Bacterial Strain Typing Research Articles

Evaluation of the bioMérieux EPISEQ-CS Software for wgMLST-Based Bacterial Strain Typing

Background: Whole-genome sequencing (WGS) is becoming the method of choice for outbreak analysis of microbial pathogens. However, the main challenge with WGS for microbial strain typing is the conversion of raw sequencing data to actionable results for epidemiology and surveillance analysis. We evaluated the bioMrieux EPISEQ-CS, a cloud-based WGS data analysis software for outbreak detection to compare the results for 4 groups of different species previously characterized by strain typing and commonly isolated in hospital-acquired infections. Methods: In total, 30 methicillin-resistant Staphylococcus aureus (MRSA), 15 Clostridioides difficile (CDIFF), 17 Pseudomonas aeruginosa (PSA), and 10 Acinetobacter baumannii (ACB) isolates were included in this study. All isolates had been previously characterized by rep-PCR using the DiversiLab system (bioMrieux, France) and saved at 70C. Before testing, samples were thawed and plated, and DNA extraction was performed on the QIAcube (Qiagen, Hilden, Germany) using the DNEasy Ultra Clean Microbial kit extraction protocol. DNA libraries were prepared using the Nextera DNA Flex Kit and sequenced on the Illumina iSeq100 platform according to manufacturer’s recommendations (Illumina, San Diego, CA). Generated sequences were uploaded into EPISEQ-CS, and wgMLST-based analysis was performed. We compared clusters generated by the DiversiLab system and EPISEQ-CS. Results: DiversiLab identified 9 MRSA clusters among 30 isolates. EPISEQ-CS reclassified 14 of 30 isolates into 5 MRSA clusters and the remaining 16 isolates were unrelated. DiversiLab identified 2 CDIFF clusters among 15 isolates. EPISEQ-CS reclassified 3 isolates into 1 CDIFF cluster and determined the remaining 12 to be unrelated. DiversiLab identified 5 PSA clusters among 17 isolates, whereas EPISEQ-CS reclassified all 17 isolates as unrelated. DiversiLab identified 2 ACB clusters among 10 isolates, whereas EPISEQ-CS reclassified 2 ACB isolates into 1 cluster and determined 8 to be unrelated. Analysis using Simpson’s diversity index (D) suggested that the EPISEQ-CS showed increased diversity when compared to DiversiLab clustering across all bacterial species analyzed in this study. Conclusions: EPISEQ-CS enabled a comprehensive wgMLST analysis, including quality control and comparative epidemiological analysis, thereby providing a more reliable method for bacterial strain typing. As WGS becomes more affordable and applicable to routine epidemiological surveillance, EPISEQ-CS provides an informative tool in the monitoring of hospital-acquired infections.Funding: NoneDisclosures: None

Association of cagA+ Helicobacter pylori strains with high urease activity and dyspepsia in Mexican adults

Introduction and aimsHelicobacter pylori (H. pylori) is associated with a higher risk of peptic ulcer and gastric cancer. The sole presence of the bacterium is not a determinant of clinical outcome, but rather the interaction of strain type and host factors determines the risk of disease. Our aim was to study the association between bacterial load, strain type, and gastric symptoms in H. pylori-positive subjects. Materials and methodsIn a community survey, a diagnostic 13C-urea breath test for H. pylori was performed on 302 volunteers that were not taking antibiotics, antacids, or proton pump inhibitors one month prior to the test. The breath test produced 25 H. pylori-positive subjects, between 25 and 74 years of age, who then took a gastric symptoms survey and were tested for the presence of the cagA genotype in gastric juice, using the Entero-test®. Bacterial load was determined as a measure of urease activity, utilizing the delta over baseline (DOB) value, obtained in the 13C-urea breath test. ResultsA total of 48% of the H. pylori-positive subjects were cagA+. A positive association was found between cagA status and high gastric urease activity (p<0.0001) and the latter was significantly associated with the presence of symptoms (p<0.0001). ConclusionGastric urease activity was strongly associated with dyspeptic symptoms and cagA+H. pylori. Elevated 13C-DOB values could be used as indicators of a higher risk for gastric disease.

