Mutations in embB gene associated with resistance to ethambutol in Mycobacterium tuberculosis strains isolated from TB patients in the west of Iran (2014–15)

AbstractIntroductionMutations in embB gene, especially those in ethambutol resistance-determining region (ERDR), are known as “hot spots”. These mutations have frequently been reported in EMB-resistant M. tuberculosis isolates, using the Sequence analysis as a precise and effective method. The aim of this study was to detect mutations in embB gene associated with resistance to ethambutol in Mycobacterium tuberculosis strains isolated from TB patients in the west of Iran (2014–15).Material and methodsThis study was performed on smear-positive patients of the west side of Iran, in the TB research center located in Kermanshah city, during 2014–15. Out of 1069 strains of Mycobacterium tuberculosis, 50 strains with pulmonary TB were selected and evaluated (22 men and 28 women; aged between 23 and 86; median age: 54.5years).ResultsMutation in the embB gene was detected in all of the seven EMB-resistance isolates and five (42.71%) cases of them were MDR. The most frequent substantiation of amino acid occurred at the codon 306 in six (64.85%) of the EMB-resistant isolates. The Met306Val substitution resulting from an A→G transition was detected in three (42.85%) EMB-resistant isolates; and the Met306Ile substitution, due to a G→A transition was also detected in three (42.85%) resistant isolates. No mutations at the embB gene were detected in susceptible strains.ConclusionOur results were similar to those that were regularly reported in earlier studies. The only mutations in the EMB-resistant isolates were found in embB 306 and 406 codons. Substantiation amino acids at codon 306 were the most frequent. The data indicated that embB 306 mutations are sufficient to induce ethambutol resistance, and detection of these mutations is advisable to be considered in the development of rapid molecular tests. Sequence analysis of the ERDR in the embB gene is adequate for rapid detection of EMB resistance, and mutations in the codon 306 are good predictive markers for resistance to EMB

Combined Effect of Levofloxacin and N-Acetylcysteine against Enterococcus faecalis Biofilm for Regenerative Endodontics: An in Vitro Study

Introduction: Endodontic treatment of necrotic immature teeth poses several clinical challenges. A major problem is the elimination of microorganisms from the root canal system. This study evaluates the in vitro antibacterial efficacy of ciprofloxacin (CIP), levofloxacin (LEV), and their combination with N-acetylcysteine (NAC) in root canals infected with Enterococcus faecalis (E. faecalis). Methods and Materials: A total of 120 human extracted teeth with single canals were prepared and randomly divided into six groups: Calcium hydroxide (CH), ciprofloxacin (CIP), levofloxacin (LEV), ciprofloxacin and N-acetylcysteine (CIP+NAC), levofloxacin and N-acetylcysteine (LEV+NAC), and normal saline as a positive control. According to the name of the groups, intracanal medicaments were placed into the canals and the teeth were restored with a temporary filling. After one week, intracanal medicament was removed and the final count of bacteria was measured. Antibacterial effect of medicament was assessed by measuring the percentage reduction in the colony counts (RCC) and scanning electron microscopy (SEM). The Mann-Whitney U test and the Kruskal-Wallis test were used to compare the overall antibacterial efficacy of the intracanal medicaments at significance level of 0.05. Results: All intracanal medicaments were significantly more effective than calcium hydroxide (P<0.05). The combination of LEV and NAC caused significantly higher reduction in colony count in comparison with other tested medicaments (P=0.001). Conclusion: The combination of LEV and NAC showed greater antibacterial activity compared with other tested medicaments against biofilm of E. faecalis. Thus, it has the potential to be used in regenerative endodontic treatments.Keywords: Antibiotics; Biofilm; Enterococcus faecalis; Regenerative Endodontic

Staphylococcal protein A (spa) typing of Staphylococcus aureus isolates causing nosocomial infections

BACKGROUND: Staphylococcal protein A (spa) typing is a typing method based on the DNA sequence analysis of staphylococcal protein A gene. The purpose of this study was to do molecular typing of Staphylococcus aureus isolated from patients in Toohid and Besat hospitals, Sanandaj, Iran, in 2014.METHODS: Clinical specimens were collected from hospitalized patients over a period of 1 year. Staphylococcus aureus isolates were identified using culture and biochemical standard methods based on the Clinical and Laboratory Standards Institute (CLSI) guideline. spa gene patterns in Staphylococcus aureus isolates were identified using spa-typing techniques.RESULTS: In total, 20 different patterns of spa gene were obtained in staphylococcus aureus isolates in this study, which included type t030 (6 cases), types t230, t459, and t701 (3 cases of each one), types t11332 and t304 (2 cases of each one), and types t325, t012, t1149, t1810, t197, t325, t7789, t808, t871, t937, t14896, t14913, t14928, and t14929 (1 case of each one). The highest prevalence belonged to types t030 (30.0%), and then, types t230, t459, and t701 (15.0% for each one). New types of t14896, t14913, t14928, and t14929 were identified during this study.CONCLUSION: There were some well-known patterns of spa types, and also we identified new types that should be studied more to qualify. Analysis of these patterns can improve insight to design nosocomial infection control programs

