Molecular epidemiological typing of Neisseria gonorrhoeae isolates identifies a novel association between genogroup G10557 (G7072) and decreased susceptibility to cefixime, Germany, 2014 to 2017

BackgroundEmerging antimicrobial resistance (AMR) challenges gonorrhoea treatment and requires surveillance.AimThis observational study describes the genetic diversity of Neisseria gonorrhoeae isolates in Germany from 2014 to 2017 and identifies N. gonorrhoeae multi-antigen sequence typing (NG-MAST) genogroups associated with AMR or some patient demographics.Methods1,220 gonococcal isolates underwent AMR testing and NG-MAST. Associations between genogroups and AMR or sex/age of patients were statistically assessed.ResultsPatients' median age was 32 years (interquartile range: 25-44); 1,078 isolates (88.4%) originated from men. In total, 432 NG-MAST sequence types including 156 novel ones were identified, resulting in 17 major genogroups covering 59.1% (721/1,220) of all isolates. Genogroups G1407 and G10557 (G7072) were significantly associated with decreased susceptibility to cefixime (Kruskal-Wallis chi-squared: 549.3442, df: 16, p < 0.001). Their prevalences appeared to decline during the study period from 14.2% (15/106) to 6.2% (30/481) and from 6.6% (7/106) to 3.1% (15/481) respectively. Meanwhile, several cefixime susceptible genogroups' prevalence seemed to increase. Proportions of isolates from men differed among genogroups (Fisher's exact test, p < 0.001), being e.g. lower for G25 (G51) and G387, and higher for G5441 and G2992. Some genogroups differed relative to each other in affected patients' median age (Kruskal-Wallis chi-squared:  47.5358, df:  16, p < 0.001), with e.g. G25 (G51) and G387 more frequent among ≤ 30 year olds and G359 and G17420 among ≥ 40 year olds.ConclusionAMR monitoring with molecular typing is important. Dual therapy (ceftriaxone plus azithromycin) recommended in 2014 in Germany, or only the ceftriaxone dose of this therapy, might have contributed to cefixime-resistant genogroups decreasing.

Bacterial sexually transmitted infections

Worldwide, the incidence of bacterial sexually transmitted infections (STIs) has shown a significant increase in recent years. In Germany, this circumstance is reflected by a rise in the number of reported syphilis cases. There has also been an uptick in the incidence of non-notifiable STIs such as gonorrhea and infections caused by Chlamydia trachomatis and Mycoplasma genitalium. A key factor in the spread of these infections is their varied clinical presentation, which includes urogenital, pharyngeal and rectal involvement as well as a large number of asymptomatic cases. New real-time multiplex PCR methods allow for rapid and targeted detection of STI pathogens. The most common bacterial STI is urogenital chlamydial infection caused by serovars D-K, which affects young adults in particular. Lymphogranuloma venereum (LGV) caused by L serovars often presents as chlamydial proctitis. In recent years, Neisseria (N.) gonorrhoeae has shown a significant development of resistance, with high-level monoresistance and multiresistance to antibiotics commonly used for treatment. It is therefore imperative that sensitivity testing of N. gonorrhoeae be performed in addition to nucleic acid amplification tests (NAATs). Increased drug resistance has also been observed for Mycoplasma genitalium, a fact that complicates treatment.

