Additional Strains Research Articles

THE LIMITING STATE OF A STEEL STRUCTURE UNDER EXTREME THERMOMECHANICAL LOADINGS

Using numerical methods, the problem of determining the strength and limiting state of a steel shell structure under thermomechanical loading is solved. The operating stresses are determined by solving a physically nonlinear boundary value problem for a shell of revolution. The classical theory of shells, based on the Kirchhoff – Love hypotheses, and the method of integrating shell equations with discrete S.K. Godunov orthogonalization are used. By integrating a system of ordinary differential equations at each point of the shell, the meridional and circumferential stresses and the corresponding deformations are calculated. When taking into account the plastic deformation of the material, the boundary value problem becomes nonlinear. The relationship between stress and strain is linearized by the method of additional strains. A limiting state criterion for thin-walled structures is proposed. In the absence of the necessary parameters for the material of construction, interpolation and extrapolation of the experimental data based on neural networks is used. The method uses the example of a muffle, which is a revolution shell structure loaded with an internal excess pressure of a hydrogen-containing gas and a non-stationary thermal field. The muffle is designed for high-temperature annealing of the electrolytic steel, and is made of non-heat-resistant St3 steel, its mechanical properties have not been sufficiently studied at temperatures above 500 °C. However, the operating temperature of the muffle can reach more than 1000 °C. Under the influence of such a thermal load, noticeable residual deformations are formed in the muffle structure and the muffle may lose its load-bearing capacity. For thermomechanical loads, a maximum temperature of 1000 °C is determined at which the limit state occurs and the operation of the muffle is not permissible. A satisfactory agreement was obtained with the actual muffle temperature during operations of 1100 °C, at which the muffle loses its load-bearing capacity.

A unique Helicobacter pylori strain to study gastric cancer development.

Helicobacter pylori colonizes a majority of the human population worldwide and can trigger development of a variety of gastric diseases. Since the bacterium is classified as a carcinogen, elucidation of the characteristics of H. pylori that influence gastric carcinogenesis is a high priority. To this end, the Mongolian gerbil infection model has proven to be an important tool to study gastric cancer progression. However, only a small number of H. pylori strains have been evaluated in the gerbil model. Thus, to identify additional strains able to colonize and induce disease in this model, several H. pylori strains were used to infect Mongolian gerbils, and stomachs were harvested at multiple timepoints to assess colonization and gastric pathology. The USU101 strain reproducibly colonized Mongolian gerbils and induced gastric inflammation in the majority of the animals 1 month after infection. Adenocarcinoma or dysplasia was observed in the majority of gerbils by 2 months post-infection. To define the contribution of key virulence factors to this process, isogenic strains lacking cagA or vacA, along with restorant strains containing a wild-type (WT) copy of the genes, were studied. The ΔcagA USU101 strain colonized gerbils at levels similar to WT, but did not induce comparable levels of inflammation or disease. In contrast, the ΔvacA USU101 strain did not colonize gerbils, and the stomach pathology resembled that of the mock-infected animals. The restorant USU101 strains expressed the CagA and VacA proteins in vitro, and in vivo experiments with Mongolian gerbils showed a restoration of colonization levels and inflammation scores comparable to those observed in WT USU101. Our studies indicate that the USU101 strain is a valuable tool to study H. pylori-induced disease.IMPORTANCEGastric cancer is the fifth leading cause of cancer-related death globally; the majority of gastric cancers are associated with Helicobacter pylori infection. Infection of Mongolian gerbils with H. pylori has been shown to result in induction of gastric cancer, but few H. pylori strains have been studied in this model; this limits our ability to fully understand gastric cancer pathogenesis in humans because H. pylori strains are notoriously heterogenous. Our studies reveal that USU101 represents a unique H. pylori strain that can be added to our repertoire of strains to study gastric cancer development in the Mongolian gerbil model.

Characterization of the exopolysaccharides produced by the industrial yeast Komagataella phaffii.

