The probiotic properties and potential of vaginal Lactobacillus spp. isolated from healthy women against some vaginal pathogens.

During the last decade, probiotic research has progressed considerably and significant advances have been made in the selection and characterization of specific probiotic strains. The most studied probiotics belong to the genus Lactobacillus. In this study, 80 Lactobacillus spp. isolated from healthy women tolerated low pH and were able to grow in the presence of bile salts. RAPD PCR technique resulted in the identification of 38 different types. These isolates were then evaluated based on adhesion capacity, antibiotic susceptibility and tolerance in simulated gastrointestinal tract. Species-specific PCR and detection of bacteriocin-related genes were also surveyed. Among the isolates, five strains-Lacticaseibacillus rhamnosus NO21, Lacticaseibacillus casei NO1, Lactiplantibacillus plantarum NO4, Lactobacillus acidophilus NO7 and Lactobacillus gasseri NO38-presented acceptable antibiotic susceptibility pattern. Further analysis showed antimicrobial activity of Lacticaseibacillus culture against various bacterial pathogens and real-time PCR showed all five strains were able to prevent the colonization of bacterial pathogens. All five selected strains produced organic acids, hydrogen peroxide and were resistant to the spermicide. In addition, they lacked haemolytic activity with the ability of hydrophobicity, auto-aggregation and co-aggregation with pathogens. These results suggest that the vaginal microbiome could be a good source for the isolation of probiotics and the strains of this study may be considered as good probiotic candidates.

Intra-hospital dissemination of clinical and environmental isolates of Stenotrophomonas maltophilia from Tehran.

Stenotrophomonas maltophilia isolates are responsible for various hospital-acquired infections and are particularly increasing in the immunocompromised patients. The aim of this study was to determine the clonal relatedness between S. maltophilia isolates originating from the clinic and environment. A total of 150 S. maltophilia isolates from patients and 1108 environmental samples obtained in three hospitals from Tehran. Following molecular identification targeting 23S rRNA gene, the clonal relatedness of the environmental and clinical isolates was determined using pulsed field gel electrophoresis (PFGE). Of the 150 clinical and 18 environmental isolates identified using phenotypic tests, the speciation of 120 and 15 was confirmed by targeting the 23S rRNA gene. The 24 common pulsotypes (PTs) and 32 single PTs were identified by PFGE. Only a small cluster was shared among the clinic and environment within a hospital; therefore, the intra-hospital dissemination of certain isolates of S. maltophilia among the clinic and environment was demonstrated.

Rise of antibiotic resistance in clinical enterococcal isolates during 2001-2016 in Iran: a review.

INTRODUCTION: The clinical significance of enterococci is mostly related to its antibiotic resistance which contributes to colonization and infection, in particular amongst the hospitalized patients. The present review has examined the literature to provide a comprehensive data on enterococci antibiotic resistance during the last 20 years in Iran. METHODS: Search engines such as Google Scholar and PubMed were used to identify all Persian and English-language articles investigating enterococci in Iran from 1996 to 2017. The search terms were "enterococci", "enterococcal", "enterococcus", "Iran", "bacterial resistance", "antibiotic resistance" and "resistance". RESULTS: Decrease in the resistance trend against ampicillin, gentamycin and ciprofloxacin was observed over a period of 15 years (2001 to 2016) in Iran. During a 10 years period from 2001 to 2015, the rate of resistance among Enterococcus faecalis species was less than Enterococcus faecium. The resistancerate, however, was considerably increased for both species during this period. The mean resistance rates for vancomycin, gentamicin, ciprofloxacin, erythromycin, nitrofurantoin, chloramphenicol, trimethoprim-sulfametoxazol, imipenem and teicoplanin were higher among complicated cases (patients with underlying debilitating disorders) compared to general cases (hospitalized or outpatients with no specific underlying disorder). CONCLUSIONS: E. faecalis and E. faecium showed a rise in the mean resistance against all the antibiotics during a 10-year period from 2010 to 2015. With the exception of penicillin and ampicillin, resistance to all antibiotics was higher amongst complicated cases compared to general patients.

