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The Haemophilus influenzae R plasmids specifying resistance against one, two, or three antibiotics which have emerged in different parts of the world were shown to have closely related but not identical plasmid cores. The gene for ampicillin resistance in the H. influenzae plasmid pKRE5367 is part of a transposon similar to Tn3, which was transposed from pKRE5367 onto RSF1010 in Escherichia coli. An indigenous H. influenzae plasmid (pW266) was isolated. Its properties correspond to those of the H. influenzae R plasmids, except for the presence of a drug resistance transposon. The in vitro-generated H. influenzae R plasmids carrying an ampicillin resistance transposon, a tetracycline resistance transposon, and a transposon for combined tetracycline-chloramphenicol resistance resembled the natural isolates. The findings support the hypothesis that the R plasmids of H. influenzae are of multiclonal evolutionary origin.

The isolation and characterization of the hepatitis A virus (HAV) and the hepatitis B virus (HBV) resulted in great advances in the serological diagnosis and the prophylaxis. About 20% of the viral hepatitis cases are caused by the HAV. The hepatitis A never becomes chronic and can be diagnosed by the detection of HAV antibodies of the IgM type. The HBV is the etiologic agent in 60% of the hepatitis cases and 10% of these become chronic. It is possible to immunize against the HBV and to reduce the number of neonatal infections.

Virulence of Yersinia enterocolitica O:8 is associated with pO:8, a 42-megadalton plasmid. We constructed a mobilizable pO:8 derivative by successive in vitro and in vivo genetic manipulations. The in vitro constructed hybrid molecule pRK290B8-5 consisting of the mobilizable vector pRK290B and a 2.9-megadalton BamHI fragment of pO:8 was conjugally transferred to a Y. enterocolitica strain of serotype O:8 which harbored the virulence plasmid pO:8. From Yersinia transconjugants, a cointegrate was isolated which apparently formed by homologous recombination between the two component plasmids. The cointegrate was mobilized into plasmidless Y. enterocolitica strains of different serotypes. The transconjugants of serotype O:8 were found to express all four plasmid-associated phenotypes: (i) mouse lethality (Ml), (ii) conjunctivitis provocation in the guinea pig eye (Con), (iii) calcium requirement for growth at 37 degrees C (Mox), and (iv) agglutinogens (Ag8). The transconjugants of serotype O:3 expressed the phenotypes Con, Mox, and Ag8 but were nonlethal for mice (Ml-). The transconjugants of serotype O:5 remained avirulent for mice (Ml-) and for the guinea pig eye (Con-) but expressed the phenotypes Mox and Ag8. These data show that the virulence plasmid is probably not functionally interchangeable within different serotypes of Y. enterocolitica.

The periods of persisting immunoglobulin M class antibodies to hepatitis B core antigen in 28 patients with acute hepatitis B infections and in 134 patients with chronic hepatitis B infections were studied by using an enzyme-linked immunosorbent assay and an indirect immunofluorescence technique. We showed that the clearance of antibodies to hepatitis B core antigen is independent of the degree of viremia in both forms of hepatitis.

The acquired immunodeficiency syndrome (AIDS) is caused by a retrovirus. LAV/HTLV-III is mainly transmitted by blood and sperm. More than 90% of the newly infected persons belong to four risk groups: male homosexuals, drug addicts, persons with multiple changing sex partners, and bisexuals. Infected individuals carry the virus and antiviral antibodies simultaneously in their blood. The antibodies can be demonstrated by the ELISA and immunofluorescence tests, but positive and questionable test results must be confirmed by the immunoblot. Not all of the persons carrying the virus will develop clinical symptoms, but the percentage of those suffering from severe illnesses rises with time and reaches 40% after 8 years. At present, there is no effective therapy and no vaccine will be ready in the near future. Therefore, it is necessary to take all precautions possible to prevent new infections.

Mobilizable virulence plasmids of Yersinia enterocolitica of serotypes O:3 and O:9 were constructed by cointegration of a mobilizable vector into the virulence plasmids. The obtained cointegrates were mobilized into plasmidless Y. enterocolitica strains of serotypes O:3, O:5, O:8, and O:9. The transfer experiments revealed the existence of two different subgroups of plasmid-associated traits. (i) Animal virulence functions (mouse lethality and conjuctivitis provocation) were only transferable to plasmid-cured derivatives of virulent parent strains (serotypes O:3, O:8, and O:9), but they were not transferable to Y. enterocolitica antigen reference strains (serotypes O:3 and O:8) or to a plasmidless clinical isolate of serotype O:5. A further striking result was that a serotype O:8 strain regained the mouse lethality trait after receipt of a plasmid from a strain not lethal to mice. These results demonstrate that plasmid-mediated animal virulence functions are not uniformly expressed within Y. enterocolitica. (ii) The second subgroup of plasmid-mediated traits (calcium dependency, surface agglutinogens, HEp-2 cell adherence, and protein release) were transferable to all Y. enterocolitica recipient strains tested (serotypes O:3, O:5, O:8, and O:9 of different origin). For the first time HEp-2 cell adherence and temperature-induced release of five major protein species are described as transferable traits.

