Climate deteriorations and Neanderthal demise in interior Iberia.

Time and circumstances for the disappearance of Neanderthals and its relationship with the advent of Modern Humans are not yet sufficiently resolved, especially in case of the Iberian Peninsula. Reconstructing palaeoenvironmental conditions during the last glacial period is crucial to clarifying whether climate deteriorations or competition and contacts with Modern Humans played the pivotal role in driving Neanderthals to extinction. A high-resolution loess record from the Upper Tagus Basin in central Spain demonstrates that the Neanderthal abandonment of inner Iberian territories 42 kyr ago coincided with the evolvement of hostile environmental conditions, while archaeological evidence testifies that this desertion took place regardless of modern humans' activities. According to stratigraphic findings and stable isotope analyses, this period corresponded to the driest environmental conditions of the last glacial apart from an even drier period linked to Heinrich Stadial 3. Our results show that during Marine Isotope Stages (MIS) 4 and 2 climate deteriorations in interior Iberia temporally coincided with northern hemisphere cold periods (Heinrich stadials). Solely during the middle MIS 3, in a period surrounding 42 kyr ago, this relation seems not straightforward, which may demonstrate the complexity of terrestrial climate conditions during glacial periods.

High prevalence of genetically diverse Borrelia bavariensis-like strains in Ixodes persulcatus from Selenge Aimag, Mongolia.

In Mongolia, Lyme borreliosis was first reported in 2003. To determine which Borrelia species may contribute to the occurrence of Lyme borreliosis in Mongolia, real-time PCR was conducted on 372 adult Ixodes persulcatus ticks collected in Selenge Aimag, the province with the highest incidence of human Lyme borreliosis. 24.5% of ticks were identified to be positive for Borrelia burgdorferi sensu lato DNA. Species differentiation using an SNP-based real-time PCR and multi-locus sequence analysis revealed that strains phylogenetically closely related to B. bavariensis (previously known as B. garinii OspA serotype 4) is the most prevalent species, showing an unexpectedly high genetic diversity.

An extraordinary endocytobiont in Acanthamoeba sp. isolated from a patient with keratitis.

In the present article, the detection and the development of a parasitic endocytobiont within host amoebae (Acanthamoeba sp.) recently isolated from the contact lens and the inflamed eye of a patient with keratitis is presented. An otherwise healthy 55-year-old female patient presented with keratitis in her inflamed left eye. She was a contact lens wearer and had no history of a corneal trauma. Acanthamoebae as well as other smaller free-living amoebae could be detected from the fluid of the contact lens storage cases by culture methods. A successful therapy could be provided consequently. Two of these Acanthamoeba strains showed intracellular aggregating organisms. Within 2 to 3 days, the host amoebae ruptured, and numerous microorganisms were released. We succeeded in detecting the mechanism of infection and intrusion of this organisms by using light and electron microscopy. Infection with this endocytobiont is a suitable model for studying the host-parasite relations while the parasites use their hosts as so-called Trojan horses (see Barker, Lambert, Brown, Infect Immun 61:3503-3510, 1992).

Telemicrobiology: a novel telemedical module for mission support in the field of infectious medicine.

Infectious diseases are among the most common diseases suffered by soldiers while serving in missions away from their home countries. The diagnosis of theses diseases requires special procedures and expertise, both of which are provided by field microbiological laboratories. In order to support the diagnostic process by means of telemedicine, a modification of the standard telemedicine workstation, i.e. a telemicrobiology module with special equipment, camera and software, has been designed and validated. This module, currently in use in two operational theaters, has stood the test in routine practice. It enables the transmission of high-quality static images of microscopic specimens or overgrown nutrient media in a matter of seconds. The inclusion of experts into diagnostic analysis through the use of telemedicine improves diagnostic specificity by avoiding false positive results and, particularly in medical parasitology, allows a treatment-essential diagnosis without the dispatch of specimens to Germany. Telemicrobiology allows the control of the entire microbiology diagnostic process by expert workstation even with only a microbiological technician on site.

Endocytobiont KC5/2 induces transformation into sol-like cytoplasm of its host Acanthamoeba sp. as substrate for its own development.

