G. Wewalka

Borrelia transfer by ticks during their life cycle: Studies on laboratory animals

Ticks of the species Ixodes ricinus were cultured in the laboratory. Yellow silver rabbits, gerbils and white mice served as blood hosts. Borrelia burgdorferi could be detected by means of an IFA test in homogenates of female ticks, their eggs as well as the respective larval and nymphal ticks. Blood infection of splenectomized gerbils and ordinary white mice or of ordinary white mice alone has been demonstrated after feeding of larval or nymphal ticks on them, respectively. Spirochetemia started 5 to 8 days after feeding and lasted for ca 3 weeks. Two distinct peaks in the cell count of spirochetal organisms per ml blood plasma could be observed on days 11-13 (5 X 10(5) to 2 X 10(6) cells/ml) and 17-19 (10(5) cells/ml), regardless whether splenectomized gerbils or white mice were used. The results display that B. burgdorferi is vertically from the female ticks to their eggs and transstadially transmitted. The transmission-rate from larval to nymphal ticks is 100%. These findings show the tick itself as a main reservoir of B. burgdorferi. The established mouse-model appears to be a useful tool to detect Borrelia carrying ticks.

Epidemiology of borrelia infections in Austria.

From April 1984 to July 1985 873 cases of Borrelia infections were registered at the Hygiene Institute of the University of Vienna. 2609 serum samples of these patients were investigated for antibodies against B. burgdorferi by means of IFA- and ELISA-tests. Erythema chronicum migrans (ECM) was recognized in 60.9% of patients, neurological abnormalities were recorded in 23.4% of which the majority manifested themselves as polyradiculitis and meningopolyneuritis (MPN). Acrodermatitis chronica atrophicans (ACA) was recognized in 11.5%. A small number of patients suffered from Lymphadenosis cutis benigna (LCB), arthritis and cardiac abnormalities. Sixty percent of patients were females and 40% males. Infections were found in all age groups ranging from 2-83 years in females and 1-85 years in males. Tick- or insect-bites prior to the onset of illness were reported by 47.2% and 15.6% of patients, respectively. The main vector is the hard tick Ixodes ricinus. Flying insects from the family tabanidae, i.e. Chrysops caecutiens and Haematopota species, must also be considered as transmitters. Antibodies to B. burgdorferi were found in 22.3%, 93.6% and 100% of sera from patients with ECM, MPN and ACA, respectively. Six of 11 patients with LCB and all with arthritis and cardiac abnormalities showed serologic reactivity. Geographically, Borrelia infections are distributed in all states of Austria. The seasonal distribution of cases show a peak in July and August, but the onset of clinical manifestation could be observed throughout the year. These results present Austria as an area where tick- or insect-borne Borrelia infections are very frequent and endemic in all Austrian states.

Isolation of spirochetes from the skin of patients with erythema chronicum migrans in Austria

Spirochetal organisms were isolated from biopsies (skin punches) of the erythematous anular skin lesion of three patients with erythema chronicum migrans. The organisms were cultivated in modified Kellys medium and - after an incubation period of 2 weeks - discovered by dark field microscopy (X 200). Compared with the Lyme disease agent Borrelia burgdorferi the organisms did not differ in shape, motility and reaction with polyclonal antiserum. Differences to B. burgdorferi were found in (i) very slow growth of the isolated organisms in modified Kellys medium and in (ii) non reactivity with monoclonal antibodies against the outer membrane protein of B. burgdorferi. It is concluded that the Austrian isolates are closely related to but not identical with the Lyme disease agent.

Austrian hard ticks as vectors of Borrelia burgdorferi, overview

Hard ticks or members of the family Ixodidae are represented by about sixteen different species in Austria (Tab. 1). Most of them are specialized and can be found only on a distinct group of host species such as birds, bats, carnivores and others. Some species are less distinct concerning their host range and the most common and wide spread tick species of Austria and as well of Central Europe is Ixodes ricinus. If the flag dragging method for tick collection is used, all three developmental stages, larvae, nymphs and adults of this species can be found nearly exclusively. Ixodes ricinus has an unusually broad ecological spectrum concerning its occurrence in many different plant associations and prefers dense structured brushwood in cov-

Indirect immunofluorescence assay (IFA), microagglutination test (MA) and enzyme-linked-immunosorbent assay (ELISA) in diagnosis of legionellosis.