Bakterielle sexuell übertragbare Infektionen

Bakterielle sexuell übertragbare Infektionen (STI) zeigen seit Jahren weltweit eine deutliche Zunahme. In Deutschland wird diese Tatsache durch steigende Meldezahlen für Syphilis bestätigt. Auch für die nicht meldepflichtigen STI Gonorrhoe, Chlamydia-trachomatis- und Mycoplasma-genitalium-Infektionen wird eine zunehmende Inzidenz beobachtet. Entscheidend für die Weiterverbreitung ist, dass das breite klinische Spektrum, welches neben Urogenitalsitus auch Pharynx und Rektum einbezieht, durch eine hohe Zahl asymptomatischer Verläufe ergänzt wird. Neue Real-Time-Multiplex-Diagnostikverfahren ermöglichen einen schnellen und gezielten Nachweis von STI-Erregern. Die häufigste bakterielle STI ist die urogenitale Chlamydieninfektion mit den Serovaren D-K, die besonders bei jungen Erwachsenen auftritt. Einer Chlamydien-Proktitis kann eine Infektion mit L-Serovaren und damit eine Lymphogranuloma-venereum (LGV)-Infektion zugrunde liegen. Neisseria (N.) gonorrhoeae zeigte in den letzten Jahren eine starke Resistenzentwicklung mit Ausbildung von Einzel- und Multiresistenzen gegenüber bisher gängigen Antibiotika. Daher ist für N. gonorrhoeae zusätzlich zum nucleic acid amplification test (NAAT) eine kulturelle Empfindlichkeitstestung durchzuführen. Auch für Mycoplasma genitalium sind Resistenzentwicklungen bekannt, die eine Therapie erschweren können.

Antimicrobial resistance of Neisseria gonorrhoeae in Germany: low levels of cephalosporin resistance, but high azithromycin resistance

Background

The widespread antimicrobial resistance of Neisseria gonorrhoeae is a serious problem for the treatment and control of gonorrhoea. Many of the previously effective therapeutic agents are no longer viable. Because N. gonorrhoeae infections are not reportable in Germany, only limited data on disease epidemiology and antimicrobial susceptibility patterns are available. The Gonococcal Resistance Network (GORENET) is a surveillance project to monitor trends in the antimicrobial susceptibility of N. gonorrhoeae in Germany in order to guide treatment algorithms and target future prevention strategies.

Methods

Between April 2014 and December 2015, data on patient-related information were collected from laboratories nationwide, and susceptibility testing was performed on 537 N. gonorrhoeae isolates forwarded from the network laboratories to the Conciliar Laboratory for gonococci. Susceptibility results for cefixime, ceftriaxone, azithromycin, ciprofloxacin and penicillin were defined according to EUCAST 4.0 standards. Percentages, medians and interquartile ranges (IQR) were calculated.

Results

Altogether, 90% of isolates were from men. The median age was 32 (IQR 25–44) years for men and 25 (IQR 22–40) years for women (p-value < 0.001). The most frequently tested materials among men were urethral (96.1%) and rectal swabs (1.7%), and among women, it was mainly endocervical and vaginal swabs (84.3%). None of the isolates were resistant to ceftriaxone. Furthermore, 1.9% (in 2014) and 1.4% (in 2015) of the isolates were resistant to cefixime, 11.9% and 9.8% showed resistance against azithromycin, 72.0% and 58.3% were resistant to ciprofloxacin, and 29.1% and 18.8% were resistant to penicillin.

Conclusions

Resistance to ceftriaxone was not detected, and the percentage of isolates with resistance to cefixime was low, whereas azithromycin resistance showed high levels during the observation period. The rates of ciprofloxacin resistance and penicillin resistance were very high across Germany. Continued surveillance of antimicrobial drug susceptibilities for N. gonorrhoeae remains highly important to ensure efficient disease management.

[Laboratory practices: diagnostics and antibiotics resistance testing of Neisseria gonorrhoeae in Germany]

