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1.
Cell Rep ; 43(4): 114022, 2024 Apr 23.
Article in English | MEDLINE | ID: mdl-38568806

ABSTRACT

Staphylococcus aureus causes the majority of skin and soft tissue infections, but this pathogen only transiently colonizes healthy skin. However, this transient skin exposure enables S. aureus to transition to infection. The initial adhesion of S. aureus to skin corneocytes is mediated by surface protein G (SasG). Here, phylogenetic analyses reveal the presence of two major divergent SasG alleles in S. aureus: SasG-I and SasG-II. Structural analyses of SasG-II identify a nonaromatic arginine in the binding pocket of the lectin subdomain that mediates adhesion to corneocytes. Atomic force microscopy and corneocyte adhesion assays indicate that SasG-II can bind to a broader variety of ligands than SasG-I. Glycosidase treatment results in different binding profiles between SasG-I and SasG-II on skin cells. In addition, SasG-mediated adhesion is recapitulated using differentiated N/TERT keratinocytes. Our findings indicate that SasG-II has evolved to adhere to multiple ligands, conferring a distinct advantage to S. aureus during skin colonization.


Subject(s)
Bacterial Adhesion , Keratinocytes , Skin , Staphylococcus aureus , Staphylococcus aureus/metabolism , Humans , Skin/microbiology , Skin/metabolism , Keratinocytes/microbiology , Keratinocytes/metabolism , Lectins/metabolism , Bacterial Proteins/metabolism , Bacterial Proteins/genetics , Phylogeny , Protein Binding
2.
J Glob Health ; 14: 04009, 2024 Feb 02.
Article in English | MEDLINE | ID: mdl-38299777

ABSTRACT

Background: Neonatal infections are a major public health concern worldwide, particularly in low- and middle-income countries, where most of the infection-related deaths in under-five children occur. Sub-Saharan Africa has the highest mortality rates, but there is a lack of data on the incidence of sepsis from this region, hindering efforts to improve child survival. We aimed to determine the incidence of possible serious bacterial infection (PSBI) in young infants in three high-burden countries in Africa. Methods: This is a secondary analysis of data from the African Neonatal Sepsis (AFRINEST) trial, conducted in the Democratic Republic of the Congo (DRC), Kenya, and Nigeria between 15 March 2012 and 15 July 2013. We recorded baseline characteristics, the incidence of PSBI (as defined by the World Health Organization), and the incidence of local infections among infants from 0-59 days after birth. We report descriptive statistics. Results: The incidence of PSBI among 0-59-day-old infants across all three countries was 11.2% (95% confidence interval (CI) = 11.0-11.4). The DRC had the highest incidence of PSBI (19.0%; 95% CI = 18.2-19.8). Likewise, PSBI rates were higher in low birth weight infants (24.5%; 95% CI = 23.1-26.0) and infants born to mothers aged <20 years (14.1%; 95% CI = 13.4-14.8). The incidence of PSBI was higher among infants delivered at home (11.7%; 95% CI = 11.4-12.0). Conclusions: The high burden of PSBI among young infants in DRC, Kenya, and Nigeria demonstrates the importance of addressing PSBI in improving child survival in sub-Saharan Africa to reach the Sustainable Development Goals (SDGs). These data can support government authorities, policymakers, programme implementers, non-governmental organisations, and international partners in reducing preventable under-five deaths. Registration: Australian New Zealand Clinical Trials Registry: ACTRN12610000286044.


Subject(s)
Bacterial Infections , Humans , Infant , Infant, Newborn , Australia , Bacterial Infections/epidemiology , Bacterial Infections/drug therapy , Democratic Republic of the Congo/epidemiology , Incidence , Kenya/epidemiology , Nigeria/epidemiology , Multicenter Studies as Topic , Clinical Trials as Topic
3.
Sci Total Environ ; 922: 171158, 2024 Apr 20.
Article in English | MEDLINE | ID: mdl-38387558

