Bjørn-Erik Kristiansen

Borrelia burgdorferi Sensu Lato and Ehrlichia spp. in Ixodes Ticks from Southern Norway

ABSTRACT We report the results of a study of the prevalence ofEhrlichia and Borrelia species in 341 questing Ixodes ricinus ticks from two locations in southern Norway. The prevalences of Borrelia burgdorferisensu lato and Ehrlichia spp. were, respectively, 16 and 11.5% at site 1 and 17 and 6% at site 2. Prevalence and species composition of Borrelia and Ehrlichiavaried with location and date of collection. The dominantBorrelia species at both sites was Borrelia afzelii, followed by Borrelia burgdorferi sensu stricto. Borrelia garinii was found in only a single tick. The dominant member of the Ehrlichia group was a recently described Ehrlichia-like organism related to the monocytic ehrlichiae. Variants of Ehrlichia phagocytophila and the agent of human granulocytic ehrlichiosis were also found. The highest prevalences for B. afzelii,B. burgdorferi sensu stricto, and theEhrlichia-like organism were observed in May. B. afzelii was most prevalent in females, less prevalent in nymphs, and least prevalent in males, while the prevalence ofEhrlichia was highest in nymphs, lower in females, and least in males. Double infections with B. afzelii andB. burgdorferi sensu stricto and with B. afzelii and the Ehrlichia-like organism were significantly overrepresented. Tick densities were highest in May, when densities of more than 200 ticks/100 m2 were observed, and declined during the summer months to densities as low as 20 ticks/100 m2. We conclude that estimates of the prevalence of tick-borne bacteria are sensitive to the choice of date and site for collection of ticks. This is the first study of tick-borneBorrelia and Ehrlichia in Norway and the lowest reported B.garinii prevalence in Northern Europe. The prevalence of the Ehrlichia-like organism is described for the first time in questing ticks.

Age-dependent prevalence of BK virus IgG and IgM antibodies measured by enzyme-linked immunosorbent assays (ELISA).

Enzyme immunoassays (ELISA) have been developed for the detection of BK virus IgG- and IgM-antibodies. Specific IgG is detected by an antigen-coated solid phase test; IgM by an antibody capture method. These methods have been used to study the age-distribution of BK virus antibodies in Tromsø county in Northern Norway. The serum panels tested were: 60 sera from paediatric patients aged 0-1 year; 220 sera from healthy persons aged 1-82 years; 74 sera from healthy blood donors; 107 sera from healthy pregnant women. The age-distribution of BKV-IgG antibodies showed that primary infections took place predominantly between the ages of 1 and 6 years, and that there were no sex differences, either in the age-specific prevalence or in the level of BKV-IgG. We found no significant differences in the prevalence of BKV-IgM antibodies in healthy children and adults and pregnant women. BKV-IgM was detected in 26 of the 461 sera tested (5.6%).

Uncomplicated urinary tract infections Bacterial findings and efficacy of empirical antibacterial treatment

Objective . To assess bacterial aetiology, antimicrobial susceptibility and efficacy of empirical treatment in uncomplicated urinary tract infections and to evaluate the dipstick as a diagnostic tool. Design . Prospective study. Setting . Clinical microbiology laboratory and 17 general practice clinics in Telemark County, Norway. Subjects . A total of 184 female patients between 15 and 65 years of age with symptoms of uncomplicated urinary tract infection. Main outcome measures . Results from dipstick testing (leucocyte esterase and nitrite), bacterial culture, susceptibility patterns and efficacy of empirical antibacterial therapy on symptoms. Results. Significant bacteruria was detected in 140 (76%) of the 184 urines. The leukocyte esterase test was of little help in predicting culture-positive UTI. A positive nitrite test accurately predicted culture-positivity, while a negative result was ambiguous. The most common bacterium, E. coli, was found in 112 (80%) of the 140 positive urines and was predominantly sensitive to ciprofloxacin (100%), mecillinam (94%), nitrofurantoin (97%), trimethoprim (88%), and sulphonamide (81%), and to a lesser extent to ampicillin (72%). In 18 patients the causative bacterium was resistant to the therapeutic agent used; 7 of these returned to their GP with persisting symptoms while in 11 symptoms resolved without further treatment. Conclusion . The study confirms E. coli as the predominant cause of uncomplicated UTI. Since in the majority of cases the bacterium found was susceptible to the locally preferred antimicrobials and the patients’ symptoms were cured, empiric therapy is found to be an effective practice in the study area and, by inference, in others with similar antimicrobial susceptibility patterns.