Recent years have seen a world-wide increase in antimicrobial resistance (AMR) in cases of infection with Neisseria gonorrhoeae (NG). NG infection is not notifiable in Germany and there is a lack of information available about the spread and AMR of NG infections. The objective of the study was to provide information on diagnostic methods and AMR testing in cases of NG infections in German laboratories. A cross-sectional survey was undertaken in Germany between June and August 2013 using an online questionnaire. Laboratories performing NG diagnostics were identified and described with regard to the diagnostic methods used, the number of tests performed, the antibiotics tested and the AMR observed, in addition to general laboratory information. In total, 188 of the 521 participating laboratories performed NG diagnostics; these were included in the further statistical analysis. 92.6 % of the 188 laboratories performed culture. A median of 60 (IQR 15-270) samples per quarter (SPQ) were tested, with an overall positivity rate of 4.1 and 6.9 % among men. Most (82.1 %) of the 151 laboratories performing NG culture tested for AMR as well. The most frequently tested antibiotics were ciprofloxacin (94.8 %), penicillin (93.1 %), doxycycline (70.0 %) and ceftriaxone (67.2 %). The most frequently observed AMR ever were those against ciprofloxacin (87.1 %), penicillin (78.3 %), doxycycline (56.6 %) and azithromycin (35.1 %; all percentages refer to laboratories). The laboratories used different standards regarding susceptibility criteria. The emergence and spread of AMR shows that it is crucial to assess and monitor the scope and trends of multidrug-resistant gonorrhea. The data collected on diagnostic methods and AMR testing in cases of NG infections in German laboratories constitute an important basis for future monitoring.

Erich Langer: the last Jewish dermatologist in Nazi Berlin. 532-41

Nazi anti-Semitism had a considerable impact on dermatology during the period 1933 to 1945. Before World War II, dermatology in German-speaking lands was at the forefront of medicine, and about 25% of the dermatologists were Jewish. Many perished during the Holocaust; others emigrated from Germany and played a major role in advancing dermatology in their new homes, especially in the United States. Erich Langer (1891-1957) was almost unique, because he survived the entire period in Berlin. Langer had been chief of dermatology at Berlin-Britz, a large city hospital, before 1933 but was discharged almost immediately after the Nazi takeover because of his Jewish roots. In June 1945 he returned to his old department and resumed charge. He became one of the key figures in rebuilding German dermatology in the immediate postwar years. He served as first chair of dermatology at the new Free University in Berlin, started two journals, and wrote several books. Until recently, very little was known about Erich Langer's mysterious tale of survival and how he evaded Nazi roundups. Fortunately, we have discovered considerable archival material that has allowed us to piece together, for the first time, a detailed account of Langer's courageous and remarkable story as the last Jewish dermatologist inNazi Berlin.

[Gonorrhea]

Infection with Neisseria gonorrhoeae is a frequent occurrence. It is almost always transmitted via sexual intercourse and the risk of infection is markedly higher for women than for men. Purulent secretion characterizes the clinical picture. After an incubation period of 2-6 days, for the most part urethritis, cervicitis, proctitis, pharyngitis, or conjunctivitis usually develops. Condoms offer good protection against gonococcal infection. The treatment of choice in Central Europe is a single dose of Cefixime.

100�Jahre Entdeckung der Spirochaeta pallida

On 3 March 1905, Fritz Schaudinn, Erich Hoffmann and Fred Neufeld, working in the women's ward of the Department of Dermatology at the Charite Hospital in Berlin, became the first people in the world to observe the causative agent of syphilis, Treponema pallidum. The pathogen's etiological significance was subsequently demonstrated by Schaudinn and Hoffmann and other scientists. The detection of Treponema pallidum was the first decisive step towards the development of diagnostic and therapeutic procedures in subsequent years.

[CD8-positive, CD30-negative cutaneous T-cell lymphoma simulating pyoderma gangrenosum]

Ulcerated primary cutaneous lymphomas are not rare, but the clinical manifestation as a pyoderma gangrenosum look-alike is extraordinary. CD8-positive lymphomas are rare, unclassifiable tumours with variable prognosis. We report on a 49-year-old patient with a large ulcerated primary cutaneous lymphoma on the left chest wall presenting as pyoderma gangrenosum. With immunohistochemical staining, most lymphocytes were shown to be CD8-positive. The CD30 antigen was not expressed. After radiotherapy with complete skin irradiation, the lymphoma regressed completely. The patient has been free of relapse for 28 months so far.

