bluuebunny/crossref_metadata_2025_split huggingface dataset:
Landscape of Bacterial Enteric Disease and Traveler´s Diarrhea in South America
Authors: Gaspar Carlos , Rios Paul , Moeller Tyler D 
Published: December 2024

Abstract
Diarrheal disease is a global public health threat. Cases of enteric disease caused by bacterial enteropathogens result in a significant health burden and can lead to antimicrobial resistance patterns that increase and evolve over time and geography, posing serious health challenges for local populations as well as civilian travelers and military personnel deployed to endemic regions. This review describes the prevalence of the most common bacterial agents of diarrheal disease in South America, as well as the distribution patterns of antibiotic resistance and predominant strains that are present in the region. Furthermore, the development of relevant prevention and treatment strategies are described, and United States Naval Medical Research Unit SOUTH disease surveillance and enteric disease research efforts in this regional context are highlighted.
Metagenomics reveals the genetic diversity between sublineages of UCYN-A and their algal host plastids
Authors: Kantor Ella Joy H , Robicheau Brent M , Tolman Jennifer , Archibald John M , LaRoche Julie 
Published: December 2024

Abstract
UCYN-A (or Cand. Atelocyanobacterium thalassa) has been recognized as a globally distributed, early stage, nitrogen-fixing organelle (the “nitroplast”) of cyanobacterial origin present in the haptophyte alga Braarudosphaera bigelowii. Although the nitroplast was recognized as UCYN-A2, not all sublineages of UCYN-A have been confirmed as nitroplasts, and full genomes are still lacking for several known sublineages. We investigated the differences between UCYN-A sublineages by sequencing and assembly of metagenomic sequences acquired from cultured biomass from NW Atlantic seawater, which yielded near-complete Metagenome Assembled Genomes (MAGs) corresponding to UCYN-A1, -A4, and the plastid of the UCYN-A4-associated B. bigelowii. Weekly time-series data paired with the recurrence of specific microbes in cultures used for metagenomics gave further insight into the microbial community associated with the algal/UCYN-A complex. The UCYN-A1 MAG was found to have 99% average nucleotide identity (ANI) to the Pacific-derived reference genome despite its Atlantic Ocean origin. Comparison of the UCYN-A4 MAG (the initial genome sequenced from this sublineage) to other genomes showed that UCYN-A4 is sufficiently genetically distinct from both UCYN-A1 and UCYN-A2 (ANI of ~83% and ~85%, respectively) to be considered its own sublineage, but more similar to UCYN-A2 than -A1, supporting its possible classification as a nitroplast. The B. bigelowii plastid sequence was compared with published plastid sequences (sharing 78% ANI with Chrysochromulina parva) adding to our understanding of genomic variation across Haptophyta organelles and emphasizing the need for further full genomic sequencing of B. bigelowii genotypes and their organelles.
Phenotypic antibiotic resistance of Mycoplasma genitalium and its variation between different macrolide resistance-associated mutations
Authors: Doelman T A , Adriaens N , Westerhuis B M , Bruisten S M , Vergunst C E , Bouwman F M , van Dam A P 
Published: December 2024

Abstract

Objectives
Mycoplasma genitalium, a sexually transmitted bacterium, faces increasing antibiotic resistance, particularly to azithromycin. However, presence of macrolide resistance-associated mutations (MRAMs) does not evidently implicate azithromycin treatment failure. This study aimed to establish an in vitro co-culture system of M. genitalium isolates and perform phenotypic susceptibility testing for different antibiotics, focusing on azithromycin to evaluate genotypic and phenotypic resistance across MRAMs.

Methods
Urine specimens testing positive for M. genitalium via nucleic acid amplification were co-cultured with Vero cells. Phenotypic susceptibility testing was performed for eight antibiotics. Growth inhibition and MIC of M. genitalium by azithromycin were compared across different MRAMs.

Results
M. genitalium was cultured from 20/40 (50.0%) positive urine samples, with phenotypic susceptibility tested in a subset. MICs ranged as follows: azithromycin (0.008–&gt;32 mg/L), levofloxacin (1–4 mg/L), moxifloxacin (&lt;0.25–1 mg/L), sitafloxacin (&lt;0.032–0.25 mg/L), minocycline (&lt;0.25–1 mg/L), doxycycline (&lt;0.125–2 mg/L), spectinomycin (&lt;2.5–&gt;25 mg/L) and lefamulin (&lt;0.004–0.063 mg/L). Isolates with A2058T demonstrated 24-, 7-, 15- and 12-fold increases in growth inhibition compared with A2058G at azithromycin concentrations of 4, 8, 16 and 32 mg/L, respectively (P &lt; 0.01). MRAMs ranked from low to high impact on MIC range were as follows: wildtype (0.008–0.016), A2058T (8–32), A2059G (≥32) and A2058G (&gt;32).

