Page 1 of 15 Secretariat : c/o IFAH, rue Defacqz, 1

- B

- 1000 Bruxelles (Belgium)

- Tel. +32

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- 543.75.72 , Fax +32

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– Internet: www.v ich sec. org **VICH GL34 (B**  **IOLOGICALS :**  **M YCOPLASMA** **) November**  **2011 For**  **consultation at Step**  **4**
**- Draft 2** 



# T ESTING FOR THE DETEC TION OF MYCOPLASMA CONTAMINA TION

Recommended for Consultation at Step 4 of the VICH Process in November 2011 by the VICH Steering C ommittee

T HIS G UIDELINE HAS BEEN DE VELOPED BY THE APPRO PRIATE VICH E XPERT W ORKING G ROUP AND IS SUBJECT TO CO NSULTATION BY THE PA RTIES , IN ACCORDANCE W ITH T HE VICH P ROCESS

. AT S TEP 7 OF THE P ROCESS THE FINAL DRA FT W ILL BE RECOMMEND ED FOR ADOPTION TO T HE

REGULATORY BODIES OF THE E UROPEAN U NION , J APAN AND USA.

## 1. INTRODUCTION

**1.1. Objective of the guideline** This VICH (Internation al Cooperation on Harmonization of Technical Requirements for Registration of Veterinary Medicinal Produ cts) guideline is intended to facilitate the harmonized licensing of new products for veterinary use. It is important that biological products for veterinary use are free of contamination with Mycoplasmas to help assure consistency of production and final product safety. Mycoplasma contaminants may be introduced into cell culture and in ovo origin biological products through the master seeds, the master cell seed (stock), starting materials of animal origin, and in processing of biological materials durin g passage and product assembly. Therefore it is necessary to demonstrate through testing that Mycoplasmas are not present, within the limits of the test, in the final product, working seeds and cells and harvests, and starting materials such as the master seed, master cell seed, and ingredients of animal origin. This guideline establishes stages of manufacture to be tested and test procedures to detect the presence of Mycoplasma contamination. It will provide a unified standard that will facilitate the m utual acceptance of test data by the relevant regulatory authorities. Methods proven equivalent to the guideline method by scientifically accepted criteria could also be acceptable. 

### 1.2. Background The present methods for testing for Mycoplasma contami nation are described in the Japanese “Minimum requirements of biological products for animal use ( 2002 )”, the European Pharmacopoeia ( 7 th Edition, 2011 , 2.6.7), and the United States Code of Federal Regulations, Title 9, 113.28. These requirements are all similar in that they require testing for Mycoplasma contamination using a broth and agar technique. The requirements do however differ in the specifics of these broth and agar tests as well as other alternative test methods that are required or approved fo r use in detecting Mycoplasma contamination. 

### 1.3. Scope of guideline This guideline describes the manner in which tests conducted to detect the presence of M ycoplasma contamination in cell culture and in ovo origin biological products for veterinary us e shall be done to assure the absence of Mycoplasma contamination. Tests on master seeds, master cell seeds (stocks), working seeds and cells, ingredients of animal origin, harvests and live final vaccine and harvests for killed products are included. Ba cterial products which grow in the mycoplasma test media and products for which mycoplasma contamination risk has been addressed through avalidated mycoplasma inactivation procedure will be considered outside this guideline.

The absence of mycoplasma con tamination in eggs used for production is controlled by appropriate testing of the flock, which is not covered by this guideline.


