical pathogen due to its remarkable ability to cause infections and to acquire resistance to the currently used antibiotics, including β-lactams, aminoglycosides, and tetracyclines. The aim of the present study was to determine the pattern of antimicrobial susceptibility and the prevalence of armA, tet(39) genes, and the insertion sequence ISAba4 in A.baumannii strains collected from burn patients referred to Shahid Motahari hospital in Tehran. 

Totally, 92 clinical isolates of A.baumannii were collected from the burn wounds of inpatients in Motahari hospital in Tehran. The isolates of Acinetobacter were identified using laboratory and microbiological tests. Then, for the identification of species, the molecular method was carrid out by detecting the presence of the blaOXA-51 gene. The pattern of antibiotics susceptibility was performed via disk diffusion and the minimum inhibitory concentration (MIC) was performed via microdilution broth, according to CLSI guidelines. The prevalence of armA, tet(39) genes and the insertion sequence ISAba4 were investigated using PCR and Sequencing.

Out of 92 A.baumannii, 95.6%, 89.2%, 97.9%, and 81.5% of the isolates were resistant to gentamicin, amikacin, imipenem, and tetracycline, respectively. All the isolates were also resistant to meropenem. The armA gene was detected in 58% of the isolates, while all strains carried tet(39) and the insertion sequence ISAba4 was detected in only 3.2% of the isolates.

Our study showed a relatively high distribution of armA, tet(39) genes, and the insertion sequence ISAba4 in clinical isolates of A.baumannii. This can lead to increased concerns and irreparable health costs. Drug administration, recognition of the pattern of antibiotic resistance in A.baumannii, and the study of the molecular epidemiology can be effective in counteracting antibiotic resistance.

Staphylococcus aureus is a major cause of nosocomial infections in the world. Efflux pumps are well known as a key role to fluoroquinolone resistance in methicillin-resistant Staphylococcus aureus (MRSA). The present study was performed to determine resistance to antimicrobial agents related to efflux pumps isolates recovered from blood cultures of patients referred to several hospitals affiliated with Shahid Beheshti University of Medical Sciences between 1396-1397.

In the present descriptive cross-sectional study, a total of 100 clinical samples were collected from blood cultures over a 12-month period. S. aureus isolates were identified using standard microbiological tests. Antimicrobial susceptibility patterns were determined using disk diffusion method and micro-dilution method. Subsequently, the presence of norA efflux pump gene was detected using PCR method. Finally, active efflux pumps were evaluated using ciprofloxacin and ethidium bromide MICs. Polymerase Chain Reaction (PCR) and sequencing were used to investigate the norA efflux pump gene. Chi-square test was used for statistical analyses.

Among 100 clinical samples, 38 out of 45 MRSA isolates (84.4%) showed resistance to ciprofloxacin. Moreover, the norA gene was found in 100% of ciprofloxacin resistant isolates. Among 38 ciprofloxacin-resistant isolates, 8 isolates showed active efflux activity by reducing EtBr and ciprofloxacin MIC values by 2 to 4 folds in the presence of CCCP (carbonyl cyanide 3-chlorophenylhydrazone).

It seems that a rising trend of antimicrobial resistance among S.aureus isolates to different antibiotics has  become a widespread concern in infection control.

Staphylococcus aureus is an opportunistic pathogenic bacterium that can provide invasive conditions by secreting various toxins. It is involved in the development of skin infections, such as swollen and ulcers. Today, one of the main problems is the treatment of Staphylococcus aureus resistant strains. The aim of the current study was to detect virulence factors and antibiotic resistance among strains isolated from wound infections of children who referred to Tehran Children’s Medical Hospital in 1396-97. A total of 59 strains of Staphylococcus aureus isolated from wound infection were collected during one year. Staphylococcus aureus was detected using biochemical tests. For antibiotic susceptibility test, antibiotic disks (Mast، UK) were used according to the CLSI 2017. For detection of virulance genes, including nuc، mecA، tsst-1، hla، hlb، hld، eta، etb، etc, PCR method was used. Vancomycin and linezolid were sensitives for all isolates and the highest resistance antibiotic was penicillin with 98.3%. The frequency distribution of genes s mecA، tsst-1، hla، hlb، hld، eta، etb، and etd were 59.3%, 37.7%, 71.2%, 57.6%, 96.6%, 100%, 11.9%, 27.1%, respectively. All isolates were sensitive to vancomycin and linezolid, and these antibiotics were the best choices for the first line of treatment for staphylococcus aureus strains. Since all isolates of Staphylococcus aureus were obtained from children wound infections and all of them contained oxfolitic A gene, control and disinfection measures seem to be important among children, because these strains have the potential to spread this gene among hospitalized patients.

