RESUMO
La infección por Neisseria gonorrhoeae (NG) es considerada de alta prioridad en salud pública, por su capacidad para desarrollar resistencia a la mayoría de los antibióticos empleados para tratarla. La presentación anorrectal suele ser asintomática y frecuente en hombres que tienen sexo con hombres (HSH). En Argentina, se recomienda terapia antibiótica dual (ceftriaxona+azitromicina/doxiciclina) como primera línea empírica. Este estudio observacional y retrospectivo se realizó para evaluar el porcentaje de positividad de NG anorrectal, el perfil de sensibilidad a penicilina, tetraciclina, ciprofloxacina, ceftriaxona, cefixima y azitromicina, así como los aspectos clínicos-epidemiológicos de los pacientes atendidos entre 20/10/2015 y 20/03/2020 en consultorios coloproctológicos de un hospital público. Se detectaron 55/436 hisopados rectales positivos para NG (13%). El 95% era HSH y 71%, VIH+. En 18/55 NG fue la única infección. Las co-infecciones más frecuentes: HPV (38%) y C. trachomatis (35%). La sensibilidad a cefalosporinas de espectro extendido (CEE) y a azitromicina fueron 100% y 98%, respectivamente. Se observó la emergencia local de los primeros cinco aislamientos de NG anorrectal con sensibilidad reducida (SR) a CEE, el primer aislamiento con categoría no-sensible a azitromicina y otro con SR a azitromicina concomitantemente con SR a CEE. Aunque el uso de terapia empírica dual sigue siendo adecuado para nuestra institución, se observó la emergencia de aislamientos con SR y NS a las drogas de primera línea, evidenciando la importancia de la vigilancia epidemiológica a nivel local para definir los tratamientos empíricos.
Neisseria gonorrhoeae (NG) infection is considered a high public health priority because of its ability to develop resistance to most of the antibiotics used to treat it.The anorectal presentation is generally asymptomatic and frequent in men who have sex with men (MSM). In Argentina, dual therapy (ceftriaxone+azithromycin/doxycycline) is recommended as first line empiric therapy.This observational and retrospective study was conducted to evaluate the percentage of anorectal NG positivity, the susceptibility profile to penicillin, tetracycline, ciprofloxacin, ceftriaxone, cefixime and azithromycin, as well as the clinical-epidemiological aspects of patients attended between 20/10/2015 and 20/03/2020 in coloproctology of a public hospital.We detected 55/436 positive rectal swabs for NG (13%). 95% were MSM and 71% were PLHIV. In 18/55 NG was the only infection. The most frequent co-infections: HPV (38%) and C. trachomatis (35%).Susceptibility to extended-spectrum cephalosporins (ESCs) and azithromycin was 100% and 98%, respectively. Local emergence of the first five anorectal NG isolates with decreased susceptibility (DS) to ESCs, the first isolate with nonsusceptible category to azithromycin and another with DS to azithromycin concomitantly with DS to ESCs were observed.Although the use of dual empirical therapy continues to be adequate for our institution, the emergence of isolates with DS and NS to first-line drugs was observed, evidencing the importance of epidemiological surveillance at the local level to define empirical treatments
Assuntos
Humanos , Masculino , Feminino , Proctite/patologia , Resistência Microbiana a Medicamentos , Gonorreia/terapia , Infecções Sexualmente Transmissíveis/terapia , Minorias Sexuais e de Gênero , Comportamento SexualRESUMO
Thraustochytrids are unicellular heterotrophic marine protists that have been described as producing a high content of polyunsaturated fatty acids (PUFAs). Among them, arachidonic acid (ARA) stands out as a precursor of several mediators of pivotal importance for the immune system. However, the biotechnological potential of thraustochytrids for ARA production has not been developed. The objective of this study is to isolate and identify native strains from different Chilean coastal environments and evaluate in vitro the effect of culture parameters such as C/N ratio (19 and 33) and temperature (15 °C and 23 °C) on biomass production and arachidonic acid content. A total of nine strains were identified and classified into four genera of the Thraustochitridae family. The Lng2 strain with 99% identity belongs to the species Ulkenia visurgenis and was the most prominent one for ARA production. Temperature had an effect on the PUFA profile but not on the ARA content nor on the biomass yield. Additionally, the C/N ratio has been identified as a key parameter. The ARA productivity increased by 92% (from 0.6 to 8.3 ARA mg/g-DW) and its total biomass by 62.7% (from 1.9 to 5.1 g/L) at a high C/N ratio (33) as compared to the control.
