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Biomedical subjects

W Stelzer

Publications and source records attributed to W Stelzer.

At least 19 recordsLinked to original sources
PubMed1992

Comparison of two media for the isolation of thermophilic Campylobacters from waste waters of different quality.

Counts of thermophilic campylobacters from 31 different waste water samples were parallel estimated with two different cultivation media. The resulting increased isolation sale obtained with an modified Charcoal-Cefoperazone-Deoxycholat-Medium (MCCD-Medium), was statistically significant. An 15.8 fold increased isolation rate, compared with the standard medium, could be estimated with the help of the geometric mean.

Abattoirs↗
PubMed1992

[The occurrence of Campylobacter in a mountain brook].

The mountain river showed fecal water pollution at all sample sites studied. The arithmetic mean values of total coliforms ranged between 28 and 196/ml. Campylobacters were isolated from all sample sites studied, with a maximum value of 1,100 Campylobacter/100 ml river water. The MCCD-medium resulted in significantly higher isolation rates of Campylobacter from water samples than the VTPRC-medium compared. Colony counts, total coliforms and Campylobacter showed numerical relations of 3831:100:1 respectively.

Campylobacter↗
PubMed1992

[The occurrence of aeromonads in a drinking water supply system].

This study concerns with the occurrence of aeromonads, coliforms and colony counts in a drinking water supply. Aeromonas contents were detected in the range of 15.0 to greater than 2,400/100 ml in the raw water samples of the man made lake. After the drinking water treatment process including fast sand filtration and chlorination aeromonads indicated in comparison to total coliforms and colony counts early and significant an after-growth of maximal 240 aeromonads/100 ml in the peripheric drinking water supply. Drinking water samples characterized by a higher water temperature resulted in the highest contents of aeromonads. The Aeromonas-Species Aeromonas sobria and Aeromonas hydrophila were isolated most frequently with 56.9 and 37.4 percent, respectively. The role of aeromonads as an indicator of after-growth in drinking water supplies is discussed.

Aeromonas↗
PubMed1991

Characterization of thermophilic campylobacters originated from a high-rate sewage treatment plant.

Campylobacter strains isolated during a one-year study from a municipal waste water treatment plant have been characterized. The study shows a considerable release of Campylobacter strains into the receiving linked river system. Campylobacters isolated here, are very similar to isolates originating from enteritic cases. In contrast to other reports we conclude that the strains released from the sewage treatment plant into the environment represent a potential risk for public health.

Bacterial Proteins↗
PubMed1991

[The occurrence and survival of Campylobacter in sewage sludge].

Campylobacter was found only in raw sewage sludge samples of the high-rate municipal sewage treatment plant studied. Campylobacters were isolated from 28.6% of the sewage sludge samples of grit tank and primary settling tank. 40% of the settled activated sludge samples contained Campylobacter. Campylobacter was never found in digested sludge of a mean sludge age of more than 90 days. The survival times of Campylobacter in sewage sludge samples ranged between some hours and 10 days. Therefore a low risk of the spread of Campylobacter in the environment due to agricultural application of digested sewage sludge is assumed.

Campylobacter↗
PubMed1991

Environmental aspects of Campylobacter infections.

Epidemiological data indicate high incidence of campylobacteriosis. Improperly prepared poultry-products, unpasteurized milk as well as non-chlorinated drinking water were shown to be the main vehicles of Campylobacter transmission to man. There is a lack of knowledge concerning the role of various environments in transmission of Campylobacter. The review summarizes the present knowledge about occurrence and survival of Campylobacters in various environments (sewage, sludge, surface water, drinking water). In conclusion risk assessment for public health is discussed.

Animals↗
PubMed1990

Identification of Campylobacter jejuni and Campylobacter coli from waste water by SDS-disc-page of whole cell protein.

Analysis of the electrophoretic profiles of whole cell proteins of Campylobacter strains from waste water was used to differentiate C. jejuni from C. coli. The results show, that biotyping of campylobacters from waste water may results in a false species differentiation. Some of the Campylobacter strains originally typed as C. coli, were proved to be atypical C. jejuni strains. Therefore, in addition to biotyping and serotyping, electrophoretic typing is recommended to ensure correct identification of Campylobacter, especially from environmental sources.

Bacterial Proteins↗
PubMed1989

In vitro studies on long-term stability of R plasmids in Escherichia coli K12.

The maintenance and stability in an E. coli K12 host of environmental isolates of R plasmids encoding gentamicin resistance during multiple passages in antibiotic-free and antibiotic-containing broth were investigated in regard to the conferred resistance phenotypes and the respective EcoRI digestion patterns. Only two plasmids belonging to the IncM group maintained stable endonuclease digestion patterns over a 15-month period in both of the media applied. Other members of this group revealed a considerable variability in their EcoRI digestion patterns, but a stability in their resistance determinants. Two IncM plasmids and an IncK plasmid exhibited partial resistance loss under nonselective conditions. The complete segregation of resistance determinants from IncOF plasmids resulted in a stably maintained cryptic core plasmid.

Anti-Bacterial Agents↗
PubMed1989

A study of Campylobacter jejuni and Campylobacter coli in a river system.

Campylobacter isolates were detected in 82.1% of river water samples moderately polluted with organic wastes. In the majority of the samples less than 10 Campylobacter cfu/100 ml were detectable. The presence of waterfowl and the faecal contamination from a poultry-farm resulted in considerable higher Campylobacter contents (greater than 240/100 ml). Correlation studies showed a high correlation coefficient (P less than 0.05) between the number of campylobacters and that of total coliforms. Campylobacter isolates were never found in river water samples of 100 ml of volume with total coliform contents less than 10/ml. Campylobacter contents and the spectrum of serotypes isolated indicate hygienic precautions for drinking water supply from oligotrophic surface waters if the water is distributed without chlorination.