### 1.4. Test Methods The guideline describes two test methods: 1) expansion in broth culture and detection by colony formatio n on nutrient agar plates; and 2) expansion in cell culture and characteristic fluorescent staining of DNA (a technique capable of detecting non

cultivatable strains). A third test methodology, nucleic acid amplification (NAT), is acknowledged, but is n ot included in this guideline. The use of validated NAT techniques is currently approved or under consideration by regulatory authorities for more rapid detection confirmation, and strain identification. Appropriately validated NAT techniques may be used as an alternative to the broth/agar culture method and/or the indicator cell culture method provided the NAT test is shown to be at least equivalent in detection limit to the test methods in this guideline. A sample that tests positive by NAT may be directly considered unsuitable for use. If confirmation of the presence of living mycoplasma in the material under test is need ed the broth/agar culture method or the indicator cell culture method should be used. Evaluation of NAT method use is encouraged i n parallel testing to further develop, compare, and refine the technique for possible inclusion in future versions of this guideline.


## 2. GUIDELINE FOR TESTING FOR MYCOPLASMA CONTAMINATION

**2.1. General test procedures for detecting My**  **coplasma cont amination**  The culture method using broth and agar is the fundamental method of Mycoplasma detection. A solid and liquid media culture method shall be used to test harvests or final batches of vaccine, and ingredients of animal origin. Master seed, maste r cell seed (stock), and working seed and cell lots shall be tested using both a solid and liquid media culture method and an indicator cell culture method with DNA stain. Should either method result in a positive test for mycoplasma the sample is conside red positive and is unsuitable for use.

Material Broth & Agar Culture DNA Stain Master Seed & Master Cell Seed Required Required Wo rking Seed & Wo rking Cell Seed Required Required Ingredient of Animal Origin 1,2 Required Harvest Wh en testing required 3 Final Product Wh en testing required 3
1 Excluding eggs 2 Unless a validated mycoplasma inactivation procedure has been applied 3 The competent authorities require testing of different combinations of harvests and final product. 

### 2.2. Culture test sy**s tem validation**  The culture method should be carried out to validate the detection limit of a laboratory’s mycoplasma detection method. A sufficient number of both solid and liquid media shall be used to insure the growth of a low level of the following 5 strains of mycoplasmas.Acholeplasma laidlawii

Mycoplasma hyorhinis Mycoplasma orale Mycoplasma synoviae Mycoplasma fermentans The species were selected to reflect a range (within a practical number) of antibiotic sensitivity (to detect inhibi tion of mycoplasma growth in the assay), fastidiousness, rapidity of growth, likelihood of being a contaminant, and pathogenicity in avian or mammalian target species. Acholeplasma laidlawii is a common cell culture contaminant of animal and possibly envi ronmental origin. Mycoplasma hyorhinis is fastidious, a common cell culture contaminant of animal origin, and a mammalian pathogen. Mycoplasma orale is antibiotic sensitive and is a common cell culture contaminant of human origin. Mycoplasma synoviae is fa stidious (having a nicoti n amide

- adenine

- dinucleotide [DPN, NAD] and cysteine requirement) and is an avian pathogen. Mycoplasma fermentans is a slow

- growing organism and a common cell culture contaminant of human origin.
Reference s of the strains used to validate the laboratory mycoplasma contamination culture test system should be of low passage level (15 or less) , and identified relative to type culture isolates, (see Appendix 3.2 for fu rther information on reference strains ). The reference strains used to validate the culture test system will be appropriate to the products tested (see table). Validation for M. synoviae is required when materials of avian origin are used at any stage in development and production. Validation for M. hyorhinis and A. laidlawii is required when materials of mammalian origin are used at any stage in development and production. Validation for M. orale is required when an antibiotic has been used at any stage in development and production. Reference Preparations shall b e used to validate each production lot of broth and agar. At least one reference strain must be used as a control with each test. **Required Reference Organisms by : product type; test method, and presence of**  **antibiotics** Vaccine type Antibiotic content T est Method A. laidlawii M.

orale M.

hyorhinis M.

synoviae M.

