Profiles of microorganisms isolated from neonates’ blood cultures, incubators, cradles, ventilators, washbasins, and health-workers of Libreville University Hospital Neonatal Service: focus on infection prevention and control measures

Background: Nosocomial infection outbreaks in neonatal services are a serious healthcare concern in both developed and developing countries, but few studies have been conducted in sub-Saharan Africa. Objective: This study explored the etiology of septicemia in neonates and associated patterns of antimicrobial susceptibility in Gabon. Methods: We analyzed cultures from neonates’ blood and swabs from medical personnel and equipment located in the neonatology service. Results: Sixty-eight microorganisms were isolated from the medical personnel and equipment; 46 microorganisms were isolated from neonates’ blood culture. Klebsiella pneumoniae spp pneumoniae was the most common bacteria found in both (30.6% and 26.9%, respectively). All Klebsiella pneumoniae spp pneumonia isolates were resistant to amoxicillin with clavulanic acid, gentamycin resistance ranged from 93% to 100%, and cephalosporin resistance ranged from 33.3% to 47%. Conclusions: Awareness of the etiology, prevalence, and outcome of nosocomial infection is the first and most important step to appropriate intervention

Cases of Impaired Oxidative Burst in HIV-Exposed Uninfected Infants’ Neutrophils—A Pilot Study

An increased risk of serious bacterial infections in HIV-exposed uninfected (HEU) infants has been demonstrated. Although neutrophils are essential for the protection of infants against bacterial infections, no study has investigated their profile in HEU infants to date. In this study, we assessed the function of neutrophils in HEU infants using the nitroblue tetrazolium reduction test. Among 25 HEU infants, 9 (36%) showed a reduced ability of their neutrophils to produce reactive oxygen species upon stimulation with bacteria. No alteration of total neutrophil counts was noted in the blood of HEU infants indicating that the alteration observed in the 36% of HEU infants may only be functional. Conclusively, impaired neutrophil function could be a factor of vulnerability in HEU infants

Vitamin D2 versus vitamin D3 as a risk factor in compromised bone health

Background: Vitamin D plays an important role in the prevention of many diseases. More than 1 billion people worldwide suffer from vitamin D deficiency. Vitamin D deficiency can contribute to the development of 16 types of cancer (breast, colon, prostate, etc.), cardiovascular diseases, stroke, autoimmune diseases, periodontal pathologies, transplant failure in endo-alveolar surgery, etc. There are several risk factors that would prevent the achievement of treatment objectives. The national protocol for deficiency rickets prevention privileges vitamin D2 versus vitamin D3 , which creates a medical risk factor compromising oral health in both children and adults. The article provides sufficient arguments in favour of vitamin D3 vs vitamin D2 prescription for prophylactic and treatment purposes. Conclusions: Considering that vitamin D deficiency is currently a global public health problem, it can be proposed to declare vitamin D deficit/deficiency a priority public health problem at the national level. Vitamin D3 should be elective in preventing deficit. Taking into account the multitude of acute and chronic diseases related to vitamin D deficiency, in order to improve the status of vitamin D in all population categories, it is necessary to include vitamin D3 in the list of molecules fully subsidized by the state and distributed free of charge at least to children under the age of 5 years and adolescents in the period of intensive growth

An evaluation of commercial fluorescent bead-based luminex cytokine assays.

The recent introduction of fluorescent bead-based technology, allowing the measurement of multiples analytes in a single 25-50 microl sample has revolutionized the study of cytokine responses. However, such multiplex approaches may compromise the ability of these assays to accurately measure actual cytokine levels. This study evaluates the performance of three commercially available multiplex cytokine fluorescent bead-based immunoassays (Bio-Rad's Cytokine 17-plex kit; LINCO Inc's 29-plex kit; and RnD System's Fluorokine-Multi Analyte Profiling (MAP) base kit A and B). The LINCO Inc kit was found to be the most sensitive assay for measuring concentrations of multiple recombinant cytokines in samples that had been spiked with serial dilutions of the standard provided by the manufacturer, followed respectively by the RnD Fluorokine-(MAP) and Bio-Rad 17-plex kits. A positive correlation was found in the levels of IFN-gamma measured in antigen stimulated whole blood culture supernatants by the LINCO Inc 29-plex, RnD Fluorokine-(MAP) and RnD system IFN-gamma Quantikine ELISA kits across a panel of controls and stimulated samples. Researchers should take the limitation of such multiplexed assays into account when planning experiments and the most appropriate use for these tests may currently be as screening tools for the selection of promising markers for analysis by more sensitive techniques

