Antifungal activities of metconazole against the emerging wheat pathogen Fusarium pseudograminearum.

Fusarium crown rot of wheat is a serious fungal disease that occurs worldwide. The disease has been emerging in the major wheat-growing areas in China since 2010. Fusarium pseudogramineaum is the predominant causative pathogen of crown rot of wheat in China. The 14α-demethylation inhibitor (DMI) fungicide metconazole has been shown to be effective against Fusarium spp., but little is known about its specific activity against F. pseudogramineaum. Metconazole exhibited strong antifungal activities against all thirty-nine F. pseudogramineaum strains collected from the major wheat-growing areas in China. Metconazole inhibited mycelial growth and conidial germ tube elongation of F. pseudograminearum. Metconazole treatment significantly reduced the production of major toxins and the expression levels of toxin biosynthesis genes. Genome-wide transcriptional profiling of F. pseudograminearum in response to metconazole indicated that the expression of genes involved in ergosterol biosynthesis, including fungicide target genes (cyp51 genes), was significantly induced by metconazole. Nine ATP-binding cassette (ABC) transporter-encoding genes were significantly expressed in response to metconazole treatment. Reduced ergosterol production and antioxidant enzyme activities were observed after metconazole treatment. Greenhouse experiments indicated a significant reduction in crown rot occurrence in wheat after seed treatment with metconazole. This study evaluated the potential of metconazole to manage wheat crown rot and provides information to understand its antifungal activities and mechanism of action against F. pseudograminearum.

The NDR kinase-MOB complex FgCot1-Mob2 regulates polarity and lipid metabolism in Fusarium graminearum.

Members of the NDR (nuclear Dbf2-related) protein-kinase family are essential for cell differentiation and polarized morphogenesis. However, their functions in plant pathogenic fungi are not well understood. Here, we characterized the NDR kinase FgCot1 and its activator FgMob2 in Fusarium graminearum, a major pathogen causing Fusarium head blight (FHB) in wheat. FgCot1 and FgMob2 formed a NDR kinase-MOB protein complex. Localization assays using FgCot1-GFP or FgMob2-RFP constructs showed diverse subcellular localizations, including cytoplasm, septum, nucleus and hyphal tip. ΔFgcot1 and ΔFgmob2 exhibited serious defects in hyphal growth, polarity, fungal development and cell wall integrity as well as reduced virulence in planta. In contrast, lipid droplet accumulation was significantly increased in these two mutants. Phosphorylation of FgCot1 at two highly conserved residues (S462 and T630) as well as five new sites synergistically contributed its role in various cellular processes. In addition, non-synonymous mutations in two MAPK (mitogen-activated protein kinase) proteins, FgSte11 and FgGpmk1, partially rescued the growth defect of ΔFgmob2, indicating a functional link between the FgCot1-Mob2 complex and the FgGpmk1 signalling pathway in regulating filamentous fungal growth. These results indicated that the FgCot1-Mob2 complex is critical for polarity, fungal development, cell wall organization, lipid metabolism and virulence in F. graminearum.

Complicated Trichosporon asahii mastoiditis in immunocompetent child.

BACKGROUND: Trichosporon asahii is an opportunistic fungus that causes infections in immunosuppressed patients. It is rarely seen in children and immunocompetent hosts. The mortality rates are still high despite early treatment with proper antifungal drugs. Trichosporon asahii mastoiditis in an immunocompetent child makes this case challenging. CASE PRESENTATION: This report presents a case of Trichosporon asahii mastoiditis which was complicated by transverse sinus thrombosis, in an otherwise healthy 21-month-old girl, and successfully treated with voriconazole. Trichosporon asahii was isolated, in three different occasions, from ear discharge of an immunocompetent healthy child, who presented with prolonged history of fever and received appropriate dosages of multiple types of antimicrobials as an outpatient but without improvement. After 48 h of starting the Voriconzole; post auricular swelling and ear discharge improved significantly. CONCLUSION: A high index of clinical and microbiological suspicion is needed for optimal diagnosis of Trichosporon infection. Trichosporon asahii can also cause infection in immunocompetent individual even without previous history of hospitalization or intervention. We emphasize the importance of early pediatric infectious evaluation and intervention.