fermentans

Avian in ovo origin vaccine Wi thout Antibiotics Broth/Agar Method 

# X X

Avian in ovo origin vaccine Wi th Antibiotics Broth/Agar Method 

# X X X
Avian cell culture origi n vaccine Wi thout Antibiotics Broth/Agar Method 

# X X X
Avian cell culture origin vaccine Wi th Antibiotics Broth/Agar Method 

# X X X XMammalian cell culture

origin vaccine Wi thout Antibiotics Broth/Agar Method 

# X X X

Mammalian cell cu lture origin vaccine W ith Antibiotics Broth/Agar Method 

# X X X X

Vaccine W ithout Antibiotics DNA Staining Method 

# X X Vaccine W ith Antibiotics DNA Staining Method 

# X X

**2.3. Culture Method**  **2.3.1. Incubation conditions**  Incubate the b roth culture medium or media in tightly stoppered containers in air. Incubate all agar plates under microaerophilic conditions (nitrogen containing 5

- 10% CO 2 ). For the solid medium or media, maintain an atmosphere of adequate humidity to prevent desiccat ion of the agar surface. 

### 2.3.2. Nutritive properties of a new batch of medium Each new lot (batch) of medium must be tested for the nutritive properties using references specified above in **Section 2. 2**  . Each testing laboratory must determine the inoculu m for each of their references that will contain a low level ( not more than 100 CFU). Inoculate the solid medium with a low level ( not more than 100 CFU) per 60 mm plate and per 100 ml container of broth medium. Use at least one agar plate and broth cont ainer for each reference. Incubate the agar and broth media and make subcultures from the broth onto agar at the specified intervals. The agar medium batch complies with the test for nutritive properties if for all the references specified , growth obtain ed does not differ by a factor greater than 5 from the value calculated with respect to the inoculum . The broth complies if Mycoplasma growth on those agar plates subcultured from the broth is achieved for each reference specified. Media formulations fou nd effective are included in **Ap pendix 3.1**  of this guideline. 

### 2.3.3. Inhibitory substances Carry out the test for nutritive properties in the presence and absence of the material to be tested at the time of prelicense and whenever there is a change in t he production method that may affect the detection of mycoplasmas. If growth of the references occurs more than one sub

- culture sooner without the test material than with the test material, or if plates directly inoculated with the test material have less than one

- fi fth of the colonies of those directly inoculated without the test material, the test material contains inhibitory substances. These substances must be neutralized or their effect otherwise countered, e.g., through passage in substrates not con taining inhibitors or dilution in a larger volume of medium, before the test for mycoplasma contamination is carried out. For the dilution technique, larger medium volumes may be used or the inoculum volume may be divided among multiple 100 ml flasks. T heeffectiveness of the neutralization or other process is confirmed by repeating the test for inhibitory substances after neutralization. 

### 2.3.4. **Test method 2.3.4.1** 

**.** The amount of inoculum for each plate of solid medium is 0.2 ml of product to be examin ed. W hen an assay for mycoplasma concerns master and working seeds, master and working cells, and ingredients of animal origin a volume of not less than 10 ml of undiluted sample shall be tested in each liquid medium. The volume of final product to be te sted in each liquid medium shall be as required by the regulatory authority issuing the marketing authorization. These are currently not less than 1 ml in Japan and the US and not less than 10 ml in the EU. Incubate the agar plates at 35oC to 38oC, micro aerophilically, for 10

- 14 days in an atmosphere of adequate humidity to prevent desiccation of the surface. Incubate the liquid media at 35o C to 38o C in tightly stoppered containers in air for 20

- 21 days. At the same time incubate an uninoculated 100 m l portion of each liquid medium and agar plates as a negative control. If any significant pH change occurs upon the addition of the product to be examined (this should be determined at the time of prelicense), the liquid medium shall be restored to its or iginal pH value by the addition of a solution of either sodium hydroxide or hydrochloric acid. Between the 2 nd and 4 th day af ter inoculation, subculture each liquid culture by inoculating at least 1 plate of each solid medium with 0.2 ml and incubate them at 35oC to 38oC microaerophilically for 10