Pathogenicity locus determinants and toxinotyping of Clostridioides difficile isolates recovered from Iranian patients.

Little is known about the toxin profiles, toxinotypes and variations of toxin Clostridioides difficile C (tcdC) in Iranian C. difficile isolates. A total of 818 stool specimens were obtained from outpatients (n = 45) and hospitalized patients (n = 773) in Tehran, Iran, from 2011 to 2017. The 44 C. difficile isolates were subjected to PCR of toxin C. difficile A (tcdA), toxin C. difficile B (tcdB), tcdA 3'-end deletion, toxinotyping and sequencing of the tcdC gene. Thirty-eight isolates (86.36%) were identified as tcdA and tcdB positive, and the remaining six isolates (13.63%) were nontoxigenic. All tcdA- and tcdB-positive isolates yielded an amplicon of 2535 bp by PCR for the tcdA 3' end. Fourteen (36.84%), seventeen (44.73%) and seven (18.43%) isolates belonged to wild-type, toxin C. difficile C subclone3 (tcdC-sc3) and tcdC-A genotype of tcdC, respectively. Thirty-one isolates (81.57%) belonged to toxinotype 0, and seven isolates (18.42%) were classified as toxinotype V. This study provides evidence for the circulation of historical and hypervirulent isolates in the healthcare and community settings. Furthermore, it was also demonstrated that the tcdC-A genotype and toxinotype V are not uncommon among Iranian C. difficile isolates.

Mitochondrial DNA G13708A variation and multiple sclerosis: Is there an association?

BACKGROUND: Multiple sclerosis (MS) is considered a pathogenetic enigma. Recently, efforts to implicate genetics in human susceptibility to MS have identified an important role of mitochondrial DNA (mtDNA). G13708A is a common mtDNA variation associated with MS in specific populations. This study tested the hypothesis that the mtDNA G13708A variation is associated with MS in an Iranian population. MATERIALS AND METHODS: Blood samples were collected from 100 MS patients and 100 unrelated healthy controls. DNA was extracted using a salting-out method, followed by polymerase chain reaction (PCR) amplification. For assessment of restriction fragment length polymorphism (RFLP), PCR products were restricted by restriction enzyme Mva I. Thereafter, the restriction products were assessed by means of an ultraviolet (UV) transilluminator following electrophoresis with 3% agarose gel. Accuracy of the genotyping procedure was assessed by direct sequencing. RESULTS: The mtDNA G13708A variation was found in 17 cases (17%) and 19 controls (19%) (P=0.7, OR: 0.8, 95% CI: 0.3-1.9). CONCLUSION: The findings of the present study fail to support the hypothesis that the G13708A mtDNA variation is associated with MS in the selected Iranian population.

Evaluation of potential probiotic characteristics and antibacterial effects of strains of Pediococcus species isolated from broiler chickens.

Pediococcus spp. were isolated from poultry rectum, faeces and food as good probiotic candidates in order to select strains to be used as probiotic in poultry feed. A total of 168 lactic acid bacteria were isolated and 51 isolates including 31 Lactobacillus spp. and 20 Pediococcus spp. were able to survive in low pH and bile salt concentration. The Pediococcus spp. were identified and their ability to form biofilm, adhesion to Caco-2 cells and antimicrobial activities against enteric pathogenic bacteria were determined. The results showed the presence of two strains, Pediococcus acidilactici P17 and P19 in rectal swab samples from 21-d old chickens with significant antibacterial activities against Salmonella enteritidis and Escherichia coli. The results suggest that only a few isolates of Pediococcus with potential probiotic activities are present in the poultry industry.

Heterogeneity in resistant fecal Bacteroides fragilis group collected from healthy people.