Antifungal action and induction of resistance by ß-aminobutyric acid against Penicillium digitatum to control green mold in orange fruit.

Green mold, caused by Penicillium digitatum, is the most economically important postharvest disease of orange fruit worldwide. The aim of this study was to evaluate the effect of ß-aminobutyric acid (BABA) treatment on the inhibition of P. digitatum both in orange fruit and in vitro as well as the possible mechanisms of action. BABA at 125 mM significantly inhibited mycelial growth, spore germination, and germ tube elongation of P. digitatum by 93.3, 90.3, and 90.5%, respectively. The relative electrical conductivity of mycelium was increased for a period of 0-36 h after treated with BABA at 125 mM. Furthermore, BABA caused a high level of malondialdehyde (MDA) in P. digitatum mycelia during four days of incubation. The ergosterol content in the plasma membrane of P. digitatum was significantly lower in BABA-treated mycelia. Also, protein and sugar leakage were increased with BABA treatment compared with that in the control. Besides, BABA caused a considerable reduction in the total lipid content of P. digitatum mycelia at 125 mM. Scanning electron microscopy (SEM) of P. digitatum treated with BABA at 125 mM showed shrunken, distorted, and collapsed mycelia. The application of BABA at 125 mM in orange fruit inoculated with P. digitatum suppressed disease incidence and disease severity by 74.6 and 77.3%, respectively, compared to untreated fruit. Moreover, the activity of defense-related enzymes, including peroxidase (POD), polyphenoloxidase (PPO), and phenylalanine ammonia-lyase (PAL) were significantly enhanced in the orange fruit treated with BABA at 125 mM.

A prospective audit of the use of diagnostic laparoscopy to establish the diagnosis of abdominal tuberculosis.

BACKGROUND: The incidence of abdominal tuberculosis is much higher in an HIV-positive cohort. The use of laparoscopy in the diagnostic work-up of suspected abdominal tuberculosis is underutilized and its use and efficacy in the context of HIV co-infection has never been examined. METHODS: A prospective clinical audit of the use of diagnostic laparoscopy was conducted in patients with clinically suspected abdominal tuberculosis but histologically or microbiologically unconfirmed tuberculosis at any site. RESULTS: From January 2008 to June 2010, 81 patients underwent diagnostic laparoscopy; 34 were male and 47 were female, with a mean age of 33 years, and 77 % were HIV-positive. Fifty-five patients (68 %) had positive histology or culture for tuberculosis. In 15 patients (19 %), histology revealed non-specific inflammation, no pathology was found in one patient, and no specimen was taken from one patient. Eighty percent of peritoneal deposits and 77 % of lymph nodes were positive for tuberculosis, whereas 35 % of ascitic fluid cultures were positive. In nine patients (11 %) an alternative diagnosis was found; nine patients (11 %) had conversion to laparotomy. There was no procedure-related death. Nine patients (11 %) died during the 2-month follow-up period. CONCLUSIONS: Diagnostic laparoscopy avoids the morbidity and mortality of laparotomy in chronically ill patients, and reduces the rate of misdiagnosis of other abdominal conditions and unnecessary long-term therapy. Diagnostic laparoscopy and tissue sampling is a viable and reliable strategy in patients with suspected abdominal tuberculosis.

Effect of Chitosan/Gum Arabic Blends Enriched by Sodium Nitroprusside or Methyl Salicylate on the Storability and Antioxidant Activity of Tomato Fruit.

