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Background: The Eucalyptus globulus extractions have been used by the traditional healers to treat diseases in the study area. Our previous study revealed that the essential oil has antimicrobial and antifungal activity. This study determined phytochemical analysis, skin irritation, acute and subacute toxicity of Eucalyptus globulus essential oil in mice and rats. Methods: The phytochemicals were analyzed using GC-MS mass spectrometry. The acute toxicity study was determined at three dose levels of 1500 mg/kg, 1750mg/kg, and 2000 mg/kg. The essential oil limit test at a dose of 1000 mg/kg was administered to mice for 28 consecutive days for sub-acute toxicity study. The mice mortality, behavioral change, injury and other signs of illness were recorded once daily. Biochemical parameters were evaluated. Liver and kidney were analyzed for histopathological analyses. The 5% ointment formulation was applied to the rat skin to determine skin irritation effects. Results: The Eucalyptus globulus essential oil showed no effect on the mice at a dose of 1500mg/kg and below, but caused signs of toxicity and death at a dose of 1750mg/kg and above compared to the controls (p0.05) in the body weights, gross abnormalities of the organs and biochemical parameters compared to the control at 1000 mg/kg subacute toxicity study. No histopathological changes were detected in the organs tested. The 5% ointment formulation did not show any abnormal skin reaction. Discussion: In the present study, the Eucalyptus globulus essential oil was comparable with other studies in terms of both chemical composition and its effects on sub-acute and topical application. Conclusion: This toxicity study demonstrated that Eucalyptus globulus essential oil is nontoxic at a relatively lower concentration.

BACKGROUND: Diarrheal disease is a major cause of mortality and morbidity for under-five children in Ethiopia. The purpose of this study was to investigate the behavioral and socioeconomic risk factors, etiology, and drug susceptibility of bacteria isolated from under-five children with acute diarrhea who were treated at Debre Berhan Referral Hospital or Health Center in Ethiopia.METHODS: A health facility based cross-sectional study design was used to investigate enteropathogens from 163 under-five children with acute diarrhea. After obtaining written consent from parents or guardians, data were collected using a standardized questionnaire. Freshly passed stool samples were collected for microbiological tests for bacteria and parasites. The chi-square test was used for assessing the relationships of variables.RESULTS: Enteropathogens were detected among 55.8% (91/163) participants. There was a 46%(75/163) bacterial culture positivity rate and a 9.8%(16/163) prevalence of parasites. The isolated enteropathogens were Escherchia coli, Klebsiella specie, Proteus species, Salmonella species, Shigella species, Enterobacter species, Giardia lamblia, Enteameba histolytica, Ascaris lumbricoides, Trichuris trichiura and Hymnoleps nana. Level of antimicrobial resistance of bacterial isolates ranged from 0 to 87.2%. Poor hand washing and poor cleaning of feeding utensils showed significant association with the presence of enteropathogens.CONCLUSION: Bacterial enteropathogens with drug resistance were observed in this study. Continuous health education and promotion about diarrheal disease for mothers/caretakers and regular surveillance of entropathogenes are recommended to reduce under-five mortality.

Lavandula angustifolia is used in traditional and folk medicines of Ankober District, North Central Ethiopia, for the treatment of several livestock and human disorders. This toxicity study aimed to investigate L. angustifolia essential oil oral toxicity in mice and skin irritation in rabbit. L. angustifolia essential oil was analyzed using gas chromatography-mass spectrometry methods and showed predominance of Eucalyptol (52.36%), Camphor (11.91%), gamma-terpinene (8.775%) and endoborneol (7.585%). Limit test at 2000 mg/kg dose was used for L. angustifolia essential oil acute toxicity test and revealed LD50 value was higher than 2000 mg/kg. For subacute toxicity study 2000mg/kg was given orally to each mouse for 21 days. The result demonstrated no significant changes (p > 0.05) in the body weights, and biochemical parameters, gross abnormalities, water, and food intake were observed. No macroscopic changes were seen in the histopathology analysis of kidneys and livers. For skin irritation test shaved rabbit skin was treated with 10% ointment formulation. Ointment of L. angustifolia oil did not affect mice skin. Generally, this toxicity study demonstrated that L. angustifolia essential oil is nontoxic.