The yeast Komagataella phaffii has become a popular host strain among biotechnology startup companies for producing recombinant proteins for food and adult nutrition applications. K. phaffii is a host of choice due to its long history of safe use, open access to protocols and strains, a secretome free of host proteins and proteases, and contract manufacturing organizations with deep knowledge in bioprocess scale-up. However, a recent publication highlighted the abundance of an unknown polysaccharide that accumulates in the supernatant during fermentation. This poses a significant challenge in using K. phaffii as a production host. This polysaccharide leads to difficulties in achieving high purity products and requires specialized and costly downstream processing steps for removal. In this study, we describe the use of the common K. phaffii host strain YB-4290 for production of the bioactive milk protein lactoferrin. Upon purification of lactoferrin using membrane-based separation methods, significant amounts of carbohydrate were co-purified with the protein. It was determined that the carbohydrate is mostly composed of mannose residues with minor amounts of glucose and glucosamine. The polysaccharide fraction has an average molecular weight of 50 kDa and consists mainly of mannan, galactomannan and amylose. In addition, a large fraction of the carbohydrate has an unknown structure likely composed of oligosaccharides. Additional strains were tested in fermentation to further understand the source of the carbohydrates. The commonly used industrial hosts, BG10 and YB-4290, produce a basal level of exopolysaccharide; YB-4290 producing slightly more than BG10. Overexpression of recombinant protein stimulates exopolysaccharide production well above levels produced by the host strains alone. Overall, this study aims to provide a foundation for developing methods to improve the economics of recombinant protein production using K. phaffii as a production host.

Evaluating the Efficacy of Ɛ-poly-lysine, Hydrogen Peroxide, and Lauric Arginate to Inhibit Listeria monocytogenes Biofilm Formation and Inactivate Mature Biofilms

Preventing the introduction of Listeria monocytogenes, subsequent biofilm formation, and persistence in food processing environments is important for reducing the risk of cross-contamination of ready-to-eat foods. This study determined the effect of Ɛ-poly-lysine (EPL), hydrogen peroxide (HP), and lauric arginate (LAE) on L. monocytogenes biofilm formation and the inactivation of mature biofilms. For inhibition studies, biofilms of L. monocytogenes Scott A (serotype 4b) and 2014L-6025 (1/2b) were developed separately at 37 °C for 48 h in the presence of sub-inhibitory concentrations (SIC) of either EPL (10 ppm), HP (2 ppm), or LAE (1.5 ppm) on polystyrene plates and stainless-steel rounds. Inactivation was determined by exposing mature biofilms on each surface to each antimicrobial at their minimum bactericidal concentration (MBC), 10xMBC, or 100xMBC for 24 h at 37 °C. The presence of these antimicrobials at SIC did not inhibit biofilm formation on either surface and their effect on mature biofilms varied by strain and surface. Application of EPL at 1xMBC (100 ppm) for 24 h resulted in greater reductions in counts of both strains on polystyrene than HP (40 ppm) and LAE (5 ppm) under the same conditions at 1xMBC (P ≤ 0.0243). Exposure of mature biofilms to LAE at 10xMBC (50 ppm) for 1 h was more effective in reducing counts on polystyrene than HP at 10xMBC (400 ppm) for the same duration (P ≤ 0.0136), and both HP and LAE applied at 100xMBC (4,000 and 500 ppm, respectively) for 24 h more effectively inactivated mature biofilms of L. monocytogenes Scott A on polystyrene compared to EPL (10,000 ppm) (P ≤ 0.0307). Application of LAE at 10xMBC for 24 h was more effective at inactivating strain Scott A on stainless steel compared to 10xMBC of EPL (1,000) or HP (P ≤ 0.0430). Future studies are needed to determine the efficacy of these and other antimicrobials on additional strains and serotypes of L. monocytogenes at temperatures relevant to food production and storage.

Insights into human norovirus cultivation in human intestinal enteroids.

