Comparing Gene Expression Between Planktonic and Biofilm Cells of Foodborne Bacterial Pathogens Through RT-qPCR.

Like most microorganisms, important foodborne pathogenic bacteria, such as Salmonella enterica, Listeria monocytogenes, and several others as well, can attach to surfaces, of either abiotic or biotic nature, and create biofilms on them, provided the existence of supportive environmental conditions (e.g., permissive growth temperature, adequate humidity, and nutrient presence). Inside those sessile communities, the enclosed bacteria typically present a gene expression profile that differs from the one that would be displayed by the same cells growing planktonically in liquid media (free-swimming cells). This altered gene expression has important consequences on cellular physiology and behavior, including stress tolerance and induction of virulence. In this chapter, the methodology to use reverse transcription-quantitative polymerase chain reaction (RT-qPCR) to monitor and comparatively quantify expression changes in preselected genes of bacteria between planktonic and biofilm growth modes is presented.

Recombinant lactate-assimilating cyanobacteria reduce high-concentration culture-associated cytotoxicity in mammalian cells.

In the fields of cultured meat, biopharmaceuticals, cell therapy, and tissue engineering, large numbers of mammalian cells are required; thus, highly-concentrated cell cultures are widely adopted. In general, such cultures can lead to cell damage caused by waste product accumulation and nutritional inadequacy. In this study, a novel co-culture system where the recombinant lactate-assimilating cyanobacterial strain, KC0110, derived from euryhaline Picosynechococcus sp. PCC 7002, and mammalian muscle cells cultured across porous membranes been developed. By using the KC0110 strain, the amount of ammonium and lactate excreted from C2C12 mouse muscle cells into the culture significantly decreased. Importantly, pyruvate and some amino acids, including pyruvate-derived amino acids, also increased significantly compared to those in monoculture of C2C12 cells. It is believed that the organic acids secreted by the KC0110 strain enhance the growth of mammalian cells, leading to a reduction in high-concentration culture-induced mammalian cell damage [lactate dehydrogenase (LDH) release] through cyanobacterial co-culture. These results show that, through co-cultivation with cyanobacteria, it is possible to culture mammalian cells, alleviating cell damage, even in highly-concentrated cultures. This study demonstrated an in vitro "symbiotic circular system" that can interchange metabolites produced by phototrophs and mammalian cells.

Aging With Emerging Social Welfare and Disappearing Filial Piety: Chinese Migrant Workers' Pathways Toward Financial Retirement Planning.

This study examines the pathways and mechanisms linking Chinese migrant workers' migration experiences and their financial retirement planning. Using a mixed-methods approach with 1083 surveys and 32 interviews, this study finds that having a good financial status and social support system and maintaining a hopeful attitude toward retirement are direct pathways toward good financial retirement planning. Good health and hope for retirement are further enhanced by a good financial status and social support. Conversely, poor health and negative employment experiences are linked to poor financial retirement planning. The qualitative findings provide a contextual understanding of the pathways identified in the quantitative analyses. Migrant workers often face a dilemma between self-reliance for retirement and relying on filial piety. These findings apply not only to Chinese migrant workers but also to all migrant workers with limited access to healthcare and public pensions for retirement.

Enhanced Accumulation of Health-Promoting Cajaninstilbene Acid in Pigeon Pea Hairy Root Cultures Cocultured with an Endophytic Fungus during Early Stages of Colonization.

Endophytic fungi can effectively regulate the biosynthesis of health-beneficial metabolites in plants. However, few studies have revealed how the accumulation of host metabolites varies during interactions with endophytic fungi. Here, pigeon pea hairy root cultures (PPHRCs) were cocultured with an endophytic fungus Penicillium rubens to explore the impact on the biosynthesis and accumulation of cajaninstilbene acid (CSA). The results showed that CSA accumulation in PPHRCs increased significantly (15.29-fold) during the early stages of P. rubens colonization (fungal attachment and invasion phases). Once P. rubens successfully colonized the intercellular gap of hairy roots to form a symbiotic relationship, the CSA levels in PPHRCs decreased drastically. Moreover, P. rubens could be recognized by plant pattern recognition receptors that regulate immunity/symbiosis, triggering the expression of genes related to pathogenesis, CSA biosynthesis, and ABC transporter. Overall, P. rubens could enhance the accumulation of health-promoting CSA in PPHRCs during the early stages of colonization.

Elicitor-mediated simultaneous accumulation of phloridzin and ursolic acid in Annurca apple peel-derived calli.

