Armauer Hansen Research Institute AHRI
Armauer Hansen Research Institute AHRI
Mariam S.H.,Addis Ababa Institute of Technology |
Mariam S.H.,Armauer Hansen Research Institute AHRI |
Zegeye N.,Debre Berhan University |
Aseffa A.,Armauer Hansen Research Institute AHRI |
Howe R.,Armauer Hansen Research Institute AHRI
BMC Microbiology | Year: 2017
Background: Food-borne infections cause huge economic and human life losses. Listeria monocytogenes and Salmonella enterica serovar Enteritidis are among the top ranking pathogens causing such losses. Control of such infections is hampered by persistent contamination of foods and food-processing environments, resistance of pathogens to sanitizing agents, existence of heterogeneous populations of pathogens (including culturable and viable but non-culturable cells) within the same food items, and inability to detect all such pathogens by culture-based methods. Modern methods such as flow cytometry allow analyses of cells at the single cell level within a short time and enable better and faster detection of such pathogens and distinctions between live and dead cells. Such methods should be complemented by control strategies including the use of beneficial bacteria that produce metabolites capable of inhibiting food-borne pathogens. In this study, broth cultures of lactic acid bacteria (LAB) isolated from fermented milk were tested for production of substances capable of inhibiting L. monocytogenes and S. Enteritidis in co-culture with LAB by assessment of colony-forming units (CFU) and live:dead cell populations by flow cytometry. Results: The LAB isolates belonged to the species Lactococcus lactis, Enterococcus faecalis and Enterococcus faecium. Some LAB were effective in inhibition. Plating indicated up to 99% reduction in CFU from co-cultures compared to control cultures. Most of the bacteria in both cultures were in the viable but non-culturable state. The flow data showed that there were significantly higher dead cell numbers in co-cultures than in control cultures, indicating that such killing was caused by diffusible substances produced by the LAB cultures. Conclusion: This study showed that metabolites from selected local LAB species can be used to significantly reduce pathogen load. However, conditions of use and application need to be further investigated and optimized for large-scale utilization. © 2017 The Author(s).
Geyesus T.,South Gondar Zonal Health Bureau |
Moges F.,Health Science University |
Eshetie S.,Health Science University |
Yeshitela B.,Armauer Hansen Research Institute AHRI |
Abate E.,Health Science University
BMC Pediatrics | Year: 2017
Background: Neonatal sepsis is a blood stream infection which is seen in the first month of life of the neonate. Bacterial profile of neonatal septicemia is constantly changing thus, current knowledge on the patterns of bacterial isolates, its antibiotic resistance profile, and associated factors, are essential to design and implement appropriate interventions. Therefore, the aim of this study was to identify bacterial etiologic agents, their antimicrobial susceptibility pattern and associated risk factors of neonatal sepsis among neonates. Methods: A cross- sectional study was conducted among neonates suspected to sepsis attending University of Gondar Hospital from September/2015 to May/2016. A total of 251 consecutive neonates with clinical sign and symptoms of sepsis were included in the study. Blood sample was collected and directly inoculated into Trypton soya broth bottle and incubated at 37 °C. After 24 h of incubation it was sub- cultured in to blood agar plate, chocolate agar plate, manitol salt agar and Macconkey. The bacterial pathogens and antimicrobial susceptibility tests were identified using standard microbiological methods. Bivariate and multivariate logistic regressions were used to identify possible associated risk factors. Prior to the study ethical clearance was obtained from the School of Biomedical and Laboratory Sciences, University of Gondar. Results: Of the 251 study participants suspected of neonatal sepsis, 117 (46.6%) showed bacterial growths, of them 120 bacteria were isolated. Gram positive bacteria were commonly isolated 81 (67.5%).The commonly isolated bacterial species were S. aureus 49 (40.8%) followed by coagulase negative Staphylococci 26 (21.6%) and K. pneumoniae19 (15.8%). The overall rate of multidrug resistance isolates was 78 (65%: CI 95%: 56.7-72.5%). Multidrug resistant (MDR) among Gram positive and negative bacteria were 56 (69.1%) and 22 (56.4%), respectively. Independent risk factors for the occurrence of neonatal sepsis were; Apgar score < 7/5 min (Adjusted odds ratio [AOR] =0.5), birth weight < 1.5 kg (AOR = 12.37), birth weight, 1.5-2.5 kg (AOR = 2.6), gestational week <37 weeks (AOR = 9) and caesarian section delivery (AOR = 5.2). Conclusion: The isolation rate of bacterial pathogens in neonatal sepsis was considerably high. In addition, nearly 70% of isolates were MDR strains. Low birth weight, low Apgar score, preterm delivery and caesarian section modes of delivery were associated risk factors. Therefore, appropriate antenatal care follow up, and health education should be encouraged, especially on the importance of natural way of delivery. © 2017 The Author(s).
