MOSP - Macao Scientific Publishers

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Characterization of physiologic races of sugarcane smut (Ustilago scitaminea) in Kenya

H. S. Nzioki, J. E. Jamoza, C. O. Olweny* and J. K. Rono

Abstract: Sugarcane smut disease caused by the fungus Ustilago scitaminea significantly reduces the yield and quality of sugarcane. The disease was first reported in Kenya in 1958, in Nyanza and Coastal provinces and currently occurs in all major sugarcane growing areas of Kenya. Planting resistant varieties is the main smut control measure in Kenya. Planting smut resistant varieties was made compulsory in Kenya in 1963. However, varieties previously confirmed resistant are now susceptible. Reports indicate that some varieties are resistant to smut in one zone and susceptible in another. An attempt was thus made to identify physiologic races of sugarcane smut in Kenya. Sugarcane smut teliospores were collected from the major sugarcane growing zones of Western Kenya in South Nyanza, Nyando, Mumias, Busia, Nzoia and west Kenya. A set of 11 sugarcane cultivars which had previously shown differential response to smut in Kenya and elsewhere were each artificially inoculated with a mixture of smut spores from each zone by dipping in a suspension of smut spores that contained 5 x 106 teliospores per ml. Susceptibility of the cultivars to smut was measured by recording the number of smut whips that appeared within 6 to 7 months after planting. The reaction of the cultivars to smut from the various zones varied from resistance to susceptible. Three cultivars were seen in smut reaction in two tests. The results suggested existence of smut races in Kenya.[...] Read More.

Keywords: Kenya, sugarcane smut, Ustilago scitaminea.

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Studies on major respiratory diseases of Camel (Camelus dromedarius) in Northeastern Ethiopia

Fekadu Kebede and Esayas Gelaye*

Abstract: A comparative serological test was carried out to identify the primary causative agent involved in the camel respiratory disease outbreak that occurred in Ethiopia. The samples were collected during and post outbreak time and analyzed for parainfulenza-3 and pasteurellosis. According to the result, parainfulenza-3 was found as a primary causative agent as 70.5% in outbreak and 6.8% in surveyed areas and there is a statistical significant variation observed between the outbreak and survey sera samples (P < 0.01). Manhaemiya hemolytica was involved as secondary bacterial complications. The association of parainfulenza-3 and pasteurellosis was also assessed and has shown that M. haemolytica A2 was a dominant serotype over others which account 50% in higher antibody titration ranging from 1:80 - 1:320 in outbreak samples. Camel respiratory diseases are still flaring up in various parts of the country and reports are coming year after year urging for an intervention measures. Further studies have been recommended on the epidemiology of the disease and the identification of the responsible pathogens and its serotypes to be involved for the development of vaccines.[...] Read More.

Keywords: Ethiopia, camel respiratory diseases, Manhaemiya hemolytica, parainfulenza-3, serotyping.

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Protease and amylase enzymes for biofilm removal and degradation of extracellular polymeric substances (EPS) produced by Pseudomonas fluorescens bacteria

I. Phyllis Molobela*, T. Eugene Cloete and Mervyn Beukes

Abstract: Removal of biofilms is difficult. In industrial settings, both the inactivation and removal of biofilms are of huge concern. If only disinfection without the removal of attached biofilms occurs, the inactivated biofilm cells may provide an ideal environment for further adhesion and growth, resulting in a complex matrix. Microbial resistance to biocides and their negative environmental impact are the main reasons for finding alternative biofilm control strategies. Enzymes may offer such an alternative. The objective of this study was to determine the effect of commercial proteases and amylases on biofilms formed by Pseudomonas fluorescens. Biofilms were grown in diluted medium containing glass wool used as the attachment surface. Extracellular polymeric substances (EPS) were extracted and EPS composition was determined. Protease (savinase, everlase and polarzyme) and amylase (Amyloglucosidase and Bacterial Amylase Novo) activity was tested on both biofilms and on extracted EPS. After testing enzymes, biofilm integrity was evaluated by scanning electron microscopy. EPS composition consisted predominantly of proteins. Everlase and Savinase were the most effective enzymatic treatments on removing biofilms and degrading the EPS.[...] Read More.

Keywords: Biofilms, extracellular polymeric substances, Pseudomonas fluorescens, proteases, amylases.

