-
Applied and Environmental Microbiology May 2010Although mycoplasmas are generally considered to be harmless commensals, some mycoplasma species are able to cause infections in pediatric, geriatric, or...
Although mycoplasmas are generally considered to be harmless commensals, some mycoplasma species are able to cause infections in pediatric, geriatric, or immunocompromised patients. Thus, accidental contamination of biologics with mycoplasmas represents a potential risk for the health of individuals who receive cell-derived biological and pharmaceutical products. To assess the efficiency of inactivation of mycoplasmas by the agents used in the manufacture of egg-derived influenza vaccines, we carried out a series of experiments aimed at monitoring the viability of mycoplasmas spiked into both chicken allantoic fluid and protein-rich microbiological media and then treated with beta-propiolactone, formalin, cetyltrimethylammonium bromide, Triton X-100, and sodium deoxycholate, which are agents that are commonly used for virus inactivation and disruption of viral particles during influenza vaccine production. Twenty-two mycoplasma species (with one to four strains of each species) were exposed to these inactivating agents at different concentrations. The most efficient inactivation of the mycoplasmas evaluated was observed with either 0.5% Triton X-100 or 0.5% sodium deoxycholate. Cetyltrimethylammonium bromide at concentrations of >or=0.08% was also able to rapidly inactivate (in less than 30 min) all mycoplasmas tested. In contrast, negligible reductions in mycoplasma titers were observed with 0.0125 to 0.025% formaldehyde. However, increasing the concentration of formaldehyde to 0.1 to 0.2% improved the mycoplasmacidal effect. Incubation of mycoplasmas with 0.1% beta-propiolactone for 1 to 24 h had a marked mycoplasmacidal effect. A comparison of the mycoplasma inactivation profiles showed that strains of selected species (Mycoplasma synoviae, Mycoplasma gallisepticum, Mycoplasma orale, Mycoplasma pneumoniae, and Acholeplasma laidlawii) represent a set of strains that can be utilized to validate the effectiveness of mycoplasma clearance obtained by inactivation and viral purification processes used for the manufacture of an inactivated egg-based vaccine.
Topics: Acholeplasma laidlawii; Animals; Cetrimonium; Cetrimonium Compounds; Chickens; Deoxycholic Acid; Eggs; Formaldehyde; Microbial Viability; Models, Biological; Mycoplasma; Mycoplasma gallisepticum; Mycoplasma pneumoniae; Mycoplasma synoviae; Octoxynol; Propiolactone; Vaccines, Inactivated; Viral Vaccines
PubMed: 20228111
DOI: 10.1128/AEM.02776-09 -
Cytotechnology Dec 2009A total of 200 cell lines including different human, monkey, mice, hamster and rat cell types were examined for mycoplasma infection status. PCR assay using...
A total of 200 cell lines including different human, monkey, mice, hamster and rat cell types were examined for mycoplasma infection status. PCR assay using generic-specific universal primers showed that 40 (20%) of the cell lines are contaminated with mycoplasma. Employment of species-specific primers within these infected cell lines revealed infection with M. hyorhinis (42.5%), M. fermentas (37.5%), M. arginini (37.5%), M. orale (12.5%) and A. laidlawii (7.5%). A number of the cultures were coinfected with 2 or 3 different species. Contaminated samples were treated with BM-Cyclin, Ciprofloxacin and mycoplasma removal agent (MRA). Mycoplasma eradication was subsequently checked by PCR following 2 weeks continuous culture of treated cells in antibiotic free culture medium. Mycoplasmal infections were eradicated in 100, 70 and 42% of infected cell lines when the samples were treated with BM-Cyclin, MRA and Ciprofloxacin, respectively. However, 12% (BM-Cyclin), 62.5% (MRA) and 82.5% (Ciprofloxacin) of mycoplasma regrowth was observed 4 months after the treatment. Notably, the risk of spontaneous culture death was 17.5, 12.5 and 0% for BM-Cyclin, MRA and Ciprofloxacin, respectively.
