Seroreactivity for spotted fever rickettsiae and co-infections with other tick-borne agents among habitants in central and southern Sweden

Patients seeking medical care with erythema migrans or flu-like symptoms after suspected or observed tick bite in the southeast of Sweden and previously investigated for Borrelia spp. and/or Anaplasma sp. were retrospectively examined for serological evidence of rickettsial infection (Study 1). Twenty of 206 patients had IgG and/or IgM antibodies to Rickettsia spp. equal to or higher than the cut-off titre of 1:64. Seven of these 20 patients showed seroconversion indicative of recent or current infection and 13 patients had titres compatible with past infection, of which five patients were judged as probable infection. Of 19 patients with medical records, 11 were positive for Borrelia spp. as well, and for Anaplasma sp., one was judged as positive. Five of the 19 patients had antibodies against all three pathogens. Erythema migrans or rash was observed at all combinations of seroreactivity, with symptoms including fever, muscle pain, headache and respiratory problems. The results were compared by screening an additional 159 patients (Study 2) primarily sampled for the analysis of Borrelia spp. or Mycoplasma pneumoniae. Sixteen of these patients were seroreactive for Rickettsia spp., of which five were judged as recent or current infection. Symptoms of arthritis, fever, cough and rash were predominant. In 80 blood donors without clinical symptoms, approximately 1 % were seroreactive for Rickettsia spp., interpreted as past infection. The study shows that both single and co-infections do occur, which illustrate the complexity in the clinical picture and a need for further studies to fully understand how these patients should best be treated.

Intra-urban air pollution in a rapidly growing Sahelian city

In this paper we analyze spatial and temporal variations of air pollution (PM(1), PM(2.5), PM(10), CO, NO(x), O(3), Toluene and Benzene) and climate in areas of different development typology in Ouagadougou, Burkina Faso. Analyses are based on measurements from fixed sites and car traverse measurements during field studies in 2007 and 2010. Large spatial and temporal variations were found, showing a generally poor air quality situation, with extreme levels of PM(10), commonly exceeding air quality guidelines of WHO. Pollution levels increase considerably with increased atmospheric stability. Important sources were transported dust and re-suspension of dust from unpaved roads, but also traffic emissions and biomass burning. The spatial variations are examined with focus on effects for variations in potential exposure depending on for example area of residence and daily activity pattern, showing that great differences are likely to exist. Ouagadougou, like most developing countries worldwide, currently experiences an extremely rapid population growth in combination with limited financial means. This is likely to create increasingly harmful air pollution situations for the rapidly growing populations of these areas, and shows an urgent need for increased understanding of the pollution situation as well as development of mitigation strategies.

Spontaneously draining acute otitis media in children: an observational study of clinical findings, microbiology and clinical course

OBJECTIVES

To study the outcome of acute otitis media (AOM) with otorrhoea in children managed initially without antibiotics, in relation to bacterial and clinical findings, and to identify those who may benefit from antibiotics.

METHODS

Otherwise healthy, not otitis prone children aged 2-16 y, presenting with AOM with spontaneous otorrhoea, were recruited from primary care and followed at selected ear, nose and throat (ENT) clinics. Specimens for bacterial investigations were obtained; symptoms were registered on a daily basis. The main outcomes measured were the frequency of children treated with antibiotics due to persisting AOM within 9 days in relation to clinical and bacteriological findings, and new AOM within 3 months.

RESULTS

Twelve of 71 children who completed the trial received antibiotics during the first 9 days due to lack of improvement. One received antibiotics after 16 days due to relapsing AOM and 6 received antibiotics after 30 days due to new AOM. At 2-4 days following inclusion, over 70% of children showed normalized eardrum status and markedly reduced secretion. Alloiococcus otitidis was found in 23 samples, Streptococcus pneumoniae in 12, Streptococcus pyogenes in 6, and Fusobacterium nucleatum in 5. Mycoplasma pneumoniae, Chlamydia pneumoniae, and Fusobacterium necrophorum were not detected. Antibiotics were prescribed more extensively to children with a pulsating eardrum and abundant purulent secretion. All children with S. pyogenes received antibiotics, whereas children with only A. otitidis did not.

CONCLUSIONS

The results suggest that antibiotics are indicated in AOM with otorrhoea and the presence of abundant purulent secretion, a pulsating eardrum, or the presence of S. pyogenes. The presence of only A. otitidis was not associated with a more prolonged course or the need for antibiotics.

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.

A novel Chlamydiaceae-like bacterium found in faecal specimens from sea birds from the Bering Sea

The family Chlamydiaceae contains several bacterial pathogens of important human and veterinary medical concern, such as Chlamydia trachomatis and Chlamydophila psittaci. Within the order Chlamydiales there are also an increasing number of chlamydia-like bacteria whose biodiversity, host range and environmental spread seem to have been largely underestimated, and which are currently being investigated for their potential medical relevance. In this study we present 16S rRNA, rnpB and ompA gene sequence data congruently indicating a novel chlamydia-like bacterium found in faecal specimens from opportunistic fish-eating sea birds, belonging to the Laridae and Alcidae families, from the Bering Sea. This novel bacterium appears to be closer to the Chlamydiaceae than other chlamydia-like bacteria and is most likely a novel genus within the Chlamydiaceae family.

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.

Mapping of hormones and cortisol responses in patients after Lyme neuroborreliosis

Background

Persistent symptoms after treatment for neuroborreliosis are common for reasons mainly unknown. These symptoms are often unspecific and could be caused by dysfunctions in endocrine systems, an issue that has not been previously addressed systematically. We therefore mapped hormone levels in patients with previous confirmed Lyme neuroborreliosis of different outcomes and compared them with a healthy control group.