- 14 days. Repeat the procedure between the 6 th and 8 th day , again between the 13 th and 15 th day, and again between the 19 th and 21 st day of the test. Incubate those agar plates inoculated on day 19, 20 , or 21 fo r 7 days. Observe the liquid medium or media every 2 or 3 days and if a color change occurs, subculture. Color change detection requires the addition of phenol red to the media.
**2.3.4.2**

**.** If the liquid medium or media shows bacterial or fungal contami nation, repeat the test. If it is not possible to read at least one plate per inoculation day, the test must be repeated.
**2.3.4.3**

**.** Include in the test, positive controls prepared by inoculating a low level ( not more than 100 CFU) of at least one of the reference species onto the agar plates and into the broth medium or media. If the test is run on a routine basis, the control species should be rotated on a regular basis. This control shall be used in each test conducted with a medium that has been va lidated for nutritive properties using references determined by the types of products being tested as specified in **Section 2.**  **2** of this guideline.



### 2.3.5. **Judgment of the culture method** At the end of the incubation period, examine all the inoculated soli d media microscopically for the presence of mycoplasma colonies. The product is negative for Mycoplasma contamination if the growth of typical Mycoplasma colonies has not occurred on any of the inoculated solid media. If growth of typical Mycoplasma colo nies has occurred on any of the solid media, the test and sample tested are considered positive for Mycoplasma contamination. Thetest is invalid if the positive controls do not show growth of mycoplasma on at least one subculture plate or the negative co ntrols are positive for mycoplasma contamination. If either of the controls is invalid the test must be repeated. If suspect colonies are observed, confirmation of mycoplasma contamination may be accomplished using an appropriate and validated method.


### 2 **.4. Indicator cell culture method**  Cell cultures are stained with a fluorescent dye that binds to DNA. Mycoplasmas are detected by their characteristic particulate or filamentous pattern of fluorescence on the cell surface, and if contamination is heavy, in the surrounding areas. Mitochondria in the cytoplasm may be stained, but may be differentiated from mycoplasma. 

### 2.4.1. **Validation of the indicator cell culture method** Using a VERO or other equivalent in efficiency indicator cell culture substrate, va lidate the procedure using an inoculum not more than 100 CFU or CFU

- like micro

- organisms of appropriate references of M. hyorhinis and M. orale. Both references must be positive when stained with the DNA stain at the end of the test. If for viral, etc. , suspensions the interpretation of results is affected by cytopathic effects, the virus may be neutralized using a specific antiserum that has no inhibitory effects on mycoplasmas, or an alternative cell culture substrate that does not allow the growth of the virus may be used. To demonstrate the absence of inhibitory effects of serum, carry out the positive control tests in the presence of neutralizing antiserum. Antiserum lots may be qualified once rather than at use. 

### 2.4.2. **Test method 2.4.2.1** 

**.** Seed the indicator cell culture at a suitable density that will yield confluence of the cells after 3 days of growth (example: 2 X 10 4 to 2 X 10 5 cells per ml, 4 X 10 3 to 2.5 X 10 4 cells/cm 2 ) in a cell culture vessel of not less than 25 cm 2 . The indicator ce ll culture should be sub

cultured without antibiotic prior to use. Inoculate 1 ml of the sample to be examined into the cell culture vessel and incubate at 35o C to 38o C.

**2.4.2.2**

**.** After at least 3 days of incubation and the cells have grown to conf luence, make a subculture onto cover slips in suitable containers or on some other surface (chambered slides) suitable for the test procedure. Seed the cells in the second subculture at a low density so that they reach only 50% confluence after 3

- 5 days o f incubation. Complete confluence must be avoided because it impairs visualization of mycoplasmas after staining.
**2.4.2.3**

**.** Remove medium from cover slips or chambered slides. Rinse the monolayer of indicator cells with phosphate buffered saline (PBS) and then fix with glacial acetic acid/methanol (1 to 3) or some other suitable fixing solution.

