PubMed HealthSearch

Biomedical subjects

M J Pickett

Publications and source records attributed to M J Pickett.

16 recordsLinked to original sources

Moraxella atlantae bacteraemia in a patient with systemic lupus erythematosis.

We describe the first reported case of human infection caused by Moraxella atlantae (formerly known as CDC group M-3) and its successful treatment with intravenous cefuroxime. The isolation and identification of this species, as well as the pathogenesis of the infection, are discussed. It is recommended that isolates of Moraxella species be speciated so that the epidemiological characteristics and pathogenesis of the infections caused by the various species may be understood more completely.

Adult

Tests for detecting degradation of gelatin: comparison of five methods.

Five methods for detecting degradation of gelatin by bacteria were compared. These were liquefaction in nutrient broth, hydrolysis in nutrient agar, hydrolysis of charcoal gelatin strips, degradation of the gelatin on strips of photographic film, and alkalinization of gelatin agar. Degradation of photographic film is a rapid and convenient method but, like hydrolysis of gelatin in broth and in agar, may fail to detect weakly positive strains of bacteria. Alkalinization of gelatin in an agar medium is a convenient and sensitive method to detect degradation of gelatin, particularly by Pseudomonas fluorescens, but this method may not be applicable to some species.

Bacteria

Recovery of an unusual Flavobacterium group IIb-like isolate from a hand infection following pig bite.

An unusual gram-negative rod (RMA 1571) was isolated from a hand infection following a pig bite. This unclassified isolate was characterized by growth requirements, microscopic examination, biochemical characteristics, antimicrobial susceptibility tests, and cellular fatty acid analysis. It was indole positive and produced yellow-pigmented growth, which placed it in the genus Flavobacterium, but its other features, including cellular fatty acid analysis, did not appear to be those of a named species.

Animals

Methods for identification of flavobacteria.

Published reports disagree on the best features for detecting and distinguishing between Flavobacterium meningosepticum (biovar IIa) and Flavobacterium species CDC group IIb (biovar IIb; Flavobacterium indologenes). This report discloses that at least some of these disagreements may reflect the methods used. To detect production of indole, a modified Kovács reagent (not Ehrlich) and a buffered tryptophan medium were optimal, but not all strains of these two biovars produced indole. To distinguish the two biovars, hydrolysis of corn starch was preferable to that of soluble potato starch. Both biovars may hydrolyze DNA; the differentiation achieved varied with the methods used. Both biovars presented pigmented growth; only IIb, however, was obviously pigmented on a 2-day blood agar plate. Acidification of D-arabinose definitively distinguished these two biovars; several additional features were useful but not definitive.

Bacteriological Techniques

Detection, identification, and comparison of Capnocytophaga, Bacteroides ochraceus, and DF-1.

Working independently, three laboratories had recognized considerable similarity among certain strains of dysgonic, fermentative, capnophilic, surface translocating, gram-negative bacilli referred to as Capnocytophaga, Bacteroides ochraceus, and Center for Disease Control biogroup DF-1. To determine the relationship among these groups, 21 strains were exchanged and independently characterized by the three laboratories. Additionally, a fourth laboratory examined the deoxyribonucleic acid homologies of the same strains. Using methods common to dental microbiology, eight of the strains had been isolated from the gingival sulcus and periodontal lesions and identified as Capnocytophaga. Three strains isolated from blood and transtracheal aspirate had been characterized by conventional anaerobic methods and recorded as B. ochraceus. Ten strains isolated from sputum, blood, throat, spinal fluid, and tracheal aspirate had been identified as DF-1 with the methods of E. O. King and a buffered single-substrate technique. All strains were similar in respect to colonial and microscopic morphology, surface translocation, biochemical features, gas-liquid chromatograms of metabolic end products, and deoxyribonucleic acid composition. We conclude that these biogroups should be termed Capnocytophaga species.

Bacterial Infections

Salient features of Haemophilus vaginalis.