Staphylococcus is a bacterium responsible for a wide range of diseases, from mild skin infections to lethal necrosis pneumonia. The aim of this study was to determine the virulence factors among methicillin resistant and sensitive strains isolated from clinical specimens of children referred to the pediatric medical center and also to be aware of their antibiotic resistance.
In the present study, 100 strains of Staphylococcus aureus, susceptible and resistant to methicillin, were collected during one year. First Biochemical tests were performed to detect Staphylococcus aureus bacteria. Then antibiotic susceptibility test was performed using antibiotic disks (MAST;England) according to CLSI guidelines. The presence of hlg, mecA, nuc and pvl genes was investigated by PCR method and sequenced.
30 samples (30%) were methicillin-resistant (MRSA) using the cefoxitin disk. The most susceptible to antibiotics, vancomycin with 100% and the highest resistance to antibiotics, penicillin with 98% were determined. The prevalence of hlg, mecA, and pvl genes was 30%, 95% and 6%, respectively.
The present study showed that vancomycin and cotrimoxazole antibiotics were the best effect against MRSA strains.

Acinetobacter baumannii is an opportunistic pathogen that has acquired a high rate of antibiotic resistance. Identification of the major elements increasing the expression of resistance genes while having a role in their transmission, can help us control the A. baumannii infections. This study aimed to determine the prevalence of ISAba2 in A. baumannii strains which include group D beta-lactamase genes among hospitalized patients.
From August 2014 to April 2015, 105 A. baumannii strains were collected from different clinical samples of patients in 5 hospitals in Tehran. The confirmation of strains was done by phenotypical tests and existence of blaOXA-51-like gene. Antibiotic susceptibility pattern of the isolates were performed by Disc Diffusion Test (DDT) and Minimum Inhibitory Concentration (MIC) according to the CLSI. ESBL producing strains were recognized with Combined Disc Diffusion Test (CDDT) while the presence of OXA genes and ISAba1and ISAba2 were analyzed using PCR reactions.
The result of this study showed that the highest and lowest rates of antibiotic resistance belonged to cefotaxim (100%) and colistin (99.05%), respectively. A total of 55 isolates (54.5%) were capable of producing ESBL. Unlike the blaOXA-58-like gene, which was not found in any of the isolates, blaOXA-51-like- was present among all the isolates.. Prevalence of blaOXA-23-like and blaOXA-24-like genes were 103 (98.09%) and 68 (64.76%), respectively and the frequency of ISAba1 and ISAba2 were 105 (100%) and 97 (92.36%), respectively.
The existence of additional elements as effective factors, can increase the expression of resistance genes and, therefore, help them to be mobile and transmitted between bacteria. Determination of these elements is, therefore, necessary for controlling infections.

Increasing emergence of fluoroquinolone resistance among clinical isolates of Klebsiella pneumoniae (K. pneumoniae), has limited the treatment options for treatment of infections caused by these bacteria. The aim of this study was to investigate the dissemination of genes encoding AcrAB and QepA efflux pumps among K. pneumoniae strains.
This study was carried out on 117 K. pneumoniae strains isolated from patients hospitalized in selected hospitals in Tehran city, 2015-2016, Iran. Antimicrobial susceptibility tests were performed using disk diffusion method (based on CLSI guidelines) and identification of acr A, acr B and qep A genes using PCR assay.
In this study, colistin and tigecycline had the best effect against clinical isolates of K. pneumoniae. According to PCR results, 110 (94%) isolates had acrA gene and 102 (87%) isolates had acrB gene, respectively. The qepA gene was not found in any of the K. pneumoniae strains.
According to the results of the present study, dissemination of the genes encoding AcrAB efflux pumps among K. pneumoniae strains, which cause resistance to fluoroquinolones, is a matter of concern. Therefore, infection control and prevention of the spread of drug-resistant bacteria requires careful management in drug prescription and identification of resistant isolates.

