Actinomycetes isolated from rhizosphere of wild Coffea arabica L. showed strong biocontrol activities against coffee wilt disease.

Coffee, the second most traded commodity globally after petroleum and is the most exported cash crop of Ethiopia. However, coffee cultivation faces challenges due to fungal diseases, resulting in significant yield losses. The primary fungal diseases affecting coffee production include coffee berry disease, wilt disease (caused by Gibberella xylarioides), and coffee leaf rust. In this study, we aimed to isolate potentially antagonistic actinomycetes from the root rhizosphere of wild Coffea arabica plants in the Yayo coffee forest biosphere in southwestern Ethiopia. Soil samples were collected from the rhizosphere, and actinomycetes were selectively isolated and identified to the genus level by morphological, physiological, and biochemical characterization. These pure isolates were screened for their antagonistic activity against Gibberella xylarioides in vitro using a dual culturing method. Promising isolates demonstrating strong inhibition of fungal mycelial growth were further investigated through in vivo experiments using coffee seedlings. A total of 82 rhizobacteria were isolated. These isolates' inhibition of fungal mycelial growth varied from 0% to 83.3%. Among them, four isolates MUA26, MUA13, MUA52, and MUA14 demonstrated the highest percentage inhibition of fungal mycelial growth: 83.3%, 80%, 76.67%, and 73.3%, respectively. Seedlings inoculated with MUA13, MUA14, and MUA26 during the challenge inoculations (Rhizobacteria + Gibberella xylarioides) exhibited the lowest disease incidence compared to the infected fungi (P < 0.05). Notably, the seedlings inoculated with MUA26 demonstrated the highest disease control efficiency, reaching 83% (P < 0.05). MUA26 was found to produce extracellular enzymes, including chitinase, protease, and lipase, which acted as inhibitors. In summary, this study highlights that MUA26, among the actinomycete isolates, exhibited significant antagonistic activity against Gibberella xylarioides f.sp. coffea. Its efficacy in controlling coffee wilt disease, both in vitro and in vivo, positions it as a potential bioinoculant for managing coffee wilt disease.

High prevalence of MRSA and VRSA among inpatients of Mettu Karl Referral Hospital, Southwest Ethiopia.

OBJECTIVE: To assess the prevalence of methicillin and vancomycin-resistant Staphylococcus aureus among patients admitted to Mettu Karl Referral Hospital. METHODS: A cross-sectional study was conducted to study the point prevalence of MRSA and VRSA. A total of 384 patients (male = 201 and female = 183) admitted to medical (109), paediatric (109) and surgical (166) wards of Mettu Karl Referral Hospital from November 2019 to April 2020 were included in the study. We studied 384 samples (166 wound swabs and 218 nasal swabs) collected from inpatients. Staphylococcus aureus was isolated, characterised and identified based on morphological and biochemical features and confirmed by PCR amplification of the nuc gene. The isolates were checked against 12 antibiotics, and MRSA isolates were primarily identified using cefoxitin (30 µg) and confirmed by amplification of mecA gene. Staphylococcus aureus resistance to Vancomycin was tested by the broth microdilution method. RESULTS: The rate of isolation of Staphylococcus aureus was 32.8% (126/384). The point prevalence of MRSA and VRSA from clinical specimens was 18.8% (72/384) and 2.6% (10/384), respectively. Of 126 Staphylococcus aureus isolated, 57.1% (72) were MRSA and 7.9% (10) were VRSA. Of the 166 samples collected from patients in the surgical ward, the rates of isolation of MRSA and VRSA were 21.1% (35/166) and 4.8% (8/166), respectively. A high rate of isolation of MRSA and VRSA was recorded among patients admitted to surgical wards compared with medical and paediatric wards. CONCLUSIONS: This study showed a high prevalence of MRSA and VRSA in the hospital. Proper implementation of infection control practices and investigation of underlying risk factors are urgently needed to mitigate the further spread of the pathogen.

Bacillus species (BT42) isolated from Coffea arabica L. rhizosphere antagonizes Colletotrichum gloeosporioides and Fusarium oxysporum and also exhibits multiple plant growth promoting activity.

BACKGROUND: Colletotrichum and Fusarium species are among pathogenic fungi widely affecting Coffea arabica L., resulting in major yield loss. In the present study, we aimed to isolate bacteria from root rhizosphere of the same plant that is capable of antagonizing Colletotrichum gloeosporioides and Fusarium oxysporum as well as promotes plant growth. RESULTS: A total of 42 Bacillus species were isolated, one of the isolates named BT42 showed maximum radial mycelial growth inhibition against Colletotrichum gloeosporioides (78%) and Fusarium oxysporum (86%). BT42 increased germination of Coffee arabica L. seeds by 38.89%, decreased disease incidence due to infection of Colletotrichum gloeosporioides to 2.77% and due to infection of Fusarium oxysporum to 0 (p < 0.001). The isolate BT42 showed multiple growth-promoting traits. The isolate showed maximum similarity with Bacillus amyloliquefaciens. CONCLUSION: Bacillus species (BT42), isolated in the present work was found to be capable of antagonizing the pathogenic effects of Colletotrichum gloeosporioides and Fusarium oxysporum. The mechanism of action of inhibition of the pathogenic fungi found to be synergistic effects of secondary metabolites, lytic enzymes, and siderophores. The major inhibitory secondary metabolite identified as harmine (ß-carboline alkaloids).

Prevalence and antibiotic susceptibility pattern of methicillin-resistant Staphylococcus aureus (MRSA) among primary school children and prisoners in Jimma Town, Southwest Ethiopia.

BACKGROUND: Staphylococcus aureus infections are increasingly reported from both health institutions and communities around the world. In particular, infections due to methicillin-resistant Staphylococcus aureus (MRSA) strains have been detected worldwide. If MRSA becomes the most common form of S. aureus in a community, it makes the treatment of common infections much more difficult. But, report on the current status of community acquired MRSA in the study area is scanty. METHODS: Community-based cross sectional study was conducted to evaluate the current prevalence and antibiotic susceptibility pattern of MRSA among primary school children and prisoners in Jimma town. MRSA was detected using Cefoxitin (30µg) disc; and epidemiologic risk factors were assessed using pre-designed questionnaires distributed to the children's parents and prisoners. A total of 354 nasal swabs were collected from primary school children and prisoners from December 2010 to March 2011 following standards microbiological methods. RESULTS: A total of 169 S. aureus isolates were recovered. The overall prevalence of MRSA among the study population was 23.08 % (39/169). Specifically, the prevalence of MRSA among primary school children and prisoners were 18.8% (27/144) and 48% (12/25), respectively. The isolated S. aureus and MRSA displayed multiple drug resistance (MDR) to 2 to 10 antibiotics. The most frequent MDR was Amp/Bac/Ery/Pen/Fox (resistance to Ampicillin, Bacitracin, Erythromycin, Penicillin, and Cefoxitin). CONCLUSION: The present study revealed that MRSA could be prevalent in the healthy community, transmitted from hospital to the community. The high distribution of MRSA could be favored by potential risk factors. Thus, for comprehensive evaluation of the current prevalence of MRSA and design control measures, consideration need to be given to the healthy community besides data coming from health institutions.