Garedew L.,University of Gondar |
Mihret A.,Addis Ababa Institute of Technology |
Mihret A.,Armauer Hansen Research Institute AHRI |
Ameni G.,Addis Ababa Institute of Technology |
And 2 more authors.
Scandinavian Journal of Infectious Diseases | Year: 2013
Background: Extrapulmonary tuberculosis (EPTB) constitutes about 10% to 20% of all cases of tuberculosis in immunocompetent patients and more than 50% of the cases in HIV-positive individuals worldwide. Little information is available on the clonal diversity of Mycobacterium species in Ethiopia from EPTB. Methods: This study was carried out on smear-negative EPTB patients to molecularly characterize Mycobacterium tuberculosis complex strains. A questionnaire, smear staining, culture, deletion typing, and spoligotyping were employed. Results: The proportional distribution of EPTB and isolates did not vary substantially (p > 0.05) amongst the socio-demographic parameters considered in the current investigation. Out of 98 fine needle aspirates processed for culture, 36.7% (36/98) were positive for mycobacterial growth. Further speciation of those culture-positive isolates showed that 88.9% were M. tuberculosis and the remaining could be non-tuberculous mycobacterial species. Spoligotyping revealed 16 clusters out of which 2 were new to the SITVIT database. The most dominant spoligotypes were SIT54, SIT53, and SIT149 in decreasing order. SIT54, SIT134, SIT173, SIT345, SIT357, SIT926, SIT91088, and SIT1580 were reported for the first time in Ethiopia. The family with the highest frequency identified was M. tuberculosis family T1, followed by family 33. Most of the strains belonged to Euro-American (61.4%) and Indo-Oceanic (36.3%) lineages. Conclusions: The present study shows the importance of M. tuberculosis as a major cause of EPTB in the study area. Moreover, the majority of isolates of M. tuberculosis were found in clusters, suggesting the possibility of the existence of recent transmission. This warrants strengthening of the control programs for EPTB in the study area. © 2013 Informa Healthcare.
Ashenafi S.,Karolinska University Hospital |
Ashenafi S.,Addis Ababa Institute of Technology |
Aderaye G.,Addis Ababa Institute of Technology |
Bekele A.,Addis Ababa Institute of Technology |
And 11 more authors.
Clinical Immunology | Year: 2014
In this study, we explored the local cytokine/chemokine profiles in patients with active pulmonary or pleural tuberculosis (TB) using multiplex protein analysis of bronchoalveolar lavage and pleural fluid samples. Despite increased pro-inflammation compared to the uninfected controls; there was no up-regulation of IFN-γ or the T cell chemoattractant CCL5 in the lung of patients with pulmonary TB. Instead, elevated levels of IL-4 and CCL4 were associated with high mycobacteria-specific IgG titres as well as SOCS3 (suppressors of cytokine signaling) mRNA and progression of moderate-to-severe disease. Contrary, IL-4, CCL4 and SOCS3 remained low in patients with extrapulmonary pleural TB, while IFN-γ, CCL5 and SOCS1 were up-regulated. Both SOCS molecules were induced in human macrophages infected with Mycobacterium tuberculosis in vitro. The Th2 immune response signature found in patients with progressive pulmonary TB could result from inappropriate cytokine/chemokine responses and excessive SOCS3 expression that may represent potential targets for clinical TB management. © 2014.