Methods

Twenty patients of a retrospective cohort of patients treated for definite Lyme neuroborreliosis were recruited 2.3 to 3.7 years (median 2.7) after diagnosis, together with 23 healthy controls. Lyme neuroborreliosis patients were stratified into two groups according to a symptom/sign score. All participants underwent anthropometric and physiological investigation as well as an extensive biochemical endocrine investigation including a short high-dose adrenocorticotropic hormone stimulation (Synacthen^®) test. In addition to hormonal status, we also examined electrolytes, 25-hydroxy-vitamin D and interleukin-6.

Results

Eight patients (40%) had pronounced symptoms 2-3 years after treatment. This group had a higher cortisol response to synacthen as compared with both controls and the Lyme neuroborreliosis patients without remaining symptoms (p < 0.001 for both comparisons). No other significant differences in the various baseline biochemical parameters, anthropometric or physiological data could be detected across groups.

Conclusions

Apart from a positive association between the occurrence of long-lasting complaints after Lyme neuroborreliosis and cortisol response to synacthen, no corticotropic insufficiency or other serious hormonal dysfunction was found to be associated with remaining symptoms after treatment for Lyme neuroborreliosis.

Diurnal and intra-urban particle concentrations in relation to windspeed and stability during the dry season in three African cities

The spatial and temporal variations of PM(2.5), PM(10) and TSP in three African cities of different sizes (Dar es Salaam, Ouagadougou and Gaborone) were investigated using portable particle counters. Three different areas (downtown, green residential and traditional residential) and a reference site were designated in each of the cities in order to detect intra-urban and temporal variability. Morning, noon and night measurements were conducted in the urban areas while observations at reference stations were made continuously over the field periods. A clear diurnal pattern in particle concentrations was found in inland Gaborone and Ouagadougou, with morning and night peaks where the latter was the highest. However, in coastal Dar es Salaam the night peak was almost absent due to delayed stabilisation of the air. Particle concentrations at the Ouagadougou reference station were extreme. The direct contribution of vehicle emissions are of secondary importance since the PM(2.5)/PM(10) ratios are low (0.1-0.3). Much of the particles are supposed to be soil particles that are entrained in the air by daytime high windspeeds followed by nighttime subsidence as the air is stabilised and windspeed decreases. However, in all three cities, resuspension are important as areas with a network of unpaved roads showed the highest concentrations of suspended particles. Generally, the central business district had the lowest concentrations of particulate matter.

Complex population structure of Lyme borreliosis group spirochete Borrelia garinii in subarctic Eurasia

Borrelia garinii, a causative agent of Lyme borreliosis in Europe and Asia, is naturally maintained in marine and terrestrial enzootic cycles, which primarily involve birds, including seabirds and migratory passerines. These bird groups associate with, correspondingly, Ixodes uriae and Ixodes ricinus ticks, of which the latter species may bite and transmit the infection to humans. Studies of the overlap between these two natural cycles of B. garinii have been limited, in part due to the absence of representative collections of this spirochete's samples, as well as of the lack of reliable measure of the genetic heterogeneity of its strains. As a prerequisite for understanding the epidemiological correlates of the complex maintenance of B. garinii, the present study sought to assess the diversity and phylogenetic relationships of this species' strains from its natural hosts and patients with Lyme borreliosis from subarctic Eurasia. We used sequence typing of the partial rrs-rrl intergenic spacer (IGS) of archived and prospective samples of B. garinii from I. uriae ticks collected predominantly on Commander Islands in North Pacific, as well as on the islands in northern Sweden and arctic Norway. We also typed B. garinii samples from patients with Lyme borreliosis and I. ricinus ticks infesting migratory birds in southern Sweden, or found questing in selected sites on the islands in the Baltic Sea and Lithuania. Fifty-two (68%) of 77 B. garinii samples representing wide geographical range and associated with I. ricinus and infection of humans contributed 12 (60%) of total 20 identified IGS variants. In contrast, the remaining 25 (32%) samples recovered from I. uriae ticks from a few islands accounted for as many as 10 (50%) IGS types, suggesting greater local diversity of B. garinii maintained by seabirds and their ticks. Two IGS variants of the spirochete in common for both tick species were found in I. ricinus larvae from migratory birds, an indication that B. garinii strains are exchanged between different ecological niches. Notably, B. garinii variants associated with I. uriae ticks were found in each of the six clusters, representing two phylogenetic lineages of this species identified among the studied samples. Our findings suggest that B. garinii in subarctic Eurasia comprises two partially overlapping populations with different levels of genetic heterogeneity, presumably, due to distinctive selective pressures on the spirochete in its marine and terrestrial enzootic cycles.

Antibody responses to borrelia IR(6) peptide variants and the C6 peptide in Swedish patients with erythema migrans

The aim of this study was to evaluate the antibody responses to different VlsE protein IR(6) peptide variants and the synthetic C6 peptide in acute and convalescent (2-3 and 6 months) serum samples from Swedish patients with clinical erythema migrans (EM). Serum samples were prospectively collected from 148 patients with EM and compared to serum samples obtained from 200 healthy blood donors. The IgG responses to 3 IR(6) peptide variants originating from Borrelia burgdorferi (B. burgdorferi) sensu stricto, B. garinii, and B. afzelii were measured by enzyme-linked immunosorbent assays (ELISAs) and compared to a commercial C6 peptide ELISA. Seropositivity rate in the IR(6) or C6 peptide ELISAs ranged from 32% to 58% at presentation, 30-52% after 2-3 months, and 20-36% after 6 months. At presentation, positive antibodies in any of the 4 ELISAs were found in 66%. In 7/52 (13%), C6-negative EM cases, serological reaction was found to the B. burgdorferi sensu stricto-derived IR(6) peptide. In patients reporting previous LB compared to those without previous LB, significantly higher seropositivity rates were noted for all IR(6) peptides, but not for the C6 peptide. In the serology of EM in Europe, C6 ELISA does not seem to cover all cases. An ELISA using a mixture of B. burgdorferi sensu stricto IR(6) peptide and the C6 peptide could be of value in the serodiagnosis of LB in Europe. Further studies on combinations of variant IR(6) peptides and the C6 peptide in other manifestations of LB are needed to address this issue.

