A modified anthrax toxin-based enzyme-linked immunospot assay reveals robust T cell responses in symptomatic and asymptomatic Ebola virus exposed individuals

Background Ebola virus (EBOV) caused more than 11,000 deaths during the 2013–2016 epidemic in West Africa without approved vaccines or immunotherapeutics. Despite its high lethality in some individuals, EBOV infection can produce little to no symptoms in others. A better understanding of the immune responses in individuals who experienced minimally symptomatic and asymptomatic infection could aid the development of more effective vaccines and antivirals against EBOV and related filoviruses. Methodology/Principle findings Between August and November 2017, blood samples were collected from 19 study participants in Lagos, Nigeria, including 3 Ebola virus disease (EVD) survivors, 10 individuals with documented close contact with symptomatic EVD patients, and 6 control healthcare workers for a cross-sectional serosurvey and T cell analysis. The Lagos samples, as well as archived serum collected from healthy individuals living in surrounding areas of the 1976 Democratic Republic of Congo (DRC) epidemic, were tested for EBOV IgG using commercial enzyme-linked immunosorbent assays (ELISAs) and Western blots. We detected antibodies in 3 out of 3 Lagos survivors and identified 2 seropositive individuals not known to have ever been infected. Of the DRC samples tested, we detected antibodies in 9 out of 71 (12.7%). To characterize the T cell responses in the Lagos samples, we developed an anthrax toxin-based enzyme-linked immunospot (ELISPOT) assay. The seropositive asymptomatic individuals had T cell responses against EBOV nucleoprotein, matrix protein, and glycoprotein 1 that were stronger in magnitude compared to the survivors. Conclusion/Significance Our data provide further evidence of EBOV exposure in individuals without EVD-like illness and, for the first time, demonstrate that these individuals have T cell responses that are stronger in magnitude compared to severe cases. These findings suggest that T cell immunity may protect against severe EVD, which has important implications for vaccine development

Antibacterial potentials and DNA study of cobalt(II) complexes containing aminophenol Schiff base moiety

The present study was carried out to investigate the effect of substituent groups on the antibacterial activities of 2-aminophenol Schiff bases and their cobalt (II) complexes. Development of new compounds with potential effects against pathogenic organisms has become necessary due to the increase in microbial resistance reported for existing antiseptics and disinfectants. In line with this, new cobalt (II) complexes with Schiff bases derived from 2-aminophenol and p-substituted benzaldehydes were synthesized. The compounds were characterized using elemental analysis, mass spectrometry, atomic absorption spectroscopy, electrospray ionization mass spectrometry, infrared spectroscopy, 1H NMR and electronic absorption spectroscopy. Results indicate that all metal complexes had a 1:2 metal ligand ratio with magnetic moments characteristic of tetrahedral geometry around the metal ion. The Schiff bases and their metal complexes were screened for in-vitro antibacterial activities against 6 human pathogenic bacteria usually found around the hospitals and homes; Escherichia coli (ATCC 8739), Staphylococcus aureus (ATCC 6538), Pseudomonas aeruginosa (ATCC 19582), Bacillus cereus (10702), Enterococcus faecalis (ATCC 29212) and Kribsella pneumonia (ATCC 10031) with ampicillin used as the reference compound. DNA binding study using calf thymus DNA revealed intercalative mode of activity. The result showed that Schiff bases exhibited moderate inhibitory activity against the tested microorganisms while Schiff base metal complexes exhibited higher antibacterial activity when compared to ampicillin. Our results indicate that these complexes can be employed as active ingredients in development of broad-spectrum antibacterial agents

Fungal contamination of the water distribution system of a tertiary hospital water supply system in a resource-limited setting