Gebreegziabiher D.,Armauer Hansen Research Institute AHRI |
Gebreegziabiher D.,Addis Ababa Institute of Technology |
Gebreegziabiher D.,Mekelle University |
Desta K.,Addis Ababa Institute of Technology |
And 4 more authors.
PLoS ONE | Year: 2014
Background: M. tuberculosis and helminth infection each affects one third of the world population. Helminth infections down regulate cell mediated immune responses and this may contribute to lower efficacy of BCG vaccination and higher prevalence of tuberculosis. Objective: To determine the effect of maternal helminth infection on maternal and neonatal immune function and immunity to TB. Methods: In this cross sectional study, eighty five pregnant women were screened for parasitic and latent TB infections using Kato-Katz and QFT-GIT tests, respectively. IFN-γ and IL-4 ELISpot on Cord blood Mononuclear Cells, and total IgE and TB specific IgG ELISA on cord blood plasma was performed to investigate the possible effect of maternal helminth and/or latent TB co-infection on maternal and neonatal immune function and immunity to TB. Result: The prevalence of helminth infections in pregnant women was 27% (n = 23), with Schistosoma mansoni the most common helminth species observed (20% of women were infected). Among the total of 85 study participants 25.8% were QFT-GIT positive and 17% had an indeterminate result. The mean total IgE value of cord blood was significantly higher in helminth positive than negative women (0.76 vs 0.47, p = 0.042). Cross placental transfer of TB specific IgG was significantly higher in helminth positive (21.9±7.9) than negative (12.3±5.1), p = 0.002) Latent TB Infection positive participants. The IFN-γ response of CBMCs to ESAT-6/CFP-10 cocktail (50 vs 116, p = 0.018) and PPD (58 vs 123, p = 0.02) was significantly lower in helminth positive than negative participants. There was no significant difference in IL-4 response of CBMCs between helminth negative and positive participants. Conclusions: Maternal helminth infection had a significant association with the IFN-γ response of CBMCs, total IgE and cross placental transfer of TB specific IgG. Therefore, further studies should be conducted to determine the effect of these factors on neonatal immune response to BCG vaccination. © 2014 Gebreegziabiher et al.
Mariam S.H.,Armauer Hansen Research Institute AHRI |
Mariam S.H.,Addis Ababa Institute of Technology
BMC Research Notes | Year: 2014
Background: Mycobacterium tuberculosis and Mycobacterium bovis are the classic agents causing tuberculosis (TB) in humans and animals respectively. Transmission of tuberculous bacteria to humans usually occurs by inhalation of aerosols containing droplets of tubercle bacilli or via consumption of contaminated foods and drinks, primarily milk. The practice of milk pooling, including from cows with TB of the udder, further exacerbates the situation by rendering the whole milk supply infective. The simultaneous presence of indigenous lactic acid bacteria (LAB) in Mycobacterium-contaminated milk is believed to confer protective effect when the milk is adequately fermented. This study assessed the effect of LAB on the viability of mycobacteria in inherently contaminated pool of raw milk during fermentation as a function of time. Findings. Growth was obtained in the pooled raw milk culture, and identified to be M. tuberculosis. This M. tuberculosis growth was undetectable in the milk culture by day 7 as assessed by plating serial dilutions of the milk culture for up to 14 days. Conclusions: Some LAB species appear to show inhibitory effect on tubercle bacilli. If proven by more rigorous, controlled experimental results regarding such effect, selected LAB (with proven safety and efficacy) may have potential applications as anti-mycobacterial agents. © 2014 Mariam; licensee BioMed Central Ltd.