Pseudomonas aeruginosa is a major cause of nosocomial infections. Different mechanisms of drug resistance and acquired-resistance genes from other bacteria, caused the treatment of infections of this opportunistic pathogen with serious problems. So even with the newer antibiotics, the treatment has failed. The use of medicinal plants is one way to develop antimicrobial agents. Given the widespread use of Urtica Dioica and Zataria multifloraherbs in traditional medicine and the potential effects against many infectious agents are going to eveluate the antibacterial effect of methanoland acetone extracts of Urtica Dioica and Zataria multiflora against metallo beta-lactamase producing Pseudomonas aeruginosa carring bla VIM and bla IMP genes.
This study was performed from October to February year 2014 on 448 burn patients hospitalized in Shahid Motahari Hospital, Tehran. For all MBL-producing strains, antibiotic resistance by disk diffusion method were done according to CLSI guidelines.CDDT method for detection of MBL and PCR and Sequencing methods for Identification of metallo beta-lactamase gene, bla IMP and bla VIM,were used. The minimum inhibitory concentrations of antibiotics meropenem, cefepime, ceftazidime, cefotaxime, ampicillin, piperacillin/ tazobactam and ceftriaxoneand the minimum inhibitory concentration of methanol and acetone extracts of Urtica Dioica and Zataria multiflora herbs were donebased on agar dilution method.
Findings: Among 83 imipenem resistant P.aeruginosa strains, 48 (57.9%) isolates produced MBL. PCR and sequencing methods confirmed that these strains were blaIMP-1positive genes, whereas none were positive for bla (VIM) genes. Hospitalized burn patients with MBL-producing P.aeruginosainfection had 4/48 (8.3%) mortality rate. It was demonstrated that Urtica Dioica and Zataria multiflora extracts had a significant antibacterial effect on regular and IMP-producing P. aeruginosa strains.
Discussion & Prevalence of MBL-producing Pseudomonas aeruginosa strains among patients is high. Also due to high resistance of chemical drugs, the use of medicinal plants such as Urtica Dioica and Zataria multiflora can be a better alternative for treatment, which requires further studies. In this study the extracts of U.dioica and Z. multiflora had a high antibacterial effect against β-lactamase producing P. aeruginosa isolates.

The increasing emergence of antimicrobial resistance among gram negative bacteria especially Enterobacteriaceae has become a global problem. Klebsiella pneumoniae is an opportunistic pathogen, which recently due to causing broad spectrum of disease and antibiotic resistance has been lionized. Efflux pumps are one of the antibiotic resistance mechanisms, which were introduced in this bacteria. Therefore, the aims of this study were detection of oqxA, oqxB, acrA and acrB genes, evaluation of expression level of oqxA and acrA genes and determination of antibiotic resistance patterns among Klebsiella pneumoniae isolated at Tehran hospitals.
In this descriptive study 83 Klebsiella pneumoniae were collected from patients attending to three hospitals in Tehran. Antibiotic susceptibility test was performed by disk diffusion method. The presence of oqxA, oqxB, acrA and acrB resistance genes was detected by PCR. The CCCP was used as efflux pump inhibitor and the oqxA, acrA genes expression level was analyzed by using real-time PCR.
The most of strains showed to have OqxAB (96%) and AcrAB (97%) pumps. The use of efflux pump inhibitor showed different results for ciprofloxacin MIC. Real-time PCR assay showed higher expression level of OqxAB (2.3 folds) and AcrAB (4 folds) pumps in resistant strains.
The existence of antibiotic resistance genes, increasing of Klebsiella pneumoniae strains, which become resistant to common antibiotics and nosocomial infections, highlights the need for particular detection, prevention and control of spread of resistant bacteria.

