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1.
Chemistry ; 30(15): e202303986, 2024 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-38221408

RESUMO

Antimicrobial peptide amphiphiles (PAs) are a promising class of molecules that can disrupt the bacterial membrane or act as drug nanocarriers. In this study, we prepared 33 PAs to establish supramolecular structure-activity relationships. We studied the morphology and activity of the nanostructures against different Gram-positive and Gram-negative bacterial strains (such as Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and Acinetobacter baumannii). Next, we used principal component analysis (PCA) to determine the key contributors to activity. We found that for S. aureus, the zeta potential was the major contributor to the activity while Gram-negative bacteria were more influenced by the partition coefficient (LogP) with the following order P. aeruginosa>E. coli>A. baumannii. We also performed a study of the mechanism of action of selected PAs on the bacterial membrane assessing the membrane permeability and depolarization, changes in zeta potential and overall integrity. We studied the toxicity of the nanostructures against mammalian cells. Finally, we performed an in vivo study using the wax moth larvae to determine the therapeutic efficacy of the active PAs. This study shows cationic PA nanostructures can be an intriguing platform for the development of nanoantibacterials.


Assuntos
Anti-Infecciosos , Staphylococcus aureus , Animais , Antibacterianos/farmacologia , Antibacterianos/química , Escherichia coli , Anti-Infecciosos/farmacologia , Peptídeos , Relação Estrutura-Atividade , Testes de Sensibilidade Microbiana , Pseudomonas aeruginosa , Mamíferos
2.
Lancet ; 399(10330): 1117-1129, 2022 03 19.
Artigo em Inglês | MEDLINE | ID: mdl-35303469

RESUMO

BACKGROUND: Population-level health and mortality data are crucial for evidence-informed policy but scarce in Nigeria. To fill this gap, we undertook a comprehensive assessment of the burden of disease in Nigeria and compared outcomes to other west African countries. METHODS: In this systematic analysis, using data and results of the Global Burden of Diseases, Injuries, and Risk Factors Study 2019, we analysed patterns of mortality, years of life lost (YLLs), years lived with disability (YLDs), life expectancy, healthy life expectancy (HALE), and health system coverage for Nigeria and 15 other west African countries by gender in 1998 and 2019. Estimates of all-age and age-standardised disability-adjusted life-years for 369 diseases and injuries and 87 risk factors are presented for Nigeria. Health expenditure per person and gross domestic product were extracted from the World Bank repository. FINDINGS: Between 1998 and 2019, life expectancy and HALE increased in Nigeria by 18% to 64·3 years (95% uncertainty interval [UI] 62·2-66·6), mortality reduced for all age groups for both male and female individuals, and health expenditure per person increased from the 11th to third highest in west Africa by 2018 (US$18·6 in 2001 to $83·75 in 2018). Nonetheless, relative outcomes remained poor; Nigeria ranked sixth in west Africa for age-standardised mortality, seventh for HALE, tenth for YLLs, 12th for health system coverage, and 14th for YLDs in 2019. Malaria (5176·3 YLLs per 100 000 people, 95% UI 2464·0-9591·1) and neonatal disorders (4818·8 YLLs per 100 000, 3865·9-6064·2) were the leading causes of YLLs in Nigeria in 2019. Nigeria had the fourth-highest under-five mortality rate for male individuals (2491·8 deaths per 100 000, 95% UI 1986·1-3140·1) and female individuals (2117·7 deaths per 100 000, 1756·7-2569·1), but among the lowest mortality for men older than 55 years. There was evidence of a growing non-communicable disease burden facing older Nigerians. INTERPRETATION: Health outcomes remain poor in Nigeria despite higher expenditure since 2001. Better outcomes in countries with equivalent or lower health expenditure suggest health system strengthening and targeted intervention to address unsafe water sources, poor sanitation, malnutrition, and exposure to air pollution could substantially improve population health. FUNDING: The Bill & Melinda Gates Foundation.