**2.4.2.4**

**.** Remove the fixing solution and discard. Wa sh the fixing solution with sterile water and dry slides completely if they are to be stained more than o ne hour later.**2.4.2.5**

**.** Add a suitable fluorescent dye that binds to DNA such as bisbenzimide stain (Hoechst compound 33258, bisbenzimidazole, 5 ug/L) and allow to stain for a suitable time.
**2.4.2.6**

**.** Remove the stain and rinse the monolayer with wate r. Mount the cover slips if applicable and examine the slides by fluorescence (for bisbenzimide stain use a 330 nm/380 nm excitation filter, LP 440 nm barrier filter) at 400 X magnification or greater.
**2.4.2.7**

**.** Compare the microscopic appearance of the test cultures with that of the negative and reference controls, examining for extranuclear fluorescence. Mycoplasmas produce pinpoints or filaments over the indicator cell’s cytoplasm. They may also produce pinpoints and filaments in the intercellular s paces. Multiple microscopic fields as validated should be examined. 

### 2.4.3

**. Judgment of the indicator cell culture method**  The product being examined is negative for Mycoplasma contamination if there is no evidence of pinpoints or filaments of extranuclea r fluorescence. If the slides inoculated with the product contain evidence of pinpoints or extranuclear fluorescence indicative of Mycoplasma the test and sample tested are considered positive for Mycoplasma contamination. The test is invalid if the posi tive controls do not show the presence of the appropriate extranuclear fluorescence of the reference organisms or the negative cell controls contain extranuclear fluorescence. If either of the controls is invalid the test must be repeated.

## 3. APPENDICES

**3.1**

**. Regional**  **examples of suitable broth and agar formulations**  **9 CFR My coplasma Broth**  Heart Infusion Broth 62.5 g Proteose Peptone #3 25.0 g Yeast Extract 12.5 ml 1 % Thallium Acetate 62.5 ml 1 % Tetrazolium Chloride 13.75 ml Penicillin (100,000 units/ml ) 12.5 ml Heat inactivated Horse Serum 250 ml H 2 O 2425 ml Mix all ingredients well and adjust pH to 7.9 with 10 Normal NaOH. Filter sterilize through a 0.2 μ filter. Dispense into sterile test vessels. Add DPN/L

- Cysteine solution before use, 2 ml/100 ml of broth.
**9 CFR My**  **coplasma A gar**  Heart Infusion Agar 25 g Heart Infusion Broth 10 g Proteose Peptone #3 10 g 1% Thalli um Acetate 25 ml H 2 O 995 ml Heat Inactivated Horse Serum 126 ml Yeast Extract 5 ml Penicillin (100,000 units/ml) 5.2 ml DPN/L

- Cysteine 21 ml Combine heart infusion agar, heart infusion broth, proteose peptone #3, Thallium acetate, and H 2 O. Mix and bring to boil, then cool. Adjust the pH to 7.9 with 10 Normal NaOH. Autoclave 20 min. at 121o C. Cool in water bath to 56o C. Aseptically add: horse serum, yeast extract, Penicillin, and DPN /L

- Cysteine. Dispense 12 ml into each 15 X 60 mm petr i dish.
**DPN/L**
**- Cy** **steine solution** Nicotiamide

- adenine

- dinucleotide (DPN, NAD) 5 g Q.S. with H 2 O to 500 ml

L

- Cysteine 5 g Q.S. with H 2 O to 500 ml Mix each chemical separately until dissolved. Mix the two solutions and filter sterilize. **Japanese Liquid Medium for My**  **coplasma** Basal Medium 50 % w/v Bovine Cardiac Muscle Extract 100 ml Meat Peptone 10 gSodium Chloride 5 g

