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Flexible electronics have introduced new challenges for efficient human-machine interactions. Hydrogels have emerged as prominent materials for electronic wearable applications due to their exceptional mechanical deformability and lightweight characteristics combined in some cases with conductive properties, and softness. Additionally, bio-interphases require multisensory response to stress, strain, temperature, and self-healing capacity. To mimic these properties, this work developed interpenetrated hydrogel networks composed of chitosan (CHI) and polyacrylic acid (PAA), combined with Fe (III) ions and varying amounts of NMBA (0-0.25 %), to achieve tailored conductivity (0.8-2.5 mS/cm), self-healing, self-standing and mechanical properties (E = 11.7-110 Pa and fracture strain = 64.9-1923 %) suitable for strain sensor applications. The results revealed a significant influence of the restrictive effect on the mobility of uncrosslinked chain segments, caused by Fe ions and NMBA, on the piezoresistance (GF 2.1-1.3) and self-healing capability of the gels. Interestingly, a transparent/turbid transition, driven by microphase separation that is characteristic of systems with high dynamic interactions, was encountered for the first time in these hydrogels. This transition was analyzed in relation to external temperature, water content, pH, and the influence of Fe ions and NMBA. The simultaneous sensitivity of these materials to temperature and pH, along with their piezoresistive and self-healing behaviour, can be highly valuable for multifunctional sensors in a wide range of applications., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)

Aims: This study aimed to investigate the presence of beta-lactams resistance genes and the clonal relationship of clinical isolates of Enterobacterales obtained from patients with and without COVID-19, in a hospital in northeastern Brazil., Methods and Results: The study analyzed 45 carbapenem-resistant clinical isolates using enterobacterial repetitive intergenic consensus (ERIC-PCR), PCR, and amplicon sequencing to detect resistance genes (blaKPC, blaGES, blaNDM, blaVIM, and blaIMP). The main species were Klebsiella pneumoniae, Serratia marcescens, and Proteus mirabilis. Detected genes included blaNDM (46.66%), blaKPC (35.55%), and both (17.79%). ERIC-PCR showed multiclonal dissemination and high genetic variability. The main resistance gene was blaNDM, including blaNDM-5 and blaNDM-7., Conclusions: The presence of Enterobacterales carrying blaKPC and blaNDM in this study, particularly K. pneumoniae, in infections and colonizations of patients with COVID-19 and non-COVID-19, highlights genetic variability and resistance to carbapenems observed in multiple species of this order., (© The Author(s) 2024. Published by Oxford University Press on behalf of Applied Microbiology International.)

Aims: To investigate the genetic profile and characterize antimicrobial resistance, including the main β-lactam antibiotic resistance genes, in Acinetobacterbaumannii isolates from a tertiary hospital in Recife-PE, Brazil, in the post-COVID-19 pandemic period., Methods and Results: Acinetobacter baumannii isolates were collected between 2023 and 2024 from diverse clinical samples. Antimicrobial resistance testing followed standardized protocols, with β-lactamase-encoding genes detected via PCR and sequencing. Investigation into ISAba1 upstream of blaOXA-carbapenemase and blaADC genes was also conducted. Genetic diversity was assessed through ERIC-PCR. Among the 78 A. baumannii, widespread resistance to multiple antimicrobials was evident. Various acquired β-lactamase-encoding genes (blaOXA-23,-24,-58,-143, blaVIM, and blaNDM) were detected. Furthermore, this is the first report of blaVIM-2 in A. baumannii isolates harboring either the blaOXA-23-like or the blaOXA-143 gene in Brazil. Molecular typing revealed a high genetic heterogeneity among the isolates, and multi-clonal dissemination., Conclusion: The accumulation of genetic resistance determinants underscores the necessity for stringent infection control measures and robust antimicrobial stewardship programs to curb multidrug-resistant strains., (© The Author(s) 2024. Published by Oxford University Press on behalf of Applied Microbiology International.)

Aims: Investigated and compared the occurrence of virulence genes fimH, mrkD, irp2, entB, cps, rmpA, and wabG, resistance genes blaKPC and blaNDM, and the genetic variability and clonal relationship of 29 Klebsiella pneumoniae clinical isolates of patients with and without COVID-19, from a hospital in Brazil., Methods and Results: All isolates were resistant to beta-lactams. The genes were investigated by PCR, and for molecular typing, enterobacterial repetitive intergenic consensus-polymerase chain reaction (ERIC-PCR) and MLST were used. The detection of blaNDM was greater (n = 23) when compared to that of blaKPC (n = 14). The virulence genes that most occurred were fimH, entB, cps, and wabG, which are responsible for adhesins, siderophore enterobactin, capsule, and lipopolysaccharides, respectively. Among the isolates, 21 distinct genetic profiles were found by ERIC-PCR, with multiclonal dissemination. Four isolates belonged to the ST11 clone., Conclusions: The occurrence of the ST11 is worrying as it is a high-risk clone involved in the dissemination of virulent strains throughout the world., (© The Author(s) 2024. Published by Oxford University Press on behalf of Applied Microbiology International.)

This study aimed to co-encapsulate ceftazidime and tobramycin in zein nanoparticles coated with chitosan and to characterize and evaluate the antibacterial and antibiofilm activity against antibiotic-resistant Pseudomonas aeruginosa and Klebsiella pneumoniae . Zein nanoparticles, synthesized using the nanoprecipitation method, were characterized by their particle size (Ø), polydispersity index (PDI), zeta potential (ζ), pH, and encapsulation efficiency (%EE). The chitosan coating provided stability, and physicochemical analyses revealed chemical interactions, efficient drug encapsulation, and thermal stability. The release kinetics demonstrated controlled release in simulated gastric and intestinal pH. The antibacterial activity, assessed by minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC), indicated effectiveness against both pathogens. Antibiofilm assays, conducted using the crystal violet method, demonstrated the inhibition and eradication of biofilms. The chitosan-coated zein nanoparticles with CAZ and/or TOB exhibited Ø (315-335 nm), PDI (<0.2), ζ (+40 to +50 mV), pH (5), and %EE (>55%). Notably, the co-encapsulation formulation (CAZ-TOB-ZNP-CH) showed enhanced antibacterial and antibiofilm activities compared to the individual formulations. These findings suggest that the developed nanoparticles present a promising alternative for treating respiratory and intestinal infections caused by antibiotic-resistant and biofilm-producing P. aeruginosa and K. pneumoniae .

