Biofilm Eradication and Inhibition of Methicillin-resistant Staphylococcus Clinical Isolates by Curcumin-Chitosan Magnetic Nanoparticles.

Biofilm-producing methicillin-resistant Staphylococcus aureus (MRSA) and coagulase-negative Staphylococci (MR-CoNS) are a clinical challenge for the treatment of healthcare-associated infections. As alternative antimicrobial options are needed, we aimed to determine the effect of curcumin-chitosan magnetic nanoparticles on the biofilm of staphylococcal clinical isolates. MRSA and CoNS clinical isolates were identified by MALDI-TOF mass spectrometry. Antimicrobial susceptibility testing was performed by broth microdilution. Nanoparticles were synthesized by co-precipitation of magnetic nanoparticles (MNP) and encapsulation by ionotropic gelation of curcumin (Cur) and chitosan (Chi). Biofilm inhibition and eradication by nanoparticles with and without the addition of oxacillin was assessed on staphylococcal strains. Cur-Chi-MNP showed antimicrobial activity on planktonic cells of MRSA and MR-CoNS strains and inhibited biofilm of MRSA. The addition of OXA to Cur-Chi-MNP increased biofilm inhibition and eradication activity against all Staphylococci strains (p=0.0007); higher biofilm activity was observed in early biofilm stages. Cur-Chi-MNP showed antimicrobial and biofilm inhibition activity against S. aureus. The addition of OXA increased biofilm inhibition and eradication activity against all Staphylococci strains. A combination treatment of Cur-Chi-MNP and OXA could be potentially used to treat staphylococcal biofilm-associated infections in its early stages before the establishment of biofilm bacterial cells.

[Analysis of the workload in medical time according to the degree of complexity of the samples and proposal of an algorithm for the equitable distribution of the workload in an anatomic pathology department]. / Análisis de la carga laboral en tiempo médico en función del grado de complejidad de las muestras y propuesta de algoritmo para la distribución equitativa del trabajo asistencial en un servicio de anatomía patológica.

INTRODUCTION: In a pathological anatomy service, the workload in medical time is analyzed based on the complexity of the samples received and its distribution among pathologists is assessed, presenting a new computer algorithm that favors an equitable distribution. METHODS: Following the second edition of the Spanish guidelines for the estimation of workload in cytopathology and histopathology (medical time) according to the Spanish Pathology Society-International Academy of Pathology (SEAP-IAP) catalog of samples and procedures, we determined the workload units (UCL) per pathologist and the overall UCL of the service, the average workload of the service (MU factor), the time dedicated by each pathologist to healthcare activity and the optimal number of pathologists according to the workload of the service. RESULTS: We determined 12 197 total annual UCL for the chief pathologist, as well as 14 702 and 13 842 UCL for associate pathologists, with an overall of 40 742 UCL for the whole service. The calculated MU factor is 4.97. The chief pathologist devoted 72.25% of his working day to healthcare activity while associate pathologists dedicated 87.09% and 82.01% of their working hours. The optimal number of pathologists for the service is found to be 3.55. CONCLUSIONS: The results demonstrate medical work overload and a non-equitable distribution of UCLs among pathologists. We propose a computer algorithm capable of distributing the workload in an equitable manner. It would be associated with the laboratory information system and take into account the type of specimen, its complexity and the dedication of each pathologist to healthcare activity.

Changes in the Progression of Chronic Kidney Disease in Patients Undergoing Fecal Microbiota Transplantation.

Chronic kidney disease (CKD) is a progressive loss of renal function in which gut dysbiosis is involved. Fecal microbiota transplantation (FMT) may be a promising alternative for restoring gut microbiota and treating CKD. This study evaluated the changes in CKD progression in patients treated with FMT. Patients with diabetes and/or hypertension with CKD clinical stages 2, 3, and 4 in this single-center, double-blind, randomized, placebo-controlled clinical trial (NCT04361097) were randomly assigned to receive either FMT or placebo capsules for 6 months. Laboratory and stool metagenomic analyses were performed. A total of 28 patients were included (15 FMT and 13 placebo). Regardless of CKD stages, patients responded similarly to FMT treatment. More patients (53.8%) from the placebo group progressed to CKD than the FMT group (13.3%). The FMT group maintained stable renal function parameters (serum creatinine and urea nitrogen) compared to the placebo group. Adverse events after FMT treatment were mild or moderate gastrointestinal symptoms. The abundance of Firmicutes and Actinobacteria decreased whereas Bacteroidetes, Proteobacteria and Roseburia spp. increased in the FMT group. CKD patients showed less disease progression after FMT administration. The administration of oral FMT in patients with CKD is a safe strategy, does not represent a risk, and has potential benefits.