Glucose 1 g Sodium L

- glutamate 0.1 g L

- arginine hydrochloride 1 g H 2 O QS to 1000 ml
Filter sterilize throu gh 0.22 μ membrane filter or sterilize at 121 o C for 15 min. Adjust the pH of the medium after sterilization to 7.2

- 7.4. Additives for 77 ml of the Basal medium; Horse Serum 10 ml Inactivated Porcine Serum 5 ml 25 % w/v Fresh Yeast Extract 5 ml 1 % w/v β

- NAD (oxidized) 1 ml 1 % w/v L

- cysteine HCL (1 H 2 O) 1 ml 0.2 % w/v phenol red 1 ml Previously filter sterilize the additives and aseptically add to the sterilized basal medium. The additives which can be sterilized by high pressure can be autoclaved. Penicillin G potassium, 500 units/ml of the medium, or Thallium acetate, 0.02 % w/v, can be added. **Japanese A gar Medium for My**  **coplasma** Basal Medium 78 ml Agar 1 g Sterilize by autoclaving 121oC for 15 min.
Additives: Horse Serum 10 ml Inactivated Porcine Serum 5 ml 25 % w/v fresh yeast extract 5 ml 1 % w/v β

- NAD (oxidized) 1 ml 1 % w/v L

- cysteine HCl (1 H 2 O) 1 ml Penicillin G potassium, 500 units per ml of medium, or thallium acetate, 0.02 % w/v can be added. Add the additives to basal/agar medium which has been liquefied by heating, and divid e into sterile petri dishes, 45

- 55 mm. Cool and allow to solidify.

**EP Hay** **flick media ( Recommended media for**  **the general detection of**  **mycoplasmas)** Liquid Medium: Beef Heart Infusion Broth (1) 90 ml Horse Serum (unheated) 20 ml Yeast Extract (250 g/L ) 10 ml Phenol Red (0.6 g/L solution) 5 ml Penicillin (20,000 I.U. per ml) 0.25 ml Deoxyribonucleic acid (2 g/L solution) 1.2 ml Adjust to pH 7.8.
Solid Medium:Prepare as described for the liquid medium above but replace beef heart infusion bro th

with beef heart infusion agar containing 15 g/L of agar.

**EP Frey**  **media ( Recommended Media for the detection of**  **M. synoviae )**  Liquid Medium: Beef Heart Infusion Broth (1) 90 ml Essential Vitamins (2) 0.025 ml Glucose monohydrate (500 g/L soluti on) 2 ml Swine serum (inactivated at 56oC for 30 min.) 12 ml β

- Nicotinamide adenine dinucleotide (10 g/L solution) 1 ml Cysteine hydrochloride (10 g/L solution) 1 ml Phenol Red (0.6 g/L solution) 5 ml Penicillin (20,000 I.U. per ml) 0.25 ml
Mix the solutions of β

- nicotinamide adenine dinuc leotide and cysteine hydrochloride and after 10 min utes, a dd the other ingredients. Adjust pH to 7.8.
Solid Medium: Beef Heart Infusion Broth (1) 90 ml Ionagar (3) 1.4 g Adjust pH to 7.8, and sterilize by autoclaving, then add: Essential Vita mins (2) 0.025 ml Glucose monohydrate (500 g/L solution) 2 ml Swine serum (unheated) 12 ml β

- Nicotinamide adenine dinucleotide (10g/L solution) 1 ml Cysteine hydrochloride (10 g/L solutions) 1 ml Phenol Red (0.6 g/L solution) 5 ml Penicillin (20,000 I.U. per ml) 0.25 ml

**EP Friis media (**  **Recommended Media for the Detection of Non** 
**- avian Mycoplasma**  **s)** Liquid Medium: Hank’s Balanced Salt Solution (modified) (4) 800 ml H 2 O 67 ml Brain Heart Infusion (5) 135 ml PPLO Broth 248 ml Yeast Extract (170 g/L) 60 ml Bacitracin 250 mg Meticillin 250 mg Phenol Red (5 g/L) 4.5 ml Horse Serum 165 ml Swine Serum 165 ml Adjust the pH to 7.40

