ABSTRACT The Enterobacter cloacae complex (ECC) is one of the major causes of hospital-acquired infections. However, achieving accurate species identification and comprehensive resistance profiling remains difficult in clinical practice, with a limited understanding of species-specific resistance patterns. ECC isolates were collected from patients with bloodstream infections at Peking Union Medical College Hospital between 2015 and 2020. Whole-genome sequencing (WGS) was performed to identify species, analyze antimicrobial resistance genes, and explore genomic variation in serial isolates. Multi-locus sequence typing (MLST) profiles were extracted from the WGS data. Phylogenetic analysis was conducted based on hsp60 sequences. Eleven hsp60 clusters were identified, with cluster VIII being the most prevalent (28/108). Average nucleotide identity (ANI)-based species classification showed Enterobacter hormaechei (31.5%) and Enterobacter xiangfangensis (15.7%) were dominant species. Five clade-cluster pairs (B-VIII, A-VI, G-XI, D-III, R-IX) accounted for 74% of isolates. A total of 90 sequence types (STs) were detected, including 29 novel STs. Resistance gene analysis revealed a high prevalence of blaACT, with distinct distribution patterns observed among different species. Twenty isolates were carbapenem-resistant, with three carrying blaNDM-1/5. Enterobacter roggenkampii was the most common species (5/20) among all carbapenem-resistant isolates, and 83.3% of the isolates showed resistance to both carbapenems and colistin. Comparative genomics of longitudinal isolates from individual patients revealed adaptive single-nucleotide polymorphisms (SNPs) in pco genes. This study provides a detailed genomic characterization of ECC isolates from bloodstream infections, highlighting species diversity, resistance gene distribution, and potential within-host evolution. These insights advocate genome-based surveillance in managing ECC infections and understanding resistance evolution in clinical contexts.IMPORTANCEEnterobacter cloacae complex (ECC) is a major cause of hospital-acquired bloodstream infections, yet species-level identification and resistance profiling remain challenging. As one of the largest whole-genome sequencing (WGS)-based studies of ECC bloodstream isolates in northern China to date, we performed whole-genome sequencing of 108 ECC isolates, revealing high genetic diversity and identifying 29 novel sequence types. We clarified the correspondence between species, clades, and clusters and highlighted Enterobacter roggenkampii as a potential high-risk species linked to carbapenem and colistin resistance. Our findings not only improve the understanding of ECC population structure and resistance evolution in China but also provide valuable genomic data for future epidemiological surveillance and species-level diagnostics.
Zhi Ting Yip, Zheng Bin Randolph Quek, Danwei Huang
ABSTRACT Environmental DNA (eDNA) provides a powerful means of monitoring biodiversity, offering high taxonomic resolution and broad spatial coverage beyond traditional methods. To characterize ecological communities, it is critical to understand shifts in species composition through time to potentially differentiate resident from transient species in the studied habitats. This study used eDNA metabarcoding to examine temporal and spatial patterns of α‐ and β‐diversity across three distinct habitat types (sandy, rocky, and mangrove) at four coastal sites in Singapore over 1 year. We targeted invertebrates using the cytochrome oxidase subunit I (COI) gene and vertebrates using the 16S rRNA gene. We recorded lower diversity at nature reserves, which harbor more rare species than unprotected habitats. β‐diversity differed significantly by site and time for both markers, though β‐dispersion generally remained consistent over time within sites for both invertebrate and vertebrate communities. The difference in marine metazoan communities was driven by high spatial and temporal turnover without strong directional trends across Singapore's coastal sites. These patterns reflect distinct, cohesive communities with limited seasonality, characteristic of equatorial climates. However, certain taxa showed monsoon‐associated distributions, except in mangrove habitats. Importantly, we suggest more mid‐ to long‐term surveys to elucidate the community of resident species. Our findings highlight the value of using eDNA methods to identify dynamic biodiversity patterns and support its use in long‐term ecological monitoring and conservation planning.
Vera Beilinson, Grischa Y. Chen, Alexis C. Hargadon
et al.
