Open Access Original Research Article

Silver Nanoparticles: Biosynthesis, Characterization and Application on Cotton Fabrics

Amr Fouda, Th. I. Shaheen

Microbiology Research Journal International, Page 1-14
DOI: 10.9734/MRJI/2017/32961

Aim: Silver nanoparticles are applied to textiles for their strong antimicrobial activity against human pathogenic bacteria which attached at clothes; improve the clinical dressing and potential uses in various medical applications. In the present study, the silver nanoparticles were synthesized by Aspergillus terreus A2-2, where the biomass filtrate of this strain was used for biosynthesis of silver nanoparticles (AgNPs). The latter is applied to cotton fabrics through pad-dry technique for rendering textiles antibacterial property toward Gram positive bacteria represented by Staphylococcus aureus ATCC 29213 and Bacillus subtilis NCTC 10400. Gram negative bacteria represented by Pseudomonas aeruginosa ATCC 9027 and Escherichia coli ATCC 8739.

Place and Duration of Study: This study was performed in collaboration between Botany & Microbiology Department, Faculty of Science, Al-azhar University and Textile Research Division, National Research Center, Dokki, Cairo, Giza, Egypt, from December 2015 until January 2017.

Materials and Methods: fungal isolate Aspergillus terreus A2-2 was isolated from soil sample collected from Helwan governorate, Egypt and used for extracellular biosynthesis of silver nanoparticles. The fungal isolate was identified by morphological characterization, and molecular identification (ITS). Physical factors such as incubation time, temperature and pH value effect on extracellular silver nanoparticles biosynthesis were assessed. Silver nanoparticles were characterized by UV-vis spectroscopy, TEM, XRD, FTIR, Zeta potential and Particle size analysis and SEM-EDX.

Results: The results depicted that, AgNPs were successfully biosynthesized using A. terreus as indicated from changing the color of medium biomass filtrate from pale yellow to dark brownish yellow. In addition, UV-Vis spectra of the formed AgNPs showed the characteristic surface plasmon resonance (SPR) absorption peak at 400 nm. Further, TEM analysis revealed that the biogenic AgNPs were found to be spherical in shape with size diameter average of 3-27 nm. The particle size of the obtained AgNPs was polydispersed mixture with diameter average of 35nm. Eventually, the treated cotton fabrics with AgNPs exhibited bacterial activity reduction with range of 87% and up to 95%, towards Gram positive bacteria represented by Staphylococcus aureus ATCC 29213 and Bacillus subtilis NCTC 10400, Gram negative bacteria represented by Pseudomonas aeruginosa ATCC 9027 and Escherichia coli ATCC 8739.

Open Access Original Research Article

Molecular Detection of Antibiotic Resistance of Helicobacter pylori from Gastric Biopsies in Abidjan (Côte d'Ivoire)

Diplo Tchépe Flore Bernadette, C. Gbonon Mbengue Valérie, Guessennd Nathalie, Yapo Adou Francis, Kakou N'gazoa Solange, Ouattara Aboulaye, Coulibaly N'golo David, Djaman Allico Joseph, Dosso Mireille

Microbiology Research Journal International, Page 1-7
DOI: 10.9734/MRJI/2017/32912

Aims: To determine the genes of resistance to amoxicillin, clarithromycin and metronidazole of Helicobacter pylori in gastric biopsies in Côte d'Ivoire.

Place and Duration: The study was performed at the department of gastroenterology of Cocody Hospital and University Center, at the laboratory of Bacteriology-Virology and at the molecular biology platform of Pasteur Institute of Côte d'Ivoire from August 2015 to December 2016.

Methodology: The rapid urease test was performed in endoscopy room and 98 positive biopsies were retained for the study. Gastric biopsies were collected and transported within a maximum of 4 hours. DNA extraction was followed by Polymerase Chain Reaction (PCR) amplification.

Results: The rdxA / frxA, 23S rRNA and pbp1 genes conferring resistance to metronidazole, clarithromycin and amoxicillin respectively were identified in 12.2% (12/98), 26.5% (26/98) and 58.2% (57/98). Cross-resistance genotypes to these three antibiotics were detected in 8.2% (8/98) of the samples.

Conclusion: These results show a high level of resistance of Helicobacter pylori to amoxicillin and presence of cross-resistance to the three commonly used antibiotics. These results support the need for an evaluation of Helicobacter pylori current therapeutic protocol in Côte d'Ivoire.

