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Colony Morphology (colony + morphology)
Selected AbstractsAnalysis of non- Saccharomyces yeast populations isolated from grape musts from Sicily (Italy)JOURNAL OF APPLIED MICROBIOLOGY, Issue 6 2008D.P. Romancino Abstract Aims:, The aim of this study was to identify the non- Saccharomyces yeast populations present in the grape must microflora from wineries from different areas around the island of Sicily. Methods and Results:, Yeasts identification was conducted on 2575 colonies isolated from six musts, characterized using Wallerstein Laboratory (WL) nutrient agar, restriction analysis of the amplified 5·8S-internal transcribed spacer region and restriction profiles of amplified 26S rDNA. In those colonies, we identified 11 different yeast species originating from wine musts from two different geographical areas of the island of Sicily. Conclusions:, We isolated non- Saccharomyces yeasts and described the microflora in grape musts from different areas of Sicily. Moreover, we discovered two new colony morphologies for yeasts on WL agar never previously described. Significance and Impact of the Study:, This investigation is a first step in understanding the distribution of non- Saccharomyces yeasts in grape musts from Sicily. The contribution is important as a tool for monitoring the microflora in grape musts and for establishing a new non- Saccharomyces yeast collection; in the future, this collection will be used for understanding the significance of these yeasts in oenology. [source] Phenotypes, serotypes and antibiotic susceptibility of Swedish Porphyromonas gingivalis isolates from periodontitis and periodontal abscessesMOLECULAR ORAL MICROBIOLOGY, Issue 2 2007G. Dahlén This study was conducted to reveal phenotypic, serological subtypes and antibiotic susceptibility among fresh isolates of Porphyromonas gingivalis in a Swedish population with periodontitis and periodontal abscess. Fifty-five subgingival strains were isolated and tentatively designated as P. gingivalis from 55 consecutive paper-point samples taken from 51 patients with periodontitis (at least one site with >6-mm pocket depth) in Sweden and were sent in for microbiological evaluation. Eight P. gingivalis strains from periodontal abscesses were also included. Four P. gingivalis strains served as reference and another four type strains were included. The strains were characterized by colony morphology, biochemical tests, enzyme profile, gas,liquid chromatography and antibiotic susceptibility. The strains were further characterized for whole cell protein profiles using sodium dodecyl sulphate,polyacrylamide gel electrophoresis (SDS,PAGE) and were identified to serotype by specific monoclonal antibodies. Among the 55 P. gingivalis strains 35 had smooth (S), 13 rough (R) and seven semi-rough colony morphologies. All strains were phenotypically homogeneous in biochemical tests, enzyme profile and antibiotic susceptibility. All strains produced phenylacetic acid and , -fucosidase. Almost all (96%) of the subgingival strains, but relatively fewer (62%) of the abscess strains, belonged to serotype A. Two subgingival and three abscess strains were classified as serotype B. No specific SDS,PAGE protein profiles were recorded for the two serotypes. The P. gingivalis strains from Swedish periodontitis cases showed homogeneity in terms of biochemical phenotypes and antibiotic susceptibility patterns. The strains fell into two serotypes, of which serotype A predominated in the periodontitis cases and serotype B was overrepresented in periodontal abscesses. [source] High phenotypic diversity in infecting but not in colonizing Staphylococcus aureus populationsENVIRONMENTAL MICROBIOLOGY, Issue 12 2007Christiane Goerke Summary In hostile environments diversity within a bacterial population may be beneficial for the fitness of the microbial community as a whole. Here we analysed the population diversity of Staphylococcus aureus in infecting and colonizing situations. In the study, performed independently in two German centres, the heterogeneity of the S. aureus population was determined by quantifying the occurrence of phenotypic variants (differences in haemolysis, pigmentation, colony morphology) in primary cultures from nose, oropharyngeal and sputum specimens from cystic fibrosis (CF) patients and in nose swabs from healthy S. aureus carriers. The