ABSTRACT Understanding the cause and consequences of bacterial strain variation remains a challenge in the study of symbioses. While the diverse reactions of the host immune system to strain variants have been well studied in pathogenesis, much less is known about how strain variation influences beneficial associations. From the complex vertebrate gut microbiome to the more tractable invertebrate models of symbiosis, the host’s cellular and molecular responses to this diversity remain largely a mystery. Here, we explore strain diversity in Vibrio fischeri, the bioluminescent bacterial symbiont of the Hawaiian bobtail squid, Euprymna scolopes. Phylogenetic analyses of the genomes of 62 V. fischeri strains, including 50 light organ-associated and 12 planktonic isolates, revealed several genes that were absent in planktonic strains, but uniformly present in symbiotic ones. To better understand the consequences of this diversity to the host, we selected five light-organ associated strains: three from E. scolopes but having different combinations of colonization factors, one from a congeneric squid host, and one from a marine fish. We colonized juvenile E. scolopes with these strains and, using RNAseq, found that (i) the most similar host transcriptomic responses occurred among the native E. scolopes strains, (ii) intermediate was the strain from the related squid, and (iii) least similar was the fish strain. Importantly, native strains downregulated immune-related genes more than non-native ones. Finally, host development was atypical or delayed when colonized by non-native strains. These experiments point the way to more targeted studies of the mechanisms underlying host responses to symbiont strain diversity.IMPORTANCEVariation among strains of a bacterial species is a powerful factor underlying the intensity of host responses during pathogenic infections. Less is known about the cellular and molecular responses of host tissues to differences between the strains present in an animal's normal microbiome. We use a natural, species-specific, symbiosis to explore the influence of strain-level differences on host gene expression and morphogenesis. Analysis of symbiotic strains from squids and fishes, as well as free-living strains, shows that the carriage of colonization determinants, while critical to competitive success among strains of a species, has a minimal effect on the transcriptional response of the host. We provide evidence that a more important driver of normal gene expression during the development of symbiosis is the history of a strain’s co-diversification with its host species. Such studies, using simple invertebrate models, allow the recognition of otherwise obscured interactions underlying the more complex microbiomes of vertebrates.
Ossifying fibromyxoid tumor (OFMT) is a rare mesenchymal tumor of uncertain histogenesis with intermediate malignant potential presenting commonly in the fifth to sixth decade in the proximal limb and limb girdle. A 65-year-old male patient presented with a slow-growing gluteal mass. Wide local excision performed showed a well-defined tumor in the subcutaneous plane with a partially hard outer shell. Microscopy showed a moderately cellular tumor having cords and nests of round to ovoid cells with moderate cytoplasm and bland nuclei embedded in a myxo-hyaline matrix. An incomplete peripheral rim of ossification was seen. Pleomorphism/high cellularity was not seen. Mitosis was <2/50 high-power field. On immunohistochemistry, both S100 and desmin were positive. A diagnosis of typical OFMT was rendered. Even though rare with many morphological mimics, OFMT should be diagnosed with precision as most of these tumors are low-grade tumors that require only wide local excision and close follow-up without any adjuvant therapy.
Ammonia-oxidizing archaea (AOA) are key players in the nitrogen cycle and among the most abundant microorganisms in the ocean, thriving even in oxygen-depleted ecosystems. AOA produce the greenhouse gas nitrous oxide (N2O) as a byproduct of ammonia oxidation. Additionally, the recent discovery of a nitric oxide dismutation pathway in the AOA isolate Nitrosopumilus maritimus points toward other N2O production and consumption pathways in AOA. AOA that perform NO dismutation when exposed to oxygen depletion, produce oxygen and dinitrogen as final products. Based on the transient accumulation of N2O coupled with oxygen accumulation, N2O has been proposed as an intermediate in this novel archaeal pathway. In this study, we spiked N2O to oxygen-depleted incubations with pure cultures of two marine AOA isolates that were performing NO dismutation. By using combinations of N compounds with different isotopic signatures (15NO2− pool +44N2O spike and 14NO2− pool +46N2O spike), we evaluated the N2O spike effects on the production of oxygen and the isotopic signature of N2 and N2O. The experiments confirmed that N2O is an intermediate in NO dismutation by AOA, distinguishing it from similar pathways in other microbial clades. Furthermore, we showed that AOA rapidly reduce high concentrations of spiked N2O to N2. These findings advance our understanding of microbial N2O production and consumption in oxygen-depleted settings and highlight AOA as potentially important key players in N2O turnover.
