Taking into consideration the needs of greener bioprocesses and novel enhancers for synthesis using microbial processes, biosurfactants, and/or biosurfactant producing microbes are emerging as an alternate source for the rapid synthesis of nanoparticles. A microemulsion technique using an oil-water-surfactant mixture was shown to be a promising approach for nanoparticle synthesis. Biosurfactants are natural surfactants derived from microbial origin composed mostly of sugar and fatty acid moieties, they have higher biodegradability, lower toxicity, and excellent biological activities. The biosurfactant mediated process and microbial synthesis of nanoparticles are now emerging as clean, nontoxic, and environmentally acceptable “green chemistry’’ procedures. The biosurfactant-mediated synthesis is superior to the methods of bacterial- or fungal-mediated nanoparticle synthesis, since biosurfactants reduce the formation of aggregates due to the electrostatic forces of attraction and facilitate a uniform morphology of the nanoparticles. In this review, we highlight the biosurfactant mediated synthesis of nanoparticles with relevant details including a greener bioprocess, sources of biosurfactants, and biological synthesized nanoparticles based on the available literature and laboratory findings.

The prevalence of methicillin-resistant Staphylococcus aureus (MRSA) is slowly rising in Ethiopia for the past few decades. Therefore, novel classes of antibiotics are indispensable to combat the increased incidence of newly emerging multidrug-resistant bacteria like MRSA. Terrestrial flora is considered as a reservoir of novel bioactive secondary metabolites as they have provided us with the largest array of natural products. In this background, the present study is intended to evaluate the in-vitro antibacterial efficacy of five medicinal plants (Ocimum lamiifolium Hochst. ex Benth., Rosmarinus officinalis L, Catharanthus roseus Linn., Azadirachta indica A. Juss and Moringa stenopetala Bac) against a panel of seven biofilm-forming MRSA. The leaves of the plants were extracted in organic solvents of varying polarity and the resultant crude extracts of respective medicinal plants were inspected for their antimicrobial activity by well diffusion technique. Minimum inhibitory concentrations (MIC) and minimum bactericidal concentrations (MBC) of the plant extracts against MRSA were determined by the broth dilution method. Besides, an anti-biofilm assay of the most potent plant extract was also performed, after which its chemical constituents were delineated by combined Gas Chromatographic and Mass Spectroscopic profiling (GC-MS). The results revealed that, of the five plants, three species including M. stenopetala, R. officinalis, and O. lamifolium exhibited significant antibacterial activity. Organic solvents with high and medium polarity were excellent in extracting antimicrobials compared to nonpolar solvents. The broadest and highest rank of activity was observed in the crude ethanolic extract of M. stenopetala. Based on the MIC/MBC ratio, the crude ethanolic extract of M. stenopetala was determined to be bacteriostatic. Anti-biofilm assay showed that the extract of M. stenopetala fairly inhibited the growth of MRSA in the preformed biofilm matrix. The GC-MS analysis of M. stenopetala revealed the presence of twelve compounds with antimicrobial activity. The present study provides new insight into the development of novel drug leads to the management of MRSA.

Background. In developing countries, the prevalence of bacterial infections is quite rampant due to several factors such as the HIV/AIDS pandemic, lack of hygiene, overcrowding, and resistance to conventional antimicrobials. Hence the use of plant-based antimicrobial agents could provide a low-cost alternative therapy. Rosmarinus officinalis is reputed as a medicinal plant in Ethiopia; however, its antibacterial activity against many of the clinical isolates remains overlooked. Methods. Tender foliage of R. officinalis was collected and extracted in ethanol (EtOH) and evaluated for their antimicrobial activity against ten multidrug-resistant (MDR) clinical isolates, human type culture pathogens, and meat-borne bacterial isolates by employing agar well diffusion assay. Results. EtOH extract of R. officinalis efficiently subdued the growth of all tested MDR clinical isolates in varying degrees. Salmonella sp. and Staphylococcus aureus were found to be the most sensitive clinical isolates. Likewise, it efficiently repressed the growth of meat-borne pathogens, particularly, S. aureus and Salmonella sp. showing its potentiality to be used as a natural antibacterial agent in the meat processing industry. The mechanism of antibiosis of plant extract against meat-borne pathogens is inferred to be bactericidal. Chemical constituents of the crude plant extract were analysed by Gas Chromatography-Mass Spectroscopy (GC-MS), Fourier Transform Infrared (FT-IR), and UV-visible spectroscopy showing genkwanin (26), camphor (13), endo-borneol (13), alpha-terpineol (12), and hydroxyhydrocaffeic acid (13) as the major compounds. Conclusion. Overall results of the present study conclude that R. officinalis could be an excellent source of antimicrobial agents for the management of drug-resistant bacteria as well as meat-borne pathogens.