proportion of heterogeneous samples, the number of clearly distinguishable isolates per sample and the qualitative differences between phenotypes was significantly higher in CF sputum specimens than in the other samples. The heterogeneity of the S. aureus population could be correlated with high bacterial densities in the sputum samples. In patients co-infected with Pseudomonas aeruginosa lower S. aureus bacterial loads and less heterogeneity in the S. aureus population were observed. Typing of all S. aureus isolates from heterogeneous samples by pulsed-field gel electrophoresis or spa typing revealed that the bacteria were polyclonal in 30%, monoclonal with minor genetic alterations in 25% or not distinguishable in 69% of the specimens. Some specimens harboured monoclonal and polyclonal variants simultaneously. Importantly, differences in antibiotic susceptibility were detected in phenotypic S. aureus variants within a single specimen. Diversification of a S. aureus population is highly favoured during chronic CF lung infection, supporting the general hypothesis that maintenance of intrahost diversity can be of adaptive value, increasing the fitness of the bacterial community. [source] First laboratory confirmation of Xylophilus ampelinus in Slovenia,EPPO BULLETIN, Issue 1 2005T. Dreo Bacterial blight of grapevine is caused by a slow-growing bacterium Xylophilus ampelinus. It has been suspected to occur in Slovenia on the basis of visual observation of characteristic symptoms in the 1960s. In the present study, symptoms were recorded in an infected vineyard during three consecutive years (2002/2004). Samples from this vineyard were tested by nested-PCR and isolation of bacteria on media was attempted. In the first year, angular lesions on leaves were highly expressed and an isolate morphologically similar to X. ampelinus was obtained from one sample. It was purified and identified as X. ampelinus using biochemical and nutritional tests, fatty acid analysis, immuno-fluorescence, nested PCR and partial sequencing of the 16S rRNA gene. The 16S rDNA sequence showed 99,100% homology to known sequences of X. ampelinus strains, including the type strain. Pathogenicity of the isolate was confirmed in tissue-cultured and potted grapevine plants. In the following two years, symptoms of bacterial blight were only faintly expressed. Using isolation on media and nested-PCR, 23 and 17 extracts prepared from 10 and 8 grapevines, respectively, were analysed. In 2003, no positive sample was found, but X. ampelinus was again isolated and identified by colony morphology and nested-PCR in 2004. [source] Heterologous complementation of the exopolysaccharide synthesis and carbon utilization phenotypes of Sinorhizobium meliloti Rm1021 polyhydroxyalkanoate synthesis mutantsFEMS MICROBIOLOGY LETTERS, Issue 2 2004Punita Aneja Abstract A reduced exopolysaccharide phenotype is associated with inability to synthesize polyhydroxyalkanaote (PHA) stores in Sinorhizobium meliloti strain Rm1021. Loss of function mutations in phbB and phbC result in non-mucoid colony morphology on Yeast Mannitol Agar, compared to the mucoid phenotype exhibited by the parental strain. This phenotype is attributed to reduction in succinoglycan synthesis. We have used complementation of this phenotype and the previously described d -3-hydroxybutyrate/acetoacetate utilization phenotype to isolate a heterologous clone containing a Bradyrhizobium japonicum phbC gene. Sequence analysis confirmed that this clone contains one of the five predicted phbC genes in the B. japonicum genome. The described phenotypic complementation strategy should be useful for isolation of novel PHA synthesis genes of diverse origin. [source] Methods for the isolation and identification of Listeria spp. and Listeria monocytogenes: a reviewFEMS MICROBIOLOGY REVIEWS, Issue 5 2005Uta Gasanov Abstract Listeria monocytogenes is an important food-borne pathogen and is widely tested for in food, environmental and clinical samples. Identification traditionally involved culture methods based on selective enrichment and plating followed by the characterization of Listeria spp. based on colony morphology, sugar fermentation and haemolytic properties. These methods are the gold standard; but they are lengthy and may not be suitable for testing of foods with short shelf lives. As a result more rapid tests were developed based on antibodies (ELISA) or molecular techniques (PCR or DNA hybridization). While these tests possess equal sensitivity, they are rapid and allow testing to be completed within 48 h. More recently, molecular methods were developed that target RNA rather than DNA, such as RT-PCR, real time PCR or nucleic acid based sequence amplification (NASBA). These tests not only provide a measure of cell viability but they can also be used for quantitative analysis. In addition, a variety of tests are available for sub-species characterization, which are particularly useful in epidemiological investigations. Early typing methods differentiated isolates based on phenotypic markers, such as multilocus enzyme electrophoresis, phage typing and serotyping. These phenotypic typing methods are being replaced by molecular tests, which reflect genetic relationships between isolates and are more accurate. These new methods are currently mainly used in research but their considerable potential for routine testing in the future cannot be overlooked. [source] Yeast diversity sampling on the San Juan Islands reveals no evidence for the spread of the Vancouver Island Cryptococcus gattii outbreak to this localeFEMS YEAST RESEARCH, Issue 4 2006James A. Fraser Abstract Biological diversity has been estimated for various phyla of life, such as insects and mammals, but in the microbe world is has been difficult to determine species richness and abundance. Here we describe a study of species diversity of fungi with a yeast-like colony morphology from the San Juan Islands, a group of islands that lies southeast of Vancouver Island, Canada. Our sampling revealed that the San Juan archipelago biosphere contains a diverse range of such fungi predominantly belonging to the Basidiomycota, particularly of the order Tremellales. One member of this group, Cryptococcus gattii, is the etiological agent of a current and ongoing outbreak of cryptococcosis on nearby Vancouver Island. Our sampling did not, however, reveal this species. While the lack of recovery of C. gattii does not preclude its presence on the San Juan Islands, our results suggest that the Strait of Juan de Fuca may be serving as a geographical barrier to restrict the dispersal of this primary human fungal pathogen into the United States. [source] Generation of endoderm-derived human induced pluripotent stem cells from primary hepatocytes,HEPATOLOGY, Issue 5 2010Hua Liu Recent advances in induced pluripotent stem (iPS) cell research have significantly changed our perspective on regenerative medicine. Patient-specific iPS cells have been derived not only for disease modeling but also as sources for cell replacement therapy. However, there have been insufficient data to prove that iPS cells are functionally equivalent to human embryonic stem (hES) cells or are safer than hES cells. There are several important issues that need to be addressed, and foremost are the safety and efficacy of human iPS cells of different origins. Human iPS cells have been derived mostly from cells originating from mesoderm and in a few cases from ectoderm. So far, there has been no report of endoderm,derived human iPS cells, and this has prevented comprehensive comparative investigations of the quality of human iPS cells of different origins. Here we show for the first time reprogramming of human endoderm-derived cells (i.e., primary hepatocytes) to pluripotency. Hepatocyte-derived iPS cells appear indistinguishable from hES cells with respect to colony morphology, growth properties, expression of pluripotency-associated transcription factors and surface markers, and differentiation potential in embryoid body formation and teratoma assays. In addition, these cells are able to directly differentiate into definitive endoderm, hepatic progenitors, and mature hepatocytes. Conclusion: The technology to develop endoderm,derived human iPS cell lines, together with other established cell lines, will provide a foundation for elucidating the mechanisms of cellular reprogramming and for studying the safety and efficacy of differentially originated human iPS cells for cell therapy. For the study of liver disease pathogenesis, this technology also provides a potentially more amenable system for generating liver disease-specific iPS cells. (HEPATOLOGY 2010;51:1810,1819) [source] Nutritional physiology and colony form in Podocoryna carnea (Cnidaria: Hydrozoa)INVERTEBRATE BIOLOGY, Issue 