Rapid Amplification Of Polymorphic DNA Research Articles

Genetic Diversity Analysis of Five Different Species of Riccia

Five species of the Riccia genus have been investigated by Rapid Amplified Polymorphic DNA (RAPD) analysis. The species is explained and demonstrated with its genetic diversity based on morphological variations. Samples were collected from different parts of the University of Dhaka growing in different habitats around the University campus area. After the study of its morphology, it has been observed that the population of this taxon shows significant variation in plant size, shape, colour, ventral scales, appendages of scales, rhizoids, and the position of male and female receptacles, etc. The RAPD marker system was employed to estimate the genetic diversity within and between the populations based on such morphological variations. Approximately 82% of the variations have been observed within and between genotypes of Riccia as revealed with both phenotypic and genotypic data. The RAPD markers are being used increasingly to analyse the phylogenetic relationship among the liverworts to give the exact framework of taxonomic identification of naturally occurring liverwort Riccia. Plant Tissue Cult. & Biotech. 32(2): 137-144, 2022 (December)

Genetic variability of spiralling whitefly Aleurodicus disperses Russell on Citrus aurantifolia Christm and Ocimum gratissimum L.

The spiralling whitefly, Aleurodicus dispersus Russell (Hemiptera: Aleyrodidae), has a wide range of anatomy, physiology, behaviour, and ecology depending on the host plant. This research looked at the genetic variations between A. dispersus populations on two separate host plants (Citrus aurantifolia and Ocimum gratissimum). The existence of host-related genetic variation in A. dispersus populations was determined using Rapid Amplification of Polymorphic DNA (RAPD) markers. Our findings revealed that the A. dispersus populations on the two host plants had a considerable amount of genetic divergence. The spiralling whiteflies on the adaxial part of Citrus aurantifolia were genetically distinct from those on the abaxial part of the same plants. Various population genetic parameters such as heterozygosity, Nei's genetic gap, and fixation indices (FST) revealed that spiralling whitefly populations vary genetically, which may be attributable to spiralling whitefly populations originating from multiple sources. These findings also have consequences for the invasive pest's quarantine safety strategy.

DNA finger printing of S. Mutans present in the saliva of caries active children and those associated with intellectual disability – An RAPD analysis

AimThe aim of this study is, to evaluate and compare the diversity of S. Mutans genotypes with respect to caries activity among normal children and intellectually disabled children, which would enable the clinician to plan better strategies for early caries detection, management and prevention. Materials and methodsGenotyping of S. Mutans was done by collecting the saliva samples from 40 caries active children (20 normal and 20 children associated with intellectual disability by Rapid amplified polymorphic DNA analysis using three arbitrarily primers (P1, P2, P3). Rapid amplified polymorphic DNA (RAPD) is preferred because of its reliability, reproducibility in generating genetic fingerprints of Streptococcus isolates. ResultsNumber of bacterial counts in Group I showed a mean of 111.6500 followed by the Group II with a mean of 102.6500. Therefore, the difference in the number of bacterial counts was not significant between the two groups (p < 0.001). Genotype encoding Primer 1 was present in almost 82.5% of the total population of both groups. Genotype encoding Primer 2 was present in 95% of the total population. Whereas, Genotype encoding Primer 3 was present in 20% of children associated with intellectual disability and 95% of normal children. Interpretation and conclusionThere was no significant difference in S. Mutans count of normal caries active children to that of caries active children with intellectual disability, but, there was a significance difference in the distribution of S. Mutans genotypes in both the groups.