The impact of methyl salicylate (MeSA) or sodium nitroprusside (SNP) in chitosan (CS)/Gum Arabic (GA) mixture on physio-chemical characteristics and antioxidant status during the postharvest ripening of green tomato fruits was studied. CS/GA-MeSA at a 1 mM formulation was the best treatment to retard firmness and titratable acidity (TA) losses. Moreover, this formulation retarded pigmentation progress where it had the lowest significant values of total carotenes (TCs) and lycopene (LYP) contents until the 15th day of the storage period, as well as efficiently faced the rise in malondialdehyde (MDA) levels. Moreover, peroxidase (POD), polyphenol oxidase (PPO), catalase (CAT), and phenylalanine ammonia-lyase (PAL) activities of tomatoes treated with CS/GA-SNP at 2 mM were significantly better than that of control in the primary stages of storage. CS/GA-SNP at a 2 mM formulation showed an extremely high significant content of total polyphenol (TP) in the early stage of storage, while CS/GA and CS/GA-MeSA at 1 and 2 mM accumulated higher significant TP contents than uncoated fruits at the late stage of storage. All formulations were characterized by FTIR spectroscopy. Furthermore, the polymer formulations exhibited strong antifungal activity against Alternaria alternata and Botrytis cinerea as major pathogens of postharvest tomatoes. Transmission electron microscope (TEM) observations for the mycelia of both fungi treated by CS/GA-MeSA at 2 mM revealed serious ultrastructural damage, including distortion of the cell wall and cell membrane and degradation of cytoplasmic organelles.

Association between reproductive cancer and fetal outcomes: a systematic review.

OBJECTIVE: This study aimed to review studies that addressed the impact of previous reproductive cancer diagnosis on selected fetal birth outcomes. MATERIALS AND METHODS: We searched PubMed and Web of Knowledge to identify peer-reviewed articles published from January 1992 to December 2012, investigating the association between reproductive cancer and birth outcomes. After applying exclusion criteria, 49 articles were identified for full review, and 36 articles were finally selected for this systematic review. The quality of the studies was assessed by independent reviewers. RESULTS: We found 13 cervical cancer studies, 16 ovarian cancer studies, and 7 corpus uteri cancers that reported subsequent pregnancies (n = 688 pregnancies in 477 women). Of these, 489 pregnancies reached third trimester. Among viable pregnancies, only 416 pregnancies had information on maturity status based on gestational age and/or birth weight. For those with cervical cancer, the preterm birth (PTB) rate was 48.5%. For those with ovarian cancer, there were no cases of PTB. For those with corpus uteri cancers, the PTB was 7.7%. All studies had small sample sizes, and there was considerable heterogeneity of results. Abortions, ectopic pregnancies, and terminations were also reported. CONCLUSIONS: Reproductive cancers may be associated to subsequent adverse fetal birth outcomes; however, the quality of evidence is still insufficient to infer a relationship between reproductive cancers treated conservatively and adverse fetal birth outcomes in subsequent pregnancies.

Association between reproductive cancer and fetal outcomes: a population-based study.

PURPOSE: This study aimed to evaluate the impact of maternal reproductive cancer diagnosis on fetal birth outcomes. MATERIALS AND METHODS: We conducted a retrospective population-based cohort study among women with a singleton live birth and diagnosed with reproductive cancer in the state of Florida (cases). We matched cases to cancer-free controls using selected sociodemographic and pregnancy-related clinical conditions. We applied logistic regression with correction for intracluster correlation using generalized estimating equations. RESULTS: Overall, 3212 (0.21%) of pregnant women had a diagnosis of reproductive cancer. Affected women had a 24% and 33% elevated risk for low birth weight (LBW) and preterm birth (PTB) infants, respectively. Compared to their white counterparts, black women with reproductive cancer had a greater risk for LBW [odds ratio (OR), 1.83; 95% confidence interval (CI), 1.37-2.44], small for gestational age (SGA) [OR, 1.64; 95% CI, 1.23-2.17], and PTB (OR, 1.47; 95% CI, 1.12-192) infants. Black women with breast cancer demonstrated significantly higher risks of LBW [adjusted odds ratio (AOR), 2.37; 95% CI, 1.56-3.60], PTB (AOR, 1.71; 95% CI, 1.15-2.56), and SGA (AOR, 1.72; 95% CI, 1.12-2.64) when compared to women of their racial group with no reproductive cancer. CONCLUSIONS: Diagnosis of reproductive cancer before or during pregnancy and within 30 days after birth is associated with adverse fetal outcomes (LBW, PTB, and SGA). These results highlight the importance of preconception and intraconception care of women with reproductive cancer diagnosis.

