Zentralblatt fur Bakteriologie. 1. Abt. Originale. A: Medizinische Mikrobiologie, Infektionskrankheiten und Parasitologie最新文献

A number of N-aryl-dithiocarbamic-esters and their N-methyl-derivatives are produced and the fungistatic action of these compounds compared with one another. It was demonstrated that N-aryl-dithiocarbamic-esters exert an intensive fungistatic action with a wide spectrum of activity, but their N-methyl-derivatives are in this respect totally inactive. The N-aryl-dithiocarbamic-esters are transformed easily into arylisothiocyanates, but their N-methyl-derivatives are unable to effect such transformation. These facts provide an indirect evidence of N-aryl-dithiocarbamic-esters to exert their fungistatic effect indeed by the formation of arylisothiocyanates in situ. The fungistatic action of a number of aryl- and aralkyl-carbylaminchlorides, respectively, was examined. The fungistatic effect of the corresponding aryl- and aralkyl-isothiocyanates was examined in parallel to decide whether a difference between these two similar types of compounds in the intensity of their fungistatic effect exists. It was demonstrated that the examined aryl- and aralkyl-carbylaminchlorides exert an intensive fungistatic effect, but their fungistatic activity is less intensive than that of the corresponding aryl- and aralkyl-isothiocyanates. It was furthermore demonstrated that the fungistatic activity of aryl-isothiocyanates is considerably increased by a chlorine atom in the meta or para position or by a bromine atom in the para position of their molecules, but the fungistatic action of the aryl-carbylaminchlorides is significantly decreased by this on the contrary, the fungistatic activity of both series of compounds is increased by 3,4-dichloro substitution.

96 strains of facultatively anaerobic actinomycetes and 2 Propionibacterium acnes strains were studied for their ability to deaminate and/or decarboxylate 13 amino acids, to reduce nitrate and nitrite, and to produce indole, using specially adapted micro-methods. Several of the tests performed were found to provide information which may aid in improving the classification and in facilitating the identification of these organisms.

A total of 550 E. coli isolates--250 from apparently healthy, and 300 from diarrhoeic West African pigmy goats were tested for colicinogenicity. 33.2% of strains from apparently healthy animals were colicinogenic as against 56% recorded for strains from animals with diarrhoea. Of the 251 colicinogenic E. coli strains from both groups of animals, 76.5% were Type I while 23.5% belonged to Type II. Identified colicins from the healthy animals consisted of types G, K, E2, A and V in decreasing frequency of occurrence, whereas those from goats with diarrhoea were made up of types V, B, E1, G, E2, E3, and Ia also in decreasing frequency of occurrence. In contrast to isolates from healthy animals, there was a marked variation in the colicin spectra of Types I and II E. coli from the diarrhoeic animals--that of Type I being much broader. The Public Health significance of possible transfer of multiple drug resistance from colicinogenic E. coli strains to other enterobacteria is also discussed.

A single case of urogenital myiasis in an 86-year-old male patient suffering from a thrombophlebitic syndrome of the left leg is described. Larvae of the flesh fly, Thyrsocnema incisilobata (Pandellé) were unequivocally established as the agent of this myiasis which means that this species is introduced into parasitological literature, for the first time, as a human parasite. The circumstances of the development of this facultative human parasitosis is discussed.

The influence of incubation temperature (37, 30 and 22 degrees C) on antibiotic susceptibility, beta-lactamase activity and growth characteristics was studied on 43 unselected strains of Y. enterocolitica (Serovar O:3 and O:9) freshly isolated from cliical specimens. Antibiotic susceptibility was measured by the disc diffusion technique and by a broth dilution test (MIC). Beta-lactamase activity was detected with chromogenic cephacetrile using standard curves prepared for 37, 30 and 22 degrees C. Continuous increase of beta-lactamase activity was found when incubation temperatures were lowered. All strains were found to be resistant by ampicillin and cephalothin at the three temperatues tested. Some strains showed an intermediate susceptibility to carbenicillin in the disc diffusion test. A temperature reduction of 37 to 30 degrees C significantly decreased the inhibitory zone diameters for the beta-lactam antibiotics ampicillin, carbenicillin and cephalothin, but also for other substances like tetracycline, chloramphenicole and cotrimoxazole. This suggests, that the observed decrease is caused by a better growth of Y. enterocolitica at 30 degrees C rather than increased beta-lactamase production. From 30 to 22 degrees C a further decrease in inhibitory zone diameters was only seen with ampicillin and carbenicillin. This seems to be mainly due to the increased B-lactamase activity observed at 22 degrees C. In contrast the resistance to cephalothin was apparently not influenced by this additional beta-lactamase activity. Resistance to cephalothin therefore depends probably more on other, not beta-lactamase-related, factors such as permeability variations of the outer membrane or modifications of binding proteins involved in the peptidolycan biosynthesis. The correlation between beta-lactamase activity at various incubation temperatures and resistance to beta-lactam antibiotics was less pronounced when the broth dilution test (MIC) was applied. Only carbenicillin showed significantly increasing MIC values from 30 to 22 degrees C. All the Y.e. strains investigated could be divided into two groups with respect to their beta-lactamase production characteristics. The first group showed continuously increasing beta-lactamase values at lower incubation temperatures. In the second group generally lower amounts of beta-lactamase values were found and temperature dependence was not observed. On the other hand variations in cell wall permeability, resulting in a diminished accessability of the cell wall bound enzymes must also be considered.

An enzyme-linked-immunosorbent-assay (ELISA) is described for the serodiagnosis of leptospirosis. Using an antigen prepared from a heated culture of a single leptospira strain (Wijnberg) the ELISA is a genusspecific test. The microscopic agglutination test (MAT) served as a reference. ELISA and MAT results agreed in 95% of the sera from 96 leptospirosis patients. One false positive was found in 217 controls. The ELISA is sensitive, specific and relatively easy to perform.

Using the HEp-2 cell line system the factors and mechanisms of group A Streptococcus adherence had been studied. It was shown that high adherence was chiefly found in strains showing attributes of virulence (presence of M protein, growth in human blood, lethality for mice). The data supplied by experiments with pepsin and LTA suggest that there exist at least two mechanisms of adherence.

Immuncyte proliferation in the spleens of mice given both a primary and a second infection sixty days later, was detected soon after the second challenge was administered. Plaque-forming cell assay for both the direct and developed plaques indicated that all cells producing antibody of both immunoglobulin classes were present in the animals when they were administered the second challenge. Hemagglutinating antibody determinations indicated that IgG antibodies are recognizable at a time when the bacilli reach a stage of maximum multiplication in the mouse host. The IgM antibodies, however, become detectable within a short time after infection in animals given either a single infection or a dual infection, one fifteen days later and the other sixty days after the first infection. It is proposed that the low level of circulating antibodies and antibody-producing cells despite continuous, as well as enhanced, antigenic challenge could be due to the fact that in the mouse footpad M. leprae may be intrinsically less antigenic than organisms that cause systemic infection. Quantitative immunoglobulin assays tended to confirm the observations on the HA studies. Present studies have once again confirmed our previous observations viz that the number of plaques in the spleens of mice infected with M. leprae increases on secondary stimulation, whether it is administered within a very short time after the primary infection or given later in the course of infection. They have also indicated that an IgG response will occur in the infected animals at a time when the bacillary multiplication enters the logarithmic phase of growth of M. leprae, They have, however, not permitted the placement of the mouse model in the overall spectrum of human leprosy.