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The prevalence of group A rotavirus infection and some risk factors in pediatric diarrhea in Zaria, North central Nigeria

Pennap Grace* and Umoh Jerald

Abstract: Group A rotavirus cause infectious, severe and dehydrating diarrhea which have great impact on childhood morbidity and mortality worldwide. This study was designed to investigate the disease burden and risk factors of rotavirus infection among children 1 - 5 years in Zaria, Nigeria. Stool samples were collected from 666 diarrheic children and 170 matched non -diarrheic controls and screened for rotavirus antigen by ELISA. Their socio-demographic information and clinical presentations were also noted. There was a 15.6 and 7.6% prevalence of rotavirus infections among the diarrheic and non-diarrheic children, respectively, with the peak of infection occurring between 1 – 6 months of age. The most common clinical features included dehydration (59.1%), fever and vomiting (41.3%), vomiting (34.6%) and fever (19.2%). Age, feeding regimen, and the presence of another person in the house with diarrhea were found to be risk factors for rotavirus diarrhea while gender and socioeconomic status were not. In view of the peak of infection in infants in the study area, rotavirus vaccine will be best administered in early infancy.[...] Read More.

Keywords: Rotavirus, prevalence, risk factors, pediatric, diarrhea.

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Use of Scopulariopsis acremonium for the production of cellulase and xylanase through submerged fermentation

Loveleen Kaur Sarao*, Maninder Arora and V. K. Sehgal

Abstract: Production of cellulase and xylanase by Scopulariopsis acremonium through submerged fermentation was studied using shake flask cultivation media. The effect of process parameters such as effect of temperature, pH and inoculum size was investigated. The enzymes were partially purified using isopropanol and used for enzyme assays. The results indicated that the maximum cellulase and xylanase having an enzyme activity of 694.45 and 931.25 IU, respectively, were produced at 30°C incubation temperature. The pH optimum to achieve these enzyme activities was 5.5 with an inoculum size of 1 x 105 spores ml-1 of tween - 80. Cellulase was deactivated at 80°C while xylanase was deactivated at 70°C.[...] Read More.

Keywords: Scopulariopsis acremonium, cellulase, xylanase, submerged fermentation.

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Antibacterial effect of chlorine dioxide and hyaluronate on dental biofilm

F. Al-bayaty,*, T. Taiyeb-ali, M. A. Abdulla and F. Hashim

Abstract: The objective of this study is to investigate antimicrobial action of chlorine dioxide (ClO2) gel and hyaluronate gel (Gengigel®) on dental biofilm. Pooled supra and subgingival dental biofilm were obtained from healthy individuals and incubated aerobically and anaerobically. Plaque bacteria investigated including Streptococcus constellatus, Streptococcus mitis, Eikenella corrodens, Fusobacterium nucleatum, dental plaque pool samples (aerobic and anaerobic) and Staphylococcus aureus and Escherichia coli as internal control microorganisms. All bacteria were grown in Brain Heart Infusion (BHI) broth and the clinical isolate strains were sub-cultured on BHI agar. Single pure colonies of bacteria were transferred into fresh BHI broth and incubated overnight. Bacterial counting was done using hemocytometer. Antibacterial activities were determined using bacteria grown on Mueller Hinton II agar and antimicrobial disc diffusion susceptibility testing with paper discs impregnated with ClO2 and Hyaluronate gels as well as by minimum inhibition concentration (MIC) test. Bacterial morphological alterations following treatment with ClO2 and Hyaluronate gels were viewed under Scanning Electron Microscope (SEM) at 3500x, 10000 x and 20000x magnification. Positive results were obtained with disc diffusion technique whereby both agents exhibited antibacterial action against the microorganisms tested. ClO2 gel produced large diameter inhibition zones while Hyaluronate gel resulted in smaller diameter inhibition zones. In MIC test the lowest MIC value of ClO2 gel (0.02% w/v) was obtained for S. aureus, S. mitis and S. constellatus. The other bacteria and pool samples of dental biofilm indicated slightly higher MIC values (0.2% w/v) for ClO2 gel. However, MIC values for Hyaluronate gel could not be determined. Under SEM, ClO2 gel produced obvious alterations to the bacterial morphology while no changes were observed after treatment with hyaluronate gel. Chlorine dioxide gel demonstrated stronger and obvious antibacterial activity.[...] Read More.

Keywords: Chlorine dioxide gel, Gengigel®, dental biofilm.

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Validation of RNA integrity from low yield experiments with Mycobacterium tuberculosis for downstream application in real time PCR

Prathna Ramchandra and A. Willem Sturm*

Abstract: RNA extraction from mycobacterial cells is more challenging than from any other cell type. We used the Trizol Reagent® with silica beads to disrupt cells of Mycobacterium tuberculosis H37Rv. This method requires minimum reagents and handling and therefore aids in maintaining RNA integrity. The efficiency of cell disruption by this method was verified by microscopic analysis of the lysate. The yield and purity were determined using the Nanodrop-1000. A total volume of 50 µl containing 224.7 ng/µL of RNA was obtained from 3.1 x 108 cells, grown under sub-optimal conditions. RNA was visualized using the gene genius optical system. A 6 week old undisturbed culture of M. tuberculosis H37Rv, gave an expression ratio of fdxA/16s of -2.094. This extraction method is suitable for use of RNA in quantitative experiments, even if the cell numbers from which the RNA is extracted are low.[...] Read More.

