ISSN 2736-1756
Research Article
Advanced Journal of Microbiology Research ISSN 2241-9837 Vol. 12 (4), pp. 001-008, April, 2018. © International Scholars Journals
Full Length Research Paper
In vitro activities of three kinds of antibiotics against Staphylococcal biofilm and planktonic cultures
T. El-Banna1, A. Abd El-Aziz1, A. Abo-Kamar1, A. Ghazal2 and R. AboZahra3*
1Microbiology Department, Faculty of Pharmacy, Tanta University, Tanta, Egypt.
2Microbiology Department, Medical Research Institute, Alexandria University, Alexandria, Egypt.
3Microbiology Department, Faculty of Pharmacy, Pharos University, Alexandria, Egypt.
Accepted 16 January, 2018
Abstract
The aim of the present study is to determine the activities of three kinds of antibiotics against Staphylococcal biofilm and planktonic cultures in vitro, and to indicate the enhancement of biofilm formation in response to stress factors such as glucose and sub-inhibitory concentrations of antibiotics by using scanning electron microscope. Biofilm forming staphylococci were identified by using the modified microtiter plate method. And the effect of different concentrations of several antibiotics (including ciprofloxacin, gentamycin and amoxicillin-clavulanic acid) on eight isolates was determined. The result showed that out of 86 Staphylococcal isolates, eight strains were found to be strong biofilm forming. Sub-MIC of the antimicrobial agents used increased the biofilm formation in some isolates. However, the preformed biofilm was very difficult to remove with most isolates even with multiples of the MIC. The biofilm MBC reached 46 times the planktonic MBC in some isolates. Scanning electron micrographs of staphylococcus aureus isolate (45S) were made in order to confirm the enhanced biofilm formation in the presence of glucose and sub-MIC of ciprofloxacin and it was found that the slime layer production increases in the presence of glucose and low concentration of ciprofloxacin.
Key words: Staphylococcal biofilms, scanning electron micrograph, antimicrobial sub-MIC activity.
A. Ghazal and R. AboZahra*, T. El-Banna, A. Abo-Kamar, A. Abd El-Aziz
Page: 1 - 8
Research Article
Advanced Journal of Microbiology Research ISSN 2241-9837 Vol. 12 (4), pp. 001-006, April, 2018. © International Scholars Journals
Full Length Research Paper
Investigation of in vitro effects of daptomycin, tigecycline and teicoplanin combinations against MRSA, VISA and VRE strains
Ahmet Yilmaz Coban1*, Aydin Deveci2, Ozlem Acicbe2, Nuriye Tasdelen Fisgin2, Alper Ciftci3, Basak Dokuzoguz4 and Belma Durupinar1
1Ondokuz Mayis University, Medical School, Department of Medical Microbiology, Samsun, Turkey.
2Ondokuz Mayis University, Medical School, Department of Clinical Microbiology and Infectious Diseases, Samsun, Turkey.
3Ondokuz Mayis University, Faculty of Veterinary Medicine, Samsun, Turkey.
4Ankara Numune Education and Research Hospital, the First Infectious Diseases and Clinical Microbiology Clinic, Ankara, Turkey.
Accepted 04 January, 2018
Abstract
Multidrug resistant (MDR) gram positive infectious agents can cause severe infections and monotherapy of these infections by current available antimicrobial agents can be problematic. Therefore, antimicrobial combination therapy may be needed for effective treatment. The study aimed to investigate in vitro effects of binary combinations of tigecycline (TGC), daptomycin (DPC) and teicoplanin (TP) against 4 methicillin resistant Staphylococcus aureus (MRSA), 2 vancomycin intermediate S. aureus (VISA) and 9 vancomycin resistant enterococci (VRE) species by E test method. Whilst, all binary combination of TGC, DPC and TP showed synergistic effect against standard strain of S. aureus and 50% of clinical MRSA isolates, all of the combinations except DPC-TP combination showed additive effect against VISA strains (Mu 3 and Mu 50). TGC-TP, DPC-TP and TGC-DPC combinations showed additive effect against 25, 60 and 50% of clinical VRE isolates, respectively. Synergistic effect was observed in combinations of TGC-TP and DPC-TGC against 2 and 1 VRE clinical isolates, respectively. Combinations of TP with any of TGC and DPC brought MIC values of TP below the level of sensitivity in all of TP resistant VRE and VISA isolates. Antagonistic effect was not observed in combinations of tested drugs against any strains. In conclusion, in vitro effectiveness of these drug combinations may reflect advantages in clinical practice for severe MDR gram positive bacterial infections.
Key words: Multidrug resistant, antimicrobial agents, methicillin resistant Staphylococcus aureus, infectious agents, vancomycin resistant enterococci.