Human noroviruses (HuNoVs) are a significant cause of epidemic and sporadic acute gastroenteritis worldwide. The lack of a reproducible culture system hindered the study of HuNoV replication and pathogenesis for almost a half-century. This barrier was overcome with our successful cultivation of multiple HuNoV strains in human intestinal enteroids (HIEs), which has significantly advanced HuNoV research. We optimized culture media conditions and generated genetically modified HIE cultures to enhance HuNoV replication in HIEs. Building upon these achievements, we now present new insights into this culture system, which involve testing different media, unique HIE lines, and additional virus strains. HuNoV infectivity was evaluated and compared in new HIE models, including HIEs generated from different intestinal segments of individual adult organ donors, HIEs from human intestinal organoids produced from directed differentiation of human embryonic stem cells that were then transplanted and matured in mice before making enteroids (H9tHIEs), genetically engineered (J4FUT2 knock-in [KI], J2STAT1 knockout [KO]) HIEs, as well as HIEs derived from a patient with common variable immunodeficiency (CVID) and from infants. Our findings reveal that small intestinal HIEs, but not colonoids, from adults, H9tHIEs, HIEs from a CVID patient, and HIEs from infants support HuNoV replication with segment and strain-specific differences in viral infection. J4FUT2-KI HIEs exhibit the highest susceptibility to HuNoV infection, allowing the cultivation of a broader range of genogroup I and II HuNoV strains than previously reported. Overall, these results contribute to a deeper understanding of HuNoVs and highlight the transformative potential of HIE cultures in HuNoV research.IMPORTANCEHuman noroviruses (HuNoVs) cause global diarrheal illness and chronic infections in immunocompromised patients. This paper reports approaches for cultivating HuNoVs in secretor positive human intestinal enteroids (HIEs). HuNoV infectivity was compared in new HIE models, including ones from (i) different intestinal segments of single donors, (ii) human embryonic stem cell-derived organoids transplanted into mice, (iii) genetically modified lines, and (iv) a patient with common variable immunodeficiency disease. HIEs from small intestine, but not colon, support HuNoV replication with donor, segment, and strain-specific variations. Unexpectedly, HIEs from one donor are resistant to GII.3 infection. The genetically modified J4FUT2 knock-in (KI) HIEs enable cultivation of a broad range of GI and GII genotypes. New insights into strain-specific differences in HuNoV replication in HIEs support this platform for advancing understanding of HuNoV biology and developing potential therapeutics.

Kajian Sosiologis Pungutan Tapera Terhadap Buruh

This article examines the impact of the Public Housing Savings Program (Tapera) on Indonesian workers from both legal and social perspectives. The program mandates a 3% salary deduction, shared between employees and employers. However, the policy has faced significant criticism for increasing financial burdens on workers, particularly during challenging economic conditions. The study employs a normative legal approach to analyze relevant regulations and assess the social impact of its implementation. The findings indicate that, while Tapera aims to improve workers' access to housing, it imposes additional financial strains. Furthermore, the lack of worker participation in the policy-making process exacerbates dissatisfaction. To address these issues, it is recommended that the government review the Tapera policy with active involvement from workers and labor unions. Alternative funding mechanisms, such as subsidies from the state budget or lighter installment schemes, should also be considered. A more inclusive and equitable approach could not only enhance the program's effectiveness but also foster stronger relationships between workers, the government, and employers, thereby achieving a better balance in its implementation.

Accessing breast cancer care in a protracted conflict: Qualitative exploration of the perspectives of women with breast cancer in northwest Syria

BackgroundWomen with breast cancer in northwest Syria, an area of protracted armed conflict, face multiple intersecting challenges to accessing care which may relate to gender, social structures, and financial constraints. Our aim was to explore the perspectives of women with breast cancer in northwest Syria about the impact of their diagnosis and experiences of accessing care. MethodsWomen who accessed diagnosis or clinical care at the Syrian American Medical Society (SAMS) oncology centre in Idlib city during 2022 were identified from hospital records; they were invited to participate in semi-structured interviews conducted in Arabic by four local female-trained researchers. Participation was voluntary and informed consent was sought. Semi-structured interviews were conducted in August and September 2022 until thematic saturation was reached. Data were audio recorded and transcribed in Arabic before translation and thematic analysis using Nvivo to identify key emerging themes. Results22 women with breast cancer were interviewed. Findings were categorised into three themes: 1. Challenges to accessing oncology care in northwest Syria 2. Interactions with healthcare workers 3. The role of community and society. All participants noted the financial strains which the breast cancer diagnosis placed on them and their families. Most also noted the additional strains of travelling long distances, either in northwest Syria or to Turkey, where referral would entail additional costs, bureaucracy or isolation from family or social support. Some participants described social impacts including the expectation that they would continue with household chores and childcare even while ill. Patients reported that strong faith, having children, compassion from healthcare staff and peer support as being important factors for coping with their diagnosis and treatment. ConclusionThough there have been improvements to breast cancer care in northwest Syria, stock-outs and the lack of availability of radiotherapy may still force women to travel to Turkey for further investigations or treatment. Our findings suggest increased support for women with breast cancer as well as their families is required. This work is a starting point for future research on this topic both in northwest Syria and other areas in Syria.