Die schutzenden Antikorper bei der Hepatitis B sind jene, die sich gegen die Oberflache des Virus richten. Dies ist auch von anderen Virusinfektionen her bekannt. Wir wissen, das die Hulle des Hepatitis B-Virus und das HBs-Antigen molekularbiologisch identisch sind. Antikorper, die sich gegen das HBs-Antigen richten, binden also mit der Oberflache des Hepatitis B-Virus und haben schutzenden Charakter, weil das infektiose Agens nun nicht mehr von der Zielzelle aufgenommen werden kann.

Die medizinische Mikrobiologie hat sich seit der Isolierung des Erregers der Infektionskrankheit Aids im Jahr 1983 intensiv mit der Frage befast, wie das humane Immundefi-zienzvirus (HIV) ubertragen wird und welche Infektionsrisiken fur Arzte, fur Schwestern und Pfleger und fur andere bei der medizinischen Versorgung von Infizierten beteiligten Personen bestehen. Um es vorwegzunehmen, wir konnen heute feststellen, das das Infektionsrisiko fur die genannten Personengruppen auserordentlich klein ist, etwa 100fach geringer als das Risiko, sich mit einem Hepatitis-Virus zu infizieren. Es ist — gottlob — bis zum heutigen Tag noch nicht berichtet worden, das sich ein Chirurg bei seiner Berufstatigkeit mit dem Aids-Virus infiziert hatte oder andererseits HIV positive Chirurgen durch ihre operative Tatigkeit Patienten infiziert hatten.

Screening the contacts of a 33-year-old father with acute hepatitis B virus (HBV) infection revealed that this four-year-old adopted son was a persistent HBV carrier with massive viremia. The infection did not occur until they had been in contact for three and a half years. Serological findings from the wife, daughter and one of the children's playmates indicated previous hepatitis B infections which had been healed with a positive immune response. It is highly probable that the son induced these infections. The history of the child with persistent HBV infection as well as the clinical course indicate a perinatally acquired HBV infection. To prevent this infection from spreading further, seven playmates with an average age of five years were actively vaccinated against hepatitis B. The success of this vaccination was compared to a control group of adults. After applying the vaccine three times at four-week intervals, the seroconversion to anti-HBs occurred earlier and the antibody titres were higher in the children. 71% of the children had produced anti-HBs after the first vaccination compared to only 13% of the adults (mean age: 33 years). The rate of seroconversion was 100% for the children after the second vaccination, compared to only 93% for the adults four to six weeks after the third vaccination.

Humoral antibodies can be induced in cotton topped (CT) marmosets with killed Herpesvirus saimiri (HVS) vaccines. The serum antibodies delayed, but did not prevent, malignant lymphoma in actively and passively immunized monkeys after inoculation with 10(3.8)TCID50 of cell-free HVS. Experiments are in progress to determine whether the vaccines are able to protect against smaller challenge dosages of HVS. The immunized monkeys were not resistant against transplantation of tumor cells. Infection with Epstein-Barr virus (EBV) and Marek's disease virus (MDV) did not protect against the tumors caused by superinfection with HVS. Attenuation of HVS was not achieved by passaging the HVS genome through different monkey species.

A double immunofluorescence staining technique is described for differentiation between cell-attached (extracellular) and ingested (intracellular) bacteria by HEp-2 cells in cell culture monolayers. This method is based upon the observation that membranes of viable mammalian cells are impermeable for antibodies but are rendered permeable by treatment with fixatives. Consequently, extracellular bacteria can be stained by specific rhodamine-labeled antibodies before fixation, and intracellular bacteria can be visualized by treatment with specific fluorescein-labeled antibodies after fixation. The accuracy and simplicity of this method is demonstrated with HEp-2 cell culture monolayers as target cells and an isogenic pair of Yersinia enterocolitica, one of which is phagocytosis resistant and the other of which is phagocytosis sensitive. Furthermore, it is shown that this staining technique is also applicable for studying the interaction of bacteria with macrophages and fibroblasts.

Isolates of Staphylococcus aureus and Staphylococcus epidermidis frequently harboured extrachromosomal DNA. From the 20 Staphylococcus aureus strains examined 85% contained extrachromosomal DNA and 65% carried more than one plasmid DNA species. The results obtained with the 19 Staphylococcus epidermidis strains analyzed were similar, 84% of the strains had extrachromosomal DNA and 68% contained several DNA species. The agarose gel electrophoresis of the DNA obtained from cleared lysates of the staphylococci proved to be efficient for the detection of plasmids and the determination of their molecular weights. The gel method appeared therefore to be suitable for the establishment of the role of plasmids in the phage typability of staphylococci. Using a Staphylococcus epidermidis strain as an example it was shown by electron microscopy that the extrachromosomal DNA demonstrated by the agarose gel electrophoresis represented covalently closed circular plasmid DNA. This plasmid DNA could be sufficiently labeled with 3H-thymidine to undertake studies on the relationship and molecular characterization of staphylococcal plasmids.