Establishing the infrastructure to conduct comparative effectiveness research toward the elimination of disparities: a community-based participatory research framework.

In Tampa, Florida, researchers have partnered with community- and faith-based organizations to create the Comparative Effectiveness Research for Eliminating Disparities (CERED) infrastructure. Grounded in community-based participatory research, CERED acts on multiple levels of society to enhance informed decision making (IDM) of prostate cancer screening among Black men. CERED investigators combined both comparative effectiveness research and community-based participatory research to design a trial examining the effectiveness of community health workers and a digitally enhanced patient decision aid to support IDM in community settings as compared with "usual care" for prostate cancer screening. In addition, CERED researchers synthesized evidence through the development of systematic literature reviews analyzing the effectiveness of community health workers in changing knowledge, attitudes and behaviors of African American adults toward cancer prevention and education. An additional systematic review analyzed chemoprevention agents for prostate cancer as an emerging technique. Both of these reviews, and the comparative effectiveness trial supporting the IDM process, add to CERED's goal of providing evidence to eliminate cancer health disparities.

Factors leading to disparity in lung cancer diagnosis among black/African American communities in the USA: a qualitative study.

OBJECTIVE: This study has two objectives: first, to explore the diagnostic experiences of black/African American (BAA) patients with lung cancer to pinpoint pitfalls, suboptimal experiences and instances of discrimination leading to disparities in outcomes compared with patients of other ethnic backgrounds, especially white patients. The second objective is to identify the underlying causes contributing to health disparities in the diagnosis of lung cancer among BAA patients. METHODS: We employed a phenomenological research approach, guiding in-depth interviews with patients self-identifying as BAA diagnosed with lung cancer, as well as caregivers, healthcare professionals and community advocates knowledgeable about BAA experiences with lung cancer. We performed thematic analysis to identify experiences at patient, primary care and specialist levels. Contributing factors were identified using the National Institute of Minority Health and Health Disparities (NIMHD) health disparity model. RESULTS: From March to November 2021, we conducted individual interviews with 19 participants, including 9 patients/caregivers and 10 providers/advocates. Participants reported recurring and increased pain before seeking treatment, treatment for non-cancer illnesses, delays in diagnostic tests and referrals, poor communication and bias when dealing with specialists and primary care providers. Factors contributing to suboptimal experiences included reluctance by insurers to cover costs, provider unwillingness to conduct comprehensive testing, provider bias in recommending treatment, high healthcare costs, and lack of healthcare facilities and qualified staff to provide necessary support. However, some participants reported positive experiences due to their insurance, availability of services and having an empowered support structure. CONCLUSIONS: BAA patients and caregivers encountered suboptimal experiences during their care. The NIMHD model is a useful framework to organise factors contributing to these experiences that may be leading to health disparities. Additional research is needed to fully capture the extent of these experiences and identify ways to improve BAA patient experiences in the lung cancer diagnosis pathway.

Adjustment disorder among first year medical students at King Saud University, Riyadh, Saudi Arabia, in 2020.