Misganaw A.C.,Armauer Hansen Research Institute AHRI |
Worku Y.A.,Addis Ababa Institute of Technology
BMC Public Health | Year: 2013
Background: Sexual violence is a major public health concern as well as human rights violation. Homeless women are far more likely to experience violence of all sorts than women in general. The objective of this study is to assess the prevalence and consequence of rape, and explore the reasons and factors associated with rape among street females in Bahir-Dar town, North West Ethiopia. Methods. This is a mixed method study which included: a survey of 395 street females age 15 - 49; key informant interview with 4 stakeholders; 5 case studies; one focus group of 10 street females and one focus group of 10 street males. Street females are those who spend most of their time on the street and who depend on the street for their life. Qualitative and quantitative data were assessed separately with thematic and statistical analysis respectively. Quantitative data was analyzed using SPSS version 16.0. Bivariate and Multivariate analysis were determined. Results: Life time prevalence of rape was 24.3% and the prevalence of rape in the last year was 11.4%. Factors like females "off" the street [OR (95% CI) =6.2 (3.0, 12.9)], being a prostitute [OR (95% CI) = 4.1 (1.5, 11.1)] and age 15-29 [OR (95% CI) =3.5 (1.1, 11.2)] were significantly associated with rape. Most, 93.8% of the rapes were not reported to legal bodies. None of the victims used condom during the rape event. Only, 4 (4.2%) of the victims used emergency contraceptive method following the rape event. Out of the total of 96 victims of rape, 13 (19.1%) and 9 (13.2%) experienced unwanted pregnancy and induced abortion respectively. Beside, 38 (41%) and 15 (22%) victims claimed genital injury and unusual vaginal discharge respectively. Psychological consequence like, hating others by 34 (35.8%), fear and concern for HIV/AIDS by 44 (46.6%), guilt feeling by 28 (29.4%) and loss of interest in sexual activity by 28 (29.4%) of victims were reported. Majority, 42.9% of victims attribute their victimization with sleeping in areas where there are many brothels. Being physically weak, long stay in street life, and sleeping around street males were reasons mentioned for rape by 11.9%, 29.7% and 15.4% of rape victims respectively. Conclusion: In general, there is a very high prevalence of rape exacting significant physical and psychological tolls in victims of the study. Therefore, timely and integrated actions of the various stakeholders working in this area are crucial to curtail this critical human rights violation. © 2013 Misganaw and Worku; licensee BioMed Central Ltd.
Ashenafi S.,Karolinska Institutet |
Ashenafi S.,Addis Ababa Institute of Technology |
Aderaye G.,Addis Ababa Institute of Technology |
Zewdie M.,Armauer Hansen Research Institute AHRI |
And 13 more authors.
Thorax | Year: 2013
Background: Diagnosis of active tuberculosis (TB) among sputum-negative cases, patients with HIV infection and extra-pulmonary TB is difficult. In this study, assessment of BCG-specific IgG-secreting peripheral plasmablasts, was used to identify active TB in these high-risk groups. Methods: Peripheral blood mononuclear cells were isolated from patients with TB and controls and cultured in vitro using an assay called Antibodies in Lymphocyte Supernatant, which measures spontaneous IgG antibody release from migratory plasmablasts. A BCG-specific ELISA and flow cytometry were used to quantify in vivo activated plasmablasts in blood samples from Ethiopian subjects who were HIV negative or HIV positive. Patients diagnosed with different clinical forms of sputum-negative active TB or other diseases (n=96) were compared with asymptomatic individuals including latent TB and non-TB controls (n=85). Immunodiagnosis of TB also included the tuberculin skin test and the interferon (IFN)-γ release assay, QuantiFERON. Results: This study demonstrated that circulating IgG+ plasmablasts and spontaneous secretion of BCG-specific IgG antibodies were significantly higher in patients with active TB compared with latent TB cases and non-TB controls. BCG-specific IgG titres were particularly high among patients coinfected with TB and HIV with CD4 T-cell counts <200 cells/ml who produced low levels of Mycobacterium tuberculosis-specific IFNγ in vitro. Conclusions: These results suggest that BCG-specific IgG-secreting peripheral plasmablasts could be successfully used as a host-specific biomarker to improve diagnosis of active TB, particularly in people who are HIV positive, and facilitate administration of effective treatment to patients. Elevated IgG responses were associated with impaired peripheral T-cell responses, including reduced T-cell numbers and low M tuberculosis-specific IFNγ production.