New investigations of a novel, recently described, non-cultivable endocytobiont of Acanthamoeba sp. reveal at least three hitherto unobserved developmental stages which shed some light on the nature of this peculiar organism. The development of the endocytobiont is closely connected with conspicuous changes in the host amoeba, inducing the transformation from gel to sol-like cytoplasm which bulges like a balloon inside the host cell. Young and transitory developmental stages were found within the homogenous, sol-like cytoplasm. The infectious stages, with their voluminous cell wall and a conspicuous ostiole, could be observed within all parts of the cytoplasm with the exception of the nucleus. It is a remarkable adaptation for this parasite to be able to induce this gel-sol transformation in order to facilitate its own development. The fate of the heavily infected host amoebae is death by rupture or lysis after being overcrowded with parasites. As no structures could be observed within the endoparasites that were comparable to other bacteria, the real nature and taxonomic position of these peculiar organisms remain obscure.

Gingivitis in young adults with Actinobacillus actinomycetemcomitans.

High intraoral load of A. actinomycetemcomitans in subjects with no or minimal periodontal disease may induce subtle changes in clinical periodontal conditions. The aim of the present study was to compare, at a site level, clinical conditions in two groups of young adults with plaque-induced gingivitis. In one group, more than 20% subgingival sites harboured cultivable A. actinomycetemcomitans (n=9), whereas in the other group, the organism was present in 20% or fewer subgingival plaque samples (n=8). Whereas no overt differences in clinical conditions could be ascertained, on average, the association between the presence of subgingival plaque and bleeding upon probing was considerably stronger (Mantel-Haenszel's common odds ratio RMH and 95% confidence interval 3.903, 2.951-5.165, P<0.001) in subjects with only a few subgingival sites harbouring A. actinomycetemcomitans as compared to subjects with a widespread intraoral distribution of the organism (R(MH)=1.637, 1.226-2.184, P<0.001). Since the proportion of sites not bleeding upon probing in the presence of supragingival plaque was slightly elevated in these subjects, the present findings may suggest a suppressed inflammatory reaction on supragingival plaque in the presence of a pronounced intraoral load of A. actinomycetemcomitans.

Intraoral distribution of Actinobacillus actinomycetemcomitans in young adults with minimal periodontal disease.

The aim of the present study was to investigate the intraoral distribution of Actinobacillus actinomycetemcomitans in young adults with minor signs of periodontal disease but harboring the organisms in the oral cavity. 17 healthy volunteers, 20 to 27 years of age, participated. Samples from mucosal surfaces of the oro-pharyngeal cavity and saliva (n = 221) as well as subgingival plaque from every tooth (n =477) were selectively cultivated for A. actinomycetemcomitans. Species identity and presence of the leukotoxin encoding gene, ltxA, were checked by multiplex polymerase chain reaction. Moreover, the leukotoxin promoter region was analyzed. No isolate harbored a 530 bp deletion in the promoter region of the leukotoxin gene, signaling minimally toxic strains. 42.1 +/- 30.4% extracrevicular and 34.4 +/- 29.5% subgingival samples were culture-positive. In extracrevicular samples, the organism could easily be recovered from cheek mucosa (62%), saliva (59%) and the palatal tonsils (41%). Mean log-transformed numbers of A. actinomycetecomitans colony forming units (CFU/ml) in culture-positive material ranged between 1.8 from the hard palate and 2.3 from 10 microl saliva. The highest prevalence in subgingival plaque was observed at maxillary 3rd molars (55%) followed by maxillary lateral incisors (50%) and mandibular 3rd molars (41%). Mean log-transformed counts of CFU/ml ranged between 2.2 at maxillary 3rd molars and 3.4 at upper central incisors. When adjusted for jaw, site and tooth type, the odds of isolating higher numbers of the organism were increased with every mm probing depth by a factor of 1.35 (p <0.05). The odds ratio for bleeding on probing was 1.38. Thus, in this young adult population with minor periodontal disease, A. actinomyetemcomitans was mainly associated with some deviation from gingival health. Of concern might be a minority of subjects (29%) with an extremely wide distribution of the organism in the oral cavity.

