Aims: The focus of this study was to isolate and to identify strains with antibacterial activity followed by a partial characterization of their extracts. Study Design: Screening and identification of bacteria having an anti-mycobacterial effect from soil and water of different biotopes of Fez Morocco were performed and active substances responsible for the biological activity were partially characterized. Place and Duration of Study: The study was carried out at laboratory of Microbial Biotechnology, Department of Biology, Faculty of Sciences and Technical, University Sidi Mohamed Ben Abdellah, BP 2202, Road of Immouzer, Fez, Morocco, during the period from January 2011 to October 2011. Methodology: Samples of soil and water of different biotopes of Fez Morocco were explored to isolate compounds-producing microorganisms. The inhibitory spectrum of the isolated bacteria was evaluated against M. smegmatis, M. aurum, S. aureus, S. haemolyticus, B. subtilis, E. coli DH5α, P. aeruginosa and Erwinia chrysanthemi by using agar well diffusion test and/or a modified spot-on-lawn assay. Identification of strains was executed on the basis of Gram stain, biochemical characteristics and PCR followed by DNA sequencing of 16S ribosomal RNA gene. Crude extracts obtained after precipitation by ammonium sulfate were exposed to proteolytic enzymes (Pepsin and proteinase K) and to heat treatment at 100ºC (15 min), 80°C (30 min), 37ºC (3h) and 4ºC (1 month). The residual activity after every treatment was assessed by agar well diffusion method. Results: Six bacteria were isolated from different biotopes of Fez Morocco having an antibacterial effect against M. smegmatis,M. aurum, Gram-positive and Gram-negative bacteria. Based on biochemical characterization and 16S rDNA sequence analysis, it was revealed that the isolates belong to the genus Bacillus. The antibacterial activity of three of them was fully affected by proteases and heat treatment at 80ºC and 100ºC but it was stable at 4ºC for a month and 37ºC during 3h. Conclusion: The lost of the activity suggests a proteinaceous nature of the bio-active compounds, which might be useful in the development of antibacterial agents after their total purification in further work against bacterial infections.
Aims: To determine the carrier rate of typhoid and paratyphoid organisms in Enugu community. Place and Duration of Study: The project was carried out in Enugu Urban in South Eastern part of Nigeria. Those enrolled in the study that lasted for one year are students, traders and civil servants. Methodology: Ninety six apparently healthy adults without any complaints, comprising of forty eight males and forty eight females were selected for the study. Blood, urine and stool samples were collected from all in the study group. The samples were subjected to standard bacteriological culture for enteric organisms at the Medical Microbiology Laboratory of University of Nigeria Teaching Hospital, Enugu. Results: Salmonella typhi was isolated from the stool of two (2.08%) of the candidates while S. paratyphi was recovered from the stool of another individual (1.04%) of the study group. No candidate gave Widal titre greater than 40 to ,O, agglutinin which is statistically significant (Anova F value 597.7, P value <0.0001). Only Two Candidates positive for S. typhi culture gave titre of 160 to, H, antigen, also Statistically significant (Anova F value 1195, P value <0.0001). Conclusion: Typhoid carrier rate in Enugu Community is 2.1% while that of paratyphoid is 1.0%. From the study females are more likely to be typhoid carriers in Enugu.
Aims: The objective of this work was to investigate the efficiency of DNA extraction from bulk soil using the Britânia® mini mixer combined with phenol extraction to study bacterial communities, from three sampling sites localized in São Gonçalo-RJ, Brazil, comparing it to a commercial kit by the PCR-DGGE technique. Study Design: Molecular fingerprints of bacterial communities in bulk soil from three sampling sites were generated by DGGE after 16S rDNA gene amplification. Place and Duration of Study: Faculdade de Formação de Professores-UERJ and Embrapa Agrobiologia between April 2010 and April 2013. Methodology: Samples of DNA, in triplicate, extracted from bulk soil at three sampling sites localized in São Gonçalo-RJ, Brazil, were obtained by two protocols of DNA extraction. The DNA samples were used as template to amplify the 16S rDNA gene using specific primers to α and β-Proteobacteria groups. The PCR products were used for a second amplification using the primers F968GC and R1401 for subsequent DGGE analysis. The products from the second amplification were subjected to DGGE and band patterns were statistically analysed. Results: The band profiles obtained from the protocol that used a hand held mini mixer were intense and showed higher similarity among the triplicates from the sampling sites. Although both methods were capable of achieving a representative DNA profile from the soil bacterial community, the band patterns produced by them for the same areas were different. Conclusion: The DGGE profile of specific groups such as α- and β-Proteobacteria was a useful tool to compare the two soil DNA extraction protocols and also to compare the community structure of the different sampled areas. The DNA extraction protocol that used the Britânia® mini mixer produced band profiles with higher values of richness, but missed some bacterial targets as the commercial kit did. Both protocols have validity for the study of bacterial communities in bulk soil. The clusters of band profiles obtained via 16S rDNA PCR-DGGE indicated differences in bacterial communities of bulk soil from the three sampling sites for different ecological succession stages localized in São Gonçalo, RJ. The diversity analysis showed that the α-Proteobacteria group was predominant in bulk soil from these sites.