The present work aimed to develop, characterize, and evaluate the antibacterial and antibiofilm activity of two nanoemulsions (NEs) containing 500 µg/mL of curcumin from Curcuma longa (CUR). These NEs, produced with heating, contain olive oil (5%) and the surfactants tween 80 (5%) and span 80 (2.5%), water q.s. 100 mL, and were stable for 120 days. NE-2-CUR presented Ø of 165.40 ± 2.56 nm, PDI of 0.254, ζ of - 33.20 ± 1.35 mV, pH of 6.49, and Entrapment Drug Efficiency (EE) of 99%. The NE-4-CUR showed a Ø of 105.70 ± 4.13 nm, PDI of 0.459, ζ of - 32.10 ± 1.45 mV, pH of 6.40 and EE of 99.29%. Structural characterization was performed using DRX and FTIR, thermal characterization using DSC and TG, and morphological characterization using SEM, suggesting that there is no significant change in the CUR present in the NEs and that they remain stable. The MIC was performed by the broth microdilution method for nine gram-positive and gram-negative bacteria, as well as Klebsiella pneumoniae clinical isolates resistant to antibiotics and biofilm and efflux pump producers. The NEs mostly showed a bacteriostatic profile. The MIC varied between 125 and 250 µg/mL. The most sensitive bacteria were Staphylococcus aureus and Enterococcus faecalis, for which NE-2-CUR showed a MIC of 125 µg/mL. The NEs and ceftazidime (CAZ) interaction was also evaluated against the K. pneumoniae resistant clinical isolates using the Checkerboard method. NE-2-CUR and NE-4-CUR showed a synergistic or additive profile; there was a reduction in CAZ MICs between 256 times (K26-A2) and 2 times (K29-A2). Furthermore, the NEs inhibited these isolates biofilms formation. The NEs showed a MBIC ranging from 15.625 to 250 µg/mL. Thus, the NEs showed physicochemical characteristics suitable for future clinical trials, enhancing the CAZ antibacterial and antibiofilm activity, thus becoming a promising strategy for the treatment of bacterial infections caused by multidrug-resistant K. pneumoniae. KEY POINTS: • The NEs showed physicochemical characteristics suitable for future clinical trials. • The NEs showed a synergistic/additive profile, when associated with ceftazidime. • The NEs inhibited biofilm formation of clinical isolates., (© 2024. The Author(s).)

Ethnopharmacological Relevance: Amburana cearensis (Allemão) A.C. Smith is a medicinal plant with wide distribution in South America, popularly known in Brazil as "cumaru" or "amburana de cheiro". In folk medicine, in the semi-arid region of Northeastern Brazil, infusions, teas and decoctions of leaves of Amburana cearensis have their practical use for treating fever, gastrointestinal disorders, inflammation, and inflammation pain. However, none of the ethnopharmacological properties has been scientifically evaluated using volatile compounds obtained from its leaves (essential oil)., Aim of the Study: This study investigated the chemical composition, acute oral toxicity, and antinociceptive and anti-inflammatory activities of the essential oil from the leaves of A. cearensis., Material and Methods: The acute toxicity of the essential oil was investigated in mice. The antinociceptive effect was evaluated using the formalin test and, abdominal writhing induced by acetic acid, being investigated the possible mechanisms of action involved in antinociception. The acute anti-inflammatory effect was investigated through models of carrageenan-induced peritonitis, yeast-induced pyrexia, and carrageenan- and histamine-induced paw inflammation., Results: No acute toxicity was observed at doses up to 2000 mg/kg; p.o. The antinociceptive effect was statistically equal to morphine. In the formalin assay, the oil showed analgesic activity in the neurogenic and inflammatory phases, having as mechanisms the cholinergic, adenosinergic system, and ATP-sensitive potassium channels (K-ATP). In peritonitis, a reduction in TNF-α and IL-1β levels and leukocyte migration were observed. The antipyretic effect was statistically superior to dipyrone. The reduction in paw edema was statistically superior to the standard in both models., Conclusion: The results obtained not only support the traditional use of the species in inflammatory conditions and pain in folk medicine but also demonstrate that this is a rich source of phytocomponents such as germacrone, which can be used as a natural and sustainable therapeutic agent with industrial applications., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Aims: Determine which sequence type (ST) clones were carrying the blaKPC, blaNDM, blaVIM, blaIMP, and blaGES genes and their variants in clinical isolates of multidrug-resistant Klebsiella pneumoniae., Methods and Results: Ten K. pneumoniae isolates were obtained from the colonized and infected patients in a public hospital in the city of Recife-PE, in northeastern Brazil, and were further analyzed. The detection of carbapenem resistance genes and the seven housekeeping genes [for multilocus sequence typing (MLST) detection] were done with PCR and sequencing. The blaKPC and blaNDM genes were detected concomitantly in all isolates, with variants being detected blaNDM-1, blaNDM-5, blaNDM-7, and blaKPC-2. The blaKPC-2 and blaNDM-1 combination being the most frequent. Molecular typing by MLST detected three types of high-risk ST clones, associated with the clonal complex 258, ST11/CC258 in eight isolates, and ST855/CC258 and ST340/CC258 in the other two isolates., Conclusions: These findings are worrying, as they have a negative impact on the scenario of antimicrobial resistance, and show the high genetic variability of K. pneumoniae and its ability to mutate resistance genes and risk of dissemination via different ST clones., (© The Author(s) 2023. Published by Oxford University Press on behalf of Applied Microbiology International.)

The COVID-19 pandemic has engendered significant scientific efforts in the understanding of its infectious agent SARS-CoV-2 and of its associated symptoms. A peculiar characteristic of this virus lies in its ability to challenge our senses, as its infection can lead to anosmia and ageusia. While ocular symptoms, such as conjunctivitis, optic neuritis or dry eyes, are also reported after viral infection, they have lower frequencies and severities, and their functional development is still elusive. Here, using combined technical approaches based on histological and gene profiling methods, we characterized the expression of SARS-CoV-2 binding sites ( Ace2/Tmprss2 ) in the mouse eye. We found that ACE2 was ectopically expressed in subtissular ocular regions, such as in the optic nerve and in the Harderian/intraorbital lacrimal glands. Moreover, we observed an important variation of Ace2 / Tmprss2 expression that is not only dependent on the age and sex of the animal, but also highly heterogenous between individuals. Our results thus give new insight into the expression of SARS-CoV-2 binding sites in the mouse eye and propose an interpretation of the human ocular-associated symptoms linked to SARS-CoV-2.

Food preference is conserved from the most primitive organisms to social animals including humans. A continuous integration of olfactory cues present both in food and in the different environmental and physiological contexts favors the intake of a given source of food or its avoidance. Remarkably, in mice, food preference can also be acquired by olfactory communication in-between conspecifics, a behavior known as the social transmission of food preference (STFP). STFP occurs when a mouse sniffs the breath of a conspecific who has previously eaten a novel food emitting specific odorants and will then develop a preference for this never encountered food. The efficient discrimination of odorants is performed by olfactory sensory neurons (OSNs). It is essential and supports many of the decision-making processes. Here, we found that the olfactory marker protein (OMP), an enigmatic protein ubiquitously expressed in all mature olfactory neurons, is involved in the fine regulation of OSNs basal activity that directly impacts the odorant discrimination ability. Using a previously described Omp null mouse model, we noticed that although odorants and their hedonic-associated values were still perceived by these mice, compensatory behaviors such as a higher number of sniffing events were displayed both in the discrimination of complex odorant signatures and in social-related contexts. As a consequence, we found that the ability to differentiate the olfactory messages carried by individuals such as those implicated in the social transmission of food preference were significantly compromised in Omp null mice. Thus, our results not only give new insights into the role of OMP in the fine discrimination of odorants but also reinforce the fundamental implication of a functional olfactory system for food decision-making., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 de Vallière, Lopes, Addorisio, Gilliand, Nenniger Tosato, Wood, Brechbühl and Broillet.)

Soft materials are attracting much attention for the development of biostructures able to mimic the movement of natural systems by remote actuation. Multi-sensitive hydrogels are among the best materials for obtaining dynamic and biocompatible soft structures for soft actuators and related biomedical devices. Nevertheless, bioinks based on naturally occurring and stimuli responsive hydrogels able to be 3D printed continues being a challenge for advanced applications. In this work 3D printable electrically and magnetically responsive, non-cytotoxic, hybrid hydrogels based on alginate and zero monovalent iron nanoparticles (NPs) are presented. The effect of NPs addition on the physico-chemical properties of the hydrogels is addressed, together with its effect on the functional electroactive and magnetoactive response. NPs concentration up to 10 % do not affect the mechanical stability of the gels, while promoting an increase actuation response., Competing Interests: Declaration of competing interest None., (Copyright © 2022 The Authors. Published by Elsevier B.V. All rights reserved.)

