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

The retention characteristics of Hawley and vacuum-formed retainers with different retention protocols

This study aimed to compare the effectiveness of two different protocols of wearing vacuum-formed retainers (VFRs) with the standard protocol of wearing Hawley retainer in maintaining the results of orthodontic treatment. This single-blind randomized clinical trial consisted of 90 patients who finished orthodontic treatment at the Department of Orthodontics of Mashhad Dental School, and required removable retainers. The participants were randomly divided into 3 groups and received the following treatments. Group 1: Hawley retainers (4 months full-time and then night-only); group 2: VFR_4M (4 months full-time and then night-only); group 3: VFR_1W (1 week full-time and then night-only). The study models were prepared after debond and at 4 and 8 months later, and intercanine width, intermolar width, arch length and the Little?s irregularity index were compared between groups. No significant differences were found in intercanine and intermolar widths between groups (P<05). Upper arch length was significantly lower in Hawley group than the two VFR groups (p<0.05), but lower arch length values were comparable. Upper irregularity index was significantly lower in two VFR groups compared to Hawley group (p<0.05), whereas in the lower jaw, only VFR_4M group showed significantly lower crowding than Hawley group (p<0.05). Both retention regimens of VFRs were more effective than Hawley retainer in maintaining arch length and tooth alignment in the upper arch. For better incisor alignment in the lower jaw, the patients should be advocated to wear VFR 4 months full-time and then at night instead of wearing Hawley retainer

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

Identification and classification of influencing factors on selection of cosmetics supplier in factor analysis method (Case study: east of Fars)

Abstract: The goal of this study is identification and classification influencing factors on selection of cosmetics supplier in factor analysis method in east of Fars. Statistical society of this research is 490 cosmetics sellers in east of Fars, included Estehban, Fasa, Darab and Neiriz cities and according to Morgan table; sample size was selected as 359 sellers. Data has been collected using a researcher made questionnaire; que stionnaire validity was obtained through conducted content and reliability was obtained by Cronbach&apos;s alpha 85.7 percent. Data analysis was conducted using SPSS and factor analysis. Results show that business history of supplier (validity of supplier) has the greatest impact in selection of supplier using factor analysis method. Also using clustering, we concluded that continuity of goods by supplier, quality of supplier services, and cosmetics products quality in cluster have high importance and how supplier manage and organize, supplier planning system for sale, goods control systems by supplier in delivering them, impact of supplier gender have lowest importance that continuity of goods by suppliers has The most important factor in a supplier selection

Flood Susceptibility Mapping Using Random Forest Machine Learning and Generalized Bayesian Linear Model

Today, the phenomenon of flooding is one of the most complex hazardous events that, more than any other natural disaster, causes deaths and finances every year in different parts of the world. Therefore, flood susceptibility mapping is the first step in a flood management program. The purpose of this study was to identify flood susceptible areas using two methods of random forest (RF) and Bayesian generalized linear model (GLMbayesian) machine learning in the Tajan watershed in Mazandaran province, Sari. Past flood distribution maps were prepared to predict future floods. Of the 263 flood locations, 80% (210 flood locations) was used for modeling and 20% (53 flood locations) was used for validation. Based on previous studies and surveying of the study area, 13 conditional factors were selected for flood zoning. The results showed that three factors of elevation (21.55), distance from the river (15.28) and slope (11.18) had the highest impact on flood occurrence in the study area, respectively. The results also showed that the AUC values for RF and GLMbayesian models were 0.91 and 0.847, respectively, indicating the superiority of the RF model and the accuracy of this model in flood susceptibility mapping in the study area. The highest flood susceptibility area in the RF model is in the very low class and the high class in the GLMbayesian model

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