Impact of influenza vaccination history in the clinical course of older adults hospitalized with COVID-19.

BACKGROUND AND PURPOSE: Some studies have shown that influenza vaccination is associated with a lower risk of SARS-CoV-2 infection; in patients with COVID-19 infection, admission to intensive care is reduced, with less need for mechanical ventilation, shorter hospital stays, and reduced mortality. This study aimed to determine if a history of annual influenza vaccination impacts the clinical course of SARS-CoV-2 infection during hospitalization. METHODS: This was an observational, prospective, cohort study of patients older than 65 admitted to the COVID-19 unit from January to June 2021. The history of influenza vaccination over the last 5 years was assessed in each patient during hospitalization. We measured the length of hospital stay, the need for admission to the intensive care unit (ICU), the patient's oxygen requirements, complications during hospitalization, and outcome (medical discharge or death). Patients with a history of vaccination against SARS-CoV-2 were not included. RESULTS: We analyzed 125 patients, 50.4% (n=63) with history of influenza vaccination and 49.6% (n=62) without a history of influenza vaccination. In-hospital mortality was 44.8%, higher in the unvaccinated (54.8%) population (p=0.008). ICU admission was 27% higher in vaccinated (35%) patients (p=0.05). Patients without a history of influenza vaccination had a higher prevalence of cardiac (8% vs. 5%, p=0.04) and renal complications (29% vs. 13%, p=0.02). Patients with a history of vaccination had a greater need for invasive mechanical ventilation (25.4%, p=0.02). CONCLUSION: In this study, a history of influenza vaccination in older adults with SARS-CoV-2 infection was related to lower in-hospital mortality.

Use of stable isotopes to reveal trophic relationships and transmission of a food-borne pathogen.

Predators in food webs are valuable sentinel species for zoonotic and multi-host pathogens such as Toxoplasma gondii. This protozoan parasite is ubiquitous in warm-blooded vertebrates, and can have serious adverse effects in immunocompromised hosts and foetuses. In northern ecosystems, T. gondii is disproportionately prevalent in Inuit people and wildlife, in part due to multiple routes of transmission. We combined data on T. gondii infection in foxes from Nunavik (northern Québec, Canada) with stable isotope data tracking trophic relationships between foxes and several of their main prey species. Red (Vulpes vulpes) and Arctic fox (Vulpes lagopus) carcasses were collected by local trappers from 2015 to 2019. We used magnetic capture PCR to detect DNA of T. gondii in heart and brain tissues, and enzyme-linked immunosorbent assay to detect antibodies in blood. By linking infection status with diet composition, we showed that infected foxes had a higher probability of consuming aquatic prey and migratory geese, suggesting that these may be important sources of T. gondii transmission in the Arctic. This use of stable isotopes to reveal parasite transmission pathways can be applied more broadly to other foodborne pathogens, and provides evidence to assess and mitigate potential human and animal health risks associated with T. gondii in northern ecosystems.

Biofilm eradication of Stenotrophomonas maltophilia by Levofloxacin and Trimethoprim-sulfamethoxazole.

Stenotrophomonas maltophilia is a non-fermenting Gram-negative drug-resistant pathogen causing healthcare-associated infections. Clinical isolates from Mexico were assessed for biofilm production by crystal violet staining. Antimicrobial susceptibility was evaluated using the broth microdilution method in planktonic and biofilm cells. The effect of antibiotics on the biofilm was visualized by fluorescence microscopy. Fifty isolates were included in the study, of which 28.0% were biofilm producers (64.2% from blood and 35.7% from respiratory samples). Resistance to levofloxacin (8.0%) and trimethoprim-sulfamethoxazole (44.0%) in planktonic cells increased to 100% in biofilm cells. Bacterial biofilm treated with several concentrations of both antibiotics was completely disrupted. In conclusion, S. maltophilia isolated from blood had higher biofilm production than those from respiratory samples. Resistance to antibiotics increased due to biofilm production. Antibiotic monotherapy might not be the best course of action for the treatment of S. maltophilia infections in Mexico, as they might also be causing biofilm production.