To characterize phenotypically and genotypically an isolate of multidrug-resistant (MDR) K. pneumoniae from a patient with septicemia in a hospital in Recife-PE, Brazil, resistance and virulence genes were investigated using PCR and sequencing the amplicons, and the plasmid DNA was also sequenced. The K74-A3 isolate was resistant to all β-lactams, including carbapenems, as well as to aminoglycosides and quinolones. By conducting a PCR analysis and sequencing, the variants bla NDM-7 associated with bla KPC-2 and the cps, wabG, fim-H, mrkD and entB virulence genes were identified. The analysis of plasmid revealed the presence of bla CTX-M15 , aac(3)-IVa, aph(3')-Ia, aph(4)-Ia, aac(6')ib-cr, mph(A) and catB3, and also the plasmids IncX3, IncFIB, IncQ1, ColRNAI and ColpVC. To our knowledge, this is the first report of the bla NDM-7 gene in Recife-PE and we suggest that this variant is located in IncX3. These results alert us to the risk of spreading an isolate with a vast genetic arsenal of resistance, in addition to which several plasmids are present that favor the horizontal transfer of these genes., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Magnetoelastic resonators are gaining attention as an incredibly versatile and sensitive transduction platform for the detection of varied physical, chemical, and biological parameters. These sensors, based on the coupling effect between mechanical and magnetic properties of ME platforms, stand out in comparison to alternative technologies due to their low cost and wireless detection capability. Several parameters have been optimized over the years to improve their performance, such as their composition, surface functionalization, or shape geometry. In this review, the working principles, recent advances, and future perspectives of magnetoelastic resonance transducers are introduced, highlighting their potentials as a versatile platform for sensing applications. First, the fundamental principles governing the magnetoelastic resonators performance are introduced as well as the most common magnetoelastic materials and their main fabrication methods are described. Second, the versatility and technical feasibility of magnetoelastic resonators for biological, chemical, and physical sensing are highlighted and the most recent results and functionalization processes are summarized. Finally, the forefront advances to further improve the performance of magnetoelastic resonators for sensing applications have been identified.

Introduction: Proteus mirabilis is one of the main pathogens that cause urinary tract infections. Therefore, the aim of this study was to analyze and compare the genetic profile of 36 clinical isolates of P. mirabilis that carry and do not carry the bla KPC and bla NDM gene with respect to virulence factors (mrpG, pmfA, ucaA, nrpG and pbtA) and antimicrobial resistance (bla VIM, bla IMP , bla SPM , bla GES, bla OXA-23-like , bla OXA-48-like , bla OXA-58-like and bla OXA-10-like )., Methods: The virulence and resistance genes were investigated by using PCR and sequencing., Results: ERIC-PCR typing showed that the isolates showed multiclonal dissemination and high genetic variability. The gene that was most found bla OXA-10-like (n = 18), followed by bla KPC (n = 10) and bla NDM (n = 8). To our knowledge, this is the first report of bla OXA-10 in P. mirabilis in Brazil, as well as the first report of the occurrence of P. mirabilis co-carrying bla OXA-10 /bla KPC and bla OXA-10 /bla NDM . The bla NDM or bla KPC carrier isolates showed important virulence genes, such as ucaA (n = 8/44.4%), pbtA (n = 10/55.5%) and nrpG (n = 2/11.1%). However, in general, the non-carrier isolates of bla KPC and bla NDM showed a greater number of virulence genes when compared to the carrier group., Conclusion: Clinical isolates of P. mirabilis, in addition to being multi-drug resistant, presented efficient virulence factors that can establish infection outside the gastrointestinal tract., (Copyright © 2021 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.)

In the wild, mice have developed survival strategies to detect volatile cues that warn them of potential danger. Specific olfactory neurons found in the Grueneberg ganglion olfactory subsystem can detect alarm pheromones emitted by stressed conspecifics, as well as kairomones involuntarily released by their predators. These volatile chemical cues allow intra- and interspecies communication of danger, respectively. Alarm pheromones, kairomones and bitter taste ligands share a common chemical motif containing sulfur or nitrogen. Interestingly, three specific bitter taste receptors (TAS2Rs) have been found in the Grueneberg ganglion neurons that are implicated in danger signalling pathways. We have recently developed a TAS2R-expressing heterologous system that mimics the Grueneberg ganglion neuron responses after kairomone stimulation. Here, we demonstrated by in vitro, ex vivo and in vivo experiments that the biological secretions from the raccoon ( Procyon lotor ) and the skunk ( Mephitis mephitis ) were acting as potent sources of kairomones. They activated the Grueneberg ganglion neurons and induced fear-related behaviours in mice. Identification of new sources of semiochemicals is a first step towards an understanding of the interspecies danger communication that takes place in the Grueneberg ganglion.

COVID-19 pandemic has given rise to a collective scientific effort to study its viral causing agent SARS-CoV-2. Research is focusing in particular on its infection mechanisms and on the associated-disease symptoms. Interestingly, this environmental pathogen directly affects the human chemosensory systems leading to anosmia and ageusia. Evidence for the presence of the cellular entry sites of the virus, the ACE2/TMPRSS2 proteins, has been reported in non-chemosensory cells in the rodent's nose and mouth, missing a direct correlation between the symptoms reported in patients and the observed direct viral infection in human sensory cells. Here, mapping the gene and protein expression of ACE2/TMPRSS2 in the mouse olfactory and gustatory cells, we precisely identify the virus target cells to be of basal and sensory origin and reveal the age-dependent appearance of viral entry-sites. Our results propose an alternative interpretation of the human viral-induced sensory symptoms and give investigative perspectives on animal models., (© 2021. The Author(s).)