Ehrlichiosis in a moose calf in Norway.

A case of granulocytic ehrlichiosis in a moose calf (Alces alces) in Norway is described. The animal was heavily infested with ticks (Ixodes ricinus), and died from a Klebsiella pneumoniae septicemia. Examination of blood smears from the calf revealed cytoplasmic inclusions (morulae) typical of infection with Ehrlichia phagocytophila in the granulocytes. Ehrlichia sp. was detected by polymerase chain reaction (PCR) in blood from the calf, and in the ticks. Sequence determination identified it as E. phagocytophila. This is the first report of ehrlichiosis in moose.

Mutant ftsI genes in the emergence of penicillin-binding proteinmediated β-lactam resistance in Haemophilus influenzae in Norway

The most important mechanism for beta-lactam resistance in beta-lactamase-negative ampicillin-resistant (BLNAR) isolates of Haemophilus influenzae is the alteration of penicillin-binding protein 3 (PBP3) as a result of ftsI gene mutations. The present study aimed to map PBP3 alterations and to determine the correlation to beta-lactam resistance in respiratory tract isolates of H. influenzae in Norway, as well as assess the contribution of clonal spread to the emergence of PBP3-mediated resistance. Twenty-three beta-lactamase negative respiratory tract isolates with resistance to penicillins and 23 susceptible control isolates were examined by determination of beta-lactam MICs, ftsI sequencing and molecular typing by pulsed-field gel electrophoresis (PFGE). Ampicillin MIC ranges in the resistant group and the control group were 1-2 mg/L and 0.125-0.5 mg/L, respectively. All isolates in the resistant group had the PBP3 substitution Asn526-->Lys and were thus categorized as group II low-BLNAR. No control isolate met the genetic BLNAR (gBLNAR) criteria. The PBP3 substitution patterns corresponded well to those observed in previous European studies. Eighty-three percent (19/23) of the resistant isolates belonged to two clones, demonstrating the capability of low-BLNAR strains of clonal dissemination. Combined analysis of ftsI DNA sequences and PFGE patterns revealed distinctly different ftsI alleles in genetically indistinguishable isolates and identical copies of the same ftsI allele in unrelated isolates. A possible explanation of this observation is the recombinational exchange of ftsI alleles. This phenomenon, as well as the possibility of endemic European gBLNAR strains, should be further investigated.

A comparison of phylogenetic group, virulence factors and antibiotic resistance in Russian and Norwegian isolates of Escherichia coli from urinary tract infection

Isolates of Escherichia coli from 31 Norwegian and 31 Russian females with significant bacteruria who presented with clinical signs of urinary tract infection (UTI) were tested for antimicrobial sensitivity, the presence of virulence genes, phylogroup distribution and clonal affinity. Twenty isolates, representing the full clonal diversity of a collection of 138 intestinal isolates of E. coli from healthy Norwegian females, served as a reference group. Russian UTI isolates belonged more often to phylogroup A and possessed fewer virulence genes than did Norwegian isolates. UTI isolates of E. coli were genetically heterogeneous and had a high degree of antimicrobial sensitivity.

Emergence of clonally related multidrug resistant Haemophilus influenzae with penicillin-binding protein 3-mediated resistance to extended-spectrum cephalosporins, Norway, 2006 to 2013

Resistance to cephalosporins in Haemophilus influenzae is usually caused by characteristic alterations in penicillin-binding protein 3 (PBP3), encoded by the ftsI gene. Resistance to extended-spectrum cephalosporins is associated with high-level PBP3-mediated resistance (high-rPBP3), defined by the second stage S385T substitution in addition to a first stage substitution (R517H or N526K). The third stage L389F substitution is present in some high-rPBP3 strains. High-rPBP3 H. influenzae are considered rare outside Japan and Korea. In this study, 30 high-rPBP3 isolates from Norway, collected between 2006 and 2013, were examined by serotyping, multilocus sequence typing (MLST), ftsI sequencing, detection of beta-lactamase genes and minimum inhibitory concentration (MIC) determination. MICs were interpreted according to clinical breakpoints from the European Committee on Antimicrobial Susceptibility Testing (EUCAST). Respiratory isolates predominated (proportion: 24/30). The 30 isolates included one serotype f isolate, while the remaining 29 lacked polysaccharide capsule genes. Resistance to extended-spectrum cephalosporins (cefixime, 29 isolates/30 isolates; cefepime, 28/30; cefotaxime, 26 /30; ceftaroline, 26/30; ceftriaxone, 14/30), beta-lactamase production (11/30) and co-resistance to non-beta-lactams (trimethoprim-sulfamethoxazole, 13/30; tetracycline, 4/30; chloramphenicol, 4/30; ciprofloxacin, 3/30) was frequent. The N526K substitution in PBP3 was present in 23 of 30 isolates; these included a blood isolate which represents the first invasive S385T + N526K isolate reported from Europe. The L389F substitution, present in 16 of 30 isolates, coincided with higher beta-lactam MICs. Non-susceptibility to meropenem was frequent in S385T + L389F + N526K isolates (8/12). All 11 beta-lactamase positive isolates were TEM-1. Five clonal groups of two to 10 isolates with identical MLST-ftsI allelic profiles were observed, including the first reported high-rPBP3 clone with TEM-1 beta-lactamase and co-resistance to ciprofloxacin, tetracycline, chloramphenicol and trimethoprim-sulfamethoxazole. Prior to this study, no multidrug resistant high-rPBP3 H. influenzae had been reported in Norway. Intensified surveillance of antimicrobial resistance is needed to guide empiric therapy.