Clonal diversity of Actinobacillus actinomycetemcomitans isolates from young adults with minimal periodontal disease.

Actinobacillus actinomycetemcomitans is a major periodontal pathogen which is associated with both early-onset periodontitis and adult cases refractory to conventional periodontal therapy, although the organism has also been shown to be widely distributed among dentate healthy individuals. The observed disease status may be associated with a variation in virulence of different strains or clones. The aim of the present study was to analyse genotype distribution as assessed by an arbitrarily primed polymerase chain reaction (AP-PCR) among 51 isolates of A. actinomycetemcomitans recovered from more than 200 young adult recruits with no or minor periodontal disease. In addition, isolates from 25 periodontitis patients as well as reference strains were genotyped. Primers amplifying (i) a specific sequence in the ltxA region, (ii) a specific 16S rRNA sequence and (iii) sequences in the leukotoxin promoter region were used to verify species identity of the strains. Three random oligonucleotide primers were employed to analyse genomic polymorphisms of the organism by means of PCR. A total of 19 genotypes could be distinguished, which were grouped by cluster analysis into 5 major clusters based on genetic similarity and a complete linkage sort. Whereas 3 clusters assembled A. actinomycetemcomitans genotypes isolated from both healthy subjects and periodontitis patients, one cluster containing 4 different genotypes exclusively comprised isolates from healthy or gingivitis subjects. Another cluster with 2 genotypes consisted of strains originating from periodontitis patients (p < 0.05). One strain characterized by a specific 530 bp deletion in the promoter region of the leukotoxin region was identified in a Ghanese patient with localized juvenile periodontitis. It was concluded that there is considerable clonal diversity of A. actinomycetemcomitans strains isolated from healthy or periodontally diseased subjects, and that genetically closely related groups might be associated with health or disease.

Absence of an especially toxic clone among isolates of Actinobacillus actinomycetemcomitans recovered from army recruits.

Actinobacillus actinomycetemcomitans is a major periodontal pathogen which is associated with early-onset and adult periodontitis. The organism has been shown to be widely distributed among dentate, healthy individuals as well. It has been demonstrated that A. actinomycetemcomitans shows great genetic diversity. An especially virulent clone of the organism (JP2-like) with a specific 530-base pair (bp) deletion in the promoter region of the leukotoxin gene has been isolated from localized juvenile periodontitis patients and related subjects of African and African-American origin. The aim of the present study was to examine the presence of this specific clone employing specific oligonucleotide primers in a polymerase chain reaction among 51 isolates of A. actinomycetemcomitans recovered from 201, 18- to 25-year-old recruits with no or minor periodontal disease. In addition, clinical isolates from 37 periodontitis patients were analyzed as well as reference strains ATCC 29524, NCTC 9710, Y4 and JP2. Primers amplifying a specific 285-bp amplification product in the ltxA region of the leukotoxin gene and a specific 547-bp amplification product of 16 S rRNA were used to genetically confirm identification of the organisms. Primers amplifying sequences in the leukotoxin promoter region were used to identify the deletion. Species specific primers definitively identified all A. actinomycetemcomitans isolates. No isolates from army recruits or the reference strains displayed the deletion in the leukotoxin promoter region. However, in the periodontitis group, a 24-year-old individual from Ghana with localized juvenile periodontitis was identified with an intraoral infection with highly toxic A. actinomycetemcomitans (JP2-like). Present results confirm previous observations of absence of a highly toxic clone of A. actinomycetemcomitans among periodontally healthy and diseased Caucasians as well as a possible presence in localized juvenile periodontitis in individuals of African origin.

A major antigenic domain of hantaviruses is located on the aminoproximal site of the viral nucleocapsid protein.