Tryptophan usage by Helicobacter pylori differs among strains

Because of its association with severe gastric pathologies, including gastric cancer, Helicobacter pylori has been subject of research for more than 30 years. Its capacity to adapt and survive in the human stomach can be attributed to its genetic flexibility. Its natural competence and its capacity to turn genes on and off allows H. pylori to adapt rapidly to the changing conditions of its host. Because of its genetic variability, it is difficult to establish the uniqueness of each strain obtained from a human host. The methods considered to-date to deliver the best result for differentiation of strains are Rapid Amplification of Polymorphic DNA (RAPD), Multilocus Sequence Typing (MLST) and Whole Genome Sequencing (WGS) analysis. While RAPD analysis is cost-effective, it requires a stable genome for its reliability. MLST and WGS are optimal for strain identification, however, they require analysis of data at the bioinformatics level. Using the StainFree method, which modifies tryptophan residues on proteins using 2, 2, 2, - trichloroethanol (TCE), we observed a strain specific pattern of tryptophan in 1D acrylamide gels. In order to establish the effectiveness of tryptophan fingerprinting for strain identification, we compared the graphic analysis of tryptophan-labelled bands in the gel images with MLST results. Based on this, we find that tryptophan banding patterns can be used as an alternative method for the differentiation of H. pylori strains. Furthermore, investigating the origin for these differences, we found that H. pylori strains alters the number and/or position of tryptophan present in several proteins at the genetic code level, with most exchanges taking place in membrane- and cation-binding proteins, which could be part of a novel response of H. pylori to host adaptation.

Rapid detection of Fusarium oxysporum f. sp. lactucae on soil, lettuce seeds and plants using loop‐mediated isothermal amplification

Fusarium oxysporum f. sp. lactucae (FOL) is a soil‐ and seedborne pathogen and the causal agent of fusarium wilt on lettuce. Four races have been identified within FOL, with different worldwide distribution. Several molecular techniques have been used to detect and identify this pathogen; however, not all of them have the optimal characteristics in terms of sensitivity to perform FOL detection in plant and seed material. A loop‐mediated isothermal amplification (LAMP) assay was developed based on the sequence‐characterized amplified region (SCAR) obtained in a previous rapid amplification of polymorphic DNA (RAPD) study. The LAMP assay has been validated according to the EPPO standard PM7/98. The LAMP assay was tested with lettuce seeds, soil and plant material, and can be used successfully to amplify DNA from each of these matrices. In seed lots artificially inoculated with FOL, the detection limit of the LAMP test was 0.004% infected seed.

Morphological characteristics of fruit bodies and basidiospores of Wolfiporia extensa

Wolfiporia cocos is a well-known traditional medicine in China, Japan, Korea, and other Asian countries owing to its numerous therapeutic properties. With the aim to determine the morphology and genetic characteristics of W. cocosten strains of W. cocos were cultivated in vitro, and subsequently, rapid amplification of polymorphic DNA was performed. To the best of our knowledge, this is the first study to examine the morphology of fruit bodies of W. cocos in Korea. W. cocos were cultured on PDA agar at different temperatures (12, 16, 20, 24, and 28oC) under 12-hour light (600 Lux) / 12-hour dark photoperiod condition for 1 month. Appearance of fruit body was the highest at 28°C condition in all the strains investigated. Honeycomb-like structure on sclerotia was observed in Andong 01, Andong 02, Andong 03, KFRI 1104, KFRI 1105, KFRI 1106, KFRI 1107, KFRI 1108, and ASI 13007 strains of . The KFRI 1103 strain formed cosmos petal-like structure on sclerotia. The average size of basidiospores was recorded as 7.55 μm in height and 3.35 μ in width.

Profenofos induced modulation in physiological indices, genomic template stability and protein banding patterns of Anabaena sp. PCC 7120

