ABSTRACT
Resumen La variabilidad genética intrapoblacional de Vultur gryphus (cóndores andinos) de las regiones de Cusco y Apurímac fue evaluada mediante amplificación y secuenciación del ADN mitocondrial correspondientes a la región control y subunidad ribosomal 12S (D-Loop-ARNr12S), y a los genes Citocromo Oxidasa subunidad I (COI) y NADH deshidrogenasa subunidad II (ND2). El ADN se extrajo a partir de cálamos de plumas de muda de ejemplares en cautiverio y silvestres. Se analizaron los principales índices de diversidad genética como son: la diversidad haplotípica, la diversidad nucleotídica, el número promedio de diferencias nucleotídicas y el número de sitios polimórficos. La tasa de éxito de amplificación mediante PCR fue de 100% para las tres regiones de ADN analizadas. Se secuenció 600 pb de la región D-Loop-ARNr12S caracterizándose cuatro haplotipos, 704 pb del gen COI caracterizándose seis haplotipos y 1090 pb del gen ND2 caracterizándose cinco haplotipos. El gen COI presentó el mayor valor de diversidad haplotípica (Hd = 0.468), la región del gen D-Loop-ARNr12S presentó el mayor índice de diversidad nucleotídica (π = 0.00086), mientras que el gen COI presentó el mayor número promedio de diferencias nucleotídicas (K = 0.52615). Los resultados muestran bajos niveles de variabilidad genética en los genes mitocondriales de los cóndores andinos de la zona de estudio, que indicarían una población con estructura genética homogénea.
Abstract The intrapopulation genetic variability of Vultur gryphus (Andean condors) from Cusco and Apurimac regions was evaluated by amplification and sequencing of mitochondrial DNA corresponding to the control region and 12S ribosomal subunit (D-Loop-RNAr12S), Cytochrome Oxidase subunit I (COI) genes and NADH dehydrogenase subunit II (ND2) gene. DNA was extracted from the calamus of feathers recollected from captive and wild specimens. The main indices of genetic diversity such as the haplotype diversity, the nucleotide diversity, the average number of nucleotide differences and the number of polymorphic sites were analyzed. The PCR amplification success rate was 100% for the three mitochondrial amplified sequences. Four haplotypes were identified from the 600 bp sequenced of D-Loop-RNAr12S region; six haplotypes from the 704 bp sequenced of the COI gene; five haplotypes from the 1090 bp sequenced of the ND2 gene. The COI gene presented the highest haplotype diversity (Hd = 0.468), the D-Loop-RNAr12S region presented the highest index of nucleotide diversity (π = 0.00086), while the COI gene presented the highest average number of nucleotide differences (K = 0.52615). The results show low levels of genetic variability in the mitochondrial genes of the Andean Condor in the study area, indicating a population with a homogeneous genetic structure.
ABSTRACT
Objectives: Carbapenem resistantAcinetobacter baumannii is an important therapeutic and infection control challenge worldwide. In this study, we investigated the prevalence and distribution of molecular mechanisms of resistance among carbapenem resistant A. baumannii species at a tertiary care setting in South India. Materials and Methods: A total of 89 non-duplicate clinical isolates of carbapenem-resistantA. baumannii were collected from critical care units of St. John's Medical College Hospital, Bengaluru, India. Polymerase chain reaction (PCR) was performed to detect blaOXA type carbapenemase blaOXA-51-like, blaOXA-23-like, blaOXA-24-like and bla OXA-58-like, MBL genes blaNDM, blaIMP, and blaVIM genes. Molecular typing of carbapenem-resistant A. baumannii strains was performed by using Rep-PCR. Results: Eighty-seven of the isolates were found to carry the blaOXA-51 gene and 81 (91%) isolates were found to have blaOXA-51-like gene and blaOXA-23, gene. The bla OXA-24 like gene was detected in two isolates of which one also carried blaOXA-51 like and one isolate carried blaVIM coding gene. The prevalence of blaNDM, blaIMP, bla VIM genes was 12(13%),14 (16%) and 57(64%) respectively. Cluster analyses revealed a 90% similarity and were divided into 5 clusters. Most of the isolates containing carbapenemases coding genes grouped under cluster A, C and UC. Considerable heterogeneity was observed within UC cluster indicating circulation of multiple strains of A. baumannii within our institution. Conclusions: Carbapenemase coding blaOXA-23, blaOXA-24 and blaOXA-51 -like were more common than blaVIM and blaNDM. The presence of blaNDM with other genes coding for carbapenemases indicate the ability of the strains to acquire novel genes despite having its share of the blaOXA like carbapenemase.