Background: Fungal contamination of hospital water distribution systems has been implicated in outbreaks of healthcare-associated infections. Objectives: To evaluate the prevalence of fungi in the water distribution system of a tertiary hospital in Nigeria. Design: This was a descriptive cross-sectional study. Methods: Swabs and water samples were collected from taps and faucets in the hospital categorized into low (Accidents and Emergency Unit, Children Emergency Unit, Acute Stroke Unit and the 24 in-patient hospital wards) and high-risk (Renal Dialysis Unit, Central Sterile Services Department, Theatres and Intensive Care Units (ICUs)) units based on the vulnerability of patients being managed there. The membrane filtration method for water analysis was used. Where possible, isolates cultured were identified to species level. In total, 105 water and 49 swab samples were collected for analysis. Results: All analysed water samples grew fungi. A total of 289 (high-risk; n  = 178; low-risk; n  = 111) and 76 fungi isolates were recorded from water and swab samples, respectively, with 31 different species identified. Aspergillus was the most predominant genus with five different species: Aspergillus niger (9.9%), terreus (4.4%), flavus (3.3%), fumigatus (8.8%) and versicolor (2.20%) isolated. Twenty-five and 18 species of fungi were identified in the low and high-risk units, respectively. The labour ward ( n  = 46; 25.8%) and modular theatre ( n  = 47; 42.3%) were the most contaminated units. Cladosporium spp. and Paecilomyces spp. were the most frequently isolated fungi in the low and high-risk units, respectively. The dialysis centre ( n  = 9; 8.1%) and renal transplant theatre ( n  = 7; 6.31%) had the lowest contamination rates in the high-risk units. Aspergillus niger , Cephalosporium curtipes , Penicillium chrysogenum and Penicillium glabrum were each identified in 4/6 units from which swabs were taken. The facility had no documented protocol for its water safety and quality. Conclusion: Our data reveal a high rate of contamination of hospital water sources by fungi, some of which are known to cause life-threatening infections. For better water treatment and water tank cleaning and disinfection, a standard protocol is advised. Ensuring that the water distribution systems in hospital settings are free of fungal contaminants is important to prevent the possibility of waterborne mycosis outbreaks

Cryptococcal Antigenemia in Nigerian Patients With Advanced Human Immunodeficiency Virus: Influence of Antiretroviral Therapy Adherence

Background. Cryptococcal meningitis has a high mortality in human immunodeficiency virus (HIV)-infected persons in Africa. This is preventable with early screening and preemptive therapy. We evaluated the prevalence of cryptococcal disease by antigen testing, possible associated factors, and outcomes in HIV-infected patients being managed in a tertiary hospital in Lagos, Nigeria. Methods. Sera were collected from 214 consenting HIV-infected participants with CD4(+) counts <250 cells/mm(3), irrespective of their antiretroviral therapy (ART) status, between November 2014 and May 2015. A cryptococcal antigen (CrAg) lateral flow assay was used for testing. Pertinent clinical data were obtained from patients and their case notes. Results. Of the 214 participants, females (124; 57.9%) outnumbered males. Mean age was 41.3 ± 9.4 (standard deviation) years. The majority (204; 95.3%) were ART experienced. The median CD4(+) cell count was 160 cells/mm(3) (interquartile range, 90–210). The overall seroprevalence of cryptococcal antigenemia was 8.9% (19 of 214); 6 of 61 (9.8%) in those with CD4(+) cell counts <100 cells/mm(3), 4 of 80 (5.0%) in the 100–200 group, and 9 of 73 (12.3%) in 200–250 cells/mm(3) group. Among ART-naive patients, 1 of 10 (10%) was CrAg positive. Twenty-seven of 214 (12.6%) had associated oral thrush. Potential baseline meningitis symptoms (3 of 214 [1.4%] experienced neck pain or stiffness and 21 of 214 [9.8%] experienced headache) were common in the study group, but the result was not statistically significant in relation to CrAg positivity. Two of 19 (10.5%) CrAg-positive patients died, 10 of 19 (52.6%) were lost to follow up, and 7 of 19 (36.8%) were alive. Empirical fluconazole was routinely given to those with low CD4 counts <100 cells/mm(3), which was unrelated to CrAg positivity (P = .018). Conclusions. We report a prevalence of 8.9% cryptococcal antigenemia in a setting where first-line antifungals are not readily available. We recommend CrAg screening for HIV-infected patients, even for patients on ART

Implementation of antimicrobial stewardship programs: A study of prescribers' perspective of facilitators and barriers.