BACKGROUND: Apple peel is rich in natural molecules, many exhibiting a significant bioactivity. In this study, our objective was to establish a novel callus line derived from the apple peel of the Italian local variety Annurca, known to accumulate high levels of dihydrochalcones and terpenes. In this regard, we tested the impact of one elicitor, yeast extract, on the expression of genes encoding key enzymes involved in phloridzin and ursolic acid biosynthesis, leading to the accumulation of these antioxidant compounds. We also assessed the bioactivity of callus extracts enriched in these phytochemicals. RESULTS: After the elicitation, data showed increased expression of genes directly related to the synthesis of phloridzin and ursolic acid that were found to accumulate within the cultures. This presumably could explain the remarkable activity of extracts from the elicited-calli in inhibiting the growth of Staphylococcus aureus and Bacillus cereus. Also, the extracts enriched in antioxidant compounds inhibited reactive oxygen species (ROS) production in human cells exposed to ultraviolet-A (UV-A) radiation. CONCLUSION: Our results underscore the vast potential of the Annurca apple peel cell line in producing natural compounds that can be employed as food components to promote human health. © 2024 The Author(s). Journal of the Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Mutagenesis selection and large-scale cultivation of non-green Chlamydomonas reinhardtii for food applications.

Background: The green alga Chlamydomonas reinhardtii is an accepted food ingredient in the United States of America (United States), the European Union, Singapore, and China. It can be consumed in unlimited quantities. As this alga is rich in nutrients, proteins, and rough polysaccharides and contains a balanced proportion of various amino acids, it is an excellent raw material for food production. Although various edible brown and green algae are available on the market, their color and strong grassy flavor have constrained their popularity among consumers, thereby limiting their application in food additives and animal feed. Methods: Chlorophyll-deficient C. reinhardtii mutants were developed using atmospheric and room temperature plasma (ARTP) technology. Results: A yellow-colored C. reinhardtii variant (A7S80) cultivated in dark conditions was isolated. This light-sensitive variant has a mutation in the chlM gene, and it can grow heterotrophically using acetate as a carbon source. Conclusion: Compared to wild-type C. reinhardtii, A7S80 has significantly lower chlorophyll levels, reduced grassy flavor, and more diverse pigments, with considerable potential for commercial application in human and animal food production, as well as in pharmaceutical and cosmetic industries.

Use of cardiac cell cultures from salmonids to measure the cardiotoxic effect of environmental pollutants.

Environmental stressors such as micro- and nanosized plastic particles (MNPs) or crude oil have a detrimental effect on aquatic animals; however, the impact upon the cardiovascular system of fish remains relatively under-researched. This study presents a novel approach for investigating the effect of crude oil and MNPs on the cardiac system of fish. We used salmonid larvae and cardiac cell cultures derived from hearts of salmonid fish and exposed them to environmental stressors. Following exposure to plastic particles or crude oil, the larvae exhibited some variation in contraction rate. In contrast, significant alterations in the contraction rate were observed in all cardiac cell cultures. The greatest differences between the control and treatment groups were observed in cardiac cell cultures derived from older brown trout. Following 7 days of exposure to MNPs or crude oil in Atlantic salmon larval hearts or cardiac cell cultures, there were only minor responses noted in mRNA expression of the selected marker genes. These findings show the use of a novel in vitro technique contributing to the existing body of knowledge on the impact of MNPs and crude oil on the cardiovascular system of salmonids and the associated risk.

Forward-reverse mutation cycles in cancer cell lines under chemical treatments.

Spontaneous forward-reverse mutations were reported by us earlier in clinical samples from various types of cancers and in HeLa cells under normal culture conditions. To investigate the effects of chemical stimulations on such mutation cycles, the present study examined single nucleotide variations (SNVs) and copy number variations (CNVs) in HeLa and A549 cells exposed to wogonin-containing or acidic medium. In wogonin, both cell lines showed a mutation cycle during days 16-18. In acidic medium, both cell lines displayed multiple mutation cycles of different magnitudes. Genomic feature colocalization analysis suggests that CNVs tend to occur in expanded and unstable regions, and near promoters, histones, and non-coding transcription sites. Moreover, phenotypic variations in cell morphology occurred during the forward-reverse mutation cycles under both types of chemical treatments. In conclusion, chemical stresses imposed by wogonin or acidity promoted cyclic forward-reverse mutations in both HeLa and A549 cells to different extents.

