Evaluation of the production of antifungal metabolites against Colletotrichum gloeosporioides in Streptomyces 5.1 by random mutagenesis

Streptomyces 5.1 is a bacterium isolated from rice soils in the south of the Tolima department (Colombia). This microorganism is characterized by its antagonistic activity against rubber tree phytopathogens like Colletotrichum gloeosporioides, the causal agent of leaf anthracnose. The antifungal activity of this Streptomyces isolate has been associated with secondary metabolites production. However, the identity of those metabolites is unknown because its purification and identification have not been possible through classic chemical studies. Therefore, aiming to contribute in the study of the secondary metabolites produced by 5.1 from a molecular approach, this research seeks to identify -preliminarily- the genomic fingerprint changes associated with the production of antifungal secondary metabolites produced by Streptomyces 5.1 through the evaluation of a mutant library of 5.1 obtained by random mutagenesis using controlled ultraviolet light exposure. The antifungal activity of obtained mutants was evaluated using Colletotrichum gloeosporioides (C1) fungus as a biosensor, isolated by the Biotechnology Institute of Universidad Nacional de Colombia. In this way, the library of mutants of 5.1, initially formed by 300 isolations, was classified into two phenotypic groups of interest: enhanced mutants (1 isolate) and null mutants (11 isolates) of secondary metabolites. The genomic changes in both groups were analyzed by obtaining the genomic profile of the isolates using Repetitive Extragenic Palindromic (Rep-PCR). The obtained profiles evidenced the presence of one additional band in the enhanced mutant, and the absence of a specific band in the non-producing mutants, both in comparison with the original strain. These bands are proposed for a future sequencing study which will define their role in the production process of metabolites with antifungal activity in Streptomyces 5.1.

Application of PCR fingerprinting using (GACA) 4 primer in the rapid discrimination of dermatophytes.

Background: Superficial fungal infections have a major impact on cosmetic health, affecting more than 20-25% of the global population, which is predominantly caused by dermatophytes. As per literature search, molecular strain typing of dermatophytes has not been investigated in India. Therefore, the present study was carried out to characterise the dermatophyte species and strains by molecular methods. Objective: To analyse the genotype variability by applying polymerase chain reaction (PCR) fingerprinting using a simple sequence repetitive oligonucleotide (GACA)4 primer to identify the species and strain variations among the dermatophytes isolated from a tertiary care centre in Chennai. Materials and Methods: From January 2010 to December 2010, 81 dermatophytes were isolated and included for the present study. A simple sequence repetitive oligonucleotide (GACA)4 was used as a single primer in the amplification process. Results: The (GACA)4‑based PCR successfully amplified all the clinical isolates. Trichophyton rubrum and T. rubrum var. raubitschekii produced identical band profiles, where the latter could not be differentiated from the T. rubrum, which are being reported for the first time from south India. Epidermophyton floccosum produced species‑specific band profiles. Intra‑species variability was not observed among the T. rubrum and E. floccosum isolates. T. mentagrophytes produced three simple, distinct band patterns, which are surprisingly different from the earlier studies. Conclusion: The PCR‑based genotype using the short primer is rapid and precise in direct identification of dermatophyte isolates by one‑step PCR to the species level and strain discrimination of the T. mentagrophytes variants.

Yeast diversity associated to sediments and water from two Colombian artificial lakes

In Colombia, knowledge of the yeast and yeast-like fungi community is limited because most studies have focused on species with clinical importance. Sediments and water represent important habitats for the study of yeast diversity, especially for yeast species with industrial, biotechnological, and bioremediation potential. The main purpose of this study was to identify and compare the diversity of yeast species associated with sediment and water samples from two artificial lakes in Universidad del Valle (Cali-Colombia). Yeast samplings were performed from fifteen sediment samples and ten water samples. Grouping of similar isolates was initially based on colony and cell morphology, which was then complemented by micro/mini satellite primed PCR banding pattern analysis by using GTG5 as single primer. A representative isolate for each group established was chosen for D1/D2 domain sequencing and identification. In general, the following yeast species were identified: Candida albicans, Candida diversa, Candida glabrata, Candida pseudolambica, Cryptococcus podzolicus, Cryptococcus rajasthanensis, Cryptococcus laurentii, Williopsis saturnus, Hanseniaspora thailandica, Hanseniaspora uvarum, Rhodotorula mucilaginosa, Saccharomyces cerevisiae, Torulaspora delbrueckii, Torulaspora pretoriensis, Tricosporon jirovecii, Trichosporon laibachii and Yarrowia lypolitica. Two possible new species were also found, belonging to the Issatchenkia sp. and Bullera sp. genera. In conclusion, the lakes at the Universidad del Valle campus have significant differences in yeast diversity and species composition between them.

