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.

Agglutinins↗

PubMed1975

Temporary skin reactions to penicillins during the acute stage of infectious mononucleosis.

During the acute stage of infectious mononucleosis (IM), 16 out of 19 patients have reacted to skin tests with ampicillin and/or benzylpenicillin or their derivatives. Two thirds reacted to ampicillin and less than half (10/19) to benzylpenicillin, or their derivatives. No reaction was observed with cloxacillin. The lack of reactivity in 3 of 7 patients and the circumstance that the frequency of reactions with the penicilloylated Escherichia coli proteins makes it likely that the greater reactivity to penicillins and in particular to ampicillin in IM is not due mainly to protein impurities, but chiefly to the antibiotic molecule as such. There was no definite relationship between reactivity and clinical involvement. After the acute stage, disappearance of skin reactivity was noted. Intracutaneous testing with penicillins may be used to monitor the increased cutaneous reactivity during acute IM, and it may be helpful when the acute stage is over to determine when a patient may use these antibiotics without side reactions.

Acute Disease↗

PubMed1975

Epidemiological markers for Pseudomonas aeruginosa. 5. Subdivision by interative numerical analysis of isolates according to lysotypes.

A computer-based numerical approach to the allocation of Pseudomonas aeruginosa bacteriphage patterns has been presented. This rendered a usefule identification of similar phage types. The grouping had epidemiological relevance. Grouping of phage typing patterns of P. aeruginosa by numerical analysis showed that the patterns of related isolations may differ in one strong lysotype reaction, occasionally even in more reactions. Thus parallels previous findings which have been based on studies of the reproducibility of the method and evaluations of differences in epidemiologically related strains from the same sources.

Bacteriophage Typing↗

PubMed1975

Epidemiological markers for Pseudomonas aeruginosa. 6. Relationship between concomitant non-mucoid and mucoid strains from the respiratory tract in cystic fibrosis.

The simultaneously occurring mucoid (M) and non-mucoid (NM) variants of Pseudomonas aeruginosa frequently observed in cultures from the respiratory tract of chronically infected cystic fibrosis patients have been studied. M cultures in vitro were unstable and easily dissociated NM colonies. In a large proportion of the cases, M and NM variants occurring simultaneously in cultures from one and the same clinical specimen were of the same pyocine type, phage type, and serogroup. In some remaining cases there were small differences between the M and NM variants such that identity between the variants from one and the same specimen was possible, although not definite. The NM dissociants from M strains were of the same type as the M variant. The possible role of cross-infection and the interaction of bacteria and host response factors continuously tending to select the unstable M variant in vivo are discussed.

Adolescent↗

PubMed1975

Gas chromatography of bacterial whole cell methanolysates. VII. Fatty acid composition of Acinetobacter in relation to the taxonomy of Neisseriaceae.

The cellular fatty acids of seventeen Acinetobacter strains were determined. Most acids identified were previously found in neisseriae and moraxellae. Specific for Acinetobacter was 2-hydroxydodecanoid acid and a few minor unidentified components. The fatty acid data were analysed by numerical methods and compared with previous results obtained for neisseriae and moraxellae. The findings were consistent with genetic evidence for some affinities of genus Acinetobacter to genus Moraxella and "false neisseriae". Occasionally, a high resemblance in fatty acid pattern was demonstrated between a Moraxella strain and certain strains of Acinetobacter, and also between an Acinetobacter strain and certain "true neisseriae". Still, the acinetobacters constituted one single cluster separated from the other genera of Neisseriaceae.

Acinetobacter↗

PubMed1974