Molecular Analysis and Expression of bap Gene in Biofilm-Forming Multi-Drug-Resistant Acinetobacter baumannii

Background: Acinetobacter baumanniiis commonly resistant to nearly all antibiotics due to presence of antibiotic resistance genes and biofilm formation. In this study we determined the presence of certain antibiotic-resistance genes associated with biofilm production and the influence of low iron concentration on expression of the biofilmassociated protein gene (bap) in development of biofilm among multi-drug-resistant A. baumannii (MDRAB). Methods: Sixty-five MDRAB isolates from clinical samples were collected. Molecular typing was carried out by random amplified polymorphism DNA polymerase chain reaction (RAPD-PCR). Biofilm formation was assayed by the microtiter method. Results: The sequence of bap was determined and deposited in the GenBank database (accession no. KR080550.1). Expression of bap in the presence of low iron was analyzed by relative quantitative real time PCR (rqRT-PCR). Nearly half of the isolates belonged to RAPD-types A and B remaining were either small clusters or singleton. The results of biofilm formation revealed that 23 (35.4%), 18 (27.7%), 13 (20%), and 11 (16.9%) of the isolates had strong, moderate, weak, and no biofilm activities, respectively. ompA and csuE genes were detected in all, while bap and blaPER-1 were detected in 43 (66%) and 42 (64%) of the isolates that showed strong and moderate biofilm activities (p ≤ 0.05), respectively. Analysis ofbapexpression by rqRT-PCR revealed five isolates with fourfold bap overexpression in the presence of low iron concentration (20 µM). Conclusion: The results suggest thatbapoverexpression may influence biofilm formation in presence of low iron concentration

Methicillin-Resistant Staphylococcus aureus Using Broth Micro Dilution Method in Iran: A Meta-Analysis (2007-2016)

Background:      Methicillin-resistant Staphylococcus aureus (MRSA) is one of the most signifuicant pathogens in Iran; it is one of the WHO-declared microbial resistance emergencies; and also one of the most important challenges facing the prevalence of resistance. The aim of this study was to detect MRSA using Broth Micro Dilution method and meta-analysis in Iran from 2007 to 2016. Methods:       Persian databases (including Magiran, Irandoc, and SID) and International databases (including pubmed, science direct, and scopus) were searched during this period (2007-2016), such that the high heterogeneity (50% < I2) in this study was analyzed using the DerSimonian Laird method. Data were categorized into subgroups based on year of study and province. Due to the high validity of the diagnosis of organisms and quantitative results, antimicrobial susceptibility test (AST) was used to detect MRSA. Data analysis was performed using statsdirect software. Results:      Based on the available data in medical databases, 678 articles were selected. In total, 29 remaining studies entered the meta-analysis phase. In this study, the overall prevalence of MRSA using MIC is 53% (95% CI: 0.42.31, 63.90); in 2016 it was 77.56% (95% CI: 76.07, 78.99) and in 2007 was 57.49% (95% CI: 53.17, 61.72). The heterogeneity was estimated to be 98.5% (95% CI: 98.4, 98.6). Conclusion:    Based on the results, there is an increasing prevalence of MRSA in Iran. These may be due to the failure or lack of infection control activities and antimicrobial selection pressure

Antibacterial effects of Artemisa aucheri leaf and Spirulina Blue-Green algae aqueous and alcoholic extracts on the multidrug-resistant Klebsiella pneumoniae isolated from the patients with pneumonia

ABSRTRACT Background and Aim: Antibacterial effects of Artemisia plant and algae have been confirmed. The purpose of this study was to evaluate the antibacterial effect of antibiotics, Spirulina blue-green algae and Artemisa aucheri leaf extracts on multidrug resistant (MDR) Klebsiella pneumoniae. Materials and Methods: Disk and well diffusion method, the growth minimum inhibitory and bactericidal concentrations (MIC and MBC) were used to evaluate antibacterial effects. Using SPPS 16 soaftware, data were analyzed by analysis of variance (ANOVA) with repeated measures and Bonferroni test (p≤0.001). Results: The MIC and MBC for amikacin, colicitin, ceftazidime were 4 and for gentamicin and nalidixic acid were 2 and 1 µg/µl, respectively. In disk and well diffusion methods, the highest growth inhibition zones belonged to ethanolic extracts (0.25 mg/ml) of Artemisia and algae. The best MIC and MBC for growth were related to ethanolic extracts of A. aucheri at the concentration of 0.15 mg/ml. The diameter of growth inhibition zone around the bacterium was directly related to the concentrations of Artemisia and Algae extracts (p = 0.000). Conclusion: Considering the beneficial antibacterial effects of Spirulina blue-green algae and A. aucheri which were confirmed in this study, extraction of the active ingredients of medicinal plants is recommended for the mass production of herbal medicines. Keywords: Antibacterial effect, Extracts, Artemisa aucheri, Spirulina blue-green algae, Klebsiella pneumonia