Exploration of laser-assisted chemical bath for enhancing synthesis of undoped and nickel-doped zinc oxide and its potential applications in water purification and mitigating antimicrobial resistance

This study aims to explore the antimicrobial and photocatalytic efficiencies of pure and Ni-doped ZnO nanostructures produced via Laser-assisted Chemical Bath Synthesis (LACBS) to develop sustainable solutions for water treatment and pathogen control amid the global water crisis exacerbated by climate change and environmental pollution. Utilizing zinc acetate dihydrate and hexamethylenetetramine, the nanostructures were synthesized with Ni doping levels of 0.0 %, 1.5 %, 3.0 %, and 4.5 %, targeting their promising photocatalytic and antimicrobial properties to combat contaminants from pharmaceuticals, agriculture, and industries. Morphological analyses using Scanning Electron Microscopy showed a transition from hexagonal particles to nanoflowers, enhancing photocatalytic activity due to increased surface-to-volume ratio. X-ray Diffraction confirmed the hexagonal wurtzite structure, with variations in peak intensities indicating improved crystallinity with Ni doping. Energy Dispersive X-ray analysis verified the purity and successful incorporation of Ni. Photocatalytic assessments indicated up to 99.24 % degradation of Methylene Orange dye under blue laser irradiation within 60 minutes, correlating with Ni content. Antimicrobial tests demonstrated effective inhibition of pathogens such as Escherichia coli, Staphylococcus aureus, and additional strains like Candida albicans and Klebsiella pneumonia, with increasing zones of inhibition corresponding to higher Ni levels, extending up to 37 mm. The results underscore the dual functionality of ZnO nanostructures for applications in sustainable water treatment and antimicrobial controls, highlighting the need for future studies to examine the impacts of further increased doping concentrations on the material properties and efficacy.

Early identification of the nosocomial spread of vancomycin-resistant Enterococcus faecium by Fourier-transform infrared spectroscopy and performance comparison with PFGE and WGS

ABSTRACT Early detection of disseminating vancomycin-resistant Enterococcus faecium (VREfm) in ICU wards is crucial for outbreak identification and the implementation of prompt infection control measures. Genotypic methods like pulsed-field gel electrophoresis (PFGE) and whole-genome sequencing (WGS) are costly and time-consuming, hindering rapid response due to batch dependency. Fourier-transform infrared spectroscopy (FT-IR) offers the potential for real-time outbreak detection and reliable strain typing. We utilized FT-IR to identify clonal VREfm dissemination and compared its performance to PFGE and WGS. Between February through October 2023, an unusually high number of VREfm were recovered at a tertiary hospital in Barcelona. Isolates were examined for antimicrobial susceptibility, carriage of vanA/vanB genes and clonality was also studied using FT-IR, PFGE, and WGS. Routine FT-IR inspections revealed recurring VREfm clustering during the outbreak's initial weeks. In total, 104 isolates were recovered from 75 patients and from multiple wards. However, only one isolate was recovered from an environmental sample, suggesting the absence of environmental reservoirs. An ST80 vancomycin-resistant (vanA) E. faecium strain was the main strain responsible for the outbreak, although a few additional VREfm strains were also identified, all belonging to CC17. PFGE and cgMLST (WGS) yielded identical clustering results to FT-IR, and WGS confirmed vanA/vanB gene carriage in all VREfm isolates. Infection control measures led to a rapid decline in VREfm isolates, with no isolates detected in November. FT-IR spectroscopy offers rapid turnaround times, sensitivity, and reproducibility, comparable to standard typing methods. It proved as an effective tool for monitoring VREfm dissemination and early outbreak detection.

Longitudinal Screening for Oral High-Risk Non-HPV16 and Non-HPV18 Strains of Human Papillomavirus Reveals Increasing Prevalence among Adult and Pediatric Biorepository Samples: A Pilot Study.

