ABSTRACT
An aggressive anthracnose disease was identified on greenhouse and home garden cultivated tamarillo (Solanum betaceum) in 2010 and 2011 in Prince George's and Montgomery counties of Maryland. Angular lesions, dark brown at the edges and tan at the interior, eventually engulfed leaves of mature, fruit bearing trees. Additional lesions were seen on petioles and stems, resulting in stem girdling. Flower clusters were also attacked, but fruit lesions were not observed. Sporulation was evident only on stem tissue. In greenhouse-cultivated 3- to 8-month-old immature plants were found to be infected in the foliar and apical regions, resulting in death. Cultures obtained from surface-sterilized leaf and stem tissue of multiple disease samples cultivated on potato dextrose agar consistently resulted in a single fungal isolate. Molecular identification was carried out by sequence analysis of the region amplified using ITS1 forward and ITS4 reverse primers (ITS1 and 2, 5.8S ribosomal RNA). Full matches were found to Glomerella acutata (anamorph Colletotrichum acutatum Simmonds). A representative sequence was submitted to GenBank as JN863589. Cultures were reddish gray with masses of macroscopically mucilaginous orange-brown spores. Conidia were fusiform, measuring 14.0 ± 2.3 × 5.7 ± 0.7 µm. No setae were present, but structures resembling immature perithecia were present, embedded in the agar, a characteristic of C. acutatum Group D isolates (2). Six immature plants (5 months old) and three mature plants (2 years old) were spray inoculated with 1 × 104 conidia per ml of water into apical regions and on the upper foliage. Plants were enclosed in clear plastic bags and incubated for 3 days. Two noninoculated plants of each age were maintained as controls. Bags were removed and plants were maintained in the greenhouse at 25°C. Within 2 weeks, all inoculated plants expressed disease symptoms. Lesions on the foliage were evident as well as the apical regions. Lesions progressed, killing the upper regions of the plant within 1 month. Isolations consistently resulted in cultures of C. acutatum. A culture obtained from infected tissue derived from the first inoculation study was used to repeat Koch's postulate. Anthracnose of tamarillo has been reported in South America and New Zealand where commercial production is concentrated, however, it is primarily a fruit disease (1). Our isolate is principally a foliar and stem pathogen. Host range for C. acutatum is wide enough that our isolate likely originated from another host since there is no widespread tamarillo production in the United States. Interestingly, solanaceous crop plants are generally subject to infection by C. coccodes, not C. acutatum, however, this may be changing (3). References: (1) L. Afanador-Kafuri et al. Phytopathology 93:579, 2003. (2) R. Lardner et al. Mycol. Res. 103:275, 1999. (3) H. Xia et al. Plant Dis. 95:219, 2011.
ABSTRACT
This article presents a review on the application of electrochemical methods of analysis in the microbiological field. The main features of potentiometry, voltammetry and amperometry are discussed including a chronological description of the systems that have been developed so far.
Subject(s)
Electrochemistry/methods , Bacteriological Techniques/methods , PotentiometryABSTRACT
This article presents a review on the application of electrochemical methods of analysis in the microbiological field. The main features of potentiometry, voltammetry and amperometry are discussed including a chronological description of the systems that have been developed so far.(AU)
Subject(s)
Bacteriological Techniques/methods , Electrochemistry/methods , Potentiometry/methodsABSTRACT
Leptine I, a glycoalkaloid only known to occur in the foliage of the wild potato species Solanum chacoense (Bitt.), is a potent feeding deterrent to the economically serious insect pest, the Colorado potato beetle (Leptinotarsa decemlineata Say). In order to demonstrate, systematically, the effectiveness of leptine I, incorporation into synthetic beetle diet trials is necessary. We describe a preparative procedure for the partial purification of leptine I by a series of steps, starting with a solid-phase C18 extraction, followed by sequential silica gel chromatography, and finally reversed-phase preparative HPLC. This preparation yields a white powder, containing leptine I as the sole glycoalkaloid, with an overall purity of greater than 65%, and is entirely suitable for incorporation into synthetic diets.
Subject(s)
Solanaceae/chemistry , Solanaceous Alkaloids/isolation & purification , Chromatography, Gel , Chromatography, High Pressure Liquid , Chromatography, Thin Layer , Plant Leaves/chemistry , Solanaceous Alkaloids/chemistryABSTRACT
This article presents a review on the application of electrochemical methods of analysis in the microbiological field. The main features of potentiometry, voltammetry and amperometry are discussed including a chronological description of the systems that have been developed so far.
Subject(s)
Bacteriological Techniques/methods , Electrochemistry/methods , Potentiometry/methodsABSTRACT
This article presents a review on the application of electrochemical methods of analysis in the microbiological field. The main features of potentiometry, voltammetry and amperometry are discussed including a chronological description of the systems that have been developed so far.
ABSTRACT
The coupling of an immunological separation (using immunomagnetic beads) with amperometric flow injection analysis detection of viable bacteria is presented. Using a solution containing Escherichia coli O157, the electrochemical response with two different mediators [potassium hexacyanoferrate(III) and 2,6-dichlorophenolindophenol] was evaluated in the FIA system. Antibody-derivatized Dynabeads were used to selectively separate E. coli O157 from a matrix. The kinetics and the capacity parameters regarding the attachment of bacteria to the immunobeads were studied. The immunomagnetic separation was then used in conjunction with electrochemical detection to measure the concentration of viable bacteria. A calibration curve of colony-forming units (cfu) against electrochemical response was obtained. The detection limit for this rapid microbiological method was 10(5) cfu mL-1, and the complete assay was performed in 2 h. Some advantages over ELISA methods are the direct detection of viable cells (and not total bacterial load) and the need for only one antibody (not enzyme-labeled), thus making the assay faster (only one washing step is necessary) and less expensive.
Subject(s)
Escherichia coli O157/isolation & purification , Immunomagnetic Separation/methods , 2,6-Dichloroindophenol/chemistry , Colony Count, Microbial , Electrochemistry , Enzyme-Linked Immunosorbent Assay , Escherichia coli O157/immunology , Ferricyanides/chemistry , Flow Injection Analysis/methodsABSTRACT
STUDY OBJECTIVE: To investigate the necessity of intensive evaluation of the intoxicated patient with normal mentation for intra-abdominal injury after blunt torso trauma. DESIGN: Retrospective study; trauma registry and medical records. SETTING: Level I regional trauma center serving a population of 2.3 million. PARTICIPANTS: Adult victims of blunt trauma more than 17 years old, admitted between January 1, 1986, and December 31, 1989, with suspected blunt abdominal injury and serum ethanol of more than 100 mg/dL and Glasgow Coma Score of 15. INTERVENTION: All patients had serum ethanol levels measured in mg/dL and computed tomography (CT) scan of the abdomen and/or diagnostic peritoneal lavage (DPL). RESULTS: Criteria were met by 92 patients. Eighty-nine underwent CT scans, two had DPL, and one had both. Of 17 patients complaining of abdominal pain and/or tenderness on palpation, six (35.3%) had blood in the peritoneal cavity demonstrated by CT scan or DPL and underwent celiotomy. All 75 patients without abdominal pain or tenderness had negative CT scan or DPL, with no missed injury. CONCLUSION: In the intoxicated blunt trauma patient with normal mentation, the physical examination is a reliable indicator of abdominal injury. Elevated alcohol level, per se, should not be considered an absolute indication for DPL or abdominal CT.
