PubMed · 5167177
The source did not provide an abstract. Follow the original record for more information.
Explore connections, maps & timelines
G L Gilbert, J F Cassidy, N M Bennett. 1971-11-27. Rat-bite fever.. https://doi.org/10.5694/j.1326-5377.1971.tb92745.x
Cite the original work for its findings. Save a collection to share your selection of sources.
KEEP EXPLORING
Continuous and repeat-batch biofilm fermentations using Actinobacillus succinogenes were performed with immobilized and suspended-cell systems. For the immobilized continuous system, plastic composite supports (PCS) containing 50% (w/w) polypropylene (PP), 35% (w/w) ground soybean hulls, 5% (w/w) dried bovine albumin, 2.5% (w/w) soybean flour, 2.5% (w/w) yeast extract, 2.5% (w/w) dried red blood cells, and 2.5% (w/w) peptone, or PP tubes (8.5 cm in length) were arranged around the agitator shaft in a grid formation. Agitation was controlled at 125 rpm and 150 rpm. Samples were taken at dilution rates of 0.2, 0.4, 0.6, 0.8, 1.0, and 1.2 h(-1) and analyzed for succinic acid production and glucose consumption (g l(-1)). For PCS bioreactors, the highest final succinic acid concentrations (10.1 g (-1), 10.4 g l(-1)) and percentage yields (62.6%, 71.6%) occurred at the dilution rate of 0.2 h(-1). PCS disks were evaluated in a repeat-batch biofilm reactor. Suspended-cell batch fermentations were performed in flasks and a repeat-batch bioreactor. The maximum concentration of succinic acid produced was 40 g l(-1). Peak succinic acid percentage yields in continuous and repeat-batch fermentations of A. succinogenes were observed in suspended-cell continuous fermentations at a dilution rate of 1.0 h(-1) (76.2%) and in PCS repeat-batch fermentations with an initial glucose concentration of 40 g l(-1) (86.7%).
The taxonomy of the members of the genus Actinobacillus associated with animals has been reviewed with focus on classification and identification including molecular based characterization, typing and identification. Out of the 22 species or species like taxa reported as Actinobacillus, 19 are associated with animals. When classified on the basis of 16S rRNA sequence based phylogenetic analysis, DNA-DNA hybridizations and phenotypic analysis, Actinobacillus sensu stricto is restricted to include A. lignieresii, A. pleuropneumoniae, A. equuli subsp. equuli, A. equuli subsp. haemolyticus (taxon 11 of Bisgaard), A. hominis, A. suis, A. ureae, A. arthritidis (taxon 9 of Bisgaard), Actinobacillus genomospecies 1 and 2 and the taxa 8 and 26 of Bisgaard. The remaining 11 species of Actinobacillus are unrelated to A. sensu stricto and should consequently be grouped with other genera or be renamed as new genera depending on new data. Identification of members of Actinobacillus at species level is possible through phenotypic characterization combined with information on host of isolation. PCR tests are available for specific detection of A. pleuropneumoniae. Only A. pleuropneumoniae is presently considered as a primary pathogen. Based on different types of RTX genes it is possible to PCR type A. pleuropneumoniae to serotype level. PCR might also be used for the specific detection of A. equuli subsp. haemolyticus. Epidemiological investigations and surveillance have so far included serotyping, multilocus enzyme electrophoresis (MLEE), ribotyping and restriction fragment length profiling.
The pleuropneumonia caused by Actinobacillus pleuropneumoniae (App) is one the most important swine respiratory diseases. Biochemical and serological tests are widely applied for App diagnosis and characterization. However, in some isolates, conflicting results are found. The present work focus on the characterization of 29 isolates biochemically classified as A. pleuropneumoniae, collected from swine in herds with or without a clinical history of pleuropneumonia. Sixteen isolates were from healthy swine, initially classified as nonserotypable A. pleuropneumoniae; they displayed differences in the molecular characterization patterns of App (genes cpx and apxI, II, and III). Those bacteria that could not be serotyped were submitted to rDNA 16S sequencing. All 29 isolates were analyzed by PCR for the presence of the apxIVA gene. Thirteen isolates (45%) were confirmed to be A. pleuropneumoniae by PCR, nine being from diseased animals (31%) and four from healthy animals (14%) with conclusive serotyping. The rDNA 16S sequencing was used to classify the other 16 isolates in related species other than A. pleuropneumoniae, resulting in eleven A. minor, three A. porcinus, and two Pasteurella sp. Because of conflicting results between biochemical tests and rDNA 16S sequencing, the biochemical characterization was repeated, and the new results were in agreement with the rDNA 16S sequencing data. Biochemical characterization proved to be efficient for the majority of the A. pleuropneumoniae isolates. Nevertheless, conventional tests can render conflicting results, and other methodologies, such as amplification of A. pleuropneumoniae specific apxIVA gene and rDNA 16S sequencing, are very useful for improved classification. We also observed a great variety in rDNA 16S sequences from different A. minor isolates.