Lipopolysaccharide was extracted with cold phenol water from Legionella pneumophila and used as antigen for ELISA. IgG and IgM antibodies were measured with the ELISA and the immunofluorescence assay (IFA). Agglutinating antibodies were measured by the microagglutination (MA) test. In tests on sera from 27 patients with confirmed Legionella infections predominantly due to L. pneumophila serogroup 1 the results with the ELISA, the IFA and the MA were compared to each other. Antibody titers obtained by the ELISA were in general much higher than those obtained by both other tests. The ELISA proved to be the most sensitive method (IgG: 91.3%, IgM: 52.2%) whereas the sensitivities of IFA and MA were IgG: 69.6%, IgM: 30.4% and 60.9%, respectively. There was low correlation of the IgG antibody titers but good correlation of the IgM titers. Further 49 sera from patients without Legionella infection were screened to calculate the specificities of the three tests which were equally good with all methods (98%).

Der Patient als Keimquelle in der Intensivpflegestation

Zusammenfassung133 Patienten einer Intensivpflegestation, die bei der Aufnahme keine Symptome bakterieller Infektion zeigten und noch keine Antibiotika erhalten hatten, wurden nach dem Zufallsprinzip zwei Gruppen zugeordnet. Eine Gruppe (+Pat.) erhielt eine Antibiotikaprophylaxe mit Penicillinen oder Cephalosporinen, die zweite Gruppe (−Pat.) erhielt keine Antibiotika. Staph. aureus war bei „−Pat.“ im Trachealsekret und in der Umgebung der häufigste potentiell pathogene Keim. Staph. aureus war im Trachealsekret und in der Umgebung der „−Pat.“ signifikant häufiger als bei „+Pat.“. Klebsiella spp. standen im Trachealsekret und in der Umgebung von „+Pat.“ an erster Stelle. Sie waren im Trachealsekret von „+Pat.“ signifikant häufiger als bei „−Pat.“. In der ersten Woche des Stationsaufenthaltes traten bei „+Pat.“ starke Veränderungen in der Keimflora der Trachealsekrete auf: die Besiedelung mit gramnegativen Keimen stieg auf fast 100% an, gleichzeitig ging die Frequenz von Staph. aureus zurück. In den Abklatschuntersuchungen aus der Patientenumgebung traten gramnegative Stäbchen bei „+Pat.“ in signifikant höheren Koloniezahlen auf als bei „−Pat.“. Die paarweisen Vergleiche von Bakterienstämmen aus den Trachealsekreten und aus der Patientenumgebung ergaben, daß „+Pat.“ gramnegative Keime und „−Pat.“ Staph. aureus signifikant häufiger an die Umgebung abgaben. Auf die Kontamination der Patientenumgebung mit Staph. aureus wirkte sich der Faktor der trachealen Intubation nicht aus. Gramnegative Keime waren im Trachealsekret von intubierten Patienten signifikant häufiger als bei nicht intubierten. Derselbe Trend zeigte sich auch in der Patientenumgebung. Die Antibiotikaprophylaxe konnte, wie die klinischen Ergebnisse der Studie zeigten, die Patienten nicht im erwarteten Ausmaß vor Infektionen schützen. Patienten, insbesondere tracheal-intubierte, die Antibiotika erhalten, sind als Streuquellen für hochresistente gramnegative Keime anzusehen.Summary133 patients in an intensive care unit, who prior to admission had not shown any signs of bacterial infection and had not received antibiotic treatment, were assigned to two groups at random. One group received antibiotic prophylaxis with penicillins or cephalosporins (+Pat.), the other group did not receive antibiotics (−Pat.). Staph. aureus was the most frequent facultative pathogen in tracheal secretions and in the environment of „−Pat.“. This organism was significantly more frequent in „−Pat.“ than in „+Pat.“ in both the tracheal secretions and the enviroment. Klebsiella spp. outnumbered all other species in „+Pat.“. They were significantly more frequent in tracheal secretions of „+Pat.“ than of „−Pat.“. In the first week of hospitalisation marked changes were seen in bacterial flora of tracheal secretions of „+Pat.“. Colonization with gramnegative bacteria rose to nearly 100%, the frequency of Staph. aureus diminishing at the same time. Monitoring by contact cultures revealed that gramnegative rods were significantly more numerous in the environment of „+Pat.“ than of „−Pat.“. Matching bacterial strains cultured from tracheal secretions and from the environment of the patients proved that „+Pat. spread significantly higher numbers of their gramnegative bacteria into the environment. The same is true of „−Pat.“ for Staph. aureus. Intubation had no noticeable effect on the degree of contamination of the surroundings with Staph. aureus. Gramnegative rods were significantly more frequent in tracheal secretions of patients with intubation than in patients without. The same trend was observed for environmental contamination. As the clinical results of this study have shown, antibiotic prophylaxis does not protect patients from infections to the extent expected. Patients, and particularly intubated patients, receiving antibiotic treatment have to be considered as sources of highly resistant gramnegative organisms.

