Previous Article | Next Article 
Journal of Clinical Microbiology, October 2005, p. 5412-5413, Vol. 43, No. 10
0095-1137/05/$08.00+0 doi:10.1128/JCM.43.10.5412-5413.2005
Molecular Diagnosis of Lymphogranuloma Venereum: PCR-Based Restriction Fragment Length Polymorphism and Real-Time PCR

LETTER
We read with interest the paper from Sturm and colleagues in
which they showed a PCR-based restriction fragment length polymorphism
(RFLP) to differentiate the lymphogranuloma venereum (LGV) biovars
from the trachoma and urogenital biovars (
6). Recently an outbreak
of rectal LGV infections among men having sex with men (MSM)
was reported with both symptomatic and asymptomatic patients
(
5). Interesting from a clinical perspective is that the LGV-based
genital ulcer disease (GUD) described by Sturm is not associated
with human immunodeficiency virus (HIV), while the recent outbreak
of rectal LGV infections in MSM is strongly associated with
HIV seropositivity. Since current commercially available diagnostics
do not offer the option of distinguishing the LGV biovars from
the other biovars and the current
ompA PCR-based RFLP analysis
for specifically identifying all individual serovars is too
time consuming (
1,
2), we developed a real-time PCR for rapid
and easy diagnosis of LGV infections which was used for clinical
and case finding purposes in this outbreak among MSM (
3). We
used the polymorphic membrane protein H gene (
pmp gene) as a
PCR target because it has a unique gap in all LGV strains of
Chlamydia trachomatis, compared to other serovars, which makes
the PCR highly specific. The following primers and probes were
selected: LGV-F (5' CTG TGC CAA CCT CAT CAT CAA 3'), LGV-R (5'
AGA CCC TTT CCG AGC ATC ACT 3'), and LGV MGB-probe (6-FAM-CCT
GCT CCA ACA GT). Reaction details are described elsewhere (
3).
This assay will be much easier than the CrP-PCR-D test followed
by AccI restriction as reported by Sturm for the diagnosis of
LGV-based GUD in South Africa. However, we realize that real-time
PCR (TaqMan, LightCycler, or Rotorgene) is not readily available
everywhere; therefore, we report here a simple adaptation of
our real-time PCR, resulting in a potentially easier assay than
the CrP-PCR-D. When only the PCR is performed using the above-described
LGV-F and LGV-R primers (so without using the probe), a PCR
product of 98 bp will be generated in the case of all serovars
in the trachoma biovar (serovars D to K), while the presence
of serovars in the LGV biovar (serovars L1, L2, L2a, and L3)
will result in a fragment of 62 bp (98 36 bp). In this
way no restriction is needed anymore, and the PCR product can
be directly analyzed at the gel level. Since the fragment is
also shorter than the CrP-PCR-D fragment of 552 bp, potentially
better amplification will be accomplished and fewer adverse
effects of inhibition or problems with DNA quality will be encountered.
Lastly, in contrast to Sturm and colleagues, we do not think that current textbooks are incomplete in the description of the clinical picture of LGV. Early symptoms with inconspicuous ulcers without inguinal buboes have been described before (4). It is probably due only to the recent advancements in diagnostic tests for LGV, as described, e.g., by Sturm and our group, that LGV cases can now be better detected during these early stages of the infection.

