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Background and Objective: Tuberculosis is one of the major problem facing of globle health. Drug resistance of mycobacterium tuberculosis to antimicrobial agent has strongly emerged the need for achiving the new drugs. Garlic as medical plants has long been taken under investigation. This study for antibacterial effect was done to determine the morphological alteration of Mycobacterium tuberculosis due to garlic choloformic extract. Garlic extract contains allicine (thio-2-propen-sulfonic acid-s-allil ester) is one of its effective antimicrobacterial substance. Materials and Methods: In a in-vitro study, the standard strain of Mycobacterium tuberculosis H37RV and clinical isolated strain was cultured in the middle broke 7H9 broth with different concentration of garlic extract in different 12, 24, 48, 72 hours. Morphological althertits of mycobacterium inspected with macroscopic and microscopic studies. Results: The garlic exteract caused conversion of rough colonies to smooth and mucoid colonies and in microscopic studies morphologic change of mycobacterium from bacilli form to coccobacilli and cocci was observed. Also 0.67 mg/ml of garlic exteract on 48h period inhibited both of sensitive (standard strain of H37RV) and resistance (clinical strains) Mycobacterium tuberculosis. Conclusion: This study showed that garlic extract in addition to inhibiting growth, change the morphology of Mycobacterium tuberculosis from baccilli to cocoibaccill form and also alter the colony apearance from rough to smooth shap.

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Background and Objective: Drug resistance to tuberculosis and especially multiple drug resistance tuberculosis (MDR-TB) variants are a serious problem in tuberculosis patients and make difficulties in controlling the disease. This study was coducted for detection of common mutations causing drug resistance of mycobacterium tuberculosis strains among tuberculosis patients using line probe assay method. Method: In this descriptive study, fifty four sputum samples of tuberculosis patients were randomly selected in health centers of Mazandaran, northern Iran during 2012. After culturing of sputum samples on Lowenstein–Jensen medium, genomic DNA was extracted from colonies using CTAB method. Molecular analysis of mutations causing resistance to five different antibiotics including Isiniazide, Rifampin, Sterptomycine, Amicasin / Canamycine, Kinolon were performed using long probe assay (LPA) method. Results: Out of 54 sputum samples, three (5.5%), three (5.5%), four (7.4%) were resistance to Kinolon, Amicasin / Canamycine and Sterptomycine, respectively. Mutation in KATG was seen in 2 samples resistant to Isiniazide. Mutation in rpoB 516 was seen in 3 samples resistant to Rifampin. Four samples (7.4%) were resistant to the two anti-tuberculosis antibiotics, while three samples were resistant to Sterptomycine and Kinolon and one sample was resistant to Rifampin and Canamycine. Conclusion: 7.4% of sputum samples were resistant to the two anti- tuberculosis antibiotics. Line probe assay is a rapid and suitable method for detecting tuberculosis drug resistance.

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Background and Objective: Bacterial resistance to Imipenem is increased in bacterial infections in Iran. In regard to the importance of Imipenem in the treatment of nosocomial infections and the key role of disc diffusion method as a major antibiotic susceptibility testing assay, this study was done to determine the prevalency of imipenem-resistant bacterial strains isolated from hospital and accuracy of Iranian imipenem disc product. Methods: In this descriptive-analytic study, 241 bacteria were isolated from patients in different wards of the Baqyatallah hospital in Tehran, Iran during 2013-14. After streaking of the organisms, identification was performed by all conventional biochemical tests. The bacterial resistance to imipenem was determined by disk diffusion method using Iranian and Mast imipenem discs. True imipenem-resistant isolates were examined for susceptibility to six different antibiotic including Ciprofloxacin, Gentamicin, Cephalexin, Azitromysin, Tetracycline and Ceftazidim, using disk diffusion method. Results: The most prevalent isolates organisms were gram-negative bacilli (Klebsiella, Escherichia coli, and Pseudomonas aeruginosa, respectively). The common clinical source was urine and wound samples, respectively. Resistant to Imipenem was 68 (25.7 %) and 19 (7.8 %) based on the results of Iranian and Mast Imipenem discs, respectively. False results for Iranian Imipenem discs was higher than Mast Imipenem discs (P<0.05). Among the 19 true Imipenem resistant isolates, 17 micro organisms were Pseudomonas aeruginosa. 57% of isolated resistant to Imipenem were isolated from ICU ward. The most resistance was seen to Gentamicin (84%) and the lowest was seen to Ciprofloxacin (63%). 84% of isolated samples were multi drug resistance. Conclusion: Although a small percentage of the isolates obtained as important nosocomial pathogens were resistant to Imipenem, but the rate of multiple resistance and high rate of isolates obtained from ICU was noticeable.