Search for antibodies against Trichinella in two synanthropic Procyonidae species from southeast Mexico: white-nosed coatis (Nasua narica) and raccoons (Procyon lotor).

Trichinella is a nematode that are spread by the consumption of parasitized meat. Carnivora, a mammalian order, serve as key hosts for this parasite. However, evidence of Trichinella in wildlife from the Neotropics is extremely scarce, with reports documenting its presence only for five carnivore species: two Felidae, one Otariidae and two Mustelidae. Other widely distributed species that are consumed as bushmeat, such as Procyonidae, have not been studied in this context. A long-term study was performed for antibodies against Trichinella in coatis (Nasua narica) and common raccoons (Procyon lotor) in southeastern Mexico. Between the summer of 2009 to the winter 2013, a total of 291 coati samples and 125 raccoon samples were collected from a tropical green area located within an urban zone. An Enzyme-linked immunosorbent assay (ELISA) was used to detect antibodies against the excretory and secretory products of Trichinella spiralis muscle larva. ELISA-positive samples were further confirmed by Western Blot analysis. Results showed no evidence of antibodies during the first two years of study. However, in 2011, a sudden appearance of anti-Trichinella occurred. The seroprevalence reached its highest peak of 43% for coatis during winter 2013 and 53% for raccoons in summer 2013. This is the first study that provides evidence of Trichinella circulation within a neotropical procyonid community.

Finding the Effective Dynamics to Make Rare Events Typical in Chaotic Maps.

Dynamical fluctuations or rare events associated with atypical trajectories in chaotic maps due to specific initial conditions can crucially determine their fate, as the may lead to stability islands or regions in phase space otherwise displaying unusual behavior. Yet, finding such initial conditions is a daunting task precisely because of the chaotic nature of the system. In this Letter, we circumvent this problem by proposing a framework for finding an effective topologically conjugate map whose typical trajectories correspond to atypical ones of the original map. This is illustrated by means of examples which focus on counterbalancing the instability of fixed points and periodic orbits, as well as on the characterization of a dynamical phase transition involving the finite-time Lyapunov exponent. The procedure parallels that of the application of the generalized Doob transform in the stochastic dynamics of Markov chains, diffusive processes, and open quantum systems, which in each case results in a new process having the prescribed statistics in its stationary state. This Letter thus brings chaotic maps into the growing family of systems whose rare fluctuations-sustaining prescribed statistics of dynamical observables-can be characterized and controlled by means of a large-deviation formalism.

Recombinant C1 inhibitor in the prevention of severe COVID-19: a randomized, open-label, multi-center phase IIa trial.

Background: Conestat alfa (ConA), a recombinant human C1 inhibitor, may prevent thromboinflammation. Methods: We conducted a randomized, open-label, multi-national clinical trial in which hospitalized adults at risk for progression to severe COVID-19 were assigned in a 2:1 ratio to receive either 3 days of ConA plus standard of care (SOC) or SOC alone. Primary and secondary endpoints were day 7 disease severity on the WHO Ordinal Scale, time to clinical improvement within 14 days, and safety, respectively. Results: The trial was prematurely terminated because of futility after randomization of 84 patients, 56 in the ConA and 28 in the control arm. At baseline, higher WHO Ordinal Scale scores were more frequently observed in the ConA than in the control arm. On day 7, no relevant differences in the primary outcome were noted between the two arms (p = 0.11). The median time to defervescence was 3 days, and the median time to clinical improvement was 7 days in both arms (p = 0.22 and 0.56, respectively). Activation of plasma cascades and endothelial cells over time was similar in both groups. The incidence of adverse events (AEs) was higher in the intervention arm (any AE, 30% with ConA vs. 19% with SOC alone; serious AE, 27% vs. 15%; death, 11% vs. 0%). None of these were judged as being related to the study drug. Conclusion: The study results do not support the use of ConA to prevent COVID-19 progression. Clinical trial registration: https://clinicaltrials.gov, identifier NCT04414631.

Planktonic and biofilm states of Staphylococcus aureus isolated from bone and joint infections and the in vitro effect of orally available antibiotics.

