Showing 8 results for Bacterium
Ameneh Alaeen, Azadeh Alaeen, Hurieh Alaeen,
Volume 14, Issue 4 (9-2011)
Abstract
Background: Mycobacterium marinum is an atypical mycobacterium that causes a type of skin infection known as fish tank granuloma affecting people who are exposed to aquatic environments and manifests with erythematous, papulonodular or plaque-like lesions of the extremities.
Case: A 15 year-old woman working in a tropical aquarium in Khomein referred with a non-tender nodule on the dorsum of fourth finger of left hand for 4 months. There were no specific findings in physical examination. Routine laboratory tests were normal. Skin biopsy was obtained which revealed suppurative granulomas, but staining of PAS and Ziel-Nelson were negative. The patient was treated with doxycycline 100 mg P.O. BID for 2 months with complete improvement of the lesions.
Conclusion: In patients with a history of work in aquatic environments who manifest erythematous, papulonodular, or plaque-like lesions of the extremities should be checked in terms of fish tank granuloma and infection with mycobacterium marinum and skin biopsy and culture should be done for lesions.
Aliasghar Farazi, – Mansoureh Jabbariasl, Masoomeh Sofian,
Volume 15, Issue 1 (4-2012)
Abstract
Background: Nowadays, one of the basic problems of tuberculosis treatment is drug resistance. This study was done to determine the drug resistance of mycobacterium strains isolated from patients with pulmonary tuberculosis to anti-tuberculosis drugs and determine the affecting factors.
Materials and Methods: In a cross-sectional study, all patients with tuberculosis who were covered by Markazi Province Health Center (917 persons) during 2005 to 2010 were included in this study. For all patients with resistant pulmonary tuberculosis, culture and antibiogram by standard method (proportional) were done. Effective factors in drug resistance were identified by logistic regression model using SPSS software.
Results: Overall, the rate of resistance in patients with smear-positive was 7.3% and the rate of MDR-TB was equivalent to 4.3%, and 0.5% of smear positive patients were resistant to all five drugs. The most resistant strains were isoniazid (68.8%), rifampin (62.5%), pyrazinamide (25%), ethambutol (21.9%), and streptomycin (21.9%), respectively. The highest rate of resistance was in the 15-45 years age group. The incidence of resistance was significantly associated with sex, grade of smear positivity, relapse of TB, and HIV infection.
Conclusion: The study of drug resistant mycobacterium strains over six years showed a growing trend. Therefore, close attention to prevent the production and dissemination of resistant strains is very essential.
Arezo Eshghinejad, Aliasghar Farazi, Babak Eshrati, Hamid Khalili, Mana Shojapour, Aazam Ahmadi, Mohamad Arjmandzadegan,
Volume 15, Issue 5 (10-2012)
Abstract
Background: Differentiation of M. tuberculosis complex organisms were assigned to one of three genotypic groups based on the combinations of polymorphisms at katG codon 463 and gyrA codon 95. Early identification of strains belonging to any particular group is very important. This study was planned to identify major genetic groups of clinically isolated Mycobacterium tuberculosis. Materials and Methods: In this cross sectional study 33 sputum samples were collected from tuberculosis patients of the Markazi province. DNA purification from isolated samples was performed by Chelex 100. Identification of isolates was confirmed by detection of katG gene and the mutation in KatG463 by using PCR method and RFLP respectively. Finally 620-bp of katG gene and 194-bp of gyrA gene purified from PCR product were sequenced. Results: Amplification of 620-bp fragment of katG gene was a good way to confirm the detection of bacteria as a molecular approach. Results of sequencing codon GyrA95 in combination by results of PCR-RFLP determined type of the major genetic group (MGG). Therefore it showed that among the 33 Mycobacterium tuberculosis isolates 12 samples were MGG 1, 15 Samples were MGG2 and 6 samples were MGG 3. Results revealed that MGG 2 was dominant form of M. tuberculosis strains of Markazi province by frequency of 45.5%. Conclusion: Based on the results of this study MGG2 occurrence was more frequent among clinical strains in Markazi province that its accordance with susceptibility of these strains to conventional antibiotics is notable. In this study, three applicable benefits from the test as: MGG typing, molecular detection of M. tuberculosis and bacterial resistance to Isoniazid were proven.