Molecular Typing of Cryptococcus neoformans Isolated from Korean Patients

Cyptococcosis is generally caused by Cryptococcus neoformans, the opportunistic agent which has two species such as C. neoformans and C. gattii. Both C. neoformans and C. gattii species contain a number of genetically diverse subgroups that can be differentiated by various molecular typing methods. We conducted a molecular epidemiological analysis of 30 clinical isolates of the C. neoformans from cryptococcosis patients who had been hospitalized between 2008 and 2010 in medical centers located in Seoul and Busan in Korea. To determine the genetic diversity, 30 strains of C. neoformans were typed using PCR fingerprinting with the microsatellite specific primer of the phage M13 and the restriction fragment length polymorphism (RFLP) of orotidine monophosphosphate pyrophosphorylase (URA5) gene. All isolates were identified as serotype A, mating type MATa and molecular type VNI. The random amplified polymorphic DNA (RAPD) profiles obtained by using two primers revealed a single pattern. Our study shows that 30 strains of clinical C. neoformans are genetically homogeneous, with all of the isolates were molecular type VN1, serotype A, mating type MATa.

Molecular Typing of Clinical Cryptococcus gattii Isolates in Korea

Cryptococcus gattii causes life-threatening yeast infection in the pulmonary and central nervous systems of humans and animals, and traditionally has been considered to restrict into the tropical and subtropical areas. Despite rare incidence of cryptococcosis caused by C. gattii in Korea, three strains of C. gattii isolated from cryptococcosis patients between 1993 and 2010 were identified. To determine the genetic diversity, 3 strains of C. gattii were typed using PCR fingerprinting with primer M13 and the restriction fragment length polymorphism (RFLP) of orotidine monophosphosphate pyrophosphorylase (URA5) gene. All isolates were identified as serotype B and MATalpha mating type. The molecular types of each strain, on the other hand, turned out to be distinct belonging to VGI, VGII or III types, respectively. Although the travel histories of the patients were not available, clinical C. gattii strains isolated in Korea may represent the diverse molecular types existing worldwide.

Molecular Characterization of Clinical and Environmental Strains of Cryptococcus neoformans Isolated from Busan, Korea

Cryptocococcus neoformans is an encapsulated yeast that can cause life-threatening infections in immunocompromised patients. In this study, the genetic variability and epidemiological relationships of clinical and environmental isolates of C. neoformans from Busan, Korea, 2000~2005 were investigated. A total of 12 strains of C. neoformans, 7 clinical and 5 environmental isolates were analyzed by random amplified polymorphic DNA (RAPD) using three different primers and PCR-fingerprinting with a minisatellite-specific core sequence of phage M13. All strains belonged to C. neoformans serotype A and mating type MATa. Two different RAPD profiles (I and II) and a single pattern by M13 PCR-fingerprinting were identified. The major RAPD profile was pattern I (8 of 12 strains) and pattern II was identified from 2 clinical and 2 environmental strains, which clearly distinguished among isolates. Clinical strains with pattern II were isolated from the patients with HIV positive. Taken together, molecular patterns provide a good characterization of strains of C. neoformans as a heterogeneous group and epidemiological relationships in clinical and environmental strains.