PubMed: 20135349
DOI: 10.1007/s10616-010-9252-6 -
International Journal of Medical... Apr 2009Polymerase chain reaction assays have become widely used methods of confirming the presence of Mollicutes species in clinical samples and cell cultures. We have... (Comparative Study)
Comparative Study
Polymerase chain reaction assays have become widely used methods of confirming the presence of Mollicutes species in clinical samples and cell cultures. We have developed a broad-range real-time PCR assay using the locked nucleic acid technology to detect mollicute species causing human infection and cell line contamination. Primers and probes specifically for the conserved regions of the mycoplasmal tuf gene (encoding elongation factor Tu) were designed. Cell culture supernatants, clinical specimens (vaginal swabs, sputum, cryopreserved heart valve tissues), and reference strains were tested for mollicute contamination as well as to exclude cross-reaction to human nucleic acids and other bacterial species. Nucleic acids were extracted using magnetic separation technology. The coamplification of the human beta2-microglobulin DNA served as an internal control. The PCR assay was highly specific and obtained an analytical sensitivity of one copy per microl sample. The 95% detection limit was calculated to 10 copies per microl sample for Mycoplasma pneumoniae and M. orale. No false-positive results were observed due to cross-reaction of walled bacterial, fungal, and human nucleic acids. To evaluate the PCR, we compared the results to two commercialized test systems. Moreover, in combination with a previously developed broad-range RT-PCR assay for the detection of bacteria in blood products, both mollicute and walled bacterial contamination can be detected simultaneously using multiplex real-time RT-PCR.
Topics: Bacterial Proteins; Base Sequence; Cell Culture Techniques; Cell Line; DNA Primers; Humans; Peptide Elongation Factor Tu; Polymerase Chain Reaction; Quality Control; Reference Standards; Sensitivity and Specificity; Sequence Alignment; Tenericutes
PubMed: 18926769
DOI: 10.1016/j.ijmm.2008.08.002 -
Transgenic Research Feb 2009Murine embryonic stem cells (mESCs) inoculated at passage P13 with the mycoplasma species M. hominis, M. fermentans and M. orale and cultured over 20 passages showed...
Murine embryonic stem cells (mESCs) inoculated at passage P13 with the mycoplasma species M. hominis, M. fermentans and M. orale and cultured over 20 passages showed reduced growth rate and viability (P < 0.0001) compared to control mESCs. Spectral karyotypic analysis of mycoplasma-infected mESCs showed a number of non-clonal chromosomal aberrations which increased with the duration of infection. The differentiation status of the infected mESCs was most affected at passage P13+6 where the infection was strongest and 46.3% of the mESCs expressed both POU5F1 and SSEA-1 markers whereas 84.8% of control mESCs expressed both markers. The percentage of germline chimeras from mycoplasma-infected mESCs was examined after blastocyst injection and embryo transfer to suitable recipients at different passages and, compared to the respective control group, was most affected at passage P13+5 (50% vs. 90%; P < 0.07). Further reductions were obtained at the same passage in the percentage of litters born (50% vs. 100%; P < 0.07) and in the percentage of pups born (22% vs. 45%; P < 0.001). Thirty three chimeras (39.8%) obtained from blastocyst injection with mycoplasma-infected mESCs showed reduced body weight (P < 0.0001), nasal discharge, osteoarthropathia, and cachexia. Flow cytometric analysis of plasma from chimeras produced with mycoplasma-infected mESCs revealed statistically significant differences in the proportions of T-cells and increased levels of IgG1 (P < 0.001), IgG2a (P < 0.05) and IgM (P < 0.05), anti-DNA antibodies (P < 0.05) and rheumatoid factor (P < 0.01). The present data indicate that mycoplasma contamination of mESCs affects various cell parameters, germline transmission, and postnatal development of the resulting chimeras.