The efflux pumps are one of the main mechanisms of resistance to antibiotics in E. coli and K. pneumoniae strains. The aim of this study is to study the association between genes coding efflux pumps AcrAB and Qep A and ciprofloxacin resistance among E. coli and K. pneumoniae clinical strains
This study was done on 100 strains of E. coli isolated from Taleghani and Labbafinejad Hospitals and 100 strains of K. pneumoniae isolated from Taleghani and Mofid Children Hospitals. Antimicrobial susceptibility tests were performed by disk diffusion method based on CLSI guidelines. Identification of genes encoding efflux pumps Acr AB and Qep A was done by PCR technique.
In this study, fosfomycin and imipenem had the best effect against E. coli clinical isolates and fosfomycin and tigecycline had the best effect against K. pneumoniae clinical isolates. PCR assay demonstrated that the prevalence of AcrA, AcrB and QepA genes among E. coli isolates were 92%, 84% and 0%, respectively and among K. pneumoniae isolates were 94%, 87% and 4%, respectively.
The prevalence of genes encoding efflux pumps in E. coli and K. pneumoniae clinical strains, which causes resistance to fluoroquinolones, is cause for concern. Therefore, controlling infection and preventing the spread of drug-resistant bacteria needs to manage medication carefully and identify resistant isolates.

Green tea polyphenols green tea is one important factor for inhibition of growth of oral bacteria. This study investigates the antibacterial effect of green tea extract on Enterococcus faecalis and Streptococcus mutans of dental plaques. A lot of 60 samples of dental plaques, the samples were placed in transport medium (TSB) and were then transported to the microbiology laboratory. The samples were cultured in blood agar medium, Mitis salivarius agar, bile esculin agar and were incubated in proximity of Co2 (5-10%) at 37 °C for 48 hours. After observing the colonies, the slides were prepared and were stained by Grams Method. To ensure the authentication and identification of microorganisms, common microbial and chemical tests were used. After determining the type of bacteria, antibiogram test was done and to determine bacterial sensitivity and resistance to green tea, sodium hypochlorite and chlorhexidine by Disc Diffiusion Agar according to CLSI (Clinical and Laboratory Standards Institute) guidelines. The data were analyzed by ANOVA and Tukey test (a=0.05) ANOVA test showed that diameter of growth inhibition of green tea was not so different from chlorhexidine for Streptococcus mutans, (P=0.305) but was significantly less than sodium hypochlorite (P=0.0001) and also the inhibitory effect of sodium hypochlorite was significantly higher than chlorhexidine (P=0.038). In Enterococcus faecalis, sodium hypochlorite was more effective than green tea and chlorhexidine (P=0.0001) and chlorhrxidine effect was significantly greater than that of green tea (P=0.0001). Sodium hypochlorite had the highest inhibitory effect on growth of Streptococcus mutans and Enterococcus faecalis. Since there was no significant difference between inhibitory effect of green tea in Streptococcus mutans and chlorhexidine, using it as a mouth wash, could be a suitable alternadive way to prevent tooth decay

The study emphasizes the reasons use of beta-lactamase inhibitors in combination with beta-lactam antibiotics. ß-lactam-ß-lactamase inhibitors are currently the most successful strategy for infections caused by extended-spectrum β-lactamase and carbapenemases bacteria.

Aim and Recently the spontaneous abortion has been thea matter of attention by researchers. Therefore, bacteria such as Listeria monocytogenes, Chlamydia trachomatis, Mycoplasmas and Streptococcus agalactia are important agents of this phenomenon. When they are not recognized in due time, we found spontaneous abortion and increase of antibiotics resistance. The aim of this study was to assess the extent of L. monocytogenes in causing human spontaneous abortions by isolation methods and PCR analysis for the presence of actA, PrfA and InlB genes. In this descriptive study, vaginal swabs were collected from a total of 96 women with spontaneous abortions who referred to Tehran`s hospitals. The samples were transported in to TSBYE broth. Then, the samples were enriched at 4 ͦ C for 1 month. Total DNA of L. monocytogenes was extracted by Fermentase kit. PCR test is performed on all samples and detected the actA, PrfA and InlB genes of L. monocytogenes. In PCR technique, actA, PrfA and InlB gene were detected 12.5%, 9.3% and 2% respectively from 96 patients with spontaneous abortions. The occurrence of pathogenic L. monocytogenes in cases of spontaneous abortions was 12.5%. It seems that the actA, PrfA and InlB genes have an important role as essential virulence determinant in pathogenic L. monocytogenes.

