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W Rabsch

Publications and source records attributed to W Rabsch.

At least 55 records · Page 3Linked to original sources
PubMed1994

[Outbreak of Salmonella paratyphi B infections in connection with consumption of smoked fish].

In the period from 2-10 August 1991 an outbreak caused by S. paratyphi B occurred in five rural areas of the district of Leipzig. Eleven patients and one excreter were involved, and mild forms of disease were observed in most cases. In three of the patients a mixed infection with S. litchfield was diagnosed. Moreover at the same time 21 cases of enteritis caused by S. litchfield and three excreters associated with this serovar were registered in these five rural areas. Both infections with S. paratyphi B and S. litchfield occurred 1-3 days after consumption of smoked halibut. The fish smoked in a smokehouse in the Grimma rural area was delivered to the shops every day. The inspection of the smokehouse and the dispatch department provided no signs of contaminations. In the smoked fish samples investigated subsequently, Salmonella were no longer detectable. The results of typing confirm the identity of all S. paratyphi B strains isolated. The possibilities of contamination of the smoked halibut are discussed. This study emphasises the possible transmission of salmonella by way of the food fish. On that occasion also a non-frequent serovar such as S. paratyphi B can be isolated and a light course of disease as e.g. febrile gastroenteritis can be observed and may attain epidemiological significance.

Adolescent↗
PubMed1993

Selective pre-enrichment of Salmonella from eggs by siderophore supplements.

Salmonella can overcome the iron limitation of iron-limited nutrient media and albumen by utilizing the siderophores ferrioxamine E and G und grow. 14 out of 18 food-poisoning Salmonella strains of different serotypes stored in hen's egg albumen (approx. 2 organisms/ml) could be detected after 6 h of pre-enrichment with buffered peptone water supplemented with ferrioxamine G (1 microgram/ml) on selective nutrient media. In contrast, only 4 of these Salmonella strains could be reisolated without supplementation. E. coli strains cannot be supplied with iron by ferrioxamines E and G. Therefore, Salmonella enteritidis phage type 4/6 could be isolated in great numbers from mixed cultures with E. coli kept in albumen. Buffered peptone water supplemented with ferrioxamine G also permitted a successful reisolation of Salmonella enteritidis from artificially contaminated eggs. Ferrioxamines E and G function as selective growth factors to enhance sensitivity in the isolation of Salmonella in other nutrient media, too.

Culture Media↗
PubMed1993

[The epidemiological analysis of Salmonella typhimurium infections in cattle--results of lysotyping and biochemotyping in the region of East Thuringia from 1974 to 1991].

597 strains of Salmonella typhimurium found in samples from cattle in Eastern Thuringia from 1974 to 1991 were investigated to their phage types and biochemotypes. 21 different combined types were found out among which the phage types n.c. 1/72/n. c.(204), 2 b/23 (92) and 1 a/9 (49) dominated at certain times. With the help of two examples it is shown that cases of Salmonellosis with Salmonella typhimurium within one farm occurring one after another can be different infections that are independent from each other. The complex typings are capable to clear up epidemiological connections and therewith support the control of infections and the protection of people's health consequently.

Animals↗
PubMed1992

Host factors versus virulence-associated bacterial characteristics in neonatal and infantile bacteraemia and meningitis caused by Escherichia coli.

Possession of P fimbriae, virulence-associated O and K antigens, haemolysin and aerobactin production, and susceptibility to 10 antimicrobial agents were studied in 63 Escherichia coli strains isolated from blood or CSF of infants who were grouped according to their clinical characteristics. These isolates were compared with 35 faecal E. coli strains from healthy infants. Individual virulence factors showed a relatively weak association with invasive infection except for P fimbriae in urosepsis and aerobactin production in meningitis. Combinations of factors were generally more predictive for defining virulent clones, particularly in infants defined as being at normal risk of developing septicaemia. Thus, 62% of isolates from such infants had characteristics typical of previously described uropathogenic or meningitis-associated clones of E. coli, compared with 32% of the isolates from high-risk infants (i.e., those defined as being at high risk of developing septicaemia) and only 9% of the faecal isolates (p less than 0.001 and less than 0.05, respectively). Overall, 45% of the episodes of invasive infection were caused by such clones, whereas risk factors (conditions considered to be associated with increased risk of invasive infection) were present in 59% of the infected infants (39% in meningitis and urosepsis, 78% in cryptogenic septicaemia and untreated bacteraemia). The results indicated that bacterial factors played a significant causative role in neonatal meningitis and urosepsis, particularly in normal-risk infants, whereas predisposing host factors contributed greatly to cryptogenic septicaemia and untreated bacteraemia.

Antigens, Bacterial↗
PubMed1992

Nationwide spread of Klebsiella oxytoca K55 in Swedish neonatal special care wards.