Objetivos: El Acinetobacter baumannii resistente a Carbapenem es un reto importante en todo el mundo para su tratamiento y para el control de infecciones hospitalarias. Nosotros estudiamos la prevalencia y los mecanismos de resistencia en aislados de un centro de atención terciario, en el sur de la India Materiales y Métodos: Se estudiaron 89 aislados clínicos de A. baumannii recolectados en unidades de cuidado crítico del Hospital St. John's Medical College en Bengaluru, India. Se realizó amplificación por PCR (Reacción en Cadena de Polimerasa) y luego tipificación molecular con la técnica Rep-PCR (PCR de elementos repetitivos palindromicos) para detectar los genes de carbapenemasa blaOXA, blaOXA-51, blaOXA-23, blaOXA-24, blaOXA-58, MBL, blaNDM, blaIMP y blaVIM. Resultados: Se encontraron 87 aislados que llevaban el gen blaOXA-51 y de ellos en 81 (91%) se encontró blaOXA-51 y blaOXA-23. El blaOXA-24 se detectó en dos aislados de los cuales uno de ellos llevaba blaOXA-51 y otro blaVIM. Los genes blaNDM, blaIMP y blaVIM se encontraron en 12 (13%),14 (16%) y 57(64%) de los aislados, respectivamente. El análisis de agrupamiento reveló un 90% de similitud entre los aislados y que podían asignarse a 5 agrupamientos. La mayoría de aislados llevaban genes de carbapenemasas de los grupos A, C y UC. Se observó mucha heterogeneidad dentro del agrupamiento UC indicando que existe circulación de múltiples cepas de A. baumannii dentro de nuestra institución. Conclusiones: Las carbapenemasas que codifican para blaOXA-23, blaOXA-24 y blaOXA-51 son más comunes que blaVIM y blaNDM en nuestra institución. La presencia de NDM con otros genes codificando para carbapenemasas indica la capacidad que tienen este tipo de aislados para adquirir nuevos genes a pesar de contar con blaOXA.
Subject(s)
Humans , Carbapenems , Acinetobacter baumannii , Genetic Variation , Drug Resistance, Microbial , Cross Infection , IndiaABSTRACT
Domestic rice (Oryza sativa L.) is one of the most important cereal crops, feeding a large number of worldwide populations. Along with various high-throughput genome sequencing projects, rice genomics has been making great headway toward direct field applications of basic research advances in understanding the molecular mechanisms of agronomical traits and utilizing diverse germplasm resources. Here, we briefly review its achievements over the past two decades and present the potential for its bright future.
Subject(s)
Crops, Agricultural , Genetics , Genome, Plant , Genetics , Genomics , High-Throughput Nucleotide Sequencing , Oryza , Genetics , PhenotypeABSTRACT
The genomic diversity of Avian leukosis virus subgroup J (ALV-J) was investigated in an experimentally infected chicken. ALV-J variants in tissues from four different organs of the same bird were re-isolated in DF-1 cells, and their gp85 gene was amplified and cloned. Ten clones from each organ were sequenced and compared with the original inoculum strain, NX0101. The minimum homology of each organ ranged from 96.7 to 97.6%, and the lowest homology between organs was only 94.9%, which was much lower than the 99.1% homology of inoculum NX0101, indicating high diversity of ALV-J, even within the same bird. The gp85 mutations from the left kidney, which contained tumors, and the right kidney, which was tumor-free, had higher non-synonymous to synonymous mutation ratios than those in the tumor-bearing liver and lungs. Additionally, the mutational sites of gp85 gene in the kidney were similar, and they differed from those in the liver and lung, implying that organ- or tissue-specific selective pressure had a greater influence on the evolution of ALV-J diversity. These results suggest that more ALV-J clones from different organs and tissues should be sequenced and compared to better understand viral evolution and molecular epidemiology in the field.
Subject(s)
Animals , Avian Leukosis Virus , Avian Leukosis , Birds , Chickens , Clone Cells , Kidney , Liver , Lung , Molecular Epidemiology , Silent MutationABSTRACT
Background: Vibrio cholerae is an autochthonous inhabitant of fresh and brackish water and estuarine system. Investigation of V. cholerae from the River Ganga seems important to find variation in CTX arrangement and genomic diversity. Objectives: To investigate V. cholerae O1 strains for the presence of virulence and regulatory genes, variation in number and organisation of the pre‑CTXФ and/or CTXФ, and for the genomic diversity. Materials and Methods: Polymerase chain reaction (PCR) was used to detect virulence and regulatory genes, type of rstR and location of CTXΦ on the chromosome. Southern hybridisation was conducted to see the number and arrangement of pre‑CTXΦ and CTXΦ. Ribotyping and pulsed‑field gel electrophoresis were used to find genetic relatedness. Results: Seven strains gave positive results by PCR for the gene encoding for ctxA, zot, ace, tcpA (El Tor), ompU, and toxR, except one strain that was negative for the ctxA. Three strains were positive for the tcpA (El Tor), ompU and toxR genes. Determination of CTX organisation showed that among the ctx‑positive strains, four harboured two copies of CTXETФ arranged in tandem and two harboured one copy of CTXETФ, and one ctx‑negative strain harboured only one copy of pre‑CTXETФ. Pulsotype and ribotype analysis showed existence of at least three pulsotype and ribotypes indicating diversity in genomic content among them. Conclusion: This study thus indicates that multiple clones (ribotypes/pulsotypes) of V. cholerae O1 carrying pre‑CTXΦ and/or CTXΦ and ctx‑negative strains were present in the water of the River Ganga, Varanasi, India.
