Acta pathologica et microbiologica Scandinavica. Section B, Microbiology最新文献

Five Escherichia coli strains were established as antigenic test strains for five new polysaccharide K antigens: K95, K96, K97, K98 and K100. K95 to K98 served already as test strains of O antigens O75, O77, O81 and O107 respectively. F147, which is test strain of K100, had O antigen O75.

Egg-grown Sendai virus was used for preparation of rabbit hyperimmune sera directed against purified whole virus and pronasetreated projectionless virus particles. These sera and convalescent sera after natural Sendai infection in guinea pigs were studied in haemolysis-inhibition (HLI), haemagglutination-inhibition (HI) and neuraminidase-inhibition (NI) tests both before and after absorption with Tween 80-ether (TE) treated virus preparations. In addition, neutralization tests using the different sera were carried out. HI and NI antibodies and the major population of neutralizing antibodies in convalescent sera were removed by absorption with TE treated virus material without changing the titre of non-HI HLI antibodies. Rabbit hyperimmune sera directed against projectionless virus particles exhibited HLI antibody titres in marked excess of HI and NI antibody titres, whereas this was not found in sera against purified whole virus. In contrast, absorption of sera against projectionless particles eliminated HI antibodies without changing the titre of non-HI HLI antibodies. The protein composition of antigenic preparations used in absorption experiments and for preparation of sera was investigated by SDS-polyacryladmie-gel electrophoresis. TH treatment had no significant effect on the polypeptide pattern of Sendai virus. Pronase-treatment predominantly affected the two glycosylated proteins of Sendai virus. The larger glycoprotein was not detectable in pronasetreated projectionless virus particles, whereas the smaller glycoprotein was present in reduced quantities.

Agglutinins against human O erythrocytes modified by the B1 strain of Newcastle disease virus were studied in paired sera of 148 patients with a 4-fold or greater rise in complement-fixing M. pneumoniae antibodies. The proportion of cases with a significant rise in NDV-O agglutinins was higher agmong the patients with pneumonia than among those with neurological or other clinical manifestations.

Escherichia donor strains having antigen K1(L) or K4(L) transfer these K antigens to recipient cells at a genetic locus (kps A) similar to that of K10(L) and K54(L) linked to ser A. In crosses between the K10 donor strain and recipient strains O8:K8(L), O8:K27(A) and O9:K57(B) all recombinants which inherit donor K antigen also inherit K antigen of recipient. This result is interpreted as non-allelism between donor and recipient K antigens, and it is assumed that the structure of all polysaccharide K antigens of strains having O antigens O8 or O9, whether termed L, A, or B, are controlled by genes which differ in their location on the chromosome from genes controlling polysaccharide K antigens associated with most other O antigens.

Some biological conditions of the focal necrotic hepatitis test for the differentiation between herpes simplex virus (HSV) types 1 and 2 were investigated. Most of 13 different strains of mice tested were found usable in the test. An upper age limit (4 weeks) for the appearance of focal necrotic liver lesions was found in one strain of mice, while this was not seen in another strain. The minimum dose in 3- to 4-week-old mice was found to be as small as 10(2) to 10(3) p.f.u. in 0.1 ml of diluent. Suckling rats and hamsters, aged up to 7 and 14 days, respectively, were found to be convenient as alternative test animals. Finally, it was observed that focal necrotic hepatitis did not develop in the nude mouse with thymic aplasia on intraperitoneal inoculation of HSV type 2. The possible involvement of the thymus in the pathogenesis of the focal necrotic lesions is briefly discussed.

In the course of a six-month-study of acute gastroenteritis in children of ages up to six years, a reo-like virus was found in 54 per cent of the faecal specimens obtained at an early stage of the disease, using electron microscopy as screening test. By means of a concentrated complement fixation antigen, composed of a related calf diarrhoea virus cultivated in tissue culture, the rise in titre was found to be significant in 96 per cent of the patients whose faeces contained the reo-like virus. Antibodies were present in the remaining 4 per cent without rise in titre. In 10 per cent of the cases with gastroenteritis infection was caused by adenovirus or Salmonella. A probable aetiological agent was found in 71 per cent of the patients. It applies to 33 per cent of all cases caused by the reo-like virus that they were nosocomial infections.

The catabolism of glutamate and fumarate was studied by radiorespirometry in selected Neisseria species. The tricarboxylic acid cycle is functioning in all species tested, in spite of the known absence of in vitro malate dehydrogenase activity in N. meningitidis, N. gonorrhoeae and N. cinerea. The results imply a pyridine nucleotide independent oxidation of malate. The oxidation of glutamate is less complete in the presence of phosphate. In N. meningitidis, N. perflava, N. flava, N. subflava and N. lactamica the catabolism of fumarate was slow and incomplete in the absence of glutamate.

The effect of evacuation of atmospheric air during transportation on recovery of anaerobic bacteria was investigated. Evacuation of atmospheric air from glass tubes by flushing with pure carbon dioxide lowered the content of oxygen to about 0.4 per cent. Three B. fragilis strains and one strain of Fusobacterium mortiferum and of Peptostreptococcus anaerobius were investigated. Bacterial recovery was determined one hour and 24 hours after evacuation of atmospheric air by pure carbon dioxide and pure nitrogen, was compared to bacterial recovery from samples transported with free access to atmospheric air. Evacuation by pure carbon dioxide significantly improved the recovery of one B. fragilis strain after 24 hours of transportation and significantly impaired the recovery of Peptostreptococcus anaerobius after one hour of transportation, while evacuation by pure nitrogen significantly improved the recovery of Peptostreptococcus anaerobius after 24 hours of transportation. In all other cases, however, no statistically significant effect on bacterial recovery was found.

The catabolism of pyruvate and acetate is selected Neisseria species was studied by radiorespirometry. Both substrates were oxidized via the tricarboxylic acid cycle. N. elongata and the "false neisserias" (N. catarrhalis, N. ovis and N. caviae) did oxidize acetate in the absence of other substrates. This can be explained if it is assumed that these species have glyoxylic acid cycle activity. In the "true neisserias" other than N. elongata, acetate was oxidized only in the presence of glutamate, indicating that these species do not possess a glyoxylic acid cycle.