RESUMO
Kraft pulp cellulose was hydrolyzed using sulfuric acid, under different thermophysical conditions of temperature, time, pulp concentration, and sonication time. The experimental design revealed the effect of these conditions and their interaction on the hydrolysis yield obtained. In addition, the top five cellulose nanocrystals (CNCs) yields from this experiment design were analyzed. The results obtained indicated that CNCs possess a morphology that can be described as individualized rod particles, with average diameters less than 50 nm and different size distribution. In the analysis of CNCs features, significant Pearson correlations were established between the crystallinity of the CNC, CNC yield, and interplanar crystallites distance (Δd/d). The thermogravimetric (DTG) profiles exhibited two CNCs degradation stages, where the second stage CNCs degradation showed a significative correlation with CNC sulfur content. In our analysis, the crystallographic parameters exhibited a correlation with the mechanical behavior of the CNC, since the potential variation between the distances of the crystalline planes is related to the stress and deformation present in the crystallites of CNCs. This study provides new knowledge regarding CNCs, further enhancing information for CNC-based industries and the processability of CNCs for the development of new materials.
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Azithromycin in combination with ceftriaxone is recommended as the first-line treatment for uncomplicated gonorrhea in many countries. Therefore, monitoring of azithromycin susceptibility of Neisseria gonorrhoeae isolates is essential. In 2019, the Clinical and Laboratory Standards Institute (CLSI) listed the MIC breakpoint for a susceptible-only category to azithromycin, but breakpoints for disk diffusion are not yet available. In this study, we evaluated the usefulness of disk diffusion for testing the susceptibility of N. gonorrhoeae isolates to azithromycin. A total of 189 clinical isolates susceptible and nonsusceptible to azithromycin were used. Agar dilution MICs were correlated with inhibition zone diameters of azithromycin disks (15-µg) manufactured by BBL and Oxoid. In addition, an interlaboratory study involving two clinical microbiology laboratories was conducted. There was a strong correlation between disk diffusion and agar dilution for BBL disks (r = -0.74; P < 0.001) and Oxoid disks (r = -0.75; P < 0.001). Using a zone diameter breakpoint of ≥27 mm (susceptible) and ≤26 mm (nonsusceptible) yielded good separation between susceptible and nonsusceptible isolates and the least number of discrepancies. Compared to agar dilution, disk diffusion showed high agreement and kappa values of 95.2% and 0.899 (P < 0.001) for BBL disks and 96.8% and 0.933 (P < 0.001) for Oxoid disks, respectively. Major and very major discrepancies were observed in isolates with azithromycin MICs (1 and 2 µg/ml, respectively) near to the breakpoint. These data illustrate that disk diffusion could be a reliable method in clinical laboratories to test susceptibility to azithromycin in N. gonorrhoeae isolates.
Assuntos
Gonorreia , Neisseria gonorrhoeae , Ágar , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Azitromicina/farmacologia , Gonorreia/tratamento farmacológico , Humanos , Testes de Sensibilidade MicrobianaRESUMO
Hydrogels of TEMPO-oxidized nanocellulose were stabilized for dry-jet wet spinning using a shell of cellulose dissolved in 1,5-diazabicyclo[4.3.0]non-5-enium propionate ([DBNH][CO2Et]), a protic ionic liquid (PIL). Coagulation in an acidic water bath resulted in continuous core-shell filaments (CSFs) that were tough and flexible with an average dry (and wet) toughness of â¼11 (2) MJ·m-3 and elongation of â¼9 (14) %. The CSF morphology, chemical composition, thermal stability, crystallinity, and bacterial activity were assessed using scanning electron microscopy with energy-dispersive X-ray spectroscopy, liquid-state nuclear magnetic resonance, Fourier transform infrared spectroscopy, thermogravimetric analysis, pyrolysis gas chromatography-mass spectrometry, wide-angle X-ray scattering, and bacterial cell culturing, respectively. The coaxial wet spinning yields PIL-free systems carrying on the surface the cellulose II polymorph, which not only enhances the toughness of the filaments but facilities their functionalization.