Genital mycoplasmas, including Mycoplasma genitalium, as sexually transmitted agents

Mycoplasmas are the smallest free-living organisms, widespread in nature. Several mycoplasma species have been isolated from humans. For 6 of them: Mycoplasma hominis, Ureaplasma urealyticum, M. primatum, M. genitalium, M. spermatophilum and M. penetrans, the genital tract is the main site of colonization. This review is concentrated on the role of mycoplasmas as sexually transmitted agents, with the emphasis to M. genitalium infections. M. hominis and U. urealyticum are isolated from the genital tract of healthy men and women with considerable frequency. The biological features (attachment properties, possible intracellular location) and experimental inoculation studies of M. genitalium indicate that this mycoplasma has pathogenic potential. Data from case-control studies, looking at men with non-gonococcal urethritis and women with cervicitis, have revealed that M. genitalium behave similarly to Chlamydia trachomatis and have revealed that carriage of M. genitalium and C. trachomatis is usually independent of one another. M. genitalium could be considered as a potential cause of sexually transmitted urethritis in men, including men with persistent or recurrent urethritis. More studies are expected to ascertain the role of M. genitalium in the female genital tract. Evidence-based data are needed to decide whether current non-gonococcal infection treatment principles are applicable or not for M. genitalium infections.

Sexually transmitted diseases in children. A practical approach

Basically, all sexually transmitted diseases occurring in adults can be transmitted to children. Patterns of transmission are as follows: intrauterine, perinatal, by sexual abuse, by voluntary sexual contact, by accidental autoinoculation or heterinoculation, or indirect transmission. In children between 2 and 10 years of age, sexual abuse is first in possible ways of transmission. Taking into consideration the age of the child, the sexually transmittable agent and the localization of the infection helps in assessing the possibility of sexual abuse.

Epidemiological features of Adamantiades-Behçet's disease in Germany and in Europe

The German Registry of Adamantiades-Behçet's disease was founded in 1990 in Berlin and it provides current data on the epidemiology, the clinical manifestations and the course of the disease in Germany on a continuous basis. A total of 218 patients, including 89 German and 100 Turkish patients, had been reported to the German Registry until October 1997. One hundred and ninety-six patients fulfilled the criteria of the Behçet's disease classification tree. The prevalence of the disease evaluated in Berlin-West was 1.68/100,000 in 1989 and had risen to 2.26/100,000 by 1994. The median age of onset was 25 years (range 5 to 66 years; German-Turks, ns). Juvenile disease was recorded in 6.9% of patients. The complete clinical picture according to the criteria of the International Study Group of Behçet's Disease developed in 15.5 months. The interval between onset of the disease and diagnosis was 35 months, which was significantly longer than the duration of the development of the complete clinical picture (p < 0.0001). The disease was diagnosed later in German (48.5 months) than in Turkish patients (25.5 months, p = 0.003). While German patients presented an equal male-to-female ratio, a male predominance was shown in Turkish patients (M:F 2.1:1, p = 0.022). Familial occurrence was detected in 2.0% of German and 15.9% of Turkish patients (p = 0.013). The frequencies of major clinical manifestations were: oral ulcers 99%, skin lesions 76%, genital ulcers 75%, ocular manifestations 59%, arthritis 59%, and positive pathergy test 52%. Clinical differences between German and Turkish patients were only found in the frequency of ocular lesions (48% vs. 66%, p = 0.025). Oral ulcers were with 72% the most common onset symptom of the disease followed by erythema nodosum (9%), uveitis (7%), arthritis (7%), genital ulcers (3%), superficial thrombophlebitis (2%) and papules/sterile pustules (2%). Uveitis and erythema nodosum as onset symptoms shortened the median interval to diagnosis to 1.5 and 15 months, respectively, while arthritis delayed diagnosis (43.5 months; p = 0.029). A severe course developed in 25% of the patients; irreversible retinal vasculitis to blindness in 15%, sterile meningoencephalitis in 8%, severe arthritis in 5%, hemoptysis in 2%, lethal outcome in 2% and bowel perforation in 1%. The relative risk of HLA-B5 positive German natives developing the disease. HLA-B5 was confirmed as a marker of severe prognosis. Cardiolipin autoantibodies were associated with cutaneous vasculitis and superficial thrombophlebitis was correlated with systemic vessel involvement.