Evaluation of phenoxymethylpenicillin treatment of acute otitis media in children aged 2-16

OBJECTIVE

To study the clinical recovery from acute otitis media (AOM) in children, 2-16 years of age, managed with or without treatment with phenoxymethylpenicillin (PcV).

DESIGN

An open, prospective randomized trial. Children aged between 2 and 16 years, presenting with one- or double-sided AOM (without perforation) with symptom duration of less than four days, were included. The children were randomized to PcV for five days or to no primary antibiotic treatment. A health score and compliance were registered on a daily basis for seven days.

SETTING

A total of 32 health centres and 72 GPs in south-east Sweden. Subjects. Children aged 2-16 presenting with earache.

MAIN OUTCOME MEASURES

Recovery time, symptom duration, frequency of complications (up to three months) and consumption of healthcare services independent of treatment with or without antibiotics.

RESULTS

A total of 179 patients carried out the trial; 92 were randomized to PcV, 87 to no primary antibiotic treatment. The median recovery time was four days in both groups. Patients who received PcV had less pain (p <0.001) and used fewer analgesics. There were no significant differences in the number of middle-ear effusions or perforations at the final control after three months. Children randomized to PcV treatment consulted less (p <0.001) during the first seven days.

CONCLUSIONS

Our investigation supports that PcV treatment of AOM does not affect the recovery time or complication rates. PcV provided some symptomatic benefit in the treatment of AOM in otherwise healthy children, aged 2-16 years.

C6 peptide ELISA test in the serodiagnosis of Lyme borreliosis in Sweden

The aim of this study was to evaluate the synthetic C6 peptide test as a first-line test in a two-tiered scheme for Borrelia serology in a clinically well-characterized population of patients with Lyme borreliosis in Kalmar County, Sweden. The study population consisted of a prospective group (n = 200), a control group (n = 255), and a retrospective group (n = 29). The test panel consisted of the Immunetics Quick ELISA C6 Borrelia assay kit (Immunetics, Cambridge, MA, USA), the Virotech Borrelia burgdorferi ELISA (Genzyme Virotech, Rüsselsheim, Germany), and the Liaison Borrelia CLIA (DiaSorin, Saluggia, Vercelli, Italy). Seroprevalence among 200 healthy blood donors was significantly lower in the C6 test (8%) compared to the Virotech ELISA (14%) and the Liaison CLIA (12%). In convalescent sera (2-3 months and 6 months post infection) from 158 patients with erythema migrans, the seropositivity in the C6 test was also significantly lower compared to both the Virotech ELISA and the Liaison CLIA. Serosensitivity in the acute phase of erythema migrans and other clinical manifestations of borreliosis did not differ significantly between the C6 test and the Virotech ELISA or the Liaison CLIA. Overall, a positive C6 test seems to correlate well with acute borreliosis. Cross-reactivity was lower in the C6 test in sera positive for Epstein-Barr virus infection as compared to the Virotech ELISA. This study supports the use of the C6 test as a screening test for borreliosis, in endemic areas.

Reduced number of interleukin-12 secreting cells in patients with Lyme borreliosis previously exposed to Anaplasma phagocytophilum

Lyme borreliosis and human granulocytic ehrlichiosis are tick-borne diseases caused by Borrelia burgdorferi and Anaplasma phagocytophilum, respectively. Infection with A. phagocytophilum has been observed to induce immunosuppression and animal studies suggest that the bacteria might also have prolonged inhibitory effects on immune cells. The aim of this study was to investigate the cytokine secretion in patients exposed previously to A. phagocytophilum and currently infected with B. burgdorferi compared with patients infected with B. burgdorferi and seronegative for A. phagocytophilum. Eight patients with erythema migrans and antibodies against A. phagocytophilum, 15 patients with erythema migrans and negative A. phagocytophilum serology and 15 non-exposed healthy individuals were included in the study. Blood mononuclear cells were stimulated with Borrelia-antigen and the number of cytokine [interleukin (IL)-4, IL-5, IL-12, IL-13 and interferon (IFN)-gamma]-secreting cells was detected by enzyme-linked immunospot (ELISPOT). This study shows that patients with a previous exposure to A. phagocytophilum and a current infection with B. burgdorferi have a lower number of Borrelia-specific cells secreting IL-12 compared to Ap seronegative patients infected with B. burgdorferi (P < 0.001), indicating impairment in the ability to mount strong Th1-responses. We suggest that this mirrors a reduced Th1 response caused by A. phagocytophilum which could influence the outcome of the Borrelia infection and, speculatively, may also have implications in other conditions.

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.

METHODS AND RESULTS

We sub-typed C. jejuni strains from migrating birds (n = 89) and humans (n = 47), using macrorestriction profiling by pulsed-field gel electrophoresis. Isolates from migrant birds often exhibited sub-types with higher levels of similarity to isolates from birds of the same species or feeding guild, than to isolates from other groups of birds. Likewise, could the vast majority of sub-types found among the migrant bird isolates not be identified among sub-types from human cases. Only two bird strains, one from a starling (Sturnus vulgaris) and one from a blackbird (Turdus merula), had sub-types that were similar to some of the human strain sub-types.

CONCLUSIONS

Isolates from one bird species, or feeding guild, often exhibited high similarities, indicating a common transmission source for individuals, or an association between certain sub-types of C. jejuni and certain ecological guilds or phylogenetic groups of birds. Sub-types occurring among wild birds were in general distinctively different from those observed in patients. The two bird isolates that were similar to human strains were isolated from bird species that often live in close associations with human settlements.

SIGNIFICANCE AND IMPACT OF STUDY

Wild birds have often been mentioned as a potential route for transmission of C. jejuni to humans. Our study demonstrates that strains isolated from birds most often are different from clinical strains, but that some strain similarities occur, notably in birds strongly associated with human activities.