IP-10 detection in urine is associated with lung diseases

<p>Abstract</p> <p>Background</p> <p>blood cytokines and chemokines have been proposed as biomarkers for tuberculosis (TB). Recently, some immune mediators found in the urine of patients with renal dysfunctions have also been suggested as potential biomarkers. Finding biomarkers for TB in urine would present several advantages over blood in terms of collection and safety. The objective of this study was to investigate the presence of cytokines and chemokines in the urine of patients with pulmonary TB at the time of diagnosis. In a subgroup, the evaluation was also performed during TB treatment and at therapy completion. Patients with lung diseases other than TB, and healthy subjects were also enrolled.</p> <p>Methods</p> <p>urine samples from 138 individuals, after exclusion of renal dysfunctions, were collected during an 18 month-period. Among them, 58 received a diagnosis of pulmonary TB, 28 resulted having lung diseases other than TB, and 34 were healthy subjects. Moreover, 18 TB patients, 9 of whom were tested 2 months after AFB smear sputum reversion and 9 of whom were cured of TB were also included. Cytokines and chemokines in urine were evaluated using a Cytometric-Bead-Array-Flex-Set. IP-10 detection in 49 subjects was also carried out in parallel by using an Enzyme Linked ImmunoSorbent Assay (ELISA).</p> <p>Results</p> <p>IFN-γ, TNF-α, IL-2, IL-8, MIP-1α, MIP-1β and RANTES were poorly detected in all urine samples. Conversely, IP-10 was consistently detected in urine and its level was significantly increased in patients with lung disease compared to healthy subjects (p < 0.001). Increased IP-10 levels were found in both pulmonary TB and lung diseases other than TB. Moreover lower IP-10 levels were found in cured-TB patients compared to the levels at the time of diagnosis, and this difference was close to significance (p = 0.06). Interestingly, we demonstrated a significant correlation between the data obtained by flow cytometry and ELISA (r²0.82, p < 0.0001).</p> <p>Conclusions</p> <p>IP-10, in contrast to IFN-γ, TNF-α, IL-2, IL-8, MIP-1α, MIP-1β and RANTES, is detectable in the urine of patients with pulmonary diseases in the absence of renal dysfunctions. Moreover, the IP-10 level in cured-TB patients is comparable to that found in healthy subjects. More studies are needed to further investigate the clinical utility of these findings.</p

Plasma cytokine levels during acute HIV-1 infection predict HIV disease progression

BACKGROUND: Both T-cell activation during early HIV-1 infection and soluble markers of immune activation during chronic infection are predictive of HIV disease progression. Although the acute phase of HIV infection is associated with increased pro-inflammatory cytokine production, the relationship between cytokine concentrations and HIV pathogenesis is unknown. OBJECTIVES: To identify cytokine biomarkers measurable in plasma during acute HIV-1 infection that predict HIV disease progression. DESIGN: Study including 40 South African women who became infected with HIV-1 and were followed longitudinally from the time of infection. METHODS: The concentrations of 30 cytokines in plasma from women with acute HIV-1 infection were measured and associations between cytokine levels and both viral load set point 12 months postinfection and time taken for CD4 cell counts to fall below 350 cells/microl were determined using multivariate and Cox proportional hazards regression. RESULTS: We found that the concentrations of five plasma cytokines, IL-12p40, IL-12p70, IFN-gamma, IL-7 and IL-15 in women with acute infection predicted 66% of the variation in viral load set point 12 months postinfection. IL-12p40, IL-12p70 and IFN-gamma were significantly associated with lower viral load, whereas IL-7 and IL-15 were associated with higher viral load. Plasma concentrations of IL-12p40 and granulocyte-macrophage colony-stimulating factor during acute infection were associated with maintenance of CD4 cell counts above 350 cells/microl, whereas IL-1alpha, eotaxin and IL-7 were associated with more rapid CD4 loss. CONCLUSION: A small panel of plasma cytokines during acute HIV-1 infection was predictive of long-term HIV disease prognosis in this group of South African women

Ethnic Variation in Inflammatory Profile in Tuberculosis

PMCID: PMC3701709This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited

Mycobacterium tuberculosis-stimulated whole blood culture to detect host biosignatures for tuberculosis treatment response

