usp－微生物限度检查

usp－微生物限度检查内容摘要：

s for each of the tests called for in the individual monograph. PROCEDURE Prepare the specimen to be tested by treatment that is appropriate to its physical characteristics and that does not alter the number and kind of microanisms originally present, in order to obtain a solution or suspension of all or part of it in a form suitable for the test procedure(s)to be carried out. For a solid that dissolves to an appreciable extent but not pletely, reduce the substance to a moderately fine powder, suspend it in the vehicle specified, and proceed as directed under Total Aerobic Microbial Count, and under Test for Staphylococcus aureus and Pseudomonas aeruginosaand Test for Salmonella species and Escherichia coli. For a fluid specimen that consists of a true solution, or a suspension in water or a hydroalcoholic vehicle containing less than 30percent of alcohol, and for a solid that dissolves readily and practically pletely in 90mLof Buffer or the media specified, proceed as directed under Total Aerobic Microbial Count,and under Test for Staphylococcus aureus and Pseudomonas aeruginosaand Test for Salmonella species and Escherichia coli. For waterimmiscible fluids, ointments, creams, and waxes, prepare a suspension with the aid of a minimal quantity of a suitable, sterile emulsifying agent (such as one of the polysorbates), using a mechanical blender and warming to a temperature not exceeding 45 ,if necessary, and proceed with the suspension as directed under Total Aerobic Microbial Count,and under Test for Staphylococcus aureus and Pseudomonas aeruginosaand Test for Salmonella species and Escherichia coli. For a fluid specimen in aerosol form, chill the container in an alcoholdry ice mixture for approximately 1hour,cut open the container, allow it to reach room temperature, permit the propellant to escape, or warm to drive off the propellant if feasible, and transfer the quantity of test material required for the procedures specified in one of the two preceding paragraphs, as appropriate. Where or the specimen, whichever is applicable, cannot be obtained from 10containers in aerosol form, transfer the entire contents from 10chilled containers to the culture medium, permit the propellant to escape, and proceed with the test on the residues. If the results of the test are inconclusive or doubtful, repeat the test with a specimen from 20more containers. Total Aerobic Microbial Count For specimens that are sufficiently soluble or translucent to permit use of the Plate Method, use that method。 otherwise, use the MultipleTube Method. With either method, first dissolve or suspend of the specimen if it is a solid, or 10mL,accurately measured, if the specimen is a liquid, in Buffer, Fluid Soybean–Casein Digest Medium,or Fluid Casein Digest–Soy LecithinPolysorbate 20Medium to make viscous specimens that cannot be pipeted at this initial 1:10dilution,dilute the specimen until a suspension is obtained,.,1:50or 1:100,etc.,that can be pipeted. Perform the test for absence of inhibitory (antimicrobial)properties as described under Preparatory Testing before the determination of Total Aerobic Microbial the specimen to the medium not more than 1hour after preparing the appropriate dilutions for inoculation. PLATE METHOD Dilute further, if necessary, the fluid so that 1mLwill be expected to yield between 30and 1mLof the final dilution onto each of two sterile petri dishes. Promptly add to each dish 15to 20mLof Soybean–Casein Digest Agar Medium that previously has been melted and cooled to approximately 45 .Cover the petri dishes, mix the sample with the agar by tilting or rotating the dishes, and allow the contents to solidify at room temperature. Invert the petri dishes, and incubate for 48to incubation, examine the plates for growth, count the number of colonies, and express the average for the two plates in terms of the number of microanisms per g or per mLof no microbial colonies are recovered from the dishes representing the initial 1:10dilution of the specimen,express the results as ―less than 10microanisms per g or per mLof specimen.‖ MULTIPLETUBE METHOD Into each of fourteen test tubes of similar size place sterile Fluid Soybean–Casein Digest Medium. Arrange twelve of the tubes in four sets of three tubes each. Put aside one set of three tubes to serve as the controls. Into each of three tubes of one set (―100‖)and into a fourth tube (A)pipet 1mLof the solution or suspension of the specimen, and mix. From tube A,pipet 1mLof its contents into the one remaining tube (B)not included in a set, and mix. These two tubes contain 100mg (or 100181。 L)and 10mg (or 10181。 L)of the specimen, respectively. Into each of the second set (―10‖)of three tubes pipet 1mLfrom tube A,and into each tube of the third set (―1‖)pipet 1mLfrom tube the unused contents of tubes Aand well,and incubate all of the tubes. Following the incubation period, examine the tubes for growth: the three control tubes remain clear and the observations in the tubes containing the specimen, when interpreted by reference to Table 1,indicate the most probable number of microanisms per g or per mLof specimen. Table Probable Total Count by MultipleTube Method Observed Combinations of Numbers of Tubes Showing Growth in Each Set Most Probable Number of Microanisms per g or per mL mg (or mL)of Specimen per Tube 100 (100181。 L) 10 (10181。 L) 1 (1181。 L) 3 3 3 1100 3 3 2 1100 3 3 1 500 3 3 0 200 3 2 3 290 3 2 2 210 3 2 1 150 3 2 0 90 3 1 3 160 3 1 2 120 3 1 1 70 3 1 0 40 3 0 3 95 3 0 2 60 3 0 1 40 3 0 0 23 Test for Staphylococcus aureus and Pseudomonas aeruginosa To the specimen add Fluid Soybean–Casein Digest Medium to make 100mL,mix,and incubate. Examine the medium for growth, and if growth is present, use an inoculating loop to st。