Assuntos
Celulose/síntese química , Hidrogéis/síntese química , Líquidos Iônicos/síntese química , Nanofibras/química , Celulose/análise , Cromatografia Gasosa-Espectrometria de Massas/métodos , Hidrogéis/análise , Líquidos Iônicos/análise , Nanofibras/análise , Resistência à TraçãoRESUMO
BACKGROUND: Neisseria gonorrhoeae isolates with reduced susceptibility or resistance to the recommended first-line antimicrobial therapy have been described in several countries. The purpose of this study was to use genome analyses to compare the molecular characteristics of N. gonorrhoeae isolates with decreased susceptibility to extended-spectrum cephalosporin from Ontario, Canada, and Argentina. METHODS: A total of 128 N. gonorrhoeae isolates, collected in 2015, were included. The susceptibility to penicillin G, tetracycline, ciprofloxacin, cefixime, ceftriaxone, and azithromycin was determined using the agar dilution method. Isolates were subjected to whole genome sequencing, and an in silico analysis was performed to identify antimicrobial resistance determinants and for genotyping. RESULTS: Decreased susceptibility to extended-spectrum cephalosporin was mainly associated with penA mosaic allele 34.001, together with an mtrR promoter A deletion and porB1b alterations G120K/A121N. N. gonorrhoeae multiantigen sequence typing ST1407 or closely related genotypes were identified circulating in both regions. CONCLUSIONS: An international multi-drug resistant clone of N. gonorrhoeae was associated with decreased susceptibility to extended-spectrum cephalosporin (ESC) in 2 different regions in America. Evidence of clonal dissemination of the organism in some regions suggests that the strength of surveillance programs and establishment of collaborative projects are essential.
Assuntos
Antibacterianos/farmacologia , Cefalosporinas/farmacologia , Farmacorresistência Bacteriana Múltipla/genética , Neisseria gonorrhoeae/efeitos dos fármacos , Neisseria gonorrhoeae/genética , Sequenciamento Completo do Genoma , Adolescente , Adulto , Idoso , Argentina , Criança , Pré-Escolar , Simulação por Computador , Feminino , Genótipo , Geografia , Gonorreia/microbiologia , Humanos , Lactente , Masculino , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Ontário , Adulto JovemRESUMO
OBJECTIVES: Our aim was to describe the molecular epidemiology and antimicrobial resistance determinants of isolates of Neisseria gonorrhoeae with decreased susceptibility and resistance to extended-spectrum cephalosporins (ESCs) in Argentina in 2011-16. METHODS: Gonococcal isolates (n=158) with decreased susceptibility and resistance to ESCs collected in 2011-16 across Argentina were subjected to WGS and antimicrobial susceptibility testing for six antimicrobials. RESULTS: In total, 50% of the isolates were resistant to cefixime, 1.9% were resistant to ceftriaxone, 37.3% were resistant to azithromycin and 63.9% of the isolates showed an MDR phenotype. Resistance and decreased susceptibility to ESCs was mainly associated with isolates possessing the mosaic penA-34.001, in combination with an mtrR promoter A deletion, and PorB1b amino acid substitutions G120K/A121N. Phylogenetic analysis revealed two main clades of circulating strains, which were associated with the N. gonorrhoeae multiantigen sequence typing (NG-MAST) ST1407 and closely related STs, and characterized by a high prevalence rate, wide geographical distribution and temporal persistence. CONCLUSIONS: N. gonorrhoeae isolates with decreased susceptibility and resistance to ESCs in Argentina have emerged and rapidly spread mainly due to two clonal expansions after importation of one or two strains, which are associated with the international MDR NG-MAST ST1407 clone. The identification of the geographical dissemination and characteristics of these predominant clones may help to focus action plans and public health policies to control the spread of ESC resistance in Argentina. Dual antimicrobial therapy (ceftriaxone plus azithromycin) for gonorrhoea needs to be considered in Argentina.
