Ingvar Eliasson

Diversities and similarities in PFGE profiles of Campylobacter jejuni isolated from migrating birds and humans

Aims:  To genetically sub‐type Campylobacter jejuni strains isolated from migratory birds, and to compare these with clinical strains collected in the same area and corresponding time period, with the aim to increase our knowledge on sub‐types occurring among wild birds and their possible impact on human disease.

Human granulocytic ehrlichiosis as a common cause of tick-associated fever in Southeast Sweden: Report from a prospective clinical study

Between May and December 1998, tick-associated febrile illness was prospectively studied in Southeast Sweden in order to assess the occurrence of human granulocytic ehrlichiosis (HGE). Inclusion criteria were fever ( ≥ 38.0°C), with or without headache, myalgia or arthralgia in patients with an observed tick bite or tick exposure within 1 month prior to onset of symptoms. Patients with clinical signs of Lyme borreliosis were included. Of the 27 patients included, we identified 4 cases of HGE. Three of the patients had coinfection with Lyme borreliosis, which presented as erythema migrans. All 27 patients presented with a 2-5 d history of fever. None of the clinical signs or laboratory parameters monitored was helpful in predicting ehrlichiosis in this group with tick-associated fever conditions. Within the HGE-negative group (n = 23), 12 patients had clinical or laboratory signs of Lyme borreliosis. For 11 patients, the aetiology of the fever remained unclear. Our results suggest that HGE is common in tick-infested areas of Southeast Sweden, and may occur as a coinfection of Lyme borreliosis. Granulocytic ehrlichiosis should be suspected in patients who present with tick-associated fever, with or without erythema migrans. Ehrlichia serology and PCR should be employed to confirm the diagnosis.

Diagnostic performance of cerebrospinal fluid chemokine CXCL13 and antibodies to the C6-peptide in Lyme neuroborreliosis.

OBJECTIVES The aim of this study was to evaluate the chemokine CXCL13 and C6 antibodies separately and in combination in paired serum/cerebrospinal fluid (CSF) samples in the laboratory diagnosis of Lyme neuroborreliosis (LNB). METHODS A large retrospective material with paired serum/CSF samples from 261 patients with clinically suspected LNB was investigated. Patients were divided into three main diagnostic groups based on original results of CSF pleocytosis and intrathecal anti-borrelia antibodies (purified flagellum). Levels of CXCL13, albumin, total IgM and IgG in paired samples and C6 antibodies in CSF were compared across diagnostic groups. RESULTS A sensitivity of 99% and a specificity of 96% were achieved for CSF-Serum CXCL13 ratio. CSF-C6 antibodies performed with a sensitivity of 99% and a specificity of 88.0%. A combination of CSF-Serum CXCL13 ratio and CSF-C6 antibodies, evaluated in parallel, revealed a sensitivity of 99% and specificity of 98%. CONCLUSIONS This study confirms CSF-CXCL13 as a reliable marker of LNB and suggests improved diagnostic performance especially in children with possible LNB.

Globally disseminated human pathogenic Escherichia coli of O25b‐ST131 clone, harbouring blaCTX‐M‐15, found in Glaucous‐winged gull at remote Commander Islands, Russia

With focus on environmental dissemination of antibiotic resistance among clinically relevant bacteria, such as the rising ESBL type of resistance among Escherichia coli, we investigated antibiotic resistance levels in wild birds in the Commander Islands and Kamchatka, Russia. Despite overall low resistance levels in randomly selected E. coli (one from each sample), we found multi-resistant ESBL-producing E. coli harbouring blaCTX-M-14 and blaCTX-M-15 using selective screening. Among these multi-resistant ESBL-producing E. coli we found one blaCTX-M-15 harbouring strain belonging to the O25b-ST131 clone, recognized for its clonal disseminated worldwide as a human pathogen. The potential in acquiring resistant bacteria of human origin, especially highly pathogenic clones, as well as downstream consequences of that, should not be underestimated but further investigated.

Isolation and Characterization of Two European Strains of Ehrlichia phagocytophila of Equine Origin

ABSTRACT We report the isolation and partial genetic characterization of two equine strains of granulocytic Ehrlichia of the genogroup Ehrlichia phagocytophila. Frozen whole-blood samples from two Swedish horses with laboratory-verified granulocytic ehrlichiosis were inoculated into HL-60 cell cultures. Granulocytic Ehrlichia was isolated and propagated from both horses. DNA extracts from the respective strains were amplified by PCR using primers directed towards the 16S rRNA gene, the groESL heat shock operon gene, and the ank gene. The amplified gene fragments were sequenced and compared to known sequences in the GenBank database. With respect to the 16S rRNA gene, the groESL gene, and the ank gene, the DNA sequences of the two equine Ehrlichia isolates were identical to sequences found in isolates from clinical cases of granulocytic ehrlichiosis in humans and domestic animals in Sweden. However, compared to amplified DNA from an American Ehrlichia strain of the E. phagocytophila genogroup, differences were found in the groESL gene and ank gene sequences.

