Unusual association of NDM-1 with KPC-2 and armA among Brazilian Enterobacteriaceae isolates

We report the microbiological characterization of four New Delhi metallo-beta-lactamase-1 (bla(NDM-1))-producing Enterobacteriaceae isolated in Rio de Janeiro, Brazil. bla(NDM-1) was located on a conjugative plasmid and was associated with Klebsiella pneumoniae carbapenemase-2 (bla(KPC-2)) or aminoglycoside-resistance methylase ( armA), a 16S rRNA methylase not previously reported in Brazil, in two distinct strains of Enterobacter cloacae. Our results suggested that the introduction of bla(NDM-1) in Brazil has been accompanied by rapid spread, since our isolates showed no genetic relationship.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Universidade Federal de São Paulo, Dept Med, Lab Especial Microbiol Clin, São Paulo, SP, BrazilDASA, Lab Diagnost Amer, São Paulo, SP, BrazilUniversidade Federal de São Paulo, Dept Med, Lab Especial Microbiol Clin, São Paulo, SP, BrazilWeb of Scienc

The Potential of Multi-Screening Methods and Omics Technologies to Detect Both Regulated and Emerging Mycotoxins in Different Matrices

Mycotoxins are well-known secondary metabolites produced by several fungi that grow and occur in different crops during both pre-harvest and post-harvest conditions. The contamination and occurrence of mycotoxins currently represent some of the major issues in the entire agri-food system. The quantification of mycotoxins in different feeds and foodstuffs is extremely difficult because of the low concentration ranges; therefore, both sample collection and preparation are essential to providing accurate detection and reliable quantification. Currently, several analytical methods are available for the detection of mycotoxins in both feed and food products, and liquid chromatography coupled with high-resolution mass spectrometry (LC-HRMS) represents the most reliable instrumental approach. In particular, the fast development of high-throughput methods has made it possible to screen and analyze, in the same analytical run and with high accuracy, multiple mycotoxins, such as those regulated, masked, or modified, and emerging ones. Therefore, the aim of this review is to provide an overview of the state of the art of mycotoxins occurrence, health-related concerns, and analyses, discussing the need to perform multi-screening approaches combined with omics technologies to simultaneously analyze several mycotoxins in different feed and food matrices. This approach is expected to provide more comprehensive information about the profile and distribution of emerging mycotoxins, thus enhancing the understanding of their co-occurrence and impact on the entire production chain

Impact of In Vitro Gastrointestinal Digestion on the Phenolic Bioaccessibility and Bioactive Properties of Insect-Containing Beef Burgers

Mealworm, migratory locust, and house cricket have recently been recognized by the European Commission as novel foods, thus being suitable in different food applications. In this work, we tested their powders as meat extenders at 5% (w/w) inclusion in beef burgers, considering their ability to vehicle phenolic compounds during simulated in vitro static gastrointestinal digestion (INFOGEST). Insect powders were abundant in different phenolic classes, recording the highest values in locust (LP; 314.69 mg/kg), followed by cricket (CP; 113.3 mg/kg) and mealworm (MWP; 51.9 mg/kg). Following a pan-cooking process, LP burgers were confirmed as the best source of phenolics, with a marked abundance of flavonoids and phenolic acids. Interestingly, the insect powders were found to affect the in vitro gastrointestinal bioaccessibility of phenolic compounds when compared with the CTR burger, likely promoted by the interactions between the phenolic compounds and proteins characterizing the tested insect powders. Among the most discriminant phenolic metabolites at the gastrointestinal level, we found several phenolic acids (mainly hydroxycinnamics), recording the highest content for the digested CP-containing burgers. Finally, stilbenes showed significant correlation values at the intestinal level with both antioxidant and enzymatic activities, while total flavonoids were the most correlated with the inhibition of acetylcholinesterase. Taken together, our preliminary findings demonstrated that insect powders added to beef burgers can promote the bioaccessibility and potential bioavailability of phenolics in the distal tracts of the intestine

Role of Platinum Nanozymes in the Oxidative Stress Response of Salmonella Typhimurium

Platinum nanoparticles (PtNPs) are being intensively explored as efficient nanozymes due to their biocompatibility coupled with excellent catalytic activities, which make them potential candidates as antimicrobial agents. Their antibacterial efficacy and the precise mechanism of action are, however, still unclear. In this framework, we investigated the oxidative stress response of Salmonella enterica serovar Typhimurium cells when exposed to 5 nm citrate coated PtNPs. Notably, by performing a systematic investigation that combines the use of a knock-out mutant strain 12023 HpxF- with impaired response to ROS (ΔkatE ΔkatG ΔkatN ΔahpCF ΔtsaA) and its respective wild-type strain, growth experiments in both aerobic and anaerobic conditions, and untargeted metabolomic profiling, we were able to disclose the involved antibacterial mechanisms. Interestingly, PtNPs exerted their biocidal effect mainly through their oxidase-like properties, though with limited antibacterial activity on the wild-type strain at high particle concentrations and significantly stronger action on the mutant strain, especially in aerobic conditions. The untargeted metabolomic analyses of oxidative stress markers revealed that 12023 HpxF- was not able to cope with PtNPs-based oxidative stress as efficiently as the parental strain. The observed oxidase-induced effects comprise bacterial membrane damage as well as lipid, glutathione and DNA oxidation. On the other hand, in the presence of exogenous bactericidal agents such as hydrogen peroxide, PtNPs display a protective ROS scavenging action, due to their efficient peroxidase mimicking activity. This mechanistic study can contribute to clarifying the mechanisms of PtNPs and their potential applications as antimicrobial agents