Aim and Extended spectrum β-lactamases (ESBLs) have emerged as a major threat worldwide with limited treatment options. This study aimed to determine the antibiotic susceptibility pattern and the evaluation of TEM genes producing in Escherichia coli and Klebsiella pneumonia isolates collected from clinical samples. Bacteria were isolated and identified from the different samples in patients sent to laboratory of shahid Beheshti University in Tehran in 2011. Isolates were then tested for antimicrobial susceptibility by disc diffusion and examined for TEM genes production by polymerase chain reaction using specific primer. Out of 100 studied nosocomial infection specimens, 50 isolates were klebsiella pneumonia of which 34 percent were ESBL producer and all were positive for TEM gene, resistance of Cefotaxime was 90 percent which is the highest degrees of resistance and lowest degrees of resistance to Imipenem was 4 percent. Among the 50 isolates of Escherichia coli of which 14 percent were ESBL producer and all were positive for TEM gene, resistance of Cefexime was 90 percent which is the highest degrees of resistance and lowest degrees of resistance to Meropenem was 6 percent. Due to relatively high prevalence of ESBL-producing bacteria in the studied population, antibiogram test are advised for appropriate treatment.

Background and An increasing emergence of multidrug resistance among Klebsiella pneumoniae nosocomial isolates has limited the therapeutic options for treatment. The beta-lactamases are the major defense of gram-negative bacteria against antibiotics. The aim of this study was the detection of ESBLs and Amp-C enzymes and MOX، FOX، and ACT genes in K. pneumoniae strains isolated from hospitalized patients in Tehran hospitals during 2011-2013. This study was conducted in 120 K. pneumoniae isolates from Imam Hossein، Taleghani and Mofid Children''s hospitals in Tehran، Iran. Antibiotic susceptibility tests were performed using Kirby-Bauer disc diffusion and Broth Microdilution methods. The detection of Amp-C and ESBLs enzymes was carried out according to CLSI guidelines. The MOX، FOX، and ACT genes were detected by PCR and sequencing methods. Among 120 K. pneumoniae strains، 24 (20%) and 68 (56. 8%) were Amp-C and ESBL positive، respectively. In this study colistin and tigecycline were found more active than other antibiotics. ACT، FOX، and MOX genes were detected in 16 (13%)، 46 (38. 33%) and 43 (35. 83%) of the isolates، respectively. The prevalence of antibiotic resistance genes detected in this study is of great concern and highlights the need for infection control measures including antibacterial management and identification of resistant isolates.

Abstract Excessive consumption of antimicrobial materials in hospitals and the community is as the main encoder, led to the emergence, development and acquisition of new bacterial resistance to antimicrobials. According to the lack of enough information about the mechanisms of the resistant genes to disinfectants and receiving no report from the country and considering the resistance or sensitivity of the isolates of the Acinetobacter baumannii MDR in facing disinfectants, this study was taken place in the selected intensive care units if the hospitals of Tehran. This experimental study which was conducted over a period of 10 months, Acinetobacter baumannii species were separated by culture and biochemical tests. The resistance and sensitivity of the isolates to antibiotics is considered according to CLSI (2012) guidelines. By multiplex PCR method blaCTX and blaTEM were detected and finally, MDR strains were treated with 2% glutaraldehyde. Of 588 samples, 131 isolates (22.28%) of Acinetobacter baumannii were isolated. The amount of the resistance to various antibiotics was in the range of the 69.4% to 100%. The frequencies of the blaTEM and blaCTX were 3.2% and 19.4%, respectively, and there was no resistance to glutaraldehyde. It seems that beside variety and prevalence of blaTEM and blaCTX, enormous mechanisms like porin and leaking systems (efflux Pumps) are responsible in the making of the resistance of Acinetobacter baumannii to disinfectants. Also these results facilitated the study of phenotypic and genotypic resistance patterns of these antimicrobials and disinfectants in different parts of the world.

