Transfer of penicillin resistance from Streptococcus oralis to Streptococcus pneumoniae identifies murE as resistance determinant.

Beta-lactam resistant clinical isolates of Streptococcus pneumoniae contain altered penicillin-binding protein (PBP) genes and occasionally an altered murM, presumably products of interspecies gene transfer. MurM and MurN are responsible for the synthesis of branched lipid II, substrate for the PBP catalyzed transpeptidation reaction. Here we used the high-level beta-lactam resistant S. oralis Uo5 as donor in transformation experiments with the sensitive laboratory strain S. pneumoniae R6 as recipient. Surprisingly, piperacillin-resistant transformants contained no alterations in PBP genes but carried murEUo5 encoding the UDP-N-acetylmuramyl tripeptide synthetase. Codons 83-183 of murEUo5 were sufficient to confer the resistance phenotype. Moreover, the promoter of murEUo5 , which drives a twofold higher expression compared to that of S. pneumoniae R6, could also confer increased resistance. Multiple independent transformations produced S. pneumoniae R6 derivatives containing murEUo5 , pbp2xUo5 , pbp1aUo5 and pbp2bUo5 , but not murMUo5 sequences; however, the resistance level of the donor strain could not be reached. S. oralis Uo5 harbors an unusual murM, and murN is absent. Accordingly, the peptidoglycan of S. oralis Uo5 contained interpeptide bridges with one L-Ala residue only. The data suggest that resistance in S. oralis Uo5 is based on a complex interplay of distinct PBPs and other enzymes involved in peptidoglycan biosynthesis.

Patient satisfaction after electroconvulsive therapy.

OBJECTIVE: We sought to determine the degree of satisfaction with bifrontal and right unilateral electroconvulsive therapy (ECT) and to investigate the relation with treatment-related variables, such as memory complaints, and patient-related variables, such as self-rated depression severity and negative affectivity. METHODS: Subjects included all patients who started a course of ECT between May 2001 and December 2003, or still were receiving continuation or maintenance ECT (C/M-ECT) at the time of the study. A psychiatric nurse that was not a member of the treatment team conducted semi-structured interviews based on a battery of questionnaires (Patient Satisfaction Survey [PSS], Mini-Mental State Examination [MMSE], Squire Subjective Memory Questionnaire [SSMQ], Beck Depression Inventory [BDI], and Positive and Negative Affect Schedule [PANAS]). RESULTS: Of 50 eligible subjects, 36 (72%) completed the survey. Fourteen patients refused to participate. At the time of the interview, 19 patients (52.8%) were hospitalized, and 14 (38.9%) were receiving C/M-ECT. The mean time between last treatment session and interview was 282 days. Diagnostic categories were depressive disorder (50%) and psychotic disorder (47.2%). Bifrontal electrode position was used in 25 (69.4%) of the study patients and unilateral in 4 (11.1%). Patients had a considerable degree of satisfaction (mean PSS 153.41; SD 16.29), although they had prominent cognitive complaints (mean score SSMQ -11.86; SD 21.30). In a multiple regression model, in which satisfaction was predicted on the basis of age, sex, and scores on BDI, SSMQ, PANAS, and GAF, only the GAF-score at the time of the interview was significantly related to satisfaction. All other predictors were not significant. CONCLUSION: Patients receiving bifrontal or right unilateral ECT do have considerable memory complaints, even a long time after their treatment. However, the degree of these complaints does not seem to predict satisfaction with the treatment. Only 38% of the variance of satisfaction could be predicted on the basis of age, sex, BDI, SSMQ, Negative Affectivity subscale of the PANAS, and GAF-scores, which proves that satisfaction with ECT is based on other factors than just the relief of symptoms or the occurrence of side-effects. The factors that contribute to patients' satisfaction remain largely unknown.

Effects of storage conditions on furocoumarin levels in intact, chopped, or homogenized parsnips.

Furocoumarins represent a family of natural food constituents with phototoxic and photomutagenic properties. They are found mainly in plants belonging to the Rutaceae and Umbilliferae such as celery, carrots, and parsnips. Parsnips (Pastinaca sativa L.) have become more and more popular as a vegetable, e.g., as a constituent of or ingredient in baby food. Previous work has shown that microbial infection of parsnip roots can result in a dramatic increase in furocoumarin levels. In this study, freshly harvested parsnips were stored as whole roots, pieces (cubes), or homogenate at +4 degrees C or -18 degrees C over various time periods under standard conditions. It was found that furocoumarin concentrations (sum of five furocoumarins: angelicin, isopimpinellin, 5-methoxypsoralen, 8-methoxypsoralen, and psoralen) in freshly harvested parsnips, analyzed by HPLC after extraction with diethyl ether and sequential solid phase (reversed-phase and silica) extraction, was generally lower than 2.5 mg/kg, and storage of parsnips in any form investigated at -18 degrees C over up to 50 days did not lead to a marked increase in furocoumarin levels. In contrast, storage of whole parsnips, but not of cubes or homogenate, at +4 degrees C resulted in a marked biphasic increase of furocoumarin concentrations after 7 and 38 days of storage up to levels of about 40 mg/kg. A dramatic increase in furocoumarin concentrations up to 566 mg/kg was observed when whole parsnips obtained from the market were kept at room temperature over 53 days, resulting in a visible microbial (mold) infection. Baby food products from the German market containing parsnips as an ingredient or constituent showed furocoumarin levels < or =0.41 mg/kg, suggesting that properly stored roots/preparations have been used. It is recommended that, after harvesting, parsnips be kept at -18 degrees C or under other conditions that prevent microbial infections.