Skip to main content
Journal of Clinical Microbiology logoLink to Journal of Clinical Microbiology
. 1996 Dec;34(12):3072–3074. doi: 10.1128/jcm.34.12.3072-3074.1996

Detection of PCR inhibitors in cervical specimens by using the AMPLICOR Chlamydia trachomatis assay.

R P Verkooyen 1, A Luijendijk 1, W M Huisman 1, W H Goessens 1, J A Kluytmans 1, J H van Rijsoort-Vos 1, H A Verbrugh 1
PMCID: PMC229461  PMID: 8940450

Abstract

To determine that susceptibility of AMPLICOR Chlamydia trachomatis PCR to inhibitory factors possibly present in cervical specimens, we obtained cervical specimens from 200 gynecology patients attending our outpatient clinic. The prevalence of C. trachomatis infection was 4.1%, as determined by cell culture. All AMPLICOR specimens were tested in one procedure as described by the manufacturer, and after the specimen was spiked with C. trachomatis, several other pretreatment protocols were used. Complete inhibition of the PCR was observed in 38 (19%) cervical specimens. Heat treatment at 95 degrees C, freeze-thawing, or 10-fold dilution of the samples reduced the initial inhibition to 9, 16, or 9%, respectively. A combination of heat treatment and 10-fold dilution reduced the inhibition to 4% of the samples. A second specimen type (swabs inoculated in 0.2 M sucrose phosphate buffer [2SP]) was also evaluated. A 10-fold dilution of the spiked 2SP specimen resulted in an inhibition rate of 6%, which was comparable to that obtained by centrifugation of the 2SP specimen prior to processing. Furthermore, it was shown that the inhibition was not correlated with blood contamination. Processing the specimens on the day of collection or the day after resulted in a higher inhibition rate than did delayed processing (27.6 versus 15.5%, respectively). An inverse correlation was found between the concentration of C. trachomatis added to the sample and the rate of inhibition observed. The inhibition was partly correlated with the pH of the cervical mucosa. Decreased inhibition was found at pH values of > or = 7.5. The effects of blood, pH, and delay in processing were all evaluated by using the AMPLICOR specimen. We conclude that the susceptibility of AMPLICOR C. trachomatis PCR to inhibiting factors in cervical specimens can be significantly reduced if the pretreatment procedure includes heat treatment or the use of 2SP transport medium. Also, a 10-fold dilution of the clinical specimen followed by heat treatment will largely prevent the inhibition of this PCR.

Full Text

The Full Text of this article is available as a PDF (178.5 KB).

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Bass C. A., Jungkind D. L., Silverman N. S., Bondi J. M. Clinical evaluation of a new polymerase chain reaction assay for detection of Chlamydia trachomatis in endocervical specimens. J Clin Microbiol. 1993 Oct;31(10):2648–2653. doi: 10.1128/jcm.31.10.2648-2653.1993. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Bauwens J. E., Clark A. M., Stamm W. E. Diagnosis of Chlamydia trachomatis endocervical infections by a commercial polymerase chain reaction assay. J Clin Microbiol. 1993 Nov;31(11):3023–3027. doi: 10.1128/jcm.31.11.3023-3027.1993. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Bianchi A., Scieux C., Brunat N., Vexiau D., Kermanach M., Pezin P., Janier M., Morel P., Lagrange P. H. An evaluation of the polymerase chain reaction amplicor Chlamydia trachomatis in male urine and female urogenital specimens. Sex Transm Dis. 1994 Jul-Aug;21(4):196–200. doi: 10.1097/00007435-199407000-00003. [DOI] [PubMed] [Google Scholar]
  4. Bobo L., Coutlee F., Yolken R. H., Quinn T., Viscidi R. P. Diagnosis of Chlamydia trachomatis cervical infection by detection of amplified DNA with an enzyme immunoassay. J Clin Microbiol. 1990 Sep;28(9):1968–1973. doi: 10.1128/jcm.28.9.1968-1973.1990. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Kellogg J. A., Seiple J. W., Klinedinst J. L., Stroll E. S., Cavanaugh S. H. Improved PCR detection of Chlamydia trachomatis by using an altered method of specimen transport and high-quality endocervical specimens. J Clin Microbiol. 1995 Oct;33(10):2765–2767. doi: 10.1128/jcm.33.10.2765-2767.1995. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Loeffelholz M. J., Lewinski C. A., Silver S. R., Purohit A. P., Herman S. A., Buonagurio D. A., Dragon E. A. Detection of Chlamydia trachomatis in endocervical specimens by polymerase chain reaction. J Clin Microbiol. 1992 Nov;30(11):2847–2851. doi: 10.1128/jcm.30.11.2847-2851.1992. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. Mahony J. B., Luinstra K. E., Sellors J. W., Pickard L., Chong S., Jang D., Chernesky M. A. Role of confirmatory PCRs in determining performance of Chlamydia Amplicor PCR with endocervical specimens from women with a low prevalence of infection. J Clin Microbiol. 1994 Oct;32(10):2490–2493. doi: 10.1128/jcm.32.10.2490-2493.1994. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Skulnick M., Chua R., Simor A. E., Low D. E., Khosid H. E., Fraser S., Lyons E., Legere E. A., Kitching D. A. Use of the polymerase chain reaction for the detection of Chlamydia trachomatis from endocervical and urine specimens in an asymptomatic low-prevalence population of women. Diagn Microbiol Infect Dis. 1994 Dec;20(4):195–201. doi: 10.1016/0732-8893(94)90003-5. [DOI] [PubMed] [Google Scholar]
  9. Williams T. W., Tyler S. D., Giercke S., Pollard D. R., McNicol P., Rozee K. R. Comparison of polymerase chain reaction and chlamydiazyme for the detection of Chlamydia trachomatis in clinical specimens. Eur J Clin Microbiol Infect Dis. 1992 Mar;11(3):233–236. doi: 10.1007/BF02098085. [DOI] [PubMed] [Google Scholar]

Articles from Journal of Clinical Microbiology are provided here courtesy of American Society for Microbiology (ASM)

RESOURCES