Whole-Genome Sequencing for Bacterial Strain Typing Using the iSeq100 Platform

Background: Hospital-acquired infections pose a significant threat to patient health. Laboratories are starting to consider whole-genome sequencing (WGS) as a molecular method for outbreak detection and epidemiological surveillance. The objective of this study was to assess the use of the iSeq100 platform (Illumina, San Diego, CA) for accurate sequencing and WGS-based outbreak detection using the bioMérieux EPISEQ CS, a novel cloud-based software for sequence assembly and data analysis. Methods: In total, 25 isolates, including 19 MRSA isolates and 6 ATCC strains were evaluated in this study: A. baumannii ATCC 19606, B. cepacia ATCC 25416, E. faecalis ATCC 29212, E. coli ATCC 25922, P. aeruginosa ATCC 27853 and S. aureus ATCC 25923. DNA extraction of all isolates was performed on the QIAcube (Qiagen, Hilden, Germany) using the DNEasy Ultra Clean Microbial kit extraction protocol. DNA libraries were prepared for WGS using the Nextera DNA Flex Library Prep Kit (Illumina) and sequenced at 2×150-bp on the iSeq100 according to the manufacturer’s instructions. The 19 MRSA isolates were previously characterized by the DiversiLab system (bioMérieux, France). Upon validation of the iSeq100 platform, a new outbreak analysis was performed using WGS analysis using EPISEQ CS. ATCC sequences were compared to assembled reference genomes from the NCBI GenBank to assess the accuracy of the iSeq100 platform. The FASTQ files were aligned via BowTie2 version 2.2.6 software, using default parameters, and FreeBayes version 1.1.0.46-0 was used to call homozygous single-nucleotide polymorphisms (SNPs) with a minimum coverage of 5 and an allele frequency of 0.87 using default parameters. ATCC sequences were analyzed using ResFinder version 3.2 and were compared in silico to the reference genome. Results: EPISEQ CS classified 8 MRSA isolates as unrelated and grouped 11 isolates into 2 separate clusters: cluster A (5 isolates) and cluster B (6 isolates) with similarity scores of ≥99.63% and ≥99.50%, respectively. This finding contrasted with the previous characterization by DiversiLab, which identified 3 clusters of 2, 8, and 11 isolates, respectively. The EPISEQ CS resistome data detected the mecA gene in 18 of 19 MRSA isolates. Comparative analysis of the ATCCsequences to the reference genomes showed 99.9986% concordance of SNPs and 100.00% concordance between the resistance genes present. Conclusions: The iSeq100 platform accurately sequenced the bacterial isolates and could be an affordable alternative in conjunction with EPISEQ CS for epidemiological surveillance analysis and infection prevention.Funding: NoneDisclosures: None

Molecular epidemiology in current times.

Motivated to find options for prevention or intervention, molecular epidemiology aims to identify the host and microbial factors that determine the transmission, manifestation and progression of infectious disease. The genotyping of cultivatable bacterial strains is performed by either anonymous fingerprinting techniques or sequence-based exploration of variable genomic sites. Multilocus sequence typing of housekeeping genes and allele profiling of the core genome have become standard techniques of bacterial strain typing that may be supplemented by whole genome sequencing to explore all single nucleotide variants and/or the composition of the accessory genome. Next, novel protocols to investigate host and microbiome based upon smart third generation sequencing technologies are being developed for an effective surveillance, rapid diagnosis and real-time tracking of infectious diseases.

Fabrication of cryptomelane FexMn1-xO2 with enhanced antibacterial activity and specific heat capacity

In recent years, the emergence of antibiotic resistant bacteria has compelled the scientific community to develop new class of antibiotics with improved efficiency. In this work, we synthesized cryptomelane type FexMn1-xO2 (for x = 0.00, 0.04, 0.08, 0.12) nanowires and performed an in-vitro study of the antibacterial activity against multidrug resistant (MDR) S. aureus (G-positive) and Extensively Drug-Resistant (XDR) S. Typhi (G-negative) strains. The samples were successfully prepared by using a simple hydrothermal method and their structural, morphological, optical and thermal properties were investigated by a range of comprehensive analytical tools. The variation of Fe concentration in the host lattice significantly influenced the physicochemical properties of the cryptomelane. The antimicrobial screenings indicated that increasing the fraction of Fe from x = 0.00 to 0.12 also increases the inhibitory zones. A maximum inhibitory zone of 25 mm for S. Typhi and 23 mm for S. aureus was observed. The antibacterial results, evaluated through the agar well-diffusion method, suggested that cryptomelane FexMn1-xO2 nanowires are remarkably efficient against both types of resistant bacterial strains and could be used for food preservation and biomedical applications.