Fluctuating Asymmetry Spotted Wing Drosophila (Diptera: Drosophilidae) Exposed to Sublethal Doses of Acetamiprid and Nicotine.

Long-term exposure to low concentrations of toxic substances can cause several adverse consequences ranging from molecular to morphological. Sublethal doses may also lead to increased tolerance in the offspring of surviving individuals. One of the consequences of such stress is deviations from the ideal body symmetry during development, reflected by increased levels of fluctuating asymmetry (FA). This research aimed to verify FA in the wing veins of insects belonging to the Drosophilidae family-Drosophila suzukii, a fruit pest controlled by the insecticide acetamiprid, a neonicotinoid. To determine whether FA varied depending on insecticides present in the diet, multigenerational cultures of D. suzukii were carried out on media supplemented with different concentrations (below the LC50) of two insecticides. Nicotine was used as a positive control. Fecundity decreased, the number of insects decreased, and breeding did not continue beyond the tenth generation. However, the FA level at different concentrations was similar, and high FA values were observed even at lower acetamiprid concentrations. We did not see significant changes in FA levels in subsequent generations. D. suzukii proved extremely sensitive to acetamiprid, and FA is a good index of this sensitivity.

Validity of reducing blood culture incubation time for the BD BACTEC FX blood culture system considering microbiological and clinical aspects.

INTRODUCTION: A blood culture (BC) test is vital for diagnosing bacteremia in clinical practice. Although incubation time varies among automated BC systems, 4-5 days is deemed to be sufficient time for the BD BACTEC FX blood culture system. This study compared the clinical and microbiological characteristics of true-positive BC samples on day 5 with those within 4 days to reduce missed true bacteremia cases. METHODS: We conducted a retrospective study of blood cultures from hospitalized patients between April 2020 and April 2023 at a tertiary care hospital in Japan. RESULTS: In total, 12,342 BC sets were collected from 6,567 patients. Gram-positive bacilli other than Bacillus spp. and Corynebacterium spp., non-albicans Candida, and yeasts other than Candida spp. were detected more frequently in BC-positive patients on day 5 than in those within 4 days. The gastrointestinal tract was the portal of entry more frequently on day 5 than within 4 days (25 % vs. 4 %, p = 0.006). CONCLUSION: A 4-day incubation period is sufficient for the BD BACTEC FX blood culture system under routine conditions. However, a 5-day incubation period may be warranted when low pathogenicity is suspected or the gastrointestinal tract is suspected as the portal of entry.

Dietary supplementation of distiller's grains yeast cultures improves performance and immunity by altering the intestinal flora of broilers.

BACKGROUND: Distiller's grains are a by-product of liquor production with a higher yield than liquor. Developing and utilizing distiller's grains well could alleviate the problem of scarce feed resources. Our present experiment was conducted with 6000 yellow-feathered broilers to study the effects of adding distiller's grains yeast cultures (DGYC) to the diet on growth performance and immunity of broilers. The broilers were divided into five groups, receiving different DGYC concentrations during two stages. Growth performance, intestinal microorganisms and immune organ development were measured. RESULTS: The results showed that groups B and D, supplemented with medium and high concentrations of DGYC, respectively, had significantly improved growth performance compared to the control group (P < 0.05). Group D also showed higher immune organ index (P < 0.01), increased serum total protein, high-density lipoprotein and immunoglobulin levels (P < 0.05) and lower levels of low-density lipoprotein, triglycerides, interleukin 1ß and tumor necrosis factor α (P < 0.05). Hematoxylin and eosin staining confirmed improved immune organ development in group D (P < 0.05). Furthermore, in high-concentration group D, levels of short-chain fatty acids (SCFA; acetic, propionic and butyric acids) in cecal chyme were significantly increased (P < 0.05). The richness (Chao1) and diversity (Faith-pd) index of cecal microbiota were significantly higher in group D compared to the control group (P < 0.05). The microbial composition in group D differed from the control and medium-concentration group B. Seven bacteria (Clostridia-UCG-014, UCG-009, DTU089, UCG-010, Campylobacter, Harryflintia, Shuttleworthia) showed significant differences (P < 0.05). After DGYC feeding, DTU089 decreased, while other SCFA-producing bacteria increased (P < 0.05). Subsequently, KEGG function and corresponding signal pathway predictions were performed on bacteria with significant differences. Group D exhibited a higher enrichment of immune function pathways (P < 0.01) and showed significant changes in four immune signaling pathways according to the signal pathway heatmap. CONCLUSION: Our data suggest that high concentrations of DGYC can be applied as a feed additive for broilers that promotes growth, improves intestinal health and enhances certain immunity. © 2024 Society of Chemical Industry.