ABSTRACT

Soil porosity and its reciprocal bulk density are important environmental state variables that enable modelers to represent hydraulic function and carbon storage. Biotic effects and their 'dynamic' influence on such state variables remain largely unknown for larger scales and may result in important, yet poorly quantified environmental feedbacks. Existing representation of hydraulic function is often invariant to environmental change and may be poor in some systems, particularly non-arable soils. Here we assess predictors of total porosity across two comprehensive national topsoil (0-15 cm) data sets, covering the full range of soil organic matter (SOM) and habitats (n = 1385 & n = 2570), using generalized additive mixed models and machine learning. Novel aspects of this work include the testing of metrics on aggregate size and livestock density alongside a range of different particle size distribution metrics. We demonstrate that porosity trends in Great Britain are dominated by biotic metrics, soil carbon and land use. Incorporating these variables into porosity prediction improves performance, paving the way for new dynamic calculation of porosity using surrogate measures with remote sensing, which may help improve prediction in data sparse regions of the world. Moreover, dynamic calculation of porosity could support representation of feedbacks in environmental and Earth System Models. Representing the hydrological feedbacks from changes in structural porosity also requires data and models at appropriate spatial scales to capture conditions leading to near-saturated soil conditions. Classification. Environmental Sciences.

4.
Article in English | MEDLINE | ID: mdl-38353679

ABSTRACT

Exposure to toxic heavy metals has been associated with the development of attention-deficit/hyperactivity disorder (ADHD). However, fewer studies have examined the associations between abnormal levels of essential trace metals and ADHD, and none have done so using saliva. We investigated whether salivary metals were associated with ADHD in adolescents aged 12 from the Family Life Project (FLP) using a nested case-control study design that included 110 adolescents who met diagnostic criteria for inattentive (ADHD-I), hyperactive-impulsive (ADHD-H), or combined type ADHD (ADHD-C) (cases) and 173 children who did not (controls). We used inductively coupled plasma optical emission spectrophotometry to measure chromium, copper, manganese, and zinc in saliva samples. We employed logistic regression models to examine associations between quartile levels of individual metals and ADHD outcomes by subtype. Salivary copper levels were significantly associated with increased odds of any ADHD diagnosis (OR = 3.31, 95% CI: 1.08-10.12; p = 0.04) and with increased odds of ADHD-C diagnosis (OR = 8.44, 95% CI: 1.58-45.12; p = 0.01). Salivary zinc levels were significantly associated with increased odds of ADHD-C diagnosis (OR = 4.06, 95% CI: 1.21-13.69; p = 0.02). Salivary manganese levels were also significantly associated with increased odds of ADHD-C diagnosis (OR = 5.43, 95% CI: 1.08-27.27, p = 0.04). This is the first study using saliva to assess metal exposure and provide a potential link between salivary levels of copper, manganese, and zinc and ADHD diagnoses in adolescents. Public health interventions focused on metal exposures might reduce ADHD incidence in low-income, minority communities.

5.
Microb Genom ; 10(2)2024 Feb.
Article in English | MEDLINE | ID: mdl-38315173

ABSTRACT

Streptococcus pneumoniae is a major cause of invasive disease of young children in low- and middle-income countries. In southern India, pneumococcal conjugate vaccines (PCVs) that can prevent invasive pneumococcal disease began to be used more frequently after 2015. To characterize pneumococcal evolution during the early time period of PCV uptake in southern India, genomes were sequenced and selected characteristics were determined for 402 invasive isolates collected from children <5 years of age during routine surveillance from 1991 to 2020. Overall, the prevalence and diversity of vaccine type (VT) and non-vaccine type (NVT) isolates did not significantly change post-uptake of PCV. Individually, serotype 1 and global pneumococcal sequence cluster (GPSC or strain lineage) 2 significantly decreased, whereas serotypes 6B, 9V and 19A and GPSCs 1, 6, 10 and 23 significantly increased in proportion post-uptake of PCV. Resistance determinants to penicillin, erythromycin, co-trimoxazole, fluoroquinolones and tetracycline, and multidrug resistance significantly increased in proportion post-uptake of PCV and especially among VT isolates. Co-trimoxazole resistance determinants were common pre- and post-uptake of PCV (85 and 93 %, respectively) and experienced the highest rates of recombination in the genome. Accessory gene frequencies were seen to be changing by small amounts across the frequency spectrum specifically among VT isolates, with the largest changes linked to antimicrobial resistance determinants. In summary, these results indicate that as of 2020 this pneumococcal population was not yet approaching a PCV-induced equilibrium and they highlight changes related to antimicrobial resistance. Augmenting PCV coverage and prudent use of antimicrobials are needed to counter invasive pneumococcal disease in this region.