Prevalence of Beijing family in Mycobacterium tuberculosis in world population: Systematic Review and Meta-Analysis

AbstractBackgroundIn this present study we decided to consider the prevalence and distribution of Beijing family in the world using meta-analysis based on systematic review of articles published and relation with drug resistance, which will provide more detailed information to clearly overview the status of this family and transmission of TB.MethodsThis study used the most available article published in literature database including PubMed, Science direct, Web of Science, Google Scholar, Biological abs, Iranmedex, and SID systematically reviewed prevalence of Beijing family. Data analyzed using meta-analysis with random effects models.ResultsFinal analyses included 264 samples that have been selected from 2811 studies. Overall Beijing family prevalence in world was estimated to be 33.2% (95% CI 31.4–35.2). Corresponding estimates by continent were Asia 44.7% (39.5–49.8), Europe 27.9% (25.6–30.1), Africa 12·5% (8.9–16.2), and America 8.9% (6.9–10.9). In all world regions, Beijing families were associated with drug resistance 81.37%.ConclusionsAccording to the results, prevalence of Beijing family in Asia is higher than similar studies in other parts of the world and this family is associated with drug resistance. Effective control program is needed in world to control the spread of drug resistance strains specially Beijing family

Prevalence of Mycobacterium tuberculosis LAM family in the worldwide population: A systematic review and meta-analysis

Background: Tuberculosis (TB) disease caused by Mycobacterium tuberculosis (MTB) is still an important cause of morbidity and mortality. Latin American and Mediterranean (LAM) is one of a family of phylogenic MTB, and its name is derived from the geographical area that has been isolated. The objective of this study is to determine the prevalence of MTB LAM family worldwide by meta-analysis and a systematic review. Methods: Data sources for this study are comprised of 70 original articles (2001–2013) that were published in the literature in several databases, including PubMed, Science Direct, Google Scholar, Biological abstracts, ISI Web of Knowledge and IranMedex. Data were analyzed using meta-analysis (Meta R, Version 2.13 package [p<0.10], CI: 95%). Results: The highest and lowest occurrence rate of the LAM family in MTB was in Europe and Asia. Totally, the prevalence of the LAM family in Europe, Africa, America and Asia was 32.10%, 29.20%, 14.4% and 0.2%, respectively. Conclusions: This study shows that MTB LAM family is prevalent in European countries. LAM sub-lineage is a major focus of studies carried out in different countries. Proper technique for prevention of transmission of MTB is necessary

Molecular Detection of Extended-Spectrum Beta-Lactamase in Isolated Bacteria from Blood Cultures

<p><strong><em>Introduction</em></strong>: ESBLs are a B -lactamases which had ability to hydrolyse third-generation cephalosporins and  aztreonam.  ESBLs producer bacteria are resistant to  a wide variety of antimicrobials and they made a serious global health concern for treatment strategies. So, aim of this study as to  molecular detection of ESBLs in  bacteria isolated from blood  cultures in hospitals from Kurdistan Province, Iran.</p><p><strong><em>M</em></strong><strong><em>e</em></strong><strong><em>thods</em></strong>: Biochemical test, antimicrobial susceptibility test by disc method, ESBL detection by NCCLs Phenotypic and PCR method for ESBL detection were applied. Results were analyzed by using SPSS 11.5 (p &lt; 0.05).</p><p><strong><em>Results</em></strong>: 96 <em>S. epidermidis </em>isolated from blood cultures, <em>E. coli</em>, Enterobacter spp., Klebsiella spp.,  <em>P.  aeruginosa</em>,  Salmonella  spp.,  <em>C.  freundii,  S.  maltophilia</em>,  also  <em>S.  aureus</em>,  and <em>S.epidermis</em>. Maximum resistance was 75% for CP and minimum resistance was 25% for GM. Of the 96 isolates, 20 (20.83%) produced ESBLs. Also 11.46%, 20.83%, 12.5%, 9.38% and 2.08%  were  positive  for  TEM, CTX-M, SHV, OXA-1  and  OXA-2  ensymes,  respectively.</p><p><strong>Conclusion</strong>: Inappropriate therapy for infections with ESBL producers is cause of prolongs hospital stay and mortality.  So, more research on drug resistance with ESBL is necessary.</p