Infant Tuberculosis in Austria- Trend Reversal since 1990?

SummarySince 1990 a relatively high number of cases of childhood tuberculosis has been observed in Austria, mainly occurring in the age-group of 0–4 years. Within this group most cases were registered in 1995. Since the beginning of 1995 the establishment of a lab-supported nationwide data collection system enables a more detailed recording of the cases diagnosed. Out of the 85 cases with infant tuberculosis registered in 1995 and 1996, 66 were diagnosed with pulmonary manifestation. In 45 cases tuberculosis was proven by culture. In nine (20%) of these cases the most likely route of infection has appeared to be direct transmission from an adult in the same household suffering from culture proven tuberculosis in the same year. For three of the cases the DNA of the isolatedMycobacterium tuberculosis strains from the adult and the infant was typed using RFLP analysis. In each case identical strains could be demonstrated.

Testing for aerobic heterotrophic bacteria allows no prediction of contamination with potentially pathogenic bacteria in the output water of dental chair units

Background: Currently, to our knowledge, quality of output water of dental chair units is not covered by specific regulations in the European Union, and national recommendations are heterogeneous. In Germany, water used in dental chair units must follow drinking water quality. In the United States of America, testing for aerobic heterotrophic bacteria is recommended. The present study was performed to evaluate whether the counts of aerobic heterotrophic bacteria correlate with the presence of potentially pathogenic bacteria such as Legionella spp. or Pseudomonas aeruginosa. Methods: 71 samples were collected from 26 dental chair units with integrated disinfection device and 31 samples from 15 outlets of the water distribution pipework within the department were examined. Samples were tested for aerobic heterotrophic bacteria at 35°C and 22°C using different culture media and for Legionella spp. and for Pseudomonas aeruginosa. Additionally, strains of Legionella pneumophila serogroup 1 were typed with monoclonal antibodies and representative samples of Legionella pneumophila serogroup 1 were typed by sequence based typing. Results: Our results showed a correlation between different agars for aerobic heterotrophic bacteria but no correlation for the count of aerobic heterotrophic bacteria and the presence of Legionella spp. or Pseudomonas aeruginosa. Conclusion: Testing for aerobic heterotrophic bacteria in output water or water distribution pipework within the departments alone is without any value for predicting whether the water is contaminated with potentially pathogenic bacteria like Legionella spp. or Pseudomonas aeruginosa.