Jolanta H. Kotlinska, Pawel Grochecki, Agnieszka Michalak
et al.
Repeated maternal separation (MS) is a useful experimental model in rodents for studying the long-term influence of early-life stress on brain neurophysiology. In our work, we assessed the effect of repeated MS (postnatal day (PND)1–21, 180 min/day) on the postnatal development of rat brain regions involved in memory using proton magnetic resonance spectroscopy (<sup>1</sup>HMRS) for tissue volume and the level of amino acids such as glutamate, aspartate, glutamine, glycine and gamma-aminobutyric acid (GABA) in the hippocampus. We assessed whether these effects are sex dependent. We also use novel object recognition (NOR) task to examine the effect of MS on memory and the effect of ethanol on it. Finally, we attempted to ameliorate postnatal stress-induced memory deficits by using VU-29, a positive allosteric modulator (PAM) of the metabotropic glutamate type 5 (mGlu5) receptor. In males, we noted deficits in the levels of glutamate, glycine and glutamine and increases in GABA in the hippocampus. In addition, the values of perirhinal cortex, prefrontal cortex and insular cortex and CA3 were decreased in these animals. MS females, in contrast, demonstrated significant increase in glutamate levels and decrease in GABA levels in the hippocampus. Here, the CA1 values alone were increased. VU-29 administration ameliorated these cognitive deficits. Thus, MS stress disturbs amino acids levels mainly in the hippocampus of adult male rats, and enhancement of glutamate neurotransmission reversed recognition memory deficits in these animals.
Lucia Verrillo, Rosita Di Palma, Alberto de Bellis
et al.
Neuroplasticity is a crucial property of the central nervous system to change its activity in response to intrinsic or extrinsic stimuli. This is mainly achieved through the promotion of changes in the epigenome. One of the epi-drivers priming this process is suberoylanilide hydroxamic acid (SAHA or Vorinostat), a pan-histone deacetylase inhibitor that modulates and promotes neuroplasticity in healthy and disease conditions. Knowledge of the specific molecular changes induced by this epidrug is an important area of neuro-epigenetics for the identification of new compounds to treat cognition impairment and/or epilepsy. In this review, we summarize the findings obtained in cellular and animal models of various brain disorders, highlighting the multiple mechanisms activated by SAHA, such as improvement of memory, learning and behavior, and correction of faulty neuronal functioning. Supporting this evidence, <i>in vitro</i> and <i>in vivo</i> data underline how SAHA positively regulates the expression of neuronal genes and microtubule dynamics, induces neurite outgrowth and spine density, and enhances synaptic transmission and potentiation. In particular, we outline studies regarding neurodevelopmental disorders with pharmaco-resistant seizures and/or severe cognitive impairment that to date lack effective drug treatments in which SAHA could ameliorate defective neuroplasticity.
Nasser M. Assery, Carlos A. Jurado, Mansour K. Assery
et al.
Peri-implantitis is an inflammatory condition induced by bacterial biofilm that affects the soft and hard tissues surrounding dental implants, compromising the success of implant therapy. Recent studies have highlighted the potential links between peri-implant health and systemic inflammation, including uncontrolled diabetes mellitus, psychological stress, cardiovascular disease, obesity, and infectious diseases such as COVID-19. As an inflammatory disease, peri-implantitis may trigger systemic inflammation by elevating circulating levels of pro-inflammatory cytokines, which could have unknown impacts on overall health. While the relationship between periodontal health and systemic conditions is better understood, the association between peri-implant disease and systemic inflammation remains unclear. Therefore, this comprehensive review aims to summarize the most recent evidence on the relationship between peri-implantitis and systemic inflammation, focusing on biological complications, microbiology, and biomarkers. This review aims to enhance our understanding of the links between peri-implantitis and systemic inflammation and promote further research in this field by discussing the latest insights and clinical implications.