To understand the mechanism underlying organophosphate pesticide toxicity, cyanobacterium Anabaena PCC 7120 was subjected to varied concentrations (0, 5, 10, 20 and 30 mg L−1) of profenofos and the effects were investigated in terms of changes in cellular physiology, genomic template stability and protein expression pattern. The supplementation of profenofos reduced the growth, total pigment content and photosynthetic efficiency of the test organism in a dose dependent manner with maximum toxic effect at 30 mg L−1. The high fluorescence intensity of 2′, 7′ –dichlorofluorescin diacetate and increased production of malondialdehyde confirmed the prevalence of acute oxidative stress condition inside the cells of the cyanobacterium. Rapid amplified polymorphic DNA (RAPD) fingerprinting and SDS-PAGE analyses showed a significant alteration in the banding patterns of DNA and proteins respectively. A marked increase in superoxide dismutase, catalase, peroxidase activity and a concomitant reduction in glutathione content indicated their possible role in supporting the growth of Anabaena 7120 up to 20 mg L−1. These findings suggest that the uncontrolled use of profenofos in the agricultural fields may not only lead to the destruction of the cyanobacterial population, but it would also disturb the nutrient dynamics and energy flow.

Molecular Identification of Rhizosphere Trichoderma spp. and Their Antagonistic Impact Against Some Plant Pathogenic Fungi

The main aim of this study was to molecular identification and determine the antagonistic impact of rhizosphere Trichoderma spp. against some phytopathogenic fungi, including (Magnaporthe grisea) pyricularia oryzae, Rhizoctonia solani and Macrophomina phasolina. Four Trichoderma isolates were isolated from rhizosphere soils of the different host plants in different locations of Egyptian governorates. The morphological characterization of isolated Trichoderma as well as using of (ITS1-5.8S-ITS2) ribosomal gene sequence acquisition and data analyses. By comparing the results of DNA sequences of ITS region, the fungi represented one isolate were positively identified as T. asperellum (1 isolate T1) and one as T. longibrachiatum (1 isolate T2) and two as Trichoderma harzianum (2 isolates T3 and T4). The results showed similarity value of (5.8S-ITS) region sequence of the two isolates, T1 (T. asperellum) and T2 (T. longibrachiatum) of (99%, 99%), respectively. The similarity value of (5.8S-ITS) region sequence with isolates of T3, T4 (T. harzianum) of (99%). On the other side, the results of molecular identification of phytopathogenic fungi represented high similarity value of (5.8S-ITS) region sequence and were identified as P.oryzae, R. solani and M. phasolina (99, 96 and 99%) respectively. Variations and genetic relationships among 4 Trichoderma isolates were investigated by using the Rapid Amplification of Polymorphic DNA (RAPD) profiles using ten random primers. All Trichoderma isolates were assessed for their antagonistic impact on phytopathogens P. oryzae, R. solani and M. phasolina. Though T. harzianum isolates were more affects than T. longibrachiatum and T. asperellum isolates, the percent inhibitory effect among T. harzianum isolates were vary much (44.8 to 91.6%). The inhibitory effect of T. asperellum isolates ranged from 42.2 to (86.0%), while T. longibrachiatum exhibiting affect ranged between (47.5%) to (83.8%).

Molecular Identification of Rhizosphere Trichoderma spp. and Their Antagonistic Impact Against Some Plant Pathogenic Fungi

The main aim of this study was to molecular identification and determine the antagonistic impact of rhizosphere Trichoderma spp. against some phytopathogenic fungi, including (Magnaporthe grisea) pyricularia oryzae, Rhizoctonia solani and Macrophomina phasolina. Four Trichoderma isolates were isolated from rhizosphere soils of the different host plants in different locations of Egyptian governorates. The morphological characterization of isolated Trichoderma as well as using of (ITS1-5.8S-ITS2) ribosomal gene sequence acquisition and data analyses. By comparing the results of DNA sequences of ITS region, the fungi represented one isolate were positively identified as T. asperellum (1 isolate T1) and one as T. longibrachiatum (1 isolate T2) and two as Trichoderma harzianum (2 isolates T3 and T4). The results showed similarity value of (5.8S-ITS) region sequence of the two isolates, T1 (T. asperellum) and T2 (T. longibrachiatum) of (99%, 99%), respectively. The similarity value of (5.8S-ITS) region sequence with isolates of T3, T4 (T. harzianum) of (99%). On the other side, the results of molecular identification of phytopathogenic fungi represented high similarity value of (5.8S-ITS) region sequence and were identified as P.oryzae, R. solani and M. phasolina (99, 96 and 99%) respectively. Variations and genetic relationships among 4 Trichoderma isolates were investigated by using the Rapid Amplification of Polymorphic DNA (RAPD) profiles using ten random primers. All Trichoderma isolates were assessed for their antagonistic impact on phytopathogens P. oryzae, R. solani and M. phasolina. Though T. harzianum isolates were more affects than T. longibrachiatum and T. asperellum isolates, the percent inhibitory effect among T. harzianum isolates were vary much (44.8 to 91.6%). The inhibitory effect of T. asperellum isolates ranged from 42.2 to (86.0%), while T. longibrachiatum exhibiting affect ranged between (47.5%) to (83.8%).