Ethnopharmacological Relevance: Verbesina macrophylla (Cass.) S.F.Blake is a medicinal plant from South America, popularly known as "asa de peixe", "asa de peixe branco", "cambará branco" or "cambará guaçu", being used by traditional communities for its healing powers in the form of teas, infusions, liqueurs and extracts, for the treatment of bacterial and fungal infections of the urinary and respiratory tracts, such as kidney problems, bronchitis, inflammation and fever. However, none of the ethnopharmacological properties has been scientifically evaluated., Aim of the Study: Based on the ethnopharmacological use of the species, this study investigated the chemical composition, and for the first time acute toxicity, hemolytic, antimicrobial, anti-inflammatory and antipyretic activities of the essential oil from leaves of V. macrophylla., Material and Methods: The essential oil was obtained from the leaves by hydrodistillation (HD), being characterized by gas chromatography coupled to mass spectrometry (GC-MS) and gas chromatography coupled to flame ionization detection (GC-FID). The antimicrobial activity was evaluated by the broth microdilution technique in bacteria and fungi that cause infections of the respiratory and urinary tract, and toxicological safety regarding hemolytic activity on human red blood cells (hRBCs), and acute toxicity in mice. The anti-inflammatory activity was evaluated by the model carrageenan-induced peritonitis with quantification of the levels of TNF-α and IL-1β in the intraperitoneal fluid, and ear edema induced by croton oil. The antipyretic activity evaluated in mice with pyrexia induced by yeast., Results: The extraction of essential oil by hydrodistillation (HD) showed a yield of 0.33 ± 0.04%, with its composition constituted mainly by sesquiterpenes of hydrocarbons (94.00%). The essential oil demonstrated antibacterial and antifungal activity, with a low rate of hemolysis in human red blood cells (hRBCs) and no clinical signs of toxicity were observed in animals after acute treatment, which suggested that the LD 50 is greater than 5000 mg/kg; p.o. The essential oil demonstrated anti-inflammatory activity reducing levels of pro-inflammatory cytokines TNF-α (38.83%, 72.42% and 73.52%) and IL-1β (37.70%, 75.92% and 87.71%), and ear edema by 49.53%, 85.04% and 94.39% at concentrations of 4, 40 and 400 mg/kg, respectively. The antipyretic activity presented by the essential oil is statistically similar to dipyrone., Conclusion: The set of results obtained, validates the main activities attributed to the traditional use of Verbesina macrophylla (Cass.) S.F.Blake. These data add industrial value to the species, considering that the antimicrobial, anti-inflammatory and antipyretic activities present results similar to the drugs already used also presenting safety. The results suggest that essential oil from V. macrophylla may be used by industry for the development of drugs with natural antimicrobial, anti-inflammatory and antipyretic effect., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Acute Cr VI water pollution due to anthropogenic activities is an increasing worldwide concern. The high toxicity and mobility of Cr VI makes it necessary to develop dual adsorbent/ion-reductive materials that are able to capture Cr VI and transform it efficiently into the less hazardous Cr III . An accurate description of chromium speciation at the adsorbent/ion-reductive matrix is key to assessing whether Cr VI is completely reduced to Cr III , or if its incomplete transformation has led to the stabilization of highly reactive, transient Cr V species within the material. With this goal in mind, a dual ultraviolet-visible and electron paramagnetic spectroscopy approach has been applied to determine the chromium speciation within zirconium-based metal-organic frameworks (MOFs). Our findings point out that the generation of defects at Zr-MOFs boosts Cr VI adsorption, whilst the presence of reductive groups on the organic linkers play a key role in stabilizing it as isolated and/or clustered Cr III ions., (© 2020 Wiley-VCH GmbH.)

Introduction: Antibiotic resistance in carbapenemase-producing Klebsiella pneumoniae is acquired and disseminated mainly by plasmids. Therefore, we aimed to investigate the occurrence of carbapenemase genes, analyze the genetic diversity by ERIC-PCR, and examine the most common plasmid incompatibility groups (Incs) in clinical isolates of K. pneumoniae from colonization and infection in patients from a hospital in Brazil., Methods: Twenty-seven isolates of carbapenem-resistant K. pneumoniae were selected and screened for the presence of carbapenemase genes and Incs by PCR, followed by amplicon sequencing., Results: The bla KPC and bla NDM genes were detected in 24 (88.8 %) and 16 (59.2 %) of the isolates, respectively. Thirteen isolates (48.1 %) were positive for both genes. The IncFIB (92.6 %) and IncQ (88.8 %) were the most frequent plasmids, followed by IncA/C, IncHI1B, and IncL/M, indicating that plasmid variability existed in these isolates. To our knowledge, this is the first report of IncHI1B in Brazil. We found eight isolates with clonal relationship distributed in different sectors of the hospital., Conclusions: The accumulation of resistance determinants, the variability of plasmid Incs, and the clonal dissemination detected in K. pneumoniae isolates demonstrate their potential for infection, colonization, and the dissemination of different resistance genes and plasmids.

Background: Strong evidence has suggested an important role of telomeres in meiosis, fertilization, and embryo development., Purpose: To determine if sperm telomere length (STL) in sperm purified by differential gradient centrifugation followed by swim-up (selected STL) is correlated with sperm quality and clinical outcomes., Methods: Relative selected STL was assessed by quantitative polymerase chain reaction (Q-PCR) in 78 consecutive assisted reproductive technology (ART) treatments during 2017. Statistical analyses were performed in the totality of patients, and in normozoospermic and non-normozoospermic patients. These included correlations between selected STL and sperm quality parameters, embryological parameters (multivariable linear regression), and clinical parameters (multivariable logistic regression)., Results: No significant correlations were found between selected STL and sperm quality in the total population. However, selected STL was significantly correlated with total sperm count (r = 0.361; P = 0.039) and sperm DNA fragmentation-post-acrosomal region pattern (r = - 0.464; P = 0.030) in normozoospermic patients. No relation was observed between selected STL and clinical outcomes in any clinical group., Conclusions: As the correlations observed in normozoospermic patients were not representative of the whole heterogeneous population, differences in the sperm characteristics of the study population may lead to discrepant results when evaluating the association of STL with sperm quality. Since the total population selected STL was not related with sperm quality and with clinical outcomes, results do not support the use of selected STL measurement to evaluate the reproductive potential of the male patient or to predict the success rates of ART treatments.

Objectives: Multidrug-resistant Klebsiella pneumoniae carrying bla NDM-1 and bla KPC-2 genes are a worldwide concern for which combination antimicrobial therapy may be the only viable option. The aim of this study was to investigate the in vitro activity of combinations of polymyxin B (PMB) with meropenem (MEM), amikacin (AMK) and gentamicin (GEN) at subinhibitory concentrations against two K. pneumoniae clinical isolates co-harbouring bla NDM-1 , bla KPC-2 and aminoglycoside-modifying enzymes and resistant to PMB., Methods: Synergy and bactericidal activity were evaluated by chequerboard and time-kill assays against two PMB-resistantK. pneumoniae clinical isolates carrying the bla NDM-1 , bla KPC-2 , aac(3)-IIa, aac(6')-Ib, aph(3')-VI and ant(2'')-Ia genes. Five combinations of PMB, MEM, AMK and GEN were evaluated., Results: The PMB/MEM and PMB/AMK combinations proved to be the best options against isolate K7R2, mainly because they demonstrated bactericidal activity when using subinhibitory concentrations of these antimicrobials. However, none of the studied combinations was bactericidal against isolate K11R2., Conclusion: The combinations used in this study showed synergy against NDM-and KPC-producing isolates but, given their bactericidal activity, the combinations of PMB/MEM and PMB/AMK were the most active against one isolate. It can also be concluded that the antimicrobials to which the bacteria were resistant could form part of combination therapy., (Copyright © 2020 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Proteus mirabilis is an opportunistic Gram-negative bacterium belonging to the family Enterobacteriaceae and is known for its ability to cause urinary tract infections. The aim of this study was to determine the value of the minimum concentration of cefazolin and meropenem on biofilm eradication, as well as the resistance profiles and genetic diversity of clinical and environmental isolates of P. mirabilis. We compared the isolates collected from a hospital environment and from an urban stream impacted in Recife-Pernambuco, Brazil. Biochemical tests were performed to determine the profiles of susceptibility, hydrophobicity, biofilm formation and eradication. The genetic diversity was verified using the ERIC-PCR method. The results revealed that two clinical isolates (ICP4 and ICP5) were multi-drug resistant, whereas the environmental isolates showed resistance only to tetracycline, except for CP 5 25S, which was resistant also to ampicillin. Of the isolates investigated, three were moderately hydrophobic, while the remaining were hydrophilic. Genetic diversity analysis verified the presence of clones indicating that the stream is harboring and disseminating bacteria of hospital origin. All isolates formed a biofilm, however, high concentrations of cefazolin and meropenem were required to eradicate the already formed biofilm. Our study analyzed the survival strategies of these bacteria in the environments investigated and corresponds to first report the use of these antibiotics to eliminate P. mirabilis biofilms.