Low genetic diversity among pathogenic strains of Erwinia psidii from Brazil / Baixa diversidade genética entre estirpes patogênicas de Erwinia psidii no Brasil

Erwinia psidii causes bacterial disease of guava in Brazil. Phenotypic and molecular characterization through rep-PCR fingerprinting of 42 strains from different geographical regions showed that E. psidii populations in Brazil have a low level of genetic diversity and suggest that contaminated plant material is the main source for pathogen dissemination in the country.

Erwinia psidii é o agente causal da seca-dos-ponteiros ou bacteriose da goiabeira no Brasil. A caracterização fenotípica e molecular através de rep-PCR de 42 estirpes patogênicas de diferentes regiões mostrou que as populações de E. psidii no Brasil têm um baixo nível de diversidade genética e sugere que material de propagação infectado é a principal fonte de disseminação do patógeno para novas áreas no país.

Caracterização fenotípica e molecular de amostras de Burkholderia mallei isoladas na Região Nordeste do Brasil / Phenotypic and molecular characterization of Burkholderia mallei isolated in northeastern Brazil

Objetivou-se com este trabalho realizar o estudo bioquímico e molecular de amostras de Burkholderia mallei isoladas de eqüídeos com diagnóstico clínico e sorológico para o mormo e provenientes da Região Metropolitana do Recife-PE e Zona da Mata dos Estados de Alagoas e Pernambuco. Foram realizadas as técnicas microbiológicas para o isolamento e identificação fenotípica de B. mallei e as técnicas moleculares de ribotipagem-PCR e RAPD-PCR. Das oito amostras estudadas, quatro apresentaram pequenas variações fenotípicas. Nas técnicas moleculares, as amostras formaram quatro grupos de diferentes perfis ribotípicos, demonstrando também quatro perfis genotípicos. Houve associação nos resultados da Ribotipagem-PCR e RAPD-PCR. As variações nos perfis ribotípicos e genotípicos foram associadas às diferentes regiões estudadas. De acordo com os resultados obtidos, conclui-se que as pequenas variações bioquímicas não estão associadas aos diferentes perfis moleculares e que essas diferenças demonstram uma heterogeneidade que está associada à procedência das amostras, indicando que a infecção nos animais ocorre por clones diferentes das amostras analisadas.

The objective of this paper was to study the molecular performance and phenotypic characterization of Burkholderia mallei isolated from horses with clinical and serological diagnosis of glanders, originating from the Metropolitan District of Recife and Zona da Mata of Pernambuco and Alagoas. The isolation and biochemical identification of B. mallei was carried out by microbiological and molecular techniques of PCR-fingerprinting and RAPD-PCR. From the eight samples studied, four showed little phenotype variations. In the molecular tests, the samples formed 4 groups of different ribotype profiles and 4 genotype profiles. There was some association of PCR-fingerprinting with RAPD-PCR results. It was concluded that the slight biochemical variations were not associated with different molecular profiles. They also indicated that these differences show heterogeneity associated with the origin of the sample, indicating that the infection was caused by clones of different strains and that the polymorphism of DNA observed could make it difficult to choose one standard strain for an immune prophylactic treatment of glanders.

Analysis of the varieties,genotypes and mating types of 110 clinical cryptococcal isolates from China / 中华微生物学和免疫学杂志

Objective To investigate the molecular epidemiology of clinical cryptococcal isolates from China by analyzing the constituents and distributions of the varieties,genotypes and mating types (MAT)of them.Methods (1)PCR fingerprinting and PCR amplification were performed by using the minisatellite-specific core sequence of wild-type phage M13 as single primer.Genotypes of the 110 cryptococcal isolates from China were assigned by comparison with the reference strains of the 8 major molecular types loaded on gel.(2)Identification of the varieties and mating types was carried out by PCR using the specific primers of the varieties and mating types.Results Of the 110 clinical cryptococcal isolates,strains of Cryptococcus neoformans var.grubii with genetype VNⅠ and mating type MATα were the most representative ones(89.1%)followed by strains of C.neoformans var.gattii(8.2%)including isolates of genotype VG I,mating type MATα(7.3%)and genotype VGⅡ,mating type MATα(0.9%);AD hybrids with the genotype VNⅢ,mating type MAT-/α and genotype VN Ⅲ,mating type MATα/-(1.8%);and isolate of C.neoformans var.neoformans with the genotype VNⅣ and mating type MATa(0.9%).Conclusion Of the clinical isolates from China,all three varieties and AD hybrids are found.The vast majority(>99%) of strains possess the α allele in MAT locus and most of them are C.neoformans vat.grubii with the genotype VN I,which accord with the data of most studies of clinical molecular epidemiology in other geographic areas.However.no genotype of VNⅡ.VGⅢ and VGⅣ isolates are found in this study.

