Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.2.1.23 (beta-galactosidase)
 14,648 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Clinical isolates of rhamnose-positive Yersinia enterocolitica (Y.e.rh+) were compared with typical rhamnose-negative Y. enterocolitica (Y.e.rh-) and with Yersinia pseudotuberculosis. The Y.e.rh+ differed from the Y.e.rh- and Y. pseudotuberculosis in their ability to ferment raffinose and lactose, utilize citrate and in their inability to grow on Hektoen enteric agar at 22 or 37 C, on Salmonella-Shigella agar at 37 C, and scant on xylose-lysine-deoxycholate agar at 37 C. An extensive temperature-dependent profile of characteristics was established for the Y.e.rh+: motility, acetoin production, citrate utilization, growth on Salmonella-Shigella agar, and ampicillin resistance occurred at 22 C but not 37 C; fermentation of melibiose, raffinose, and cellobiose occurred within 24 h at 22 C, but not before 5 days at 37 C; fermentation of rhamnose and production of beta-galactosidase occurred within 24 h at 22 C, but not before 48 h at 37 C; greater resistance to ampicillin, chloramphenicol, streptomycin, kanamycin, carbenicillin, and gentamicin was observed at 22 than 37 C; and good growth on xylose-lysine-deoxycholate agar occurred at 22 but not 37 C. For optimal recovery of Y.e.rh+ from mixed culture, e.g., stools, two MacConkey plates should be inoculated and incubated, one at 37 C, and one at 22 C. Lactose-negative colonies appearing after 48 h on the 22 C MacConkey agar but not the 37 C MacConkey agar should be considered possible Y.e.rh+. Biochemicals should be tested in duplicate, one set incubated at 22 C, one set at 37 C. Antibiotic susceptibility tests of Y.e.rh+ isolates should be incubated at both 37 C and at a lower temperature to allow the greatest expression of resistance of these organisms to the various antibiotics.
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PMID:Temperature-dependent cultural and biochemical characteristics of rhamnose-positive Yersinia enterocolitica. 125 9

Six strains of serotypes 1 or 2 of Y. pseudotuberculosis were isolated from dead squirrel monkeys, a cotton-top tamarin and a marmoset hybrid. All strains harboured a 71.6 kb plasmid, all were totally oxacillin-resistant and partially resistant to cephalosporins. Biochemically, serotypes 1 and 2 differed from each other in their beta-galactosidase production in a nonfermenter system, whereas the lack of rhamnose, maltose, salicin and trehalose fermentation seemed to be attributable to technical causes.
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PMID:In vitro characteristics of Yersinia pseudotuberculosis of nonhuman primate origin. 148 29

Four genes, fagA, B, C and D, encoding products with 32-47% identity to proteins involved in bacterial iron uptake systems, were identified immediately downstream of the Corynebacterium pseudotuberculosis phospholipase D gene. beta-Galactosidase assays on a C. pseudotuberculosis strain carrying a fagA-lacZ fusion indicated that the putative fagABC operon was poorly expressed in iron-rich media. However, similar experiments in iron-limited media resulted in an approximately three-fold increase in beta-galactosidase activity, suggesting that this operon is regulated by iron in vitro. Although no defect in iron utilization could be determined for a C. pseudotuberculosis fagB(C) mutant in vitro, this mutant showed reduced virulence compared to wild-type in a goat model of caseous lymphadenitis. Thus, expression of the fag genes in the host appears to contribute to virulence.
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PMID:Identification and role in virulence of putative iron acquisition genes from Corynebacterium pseudotuberculosis. 1193 92

One hundred and fourteen strains of non-lactose fermenters and 127 lactose fermenters on MacConkey's agar have been compared in the 5% and 1% lactose tests and in beta-galactosidase production, using ortho-nitro-phenyl-beta-D-galactopyranoside (O.N.P.G.) as a test substance. The superiority of the O.N.P.G. test in the number of positive results and its rapidity is shown. In general, late or non-lactose fermenting strains of genera, usually lactose-positive, yield a rapidly positive O.N.P.G. reaction. Forty-one wild strains of Salmonella, Proteus, Providencia, and Pseudomonas aeruginosa were found negative in all three tests. Of 1,075 stock strains of Salmonella examined in the O.N.P.G. test, all were negative except nine; four of these were lactose-positive strains. For practical purposes, Salmonella strains in Great Britain may be regarded as O.N.P.G. negative. Among 100 stock strains of Arizona there was considerable variation of behaviour in the O.N.P.G. test and in the 5% and 1% lactose tests. Most strains of Arizona can be considered to yield a positive O.N.P.G. test but a minority give a negative result. The test is recommended for routine use in the differentiation of Salmonella from other enterobacteria and for use in bacterial identification. The 5% lactose fermentation test in parallel is suggested when the O.N.P.G. test is used for isolating routine pathogens, because organisms such as Shigella sonnei, Shigella dysenteriae 1, and Pasteurella pseudotuberculosis are O.N.P.G. positive.
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PMID:BETA-GALACTOSIDASE AND LACTOSE FERMENTATION IN THE IDENTIFICATION OF ENTEROBACTERIA INCLUDING SALMONELLAE. 1414 33