Assuntos
Antibacterianos/farmacologia , Cefalosporinas/farmacologia , Farmacorresistência Bacteriana Múltipla/genética , Gonorreia/epidemiologia , Gonorreia/microbiologia , Neisseria gonorrhoeae/efeitos dos fármacos , Adolescente , Adulto , Argentina/epidemiologia , Criança , Pré-Escolar , Farmacorresistência Bacteriana , Feminino , Genoma Bacteriano , Humanos , Masculino , Testes de Sensibilidade Microbiana , Epidemiologia Molecular , Filogenia , Estudos Retrospectivos , Adulto JovemRESUMO
In the final process of the bleached kraft pulp there are some cellulose fibers that are separated from the main fibers stream; these fibers are rejected and considered as a low quality fibers, these fibers are known as rejected fiber (RF). In the present work the potential use of these fibers for Cellulose Nanocrystals (CNCs) synthesis was studied. The physical and chemical properties of synthesized CNCs were characterized through different techniques such as Atomic Force Microscopy (AFM), Scanning Electron Microscopy (SEM), X-Ray Diffraction (XRD), Fourier-Transform Infrared Spectroscopy (FTIR), and Thermogravimetric Analysis (TGA). Results demonstrate the feasibility of CNCs synthesis with a yield of 28.1% and 36.9%, and crystallinity of 73.5% and 82.7%. Finally, the morphology and synthesis conditions suggest that this industrial reject fiber (RF) could be used as a source for the CNCs production, thus adding value to the kraft process and opening new possibilities for innovation in the pulp industry.
RESUMO
BACKGROUND: The emergence of Neisseria gonorrhoeae strains with decreased susceptibility to cephalosporins represents a major concern globally. The aim of this study was to examine the phenotypic and molecular characteristics of N. gonorrhoeae isolates with decreased susceptibility to ceftriaxone and cefixime in Argentina. METHODS: A total of 1987 isolates were collected during 2009 and 2013. The susceptibility to penicillin G, tetracycline, ciprofloxacin, cefixime, ceftriaxone, and azithromycin was determined using the agar dilution method. The major extended-spectrum cephalosporin resistance determinants (penA, mtrR, and porB1b) were sequenced in 42 N. gonorrhoeae isolates that showed decreased susceptibility to ceftriaxone (minimum inhibitory concentration [MIC], 0.06-0.125 mg/L) and cefixime (MIC, 0.125-0.25 mg/L). Genotyping by N. gonorrhoeae multiantigen sequence typing (NG-MAST) was performed. RESULTS: Between 2009 and 2013, there was a shift in the modal MICs for ceftriaxone. Among the 42 isolates exhibiting decreased susceptibility to ceftriaxone and cefixime, 95.2% were resistant to penicillin G, 95.2% to tetracycline, 97.6% to ciprofloxacin, and 33.3% to azithromycin. Thirty-five (83.3%) of the 42 isolates had a mosaic penA allele XXXIV, which has been previously associated with resistance to ceftriaxone and cefixime as well as treatment failures. The isolates that contained the mosaic penicillin-binding protein 2 (PBP2) XXXIV were associated with NG-MAST ST1407 or closely related genotypes. CONCLUSIONS: In Argentina, N. gonorrhoeae isolates with decreased susceptibility to cefixime and ceftriaxone have now emerged, mostly due to the introduction of the internationally spread multidrug-resistant NG-MAST ST1407.