scholarly journals In situ studies with membrane diffusion chambers of antibiotic resistance transfer in Escherichia coli.

1982 ◽  
Vol 44 (4) ◽  
pp. 838-843 ◽  
Author(s):  
M R Altherr ◽  
K L Kasweck
Keyword(s):  
Escherichia Coli ◽  
Antibiotic Resistance ◽  
Membrane Diffusion ◽  
Diffusion Chambers ◽  
In Situ Studies ◽  
Resistance Transfer

A survival study of Escherichia coli in a south African river using membrane diffusion chambers

1995 ◽  
Vol 31 (5-6) ◽  
pp. 185-188 ◽  
Author(s):  
C. M. E. de Wet ◽  
S. N. Venter ◽  
N. Rodda ◽  
R. Kfir ◽  
M. C. Steynberg ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
South African ◽  
The Other ◽  
Membrane Diffusion ◽  
Diffusion Chambers ◽  
E Coli ◽  
Significant Difference ◽  
Survival Pattern ◽  
The One ◽  
Different Parts

Studies to describe the survival of Escherichia coli were performed at two sites in a river. The one site was dominated by domestic discharge and the other by industrial inputs. E coli suspensions within membrane diffusion chambers were immersed in the river at the selected sites. An identical chamber was submerged in river water in the laboratory as a comparison. Two test runs were performed, one during winter (July) and one during summer (December). Samples to determine the survival of E coli was taken on a scheduled basis. Results obtained showed no significant difference between the survival pattern of E coli as determined during the summer and winter periods or in the different parts of the river. The same survival pattern was observed for the studies performed in the laboratory.

scholarly journals Detection and characterization of verotoxin-producing strains among sorbitol non-fermenting Escherichia coli

2001 ◽  
Vol 7 (4-5) ◽  
pp. 756-762
Author(s):  
A. Jafari ◽  
M. Katouli ◽  
F. Shokouhi ◽  
S. Bouzari
Keyword(s):  
Escherichia Coli ◽  
Polymerase Chain Reaction ◽  
Antibiotic Resistance ◽  
Multidrug Resistance ◽  
High Rate ◽  
Cell Adherence ◽  
Chain Reaction ◽  
Resistance Transfer ◽  
Polymerase Chain

The presence of genes for verotoxin 1 and 2 [VT1 and 2] among sorbitol non-fermenting Escherichia coli isolates from diarrhoeal cases was assessed using polymerase chain reaction assay. Of 60 [88%] positive isolates, 37 [62%] harboured VT1 and 23 [38%] both VT1 and VT2. In HeLa cell adherence assay, 48 [71%] isolates exhibited mannose-resistant adherence to HeLa cells. Multidrug resistance was observed in 56 [82%] isolates, with ampicillin, chloramphenicol, streptomycin, sulfamethoxazole-trimethoprim and tetracycline pattern being the most common. There were 13 common and 22 single biochemical phenotypes identified. Isolates belonging to common biochemical phenotypes normally had a similar pattern of adherence and VT production, but differed greatly in their pattern of antibiotic resistance, pointing to a high rate of antibiotic-resistance transfer among these isolates.

Preparation of integrated circuits for TEM electromigration in situ studies

1986 ◽  
Vol 44 ◽  
pp. 882-883
Author(s):  
J. V. Maskowitz ◽  
W. E. Rhoden ◽  
D. R. Kitchen ◽  
R. E. Omlor ◽  
P. F. Lloyd
Keyword(s):  
Integrated Circuits ◽  
Crystallographic Orientation ◽  
Silicon Wafers ◽  
Minimum Size ◽  
Test Vehicle ◽  
In Situ Studies ◽  
Boron Doped ◽  
Doped Silicon ◽  
Drill Holes

The fabrication of the aluminum bridge test vehicle for use in the crystallographic studies of electromigration involves several photolithographic processes, some common, while others quite unique. It is most important to start with a clean wafer of known orientation. The wafers used are 7 mil thick boron doped silicon. The diameter of the wafer is 1.5 inches with a resistivity of 10-20 ohm-cm. The crystallographic orientation is (111).Initial attempts were made to both drill and laser holes in the silicon wafers then back fill with photoresist or mounting wax. A diamond tipped dentist burr was used to successfully drill holes in the wafer. This proved unacceptable in that the perimeter of the hole was cracked and chipped. Additionally, the minimum size hole realizable was > 300 μm. The drilled holes could not be arrayed on the wafer to any extent because the wafer would not stand up to the stress of multiple drilling.

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