Selection of marine bacterial consortia efficient at degrading chitin leads to the discovery of new potential chitin degraders.

Chitin degradation is a keystone process in the oceans, mediated by marine microorganisms with the help of several enzymes, mostly chitinases. Sediment, seawater, and filter-feeding marine invertebrates, such as sponges, are known to harbor chitin-degrading bacteria and are presumably hotspots for chitin turnover. Here, we employed an artificial selection process involving enrichment cultures derived from microbial communities associated with the marine sponge Hymeniacidon perlevis, its surrounding seawater and sediment, to select bacterial consortia capable of degrading raw chitin. Throughout the artificial selection process, chitin degradation rates and the taxonomic composition of the four successive enrichment cultures were followed. To the best of our knowledge, chitin degradation was characterized for the first time using size exclusion chromatography, which revealed significant shifts in the numbered average chitin molecular weight, strongly suggesting the involvement of endo-chitinases in the breakdown of the chitin polymer during the enrichment process. Concomitantly with chitin degradation, the enrichment cultures exhibited a decrease in alpha diversity compared with the environmental samples. Notably, some of the dominant taxa in the enriched communities, such as Motilimonas, Arcobacter, and Halarcobacter, were previously unknown to be involved in chitin degradation. In particular, the analysis of published genomes of these genera suggests a pivotal role of Motilimonas in the hydrolytic cleavage of chitin. This study provides context to the microbiome of the marine sponge Hymeniacidon perlevis in light of its environmental surroundings and opens new ground to the future discovery and characterization of novel enzymes of marine origin involved in chitin degradation processes.IMPORTANCEChitin is the second most abundant biopolymer on Earth after cellulose, and the most abundant in the marine environment. At present, industrial processes for the conversion of seafood waste into chitin, chitosan, and chitooligosaccharide (COS) rely on the use of high amounts of concentrated acids or strong alkali at high temperature. Developing bio-based methods to transform available chitin into valuable compounds, such as chitosan and COS, holds promise in promoting a more sustainable, circular bioeconomy. By employing an artificial selection procedure based on chitin as a sole C and N source, we discovered microorganisms so-far unknown to metabolize chitin in the rare microbial biosphere of several marine biotopes. This finding represents a first important step on the path towards characterizing and exploiting potentially novel enzymes of marine origin with biotechnological interest, since products of chitin degradation may find applications across several sectors, such as agriculture, pharmacy, and waste management.

Cigarette Smoke-Induced Epithelial-to-Mesenchymal Transition: Insights into Cellular Mechanisms and Signaling Pathways.

This review delves into the molecular complexities underpinning the epithelial-to-mesenchymal transition (EMT) induced by cigarette smoke (CS) in human bronchial epithelial cells (HBECs). The complex interplay of pathways, including those related to WNT//ß-catenin, TGF-ß/SMAD, hypoxia, oxidative stress, PI3K/Akt, and NF-κB, plays a central role in mediating this transition. While these findings significantly broaden our understanding of CS-induced EMT, the research reviewed herein leans heavily on 2D cell cultures, highlighting a research gap. Furthermore, the review identifies a stark omission of genetic and epigenetic factors in recent studies. Despite these shortcomings, the findings furnish a consolidated foundation not only for the academic community but also for the broader scientific and industrial sectors, including large tobacco companies and manufacturers of related products, both highlighting areas of current understanding and identifying areas for deeper exploration. The synthesis herein aims to propel further research, hoping to unravel the complexities of the EMT in the context of CS exposure. This review not only expands our understanding of CS-induced EMT but also reveals critical limitations in current methodologies, primarily the reliance on 2D cell cultures, which may not adequately simulate more complex biological interactions. Additionally, it highlights a significant gap in the literature concerning the genetic and epigenetic factors involved in CS-induced EMT, suggesting an urgent need for comprehensive studies that incorporate these types of experiments.

Unlocking specialized metabolism in medicinal plant biotechnology through plant-microbiome interactions.

Medicinal plants produce specialized metabolites (SM) that are used as drugs. However, due to low yields of field cultivation and the increasing market demand, this production method often failed to meet supply needs. Biotechnological alternatives, such as in vitro plant cultures, offer promising solutions. Nonetheless, SM production in these systems remains too low for industrial exploitation, necessitating an elicitation step to induce the plant defense metabolism. Traditional elicitation methods mimic environmental conditions that trigger plant-specialized metabolism, often with an artificial signal that mimics microbial interaction. Recent insights into the essential role of the plant microbiota, provides new opportunities for elicitation strategies by microbial coculture in a controlled environment. The successful co-culture of in vitro medicinal plants with synthetic microbial communities could enable sustainable production of pharmaceutically important SM.