BACKGROUND: The general health and well-being of medical students has become a matter of concern, as medical students have higher levels of stress than their nonmedical peers. Long-standing stress may lead to serious outcomes, such as depression, anxiety, poor quality of life, or adjustment disorders. This study aimed to estimate the proportion of first year medical students who have adjustment disorder and explore possible risk factors. MATERIALS AND METHODS: This cross-sectional study was conducted among all first-year medical students at King Saud University, College of Medicine, Saudi Arabia. The adjustment disorder-new model 20 (ADNM-20) was used to assess adjustment disorder with the stressor and item lists. The item list scores were summed and a cutoff point >47.5 was designated as a high risk of developing the disorder. Descriptive analysis included computing mean and standard deviation for continuous variable while frequency and percentages for categorical variables. Chi-square test and logistic regression analysis determined risk factors for having an adjustment disorder and the stress of attending a medical school. RESULTS: The study enrolled 267 students but only 128 completed the ADNM-20 survey. Out of 267 students, the most commonly reported recent stressor was too much/too little work, and 52.8% reported having difficulty in meeting deadlines. The most common core symptom expressed by the medical students was avoidance behavior with a mean score of 10.91 ± 3.12, followed by preoccupation with stressors with a mean score of 10.66 ± 3.10. The factors significantly associated with having adjustment disorder were being female, younger age, recent illness of a loved one, having family conflicts, and having too much or too little work. CONCLUSION: First year medical students are at increased risk of adjustment disorder. Screening and awareness programs may be considered for preventing adjustment disorder. Increased student-staff interactions may provide support to adapt to their new environment and help reduce social adjustment difficulties.

A Problem in NIH and Federally Funded Prostate Cancer Interventional Clinical Trials.

BACKGROUND: Obesity, diagnosed in 41.1% of African American (AA) men, is a risk factor for prostate cancer (PCa) recurrence, progression, and increased mortality. Obesity is associated with aggressive PCa only in AA men and not White American (WA) men. The overall health of AA PCa patients is also more likely to be adversely affected by comorbid type 2 diabetes (T2D), often an outcome of obesity and a cause of reduced odds of PCa survival. This evidence suggests that preventing and controlling comorbid obesity and T2D in AA men diagnosed with PCa should be a research funding priority. AIM: The aim of this study is to determine if federally funded PCa clinical trials controlled T2D and obesity. METHODS: Completed interventional PCa clinical trials conducted in the USA, funded by the NIH or other federal agency, which included males aged 18-64 years, and reported study protocols were included in the study. We examined the intervention modalities used in the trials to determine if any attempted to control obesity and T2D. RESULTS: Fifty-eight trials met the study inclusion criteria. Of these 11 were excluded from the analysis as they did not report AA men. A total of 5802 men participated in the remaining 47 trials. Of these, 917 (15.8%) were AA and 4885 (84.2%) were WA men. Forty (85.1%) trials used pharmaceutical medication therapies or other clinical procedures. None of the medications or clinical procedures used were indicated for treatment of obesity and T2D. 5 (10.6%) trials addressed treatment preferences, survivorship, coping, function, and incontinence among PCa patients. Only 2 (4.25%) trials examined weight loss and diet. CONCLUSIONS: None of the completed federally funded PCa clinical trials that included AA men used methods to control T2D. Only an insignificant number (4.25%) attempted to control obesity. This gap in therapeutic optimization to control these comorbid conditions indicates a critical area in need of federal funding priority.

New Hydrolase from Aeromicrobium sp. HA for the Biodegradation of Zearalenone: Identification, Mechanism, and Application.

Zearalenone (ZEN) is an estrogenic mycotoxin most frequently found in cereals that can cause reproductive disorders in livestock and pose a severe threat to animal husbandry. In this study, we isolated a ZEN-degrading Aeromicrobium strain from soil and found that ZenH, a hydrolase, is responsible for the hydrolysis of ZEN through comparative proteomics and biochemical studies. ZenH exhibited the highest similarity with lactone hydrolase ZHD607 from Phialophora americana at 21.52%. ZenH displayed maximal enzymatic activity at pH 7.0 and 55 °C with a Michaelis constant of 12.64 µM. The catalytic triad of ZenH was identified as S117-D142-H292 by molecular docking and site-directed mutagenesis. ZenH catalyzed the hydrolysis of ZEN to a novel metabolite, (S,E)-4-hydroxy-2-(10-hydroxy-6-oxoundec-1-en-1-yl)-7-oxabicyclo[4.2.0]octa-1,3,5-trien-8-one, which exhibited significantly lower estrogenic toxicity than ZEN. This study illustrates a novel ZEN-degrading enzyme and reveals a new degradation product. Furthermore, the enzyme showed good potential for detoxifying ZEN during food processing.