Sero-Epidemiology of Legionellosis in Austria

Out of 1961 patients with the clinical diagnosis of atypical pneumonia 11 cases (0.65%) of recent Legionella infections were diagnosed by indirect immunofluorescence test (IFA). A higher incidence (1.37%) has been found in 364 patients in whom clinicians suspected a Legionella infection and therefore asked for serological testing. Prevalence of antibodies (greater than or equal to 1:32) reacting with antigens of L. pneumophila serogroup 1 to 6 was highest to serogroup 6 (37%), and lowest to serogroup 1 (4.3%). Specificity of IFA for reciprocal titer of 128 to L. pneumophila serogroup 1 was calculated with 99.5%, for serogroup 6 with only 87.7%. Morbidity of severe Legionella pneumonias in Austria can be estimated at about 1.5 cases per 100 000 inhabitants.

Antibiotikakonzentrationen im Wundsekret und im Knochen bei gleichzeitiger Gabe von Mezlocillin und Oxacillin

ZusammenfassungEine Kombination von Mezlocillin und Oxacillin wurde für die antibiotische Kurzzeitprophylaxe bei alloarthroplastischen Operationen eingesetzt. Antibiotikakonzentrationen wurden aus dem Serum, dem Wundsekret, der tiefen Redon-Drainage und aus Knochen bestimmt. Eine halbe Stunde nach kombinierter Gabe von 4 g Mezlocillin +2 g Oxacillin i. v. betrugen die Wundsekretspiegel 20% der entsprechenden Serumspiegel. Nach vier Stunden waren die Wundsekretspiegel angestiegen und lagen für Mezlocillin 2,66mal und für Oxacillin 5,37mal höher als die Serumspiegel. Nach acht Stunden waren die Wundsekretspiegel circa auf die Hälfte abgesunken, befanden sich aber immer noch weit im antimikrobiell wirksamen Bereich. Der parallele Konzentrationsverlauf von Mezlocillin und Oxacillin im Wundsekret deutet darauf hin, daß die beiden Antibiotika trotz unterschiedlicher Serumhalbwertszeiten (t 50% ß) sehr ähnliche Halbwertszeiten im Wundsekret besitzen. Die Knochenkonzentrationen in der Spongiosa machten ein bis zwei Stunden nach Antibiotikainfusion circa 10% der Serumspiegel aus.SummaryMezlocillin and oxacillin have been used in combination for short-term antibiotic prophylaxis in orthopedic surgery. Antibiotic concentrations were measured in serum, wound secretions from subcutaneous tubings and bone. Half an hour after the i. v. application of 4 g mezlocillin +2 g oxacillin, the concentrations in wound secretions were 20% of the serum levels. After four hours the levels of both antibiotics in wound secretions increased to 2.66 times the serum levels of mezlocillin, and 5.37 times those of oxacillin. After eight hours the concentrations in wound secretions dropped to about one half, but remained well within therapeutic levels. The parallel course of the concentrations of both antibiotics in wound secretions indicates that mezlocillin and oxacillin have very similar half-lives in wound secretions, although the serum half-lives (t 50% ß) of the two antibiotics are different. The concentrations obtained from cancellous bone were approximately. 10% of the serum levels one to two hours after the antibiotic infusion.Mezlocillin and oxacillin have been used in combination for short-term antibiotic prophylaxis in orthopedic surgery. Antibiotic concentrations were measured in serum, wound secretions from subcutaneous tubings and bone. Half an hour after the i. v. application of 4 g mezlocillin + 2 g oxacillin, the concentrations in wound secretions were 20% of the serum levels. After four hours the levels of both antibiotics in wound secretions increased to 2.66 times the serum levels of mezlocillin, and 5.37 times those of oxacillin. After eight hours the concentrations in wound secretions dropped to about one half, but remained well within therapeutic levels. The parallel course of the concentrations of both antibiotics in wound secretions indicates that mezlocillin and oxacillin have very similar half-lives in wound secretions, although the serum half-lives (t 50% beta) of the two antibiotics are different. The concentrations obtained from cancellous bone were approximately. 10% of the serum levels one to two hours after the antibiotic infusion.