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 (> or = 38.0 degrees 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.

Isolation and characterization of two European strains of Ehrlichia phagocytophila of equine origin

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.

First long-term study of the seroresponse to the agent of human granulocytic ehrlichiosis among residents of a tick-endemic area of Sweden

The seroprevalence of granulocytic ehrlichiosis has been documented in several studies, but little data exists on incidence rates. Using sera stored from an earlier study on Lyme borreliosis, 290 residents of Aspö Island could be followed prospectively during two tick seasons (1992-1994). Immunoglobulin G antibodies to granulocytic ehrlichiosis were detected by an immunofluorescence assay using Ehrli- chia equi as antigen. Seroprevalence rates increased significantly over time, and at the 1994 follow-up, 28% of the residents were seropositive. Negative-to-positive seroconversion (incidence) rates were 3.9% and 11.1%, respectively, during the two seasons. A highly significant correlation was found between a positive serologic response for granulocytic ehrlichiosis and Borrelia burgdorferi. No such correlations were found for clinical Lyme borreliosis, self-reported arthralgia or number of recorded tick bites. It was concluded that granulocytic ehrlichiosis is highly endemic in this part of Sweden, with a seroconversion rate as high as 11% over a single tick season. Further studies are necessary to correlate these findings with clinical signs of human granulocytic ehrlichiosis.

[Varying clinical picture and course of human granulocytic ehrlichiosis. Twelve Scandinavian cases of the new tick-borne zoonosis are presented]

In the twelve clinical cases of human granulocytic ehrlichiosis (HGE) so far identified in Scandinavia (ten in Sweden, two in Norway), clinical presentation varied from a mild febrile illness to a severe septic condition with such systemic complications as acute respiratory distress syndrome (ARDS). Laboratory verification was based on PCR (polymerase chain reaction) in ten cases, and on serology in two cases. Sequence analysis of 16S rDNA showed the infectious agents to belong to the Ehrlichia phagocytophila genogroup. Seroprevalence data indicate widespread human exposure to granulocytic Ehrlichia; mean seroprevalence, 15-20% of 1,000 clinical sera from tick-exposed patients (mainly from Sweden and Norway). Proposals for diagnostic criteria and procedures, and case management are presented in the article.

Surveillance of antibiotic resistance in ICUs in southeastern Sweden. ICU Study Group of the South East of Sweden

BACKGROUND

A study was designed to assess a computer-based program for continuous registration of antibiotic resistance, statistics concerning severity of illness, and consumption of antibacterial drugs.

METHODS

The frequency of antibiotic resistance among bacteria in eight ICUs in southeastern Sweden was investigated yearly from 1995 through 1997. The antibiotic consumption in the ICUs was registered as defined daily doses (DDD) and compared to severity of illness (APACHE-II scores).

RESULTS

There was a statistically significant increase in ampicillin resistance among Enterococcus spp. between 1996 and 1997, which was due to a shift from Enterococcus faecalis to Enterococcus faecium. A high prevalence of resistance among coagulase-negative staphylococci to oxacillin (approximately 70%), ciprofloxacin (approximately 50%), fucidic acid (approximately 50%) and netilmicin (approximately 30%) was seen in all ICUs during the whole study period. There was a statistically significant increase in ciprofloxacin resistance among Escherichia coli and Enterococcus spp. The resistance among Enterobacter spp. to cefotaxime decreased but this change was not statistically significant. Efforts were made to avoid betalactam antibiotics, except carbapenems, for treatment of infections caused by Enterobacter spp. and the consumption of cephalosporins decreased whereas the consumption of carbapenems increased. The total antibiotic consumption decreased by 2.5% during the study period. There was no correlation between APACHE II scores and antibiotic consumption.

CONCLUSIONS

Each ICU within a hospital ought to have a program for "on-line" antibiotic resistance surveillance of drugs used in that unit so that changes in empirical treatment can be made when there is an increase in antibiotic-resistant isolates within that unit.

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.

Thermal oral-pharyngeal stimulation and elicitation of swallowing

The influence of thermal stimulation of the oral and pharyngeal mucosa on the elicitation of swallowing was studied in 14 healthy volunteers. The Repeated Dry Swallowing Test was used to study the ability to elicit swallows. The test consists of 11 manometrically recorded dry swallows performed at maximum speed. The time between swallows 1 and 11 (Swallowing Test Time) is considered a measure of the ease of eliciting the swallowing reflex. The study includes two controlled experiments, each consisting of an active test done immediately after a cold stimulus and a control done after a stimulus at body temperature. In one experiment the stimulus consisted of stimulation of the fauces with a laryngeal mirror and in the other of swallowing water. Each subject served as his or her own control. The order of the tests was randomized and the results read blindly. In the mirror experiment, the swallowing test times obtained after application of a cold laryngeal mirror did not differ significantly from those obtained after stimulation at body temperature. In the water experiment, swallowing test times were shorter after swallowing cold water compared to those after swallowing water at body temperature in 11 of the 14 volunteers (n.s.). The concept that swallowing is significantly facilitated by cold applied to the oral-pharyngeal mucosa was thus not supported by the present study. The importance of these findings is discussed.