Introduction: This study investigated the genetic environment of bla KPC-2 in Klebsiella pnemoniae multi-drug resistant clinical isolates., Methods: Four carbapenemase gene isolates resistant to carbapenems, collected from infected patients from two hospitals in Brazil, were investigated using polymerase chain reaction and plasmid DNA sequencing., Results: The bla KPC-2 gene was located between ISKpn6 and a resolvase tnpR in the non-Tn4401 element (NTEKPC-IId). It was detected on a plasmid belonging to the IncQ1 group., Conclusions: To our knowledge, this is the first report of the presence of the bla KPC-2 gene in the NTEKPC-IId element carried by plasmid IncQ1 from infections in Brazil.

Objectives: Carbapenemase-producing Enterobacterales are frequently involved in healthcare-associated infections worldwide. The objectives of this study were to investigate (i) the frequency of the main genes encoding carbapenemases, 16S rRNA methylases and aminoglycoside-modifying enzymes (AMEs) as well as the mcr gene and (ii) the clonal relationship of enterobacteria isolates resistant to carbapenems and aminoglycosides from colonisation and infection in patients from hospitals in northeastern Brazil., Methods: Antimicrobial susceptibility was determined using an automated VITEK®2 system. Presence of carbapenemase, AME and 16S rRNA methylase genes as well as the mcr gene was determined by PCR and amplicon sequencing. Genetic variability was determined by ERIC-PCR., Results: A total of 35 isolates resistant to carbapenems and aminoglycosides were selected for this study. Klebsiella pneumoniae was most common (45.7%), followed by Proteus mirabilis (28.6%) and Serratia marcescens (25.7%). AME genes were found in 97.1% of isolates, most commonly aph(3')-VI and aac(6')-Ib. The bla NDM-1 and bla KPC-2 genes were detected in 25.7% and 88.6% of isolates, respectively; five isolates harboured these genes concomitantly. According to the literature, this is the first report of the association of bla NDM-1 and bla KPC-2 in P. mirabilis and S. marcescens in Brazil. The isolates showed a multiclonal profile by ERIC-PCR., Conclusion: The emergence of bla NDM-1 associated with bla KPC-2 and AME genes in K. pneumoniae, P. mirabilis and S. marcescens isolates with a multiclonal profile is of concern as this limits therapeutic options. These results should alert medical authorities to establish rigorous detection methods to reduce the spread of these antimicrobial resistance genes., (Copyright © 2019 International Society for Antimicrobial Chemotherapy. Published by Elsevier Ltd. All rights reserved.)

We have performed a study of the magnetic, magnetoelastic, and corrosion resistance properties of seven different composition magnetoelastic-resonant platforms. For some applications, such as structural health monitoring, these materials must have not only good magnetomechanical properties, but also a high corrosion resistance. In the fabricated metallic glasses of composition Fe73-xNixCr5Si10B12, the Fe/Ni ratio was varied (Fe+Ni=73% at.) thus changing the magnetic and magnetoelastic properties. A small amount of chromium (Cr5) was added in order to achieve the desired good corrosion resistance. As expected, all the studied properties change with the composition of the samples. Alloys containing a higher amount of Ni than Fe do not show magnetic behavior at room temperature, while iron-rich alloys have demonstrated not only good magnetic properties, but also good magnetoelastic ones, with magnetoelastic coupling coefficient as high as 0.41 for x=0 in the Fe73Ni0Cr5Si10B12 (the sample containing only Fe but not Ni). Concerning corrosion resistance, we have found a continuous degradation of these properties as the Ni content increases in the composition. Thus, the corrosion potential decreases monotonously from 46.74 mV for the x=0, composition Fe73Ni0Cr5Si10B12 to -239.47 mV for the x=73, composition Fe0Ni73Cr5Si10B12., Competing Interests: The authors declare no conflict of interest.

Introduction: The objective of this study was to characterize genes of aminoglycoside modifying enzymes (AMEs) in colonizing and infecting isolates of E. aerogenes harboring bla KPC from patients at a public hospital in Recife-PE, Brazil., Methods: We analyzed 29 E. aerogenes clinical isolates resistant to aminoglycosides. AMEs genes were investigated by PCR and sequencing., Results: Colonizing and infecting isolates mainly presented the genetic profiles aac(3)-IIa/aph(3')-VI or ant(2")-IIa/aph(3')-VI. This is the first report of aph(3')-VI in E. aerogenes harboring bla KPC in Brazil., Conclusions: The results highlight the importance in establishing rigorous methods for the surveillance of resistance genes, especially in colonized patients.

Introduction: The emergence of New Delhi metallo-β-lactamase (NDM) is concernig because it reduces the antibiotic therapy options for bacterial infections., Methods: Resistant and virulent genes from an isolate of Klebsiella pneumoniae derived from a patient with sepsis in a hospital in Recife-PE, Brazil, were investigated using PCR and DNA sequencing., Results: bla NDM-1, aac(6')-Ib-cr and acrB resistance genes, and cps and mrkD virulence genes were detected., Conclusions: To our knowledge, this is the first report on bla NDM-1 in Recife-PE. This detection alerts researchers to the need to control the spread of bla NDM-1 resistance gene by this bacterium in Brazil.

Introduction: The relationships between phagocytosis, and mucoid phenotype, plasmid profile and virulence, and resistance genetic characteristics of Klebsiella pneumoniae clinical isolates were evaluated., Methods: Thirty isolates were used to determine the mucoid aspect. Four were selected for analysis of phagocytosis by alveolar macrophages., Results: Thirty percent of the samples presented the mucoid phenotype. The phagocytosis rate ranged from 21.5% to 43.43%. Phagocytosis was not correlated with the plasmid profile, but was apparently correlated with mucoid phenotype and antibiotic susceptibility., Conclusions: Several virulence factors act in parallel in K. pneumoniae to impair host defense.

This work aimed to investigate the chemical composition, antimicrobial, antinociceptive, acute toxicity and antioxidant activity of the essential oil of Algrizea minor (EOAm). The essential oil presented as the major constituents β-Pinene (56.99%), α-Pinene (16.57%), Germacrene D (4.67%), Bicyclogermacrene (4.66%), (E)-Caryophyllene (3.76%) and Limonene (1.71%). It was verified that the essential oil did not show acute toxicity in the maximum dose of 5,000 mg/kg. In the evaluation of the antinociceptive activity it was verified that the essential oil reduced in 65.84% the number of writhing in the mice, reducing the pain in 59.17%, and the mechanism of action in pain reduction was opioid, similar to morphine. The essential oil also presented significant antimicrobial against Gram positive and Gram-negative bacteria and fungi, and the antioxidant activity was relevant. Therefore, these results demonstrate the great potential for the future development of pharmaceutical products with the essential oil of Algrizea minor (EOAm).