Normal nonpathogenic flora would represent a constant lake of resistance genes potentially transferable to human pathogens. To assess the prevalence of resistance genes and genetic variability of Bacteroides fragilis group (BFG) from normal flora, 177 Bacteroides isolates obtained from the fecal samples of healthy individuals. These isolates were subjected to antibiotic susceptibility testing and pulsed field gel electrophoresis (PFGE). The isolates were further tested for the presence of ermF, tetQ and bft genes by PCR. Our results indicated the presence of different clonal strains (1 common type and 57 single types) among the resistant isolates. The resistance rate for the six antibiotics in this study was between 1% and 95%. Most of the isolates (99%) were susceptible to metronidazole. ermF and tetQ were detected in all erythromycin and tetracycline resistant isolates. None of the isolates were carried bft gene. These data suggest dissemination of heterogenic clonal groups in healthy persons and resistance to 5 high commonly used antibiotics.

Antimicrobial resistance pattern and genetic correlation in Enterococcus faecium isolated from healthy volunteers.

Enterococci are known as a cause of nosocomial infections and this aptitude is intensified by the growth of antibiotic resistance. In the present study, Enterococcus faecium isolates from healthy volunteers were considered to determine the antibiotic resistance profiles and genetic correlation. A total 91 normal flora isolates of enterococci were included in this study. Identification of Enterococcus genus and species were done by biochemical and PCR methods, respectively. Sensitivity for 10 antibiotics was determined and genetic relatedness of all isolates was assessed using Repetitive Element Palindromic PCR (REP-PCR) followed by Pulse Field Gel Electrophoresis (PFGE) on the representative patterns. None of the isolates were resistant to teicoplanin, vancomycin, quinupristin-dalfopristin, linezolid, chloramphenicol, ampicillin and high-level gentamicin. On the other hand, the resistance rate was detected in 30.7%, 23%, and 3.29% of isolates for erythromycin, tetracycline and ciprofloxacin, respectively. The results of PFGE showed 19 (61.5% of our isolates) common types (CT) and 35 (38.5%) single types (ST) amongst the isolates. This is the first study to describe antibiotic resistance pattern and genetic relationship among normal flora enterococci in Iran. This study showed no prevalence of Vancomycin Resistant Enterococci (VRE) and high degrees of diversity among normal flora isolates by genotyping using PFGE.

Virulence and antimicrobial resistance of Enterococcus faecium isolated from water samples.

UNLABELLED: The aim of this study was to determine the incidence of Enterococcus species and six virulence factors of Enterococcus faecium which were isolated from surface water and wells. Fifteen different water samples, which were used for drinking as well as agricultural irrigation, were collected from nine private wells and surface water from six rivers located at the east of Tehran. The Ent. faecium isolates were tested for their resistance to 10 antibiotics and their virulence factors were detected using multiplex PCR for esp, acm, gelE, asa1, cylA and hyl genes. The most predominant species in 315 isolates were Ent. faecium (n = 118) followed by Enterococcus galinarom (n = 110), Enterococcus mundeti (n = 18), Enterococcus hirea (n = 37) and Enterococcus casselifelavus (n = 32). The resistance rates were observed in 41·5, 27·1, 12·7, 6·8 and 1·7% isolates for tetracycline, erythromycin, ampicillin, ciprofloxacin and chloramphenicol respectively. None of the Ent. faecium isolates were resistant to vancomycin, teicoplanin, linezolid, gentamicin and quinuspristin-dalfopristin. Virulence determinant was found in 84·7, 33·9, 16·1 and 2·5% of isolates for acm, asa1, esp, cylA respectively. None of the isolates carried hyl and gelE gene. The presence of virulence factors and antibiotic resistance indicated that water might be an important source of dissemination of virulent enterococci. SIGNIFICANCE AND IMPACT OF THE STUDY: Contamination of drinking or recreational water by human or animal faecal waste is a major public health threat. In this study, we determine the incidence of Enterococcus species and six virulence factors of Enterococcus faecium which were isolated from surface water and wells. Results from this study suggest that the presence of Ent. faecium in natural and well waters was found to be significant in rural areas of Tehran. Resistant to erythromycin among Ent. faecium was relatively high and the incidence of acm and asa1 among our isolates was common overall.