Adsorption, antimicrobial and wound healing activities of biosynthesised zinc oxide nanoparticles

Using plant extracts has been interesting as possible eco-friendly methods to synthesis and stabilize different types of nanoparticles. Zinc oxide nanoparticles (ZnO-NPs) can be used as effective adsorbent due to their high surface area to volume ratio and high spontaneous adsorption properties. In this research, ZnO-NPs were synthesized and stabilized to use as an effective adsorbent material for removing two carcinogenic azo dyes: Malachite green and Congo red. It is also used as an antibacterial active material to enhance mouse skin wound healing. The fabrication and stabilization of ZnO-NPs were performed using Aloe barbadensis leaf extract. The morphology and structure of the as-synthesized ZnO-NPs were investigated by X-ray diffraction, scanning electron microscopy, Fourier transforms infrared spectroscopy and UV–Vis spectroscopy. The fabricated ZnO-NPs were applied as an adsorbent for the removal of Malachite green, a cationic azo dye, and Congo red, an anionic azo dye. The ZnO-NPs achieved adsorption efficiency of 90.7% for Malachite green azo dye within 90 min at the maximum amount of 70 mg/ml. Congo red dye was adsorbed at the efficiency of 92.30% within 120 min at 80 mg/ml maximum concentration of ZnO-NPs. Using the batch process, different parameters (time, pH, amount of adsorbent) during the adsorption process were elucidated. The results confined the applicability of ZnO-NPs as an efficient adsorbent for Malachite green and Congo red dyes. Also, the synthesised ZnO-NPs demonstrated a powerful antimicrobial activity against four types of bacterial strains of Bacillus subtilis, Klebsiella pneumonia, Bacillus licheniformis and Escherichia coli, and two types of fungi strains of Aspergillus niger and Candida albicans. The healing efficiency of mouse wound was studied using ZnO-NP/silica gel (ZnO-NP/SG) dressings due to its extensive evidence on healing property. The microscopic investigations of the wound area are reduced significantly using ZnO-NP/SG-30 ppm dressings within 11 days of observation as compared to ZnO-NPs of the control sample. These findings elaborated that as-synthesized dressing enhanced the skin repairing on the wound surface and support its usage in the future.

MinMLST: machine learning for optimization of bacterial strain typing.

High-resolution microbial strain typing is essential for various clinical purposes, including disease outbreak investigation, tracking of microbial transmission events and epidemiological surveillance of bacterial infections. The widely used approach for multilocus sequence typing (MLST) that is based on the core genome, cgMLST, has the advantage of a high level of typeability and maximal discriminatory power. Yet, the transition from a seven loci-based scheme to cgMLST involves several challenges, that include the need by some users to maintain backward compatibility, growing difficulties in the day-to-day communication within the microbiology community with respect to nomenclature and ontology, issues with typeability, especially if a more stringent approach to loci presence is used, and computational requirements concerning laboratory data management and sharing with end-users. Hence, methods for optimizing cgMLST schemes through careful reduction of the number of loci are expected to be beneficial for practical needs in different settings. We present a new machine learning-based methodology, minMLST, for minimizing the number of genes in cgMLST schemes by identifying subsets of informative genes and analyzing the trade-off between gene reduction and typing performance. The results achieved with minMLST over eight bacterial species show that despite the reduction in the number of genes up to a factor of 10, the typing performance remains very high and significant with an Adjusted Rand Index that ranges between 0.4 and 0.93 in different species and a P-value < 10-3. The identification of such optimized MLST schemes for bacterial strain typing is expected to improve the implementation of cgMLST by improving interlaboratory agreement and communication. The python package minMLST is available at https://PyPi.org/project/minmlst/PyPI and supported on Linux and Windows. Supplementary data are available at Bioinformatics online.