Conclusions
This study revealed that M. genitalium isolates vary in azithromycin-induced growth inhibition across MRAMs, potentially explaining differences in clinical treatment efficacy. Phenotypic susceptibility testing for other antibiotics demonstrated relatively low MICs. Future studies should incorporate clinical treatment efficacy and symptom severity to optimize treatment for M. genitalium.
Evaluating the effects of ivacaftor exposure on Staphylococcus aureus small colony variant development and antibiotic tolerance
Authors: Bollar Gretchen E , Shaffer Kendall M , Keith Johnathan D , Oden Ashley M , Dowell Alexander E , Ryan Kevin J , Acosta Edward P , Guimbellot Jennifer S , Kiedrowski Megan R , Birket Susan E 
Published: December 2024

Abstract

Background
Ivacaftor exhibits anti-staphylococcal properties but does not clear Staphylococcus aureus from the lungs of people with cystic fibrosis (pwCF). We assessed whether exposure to therapeutic concentrations of ivacaftor could allow S. aureus to form small colony variants (SCVs), a phenotype commonly associated with bacterial persistence.

Methods
Humanized G551D-CFTR (hG551D) rats were treated with ivacaftor for 7 days. Concentrations in the plasma, epithelial lining fluid and lung tissue lysate were measured using LC-MS/MS. Survival of S. aureus during ivacaftor treatment was assessed in an hG551D rat model of lung infection. S. aureus adaptation to therapeutic concentrations of ivacaftor was investigated in vitro by serial passage in the presence of 10 µM ivacaftor. Bacterial survival in the presence of antimicrobials was evaluated using growth curves and density assays.

Results
Ivacaftor plasma concentrations of treated hG551D rats reached 3.488 ± 1.118 µM, with more variable concentrations in the epithelial lining fluid and lung tissue lysate. During S. aureus infection, ivacaftor-treated hG551D rats returned similar numbers of bacteria from the lung, compared with vehicle-treated controls. Exposure of S. aureus to ivacaftor in vitro led to the formation of ivacaftor-tolerant SCVs with an unstable phenotype and increased antibiotic tolerance.

Conclusions
Treatment with ivacaftor did not alter S. aureus burden in the cystic fibrosis rat and led to the formation of tolerant SCVs in vitro, suggesting that development of an SCV phenotype may allow S. aureus to persist in the cystic fibrosis lung during ivacaftor therapy.
Paediatricians’ knowledge, perceptions, preparedness and involvement towards paediatric antimicrobial stewardship in Pakistan: findings and the implications
Authors: Mustafa Zia Ul , Khan Amer Hayat , Salman Muhammad , Harun Sabariah Noor , Meyer Johanna C , Godman Brian 
Published: December 2024

Abstract

Introduction
Antibiotics are frequently prescribed for neonates and children. However, this can be excessive with inappropriate prescribing leading to increased antimicrobial resistance (AMR). Paediatricians are key initiators of antibiotics. Consequently, their awareness, perceptions, readiness and potential barriers towards hospital-based antimicrobial stewardship programmes are of considerable importance, especially in Pakistan with high rates of AMR.

Materials and methods
A web-based cross-sectional survey among paediatricians from June to August 2023 using a validated questionnaire. Paediatricians from all four Provinces and the capital territory of Pakistan were invited from randomly selected public and private sector hospitals.

Results
383 paediatricians participated (79.8% response rate). Most were male (87.7%), aged 35 years or less (55.4%), working in tertiary care hospitals (68.4%) and undertaking 51–100 child consultations every day (45%). Only 15% reported obtaining training on antibiotic usage, AMR and/or antimicrobial stewardship. Only 7.6% confirmed functional antimicrobial stewardship programmes in their institutions. Most had adequate knowledge of antibiotic use and AMR. However, key issues were not fully understood with only 27.4% believing antibiotics were being overused among children. Paediatricians with less experience, and who undertook fewer consultations per day, had significantly lower knowledge scores. Most participants were prepared to initiate antimicrobial stewardship programmes; however, perceived barriers included a lack of online learning sources, treatment guidelines and support from hospital administration.