Basak Dokuzoguz and Belma Durupinar, Alper Ciftci, Nuriye Tasdelen Fisgin, Ozlem Acicbe, Aydin Deveci, Ahmet Yilmaz Coban*
Page: 1 - 6
Research Article
Advanced Journal of Microbiology Research ISSN 2241-9837 Vol. 12 (4), pp. 001-004, April, 2018. © International Scholars Journals
Full Length Research Paper
A binding of ECM proteins - collagen, fibronectin, albumin and vitronectin by Bacteriocinogennic enterococci isolated from chicken and rabbits
Igor Štyriak2*, Viola Strompfová1, Iveta Štyriaková2, Monika Simonová1 and Andrea Lauková1
1Institute of Animal Physiology, Slovak Academy of Sciences, Košice, Slovakia.
2Institute of Geotechnics, Slovak Academy of Sciences, Košice, Slovakia.
Accepted 09 February, 2018
Abstract
Ten Bacteriocinogennic enterococci, isolates from chicken and rabbits, were examined for their binding of collagen, fibronectin, albumin and vitronectin in tubes with Nutrient broth No.2. For ECM binding examination, enterococci were grown in MRS broth under normal air conditions at 37°C. Individual strains expressed binding of selected glycoproteins to various degrees, however, vitronectin was bound the best from these four ECM proteins. These observations lead to suggestion that at least one mode of enterococcal attachment utilizes glycosaminoglycan chains present on the surface of adherent cells. Significance and impact of the study is that some animal strains are comparable with the commercially used strains with respect to their ECM ability. As this feature is important for probiotic bacteria to be able to colonize intestine, these strains could be considered for their wider use in fermented feed for animals.
Key words: Enterococcus, extracellular matrix, collagen, fibronectin, albumin and vitronectin.
Monika Simonová and Andrea Lauková, Viola Strompfová, Igor Štyriak*, Iveta Štyriaková
Page: 1 - 4
Research Article
Advanced Journal of Microbiology Research ISSN 2241-9837 Vol. 12 (4), pp. 001-008, April, 2018. © International Scholars Journals
Full Length Research Paper
Determination of the ability of microorganisms isolated from mechanic soil to utilise lubricating oil as carbon source
A. Sebiomo1*, S. A. Bankole2 and A. O. Awosanya1
1Department of Biological Sciences, Tai Solarin University of Education, Ijagun, Ijebu-Ode, Ogun State, Nigeria.
2Department of Microbiology, Olabisi Onabanjo University, Ago-Iwoye, Ogun State, Nigeria.
Accepted 11 January, 2018
Abstract
Ten bacteria and five fungi capable of utilising lubricating oil as carbon source were isolated from mechanic soil. The growth profiles were determined by monitoring the optical density, total viable counts, dry weights and pH of the culture utilizing lubricating oil as sole carbon and energy source. The total viable counts increased significantly with optical density and dry weights of fungi as the days of incubation progressed until the 14th day (P < 0.001). There was significant decrease in pH (P < 0.001) as fungal cells metabolised lubricating oil, Pseudomonas aeruginosa produced the highest optical density and viable count values of 0.441 and 8.31 to the end of 14th day of incubation among all bacterial isolates used in this study. P. aeruginosa also presented lowest pH value of 6.53 after 14 days of incubation between all bacterial isolates. Bacillus licheniformis and Enterobacter aerogenes recorded the lowest optical density and viable count values of 0.19 and 8.1 of all bacterial isolates after 14th day of incubation, Enterobacter aerogenes had the highest pH value of 6.8. Of all the fungal isolates used in this study Aspergillus niger and Aspergillus terreus recorded the highest dry weight and viable count values of 19.3 and 6.41. Trichoderma sp. had the lowest pH, dry weight and viable count values of 5.1, 17 and 6.3, respectively, Aspergillus flavus had the highest pH of 5.6. Correlation analysis indicated negative correlation between optical density and pH (correlation coefficient = +0.174) and between viable counts and pH (correlation coefficient = +0.159), there was positive correlation between viable counts and optical density (correlation coefficient = 0.735). For the fungal isolates there was negative correlation between dry weights and pH (correlation coefficient = +0.958) and between viable counts and pH (correlation coefficient = -0.830). The correlation analysis between fungal dry weights and viable counts showed positive correlation (0.786). The utilization of hydrocarbon in lubricating oil resulted in gradual reduction in the oil layer and complete disappearance of the oil with prolonged incubation. This study has shown that the microorganisms isolated from mechanic soils have potential application in the bioremediation of sites polluted with lubricating oil.