4 2008Dirk Bumann Abstract. We compared growth rates and final morphological states of the athecate colonial hydroid Podocoryna carnea in two nutritional environments: one varying the quantity of food provided at a fixed interval and the second varying the time between feedings of a fixed quantity. In both environments, replicate colonies were either fed uniformly, or fed on only one side and starved on the other. In addition, we fed colonies fluorescence-labeled cultures of Artemia salina and documented the subsequent distribution of label. We found that both the growth rates and the final morphological state varied logarithmically with food supply. Heterogeneous feeding had a marked effect on colony morphology, with a sharp boundary in polyp number, stolon density, and polyp size forming at the fed,unfed interface. The distribution of fluorescence was correlated with sites of colony growth. These results confirm and extend early work on the priority of growth zones in colonial hydroids, and present new challenges for understanding the relationship among energy metabolism, gastrovascular circulation, and colony form. [source] Effects of repeated cycles of acid challenge and growth on the phenotype and virulence of Salmonella entericaJOURNAL OF APPLIED MICROBIOLOGY, Issue 5 2008K.A.G. Karatzas Abstract Aims:, The aim of the study was to investigate how stresses like low pH, which may be encountered in farms or food preparation premises, shape populations of Salmonella enterica by the selection of stress-resistant variants. Methods and Results:, Stationary-phase cultures of S. enterica serovar Enteritidis and serovar Typhimurium (one strain of each) were exposed to pH 2·5 for up to 4 h, followed by growth at pH 7 for 48 h. This process was repeated 15 times in two separate experiments, which increased the acid resistance of the three out of four populations we obtained, by three- to fourfold. Sustainable variants derived from the populations showed changes in colony morphology, expression of SEF17 fimbriae, growth, increased heat resistance and reduced virulence. Conclusions:, The study demonstrates that low pH environments can select for populations of S. enterica with persistent phenotypic changes such as increased acid resistance and occasionally increased SEF17 expression and lower virulence. Significance and Impact of the Study:, There is a common belief that increased acid resistance coincides with increased virulence. This study demonstrates for the first time that increased acid resistance often impairs virulence and affects the general phenotype of S. enterica. [source] Efficient removal of hexavalent chromium by a tolerant Streptomyces sp. affected by the toxic effect of metal exposureJOURNAL OF APPLIED MICROBIOLOGY, Issue 6 2007D.K. Morales Abstract Aims:, To isolate and analyse chromium-resistant micro-organisms suitable for bioremediation. Methods and Results:, Strain CG252, with a minimal inhibitory concentration of 500 ,g ml,1, was isolated from contaminated soils and identified as a Streptomyces sp. by 16S rDNA sequence analysis. Assays carried out at various Cr(VI) concentrations indicated that chromium removal was more efficient at lower concentrations and that this activity resulted in accumulation of Cr(III). Atomic adsorption analysis indicated that the chromium removed was not associated with cell mass and activity assays showed that the capacity to reduce Cr(VI) was most probably due to a soluble cytosolic enzyme. Cells grown as biofilms showed enhanced removal of Cr(VI) with respect to planktonic cells, while analysis of growth and colony morphology indicated that Cr(VI) had a toxic effect on this strain. Conclusions:,Streptomyces sp. CG252 tolerated heavy metals and elevated levels of chromium, despite its negative effect on growth and development, and was efficient at removing Cr(VI) by promoting reduction to Cr(III). Significance and Impact of the Study:, Strain CG252's capacity to tolerate heavy metals and to reduce Cr(VI) to the less toxic Cr(III), especially when forming biofilms, makes it a promising candidate for detoxification of sites containing this heavy metal. [source] Cytotoxic Bacillus spp. belonging to the B. cereus and B. subtilis groups in Norwegian surface watersJOURNAL OF APPLIED MICROBIOLOGY, Issue 5 2004Ř. Řstensvik Abstract Aims:, To investigate the presence and numbers of Bacillus spp. spores in