is an important opportunistic pathogen that commonly causes nosocomial infections and contributes to substantial morbidity and mortality. We sought to investigate the antibiotic resistance profile, ...pathogenic potential and the clonal relationships between
(
= 25) isolated from patients and sources at a tertiary care hospital's intensive care units (ICUs) in the northern region of Brazil. Most of
isolates (
= 21, 84%) were classified as multidrug resistant (MDR) with high-level resistance to β-lactams, aminoglycosides, quinolones, tigecycline, and colistin. All the 25 isolates presented extended-spectrum beta-lactamase-producing (ESBL), including carbapenemase producers, and carried the
(100%),
(100%),
variants (
= 24, 96%),
group (
= 21, 84%) and
group (
= 18, 72%) genes. The K2 serotype was found in 4% (
= 1) of the isolates, and the K1 was not detected. The virulence-associated genes found among the 25 isolates were
D (
= 24, 96%),
H-1 (
= 22, 88%),
B (100%),
A (
= 10, 40%),
S (
= 15, 60%). The genes related with efflux pumps and outer membrane porins found were
(100%),
C (
= 24, 96%),
K (
= 22, 88%),
K35 (
= 15, 60%), and
K36 (
= 7, 28%). ERIC-PCR was employed to determine the clonal relationship between the different isolated strains. The obtained ERIC-PCR patterns revealed that the similarity between isolates was above 70%. To determine the sequence types (STs) a multilocus sequence typing (MLST) assay was used. The results indicated the presence of high-risk international clones among the isolates. In our study, the wide variety of MDR
harboring β-lactams and virulence genes strongly suggest a necessity for the implementation of effective strategies to prevent and control the spread of antibiotic resistant infections.
Low density sugarcane plantation (LDSP) has been implemented by some sugarcane producers in Brazil, aiming to save seeds and operational costs. The study was carried out in the municipality of Areia, ...Paraíba, Brazil. Five planting densities were used, varying from 5 to 25 m-2 of buds arranged in randomized blocks, with four replications. Data were measured annually over three cultivation cycles (2017 to 2020), during which the field was fertilized with NPK and the harvests were carried out manually without prior burning. The lower planting density presents higher productivity only in the cane plant (101.03 t ha-1) due to the higher plant height (2.37 m) and the higher number of stalks (11 stalks m-2), suggesting that these variables are due to the greater availability of light, water and photosynthate. However, there is a drastic reduction in sugarcane yield for this lower population in the 2nd ratoon by up to 65.62%, which is correlated with number of stalks per meter. We demonstrate the agronomic viability of LDSP in the population of 10 buds m-2 in relation to conventional planting of sugarcane until the 2nd ratoon. Data are important for future studies to present additional considerations for other production factors, such as the effects of mechanized harvesting and the management of nutrients and water, assessing the sustainability of this large-scale planting system.
Abstract
Objectives
Gonorrhoea and antimicrobial resistance (AMR) in Neisseria gonorrhoeae are major public health concerns globally. Enhanced AMR surveillance for gonococci is essential worldwide; ...however, recent quality-assured gonococcal AMR surveillance in Latin America, including Brazil, has been limited. Our aims were to (i) establish the first nationwide gonococcal AMR surveillance, quality assured according to WHO standards, in Brazil, and (ii) describe the antimicrobial susceptibility of clinical gonococcal isolates collected from 2015 to 2016 in all five main regions (seven sentinel sites) of Brazil.
Methods
Gonococcal isolates from 550 men with urethral discharge were examined for susceptibility to ceftriaxone, cefixime, azithromycin, ciprofloxacin, benzylpenicillin and tetracycline using the agar dilution method, according to CLSI recommendations and quality assured according to WHO standards.
Results
The levels of resistance (intermediate susceptibility) to tetracycline, ciprofloxacin, benzylpenicillin and azithromycin were 61.6% (34.2%), 55.6% (0.5%), 37.1% (60.4%) and 6.9% (8.9%), respectively. All isolates were susceptible to ceftriaxone and cefixime using the US CLSI breakpoints. However, according to the European EUCAST cefixime breakpoints, 0.2% (n = 1) of isolates were cefixime resistant and 6.9% (n = 38) of isolates had a cefixime MIC bordering on resistance.
Conclusions
This study describes the first national surveillance of gonococcal AMR in Brazil, which was quality assured according to WHO standards. The high resistance to ciprofloxacin (which promptly informed a revision of the Brazilian sexually transmitted infection treatment guideline), emerging resistance to azithromycin and decreasing susceptibility to extended-spectrum cephalosporins necessitate continuous surveillance of gonococcal AMR and ideally treatment failures, and increased awareness when prescribing treatment in Brazil.
