Jackson L, Langlois B E, Dawson K A
Department of Animal Sciences, University of Kentucky, Lexington 40546-0215.
J Clin Microbiol. 1992 Aug;30(8):2113-7. doi: 10.1128/jcm.30.8.2113-2117.1992.
Research has shown that various percentages of fecal Escherichia coli isolates obtained from healthy subjects may be beta-glucuronidase negative. The ability to detect beta-glucuronidase activity among fecal E. coli isolates from healthy subjects may be affected by assay conditions. A study was conducted in which agar and broth media containing 4-methylumbelliferyl-beta-D-glucuronide (MUG) were used to examine beta-glucuronidase activities of fecal isolates from healthy swine. Rectal swabs were plated on MacConkey agar plus 100 mg of MUG per liter (MAC-MUG) and incubated at 35 degrees C for 24 h. Each of 986 isolates picked from MAC-MUG was inoculated into duplicate tubes of lauryl tryptose broth plus 50 mg of MUG per liter (LT-MUG). One set of tubes was incubated at 35 degrees C and the other set of tubes was incubated at 44.5 degrees C. Gas production and hydrolysis of MUG, indicated by fluorescence when observed with UV light with a wavelength of 360 nm, were determined after incubation for 24 and 48 h. A higher percentage (P less than 0.01) of isolates was MUG positive at 44.5 degrees C than at 35 degrees C after 24 h of incubation in LT-MUG. A higher percentage (P less than 0.01) of isolates was MUG positive after 48 h than after 24 h of incubation at both 35 and 44.5 degrees C. A lower percentage of isolates (P less than 0.05) was observed to be MUG positive on MAC-MUG agar compared with their MUG reactions in LT-MUG at 35 and 44.5 degrees C. Approximately 89% of the isolates identified were beta-glucuronidase-positive E. coli. The largest proportion of MUG-positive E. coli was detected with LT-MUG at 35 degrees C after 48 h of incubation.
研究表明，从健康受试者获得的不同比例的粪便大肠杆菌分离株可能为β-葡萄糖醛酸酶阴性。检测健康受试者粪便大肠杆菌分离株中β-葡萄糖醛酸酶活性的能力可能受检测条件影响。开展了一项研究，使用含有4-甲基伞形酮-β-D-葡萄糖醛酸（MUG）的琼脂和肉汤培养基检测健康猪粪便分离株的β-葡萄糖醛酸酶活性。将直肠拭子接种于每升含100 mg MUG的麦康凯琼脂（MAC-MUG）上，于35℃培养24小时。从MAC-MUG平板上挑取的986株分离株分别接种到每升含50 mg MUG的月桂基胰蛋白胨肉汤（LT-MUG）的双份试管中。一组试管于35℃培养，另一组试管于44.5℃培养。培养24小时和48小时后，通过在波长360 nm紫外光下观察荧光来测定气体产生情况以及MUG的水解情况。在LT-MUG中培养24小时后，44.5℃时MUG阳性的分离株比例高于35℃时（P<0.01）。在35℃和44.5℃培养48小时后MUG阳性的分离株比例均高于培养24小时后（P<0.01）。与在35℃和44.5℃时LT-MUG中的MUG反应相比，观察到在MAC-MUG琼脂上MUG阳性的分离株比例较低（P<0.05）。鉴定出的分离株中约89%为β-葡萄糖醛酸酶阳性大肠杆菌。培养48小时后，在35℃时LT-MUG检测到的MUG阳性大肠杆菌比例最高。