Behnam Rafiee, Nader Mosavari, Ali Asghar Farazi, Razie Nazari, Rouholah Keshavarz, Keyvan Tadayon,
Volume 15, Issue 6 (11-2012)
Abstract
Background: Tuberculosis is an old problem that is currently considered a great challenge. Noticing Iran’s borders with Afghanistan and Pakistan, which are among the 22 high burden countries around the world, the present study was conducted to analyze the current molecular epidemiology of TB and survey genetic diversity of Mycobacterium tuberculosis strains in Markazi province, Iran. Materials and Methods: In this experimental study, 57 sputum specimens from smear positive patients admitted to health centers in Markazi province were cultured on specific mycobacterial culture media. Genomic DNA was extracted by standard protocols of WHO and digested separately by PvuII and AluI. Electrophoresis was performed and DNA fragments were transferred to positively charged nylon membrane by southern blotting method and hybridization by PGRS probe. The hybridized strains were subsequently detected by enzymatic reaction and analyzed. Results: Genotyping of the isolates by PGRS-RFLP with Pvu II and AluI displayed a wide range of genetic diversity so that 50 and 45 genotypes were identified, respectively. Conclusion: Noticing the great diversity of PGRS in the Mycobacterium tuberculosis strains, it can be concluded that in the study population, the majority of the patients hadtuberculosis with different etiologies. Therefore, it seems that reactivation of latent infection has had the main role in the spread of tuberculosis
Behnaz Taheri, Siyamak Samiee, Mehdi Paryan, Ehsanollah Ghaznavi-Rad,
Volume 16, Issue 5 (8-2013)
Abstract
Background: The emergence of drug-resistant strain of M.tuberculosis is one of the most critical issues facing TB researchers and clinicians. Rapid diagnosis of drug-resistant tuberculosis is essential for the prompt initiation of effective second-line therapy to improve treatment outcome and limit transmission of this obstinate disease. The aim of this study is to develop a Real-time PCR assay for the detection of mutations in RRDR (rifampcin resistance determinant region) of rpoB which conferring rifampicin resistance in Mycobacterium tuberculosis.
Materials and Methods: In this experimental study, the primer and probe set were designed for a RRDR region of rpoB gene using a specialized software. Clinical specimens that had previously been evaluated resistant or sensitive by using convential method, were used for assessing the clinical sensitivity and specificity of the assay.
Results: The clinical sensitivity of the assay was determined 100%. The primers and the probes were rpoB specific and no cross-reaction was observed with other microorganisms and human genome bioinformatically. The clinical specificity of developed Real-time PCR assay was examined experimentally using 25 negative samples and determined to be 100%.
Conclusion: The developed real-time PCR assay can be used as an appropriate and efficient tool for the rapid detection of rifampicin-resistant Mycobacterium tuberculosis.
Majid Talebi, Dariush Minai-Tehrani, Mohammad Fazilati, Arash Minai-Tehrani,
Volume 20, Issue 9 (12-2017)
Abstract
Abstract
Background: Lipases are one of the groups of enzymes which are important in medicine and industry. In gastrointestinal tract of human, lipase catalysis break down of triglyceride. Bacteria have also lipases which break down triglyceride in their culture medium and can use its fatty acids as carbon source. Dicyclomine is an antispasmodic drug that relieves smooth muscle spasm of the gastrointestinal tract. Few drugs have been determined to inhibit lipase activity, in this research; dicyclomine was introduced as an inhibitor of lipase, for the first time.
Materials and Methods: Lipase was extracted from Pseudomonas aeruginosa and the effect of dicyclomine was tested on its activity. The bacterium was cultured in medium with olive oil as carbon source and the supernatant was used for enzyme assay. For monitoring the enzyme activity, Para nitrophenyl palmitate (pNPP) was used as a substrate and the induced product was measured by visible spectrophotometer. Lineweaver-Burk plot was utilized for revealing the type of binding.