Hantavirus nucleocapsid protein has recently been shown to be an immunodominant antigen in hemorrhagic with renal syndrome (HFRS) inducing an early and long-lasting immune response. Recombinant proteins representing various regions of the nucleocapsid proteins as well as segments of the G1 and the G2 glycoproteins of hantavirus strains CG18-20 (Puumala serotype) and Hantaan 76-118 have been expressed in E. coli. The antigenicity of these proteins was tested in enzyme immunoassays and immunoblots. These studies revealed that human IgG immune response is primarily directed against epitopes located within the amino acid residues 1 to 119 of the amino terminus of viral nucleocapsid proteins. This fragment was recognized by all HFRS patient sera tested (n = 128). The corresponding enzyme immunoassays proved to be more sensitive than the indirect immunofluorescence assays. Furthermore, the majority of bank vole monoclonal antibodies raised against Puumala virus reacted specifically with this site. A recombinant G1 protein (aa 59 to 401) derived from the CG 18-20 strain was recognized by 19 out of 20 sera from HFRS patients.

A longitudinal study of Actinobacillus actinomycetemcomitans in army recruits.

During recruiting examinations 201 recruits, 18-25 yr old, were examined for subgingival and extracrevicular Actinobacillus actinomycetemcomitans. The organism was isolated in 55 subjects, most often at low levels. Cluster analysis revealed 3 clusters with no (A, n = 86) or minor (B, n = 92) periodontal disease and low DMF-S, as well as established periodontitis, increased D + DF-S and high DMF-S (C, n = 22). When leaving the 12-months' service, 105 recruits were re-examined (54 cluster A, 41 cluster B, 9 cluster C subjects, 1 recruit who was not clustered). An increase of periodontal probing depth (PPD) of > or = 3 mm at 1 or more sites occurred in 33 subjects: 9 (17%) in cluster A, 16 (39%) in cluster B, 7 (78%) in cluster C and in the not-clustered recruit. Considerable variation in frequency distributions of PPD alterations was observed, therefore significant (p < 0.1) mean increase (1-sample t-test) and skew g1 (S-statistic) were additionally considered to define an "active" case. A total of 7 recruits (6.7%) met the criteria. Logistic regression analysis revealed a significant influence of self-reported smoking habits on activity status. Thus, heavy smokers (> 20 cigarettes/d) had a 14-fold higher risk (p = 0.030) for developing or progressing periodontitis compared to non- or light smokers (< 10 cigarettes/d). In particular, cluster B recruits appeared to have a lower risk (p = 0.11) for developing periodontitis than cluster C recruits (established periodontitis, high DMF-S). A. actinomycetemcomitans was isolated in 29 recruits (27.6%) at baseline and 30 recruits (28.6%) after 12 months. Presence of the organism was not a risk factor for periodontitis. However, in active subjects, significantly more samples were only A. actinomycetemcomitans-positive at re-examination compared to inactive recruits. It was concluded that smoking is a significant risk factor for periodontitis. Subjects with established periodontitis tend to deteriorate further. A. actinomycetemcomitans seems not to increase the risk for developing or progressing periodontitis in this age group. Longer studies involving larger populations are needed to confirm these observations.

Natural distribution of oral Actinobacillus actinomycetemcomitans in young men with minimal periodontal disease.

A total of 1005 subgingival and extracrevicular samples from 201 male recruits, 18-25 yr old, were selectively cultivated for Actinobacillus actinomycetemcomitans. The organism was isolated in 55 subjects (27%); 9.5% of pooled subgingival plaque samples from first molars, 14% cheek mucosa, 20% dorsum of tongue and 20% saliva samples were culture-positive. In order to divide the study population into distinct clinical categories, cluster analysis was performed, based on previous caries experience, probing pocket depth categories, bleeding scores, visible plaque and calculus. Two clusters (n = 86 and n = 92, respectively) were identified with no or minimal periodontal disease (mean +/- standard deviation % of periodontal probing depth 1-2 mm 78.7 +/- 10.4% and 57.4 +/- 12.6%, respectively; virtually no periodontal probing/depth in excess of 4 mm) and a relatively low DMF-S (22 +/- 13). A third cluster (n = 22) had, in contrast, a high DMF-S (47.7 +/- 17.2) and a relatively high % of periodontal pockets of > or = 5 mm (5.9 +/- 5.2%). Prevalence of A. actinomycetemcomitans in this cluster was 41%, while the organism was found in 23% and 27% in the minimally diseased populations (p < 0.15). Whereas no heterogeneity of associations between subgingival and extracrevicular occurrence of the organism could be ascertained in different clusters, the organism was significantly more often identified in extracrevicular material, especially dorsum of tongue samples, compared with subgingival plaque (McNemar's chi2 = 12.45, p < 0.001). Multiple linear regression analysis revealed the number of A. actinomycetemcomitans positive samples as well as the % of sites bleeding on probing being positively associated with the % of sites with a probing pocket depth of > or = 5 mm (R2 = 0.345, p < 0.0001). The present large-scale investigation points to the wide distribution of this putative periodontopathogen in young individuals with minimal periodontal disease.