Determination of Antibiotic Resistance Pattern of Bacteria Isolated from Blood, Cerebrospinal Fluid, and Urine Samples in Neonatal Intensive Care Unit of Ali Asghar Hospital, Iran during 2013-15

Background: Infections are one of the most important causes of death in infants, especially in developing countries. Inappropriate use and administration of antibiotics can contribute to the resistance and spread of infection. In this study, we determined the antibiotic resistance pattern of the bacteria isolated from clinical samples of blood, cerebrospinal fluid, and urine in the neonatal intensive care unit (NICU) of Ali Asghar Hospital, Iran during 2013-2015.Methods: For the purposes of the study, clinical samples of blood, cerebrospinal fluid, and urine were collected from the NICU of Ali Asghar Hospital during 2013-15. The type of bacterial strain and antibiotic susceptibility pattern was determined by routine microbiological tests. The collected data were analysed in SPSS software (version 19), using χ2, Student’s t-test, and ANOVA test for comparison.Results: In total, 240 positive culture samples (118 blood, 117 urine, and 5 cerebrospinal fluid samples) were collected for this research. The most common isolates in the blood, urine, and cerebrospinal fluid samples were Staphylococcus epidermidis (63.6%), Klebsiella (35%), and Acinetobacter Baumannii (40%), respectively. The highest antibiotic resistance in S. epidermidis isolated from blood samples was found against amikacin and cefotaxime, while linezolid and vancomycin were the most effective antibiotics against S. epidermidis. Moreover, ciprofloxacin and nitrofurantoin were the most effective antibiotics against Klebsiella isolated from urine samples, while this bacterial strain had the highest resistance to imipenem and ampicillin. Despite the fact that A. Baumannii strains were resistant to most studied antibiotics, ceftazidime and ceftriaxone had an acceptable antibacterial effect against these isolates.Conclusion: Continuous surveillance for antibiotic susceptibility, rational use of antibiotics, and the strategy of antibiotic cycling can provide some answers to the emerging problem of antibiotic resistance.

A study of the biological activity of 4-(Para-Substituted phenyl)-1,2,3-Selenadiazole derivatives as anti-oxidant and anti-breast cancer

In present work, five ligands of substituted 1,2,3-selenadiazole have been synthesized and characterized and they tested as possible anti-oxidant and anti-breast cancer. The synthesized compounds were prepared by the reaction of selenium dioxide with a series of semicabazone derivatives in glacial acetic acid. The prepared compounds have been characterized using different methods. The biological activity of 1,2,3-selenadiazole compounds were examined against the growth of two types of bacterial strains (E.coli and staphylococcus aureus). Also this study included determined the activity of 1,2,3-selenadiazole derivatives as antioxidants, and measured their ability toward α, α-diphenyl-β-picrylhydrazyl (DPPH) free radical scavenging. It has been found that they have a good activity to reduce free radical’s effects. Inhibition of 1,2,3-selenadiazole derivatives was carried out against human breast cancer cells (MCF-7) growth by MTT , the measurements showed that the derivatives had a higher inhibition rate than the complexes , the IC50 of compounds D3 and D4 was ( 89.5 and 44.3) µg/ ml respectively

Nano-synthesis, spectroscopic characterisation and antibacterial activity of some metal complexes derived from Theophylline

The novel was assembled by the ultrasonic sonication method of three new ligand-metal nano complexes with Ni(II), Cu(II), and Co(II) of theophylline derivative. This method was used to produce smaller, small distributed nanoparticles and without any aggregations. Molar conductance, FT-IR,1HNMR, UV–Vis., solubility, flame atomic absorption, and (C.H.N) elemental analysis were used to describe and to suggest the structure of the new ligand and nanocomplexes. Engagement of all spectroscopic data indicates that the new ligand (L) acts as a bidentate ligand with its metal ions. The molar conductance reveals that the nanocomplexes were non-electrolytes. The size and morphology of nano complexes measured by TEM were in range (12-18) nm. The biological activities of the synthesised metal nano complexes were assayed against four types of bacterial strains, Staphylococcus aureus, Bacillus subtilis (gram-positive bacteria) and Klebsiella pneumonia, Escherichia Coli (gram-negative bacteria). The results show remarkable leverage compared to the parent ligand in the present nano complexes.