Paralogous FgIDO genes with differential roles in tryptophan catabolism, fungal development and virulence in Fusarium graminearum.

Indoleamine 2,3-dioxygenase (Ido) is a tryptophan-degrading enzyme that is widely distributed across species. Ido catalyzes the first step of tryptophan (TRP) degradation and drives the de novo synthesis of nicotinamide adenine dinucleotide (NAD+) coenzymes via the kynurenine (KYN) pathway. The budding yeast Saccharomyces cerevisiae possesses a single IDO gene (BNA2) that is responsible for NAD+ synthesis, whereas a number of fungal species contain multiple IDO genes. However, the biological roles of IDO paralogs in plant pathogens remain unclear. In the current study, we identified three FgIDOs from the wheat head blight fungus Fusarium graminearum. FgIDOA/B/C expression was significantly induced upon TRP treatment. Targeted disruption of FgIDOA and/or FgIDOB caused different levels of NAD+ auxotrophy, thus resulting in pleotropic phenotypic defects. Loss of FgIDOA resulted in abnormal conidial morphology, reduced mycelial growth, decreased virulence in wheat heads and reduced deoxynivalenol accumulation. Exogenous addition of KYN or various intermediates involved in the KYN pathway rescued auxotrophy of the mutants. Metabolomics analysis revealed shifts toward alternative TRP degradation pathways to melatonin and indole derivatives in mutants lacking FgIDOB. Upregulation of partner genes in auxotrophic mutants and the capacity to rescue the auxotroph by overexpressing a partner gene indicated functional complementation among FgIDOA/B/C. Taken together, the results of this study provide insights into differential roles in paralogous FgIDOs and how fungal TRP catabolism modulates fungal development and virulence.

The Prevalence of Depression and Anxiety in Post-bariatric Surgery Patients at King Khalid University Hospital, Riyadh.

Background Obesity negatively impacts mental and physical health and is a leading cause of disease worldwide. Obesity affects 33% of Saudi adults, with 10% being morbidly obese (body mass index, BMI >40 kg/m2). This study explored the association between bariatric surgery (BS) and a predisposition or exacerbation of depressive and anxiety symptoms. Material and methods A cross-sectional study of patients who underwent bariatric surgery at the King Khalid University Hospital in Riyadh, Saudi Arabia, was conducted between February 2016 and December 2021. The patients were contacted by phone to complete a self-administered questionnaire on demographic information, chronic medical diseases, psychiatric diseases, body mass index, and type of bariatric surgery. In addition, they completed the patient health questionnaire-9 (PHQ-9) and general anxiety disorder-7 (GAD-7) questionnaire to screen for patients' depression and anxiety symptoms. Results The findings of the 367 BS patients showed that 20.7% of the patients were considered to have mild anxiety, 11.2% had moderate anxiety, and 8.7% had high anxiety levels. However, regarding depression, 46.9% had extremely low levels of depression, followed by mild depression in 29.4% and moderate depression in 11.2%. Furthermore, another 8.2% of BS patients had moderately high depression levels, and 4.4% had severe depression. The anxiety and depression levels of the patients in this study did not show any statistically significant changes postoperatively in the short, medium, or long term. On the other hand, almost all of the patients 97% who underwent bariatric surgery were satisfied with the outcome of their surgery. Conclusion Few BS patients had high symptoms of depression and anxiety. We recommend pre- and postoperative psychiatric assessment for all bariatric surgery patients as surgical protocol.

Isolation, Characterization, and Application of Clostridium sporogenes F39 to Degrade Zearalenone under Anaerobic Conditions.