A total of 78 strains of Haemophilus vaginalis were examined for 104 features. All strains fermented dextrin, maltose, and starch. Additionally, more than 90% of the strains fermented galactose, glucose, and ribose. Arbutin, cellobiose, melibiose, rhamnose, and salicin were not fermented by any of these strains. None of the strains acidified any of 14 alcohols or alkalinized any of 25 organic salts and amides. More than 90% of the strains hemolyzed human blood agar and hydrolyzed hippurate. No strain hemolyzed sheep blood agar. A recommendation is included for those minimal features that best differentiate H. vaginalis from other oxidase- and catalase-negative, gram-negative organisms.

Bacitracin

Pseudomonas vesicularis from cervical specimens.

Biochemical characteristics and antibiotic susceptibilities of five strains of Pseudomonas vesicularis isolated from cervical cultures are reported. The organisms were recovered from Thayer-Martin medium, which, because of its inhibitory properties, restricts over-growth by most other species. Our findings agree with those of Kaltenbach and associates (J. Clin. Microbiol., 1:339--344, 1975) on the importance of esculin hydrolysis, maltose oxidation, and pigmentation in the identification of P. vesicularis. Comparative carbohydrate oxidation studies showed agreement in three of four methods (oxidative attack, buffered single substrate, King oxidative/fermentative medium). No oxidation of carbohydrates was observed in commercial oxidative/fermentative medium. In addition to biochemical characteristics, antibiograms can be useful auxiliary aids in the identification of P. vesicularis and in its differentiation from P. diminuta, a closely related species.

Anti-Bacterial Agents

Susceptibility of Acinetobacter calcoaceticus var. anitratus (Herellea vaginicola) to minocycline.

The in vitro activity of minocycline against Acinetobacter calcoaceticus var. anitratus (Herellea vaginicola) was examined. All strains of A. anitratus were inhibited by minocycline at concentrations of 0.4 mug/ml or less. The strains studied were considerably more susceptible to minocycline than tetracycline. No difference between the susceptibility to minocycline and tetracycline was seen with Escherichia coli, Klebsiella pneumoniae, Enterobacter and Proteus sp. A regression line of the log minimal inhibitory concentration (MIC) values and the diameter of the zone of inhibition, determined by the Kirby-Bauer technique, showed good linear correlation for minocycline. Comparison of the disk diffusion results and MICs indicated that an inhibitory zone size of 19 mm produced by a 30-mug minocycline disk was equivalent to a MIC of 3.1 mug/ml, a serum concentration achieved by oral administration of the drug. When the zone of inhibition was greater than 19 mm, however, there was poor correlation with the MIC for Enterobacteriaceae.

Acinetobacter

Recovery of Yersinia enterocolitica from streams and lakes of California.

Stream and lake water from the Mammoth Lakes region of California was sampled for Yersinia enterocolitica. From 10 of the 34 sites examined, organisms were isolated that were biochemically identified as Y. enterocolitica. Only one of the ten strains could be serologically confirmed. This strain was identified as Y. enterocolitica serotype 16. Although an outbreak of enteritis in the area prompted this study, no correlation with gastrointestinal disease could be established since the majority of the strains were untypeable.

California

Rapid method for identification of gram-negative, nonfermentative bacilli.

A rapid system (OA), based on oxidative attack of substrates, was developed for identification of gram-negative, nonfermentative bacillia (NFB). One hundred and twelve strains of NFB from 25 species (representing the genera Pseudomonas, Alcaligenes, Acinetobacter, Bordetella, Flavobacterium, Moraxella, and Xanthomonas) were assayed by OA, buffered single substrate, and oxidative/fermentative methods. The 38 substrates consisted of salts of organic acids, nitrogen-containing compounds, alcohols, and carbohydrates. Ninety-four percent of the test strains were identified by the OA method in 24 h, and 99% were identifiable in 48 h. Reproducibility was 99%. Correlation with buffered single substrate was 98% (all substrates) and 90% with the oxidative/fermentative method (carbohydrates only). Biochemical profiles of all strains are presented, as well as tables showing the most useful tests for identification.

Acinetobacter

Deoxyribonuclease: detection with a three-hour test.

A three-hour test has been developed to determine deoxyribonuclease activity of Enterobacteriaceae and staphylococci. The test is inexpensive and easy to perform. The rapid deoxyribonuclease test and the conventional method showed complete agreement with the strains tested.

Deoxyribonucleases