Subject(s)
Pneumococcal Infections , Streptococcus pneumoniae , Child , Humans , Child, Preschool , Vaccines, Conjugate , Trimethoprim, Sulfamethoxazole Drug Combination , Metagenomics , Pneumococcal Infections/epidemiology , Pneumococcal Infections/prevention & control , Pneumococcal Vaccines , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/therapeutic use , India/epidemiology
6.
Birth Defects Res ; 116(1): e2287, 2024 Jan.
Article in English | MEDLINE | ID: mdl-38116905

ABSTRACT

BACKGROUND: Congenital hydrocephalus (CH) is a life-threatening neurological condition that results from an imbalance in production, flow, or absorption of cerebrospinal fluid. Predicted outcomes from in utero diagnosis are frequently unclear. Moreover, conventional treatments consisting primarily of antenatal and postnatal surgeries are often unsuccessful, leading to high mortality rates. Causes of CH can range from secondary insults to germline pathogenic variants, complicating diagnostic processes and treatment outcomes. Currently, an updated summary of CH genetic etiologies in conjunction with clinical testing methodologies is lacking. This review addresses this need by generating a centralized survey of known genetic causes and available molecular tests for CH. METHODS: The scoping review protocol was registered with the Open Science Framework and followed the Arksey and O'Malley framework and the Joanna Briggs Institute methodology. The Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR) was utilized to define search guidelines and screening criteria. RESULTS: Our survey revealed a high number of genetic etiologies associated with CH, ranging from single gene variants to multifactorial birth defects, and additionally uncovered diagnostic challenges that are further complicated by changes in testing approaches over the years. Furthermore, we discovered that most of the existing literature consists of case reports, underscoring the need for studies that utilize CH patient research cohorts as well as more mechanistic studies. CONCLUSIONS: The pursuit of such studies will facilitate novel gene discovery while recognizing phenotypic complexity. Addressing these research gaps could ultimately inform evidence-based diagnostic guidelines to improve patient care.


Subject(s)
Hydrocephalus , Female , Pregnancy , Humans , Hydrocephalus/diagnosis , Hydrocephalus/genetics , Germ-Line Mutation , Prenatal Diagnosis
7.
bioRxiv ; 2023 Nov 21.
Article in English | MEDLINE | ID: mdl-38045275

ABSTRACT

Staphylococcus aureus causes the majority of skin and soft tissue infections, but this pathogen only transiently colonizes healthy skin. However, this transient skin exposure enables S. aureus to transition to infection. Initial adhesion of S. aureus to skin corneocytes is mediated by surface protein G (SasG). Here, phylogenetic analyses reveal the presence of two major divergent SasG alleles in S. aureus, SasG-I and SasG-II. Structural analyses of SasG-II identified a unique non-aromatic arginine in the binding pocket of the lectin subdomain that mediates adhesion to corneocytes. Atomic force microscopy and corneocyte adhesion assays indicated SasG-II can bind to a broader variety of ligands than SasG-I. Glycosidase treatment resulted in different binding profiles between SasG-I and SasG-II on skin cells. Additionally, SasG-mediated adhesion was recapitulated using differentiated N/TERT keratinocytes. Our findings indicate that SasG-II has evolved to adhere to multiple ligands, conferring a distinct advantage to S. aureus during skin colonization.

9.
Public Health ; 224: 215-223, 2023 Oct 17.
Article in English | MEDLINE | ID: mdl-37856904

ABSTRACT

OBJECTIVES: Between 1997 and 2021, the number of children looked after (CLA) in Wales, UK, increased steadily, with stark inequalities. We aimed to assess how deprivation and maternal and child perinatal characteristics influence the risk of becoming CLA in Wales. STUDY DESIGN: We constructed a prospective longitudinal cohort of children born in Wales between April 2006 and March 2021 (n = 395,610) using linked administrative records. METHODS: Survival models examined the risk of CLA from birth by small-area deprivation and maternal and child perinatal characteristics. Population attributable fractions quantify the potential impact of action on modifiable risk factors. RESULTS: Children from the most deprived fifth of the population were 3.4 times more likely to enter care than those in the least deprived (demographic adjusted hazard ratios [aHRs] 3.40, 95% confidence interval [CI] 3.08, 3.74). Maternal mental health problems in pregnancy (fully aHR, 2.03, 95% CI 1.88, 2.19) and behavioural factors, such as smoking (aHR 2.46, 95% CI 2.34-2.60), alcohol problems (aHR 2.35, 95% CI 1.70-3.23) and substance use in pregnancy (aHR 5.72, 95% CI 5.03-6.51), as well as child congenital anomalies (aHR 1.46, 95% CI 1.16-1.84), low birth weight (aHR 1.28, 95% CI 1.17, 1.39) and preterm birth (aHR 1.16, 95% CI 1.06, 1.26), were associated with higher risk of CLA status. The risk of CLA in the population may be reduced by 35% (95% CI 0.33, 0.38) if children in the two most deprived fifths of the population experienced the conditions of those in the least deprived. CONCLUSIONS: Deprivation and perinatal maternal health are important modifiable risk factors for children becoming CLA. Our analysis provides insight into the mechanisms of intergenerational transfer of disadvantage in a vulnerable section of the child population and identifies targets for public health action.