Genotyping methods for monitoring the epidemic evolution of A. baumannii strains.

Acinetobacter baumannii is clustered with other phenotypically similar species into what has commonly become known as the ACB complex: A. calcoaceticus, A. pittii and, A. nosocomialis. The ecology and pathology of most of these species are not well understood, mainly because current specific phenotypic techniques have, to date, been insufficient. This has inhibited both the precise identification of, as well as the ability to discriminate between, these clinically important and closely related Acinetobacter strains.However, new genotypic methods have greatly enhanced our capacity to identify the ACB complex. This has resulted in the implementation of more rational infection control programs. Several genotypic identification methods are explored in this study, including non-polymerase chain reaction (PCR)-based and PCR-based methods. These methods include ribotyping, pulsed-field gel electrophoresis, 16S rRNA identification, multilocus sequence typing, single locus sequence typing, restriction fragment length polymorphism analysis, restriction analysis of 16S-23S rRNA intergenic spacer sequences, rapid amplification of polymorphic DNA, and repetitive extragenic palindromic PCR; however, there is no current single ideal genotyping method. Each one has its own advantages and disadvantages. With this in mind we reviewed current and new genotyping methods used to characterize the Acinetobacter species.

Correlation between morphological, chemical and RAPD markers for assessing genetic diversity in Withania somnifera (L.) Dunal

Genetic diversity among 14 Withania accessions were studied using morphological, chemical, and RAPD (Rapid Amplification of Polymorphic DNA) markers. On the basis of morphological variation and maximum assimilation of chemical constituents, wild accessions were considered elite as compared to cultivated. The molecular study showed that a total of 12 DNA fragments were amplified with five random decamer primers 75% of which were polymorphic. Genetic similarity matrix based on the Dice index detected coefficients ranging from 0.556 to 0.941. These coefficients were used to construct a dendrogram using unweighted pair group method with arithmetic mean (UPGMA). These accessions were clustered into two major groups; the first group included AGB-009, AGB-012, AGB-042, AGB-030, AGB-053, AGB-019, AGB-017, AGB-002, and AGB-003; the second included AGB-025, AGB-001, AGB-036, AGB-015, and AGB-055. The highest similarity among the Ashwagandha accessions was observed between AGB-009 and AGB-030, AGB-009 and AGB-012, AGB-042 and AGB-030, AGB-025 and AGB-001, AGB-036 and AGB-015, AGB-015 and AGB-055 and between AGB-015 and AGB-055. The most distant populations in the dendrogram were AGB-053 and AGB-055. The combination of morphological, chemical, and molecular markers assessment will be useful in studying the genetic diversity of Withania for identification, conservation, breeding, improvement activities, and in order to achieve elite type in terms of bioactive metabolites.

Evaluation of powdery mildew-resistance of grape germplasm and rapid amplified polymorphic DNA markers associated with the resistant trait in Chinese wild Vitis.