Objective: Urinary tract infection (UTI) is a common and grave health problem in the world. In fact, patients with diabetes mellitus have an immense risk for developing UTI. The development of resistance among uropathogens to antibiotics is a major crisis which limits the use of drug of choice for the treatment of UTI. On this view point, the aim of the present study is to elucidate the prevalence of UTI, associated factors, causative agents and their antimicrobial susceptibility amongst diabetic patients attending Arba Minch Hospital, Arba Minch, Ethiopia. Material and methods: A facility based cross-sectional study was carried out in diabetic patients visiting the Internal Medicine Unit of Arba Minch Hospital (AMH) during the study period (March to May 2016). Pre-tested structured questionnaire was used for collecting the data pertaining to socio-demographic characteristics and possible risk factors. In order to quantify the uropathogens, midstream urine samples were collected in sterile leak proof culture bottles and streaked onto diverse bacteriological media. All the positive urine cultures showing significant bacteriuria as per the Kass count (>105 organisms/mL) were further subjected to biochemical tests. The antimicrobial susceptibility test was performed to determine the resistance/susceptibility pattern of isolated uropathogens. Data entry and analysis were done using Statistical Package for Social Services, version 20. Results: In total, 239 diabetic patients were included in the study of which 60.2% (n=144) were females. A total of 81 (33.8%) diabetic patients had positive urine cultures. Sixty-eight (83.9%) female diabetic patients had significant bacteriuria (p=0.000). Fifty-two (64.1%) participants had drinking habit and 79 (97.5%) of respondents had higher glucose levels (≥126 mg/dL) (p=0.004 and p=0.003), respectively. According to the biochemical tests, in a total of 90 isolates from patients with significant bacteriuria, eight species of uropathogens such as Escherichia coli, Klebsiella sp., Proteus sp., Citrobacter spp., Staphylococcus aureus, Coagulase negative Staphylococcus (CNS), Enterococcus faecalis and yeast isolates were identified. The antibiogram evidenced that 79.6% (n=51) of Gram-negative bacteria were invariably resistant to amoxicillin and penicillin whereas 73.4% (n=47) and 65.6 % (n=42) of them were resistant to trimethoprim, erythromycin and chloramphenicol, respectively. Regarding the Gram-positive bacteria, high degree of resistance was exhibited towards penicillin and trimethoprim (100%, n=24) followed by amoxicillin (83.3%, n=20) and gentamicin (62.5%, n=15). Invariably, all the Gram-positive cocci and Gram-negative bacilli were susceptible (100%) to amikacin, doxycycline, ceftriaxone and nitrofurantoin. Conclusion: The prevalence of UTI is higher in diabetic patients. Results revealed that the predominant pathogens of UTI were Gram-negative bacilli (Enterobacteriaceae), particularly E. coli. Significant bacteriuria had an association with the consumption of alcohol, gender and glucose level. Based on the results of antimicrobial susceptibility tests, it might be inferred that the antibiotics such as amikacin, doxycycline, ceftriaxone and nitrofurantoin are the drugs of choice for the management of both Gram-negative and Gram-positive uropathogenic bacteria in the study area. Cite this article as: Mama M, Manilal A, Gezmu T, Kidanewold A, Gosa F, Gebresilasie A. Prevalence and associated factors of urinary tract infections among diabetic patients in Arba Minch Hospital, Arba Minch province, South Ethiopia. Turk J Urol 2019; 45(1): 56-62.