Most high-risk oral human papillomavirus research has focused on prevalent HPV16 and HPV18, with fewer studies focused on other high-risk strains incorporated into the nine-valent HPV vaccine. Therefore, the objective of this study was to determine the oral prevalence of non-HPV16 and non-HPV18 high-risk strains. A total of n = 251 existing biorepository saliva samples were screened using validated primers and qPCR. A total of n = 72 samples tested positive for HPV, including HPV31, HPV33, HPV35, HPV52, and HPV58. In addition, there were also significant increases in the prevalence of these high-risk strains (2011-2014, 21.3%) following the nine-valent HPV vaccine's introduction (2015-2019, 36.2%). However, the distribution of HPV-positive samples was nearly equal among males and females (52.8%, 47.2%, respectively, p = 0.5485), although the majority (66.7%) of the HPV-positive samples were within the HPV vaccination age (11 to 26 years) or catch-up range (27 to 45 years). These data demonstrated that the prevalence of high-risk oral HPV may be higher than anticipated, highly concentrated among patients within the recommended vaccination age range, and may be increasing over time-providing new evidence and support for the nine-valent HPV vaccine that covers these additional high-risk HPV strains.

Xanthomonas Strains Isolated from Hosts in the Family Araceae Reveal Diverse Phylogenetic Relationships and Origins.

The family Araceae, comprising ornamentals including Anthurium, Dieffenbachia, Philodendron, Colocasia, and Zantedeschia, is susceptible to Xanthomonas pathogens. Previous analyses have established heterogeneity in aroid strains, yet unresolved taxonomic positions and dynamics between Xanthomonas and frequently associated Stenotrophomonas in aroids necessitate in-depth genetic investigation to resolve these complex relationships. This study utilized multilocus sequence analysis of housekeeping genes atpD, dnaA, dnaK, gltA, and gyrB to investigate 59 aroid strains, selected based on hosts, time, and geographical origins. After adding sequences from additional strains from NCBI GenBank, analysis of 161 concatenated sequences indicated that all aroid strains fell within Xanthomonas and Stenotrophomonas. Thirty-six strains isolated from Anthurium grouped under X. phaseoli, with outliers including one strain each in X. arboricola and X. sacchari and two in Stenotrophomonas. Six strains from Caladium, Dieffenbachia, and Philodendron formed host-specific subgroups within X. euvesicatoria. One strain from Dieffenbachia aligned with X. campestris, whereas strains from Colocasia, Aglaonema, and Spathiphyllum clustered with X. sacchari. Apart from the zantedeschia strain described as X. arboricola pv. zantedeschiae, two colocasia, one epipremnum, and one anthurium strain joined the X. arboricola group. Overall, this study revealed significant heterogeneity among aroid strains, with anthurium strains clustering closely despite distant geographical origins. The analysis underscores the complexity of host-pathogen specificity within Xanthomonas and emphasizes the need for further taxonomic clarification through whole-genome analysis of representative strains. The findings of this research will facilitate strain selection for inclusivity and exclusivity panels in developing diagnostic assays for X. phaseoli and xanthomonads affecting aroids.

Bile acid-sensitive human norovirus strains are susceptible to sphingosine-1-phosphate receptor 2 inhibition.