Aim: Electricity generation from wastes using Microbial Fuel Cells (MFCs). Materials and Methods:Bacillus sp._1, Bacillus sp._3 Pseudomonas sp., and Citrobacter sp., isolated from soil sediment were used for electricity generation in sewage water, glucose, soil sediment and acetate containing medium under different incubation periods. Results: Of the four isolates, generation of electricity started from 1 hour of incubation and reached maximum at 2h of incubation by Pseudomonas sp., and Bacillus sp., then declined but Citrobacter sp., showed gradual increase till stationary phase of growth. In glucose containing medium, during log phase of growth Bacillus sp._1, showed maximum of 336±0.4 mV. In non-supportive acetate medium Citrobacter sp., generated 316±0.3 mV during 1 h of incubation. Also in soil sediment medium Citrobacter sp., generated maximum of 160±1.2 mV during 5h of incubation. Conclusion: It is recommended that a longer incubation period required in complex medium for electricity generation.
Aims: To optimize fermentation conditions for microbial production of levan polymer on a low-price productive medium. Also to purified levan from Bacillus sp. V8 strain, characterization the levan polymer by 13C NMR spectroscopy and physicochemical properties. Study Design: Optimization of environmental factors for levan production. Polymer purification and identification. Place and Duration of Study: Agric. Microbiology Dept., Fac. of Agriculture, Ain Shams Univ., Cairo, Egypt, between January 2012 and December 2013. Methodology:Bacillus lentus V8 strain was used as producer of levan. This strain was grown on productive medium. Cell dry weight and levan polymer were determined in all the samples at the end of the fermentation period. Study on optimal levan production conditions such as initial pH, incubation temperatures, shaking speed, inoculum size. The parameters of growth and levan were calculated from the exponential phase. Isolation and identification of levan polymer. Results: Effect of some environmental factors on growth and levan production by Bacillus lentus V8 strain on medium supplemented with sucrose or black strap sugar cane molasses was investigated. Results indicated that the productive medium with initial pH 6.5, 10% inoculum size, incubated at 30ºC, 150rpm shaking speed gave 51.40 or 45.34gL-1 of levan dry weight on medium supplemented with sucrose or black strap sugar cane molasses, respectively. With respect to biological activity of Bacillus lentus V8 strain on modified medium supplemented with sucrose or black strap sugar cane molasses using shake flasks as a batch culture, results reveal that the fermentation period for highest cell dry weight 2.99 or 2.89gL-1 was obtained after 48 h or 66 h, respectively. The highest levan dry weight (57.95 or 49.86gL-1) and biopolymer yield (23.18 or 36.93%) on modified medium supplemented with sucrose or black strap sugar cane molasses were achieved after 60 h, respectively. A highly positive correlation coefficient between incubation period and cell dry weight, levan dry weight, polymer dry weight yield, effective yield and Yp/x, R2 values ranged from (0.91 to 0.97) and (0.89 to 0.96) on medium supplemented with sucrose or black strap sugar cane molasses, respectively. The levan produced by tested strain was identified by 13C NMR and characterized by being white color, soluble in water and precipitated with alcohol, it contains 40.86% carbon and 0.98% ash. Conclusion: The highest amount of levan was produced by Bacillus lentus V8 strain on productive medium supplemented with sucrose [or] black strap sugar cane molasses with pH 6.5, 10% inoculum size and incubated at 30ºC for 60h at 150rpm. Characterization the levan polymer by 13C NMR spectroscopy and physicochemical properties.
The study was carried out to investigate the distribution and prevalence of some multidrug resistant nosocomial pathogens in various selected hospitals in Ilorin. Various hospitals sections were assessed. This finding revealed that Klebsiella pneumoniae was predominant with 14.9% followed by E. coli, Streptococcus sp and Acinetobacter sp of 12.4%, 12.3% and 12.2% respectively. All Gram negative bacteria were susceptible to Ofloxacin, Ciprofloxacin Cephalexin and resistant to Chloramphenicol, Septrin, Vancomycin and Ampicillin while, Gram positive bacteria were found to be susceptible to Ofloxacin, Vancomycin and Ampicillin and resistant to septrin, Augmentin and tetracycline. Acinetobacter and Pseudomonas were found to display high level of resistance to most tested antibiotics with varying magnitude. Six of the isolates harboured R-plasmid acquired transfer of mobile genetic element. Gene coding for antibiotics resistance were located on the plasmid while the other three isolates without plasmids may have their gene coding located on their chromosomal DNA. It was concluded that the principle of antimicrobial stewardship is urgently needed to preserve efficacy of available antimicrobial agents.