Supplementary data are available online at https://www.sciencedirect.com/science/article/pii/S1472979221000329?via%3Dihub#appsec1 .Host markers to monitor the response to tuberculosis (TB) therapy hold some promise. We evaluated the changes in concentration of Mycobacterium tuberculosis (M.tb)-induced soluble biomarkers during early treatment for predicting short- and long-term treatment outcomes. Whole blood samples from 30 cured and 12 relapsed TB patients from diagnosis, week 1, 2, and 4 of treatment were cultured in the presence of live M.tb for seven days and patients followed up for 24 weeks after the end of treatment. 57 markers were measured in unstimulated and antigen-stimulated culture supernatants using Luminex assays. Top performing multi-variable models at diagnosis using unstimulated values predicted outcome at 24 months after treatment completion with a sensitivity of 75.0% (95% CI, 42.8–94.5%) and specificity of 72.4% (95% CI, 52.8–87.3%) in leave-one-out cross validation. Month two treatment responder classification was correctly predicted with a sensitivity of 79.2% (95% CI, 57.8–92.9%) and specificity of 92.3% (95% CI, 64.0–99.8%). This study provides evidence of the early M.tb-specific treatment response in TB patients but shows that the observed unstimulated marker models are not outperformed by stimulated marker models. Performance of unstimulated predictive host marker signatures is promising and requires validation in larger studies.Bill and Melinda Gates Foundation (TB Drug Accelerator Program, grant number 48941); Action TB by GSK; EDCTP (01.T.d1, Grant number 2004.1.R.d1); the South African Technology for Human Resources and Industry Program (THRIP); and an International Collaborations in Infectious Diseases Research grant from the National Institute of Allergy and Infectious Diseases (grant number 5U01IA115619). This research was also partially funded by the South African government through the South African Medical Research Council, through a grant from the Strategic Health Innovations Partnership (SHIP) unit, by the South African National Research Foundation through a South African Research Chair Initiative: Biomarkers for TB (grant number 86535) and a South African Department of Science and Innovation/National Research Foundation funded Centre of Excellence in Biomedical Tuberculosis Research

Label-free electrochemical impedance biosensor to detect human interleukin-8 in serum with sub-pg/ml sensitivity

Biosensors with high sensitivity and short time-to-result that are capable of detecting biomarkers in body fluids such as serum are an important prerequisite for early diagnostics in modern healthcare provision. Here, we report the development of an electrochemical impedance-based sensor for the detection in serum of human interleukin-8 (IL-8), a pro-angiogenic chemokine implicated in a wide range of inflammatory diseases. The sensor employs a small and robust synthetic non-antibody capture protein based on a cystatin scaffold that displays high affinity for human IL-8 with a KD of 35 ± 10 nM and excellent ligand specificity. The change in the phase of the electrochemical impedance from the serum baseline, ∆θ(ƒ), measured at 0.1 Hz, was used as the measure for quantifying IL-8 concentration in the fluid. Optimal sensor signal was observed after 15 min incubation, and the sensor exhibited a linear response versus logarithm of IL-8 concentration from 900 fg/ml to 900 ng/ml. A detection limit of around 90 fg/ml, which is significantly lower than the basal clinical levels of 5-10 pg/ml, was observed. Our results are significant for the development of point-of-care and early diagnostics where high sensitivity and short time-to-results are essential

Whole-Blood Flow-Cytometric Analysis of Antigen-Specific CD4 T-Cell Cytokine Profiles Distinguishes Active Tuberculosis from Non-Active States

T-cell based IFN-γ release assays do not permit distinction of active tuberculosis (TB) from successfully treated disease or latent M. tuberculosis infection. We postulated that IFN-γ and IL-2 cytokine profiles of antigen-specific T cells measured by flow-cytometry ex vivo might correlate with TB disease activity in vivo. Tuberculin (PPD), ESAT-6 and CFP-10 were used as stimuli to determine antigen-specific cytokine profiles in CD4 T cells from 24 patients with active TB and 28 patients with successfully treated TB using flow-cytometry. Moreover, 25 individuals with immunity consistent with latent M. tuberculosis infection and BCG-vaccination, respectively, were recruited. Although the frequency of cytokine secreting PPD reactive CD4 T cells was higher in patients with active TB compared to patients with treated TB (median 0.81% vs. 0.39% of CD4 T cells, p = 0.02), the overlap in frequencies precluded distinction between the groups on an individual basis. When assessing cytokine profiles, PPD specific CD4 T cells secreting both IFN-γ and IL-2 predominated in treated TB, latent infection and BCG-vaccination, whilst in active TB the cytokine profile was shifted towards cells secreting IFN-γ only (p<0.0001). Cytokine profiles of ESAT-6 or CFP-10 reactive CD4 T cells did not differ between the groups. Receiver operator characteristics (ROC) analysis revealed that frequencies of PPD specific IFN-γ/IL-2 dual-positive T cells below 56% were an accurate marker for active TB (specificity 100%, sensitivity 70%) enabling effective discrimination from non-active states. In conclusion, a frequency lower than 56% IFN-γ/IL-2 dual positive PPD-specific circulating CD4 T-cells is strongly indicative of active TB