EPIDEMIOLOGICAL MARKERS FOR PSEUDOMONAS AERUGINOSABERGAN, TOM; MIDTVEDT, TORE
doi: 10.1111/j.1699-0463.1975.tb00062.xpmid: 805509
A non‐lysogenic strain of Pseudomonas aeruginosa maintained its phage sensitivity pattern and serogroup specificity unchanged for 10 weeks in ex‐germfree, mono‐contaminated rats before infection with phage. After infection with phage, phage conversions of serogroup specificity and lysotype were observed. With the same combination of bacterial and phage strains, the same serogroup was obtained in vitro and in vivo. In vitro conversion occurred also to serogroups that were not detected in vivo. Upon lyophilization, converted bacterial clones from the in vivo experiment lost their phage and simultaneously reverted to the original phage type and serogroup. These findings may have implications for the understanding of the degree of stability in epidemiological typing results for P. aeruginosa.
QUANTITATIVE STUDIES OF DIRECT AND INDIRECT IMMUNOFLUORESCENT STAINING OF SALMONELLA BACTERIAKARLSSON, K.‐A.; THORE, A.; KUDYNOWSKI, J.
doi: 10.1111/j.1699-0463.1975.tb00064.xpmid: 48326
Salmonella bacteria were stained with serial dilutions of anti‐Salmonella conjugates of different F/P ratios and the staining intensity was measured quantitatively in an ultramicrofluorometer. In any given dilution of the conjugates, a stronger fluorescence was obtained with the more highly labelled conjugates. The dependence of fluorescence intensity on F/P ratio varied with the dilution of the conjugate. Similar results were obtained by the indirect immunofluorescence method. In four bacterial systems the direct and indirect immunofluorescent staining methods were compared quantitatively. The indirect method was 5 to 30 times more sensitive than the direct comparing the last dilutions giving a positive reaction by visual observations. The standard deviation of the intensity values of the stained bacterial cells was between 10 and 40 per cent of the mean. Different sources of variation in the quantitative measurement technique are discussed.
ESCHERICHIA COLI SEROGROUPS IN BREAST‐FED AND BOTTLE‐FED INFANTSØRSKOV, F.; SøRENSEN, K. BIERING
doi: 10.1111/j.1699-0463.1975.tb00065.xpmid: N/A
1) Eighty‐seven breast‐fed and 95 bottle‐fed infants were examined for differences in Escherichia coli serogroup pattern. 2) The serogroup composition was less complex in breast‐fed infants. Fewer serogroups were found in the individual breast‐fed child. However, with few exceptions, the same O groups were found in the two groups of infants. The prevalent O groups were among those also found most frequently in faeces from adults. 06 strains were more common in the breast‐fed group, while 07 and 016 were not at all found in that group. 3) A special search for E. coli strains with K1 antigen showed that this antigen predominated in the bottle‐fed infants. 4) Klebsiella and other Enterobacteriaceae were more frequently found among bottle‐fed infants. 5) It is concluded that the intestinal milieu exerts a selective pressure which may result in a selection of different serotypes in two different intestinal milieus such as those examined.
THE ESTABLISHMENT OF K99, A THERMOLABILE, TRANSMISSIBLE ESCHERICHIA COLI K ANTIGEN, PREVIOUSLY CALLED “Kco”, POSSESSED BY CALF AND LAMB ENTEROPATHOGENIC STRAINSØRSKOV, I.; ØRSKOV, F.; SMITH, H. WILLIAMS; SOJKA, W. J.
doi: 10.1111/j.1699-0463.1975.tb00066.xpmid: 1093354
The transmissible antigen in enteropathogenic E. coli strains from calf and lamb, previously called Kco, is established as the E. coli K99 antigen. It is probably of protein nature since it is destroyed by heating. It is pointed out that other antigens present, growth medium and unknown factors are of great importance for the demonstration of this antigen.