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G Havemeister

Publications and source records attributed to G Havemeister.

At least 19 recordsLinked to original sources
PubMed1995

Comparison of BGB-MUG and LSTB-MUG in microbiological surveillance of recreational waters.

Recreational water surveillance is an important tool to prevent health hazards for the population. Therefore distinct guide and imperative values for fecal indicators are listed in the EC directive about water quality control. The detection methods, however, give laboratories some room to choose their own method, which has led to difficulties in the comparability of results. In 1989 an ad-hoc working group of the coastal countries of Germany established detection methods, which by now are obligatory for these countries. Fecal and total coliforms (FC and TC) are detected by a triplicate mpn-procedure using brilliant green-bile-lactose broth supplemented with tryptophane and 4-methylumbelliferyl-beta-D-glucuronide (BGB-MUG) as selective medium. Gas-, fluorescence- and indole-positive cultures are considered fecal coliform-positive. In the last years rises in TC but not in FC counts were observed in fresh waters. A study was carried out to evaluate the official method in another bathing season, to determine bacterial species leading to false-positive TC cultures and to compare BGB-MUG with laurylsulphate-tryptophane-MUG (LSTB-MUG). Water samples of different salinities and nutrient input were collected in weekly intervals from April to October. FC and TC concentrations were determined and all TC-positive cultures were differentiated further. The FC counts obtained by enrichment in BGB-MUG or LSTB-MUG were nearly identical, the rate of fluorescence-positive, indole-negative tubes being approximately 0.6%. Differentiation of FC-negative cultures showed a false-negative rate of 2.87% for BGB-MUG and of 8% for LSTB-MUG. During the summer months TC counts in BGB-MUG exceeded FC counts by far at most of the sampling sites. This effect was much less pronounced in LSTB-MUG; the difference between both enrichment media being significant. Differentiation of presumptive TC from BGB-MUG resulted in a high percentage of Aeromonas spp. in fresh waters. LSTB-MUG was clearly more selective for TC than BGB-MUG, but still with an average of 10% of the test tubes being false TC-positive (BGB-MUG 46%). The sensitivity of BGB-MUG was below 60% (LSTB-MUG 89%). LSTB-MUG should be preferred as enrichment medium in mpn-examination of recreational water, if no further differentiation is carried out. The selectivity for TC is better than in BGB-MUG and the only slight inhibitory effects can be tolerated.

Aeromonas↗
PubMed1995

Evaluation of MUG-supplemented media for the detection of E. coli in recreational water surveillance.

Four media containing 4-methylumbelliferyl-beta-D-glucuronide were evaluated as a non-confirmatory procedure for E. coli detection in recreational water surveillance. The media included ECD-Agar for membrane filtration and laurylsulphate-tryptose, brilliant-green-bile and lactose as broth media in a three tube most probable number procedure. From six representative water sites, samples were collected weekly over a typical summer season (17.05-27.09.1994) and processed as parallels, using each media at two different incubation temperatures (36 degrees/44 degrees C). Results showed that incubation temperature had no impact on E. coli counts. Each media at a given temperature could be regarded as individual enrichment procedure. None of these enrichment procedures showed a constant and predictable higher sensitivity during the sampling period at all sites compared to the others tested. For parallel results, the rate of agreement, based upon EC-guideline (76/160/EWG) staging of recreational water quality, was 85% for membrane filtration and 75% for the MPN-procedure results. Marked differences could be observed in false-positive specificity showing correlation to the selective characteristics of the media. Subsequently lactose-broth at 44 degrees C performed worst with 30% non verifiable results, while ECD-agar and laurysulphate-tryptose-broth, both at 44 degrees C, had a nearly 100% confirmation rate. Thus, combining high specificity with no lack in sensitivity these two MUG-supplemented media seem to be best suited for E. coli detection in routine recreational water surveillance.

Colony Count, Microbial↗
PubMed1992

[Growth behavior of Enterobacteriaceae in BRILA-MUG-broth and in different modifications of broth].

