Occurrence of Bacterial Stem Rot, Caused by Erwinia chrysanthemi, on Field-Grown Tomato in Florida.

In September 1997, wilted 4-week-old tomato (Lycopersicon esculentum Mill.) plants were observed in a commercial production field in St. Lucie County, FL. Closer inspection of affected plants revealed hollow stems and petioles with dark, water-soaked lesions. Diseased tissue was macerated and streaked onto nutrient agar (NA) and crystal violet pectate (CVP) agar. After incubation for 2 days at 30°C, isolates produced pits on the CVP agar. Isolates were transferred onto NA and the incubation and transfer procedure was performed two additional times to obtain pure cultures. Suspensions of bacterial cells were injected into tomato and tobacco leaves to test for a hypersensitive or pathogenic reaction. Isolates produced collapsed necrotic tissue on tomato while no reaction was observed on tobacco. Tests for differentiating species and subspecies in the 'carotovora' group of Erwinia were conducted following the protocol of Dickey and Kelman (1). With known cultures of E. carotovora subsp. carotovora and E. chrysanthemi as controls, the isolate from tomato was determined to function as a facultative anaerobe, utilize asparagine as a sole source of carbon and nitrogen, and give positive reactions for pectate degradation, phosphatase, and growth at 37°C. Known cultures of E. carotovora subsp. carotovora, E. chrysanthemi, and the tomato isolate were grown on trypticase soy broth agar for 24 h at 28°C and their cellular fatty acids derivatized to fatty acid methyl esters (FAMEs). Statistical analyses of FAME profile data (MIDI Microbial Identification System, Newark, DE, version 3.60) identified the tomato isolate as Erwinia chrysanthemi. Pathogenicity was determined by inoculating 50-day-old tomato plants (cv. SunPride) with a suspension of E. chrysanthemi obtained from nutrient broth plates incubated at 24°C for 60 h. Three plants each were inoculated with the E. chrysanthemi identified from tomato, sterile water, and known cultures of E. chrysanthemi and E. carotovora subsp. carotovora by placing a drop at the junction of the petiole and stem and passing a sterile needle through the drop into the stem. Plants were maintained in a greenhouse. Dark, water-soaked cankers were observed on the stems of plants inoculated with E. chrysanthemi, including the tomato isolate and E. carotovora subsp. carotovora, after 7 days. No symptoms were observed on plants inoculated with sterile water. Reisolation of the pathogen and identification was performed with tissue from one of the symptomatic inoculated plants. Analyses of FAMEs confirmed E. chrysanthemi as the causal agent. This is the first report of E. chrysanthemi causing a vascular disease of field-grown tomato in Florida. Reference: (1) R. S. Dickey and A. Kelman. 1988. Pages 44-59 in: Laboratory Guide for Identification of Plant Pathogenic Bacteria. N. W. Schaad, ed. American Phytopathological Society, St. Paul, MN.

Use of drugs by children.

To obtain information on the use of prescribed and non-prescribed drugs in the general population of children 1590 children were surveyed in 1984-5 by weekly questionnaires filled out by parents. Drugs were taken in 13% of the 26 weeks studied and on 9% of the 182 days. Use in the summer and winter was similar. More than half (56%) of all drugs were taken on Saturdays and Sundays. Boys took drugs on 11% of days and girls on 8% of days. Almost half (45%) of drugs taken were not prescribed. Drugs acting on the respiratory tract and on coughs accounted for 42.2% of the drugs used. Analgesics were taken on 14.0% of days and antimicrobials on 12.5%. Aspirin accounted for 14.9% of all drugs used in any one week and for 31.7% of drugs obtained without prescription. Aspirin, paracetamol, triprolidine-pseudoephedrine (Actifed), ampicillin or amoxycillin, and salbutamol were the drugs most frequently used. The widespread use of drugs obtained without prescription suggests that community pharmacists and parents would benefit from further education on the choice of treatment in relation to symptoms. Doctors should be aware of the extent of treatment with non-prescription drugs and consider playing a greater part in advising on its indications.

Plasma concentrations of clonazepam after single rectal administration.

Clonazepam was administered rectally to six children aged 1.4 to 4.7 years in a dose of 0.05 mg/kg and to five children aged 1.4 to 4.1 years in a dose of 0.1 mg/kg. Plasma concentrations indicate that it is rapidly absorbed, and it may therefore be an alternative to rectal administration of diazepam in continuing convulsions.

Re-evaluation of saliva for monitoring theophylline concentrations.

Variability of the mixed saliva/plasma theophylline relation was examined in seven children aged 2 to 13 years. Good correlation between plasma and saliva concentrations was found, but on the three occasions there was considerable inter- and intrapatient variability. There was no significant or consistent relation between unstimulated and stimulated saliva concentrations or between saliva concentrations and sample volumes. Plasma theophylline concentrations cannot be predicted accurately from saliva values.

Theophylline dose prediction.

Two methods of predicting the optimal dose of theophylline in children aged 2 to 13 years were assessed. The observed plasma concentration was within 95% confidence limits of that predicted on eight of 14 occasions using a traditional multiple point pharmacokinetic method. Using a nomogram derived from the plasma concentration 6 hours after dosing and the logarithm of the calculated dose, which were significantly correlated, there was a significant relation between the dose predicted and the actual dose required to produce a concentration of 55 mumol/l.