ABSTRACT
Amplified fragment length polymorphism (AFLP) was used to analyze the genetic diversity of 14 strains of Xanthomonas arboricola pv. pruni and seven strains of X. axonopodis pv. phaseoli, which are used in xanthan production studies. Relationships identified by the AFLP profiles were assessed for xanthan production capacity, geographical location and host plant. Strains were isolated from 10 different geographic regions in South and Southeast States in Brazil. Data were analyzed for genetic similarity using the Dice coefficient and subjected to UPGMA cluster analysis. A total of 128 AFLP fragments were generated from four primer combinations: EcoRI+C/MseI+0, EcoRI+A/MseI+0, EcoRI+G/MseI+T and EcoRI+G/MseI+A. Of these, 96.1 percent were polymorphic. X. axonopodis pv. phaseoli (S D = 0.27) was shown to be more polymorphic than X. arboricola pv. pruni (S D = 0.58). All 14 pathovar pruni strains were included in a single main group (S D = 0.58), while the pathovar phaseoli strains were divided into three separate groups, with one group containing five strains (S D = 0.38) and two isolated groups (S D = 0.31 and 0.27) composed of only one strain each. Species were distinguished by three and eight specific AFLP markers present in the pathovar phaseoli and the pathovar pruni, respectively. For the unique strain without xanthan production capacity (X. axonopodis pv. phaseoli str. 48), nine specific AFLP bands were found. There was no evidence that geographic area or host plant influenced genetic heterogeneity. Correlations between AFLP patterns and xanthan production capacity were found in some strains, but were not consistent enough to establish a relationship.
Subject(s)
Amplified Fragment Length Polymorphism Analysis , DNA Fingerprinting , Genetic Variation , Xanthomonas axonopodis/genetics , Xanthomonas axonopodis/isolation & purification , Xanthomonas/genetics , Xanthomonas/isolation & purification , Methods , Methods , VirulenceABSTRACT
BACKGROUND: The evidence for H. pylori as a gastrointestnal pathogen is now very strong, if not overwhelming. Among the pathogenic factors of H. pylori, flagella and urease are considered to be major factors causing the gastrododenal disease. We observed the gene diversity of H. pylori using the PCR-amplified 1.4Kb fla A gene and 0.9Kb ure B gene and examined the relationship between the gene pattern and the gastroduodenal disease. METHOD: Fifty-one cases of isolated strains were cultured at the Helicobacter-selective blood agar plates. To compare the gene diversity among the isolates of gastroduodenal disease genotypes was analyzed by PCR-based RFLP. 1.4Kb fla A gene and 0.9Kb ure B genes from isolates were amplified by PCR and digested with Hae 3 restriction enzymes to observe the restriction fragment length polymophysm. Protein patterns were also compared to examine the antigenic variations. Total cell proteins, and octyl-glucose extracts from isolates were analyzed by SDS-PAGE gel electrophoresis. RESULTS: 41 cases (80.4%) of H. pylori were isolated in the 51 cases of gastroduodenal diseases. We could classify theses isolates 3 types of PCR-RFLP in the fla A gene, 900+500bp, 500+500+400bp, 600+800bp, and 9 types in the ure B gene. PCR-RFLP in the fla A gene and ure B gene of the isolates was different from the standard strain of Australia and the genetic diversity was not related to the types of the gastroduodenal disease. We demonstrated variations in the protein pattern and antigenic profiles among the isolates by SDS-PAGE analysis. These data also did not show any relationship between protein pattern and types of gastroduodenal diseases. CONCLUSION: Tese studies showed many different gene diversity in the flagella and urease gene without any relationship with the types of gastoduodenal disease. And variable protein pattern were noted among the strains of H. pylori. Further studies to demonstrate the pathgenecity of H. pylori should be continued even if there was no relationship between the genomic diversity of the flagella or urease and the types of gastroduodenal disease.