Topics: Animals; Biomarkers; Blastocyst; Cell Differentiation; Cell Survival; Chimera; Embryo, Mammalian; Embryonic Stem Cells; Female; Fibroblasts; Germ Cells; Immunoglobulin G; Karyotyping; Male; Mice; Mycoplasma; Pregnancy
PubMed: 18819014
DOI: 10.1007/s11248-008-9218-z -
Applied and Environmental Microbiology Sep 2008In this study, we describe our results on the evaluation of the ability of different permissive mammalian cell lines to support the biological enrichment of mycoplasma...
In this study, we describe our results on the evaluation of the ability of different permissive mammalian cell lines to support the biological enrichment of mycoplasma species known to be bacterial contaminants of cell substrates. The study showed that this approach is able to significantly improve the efficiency of mycoplasma detection based on nucleic acid testing or biochemical technologies (e.g., MycoAlert mycoplasma detection). Of 10 different cell lines (Vero, MDBK, HEK-293, Hep-G2, CV-1, EBTr, WI-38, R9ab, MDCK, and High Five) used in the study, only MDCK cell culture was found to support the efficient growth of all the tested mycoplasmas (Mycoplasma arginini, M. bovis, M. fermentans, M. gallinaceum, M. gallisepticum, M. synoviae, M. hominis, M. hyorhinis, M. orale, M. salivarium, and Acholeplasma laidlawii) known to be most frequently associated with contamination of cell substrates and cell lines in research laboratories or manufacturing facilities. The infection of MDCK cells with serial dilutions of each mycoplasma species demonstrated that these common cell line contaminants can be detected reliably after 7-day enrichment in MDCK cell culture at contamination levels of 0.05 to 0.25 CFU/ml. The High Five insect cell line was also found to be able to support the efficient growth of most mycoplasma species tested, except for M. hyorhinis strain DBS1050. However, mycoplasma growth in insect cell culture was demonstrated to be temperature dependent, and the most efficient growth was observed when the incubation temperature was increased from 28 degrees C to between 35 and 37 degrees C. We believe that this type of mycoplasma enrichment is one of the most promising approaches for improving the purity and safety testing of cell substrates and other cell-derived biologics and pharmaceuticals.
Topics: Animals; Bacteriological Techniques; Cell Culture Techniques; Cell Line; Chlorocebus aethiops; Coculture Techniques; DNA, Bacterial; Dogs; Insecta; Mycoplasma; Mycoplasma Infections; Polymerase Chain Reaction; Sensitivity and Specificity; Vero Cells
PubMed: 18606798
DOI: 10.1128/AEM.00720-08 -
Indian Journal of Medical Microbiology Oct 2007A two-stage nested polymerase chain reaction (PCR) assay system was described that amplifies the 16S-23S rRNA spacer region sequences of Mycoplasma and Acholeplasma...
PURPOSE
A two-stage nested polymerase chain reaction (PCR) assay system was described that amplifies the 16S-23S rRNA spacer region sequences of Mycoplasma and Acholeplasma infections in cell cultures and virus stocks.
METHODS
Established cell lines and virus stocks were screened for the presence of Mycoplasma by using nested PCR using two sets of outer and inner primers, amplifies 16S-23S rRNA. PCR and restriction fragment length polymorphism (RFLP) assay was used to detect and identify most of the species-specific Mycoplasmas involved in cell cultures and virus stock contaminants. Infected cultures detected by PCR-RFLP were further treated with BM-cyclin (5 microg/mL) and passaged for three times and tested for Mycoplasma infections by PCR-RFLP.
RESULTS
Mycoplasma pirum and Mycoplasma orale infections were detected by nested PCR. Species specificity was identified by using RFLP of Vsp I, Cla I and Hin dIII restriction enzymes. Mycoplasma infections were cured by treatment with BM-cyclin. This was further confirmed by non-amplification of PCR amplimers in BM-cyclin treated vs. non-treated cultures.