Results: This research has shown that dicyclomine can inhibit lipase. Inhibition plot determined that the drug can inhibit the enzyme by competitive manner. Calculation of Ki and IC50 values showed that the drug can bind to the enzyme with high affinity. The study of enzyme activity in different pH and temperature revealed that optimum activity of enzyme, in the presence or absence of the drug, was observed in pH 8 and 60oC.
Conclusion: For the first time, dicyclomine was introduced as an inhibitor of lipase and the kinetics factors of the drug were investigated.
Ali Reza Morad Abadi, Mohammad Arjomandzadegan, Navid Emami, Manijeh Kahbazi, Azam Ahmadi, Saeed Falahat, Seyyed Hossein Hosseini, Mehdi Kargaran, Parisa Khosravi,
Volume 21, Issue 4 (8-2018)
Abstract
Background and Aim: Ziehl Nelson staining, fluorescent and also culture are the standard methods for the diagnosis of tuberculosis. In this study, the performance of conventional cultivation methods was compared with Flash PCR.
Materials and Methods: A total of 56 sputum samples from patients with suspected tuberculosis in Tuberculosis Center of Arak city were collected and Ziehl–Neelsen and culture in Löwenstein–Jensen medium were accomplished. Moreover, DNA from all of the 56 sputum samples was extracted by Chelex100 method. Molecular evaluation was accomplished by Flash PCR kit containing probes and primers for gene amplification IS6110. Positive and negative controls together with samples were used in a MTC410 apparatus for amplification. FD-12 apparatus was used to evaluate the results. In addition, electrophoresis on agarose was used for confirmation of the results.
Findings: From 56 sputum samples of suspected TB patients, 20 samples were positive and 36 samples were negative on microscopic evaluation and culture methods. FLASH-PCR molecular analysis showed that all of 20 positive samples were positive in molecular methods, too. On the other hand, three of sputum samples that were negative by culture and staining were positive in FLASH-PCR method. One of these 3 patients, received Isoniazid, pyrazinamide and ethambutol antibiotic by responsible medicine. All results were confirmed using conventional electrophoresis.
Conclusion: In some negative samples, possibly because of the small number of bacteria in sample or a defect in the sampling, the Flash PCR may due good advantages. Therefore, due to the low cost, this method is recommended for routine use.
Elham Pishgar, Milad Makhfian,
Volume 22, Issue 2 (6-2019)
Abstract
Background and Aim: A variety of bacteria like Staphylococcus aureus utilize quorum sensing to perform their important activities such as biofilm formation and production of virulence factors. Interfering with the bacterial QS will disable the bacteria to perform above-mentioned vital activities. The principal aim of the study was to evaluate the effects of five plant extracts against bacterial Quorum sensing of Staphylococcus aureus.
Materials and Methods: Thirteen strains of Staphylococcus aureus were isolated from patients with dental implant infection and identified. The plant species were collected from vicinity gardens of Fars Province and extracted using 96% ethanol. The anti-QS and antimicrobial susceptibility methods were then carried out to evaluate their bactericidal and QS properties with the use of Agrobacterium tumefaciens NTL/PZLR4. Furthermore, the biofilm production of the isolates was evaluated by microtiter plate (MTP) assay.
Ethical Considerations: This study with research ethics codes 01-16-1-1959 and 73/118248 has been approved by research ethics committee at Islamic Azad University, Jahrom and research sciences branch, respectively.
Findings: The results of the study disclosed that the extract of raspberry blossom possesses significantly (p<0.05) anti-QS property (>21 mm). The anti-QS activity was proved by creating clear halo sides of the wells formed by Agrobacterium tumefaciens NTL/PZLR4. Moreover, the extracts of tarragon, wheat flower, flixweed and basil showed antimicrobial properties.
Conclusion: According to the anti-biofilm and anti-QS properties of raspberry blossom extract against the isolates of Staphylococcus aureus, it could be considered as a mouthwash against dental bacterial infection with the identification of active compounds in the raspberry.