Both substances, brilliant green and bile, inhibit the growth of gram-positive bacteria in culture media and selectively enrich gram-negative bacteria. Therefore, the brilliant green-lactose-bile broth (BRILA) and the BRLA broth supplemented with tryptophan and methyl-umbelliferyl-beta-D-glucuronide (BRILA-MUG) contain brilliant green as well as bile. Because BRILA-MUG broth as a selective enrichment and differentiating medium of faecal coliform and total coliform bacteria, E. coli and coliforms, respectively, is recommended for testing samples of surface water according to the EC guidelines for bathing waters (no. 76/160 EWG), the question arose of the optimal combination of components in the BRILA-MUG broth. As the described investigations show, the addition of buffer substances did not improve the culture properties of the BRILA-MUG broth. However, the original BRILA broth was improved by supplementing it with buffer substances such as CaCO3 or Na2HPO4. The same effect of culture improvement was obtained by removing brilliant green. This modification of BRILA broth is practically identic with the well-known MacConkey broth. On the other hand, the modification of omitting bile from the original BRILA broth causes a remarkable impairment of the culture properties lowering bacterial counts per ml by 3-5 log. The observations suggest that brilliant green inhibits both, gram-positive bacteria as well as the gram-negative Enterobacteriaceae. Therefore, it is a selective substance of doubtful usefulness.

Anti-Infective Agents, Local↗
PubMed1991

Determination of totalcoliform and faecalcoliform bacteria from bathing water with FLUOROCULT-BRILA-broth.

The BRILA-MUG one-tube-test in connection with the MPN-method can be used successfully to determine with sufficient reliability the number of indices of total coliforms and faecal coliforms according to the EC-Directive for bathing waters. Using the one-tube-test and determination of gas production, fluorescence and indole production is, from the hygienic point of view for surface waters, equal in value to subculture and biochemical identification. The test needs only a minimum of material and laboratory staff. Differences between this test and other more extensive tests with several biochemical identification steps are negligible. The work load for bathing water monitoring would not be justified in this case. Due to the occurrence of Aeromonas, the values for total coliforms compared to a determination with biochemical identification are higher in some cases. A high contamination with Aeromonas indicates a high polluted surface water with a high degree of eutrophication. This is an important additional criterion for the evaluation of bathing waters, even when a direct dependence on faecal contamination does not exist in every case. The degree of an up-to-date faecal contamination can be estimated by the pollution with faecal coliforms.

Aeromonas↗
PubMed1991

[Comparative studies of fresh and seawater for the determination of total coliform and fecal coliform bacteria according to the European Economic Community guideline 76/160 (bathing water) by the use of the most-probable-number method with BRILA-MUG broth and differentiation according to the drinking water ordinance].

During the summer season of 1989 about 222 samples of bathing water (Northsea, Baltic Sea and inland waters) were investigated, i.e. 2 times 1998 dilution tubes (1501 positive) were tested. Results with BRILA-MUG and lactose-bouillon were compared and additional 97 samples were tested with one respectively three colonies by confirmative tests. -- The BRILA-MUG one-tube-test (gas, fluorescence and indol) has as expected larger numbers of total coliforms (GC) and faecal coliforms (FC) in comparison with corresponding numbers for E. coli and coliform bacteria according to German law for drinking water (TrinkwV). -- BRILA-MUG and lactose-bouillon with the same identification mode according to "TrinkwV" has corresponding results concerning E. coli and coliform bacteria. -- Following the identification mode according to "TrinkwV" the total coliforms (GC/gas in BRILA-MUG) depending on the origin proved 60-80% as coliform bacteria. Additional API-tests showed that the other bacteria are coliform bacteria too or bacteria which can be considered as indicators for water pollution. -- Faecal coliforms (FC/fluorescence and indol-positive) depending on the origin proved 70-90% as E. coli, if following the identification mode according to "TrinkwV". Using 3 instead of 1 colony per positive dilution tube for identification the positive results increased approximately by 9%. 15% of negative results with the identification mode according to "TrinkwV" proved as E. coli-positive with identification according to API-system, i.e. the corresponding rate of E. coli-positive tubes will therefore be higher than shown above. The BRILA-MUG one-tube-test in connection with the MPN-method can be used successfully to determine the number of total and faecal coliforms according to the EEC-directive for bathing waters. The test needs only a minimum of material and also a minimum of laboratory staff. Differences between this test and other more extensive tests with several biochemical identification steps are negligible. The work load for bathing water tests would not be justified in this case.