Aims: This study was conducted to determine the occurrence of serologically cross-reactive enterobacteriaceae in food samples. Place and Duration of Study: This study was conducted in Industrial Microbiology Laboratory, IFST, BCSIR, Dhaka, Bangladesh during January-November, 2013. Methodology: 14 Enterobacteriaceae was isolated from food samples and identified. Serological reaction was determined by slide agglutination method. Results: Among 14 isolates, 6 were identified to be Cronobacter spp., 3 to be Shigella spp., 2 to be Enterobacter spp., 2 to be Escherichia coli and 1 as Klebsiella spp. Three of the isolates belonging to Cronobacter showed extremely strong cross-reactivity with Salmonella spp., Shigella spp. and Vibrio cholerae. Other isolates gave relatively weak but significant cross-reactions. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) of cell surface protein also showed similar bands in the isolates as type strains of Salmonella, Shigella and Vibrio cholerae. Conclusion: The results indicate that Salmonella spp., Shigella spp. and Vibrio cholerae surface antigens are shared by Enterobacteriaceae present in food.
Aims: To observe the antifungal resistance pattern, virulence attributes and spectrum of Candida species in oral cavities of patients with periodontal diseases and healthy individuals. Study Design: A total number of 52 patients with periodontal disease and 100 healthy subjects were included in the study. Place and Duration: The study was carried out in the Apex Regional STD Teaching, Training and Research Centre, VMMC and Safdarjang Hospital and Department of Biosciences, Jamia Millia Islamia, New Delhi. Duration of the study was from December 2011 to June 2013. Methodology: Oral swabs were collected from the patients and control group. The specimens were cultured for Candida and the species identified, according to standard protocols. Antifungal susceptibility testing and virulence tests were performed. Results: Out of 52 patients screened 11 yielded (21%) different Candida species, with Candida albicans (83%) being the commonest and non Candida albicansCandida (NCAC) species accounting for 17 %. Among 100 healthy controls, 23 were colonized by various Candida species, with Candida albicans again as the predominant species. A significant difference (P =.002) was observed in the secretion of proteinase enzyme between the isolates from cases and controls. However, in the distribution of Candida species, antifungal resistance patterns, phospholipase secretion and biofilm formation there was no such significant difference. Conclusion: Our results reveal that there is no significant difference in the distribution of Candida species among healthy subjects and patients with periodontal diseases. Antifungal resistance patterns and expression of some of the important virulence attributes also revealed no differences between the isolates from patients and control populations.
Aim: The microbiological quality of Ikpoba River, Benin City-Nigeria and the surrounding borehole waters was investigated to assess the extent of pollution from Guinness Nigeria Plc, Benin City. Methodology: Microbiological parameters analyzed were total bacterial, fungal and coliform counts, and identification for indicator organisms. Results: For river water samples (RW1-RW4), mean total viable aerobic bacterial, fungal and coliform counts ranged from 0.06x108 to 35.0x108 CFU/mL, 0.6x104 to 2.5x104 CFU/mL, and 0.006x106 to 2.3x106 CFU/mL respectively; and for borehole water samples (BH1-BH5), mean counts ranged from 1.3x104 to 3.3x104 CFU/mL for bacteria, 4.0x10 to 8.2x10 CFU/mL for fungi, and 0 to 6.1x102 CFU/mL for coliforms. Only BH1 and BH5 showed the absence of coliforms. Conclusion: From the results of this study, it was observed that the effluent discharge from Guinness Nigeria Plc may not totally be responsible for the microbial contamination of the Ikpoba River and the surrounding borehole waters, as other sources of contamination, especially from human activities, were noticed. It is therefore important that governments and concerned institutions put measures in place to remove the sources of contamination in water bodies that supply locals with water for household use. Industrial effluent also, should be effectively treated before they are discharged into the water body and industries should strictly adhere to the standards and guidelines specified by various water and environment regulating bodies.
Aims: The antibacterial activity of medicinal plants against human pathogens has been evaluated by a number of studies. However, a few research works have been done on pus cell pathogens. So this research work was aimed to determine the antibacterial effect of Croton bonplandianum against bacterial isolates from pus cells causing wound infections and to compare the antibacterial effect of various solvent extracts of different parts of Croton bonplandianum with streptomycin against the isolated bacterial pathogens from wounds. Study Design:In vitro assay of antibacterial activity Place and Duration of Study: Post Graduate and Research Department of Biochemistry at Government Arts College (Autonomous), Kumbakonam, Tamilnadu, India, between January to June, 2011. Methodology: The isolated bacterial pathogens such as Pseudomonas aeruginosa, Staphylococcus aureus, Enterococcus faecalis, Enterobacter aerogenes and Escherichia coli were used for the evaluation of antibacterial activity of C. bonplandianum by well diffusion method. Results: The fresh latex showed highest inhibitory activity against E. coli (32 mm) and E. faecalis (30 mm) followed by aqueous and ethanol extracts of latex showed highest inhibitory activity against E. aerogenes (26 mm) than other solvent extracts. The ethanol and benzene extracts of leaf showed highest inhibitory activity against S. aureus (20 mm). The chloroform extract of fruits showed maximum inhibitory activity against E. coli (21 mm) when compared to other solvent extracts. The latex extracts of C. bonplandianum showed better results as compared to leaf and fruit extracts. Conclusion: The results of present study supports that the traditional use of C. bonplandianum as antimicrobial agent in wound infections.