[Does the infectious disease, human ehrlichiosis, exist in Sweden? Ticks get a hold of new zoonoses]

Human ehrlichiosis diseases, decently recognised as emerging human infections in the USA, are caused by vector-borne, strictly intracellular bacteria of the family Rickettsiaceae. Human monocytic ehrlichiosis is caused by Ehrlichia schaffeensis, whereas the agent causing human granulocytic ehrlichiosis (HGE) has yet to be identified [1]. The putative increase in the occurrence of these primary zoonoses is dependent on the complex relationship between the infectious agents, the vectors, and the hosts (rodents, deer) which constitute the wild-life reservoir. In Scandinavia, granulocytic ehrlichiosis is well known in veterinary medicine. Pasture fever in cattle and sheep is caused by Ehrlichia phagocytophila, whereas granulocytic ehrlichiosis in horses and dogs is caused by a new, recently characterised Ehrlichia species [2]. All species of Ehrlichia causing granulocytic ehrlichiosis are closely related both genetically and antigenically, and are all transmitted by ticks of the genus Ixodes. In Sweden, veterinary cases of granulocytic ehrlichiosis are characterised by a geographical distribution corresponding well with that of Ixodes ricinus, and a seasonal distribution similar to that of Lyme borreliosis. In Europe, clinical cases of HGE have so far been reported only from Slovenia [5], though seroprevalence figures of 8-17 per cent have been reported for tick-exposed populations [6, 7]. As most cases are probably subclinical, and as clinical symptoms, when present, are non-specific, clinical diagnosis is dependent on the clinician's awareness of the existence of the disease. Laboratory diagnostic tests are now available at Kalmar.

Hepatitis A vaccination by intracutaneous low dose administration: a less expensive alternative

We investigated the immune response to three different intracutaneous (i.c.) doses of inactivated hepatitis A vaccine: 72, 144, and 216 ELISA units (EU). The response was measured using a quotient score derived from a commercial enzyme-linked immunosorbent assay (HAVAB Abbott) and translated to IU per liter using a World Health Organization standard serum for hepatitis A virus antibody. The results were compared with the results obtained after an intramuscular (i.m.) full dose, i.e. 1,440 EU, at 0 and 6-12 months. As estimated from antibody concentration, 3 lots of 144 EU i.c. with 100% or two lots of 216 EU i.c. with 98% seroconversion results in at least as good early protection as the standard immunization with one lot of 1,440 EU i.m., (79% with our method). Indeed, only two doses of 144 EU vaccine (90% seroconversion) seem to give results comparable to the standard procedure. After the booster dose the median antibody concentration is 1,290 IU/l for the 144 EU vaccine and 837 for the 216 EU one, compared with an antibody response of 990 IU/l for the standard 1,440 EU i.m. vaccination. In conclusion, three doses of 144 EU vaccine i.c. or, as an alternative, two doses of 216 EU at monthly intervals give good early protection (e.g. before travel). After the booster dose, which is given 6 months to 1 year later, the serological response is comparable to the standard procedure of two doses of the 1,440 EU vaccine given i.m. and with 100% seroconversion in all three programs.

Erythromycin in acute laryngitis in adults

Moraxella catarrhalis and Hemophilus influenzae are isolated from the nasopharynx in 50% to 55% and 8% to 15%, respectively, of cases of acute laryngitis in adults. This finding indicates that these organisms, M catarrhalis in particular, are in some way involved in the pathogenesis of the disorder. In the present double-blind, placebo-controlled trial, the effect of erythromycin ethylsuccinate (0.5 g twice a day for 5 days) on the elimination of nasopharyngeal pathogens and reduction of clinical signs of upper respiratory tract infection, as well as on subjective complaints, was evaluated in 106 adults with acute laryngitis. The bacterial isolation rates at presentation were M catarrhalis 50%, H influenzae 18%, and Streptococcus pneumoniae 4%. In the 99 patients who completed the study, the elimination of M catarrhalis after 1 week was better in the erythromycin group (25 of 30 cases) than in the placebo group (6 of 19 cases; p < or = .00038). The elimination of H influenzae was unaffected by erythromycin. Otolaryngologic examination did not reveal any significant group differences regarding laryngitis, pharyngitis, or rhinitis. Voice quality was improved after 1 week, irrespective of treatment. However, as compared to the placebo group, the erythromycin group reported fewer voice complaints after 1 week and fewer coughing complaints after 2 weeks. As acute laryngitis in adults is self-limiting, and subjective symptoms are spontaneously reduced after 1 week in most cases, antibiotic treatment does not seem warranted as a general policy. However, erythromycin may be justified in patients who are professionally dependent on voice function.

Possible role of short-term parenteral nutrition with fat emulsions for development of haemophagocytosis with multiple organ failure in a patient with traumatic brain injury

We describe a case of life-threatening haemophagocytosis after a short term nutrition with fat emulsion in a 21-year-old woman who sustained an isolated traumatic brain injury. Hypertriglyceridemia and "creaming plasma" were observed after a three-day period of parenteral fat nutrition (Intralipid 20%). She also developed rash, high fever (40-41 degrees C), hypertension, raised intracranial pressure, hepatic and renal failure, haemolysis, marked thrombocyto- and leucopenia, coagulation disorder and pulmonary failure. These symptoms, together with a typical bone marrow smear, indicated haemophagocytosis with hyperactivation of the monocyte-macrophage system. We suggest that the hyperactivation was an effect of fat retention or agglutination of the fat particles; the initial triggering mechanism may emanate from the brain damage by hypercytokinaemia. The steroid treatment given most likely contributed to the successful outcome, as indicated by the stepwise improvement related in time to the steroid infusions.

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

In Moraxella (Branhamella) catarrhalis and Moraxella 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 in Branhamella 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 in Moraxella 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.

Production of betalactamase by respiratory tract bacteria in children: relationship to antibiotic use

Sales of antibiotics have increased in Sweden during the past decade. This has been paralleled by an increase in the frequency of beta-lactamase-producing respiratory tract bacteria. To investigate the effects of regional differences in use of antibiotics on beta-lactamase production in respiratory tract bacteria, we collected nasopharyngeal specimens and information about antibiotic use from 1133 children attending day-care centres in four rural municipalities with low use, and one urban municipality with high use of antibiotics, use being assessed from pharmacy sales. The frequency of beta-lactamase production among isolates of Branhamella catarrhalis and Moraxella nonliquefaciens was significantly higher in the urban municipality. This appeared to be a long-term ecological effect of differences in the level of use of antibiotics between the urban and rural populations, rather than an effect of recent antibiotic treatment of individual patients.

