No abstract

Summary. Clinical isolates of corroding, gram-negative, anaerobic bacilli (provisionally identified as Bacteroides ureolyticus) from superficial ulcers and soft tissue infections (1 9, non-gonococcal, non-chlamydia1 urethritis (1 2) and adult periodontal disease (14) were compared with reference strains of B. ureolyticus, B. gracilis and Wolinella recta in a series of conventional tests of morphology, biochemical activity, tolerance of dyes and bile salts, and antibiotic sensitivity, gas-liquid chromatographic analysis of metabolic products, and in whole-cell analysis by pyrolysis-mass spectrometry (Py-MS). A numerical taxonomic approach was used with the results of conventional tests and the grouping obtained was compared with that obtained by Py-MS. All the ulcer and soft-tissue isolates and the urethritis isolates were oxidaseand urease-positive and formed a homogeneous set consistent with the reference strain of B. ureolyticus. The dental isolates differed from B. ureolyticus strains and were heterogeneous amongst themselves. None corresponded with the reference strains of B. gracilis or W . recta. The conventional and Py-MS approaches to c haracterisation produced similar groupings and each distinguished between a single cluster of ulcer-urethritis strains and several clusters of dental strains, although the dendrograms derived from the two approaches differed in the order of the clusters; in the Py-MS dendrogram one subcluster of four dental strains came within the main ulcer-urethritis cluster and a cluster of five ulcer strains was separated as a distinct group.

SYNOPSIS A case of meningitis caused by Pseudomonas maltophilia is described, which was unusual in that it appeared to lack the predisposing factors commonly associated with this organism. Attention is drawn to the difficulties which may be encountered in the identification ofPs. maltophilia.Since the first description of the species by Hugh and Ryschenkow (1961) For many years he had been breathless on exertion as a result of emphysema and he had had an exacerbation of cough and sputum three months previously which had been successfully treated with a short course of co-trimoxazole. Four years before admission he had had a subtotal thyroidectomy for thyrotoxicosis.On examination he was semiconscious and disorientated with a temperature of 38 2°C. There was marked neck stiffness, and Kernig's sign was positive. The fundi were normal. The chest was emphysematous but there was no clinical evidence of pulmonary infection, and the only other abnormal physical sign was an enlarged prostate.Preliminary investigations revealed a peripheral blood leucocyte count of 13 000 per mm3, 90% of the cells being neutrophil polymorphonuclears; the ESR was 18 mm in 1 hour. The urine was sterile, and a chest radiograph revealed emphysema and changes consistent with industrial exposure to dust. The cerebrospinal fluid was faintly turbid; it contained 30 RBC and 92 WBC per mm3 (95 % of the WBC

Summary. Clinical strains presumptively identified as Streptococcus milleri (60), and blind coded collection strains (2 1) were characterised in conventional tests and pyrolysis mass spectrometry. Comparison of the clusters found by these two approaches revealed five clearly distinct centres of variation. Three corresponded to the DNA homology groups suggested by Whiley and Hardie (1989) as representing the species S. anginosus, S. intermedius and S. constellatus; a fourth comprised three Lancefield group C B-haemolytic strains; the fifth may represent a biotype of S. anginosus. The characteristics of the latter group are described.

No abstract