Berhanu Andualem

Isolation and screening of antibiotic producing actinomycetes from soils in Gondar town, North West Ethiopia

Objective To isolate and screen antibiotic producing actinomycetes from potential soil samples of Gondar town, Ethiopia.

Combined antibacterial activity of stingless bee (Apis mellipodae) honey and garlic (Allium sativum) extracts against standard and clinical pathogenic bacteria

OBJECTIVE To investigate the synergic antibacterial activity of garlic and tazma honey against standard and clinical pathogenic bacteria. METHODS Antimicrobial activity of tazma honey, garlic and mixture of them against pathogenic bacteria were determined. Chloramphenicol and water were used as positive and negative controls, respectively. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration of antimicrobial samples were determined using standard methods. RESULTS Inhibition zone of mixture of garlic and tazma honey against all tested pathogens was significantly (P≤0.05) greater than garlic and tazma honey alone. The diameter zone of inhibition ranged from (18±1) to (35±1) mm for mixture of garlic and tazma honey, (12±1) to (20±1) mm for tazma honey and (14±1) to (22±1) mm for garlic as compared with (10±1) to (30±1) mm for chloramphenicol. The combination of garlic and tazma honey (30-35 mm) was more significantly (P≤0.05) effective against Salmonella (NCTC 8385), Staphylococcus aureus (ATCC 25923), Lyesria moncytogenes (ATCC 19116) and Streptococcus pneumonia (ATCC 63). Results also showed considerable antimicrobial activity of garlic and tazma honey. MIC of mixture of garlic and tazma honey at 6.25% against total test bacteria was 88.9%. MIC of mixture of garlic and tazma honey at 6.25% against Gram positive and negative were 100% and 83.33%, respectively. The bactericidal activities of garlic, tazma honey, and mixture of garlic and tazma honey against all pathogenic bacteria at 6.25% concentration were 66.6%, 55.6% and 55.6%, respectively. CONCLUSIONS This finding strongly supports the claim of the local community to use the combination of tazma honey and garlic for the treatment of different pathogenic bacterial infections. Therefore, garlic in combination with tazma honey can serve as an alternative natural antimicrobial drug for the treatment of pathogenic bacterial infections. Further in vivo study is recommended to come up with a comprehensive conclusion.

Serum Concentration of Selenium in Diarrheic Patients with and without HIV/AIDS in Gondar, Northwest Ethiopia

Background: Selenium deficiency is known to be a major public health problem, associated with increased risk of mortality with AIDS and AIDS-related complex, diarrhea included compared to those of healthy controls. In Ethiopia, there are no studies conducted on serum selenium status diarrheic patients with and without HIV infection. Therefore, the present study was aimed at determining the level of serum selenium in HIV infected and sex and aged matched HIV negative diarrheic patients.. Methods: This was a cross-sectional study of 206 (97 HIV seronegative and 109 HIV seropositive) diarrheic patients of both genders seen at University of Gondar Hospital, Gondar, Ethiopia. Serum selenium was measured by inductively coupled plasma-mass spectrometer. Results: The mean and standard deviation of serum selenium levels in HIV seropositives was 5.90 ± 2.78 μg/dl and in HIV seronegatives was 6.99 ± 4.26 μg/dl. Deficiency of selenium was seen in 95.9% and 71.56% of diarrheic patients with and without HIV co-infection, respectively. The over all selenium deficiency was observed in 83.0% of patients included in the study irrespective of their HIV serostatus while 85.3%of the patients infected with HIV and 80.4% of patients without HIV infection had serum selenium level below 7μg/dl. The low serum selenium level was not associated with presence or absence of intestinal parasites neither with sociodemographic variables such as age, residence, marital status, occupation, monthly income. The mean serum selenium level of all male cases was statistically significantly lower than that of the females (P<0.05). Conclusion: Our results show high prevalence of selenium deficiencies in HIV seropositive and seronegative diarrheic patients in Gondar, Ethiopia. Although this is a small group of study subjects, the findings may be used as a tool to suggest further in-depth prospective clinical trials to determine whether selenium supplements may be of public health benefit among HIV-infected populations as a stand-alone therapeutic approach and potentially as an adjuvant to antiretroviral therapy.

Production of microbial medium from defatted brebra (Milletia ferruginea) seed flour to substitute commercial peptone agar.