In a nationwide survey of invasive bacterial infections in Swedish neonates, 36% of Klebsiella spp. were Klebsiella oxytoca serotype K55. This unexpectedly high proportion of K55 infections was due to clusters of infection in neonatal special care wards, and at first seemed attributable to nosocomial spread of a K. oxytoca strain of high virulence. Factors predisposing infants to infection were, however, found irrespective of whether the infecting strain was of serotype K55 or not. Additionally, the prevalence rates of a potential virulence factor, siderophore production, were similar among the two groups of strains. During the same period of time a K. oxytoca K55 with similar biochemical phenotype and drug resistance pattern was found to be spread among the neonates in 12 of 22 neonatal wards in Sweden. The increased proportion of invasive neonatal K. oxytoca K55 infections thus seemed to reflect a high rate of colonization rather than an increased virulence of the K55 strain.

Disease Outbreaks↗
PubMed1991

The specificity of bacterial siderophore receptors probed by bioassays.

The ability to utilize siderophores of bacterial and fungal origin has been studied in wild-type and mutant strains of the enterobacterial genera Salmonella, Escherichia, Shigella, Moellerella, Klebsiella, Enterobacter, Hafnia, Pantoea, Ewingella, Tatumella, Yersinia, and in the non-enterics Aeromonas, Pseudomonas and Aureobacterium. Although only a few representative strains were tested, the results show characteristic genus-specific differences in the utilization of hydroxamate and catecholate siderophores. Moreover, the different response to structural alterations of certain siderophore classes by some wild-type and mutant strains points to variable interacting receptor domains.

Bacteria↗
PubMed1991

Different systems for iron supply of Salmonella typhimurium and Escherichia coli wild strains as tool for typing.

Hitherto the siderophore-pattern analysis included bioassays to detect enterobactin,aerobactin and other siderophores of Enterobacteriaceae. In addition, 2,3-dihydroxybenzoic acid, the precursor of enterobactin, and new hydroxamate siderophores could be examined by means of two new Salmonella mutants as indicator strains. In this manner the siderophore pattern analysis extends its discriminating ability. Among 167 Salmonella typhimurium strains tested, we detected 5 siderophore patterns. 6 siderophore patterns could be detected among a total of 204 E. coli strains. Using siderophore pattern analysis for clinical-epidemiological and ecological purposes appropriate technical methods can be recommended.

Biological Assay↗
PubMed1989

[Diagnosis of salmonellosis].

The determination of clonal identity of bacterial isolates of Salmonella, in particular epidemiological important serovars of Salmonella, is an unequivocal prerequisite for the study of the epidemic process of salmonellosis. This is demonstrated for the serovar S. typhimurium by means of classical as well as molecular methods for epidemiological subdifferentiation.

Animals↗
PubMed1989

[Epidemiology of salmonellosis].

The diagnostically and in regard to surveillance rather comprehensively recorded salmonellosis bear the character of a model of zoonotic diarrhoeal diseases. Whereas those serovars predominantly adapted to human beings or animal species are without any importance in this connection, such serovars with own epizootic processes in different animal species with or without causing illness are able to be transferred to human beings via foods of animal origin and to act as etiological agents of gastroenteritis. Some strains of them equipped by special properties often encoded by plasmids can be transferred from man to man, too. In GDR in 1987 S. enteritidis (34.0%), S. typhimurium (17.9%), S. manhattan (7.7%) and S. agona (7.4%) amounted to two thirds of all the salmonella isolates in connection with human enteritis. For analyzing epizootic-epidemic processes in the case of rare serovars the identity of serovars is sufficient in first approximation, in the case of frequently isolated serovars the complex typing of the concerned strains by using epidemiological laboratory methods is required.

Animals↗
PubMed1988

Further differentiation of Enterobacteriaceae by means of siderophore-pattern analysis.

By means of a combination of 5 siderophore bioassays using several indicator strains, genera, species and subspecies of Enterobacteriaceae can be further differentiated. Enterobactin, aerobactin and other siderophores produced can be detected. Each strain shows specific pattern which we called siderophore-pattern. It is easy to separate Morganella, Proteus, Providencia, Yersinia strains from the genera Salmonella, Shigella, Escherichia coli, Enterobacter, Citrobacter, Klebsiella, Serratia. Enterobacter agglomerans strains differ from other Enterobacter species with respect to their siderophore pattern. In Salmonella strains there are differences between the subspecies I and IV. Additionally the most strains of Salmonella subspecies I from nosocomial infections produced aerobactin, in the most cases determined by plasmids. Among Shigella strains different siderophore pattern exist according to other epidemiological markers. S. flexneri strains of serovar 6 produced contrary to the strains of other serovars enterobactin. By means of the siderophore-pattern analysis E. coli strains of serovars 01; 02; 018 can be further differentiated. E. coli 01:K1 strains containing the fimbrial antigen F11 produced aerobactin whereas the F9 strains did not. All Hafnia alvei strains produced a uniform siderophore pattern, different from all other members of the enterobacteriaceae family. With this aim Hafnia alvei strains can be easily separated under practical conditions.

Enterobacteriaceae↗
PubMed1988

Investigations of Salmonella strains from different clinical-epidemiological origin with phenolate and hydroxamate (aerobactin)--siderophore bioassays.

