ASIAN CITRUS PSYLLIDS (STERNORRHYNCHA: PSYLLIDAE) AND GREENING DISEASE OF CITRUS: A LITERATURE REVIEW AND ASSESSMENT OF RISK IN FLORIDA
The Asian citrus psyllid, Diaphorina citri Kuwayama, was discovered in Florida in 1998. It can be one of the most serious pests of citrus if the pathogens that cause citrus greening disease (huanglongbing) are present. Citrus greening recently has been reported in Brazil by Fundecitrus, Brazil. The establishment of D. citri in Florida increases the possibility that the disease may become established. Diaphorina citri can be separated from about 13 other species of psyllids reported on citrus. The biology of D. citri makes it ideally suited to the Florida climate. Only two species, D. citri and Trioza erytreae (del Guercio), have been implicated in spread of citrus greening, a disease caused by highly fastidious phloem-inhabiting bacteria. The disease is characterized by blotchy mottle on the leaves, and misshapen, poorly colored off-tasting fruit. In areas where the disease is endemic, citrus trees may live for only 5-8 years and never bear usable fruit. The disease occurs throughout much of Asia and Africa south of the Sahara Desert, on several small islands in the Indian Ocean, and in the Saudi Arabian Peninsula. Transmission of citrus greening occurs primarily via infective citrus psyllids and grafting. It is transmissible experimentally through dodder and might be transmitted by seed from infected plants and transovarially in psyllid vectors. Citrus greening disease is restricted to Citrus and close citrus relatives because of the narrow host range of the psyllid vectors. Management of citrus greening disease is difficult and requires an integrated approach including use of clean stock, elimination of inoculum via voluntary and regulatory means, use of pesticides to control psyllid vectors in the citrus crop, and biological control of psyllid vectors in non-crop reservoirs. There is no place in the world where citrus greening disease occurs that it is under completely successful management. Eradication of citrus greening disease may be possible if it is detected early. Research is needed on rapid and robust diagnosis, disease epidemiology, and psyllid vector control.
Then and now: use of 16S rDNA gene sequencing for bacterial identification and discovery of novel bacteria in clinical microbiology laboratories.
In the last decade, as a result of the widespread use of PCR and DNA sequencing, 16S rDNA sequencing has played a pivotal role in the accurate identification of bacterial isolates and the discovery of novel bacteria in clinical microbiology laboratories. For bacterial identification, 16S rDNA sequencing is particularly important in the case of bacteria with unusual phenotypic profiles, rare bacteria, slow-growing bacteria, uncultivable bacteria and culture-negative infections. Not only has it provided insights into aetiologies of infectious disease, but it also helps clinicians in choosing antibiotics and in determining the duration of treatment and infection control procedures. With the use of 16S rDNA sequencing, 215 novel bacterial species, 29 of which belong to novel genera, have been discovered from human specimens in the past 7 years of the 21st century (2001-2007). One hundred of the 215 novel species, 15 belonging to novel genera, have been found in four or more subjects. The largest number of novel species discovered were of the genera Mycobacterium (n = 12) and Nocardia (n = 6). The oral cavity/dental-related specimens (n = 19) and the gastrointestinal tract (n = 26) were the most important sites for discovery and/or reservoirs of novel species. Among the 100 novel species, Streptococcus sinensis, Laribacter hongkongensis, Clostridium hathewayi and Borrelia spielmanii have been most thoroughly characterized, with the reservoirs and routes of transmission documented, and S. sinensis, L. hongkongensis and C. hathewayi have been found globally. One of the greatest hurdles in putting 16S rDNA sequencing into routine use in clinical microbiology laboratories is automation of the technology. The only step that can be automated at the moment is input of the 16S rDNA sequence of the bacterial isolate for identification into one of the software packages that will generate the result of the identity of the isolate on the basis of its sequence database. However, studies on the accuracy of the software packages have given highly varied results, and interpretation of results remains difficult for most technicians, and even for clinical microbiologists. To fully utilize 16S rDNA sequencing in clinical microbiology, better guidelines are needed for interpretation of the identification results, and additional/supplementary methods are necessary for bacterial species that cannot be identified confidently by 16S rDNA sequencing alone.
cloud computing social network regression model gene expression sample size confidence interval logistic regression social science systematic review linear regression model cloud datum xml document immune system carbon dioxide amino acid logistic regression model keyword search mental model process analysi background and objective encrypted datum quantitative assessment plant growth escherichia coli sequence analysi discourse analysi scientific publication channel condition immune response choice behavior programming paradigm natural selection organic matter odds ratio social structure microbial community signal transduction membrane protein encrypted cloud datum encrypted cloud lactic acid plant root oral cavity quorum sensing gene transfer antibiotic resistance cardiac surgery critical discourse analysi dental cary cell count marine ecosystem recombinant dna oxidative stres critical discourse aquatic ecosystem horizontal gene transfer bibliographic reference ribosomal rna horizontal gene lactic acid bacterium plasma membrane acute kidney acute kidney injury resistance gene cell survival genetic selection acid bacterium physiological aspect gram-negative bacterium social characteristic social inequality ranked keyword search ranked keyword abbott laboratory dental plaque oligonucleotide probe base pairing resistant bacterium antibiotic resistance gene lactobacillus acidophilu gram-positive bacterium genetic heterogeneity biofilm development nitrogen cycle microbial biofilm transcription, genetic interface device component metabolic process, cellular national origin biological adaptation to stress clone cell ethanol 0.62 ml/ml topical gel clinical act of insertion genetic translation proces hereditary disease greater than cognition disorder phobia, social nucleic acid hybridization gel electrophoresis (lab technique) stimulation (motivation) meta analysis (statistical procedure) the superficial genome, bacterial amino acid metabolism, inborn error denial (psychology) immunoglobulin lambda-chain fifty nine reservoir device component document completion status - documented gastrointestinal tract structure genus (mathematics) domain of discourse phylum (taxon) intestinal microbiome microbiota (plant) genus mycobacterium antibiotic resistance, microbial ammonia measurement ammonia oxidation models, mental anabolic steroid actinobacteria clas fecal microbiota transplantation kidney failure, acute gene transfer, horizontal ferrosoferric oxide dennis fairclough ruth teitelbaum shoshana wodak excretory function entity name part qualifier - adopted cessation of life anatomical layer biopolymer sequencing ephrin type-b receptor 1, human one thousand copy (object) review [publication type] promotion (action) pathogenic organism