surface waters and examine isolates belonging to the B. cereus and B. subtilis groups for cytotoxicity, and to discuss the presence of cytotoxic Bacillus spp. in surface water as hazard identification in a risk assessment approach in the food industry. Methods and Results:, Samples from eight different rivers with variable degree of faecal pollution, and two drinking water sources, were heat shocked and examined for the presence of Bacillus spp. spores using membrane filtration followed by cultivation on bovine blood agar plates. Bacillus spp. was present in all samples. The numbers varied from 15 to 1400 CFU 100 ml,1. Pure cultures of 86 Bacillus spp. isolates representing all sampling sites were characterized using colony morphology, atmospheric requirements, spore and sporangium morphology, and API 50 CHB and API 20E. Bacillus spp. representing the B. cereus and B. subtilis groups were isolated from all samples. Twenty-one isolates belonging to the B. cereus and B. subtilis groups, representing eight samples, were screened for cytotoxicity. Nine strains of B. cereus and five strains belonging to the B. subtilis group were cytotoxic. Conclusions:, The presence of cytotoxic Bacillus spp. in surface water represents a possible source for food contamination. Filtration and chlorination of surface water, the most common drinking water treatment in Norway, do not remove Bacillus spores efficiently. This was confirmed by isolation of spores from tap water samples. Significance and Impact of the Study:, Contamination of food with water containing low numbers of Bacillus spores implies a risk for bacterial growth in foods. Consequently, high numbers of Bacillus spp. may occur after growth in some products. High numbers of cytotoxic Bacillus spp. in foods may represent a risk for food poisoning. [source] Differentiation of Candida dubliniensis from Candida albicans on rosemary extract agar and oregano extract agarJOURNAL OF CLINICAL LABORATORY ANALYSIS, Issue 3 2008Érico Silva de Loreto Abstract Candida dubliniensis is a recently described pathogenic species which shares many phenotypic features with Candida albicans and therefore, may be misidentified in microbiological laboratories. Because molecular methods can be onerous and unfeasible in routine mycological laboratories with restricted budgets such as those in developing countries, phenotypic techniques have been encouraged in the development of differential media for the presumptive identification of these species. We examined the colony morphology and chlamydospore production of 30 C. dubliniensis isolates and 100 C. albicans isolates on two new proposed media: rosemary (Rosmarinus officinalis) extract agar (REA) and oregano (Origanum vulgare) extract agar (OEA). These substrates are traditionally used as spices and medicinal herbs. In both of these media, all C. dubliniensis isolates (100%) showed rough colonies with peripheral hyphal fringes and abundant chlamydospores after 24 to 48,hr of incubation at 25°C. In contrast, under the same conditions, all isolates of C. albicans (100%) showed smooth colonies without hyphal fringes or chlamydospores. In conclusion, REA and OEA offer a simple, rapid, and inexpensive screening media for the differentiation of C. albicans and C. dubliniensis. J. Clin. Lab. Anal. 22:172,177, 2008. © 2008 Wiley-Liss, Inc. [source] Salmonella enterica phage-resistant mutant colonies display an unusual phenotype in the presence of phage Felix 01LETTERS IN APPLIED MICROBIOLOGY, Issue 6 2007G. O'Flynn Abstract Aims:, To investigate irregular colony morphology formation in Salmonella enterica serovar Typhimurium DPC6046 in the presence of a lytic phage, Felix 01. Methods and Results:, Phage-resistant derivatives of the parent strain DPC6046 were isolated which exhibited an irregular colony morphology. These were subjected to viability studies by using confocal scanning laser microscopy and live/dead BacLight stain to evaluate the cell viability within the colony. The phenomenon was also observed with other S. enterica serotypes tested which were normally sensitive to phage Felix. In the case of strain DPC6046, dead cells were clearly evident at the irregular edges of the phage-resistant colonies in locations where the cell density was lower. This colony morphology was not apparent with two other Salmonella phages tested. Conclusions:, These findings support the hypothesis that