In the period between 1983 and 1987 autopsies were carried out on 120 drug victims at the Institute for Forensic Medicine in Hamburg, and 93 cases were serologically tested for hepatitis B. It was found that 50 cases (54%) were positive for anti-HBc, 39 (42%) for anti-HBs, and 5 cases (5%) for HBsAg. The prevalence of hepatitis-B-virus markers was dependent upon the age of the victims. In 81% inflammatory alterations of the liver (including unspecific reactive hepatitis) were diagnosed histologically. The pathogenesis of these serological and pathomorphological findings is discussed. Drug addicts are a group at risk for hepatitis B, and it can spread on account of the epidemiological connection with other risk groups, e.g., prostitutes and homosexuals. Postmortem serological investigations for hepatitis markers proved to be a well-established and reproducible means of differentiating histopathological liver alterations.

Methicillin resistance is usually not detected by routine laboratory methods. With the aid of a method that facilitates in vitro detection of methicillin resistance 8.6% of our Staph. aureus strains and 42% of the coagulase-negative staphylococci proved to be resistant towards this antibiotic.

53 persons at high risk for hepatitis B infection have been vaccinated with a hepatitis B vaccine produced in the Hygiene Institute of the University of Göttingen. The vaccine proved to be without side effects in all vaccinees. Only minor complaints at the site of inoculation were registered. Three vaccinations are necessary. Protective antibodies were present in 96% of the vaccinees after the third inoculation. The female vaccinees developed anti HBs earlier than the males, moreover they showed significantly higher antibody titers. A simultaneous active and passive immunization is possible. To minimize the risk of contracting a hepatitis B or a non A- non B hepatitis as a result of the vaccination only such vaccines should be used which have been prepared from sera containing anti-HBe and which have been inactivated with a high dose of formaldehyde.

The association of Campylobacter pyloridis with antrum gastritis and peptic ulcers was described. We investigated antral biopsies from 180 patients who underwent gastroscopy. By culture or Gram stain or both, we found overall 98 (54%) of them to be positive for C. pyloridis. In the various groups the following percentages were found to be positive: normal antral mucosa 3% (n = 30); moderate superficial antrum gastritis, 49% (n = 83); severe superficial antrum gastritis, 86% (n = 44); duodenal ulcer, 83% (n = 54); and gastric ulcer, 72% (n = 18). A serological screening that used a complement fixation test yielded the following results: highest rates of positive complement fixation titers were seen in patients with severe gastritis and those with duodenal ulcers, both with 79%; the lowest incidence was in a group of 20 blood donors, with 5%. Positive complement fixation titers in gastritis patients also correlated well with characteristic patterns on immunoglobulin G and A immunoblots, while there was no specific reactivity observed on immunoglobulin M immunoblots.

Ampicillin-resistant Haemophilus influenzae does occur now in the FRG. In one isolate a plasmid with resistance genes (R-factor) could be demonstrated as cause of the ampicillin resistance. This R-factor influences production of a beta-lactamase of the TEM type which destroys ampicillin. The infectious nature of the ampicillin resistance was proven by the fact that it was transferable to other bacterial species through cocultivation. Parallel to ampicillin resistance tetracycline resistant Haemophilus influenzae has occurred in the FRG. Here the resistance was equally bound to plasmids. These R-factors are infectious as well. Molecular analysis of the 3 isolated resistance factors in Haemophilus influenzae showed that they carry the same resistance genes which are known from R-factors of Enterobacteriaceae. In the therapy of purulent infections due to Haemophilus influenzae such as childhood meningitis one can no longer rely on general ampicillin sensitivity of the offender. Apart from ampicillin and tetracycline resistant Haemophilus influenzae chloramphenicol resistance has been observed in a few cases.

Sera from 367 patients presumed to have NANB hepatitis were screened for reverse transcriptase activity. In 29 cases significantly increased enzyme activities could be observed. In contrast, sera from 338 patients did not contain significant reverse transcriptase activities. 207 healthy individuals, 7 patients with hepatitis A and 6 patients with hepatitis B who served as controls were all negative for reverse transcriptase activity. The specificity of the enzyme assay was demonstrated by estimation of reverse transcriptase activity in sera from 10 "healthy" HIV-1-antibody positive individuals. In 3 out of 10 cases significant reverse transcriptase activity was observed associated with the human immunodeficiency virus. Our results indicate that the presence of particle-associated reverse transcriptase activity in serum from patients with NANB hepatitis is indicative of the presence of a retrovirus-like agent in these cases. However, the relatively low prevalence of reverse transcriptase positive cases associated with the NANB hepatitis makes it rather questionable whether this agent is a frequent and specific factor in the etiology of NANB hepatitis.