Serological Evidence of Ehrlichia Infection in Swedish Lyme borreliosis Patients

We studied sera from patients who had participated in a prospective study of borreliosis in Sweden and had acquired tick bites in areas of the country with a high prevalence of granulocytic ehrlichial infections in animals. The sera were examined for IgG anti Ehrlichia antibodies by an indirect immunofluorescence assay using a locally isolated bovine Ehrlichia antigen. Confirmation of the serological results was done at the Unité des Rickettsies, Marseille, France. Three out of 37 of the investigated patients and 1 out of 100 investigated healthy blood donors had significant antibody titres to granulocytotropic Ehrlichiae. No patient or blood donor had specific antibody titres to Ehrlichia chaffeensis. These data suggest that Scandinavian Ehrlichia species can infect and evoke immunological response in tick-exposed humans.

Beta-Lactamase Production in the Upper Respiratory Tract Flora in Relation to Antibiotic Consumption: A Study in Children Attending Day Nurseries

The occurrence of beta-lactamase production in Haemophilus influenzae, Branhamella catarrhalis and Moraxella nonliquefaciens was compared in 191 healthy children attending day nurseries in 2 municipalities differing with regard to the prescription rate of beta-lactam antibiotics. A significantly higher frequency of beta-lactamase production was recorded in M. nonliquefaciens isolated in the municipality with the higher prescription rate. A corresponding difference was not recorded for H. influenzae or B. catarrhalis. Approximately 75% of the nasopharyngeal pathogens H. influenzae, B. catarrhalis and Streptococcus pneumoniae, as well as the commensal M. nonliquefaciens, were eliminated and often replaced by other strains of either species over a period of one month. Although none of the children were on antibiotics a substantial proportion of the acquired strains produced beta-lactamase. This suggested that the carrier rate of beta-lactamase producing strains of the respiratory tract is not only related to the effect of recent antibiotic treatment but also to the prevalence of such strains in the population.

Characterization of cell-bound papain-soluble beta-lactamases in BRO-1 and BRO-2 producing strains ofMoraxella (Branhamella) catarrhalis andMoraxella nonliquefaciens

InMoraxella (Branhamella) catarrhalis andMoraxella nonliquefaciens strains isolated from clinical specimens in the south of Sweden two variants of beta-lactamase were distinguished by isoelectric focusing (IEF). The BRO-1 (Ravasio type) enzyme was the most common inBranhamella catarrhalis, constituting about 90% of the beta-lactamase found in this species, while the BRO-2 enzyme (1908 type) was as common as BRO-1 inMoraxella nonliquefaciens. The determinants mediating the production of BRO-1 and BRO-2 were both transferable by conjugation. Cell-bound beta-lactamase from reference strains producing BRO-1 and BRO-2 could be solubilized by papain digestion. The isoelectric point of the solubilized enzymes differed distinctly between BRO-1 (pI 6.5) and BRO-2 (pI 6.9). The molecular species of BRO-1 and BRO-2 released by papain digestion were purified by affinity chromatography with phenylboronic acid agarose gel. They had identical molecular weights of approximately 28,000. Their kinetic constants were indistinguishable for a number of substrates and beta-lactamase inhibitors.

Plasmid-Mediated β-Lactamase in Branhamella catarrhalis

SummaryThe plasmid-mediated β-lactamase in Branhamella catarrhalis (BRO-1), also occurring in Moraxella nonliquefaciens, differs from other known plasmid-mediated β-lactamases in Gram-negative bacteria regarding substrate profile and isoelectric point.B. catarrhalis strains previously reported to produce β-lactamases deviating from BRO-1 were tested, and the β-lactamases did not differ significantly from BRO-1 in substrate profile, isoelectric point or relative substrate affinity index (RSAI). Further investigations of strains of various geographic origin should be undertaken. RSAI seems to be a useful tool for screening of β-lactamases in B. catarrhalis since values for a large number of strains can easily be determined. The previously reported conjugational transfer of BRO-1 production within species B. catarrhalis and from M. nonliquefaciens to B. catarrhalis was confirmed. Four bands of extrachromosomal DNA were regularly detected by agarose gel electrophoresis in β-lactamase-producing as well as in β-lactamase-negative strains of B. catarrhalis and M. non-liquefaciens, provided that the excessive nuclease activity in the preparations was inhibited.

Beta-lactamase production in the upper respiratory tract flora.

In order to determine the recovery rate of species of the generaHaemophilusandMoraxella(including subgenusBranhamella)from the upper respiratory tract and the incidence ofβ-lactamase production within these genera, cultures were made of nose and throat swab specimens and adenoid tissue in 50 children undergoing adenoidectomy.Haemophilus influenzaewas isolated from 92% of the children. All children harboured strains ofHaemophilusspp. and in 46%, at least one strain produced the TEM-1β-lactamase.Branhamella catarrhalisand/orMoraxella nonliquefacienswere isolated from 82% of the children and strains producing the BRO-1β-lactamase from 34%. Overall, TEM-1 and/or BRO-1 producing strains were recovered from 60% of the investigated patients. Theβ-lactamase production was found to be transferable by conjugation within the respective genera. It is suggested that the apathogenic species may be a source of transferable determinants mediatingβ-lactamase production in the upper respiratory tract.