the unusual morphology is due to reversion to phage sensitivity and consequent cell death within the colony as it forms. Significance and Impact of the Study:, The irregular colony morphology observed is peculiar to phage Felix. The confocal scanning laser microscopy methodology allowed the basis for the irregular morphology to be elucidated. [source] Selective medium based on tyrosine metabolism for the isolation and enumeration of Brevibacillus brevis (Bacillus brevis)LETTERS IN APPLIED MICROBIOLOGY, Issue 5 2000S.G. Edwards Aims: To develop a selective medium for the enumeration of Brevibacillus brevis Nagano spores from soil and plant material. Methods and Results: Tyrosine agar was developed as a selective medium and compared with nutrient agar for the enumeration of B. brevis Nagano spores from sterile and non-sterile plant and soil extracts. Brevibacillus brevis Nagano colonies could be easily identified only on tyrosine agar due to their clear halo and distinct colony morphology. Identification was confirmed by thin layer chromatography of the antibiotic, gramicidin S, produced by this strain. Conclusions: Tyrosine agar was shown to be a suitable selective medium for the enumeration of B. brevis Nagano. Significance and impact of the study: The medium developed, tyrosine agar, can be used to monitor the population of the biological control agent, B. brevis Nagano, and will allow detailed studies within the crop environment. [source] Phenotypes, serotypes and antibiotic susceptibility of Swedish Porphyromonas gingivalis isolates from periodontitis and periodontal abscessesMOLECULAR ORAL MICROBIOLOGY, Issue 2 2007G. Dahlén This study was conducted to reveal phenotypic, serological subtypes and antibiotic susceptibility among fresh isolates of Porphyromonas gingivalis in a Swedish population with periodontitis and periodontal abscess. Fifty-five subgingival strains were isolated and tentatively designated as P. gingivalis from 55 consecutive paper-point samples taken from 51 patients with periodontitis (at least one site with >6-mm pocket depth) in Sweden and were sent in for microbiological evaluation. Eight P. gingivalis strains from periodontal abscesses were also included. Four P. gingivalis strains served as reference and another four type strains were included. The strains were characterized by colony morphology, biochemical tests, enzyme profile, gas,liquid chromatography and antibiotic susceptibility. The strains were further characterized for whole cell protein profiles using sodium dodecyl sulphate,polyacrylamide gel electrophoresis (SDS,PAGE) and were identified to serotype by specific monoclonal antibodies. Among the 55 P. gingivalis strains 35 had smooth (S), 13 rough (R) and seven semi-rough colony morphologies. All strains were phenotypically homogeneous in biochemical tests, enzyme profile and antibiotic susceptibility. All strains produced phenylacetic acid and , -fucosidase. Almost all (96%) of the subgingival strains, but relatively fewer (62%) of the abscess strains, belonged to serotype A. Two subgingival and three abscess strains were classified as serotype B. No specific SDS,PAGE protein profiles were recorded for the two serotypes. The P. gingivalis strains from Swedish periodontitis cases showed homogeneity in terms of biochemical phenotypes and antibiotic susceptibility patterns. The strains fell into two serotypes, of which serotype A predominated in the periodontitis cases and serotype B was overrepresented in periodontal abscesses. [source] Two epithelial cell invasion-related loci of the oral pathogen Actinobacillus actinomycetemcomitansMOLECULAR ORAL MICROBIOLOGY, Issue 1 2004L. Li Two invasion-related loci, apiA and the two-gene operon apiBC, were isolated from the oral pathogen Actinobacillus actinomycetemcomitans UT32. apiA encodes a 32.5 kDa protein that migrates on SDS-PAGE as a 101 kDa protein as detected by Western blot analysis or silver staining of an outer membrane-enriched fraction of Escherichia coli transformants. E. coli expressing ApiA have a different phenotype than the host vector, in broth and on solid media, and a colony morphology that resembles that of fresh A. actinomycetemcomitans isolates. These E. coli transformants bound to chicken collagen type II, human collagen type II, III, V and fibronectin. apiB and apiC encode proteins of 130.1 and 70.6 kDa, respectively. ApiBC conferred on E. coli