The resistance of wild Vitis germplasm, including Chinese and American wild Vitis and Vitis vinifera cultivars, to powdery mildew (Uncinula necator Burr.) was evaluated for two consecutive years under natural conditions. Most of the Chinese and North American species displayed a resistant phenotype, whereas all of the European species were highly susceptible. The Alachua and Conquistador accessions of Vitis rotundifolia species, which originated in North America, were immune to the disease, while Baihe-35-1, one of the accessions of Vitis pseudoreticulata, showed the strongest resistance among all Chinese accessions evaluated. Three rapid amplified polymorphic DNA (RAPD) markers, OPW02-1756, OPO11-964, and OPY13-661, were obtained after screening 520 random primers among various germplasm, and these markers were found to be associated with powdery mildew resistance in Baihe-35-1 and in some Chinese species, but not in any European species. Analysis of F₁ and F₂ progenies of a cross between resistant Baihe-35-1 and susceptible Carignane (V. vinifera) revealed that the three RAPD markers were linked to the powdery resistant trait in Baihe-35-1 plants. Potential applications of the identified RAPD markers for gene mapping, marker-assisted selection, and breeding were investigated in 168 F₂ progenies of the same cross. Characterization of the resistant phenotype of the selected F₂ seedlings for breeding a new disease-resistant grape cultivar is in progress.

Genetic diversity and gene differentiation among ten species of Zingiberaceae from Eastern India.

In the present study, genetic fingerprints of ten species of Zingiberaceae from eastern India were developed using PCR-based markers. 19 RAPD (Rapid Amplified polymorphic DNA), 8 ISSR (Inter Simple Sequence Repeats) and 8 SSR (Simple Sequence Repeats) primers were used to elucidate genetic diversity important for utilization, management and conservation. These primers produced 789 loci, out of which 773 loci were polymorphic (including 220 unique loci) and 16 monomorphic loci. Highest number of bands amplified (263) in Curcuma caesia whereas lowest (209) in Zingiber cassumunar. Though all the markers discriminated the species effectively, analysis of combined data of all markers resulted in better distinction of individual species. Highest number of loci was amplified with SSR primers with resolving power in a range of 17.4–39. Dendrogram based on three molecular data using unweighted pair group method with arithmetic mean classified all the species into two clusters. Mantle matrix correspondence test revealed high matrix correlation in all the cases. Correlation values for RAPD, ISSR and SSR were 0.797, 0.84 and 0.8, respectively, with combined data. In both the genera wild and cultivated species were completely separated from each other at genomic level. It also revealed distinct genetic identity between species of Curcuma and Zingiber. High genetic diversity documented in the present study provides a baseline data for optimization of conservation and breeding programme of the studied zingiberacious species.

Biological Characteristics of Fish Germ Cells and their Application to Developmental Biotechnology

We have revealed several unique characteristics of germ cell development using rainbow trout, including the fact that spermatogonia transplanted into the peritoneal cavity of newly hatched embryos migrate toward recipient gonads, that spermatogonia transplanted into female recipients start oogenesis and produce functional eggs and that diploid germ cells transplanted into triploid trout can complete gametogenesis. By combining these unique features of fish germ cells, we established allogeneic and xenogeneic transplantation systems for spermatogonia in several fish species. Spermatogonia isolated from the mature testes of vasa-green fluorescent protein (Gfp) transgenic rainbow trout were transplanted into the peritoneal cavity of triploid masu salmon newly hatched embryos. These spermatogonia migrated toward recipient salmon genital ridges with extending pseudopodia and were subsequently incorporated into them. We further confirmed that the donor-derived spermatogonia resumed gametogenesis and produced sperm and eggs in male and female salmon recipients, respectively. By inseminating the resulting eggs and sperm, we obtained only rainbow trout offspring in the F1 generation, suggesting that the triploid salmon recipients produced functional gametes derived only from donor trout. We further confirmed that this intra-peritoneal transplantation of germ cells is applicable to several marine fishes, which could be of benefit in the production of bluefin tuna that has a large broodstock (>100 kg) and is difficult to maintain in captivity. Gamete production of bluefin tuna could be more easily achieved by generating a surrogate species, such as mackerel, that can produce tuna gametes.