AIMS: To demonstrate the in vitro activity of orally available antibiotics against Staphylococcus aureus isolated from bone or orthopedic implant materials. The biofilm eradication of the combination of three antibiotics was also assessed. METHODS AND RESULTS: Clinical isolates from orthopedic infection samples were collected, and S. aureus isolates were classified according to their biofilm production and composition. Almost all S. aureus isolates (n = 36, 97.3%) produced biofilm and the major biofilm components were polysaccharides. Antimicrobial susceptibility was determined in planktonic (minimal inhibitory concentration; MIC) and biofilm cells (minimal biofilm eradication concentration; MBEC) using the MBEC Calgary Device. Overall, the MBEC ranged higher than the MIC. When combined at borderline-susceptible concentrations, moxifloxacin-rifampin and doxycycline-rifampin were both able to eradicate biofilms in a third of the strains whereas the doxycycline-moxifloxacin combination proved ineffective at eradicating biofilm, inhibiting it only in three strains. CONCLUSIONS: We propose rifampin in combination with moxifloxacin or doxycycline for the design of clinical trials of bone and/or orthopedic device infection without proper debridement or material retention.

Environmental variables drive spatial patterns of trophic diversity in mammals.

Understanding environmental drivers of species diversity has become increasingly important under climate change. Different trophic groups (predators, omnivores and herbivores) interact with their environments in fundamentally different ways and may therefore be influenced by different environmental drivers. Using random forest models, we identified drivers of terrestrial mammals' total and proportional species richness within trophic groups at a global scale. Precipitation seasonality was the most important predictor of richness for all trophic groups. Richness peaked at intermediate precipitation seasonality, indicating that moderate levels of environmental heterogeneity promote mammal richness. Gross primary production (GPP) was the most important correlate of the relative contribution of each trophic group to total species richness. The strong relationship with GPP demonstrates that basal-level resource availability influences how diversity is structured among trophic groups. Our findings suggest that environmental characteristics that influence resource temporal variability and abundance are important predictors of terrestrial mammal richness at a global scale.

Molecular characterization and genotyping of isolates from cancer patients with Clostridioides difficile infection or asymptomatic colonization.

Introduction. Cancer patients with Clostridioides difficile infection (CDI) are at a higher risk for adverse outcomes. In addition, a high prevalence of Clostridioides difficile asymptomatic colonization (CDAC) has been reported in this vulnerable population.Gap Statement. The molecular characteristics and potential role of CDAC in healthcare-related transmission in the cancer population have been poorly explored.Aim. We aimed to compare the molecular and genotypic characteristics of C. difficile isolates from cancer patients with CDAC and CDI.Method. We conducted a prospective cohort study of cancer patients with CDAC or CDI from a referral centre. Molecular characterization, typification and tcdC gene expression of isolates were performed.Results. The hospital-onset and community-onset healthcare facility-associated CDI rates were 4.5 cases/10 000 patient-days and 1.4 cases/1 000 admissions during the study period. Fifty-one C. difficile strains were isolated: 37 (72 %) and 14 (28 %) from patients with CDI or CDAC, respectively. All isolates from symptomatic patients were tcdA+/tcdB+, and four (10 %) were ctdA+/ctdB+. In the CDAC group, 10 (71 %) isolates were toxigenic, and none were ctdA+/ctdB+. The Δ18 in-frame tcdC deletion and two transition mutations were found in five isolates. After bacterial typing, 60 % of toxigenic isolates from asymptomatic carriers were clonal to those from patients with C. difficile-associated diarrhoea. No NAP1/027/BI strains were detected.Conclusions. We found a clonal association between C. difficile isolates from patients with CDAC and CDI. Studies are needed to evaluate the potential role of asymptomatic carriers in the dynamics of nosocomial transmission to support infection control measures and reduce the burden of CDI in high-risk groups.

Toxoplasma gondii and related Sarcocystidae parasites in harvested caribou from Nunavik, Canada.

