H. C. Zanen

Colony Variants of Neisseria Meningitidis Strain 2996 (B: 2b: P1.2): Influence of Class-5 Outer Membrane Proteins and Lipopolysaccharides

Different colonial morphologies were found among colonies of Neisseria meningitidis strain 2996 (B:2b:P1.2). Examination of cultures, selected on the basis of colony transparency or opacity, revealed that both lipopolysaccharides (LPS) and class-5 outer membrane proteins (OMP) are associated with differences in colonial morphology. Among 13 variants, four LPS variants and two class-5 OMP variants were recognised. All variants were non-fimbriate. The LPS variations were confirmed by immunoprecipitation. In addition to these qualitative variations of LPS, meningococci synthesise LPS of different molecular size depending upon growth phase; larger LPS molecules were found after analysis of stationary-phase cultures than with exponential-phase cultures. These changes did not cause a change in serotyping characteristics. The recognition in this study of intra-strain heterogeneity of meningococcal LPS and class-5 OMPs is important for the understanding of meningococcal pathogenicity. This heterogeneity was also detected in simultaneous isolates from different sites of a patient.

Rapidly decreased serum IgG to Campylobacter pylori following elimination of Campylobacter in histological chronic biopsy Campylobacter-positive gastritis

The anaerobic bacterium Campylobacter pylori (Cp) is thought to be associated with chronic gastritis. This paper presents clinical data underpinning this view. Five patients with histological chronic gastritis as determined by diagnostic endoscopy, which was associated with Cp as determined by positive biopsy cultures, all possessed statistically raised serum IgG ELISA titers to Cp during a longitudinal period of observation of 15 months. Treatment with the antibiotics amoxycillin (clamoxyl) or colloidal bismuth subcitrate (denol) eliminated Cp within one month. Associated with this, serum IgG ELISA titers were found to decrease sharply and rapidly. Tagamet and spiramycin had little effect. Although the data are preliminary, they support the assumed Cp involvement in chronic gastritis and suggest that specific serum IgG ELISA titers to Cp are useful parameters in monitoring disease status, exceeding bacteriological culture of biopsy specimens in speed and convenience.

Meningococcal disease in The Netherlands, 1959–1981: The occurrence of serogroups and serotypes 2a and 2b of Neisseria meningitidis

By means of a filter radioimmunoassay and the use of monoclonal anti-2a and anti-2b antibodies, we have serotyped 3164 of 3688 strains of Neisseria meningitidis isolated from patients in The Netherlands between 1959 and 1981. Serotypes 2a and 2b were distributed differently among the major serogroups A, B, C, and W-135. Neither of the types was found among group A strains. Type 2b strains of serogroup B emerged in 1965, causing a country-wide epidemic which reached a peak incidence in March and April of 1966 and continued to predominate within group B until 1979. Type 2a strains of serogroup C were responsible for a substantial number of sporadic cases over a long period without any association with outbreaks or with a shift in the pattern of the serogroup. After the appearance of group W-135 in 1971, W-135 strains caused a small non-focal epidemic wave. The upsurge of disease due to virulent sub-populations of strains B:2b and C:2a appeared to be closely related to a basic pattern of regular cyclical waves with peak intervals which differed for serogroups A, B, and C. In recent years both serotype 2a and 2b strains within the different serogroups fell to insignificant numbers. Our results show that retrospective large-scale serotyping of collected strains provides insight into the epidemiological patterns of endemic meningococcal disease.

Association of meningococcal serogroups and types with the course of disease, the Netherlands 1959-1983 (n = 1221)

To study the association of meningococcal serogroups with the course of disease, histories of 1221 patients were reviewed. The meningococci from these patients constituted a sample from isolates collected and serogrouped systematically in the Netherlands since 1959. 64% of the 1221 isolates were group B. The case-fatality rate (CFR) was 5.1%. CFR was lowest in group A (2.3%) and highest in group W-135 disease (18%)(p < 0.01). The occurrence of septicaemia without meningitis (CFR: 15.3%) was similarly distributed among the serogroups (A: 4.0%; W-135: 30%). The CFR in group B disease was significantly associated with serotype 2b (B:2b) strains. Sequelae occurred in 7.9% of patients (hearing loss 3.2%). Sequelae were remarkably prevalent after disease due to minor serogroups (X and Y: 4 of 12). In a log-linear analysis, both age and serogroup were significantly associated with CFR and with the occurrence of septicaemia and sequelae.

Epidemiology of meningococcal (sub)types in the Netherlands

The number of cases of meningococcal disease increased in The Netherlands during the period 1982–1986. In 1986 we estimated the attack rate to be over 3/100,000 pop./year, which is still below the epidemic levels reached in 1946–1947 and in 1966. The serogroup B increased from 98 strains in 1982 to 275 strains in 1986 (an increase of 281%) and its fraction among the isolated strains rose from 47 to 77%. The B: 15:p1.16 complex was not the driving force: its share of the group B strains never exceeded 20%. Many epidemiological and clinical aspects of disease due to B: 15:p1. 16 strains were similar to those described in other countries.

Neisseria meningitidis type 15/subtype Pl. 16 in the Netherlands

Age. For the 77 patients known at present we calculated a median age of over 12 years, which is much higher than the median age of 3.0 years in the total group of 598 patients with serogroup B disease during the period 1980-84 (Fig. 1). For comparing the seperate years we used three parameters: median age, mean age and fraction over 4 years old (Fig. 2). There is a steady increase in age from 1982 on. This tendency is still present; the last months hardly any patient younger than 10 years was encountered.