Discussion
Paediatricians had appropriate knowledge about antibiotic use and AMR although concerns with antibiotic use. Important barriers to integrating antimicrobial stewardship programmes were identified, which need addressing for these to become routine.
Back to Basics: Unraveling the Fundamentals of Lateral Flow Assays
Authors: Restrepo-Cano Valentina , García-Huertas Paola , Caraballo-Guzmán Arley , Sánchez-Jiménez Miryan M , Torres-Lindarte Giovanny 
Published: December 2024

Abstract

Background
Lateral flow assay (LFA) is a rapid analytical technique that has been implemented as a point-of-care approach for analyte detection. Given the rapid expansion of the use of LFA as a point-of-care testing strategy, LFA development has been subjected to extensive research, which has resulted in upgraded designs and technologies, improving levels of specificity and costs associated with manufacturing. This has allowed LFA to become an important option in rapid testing while maintaining appropriate limits of detection for accurate diagnoses.

Content
This review focuses on the theoretical basis of LFA, its components, formats, multiparametric possibilities, labels, and applications. Also, challenges associated with the technique and possible solutions are explored.

Summary
We explore LFA as a detection technique, its benefits, opportunities for improvement, and applications, and how challenges to its design can be approached.
Development of a Modified QuEChERS Extraction for the Detection of Rosemary Extracts (E392) Expressed as Sum of Carnosol and Carnosic Acid in Food by LC-MS/MS
Authors: Wong Yiu-Tung , Leung Tak-Shing , Fung Wai-Hong 
Published: December 2024

Abstract

Background
Rosemary extracts are derived from the leaves of Rosmarinus officinalis and commonly employed as a natural food preservative. They serve as natural antioxidants in food, preventing spoilage and extending shelf life.

Objective
This study aimed to develop a modified quick, easy, cheap, effective, rugged, and safe (QuEChERS) extraction with liquid chromatography tandem mass spectrometry (LC-MS/MS) for the analysis of rosemary extracts in food as the sum of its markers carnosol and carnosic acid.

Method
Carnosol and carnosic acid in food were extracted by a modified QuEChERS extraction after the addition of analyte protectants during extraction and analyzed by LC-MS/MS via an internal standard calibration method. 2,2'-isopropylidienediphenol and podocarpic acid were used as internal standards for carnosol and carnosic acid, respectively.

Results
The limit of detection (LOD) of carnosol and carnosic acid were all less than 1 mg/kg, while their corresponding values of limit of quantitation (LOQ) ranged from 1.44 to 3.12 mg/kg in various matrixes. Spike recoveries at three fortification levels (10, 50, and 300 mg/kg) were all within 90–110% with RSD less than 10% in all cases.

Conclusions
A modified QuEChERS extraction with LC-MS/MS detection for the analysis of rosemary extracts in food was successfully developed, validated, and demonstrated to be fast, robust, and reliable.

Highlights
The developed modified QuEChERS extraction with LC-MS/MS detection offered a fast and efficient way to analyze rosemary extracts in various foods during a routine food surveillance program.
Validation of Enzytec™ Liquid Combi Sucrose/D-Glucose for Enzymatic Determination of Sucrose and D-Glucose in Selected Foods and Beverages: First Action 2024.05
Authors: Lacorn Markus , Hektor Thomas 
Published: December 2024

Abstract

Background
Sucrose is produced in the greatest quantity of all industrially produced organic substances and can be used in almost all processed foods. Glucose is the most abundant monosaccharide and contained in many foodstuffs naturally or added as an ingredient.

Objective
To validate the performance of the Enzytec™ Liquid Combi Sucrose/D-Glucose test kit for the determination of sucrose and D-glucose in juices, chocolate, breakfast cereals, ice cream, sweetened condensed milk, wine, beer, and soft drinks.

Methods
The kit contains all reagents in a ready-to-use format and is suitable for automation. Sucrose is cleaved by β-fructosidase. The resulting D-glucose from sucrose and glucose originally in the sample are phosphorylated and react in a NADH-generating reaction afterwards. β-Fructosidase is not present in the glucose system. The amount of NADH produced is equivalent to the amounts of sucrose and D-glucose and is measured at 340 nm within 30 min.