DNA aptamers represent a way to target cancer cells at a molecular level and continue to be developed with a view to improve treatment and imaging in cancer medicine. AT11-L0, derived from the DNA sequence AT11, forms a single major parallel G-quadruplex (G4) conformation and exhibits an anti-proliferative activity similar to that of AT11 and AS1411 aptamers. On the other side, acridine orange derivatives represent a valuable class of G4 ligands. Herein, we evaluate AT11-L0 G4 as a supramolecular carrier for the delivery of acridine ligands C3, C5 and C8 to HeLa cancer cells. The CD titrations suggest no changes in the chiroptical signal upon addition of an excess of ligands maintaining the parallel G4 topology and C8 stabilizes the structure for more than 20 °C. All the ligands exhibit high affinity (micromolar range) towards AT11-L0 G4, and the respective complexes against nucleolin (nanomolar range) suggesting that the ligands do not negatively affect the recognition of the nucleolin by AT11-L0 G4. NMR studies showed that AT11-L0 forms a G4 containing four G-tetrad layers. Ligand C8 binds AT11-L0 G4 through π-π stacking of the acridine moiety onto the top-tetrad with the involvement of additional interactions with the ligand's side chain and iodobenzene ring. In vitro, the complexes lowered the ligand's cytotoxicity towards non-malignant cells but have a weak inhibitory effect in HeLa cancer cells, except for the AT11-L0-C5 complex. All complexes are efficiently internalized into nucleolin-positive HeLa cells. Overall, these results suggest that AT11-L0 can act as an aptamer by targeting nucleolin and a delivery system of cytotoxic ligands for cervical cancer.

The increase in urbanization and industrialization has contributed to the contamination of different environments by means of xenobiotic compounds, such as heavy metals, causing changes in microbial communities. Among these metals, the Mercury (Hg 2+ ) is one the most prevalent toxic metals for the environment The present study aimed to evaluate the effect of mercury on the formation of biofilm by environmental (collected from urban stream water) and clinical isolates of Klebsiella pneumoniae. In addition, antibiotic resistance, virulence factors, and genetic diversity were investigated. Taxonomic identity of eight isolates (one reference, two clinical, and five environmental isolates) was performed by MALDI-TOF-MS, while the antibiotic susceptibility profile was assessed by the disc diffusion method. The ability to form biofilms was evaluated by culture on Congo red agar and by crystal violet staining. Biofilm structure was analyzed by scanning electron microscopy. The hydrophobicity profile and the presence of the virulence genes cps, fimH, and mrkD was investigated. The presence of merA and its relationship with antimicrobial resistance were also assessed. The identity of all isolates was confirmed by MALDI-TOF-MS, and different profiles of resistance to mercury and antibiotics as well as of biofilm formation were identified for the clinical and environmental isolates. All isolates were hydrophilic and positive for the virulence genes cps, fimH, and mrkD; only the clinical isolate K36-A2 was positive for merA. The diversity of the isolates was confirmed by ERIC-PCR, which revealed high heterogeneity among the isolates. In conclusion, the data demonstrate that the investigated isolates present different responses to exposure to Hg 2+ and correspond to distinct populations of K. pneumoniae disseminated in the investigated environment. The data obtained in this work will aid in understanding the mechanisms of survival of this pathogen under adverse conditions., (Copyright © 2018. Published by Elsevier Inc.)

Sperm telomere length (STL) is a promising new parameter for sperm quality analysis that may elucidate the molecular mechanisms underlying the idiopathic cases of male factor infertility, which represent almost half of all the male factor infertility cases worldwide. Telomeres consist of nucleoprotein structures present at the ends of eukaryotic chromosomes, whose protective functions maintain the genomic stability. Their role in reproduction includes an active intervention during gametogenesis, fertilization, and preimplantation embryo development. In consonance, studies have shown that compromised telomere homeostasis is associated with male infertility. Since critically short telomeres have their function affected, assessing STL may be a fast and economic method for sperm quality analysis and expectantly contribute to improve the success of fertility treatments. This hypothesis is supported by several reports associating STL with seminal parameters, sperm genome integrity, and clinical outcomes. However, there are other studies in the literature that do not demonstrate these associations. Additionally, it is still not clear whether the lengthening mechanisms of telomeres occurring during early embryo development resume the inherited telomere length. Further research is essential to clarify the suitability of STL as a biomarker for male infertility, before it could be routinely implemented in medically assisted reproduction centers. Understanding the molecular mechanisms underlying STL function and dynamics will provide us new insights into the origins of male infertility and a possible new useful tool as an outcome predictor for assisted reproduction., (© The Author(s) 2018. Published by Oxford University Press on behalf of Society for the Study of Reproduction.)

The main parameters of magnetoelastic resonators in the detection of chemical (i.e., salts, gases, etc.) or biological (i.e., bacteria, phages, etc.) agents are the sensitivity S (or external agent change magnitude per Hz change in the resonance frequency) and the quality factor Q of the resonance. We present an extensive study on the experimental determination of the Q factor in such magnetoelastic resonant platforms, using three different strategies: (a) analyzing the real and imaginary components of the susceptibility at resonance; (b) numerical fitting of the modulus of the susceptibility; (c) using an exact mathematical expression for the real part of the susceptibility. Q values obtained by the three methods are analyzed and discussed, aiming to establish the most adequate one to accurately determine the quality factor of the magnetoelastic resonance., Competing Interests: The authors declare no conflict of interest.

Introduction: Pseudomonas aeruginosa, an important pathogen globally, presents several resistance mechanisms. This study aimed to investigate the presence of bla GES in clinical isolates of Pseudomonas aeruginosa obtained from various clinical specimens from patients admitted to three different hospitals in Recife, Brazil. The Guiana extended spectrum beta-lactamase (GES) enzymes are responsible for conferring broad spectrum resistance to beta-lactam drugs, including the carbapenems., Methods: A total of 100 carbapenem-resistant P. aeruginosa isolates underwent polymerase chain reaction (PCR) testing to identify bla GES, bla KPC, bla SPM-1, bla IMP, and bla VIM. Additionally, PCR products positive for bla GES were sequenced. The clonal profiles of these same isolates were then determined by means of enterobacterial repetitive intergenic consensus (ERIC)-PCR analysis., Results: PCR analysis revealed that four isolates harbored bla GES; DNA sequencing showed that two harbored bla GES-1 and two bla GES-11. Beta-lactamase genes bla SPM-1, bla IMP, bla VIM, and bla KPC were investigated; none of these genes was detected. Automated susceptibility testing methods (Vitek®2, bioMérieux) showed that the bla GES-1-positive isolates were only susceptible to polymyxin B. The patterns obtained with ERIC-PCR methods showed clonal relationship between the two isolates that harbored bla GES-11, whereas different clonal profiles were found in the isolates harboring bla GES-1., Conclusions: We detected the presence of bacterial isolates positive for two different variants of the enzyme GES in three different hospitals from Recife, Brazil. These enzymes have a great capacity for dissemination among Gram-negative bacteria and confer broad-spectrum resistance to beta-lactam antibiotics and to the carbapenems.

Purpose: The occurrence of quinolone-resistance genes (qnrA, qnrB and qnrS), the presence of mutations in gyrA, gyrB and parC, as well as the expression of efflux pumps (acrB and acrF) and mutations in the gene ramR., Methodology: Were investigated in 30 blaKPC-2-positive isolates of Klebsiella pneumoniae taken from infection and colonization in hospital patients from Recife-PE, Brazil. The detection of the qnr, acrB and acrF genes and analysis of the mutations in ramR and the quinolone-resistance-determining regions of gyrA, gyrB and parC were performed by PCR followed by DNA sequencing., Results: Among the isolates analysed, 73.3 % (n=22) presented the qnrB gene. For the DNA sequencing, six isolates (K3-A2, K12-A2, K25-A2, K27-A2, K19-A2 and K3-C2) were selected and the qnrB1 and qnrB12 variants were detected. This is the first ever report, to the best of our knowledge, of the presence of qnrB12 in K. pneumoniae. This is also the first report, to the best of our knowledge, of the presence of qnrB1 or qnrB12 with blaKPC-2 in K. pneumoniae in Brazil. Mutations were observed in gyrA S83 and in ramR. All isolates presented genes for the acrB and acrF efflux pumps and the reverse transcription PCR performed showed that the pumps were being expressed., Conclusion: KPC-2-positive isolates colonizing patients, which also showed qnrB, mutation in gyrA and efflux pumps, may be important reservoirs for disseminating these resistance mechanisms in the hospital environment.