10.
J Clin Microbiol ; 61(3): e0141222, 2023 03 23.
Article in English | MEDLINE | ID: mdl-36840569

ABSTRACT

Staphylococcus epidermidis infections can be challenging to diagnose due to the species frequent contamination of clinical specimens and indolent course of infection. Nevertheless, S. epidermidis is the major cause of late-onset sepsis among premature infants and of intravascular infection in all age groups. Prior work has shown that bacterial virulence factors, antimicrobial resistances, and strains have up to 80% in-sample accuracy to distinguish hospital from community sources, but are unable to distinguish true bacteremia from blood culture contamination. Here, a phylogeny-informed genome-wide association study of 88 isolates was used to estimate effect sizes of particular genomic variants for isolation sources. A "polygenic score" was calculated for each isolate as the summed effect sizes of its repertoire of genomic variants. Predictive models of isolation sources based on polygenic scores were tested with in-samples and out-samples from prior studies of different patient populations. Polygenic scores from accessory genes (AGs) distinguished hospital from community sources with the highest accuracy to date, up to 98% for in-samples and 65% to 91% for various out-samples, whereas scores from single nucleotide polymorphisms (SNPs) had lower accuracy. Scores from AGs and SNPs achieved the highest in-sample accuracy to date, up to 76%, in distinguishing infection from contaminant sources within a hospital. Model training and testing data sets with more similar population structures resulted in more accurate predictions. This study reports the first use of a polygenic score for predicting a complex bacterial phenotype and shows the potential of this approach for enhancing S. epidermidis diagnosis.


Subject(s)
Bacteremia , Staphylococcal Infections , Humans , Staphylococcus epidermidis/genetics , Staphylococcal Infections/diagnosis , Staphylococcal Infections/microbiology , Genome-Wide Association Study , Bacteremia/diagnosis , Bacteremia/microbiology , Genomics , Coagulase/genetics
11.
Antimicrob Agents Chemother ; 67(3): e0074922, 2023 03 16.
Article in English | MEDLINE | ID: mdl-36744906

ABSTRACT

Resistance-nodulation-division (RND) superfamily efflux pumps promote antibiotic resistance in Gram-negative pathogens, but their role in Gram-positive pathogens, including methicillin-resistant Staphylococcus aureus (MRSA) is undocumented. However, recent in vitro selections for resistance of S. aureus to an antimicrobial fatty acid, linoleic acid, and an antibiotic, rhodomyrtone, identified H121Y and C116R substitution variants, respectively, in a TetR family regulator, FarR, promoting increased expression of the RND pump FarE. Hypothesizing that in vivo selection pressures have also promoted the emergence of FarR variants, we searched available genome data and found that strains with FarRH121Y from human and bovine hosts have emerged sporadically in clonal complexes (CCs) CC1, CC30, CC8, CC22, and CC97, whereas multiple FarR variants have occurred within CC5 hospital-associated (HA)-MRSA. Of these, FarRE160G and FarRE93EE were exclusive to CC5, while FarRC116Y, FarRP165L, and FarRG166D also occurred in nonrelated CCs, primarily from bovine hosts. Within CC5, FarRC116Y and FarRG166D strains were polyphyletic, each exhibiting two emergence events. FarRC116Y and FarRE160G were individually sufficient to confer increased expression of FarE and enhanced resistance to linoleic acid (LA). Isolates with FarRE93EE were most closely related to S. aureus N315 MRSA and exhibited increased resistance independently of FarRE93EE. Accumulation of pseudogenes and additional polymorphisms in FarRE93EE strains contributed to a multiresistance phenotype which included fosfomycin and fusidic acid resistance in addition to increased linoleic acid resistance. These findings underscore the remarkable adaptive capacity of CC5 MRSA, which includes the polyphyletic USA100 lineage of HA-MRSA that is endemic in the Western hemisphere and known for the acquisition of multiple resistance phenotypes.