Results
The linear measurement range for a 100 µL test volume is from 17 to 2500 mg/L sucrose and 4 to 2000 mg/L D-glucose. Trueness was checked by using four Certified Reference Materials (CRM) and resulted in recoveries from 96 to 105%. Spiking of juices, ice cream, sweetened condensed milk, and shandy resulted in recoveries between 98 and 106% for both systems. Intermediate precision was 3% or lower for sucrose and glucose. For automation, three applications with different test volumes were validated. Linearity is given from 3.8 to 9500 mg/L for sucrose and 2.4 up to 10000 mg/L for glucose.

Conclusion
The method is robust and accurate for manual and automated applications. The method was approved as an AOAC Official Method of Analysis℠.

Highlights
The ready-to-use components of the test kit have a shelf of at least 29 months.
Effect of inulin on small extracellular vesicles microRNAs in milk from dairy cows with subclinical mastitis
Authors: Yu Wanjie , Nan Xuemei , Schroyen Martine , Wang Yue , Zhou Mengting , Tang Xiangfang , Xiong Benhai 
Published: December 2024

Abstract
Milk contains microRNAs (miRNA) that are shielded by small extracellular vesicles (sEVs). Beyond variations among individuals, many factors including nutrition play a role in shaping miRNA expression profiles. This study is to explore milk-derived sEVs-miRNA variations induced by inulin supplementation in subclinical mastitis-suffering cows. Fourteen lactating cows diagnosed with subclinical mastitis were equally assigned to either an inulin or a control group. Apart from total mixed rations, cows in the inulin group were provided with 300 g/d inulin during the morning feeding, while the control group did not receive any supplement. Following 1 wk of adaptation and 5 wk of treatment, sEVs-miRNA were isolated from the milk of each cow. RNA is subjected to high-throughput sequencing and differentially expressed (DE) miRNA (P &lt; 0.05 and ∣ log2FC∣&gt; 1) were detected through bioinformatics analysis. Gene Ontology (GO) enrichment and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were conducted to examine the target genes of DE miRNA. A sum of 350 miRNA was discovered, including 332 in the control group and 249 in the inulin group. Among these, 9 miRNA showed differential expression within the 2 groups, including 3 upregulated and 6 downregulated in the inulin group. The DE miRNA participates in regulating organismal systems, cellular processes, and signal transduction, which may affect inflammatory response and milk production. Overall, our study provides insight into the micromolecular-level mechanism of inulin in alleviating subclinical mastitis in dairy cows.
Identification of transcriptional regulators and signaling pathways mediating postnatal rumen growth and functional maturation in cattle
Authors: Pokhrel Binod , Tan Zhendong , Jiang Honglin 
Published: December 2024

Abstract
The rumen plays an essential role in the physiology and health of ruminants. The rumen undergoes substantial changes in size and function from birth to adulthood. The cellular and molecular mechanisms underlying these changes are not clear. This study aimed to identify the transcription factors (TFs) and signaling pathways mediating these changes in cattle. We found that the ratios of the emptied rumen, reticulum, omasum, and abomasum to body weight in adult steers were 4.8 (P &lt; 0.01), 3.1 (P &lt; 0.01), 6.0 (P &lt; 0.01), and 0.8 (P = 0.9) times those in neonatal calves, respectively. The length of rumen papillae and the thickness of rumen epithelium, tunica mucosa and submucosa, tunica muscularis, and tunica serosa increased 7.4-, 2.0-, 3.0-, 2.9-, and 4.6-fold (P &lt; 0.01 for all), respectively, from neonatal calves to adult steers. However, the density of rumen papillae was lower in adult steers than in neonatal calves (P &lt; 0.05). The size of rumen epithelial cells was not different between neonatal calves and adult steers (P = 0.57). RNA sequencing identified 2,922 genes differentially expressed in the rumen between neonatal calves and adult steers. Functional enrichment analyses revealed that organ development, blood vessel development, Ras signaling, and Wnt signaling were among the functional terms enriched in genes downregulated in adult steers vs. neonatal calves and that fatty acid metabolism, immune responses, PPAR signaling, and Rap1 signaling were among those enriched in genes upregulated in adult steers vs. neonatal calves. Serum response factor (SRF), interferon regulatory factor 4, and purine-rich single-stranded DNA-binding protein alpha were among the major candidate TFs controlling the expression of genes upregulated, while TCF4, inhibitor of DNA binding 4, and snail family transcriptional repressor 2 were among those controlling the expression of genes downregulated in adult steers vs. neonatal calves. Taken together, these results suggest that the rumen grows by increasing the number, not the size, of cells from birth to adulthood, that the absorptive, metabolic, immune, and motility functions of the rumen are acquired or significantly enhanced during the postnatal life, and that the changes in rumen size and function from birth to adulthood are mediated by many candidate TFs, including SRF and TCF4, and many candidate signaling pathways, including the PPAR and Wnt signaling pathways.
Alleviation of lipopolysaccharide-induced heart inflammation in poultry treated with carnosic acid via the NF-κB and MAPK pathways
Authors: Liu Sirui , Liang Wanqing , Wu Jiaxin , Bao Endong , Tang Shu 
Published: December 2024