Human noroviruses (HuNoVs) are a diverse group of RNA viruses that cause endemic and pandemic acute viral gastroenteritis. Previously, we reported that many HuNoV strains require bile or bile acid (BA) to infect human jejunal intestinal enteroid cultures. BA was not essential for the replication of a pandemic-causing GII.4 HuNoV strain. We found the hydrophobic BA glycochenodeoxycholic acid (GCDCA) promotes the replication of the BA-dependent strain GII.3 in jejunal enteroids. Furthermore, we found that inhibition of the G-protein-coupled BA receptor, sphingosine-1-phosphate receptor 2 (S1PR2), by JTE-013, reduced GII.3 infection dose-dependently and inhibited GII.3 cellular uptake in enteroids. Herein, we sought to determine whether S1PR2 is required for other BA-dependent HuNoV strains, the BA-independent GII.4, and whether S1PR2 is required for BA-dependent HuNoV infection in HIEs from other small intestinal segments. We found a second S1PR2 inhibitor, GLPG2938, reduces GII.3 infection dose-dependently, and an S1PR2 agonist (CYM-5520) enhances GII.3 replication in the absence of GCDCA. GII.3 replication also is abrogated in the presence of JTE-013 and CYM-5520. JTE-013 inhibition of S1PR2 in jejunal HIEs reduces GI.1, GII.3, and GII.17 (BA-dependent) but not GII.4 Sydney (BA-independent) infection, providing additional evidence of strain-specific differences in HuNoV infection. Finally, GII.3 infection of duodenal, jejunal, and ileal lines derived from the same individual is reduced with S1PR2 inhibition, indicating a common mechanism of BA-dependent infection among multiple segments of the small intestine. Our results support a model where BA-dependent HuNoVs exploit BA effects on S1PR2 to infect the entire small intestine.IMPORTANCEHuman noroviruses (HuNoVs) are important viral human pathogens that cause both outbreaks and sporadic gastroenteritis. These viruses are diverse, and many strains are capable of infecting humans. Our previous studies have identified strain-specific requirements for hydrophobic bile acids (BAs) to infect intestinal epithelial cells. Moreover, we identified a BA receptor, sphingosine-1-phosphate receptor 2 (S1PR2), required for infection by a BA-dependent strain. To better understand how various HuNoV strains enter and infect the small intestine and the role of S1PR2 in HuNoV infection, we evaluated infection by additional HuNoV strains using an expanded repertoire of intestinal enteroid cell lines. We found that multiple BA-dependent strains, but not a BA-independent strain, all require S1PR2 for infection. In addition, BA-dependent infection requires S1PR2 in multiple segments of the small intestine. Together, these results indicate that S1PR2 has value as a potential therapeutic target for BA-dependent HuNoV infection.

In Vivo Visualization of Calcium Transients during Fertilization and Early Development in C. elegans.

Calcium is an important signaling molecule during the oocyte-to-embryo transition (OET) and early embryogenesis. The hermaphroditic nematode Caenorhabditis elegans provides several unique advantages for the study of the OET as it is transparent and has an ordered gonad that produces one mature oocyte every ~23 min at 20 °C. We have modified the genetically encoded calcium indicator jGCaMP7s to fluorescently indicate the moment of fertilization within a living organism. We have termed this reporter "CaFE" for Calcium during Fertilization in C. elegans. The CaFE reporter wasengineered into a safe harbor locus in single copy, has no significant impact on physiology or fecundity, and produces a robust signal upon fertilization. Here, a series of protocols is presented for utilizing the CaFE reporter as an in vivo tool for dissecting the OET and embryogenesis. We include methods to synchronize worms, examine the effects of RNAi knockdown, mount worms for imaging, and to visualize calcium in oocytes and embryos. Additionally, we present the generation of additional worm strains to aid in this type of analysis. Demonstrating the utility of the CaFE reporter to visualize the timing of fertilization, we report that double ovulation occurs when ipp-5 is targeted by RNAi and that only the first oocyte undergoes immediate fertilization. Furthermore, the discovery of single-cell calcium transients during early embryogenesis is reported here, demonstrating that the CaFE reporter persists into early development. Importantly, the CaFE reporter in worms is simple enough to use for incorporation into course-based undergraduate research (CURE) laboratory classes. The CaFE reporter, coupled with the ordered gonad and ease of RNAi in worms, facilitates inquiry into the cell-cell dynamics required to regulate internal fertilization and early embryogenesis.

Epidemiology of Clostridioides difficile infection at one hospital 10 years after an outbreak of the epidemic C. difficile strain BI/027: changing strain prevalence, antimicrobial susceptibilities, and patient antibiotic exposures.

In contrast to the epidemiology 10 years earlier at our hospital when the epidemic restriction endonuclease analysis (REA) group strain BI accounted for 72% of Clostridioides difficile isolates recovered from first-episode C. difficile infection (CDI) cases, BI represented 19% of first-episode CDI isolates in 2013-2015. Two additional REA group strains accounted for 31% of isolates (Y, 16%; DH, 12%). High-level resistance to fluoroquinolones and azithromycin was more common among BI isolates than among DH, Y, and non-BI/DH/Y isolates. Multivariable analysis revealed that BI cases were 2.47 times more likely to be associated with fluoroquinolone exposure compared to non-BI cases (95% confidence interval [CI]: 1.12-5.46). In addition, the odds of developing a CDI after third- or fourth-generation cephalosporin exposure was 2.83 times for DH cases than for non-DH cases (95% CI: 1.06-7.54). Fluoroquinolone use in the hospital decreased from 2005 to 2015 from a peak of 113 to a low of 56 antimicrobial days/1,000 patient days. In contrast, cephalosporin use increased from 42 to 81 antimicrobial days/1,000 patient days. These changes correlated with a decrease in geometric mean MIC for ciprofloxacin (61.03 to 42.65 mg/L, P = 0.02) and an increase in geometric mean MIC for ceftriaxone (40.87 to 86.14 mg/L, P < 0.01) among BI isolates. The BI strain remained resistant to fluoroquinolones, but an overall decrease in fluoroquinolone use and increase in cephalosporin use were associated with a decrease in the prevalence of BI, an increased diversity of C. difficile strain types, and the emergence of strains DH and Y.