Caribou are keystone species important for human harvest and of conservation concern; even so, much is unknown about the impact of parasites on caribou health and ecology. The aim of this study was to determine the seroprevalence, tissue prevalence, and diversity of tissue-dwelling coccidian parasites (including Toxoplasma gondii, Neospora caninum and Sarcocystis spp.) in 88 migratory caribou (Rangifer tarandus) harvested for human consumption in two communities in Nunavik, Québec, Canada. Both T. gondii and N. caninum have potential to cause abortions and neurological disease in caribou. Seroprevalence for antibodies to T. gondii using ELISA on fluid from thawed hearts was 18% overall, and no DNA of T. gondii was detected in tissues, which has positive implications for food safety since this parasite is zoonotic. Seroprevalence for antibodies to N. caninum using competitive ELISA was 5%, and DNA of N. caninum was detected in only one heart sample. DNA of Sarcocystis, a non-zoonotic, related coccidian, was detected in tissue samples from 85% of caribou, with higher prevalence in heart (82%) than skeletal muscle (47%). This is the first time that Sarcocystis spp. from caribou in Canada have been identified to species level, many of which have been described in reindeer from Fennoscandia. The high prevalence and diversity of Sarcocystis spp. suggests intact trophic relationships between canids and caribou in Nunavik. Besnoitia spp. was serendipitously detected in three muscle samples, a parasite previously associated with skin lesions in caribou in Nunavik. Community-level differences in T. gondii exposure and prevalence of Sarcocystis spp. in skeletal muscle tissues may reflect differences in hunter selection of individual animals and muscles, or possibly regional differences in the ecology of carnivore definitive hosts for these parasites. Further work is needed to explore effects of tissue coccidians in caribou, their taxonomic classifications, and community level differences in parasite prevalence and diversity.

New insights into cancer: MDM2 binds to the citrullinating enzyme PADI4.

PADI4 is one of the human isoforms of a family of enzymes implicated in the conversion of arginine to citrulline. MDM2 is an E3 ubiquitin ligase which is crucial for down-regulation of degradation of the tumor suppressor gene p53. Given the relationship between both PADI4 and MDM2 with p53-signaling pathways, we hypothesized they may interact directly, and this interaction could be relevant in the context of cancer. Here, we showed their association in the nucleus and cytosol in several cancer cell lines. Furthermore, binding was hampered in the presence of GSK484, an enzymatic PADI4 inhibitor, suggesting that MDM2 could bind to the active site of PADI4, as confirmed by in silico experiments. In vitro and in silico studies showed that the isolated N-terminal region of MDM2, N-MDM2, interacted with PADI4, and residues Thr26, Val28, Phe91 and Lys98 were more affected by the presence of the enzyme. Moreover, the dissociation constant between N-MDM2 and PADI4 was comparable to the IC50 of GSK484 from in cellulo experiments. The interaction between MDM2 and PADI4 might imply MDM2 citrullination, with potential therapeutic relevance for improving cancer treatment, due to the generation of new antigens.

Atroposelective Brønsted Acid-Catalyzed Photocyclization to Access Chiral N-Aryl Quinolones with Low Rotational Barriers.

Herein, a novel route to atropisomeric N-aryl quinolones with low rotational barriers is demonstrated, leveraging a dual photochemical/organocatalytic approach to the required ring closure in up to 94% yield and up to >99% ee. The use of a continuous flow system allows for impurity suppression and enables rapid scale-up to a decagram scale.

The intrinsically disordered, epigenetic factor RYBP binds to the citrullinating enzyme PADI4 in cancer cells.

RYBP (Ring1 and YY 1 binding protein) is a multifunctional, intrinsically disordered protein (IDP), best described as a transcriptional regulator. It exhibits a ubiquitin-binding functionality, binds to other transcription factors, and has a key role during embryonic development. RYBP, which folds upon binding to DNA, has a Zn-finger domain at its N-terminal region. By contrast, PADI4 is a well-folded protein and it is one the human isoforms of a family of enzymes implicated in the conversion of arginine to citrulline. As both proteins intervene in signaling pathways related to cancer development and are found in the same localizations within the cell, we hypothesized they may interact. We observed their association in the nucleus and cytosol in several cancer cell lines, by using immunofluorescence (IF) and proximity ligation assays (PLAs). Binding also occurred in vitro, as measured by isothermal titration calorimetry (ITC) and fluorescence, with a low micromolar affinity (~1 µM). AlphaFold2-multimer (AF2) results indicate that PADI4's catalytic domain interacts with the Arg53 of RYBP docking into its active site. As RYBP sensitizes cells to PARP (Poly (ADP-ribose) polymerase) inhibitors, we applied them in combination with an enzymatic inhibitor of PADI4 observing a change in cell proliferation, and the hampering of the interaction of both proteins. This study unveils for the first time the possible citrullination of an IDP, and suggests that this new interaction, whether it involves or not citrullination of RYBP, might have implications in cancer development and progression.