Abstract
In intensive poultry farming, environmental stress, pathogen infections, and noise can negatively impact growth or cause sudden death, leading to economic losses. The prevalent use of antibiotics as feed additives to prevent diseases in broilers has raised concerns about antibiotic resistance and highlighted the need for safer and more effective alternatives. Carnosic acid (CA), a bioactive compound derived from rosemary, exhibits notable pharmacological properties, including anti-inflammatory and antioxidant effects. This study investigates CA’s efficacy in mitigating lipopolysaccharide (LPS)-induced heart inflammation in broilers. Broilers were pretreated with CA at varying doses (20, 40, and 80 mg/kg) for 7 days then exposed to LPS (200 mg/kg) for 24h to induce an inflammatory response. LPS treatment increased the levels of the cardiac damage markers creatine kinase-MB (CK-MB) and lactate dehydrogenase (LDH) and inflammatory cytokines tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), interleukin-1β (IL-1β), and inducible nitric oxide synthase (iNOS), but these effects were markedly decreased in CA-pretreated poultry. Histopathological analysis indicated that CA mitigated myocardial fiber rupture and inflammatory cell infiltration. Immunohistochemistry showed that CA sustained high expression levels of the protective protein crystallin alpha B (CRYAB), the expression of which was reduced by LPS. Mechanistic studies demonstrated that CA regulates key inflammatory signaling pathways via inhibiting LPS-induced activation of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) by reducing the phosphorylation of p65 and inhibitor of nuclear factor kappa-B alpha (IκBα). Additionally, CA attenuated mitogen-activated protein kinase (MAPK) pathway activation, as evidenced by decreased phosphorylation of c-Jun N-terminal kinase (JNK), extracellular signal-regulated kinase (ERK), and p38 in the CA-treated groups compared to the LPS-only groups. These findings suggest that CA exerts a protective effect against LPS-induced cardiac inflammation by enhancing CRYAB expression and modulating the NF-κB and MAPK pathways. Importantly, the findings emphasize CA’s potential as a natural feed additive to enhance cardiac health in poultry and present a promising alternative to conventional antibiotics in livestock management. Further research is needed to investigate its broader applications in animal health and other inflammatory conditions.
Export-Led Decay: The Trade Channel in the Gold Standard Era
Authors: Candia Bernardo , Pedemonte Mathieu 
Published: December 2024

Abstract
Flexible exchange rates can facilitate price adjustments that buffer macroeconomic shocks. We test this hypothesis using adjustments to the gold standard during the Great Depression. Using novel monthly data on city-level economic activity, sectoral employment, and export data, we show that American exporting cities were significantly affected by changes in bilateral exchange rates. We calibrate a general equilibrium model to obtain aggregate effects from cross-sectional estimates. We show that the trade channel deepened the Great Depression and was a key driver of the economic recovery in 1933.
Compatibility of emerging AI regulation with GATS and TBT: the EU Artificial Intelligence Act
Authors: Soprana Marta 
Published: December 2024

Abstract
Governments have recently started to design policies that are specific to artificial intelligence (AI), which is projected to become the dominant technology in the decades to come. AI is increasingly permeating all aspects of the digital economy, including trade in goods and services, giving rise to concerns whether emerging AI-specific regulation may run afoul of international economic law (IEL). However, studies on the law of the World Trade Organization have yet to pay close attention to the European Union (EU) Artificial Intelligence Act (AI Act), the first binding regulation of its kind in the world. This paper seeks to address this gap in the literature. It examines the compatibility of emerging AI regulation with multilateral trade rules, using the EU AI Act as a case study. More specifically, it analyses to what extent the EU AI Act’s disciplines on prohibited AI systems are likely to violate the EU’s existing obligations and commitments enshrined in the Agreement on Technical Barriers to Trade and the General Agreement on Trade in Services. This paper demonstrates that there is potential for conflict between the EU regulation and these two multilateral trade agreements. It also suggests that, although emerging AI regulation can represent a challenge for the future of IEL, the latter can play a role in guiding and shaping AI-specific regulation moving forward.