Assuntos
Carga Global da Doença , Saúde da População , África Ocidental/epidemiologia , Feminino , Humanos , Recém-Nascido , Expectativa de Vida , Masculino , Nigéria/epidemiologia
3.
Mater Today (Kidlington) ; 67: 371-398, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37790286

RESUMO

Three-dimensional (3D) printing is a rapidly growing technology with a significant capacity for translational applications in both biology and medicine. 3D-printed living and non-living materials are being widely tested as a potential replacement for conventional solutions for testing and combating antimicrobial resistance (AMR). The precise control of cells and their microenvironment, while simulating the complexity and dynamics of an in vivo environment, provides an excellent opportunity to advance the modeling and treatment of challenging infections and other health conditions. 3D-printing models the complicated niches of microbes and host-pathogen interactions, and most importantly, how microbes develop resistance to antibiotics. In addition, 3D-printed materials can be applied to testing and delivering antibiotics. Here, we provide an overview of 3D printed materials and biosystems and their biomedical applications, focusing on ever increasing AMR. Recent applications of 3D printing to alleviate the impact of AMR, including developed bioprinted systems, targeted bacterial infections, and tested antibiotics are presented.

4.
Pediatr Blood Cancer ; 70(7): e30397, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37101362

RESUMO

BACKGROUND: Nutritional deficiencies are prevalent in sickle cell disease (SCD) and may be associated with worse pain outcomes. Gut dysbiosis has been reported in patients with SCD and may contribute to both nutritional deficiencies and pain. OBJECTIVES: We tested the association of nutrition, fat-soluble vitamin (FSV) deficiency, and gut microbiome composition on clinical outcomes in SCD. Second, we measured the association between diet and exocrine pancreatic function on FSV levels. METHODS: Using case control design, we enrolled children with SCD (n = 24) and matched healthy controls (HC; n = 17, age, sex, race/ethnicity). Descriptive statistics summarized demographic and clinical data. Wilcoxson-rank tests compared FSV levels between cohorts. Regression modeling tested the association between FSV levels and SCD status. Welch's t-test with Satterthwaite adjustment evaluated associations between microbiota profiles, SCD status, and pain outcomes. RESULTS: Vitamin A and D levels were significantly decreased in participants with HbSS as compared to HC (vitamin A, p = < .0001, vitamin D, p = .014) independent of nutritional status. FSV correlated with dietary intake in SCD and HC cohorts. Gut microbial diversity was reduced in hemoglobin SS (HbSS) compared to hemoglobin SC (HbSC) and HC, p = .037 and .059, respectively. The phyla Erysipelotrichaceae and Betaproteobacteria were higher in SCD children reporting the highest quality-of-life (QoL) scores (p = .008 and .049, respectively), while Clostridia were higher in those with lower QoL scores (p = .03). CONCLUSION: FSV deficiencies and gut dysbiosis are prevalent in children with SCA. Gut microbial composition is significantly different in children with SCD with low QoL scores.


Assuntos
Anemia Falciforme , Deficiência de Vitamina D , Humanos , Criança , Projetos Piloto , Estado Nutricional , Vitamina A , Qualidade de Vida , Disbiose/complicações , Anemia Falciforme/complicações , Hemoglobina Falciforme , Vitaminas , Dor
5.
J Appl Microbiol ; 132(5): 3891-3906, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35129256

