Evaluation of Pseudosel Agar as an Aid in the Identification of Pseudomonas aeruginosa

Growth of Pseudomonas aeruginosa and thirty-five other species of gramnegative bacilli was observed on 0.03% cetrimide in heart infusion agar medium and Pseudosel agar (BBL). The 0.03% cetrimide agar was more selective for growth of P. aeruginosa than was Pseudosel agar; however, certain bacteria other than P. aeruginosa also grew on the former medium. Although Pseudosel agar was not a highly selective medium for P. aeruginosa, it was preferable to technicolor agar for detection of the pyocyanin and pyorubin pigments produced by P. aeruginosa.     

Iodine as an Aid in Identification of Asci and Ascospores of Schizosaccharomyces octosporus

Transverse paraffin sections of mature greenwood stems of rose (Rosa x hybrida) and flowering dogwood (Cornus florida L.) were stained with Bismarck brown followed by azure B or tolnidine blue O. The Bismarck brown was replaced by thiazin dye metachromasia in all structures except the cuticle which remained brown or yellow. The interface between the cuticle and exterior cell walls of the epidermis was delineated clearly.     

Lysozyme Production as an Aid for Identification of Potentially Pathogenic Strains of Staphylococci

Lysozyme production is a frequent property of potentially pathogenic staphylococci. In the present study, 1,186 strains of human origin, 85 strains of animal origin, and 156 strains of Staphylococcus albus (epidermidis) were tested. Of 1,114 coagulase-positive strains of human and animal origin, 1,098 were lysozyme-positive (98.5%). On the other hand, of 157 coagulase-negative strains which, based on further investigations, belong to the potentially pathogenic staphylococci, all were lysozyme-positive. All of the 156 strains (100%) belonging to the species S. albus (epidermidis) were lysozyme-negative. We conclude that lysozyme production is a better index of potentially pathogenic staphylococci than the measurement of free coagulase, especially in cases of strains of animal origin. It is possible that lysozyme production allows a differentiation between pathogenic and nonpathogenic coagulase-negative staphylococci.     

Two-Tube Test for the Rapid Identification of Prompt Lactose-Fermenting Genera Within the Family Enterobacteriaceae

One hundred and fifty-nine prompt lactose-fermenting strains of Enterobacteriaceae were tested for H(2)S production, ornithine decarboxylase activity, motility, and citrate utilization by using two different sets of test media. It was shown that the three tests first mentioned could be carried out in a single tube, the results being as reliable as when each was done separately. Simmons medium was preferred for the detection of citrate utilization. Since these four tests require only two tubes, they are considered more convenient in routine diagnostics. A combined medium for the detection of H(2)S production and motility is described.     

Needle Biopsy as an Aid to the Precise Diagnosis of Intrathoracic Disease

The place of needle biopsy of the lung and pleura in the diagnosis of intrathoracic disease was assessed by means of an analysis of the results of this procedure in 78 cases involving 111 separate biopsy attempts. The Vim-Silverman needle was used throughout. Needle biopsy of the lung, restricted to cases with localized radiological lesions peripherally situated and suggesting neoplasm, yielded a specific diagnosis in 29 of 48 patients. The comparison with other diagnostic aids, bronchoscopy, sputum cytology and scalene node biopsy, was favourable, at least in the case of peripheral tumours. There were eight complications, only three of which were of significance. Needle biopsy of the pleura proved to be a less rewarding procedure, a specific diagnosis being obtained in only seven of 30 cases. There were, however, no serious complications with this latter procedure. It was concluded that needle biopsy is of some value as a relatively safe addition to diagnostic techniques in chest disease.     

Analysis of Multimolecular Enzymes as an Aid to the Identification of Certain Rapidly Growing Mycobacteria, using Starch Gel Electrophoresis

Four species of rapidly growing mycobacteria were shown to have multi-molecular forms of esterase and catalase. The number and positions of bands of esterases after electrophoresis in starch gel were characteristic for each of the species Mycobacterium phlei, M. smegmatis, M. fortuitum and M. rhodochrous . Strains of these species are readily identified within 4 days by the method. M. smegmatis and M. fortuitum had esterases which were still active after heating at 100° for 10 min.