Selective activation of α7 nicotinic acetylcholine receptor by PHA-543613 improves Aß25-35-mediated cognitive deficits in mice.

Agonists of α7 nicotinic acetylcholine receptors (nAChRs) are currently being considered as therapeutic approaches for managing cognitive deficits in Alzheimer's disease (AD). Present study was designed to evaluate the effect of α7 nAChR selective activation by PHA-543613 (PHA) on beta-amyloid (Aß)25-35-mediated cognitive deficits in mice. For this purpose, PHA (1mg/kg, i.p.), a selective α7 nAChR agonist, and galantamine (Gal) (3mg/kg, s.c.), an acetylcholine-esterase inhibitor (AChEI) effects on α7 nAChR were tested in Aß25-35-received (intracerebroventricular, 10 nmol) mice model of AD. Methyllycaconitine (MLA) (1mg/kg, i.p.), a α7 nAChR antagonist, was used for receptor blockage effects evaluation. Working and reference memory in animals was assessed by the Morris water maze (MWM) task. The mRNA and protein levels of α7 subunit were analyzed by real-time PCR and Western blotting, respectively. PHA and Gal, ameliorate Aß-impaired working and reference memory. However, Gal had less effect than PHA in this regard. Pretreatment with MLA reverses both Gal and PHA effects in MWM. PHA and Gal treatment prevent Aß-induced α7 subunit protein reduction, but Gal has lesser effect than PHA. This effect blocked by pretreatment with MLA. In neither the pretreatment nor treatment group, the mRNA levels of nAChR α7 subunit were significantly changed. Therefore, α7 nAChR activation, reduces Aß-induced cognitive deficits and increases the α7 protein level and subsequent neuron survival. However, blockage of receptor, increases Aß toxicity and cognitive impairment and reduces the α7 nAChR protein level and flowing neuroprotection.

Lung tissue engineering and preservation of alveolar microstructure using a novel casting method.

We used a rat model to decellularize and seed alveolar cells on a three-dimensional lung scaffold to preserve alveolar microarchitecture. We verified the preservation of terminal respiratory structure by casting and by scanning electron microscopy (SEM) of the casts after decellularization. Whole lungs were obtained from 12 healthy Sprague-Dawley rats, cannulated through the trachea under sterile conditions, and decellularized using a detergent-based method. Casting of both natural and decellularized lungs was performed to verify preservation of the inner microstructure of scaffolds for further cell seeding. Alveolar cell seeding was performed using green fluorescent protein (GFP) lung cells and non-GFP lung cells, and a peristaltic pump. We assessed cell seeding using histological and immunohistochemical staining, and enzymatic evaluation. All cellular components were removed completely from the scaffolds, and histological staining and SEM of casts were used to verify the preservation of tissue structure. Tensile tests verified conservation of biomechanical properties. The hydroxyproline content of decellularized lungs was similar to native lung. Histological and immunohistochemical evaluations showed effective cell seeding on decellularized matrices. Enzymatic measurement of trypsin and alpha 1 antitrypsin suggested the potential functional properties of the regenerated lungs. Casts produced by our method have satisfactory geometrical properties for further cell seeding of lung scaffolds. Preservation of micro-architecture and terminal alveoli that was confirmed by SEM of lung casts increases the probability of an effective cell seeding process.

Molecular analysis of pbp2b in Streptococcus pneumonia isolated from clinical and normal flora samples.