RESUMO

AIM: This study aimed to investigate the isolation rate, antibiotic resistance and virulence genes of Salmonella enterica serovar from two commercial farms in Nigeria. METHODS AND RESULTS: Salmonella isolation was performed according to the United States Food and Drug Agency (USFDA) method. Serotyping, antimicrobial susceptibility testing, detection of resistance and virulence genes were done using the Kauffman-White Scheme, disc diffusion, minimum inhibitory concentration and real-time polymerase chain reaction techniques. Salmonella serovars were isolated from only farm A at 22/50 (44.0%) while none were isolated from farm B. Salmonella Typhi, 9 (40.9%); Salmonella Typhimurium, 2 (9.1%), Salmonella Enteritidis, 2 (9.1%), Salmonella Pullorum, 1 (4.5%), Salmonella Kentucky, 4 (18.2%) were identified while 4 (18.2%) were untypable. Sixteen isolates (72.7%) showed multiple drug resistance and 17 different resistance profile types with AMP-CHL-TRM-SXT as the most prevalent pattern. Resistance genes (blaTEM, 12/22 (54.5%) and virulence genes (InvA, sopB, mgtC and spi4D, 22/22 (100.0%), ssaQ, 16/22 (72.7%) and spvC, 13/22 (59.1%) were found, while blaSHV, blaCTX-M, floR, tetA, tetB, tetG and LJSGI-1 genes were absent. CONCLUSION: Pathogenic Salmonella were isolated from the chicken droppings in this study. Most of these strains were resistant to antibiotics and possessed characteristics of virulence. SIGNIFICANCE AND IMPACT OF THE STUDY: Chicken droppings from this study area contained pathogenic strains of Salmonella and a rare occurrence of Salmonella Typhi. The study revealed that the environment and the food chain could be at risk of contamination of highly virulent and antimicrobial-resistant strains of Salmonella. These could affect the profitability of the poultry industry and food consumption. There is a need for caution in indiscriminate disposal of poultry waste and the use of uncomposted chicken droppings in soil amendment.


Assuntos
Salmonelose Animal , Salmonella enterica , Animais , Antibacterianos/farmacologia , Galinhas , Farmacorresistência Bacteriana/genética , Fazendas , Nigéria , Aves Domésticas , Salmonelose Animal/epidemiologia , Salmonella typhi , Sorogrupo , Virulência/genética
6.
Proc Natl Acad Sci U S A ; 115(21): 5510-5515, 2018 05 22.
Artigo em Inglês | MEDLINE | ID: mdl-29735685

RESUMO

In the African meningitis belt, a region of sub-Saharan Africa comprising 22 countries from Senegal in the west to Ethiopia in the east, large epidemics of serogroup A meningococcal meningitis have occurred periodically. After gradual introduction from 2010 of mass vaccination with a monovalent meningococcal A conjugate vaccine, serogroup A epidemics have been eliminated. Starting in 2013, the northwestern part of Nigeria has been affected by yearly outbreaks of meningitis caused by a novel strain of serogroup C Neisseria meningitidis (NmC). In 2015, the strain spread to the neighboring country Niger, where it caused a severe epidemic. Following a relative calm in 2016, the largest ever recorded epidemic of NmC broke out in Nigeria in 2017. Here, we describe the recent evolution of this new outbreak strain and show how the acquisition of capsule genes and virulence factors by a strain previously circulating asymptomatically in the African population led to the emergence of a virulent pathogen. This study illustrates the power of long-read whole-genome sequencing, combined with Illumina sequencing, for high-resolution epidemiological investigations.


Assuntos
Epidemias , Meningite Meningocócica/epidemiologia , Vacinas Meningocócicas/administração & dosagem , Neisseria meningitidis/isolamento & purificação , Proteínas Virais/genética , Virulência/genética , África Ocidental/epidemiologia , Antígenos de Bactérias/genética , Antígenos de Bactérias/imunologia , Perfilação da Expressão Gênica , Humanos , Meningite Meningocócica/microbiologia , Meningite Meningocócica/prevenção & controle , Vacinas Meningocócicas/imunologia , Neisseria meningitidis/classificação , Neisseria meningitidis/genética , Neisseria meningitidis/imunologia , Vigilância da População , Análise Espaço-Temporal
7.
Analyst ; 145(7): 2525-2542, 2020 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-32123889