Subject(s)
Methicillin-Resistant Staphylococcus aureus , Staphylococcal Infections , Animals , Cattle , Humans , Staphylococcus aureus/genetics , Staphylococcal Infections/drug therapy , Staphylococcal Infections/epidemiology , Linoleic Acid/pharmacology , Linoleic Acid/metabolism , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/metabolism , Microbial Sensitivity Tests
12.
bioRxiv ; 2023 Dec 29.
Article in English | MEDLINE | ID: mdl-38234816

ABSTRACT

Aim: Streptococcus pneumoniae (Spn) acquires genes for macrolide resistance, MEGA or ermB, in the human host. These genes are carried either in the chromosome, or on integrative conjugative elements (ICEs). Here, we investigated molecular determinants of the acquisition of macrolide resistance. Methods and Results: Whole genome analysis was conducted for 128 macrolide-resistant pneumococcal isolates to identify the presence of MEGA (44.5%, 57/128) or ermB (100%), and recombination events in Tn916-related elements or in the locus comCDE encoding competence genes. Confocal and electron microscopy studies demonstrated that, during the acquisition of macrolide resistance, pneumococcal strains formed clusters of varying size, with the largest aggregates having a median size of ~1600 µm2. Remarkably, these pneumococcal aggregates comprise both encapsulated and nonencapsulated pneumococci, exhibited physical interaction, and spanned extracellular and intracellular compartments. We assessed the recombination frequency (rF) for the acquisition of macrolide resistance by a recipient D39 strain, from pneumococcal strains carrying MEGA (~5.4 kb) in the chromone, or in large ICEs (>23 kb). Notably, the rF for the acquisition of MEGA, whether in the chromosome or carried on an ICE was similar. However, the rF adjusted to the acquisition of the full-length ICE (~52 kb), compared to that of the capsule locus (~23 kb) that is acquired by transformation, was three orders of magnitude higher. Finally, metabolomics studies revealed a link between the acquisition of ICE and the metabolic pathways involving nicotinic acid and sucrose. Conclusions: Extracellular and intracellular pneumococcal clusters facilitate the acquisition of full-length ICE at a rF higher than that of typical transformation events, involving distinct metabolic changes that present potential targets for interventions.

13.
J Glob Health ; 12: 04084, 2022 Nov 21.
Article in English | MEDLINE | ID: mdl-36403158

ABSTRACT

Background: Hospital referral and admission in many- low and middle-income countries are not feasible for many young infants with sepsis/possible serious bacterial infection (PSBI). The effectiveness of simplified antibiotic regimens when referral to a hospital was not feasible has been shown before. We analysed the pooled data from the previous trials to compare the risk of poor clinical outcome for young infants with PSBI with the two regimens containing injectable procaine penicillin and gentamicin with the oral amoxicillin plus gentamicin regimen currently recommended by the World Health Organization (WHO) when referral is not feasible. Methods: Infant records from three individually randomised trials conducted in Africa and Asia were collated in a standard format. All trials enrolled young infants aged 0-59 days with any sign of PSBI (fever, hypothermia, stopped feeding well, movement only when stimulated, or severe chest indrawing). Eligible young infants whose caretakers refused hospital admission and consented were enrolled and randomised to a trial reference arm (arm A: procaine benzylpenicillin and gentamicin) or two experimental arms (arm B: oral amoxicillin and gentamicin or arm C: procaine benzylpenicillin and gentamicin initially, followed by oral amoxicillin). We compared the rate of poor clinical outcomes by day 15 (deaths till day 15, treatment failure by day 8, and relapse between day 9 and 15) in reference arm A with experimental arms and present risk differences with 95% confidence interval (CI), adjusted for trial. Results: A total of 7617 young infants, randomised to arm A, arm B, or arm C in the three trials, were included in this analysis. Most were 7-59 days old (71%) and predominately males (56%). Slightly over one-fifth of young infants had more than one sign of PSBI at the time of enrolment. Severe chest indrawing (45%), fever (43%), and feeding problems (25%) were the most common signs. Overall, those who received arm B had a lower risk of poor clinical outcome compared to arm A for both per-protocol (risk difference = -2.1%, 95% CI = -3.8%, -0.4%; P = 0.016) and intention-to-treat (risk difference = -1.8%, 95% CI = -3.5%, -0.2%; P = 0.031) analyses. Those who received arm C did not have an increased risk of poor clinical outcome compared to arm A for both per-protocol (risk difference = -1.1%, 95% CI = -2.8%, 0.6%) and intention-to-treat (risk difference = -0.8%, 95% CI = -2.5%, 0.9%) analyses. Overall, those who received arm B had a lower risk of poor clinical outcome compared to the combined arms A and C for both per-protocol (risk difference = -1.6%, 95% CI = -3.5%, -0.1%; P = 0.035) and intention-to-treat (risk difference = -1.4%, 95% CI = -2.8%, -0.1%; P = 0.049) analyses. Conclusions: Analysis of pooled individual patient-level data from three large trials in Africa and Asia showed that the WHO-recommended simplified antibiotic regimen B (oral amoxicillin and injection gentamicin) was superior to regimen A (injection procaine penicillin and injection gentamicin) and combined arms A and C (injection procaine penicillin and injection gentamicin, followed by oral amoxicillin) in terms of poor clinical outcome for the outpatient treatment of young infants with PSBI when inpatient treatment was not feasible. Registration: AFRINEST study [9] is registered with the Australian New Zealand Clinical Trials Registry: ACTRN12610000286044. SATT Bangladesh study [10] is registered with ClinicalTrials.gov: NCT00844337. SATT Pakistan study [11] is registered at ClinicalTrials.gov: NCT01027429.