[Molecular epidemiology of Neisseria gonorrhoeae: effect of sex and sexual orientation on the distribution of gonococcal types]

Auxotype/serovar (A/S) classification enables precise characterisation of Neisseria gonorrhoeae. In the present study we evaluated whether sex and sexual preference of the patient influence the auxotype/serovar class of the infecting gonococcal strain. In male patients prototrophic/IB-3 was the most frequently isolated A/S class. By contrast, in female patients the A/S class (P)AH(U)/IA-1/2 was significantly (p < 0.005) more frequently isolated than in male patients. Analysis of our data according to sexual preference of the patients showed that in heterosexual patients the two mentioned A/S classes were leading, whereas in homo- and bisexual patients A/S classes prototrophic/IB-2 (p < 0.0001) and Pro/IB-2/16 (p < 0.0001) were isolated significantly more often. Our data are a strong indication that the host environment is also responsible for the selection of N. gonorrhoeae strains with certain typing characteristics.

Epidemiology of sexually transmitted diseases. What does it tell us?

Incidence numbers of Neisseria gonorrhoeae, Treponema pallidum and Chlamydia trachomatis differ substantially in different countries at different times. In European countries, the incidence of gonorrhea and of primary and secondary syphilis currently is extremely low. In North American countries gonorrhea incidence declined at a very slow annual rate and syphilis incidence increased. Chlamydial infections show a profile that seems to be delayed by two decades from infections with Neisseria gonorrhoeae. Our efforts in the future should be directed to prevent the resurgence of gonorrhea and syphilis and to achieve the same success with chlamydial infections. Poor populations in developed and developing countries, which have similar demographic, social and economic characteristics, represent one important target group for control programs. Education of young and poor people represent the challenge of the future for sexually transmitted diseases control strategies. Combined strategies also will have an effect on incurable viral STD.

[Molecular epidemiology of Neisseria gonorrhoeae: typing with combined auxotype/serovar classification]

Auxotyping or determination of serovars of N. gonorrhoeae used separately can be for a limited differentiation of strains only. Combined auxotype/serovar (A/S)-classification was examined for its discriminatory ability on 360 gonococcal strains isolated over 9 years in the area of Heidelberg. The prototrophic, prolin requiring and (P)AH(U)-auxotype were the 3 most frequent auxotypes. 33 different serovars were identified. Protein-IB-serovars dominated by 75%. IB-3, IB-2 and IA-1/2 were the most frequent serovars. The (P)AH(U) auxotype is statistically significant associated with serovar IA-1/2, the PA(U) auxotype with serovar IB-2/16 and the prolin requiring auxotype with serovar IB-1. Combined typing resulted in 68 different A/S classes. The 3 most frequent classes were Proto/IB-3, (P)AH(U)/IA-1/2 and Proto/IB-2/16. The number of the A/S classes identified per year rose generally with the number of the isolated strains. Our data show the heterogeneity and dynamics of a gonococcal population. A/S classification permits the epidemiological differentiation of a gonococcal population in endemic, transient and microepidemic strains.

[Local and systemic humoral immune response to protein I of Neisseria gonorrhoeae]

Knowledge of the immune response to natural infection with Neisseria gonorrhoeae is presupposition for the development of a gonococcal vaccine. Pili and protein I have gained importance for a subunite vaccine. A pilus vaccine proved to be ineffective in a field trial due to extensive pilus variability. According to an alternative strategy protein I may represent an important vaccine candidate for a gonococcal vaccine. To study the local and systemic, humoral immune response to N. gonorrhoeae cervical secretion, vaginal fluid and serum from prostitutes and family planning patients were compared by the use of a protein I ELISA. In local secretions and in serum patients in the study group showed significantly higher anti-protein-I-IgA-levels than patients in the control group. In cervical secretion immune response to an acute gonococcal infection consisted of a short lived, significant increase of anti-protein-I-IgA, while anti-protein-I-IgG showed a lower, but longer lasting significant increase. The course of the immune response in vaginal fluid reflected the immune response of cervical secretion at a lower level. In serum antigenic stimulus of a local gonococcal infection resulted in a significant but short lived protein I specific IgG immune response. In local infection with N. gonorrhoeae protein I represents a target antigen of the local and systemic immune response. Clear differences exist between local and systemic humoral immune response in the protein I reactive immunoglobulin class and in the course of reactivity. In the future it may be possible to define epitopes on protein I which induce protective immunity.