a slightly enhanced ability to bind to collagen type III. ApiA- and ApiB-deficient mutants were constructed in A. actinomycetemcomitans. The ApiB-mutant had 4-fold diminished invasion of KB cells; the ApiA-mutant had increased invasion. Both loci were found in all A. actinomycetemcomitans strains, although polymorphism was detected only for apiBC. The deduced sequences of these invasion-related proteins are homologous to members of the YadA adhesin/invasin family. [source] Differentiation of Streptococcus mutans and Streptococcus sobrinus via genotypic and phenotypic profiles from three different populationsMOLECULAR ORAL MICROBIOLOGY, Issue 1 2001Y. Li Routine identification of Streptococcus mutans and Streptococcus sobrinus is generally based upon growth on various selective media, colony morphology and biochemical characteristics. We examined various approaches of differentiating these two species through a combination of the conventional phenotypic methodology with chromosomal DNA fingerprint (CDF) and arbitrarily primed polymerase chain reaction (AP-PCR) methods. Initially, ten ATCC type strains and 20 randomly selected clinical isolates of mutans streptococci (MS) were characterized and grouped into two major types based on patterns generated by the CDF using HaeIII digestion. The CDF's patterns with restriction fragments equal to or greater than 6.6 kb were defined as the CDF-1 group. The CDF's patterns with restriction fragments less than 6.6 kb were defined as the CDF-2 group. Both groups were then examined for biotype, serotype, and composition of DNA via thermal denaturation. AP-PCR was applied and evaluated for the capability of delineating S. mutans from S. sobrinus strains. Results of this study showed that all CDF-1 strains fit within a G+C range of 36.2% to 42.2%, whereas the CDF-2 strains had a G+C range of 45.8% to 47.0%. The serotyping assay exhibited 100% sensitivity, 90% specificity and 86.7% agreement with the CDF. The biotyping assay presented the poorest specificity (38.5%), indicating the highest variability. The capability of AP-PCR in differentiation of S. mutans from S. sobrinus was comparable to the CDF method, suggesting that either of these two approaches can and may serve as a viable alternative method to serotyping or biotyping of MS. [source] Prevalence and phenotypic evaluation of Candida dubliniensis in pregnant women with vulvovaginal candidosis in a university hospital in AnkaraMYCOSES, Issue 1 2007E. Us Summary Candida dubliniensis is very similar to Candida albicans in terms of genotypic and phenotypic characteristics. As the hormonal milieu of the vagina during pregnancy, characterised by a lack of maternal cell-mediated immunity, enhances Candida colonisation and serves as a risk factor for symptomatic expression, investigation into the isolation of C. dubliniensis in vaginal discharges of pregnant women with vulvovaginal candidosis was made. A total of 77 Candida isolates obtained from 60 patients positive for vulvovaginal candidosis collected from 218 pregnant women were investigated for C. dubliniensis subsistence. In total 41 Candida species phenotypically identified as C. albicans on the basis of a positive germ tube test and carbohydrate assimilation tests were screened for the presence of C. dubliniensis. Phenotypic tests for differentiation of C. dubliniensis from C. albicans, such as growth at 42 and 45 °C on Sabouraud dextrose agar, appearance on CHROMagar and colony morphology on Cornmeal,Tween-80 agar and Staib agar were carried out. Only one strain (2.43%) was phenotypically identified as C. dubliniensis. According to our study, a combination of at least five phenotypic methods is necessary for an exact diagnosis of C. dubliniensis. Large-scale studies of pregnant women are required to discover the aetiological importance of this yeast. [source] Initial Candida dubliniensis isolate in Candida spp. positive haemocultures in Turkey between 2001 and 2004MYCOSES, Issue 1 2006Alper Tekeli Summary Candida dubliniensis which was first recognized in 1995 can be easily misidentified because of its phenotypic similarities with Candida albicans. In this study blood samples of patients from various departments of Ankara University Medical Faculty between January 2001,June 2004 were investigated for the distribution of Candida spp. and the presence of C. dubliniensis. Culture positive 67 fungi were included