Antibacterial and therapeutic potential of historic deposits of silesian healing clay - terra sigillataSilesiaca.

ETHNOPHARMACOLOGICAL RELEVANCE: The increasing evolution of pathogen resistance is a global problem that requires novel solutions. Recently, an increased interest in ethnomedicinal sources can be observed in the derivation of new medicines. The return to traditional medicinal formulations handed down for generations is being followed, but it is necessary to revise them again, taking into account the generally accepted research protocol. AIM OF THE STUDY: We aimed to evaluate the antimicrobial potential of historical deposits of Silesian healing clay (SHC), used in ethnomedicine against Gram-positive bacteria and to assess their biological activity using a primary dermal fibroblast line (NHDF) and a model monocyte line (THP1). MATERIALS AND METHODS: Information on medicinal clay deposits that occur in Silesia and are traditionally used in ethnomedicine or ancient medicine and known as terra sigillata Silesiaca or SHC, was selected on available source materials and old prints and maps from the archives of the Polish Geological Institute (Wroclaw, Poland). Subsequently, their places of occurrence were identified and traced in the field by taking three deposits from the Silesia territory: Upper Silesia (D1), Opole Silesia (D2), and Lower Silesian (D3) Voivodeships for analysis. Their basic parameters and antimicrobial efficacy against pathogenic bacteria, Gram-positive streptococci and staphylococci, including methicillin-resistant strains, were examined. The study evaluated the effects of clays on growth and vitality using a primary dermal fibroblast line (NHDF) and a monocytic line (THP1). Studies were performed on a cell culture model to determine the effects on tissue regeneration (fibroblasts) and anti-inflammatory effects (monocytes). The study attempted to identify the mechanism of antimicrobial action, especially the textural characteristics and geochemical composition, as well as the environmental reaction (pH). RESULTS: SHCs were classified into the following textural classes: clay loam (D1), clay (D2), and sand (D3). The tested deposits have antimicrobial properties that reduce the bacterial population (104 CFU) compared to the control (108 CFU). The antimicrobial effect depends on the type of clay and the species or strain of bacteria used. In-house studies clearly showed that Staphylococcus aureus Pcm 2054 and Staphylococcus epidermidis MRSE ATCC 2538 cells were completely adsorbed by clay minerals from clay D3.13. Furthermore, 10% leachates also showed an antimicrobial effect, as a reduction in bacterial populations was observed ranging from 91 to 100%. The results showed stimulation of fibroblast culture proliferation and inhibition of the growth of inflammatory cells (monocytes). CONCLUSION: SHCs tested have antimicrobial potential, in particular D2.7, D2.11, and D3.13. The D3.13 deposit had a bactericidal effect against the staphylococci tested. Aqueous solutions of clays also showed bacteriostatic effect. The results obtained in cell culture model tests indicate properties that modulate the healing process - stimulation of fibroblast growth (NHDF line) and inhibition of monocyte growth (THP1 line).

Every Crisis Is an Opportunity: Advancing Blood Culture Stewardship During a Blood Culture Bottle Shortage.

The current manufacturing disruption of BACTEC blood culture bottles has drawn attention to diagnostic stewardship around blood culture utilization. In this perspective, we offer strategies for implementing blood culture stewardship using a graded approach based on a hospital's blood culture bottle supply. These strategies should inform plans to mitigate the impact of the shortage on patient care and reinforce fundamental principles of blood culture stewardship.

Advancing 3D Spheroid Research through 3D Scaffolds Made by Two-Photon Polymerization.

Three-dimensional cancer cell cultures have been a valuable research model for developing new drug targets in the preclinical stage. However, there are still limitations to these in vitro models. Scaffold-based systems offer a promising approach to overcoming these challenges in cancer research. In this study, we show that two-photon polymerization (TPP)-assisted printing of scaffolds enhances 3D tumor cell culture formation without additional modifications. TPP is a perfect fit for this task, as it is an advanced 3D-printing technique combining a µm-level resolution with complete freedom in the design of the final structure. Additionally, it can use a wide array of materials, including biocompatible ones. We exploit these capabilities to fabricate scaffolds from two different biocompatible materials-PEGDA and OrmoClear. Cubic spheroid scaffolds with a more complex architecture were produced and tested. The biological evaluation showed that the human ovarian cancer cell lines SKOV3 and A2780 formed 3D cultures on printed scaffolds without a preference for the material. The gene expression evaluation showed that the A2780 cell line exhibited substantial changes in CDH1, CDH2, TWIST, COL1A1, and SMAD3 gene expression, while the SKOV3 cell line had slight changes in said gene expression. Our findings show how the scaffold architecture design impacts tumor cell culture 3D spheroid formation, especially for the A2780 cancer cell line.