Streptococcus pneumoniae is an important bacterial pathogen responsible for respiratory infections, bacteraemia, and meningitis remains an important cause of disease and mortality in infants and younger children around the world, with penicillin being considered the drug of choice for the treatment of infections. However, penicillin-resistant S. pneumonia is now becoming endemic worldwide. In this study, a total of 80 pneumococcal isolates were collected from different clinical sources as well as normal flora. These isolates were subjected to antimicrobial susceptibility testing and MIC determination. The penicillin-binding proteins, pbp2b, were amplified by PCR, and they were sequenced. The genetic relationship of the penicillin-resistant isolates was performed by BOX PCR. Overall, 36 pneumococcal (45 %) isolates were found to be resistant to penicillin with different MICs. The majority of them (80 %) were intermediately resistant with MIC of 0.12-1 µg/ml, whereas 20 % of isolates were penicillin resistant with MICs of >2 µg/ml. The results identified seven groups which were based on the amino acid substitutions of pbp2b. Sequencing analysis revealed that the most prevalent mutation was the substitution of Adenine for Thymine at the position 445 which is next to the second PBP2b-conserved motif (SSN). This study indicates that resistance to penicillin appears to be dependent on specific mutations in pbp2b, and the substitution in S620 → T near to the third PBP2b-conserved motif appears to be important in developing highly antibiotic-resistant isolates. Moreover, there was a positive correlation between the mutations in pbp2b gene and MIC.

3D printed metal columns for capillary liquid chromatography.

Coiled planar capillary chromatography columns (0.9 mm I.D. × 60 cm L) were 3D printed in stainless steel (316L), and titanium (Ti-6Al-4V) alloys (external dimensions of ~5 × 30 × 58 mm), and either slurry packed with various sized reversed-phase octadecylsilica particles, or filled with an in situ prepared methacrylate based monolith. Coiled printed columns were coupled directly with 30 × 30 mm Peltier thermoelectric direct contact heater/cooler modules. Preliminary results show the potential of using such 3D printed columns in future portable chromatographic devices.

A small size 1-3 atm pulsed CO2 laser with series-connected spark gaps ultraviolet preionization.

A small size pulsed CO2 laser with rounded edge flat profiled electrodes and variable gas pressure in 1-3 atm range has been constructed and characterized. The perionization system consists of a pair of 16 series-connected spark gaps located along either side of the main electrodes by which, the number of required preionization capacitors is reduced to 4. Sharpening of the main discharge has been performed using a 300 pF peaking capacitor. A maximum energy of 160 mJ/pulse was obtained for CO2:N2:He≡1:1:8 gas mixture and 33 kV discharge voltage. By increasing the laser gas pressure in 1-3 atm range, the duration of spike and tail parts of the laser pulses have been reduced from 110 ns and 4 µs to 37 ns and 1 µs, respectively.

ABCD2 score and BNP level in patients with TIA and cerebral stroke.

Scoring systems have been designed to help physicians in early prediction of cerebral stroke following Transitional Ischemic Attack (TIA). ABCD2 system is one of these scoring systems. Considering increase of brain natriuretic peptide following cerebral ischemic stroke, BNP level may be associated with incidence of ischemic stroke following TIA. The present study evaluates ABCD2 score, BNP level in patients with TIA and incidence of cerebral stroke. This cross sectional-analytical study evaluated 78 patients with TIA. ABCD2 score was calculated for all patients based on some criteria including age, blood pressure, clinical manifestations (speech/motor disorder), symptoms duration and diabetes. BNP level was measured at the reference laboratory when the patient referred to the treatment center. The patients were followed up for 6 months considering incidence of cerebral stroke and TIA. Mean age of the patients was 66.53 +/- 13.08 years and the sample was consisted of 62.8% male and 37.2% female patients. Mean BNP level and mean ABCD2 score was 611.31 +/- 125.61 and 4.61 +/- 10.99 in all patients, respectively. During follow-up period, TIA recurrence and cerebral stroke were, respectively seen in 11.5 and 3.8% of cases. Mortality was reported in 5.1% of the patients. BNP was significantly higher in cases with recursive TIA (p = 0.03). But, there was not any difference considering ABCD2 score (p = 0.38). BNP is capable of predicting TIA recurrence following first TIA and it can be used in this case.

Design and implementation of a hybrid genetic algorithm and artificial neural network system for predicting the sizes of unerupted canines and premolars.