Pyoderma gangrenosum followed by subcorneal pustular dermatosis in a patient with IgA paraproteinemia

Six months after the occurrence of pyoderma gangrenosum, subcorneal pustular dermatosis developed in a 60-year-old woman. The patient's serum was found to contain an IgA-lambda paraprotein. Although similar cases have been reported, this case is unique in that a distinct episode of pyoderma gangrenosum was followed by subcorneal pustular dermatosis.

[High-level tetracycline-resistance of Neisseria gonorrhoeae]

High level tetracycline resistance of Neisseria gonorrhoeae is mediated by a 25.2-MD plasmid and is characterized by a minimal inhibitory concentration of 16 micrograms/ml or more. The 25.2-MD plasmid originated through the insertion of the streptococcal tetM determinant into the 24.5-MD transfer plasmid of N. gonorrhoeae. In the present study the prevalence of N. gonorrhoeae with high-level tetracycline resistance in the Heidelberg gonococcal population between 1981 and 1989 was determined. Among 1765 N. gonorrhoeae isolates, one strain with high-level tetracycline resistance was identified. The presence of the 25.2-MD plasmid in this strain was demonstrated by plasmid-agarose gel electrophoresis. The auxotype/serovar class proline-/IB-1 indicates the importation of this strain from the USA. The 25.2-MD recombinant plasmid, in contrast to the 24.5 MD transfer plasmid, has a rather wide host range, which is favourable to the occurrence both of high-level tetracycline resistance and of beta-lactamase plasmids in N. meningitidis.

Current status of serotyping of Neisseria gonorrhoeae

Protein I has become the basis of serotyping of N. gonorrhoeae. A panel of 12 anti-protein I monoclonal antibodies is supplied by Syva Company, Palo Alto, CA, through distributors for research purposes only. These distributors are responsible for storing the monoclonal antibodies, supplying research groups and training new users, particularly in the interpretation of coagglutination reactions. A European Workshop was held in Heidelberg, Federal Republic of Germany in July 1988 to discuss serotyping with these antibodies. The current uses of serotyping of N. gonorrhoeae include epidemiological studies, clinical purposes and surveillance of antibiotic resistance and plasmid carriage. Predominant serovars may be subtyped either by additional antibodies or with the use of another technique, such as auxotyping, determination of antibiotic sensitivities, plasmid analysis or genetic fingerprinting. Conversely, there is growing evidence that it may be appropriate to group certain serovars together. Data collected during prevalence studies could be combined with clinical information and an international data bank set up. This supposes a close future collaboration of all groups involved in the epidemiology of N. gonorrhoeae.

Evaluation of a non-radioactive DNA probe for confirmatory identification of Neisseria gonorrhoeae

A biotinylated DNA probe combined with a streptavidin-peroxidase complex for the identification of culture isolates of N. gonorrhoeae (Ortho diagnostic systems, Neckargemünd, FRG) was compared with the conventional carbohydrate utilisation test as reference. All 118 strains identified by the reference method as N. gonorrhoeae also gave positive reactions with the DNA hybridisation assay. However, with this test 2 of 23 non-gonococcal Neisseria or Branhamella species were identified as N. gonorrhoeae as well. The study shows that the DNA hybridisation technique can principally be used for the confirmatory identification of N. gonorrhoeae, but since specificity is particularly essential for confirmatory identification, the DNA hybridisation assay evaluated cannot be recommended for routine diagnosis.

