Computer-assisted identification of anaerobic bacteria.

A computer program was developed to identify anaerobic bacteria by using simultaneous pattern recognition via a Bayesian probabilistic model. The system is intended for use as a rapid, precise, and reproducible aid in the identification of unknown isolates. The program operates on a data base of 28 genera comprising 238 species of anaerobic bacteria that can be separated by the program. Input to the program consists of biochemical and gas chromatographic test results in binary format. The system is flexible and yields outputs of: (i) most probable species, (ii) significant test results conflicting with established data, and (iii) differential tests of significance for missing test results.     

Computer-assisted identification of anaerobic bacteria.

A computer program was developed to identify anaerobic bacteria by using simultaneous pattern recognition via a Bayesian probabilistic model. The system is intended for use as a rapid, precise, and reproducible aid in the identification of unknown isolates. The program operates on a data base of 28 genera comprising 238 species of anaerobic bacteria that can be separated by the program. Input to the program consists of biochemical and gas chromatographic test results in binary format. The system is flexible and yields outputs of: (i) most probable species, (ii) significant test results conflicting with established data, and (iii) differential tests of significance for missing test results.     

卡他莫拉菌UspA1蛋白多克隆抗体的制备及鉴定

为制备抗卡他莫拉菌(Moraxella catarrhalis,Mc)表面蛋白UspA1胞外结构域的多克隆抗体(PcAb),对UspA1蛋白进行生物信息学分析,获取胞外结构域中抗原表位最为丰富的肽段,找到其对应的基因序列并引入大肠杆菌偏好性密码子,对其优化后化学合成全基因序列。将该基因序列按常规方法克隆入表达载体p ET-28a(+)后表达重组UspA1-His融合蛋白并纯化。以该纯化抗原免疫新西兰大白兔,经4次免疫后,用Protein A亲和层析柱从抗血清中纯化出抗UspA1-His融合蛋白PcAbIgG。经免疫荧光法、酶联免疫吸附法及Western blotting鉴定,抗UspA1-His融合蛋白PcAb能特异性识别UspA1蛋白的表面暴露区。该多抗的制备为下一步建立卡他莫拉菌快速检测技术奠定了基础。     

Species-forming involution of pathogenic bacteria as a biological pattern (exemplified by bacteria of the genus Moraxella)

The author advances a hypothesis stating that a species disappearing as a result of new conditions evolving in a colonized animal or human body, unfavorable for the existence of this species, does not become extinct, but reverts into newly developing species due to the loss of its properties and acquiring new properties corresponding to new conditions. Thus the genus is preserved through the loss of species characteristics by individual organisms. The advanced hypothesis is substantiated by the analysis of the relevant processes observed in cases of infectious keratoconjunctivitis in humans and cattle, caused by bacteria of the genus Moraxella. The data indicating the possibility of such reversion in the genera Neisseria and Bordetella are presented.     

Classification and identification of bacteria by Fourier-transform infrared spectroscopy.

This study describes a computer-based technique for classifying and identifying bacterial samples using Fourier-transform infrared spectroscopy (FT-IR) patterns. Classification schemes were tested for selected series of bacterial strains and species from a variety of different genera. Dissimilarities between bacterial IR spectra were calculated using modified correlation coefficients. Dissimilarity matrices were used for cluster analysis, which yielded dendrograms broadly equated with conventional taxonomic classification schemes. Analyses were performed with selected strains of the taxa Staphylococcus, Streptococcus, Clostridium, Legionella and Escherichia coli in particular, and with a database containing 139 bacterial reference spectra. The latter covered a wide range of Gram-negative and Gram-positive bacteria. Unknown specimens could be identified when included in an established cluster analysis. Thirty-six clinical isolates of Staphylococcus aureus and 24 of Streptococcus faecalis were tested and all were assigned to the correct species cluster. It is concluded that: (1) FT-IR patterns can be used to type bacteria; (2) FT-IR provides data which can be treated such that classifications are similar and/or complementary to conventional classification schemes; and (3) FT-IR can be used as an easy and safe method for the rapid identification of clinical isolates.     

Isolation and identification of fecal bacteria from adult swine.

An examination of the fecal microflora of adult swine was made with regard to the efficiency of several roll tube media in enumeration and recovery of anaerobes, the effects of medium constituents on recovery, and the isolation and identification of the predominant kinds of bacteria. Total number of organisms by microscopic bacterial counts varied among fecal samples from 4.48 X 10(10) to 7.40 X 10(10) bacteria/g (wet weight). Comparison of different nonselective roll tube media indicated that about 30% of the fecal bacteria could be recovered with a rumen fluid (40%, vol/vol) medium (M98-5). Recoveries of 21 and 15%, respectively, were obtained with M10 and rumen fluid-glucose-cellobiose agar (RGCA) media. Rumen fluid, Trypticase, sugars, and CO2 gas phase were important components required for maximum recovery with this medium. Similar high recoveries of anaerobes were also obtained with M98-5 containing swine cecal extract of place in rumen fluid or M10 plus swine cecal extract. Significantly lower recoveries were observed with RCGA, media supplemented with swine fecal extracts, reinforced clostridial medium, brain heart infusion agar, and prereduced blood agar. Ninety percent of the bacteria isolated from roll tube media were gram positive and consisted of facultatively anaerobic streptococci, Eubacterium sp., Clostridium sp., and Propionibacterium acnes. The remainder of the flora (8%) included several other species of anaerobes and Escherichia coli. Rumen fluid (or volatile fatty acids), Trypticase, and yeast extract additions to basal media stimulated the growth of anaerobic strains. Variation in the relative proportions of the predominant fecal microflora was observed. This work indicates that satisfactory enumeration, isolation and cultivation of the predominant microflora in swine feces can be obtained when strict anaerobic culture methods and a rumen fluid medium are used.     

Improved identification of methanogenic bacteria by fluorescence microscopy.

Methanogenic bacteria can be tentatively identified by fluorescence microscopy. This technique was improved by carefully selecting a series of excitation and barrier filters that matched the excitation and emission spectra of some unique coenzymes viz., F420 and F350, in methanogenic bacteria.     

Improved identification of methanogenic bacteria by fluorescence microscopy.

Methanogenic bacteria can be tentatively identified by fluorescence microscopy. This technique was improved by carefully selecting a series of excitation and barrier filters that matched the excitation and emission spectra of some unique coenzymes viz., F420 and F350, in methanogenic bacteria.