Comparison of calculated culturable counts (CFUs), live and dead cell populations and VBNC cells from control cultures and co-cultures of L. monocytogenes (A) and S. Enteritidis (B). C = control cultures, E = co-cultures, CC = culturable count. Figure S1. Comparative colony sizes of L. monocytogenes plate cultures from Transwell control culture (A) and co-culture (B). (A) 1 µL of a 10–3 dilution plated, (B) 1 µL of a 10–1 dilution plated. (A) after 24 hrs of incubation of plated culture, (B) after 48 hrs of incubation of plated culture. Very similar patterns were observed for S. Enteritidis control culture and co-culture samples. Figure S2. Turbidity of fluid from upper and lower chambers of control cultures and co-cultures. Fluid was withdrawn from upper and lower chambers of L. monocytogenes (tubes 1-4) or S. Enteritidis (tubes 5-8) at the end of the experiments. Tubes 1 and 2: fluid from upper and lower chambers respectivey, of L. monocytogenes control culture. Tubes 3 and 4: fluid from upper and lower chambers respectivey, of L. monocytogenes co-culture. Tubes 5 and 6: fluid from upper and lower chambers respectivey, of S. Enteritidis control culture. Tubesd 7 and 8: fluid from upper and lower chambers respectivey, of S. Enteritidis co-culture. (DOCX 243 kb)

Background Among children diagnosed to have chronic rheumatic valvular heart disease (RHD) in Ethiopia, many have been observed to develop recurrence of rheumatic fever (RF) despite secondary prophylaxis. This study determined the throat culture positivity rate and drug susceptibility pattern of beta hemolytic streptococci (BHS) isolated from children attending a specialized cardiac clinic in Ethiopia. Methods Throat swabs were collected from 233 children receiving benzathine penicillin injection as secondary prophylaxis for RHD and cultured. The bacterial isolates were characterized using Matrix Assisted Laser Desorption/Ionization-Time of Flight (MALDI-TOF) mass spectrometry. Drug susceptibility was tested with the Kirby Bauer disc diffusion method. Anti-streptolysin O (ASO) titers were determined using ASO latex reagents. Results The throat culture positivity rate for BHS was 24 % (56/233). Among the BHS bacterial strains isolated, four were characterized as S. pyogenes and another four as S. dysgalactiae subsp. equisimilis (Lancefield group A, C and G). All BHS were susceptible to penicillin except one isolate of S. agalactiae. Among 233 children enrolled, 46(19.7 %) showed increased ASO titer. Children who received antibiotic prophylaxis within 2-weeks of last injection had significantly lower BHS throat culture positivity rate than those injected every 4-weeks (p = 0.02). Children who missed at least one prophylaxis within the last 6 months had a higher BHS culture positivity rate than those who did not miss any (p = 0.0003). Conclusions The presence of groups A, C and G streptococci in the throat of children under secondary prophylaxis for RHD and increased ASO titer suggests failure of the regimen. This calls for further investigation into the causes of inadequate prophylaxis (including bioavailability of drugs used, optimal duration and patient compliance) and intervention.