Acute laryngitis in adults: results of erythromycin treatment

Previous studies of acute laryngitis in adults have shown high nasopharyngeal isolation rates of B. catarrhalis and H. influenzae. Phenoxymethylpenicillin had no effect on the clinical course. In the present study, 106 patients with acute laryngitis were treated with erythromycin 0.5 g x 2 V or placebo. During the first week the isolation rate of B. catarrhalis was reduced from 60 to 10% in the erythromycin group compared to 34 to 27% in the placebo group (p less than 0.01). The elimination of H. influenzae, isolated in 19% at the acute visit, did not differ between the two groups. As compared to controls, erythromycin treated patients reported significantly lower scores of subjective voice disturbance after 1 week and cough after 2 weeks. Laryngological examination and voice evaluation failed to reveal any differences between the groups.

Diagnosis of psychogenic dysphonia

Background factors, symptoms and signs were analysed in 40 consecutive patients with psychogenic dysphonia. Their voice profile was compared with that of 40 patients with infectious laryngitis. The majority of the patients were young females, non-smokers, who were not professional voice users. Criteria for acute infectious laryngitis prior the voice disorder were met in no more than 10% of the patients. Nevertheless as many as 40% of the patients had been treated with various antibiotics. The prevalence of reported asthma/allergy-like symptoms was high, 37.5%. Perceptual analysis of voice profiles demonstrated similarity of aberrancies in psychogenic dysphonia and in acute laryngitis. Since it may be difficult to distinguish psychogenic dysphonia from acute laryngitis, careful analysis of anamnestic data may be helpful for a correct diagnosis.

Emergence and persistence of beta-lactamase-producing bacteria in the upper respiratory tract in children treated with beta-lactam antibiotics

PURPOSE

To assess the ecologic impact, in terms of selection of beta-lactamase-producing respiratory tract bacteria, of a single course of peroral beta-lactam antibiotics.

PATIENTS AND METHODS

One-hundred fifty consecutive children with clinical signs of bacterial respiratory tract infection were randomly assigned to a seven-day course of treatment with either penicillin V, amoxicillin, or cefaclor. Bacteriologic specimens were collected before treatment, at its termination, and at follow-up four weeks later.

RESULTS

All three drugs investigated caused a similar increase in beta-lactamase-producing bacteria, both in absolute and relative terms, an increase that persisted over a period of at least one month after completion of treatment.

CONCLUSION

Penicillin V, amoxicillin, and cefaclor all act as selective agents for beta-lactamase-producing bacteria in the upper respiratory tract. Treatment with a peroral beta-lactam antibiotic puts patients at risk of becoming persistent carriers of beta-lactamase-producing bacteria.

Evaluation of four qualitative methods for detection of beta-lactamase production in Staphylococcus and Micrococcus species

Four qualitative methods for the detection of beta-lactamase production in Staphylococcus and Micrococcus species were evaluated and compared with a quantitative macroiodometric reference method. The disc diffusion test with penicillin G and the cloverleaf method could not separate beta-lactamase-positive from beta-lactamase-negative strains. Two applications of the chromogenic cephalosporin test, using uninduced strains and strains grown on blood agar plates, gave a large number of false negative and false positive results. False negative reactions were most common among uninduced strains, while the false positive reactions were most often recorded for Staphylococcus saprophyticus. A high degree of efficiency was recorded for the nitrocefin spot test, using induced strains grown on antibiotic susceptibility agar, and for the starch-iodine plate method. The starch-iodine plate with methicillin as inducer gave the most reliable results.

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.

Expression of the myc protooncogene in canine rhabdomyosarcoma

The expression of the protooncogene c-myc in a canine rhabdomyosarcoma was examined. It was found that this highly malignant tumour contained vast quantities of RNA that hybridized with a cDNA probe for c-myc. Restriction fragment length analysis after endonuclease digestion of tumour DNA did not reveal any rearrangements in this gene locus. The potential role of this oncogene in the development of canine rhabdomyosarcoma is discussed.

Beta-lactamase production in the upper respiratory tract flora

In order to determine the recovery rate of species of the genera Haemophilus and Moraxella (including subgenus Branhamella) from the upper respiratory tract and the incidence of beta-lactamase production within these genera, cultures were made of nose and throat swab specimens and adenoid tissue in 50 children undergoing adenoidectomy. Haemophilus influenzae was isolated from 92% of the children. All children harboured strains of Haemophilus spp. and in 46%, at least one strain produced the TEM-1 beta-lactamase. Branhamella catarrhalis and/or Moraxella nonliquefaciens were isolated from 82% of the children and strains producing the BRO-1 beta-lactamase from 34%. Overall, TEM-1 and/or BRO-1 producing strains were recovered from 60% of the investigated patients. The beta-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 mediating beta-lactamase production in the upper respiratory tract.

Upper respiratory tract infections. Ecological and therapeutic aspects of beta-lactamase production with special reference to Branhamella catarrhalis

Available data indicate that the most common beta-lactamase produced by Branhamella catarrhalis is plasmid mediated. The same enzyme occurs in Moraxella nonliquefaciens, a commensal in the upper respiratory tract. The ability to produce the enzyme, which is known as BRO-1, can be transferred by conjugation from M. nonliquefaciens to B. catarrhalis. Since the first beta-lactamase-producing strains of B. catarrhalis appeared in 1977, the frequency of beta-lactamase production has increased rapidly; figures as high as 76% have been reported. The plasmid-mediated beta-lactamase TEM-1 occurs in several species of the genus Haemophilus. While the frequency of beta-lactamase production in H. influenzae is reported to be 10-15%, the incidence is significantly higher in non-pathogenic Haemophilus species. Both phenoxymethyl-penicillin and ampicillin promote the occurrence of beta-lactamase-producing strains, but the selective pressure exerted by ampicillin seems to be more pronounced. It may be possible to reduce the ecological effects of the penicillins by avoiding overdiagnosis of the most common bacterial infections of the respiratory tract, and by shortening the courses of antibiotic treatment.