Effects of bacteria and nitrogen fertilizer on promoting maize (Zea mays L.) growth, yield and chemical constituents

A field experiment was carried out during two successive summer seasons (2016/ 2017- 2017/2018), at the College of Agricultural Studies, Sudan University of Sciences and Technology, to assess the effect of bacterial strains, nitrogen and their combinations on the performances of two maize genotypes Hudibi2 (C1) and ZML309 (C2). The form of two types of bacterial strains Bacillus megatherium var. phosphorous + Azotobacter spp + Azospirillium spp (B1) and Bacillus megatherium var. phosphorous + Azotobacter spp + Flavobacterium spp (B2), nitrogen applied at rates of 80kg/f (N) plus control. The treatments were arranged in a Randomized Complete Block Design (RCBD) in four replicates. The results showed that the combinations of B1 and B2 with N increased plant growth compared to B1, B2, and N each alone at both seasons. The general trend was the combinations (B2+N, B1+N) had significant effect on all growth parameters in both seasons. Yield components increased with combination (B2+N) followed by (B1+N), the maximum seed yield (5.0 and 2.8t/ha) was achieved by the interaction of (C2*B2+N) in the first season and (C2*B1+N) in the second season, respectively. Generally, in among all treatments, the combination of B2+N increased nitrogen content, crude protein and fiber irrespective to maize genotypes. Moreover, C2 showed the highest values as compared to C1. In conclusion, improvement in maize plant growth and yield are more prominent and significant when genotype ZML309 inoculated with Bacillus megatherium var. phosphorous + Azotobacter spp + Flavobacterium spp and supplemented with 80kg/f nitrogen.

In Vitro Preliminary Evaluation of Bacterial Attachment on Grooved and Smooth Healing Abutments

This in vitro preliminary study investigated the attachment of Fusobacterium nucleatum and Porphyromonas gingivalis on titanium alloy healing abutments, which differed in their surface macro-morphology: one was groove-marked while the other was completely smooth. Altogether, twenty implant-healing abutments, ten of each macro-morphology, were evaluated with a single type of bacterial strain. Accordingly, four groups of five abutments each were created. The sterilized healing abutments with the cultured bacteria were placed under anaerobic conditions for 48 h at 37 °C. Afterwards, the abutments were examined with a scanning electron microscope, at a 2500x magnification. Attached bacteria were quantified in the four vertical quarters within the grooved abutments and in the two most coronal millimeters of the smooth abutments. The results were analyzed by applying two-way ANOVA, with square root transformation for a normal distribution. The bacterial attachment of both strains was statistically significantly larger in the grooved abutment areas than on the smooth surfaces (p ≤ 0.0001), twenty times so for Porphyromonas gingivalis and a hundred times so for Fusobacterium nucleatum.

Using the Hair Removal Laser in the Axillary Region and its Effect on Normal Microbial Flora.

Introduction: The axillary hair removal laser is one of the most often used procedures to treat unwanted hairs in that region. Employing this technology can be helpful in decreasing the bromhidrosis. Methods: In the present research, a clinical trial study over the effect of the hair removal laser on normal microbial flora at the axillary region is presented. The intervention group consisted of 30 women referred to the dermatologic clinic for the purpose of removing axillary hair by the alexandrite 755 nm laser and the control group consisted of 30 women referred to the same clinic for any other reasons. Both groups were evaluated for the type of bacterial strains on the first visit and after three and six months. Results: The results showed that the sense of sweat smell improved by about 63% after the last laser session. The frequency of all bacterial strains decreased in the intervention group except Staphylococcus epidermidis which was significant. In the control group, there was no significant decrement in any bacterial strains and even the prevalence of more strains including Staphylococcus aureus and S. epidermidis increased. Counting the mean bacterial colon showed a slight decrement of the bacterial count following the laser. Conclusion: The use of laser radiation, even with the aim of hair removal, can alter the microbial flora, and it can be accompanied by the improvement of the smell of sweat. The effect of the laser on different bacterial strains is quite different, which can depend on the amount of energy, the wavelength, the characteristics of the area under the laser, and also the structural properties of the membrane of the microorganism itself.

Synthesis and property of polyurethane elastomer for biomedical applications based on nonaromatic isocyanates, polyesters, and ethylene glycol