Introduction: Rheumatic heart disease (RHD) remain significant causes of cardiovascular disease and mortality in children particularly in the developing countries. This study aims to evaluate ASO titer in rheumatic heart disease patients who are on secondary prophylaxis. Methods: A cross sectional study method was employed to collect blood sample from RHD patients (children) who are on secondary prophylaxis at pediatric clinic of Debre Brehan referral hospital. The blood sample was collected, transported and processed based on standard operating procedures (SOPs) for ASO titer determination. And finally, the data was analyzed using SPSS version 21and P-value less than or equal to 0.05 was taken as statistically significant. Result: A total of 123 children on secondary prophylaxis for RHD; in the age range of 5-15 years are included. Of these, 65 (52.8) were male and 58 (47.2%) were female; 69 (56.1%) were from rural and 54 (43.9%) were from urban area. The highest frequency of participant 52 (42.3%) were in the age group of 9-12 years. Among participants 74 (60.2%) had history of pharyngitis. The result of ASO titer shows 78 (63.4%) were positive in antistreptolysin O slide agglutination test; 30 (24.4%) patients have 400IU/ml ASO titer, 19 (15.4%) patients have 600 IU/ml ASO titer, 17 (13.8%) patients have ASO titer 800 IU/ml and 12 (9.8%) patients have ASO titer >1000 IU/ml. Conclusion: This study suggest that in most children admitted with RHD have recent streptococcal infection as evident by raised ASO titer.

Anti-streptolysin O (ASO) titer assists for the diagnosis of Group A, Group C and Group G streptococcal infections and their sequele. Reference value of Anti-streptolysin O titer is not available for Ethiopian populations. This study determined the upper limit of normal reference value in apparently healthy children. Participants with a history of streptococal disease were excluded. A total of 127 blood samples were collected from 127 participants with age range of 5-15 years. Serum was used to determine Anti-Streptolysin O-titers. The average ASO Upper limits of Normal (ULN) titer for the total participants was 360 IU/ml with a median 200 IU/ml. The ASO ULN for both male and female children was 320 IU/ml with a median of 200IU/ml. The highest ASO ULN was observed for the age group of 9-12 years (400 IU/ml with median of 200 IU/ml) followed by 360 IU/ml for the age group 5-8 years and age group 13-15 years with a median of 200 IU/ml. This finding shows that ASO ULN are similar to those reported in countries with different climates and populations. Package inserts interpreting ASO titer > 400 IU/ml as recent streptococcal infection is applicable for Ethiopian population.

Background Food-borne infections cause huge economic and human life losses worldwide. The most common contaminants of foods include Listeria monocytogenes Salmonellae and Staphylococcus aureus. L. monocytogenes is most notorious due to its tolerance to common food preservation methods and the risks it poses, including higher fatality rates. Safer, more efficacious control methods are thus needed. Along with food-borne pathogens, lactic acid bacteria (LAB) can also be found in foods. Some LAB isolates inhibit pathogenic bacteria by various mechanisms, including by production of antimicrobial metabolites. Methods The potential of cell-free culture supernatants (CFS) derived from broth cultures of selected local LAB and yeast isolates, some of which were subjected to various treatments, were tested for inhibition of L. monocytogenes, Salmonella spp. and S. aureus in in vitro culture by incorporating various proportions of the CFSs into the growth medium concurrently with inoculation (co-cultures) or following limited proliferation after inoculation of the pathogens (delayed cultures). The effects of the CFSs on various growth parameters were assessed. Results CFS from the LAB isolates were strongly inhibitory when co-cultured. The inhibitory activities were stable following heat or protease treatment of the CFSs. Inhibitory activity was dependent primarily on active substance(s) secreted into the supernatant. In all co-cultures, CFS proportion-dependent progressive decrease in the number of colonies was observed and both growth rates and number of generations were reduced with significantly fewer numbers of colony forming units, whereas generation times were significantly increased compared to those of controls. Transfer from co-cultures to fresh broth showed inhibited cultures contained bacteria that can re-grow, indicating the presence of viable bacteria that are undetectable by culture. Growth rates in CFS-treated delayed cultures were also reduced to varying degrees with the number of colonies in some cultures being significantly less than the corresponding control values. CFSs were active against both Gram-positive and –negative bacteria. Conclusions Active metabolites produced and secreted by LAB into the growth medium were effective in inhibiting the tested pathogens. Early addition of the CFSs was necessary for significant inhibition to occur. Further studies will help make these findings applicable to food safety.

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. Electronic supplementary material The online version of this article (doi:10.1186/s12866-017-0944-3) contains supplementary material, which is available to authorized users.