Enterobacter aerogenes and Enterobacter cloacae complex are the two species of this genus most involved in healthcare-associated infections that are ESBL and carbapenemase producers. This study characterized, phenotypically and genotypically, 51 isolates of E. aerogenes and E. cloacae complex originating from infection or colonization in patients admitted to a public hospital in Recife, Pernambuco, Brazil, by antimicrobial susceptibility profile, analysis of β-lactamase genes (blaTEM, blaSHV, blaCTX-M, blaKPC, blaVIM, blaIMP and blaSPM), PCR and DNA sequencing, plasmid profile and ERIC-PCR. In both species, the genes blaTEM, blaCTX-M and blaKPC were detected. The DNA sequencing confirmed the variants blaTEM-1, blaCTX-M-15 and blaKPC-2 in isolates. More than one gene conferring resistance in the isolates, including the detection of the three previously cited genes in strains isolated from infection sites, was observed. The detection of blaCTX-M was more frequent in isolates from infection sites than from colonization. The gene blaKPC predominated in E. cloacae complex isolates obtained from infections; however, in E. aerogenes isolates, it predominated in samples obtained from colonization. A clonal relationship among all of E. aerogenes isolates was detected by ERIC-PCR. The majority of E. cloacae complex isolates presented the same ERIC-PCR pattern. Despite the clonal relation presented by the isolates using ERIC-PCR, different plasmid and resistance profiles and several resistance genes were observed. The clonal dissemination and the accumulation of β-lactam resistance determinants presented by the isolates demonstrated the ability of E. aerogenes and E. cloacae complex, obtained from colonization and infection, to acquire and maintain different resistance genes.

The ultrastructural alterations caused by polymyxin B and meropenem and by the association between polymyxin B and meropenem were investigated in two multiresistant isolates of Klebsiella pneumoniae (K3-A2 and K12-A2) carriers of blaKPC-2, coming from infection and colonization in patients in a public hospital in Recife, Brazil. The ultrastructural changes were detected by transmission electron microscopy and scanning. The susceptibility of the isolates to antimicrobials was tested by the disc diffusion method and microdilution in broth. The analysis by electron microscopy showed that the isolates presented morphological and ultrastructural cellular changes when subjected to a clinically relevant concentration of antimicrobials alone or in combination. When subjected to meropenem, they presented retraction of the cytoplasmic material, rupture of the cell wall and extravasation of the cytoplasmic content. When submitted to polymyxin B, the isolates showed condensation of the ribosomes, DNA clotting, cell wall thickening and the presence of membrane compartment. When subjected to polymyxin B and meropenem in combination, the isolates showed a higher intensity of the ultrastructural changes visualized. This is the first report of the ultrastructural changes caused by polymyxin B and meropenem in multiresistant isolates of K. pneumoniae carriers of the blaKPC-2 gene. It should be noted that even when the K. pneumoniae isolates were multiresistant carriers of the blaKPC-2 gene, they underwent important structural change owing to the action of polymyxin B and meropenem.

Pseudomonas aeruginosa, Acinetobacter spp. and Klebsiella spp. are three of the pathogens most frequently involved in infections of cancer patients, and the production of β -lactamases is a major mechanism of resistance due to its wide diversity of existing enzymes. Therefore, the aim of the present study was to investigate the microbiological profile and data related to patients and infections, and to search for β -lactamase genes in bacterial isolates from hospitalized cancer patients in a hospital in Recife, Pernambuco, Brazil. A total of 169 isolates were recovered between 2012 and 2014, of which 58 were P. aeruginosa, 36 were Acinetobacter spp. and 75 were Klebsiella spp. A high percentage of carbapenem resistance was observed in P. aeruginosa and Acinetobacter spp. Among the carbapenem-resistant bacteria, the blaSPM-1 gene was detected in P. aeruginosa (35.5 %) and Acinetobacter spp. (3.8 %), while blaKPC was detected in P. aeruginosa (25.8 %) only. Among the third- and fourth-generation cephalosporin-resistant strains, in Klebsiella spp. we detected the genes blaTEM (30.6 %), blaCTX-M (58.3 %) and blaKPC (5.6 %), and in Acinetobacter spp. only blaTEM (25.9 %). This the first report of an Acinetobacter baumannii blaSPM-1 gene carrier that has been isolated in Brazil. The most frequent cancer types were bowel tumour [14.8 %; 95 % confidence interval (CI95 %) 9.8-21.1 %], breast cancer (13.6 %; CI95 % 8.8-19.7 %) and prostate cancer (11.2%; CI95 % 6.9-17.0 %). These results therefore provide knowledge of susceptibility profile and resistance mechanisms and thus can contribute to the strategic formulation of hospital infection control plans and the rational use of antimicrobials, reducing mortality from infection levels in cancer patients.

Eighty-five isolates of Klebsiella pneumoniae and Enterobacter spp., originating from hospital- and community-acquired infections and from oropharyngeal and faecal microbiota from patients in Recife-PE, Brazil, were analyzed regarding the presence of irp2 gene. This is a Yersinia typical gene involved in the synthesis of siderophore yersiniabactin. DNA sequencing confirmed the identity of irp2 gene in five K. pneumoniae, five Enterobacter aerogenes and one Enterobacter amnigenus isolates. To our knowledge in the current literature, this is the first report of the irp2 gene in E. amnigenus, a species considered an unusual human pathogen, and in K. pneumoniae and E. aerogenes isolates from the normal microbiota and from community infections, respectively. Additionally, the analyses of nucleotide and amino acid sequences suggest the irp2 genes derived from isolates used in this study are more closely related to that of Yersinia pestis P.CE882 than to that of Yersinia enterocolitica 8081. These data demonstrated that K. pneumoniae and Enterobacter spp. from normal microbiota and from community- and hospital-acquired infections possess virulence factors important for the establishment of extra-intestinal infections., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Introduction: There is a mechanism of macrolide resistance in Staphylococcus spp. which also affects the lincosamides and type B streptogramins characterizing the so-called MLSB resistance, whose expression can be constitutive (cMLSB) or inducible (iMLSB) and is encoded mainly by ermA and ermC genes. The cMLSB resistance is easily detected by susceptibility testing used in the laboratory routine, but iMLSB resistance is not. Therapy with clindamycin in cases of infection with isolated iMLSB resistance may fail., Objective: To characterize the phenotypic (occurrence of cMLSB and iMLSB phenotypes) and molecular (occurrence of ermA and ermC genes) profiles of MLSB resistance of clinical isolates of susceptible and methicillin-resistant Staphylococcus aureus and CNS (coagulase-negative Staphylococcus) from patients of a university hospital, in Pernambuco., Methods: The antimicrobial susceptibility of 103 isolates was determined by the disk diffusion technique in Mueller-Hinton agar followed by oxacillin screening. The iMLSB phenotype was detected by D test. Isolates with cMLSB and iMLSB phenotypes were subjected to polymerase chain reaction (PCR) for the detection of ermA and ermC genes., Results: The cMLSB and iMLSB phenotypes were respectively identified in 39 (37.9%) and five (4.9%) isolates. The iMLSB phenotype was found only in four (10.8%) methicillin-susceptible S. aureus and one (4.5%) methicillin-resistant S. aureus. In the 44 isolates subjected to PCR, four (9.1%) only ermA gene was detected, a lower frequency when compared to only ermC 17 (38.6%) gene and to one (2.3%) isolate presenting both genes., Conclusion: In the Staphylococcus spp. analyzed, the ermC gene was found more often than the ermA, although the iMLSB phenotype had been less frequent than the cMLSB. It was important to perform the D test for its detection to guide therapeutic approaches., (Copyright © 2016 Elsevier Editora Ltda. All rights reserved.)