Potential diagnostic value of sampling oral mucosal surfaces for Actinobacillus actinomycetemcomitans in young adults.

Actinobacillus actinomycetemcomitans has been implicated in the pathogenesis of several forms of early onset and refractory adult periodontitis. Early diagnosis of colonization of the oral cavity might be of importance in order to initiate preventive measures. The aim of the present study was to determine the potential diagnostic value of oral mucosal and salivary tests to identify, among healthy young men with no or minor periodontal disease, individuals colonized by A. actinomycetemcomitans. Two hundred and one male recruits, 18-25 yr of age, took part in the present study. Mean values of periodontal parameters suggested only minor periodontal disease. Of the sites, 64.8 +/- 17.6% (mean +/- SD) had a periodontal probing depth (PPD) of 1 or 2 mm, only 1.6 +/- 2.9% deep sites of > or = 5 mm were detected. More than 1000 subgingival and extracrevicular samples were selectively cultivated for A. actinomycetemcomitans. The organism was isolated in 55 subjects (27%). The odds for presence of at least 1 deep site of 5 mm was increased by a factor 1.99 if A. actinomycetemcomitans, could be recovered. In identifying subjects colonized by A. actinomycetemcomitans, diagnostic test parameters sensitivity and predictive value for a negative test were 74.5 +/- 5.9% and 91.1 +/- 2.3%, respectively, for both saliva and dorsum of tongue samples. In contrast, pooled subgingival plaque from mesial surfaces of 1st molars was only 34.5 +/- 6.4% sensitive; the negative predictive value was 80.2 +/- 3.0%. The results point to a high diagnostic value of oral mucosal and especially saliva samples to identify young adult individuals colonized by A. actinomycetemcomitans.

Seroprevalence of hantavirus antibodies in Germany as determined by a new recombinant enzyme immunoassay.

In order to elucidate the epidemiological importance of hemorrhagic fever with renal syndrome in Germany, the prevalence of antibodies against hantaviruses was determined in 13,358 sera from residents of various geographic regions, 1,284 sera from occupational risk groups and 287 sera from chronic hemodialysis patients. Serological investigations were performed using a highly specific transferable solid phase enzyme immunoassay based on the recombinant nucleocapsid proteins of a Hantaan and a Puumala serotype strain. The overall antibody prevalence was found to be 1.68%. In the serum panels from western and southern Germany, it was determined to be 1.83% on average in contrast to only 0.8% in the panel from eastern Germany. An endemic focus revealing an antibody prevalence of 3.12% was detected in a low-mountain area called Suebian Alb, which is located in the federal state of Baden-Württemberg. Occupational risk groups and a group of chronic hemodialysis patients showed a significantly elevated antibody prevalence ranging from 3.3% to 10%. The Puumala serotype was found to be the prevailing virus, but the percentage of sera predominantly recognizing the Hantaan nucleocapsid protein increased towards the south and the east and was significantly elevated in dialysis patients.

[Pulmonary aspergillosis in an immunocompetent female patient]. / Pulmonale Aspergillose bei einer immunkompetenten Patientin.

Symptoms of bronchopneumonia developed over 4 months in a 63-year-old woman in previously good health. The symptoms worsened despite treatment with tetracycline (500 mg twice daily for 10 days). Middle-lobe pneumonia was diagnosed both clinically and radiologically, but monotherapy with ofloxacin (200 mg twice daily) was ineffective, as well as combined treatment with gentamycin (80 mg), oxacillin (1 g) and azlocillin (5 g), each three times daily intravenously. Bronchoscopy revealed obstruction of the lumen of the right middle lobe bronchus by viscous purulent secretion which contained a high count of Aspergillus fumigatus, previously found in several sputum samples. The inflammatory process regressed completely within 12 days on itraconazole (200 mg twice daily), combined with nystatin inhalation (100,000 IU five times daily). The only possible aetiologically significant risk factor in this immunocompetent woman could have been her frequent use of a bio-waste container.