RESUMO

Nearly 7% of the world's population live with a hemoglobin variant. Hemoglobins S, C, and E are the most common and significant hemoglobin variants worldwide. Sickle cell disease, caused by hemoglobin S, is highly prevalent in sub-Saharan Africa and in tribal populations of Central India. Hemoglobin C is common in West Africa, and hemoglobin E is common in Southeast Asia. Screening for significant hemoglobin disorders is not currently feasible in many low-income countries with the high disease burden. Lack of early diagnosis leads to preventable high morbidity and mortality in children born with hemoglobin variants in low-resource settings. Here, we describe HemeChip, the first miniaturized, paper-based, microchip electrophoresis platform for identifying the most common hemoglobin variants easily and affordably at the point-of-care in low-resource settings. HemeChip test works with a drop of blood. HemeChip system guides the user step-by-step through the test procedure with animated on-screen instructions. Hemoglobin identification and quantification is automatically performed, and hemoglobin types and percentages are displayed in an easily understandable, objective way. We show the feasibility and high accuracy of HemeChip via testing 768 subjects by clinical sites in the United States, Central India, sub-Saharan Africa, and Southeast Asia. Validation studies include hemoglobin E testing in Bangkok, Thailand, and hemoglobin S testing in Chhattisgarh, India, and in Kano, Nigeria, where the sickle cell disease burden is the highest in the world. Tests were performed by local users, including healthcare workers and clinical laboratory personnel. Study design, methods, and results are presented according to the Standards for Reporting Diagnostic Accuracy (STARD). HemeChip correctly identified all subjects with hemoglobin S, C, and E variants with 100% sensitivity, and displayed an overall diagnostic accuracy of 98.4% in comparison to reference standard methods. HemeChip is a versatile, mass-producible microchip electrophoresis platform that addresses a major unmet need of decentralized hemoglobin analysis in resource-limited settings.


Assuntos
Eletroforese em Microchip/métodos , Hemoglobinas/análise , Papel , Hemoglobina Falciforme/análise , Humanos , Processamento de Imagem Assistida por Computador , Miniaturização , Sistemas Automatizados de Assistência Junto ao Leito , Interface Usuário-Computador
10.
J Transl Med ; 16(1): 239, 2018 08 30.
Artigo em Inglês | MEDLINE | ID: mdl-30165857

RESUMO

Non-typhoidal Salmonella usually induces self-limiting gastroenteritis. However, in many parts of Africa, especially in individuals who are malnourished, infected with malaria, or have sickle cell disease, the organism causes serious and potentially fatal systemic infections. Since the portal of entry of non-typhoidal Salmonella into the systemic circulation is by way of the intestine, we argue that an increased gut permeability plays a vital role in the initiation of invasive non-typhoidal Salmonella in these patients. Here, we will appraise the evidence supporting a breach in the intestinal barrier and propose the mechanisms for the increased risks for invasive non-typhoidal Salmonella infections in these individuals.


Assuntos
Anemia Falciforme/complicações , Microbioma Gastrointestinal , Intestinos/patologia , Infecções por Salmonella/complicações , Infecções por Salmonella/fisiopatologia , África , Anemia Falciforme/microbiologia , Antibacterianos/uso terapêutico , Humanos , Malária/complicações , Desnutrição/complicações , Modelos Teóricos , Permeabilidade , Risco , Salmonella , Febre Tifoide
11.
N Engl J Med ; 379(14): 1382-3, 2018 10 04.
Artigo em Inglês | MEDLINE | ID: mdl-30284804
12.
Am J Hematol ; 91(9): 938-46, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-27237467

RESUMO

Individuals with sickle cell anemia (SCA) have increased susceptibility to infections, secondary to impairment of immune function. Besides the described dysfunction in innate immunity, including impaired opsonization and phagocytosis of bacteria, evidence of dysfunction of T and B lymphocytes in SCA has also been reported. This includes reduction in the proportion of circulating CD4+ and CD8+ T cells, reduction of CD4+ helper: CD8+ suppressor T cell ratio, aberrant activation and dysfunction of regulatory T cells (Treg ), skewing of CD4+ T cells towards Th2 response and loss of IgM-secreting CD27 + IgM(high) IgD(low) memory B cells. These changes occur on the background of immune activation characterized by predominance of memory CD4+ T cell phenotypes, increased Th17 signaling and elevated levels of C-reactive protein and pro-inflammatory cytokines IL-6 and TNF-α, which may affect the immunogenicity and protective efficacy of vaccines available to prevent infections in SCA. Thus, in order to optimize the use of vaccines in SCA, a thorough understanding of T and B lymphocyte functions and vaccine reactivity among individuals with SCA is needed. Studies should be encouraged of different SCA populations, including sub-Saharan Africa where the burden of SCA is highest. This article summarizes our current understanding of lymphocyte biology in SCA, and highlights areas that warrant future research. Am. J. Hematol. 91:938-946, 2016. © 2016 Wiley Periodicals, Inc.


