Outbreak of amoxicillin-resistant Haemophilus influenzae type b: variable number of tandem repeats as novel molecular markers

An outbreak caused by amoxicillin-resistant Haemophilus influenzae type b was noted among patients suffering from chronic obstructive pulmonary disease. Since infections were clustered in time and place, an ongoing outbreak was suspected. The spread of the strain and the course of the outbreak could be followed by random amplification of polymorphic DNA (RAPD) analysis of the different bacterial isolates. In addition, studies were aimed at the determination of length polymorphism in regions of repetitive DNA. By PCR-mediated amplification of variable number of tandem repeat regions (VNTRs), additional insight into the genome composition of the epidemic strain was gained. Our results show that VNTRs comprising repeat units that are 3, 5, or 6 nucleotides in length provided stable genetic markers that can be used for molecular typing of H. influenzae type b. VNTRs built from tetranucleotide units, however, appear to be hypervariable and not suited for epidemiological studies. The observed variability in this latter class of VNTRs might be reminiscent of the bacterium's capacity to deal with unfavorable host factors.

Acinetobacter, an infrequent cause of community acquired bacterial meningitis

A 19-year-old previously healthy woman developed meningitis due to Acinetobacter calcoaceticus. This is a Gram-negative coccobacillus belonging to the family Neisseriaceae. Most reported cases of Acinetobacter meningitis were hospital-acquired and due to strains highly resistant to amoxycillin. Our patient was treated with amoxycillin and recovered without sequelae.

Diagnostic tools in Lyme borreliosis: clinical history compared with serology

The occurrence of a history of clinical Lyme borreliosis and the prevalence of positive antibodies to Borrelia burgdorferi were studied in 431 Dutch hunters. The majority of the hunters (336 or 78%) did not report any complaints and had no positive IgG antibodies to B. burgdorferi. Sixty-five hunters (15.1%) had no clinical manifestations but did not have positive antibodies to B. burgdorferi. Only 1.9% of the population studied had had past symptoms of definite or probable Lyme borreliosis. Likelihood ratios were high (21.3) for the recognition of erythema migrans, but much lower for tick bites (3.6) or positive IgG Lyme serology (3.5). Clinical history turned out to be a more powerful diagnostic tool than Lyme serology.

Is there any evidence for an association between ankylosing spondylitis and Borrelia burgdorferi infection?

The suggested relationship between Borrelia burgdorferi and seronegative spondyloarthropathies has been studied in 125 patients with ankylosing spondylitis (AS). IgG antibodies to Borrelia burgdorferi were present in 11 of 125 patients (8.8%) and in 25 of 125 controls (20%). No patient had clinical Lyme borreliosis. HLA-B27 status was known for 82 patients with AS. There was no difference between B27+ and B27 patients. This study provides no evidence that Borrelia burgdorferi is associated with AS.

Lyme arthritis in The Netherlands: a nationwide survey among rheumatologists

A nationwide survey among all 118 Dutch rheumatologists (response rate 85%) yielded 42 patients with Lyme arthritis. The arthritis was nonpersistent in all these patients. A tick bite was reported by 23 of these 42 patients (55%). Erythema migrans was recalled by 19 patients (45%). Cardiac manifestations occurred in 4 patients (9%) and neurologic symptoms in 14 patients (33%). By immunoabsorbent assay or immunofluorescence technique 37 patients (88%) had positive IgG antibodies to Borrelia burgdorferi. The distribution of HLA-DR alleles of 28 of these patients was not different from the healthy population. The response to antibiotic treatment was considered good in 34 patients (81%). The clinical features of the Dutch patients with Lyme arthritis closely resemble the description of the disease reported from the United States.

Amplification of Borrelia burgdorferi DNA in skin biopsies from patients with Lyme disease

To determine whether the polymerase chain reaction could contribute to a better diagnosis of Lyme disease, skin biopsy samples from patients suffering from erythema chronicum migrans or acrodermatitis chronica atrophicans were tested for the presence of Borrelia burgdorferi by a polymerase chain reaction assay, which was specific for European strains. The spirochete could not be detected microscopically in any of the 15 biopsy samples obtained from nine patients. However, B. burgdorferi could be isolated from seven of eight of these samples, which indicated the presence of spirochetes. Using a nested polymerase chain reaction, we were able to detect B. burgdorferi-specific sequences in 12 of the 15 biopsy samples. Biopsy samples from three of four patients with erythema chronicum migrans and four of five patients with acrodermatitis chronica atrophicans were found to be positive for B. burgdorferi. The spirochete could be isolated from the biopsy sample, from a patient with erythema chronicum migrans who tested negative, which suggests a false-negative polymerase chain reaction result probably on account of the low number of spirochetes present in the lesion. The positive polymerase chain reaction for lesions from patients with acrodermatis chronica atrophicans supports the concept that B. burgdorferi can persist in the skin over a long period of time. From these results, it was concluded that the polymerase chain reaction is a valuable technique for the diagnosis of Lyme disease.