Abstract there are serological evidences about association between Mycoplasma pneumonia and cardiovascular diseases. It has been suggested that this Microorganism may have an important role in the progression of atherosclerosis. The aim of this study is to determine the presence of mycoplasma genome in atherosclerotic plaques by PCR. This study was done on fifty atherosclerotic plaques specimens from patients with aortic aneurysms and carotid artery stenosis and limb ischemia. All patients underwent surgery. The specimens were analyzed by PCR for the presence of 16srRNA genus specific gene. Male and female were 43 and 7, respectively. Risk factors were consisted of hypertension, hyperlipidemia, diabetes mellitus, smoking, history of IHD and myocardial infarction. Statistical analysis was performed through SPSS program version 16. This investigation showed the presence of Mycoplasma genome in 20% of atherosclerotic plaques. In positive cases, eight patients had aortic aneurysm and two patients had carotid artery stenosis. Among all patients, hyperlipidemia in 26%, hypertension in 52%, mellitus diabetes in 20%, smoking in 52%, IHD in 38% and history of MI in 10% of cases were seen. Our results demonstrated the presence of Mycoplasma genome in atherosclerotic plaques. The results supported the correlation between Mycoplasma pneumonia and atherosclerosis. In addition, display inflammation by this organism accompanied by risk factors, had important role in atherosclerosis progression.

Resistance of Helicobacter pylori to different antibiotics leads to recurrent infection which is an important risk factor for peptic ulcer disease and gastric cancer. This study was done to determine the effect of cinnamon on eradication of Helicobacter pylori. After taking biopsies from patients with dyspepsia، 60 patients infected with the Helicobacter pylori were selected. Samples were transported to the laboratory، cultured on Brucella agar containing 10% horse serum، vancomycin، polymyxin، trimethoprim and amphoteripcin and incubated at 37 ° C for 5-7 days under microaerophilic conditions. Grown colonies were identified by using standard microbiological and biochemical tests. To extract cinnamon oil، we obtained the concentrate from bark of Cinnamon trees by Clevenger distillation apparatus. Antibiotic susceptibility of Helicobacter pylori to metronidazole، amoxicillin، clarithromycin، tetracycline and disks impregnated with extracts of Cinnamon was determined by disk diffusion method according to the CLSI guidelines. Sensitivity of Helicobacter pylori to different agents was as follows: clarithromycin 76%، tetracycline 62%، amoxicillin and metronidazole 100% and Cinnamon oil 100%. Cinnamon plant can be effective in eradicating Helicobacter pylori.

Diagnosis of bacterial causes of cutaneous infections and determination of their resistance to different antibiotics is required for choosing the optimal treatment. This study was performed on bacterial cultures which were taken from patients with cutaneous infections. Samples were collected from 110 patients with cutaneous infections referred to the clinical laboratories in Shohada and Loghman in 1388-1389. The samples were cultured by routine microbiological methods for isolation of microbial agents. The antibiogram disc agar diffusion technique was used to evaluate the sensitivity of microbial agents to antibiotics. The bacteria causing cutaneous infection in the order of their prevalence included Staphylococcus aureus (31%), Escherichia coli (22%), coagulase-negative Staphylococci (12%), Streptococcus spp (8%), Enterobacter (8%), Klebsiella (5%), Acinetobacter (5%), Pseudomonas spp (4%), Enterococcus (3%) and Proteus (2%). The most resistance organisms were Acinetobacter (86%), Enterobacter (81.7%), Enterococcus (78.4%), and the most sensitive organisms were Proteus (61.1%) and Streptococcus spp (60.7%). Staphylococcus aureus is the most common microbial agents of cutaneous infections. In order to prevent bacterial resistance to antibiotics we must prescribe antibiotics based on bacterial culture and antibiograms.