Plasmid-mediated beta-lactamase in Branhamella catarrhalis

The plasmid-mediated beta-lactamase in Branhamella catarrhalis (BRO-1), also occurring in Moraxella nonliquefaciens, differs from other known plasmid-mediated beta-lactamases in Gram-negative bacteria regarding substrate profile and isoelectric point. B. catarrhalis strains previously reported to produce beta-lactamases deviating from BRO-1 were tested, and the beta-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 beta-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 beta-lactamase-producing as well as in beta-lactamase-negative strains of B. catarrhalis and M. non-liquefaciens, provided that the excessive nuclease activity in the preparations was inhibited.

Serological identification of Branhamella catarrhalis. Serological evidence for infection

A protein antigen--P-antigen--characteristic of Branhamella catarrhalis has been described. Precipitating antibodies against this antigen occur in a majority of healthy human sera; serological evidence for a pathogenic role of B. catarrhalis is accumulating. The occurrence of complement-fixing antibodies has been demonstrated during bronchopulmonary infection with B. catarrhalis and in maxillary sinusitis. Increases in antibody titres assessed by an enzyme-linked immunosorbent assay (ELISA) technique have been reported in children with acute otitis media. An ELISA, using purified P-antigen, for the evaluation of IgG, IgM and IgA antibodies against B. catarrhalis is being developed.

Binding of aggregated human serum albumin to M12 and some other types of group A streptococci

In radiobinding tests many group A, C and G streptococci react with IgG and IgA, irrespective of the antigen-combining sites, as well as with various other serum proteins, e.g. human serum albumin (HSA). The present study demonstrated that glutaraldehyde-aggregated, radiolabelled HSA (a*HSA), in comparison to monomeric HSA, binds more avidly to streptococci. Of group A streptococci, strains representing types M6, M12, M18, M46, M55 and M57 displayed pronounced binding of a*HSA whereas a number of other serotypes were non-reactive. The streptococcal sites involved proved to be relatively heat-resistant and highly sensitive to trypsin treatment. Human fibrinogen counteracted the binding of a*HSA. The uptake by M12 was inhibited strongly by rabbit antiserum raised against M12, whereas other antisera were less active. The results suggest that the bacterial structure binding a*HSA is a protein and that, in at least one serotype, M12, the binding occurs to the M-protein.

Characterization of the plasmid-mediated beta-lactamase in Branhamella catarrhalis, with special reference to substrate affinity

The plasmid-mediated Branhamella catarrhalis beta-lactamase BRO-1, also found in Moraxella nonliquefaciens, was characterized as regards substrate profile, isoelectric point and relative substrate affinity index (RSAI) to various substrates and compared in these aspects with the TEM-1 enzyme of Haemophilus influenzae. As measured by a biological assay and with high performance liquid chromatography (HPLC), BRO-1 was found to hydrolyse carbenicillin, mecillinam, methicillin and cefaclor with a higher rate than TEM-1. The only substrates having a relative rate of hydrolysis higher for TEM-1 than for BRO-1 were ampicillin and cephaloridine. The rates of hydrolysis registered with these two methods were comparable for all but 2 of 13 tested substrates. Isoelectric focusing yielded a main band at pH 5.6 and several satellite bands consistent with those reported by other authors for Branhamella enzymes having a substrate profile similar to that of BRO-1. A tenfold or higher difference in RSAI between BRO-1 and TEM-1 was recorded for five of the 15 compounds tested. BRO-1 seems to be the most common beta-lactamase in Bran. catarrhalis, irrespective of geographic origin. Its substrate profile, isoelectric pattern and RSAI differ from those of other known plasmid-mediated beta-lactamases described, thus justifying a specific designation.

Inefficacy of penicillin V in acute laryngitis in adults. Evaluation from results of double-blind study

Patients with acute laryngitis following an upper respiratory tract infection are often treated with antibiotics for their voice complaints, although, to our knowledge, the effect of such therapy has not been examined. In the present study, comprising 100 adults with laryngitis, the rate of resolution of vocal symptoms, as estimated from voice recordings or subjectively by the patients, was the same in patients who received penicillin V (pcV) as in those who received placebo. Similarly, the degree of rhinorrhea/nasal congestion and cough was not significantly influenced by pcV treatment. At the acute visit, nasopharyngeal cultures revealed Branhamella catarrhalis in 50%, Hemophilus influenzae in 15% and Streptococcus pneumoniae in 1% of the patients; the rate of elimination of these bacteria was the same in the pcV as in the placebo group. Thus, while suggesting that B catarrhalis and H influenzae are important for the pathogenesis of the disorder, our results do not provide support for the use of pcV in acute laryngitis.

Poly-L-arginine and an N-formylated chemotactic peptide act synergistically with lectins and calcium ionophore to induce intense chemiluminescence and superoxide production in human blood leukocytes. Modulation by metabolic inhibitors, sugars, and polyelectrolytes