The aim of this study was to develop a novel hybrid genetic algorithm and artificial neural network (GA-ANN) system for predicting the sizes of unerupted canines and premolars during the mixed dentition period. This study was performed on 106 untreated subjects (52 girls, 54 boys, aged 13-15 years). Data were obtained from dental cast measurements. A hybrid GA-ANN algorithm was developed to find the best reference teeth and the most accurate mapping function. Based on a regression analysis, the strongest correlation was observed between the sum of the mesiodistal widths of the mandibular canines and premolars and the mesiodistal widths of the mandibular first molars and incisors (r = 0.697). In the maxilla, the highest correlation was observed between the sum of the mesiodistal widths of the canines and premolars and the mesiodistal widths of the mandibular first molars and maxillary central incisors (0.742). The hybrid GA-ANN algorithm selected the mandibular first molars and incisors and the maxillary central incisors as the reference teeth for predicting the sum of the mesiodistal widths of the canines and premolars. The prediction error rates and maximum rates of over/underestimation using the hybrid GA-ANN algorithm were smaller than those using linear regression analyses.

Functionalization of lactose as a biological carrier for bovine serum albumin by electrospraying.

Electrohydrodynamic atomization (EHDA) is an attractive technique to make new types of composite particles for pharmaceutical use. The aim of this work is to prove that EHDA can be successfully used to attach nano/micro-particles of protein to lactose, the commonly used excipient for pulmonary delivery, keeping all the biological properties of the protein after dissolution of the complex. Bovine serum albumin (BSA) was used as a model protein. The atomization of BSA was tested with two different solvents, dimethyl sulfoxide (DMSO) and ethanol. The process using DMSO resulted in the formation of a thin layer of protein while the tests using ethanol resulted in the formation of spherical particles with mean diameters around 700 nm. Ethanol as solvent was also used to produce a composite formed by BSA adsorbed at the surface of lactose by electrostatic forces. No denaturation or significant conformational changes of the protein were observed, although an increase in the exposition of the lactose to the jet of the solution decreases the reproducibility of the method. Due to the absence of denaturation in the model protein, this new approach can be tested for the production of new formulations for dry powders for drug delivery systems.

Gene Diversity of Trichomonas vaginalis Isolates.

BACKGROUND: Trichomonas vaginalis is protozoan parasite responsible for trichomoniasis and is more common in high-risk behavior group such as prostitute individuals. Interest in trichomoniasis is due to increase one's susceptibility to viruses such as herpes, human papillomavirus and HIV. The aim of this study was to find genotypic differences between the isolates. METHODS: Forty isolates from prisoners' women in Tehran province were used in this study. The random amplified polymorphic DNA (RAPD) technique was used to determine genetic differences among isolates and was correlated with patient's records. By each primer the banding pattern size of each isolates was scored (bp), genetic differences were studied, and the genealogical tree was constructed by using NTSYS software program and UPGMA method. RESULTS: The least number of bands were seen by using primer OPD8 and the most by using OPD3. Results showed no significant difference in isolates from different geographical areas in Iran. By using primer OPD1 specific amplified fragment with length 1300 base pair were found in only 8 isolates. All these isolates were belonged to addicted women; however, six belonged to asymptomatic patients and two to symptomatic ones. CONCLUSION: There was not much genetic diversity in T vaginalis isolates from three different geographical areas.

Effect of renal transplantation on visual evoked potential abnormalities of chronic renal failure.

BACKGROUND: Cranial neuropathies including optic nerve involvement are well-known complications of chronic renal failure (CRF), but most clinicians often do not follow the progression of these damages during course of CRF or their reversibility after treatment. So, this study evaluates effects of renal transplantation on visual system functions using visual-evoked potentials (VEP). METHODS AND MATERIALS: Forty CRF transplantation candidates and 40 control healthy persons underwent VEP before transplantation. VEP was repeated 3 months later for patients who had successful grafts. RESULTS: None of recorded VEP changes were significant in our study, although the absolute number of normal parameters increased after transplantation. In patients who had less than 1 year duration of CRF, more positive changes were observed after transplantation (p < .05). CONCLUSION: Our study showed the VEP changes were not significant. This may have been due to the delay in transplantation. CRF duration had a significant effect on almost all parameters of VEP which means that the longer duration of CRF lead to a decreased probability of VEP changes to return to normal after transplantation.