Conjunctivitis is a common eye infection that can decrease vision or even cause blindness. The disease has different etiologies including bacterial, viral, fungal, parasitic and chemical agents. The aim of this study was to determine the etiological agents of bacterial conjunctivitis and the prevalence of various bacteria in Farabi Hospital Tehran in 1389-1390. This study is descriptive; 60 samples from patients with conjunctivitis were examined. Samples were cultured on enriched media like blood agar and chocolate agar; also on selective and differential media such as EMB or MacConkey agar in the laboratory. Prepared smears were stained by Gram and Giemsa methods. In addition, fungal infections were examined by Conlocal scan. Bacterial prevalence in clinical samples of community was calculated; and relationship between Conjunctivitis and age or sex with was studied. From 60 patients, 55 percent were women; average age was 20±17. 53.3 percent of smears and 72% of cultures were positive. 41.7 percent of positive smears were gram positive cocci; most prevalent bacteria were coagulase negative staphylococci, especially Staphylococcus epidermidis (20 percent). There was no significant relationship between the prevalence of conjunctivitis and age or sex. Frequency of bacterial agents in patients with conjunctivitis are high.

Propolis, a natural product of the honeybee, is currently used as an anti-inflammatory and antimicrobial agent. Using different antibacterial agents is an important step to reduce the number of microorganisms within the root canal and improve the endodontic treatment prognosis. The present in vitro study investigated the antibacterial efficacy of Propolis against Enterococcus faecalis compared to calcium hydroxide. In this experimental study, 42 single-rooted human teeth were selected and their smear layer was completely removed after access cavity and canal preparation. After infecting the prepared canals with Enterococcus faecalis species, negative control group was used during sterilization period and in two groups of 18 each, canals were filled with 30%propolis extract and calcium hydroxide, respectively. No material was added to the positive control group. The specimens were stored in CO2 incubator for 72 hours, 1 week and 1 month and afterwards, samples were taken from inside the canals and Enterococcus faecalis colonies were counted. Number of colonies at different time intervals was statistically analyzed using Kruskal-Wallis test. Mann-Whitney U test was used to compare the number of colonies after using the understudy medicaments. Number of colonies was 55,000±46,368.09 and 43,333.33±48,027.077 after incubation for 72 hours and using 30% Propolis extract and calcium hydroxide, respectively. After 1 week incubation, number of colonies was 166.67±408.25 in the Propolis group and zero in the calcium hydroxide group. No colonies were observed after 1 month incubation in both groups. No significant differences were noted between two medicaments at different time intervals. In general, antimicrobial activity of Propolis against Enterococcus faecalis species was comparable with that of calcium hydroxide at different time intervals. Therefore, it can be used as an alternative natural material for disinfection of canals during endodontic treatment.

The aim of this study was to compare the effect of Mtwo rotary system and step back hand system in reduction of enterococcus faecalis bacteria from the root canals of human extracted teeth.

In this study, 62 human extracted teeth were divided into two equal experimental groups with 23 teeth each and one control group two extra control groups with 5 teeth each as negative and positive were chosen for confirmation of the canal reinfection too. All of the samples were prepared by K Flie No 20 and Gates Glidden No 2 & 3 before sterilization. Then the teeth were autoclaved and reinfected with enterococcus faecalis. The experimental groups were instrumented either with Mtwo system or step back system. Bacteriological samples were taken after instrumentation to determine the amount of remaining bacteria.

In the group 1, fourteen samples and in the group 2, twelve samples represented complete reduction of bacteria. There was not statistically significant difference between two techniques (p>0.05)

Both Mtwo and step back systems are the same on reduction of the bacteria from root canal system, up to the same apical size.