CONCLUSIONS
Regular monitoring of cell cultures for Mycoplasma infections and identification of species-specific Mollicutes will identify the source of contaminations. This approach can be used for quality control of the biological reagents used in cell culture and virology laboratories.
Topics: Anti-Bacterial Agents; Cell Culture Techniques; DNA, Bacterial; DNA, Ribosomal Spacer; Diterpenes; Minocycline; Mycoplasma; Polymerase Chain Reaction; Polymorphism, Restriction Fragment Length; Quality Control; Virology
PubMed: 18087086
DOI: 10.4103/0255-0857.37340 -
Journal of Applied Microbiology Apr 2008Introduction of a protocol for broad-range diagnosis of bacterial infections, which remain negative in culture.
AIM
Introduction of a protocol for broad-range diagnosis of bacterial infections, which remain negative in culture.
METHODS AND RESULTS
The new TaqMan real-time PCR assay amplifies part of the 16S rRNA gene. Species are identified by subsequent sequencing and phylogenetic blast analysis. The analytical sensitivity showed to be 50 fg DNA per PCR. The lowest detectable bacterial cell concentration in blood was 1000 CFU per 200 mul EDTA-blood. The utility in clinical routine diagnosis was evaluated by testing 136 clinical specimens. Bacterial pathogens were detected in 33 samples (24.3%) either by culture or molecular diagnosis. In 10 culture negative cases, pathogens such as Mycoplasma timone/orale, Ureaplasma parvum/urealyticum, Treponema pallidum, different streptococci and staphylococci were identified by molecular diagnosis only.
CONCLUSIONS
The introduced broad-range real-time PCR protocol showed to be useful in the clinical routine in cases where bacterial infection was highly anticipated but culture remained negative. However, the obtained data have to be always interpreted with caution and in conjunction with the clinical data, crossing-point values and with the Blast result of both the sample and the controls.
SIGNIFICANCE AND IMPACT OF THE STUDY
This work introduces a new and well-evaluated broad-range real-time PCR protocol for diagnosis of bacterial infections.
Topics: Bacteremia; Bacterial Typing Techniques; Base Sequence; Genes, Bacterial; Humans; Molecular Sequence Data; RNA; RNA, Ribosomal, 16S; Reverse Transcriptase Polymerase Chain Reaction; Sequence Alignment; Taq Polymerase
PubMed: 18028360
DOI: 10.1111/j.1365-2672.2007.03648.x -
Biologicals : Journal of the... Mar 2008A panel of 30 putative Mycoplasma fermentans strains, isolated from various sources including human, ovine and cell lines, were tested by a previously described...
A panel of 30 putative Mycoplasma fermentans strains, isolated from various sources including human, ovine and cell lines, were tested by a previously described polymerase chain reaction (PCR) to confirm their identity by amplification of a conserved 206 bp region of the insertion sequence IS1550. In addition, the application of another PCR based on the major part of the IS1550 element showed one or two products of different length (1144 and 1341 bp) enabling M. fermentans strains to be divided into two types designated as Type A and Type B. A PCR, which amplifies the macrophage activating lipopeptide gene (malp), supported the identification of all the strains as M. fermentans. Thirteen other species of Mycoplasma from human sources gave negative results in these tests, with the exception of Mycoplasma orale, which was detected by both IS1550-PCRs based on the major part and the conserved 206 bp region of the IS1550 element. This study suggests that all M. fermentans isolates possess both the IS1550 element and the malp gene. In contrast to the IS1550, the malp gene is shown to be species-specific and the use of a malp PCR described here could prove to be a useful adjunct to IS1550 detection as confirmation of the presence of M. fermentans in clinical material.