Assuntos
Anemia Falciforme/imunologia , Subpopulações de Linfócitos/imunologia , Vacinas/imunologia , Anemia Falciforme/terapia , Subpopulações de Linfócitos B , Humanos , Subpopulações de Linfócitos T
13.
Pediatr Blood Cancer ; 63(5): 781-5, 2016 05.
Artigo em Inglês | MEDLINE | ID: mdl-26840500

RESUMO

While encapsulated bacterial agents, particularly Streptococcus pneumoniae, are recognized as important microbes that are associated with serious illness in hosts with sickle cell disease (SCD), multiple pathogens are implicated in infectious manifestations of SCD. Variations in clinical practice have been an obstacle to the universal implementation of infection preventive management through active, targeted vaccination of these individuals and routine usage of antibiotic prophylaxis. Paradoxically, in low-income settings, there is evidence that SCD also increases the risk for several other infections that warrant additional infection preventive measures. The infection preventive care among patients with SCD in developed countries does not easily translate to the adoption of these recommendations globally, which must take into account the local epidemiology of infections, available vaccines and population-specific vaccine efficacy, environment, health care behaviors, and cultural beliefs, as these are all factors that play a complex role in the manifestation of SCD and the prevention of infectious disease morbidity.


Assuntos
Anemia Falciforme , Vacinas Pneumocócicas/uso terapêutico , Pneumonia Pneumocócica , Streptococcus pneumoniae , Anemia Falciforme/complicações , Anemia Falciforme/epidemiologia , Países em Desenvolvimento , Humanos , Pneumonia Pneumocócica/epidemiologia , Pneumonia Pneumocócica/etiologia , Pneumonia Pneumocócica/prevenção & controle
14.
Pediatr Blood Cancer ; 63(1): 98-104, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26275071

RESUMO

BACKGROUND: Sickle cell anemia (SCA) is an inherited hematological disorder that causes a large but neglected global health burden, particularly in Africa. Hydroxyurea represents the only available disease-modifying therapy for SCA, and has proven safety and efficacy in high-resource countries. In sub-Saharan Africa, there is minimal use of hydroxyurea, due to lack of data, absence of evidence-based guidelines, and inexperience among healthcare providers. PROCEDURE: A partnership was established between investigators in North America and sub-Saharan Africa, to develop a prospective multicenter research protocol designed to provide data on the safety, feasibility, and benefits of hydroxyurea for children with SCA. RESULTS: The Realizing Effectiveness Across Continents with Hydroxyurea (REACH, ClinicalTrials.gov NCT01966731) trial is a prospective, phase I/II open-label dose escalation study of hydroxyurea that will treat a total of 600 children age 1-10 years with SCA: 150 at each of four different clinical sites within sub-Saharan Africa (Angola, Democratic Republic of Congo, Kenya, and Uganda). The primary study endpoint will be severe hematological toxicities that occur during the fixed-dose treatment phase. REACH has an adaptive statistical design that allows for careful assessment of toxicities to accurately identify a safe hydroxyurea dose. CONCLUSIONS: REACH will provide data that address critical gaps in knowledge for the treatment of SCA in sub-Saharan Africa. By developing local expertise with the use of hydroxyurea and helping to establish treatment guidelines, the REACH trial results will have the potential to transform care for children with SCA in Africa.