Open Access Original Research Article

Evaluation of Antimicrobial Potency and Phytochemical Screening of Persea americana Leaf Extracts against Selected Bacterial and Fungal Isolates of Clinical Importance

O. E. Ajayi, S. I. Awala, O. T. Olalekan, O. A. Alabi

Microbiology Research Journal International, Page 1-11
DOI: 10.9734/MRJI/2017/24508

Aim: The quest for novel bioactive from natural sources informed the evaluation of the antimicrobial alongside the phytochemical composition of leaf extracts of Persea americana obtained from Akure, Ondo State, Nigeria.

Study Design: This study assessed the prospective antimicrobial efficacy of Persia americana against selected clinically relevant bacteria and fungi.

Place and Duration of Study: The study was conducted between April and September, 2015 at the Microbiology Laboratory of the Federal University of Technology, Akure, Ondo State, Nigeria.

Methodology: Clinical isolates (Bacillus cereus, Bacillus subtilis, Pseudomonas aeruginosa, Salmonella typhi, Staphylococcus aureus, Shigella flexneri, Escherichia coli, Candida albicans) and typed cultures (Escherichia coli ATCC 35218, Pseudomonas aeruginosa ATCC 27853, Staphylococcus aureus ATCC 43300, Salmonella typhi ATCC 33489) were obtained from the Pathology and Clinical Laboratory of the Lagos State University Teaching Hospital, Lagos State, Nigeria while Aspergillus fumigatus, Aspergillus niger and Aspergillus flavus were obtained from the culture collection center of the Department of Microbiology, FUTA. The authenticity of the bacterial and fungal isolates were confirmed using standard procedures. Persea americana leaves were collected from a building opposite BTO hall Ilesha garage, Akure, Ondo State and identified at the Department of Crop, Soil and Pest Management, Federal University of Technology, Akure. Antimicrobial activities of the leaves extract were assessed on clinical and typed microbial cultures using standard microbiological procedures.

Results: The extracts displayed varying antimicrobial activities against all the test organisms with zones of inhibition ranging from 10.27 mm to 34.20 mm. The leaves extracts were effective against all the organisms; with the methanolic P. americana extract having the highest antibacterial activity (34.20 mm) while the acetone extract had the highest antifungal activity (12.60 mm). The phytochemical analysis revealed the presence of tannins, flavonoids, terpenoids, alkaloids and saponins.

Conclusion: This study supports the claims that P. americana leaves could be promising in the development of drugs to combat human diseases especially those of fungal and bacterial origin.

Open Access Original Research Article

Isolation, Characterization and Antibiotic Susceptibility of Mycoplasma hominis and Ureaplasma urealyticum from Infertile and Pregnant Women in Lagos, Nigeria

Eugene Ikeh, Mike Ebie, John Allanana, John Oluwle, Nneoma Idika

Microbiology Research Journal International, Page 1-7
DOI: 10.9734/MRJI/2017/33323

Background: Mycoplasma hominis and Ureaplasma urealyticum are potentially pathogenic agents, playing aetiologicroles in both genital infections and infertility. In human in-vitro fertilization systems, the presence of U. urealyticum in either semen or female genital tract results in a decline of pregnancy rate per embryo transfer as well as neonatal infections. M. hominis has been associated with bacterial vaginosis, pelvic inflammatory disease, postabortal fever, and a number of gynecological infections.

Aim: The aim of this study is to isolate, characterize and determine the antibiotic susceptibility of M. hominis and U. urealyticum isolates from infertile and pregnant women in Lagos, Nigeria.

Materials and Methods: The samples were collected from Obstetrics and Gynaecology clinics of Lagos University Teaching Hospital and 68 Nigerian Army reference hospital Yaba. A total of 270 specimens of urine and HVS were collected from 135 women attending the clinics for routine consultations. One hundred and eighty HVS and urine specimens were from 90 married infertile women attending the clinics as part of a work-up for fertility investigations after failing to conceive for at least one year of unprotected sexual intercourse. Ninety HVS and urine specimens were from 45 pregnant women attending the clinics for routine antenatal care. None of the subjects expressed any symptom of genitourinary tract infections. All the specimens were inoculated into Mycoplasma broth and subsequently Blood Agar plates, incubated appropriately and identified. Antibiotic susceptibility tests were carried out on the 52 isolates. Polymerase chain reaction (PCR) was used to detect the organisms in all the collected specimens.