OBJECTIVE To investigate and optimize microbial media that substitute peptone agar using brebra seed defatted flour. METHODS Defatted process, inoculums preparation, evaluation of bacterial growth, preparation of cooked and hydrolyzed media and growth turbidity of tested bacteria were determined. RESULTS Two percent defatted flour was found to be suitable concentration for the growth of pathogenic bacteria: Escherichia coli (ATCC 25922) (E. coli), Pseudomonas aeruginosa (ATCC 27853), Salmonella (NCTC 8385) and Shigella flexneri (ATCC 12022) (S. flexneri), while 3% defatted flour was suitable for Staphylococcus aureus (ATCC 25923) (S. aureus). E. coli (93±1) and S. flexneri (524±1) colony count were significantly (P≤0.05) greater in defatted flour without supplement than in supplemented medium. E. coli [(3.72×10(9)±2) CFU/mL], S. aureus [(7.4×10(9)±2) CFU/mL], S. flexneri [(4.03×10(9)±2) CFU/mL] and Salmonella [(2.37×10(9)±1) CFU/mL] in non-hydrolyzed sample were statistically (P≤0.05) greater than hydrolyzed one and commercial peptone agar. Colony count of Salmonella [(4.55×10(9)±3) CFU/mL], S. flexneri [(5.40×10(9)±3) CFU/mL] and Lyesria moncytogenes (ATCC 19116) [(5.4×10(9)±3) CFU/mL] on raw defatted flour agar was significantly (P≤0.05) greater than cooked defatted flour and commercial peptone agar. Biomass of E. coli, S. aureus, Salmonella and Enterococcus faecalis in non-hydrolyzed defatted flour is highly increased over hydrolyzed defatted flour and commercial peptone broth. CONCLUSIONS The defatted flour agar was found to be better microbial media or comparable with peptone agar. The substances in it can serve as sources of carbon, nitrogen, vitamins and minerals that are essential to support the growth of microorganisms without any supplements. Currently, all supplements of peptone agar are very expensive in the market.

The Isolation Rate of Pseudomonas aeruginosa Opportunistic Pathogen and their Antimicrobial Responses in HIV-1 Positive and Negative Diarrhoea Patients at North-West Part of Ethiopia

Background: Pseudomonas aeruginosa is an opportunistic pathogen in immune-compromised patients. However, reports of infections of Pseudomonas aeruginosa were limited in patients infected with HIV. The aim of the study was to determine the frequency of isolation and sensitivity pattern of P. aeruginosa against the commonly used antibiotics in HIV-1 positive and negative diarrheic patients. Methods: Laboratory based cross-sectional study of 312 (199 HIV seropositive and 113 HIV seronegative) diarrheic patients of both genders were investigated at University of Gondar Hospital, Gondar, Ethiopia. P. aeruginosa isolates were isolated from diarrheic stool and identified as per standard methods and tested for antimicrobial susceptibility. Result: Pseudomonas aeruginosa was isolated from 29.5% (92/312) of diarrheic patients, of which 20.5% were from HIV positive subjects. Out of 58 H. zoster positive diarrhoea patients, 47 (81%) were HIV positive and 11 (19%) were HIV seronegative (P < 0.002). The proportion of patients with weight loss and P. aeruginosa infection was significantly higher in those with HIV co-infection (P < 0.05). Among P. aeruginosa isolates 96.4%, 78.6%, 73.2%, 71.4%, 68.8% and 62.5% were sensitive to polymyxin B, gentamycin, norfloxacin, kanamycin, ciprofloxacin and nalidixic acid, respectively. The highest resistance observed was against ampicillin (96.4%), tetracycline (92%), trimethoprim-sulphamethoxazole (89.3%) and chloramphenicol (74.1%). One hundred nine (97.3%) out of the 112 P. aeruginosa isolates were found to be multiple drug resistant. Conclusion: Though high proportion of P. aeruginosa strains were reported in HIV seropositive diarrheic patients, detailed investigation is important to get comprehensive information for better treatment of diarrhoea in HIV /AIDS patients. In this study, ampicillin, tetracycline, trimethoprim-sulphamethoxazole and chloramphenicol may not be used for the treatment of P. aeruginosa infection, unless culture and sensitivity tests are done prior to treatment. Effective public health measures such as prevention of infections through quality environmental sanitation and personal hygiene should be emphasized.