Polyurethane (PU) elastomers were synthesized by the reaction of HDI or IPDI diisocyanates and poly(ε-caprolactone) (PCL or poly(ethylene adipate) (PA) diols and ethylene glycol as a polymer chain extender. IR, 1H, and 13C NMR spectroscopy and X-ray analysis were used for the structural analysis of the formed films. The molecular weight distribution was examined by GPC chromatography. Based on the measured contact angles, free surface energy parameters were calculated. The obtained results were analyzed for the possible use of these polyurethanes as biomaterials. The most promising in this respect was PU-3, which was synthesized from IPDI and PCL. This was due to its high molecular weight of approximately 90,000, the presence of a crystalline phase, and the relatively high hydrophobicity, with a SEP value below 25 mJ/m2. These films showed a good resistance to hydrolysis during incubation in Baxter physiological saline during 6 weeks. Both Gram-positive (Bacillus sp.) and Gram-negative (Pseudomonas sp.) types of bacterial strains were used to test the biodegradation property. Synthesized PUs are biodegradable and showed moderate or even mild cytotoxicity against human normal fibroblasts (BJ) and immortalized keratinocytes (HaCaT), estimated with direct contact assay. The most biocompatible was PU-3 film, which revealed rather mild reactivity against both cell lines, and the least was PU-2 film, synthesized from HDI and PA (severe toxicity for HaCaTs).

In vitro evaluation of the erosive effect of probiotic drink on tooth enamel

Abstract Purpose: The study aimed to evaluate the erosive activity of six probiotic drinks (PD) on tooth enamel. Methods: Forty-eight extracted human teeth premolar free of hypocalcification and carious were used in this study. The erosive activity was evaluated by measuring the pH, titratable acidity (TA), tooth weight loss, and the rate of calcium release after 5-min exposure daily over 7 days. Results: The pH of the PD was found to be in acidic range (3.08–4.10) with different TA values depending on the bacterial strain presence. The highest pH value showed minimum TA. The erosion was determined by the rate of calcium release and weight loss from the enamel surface on exposure to PD. Most of the samples showed consistent calcium reabsorption to the tooth enamel after 5 min of exposure daily over 7 days. However, all the samples showed persistent weight loss over 7 days' exposure. Conclusion: Although PD was found to be acidic, it exhibited low erosive activity, most probably due to the presence of high calcium content and certain bacterial strains in the drink. The number and type of bacterial strain in the drink did not significantly contribute to the erosion of the enamel, as no calcium loss was found except for certain drinks of repeated exposure in days 3 and 5. However, consistent weight loss was measured over a period of 7 days. In conclusion, PD does not cause any calcium loss on tooth enamel. Other than beneficial to the gut, it also promotes calcium reabsorption to the tooth enamel.

Изучение особенностей выращивания объектов аквакультуры ваквапонической установке совместно c растениями и бактериальным штаммом

The article touches upon the acute problems of eco-agriculture and decreasing quantity and quality of food products in large cities. The solution to the main problem of agriculture at present – namely, increasing the yield of biological products - should be obtained through the use of new technologies and modern methods of growing fish and agricultural products. Joint cultivation of different types of fish, agricultural plants and bacterial strains in a modular installation opens up enormous opportunities to make the production more efficient, to reduce the time for growing plants, and to obtain safe products. In cultivation process the waste products of farmed fish become the fertilizers for growing crops by the hydroponic method. The data on growing tilapia and strawberries in the aquaponic unit with addition of a bacterial strain are presented. In the course of the experiment there was analyzed the physiological state of tilapia: indicators of weight gain, fatness ratio. Joint cultivation of fish and plants in the unit leads to accumulating high concentrations of nitrogen compounds in plants, which not only gives the product unpleasant taste, but can also result in health problems of the end user. The accumulation of nitrates in plants reduces the diversity of farmed agricultural products. There was carried out an experiment on using bacterial isolate (bacterial strain) to reduce the proportion of nitrates in the system and accelerate the development of plants. Adding a bacterial strain to the plant reduced the level of nitrates. Besides, possessing the economically useful properties (stimulation of plant growth and development), the bacterial strain inhibited the development of pathogens. The practical value is the opportunity to get safe and environmentally friendly fish and vegetable products in a shorter time.