Preventing Secondary Cases of Meningococcal Disease by Identifying and Eradicating Disease-Causing Strains in Close Contacts of Patients

In Norway, the use of chemoprophylaxis after cases of meningococcal disease is not recommended. Instead, household members less than 15 years are treated with penicillin for 7 days. Failures of this treatment have been reported. We therefore used DNA fingerprinting to identify the disease-causing strain in healthy contacts combined with selective rifampicin prophylaxis to these carriers to prevent secondary cases. During a 2-year period (1987-89) there were 13 cases of meningococcal disease in the County of Telemark (165000 inhabitants). 65 (14.7%) out of 441 contacts to these 13 patients harbored meningococci in their throat; 16 (3.6%) carried the disease-causing strain. Only 1 carrier fulfilled the criteria for being treated with penicillin; 8 were adults and the remaining 7 were not household members. No secondary cases of meningococcal disease occurred during the study period or the following 12 months. During the 4-year period (1984-87) preceding the study period there were 39 cases of meningococcal disease in Telemark; 7 of them were index cases for 12 bacteriologically verified and 4 clinically suspected secondary cases of meningococcal disease. We conclude that selective prophylaxis with rifampicin seems to be more efficient that penicillin treatment of household members less than 15 to prevent secondary cases of meningococcal disease.

Detection of genital papillomavirus types by polymerase chain reaction using common primers

We describe the detection of eight genital human papillomavirus (HPV) types, including HPV16 and HPV18, by PCR amplification of a 323 base‐pair region of the genome within the LI open reading frame (ORF). The primer sequences are: TGYAAATATCCWGATTWTWT and GTATCWACMA‐CAGTAACAAA. The method will detect purified HPV16 DNA down to a concentration of as little as a single molecule in 100 μl. The method is also applicable to purified DNA and crude lysates from tumour biopsies. Typing of the PCR product can be achieved with specific oligonucleotide probes.

Human papillomavirus infection in Norwegian women with cervical cancer

The objective of the present study was to determine the prevalence of human papillomavirus (HPV) infections in Norwegian women with cervical cancer. We used the polymerase chain reaction (PCR) and Southern blot techniques to assess the prevalence of HPV in cervical biopsies of 133 women admitted to the Norwegian Radium Hospital for treatment of cervical cancer. At the time of sampling (from February 1988 to April 1989) about 85% of Norwegian women with cervical cancer were treated at the Norwegian Radium Hospital. HPV was found in biopsies of 91 (68%) of women with cancer; 70 (53%) biopsies contained HPV type 16, 19 (14%) HPV type 18, 4 (3%) HPV type 33, 2 (1.5%) HPV type 11, and 3 (2%) HPV DNA of unknown type (HPVX). Five percent of biopsies were doubly infected, chiefly with HPV 16 + 18. We found a significant association between HPV 18 and low age, poorly differentiated tumors and adenocarcinomas. Our results show that there is an association between HPV types 16 and 18 and cervical cancer also in a Norwegian setting. PCR was more sensitive than Southern blotting for detection of HPV. Thirty‐six (27.5%) of cancer biopsies were positive by PCR but negative by Southern blotting, as against 49 (73.5%) positive by both methods; we also encountered 4 samples positive by Southern blotting and negative by PCR. In 23/53 cancer biopsies positive by Southern blotting we found evidence for integrated or rearranged HPV genomes.