Baculovirus expression of the nucleocapsid protein of a Puumala serotype Hantavirus.

Recombinant baculoviruses were generated harboring the entire coding region of the S segment cDNA of Hantavirus strain CG 18-20 that belongs to the Puumala serotype. The recombinant nucleocapsid protein was expressed in Sf9 cells and shown to be antigenically identical with the authentic viral nucleocapsid protein by means of immunoblot analysis. Acute-phase and convalescent sera from European HFRS patients recognized the recombinant nucleocapsid protein in Western blots and the recombinant Baculovirus in indirect immunofluorescence assays. Insect cells infected with the recombinant Baculoviruses proved to be a suitable noninfectious substitute for Hantavirus-infected Vero E6 cells as an antigen source for immunodiagnostic assays allowing the detection of antibodies in HFRS patients.

Western blot as a tool in the diagnosis of Lyme borreliosis.

Borrelia burgdorferi is the causative agent of Lyme borreliosis, a multisystem disorder, which can mimic numerous immune disorders and inflammatory diseases. Laboratory diagnosis of Borrelia infection relies on immunodiagnostic assays, which, however, are hampered by unsatisfactory specificity. The Western blot technique has been employed to analyze the humoral immune response in Lyme borreliosis and is used as a serodiagnostic confirmation test. The most important immunodominant proteins of Borrelia burgdorferi are the 94 kDa, 60 kDa, 41 kDa (flagellin), 34 kDa (Osp B), 31 kDa (Osp A), 30 kDa, 21 kDa (Osp C), and 17/18 kDa proteins. Whereas the 60 kDa, 41 kDa, and 34 kDa constituents reveal a marked cross-antigenicity with other spirochetes and even more distantly related bacteria, antibodies against the 94 kDa, 31 kDa and 21 kDa proteins are largely species-specific. The early immune response in Lyme borreliosis is triggered mainly by the flagellin. In the later stage a wide range of immunogenic proteins is involved, with the 94 kDa antigen being the best marker for late immune response. If the Western blot is used for diagnostic purposes the differences between early and late-stage immunogenicity of Borrelia proteins must be taken into account. Interpretation criteria for blot positivity in early-stage borreliosis are primarily based on the presence of the 21 kDa band and the semiquantitatively recorded intensity of the 41 kDa band. In the diagnosis of late-stage infection, blot positivity relies on the presence of the 94 kDa, 39 kDa, 31 kDa, 30 kDa and 21 kDa bands.

Humoral immune response against Helicobacter pylori as determined by immunoblot.

An immunoblot method has been evaluated to diagnose Helicobacter pylori infection serologically by comparing 69 serum specimens from patients with a positive Gram stain and/or culture result and a positive urease test on biopsy material, as well as 51 serum specimens from patients with at least 4 negative urease tests, and negative microscopy and culture results. Sensitivity and specificity was found to be 100%. Recognition of the cross-reacting flagellin (66 kDa), flagellar sheath protein (51 kDa), and a 14 kDa protein are not a criterion for a current H. pylori infection. On the other hand, any combination of at least two of the 180, 120, 90, 75, 67, 29.5 and 19 kDa bands were diagnostic of infection. Three H. pylori strains, which were compared with both gel electrophoretic analyses and immunoblot reactivity, exhibited in part strong qualitative and quantitative differences that particularly affect the 120 kDa pathogenic factor, the large urease subunit and other proteins especially in the molecular mass range from 50 to 67 kDa. IgG immunoblot patterns showed that the choice of H. pylori strain, as well as a reproducible and standardizable antigen preparation, is of great importance for the reliability of serodiagnostic tests. The immunoblot method was found to be a valuable tool for the semi-quantitative confirmation of results achieved with other serological methods as well as optimization and quality control of the antigens used for serodiagnostic purposes.