Assuntos
Anemia Falciforme/tratamento farmacológico , Hidroxiureia/uso terapêutico , África Subsaariana/epidemiologia , Anemia Falciforme/epidemiologia , Criança , Pré-Escolar , Humanos , Lactente , Estudos Prospectivos
15.
Clin Infect Dis ; 61 Suppl 4: S325-31, 2015 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-26449948

RESUMO

BACKGROUND: Etiologic agents of childhood bacteremia remain poorly defined in Nigeria. The absence of such data promotes indiscriminate use of antibiotics and delays implementation of appropriate preventive strategies. METHODS: We established diagnostic laboratories for bacteremia surveillance at regional sites in central and northwest Nigeria. Acutely ill children aged <5 years with clinically suspected bacteremia were evaluated at rural and urban clinical facilities in the Federal Capital Territory, central region and in Kano, northwest Nigeria. Blood was cultured using the automated Bactec incubator system. RESULTS: Between September 2008 and April 2015, we screened 10,133 children. Clinically significant bacteremia was detected in 609 of 4051 (15%) in the northwest and 457 of 6082 (7.5%) in the central region. Across both regions, Salmonella species account for 24%-59.8% of bacteremias and are the commonest cause of childhood bacteremia, with a predominance of Salmonella enterica serovar Typhi. The prevalence of resistance to ampicillin, chloramphenicol, and cotrimoxazole was 38.11%, with regional differences in susceptibility to different antibiotics but high prevalence of resistance to readily available oral antibiotics. CONCLUSIONS: Salmonella Typhi is the leading cause of childhood bacteremia in central Nigeria. Expanded surveillance is planned to define the dynamics of transmission. The high prevalence of multidrug-resistant strains calls for improvement in environmental sanitation in the long term and vaccination in the short term.


Assuntos
Bacteriemia/epidemiologia , Infecções por Salmonella/epidemiologia , Infecções por Salmonella/microbiologia , Salmonella typhi/isolamento & purificação , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Bacteriemia/diagnóstico , Bacteriemia/microbiologia , Pré-Escolar , Farmacorresistência Bacteriana Múltipla , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Programas de Rastreamento , Nigéria/epidemiologia , Salmonella paratyphi A/efeitos dos fármacos , Salmonella paratyphi A/genética , Salmonella paratyphi A/isolamento & purificação , Salmonella typhi/efeitos dos fármacos , Salmonella typhi/genética , Febre Tifoide/epidemiologia , Febre Tifoide/microbiologia
16.
Nutrients ; 16(12)2024 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-38931212

RESUMO

Low levels of vitamin D in maternal and cord blood have been associated with neonatal sepsis. This study assessed the association of vitamin D metabolites (25(OH)D, 3-epi-25(OH)D3, and 24,25(OH)2D3) levels in maternal and cord blood with newborn sepsis evaluation in Nigerian mother-infant dyads. Maternal and cord blood from 534 mothers and 536 newborns were processed using liquid chromatography-tandem mass spectrometry. Spearman correlation was used to compare continuous variables, Mann-Whitney for dichotomous variables, and Kruskal-Wallis for two or more groups. High cord percent 3-epi-25(OH)D3 levels were positively associated with newborn evaluation for sepsis (p = 0.036), while maternal and cord 25(OH)D and 24,25(OH)2D3 levels were not. Being employed was positively associated with maternal and newborn 3-epi-25(OH)D3 concentrations (p = 0.007 and p = 0.005, respectively). The maternal 3-epi-25(OH)D3 and percent 3-epi-25(OH)D3 were positively associated with vaginal delivery (p = 0.013 and p = 0.012, respectively). Having a weight-for-age Z-score ≤ -2 was positively associated with newborn percent 3-epi-25(OH)D3 levels (p = 0.004), while a weight-for-length Z-score ≤ -3 was positively associated with maternal and newborn percent 3-epi-25(OH)D3 levels (p = 0.044 and p = 0.022, respectively). Our study highlights the need to further investigate the biological role of 3-epi-25(OH)D3 and its clinical significance in fetal growth and newborn outcome.