Animals↗
PubMed1988

Characterization of Campylobacter jejuni and Campylobacter coli isolated from waste water.

The raw sewage samples of the investigated municipal sewage plant (sewage flow of about 30,000 m3/d) contained about 10(3) campylobacters/100 ml. The sewage plant reduced 80.8% of organic wastes (COD), 85.0% of colony counts (20 degrees C), 92.5% of total coliforms and 88.0% of campylobacters. The sewage plant effluent contained an average of 1.3 X 10(2) campylobacters/100 ml. About 10(10) campylobacters are discharged with the effluent of the high-output sewage plant into the receiving water every day. No reduction of the indicator bacteria was found in the activated sludge tank, there was, however, a significant reduction (94.5%) of campylobacters. In total, 94 strains were differentiated by biotyping and serotyping. 59.6% were found to be Campylobacter jejuni and 40.4% were Campylobacter coli. 8 Serotypes were found among the C. jejuni strains and 12 among C. coli. The raw sewage of the investigated oxidation pond treatment plant contained an average of 51 campylobacters/100 ml. The sewage plant effluent did not show campylobacters in any case.

Bacterial Typing Techniques↗
PubMed1988

[Isolation and characterization of gentamicin resistance plasmids of coliform bacteria from the waste water of a water treatment plant].

Gentamicin resistance coliforms detected continuously in raw and purified waste water samples of a sewage treatment plant made up less than 0.1% of all coliforms. 43.9%; 31.4%; 13.3% and 11.3% of gentamicin-resistant coliforms were identified as Enterobacter, E. coli, Klebsiella and Citrobacter, respectively. R plasmids encoding a gentamicin resistance phenotype were isolated and characterized. They range between 55 and 60 MD in size and belong to 3 incompatibility groups (IncOF, IncM, IncK). Using restriction endonucleolytic digestion of plasmids, they could be further characterized and subtyped. In contrast to moderate molecular alterations observed among the IncM plasmids, the IncOF plasmids reveal a high stability of restriction pattern. This IncOF plasmid was predominantly found in E. coli wild strains and detected continuously.

Citrobacter↗
PubMed1988

[The occurrence of antibiotic resistant coliforms in the waste water of a water treatment plant].

Colony counts and total coliforms of the investigated biological treatment plant were decreased by more than 90% on average. In activated sludge processes the colony counts increased, whereas total coliforms did not show significant differences between raw sewage and activated sludge processes. With regard to the antibiotics tetracycline, chloramphenicol, kanamycin and gentamicin raw sewage samples contained on average 10(3) antibiotic resistant coliforms/ml. From agar plates supplemented with antibiotics a total of 896 strains were characterized. Single resistant E. coli strains (29.3%) were isolated most frequently from agar plates supplemented with tetracycline. However, coliforms isolated from agar plates which were supplemented with chloramphenicol, kanamycin and gentamicin showed a prevalent resistance to 5 and 6 antibiotics tested. The variety of resistance patterns of gentamicin-resistant coliforms was determined by few plasmids encoding gentamicin resistance only.

Chloramphenicol Resistance↗
PubMed1988

[Detection of Campylobacter jejuni and C. coli in waste water].

For the detection of C. jejuni and C. coli in waste water the content of rifampicin in selective media was reduced from 10 micrograms/ml (Bolton and Robertson 1982) to 5 micrograms/ml and the content of polymymyxin B was increased from 0,25 microliter/ml (Skirrow 1977) to 2.5 micrograms/ml. On the Basis of this modification the isolation of C. jejuni and C. coli from waste water samples by membrane filter technique as well as by enrichment procedure was possible. Before inoculation of waste water samples the enrichment broth was preincubated at least 1 d at 37 degrees C under microaerophilic conditions. The Campylobacter test strains showed significant differences of growth between preincubated and non preincubated enrichment broth in the first hours of incubation.

Bacteriological Techniques↗
PubMed1986

[Comparative study of the detection of Pseudomonas aeruginosa in water].

In this report we examined quantitatively (MPN-procedure) various methods of isolating Ps. aeruginosa from surface waters. When comparing different media (malachitgreen broth, Preuss-broth, selenite broth, asparagine broth, malachitgreen/acetamide broth) the enrichments in malachitgreen and asparagine showed the highest isolation frequencies after an 48 h incubation time. In heavily polluted river water the results can be improved by a second enrichment step in acetamide broth. Dependent on the river water pollution 0...11,000 Ps. aeruginosa/l were detected. In waste water up to 2.4 X 10(6) Ps. aeruginosa/l were isolated. The results emphasize the significance of water as a reservoir and a source of distribution of Ps. aeruginosa in the environment.

Acetamides↗
PubMed1986

[Occurrence of gentamicin-resistant coliforms in river water samples].

In river water samples 0.006...0.3% of total coliforms were detected as gentamicin resistant. Among gentamicin resistant coliforms most strains (86.5%) could be identified as Klebsiella. Most frequently a Gm-plasmid of about 150 Md was isolated harboring in Klebsiella oxytoca, K. pneumoniae and E. coli strains. All gentamicin resistant wild strains transferred the resistance to E. coli K-12. Most Klebsiella strains harbored several plasmids, R-plasmids and others. There were not any differences in plasmid profiles between sensitive and resistant strains.

Drug Resistance, Microbial↗