Frequency of needle stick injuries among healthcare providers during large-scale SARS-CoV-2 vaccination brigades.

The frequency of needle stick-related accidents in large-scale vaccination brigades during the COVID-19 pandemic is unknown. We determined the incidence of needle stick injuries (NIs) from the SARS-CoV-2 vaccination brigades in the Monterrey metropolitan area. We calculated the rate of NI by 100,000 doses administered from a registry of over 4 million doses.

Association of the Interleukin 1B-31*C Proinflammatory Allele with the Severity of COVID-19 Patients: A Preliminary Report.

Individuals with no known comorbidities or risk factors may develop severe coronavirus disease 2019 (COVID-19). The present study assessed the effect of certain host polymorphisms and viral lineage on the severity of COVID-19 among hospitalized patients with no known comorbidities in Mexico. The analysis included 117 unrelated hospitalized patients with COVID-19. Patients were stratified by whether they required intensive care unit (ICU) admission: the ICU group (n = 40) and non-ICU group (n = 77). COVID-19 was diagnosed on the basis of a positive severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) reverse transcription-polymerase chain reaction (RT-PCR) assay and clinical and radiographic criteria. The presence of the IL1B-31 (T/C) polymorphism was determined for all patients using PCR and nucleotide sequencing. Genotyping of the IL-4 (-590, T/C) and IL-8 (-251, T/A) polymorphisms was performed by the amplification refractory mutation system-PCR method. Genotyping of IL1-RN was performed using PCR. Viral genome sequencing was performed using the ARTIC Network amplicon sequencing protocol using a MinION. Logistic regression analysis identified the carriage of IL-1 B*-31 *C as an independent potential risk factor (odds ratio [OR] = 3.1736, 95% confidence interval [CI] = 1.0748-9.3705, p = 0.0366) for ICU admission and the presence of IL-RN*2 as a protective factor (OR = 0.4371, 95% CI = 0.1935-0.9871, p = 0.0465) against ICU admission. Under the codominant model, the CC genotype of IL1B-31 significantly increased the risk of ICU admission (OR: 6.38, 95% CI: 11.57-25.86, p < 0.024). The IL1B-31 *C-IL-4-590 *T haplotype increased the risk of ICU admission (OR = 2.53, 95% CI = 1.02-6.25, p = 0.047). The 42 SARS-CoV-2 genomes sequenced belonged to four clades, 20A-20D. No association was detected between SARS-CoV-2 clades and ICU admission or death. Thus, in patients with no known comorbidities or risk factors, the IL1B-31*C proinflammatory allele was observed to be associated with the risk of ICU admission owing to COVID-19.

Survey of Toxoplasma gondii in Urban and Rural Squirrels (Sciuridae) in Manitoba, Canada.

The coccidian parasite Toxoplasma gondii is found worldwide infecting warm-blooded vertebrates. Felids are the definitive hosts; other species act as intermediate hosts. Squirrels (Sciuridae) generally have high population densities in cities and forage and cache food on the ground, where they may come into contact with T. gondii oocysts or be preyed upon by cats and other carnivores. This environment might make squirrels important intermediate hosts of T. gondii in cities, and infection rates could indicate environmental levels of oocysts in soil. We investigated whether urban squirrels would be more exposed to T. gondii infection than rural squirrels with samples collected from American red squirrels (Tamiasciurus hudsonicus), eastern grey squirrels (Sciurus carolinensis), northern flying squirrels (Glaucomys sabrinus), and least chipmunks (Tamias minimus) in and around Winnipeg, Manitoba, Canada. We tested 230 tissue samples from 46 squirrels for T. gondii DNA by quantitative PCR and 13 serum samples from grey squirrels for T. gondii antibodies by competitive ELISA. We found no evidence of infection in any squirrel, indicating that squirrels are probably not important intermediate hosts of T. gondii in cities and that consumption of oocysts in the soil in general may not be an important contributor to transmission in colder environments.