With the development of agriculture and industry, the increase in nitrogen (N) deposition has caused widespread concern among scientists. Although emission reduction policies have slowed N releases in Europe and North America, the threat to biodiversity cannot be ignored. Arbuscular mycorrhizal (AM) fungi play an important role in the establishment and maintenance of plant communities in forest ecosystems, and both their distribution and diversity have vital ecological functions. Therefore, we analyzed the effects of long-term N addition on AM fungi and understory herbaceous plants in a Korean pine plantation in northern China. The soil properties, community structure, and diversity of AM fungi and understory herbaceous plants were detected at different concentrations of NH4NO3 (0, 20, 40, 80 kg N ha−1 year−1) after 7 years. The results showed that long-term N deposition decreased soil pH, increased soil ammonium content, and caused significant fluctuations in P elements. N deposition improved the stability of soil aggregates by increasing the content of glomalin-related soil protein (GRSP) and changed the AM fungal community composition. The Glomus genus was more adaptable to the acidic soil treated with the highest N concentration. The species of AM fungi, understory herbaceous plants, and the biomass of fine roots were decreased under long-term N deposition. The fine root biomass was reduced by 78.6% in the highest N concentration treatment. In summary, we concluded that long-term N deposition could alter soil pH, the distribution of N, P elements, and the soil aggregate fractions, and reduce AM fungal and understory herb diversity. The importance of AM fungi in maintaining forest ecosystem diversity was verified under long-term N deposition.
Oxytocin is a hormone secreted from definite neuroendocrine neurons located in specific nuclei in the hypothalamus (mainly from paraventricular and supraoptic nuclei), and its main known function is the contraction of uterine and/or mammary gland cells responsible for parturition and breastfeeding. Among the actions of the peripherally secreted oxytocin is the prevention of different degenerative disorders. These actions have been proven in cell culture and in animal models or have been tested in humans based on hypotheses from previous studies. This review presents the knowledge gained from the previous studies, displays the results from oxytocin intervention and/or treatment and proposes that the well described actions of oxytocin might be connected to other numerous, diverse actions of the biomolecule.
Neospora caninum is a protozoan parasite, the etiologic agent of Neosporosis—a common cause of abortion in cattle worldwide. Herd level prevalence of Neosporosis could be as high as 90%. However, there is no approved treatment and vaccines available for Neosporosis. MicroRNA (miRNA) based prophylaxis and therapeutics could be options for Neosporosis in cattle and other animals. The current study aimed to investigate the genome of Neospora caninum to identify and characterize the conserved miRNAs through Expressed Sequence Tags (ESTs) dependent homology search. A total of 1,041 mature miRNAs of reference organisms were employed against 336 non-redundant ESTs available in the genome of Neospora caninum . The study predicted one putative miRNA “nca-miR-9388-5p” of 19 nucleotides with MFEI value -1.51 kcal/mol and (A + U) content% 72.94% corresponding with its pre-miRNA. A comprehensive search for specific gene targets was performed and discovered 16 potential genes associated with different protozoal physiological functions. Significantly, the gene “Protein phosphatase” was found responsible for the virulence of Neospora caninum . The other genes were accounted for gene expression, vesicular transport, cell signaling, cell proliferation, DNA repair mechanism, and different developmental stages of the protozoon. Therefore, this study finding will provide pivotal information to future aspirants upon Bovine Neosporosis. It will also serve as the baseline information for further studies of the bioinformatics approach to identify other protozoal miRNAs.
Lidia Węglińska, Adrian Bekier, Katarzyna Dzitko
et al.