Topics: Animals; Cell Line; DNA, Bacterial; DNA, Ribosomal; Humans; Mycoplasma fermentans; Polymerase Chain Reaction; RNA, Ribosomal, 16S; Sequence Analysis, DNA; Sheep
PubMed: 17892949
DOI: 10.1016/j.biologicals.2007.07.003 -
Pharmeuropa Bio Nov 2006European Pharmacopoeia (Ph. Eur.) general chapter 2.6.7. Mycoplasma requires for the culture test reference strains of mycoplasma field isolates with fewer than 15...
European Pharmacopoeia (Ph. Eur.) general chapter 2.6.7. Mycoplasma requires for the culture test reference strains of mycoplasma field isolates with fewer than 15 passages for validation and run control and in the test for inhibitory substances. Low passage field isolates of 5 mycoplasma strains (Mycoplasma hyorhinis, Mycoplasma synoviae, Mycoplasma fermentans, Mycoplasma orale and Acholeplasma laidlawii) have been prepared for this purpose and a small scale collaborative study involving European laboratories was carried out to confirm the suitability of the material for the intended purpose. Strains were prepared as 1 ml samples in frozen format and are stored below -60 degrees C. Each laboratory determined a titre for the material on their in-house media. A secondary part of the study also compared the growth of prediluted samples on the different culture media. Results of the study confirm that the material is suitable for use as a biological reference preparation (BRP) and an estimated titre has been provided for each strain based on the results of the study. It was noted that differences in the culture media used in the different laboratories did not have a detrimental effect on titre estimation. The estimated titre is intended as a guide for users to validate the use of the reference material in house. The candidate BRPs were adopted by the European Pharmacopoeia Commission on June 28, 2006 and are available for use from EDQM. A revision to chapter 2.6.7, including reference to the use of nucleic acid amplification techniques (NAT) was also adopted in June 2006 and will appear in the European Pharmacopoeia version 5.8 in January 2007 and come into force the 1st of July 2007. While it was not part of the study a number of participants also performed in-house NAT assays on the study material. Preliminary findings from these studies are presented.
Topics: Colony Count, Microbial; Culture Media; DNA, Bacterial; Europe; Mycoplasma; Nucleic Acid Amplification Techniques; Pharmacopoeias as Topic; Reference Standards
PubMed: 17270132
DOI: No ID Found -
Brazilian Journal of Medical and... Jul 2006A total of 301 cell cultures from 15 laboratories were monitored for mycoplasma (Mollicutes) using PCR and culture methodology. The infection was detected in the cell...
A total of 301 cell cultures from 15 laboratories were monitored for mycoplasma (Mollicutes) using PCR and culture methodology. The infection was detected in the cell culture collection of 12 laboratories. PCR for Mollicutes detected these bacteria in 93 (30.9%) samples. Although the infection was confirmed by culture for 69 (22.9%) samples, PCR with generic primers did not detect the infection in five (5.4%). Mycoplasma species were identified with specific primers in 91 (30.2%) of the 98 samples (32.6%) considered to be infected. Mycoplasma hyorhinis was detected in 63.3% of the infected samples, M. arginini in 59.2%, Acholeplasma laidlawii in 20.4%, M. fermentans in 14.3%, M. orale in 11.2%, and M. salivarium in 8.2%. Sixty (61.2%) samples were co-infected with more than one mycoplasma species. M. hyorhinis and M. arginini were the microorganisms most frequently found in combination, having been detected in 30 (30.6%) samples and other associations including up to four species were detected in 30 other samples. Failure of the treatments used to eliminate mycoplasmas from cell cultures might be explained by the occurrence of these multiple infections. The present results indicate that the sharing of non-certified cells among laboratories may disseminate mycoplasma in cell cultures.
Topics: Base Sequence; Cells, Cultured; DNA, Bacterial; Electrophoresis, Agar Gel; Humans; Molecular Sequence Data; Polymerase Chain Reaction; Tenericutes
PubMed: 16862282
DOI: 10.1590/s0100-879x2006000700009