Assuntos
Sangue Fetal , Vitamina D , Humanos , Feminino , Nigéria , Recém-Nascido , Adulto , Sangue Fetal/química , Vitamina D/sangue , Gravidez , Deficiência de Vitamina D/sangue , Adulto Jovem , Sepse Neonatal , Mães , Masculino , Espectrometria de Massas em Tandem
17.
Polymers (Basel) ; 15(15)2023 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-37571209

RESUMO

Rapid and reliable point-of-care (POC) diagnostic tests can have a significant impact on global health. One of the most common approaches for developing POC systems is the use of target-specific biomolecules. However, the conjugation of biomolecules can result in decreased activity, which may compromise the analytical performance and accuracy of the developed systems. To overcome this challenge, we present a polymer-based cross-linking protocol for controlled and directed conjugation of biological molecules. Our protocol utilizes a bifunctional thiol-polyethylene glycol (PEG)-hydrazide polymer to enable site-directed conjugation of IgG antibodies to the surface of screen-printed metal electrodes. The metal surface of the electrodes is first modified with thiolated PEG molecules, leaving the hydrazide groups available to react with the aldehyde group in the Fc fragments of the oxidized IgG antibodies. Using anti-Klebsiella pneumoniae carbapenemase-2 (KPC-2) antibody as a model antibody used for antimicrobial resistance (AMR) testing, our results demonstrate a ~10-fold increase in antibody coupling compared with the standard N-hydroxysuccinimide (NHS)-based conjugation chemistry and effective capture (>94%) of the target KPC-2 enzyme antigen on the surface of modified electrodes. This straightforward and easy-to-perform strategy of site-directed antibody conjugation can be engineered for coupling other protein- and non-protein-based biological molecules commonly used in POC testing and development, thus enhancing the potential for improved diagnostic accuracy and performance.

18.
Am J Trop Med Hyg ; 109(2): 322-326, 2023 08 02.
Artigo em Inglês | MEDLINE | ID: mdl-37460088

RESUMO

Primary amebic meningoencephalitis (PAM) is a rare and lethal infection caused by Naegleria fowleri. We report an epidemiological and environmental investigation relating to a case of PAM in a previously healthy boy age 8 years. An interview of the patient's family was conducted to determine the likely exposure site and to assess risk factors. Data from the United States Geological Survey site at Waterloo, NE, on the Elkhorn River were used to estimate water temperature and streamflow at the time and site of exposure. Data from the National Weather Service were used to estimate precipitation and ambient air temperature at the time and site of exposure. Despite conventional treatment, the patient died 2 days after hospital admission. The patient participated in recreational water activities in the Elkhorn River in northeastern Nebraska 5 days before symptom onset. In the week before exposure, water and ambient air high temperatures reached annual highs, averaging 32.4°C and 35.8°C, respectively. The day before infection, 2.2 cm of precipitation was reported. Streamflow was low (407 ft3/s). Infections in several northern states, including Nebraska, suggest an expanding geographic range of N. fowleri transmission, which may lead to increased incidence of PAM in the United States. Similar environmental investigations at suspected exposure sites of future cases will allow data aggregation, enabling investigators to correlate environmental factors with infection risk accurately.


Assuntos
Amebíase , Infecções Protozoárias do Sistema Nervoso Central , Meningoencefalite , Naegleria fowleri , Masculino , Humanos , Estados Unidos/epidemiologia , Criança , Nebraska , Infecções Protozoárias do Sistema Nervoso Central/diagnóstico , Infecções Protozoárias do Sistema Nervoso Central/epidemiologia , Água , Rios , Meningoencefalite/epidemiologia , Meningoencefalite/diagnóstico , Amebíase/epidemiologia , Amebíase/diagnóstico
19.
SAGE Open Med ; 11: 20503121231175322, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37223673