Robust approach leading to novel densely functionalized four-cyclic benzo[e]pyrazolo[5′,1′:2,3]pyrimido[4,5-b][1,4]diazepines with antibacterial activity toward resistant strains

A straightforward approach for the regioselective synthesis of various derivatives of benzo[e]pyrazolo[5′,1′:2,3]pyrimido[4,5-b] [1, 4] diazepine as a novel heterocyclic system from the annulation of 6-bromo-7-chloro-3-cyano-2-(ethylthio)-5-methylpyrazolo[1,5-a]pyrimidine with several 2-amino-N-substituted benzamides as bident nucleophiles in the presence of K2CO3 and DMF has been disclosed. The right regioisomer was elucidated by 2D-NOESY NMR spectroscopy, as well. Most of the novel synthetic compounds exhibited antimicrobial activity though relatively at high concentrations against multi-drug-resistant Klebsiella pneumoniae and Escherichia coli clinical isolates possessed of strong biofilm formation ability. N-Cyclohexyl-substituted pyrazolopyrimidobenzodiazepine (3 h) as the most potent compound represented 100% growth inhibitory on both types of bacterial strains, which brings promises for further changes to develop potential antimicrobial drugs.

Synthesis and In vitro Antibacterial, Antitubercular Studies of Novel Fluoroquinolones Analogs Containing 4-substituted Sec Amine

Background: Tuberculosis is a contagious, air borne disease and second leading cause of death among infectious diseases worldwide. Fluoroquinolones are well-known antibacterial agents and they were recommended as second-line of antitubercular drugs. Method: A series of novel fluoroquinolone analogs 6-24 was effectively synthesized. An attempt was made by tagging the substituted pyrazole on to fluoroquinolones for the first time at C-7 position. The newly synthesized compounds were characterized by FTIR, 1HNMR, ESI-MS, HR-MS and elemental analysis. The in vitro antibacterial activity of all the title compounds was investigated against various gram positive, gram negative bacterial organisms and in vitro antitubercular activity against Mycobacterium Tuberculosis H37Rv strain. Result: Most of the synthesized compounds showed comparable activity against the entire gram positive and gram negative bacterial organisms. Fluoroquinolone 16 showed enhanced activity against both type of bacterial strains and compound 11showed promising activity against MTB-H37Rv strain. Conclusion: Some of the novel fluoroquinolone analogs (11, 16) showed potent antibacterial, antitubercular activity.

(1S,2S)-Cyclohexane-1,2-diamine-based Organosilane Fibres as a Powerful Tool Against Pathogenic Bacteria

An urgent need to find an effective solution to bacterial resistance is pushing worldwide research for highly effective means against this threat. Newly prepared hybrid organosilane fibres consisting of a (1S,2S)-cyclohexane-1,2-diamine derivative, interconnected in the fibre network via covalent bonds, were fully characterised via different techniques, including FTIR, TGA-FTIR, SEM-EDS, and solid-state NMR. Fibrous samples were successfully tested against two types of pathogenic bacterial strains, namely Staphylococcus aureus, and Pseudomonas aeruginosa. The obtained results, showing >99.9% inhibition against Staphylococcus aureus and Pseudomonas aeruginosa in direct contact compared to the control, may help particularly in case of infections, where there is an urgent need to treat the infection in direct contact. From this point of view, the above-mentioned fibrous material may find application in wound healing. Moreover, this new material has a positive impact on fibroblasts viability.

Thermal analysis of synovial fluids in different stages of osteoarthritis and after bacterial infections

The analysis of synovial fluid is an important method in diagnosing and handling septic arthritis. To achieve a quick diagnosis could be a great advantage in the therapy. The differential scanning calorimetry (DSC) proved to be a useful technique in the differential diagnosis of tumors using blood plasma or sera. The aim of this paper is to show up some characteristic thermal parameters in the diagnosis of different grades of arthritis, which are in good agreement with the severity of disease checked by conventional X-ray supported grading. To follow the effect of different bacterial strains, the synovial fluids were inoculated by three types of bacterial strains (with 103–105 CFU mL−1 concentrations) at 37 °C and stored trough 24 h. After that, they were denatured in 20–90 °C temperature range with 0.3 K min−1 scanning rate. The change in the maximum denaturation temperature (Tm) and calorimetric enthalpy (∆H) monitored the severity of sepsis and depended on the type of bacteria. The proliferation characteristics of bacteria should be strain specific. The synovial fluid samples inoculated with the most frequently occurring bacteria were monitored in isotherm mode (isoperibol calorimeter) at 37 °C up to the end of the proliferation. The isoperibolic scans clearly demonstrated specific, concentration-dependent representative curves in case of each bacterium (duration of proliferation, maximum of proliferation rates, etc.). Therefore, thermal analysis of human synovial fluid samples by DSC or isoperibolic calorimetry could be a useful tool in the staging of osteoarthritis and the diagnostics of septic arthritis.