- 7.45
Solid Medium: Hank’s Balanced Salt Solution (modified) (4) 200 ml DEAE

- dextran 200 mg Ionagar (3) 15.65 g Mix well and sterilize by autoclaving. Coo l to 100o C. Add this to 1740 ml of the liquid medium described above.**EP Media Sub parts**

(1) Beef Heart Infusion Broth Beef Heart (for preparation of the infusion) 500 g Peptone 10 g Sodium Chloride 5 g H 2 O QS to 1000 ml Sterilize by a utoclaving. (2) Essential Vitamins Biotin 100 mg Calcium pantothenate 100 mg Choline chloride 100 mg Folic acid 100 mg i

- Inositol 200 mg Nicotinamide 100 mg Pyridoxal hydrochloride 100 mg Riboflavin 10 mg Thiamine hydrochloride 100 mg H 2 O QS to1000 ml (3) Ionagar A highly refined agar for use in microbiology and immunology, prepared by an ion

exchange procedure which results in a product having superior purity, clarity, and gel strength. It contains approximately: H 2 O 12.2 % Ash 1.5 % Acid insoluble ash 0.2 % Chlorine 0.0 % Phosphate (calculated as P 2 O 5 ) 0.3 % Total Nitrogen 0.3 % Copper 8 ppm Iron 170 ppm Calcium 0.28 % Magnesium 0.32 % (4) Hank’s Balanced Salt Solution (modified) Sodium chloride 6.4 g Potassium chloride 0.32 g Magnesium sulphate heptahydrate 0.08 g Magnesium chloride hexahydrate 0.08 g Calcium chloride, anhydrous 0.112 g Disodium hydrogen phosphate dihydrate 0.0596 g Potassium dihydrogen ph osphate, anhydrous 0.048 g H 2 O QS to 800 ml (5) Brain heart infusion Calf brain infusion 200 g Beef heart infusion 250 g Proteose peptone 10 g Glucose 2 gSodium chloride 5 g

Disodium hydrogen phosphate, anhydrous 2 .5 g H 2 O QS to 1000 ml (6) PPLO broth Beef heart infusion 50 g Peptone 10 g Sodium chloride 5 g H 2 O QS to 1000 ml
**Bisbenzimide stain solution for DNA Staining**  Hoechst compound 33258 (bisbenzimidazole), 5 μg per liter of buffered aqueo us solution. Note: The solution should be protected from light.


### 3.2

**. My**  **coplasma Reference**  **s**
S tandardization of testing between laboratories and between regio ns would be enhanced by use of r eferences common within or between regions, T his has been shown to be presently impractical due to the difficulty of producing consistent batches of lyophilized references and the shipping issues with frozen references. Therefore, regions or laboratories may use their own references, providing that they are of low pas sage level (15 or less), identified relative to type culture isolates, stable, and appropriately validated as suitable for use in the context of this guideline. It is strongly recommended to include in the validation of detection limit a comparison to t he EDQM reference strains (described below) for international recognition

. Regions or l aboratories may produce their own validated references, or may acquire commonly available and appropriately validated references , such as the following produced by the E DQM

.

The 5 strains of Mycoplasma listed in **Section 2.3** were isolated by laboratories of the European Union and donated to the European Directorate for the Quality of Medicines and Health Care (EDQM). EDQM produced a sufficient quantity of these frozen re fe rences, and perform ed an intra

- region EU validation/stability study ( C. Milne, A. Daas. Establishment of European Pharmacopoeia Mycoplasma Reference Strains. Pharmeuropa Bio 2006(1):57

- 72). Completion of further validation studies by the regulatory agen cies and the industries in Japan, USA, and Canada confirmed that the strains are very suitable for use in the context of this guideline

. (VICH Collaborative Study on the Ph. Eur. Mycoplasma Reference Strains: EDQM Report Compiling and Analysing the Data Se t for the VICH Collaborative Study on the European Pharmacopoeia Mycoplasma Reference Strains, EDQM Administrator Representative, C. Milne, 2010.) The BQME WG commends the Staff at the EDQM for their efforts and perseverance in producing and validating the se very excellent references.

