Zentralblatt fur Bakteriologie, Mikrobiologie, und Hygiene. Series A, Medical microbiology, infectious diseases, virology, parasitology最新文献

296 strains of Listeria monocytogenes have been submitted for confirmation and further studies to the Listeria Reference Laboratory at the Institute of Hygiene in Würzburg, Federal Republic of Germany. They have been isolated between 1969 and 1985 from human cases in the Federal Republic and West Berlin. The results of an analysis of the respective cases are presented here on the basis of questionnaires. A steady increase of Listeria isolations has been noted during the past few years. The largest number of strains originated from the district Nordrhein-Westfalen which has the largest population of all German federal districts. The highest incidence calculated from the number of strains and total population was found for the district of Saarland. There was no predominance detectable of listeriosis among the rural population. 60% of the strains came from patients living in urban areas. In 6 out of 21 cases of neonatal listeriosis at least one of the parents was engaged in professional medical services. The most frequently observed clinical entities were meningitis (41.14%) and septicaemia (36.00%). Among the newborns septicaemia was predominant with 40.90%. Listeriosis during pregnancy and among newborns was connected with 53.57% of all strains isolated. The questionnaire revealed for the underlying conditions in 35% and in 24% of cases malignancies and organ transplantations, respectively. There was no increased rate of predominance found among the elderly. However, 50% of all strains isolated originated from newborns. The sex distribution was almost equal; 52.56% from males of the total number of isolates and 51.22% from males among the newborns. 67% of these which had a meningitis after the first weeks of life were male. There was no seasonal incidence detectable. Serovar 4b was found in 66.22% of all isolates tested. 295 strains produced acid from rhamnose and alpha-methyl-d-mannose, but not from d-xylose and were thus typical for L. monocytogenes. One strain needs further studies.

The uptake of (14C)erythromycin into Staphylococcus aureus was investigated by use of a rapid centrifugation method. Erythromycin uptake was saturable with time and with increasing erythromycin concentrations (apparent uptake constant Km = 6.0 x 10(-7) moles/l). Inhibitors of glycolysis, respiration and oxidative phosphorylation did not influence the uptake process but uptake was decreased by reducing temperature. Increases of erythromycin uptake, decreases of half life times of the uptake reaction and a log dose linked to enhancement of antimicrobial activity were seen with alkaline pH levels of the incubation medium. The experimental data conform well with the concept of non ionic diffusion. The high affinity of erythromycin to the intracellular ribosomal target site probably generates the driving force of uptake and the unionized antibiotic obviously represents the antimicrobially active molecular form.

The present study includes twelve patients with second and third degree fresh burns involving 10-70 per cent total body surface area. Standardized surface swab, gaze pad contact, Rodac plates, and burn wound biopsy cultures were obtained twice per week. The various techniques were compared by 48 independent measurements. Confluent growth occur in more than 70 per cent of the Rodac agar plates. There was a significant (alpha less than 1%) correlation between the results of the surface swab and the gaze pad method. A comparison of the number of viable bacteria detected with the burn wound biopsy technique and the surface methods (gaze pad and surface swab) showed no significant correlation. In addition, the number of colony forming units in 8 parallel cultures obtained from different sites of the burn wound was determined. The standard error of mean (SEM) varied between 1.01 log (biopsy), 0.91 log (gaze pad) and 0.61 log (surface swab). Several case reports emphasize that the quantitative biopsy culture seems to give most reliable data in predicting burn wound sepsis.

In cultures of 9 budvicia aquatica and 5 "Pragia fontium" strains production of distinct bacteriocin-like agents was proved. It is suggested to call them aquaticins and fonticins. They display strain specific antibacterial activities towards both genera; however, they are not active towards Escherichia coli or Shigella sonnei indicators. Their inhibition zones are conspicuously narrow (turbid or clear). Their spontaneous production may be enhanced by UV-induction of producing bacteria. They are readily set free into the medium; no intracellular accumulation occurs. With only one exception, they are trypsin-resistant and remarkably heat-sensitive, being damaged at 45 degrees C to 55 degrees C. All these results suggest that aquaticins and fonticins are of corpuscular character. This assumption was proved true by electron microscopic observation of one of the fonticins: this resembles contracted tails of bacteriophage T4.

The assimilation of 43 different carbon substrates by 93 clinical strains of Pseudomonas aeruginosa was studied by a new miniaturized rapid method. Reading of assimilation results was done photometrically after 18-20 h incubation and the resulting data were captured and stored by a microcomputer. The differentiating capacity of the assimilation tests were verified by comparing the results of 41 strains of Pseudomonas fluorescens, 48 strains of Pseudomonas putida, 52 strains of Pseudomonas maltophilia and respectively 10 strains of Pseudomonas pseudomallei and Pseudomonas cepacia. The assimilation pattern obtained from the Pseudomonas aeruginosa strains agreed to those described in literature and because of miniaturization, standardisation, facility of use and automatic reading the method seems to be suitable for routine laboratory work.

A competitive passive hemagglutination assay (cPHA) easy to perform and a highly sensitive ELISA have been investigated for detection of diphtheria toxin from cultures and from human serum. The sensitivity of the cPHA (8 ng toxin/ml) was high enough to detect toxin in pure cultures containing C. diphtheriae. For this application the cPHA proved to be a simple and reproducible alternative to the Elek-Ouchterlony test. Toxin in culture filtrates of nasal and tonsillar swabs containing toxinogenic strains of C. diphtheriae together with germs of the physiological flora and toxin in serum can be detected with the more sensitive Biotin/Streptavidin ELISA (0.6 ng toxin/ml). This allows the confirmation of the clinical diagnosis "diphtheria" within 24-48 h.

An alternative approach to malaria vaccine with the use of Plasmodium berghei NK65XAT (XAT) is reviewed. XAT is a permanent low virulence strain derived from high virulence P. berghei NK65 (NK65) by irradiation. Although one organism of parent NK65 could kill one mouse, as many as 10(7) XAT parasites caused modest self limiting parasitaemia in immuno-competent mice. In the mice recovered from XAT infection, long lasting immunity to challenge not only by parent NK65, but also by ANKA so far as different species of rodent Plasmodia was seen. The XAT parasites invaded selectively into immature erythrocytes. Because of this feature, the attenuated parasite might induce potent and long-lasting immunity presumably with the background of MHC antigen expression on infected cells. Immunopathologic reactions in mice infected with XAT were modest comparing to those seen in mice with parent NK65 infection. Attenuation was also tested using P. yoelii nigeriensis with which cyclical transmission with A. stephensi was established. Although similar attenuation occurred by X-ray irradiation, produced parasites eventually reverted to virulence after several animal passages. Irradiation was also attempted to induce attenuated P. falciparum mutant and a parasite of a slow multiplication feature was obtained in an experiment. We would propose an alternative approach in the study of malaria vaccine using attenuated live organisms which confers potent and long lasting immunity to the host.