Criticality and universality in neuronal cultures during "up" and "down" states.

The brain can be seen as a self-organized dynamical system that optimizes information processing and storage capabilities. This is supported by studies across scales, from small neuronal assemblies to the whole brain, where neuronal activity exhibits features typically associated with phase transitions in statistical physics. Such a critical state is characterized by the emergence of scale-free statistics as captured, for example, by the sizes and durations of activity avalanches corresponding to a cascading process of information flow. Another phenomenon observed during sleep, under anesthesia, and in in vitro cultures, is that cortical and hippocampal neuronal networks alternate between "up" and "down" states characterized by very distinct firing rates. Previous theoretical work has been able to relate these two concepts and proposed that only up states are critical whereas down states are subcritical, also indicating that the brain spontaneously transitions between the two. Using high-speed high-resolution calcium imaging recordings of neuronal cultures, we test this hypothesis here by analyzing the neuronal avalanche statistics in populations of thousands of neurons during "up" and "down" states separately. We find that both "up" and "down" states can exhibit scale-free behavior when taking into account their intrinsic time scales. In particular, the statistical signature of "down" states is indistinguishable from those observed previously in cultures without "up" states. We show that such behavior can not be explained by network models of non-conservative leaky integrate-and-fire neurons with short-term synaptic depression, even when realistic noise levels, spatial network embeddings, and heterogeneous populations are taken into account, which instead exhibits behavior consistent with previous theoretical models. Similar differences were also observed when taking into consideration finite-size scaling effects, suggesting that the intrinsic dynamics and self-organization mechanisms of these cultures might be more complex than previously thought. In particular, our findings point to the existence of different mechanisms of neuronal communication, with different time scales, acting during either high-activity or low-activity states, potentially requiring different plasticity mechanisms.

Prevalence, risk factors, microbiological results and clinical outcome in unexpected positive intraoperative cultures in unclear and presumed aseptic hip and knee revision arthroplasties - A ten-year retrospective analysis with a minimum follow up of 2 years.

Background: The aim of this study was to assess the prevalence, microbiological spectrum, risk factors, and clinical outcomes of unexpected-positive-intraoperative-cultures (UPIC) in presumed aseptic and unclear revision-total-hip-/knee-arthroplasties (rTHA and rTKA) compared to culture-negative (CN) revisions. Methods: This study reviewed all International-consensus-meeting-2018 (ICM 2018) negative or inconclusive rTHA (n = 751) and rTKA (n = 679) performed at our institution from 2011 to 2020 with a minimum follow-up of two years. A Kaplan-Meier-analysis was performed to determine the septic and aseptic-free implant survival in cases with UPIC's and matched culture-negative cases. Patient demographics, risk factors, microbiological spectrum and clinical outcomes were evaluated. Results: There were significantly more UPIC cases in rTHA 196/751 (26.1 %) compared to rTKA 113/679 (16.6 %); (p < 0.001). UPICs in rTKA and rTHA have a lower septic and aseptic implant-free-survival compared to CN revisions. Patients with a history of nickel allergy have a higher risk of an UPIC in rTHA and rTKA (p < 0.001). Septic re-revisions after UPIC had a significantly (H: p = 0.004; K: p = 0.030) shorter time period to the primary/previous surgery (H: 84 (IQR:41-797); K: 115 (IQR:55-446)) compared to patients with aseptic re-revisions after UPIC (H:1248 (IQR:178-3534); K: 827 (IQR:361-1183)). Conclusion: UPICs have a higher rate of septic and aseptic failure than CN outcomes. UPICs are twice as common in rTHA compared to rTKA. Preoperative PJI workup reduces the UPIC rate. Nickel allergy is a risk factor for UPIC. Early revisions with UPICs after primary THA or TKA have a higher risk of septic failure. The translational potential of this article: This article provides new information on revision rates for UPIC and potential risk factors for UPIC and its treatment failure.