Molecular Characterization of Macrophomina phaseolina, the Incitant of Coleus forskohlii Revealed by RAPD Markers

Coleus forskohlii belong to family lamiaceae is one of the commercial plants grown extensively in the country, the chemical found in the Coleus which has both medicinal application and gives great economy to the industrial organizations. Unfortunately, these plants are being highly succumbed to serious diseases like wilt and root rot caused by a fungus, hence the growers and industrialists are facing severe problem in safeguarding this crop in the field irrespective of the agro climatic conditions. Root rot disease, is one of the major diseases of Coleus forskohlii which, is caused by Macrophomina phaseolina, Pathogen variability was studied at both morphological and molecular level using cultural characteristics and Rapid Amplification of Polymorphic DNA (RAPD) analysis respectively. Totally thirty two isolates were isolated from roots of Coleus forskohlii. In RAPD 165 bands were obtained out of them 121 bands (73.3%) were polymorphic with a similarity coefficient of 0.48-0.66. Clusters analysis of RAPD data when Unweighted Pair Group Method with Arithmetic Mean (UPGMA) Tree constructed using NTSYS, it showed 6 groups. Among them two were major clusters and 4 were minor clusters with similarity coefficient 0.48-0.66. The pathogenicity of the isolates was tested on Coleus forskohlii plants. Analysis of the pathogenicity tests results revealed that the isolates grouped under two major clusters which were different from the one obtained using RAPD data. The results indicate that the data from RAPD analysis and Pathogenicity tests do not correlate with each other.DOI: http://dx.doi.org/10.3126/ijls.v5i1.5598 International Journal of Life Sciences Vol.5(1) 2011 44-50

Difference in cultivation characteristics and genetic polymorphism between Chinese and Japanese strains of Wolfiporia cocos Ryvarden et Gilbertson (Poria cocos Wolf)

Poria, a dried sclerotium of Wolfiporia cocos Ryvarden et Gilbertson (Polyporaceae) has been used as a crude drug in both Chinese and Japanese (Kampo) traditional medicines. Recently, cultivated products of Chinese Poria strains have accounted for most of the market, while the cultivation of Japanese Poria strains has not been successful. Aiming to determine the relationship between the differences in cultivation characteristics and genetic polymorphism, we conducted a field cultivation experiment, a rot test, and rapid amplification of polymorphic DNA (RAPD) analysis of Poria strains collected from China and Japan: 3 Chinese and 7 Japanese strains. In field cultivation, although there was no marked inferiority of Japanese strains to Chinese ones in either mycelium propagation or the rate of sclerotium formation, Chinese strains formed whiter sclerotia with a mean size more than twice that of Japanese ones. Representatives of Chinese and Japanese strains, Yunnan and Kaimondake, respectively, were tested for wood-rotting ability. More wood was utilized and the wood color was darker in trials of the Yunnan strain. Amplifications of total DNA of these 10 fungal strains with 2 primers, PC-6 and PC-11, in RAPD analysis showed a difference in the amplicon profile between Japanese and Chinese strains, suggesting differences in their genetic background.

Isolation of methicillin-resistant Staphylococcus aureus from caprine mastitis cases

There is no report on isolation of methicillin-resistant Staphylococcus aureus (MRSA) strains from mastitis infection in goats. This study reports two MRSA strains that were isolated from caprine mastitis. A total of 42 Staphylococcus aureus (S. aureus) strains collected from caprine mastitis cases between 2008 and 2009 were examined. Two (4.8%) out of 42 S. aureus strains were identified as MRSA by Kirby–Bauer disc diffusion and mecA polymerase chain reaction (PCR) methods. Based on the coa gene polymorphism, the goat strains were grouped into 6 types. By using rapid amplified polymorphic DNA (RAPD) assay, 10 different patterns were obtained from 42 S. aureus strains, and strains were located in 6 sub-groups. A total of 71% (n=30) of the strains were clustered in one main group and placed 4 sub-groups by RAPD assay. The two MRSA strains produced identical patterns and distinguished from other S. aureus strains by RAPD method. This paper is the first report of MRSA isolation from caprine clinical mastitis cases.