Differential adaptation of the yeast Candida anglica to fermented food

A single strain of Candida anglica, isolated from cider, is available in international yeast collections. We present here seven new strains isolated from French PDO cheeses. For one of the cheese strains, we achieved a high-quality genome assembly of 13.7 Mb with eight near-complete telomere-to-telomere chromosomes. The genomes of two additional cheese strains and of the cider strain were also assembled and annotated, resulting in a core genome of 5966 coding sequences. Phylogenetic analysis showed that the seven cheese strains clustered together, away from the cider strain. Mating-type locus analysis revealed the presence of a MATa locus in the cider strain but a MATalpha locus in all cheese strains. The presence of LINE retrotransposons at identical genome position in the cheese strains, and two different karyotypic profiles resulting from chromosomal rearrangements were observed. Together, these findings are consistent with clonal propagation of the cheese strains. Phenotypic trait variations were observed within the cheese population under stress conditions whereas the cider strain was found to have a much greater capacity for growth in all conditions tested.

Advances in the metabolic engineering of Escherichia coli for the production of serotonin and its precursor, tryptophan

Serotonin, a monoamine neurotransmitter, participates in signal transduction in the nervous systems of organisms. It is essential in the coordination of movement and regulation of mood. As the production of serotonin via chemical synthesis and tissue extraction is limited, production by microorganisms has attracted considerable attention in recent years. Tryptophan is an essential precursor for serotonin biosynthesis; this amino acid can be converted to serotonin through hydroxylation and decarboxylation. In vivo, the tryptophan regulatory network and synthetic pathway are complex. This paper discusses existing methods of serotonin production and introduces the metabolic pathway of serotonin biosynthesis by microorganisms. Additionally, metabolic strategies for the efficient production of tryptophan in Escherichia coli are summarised. Strategies for serotonin synthesis by engineered E. coli are identified. Finally, suggestions for constructing additional efficient serotonin-producing strains are presented.

A mutation in Themis contributes to anaphylaxis severity following oral peanut challenge in CC027 mice

The development of peanut allergy is due to a combination of genetic and environmental factors, although specific genes have proven difficult to identify. Previously, we reported that peanut-sensitized Collaborative Cross strain CC027/GeniUnc (CC027) mice develop anaphylaxis upon oral challenge to peanut, in contrast to C3H/HeJ (C3H) mice. This study aimed to determine the genetic basis of orally induced anaphylaxis to peanut in CC027 mice. A genetic mapping population between CC027 and C3H mice was designed to identify the genetic factors that drive oral anaphylaxis. Atotal of 356 CC027xC3H backcrossed mice were generated, sensitized to peanut, then challenged to peanut by oral gavage. Anaphylaxis and peanut-specific IgE were quantified for all mice. T-cell phenotyping was conducted on CC027 mice and 5 additional Collaborative Cross strains. Anaphylaxis to peanut was absent in 77% of backcrossed mice, with 19% showing moderate anaphylaxis and 4% having severe anaphylaxis. There were 8 genetic loci associated with variation in response to peanut challenge-6 associated with anaphylaxis (temperature decrease) and 2 associated with peanut-specific IgE levels. There were 2 major loci that impacted multiple aspects of the severity of acute anaphylaxis, at which the CC027 allele was associated with worse outcome. At one of these loci, CC027 has a private genetic variant in the Themis gene. Consistent with described functions of Themis, we found that CC027 mice have more immature T cells with fewer CD8+, CD4+, and CD4+CD25+CD127- regulatory T cells. Our results demonstrate a key role for Themis in the orally reactive CC027 mouse model of peanut allergy.