BackgroundDespite promising signs of the benefits associated with Antimicrobial Stewardship Programs (ASPs), there remains limited knowledge on how to implement ASPs in peculiar settings for a more elaborate impact. This study explored prescriber experiences and perceptions of the usefulness, and feasibility of strategies employed for the implementation of antimicrobial stewardship (AMS) interventions as well as challenges encountered.MethodsThis is a cross-sectional mixed-method survey of prescribers' perspective of the facilitators and barriers of implementing ASP. The quantitative approach comprised of a semi-structured questionnaire and data collected were analyzed using SPSS version 26 while the qualitative approach used focus group discussions followed by content analysis.ResultsOut of the thirty people that participated in the workshop, twenty-five completed the questionnaires which were analyzed. The respondents included 15 (60.0%) medical doctors and 10 (40.0%) pharmacists. The mean age of the respondents was 36.39±7.23 years with mean year of practice of 9.48±6.01 years. Majority of them (84.0%) were in a position to provide input on the implementation of AMS in their facilities, although their managements had the final decision. The pharmacists (100%) were more likely to agree that antibiotic resistance was a problem for their practice than the medical doctors (78.6%) while equal number (80.0%) of respondents (pharmacists and medical doctors) believed that inappropriate prescribing was a problem. Having a specialized and dedicated team with effective monitoring was recognized as crucial for effective ASP while inadequate personnel was identified as a major barrier. We identified stakeholder's engagement, policies and regulation, as well as education as themes for improving AMS in the country.ConclusionThe results gave insight into the prescribers' perspective on the facilitators and barriers to antimicrobial stewardship; challenges and possible solutions to implementing ASPs in health facilities in Lagos State. We further identified pertinent contextual factors that need to be addressed when developing ASPs in healthcare facilities in a resource-poor setting

Prior subclinical histoplasmosis revealed in Nigeria using histoplasmin skin testing

Disseminated histoplasmosis is an AIDS-defining illness. Histoplasmosis is commonly misdiagnosed as tuberculosis. Nigeria has the second highest number of people living with HIV/AIDS in Africa. The present study was carried out to investigate the prevalence of skin sensitivity amongst Nigerians to histoplasmin.A cross-sectional study was conducted in six centres across five geopolitical zones of Nigeria.We recruited both healthy non-HIV and HIV-positive adults with CD4 count ≥ 350 cells/mm3 regardless of their ART status from March to May 2017. Skin tests were performed intradermally; induration ≥5 mm were considered to be histoplasmin positive.750 participants were recruited from Lagos (n = 52), Yola (n = 156), Ilorin (n = 125), Calabar (n = 120), Ibadan (n = 202) and Benin (n = 95). 467 (62.3%) were HIV negative, 247 (32.9%) were HIV positive and 36 (4.8%) did not know their HIV status. A total of 32/735 (4.4%) participants had a positive skin test. Study centre (p<0.001), education (p = 0.002) and age (p = 0.005) appeared to be significantly associated with positive skin reactivity at the 0.5% significance level, while sex (p = 0.031) and occupation (p = 0.031) would have been significant at the 5% significance level. Males had a higher rate of reactivity than females (p = 0.031, 7% vs 3%). The highest positive rates were recorded from Benin City (13/86 (15%)) and Calabar (7/120 (6%)) and no positives were recorded in Lagos (p<0.001). HIV status was not statistically significant (p = 0.70).Histoplasmosis diagnostics should be included in the Nigerian HIV guidelines. Epidemiological vigilance of progressive disseminated histoplasmosis should be considered by local health authorities

Isolation and molecular identification of Fusobacterium nucleatum from Nigerian patients with oro-facial infections.