Raised serum IgA to common cell envelope antigens supports enterobacterial inductive contribution to pathogenesis of secondary ankylosing spondylitis

Ankylosing spondylitis (AS) is closely associated with the histocompatibility antigen HLA-B27. Pathogenesis of AS is thought to involve interactions between B27 and certain enterobacterial antigens. However, enterobacterial involvement is uncertain and contested by some. The present paper demonstrates raised serum IgA to a common enterobacterial heat modifiable major outer membrane protein (h-momp; Mr 35,000) in active AS (N = 25; IgA = 1485 +/- 20) compared with controls, who were hospital patients without known arthropathies or gastro-intestinal disease (N = 12; IgA = 548 +/- 59). Serum IgG and IgM did not differ statistically. Raised serum IgA to h-momp might indicate enterobacterial antigenic stimulation from the gastro-intestinal tract and thus support an inductive contribution of enterobacterial antigens to the pathogenesis of secondary AS. It does not necessarily imply direct involvement in the pathogenesis of primary AS. H-momp appears to be a convenient tool for serological studies of AS and at present is likely to be more suitable than other bacterial antigens.

Protein, lipopolysaccharide and polysaccharide typing of Escherichia coli from patients with neonatal meningitis

The capsular K 1 serotype accounts for about 80 ~ of the isolates of Escherichia coli from patients with neonatal meningitis (Sarff et al., 1975, Zanen et al., 1979). The number of different O-serotypes of these strains is limited (Sarff et al., 1975). Escherichia coli strains isolated from meningitis patients in the Netherlands between 1976 and 1981 could be classified in one of the following O-serotypes : 083, O 18, 07, O 14, O 1 and O-autoagglutinable 1 (92 ~ of the K 1-strains). since cell-envelope proteins of these isolates have only incompletely been investigated (Achtman, 1980), we have analysed 98 strains uisng SDS-polyacrylamide gel electrophoretic separation of cellenvelope components (SDS-PAGE). At the same time, these gels allow a detailed analysis of the lipopolysaccharides by combining the SDS-PAGE with immunochemical detection using O-serotype specific antisera raised in rabbits (see below).

Streptococcus suis meningitis: a health hazard to pig meat handlers

In Europe, Streptococcus suis type 2 is a frequent cause of disease in pigs. The bacterium has been isolated from diseased pigs with septicaemia, endocarditis, arthritis, pneumonia and meningitis and from the palatine tonsils of healthy pigs (De Moor, 1963; Williams et al., 1973; Lamont et al., 1980; Perch et al., 1983). S. suis type 2 also causes meningitis in man (Perch et al., 1968; Agass and Willoughby, 1977; Shneerson et al., 1980). We have analysed the history of 58 patients with S. suis meningitis with special reference to the portal of entry; 29 cases occurred in the Netherlands and another 29 cases were collected from the literature. The age of these patients was 21 to 76 years, 52 were men and 6 were women. Contact with pigs or pork was mentioned in 54 cases. In 51 this contact was related to their occupation; 19 persons were pig-keepers or farmers, 24 were slaughterhouse workers or butchers and 8 worked in other jobs requiring contact with pigs or pork (meat factory, transport). Three persons had contact with pigs or pork outside of their occupation. In many patients clinical signs of septicaemia preceded the onset of meningitis and 69% had a positive blood culture. Small wounds and septic lesions on the hands were assumed to be the portal of entry in 14 patients. In 39 cases the portal of entry was not clear, and in 5 patients information on this subject was not available. It is a serious disease: of 58 patients 4 died, 32 suffered from deafness, 8 from arthritis and 2 from blindness, due to endophthalmitis, a complication of the disease. Between the patients in the Netherlands and those from the literature no essential differences were found with respect to all parameters mentioned above. Cutaneous lesions of the hands of workers in the pig meat industry are often infected by group A streptococci of human (!) origin. Cutaneous infections (without signs of systemic disease) caused by S. suis type 2 are not mentioned in the literature. This may be due to unfamiliarity with S. suis. Experimental studies indicate that pigs can be infected both by inoculating S. suis type 2 into wounds and by spraying them into the nose or the mouth. It is likely that man also can be infected by these two routes. It may be relevant that we found S. suis type 2 in the palatine tonsils of 50~ of 143 pigs slaughtered in the Netherlands. Some data on the risk of acquiring S. suis meningitis in the Netherlands is shown in Table 1. Pig-keepers and slaughterers seem to run a greater risk than butchers. In summary the transmission of S. suis type 2 from pigs to people working in the meat industry takes place through direct contact with skin lesions and probably also by the oral and respiratory route. Adequate first aid in cases of injury of the hands and the wearing of gloves and protective clothes might help in preventing this serious occupational disease.

Immunochemical characterization of meningococcal serotype antigens by immunodiffusion and SGIP

The electronic device (2), consisting of amplifiers, an analog digital (AD) converter, a timer (1) and a tube counter, steers the printing device (3). After each measurement, tube number, time of measurement and mV are printed out. The mV values are converted into absorbance expressed as Klettunits, corrected for initial mV, tube diameter and instrument factors with a Diehl Alphatronic (Diehl Datensystem Niirnberg, West-Germany) desk computer. The complete instrument fits in an incubator room of 40 • 40 • 100 cm. A linear relation between turbidity and viable counts was found between 2 x 107 and 8 x 109 c.f.u./ml (r > 0.99). The aeration resulted in a remarkable increase of bacteria (from 45 % in staphylococci up to 123 ~ in Pseudomonas aeruginosa as measured turbidimetrically. No surface growth or pellicle formation was observed with the latter strain because of the regular stirring. Mechanical damage of bacteria by the stirring rod was small. Because of its small size, the instrument can be used for anaerobic cultures by placing it in an anaerobic cabinet. Yields of 8 x 109 c.f.u./ml of Bacteroidesfragilis were obtained. In research laboratories the instrument is more versatile than the commercial types.