Subject(s)
Anti-Bacterial Agents , Bacterial Infections , Humans , Infant , Male , Africa , Amoxicillin/therapeutic use , Anti-Bacterial Agents/therapeutic use , Australia , Bacterial Infections/drug therapy , Fever , Gentamicins/therapeutic use , Pakistan , Penicillin G Procaine/therapeutic use , Referral and Consultation , Randomized Controlled Trials as Topic , Infant, Newborn , Female , Drug Therapy, Combination
14.
Microbiol Spectr ; 10(3): e0000922, 2022 06 29.
Article in English | MEDLINE | ID: mdl-35583495

ABSTRACT

Numerous host and environmental factors contribute to persistent and intermittent nasal Staphylococcus aureus carriage in humans. The effects of worsening glycemia on the odds of S. aureus intermittent and persistent nasal carriage was established in two cohorts from an adult Mexican American population living in Starr County, Texas. The anterior nares were sampled at two time points and the presence of S. aureus determined by laboratory culture and spa-typing. Persistent carriers were defined by the presence of S. aureus of the same spa-type at both time points, intermittent carriers were S. aureus-positive for 1 of 2 swabs, and noncarriers were negative for S. aureus at both time points. Diabetes status was obtained through personal interview and physical examination that included a blood draw for the determination of percent glycated hemoglobin A1c (%HbA1c), fasting plasma glucose, and other blood chemistry values. Using logistic regression and general estimating equations, the odds of persistent and intermittent nasal carriage compared to noncarriers across the glycemic spectrum was determined controlling for covariates. Increasing fasting plasma glucose and %HbA1c in the primary and replication cohort, respectively, were significantly associated with increasing odds of S. aureus intermittent, but not persistent nasal carriage. These data suggest that increasing dysglycemia is a risk factor for intermittent S. aureus nasal carriage potentially placing those with poorly controlled diabetes at an increased risk of acquiring an S. aureus infection. IMPORTANCE Factors affecting nasal S. aureus colonization have been studied primarily in the context of persistent carriage. In contrast, few studies have examined factors affecting intermittent nasal carriage with this pathogen. This study demonstrates that the odds of intermittent but not persistent nasal carriage of S. aureus significantly increases with worsening measures of dysglycemia. This is important in the context of poorly controlled diabetes since the risk of becoming colonized with one of the primary organisms associated with diabetic foot infections can lead to increased morbidity and mortality.