By means of phenolate siderophore negative S. typhimurium mutants as indicators, a bioassay for the detection of phenolate production was applied in Salmonella species. Different Salmonella strains have a weak or normal phenolate siderophore production. Host-adapted Salmonella strains show weak, other strains of Salmonella show normal growth zones of the indicator strain. Besides phenolate siderophore production there are defined S. typhimurium strains, exhibiting phage type ut/ut, biochemical type a and some strains of S. wien, S. infantis and S. haifa from nosocomial infection producing hydroxamate siderophore (aerobactin) as a compotent of a second iron uptake system.

Biological Assay↗
PubMed1987

A new hydroxamate siderophore for iron supply of Salmonella.

A new hydroxamate siderophore was isolated from Salmonella stanleyville strain 207/81. The organism exhibited an unusual siderophore pattern in failing to synthesize enterobactin and aerobactin. The purified siderophore was characterized by cross-feeding, paper chromatography, thin layer chromatography and paper electrophoresis. In respect to iron supply of Salmonella strains there were relationships between this and other well-known siderophores, e.g. enterobactin, aerobactin, rhodotorulic acid and ferrichrome. The new hydroxamate siderophore was detected in all Salmonella strains tested. One of the mechanisms for acquisition of iron by bacteria is the excretion of iron specific chelators, termed siderophores, the function of which is to sequester and transport iron via specific transport proteins into the cell. In Salmonella strains two types of siderophores were found. There are strains which produce enterobactin alone and some which produce enterobactin and aerobactin. In screening investigations of Salmonella, in respect to their "siderophore pattern" strains with unusual properties were detected. Beside others, the strain Salmonella stanleyville 207/81 was unable to synthesize enterobactin or aerobactin. Investigations on the effective iron supply system, presented in this paper, led to a new hydroxamate, later found in all Salmonella strains tested.

Biological Assay↗
PubMed1986

[Excretion of 2,3-dihydroxybenzoic acid by an enterobactin-negative multiresistant wild strain of Salmonella typhimurium].

In investigations of iron siderophores produced by different Salmonella typhimurium strains we found a strain deficient in enterobactin production. Using microbiological and chemical methods, we detected the production and excretion of 2,3-dihydrobenzoic acid, a metabolite of the enterobactin biosynthesis pathway. The strain was able to produce aerobactin. We suggest that the iron uptake of pathogenic strains can be mediated by aerobactin alone. For a correct enterobactin bioassay it is necessary to use a mutant unable to grow on 2,3-dihydroxybenzoic acid.

Chromatography, Paper↗
PubMed1985

[Iron uptake of Salmonella typhimurium strains from different epidemiological sources].

All Salmonella typhimurium strains tested were able to use iron from transferrin. In buffered nutrient broth -- poor in iron-content -- the strains were tested in 59FeCl3 and 59Fe-transferrin uptake in different growth phases. In the early log phase the strains are able to catch the 59Fe3+ in a very great amount as it is necessary for the growth. The content of 59Fe per cell was in the late log phase reduced until to a value, which seen to be enough for growth. The acquisition of 59Fe-transferrin between the early and late log phase tested by 4 S.typhimurium strains was different.

Chlorides↗
PubMed1985

[Bioassay for the detection of hydroxamate-iron-chelators (Aerobactin)].

Different Salmonella strains were tested for aerobactin production in a hydroxamate-bioassay with the aerobactin indicator strain E. coli LG 1522. The majority of hospital strains of Salmonella typhimurium produce hydroxamate siderophore. On the other hand S. typhimurium strains belonging to phage type n. c. 1/72/n. c., biochemical type b from human and animal sources, were unable to produce this siderophore. Serotypes other than S. typhimurium for example the multiresistent S. wien hospital strains, which were isolated in western europe and in the GDR, can excreate hydroxamate siderophore. Plasmids pIE 528 and pIE 5 234 isolated from Salmonella hospital strains produce hydroxamate siderophore in the enterobactin negative Salmonella typhimurium-strain enb-7. Thus, the hydroxamate bioassay may be a useful supplementary test for epidemiological strain characterization.

Biological Assay↗
PubMed1983

[Plasmid patterns of Salmonella typhimurium lysotype n.c. 1/72/n.c. strains from East Germany].

Salmonella typhimurium strains isolated in the German Democratic Republic between 1972 and 1980 mainly belong to phage type n.c.1/72/n.c. and biochemotype b. Nearly all of these strains are characterized by an identical basic plasmid pattern. Thus, they may be considered to be independent isolates of the same epidemic strain. Moreover, some multiple drug resistant offsprings of that epidemic strain have been characterized by their carriage of an additional IncH-1 R plasmid. However, a few strains of phage type n.c.1/72/n.c. were found to differ fundamentally in their plasmid patterns from that of the epidemic strain. The phage pattern of these strains is determined by a conjugative R plasmid belonging to the incompatibility group IncI4. Despite of the same phage- and biochemotype these strains must be considered non-related with the epidemic strain, therefore. The analysing of the plasmid pattern of bacterial strains turns out to be an important contribution to the investigation of epidemic processes.

Anti-Bacterial Agents↗