Killed herpesvirus cancer vaccines were prepared by inactivation of oncogenic herpesviruses (Herpesvirus saimiri and Herpesvirus ateles) with heat and formaldehyde. The killed vaccines, which are not free of viral nucleic acid, were safe in 121 vaccinated monkeys of 4 different species. Some of these monkeys have now been under observation for 2 years. The vaccines induced high titers of specific humoral antibodies in all vaccinated monkeys. The killed vaccines proved to be efficient against the i.m. challenge with cell-free oncogenic herpesviruses. The challenged animals remained clinically well without signs of an infection and have now been under observation for 1 year, while the nonvaccinated control monkeys died of malignant lymphoma 34 to 52 days after inoculation. The protection against H. saimiri could be passively transmitted with the serum of the vaccinated monkeys. The vaccination did not prevent but delayed tumor development after tumor cell transplantation. The resistance against the oropharyngeal route of infection remains to be determined.

Perinatal transmission of hepatitis B virus does not occur before the beginning of labor. Therefore, neither an embryopathy nor a fetopathy appears to be caused by an acute or chronic HBV infection during pregnancy. There is no necessity to interrupt pregnancy for the reason of a HBV infection. Transmission of HBV infection, however, may take place during delivery. By simultaneous administration of hepatitis B immunoglobulin and the HBV vaccine to the newborn infant directly after birth, perinatal infection with HBV can be prevented. This immunization procedure leads to a rapid and efficient anti-HBs response in the newborn comparable to that of adults. Protection against HBV infection by passive immunization is sufficient until active anti-HBs antibody formation is starting. The hepatitis B vaccine consists of the purified non-infectious surface of the HB virus. Due to the physical purification and chemical inactivation of the hepatitis B surface antigen (HBsAg) from human sera, the vaccine is considered to be safe. It is not harmful and exhibits an excellent compatibility in newborn infants.

A recombinant vaccine against hepatitis B derived from yeast cells (Gen-HB-Vax, Co. MSD/Behring) has been evaluated in 59 healthy young volunteers (37 men, 22 women) with an average age of 24.4 years. The seroconversion rate was 100%, and no major side effects were observed. During a follow-up period of 24 months concentrations of antibodies against HBsAg were shown to decline to one tenth within 16 to 17 months. Triple vaccination led to protective antibody titres for about 27 months on average. Based on these findings we suggest the following recommendations concerning revaccination: an anti-HBs titre of more than 10,000 mIU/ml four weeks after third vaccination should be reassessed 3-5 years later, and titres between 1000 and 10,000 mIU/ml after 2-3 years. A control of the antibody titre should be performed after 1-2 years if the titre is 200-1000 mIU/ml after the third vaccination, and after 6-12 months if it is 100-200 mIU/ml. Antibody titres between 10 and 100 mIU/ml should already be reassessed about 3-6 months later. We recommend an immediate revaccination for persons with anti-HBs titres below 10 mIU/ml. This corresponds to the course of antibody concentrations which could be seen in former studies with the conventional serum-derived vaccine. Maximum anti-HBs titres are slightly below those observed with the serum-derived vaccine.

Two strains of Vibrio parahaemolyticus were isolated from stool specimens of a patient who came down with gastroenteritis 20 hours after eating imported mussels which had not been cooked sufficiently. This is the first documented case of V. parahaemolyticus enteritis acquired in the Federal Republic of Germany.

HERPESVIRUSES are the most important candidates for human cancer agents. The Epstein–Barr virus (EBV) in particular is suspected of being the causal agent in Burkitt's lymphoma and nasopharyngeal carcinoma1. Immunological principles, well understood from vaccine prophylaxis of viral diseases, provide the potential for the eventual control of herpesvirus-induced neoplasia. The development of safe and efficient cancer vaccines with the human candidate herpesviruses is, however, difficult, as there are no reliable in vitro or experimental animal methods for detecting oncogenic potential in preparations which might be applicable to the human subject. We are studying the problems of herpesvirus cancer vaccines in non-human primates. Two members of the herpesvirus family, H. saimiri (HVS) and H. ateles (HVA), induce malignant lymphoma and leukemia in several New World monkey species2,3. HVS-induced lymphoma in cotton topped (CT) marmoset monkeys (Saguinus oedipus) has been used in this study as all monkeys inoculated with HVS regularly develop malignant lymphoma within two months4,5. This investigation describes the effect of a killed herpesvirus cancer vaccine in protecting non-human primates against malignant lymphoma.