Radioactive ^{27}Mg (t_{1/2}=9.5 min) was implanted into GaN of different doping types at CERN's ISOLDE facility and its lattice site determined via β^{-} emission channeling. Following ...implantations between room temperature and 800 °C, the majority of ^{27}Mg occupies the substitutional Ga sites; however, below 350 °C significant fractions were also found on interstitial positions ∼0.6 Å from ideal octahedral sites. The interstitial fraction of Mg was correlated with the GaN doping character, being highest (up to 31%) in samples doped p type with 2×10^{19} cm^{-3} stable Mg during epilayer growth, and lowest in Si-doped n-GaN, thus giving direct evidence for the amphoteric character of Mg. Implanting above 350 °C converts interstitial ^{27}Mg to substitutional Ga sites, which allows estimating the activation energy for migration of interstitial Mg as between 1.3 and 2.0 eV.
Chitosan (CS) is a promising biopolymer and has been tested as a complement to the action and compensation of toxicity presented by anti-tuberculosis drugs. The present work studied the adjuvant ...effect of CS with the drug ethambutol (EMB) as a compound (CS-EMB), to explore its antimicrobial and cytotoxic activity, using transmission electron microscopy (TEM), to examine ultracellular changes that represent possible antimycobacterial action of CS on
Mycobacterium tuberculosis
(
Mtb
). Antimycobacterial activities were tested against reference strains
Mtb
ATCC® H37Rv and multidrug resistant (MDR). In vitro cytotoxicity tests were performed on Raw 264.7. For the studied compounds, morphological, ultrastructural, and physical–chemical analyses were performed. Drug-polymer interactions that occur through the H bridges were confirmed by physical–chemical analyses. The CS-EMB compound is stable at pHs of 6.5–7.5, allowing its release at physiological pH. The antibacterial activity (minimum inhibitory concentration) of the CS-EMB compound was 50% greater than that of the EMB in the H37Rv and MDR strains and the ultrastructural changes in the bacilli observed by TEM proved that the CS-EMB compound has a bactericidal action, allowing it to break down the
Mtb
cell wall. The cytotoxicity of CS-EMB was higher than that of isolated EMB, IC50 279, and 176 μg/mL, respectively. It is concluded that CS-EMB forms a promising composite against strains
Mtb
H37Rv and multidrug resistant (MDR-TB).
Key points
•
Our study will be the first to observe ultrastructurally the effects of the CS-EMB compound on Mtb cells.
•
CS-EMB antimicrobial activity in a multidrug-resistant clinical strain.
•
The CS-EMB compound has promising potential for the development of a new drug to fight tuberculosis.
Biomass burning in the Brazilian Amazon is modulated by climate factors, such as droughts, and by human factors, such as deforestation, and land management activities. The increase in forest fires ...during drought years has led to the hypothesis that fire activity decoupled from deforestation during the twenty-first century. However, assessment of the hypothesis relied on an incorrect active fire dataset, which led to an underestimation of the decreasing trend in fire activity and to an inflated rank for year 2015 in terms of active fire counts. The recent correction of that database warrants a reassessment of the relationships between deforestation and fire. Contrasting with earlier findings, we show that the exacerbating effect of drought on fire season severity did not increase from 2003 to 2015 and that the record-breaking dry conditions of 2015 had the least impact on fire season of all twenty-first century severe droughts. Overall, our results for the same period used in the study that originated the fire-deforestation decoupling hypothesis (2003-2015) show that decoupling was clearly weaker than initially proposed. Extension of the study period up to 2019, and novel analysis of trends in fire types and fire intensity strengthened this conclusion. Therefore, the role of deforestation as a driver of fire activity in the region should not be underestimated and must be taken into account when implementing measures to protect the Amazon forest.
Sister chromatids are tethered together by the cohesin complex from the time they are made until their separation at anaphase. The ability of cohesin to tether sister chromatids together depends on ...acetylation of its Smc3 subunit by members of the Eco1 family of cohesin acetyltransferases. Vertebrates express two orthologs of Eco1, called Esco1 and Esco2, both of which are capable of modifying Smc3, but their relative contributions to sister chromatid cohesion are unknown. We therefore set out to determine the precise contributions of Esco1 and Esco2 to cohesion in vertebrate cells. Herewe show that cohesion establishment is critically dependent upon Esco2. Although most Smc3 acetylation is Esco1 dependent, inactivation of the ESCO1 gene has little effect on mitotic cohesion. The unique ability of Esco2 to promote cohesion is mediated by sequences in the N terminus of the protein. We propose that Esco1-dependent modification of Smc3 regulates almost exclusively the noncohesive activities of cohesin, such as DNA repair, transcriptional control, chromosome loop formation, and/or stabilization. Collectively, our data indicate that Esco1 and Esco2 contribute to distinct and separable activities of cohesin in vertebrate cells.
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