Apical leakage of tissue fluids around root canal space was cited as the most common cause of root canal treatment failures, for which, fillings of root canal with root filling materials was suggested to achieve adequate apical seal and to prevent leakage. Due to the importance of adequate apical seal, different root canal filling materials were developed and used for this purpose. The purpose of this study was to compare bacterial apical leakage through root canal filling materials of Resilon, GuttaFlow and Gutta-Percha with AH26 sealer. In this in vitro experimental study, 55 single-rooted teeth with healthy roots meeting the study inclusion criteria were selected and randomly divided in 3 experimental groups each containing 15 specimens and 2 positive and negative control groups each with 5 samples. The teeth crown were sectioned near the CEJ, the teeth canals were instrumented with step- back technique while group 1 was obturated with Gutta-Percha, and group 2 with Resilon using a cold condensation technique. Group 3 was obturated with GuttaFlow as recommended by manufacturer. Two-chamber bacterial methods were used to assess bacterial apical leakage by means of Enterococcus Faecalis bacterium during a 60 days time interval. The data were analyzed by Kaplan-Meier test. In root canals filled with Resilon, the median of the day in which leakage was occurred was 17, in Gutta-Percha specimens it was 18 and in canals filled with GuttaFlow the median was 19. 93.3% of the roots filled with each Resilon or Gutta-Percha showed apical bacterial leakage during 60 days while in canals filled with GuttaFlow, the leakage was observed in 80%. Kaplan-Meier test showed no significant differences comparing the day in which the leakage was occurred or the overall incidence of leakage in three materials. Under the conditions of the present study, three root canal filling materials showed similar rates of apical bacterial leakage as no significant statistical differences were noted among them.

Presence of the beta-lactamase enzyme results in microbial resistance to beta-lactam and cell wall synthesis inhibitor antibiotics. This study was conducted to compare effects of Calendula officinalis extract and cephalosporines, as a cell wall synthesis inhibitor antibiotic, on bacteria isolated from patients with cellulitis. This experimental study was done on bacteria isolated from 100 patients. Calendula officinalis extract was prepared by perculation with methanol 85%. Solvent was vaporized and lyophilized. Antibacterial effects of the herb extract, cefixim, cephalexin, ceftriaxone, ceftizoxime, and cefazolin were evaluated by two methods of disc diffusion and MIC. Statistical analysis was performed by ANOVA and paired t- test. Streptococcus pyogenes, Enterococcus fecalis, Staphylococcus, (MRSA) and Staphylococcus saprophiticus were susceptible in dilutions of 1:128 of Calendula officinalis extract. In disc diffusion, 100% of Streptococcus, Enterococcus fecalis, MRSA and 50% of Staphylococcus saprophiticus were susceptible to Calendula officinalis extract. Gram negative bacteria, including E.coli, Proteus, Klebsiella, Serattia, and Pseudomonas were resistant. Diameter of no growth of bacteria among gram positive and negative bacteria was significantly different in Calendula officinalis extract (p< 0.001). It seems that Calendula officinalis extract can be used in combination with antibiotics for the treatment of cellulitis.

Although current medicine has some advantages compared with traditional medicine, one of its important problems is overuse of chemical drugs that leads to drug resistance and side effects. According to antibacterial effects of Glycyrrhiza glabra extracts, this study was conducted to Compare effects of Glycyrrhiza glabra and nalidixic acid and nitrofurantoin on isolated bacteria from urinary tract infections and stones

This is an experimental study was done on 100 patients with urinary tract infections and stones. Glycyrrhiza glabra extract was taken from risome of 3- or 4- year herb by method of perculation with methanol 85% solvent. Solvent was vaporized by rotary and lyophilized. Antibacterial effects of extract, nitrofurantoin and nalidixic acid were evaluated by two methods of disc diffusion and MIC. Statistical analysis was performed by ANOVA and paired t- test.

In disc diffusion, 100% of Streptococcus and MRSA and 33% of E.coli were susceptible to Glycyrrhiza glabra extract. In MIC, Streptococcus, MRSA, Enterococcus fecalis in 1:128 dilution, and E.coli in 1:64 dilution of Glycyrrhiza glabra extract were susceptible. Klebsiella, Serattia, and Entrococcus facium were resistant. Diameter of no growth of bacteria among gram positive and negative bacteria were significantly different in Glycyrrhiza glabra extract and nitrofurantoin groups (p<0.05), and was non significantly different in nalidixic acid group (p=0.9).

It seems that Glycyrrhiza glabra extract with antibiotics can be useful in the treatment of urinary tract infections.