Congenital and acquired toxoplasmosis caused by the food- and water-born parasite <i>Toxoplasma gondii</i> (<i>T. gondii</i>) is one of the most prevalent zoonotic infection of global importance. <i>T. gondii</i> is an obligate intracellular parasite with limited capacity for extracellular survival, thus a successful, efficient and robust host cell invasion process is crucial for its survival, proliferation and transmission. In this study, we screened a series of novel 1,3,4-thiadiazole-2-halophenylamines functionalized at the C5 position with the imidazole ring (<b>1b</b>–<b>12b</b>) for their effects on <i>T. gondii</i> host cell invasion and proliferation. To achieve this goal, these compounds were initially subjected to in vitro assays to assess their cytotoxicity on human fibroblasts and then antiparasitic efficacy. Results showed that all of them compare favorably to control drugs sulfadiazine and trimethoprim in terms of <i>T. gondii</i> growth inhibition (IC<sub>50</sub>) and selectivity toward the parasite, expressed as selectivity index (SI). Subsequently, the most potent of them with <i>meta</i>-fluoro <b>2b</b>, meta-chloro <b>5b</b>, meta-bromo <b>8b</b>, meta-iodo <b>11b</b> and para-iodo <b>12b</b> substitution were tested for their efficacy in inhibition of tachyzoites invasion and subsequent proliferation by direct action on established intracellular infection. All the compounds significantly inhibited the parasite invasion and intracellular proliferation via direct action on both tachyzoites and parasitophorous vacuoles formation. The most effective was <i>para</i>-iodo derivative <b>12b</b> that caused reduction in the percentage of infected host cells by 44% and number of tachyzoites per vacuole by 93% compared to non-treated host cells. Collectively, these studies indicate that 1,3,4-thiadiazoles <b>1b</b>–<b>12b</b>, especially <b>12b</b> with IC<sub>50</sub> of 4.70 µg/mL and SI of 20.89, could be considered as early hit compounds for future design and synthesis of anti-<i>Toxoplasma</i> agents that effectively and selectively block the invasion and subsequent proliferation of <i>T. gondii</i> into host cells.
Rebecca Kofod Vinding, Daniela Rago, Rachel S. Kelly
et al.
The relationship between developmental milestone achievement in infancy and later cognitive function and mental health is well established, but underlying biochemical mechanisms are poorly described. Our study aims to discover pathways connected to motor milestone achievement during infancy by using untargeted plasma metabolomic profiles from 571 six-month-old children in connection with age of motor milestones achievement (Denver Developmental Index) in the Copenhagen Prospective Studies on Asthma in Childhood 2010 (COPSAC2010) mother–child cohort. We used univariate regression models and multivariate modelling (Partial Least Squares Discriminant Analysis: PLS-DA) to examine the associations and the VDAART (Vitamin D Antenatal Asthma Reduction Trial) cohort for validation. The univariate analyses showed 62 metabolites associated with gross-motor milestone achievement (<i>p</i> < 0.05) as well as the PLS-DA significantly differentiated between slow and fast milestone achievers (AUC = 0.87, <i>p</i> = 0.01). Higher levels of tyramine-O-sulfate in the tyrosine pathway were found in the late achievers in COPSAC (<i>p</i> = 0.0002) and in VDAART (<i>p</i> = 0.02). Furthermore, we observed that slow achievers were characterized by higher levels of fatty acids and products of fatty acids metabolism including acyl carnitines. Finally, we also observed changes in the lysine, histidine, glutamate, creatine and tryptophan pathways. Observing these metabolic changes in relation to gross-motor milestones in the first year of life, may be of importance for later cognitive function and mental health.
Maria Vittoria Salvati, Claudia Del Vecchio, Lesley Bell-Sakyi
et al.