Zearalenone (ZEN) is produced by Fusarium spp. and is widely found in moldy wheat, corn, and other grains. ZEN has a strong toxicity and causes reproductive and immune disorders and estrogenic syndrome in animals and humans. Biodegradation has been demonstrated as an efficient way to control the hazardous effect of ZEN. A promising way to apply biodegradation in feed is to introduce anaerobic ZEN-degrading microorganisms, which can function during the digestion process in animal intestines. The aim of this study was to isolate anaerobic ZEN-degrading bacteria from anaerobic environments. A strain named F39 was isolated from animal intestinal contents and had a ZEN-degradation rate of 87.35% in 48 h to form trace amount of α- and ß-zearalenol. Based on the morphological and physiological properties and phylogenetic analysis of 16S rRNA and rpoB gene sequences, F39 was identified as Clostridium sporogenes. The optimum temperature for the growth of F39 was 37 °C, the optimum pH was 7.0, and the most suitable carbon source was beef extract, while the optimal conditions for the degradation of ZEN were as follows: 35 °C, pH 7.0, and GAM medium. ZEN was degraded by F39 with a high efficiency in the concentration range of 1-15 mg/L. The bioactive factors responsible for ZEN degradation were mainly distributed intracellularly. F39 can degrade most of the ZEN present, but a small amount is broken down into two secondary metabolites, α- and ß-zearalenol, and the toxicity of the degradation products is reduced. With an efficiency of 49%, F39 can more effectively degrade ZEN in wheat-based feedstuffs than in other feedstuff, and the degradation efficiency was pH related. To the best of our knowledge, this is the first report of Clostridium sporogenes F39's ability to maintain the biodegradation potentials.

Nanozyme-strip based on MnO2 nanosheets as a catalytic label for multi-scale detection of aflatoxin B1 with an ultrabroad working range.

Lateral flow immunoassay (LFIA) is the most effective real-time detection method for aflatoxin B1 (AFB1). Here, we constructed a nanozyme-strip based on MnO2 nanosheets (MnO2 NSs) as a catalytic label for detection of AFB1. By taking advantage of the MnO2-TMB catalytic amplified system, the new test achieves rapid detection with high sensitivity and ultrawide range. The limit of detection of the assay was 15 pg mL-1, which was over 100-fold lower than the maximum limit set by the European Union (EU) of AFB1 in foods. In addition, the strip test could offer 7 dynamic detection ranges, spanning 4 orders of magnitude, which could cater to the varieties of limits on AFB1 residues in foods and feeds set by different countries. The estimated recoveries were in the range of 85.67%-106.38% with coefficients of variations (CVs) less than 9.68%. Overall, the developed approach is a rapid, reliable, sensitive and widely available tool for on-site detection of AFB1.

Meta-analytic magic, ivermectin, and socially responsible reporting.

Some clinicians prescribe ivermectin for COVID-19 despite a lack of support from any credible South African professional body. They argue that when faced by clinical urgency, weak signals of efficacy should trigger action if harm is unlikely. Several recent reviews found an apparent mortality benefit by including studies at high risk of bias and with active rather than placebo controls. If these studies are discounted, the pooled mortality effect is no longer statistically significant, and evidence of benefit is very weak. Relying on this evidence could cause clinical harm if used to justify vaccine hesitancy. Clinicians remain responsible for ensuring that guidance they follow is both legitimate and reliable. In the ivermectin debate, evidence-based medicine (EBM) principles have largely been ignored under the guise thatin a pandemic the 'rules are different', probably to the detriment of vulnerable patients and certainly to the detriment of the profession's image. Medical schools and professional interest groups are responsible for transforming EBM from a taught but seldom-used tool into a process of lifelong learning, promoting a consistent call for evidence-based and unconflicted debate integral to clinical practice.

A direct competitive nanozyme-linked immunosorbent assay based on MnO2 nanosheets as a catalytic label for the determination of fumonisin B1.

