Revista latinoamericana de microbiologia最新文献

Environmental changes induce a cellular response characterized by a modification in the genetic expression and physiology of the cell. This modification allows the cell to survive and adapt to the new environment. Current studies on cellular stress response are mainly focused on the identification of the genetic expression patterns (transcriptome, proteome). and their relation with the biochemical (metabolome), structural and functional changes displayed by the cells under stress. In the symposium on Cellular Response to Stress, four works were presented about the stress effect on cellular functions of bacteria and fungi: 1) nutritional stress in Escherichia coli and DNA damage and mutagenesis. 2) nutritional and oxidative stress in Candida glabrata and subtelomeric silencing, 3) cold stress in E. coli and RNA degradation, and 4) oxidative and heat stress in E. coli and differential protein synthesis.

Contamination of soil and water with petroleum hydrocarbons has significantly increased as a result of accidental spills, thus, several biological systems have been applied to cleanup and rehabilitate the negatively impacted regions. The present review discusses the fundamental principles required to understand the effectiveness of some bioremediation systems applied to soil and water contaminated with petroleum hydrocarbons and other organic pollutants. The practical aspects of several experimental approaches such as composting and soil amendment application, plant utilization and rhizosphere microbial activity as a keystone during phytoremediation, slurry bioreactors utilization, and potential utilization of microalgae to decontaminate wastewater, are also described.

Functional genomics is changing our understanding of biology and changing our approach to biological research. It brings about concerted, high-throughput genetics with analyses of gene transcripts, proteins, and metabolites to answer the ultimate question posed by all genome-sequencing projects: what is the biological function of each and every gene? Functional genomics is stimulating a change in the research paradigm away from the analysis of single genes, proteins, or metabolites towards the analysis of each of these parameters on a global scale. By identifying and measuring several, if not the entire, molecular group of actors that take part in a given biological process, functional genomics offers the panorama of obtaining a truly holistic representation of life. Functional genomics methods are defined by high-throughput methods which are, not necessarily hypothesis-dependent. They offer insights into mRNA expression, protein expression, protein localization, and protein interactions and may cast light on the flow of information within signaling pathways. At its beginning, biology involved observing nature and experimenting on its isolated parts. Genomic research now generates new types of complex observational data derived from nature. This review describes the tools that are currently being used for functional genomics work and considers the impact that this new discipline on microbiology research.

Hp diagnostic is made by invasive methods using gastric biopsy of antrum, for culture and histological study. Non invasive are serology and urea breath test. 152 Hp from 19 children's with acute gastritis (46. 1%); 9 Hp from an adult. There had ampicillin resistance, 27. 4%, claritromicin 21. 8%, metronidazol 58. 4% and tetracycline 31. 5%, the 21 % susceptible to four anti-microbial. RAPD-PCR with 4 primers gave 44 profiles, related with clinical profile. In 7 children, there were two profiles RAPD. Three were similar but different each other. AFLP 23 adults 151 Hp; cagA and vacA genotypes gave unique patterns for each patient. The genes cagA, babA and oipA, secuencing and compared with reported Hp (Genbank); gave high polymorfism. Everything indicates that there are colonization with multiple Hp strains in Mexicans. In 645 sera from 352 children: 36.9% with Hp, the 46. 9% gave him/her anti-shits and 16. 2% antibodies to urease. Adults 293 (89. 1%) with Hp, 78. 9% gave anti-CagA and 59% antibodies to urease. The expression of IL-8 was bigger in infected children that in not infected and more significant in peptic ulcer. Genomic library Cag-PAI revealed 90% (Hp) positive, they had the complete PAI, 2 were incomplete and three negatives. PCR -LiPA LiPA (LineProbe Assay) is suggestive for genotyping assays.

About the characterization and distribution of novel nitrogen-fixing Burkholderia species associated with maize and other plants and their potential use on the plant growth was presented in this symposium. The symposium included studies directed to the revegetation of eroded areas by using plant growth promoting rhizo-bacteria and mycorrizal fungi associated with desert plants, as well as studies related with the resistance of arbuscular mycorrhizal fungi to heavy metals associated with the environmental pollution. In addition, the identification and characterization of a 31-kb chromosomal fragment from Pseudomonas syringae pv. phaseolicola was presented; such a fragment, involved with the phaseolotoxin synthesis, showed characteristic features of a bacterial pathogenicity island.

In this review we cover the biological control of insects, bacteria and fungus that affect different crops. Using different microorganism as bacteria viruses and fungus can do the biological control of these important problems. In this work we describe with detail the mode of action of the different microorganisms used to control insects and plant diseases. We also present novel strategies to improve the efficiency of these microorganisms against their targets and we present the development and production of several formulations to be used in the fields for the biological control of some plant problems.

The identification of microorganisms by whole genome DNA fingerprinting was tested "in silico". 94 HPV genome sequences were submitted to virtual hybridization analysis on a DNA chip with 342 probes. This Universal Fingerprinting Chip (UFC) constitutes a representative set of probes of all the possible 8-mer sequences having at least two internal and non contiguous sequence differences between all them. A virtual hybridization analysis was performed in order to find the fingerprinting pattern that represents the signals produced for the hybridization of the probes allowing at most a single mismatch. All the fingerprints for each virus were compared against each other in order to obtain all the pairwise distances measures. A match-extension strategy was applied to identify only the shared signals corresponding to the hybridization of the probes with homologous sequences between two HPV genomes. A phylogenetic tree was constructed from the fingerprint distances using the Neighbor-Joining algorithm implemented in the program Phylip 3.61. This tree was compared with that produced from the alignment of whole genome HPV sequences calculated with the program Clustal_X 1.83. The similarities between both trees are suggesting that the UFC-8 is able to discriminate accurately between viral genomes. A fingerprint comparative analysis suggests that the UFC-8 can differentiate between HPV types and sub-types.