Evaluación de la técnica de MSP-PCR para la caracterización molecular de aislamientos de Rhodotorula mucilaginosa provenientes de la Patagonia noroccidental / Assessment of the MSP-PCR technique for the molecular characterization of Rhodotorula mucilaginosa isolates from northwestern Patagonia

La identificación rápida de levaduras de origen ambiental o clínico es de importancia para el estudio de la biodiversidad de estos microorganismos y para la detección de posibles patógenos. Rhodotorula mucilaginosa es una levadura ubicua y pigmentada, capaz de producir infecciones en pacientes inmunocomprometidos. En este trabajo se evaluó la utilidad de la técnica de fingerprinting conocida como MSP-PCR (Micro/Minisatellite-Primed PCR) en la caracterización e identificación de aislamientos ambientales de R. mucilaginosa provenientes de la Patagonia noroccidental. Sobre la base de sus caracteres fenotípicos, de un total de 200 levaduras pigmentadas se seleccionaron 110 aislamientos que presuntamente corresponderían a la especie R. mucilaginosa. Se evaluaron los iniciadores (GTG)5, (GAC)5 y M13 en aislamientos representativos, y se seleccionó el iniciador (GTG)5 por ser el que permitió una mejor agrupación de los aislamientos pertenecientes a R. mucilaginosa y una mejor diferenciación de éstos con los de especies filogenéticamente próximas. Utilizando dicho iniciador, el 87% de los aislamientos de R. mucilaginosa presentó un perfil de MSP-PCR similar (> 60%) al de la cepa de referencia CBS 316T de R. mucilaginosa. La técnica de MSP-PCR resultó efectiva, tanto para caracterizar e identificar un número elevado de aislamientos ambientales de R. mucilaginosa como para detectar polimorfismos en la especie.

The rapid identification of environmental or clinical yeast isolates is important for biodiversity studies and the detection of probable pathogens. Rhodotorula mucilaginosa is a ubiquitous and pigmented yeast capable of infecting immunocompromised patients. In this study, we evaluated the Micro/mini satellite-primed PCR (MSP-PCR) fingerprinting method for the characterization and identification of R. mucilaginosa isolates from natural environments in northwestern Patagonia. There were selected 110 putative R. mucilaginosa isolates from 200 environmental pigmented yeast isolates on the basis of phenotypic criteria. (GTG)5, (GAC)5 and M13 primers were initially evaluated in representative R. mucilaginosa isolates. (GTG)5 allowed a good grouping of these isolates and, at the same time, a good differentiation among closely related species, and thus was selected for subsequent studies. R. mucilaginosa isolates (87%) presented similar (> 60%) MSP-PCR profiles to those of the reference strain CBS 316T. The MSP-PCR technique was effective, both, for the characterization and identification of a large number of R. mucilaginosa environmental isolates as well as for the detection of polymorphisms within the species.