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Background and Objective: Ciprofloxacin is effective against a wide range of bacteria, particularly Enterobacteriaceae. However, studies have shown that the resistance of Escherichia coli to ciprofloxacin is enhanced. Thyme is one of the medicinal plants whose essential oil has anti-microbial effects. This study was aimed to investigate the antimicrobial properties of local Thyme essential oil alone and in combination with ciprofloxacin on Escherichia coli mutant strain with intermediate resistance.
Methods: In this descriptive laboratory study, Thyme plants (10 samples) were collected from Lorestan Province, west of Iran during 2016. Theses samples belonged to T. eriocali species. Plant essential oil was extracted by distillation method with Clevenger equipment. The antimicrobial properties of local thyme were determined by measuring minimum inhibitory concentration (MIC) of it alone and in combination with ciprofloxacin using sequential dilution method (macrodilution and microdilution methods) in Escherichia coli strains. Minimum bactericidal concentration (MBC) was measured by cultivation method. The interaction between essential oil and ciprofloxacin was determined by calculation of fractional inhibitory concentration index (FICI).
Results: MIC of essential oil for wild type strain MG1655 and mutant strain RE6 was 8 and 10 µl/ml, respectively. MBC was equal to MIC. 0.4 µl/ml of essential oil decreased 45 fold the MIC of ciprofloxacin in mutant strain and produced synergistic interaction (FICI=0.06).
Conclusion: Thyme essential oil in concentration less than its MIC in combination with ciprofloxacin via synergistic interaction reduces antibiotic MIC and antibiotic resistance.

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Background and Objective: The emergence of drug resistance in Mycobacterium tuberculosis and especially drug resistant strains has created problems for the treatment of tuberculosis control, worldwide. This study was performed to evaluate the changes in N-acetyltransferase (NAT) pattern of methylsonone in patients who did not respond to first-line treatment for Mycobacterium tuberculosis.
Methods: This descriptive-analytical study was performed on 200 patients with tuberculosis. After preparing the blood sample, saturated salt method was used to extract DNA. For the determination of quantity and quality of DNA, two methods of spectrophotometry and electrophoresis on agarose gel were used. The methylation pattern of NAT1 gene was investigated by HRM method.
Results: 34 patients were resistant to the first line of treatment. 18 patients showed hypermethylation pattern, 12 patients showed non-methylated pattern and 4 patients showed hypomethylated pattern. 166 patients were not resistant to the first line, of which 23 patients in hypermethylated group, 120 patients in group Non-methylated and 23 patients were in the hypomethylated row. There was a statistically significant relationship between methylation level and drug resistance (P<0.05).
Conclusion: This study showed that resistance to first-line treatment of Mycobacterium tuberculosis was related to the level of N-acetyltransferase gene methylation.

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Background and Objective: Pseudomonas aeruginosa is an opportunistic pathogen that is a major cause of mortality in immunocompromised patients. One of the most important mechanisms of resistance of this bacterium is biofilm formation. The aim of this study was done to determine the Effect of Morin on Expression of Biofilm Gene of Pseudomonas aeruginosa Isolated from burn wounds by Real time PCR.
Methods: In this descriptive-analytic study 60 sample were collected from burn wounds of patients admitted to the hospitals in Tehran, Iran. Samples were identified by using biochemical methods. The DNA of the isolates was extracted and then antimicrobial activity of morin analyzed by microbroth dilution assay. The presence of biofilm production genes was investigated by PCR. Finally, the expression of lasI gene in combination with Sub-MIC concentration of morin in biofilm-producing bacteria was evaluated using Real time PCR.
Results: From 60 samples that analyzed by Multiplex-PCR, 12 (20%) Pseudomonas aeruginosa strains were isolated in which 12 isolates (100%) were carried lasI and lasR, genes, respectively. 3 isolates (25%) were carried rhlI gene. Sub-MIC concentration of morin in biofilm-producing bacteria reduced lasI gene expression in Pseudomonas aeruginosa.
Conclusion: Morin has significant efficacy on Pseudomonas aeruginosa and could be a good alternative for treatment of antibiotic resistant isolates.

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Background and Objective: Staphylococcus aureus is one of the most common causes of bacterial keratitis and conjunctivitis. This study was done to determine the efficacy of fluoroquinolones on Methicillin-resistant Staphylococcus aureus (MRSA) strains isolated from external ocular infections.
Methods: This descriptive-analytical study was conducted on 187 pateiants (2 months to 61 years old) with symptoms of conjunctivitis and keratitis who were hospitalized or referred to the emergency department of hospitals in Golestan and Mazandaran provinces, Iran during 2020-22. The samples were taken from the external infection of the patients’ eyes. Methicillin-resistant Staphylococcus aureus isolates were identified by standard phenotypic microbiological and molecular detection (PCR) methods. The broth microdilution method determined sensitivity to quinolones and the minimum inhibitory concentration (MIC) in the 0.06-64 μg/ml range.
Results: The frequency of ocular MRSA isolates (n=52) was significantly higher in spring, females and patients aged 1-30 years (P<0.05). Among the MRSA isolates causing conjunctivitis, the highest rates of resistance were observed against ciprofloxacin (n=18, 48.64%), enoxacin (n=17, 45.95 %), and ofloxacin (n=17, 45.95%). The MIC of gemifloxacin that inhibited the growth of 90% of MRSA isolates from conjunctivitis (MIC90=0.25 μg/ml) was 32-fold lower than that of ciprofloxacin.
Conclusion: Depending on the season and age, staphylococcus aureus may be the most common cause of bacterial conjunctivitis and keratitis. Considering the in vitro antibacterial potential of gemifloxacin, this antibiotic can be used to treat the bacterial external eye infections.