[The modern diagnosis of gonorrhea]

Modern identification of Neisseria gonorrhoeae may be either accomplished by direct detection of gonococcal antigen, i.e. without microbiological culturing, or, following culturing, by rapid culture confirmation. The direct detection of gonococcal antigen in an enzyme immuno-assay (Gonozyme) shows reduced specifity especially with mixed microbial flora, and decreased sensitivity with small numbers of organisms. Culture confirmation may be achieved by a rapid sugar degradation test (API----quadFERM+), by specific enzyme detection using chromogenic substrates (Gonochek II), or by demonstration of protein I specific for Neisseria gonorrhoeae by means of monoclonal antibodies (Mikrotrak, Phadebact monoclonal GC, Gonogen II). Detection of protein I is highly sensitive and specific in both the tests of immunofluorescence and coagglutination.

Monoclonal antibodies to protein I for serotyping of Neisseria gonorrhoeae: correlation of serotype with bactericidal activity

Seven monoclonal antibodies have been used for the serotyping of one hundred Neisseria gonorrhoeae wild strains, randomly selected from nine U.S. cities, and seven serotype reference strains by the co-agglutination method. As determined by gel-immunoradioassay, the monoclonal antibodies recognized the protein I trimer of a single or a limited subset of serotype reference strains. All but three strains were typable by one or two of the antibodies. The most common serotypes were 1.3 (26%), 1 (20%), 5 (17%), 5.7 (11%) and 9 (10%). To correlate typing results with ability for killing of these antibodies, susceptibility of typed and non-typed strains to killing was studied. Susceptibility was significantly associated with typing by the serotype 7 (p = 0.011) and serotype 9 (p = 0.033) specific monoclonal antibodies. Reaction of antibodies recognizing epitopes on the protein IB molecule with a given strain predicted in an average of 43% of strains (49% of strains of serotype 5, 62% of serotype 7, 29% of serotype 8, and 33% of serotype 9) its susceptibility to killing by the typing antibodies. In contrast, only 15% of the strains (15% of strains of serotype 1 and 15% of serotype 3) were killed by their typing antibodies, recognizing epitopes on the protein IA molecule. These monoclonal antibodies might prove to be important for the isolation and structural characterization of epitopes responsible for susceptibility of the gonococcus to killing and thus for the development of a vaccine against invasive gonococcal disease.

[Complement-independent bulla formation in pemphigus vulgaris by IgG4]

In cryostat sections from lesional skin of a patient with pemphigus, a typical pattern of IgG deposits was detected at the epidermal intercellular space. However, there were no deposits of complement (C) components. By the highly sensitive APAAP technique using monoclonal antibodies, it was demonstrated that the IgG deposits consisted exclusively of IgG4. IgG subclass analysis of serum autoantibodies against epidermal intercellular substance antigen revealed an identical subclass restriction to IgG4. The IgG4 portion of the serum IgG fraction was significantly increased. Since IgG4 is known to be a an almost ineffective activator of complement, the lack of deposits of C components is not surprising. Our ex vivo observations suggest that complement is not essential for the induction of pemphigus acantholysis.

[Current status of vaccine development in sexually transmissible diseases]

A prophylactic vaccine represents a major hope for the control of sexually transmitted diseases. The current general vaccine strategies and the status of vaccine development against infections with Neisseria gonorrhoeae, Treponema pallidum, Chlamydia trachomatis and Herpes simplex virus are described. Vaccines consisting of whole infectious agents are replaced by protective subunits. A subunit vaccine has the advantage to be free from other components, which are not relevant for protection and which may confer unwanted side effects. At the present time vaccine development against infections with Neisseria gonorrhoeae and Herpes simplex virus seems to be the most progressed. With monoclonal antibodies several surface components could be identified, which are of importance for the pathomechanism. With Treponema pallidum and Chlamydia trachomatis the development is delayed by unsolved problems of immunity. For the production of vaccines molecular-biologic methods, like protein synthesis or gene-cloning will be used. Genetically modified live vaccines or polytope hybrid vaccines will gain importance in the future.