Analysis of Salmonella enterica serotype Enteritidis isolated from human and chickens by repetitive sequence-PCR fingerprinting, antibiotic resistance and plasmid profiles

A total of 22 Salmonella enterica serotype Enteritidis (S. Enteritidis) strains isolated from human and chicken were subjected to DNA fingerprinting by repetitive sequence PCR using ERIC and BOX primers, antibiotic resistance and plasmid patterns. Both ERIC and BOX PCR amplification data revealed a highly genetic homogeneity between isolates from human and chicken except one isolate, which originated from chicken and showed a different DNA band pattern from others. Eleven of 22 S. Enteritidis isolates (50%) were resistant to more than one antibiotics and characterized by 5 resistance patterns. The most common pattern was penicillin resistant (63.6%). Only one isolate from chicken showed a multiple drug resistance patterns to 4 antibiotics. All 22 S. Enteritidis isolates harbored more than two plasmids with eight different plasmid profiles including two to six plasmids with approximate molecular size ranging from 1.9 to 21 kb. A band of 15 kb size was detected in all isolates tested, however, the band sizes smaller than 15 kb were found only in isolates from chicken.

Genomic Differentiation Among Oyster Mushroom Cultivars Released in Korea by URP-PCR Fingerprinting

URP primers of 20 mer derived from repetitive sequence of rice were used to assess genetic variation of oyster mushroom consisting of 10 cultivars of Pleurotus ostreatus, two cultivars of P. florida and two cultivars of P. sajor-caju which were registered in Korea. URP2F and URP38F primers produced cultivar-specific PCR polymorphic bands in the Pleurotus species. UPGMA cluster analysis using the URP-PCR data showed that 14 Pleurotus cultivars are genetically clustered into large three groups. The URP-PCR data provided important information for more efficient breeding strategies of Pleurotus cultivars.

Development and verification of PCR-fingerprinting HLA-DPB1 genotyping / 中华器官移植杂志

To accelerate the identification of HLA-DPB1 matched marrow donors from unrelated population, a very simple HLA-DPB1 genotyping method called PCR-fingerprinting (PCRF) was developed according to the theory about homoduplex and heteroduplex formation from different PCR coding strands and non-coding ones. Unlike PCR-SSCP, strict laboratory condition is not needed in the PCRF. After denaturing at 94℃ for 2 min and cooling at 37℃ for 8 min, the PCR product was separated by 8% PAGE for 5 h and polymorphism band patterns would appear when the gel staining was completed with either EB or silver staining procedure. To confirm its reliability, 21 individuals from 9 family whose DPB1 genotypes assigned by PCR-RFLP were verified. It was found that there were 8 PCRF patterns corresponding to the 9 HLA-DPB1 genotypes from the 21 cases and the same DPB1 genotypes produced identical PCRF pattern except one pair.The factors on efficient separation of heteroduplexes and homoduplexes were also discussed.

PCR Fingerprinting Analysis of Genes Encoding Penicillin-binding Proteins of Multidrug-resistant Streptococcus pneumoniae Isolated from Korea / 감염

BACKGROUND: The rate of pneumococcal resistance in Korea has surged up to the world's highest level in a short period. To investigate the genetic relatedness and the spread of resistant pneumococci within Korea, and to obtain the basic data about structural changes of penicillin-binding proteins(PBPs), we performed a fingerprinting analysis of PBP 1A, 2X, and 2B genes of multidrug-resistant pneumococci isolated in Korea. METHODS: A total of 22 pneumococcal strains isolated from clinical specimens in 2 university-affiliated hospitals during the period from 1989 to 1996 were tested. PBP 1A, 2X, and 2B genes were amplified from chromosomal DNA by the polymerase chain reaction with specific primers. Amplified products were digested with HinfI or MseI and DdeI and were followed by end-labeling with [alpha-32P] dCTP. Direct comparison of fingerprinting patterns between resistant strains and dendrogram analysis which was based on the UPGMA method were carried out. RESULTS: Fingerprinting analysis of PBP 1A, 2X, and 2B genes digested with HinfI showed that 17 out of 22 strains had almost identical patterns. Dendrogram showed that clusters with greater than 90% similarities existed in 77%, 77%, and 82% of strains with PBP 1A, PBP 2X, PBP 2B, respectively. Fingerprinting patterns with MseI and DdeI were the same as those with HinfI. CONCLUSION: Data from PCR fingerprinting analysis of PBP 1A, 2X, 2B genes of multidrug- resistant pneumococci in this study indicate the genetic relatedness between the resistant strains and suggest the possible spread of pneumococcal resistance within Korea.