Understanding Intimate Partner Femicide and Attempted Intimate Partner Femicide During and After COVID-19: A Comprehensive Strain-Based Approach

Intimate partner femicide (IPF) and attempted intimate partner femicide (AIPF) are severe forms of violence and global phenomena occurring in all societies worldwide. However, explaining IPF and AIPF is a complex and challenging endeavor. This article delves into the evolution of IPF and AIPF in Portugal during and after COVID-19, seeking to comprehend the underlying explanatory factors through a comprehensive strain-based approach. IPF rates during the COVID-19 pandemic have remained relatively stable, comparable to those observed before the pandemic, following a pattern akin to that documented in other countries. However, a significant increase in AIPF occurred during the COVID-19 pandemic, and a slight uptick in IPF indicators was noted toward the end of the pandemic period (2022). Perpetrators faced various strains, such as separation and financial difficulties, along with experiencing emotions like anger, jealousy, anxiety, and depression, leading to instances of IPF and AIPF. The COVID-19 crisis and associated restrictions introduced additional strains, including social isolation, economic losses, anxiety, and widespread fear, which may contribute to psychological distress, stress, and depression, thereby heightening the likelihood of committing IPF and AIPF. The pandemic restrictions also resulted in limited access to support and protection services, hindering victims from seeking help. Establishing a contingency plan for use in future crises (including pandemics) is imperative to promote support for victims and prevent situations of IPF and AIPF.

COVID-19 experience of people with severe mental health conditions and families in South Africa.

People with severe mental health conditions, such as schizophrenia, and their family caregivers are underserved in low- and middle-income countries where structured psychosocial support in the community is often lacking. This can present challenges to recovery and for coping with additional strains, such as a pandemic. This study explored the experiences and coping strategies of people with lived experience of a severe mental health condition, and family caregivers, in South Africa during the initial stages of the coronavirus disease 2019 (COVID-19) pandemic. This qualitative study was conducted in the Nelson Mandela Bay District, Eastern Cape, South Africa, in the most restrictive period of the COVID-19 lockdown. Telephonic qualitative interviews were conducted with people with lived experience (n = 14) and caregivers (n = 15). Audio recordings were transcribed and translated to English from isiXhosa. Thematic analysis was conducted with NVivo 12. Participants described negative impacts including increased material hardship, intensified social isolation and heightened anxiety, particularly among caregivers who had multiple caregiving responsibilities. Coping strategies included finding ways to not only get support from others but also give support, engaging in productive activities and taking care of physical health. The main limitation was inclusion only of people with access to a telephone. Support needs for people with severe mental health conditions and their families should include opportunities for social interaction and sharing coping strategies as well as bolstering financial security. These findings indicate that current support for this vulnerable group is inadequate, and resource allocation for implementation of additional community-based, recovery-focused services for families must be prioritised.

Pichia kurtzmaniana f.a. sp. nov., with the transfer of eight Candida species to Pichia.

Three yeast strains belonging to the ascomycetous yeast genus Pichia were isolated from two soil samples from Yunnan and Guizhou provinces and a marine water sample from Liaoning province, PR China. Phylogenetic analyses based on the sequences of the D1/D2 domains of the large subunit(LSU) rRNA gene and the internal transcribed spacer (ITS) region indicate that these three strains, together with 12 additional strains isolated from various substrates collected in different regions or countries of the world, represent a novel species of the genus Pichia, for which the name Pichia kurtzmaniana sp. nov. (holotype: strain CGMCC 2.7213) is proposed. The novel species differs from its close relatives Candida californica by eight (1.5 %) and 26 (11.1 %) mismatches in the D1/D2 domains and the ITS region, respectively; and from Pichia chibodasensis by 11 (2.1 %) and 20 (8.7 %) mismatches in the D1/D2 domains and the ITS region, respectively. In addition, eight Candida species which belong to the Pichia clade are transferred to the genus Pichia, resulting in the proposal of the following new combinations: Pichia cabralensis comb. nov., Pichia californica comb. nov., Pichia ethanolica comb. nov., Pichia inconspicua comb. nov., Pichia phayaonensis comb. nov., Pichia pseudolambica comb. nov., Pichia rugopelliculosa comb. nov., and Pichia thaimueangensis comb. nov.