A direct competitive nanozyme-linked immunosorbent assay (dcNLISA) based on MnO2 nanosheets (MnO2 NSs) as a nanozyme label was developed for the highly sensitive determination of fumonisin B1 (FB1). MnO2 NS-labeled fumonisin B1-bovine serum albumin was easily synthesized as a competing antigen for the dcNLISA. And color changes derived from the MnO2-3,3',5,5'-tetramethylbenzidine (TMB) system were exploited as the output signals of the dcNLISA. Several experimental parameters including the concentrations of the coating antibody, pH values, ionic strength and methanol concentration were optimized. Under the optimal conditions, the proposed method demonstrated a linear range (1.17-20.74 ng mL-1) with a reliable correlation coefficient (R2 = 0.9989), a satisfactory limit of detection (0.63 ng mL-1) and high selectivity for the detection of FB1. The recoveries of FB1 in spiked corn and wheat samples were in the range of 85.31-108.16% with coefficients of variation (CVs) ranging from 6.14% to 9.23%. Meanwhile, the testing results showed good consistency (R2 = 0.9892) between the developed dcNLISA and the reference method, liquid chromatography/mass spectrometry/mass spectrometry (LC-MS/MS) method. The proposed method was proven to be simple, sensitive, cost-effective and reliable for the screening of FB1 in cereals.

A position statement and practical guide to the use of particulate filtering facepiece respirators (N95, FFP2, or equivalent) for South African health workers exposed to respiratory pathogens including Mycobacterium tuberculosis and SARS-CoV-2.

SUMMARY: Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is transmitted mainly by aerosol in particles <10 µm that can remain suspended for hours before being inhaled. Because particulate filtering facepiece respirators ('respirators'; e.g. N95 masks) are more effective than surgical masks against bio-aerosols, many international organisations now recommend that health workers (HWs) wear a respirator when caring for individuals who may have COVID-19. In South Africa (SA), however, surgical masks are still recommended for the routine care of individuals with possible or confirmed COVID-19, with respirators reserved for so-called aerosol-generating procedures. In contrast, SA guidelines do recommend respirators for routine care of individuals with possible or confirmed tuberculosis (TB), which is also transmitted via aerosol. In health facilities in SA, distinguishing between TB and COVID-19 is challenging without examination and investigation, both of which may expose HWs to potentially infectious individuals. Symptom-based triage has limited utility in defining risk. Indeed, significant proportions of individuals with COVID-19 and/or pulmonary TB may not have symptoms and/or test negative. The prevalence of undiagnosed respiratory disease is therefore likely significant in many general clinical areas (e.g. waiting areas). Moreover, a proportion of HWs are HIV-positive and are at increased risk of severe COVID-19 and death. RECOMMENDATIONS: Sustained improvements in infection prevention and control (IPC) require reorganisation of systems to prioritise HW and patient safety. While this will take time, it is unacceptable to leave HWs exposed until such changes are made. We propose that the SA health system adopts a target of 'zero harm', aiming to eliminate transmission of respiratory pathogens to all individuals in every healthcare setting. Accordingly, we recommend: the use of respirators by all staff (clinical and non-clinical) during activities that involve contact or sharing air in indoor spaces with individuals who: (i) have not yet been clinically evaluated; or (ii) are thought or known to have TB and/or COVID-19 or other potentially harmful respiratory infections;the use of respirators that meet national and international manufacturing standards;evaluation of all respirators, at the least, by qualitative fit testing; andthe use of respirators as part of a 'package of care' in line with international IPC recommendations. We recognise that this will be challenging, not least due to global and national shortages of personal protective equipment (PPE). SA national policy around respiratory protective equipment enables a robust framework for manufacture and quality control and has been supported by local manufacturers and the Department of Trade, Industry and Competition. Respirator manufacturers should explore adaptations to improve comfort and reduce barriers to communication. Structural changes are needed urgently to improve the safety of health facilities: persistent advocacy and research around potential systems change remain essential.