Results: Of the 90 HVS specimens collected from infertile women, 9 (10.0%) were positive for M. hominis, while 21 (23.3%) were positive for U. urealyticum. For the pregnant women using HVS specimens, 6 (13.3%) were positive for M. hominis while 5 (11.1%) were positive for U. urealyticum. The first void urine specimens gave lower values in both the infertile and pregnant women. Prevalence of U. urealyticum was higher in infertile women than in pregnant women (p<0.05). The PCR technique gave higher values of 78.5% and 71.1% using HVS specimens for the infertile and pregnant women respectively for Mycoplasma/Urealyticum species. The antibiotic susceptibility test showed that all the isolates of M. hominis (n=18) were sensitive to Tetracycline (100%) and Ciprofloxacin (100%) while all the isolates of U. urealyticum (n=34) were sensitive to Tetracycline (100%) and Erythromycin (100%).

Conclusion: The significantly higher prevalence of U. urealyticum infection in infertile women (23.3%) compared to the lower prevalence in pregnant women (11.1%) may suggest that U. urealyticum can be incriminated in infertility. HVS specimen is preferred over urine specimens for the detection of Mycoplasma and Ureaplasma. Application of the PCR method, where affordable, is recommended for rapid and sensitive detection of Mycoplasma and Ureaplasma in HVS specimens. Tetracycline may be the antibiotic of choice, unless contraindicated, for the treatment of the infections, although the sample size was small.

Open Access Original Research Article

Radical Scavenging Capacity and Efficacy of Myristica fragrans (Nutmeg) Metabolites on Cladosporum herbarum of Food Origin

Simiat Olanike Jimoh, Olaoniye Habeebat Labo-Popoola, Kazeem Adelani Alabi

Microbiology Research Journal International, Page 1-8
DOI: 10.9734/MRJI/2017/31962

Aim: To determine radical scavenging capacity and efficacy of Myristica fragrans metabolites on fungi of food origin.

Study of Design: Pretreatment and processing of Myristica fragrans, solvent extraction technique, phytochemical screening, radical scavenging activity, total phenolic concentration assay, essential oil extraction and evaluation of antifungal activity.

Place and Duration of Study: Microbiology Unit, Department of Biological Sciences, College of Natural and Applied Sciences, Fountain University Osogbo, Osun State, Nigeria between October, 2015 and July, 2016.

Methodology: Crude extract of Myristica fragrans seed was obtained using organic solvent (distilled water, ethyl acetate and ethanol) with solvent extraction technique and preliminary phytoconstituents was determined. The essential oil was extracted by hydrodistillation technique and isolated with petroleum ether. Metabolites present in the essential oil were quantified using Gas Chromatography Flame Ionization Detection (GCFID). Antifungal activity of Myristica fragrans oil and crude extract were investigated using agar well diffusion method. Folin-Ciocalteu and 2,2, diphenyl picryl hydrazyl (DPPH) radical scavenging assays were employed to determine total phenolic content and antioxidant activity respectively.

Results: Preliminary phytochemical screening of Myristica fragrans seed revealed the existence of alkaloid, phenols, flavonoids, terpenes, saponins, glycosides, tannins, steroids and phenolic compounds. The percentage yield of Myristica fragrans oil extracted was 3.25%. Thirty-six metabolites were quantified in Myristica fragrans essential oil using GCFID among which are sabinene (26.58%), myristicin (13.55%), alpha-pinene (11.84%), terpinene-4-ol (9.35%), limonene (5.74%), safrole (5.40%), alpha-terpineol (4.51%), alpha-myrcena (3.82%), gama- terpinene (3.71%), alpha-terpinolene (3.19%), pinene-2-ol (1.84%), elimicin (1.27%) and isoeugenol (1.13%) respectively. Highest scavenging and antifungal activities were observed in ethyl acetate extract of Myristica fragrans compared to Beta-carotene and antifungal drug (Fluconazole) used as control at varying concentrations.

Conclusion: Presence of thirty-six different phytoconstituents (metabolites) in Myristica fragrans essential oil poses the potential of providing useful drugs for treating food-borne infection and reduction of oxidative stress in the body other than its general uses as spices and flavoring agent.