PubMed | Addis Ababa Institute of Technology and Armauer Hansen Research Institute AHRI
Type: | Journal: European journal of medical research | Year: 2016
Hepatitis, a highly contagious viral infection, is one of the leading killer diseases globally caused by hepatitis virus. Among the existing viral causes for hepatic failure, hepatitis B virus (HBV) plays a significant role with devastating implications, especially when combined with other viral infections such as human immunodeficiency virus (HIV). Co-infection with hepatitis B virus and HIV leads to increased morbidity and mortality as compared to independent HIV and HBV infections. In this study, we aimed to assess the seroprevalence of HBV and HIV coinfection and associated risk factors among pregnant women in a selected hospital facility around Addis Ababa, Ethiopia.A total of 215 pregnant women were recruited between July and October 2014 from Tirunesh Beijing General Hospital. A pretested and structured questionnaire was used to collect socio-demographic characteristics and possible risk factors. In addition, 5 ml venous blood was collected and centrifuged to estimate the seroprevalence of HBV and HIV. Descriptive statistics and logistic regression analysis were done and a P value less than 0.05 was considered statistically significant.The overall prevalence of hepatitis B virus infection was 13 (6%). This positivity was different across different age categories: 1 (11.1%), 3 (4.5%), 6 (6%), 1 (3.2%), and 2 (25%) among those between 15-19, 20-24, 25-29, 30-34, and 35-39 years, respectively. However, a statistically significant association was not established between age and HBV. Among the total, 9 (4.2%) of the positive cases were detected among primary school completed. Multivariate analyses indicated that history of abortion (p = 0.003), history of surgery (p = 0.0.022), and tattooing (p = 0.033) were significantly associated with HBV infection. A total of 9 (4.2%) women were found to be HIV seropositive, of whom 2 (22.2%) were co-infected with HBV.We observed a relatively higher seroprevalence of HBV infection among pregnant women in the study area, in which majority of the cases had underlying risk factors for acquiring the infection. Since none of the mothers were vaccinated for HBV, the possibility of perinatal transmission is inevitable. Hence, routine screening and immunization against HBV during pregnancy and health education are highly warranted to alleviate the situation.
PubMed | Biostatistics Unit, World Health Organization, University of Nigeria, Armauer Hansen Research Institute AHRI and 6 more.
Type: Journal Article | Journal: PloS one | Year: 2016
There are limited data on the performance of the use of fixed-dose combination (FDC) TB drugs when used under programmatic settings in high TB-endemic countries. We evaluated the efficacy and safety of FDC versus loose formulation (LF) TB treatment regimens for treatment of pulmonary TB (PTB) in the context of actual medical practice in prevailing conditions within programmatic settings in five sites in two high TB-burden African countries.A two-arm, single-blind, randomized clinical trial comparing FDCs with separate LFs involving 1000 adults newly diagnosed with culture positive PTB was conducted at five sites in two African countries between 2007 and 2011. Participants were randomized to receive daily treatment with anti-TB drugs given as either FDC or separate LFs for 24 weeks (intensive phase- 8 weeks of isoniazid, rifampicin, ethambutol and pyrazinamide; continuation phase- 16 weeks of rifampicin and isoniazid). Primary outcome measures were microbiological cure and safety at the end of six months treatment; pre-specified non-inferiority margin for difference in cure rate was 4%. The primary efficacy analysis was based on the modified intent to treat (mITT) cohort comprising all randomized patients with a positive baseline culture result for TB and who received at least one dose of study treatment. Patients missing end of treatment culture results were considered failures. Further analyses were done in which mITT patients without an end of treatment (EOT) culture were excluded in a complete case analysis (mITTcc) and a per protocol cohort analysis defined as mITTcc patients who received at least 95% of their intended doses and had an EOT culture result.In the mITT analysis, the cure rate in the FDC group was 86.7% (398/459) and in the LF group 85.2% (396/465) (difference 1.5-% (90% confidence interval (CI) (-2.2%- 5.3%)). Per Protocol analysis showed similar results: FDC 98.9% (359/363) versus LF 96.9% (345/356), (difference 2.0% (90% CI: 0.1%- 3.8%)). The two arms showed no significant differences in terms of safety, early culture conversion and patient adherence to treatment.The comparison of the two drug regimens satisfied the pre-specified non-inferiority criterion. Our results support the WHO recommendations for the use of FDC in the context of actual medical practice within health services in high TB-endemic countries.ISRCTN Registry 95204603.