Subject(s)
Staphylococcal Infections , Staphylococcus aureus , Adult , Blood Glucose , Carrier State/epidemiology , Glycated Hemoglobin , Humans , Mexican Americans , Staphylococcal Infections/diagnosis , Staphylococcal Infections/epidemiology , Staphylococcus aureus/genetics
15.
Trends Microbiol ; 30(11): 1036-1044, 2022 11.
Article in English | MEDLINE | ID: mdl-35597716

ABSTRACT

Tuberculosis (TB) remains a leading infectious cause of death worldwide. Reducing TB infections and TB-related deaths rests ultimately on stopping forward transmission from infectious to susceptible individuals. Critical to this effort is understanding how human host mobility shapes the transmission and dispersal of new or existing strains of Mycobacterium tuberculosis (Mtb). Important questions remain unanswered. What kinds of mobility, over what temporal and spatial scales, facilitate TB transmission? How do human mobility patterns influence the dispersal of novel Mtb strains, including emergent drug-resistant strains? This review summarizes the current state of knowledge on mobility and TB epidemic dynamics, using examples from three topic areas, including inference of genetic and spatial clustering of infections, delineating source-sink dynamics, and mapping the dispersal of novel TB strains, to examine scientific questions and methodological issues within this topic. We also review new data sources for measuring human mobility, including mobile phone-associated movement data, and discuss important limitations on their use in TB epidemiology.


Subject(s)
Epidemics , Mycobacterium tuberculosis , Tuberculosis , Antitubercular Agents/therapeutic use , Humans , Mycobacterium tuberculosis/genetics , Tuberculosis/epidemiology , Tuberculosis/microbiology
16.
Sci Rep ; 12(1): 7085, 2022 04 30.
Article in English | MEDLINE | ID: mdl-35490195

ABSTRACT

The thin layer of soil at the earth's surface supports life, storing water and nutrients for plant uptake. These processes occur in the soil pore space, often half the soil volume, but our understanding of how this volume responds to environmental change is poor. Convention, has been to predict soil porosity, or its reciprocal bulk density (BD), from soil texture using pedotransfer functions (PTFs). A texture based approach, invariant to environmental change, prevents feedback from land use or climate change to soil porosity. Moreover, PTFs are often limited to mineral soils with < 20% soil organic matter (SOM) content. Here, we develop an analytical model to predict soil porosity, or BD, as a function of SOM. We test it on two comprehensive, methodologically consistent, temperate national-scale topsoil data sets (0-15 cm) (Wales, n = 1385; Great Britain, n = 2570). The purpose of the approach is to generate an analytical function suitable for predicting soil porosity change with SOM content, while providing insight into the main grain-scale factors determining the porosity emergence. The newly developed function covering the entire SOM gradient allows for impacts of land use, management or climate change to feedback on soil porosity or bulk density through decadal dynamic changes in SOM.


Subject(s)
Plants , Soil , Minerals , Porosity , Water
17.
Case Rep Womens Health ; 33: e00383, 2022 Jan.
Article in English | MEDLINE | ID: mdl-35127457

ABSTRACT

BACKGROUND: Intravesical mesh erosion is an uncommon late complication of placement of a synthetic mid-urethral sling (MUS) for the treatment of stress urinary incontinence, and only a few cases have been reported. Optimal management remains controversial, though there is a tendency toward surgical removal through a variety of routes. However, surgical removal comes with its own risks and is not necessarily associated with an improvement in symptoms. We, herein present the first case of a conservatively managed intravesical mesh erosion following MUS placement. CASE: Nine years after insertion of a tension-free vaginal tape (TVT), a patient presented with persistent lower abdominal pain and dysuria. Flexible cystoscopy demonstrated an erosion of the tape through the bladder wall. The patient declined surgical intervention at the time. Therefore, she was commenced on regular methenamine hippurate and vaginal oestrogen, and kept under surveillance with regular cystoscopies. Her symptoms responded to this treatment and 6 years later remained well controlled on this regime. CONCLUSION: This case demonstrates that conservative management may be a safe and appropriate option for patients who decline surgical excision of mesh erosion.