Key words: Bacteria, fungi, lubricating oil, biodegradation.
S. A. Bankole and A. O. Awosanya, A. Sebiomo*
Page: 1 - 8
Research Article
Advanced Journal of Microbiology Research ISSN 2241-9837 Vol. 12 (4), pp. 001-006, April, 2018. © International Scholars Journals
Full Length Research Paper
Isolating endophytic fungi from evergreen plants and determining their antifungal activities
Changhong Liu1*, Tingting Liu1, Fengfeng Yuan1 and Yucheng Gu2
1State Key Laboratory of Pharmaceutical Biotechnology, School of Life Science, Nanjing University, Nanjing 210093, China.
2Syngenta, Jealott’s Hill International Research Centre, Bracknell, Berkshire, UK.
Accepted 17 January, 2018
Abstract
A total of 262 strains of endophytic fungi were isolated from 23 evergreen plant species collected from Zijin Mountain in Nanjing, China. Two-hundred and three of the fungi isolates were classified into 23 taxa in 19 genera based on colony morphology and microscopic observation of mycelia and asexual/sexual spores. The highest richness was obtained from Cedrus deodara (28), while the highest diversity of identified species (6) was isolated from Sabina procumbens. Some fungi appeared to be host-specific, such as Botrytis ricini lt300, Geotrichum candidum lt274 and Lacellina graminicola lt256, while other strains (e.g. Alternaria alternata lt222, Anthina sp. Lt147, Colletotrichum gloeosporioids lt305 and Fusarium solani lt293) were commonly isolated from a range of plants. The richness of the endophytic fungi recovered from plant branches was significantly higher than those from leaves. Moreover, about 70% of the obtained endophytic fungi could produce antifungal metabolites against at least one plant pathogenic fungi. The EtOAc extracts of seven species of Anthina sp. lt147, C. gloeosporioids lt305, Ectostroma sp. Lt144, Fusarium decemcellulare lt183, Fusarium oxysporum lt173, Paraconiothyrium brasiliense lt161 and C. montemartinii lt198 showed broad inhibition against the growth of all the six phytopathogens with the inhibition rates from 20 to 80%. These results indicated that endophytic fungi may play an important role in protection of the evergreen plants from disease as well as an excellent resource for searching for natural antifungal compounds.
Key words: Endophytic fungi, evergreen plants, antifungal activity.
Fengfeng Yuan and Yucheng Gu, Tingting Liu, Changhong Liu*
Page: 1 - 6
Research Article
Advanced Journal of Microbiology Research ISSN 2241-9837 Vol. 12 (4), pp. 001-008, April, 2018. © International Scholars Journals
Full Length Research Paper
Microbial morphology and community structure in a suspended carrier biofilm reactor as a function of substrate loading rates
Fu Bo1, 2, Liao Xiaoyi1, Ding Lili1, Xu Ke1 and Ren Hongqiang1*
1State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210093, Jiangsu, China.
2Laboratory of Environmental Biotechnology, School of Environmental and Civil Engineering, Jiangnan University, Wuxi 214122, Jiangsu, China.
Accepted 13 January, 2018
Abstract
An aerobic suspended carrier biofilm reactor was efficient in simultaneous organic carbon and nitrogen removal, with COD removal efficiencies of 87.1–99.0% and simultaneous nitrification and denitrification (SND) efficiencies about 96.7-98.8%. The effects of substrate loading on microbial morphology and community structure were investigated by environmental scanning electron microscopy (ESEM), denaturing gel gradient electrophoresis (DGGE) and fluorescence in situ hybridization (FISH). Biofilms formed at different substrate loadings had different morphology and community structures. A higher substrate concentration resulted in denser and thinner biofilms, while a lower substrate concentration resulted in looser and thicker biofilms with significant presence of filamentous bacteria. Both sequence analysis of DGGE bands and FISH analysis indicated the dominance of β-Proteobacteria in the biofilm communities, especially Zoogloea. FISH analysis revealed that the relative abundance of β-proteobacteria ammonia oxidizing bacteria (AOB) was positively correlated with ammonium concentrations, whereas Nitrospira-like nitrite-oxidizing bacteria (NOB) were negatively affected by ammonia and nitrite concentrations. The presence of denitrifying bacteria, Hydrogenophaga spp., Hyphomicrobium spp. and Rhizobium spp. suggested that not only the oxygen microgradients within the biofilm but also aerobic denitrifiers may be responsible for SND in the aerobic biofilm.
Key words: Microbial community structure, microbial morphology, substrate loading, suspended carrier biofilm.
Xu Ke and Ren Hongqiang*, Fu Bo, Ding Lili, Liao Xiaoyi
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