Paradimorphite, beta-As4S3, a vintage new mineral from Solfatara di Pozzuoli and Vesuvius, Napoli, Italy

The new mineral paradimorphite corresponds to the high temperature polymorph of As4S3, whose existence was supposed by Arcangelo Scacchi in 1850 in the fumaroles at the Solfatara di Pozzuoli, Campi Flegrei, near Napoli, Italy. Crystals of paradimorphite are orange yellow, transparent or semitransparent, with adamantine lustre. Habit is prismatic and observed forms are {110}, {101}, {111}, {100}, {010} and {001}. Tenacity is brittle, no distinct cleavage is observed and fracture is conchoidal. The mineral does not fluoresce in long- or shortwave ultraviolet light. No twinning is apparent. The streak is saffron yellow. Hardness (Mohs) = 1-2. The observed density is 3.510(3) g/cm(3), calculated density is 3.500 g/cm(3). The mineral is orthorhombic, space group Pnma, with a = 9.1577(7), b = 8.0332(6), c = 10.2005(8) angstrom, V = 750.41(10) angstrom(3) and Z = 4. The eight strongest powder X-ray diffraction lines are [d(obs) angstrom(I)(hkl)]: 6.299(48)(011), 5.186(100)(111), 4.174(31)(201), 3.133(34)(022), 3.116(58)(212), 2.980(41)(122), 1.846 (27)(413) and 1.808(23)(134). The structure was refined to R = 0.0229 for 979 reflections with I >2 sigma(I). Crystals of paradimorphite contain As4S3 molecules, of idealised C-3v symmetry, with the four arsenic atoms in a triangular pyramidal arrangement, with sulfur atom bridges on the three adjacent apical edges. Molecular dimensions and conformation are identical within standard uncertainties with those of the low-temperature polymorph dimorphite. No substantial differences, neither in the molecular packing nor in the molecular orientation, could be observed; minor differences being related to intermolecular distances only

Charged molecular silica trigger in vitro NETosis in human granulocytes via both oxidative and autophagic pathways

OBJECTIVE: Neutrophils play a key role in immunity and are known to respond to exogenous threats by releasing neutrophil extracellular traps (NETs) through NETosis, a process involving the release of neutrophils nuclear DNA decorated with proteins into the extracellular space. In this study, attention has been focused on the ability of differently charged molecular systems polyhedral oligomeric silsesquioxanes (POSS) to induce NETosis. MATERIALS AND METHODS: NETs formation was induced by phorbol myristate acetate (PMA) (positive control) and POSS treatment and visualized by confocal microscopy. Moreover, NETs production was quantified by Sytox green staining. Oxidative stress, autophagy as well as endocytosis involvement in the observed phenomena was evaluated by a specific inhibitory approach. RESULTS: Results obtained in this study demonstrate a POSS time and dose-dependent ability in inducing NETs release irrespectively to their charge. POSS induced NETosis is a consequence of their internalization, as demonstrated by the strong reduction in NETs formation after endocytosis inhibition. Moreover, POSS induced NETosis involves both an increase in superoxide anion generation and autophagy pathway activation as demonstrated by the protective effect displayed by sodium azide and wortmannin. CONCLUSIONS: Data presented in this study indicate that nanomaterials and molecular systems could have a role in the onset of inflammatory phenomena

Bioprospecting antimicrobials from lactiplantibacillus plantarum: Key factors underlying its probiotic action

Lactiplantibacillus plantarum (L. plantarum) is a well‐studied and versatile species of lactobacilli. It is found in several niches, including human mucosal surfaces, and it is largely employed in the food industry and boasts a millenary tradition of safe use, sharing a long‐lasting relationship with humans. L. plantarum is generally recognised as safe and exhibits a strong probiotic character, so that several strains are commercialised as health‐promoting supplements and functional food products. For these reasons, L. plantarum represents a valuable model to gain insight into the nature and mechanisms of antimicrobials as key factors underlying the probiotic action of health‐promoting microbes. Probiotic antimicrobials can inhibit the growth of pathogens in the gut ensuring the intestinal homeostasis and contributing to the host health. Furthermore, they may be attractive alternatives to conventional antibiotics, holding potential in several biomedical applications. The aim of this review is to investigate the most relevant papers published in the last ten years, bioprospecting the antimicrobial activity of characterised probiotic L. plantarum strains. Specifically, it focuses on the different chemical nature, the action spectra and the mechanisms underlying the bioactivity of their antibacterial and antiviral agents. Emerging trends in postbiotics, some in vivo applications of L. plantarum antimicrobials, including strengths and limitations of their therapeutic potential, are addressed and discussed

Indoor Radon Surveying and Mitigation in the Case-Study of Celleno Town (Central Italy) Located in a Medium Geogenic Radon Potential Area

Indoor radon surveying and remediation were implemented in a single-family home affected by high levels of indoor radon in the Celleno municipality (central Italy) with the aim of identifying the contribution of radon sources, evaluating the factors affecting radon entry into the building, and reducing radon risk. Average radon levels were relatively low at the ground floor (286 ± 202 Bq m−3) and first floor (167 ± 84 Bq m−3) in autumn when the temperature was still warm and the windows were open, but increased up to 2776 ± 1768 Bq m−3 and 970 ± 202 Bq m−3 in the first half of December, when the heating system was on and the windows were closed. The inner walls of the pilot room at the ground floor, semi buried on one side, were then treated with a waterproof product (a silane terminated polymer) and the average radon was halved (1475 ± 1092 Bq m−3) in the following month, which was still characterised by winter conditions. Radon entry in the room was identified and sealed with the same product, and a radon accumulation space behind a NE-SW oriented wall was naturally ventilated, reducing radon below the reference level in April with northerly winds conditions