Various cationic polyelectrolytes (poly-alpha-amino acids and histones), lectins, the chemotactic peptide, f-methionyl-leucyl-phenylalanine (fMLP), the calcium ionophore A23187, and phorbol myristate acetate (PMA) were investigated regarding their capacity to induce luminol-dependent chemiluminescence (LDCL) and superoxide production by human blood leukocytes. Although when tested individually, poly-L-arginine (PARG), phytohemagglutinin (PHA), concanavalin A (Con A), or fMLP induced only a low to moderate LDCL response, very intense synergistic CL reactions were obtained by mixtures of PARG + PHA, PARG + Con A, PARG + PHA + fMLP, Ca2 + ionophore + PARG + PHA + fMLP, and PARG + PMA. The sequence of addition of the various agents to WBC in the presence of luminol absolutely determined the intensity of the LDCL signals obtained, the highest reactions being achieved when the WBC were preincubated for 2-3 min with A23187 followed by the sequential addition of fMLP, PARG, and PHA. These "multiple hits" induced CL reactions which were many times higher than those obtained by each factor alone. On the other hand, neither poly-L-lysine, poly-L-ornithine, poly-L-histidine, nor poly-L-asparagine, when employed at equimolar concentrations, cooperated efficiently with PHA and fMLP to trigger synergistic LDCL responses in leukocytes. Concomitantly with the induction of LDCL, certain ligand mixtures also triggered the production of superoxide. The LDCL which was induced by the "cocktail" of agents was markedly inhibited by sodium azide (93% inhibition), but to a lesser extent by catalase (10% inhibition) or by superoxide dismutase (20%-60% inhibition). On the other hand, scavengers of singlet oxygen and OH (sodium benzoate, histidine) did not affect the synergistic LDCL responses induced by these multiple ligands. Cytochalasin B also markedly inhibited the LDCL responses induced either by soluble stimuli or by streptococci preopsonized either with histone or with polyanethole sulfonate. The LDCL responses which were induced by mixtures of PARG and concanavalin A were also strongly inhibited by mannose, alpha-methyl mannoside, and poly-L-glutamic acid. The data suggest that the LDCL responses induced by the soluble ligands involved a myeloperoxidase-catalyzed reaction. The possible employment of "cocktails" of ligands to enhance the bactericidal effects of PMNs, macrophages, and natural killer cells on microbial cells and mammalian targets is discussed.

Cationic polyelectrolytes, liquoid and leukocyte extract modulate the binding of IgG to group A streptococcal Fc-receptors

Various polyelectrolytes were investigated regarding their capacity to inhibit the binding of human IgG to Fc-receptors on group A streptococci, type M1. Of cationic substances, protamine and arginine-rich histone inhibited significantly, while lysine-rich histone, concanavalin A, lysozyme, polymyxin B, ribonuclease and tuftsin did not. Of anionic materials, liquoid was inhibitory, in contrast to chondroitin sulphate, dextran sulphate, DNA and heparin. Washing experiments showed that the inhibition was caused by binding of the polyelectrolytes to the streptococci. The finding that heated IgG inhibited the binding of histone to the streptococci also indicated a close relation between the binding sites for these compounds. Diffusion-in-gel experiments with alkaline extract of M1 demonstrated that the substances blocking the IgG Fc-receptor were bound to polyglycerophosphate, suggesting that the inhibition of the IgG uptake was due to interaction with lipoteichoic acid. Leukocyte and platelet extracts could modify the binding of IgG, probably by an enzymatic digestion of the receptors. The arginine-rich histone was also capable of inhibiting the binding of IgG to type M15 group A streptococci and to one group G strain. However, the polyelectrolytes had no effect on the binding of IgG to Staphylococcus aureus or of IgA to type 4 group A streptococci.

Quantitation of M antigen in Lancefield extracts of group A streptococci type 12 using electro-immuno assay

Anti-type 12 serum incorporated in agarose-polyethylene glycol gel in a concentration of 1.5% (vol/vol) was found to enable a distinct "rocket" precipitate in electro-immuno assay using hot hydrochloric acid extract of type 12 group A streptococci. This precipitate was removed by trypsin treatment of the extract and on addition of anti-M12 typing serum but not of five other typing sera to the extract. The streptococcal component responsible for this precipitate was eluted from a CM-cellulose ion exchange column at pH 6.5. These findings demonstrated that the precipitate was caused by the M12 antigen. Crossed immuno-electrophoresis of hot hydrochloric acid extracts of three different type 12 group A streptococci showed that the electrophoretic mobility of the M12 antigens was similar in the three extracts. A linear correlation was obtained between the concentration of the M12-antigen and the height of the precipitate obtained in the electro-immuno assay using different dilutions of a standard type 12 extract. M12 antigen could thus be quantitated by the electro-immuno assay. In quantitation experiments, uniformly prepared extracts of five randomly selected, freshly-isolated type 12 strains were found to contain from 130 to 1850% of M12 antigen, respectively (expressed in % of the content of the standard type 12 extract).

A protein antigen characteristic of Branhamella catarrhalis. Serological identification of the genus

Precipitation patterns of sonicated, acid-extracted and other extracts from Branhamella catarrhalis were examined by double diffusion-in-gel technique, using antiserum to B. catarrhalis. Acid extract gave rise to 4 distinct precipitates. One of these lines was further studied. The bacterial component responsible for this line was trypsin-sensitive, indicating that it was a protein. It was anodally localized by crossed immunoelectrophoresis. By absorption of antiserum with whole bacteria, the precipitating capacity of the serum was diminished, suggesting that the protein antigen (P-antigen) was exposed on the bacterial surface. F(ab')22-fragments of IgG from antiserum, but not from normal rabbit serum, precipitated the P-antigen, indicating that it was a true antigen-antibody reaction. It was possible to make an IgG preparation monospecific for the P-antigen, by absorbing antiserum with trypsinized bacterial extract. 31 strains of B. catarrhalis, 9 strains of N. gonorrhoeae, 10 strains of N. meningitis, 12 other Neisseria spp. and 2 strains of H. influenzae were investigated for presence of cros-reacting surface antigens, using IgG monospecific for the P-antigen and 125I-labelled protein A from Staphylococcus aureus. After antibody exposure, all 31 strains of B. catarrhalis showed abundant uptake of protein A. No significant uptake was detected on any other investigated strain. Hence, the P-antigen appears to be characteristic of B. catarrhalis. The possibility of a serological identification of the species is introduced. Precipitating antibodies against the P-antigen were demonstrated in 69% of normal human sera.