In this brief communication we describe the occurrence of a KPC-producing Serratia marcescens isolate in a home-care patient from Recife, Brazil. The blaKPC, blaSPM, blaIMP, blaVIM, blaOXA, blaCTX-M, blaSHV, blaTEM and blaGES genes were investigated by Polymerase Chain Reaction (PCR) and DNA sequencing. The isolate was positive for blaKPC-2 and blaTEM-1 and was resistant to aztreonam, cefepime, cefotaxime, imipenem, meropenem, gentamicin, ciprofloxacin and cefazidime, and susceptible only to amikacin, tigecycline and gatifloxacin. This is the first report in Brazil of KPC-producing S. marcescens clinical isolate outside of a hospital environment. Caregivers should be alert for the presence of this isolate in the community setting.

Introduction: Infections caused by Klebsiella pneumoniae carbapenemase (KPC)-producing isolates pose a major worldwide public health problem today., Methods: A carbapenem-resistant Proteus mirabilis clinical isolate was investigated for plasmid profiles and the occurrence of β-lactamase genes., Results: The isolate exhibited resistance to ertapenem and imipenem and was susceptible to meropenem, polymyxin, and tigecycline. Five plasmids were identified in this isolate. DNA sequencing analysis revealed the presence of bla KPC-2 and bla TEM-1 genes. An additional PCR using plasmid DNA confirmed that bla KPC-2 was present in one of these plasmids., Conclusions: We report the detection of bla KPC-2 in P. mirabilis in Brazil for the first time. This finding highlights the continuous transfer of bla KPC between bacterial genera, which presents a serious challenge to the prevention of infection by multidrug-resistant bacteria.

The aim of this study was to characterize the ultrastructural effects caused by β-lactam antibiotics in Klebsiella pneumoniae isolates. Three K. pneumoniae clinical isolates were selected for the study with resistance profiles for third-generation cephalosporins, aztreonam, and/or imipenem and with different resistance genes for extended-spectrum β-lactamases (ESBL) or Klebsiella pneumoniae carbapenemase (KPC). Two K. pneumoniae isolates obtained from the microbiota, which were both resistant to amoxicillin and ampicillin, were also analyzed. In accordance with the susceptibility profile, the clinical isolates were subjected to subminimum inhibitory concentrations (sub-MICs) of cefotaxime, ceftazidime, aztreonam, and imipenem and the isolates from the microbiota to ampicillin and amoxicillin, for analysis by means of scanning and transmission electron microscopy. The K. pneumoniae isolates showed different morphological and ultrastructural changes after subjection to β-lactams tested at different concentrations, such as cell filamentation, loss of cytoplasmic material, and deformation of dividing septa. Our results demonstrate that K. pneumoniae isolates harboring different genes that encode for β-lactamases show cell alterations when subjected to different β-lactam antibiotics, thus suggesting that they possess residual activity in vitro, despite the phenotypic resistance presented in the isolates analyzed.

Klebsiella pneumoniae strains can produce different virulence factors, such as fimbrial adhesins and siderophores, which are important in the colonization and development of the infection. The aims of this study were to determine the occurrence of fimH, mrkD, and irp2 virulence genes in 22 KPC-2-producing K. pneumoniae isolates as well as 22 not producing-KPC isolates, from patients from different hospitals in Recife-PE, Brazil, and also to analyze the clonal relationship of the isolates by enterobacterial repetitive intergenic consensus-polymerase chain reaction (ERIC-PCR). The genes were detected by PCR and DNA sequencing. The bla KPC-2 gene was identified in 22 KPC-positive isolates. On analyzing the antimicrobial susceptibility profile of the isolates, it was detected that polymyxin and amikacin were the antimicrobials of best activity against K. pneumoniae. On the other hand, five isolates exhibited resistance to polymyxin. In the KPC-positive group, was observed a high rate of resistance to cephalosporins, followed by carbapenems. Molecular typing by ERIC-PCR detected 38 genetic profiles, demonstrating a multiclonal spread of the isolates analyzed. It was observed that the virulence genes irp2, mrkD, and fimH were seen to have together a higher frequency in the KPC-positive group. The accumulation of virulence genes of KPC-positive K. pneumoniae isolates, observed in this study, along with the multi-resistance impose significant therapeutic limitations on the treatment of infections caused by K. pneumoniae.

Introduction: The high prevalence of Klebsiella pneumoniae infections is related to the ability of K. pneumoniae to acquire and disseminate exogenous genes associated with mobile elements, such as R plasmids, transposons and integrons. This study investigated the presence of class 1 integrons in clinical and microbiota isolates of K. pneumoniae belonging to different phylogenetic groups and correlated these results with the antimicrobial resistance profiles of the studied isolates., Methods: Of the 51 isolates of K. pneumoniae selected for this study, 29 were from multidrug-resistant clinical isolates, and 22 were from children's microbiota. The susceptibility profile was determined using the disk diffusion method, and class 1 integrons were detected through polymerase chain reaction (PCR)., Results: The results showed that none of the 22 microbiota isolates carried class 1 integrons. Among the 29 clinical isolates, 19 (65.5%) contained class 1 integrons, and resistance to sulfamethoxazole/trimethoprim was identified in 18 of these isolates (94.7%). Among the K. pneumoniae isolates with class 1 integrons, 47% belonged to the KpI phylogenetic group, and one isolate (14.3%) carrying these genetic elements belonged to the KpIII group., Conclusions: The wide variety of detected class 1 integrons supports the presence of high rates of antimicrobial resistance, genetic variability, and rapid dissemination of beta-lactamase genes among K. pneumoniae clinical isolates in recent years in hospitals in Recife-PE, Brazil. The findings of this study indicate that the surveillance of K. pneumoniae integrons in clinical isolates could be useful for monitoring the spread of antibiotic resistance genes in the hospital environment.

This paper describes the processing of silver-nanoparticle-doped poly(vinylidene fluoride). The effects of the concentration and size of the filler on the electroactive phase of the polymer and the optical and electrical properties are discussed. Spherical silver nanoparticles incorporated into the poly(vinylidene fluoride) polymeric matrix induce nucleation of the electroactive γ phase. The electroactive phase content strongly depends on the content and size of the nanoparticles. In particular, there is a critical nanoparticle size, below which the filler losses its nucleation efficiency due to its small size relative to that of the polymer macromolecules. Furthermore, the presence of surface plasmon resonance absorption in the composites is observed, which once again shows a strong dependence on the concentration and size of the particles. The absorption is larger for higher concentrations, and for a given concentration increases with particle size. This behavior is correlated to the electrical response and is related to the extra bands and electrons provided by the nanoparticles in the large energy band gap of the polymer., (Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)