REFERENCES
1 - Lister, N. A., S. N. Tabrizi, C. K. Fairley, and S. Garland. 2004. Validation of Roche COBAS Amplicor assay for detection of Chlamydia trachomatis in rectal and pharyngeal specimens by an omp1 PCR assay. J. Clin. Microbiol. 42:239-241.[Abstract/Free Full Text]
2 - Morré, S. A., J. M. Ossewaarde, J. Lan, G. J. van Doornum, J. M. Walboomers, D. M. MacLaren, C. J. L. M. Meijer, and A. J. C. van den Brule. 1998. Serotyping and genotyping of genital Chlamydia trachomatis isolates reveal variants of serovars Ba, G, and J as confirmed by omp1 nucleotide sequence analysis. J. Clin. Microbiol. 36:345-351.[Abstract/Free Full Text]
3 - Morré, S. A., J. Spaargaren, J. S. A. Fennema, H. J. C. de Vries, R. A. Coutinho, and A. S. Peña. 2005. Real-time polymerase chain reaction to diagnose lymphogranuloma venereum. Emerg. Infect. Dis. 11:1311-1312. [Online.] http://www.cdc.gov/ncidod/EID/vol11no08/05-0535.htm.[Medline]
4 - Perine, P. L., and W. E. Stamm. 1999. Lymphogranuloma venereum, p. 423-432. In K. K. Holmes, P. A. Mårdh, P. F. Sparling, et al. (ed.), Sexually transmitted diseases. McGraw-Hill, New York, N.Y.
5 - Spaargaren, J., J. S. A. Fennema, S. A. Morré, H. J. C. de Vries, and, R. A. Coutinho. 2005. New lymphogranuloma venereum Chlamydia trachomatis variant, Amsterdam. Emerg. Infect. Dis. 11:1090-1092.[Medline]
6 - Sturm, P. D., P. Moodley, K. Govender, L. Bohlken, T. Vanmali, and A. W. Sturm. 2005. Molecular diagnosis of lymphogranuloma venereum in patients with genital ulcer disease. J. Clin. Microbiol. 43:2973-2975.[Abstract/Free Full Text]
| | | | | |
Servaas A. Morré*
VU University Medical Center Faculty of Medicine Laboratory of Immunogenetics Section Immunogenetics of Infectious Diseases Van der Boechorststraat 7 1081 BT, Amsterdam, The Netherlands
Joke Spaargaren
Johan S. A. Fennema
Municipal Health Service Amsterdam, The Netherlands
Henry J. C. de Vries
Academic Medical Center Amsterdam, The Netherlands
|
| | | | | |
* Phone: 31-20-4449375, Fax: 31-20-4448418, E-mail: samorretravel{at}yahoo.co.uk |
Authors' Reply

LETTER
We agree that the absence of a restriction step in a diagnostic
nucleic acid amplification test (NAAT) makes the test easier
to perform. It would be interesting to compare test performance
parameters of the CrP-PCR-D test with the test described by
Morre et al.
Regarding the textbook description of clinical presentation of LGV, we do not dispute whether the clinical entity of inconspicuous ulcers followed by inguinal lymphadenopathy exists or not. We do see such cases in South Africa regularly. What is missing in the textbooks is that patients also present with larger, painful lesions before the lymphadenopathy develops. Such ulcers are not inconspicuous at all. As such ulcerscannot be differentiated clinically from genital ulcers with other etiology without the help of a diagnostic NAAT, these have so far been misdiagnosed. We recently completed a prospective study to describe in detail the clinical presentation of this early stage of LGV and confirmed the observations as published in our paper.
| | | | | |
Patrick D. J. Sturm*
Prashini Moodley
Keshnee Govender
Louise Bohlken
Trusha Vanmali
A. Willem Sturm
Department of Medical Microbiology Nelson R. Mandela School of Medicine Private Bag 7 Congella 4013, South Africa
|
| | | | | |
* Phone: 27-31-2604395 Fax: 27-31-2604431 E-mail: sturm{at}kznu.ac.za |
Journal of Clinical Microbiology, October 2005, p. 5412-5413, Vol. 43, No. 10
0095-1137/05/$08.00+0 doi:10.1128/JCM.43.10.5412-5413.2005
This article has been cited by other articles:
-
Herring, A, Richens, J
(2006). Lymphogranuloma venereum. Sex. Transm. Infect.
82: iv23-iv25
[Full Text]
-
Martin, I M C, Alexander, S A, Ison, C A, Macdonald, N, McCarthy, K, Ward, H
(2006). Diagnosis of lymphogranuloma venereum from biopsy samples.. Gut
55: 1522-1523
[Full Text]