Determination of variability in monosporidial lines of Tilletia indica by RAPD analysis

Genetic variability in 23 monosporidial lines developed from five isolates of Tilletia indica causing Karnal bunt of wheat isolated from four wheat growing states of India was determined by using 19 rapid amplified polymorphic DNA (RAPD) markers. Amplification profile generated with all the 19 primers produced 3–16 numbers of bands of 1.5–5 kb size. High level of polymorphism (95.2%) suggested wide range of variability. Maximum Jaccard's similarity coefficient (80%) was observed between KB2MsB and KB2MsC followed by KB5MsC and KB5MsE with 75% similarity, whereas it was minimum between KB3MsA and Kb4MsB (47%). The dendrogram derived from the fingerprint analysis with 19 RAPD primers by using UPGMA showed different levels of genetic similarity among monosporidial lines. At 35% genetic similarity, the monosporidial lines were grouped in two clusters. Some primers, viz., OPN-1, OPN-6, OPN-9, OPN-12, OPN-13, OPN-18, OPM-2, OPM-8, OPM-10, OPB-8, OPB-17 and OPB-20 showed 100% polymorphism. The RAPD fingerprint generated by OPN-1 and OPM-3 were analysed and showed high range of variation in genetic make-up of monosporidial lines.

Environmental and clinical epidemiology of Aspergillus terreus: data from a prospective surveillance study

Aspergillus terreus may be resistant to amphotericin B and is associated with significant morbidity and mortality in immunocompromised patients. Local incidence is influenced by the density of airborne Aspergillus spp. spores which may in turn depend on meteorological factors. Once-weekly environmental samples were collected prospectively inside and outside the University Hospital of Cologne, Germany (UHC) and haematological patients were screened for nasal Aspergillus spp. colonisation and monitored for invasive fungal disease (IFD). RAPD (rapid amplification of polymorphic DNA)-polymerase chain reaction (PCR) and amphotericin B susceptibility testing were performed on all A. terreus isolates. A total of 4919 colony-forming units (cfu) were isolated (2212 indoors, 2707 outdoors). Further identification revealed A. fumigatus (73.5%), A. niger (4.3%), A. flavus (1.7%), A. terreus (0.2%) and non-Aspergillus fungi (20.3%). RAPD-PCR did not reveal clonal relationships between the A. terreus isolates. All A. terreus isolates displayed complete resistance to amphotericin. The B. Aspergillus spp. conidia exposure was lowest in June and highest in November inside and outside UHC. Conidia load correlated with the season and the relative humidity, with increasing spore counts during dry periods. One out of 855 nasal swabs was positive for A. niger. The patient did not develop IFD. A. terreus is unlikely to be a relevant pathogen at the UHC. Results from RAPD-PCR suggested a wide epidemiological variety of strains rather than a common source of contamination. Nasal swab surveillance cultures for early detection of Aspergillus spp. colonisation were not useful in identifying patients who may develop IFD. The risk of IFD at the UHC may increase in autumn and during dry periods.

Phosphate solubility and biocontrol activity of Trichoderma harzianum

Biological control of soilborne plant pathogens is a possible alternative to the use of chemical pesticides, which are harmful to the environment. Under greenhouse and field conditions, several isolated strains of the fungus Trichoderma have been found to be effective biocontrol agents of various soilborne plant pathogenic fungi. The use of phosphate solubilizing microorganisms (PSMs) has a considerable synergistic effect on the growth and development of crop plants. In the present study, T. harzianum was isolated from 10 different agro-climatic zones of Karnataka and tested for the potential of antagonistic activity against the plant pathogen Xanthomonas and the ability of phosphate solubility under in vitro conditions. Variations within the 10 isolates of T. harzianum were assayed using the Rapid Amplification of Polymorphic DNA (RAPD) method.