Introduction: Crimean–Congo hemorrhagic fever (CCHF) is a severe disease of humans caused by CCHF orthonairovirus (CCHFV), a class 4 pathogen. <i>Hyalomma </i>ticks are the viral reservoir, and they represent the main vector. CCHFV can be transmitted to its hosts during tick blood feeding. We have previously shown that CCHFV can persistently infect <i>Hyalomma</i>-derived tick cell lines without any cytopathic effect. However, the mechanism allowing for the establishment of a persistent viral infection in ticks is still unknown. It has been recently reported that Hazara orthonairovirus (HAZV) can be used as a BSL-2 model virus instead of CCHFV to study viral/vector interaction. The aim of our study is to elucidate the mechanism that allows establishment of persistent CCHFV infection in ticks using HAZV as a model. Methods: We used classical and molecular methods applied to virology to characterize the establishment of persistent HAZV infection in two <i>Hyalomma</i><i> </i><i>anatolicum</i>-derived cell lines—HAE/CTVM8 and HAE/CTVM9. Results: As for CCHFV, we showed that HAZV persistently infects tick cells without any sign of cytopathic effect and that infected cells can be cultured for more than one year. The persistent infection is characterized by a low viral titer compared to the initial time points. Interestingly, short viral-derived DNA forms (vDNAs) start to be detected in parallel with the beginning of viral replication and are maintained in persistently-infected cells. Experiments with the antiretroviral drug AZT suggest that vDNAs are produced by retrotranscriptase activity. Furthermore, we collected evidence that vDNAs are not integrated and seem to be involved in the downregulation of viral replication by promoting cell survival. Conclusion: vDNA synthesis might represent a strategy to control the replication of RNA viruses in ticks, as recently demonstrated in insects, allowing for persistent infection of virus vectors.
Rhizoctonia solani, one of the most detrimental necrotrophic pathogens, causes rice sheath blight and poses a severe threat to production. Focus on the function of effectors secreted by necrotrophic pathogens during infection has grown rapidly in recent years. However, little is known about the virulence and mechanisms of these proteins. In this study, we performed functional studies on putative effectors in R. solani and revealed that AGLIP1 out of 13 putative effectors induced cell death in Nicotiana benthamiana. AGLIP1 was also demonstrated to trigger cell death in rice protoplasts. The predicted lipase active sites and signal peptide (SP) of this protein were required for the cell death-inducing ability. AGLIP1 was greatly induced during R. solani infection in rice sheath. The AGLIP1’s virulence function was further demonstrated by transgenic technology. The pathogenesis-related genes induced by pathogen-associated molecular pattern and bacteria were remarkably inhibited in AGLIP1-expressing transgenic Arabidopsis lines. Ectopic expression of AGLIP1 strongly facilitated disease progression in Arabidopsis caused by the type III secretion system-defective mutant from Pseudomonas syringae pv. tomato DC3000. Collectively, these results indicate that AGLIP1 is a possible effector that plays a significant role in pathogen virulence through inhibiting basal defenses and promoting disease development in plants.
Alyssa C. Fears, Rebecca C. Metzinger, Stephanie Z. Killeen
et al.
Abstract Background A multipurpose contact lens cleaning solution (MPS) containing novel active ingredients under development was compared to two commercially available MPS solutions for effectiveness against Acanthamoeba isolates. Methods The Acanthamoeba isolate A. castellanii was propagated for trophozoite or cyst-containing cultures for the purpose of assessment of effectiveness of each MPS. An alamar blue-based cellular respiration assay was used to assess effectiveness against trophozoites; Trypan blue hemocytometer-based microscopic counts measured cysticidal effects. To assess the general antimicrobial potency of each solution as controls for the anti-amoebic assays, comparative bactericidal effectiveness using Serratia marcenses was also performed. Results Minimal effectiveness against either Acanthamoeba form was observed from either commercial MPS. In contrast, the novel MPS achieved complete kill within 1 h contact time for both Acanthamoeba trophozoite and cysts. Each commercial MPS required 6 h contact time to achieve a two to three log reduction in S. marcenses. In contrast, the experimental MPS achieved disinfection in 60 min contact time, and complete kill (< 1 CFU) at 90 min. Conclusions Results suggest that the inclusion of a novel ingredient combination within the MPS under development clearly is required and is ideal for rapid and effective killing of Acanthamoeba species in the context of contact lens disinfection systems. The representative commercially available MPS used in this testing provided minimal effectiveness against the protozoa regardless of contact time. In addition, comparative results with the bacterial agent in the control study show distinct differences in the speed to disinfection with the novel MPS. Future MPS development should consider inclusion of novel chemical entities that are effective against Acanthamoeba species to speed disinfection and further reduce the exposure potential of users of contact lenses and cleaning systems.