18.
PLoS One ; 17(2): e0264548, 2022.
Article in English | MEDLINE | ID: mdl-35226694

ABSTRACT

Accurate assessment and monitoring of the Plasmodium falciparum Kelch 13 (pfk13) gene associated with artemisinin resistance is critical to understand the emergence and spread of drug-resistant parasites in malaria-endemic regions. In this study, we evaluated the genomic profile of the pfk13 gene associated with artemisinin resistance in P. falciparum in Nigerian children by targeted sequencing of the pfk13 gene. Genomic DNA was extracted from 332 dried blood (DBS) spot filter paper samples from three Nigerian States. The pfk13 gene was amplified by nested polymerase chain reaction (PCR), and amplicons were sequenced to detect known and novel polymorphisms across the gene. Consensus sequences of samples were mapped to the reference gene sequence obtained from the National Center for Biotechnology Information (NCBI). Out of the 13 single nucleotide polymorphisms (SNPs) detected in the pfk13 gene, five (F451L, N664I, V487E, V692G and Q661H) have not been reported in other endemic countries to the best of our knowledge. Three of these SNPs (V692G, N664I and Q661H) and a non-novel SNP, C469C, were consistent with late parasitological failure (LPF) in two States (Enugu and Plateau States). There was no validated mutation associated with artemisinin resistance in this study. However, a correlation of our study with in vivo and in vitro phenotypes is needed to establish the functional role of detected mutations as markers of artemisinin resistance in Nigeria. This baseline information will be essential in tracking and monitoring P. falciparum resistance to artemisinin in Nigeria.


Subject(s)
Plasmodium falciparum
19.
Sci Rep ; 12(1): 1379, 2022 01 26.
Article in English | MEDLINE | ID: mdl-35082379

ABSTRACT

Soil organic carbon (SOC) concentration is the fundamental indicator of soil health, underpinning food production and climate change mitigation. SOC storage is highly sensitive to several dynamic environmental drivers, with approximately one third of soils degraded and losing carbon worldwide. Digital soil mapping illuminates where hotspots of SOC storage occur and where losses to the atmosphere are most likely. Yet, attempts to map SOC often disagree. Here we compare national scale SOC concentration map products to reveal agreement of data in mineral soils, with progressively poorer agreement in organo-mineral and organic soils. Divergences in map predictions from each other and survey data widen in the high SOC content land types we stratified. Given the disparities are highest in carbon rich soils, efforts are required to reduce these uncertainties to increase confidence in mapping SOC storage and predicting where change may be important at national to global scales. Our map comparison results could be used to identify SOC risk where concentrations are high and should be conserved, and where uncertainty is high and further monitoring should be targeted. Reducing inter-map uncertainty will rely on addressing statistical limitations and including covariates that capture convergence of physical factors that produce high SOC contents.

20.
BJOG ; 129(5): 743-751, 2022 Apr.
Article in English | MEDLINE | ID: mdl-34597459

ABSTRACT

OBJECTIVE: To compare pregnancy rates and outcomes for women with cystic fibrosis in the UK with those of the general population and assess the effect of the introduction of disease-modifying treatment. DESIGN: A population-based longitudinal study, 2003-17. SETTING: United Kingdom. POPULATION: Women aged 15-44 years in the UK cystic fibrosis (CF) Registry compared with women in England and Wales. METHODS: We calculated pregnancy and live-birth rates for the CF population and the general population of England and Wales. For women with CF we compared pregnancy rates before and after ivacaftor was introduced in 2013. We further used CF registry data to assess pregnancy outcomes for mothers with CF, and to assess the relationship between maternal pre-pregnancy lung function and nutritional status and child gestational age. MAIN OUTCOME MEASURES: Pregnancy and live-birth rates and child gestational age. RESULTS: Of 3831 women with CF, 661 reported 818 pregnancies. Compared with the general population, the pregnancy rate was 3.3 times lower in the CF population (23.5 versus 77.7 per 1000 woman-years); the live-birth rate was 3.5 times lower (17.4 versus 61.4 per 1000 woman-years) with 70% of pregnancies in CF women resulting in live births; termination of pregnancy rates were also lower (9% versus 22%). Pregnancy rates increased post-ivacaftor for eligible women with CF, from 29.7 to 45.7 per 1000 woman-years. There was no association between pre-pregnancy lung function/nutrition status and gestational age. CONCLUSIONS: Pregnancy rates in women with CF are about one-third of the rates in the general population with favourable outcomes, and increased for eligible women post-ivacaftor. TWEETABLE ABSTRACT: Pregnancy rates in women with CF are about a third of the rate in England and Wales with 70% live births. Ivacaftor increases the rate.


Subject(s)
Cystic Fibrosis , Adolescent , Adult , Cystic Fibrosis/drug therapy , Cystic Fibrosis/epidemiology , Cystic Fibrosis Transmembrane Conductance Regulator , Female , Humans , Longitudinal Studies , Pregnancy , Pregnancy Rate , United Kingdom/epidemiology , Young Adult
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