to the study. Phenotypic tests such as chlamydospore formation, colony morphology on Staib agar, growth at 45 °C, carbohydrate assimilation profiles were investigated for identification and differentiation of C. dubliniensis from C. albicans. To confirm the results polymerase chain reaction were used for suspected C. albicans and C. dubliniensis isolates. Among 38 germ tube and chlamydospore forming isolates, 37 of them were found as C. albicans and one as C. dubliniensis. The incidence of C. dubliniensis in our hospital is still low, this is the first C. dubliniensis isolate as an agent of candidaemia reported from Turkey. [source] Characterization of agrobacteria from weeping fig (Ficus benjamina)PLANT PATHOLOGY, Issue 5 2001A. Zoina Ficus benjamina plants, galled both at epi- and hypogeous parts, were observed in Italy and in The Netherlands, and these were the first records of the appearance of weeping fig crown gall in Europe. A total of 241 Agrobacterium isolates was obtained from 41 tumours and studied for their morphological, physiological and phytopathological characters. Two main groups of agrobacteria were distinguished by their colony morphology and through classical biovarietal tests that allowed allocation of 86 isolates into biovar 1 and 155 into an intermediate biovar rather different from any of the three biovars defined for agrobacteria. Most of the isolates were unable to utilize mannopine, nopaline or octopine as C and N sources; only 62 strains utilized nopaline. However, when nonopine-utilizing strains were inoculated into F. benjamina, only nopaline was detected in the developing tumours. BIOLOG ML 1Ô system analysis applied to 50 representative strains allowed identification of the biovar 1 isolates as Agrobacterium tumefaciens and most of the intermediate biovar isolates as the newly proposed species Agrobacterium fici. Analysis of sensitivity to a set of 14 antibiotics confirmed the allocation of the 50 strains into two well defined main clusters matching the BIOLOG identification. Out of 141 tumorigenic isolates, 66 were sensitive in vitro to agrocine 84, but four of these strains showed scarce or no sensitivity to the antagonist A. radiobacter K84 when tested in fig plants. The two types of agrobacteria could usually be isolated from the same tumours. Tumorigenic strains were able to induce tumours in six herbaceous plant species, in eight to 10 out of 12 woody plants and in six to eight out of nine Ficus species, indicating a wide host-range Ti plasmid. Agrobacteria were able to survive and move in the vascular system of galled ficus plants and to induce tumour growth in stem-cutting propagated plants. Moreover, agrobacteria were detected in many healthy F. benjamina plants as part of the endophytic microflora. These findings suggest potential for spread of the disease through latently infected plant propagation material produced as cuttings or by tissue culture. [source] A Chinese,Japanese boy with black dot ringworm due to Trichophyton violaceumTHE JOURNAL OF DERMATOLOGY, Issue 3 2006Maho KONDO ABSTRACT A 4-year and 8-month-old Chinese-Japanese boy, who had been visiting Dalian, China frequently, developed multiple alopecia lesions 1 year previously. At his initial visit to our department, multiple patchy alopecia with black dots was observed in the parietal scalp area. Multiple erythematous macules were also seen on the face, nape and right dorsum of the hand. A diagnosis of tinea capitis and tinea corporis was obtained on the basis of potassium hydroxide (KOH) microscopic examination of hair and scales from the lesions. Colonies grown on Sabouraud cycloheximide-chloramphenicol agar culture were examined using Fungi-Tape and MycoPerm-blue, and numerous microconidia and a small number of macroconidia were observed. Trichophyton violaceum was identified as the causative organism on the basis of colony morphology, microscopic morphology and molecular biology technique. As T. violaceum infection is not often seen in Japan, we suspected that the patient was infected by T. violaceum during his stay in Dalian. Conidia formation is rarely observed with T. violaceum, and only five cases with T. violaceum macroconidia formation have been reported in Japan (including this case). We also report the method for visualizing conidia formation of T. violaceum using Fungi-tape and MycoPerm-blue. [source] | ||||||||||||||||||||||||||||