For DNA staining validation, the following strains may also prove useful: M. hyorhinis

-- AT CC 29052 M. orale

-- AT CC 23714

### 3.3. **Glossary**

**Batch (lot, serial) of starting material of animal origin** The total quantity of h omogenous material (e.g., cells, serum) identified by a unique serial number.
**Cell**
**- seed system**  A system whereby successive final lots (batches) of a product are manufactured by culture in cells derived from the same master cell seed. A number of contain ers from the master cell seed are used to prepare a working cell seed.
**Cell lines** Cultures of cells >10 passages or subcultures from the tissue of origin and having a high capacity for multiplication in

- vitro. **Final product, batch, lot, or serial** A collection of closed, final containers or other final dosage units that are expected to be homogeneous and equivalent with respect to risk of contamination during filling or preparation of the final product. The dosage units are filled, or otherwise prepa red, from the same final bulk product, freeze

- dried together (if applicable) and closed in one continuous working session. They bear a distinctive number or code identifying the final lot (batch, serial). W here a final bulk product is filled and/or freez e - dried on several separate sessions, there results a related set of final lots (batches, serials) that are usually identified by the use of a common part in the distinctive number or code; these related final lots (batches, serials) are sometimes referred to as sub

- batches, subserials, sub

- lots or filling lots. For the purposes of mycoplasma testing, a single sub

- batch may be considered representative of the batch.
**Harvests** Material derived on one or more occasions from a single production culture inocu lated with the same working seed lot (single harvest) or pooled material containing a single strain or type of micro

- organism or antigen and derived from a number of eggs, cell culture containers, etc. that are processed at the same time (monovalent pooled harvest). **Master cell seed (stock)** A collection of aliquots of cells (primary or cell line) of a single passage level for use in the preparation of the product, distributed into containers in a single operation, processed together and stored in such a manner as to ensure uniformity and stability and to prevent contamination. Master cell seed is usually stored at temperatures of

- 70oC or lower.

**Master seed** A co llection of closed containers of a culture of micro

- organisms of a single passage level used for the production of all batches of a designated veterinary biological product, distributed from a single bulk into containers and processed together in a single operation in such a manner as to ensure uniformity and stability and to prevent contamination. **Microaerophilic condition** A nitrogen atmosphere containing 5

- 10% carbon dioxide and sufficient humidity to prevent drying of the agar plates.**Passage**

One tr ansfer of cells or microorganisms followed by the normally used incubation period for the cell or microorganism concerned. **Primary cell cultures**  Primary cell cultures are cultures of cells essentially unchanged from those in the animal tissues from whic h they have been prepared and being no more than 10 in

- vitro passages to the test level from the initial preparation from the animal tissue. The first in

- vitro cultivation is regarded as the first passage of the cells
**Seed**
**- lot sy** **stem:** A system in which s uccessive batches of a product are derived from the same master seed virus. For routine production, a working seed virus may be prepared from the master seed virus. **Working cell seed (stock)** A collection of aliquots of cells derived from the master cel l seed and at the passage level used in the preparation of production cell cultures. The working cell seed is distributed into containers, processed and stored as described for master cell seed. The term includes production cell seed. **Working Reference s**  A passage of the Reference strains of Mycoplasma produced in the testing laboratory for use as controls to satisfy the reference requirements specified in this document. **Working seed** A collection of aliquots of a microorganism derived from the master seed virus and at the passage level used in the preparation of product. Wo rking seed virus is distributed into containers and stored as described for master seed virus. The term includes production seed.