RESUMO

Objectives: Bacteremia due to invasive Salmonella enterica has been reported earlier in children in Nigeria. This study aimed to detect the virulence and antibiotic resistance genes of invasive Salmonella enterica from children with bacteremia in north-central Nigeria. Method: From June 2015 to June 2018, 4163 blood cultures yielded 83 Salmonella isolates. This is a secondary cross-sectional analysis of the Salmonella isolates. The Salmonella enterica were isolated and identified using standard bacteriology protocol. Biochemical identifications of the Salmonella enterica were made by Phoenix MD 50 identification system. Further identification and confirmation were done with polyvalent antisera O and invA gene. Antimicrobial susceptibility testing was done following clinical and laboratory standard institute guidelines. Resistant genes and virulence genes were determined using a real-time polymerase chain reaction. Result: Salmonella typhi 51 (61.4%) was the most prevalent serovar, followed by Salmonella species 13 (15.7%), choleraesuis 8 (9.6%), enteritidis 6 (7.2%), and typhimurium 5 (6.1%). Fifty-one (61.4%) of 83 Salmonella enterica were typhoidal, while 32 (38.6%) were not. Sixty-five (78.3%) of the 83 Salmonella enterica isolates were resistant to ampicillin and trimethoprim-sulfamethoxazole, followed by chloramphenicol 39 (46.7%), tetracycline 41 (41.4%), piperacillin 33 (33.9%), amoxicillin-clavulanate, and streptomycin 21 (25.3%), while cephalothin was 19 (22.9%). Thirty-nine (46.9%) of the 83 Salmonella enterica isolates were multi-drug resistant, and none were extensive drug resistant or pan-drug resistant. A blaTEM 42 (50.6%), floR 32 (38.6%), qnrA 24 (28.9%), tetB 20 (20.1%), tetA 10 (10.0%), and tetG 5 (6.0%) were the antibiotic resistance genes detected. There were perfect agreement between phenotypic and genotypic detection of antimicrobial resistance in tetracycline, ciprofloxacin, and chloramphenicol, while beta-lactam showed κ = 0.60 agreement. All of the Salmonella enterica isolates had the virulence genes invA, sopB, mgtC, and sip4D, while 33 (39.8%), 45 (51.8%), and 2 (2.4%) had ssaQ, spvC, and ljsGI-1, respectively. Conclusion: Our findings showed multi-drug resistant Salmonella enterica in children with bacteremia in northern Nigeria. In addition, significant virulence and antimicrobial resistance genes were found in invasive Salmonella enterica in northern Nigeria. Thus, our study emphasizes the need to monitor antimicrobial resistance in Salmonella enterica from invasive sources in Nigeria and supports antibiotic prudence.

20.
Sci Rep ; 13(1): 10306, 2023 06 26.
Artigo em Inglês | MEDLINE | ID: mdl-37365355

RESUMO

Infections caused by multi-drug resistant Enterobacterales (MDR-E) are difficult to treat and cause significant mortality, especially in developing countries. This study characterized the phenotypic and genotypic profiles of 49 randomly selected beta-lactam resistant MDR-E previously isolated from patients being managed in hospitals in Nigeria using whole genome sequencing. The study isolates exhibited 85.5% resistance to 3rd generation cephalosporins and 65.3% resistance to carbapenems. The blaTEM-1B (29, 59.2%), blaCTX-M-15 (38, 77.6%), and blaNDM-1 (17, 51.5%) were the most common penicillinase, ESBL, and carbapenem resistant genes across isolates, respectively. Seventeen (45%) of blaCTX-M-15 was carried on the insertion sequence ISEc9 while blaNDM-1 (11, 64.7%) were associated with ISEc33. None of the 21 plasmids detected were associated with ß-lactamase genes. Higher resistance rates were found in E. coli ST-88 (n = 2) and the high-risk ST-692 (n = 2). For Klebsiella species, the high-risk clones ST-476 (n = 8) and ST-147 (n = 3) predominated and had higher phenotypic resistance rates and higher number of AMR genes. The mechanisms and pattern of antibiotic resistance differ from patterns previously described with isolates harbouring a wide range of AMRGs. The detection of several chromosomally mediated carbapenemases in our study also represents a significant finding that warrants further investigation to better understand its' implications for clinical practice and public health. The selected MDR-Es were found to be pan-susceptible to tigecycline and had very low resistance to fosfomycin, suggesting a potential for these as empiric treatments. A surveillance approach incorporating both conventional laboratory techniques and modern molecular techniques is essential for the comprehensive characterization of the emergence and dissemination of antimicrobial resistance in Enterobacterales infections within Nigeria.


Assuntos
Escherichia coli , beta-Lactamas , Humanos , Antibacterianos/farmacologia , Nigéria/epidemiologia , Testes de Sensibilidade Microbiana , beta-Lactamases/genética , Carbapenêmicos , Resistência beta-Lactâmica/genética , Hospitais
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