[Classification of Gonococcus: auxanologic and serologic aspects using monoclonal antibodies]

500 N. gonorrhoeae strains from the area of Lübeck/West Germany, collected in 1976-84, were auxologically and serologically classified by means of monoclonal antibodies from the Genetic Systems Corporation, Seattle, Washington (USA), against gonococcal outer membrane protein I. During the first years, auxological classification showed high proportions of AHU-strains (40%), which amounted to 20% over the total observation period. PPNG and DGI strains have characteristic type patterns. Our synopsis of serovars corresponds with the results obtained in a recent world-wide study. Combined auxological and serological classification shows two N. gonorrhoeae pools, 18% each, which cannot be further distinguished: AHU/A1 and prototrophic/B3. The advantages of the system have been proved in answering plain epidemiological questions. For further discrimination, an additional independent classification method might be useful.

[Serotyping Neisseria gonorrhoeae]

To control gonorrhea an understanding of pathogenesis and epidemiology is necessary. To achieve this goal a serologic typing system recognizing antigenic variants of the gonococcus is needed. The serotyping systems proposed in past years are described and their clinical relevance discussed. At the moment two typing systems based on protein I and monoclonal antibodies are available. Protein I serotypes are correlated with the killing of Neisseria gonorrhoeae by bactericidal antibodies and may play a role in the future development of a gonococcal vaccine. The serovar system permits precise analysis of gonococcal populations and can be used especially for epidemiologic studies. The possibility of discriminating between reinfection and therapy failure can be of importance in therapeutic studies. A microepidemiologic analysis for partner identification is possible by combined determination of serovar and auxotype. Both monoclonal typing systems represent standardized monospecific reagents which, besides serotyping, will be used for the diagnosis of gonococcal disease as well.

Epidemiological analysis of Neisseria gonorrhoeae in the Federal Republic of Germany by auxotyping and serological classification using monoclonal antibodies

We evaluated a new serological classification system for Neisseria gonorrhoeae based on monoclonal antibodies directed against epitopes on the outer membrane protein I, in conjunction with auxotyping, to analyse gonococci from two cities in the Federal Republic of Germany. Isolates of N gonorrhoeae were collected during 1976-8 and 1980-2 in Lübeck, and during 1980-2 in Heidelberg. Between the two study periods in Lübeck, we observed an appreciable decrease in strains of the auxotype that requires arginine, hypoxanthine, and uracil (AHU-) and with serovar class PrIA-1 and the emergence of strains with the proline requiring auxotype and PrIB-1 serovar class. Serovar PrIA-1 accounted for 89 (97%) of 92 strains with the AHU- auxotype as opposed to 12 (4%) of 297 strains with other auxotypes (p less than 0.0001). Disseminated gonococcal infection was associated with AHU-/PrIA-1 strains. Penicillinase producing N gonorrhoeae (PPNG) strains belonged to eight different auxotype and serovar classes, which indicated that different strains had been imported. Classification of strains of N gonorrhoeae by auxotype and serovar class permits analysis of temporal changes in gonococcal populations, and of migrations of gonococci between different geographical areas. Typing N gonorrhoeae, together with assessing antibiotic susceptibilities, may prove useful for further studies of the epidemiology and control of gonorrhoea.

[Gonococcal surface antigens and their significance for serotyping and vaccines]

Outer membrane components of Neisseria gonorrhoeae play an important role in the initial steps of infection. Precise knowledge about the surface antigens is needed for the development of a serotyping system and of a vaccine against local and systemic gonorrhea. Structure, antigenicity, and function of the best-known membrane components, i.e., lipopolysaccharide, protein I, protein II, protein III, and pili, are discussed. Lipopolysaccharide is a strong immunogen and induces bactericidal antibodies, but is unsuitable for use as a vaccine because of its toxicity. Protein I and protein III are stable proteins, not subject to antigenic variation. Antibodies against protein I, which are able to kill N. gonorrhoeae, are detectable in the serum of patients with disseminated gonococcal infection. Protein II and pili are highly variable antigens with constant, very slightly immunogenic regions. To interrupt the pathomechanism of gonococcal infection at different stages, future vaccines should contain more than one surface antigen.