Keywords: Mycobacteria, RNA extraction, RNA purification, quantitation.

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Association among the Rv2629 gene, rpoB gene, RFP resistance and Beijing genotype in M. tuberculosis clinical isolates

Junxian Zhang, Xueqiong Wu*, Yourong Yang, Yan Zhuang, Bo Wang, Jianqin Liang, Yan Liang, Hongmin Li and Chuihuan Li

Abstract: Rifampin (RFP) is a major first-line anti-tuberculosis drug. The molecular assay currently used is the detection of rpoB gene mutations in M. tuberculosis. Recently, the Rv2629 191C allele was found to have a correlation with RFP resistance, and might become a valuable marker for the detection of RFP resistance or the Beijing genotype. We studied the association among the Rv2629 gene, rpoB gene, RFP resistance and Beijing genotype in 69 M. tuberculosis clinical isolates using DNA sequencing, conventional drug susceptibility and spoligotyping. The 191C allele was present in 92.8% (64/69) isolates. Of 29 RFP-sensitive strains, none exhibited any mutations in rpoB genes, only one strain (3.4%) was found to carry the 191A allele and 28 strains (96.6%) had the 191C alleles. Of 40 RFP-resistant strains, 30 (75%) strains had rpoB gene mutations, only 4 strains (10%) carried 191A alleles, and 36 strains (90%) exhibited 191C alleles. The 191C allele was also present in INH-sensitive, SM -sensitive or EMB-sensitive isolates. Spoligotyping analysis showed 8 distinct spoligotyping patterns. 81.1% (30/37) strains were divided into one big cluster, which had a characteristic of the Beijing genotype. Rv2629 191C allele was present in 93.3% (28/30) Beijing genotype strains, but also in non- Beijing genotype strains. These results indicate that high association is present between the ropB gene and RFP resistance. No association is present between the Rv2629 191C allele and RFP resistance, or between the Beijing genotype and RFP resistance.[...] Read More.

Keywords: M. tuberculosis, Rv2629, rpoB, rifampin resistance, spoligotyping.

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Use of RT-PCR in diagnosis of infectious hematopoietic necrosis in rainbow trout hatcheries, Iran

Mehdi Raissy,*, Hasan Momtaz, Mahsa Ansari and Manouchehr Moumeni

Abstract: Distribution of Infectious Hematopoietic Necrosis (IHN) was studied in rainbow trout fish farms in Chaharmahal and Bakhtyari Province which is a major trout culture region in Iran. Overall 150 suspected rainbow trout fry with less than 3 g body weight from 30 fish farms in Chaharmahal and Bakhtyari Province, Iran, were studied and fishes of 10 hatcheries (33.3% of all studied farms) found to be infected with IHNV. Reverse transcriptase polymerase chain reaction (RT-PCR) was applied to the detection of infectious hematopoietic necrosis virus (IHNV). The product of 371 bp was amplified from the RNA extracts of infected organs of suspected fish. DNA sequencing of the PCR products demonstrated specificity of the amplification. The RT-PCR was found to be a simple, highly specific and sensitive method allowing diagnosis of IHN in a short time.[...] Read More.

Keywords: Reverse transcription-polymerase chain reaction (RT-PCR), IHN, rainbow trout.

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Plant growth promoting activities of fluorescent pseudomonads associated with some crop plants

A. Suresh, P. Pallavi, P. Srinivas, V. Praveen Kumar, S. Jeevan Chandra and S. Ram Reddy*

Abstract: Fluorescent pseudomonads (FP), a major component of rhizobacteria, promote the plant growth through their multifarious activities. In the present investigations, 10 strains of fluorescent pseudomonads isolated from the rhizosphere soils of bajra (Pennisetum glaucum), jowar (Sorghum vulgare), rice (Oryza sativa) and maize (Zea mays) were screened for their plant growth promoting activity based on their ability to produce hydrogen cyanide (HCN), siderophores, proteases, indole acetic acid (IAA), broad spectrum antifungal activity against pathogenic fungi and phosphate solubilization. The results indicated that most of the isolates tested possess plant growth promoting traits. These isolates can be used as potential biofertilizers and also as biocontrol agents.[...] Read More.

Keywords: PGPR, indole acetic acid, hydrogen cyanide, protease, phosphate solubilization, antagonism.

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