Summary. Two primer sets were chosen for the detection of Haemophilus inzuenzae in cerebrospinal fluid by polymerase chain reaction (PCR) DNA amplification. One primer set was selected from sequences encoding a capsulation-associated protein and reacted with target DNA from all 15 capsulate H . inzuenzae strains (all serotypes) examined. The other primer set was selected from the DNA sequence of a gene encoding for outer-membrane protein P6 and reacted with the 15 capsulate and 10 non-capsulate strains of H . inyuenzae tested. This primer set also reacted with the closely related species H . haemolyticus and H . aegyptius, and with two of nine H . parainzuenzae strains. In reconstruction experiments, PCR DNA amplification was able to detect as few as five H . inzuenzae cells when 40 cycles of amplification were used. Two hundred cerebrospinal fluid (CSF) samples collected consecutively from patients suffering from meningitis were investigated by PCR ; 40 were culture-positive for H . inzuenzae and 39 of these were also clearly positive in the PCR test with both primer sets. Contamination occurred to some extent with 40 cycles of amplification but was completely eliminated when the number of cycles was reduced to 35. We conclude that the two primer sets are appropriate for the detection of H . inzuenzae by PCR, each having its own specificity. When these two primer sets are used, PCR is a technique of equivalent sensitivity to culture for the detection of H . inzuenzae in CSF.
In order to determine the presence and distribution of Haemophilus influenzae in lung tissue sections, we obtained lung explants from 49 lung transplant recipients with cystic fibrosis (CF) (n = 16), chronic obstructive pulmonary disease (COPD) including emphysema (n = 16), bronchiectasis (n = 5), pulmonary hypertension (n = 9), Langerhans cell histiocytosis (n = 1), and idiopathic pulmonary fibrosis (n = 2). Analysis was done by selective culturing, immunoperoxidase (IP) staining, and by polymerase chain reaction (PCR). H. influenzae was cultured from specimens of the lung explants from one CF and one COPD patient. IP staining of tissue sections was positive in 24 patients (10 CF patients, eight COPD patients, two bronchiectasis patients, and four patients with noninfectious pulmonary diseases). IP-positive tissue sections were PCR-positive, and IP-negative sections were PCR-negative. H. influenzae was more frequently detected in tissue sections of lung explants from CF and COPD patients than from patients with bronchiectasis or noninfectious pulmonary diseases. H. influenzae was diffusely present in the epithelium, the submucosa of the bronchi, the bronchioles, the interstitium, and the alveolar epithelium. H. influenzae was localized extracellularly alone and in bacterial clusters, and was also associated with macrophages in CF patients. The results of this study demonstrate that H. influenzae is often present in the lungs of patients with end-stage pulmonary disease, especially CF and COPD patients. H. influenzae is diffusely present in the respiratory epithelium and subepithelial layers of the lungs of these patients.
Ixodes ticks transmit Borrelia burgdorferi sensu lato (s.l.), the causative agent of Lyme borreliosis (LB). These tick species also transmit Borrelia miyamotoi, which was recently found to cause infections in humans. We were interested in the prevalence of B. miyamotoi infection in ticks and natural hosts in The Netherlands, and to what extent ticks are co-infected with B. burgdorferi. In addition, erythema migrans has been sporadically described in B. miyamotoi-infected patients, but these skin lesions might as well represent co-infections with B. burgdorferi s.l. We therefore investigated whether B. miyamotoi was present in LB-suspected skin lesions of patients referred to our tertiary Lyme disease clinic. 3360 questing Ixodes ricinus nymphs as well as spleen tissue of 74 rodents, 26 birds and 10 deer were tested by PCR for the presence of B. miyamotoi. Tick lysates were also tested for the presence of B. burgdorferi s.l. Next, we performed a PCR for B. miyamotoi in 31 biopsies from LB-suspected skin lesions in patients visiting our tertiary Lyme center. These biopsies had been initially tested for B. burgdorferi s.l. by PCR, and the skin lesions had been investigated by specialized dermatologists. Out of 3360 unfed (or questing) nymphs, 313 (9.3%) were infected with B. burgdorferi s.l., 70 (2.1%) were infected with B. miyamotoi, and 14 (0.4%) were co-infected with B. burgdorferi s.l. and B. miyamotoi. Co-infection of B. burgdorferi s.l. with B. miyamotoi occurred more often than expected from single infection prevalences (p=0.03). Both rodents (9%) and birds (8%) were found positive for B. miyamotoi by PCR, whereas the roe deer samples were negative. Out of 31 LB-suspected skin biopsies, 10 (32%) were positive for B. burgdorferi s.l. while none were positive for B. miyamotoi. The significant association of B. burgdorferi s.l. with B. miyamotoi in nymphs implies the existence of mutual reservoir hosts. Indeed, the presence of B. miyamotoi DNA indicates systemic infections in birds as well as rodents. However, their relative contributions to the enzootic cycle of B. miyamotoi requires further investigation. We could not retrospectively diagnose B. miyamotoi infection using biopsies of LB-suspected skin lesions, supporting the hypothesis that B. miyamotoi is not associated with LB-associated skin manifestations. However, this warrants further studies in larger sets of skin biopsies. A prospective study focused on acute febrile illness after a tick bite could provide insight into the incidence and clinical manifestations of B. miyamotoi infection in The Netherlands.
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