Fusobacterium nucleatum is one of the most common anaerobic bacteria present in the oral cavity and is often isolated from infections involving other body sites. To characterise F. nucleatum strains from patients attending a teaching hospital in Nigeria in order to provide information on the methods for accurate identification of anaerobes in clinical specimen. Fusobacterium nucleatum specie from 50 patients presenting with oro-facial infections were studied by culture on Fusobacterium selective agar and fastidious anaerobe agar. The isolates were characterised based on colonial morphology, microscopy, lipase production, susceptibility to kanamycin and colistin and resistance to vancomycin. Biochemical tests were performed using a commercial test kit. The identity of the isolates was confirmed based on molecular characterization performed using polymerase chain reaction (PCR) analysis. Forty-eight (96%) F. nucleatum isolates were obtained from the 50 patients by culture and all the isolates were identified by colonial appearance and microscopy based on their unique spindle shape with tapered ends. Only 26 (54.2%) of the 48 isolates were identified by commercial API 20A test kit while PCR confirmed the identity of all the isolates. Anaerobes are involved in human infections and their study is quite cumbersome due to tedious nature and high cost of the techniques involved. Cultural method is reliable in the isolation and identification of F. nucleatum species. PCR is a rapid and simple method that can complement the phenotypic identification of anaerobes and would assist in their full identification

Fluconazole susceptibility and ERG11 gene expression in vaginal candida species isolated from Lagos Nigeria

Fluconazole resistance is an important type of resistance in Candida because in most countries, fluconazole is the drug of choice for vulvovaginal candidiasis. Candida species resist fluconazole by various mechanisms but there is paucity of data on these in our environment. Such mechanisms include among others, over-expression of the ERG11 gene, which codes for synthesis of the target enzymes in the fungus. The aim of this study was to screen Candida spp. resistant to fluconazole for the expression of ERG11 gene. Fluconazole susceptibility test was performed on 28 clinical strains of Candida species previously obtained from students of a School of Nursing in Lagos, Nigeria. They were identified by API Candida, CHROMagar candida and germ tube test. Using 25 mcg discs, fluconazole susceptibility was determined by the disc diffusion method and results were interpreted in accordance with the Clinical Laboratory Standard Institute (CLSI) criteria; sensitive (S), resistant (R) and susceptible dose dependent (SDD). The R and SDD isolates were subsequently evaluated for the presence of ERG11 gene. Of the 28 clinical isolates, 14 were identified as C. albicans and six as C. tropicalis. The remaining isolates were identified as C. glabrata (2), C. famata (2) C. kefyr (2) one each of C. parapsilosis and C. guilliermondii respectively. In this study, 18 were susceptible (S) to fluconazole, eight were SDD and two were resistant to the antifungal agent. Out of the 14 C. albicans isolates, 12 were susceptible, one showed high level resistance and similar number showed susceptible dose dependence. ERG11 was detected in three susceptible dose dependent Candida species. This analysis demonstrates that susceptible dose dependence should not be overlooked as it may be associated with the presence of ERG11 gene and resistance to fluconazole. There is a need to consider routine antifungal susceptibility testing for Candida species causing vulvovaginitis.</p

Antimicrobial stewardship programmes in healthcare facilities in Lagos State, Nigeria: a needs assessment

ABSTRACT: Objectives: Optimising antibiotic use in healthcare settings through antimicrobial stewardship programmes (ASPs) is critical to effectively treat infections, protect patients from harms caused by unnecessary antibiotic use, and combat antimicrobial resistance. This needs assessment was designed to provide the current status of ASPs in healthcare facilities in Lagos State and identify gaps for future interventions. Methods: A descriptive cross-sectional survey was conducted using a self-administered questionnaire to ascertain the extent and nature of ongoing ASPs among selected healthcare facilities and identify gaps for future interventional studies. Results: Of 32 questionnaires distributed, 25 (78%) were completed and returned from three tertiary, six secondary, eleven primary and five private healthcare facilities. The mean years of practice of respondents was 13.96 ± 7.8 years (2–31 years). Six facilities (24%) had a team responsible for ASP operating at varying degrees of capacity, while five (20%) had a formal ASP. All six facilities with an antimicrobial stewardship (AMS) team had a medical doctor as the team lead, and 5 (20%) also had a pharmacist involved in implementation efforts. Routine pre-authorisation for specific antibiotic was performed in six facilities (24%), four of which monitor pre-authorisation interventions. Only two facilities (8%) performed prospective audit and feedback for specific antibiotic agents. Private healthcare facilities were more likely to have information technology (IT) capability to support the needs of AMS activities. Conclusion: This study revealed minimal ASP activities in healthcare facilities in Lagos State and highlighted possibilities of leveraging on available IT resources for a co-ordinated AMS strategy