MIDI (United States)

A pattern recognition algorithm was developed that was capable of accurately identifying the presence of specific microbial species in gut samples from the sample's composite fatty acid signature. We focused on 51 different species found in the human gut and 61 different fatty acids produced by those species. The unique fatty acid signatures of the individual microorganisms were obtained by gas chromatography (provided by MIDI Inc). Several algorithms were developed in Matlab to differentiate individual species using the fatty acid composition data of the simulated mixtures. These algorithms utilized Hamming distance, least‐squares optimization, and combinatorics methods to identify the presence of each species. The algorithms were tested against myriad virtual samples to analyze their ability to detect the presence of selected species. While more complex mixtures of species decreased the probability of detection, we found that utilizing a constrained least‐squares method with Hamming‐based filters provided high probabilities of detection for all tested samples. This algorithm was capable of detecting the presence of a selected species over 90% of the time for instrument tolerances as high as 15%.

Em função da relevância de mecanismos fortes de suporte à gestão empresarial nas incubadoras, para que possam auxiliar de forma eficiente no processo de negócio das novas empresas e, conseqüentemente, aumentar suas chances de sucesso, este artigo visa apresentar uma proposta de gestão por indicadores de desempenho para empresas de base tecnológica em formação e crescimento. Logo, compreende a conceituação necessária à concepção do modelo, o estabelecimento de uma empresa padrão no contexto de incubação, a definição das bases de direcionamento para o estabelecimento de indicadores de desempenho e a formatação de uma planilha de indicadores de desempenho e coleta de dados para avaliação. De forma conclusiva, apresenta considerações positivas sobre o modelo desenvolvido na prática.

Campylobacter curvus is a rarely encountered Campylobacter species in human, animal, and environmental samples. During the course of two investigations, one involving a search for possible bacterial agents causing bloody gastroenteritis and a second concerning a small outbreak of Brainerd's diarrhea in northern California, 20 strains of C. curvus or C. curvus-like organisms were isolated by a microfiltration technique and prolonged incubation. The results suggest that C. curvus may be an underappreciated Campylobacter that may be involved in sporadic and outbreak cases of bloody or chronic diarrhea in humans.

A series of four case reports are presented. OBJECTIVE The case reports document completion of lumbar discography with gadolinium contrast followed by successful computed tomography scanning of intradiscal gadolinium. Lumbar discography using gadolinium in cases of iodinated contrast allergy with magnetic resonance imaging used to visualize intradiscal gadolinium after the procedure has been described. To the authors' knowledge, there are no reports of gadolinium discography followed by computed tomography scanning of intradiscal gadolinium. The reported cases involved a chart review, performance of discography with gadolinium under fluoroscopic guidance, and postdiscography computed tomography scanning of the discs injected during the procedure. Gadolinium was visible under fluoroscopy in all four cases. It was visualized on postdiscography computed tomography scans performed both early and late after the procedure. Normal discs retained gadolinium for a longer period than discs with annular disruption. Gadolinium discography is a safe, viable alternative to conventional discography in the setting of a patient with iodinated contrast allergy. Postdiscography computed tomography scans adequately visualize intradiscal gadolinium in a more timely and cost-effective manner than magnetic resonance imaging.

The epidemiologic relatedness of methicillin-resistant Staphylococcus aureus (MRSA) isolates is currently determined by analysis of chromosomal DNA restriction patterns by pulsed-field gel electrophoresis (PFGE). We have evaluated an alternative typing system (MicroSeq StaphTrack Kit; Perkin-Elmer Biosystems) based on the sequence analysis of the chromosomally encoded polymorphic repeat X region of the S. aureus protein A (spa) gene. A total of 69 clinical MRSA isolates were divided into 18 groups according to the number and nucleotide sequences of the spa repeats. Molecular typing results obtained both by spa sequencing and from the PFGE patterns were concordant except for one group, which contained 20 isolates recovered over a 2-year period from hospitalized patients at the Mayo Clinic. Although the spa typing patterns were indistinguishable for those isolates, PFGE analysis yielded seven related but distinguishable patterns. Further coagulase gene sequence analysis subtyped those 20 strains into four groups which followed distinct temporal and geographic distributions. During a 2-year epidemic period there were up to 7 fragment changes in PFGE patterns among epidemiologically related isolates, suggesting that PFGE may be unsuitable for long-term typing of strains involved in epidemics. Although more limited than PFGE in discriminatory power, spa sequencing analysis could be used as a screening method for typing of MRSA strains because of the shorter turnaround time, ease of use, and the inherent advantages of sequence analysis, storage, and sharing of information.

Because identification of the species within the "Streptococcus milleri" group is difficult for the clinical laboratory as the species share overlapping phenotypic characteristics, we wished to confirm biochemical identification with identification by 16S rRNA gene sequence analysis. Ninety-four clinical isolates previously identified as the "Streptococcus milleri" group were reclassified as S. anginosus, S. constellatus, or S. intermedius with the API 20 Strep system (bioMerieux Vikek, Hazelton, Mo.) and the Fluo-card (Key Scientific, Round Rock, Tex.). In addition, we determined the Lancefield group, hemolysis, colony size, colony texture, repetitive extragenic palindromic PCR (rep-PCR) pattern, and cellular fatty acid (CFA) profile (MIDI, Newark, Del.). 16S rRNA gene sequence analysis with 40 selected representative strains showed three distinct groups, with S. constellatus and S. intermedius found to be more closely related to each other than to S. anginosus, and further distinguished a biochemically distinct group of urogenital isolates within the S. anginosus group of isolates. Except for strains unreactive with the Fluo-card (8%), all S. anginosus and S. intermedius strains identified by sequencing were similarly identified by biochemical testing. However, 23% of the selected S. constellatus isolates identified by sequencing (9% of all S. constellatus isolates) would have been identified as S. anginosus or S. intermedius by biochemical tests. Although most S. anginosus strains formed one unique cluster by CFA analysis and most S. constellatus strains showed similar rep-PCR patterns, neither method was sufficiently dependable for identification. Whereas Lancefield group or lactose fermentation did not correspond to sequence or biochemical type, S. constellatus was most likely to be beta-hemolytic and S. intermedius was most likely to have a dry colony type. The most frequent isolate in our population was S. constellatus, followed by S. anginosus. There was an association of S. anginosus with a gastrointestinal or urogenital source, and there was an association of S. constellatus and S. intermedius with both the respiratory tract and upper-body abscesses.