Examination of specific DNA by PCR in patients with different forms of Lyme borreliosis

BACKGROUND

Borrelial specific DNA was examined in a group of 62 patients with different forms of Lyme borreliosis (LB) (32 patients suffered from neuroborreliosis, 19 manifested erythema migrans, and 11 joint involvement).

METHODS

Nested-PCR system with five newly derived primers was used in parallel. The study was organized prospectively, the presence of DNA was tested for plasma, CSF, joint fluid and urine before treatment, and plasma, joint fluid and urine were examined after treatment.

RESULTS

Before therapy, 36 patients (58.1%) were DNA positive on the whole; 21 positive patients (65.6%) were found in the group of neuroborreliosis, 8 (42.1%) showed signs of skin involvement, and 7 (63.6%) were positive in arthritis. After treatment, 11 patients (36.7%) were positive in neuroborreliosis, 3 (17.6%) in skin form, and 6 (54.5%) in joint form of LB. Among 97 positive amplifications the most frequent target was found in primer corresponding with 16S rDNA (50 samples, 51.5%). Lower but very similar results were obtained with primers for OspA (18 positive amplifications; 18.6%), OspC (13 positive amplifications; 13.4%), and flagellin (13 positive amplifications; 13.4%). There were 11 patients in whom only DNA and no specific antibodies were found.

CONCLUSIONS

Specific DNA was found in all clinical groups of LB with similar sensitivity. Examination of the borrelial DNA in urine displayed the same sensitivity as in CSF and had a two times higher sensitivity than in plasma.

[First experience with detecting bacterial DNA in the cerebrospinal fluid of patients with purulent meningitis using broad spectrum multiplex nested PCR]

OBJECTIVES

To propose and verify a PCR assay for detecting Escherichia coli, Haemophilus influenzae, Listeria monocytogenes, Staphylococcus species, Streptococcus pneumoniae and Neisseria meningitidis serogroups B and C in a single sample of the cerebrospinal fluid of patients with purulent meningitis.

MATERIAL AND METHODS

DNA from the cerebrospinal fluid was isolated using the QIAamp DNA Mini Kit. PCR was performed as two-step amplification (nested PCR). For E. coli, H. influenzae, L. monocytogenes, S. species and S. pneumoniae, universal and species-specific primers encoding bacterial 16S rDNA were used in the first and second reaction, respectively. For N. meningitidis serogroups B and C, an amplification system with primers for the SiaD gene was utilized.

RESULTS

Of 25 patients examined at the beginning of their treatment, bacterial DNA was detected in the cerebrospinal fluid of 17 (68 %) of them. Those were six cases of N. meningitidis serogroup B, four of N. meningitidis serogroup C, five of S. pneumoniae, one of H. influenzae and one of L. monocytogenes. Of 7 patients in whom antibiotic therapy was initiated prior to diagnostic lumbar puncture, PCR was positive in four cases.

CONCLUSIONS

The proposed nested PCR approach is faster than traditional culture methods and suitable for early laboratory diagnosis of infectious agents. When compared to culture methods, the technique offers slightly higher positivity (by 16 %). This is similar in samples analyzed after the initiation of antibiotic therapy. The PCR method never detected other bacteria than the cultured ones.

[Detection of anti-Ehrlichia antibodies and direct demonstration of Ehrlichia nucleic acid using the polymerase chain reaction (PCR) in patients in the Czech Republic]

PURPOSE OF THE STUDY

In patients presenting symptoms with a suspicion of ehrlichiosis we determined antiehrlichia antibodies and investigated the presence of Ehrlichia nucleic acid in the plasma.

MATERIAL AND METHODS

In our group were 46 patients with tick sucks in their case history, who presented symptoms compatible with ehrlichiosis. Anti-Ehrlichia antibodies were determined by an indirect immunofluorescent test with a commercial kit from MRL Diagnostics. Ehrlichia DNA was detected using a nested PCR - the target sequence was a part of the antigen Anaplasma phagocytophilum.

RESULTS

Antibodies against HGE agents were demonstrated in 28 % of the patients; 10.5 % of the patients had in their serum antibodies reacting to the Ehrlichia chaffeensis antigen. The nucleic acid of A. phagocytophilum was detected in 11 % of the patients.

CONCLUSIONS

The Czech population is relatively often exposed to Ehrlichia infections. Although most cases are asymptomatic, we should bear in mind this diagnosis, especially in immunodeficient patients, where early treatment may prevent a complicated course of the disease.