Bathing Beaches↗
PubMed1990

[Reactions of different Enterobacteriaceae and Vibrionaceae species in BRILA-MUG (Fluorocult) bouillion].

In order to test the usefulness of BRILA-MUG (= Fluorocult) medium (Merck) for isolation and identification of total coliforms and faecal coliforms in surface water according to the EC guidelines for bathing waters a total of 969 strains of different Enterobacteriaceae and Vibrionaceae species was examined under different culture conditions. These included 486 E. coli (reference strains of O-groups 1-170, enterotoxin and Verotoxin-producing strains), 149 Salmonella (subspecies I-VI), 92 Yersinia, 44 Shigella, 64 Vibrio, 16 Aeromonas, and 118 strains of other Enterobacteriaceae species. After 48 h incubation at 36 degrees C 372 (82.0%) of 486 E. coli showed the typical reactions of gas formation, fluorescence (beta-glucuronidase activity), and indole production. Examination of fluorescence after addition of 1 N NaOH (0.5 ml), or testing of indole production after subculture in tryptophane containing broth improved the amount of typical reactions to 434 (95.4%). Incubation at 44 degrees C for 48 h gave less favourable results as compared with that at 36 degrees C. Out of 483 strains of other species 3.9% Salmonella strains of subspecies II-IV, 6.25% Citrobacter freundii, and 50% Edwardsiella tarda strains yielded reactions typical of E. coli. Shigella and Yersinia strains occasionally produced indole or fluorescence, but never visible gas.

Culture Media↗
PubMed1990

[The determination of total coliform and fecal coliform bacteria for quality control of bathing waters using the EC guideline 76/160 most probable number and BRILA-MUG broth].

In the monitoring of bathing waters according to EC Guideline 76/160 EWG, total coliform and faecal coliform bacteria have to be regularly determined by a quantitative method. This requirement can be fulfilled with sufficient reliability by the MPN method. Therefore, a procedure had to be developed which on the one hand is practical and not laborious, and on the other hand warrants a sufficiently specific, quantitative bacteriological diagnostic. The commercially available BRILA-MUG-broth appeared suitable for this purpose as it allows a direct determination of total as well as faecal coliform bacteria in the same assay. By this method, total coliform bacteria are recognized by gas production from lactose whereas faecal coliform bacteria additionally produce indole and liberate fluorochrome from MUG. Theoretical considerations and practical experiences showed that the rate of false-positive as well as false-negative results was within a range of 10% if compared with reactions described in the literature. Some factors which may influence the results are discussed.

Colony Count, Microbial↗
PubMed1982

[Faecal streptococci as indicator organisms of drinking water].

The rules of the European Economic Community to harmonize the hygienic quality of drinking water write out the faecal streptococci as indicator organisms. This operating definition of the faecal streptococci prohibits its taxonomic limitation to enterococci or group D streptococci. Therefore, we have undertaken studies concerning the methods for routine examinations. Comparative investigations of selective enrichment broths showed no significant differences of the end concentration of glucose in the range of 0.5-1.0% and of sodium azide in the range of 0.02-0.05%. 36 degrees C was a better incubation temperature than 44 degrees C and the results were better after 24 h than after 48 h. Comparative investigations of selective plating media showed less selectivity of the bile-aesculin agar and gentamicinthallous-carbonate agar than that on the one hand of citrate-azide-tween-carbonate agar, KF streptococcal agar or Slanetz-Bartley enterococcal agar, and on the other hand of kanamycin-aesculin-azide agar. All together the kanamycin-aesculin-azide agar seems to be a little better than the other media (Table 2) 356 strains of faecal streptococci were isolated from the studied media. More than 20 characteristics were investigated and, there upon, the strains were differentiated (Table 3). S. faecalis predominates in human materials, i.e. urine, S. faecium and S. durans were isolated specially from sewage and waste water (Table 4). The single species of faecal streptococci grow specificly on the different selective media, and therefore, each agar specimen prefers the one or other species more or less selectively (Table 5).

Azides↗
PubMed1982

[Elimination of bacteria and viruses by flocculation in treated sewage].

In laboratory experiments the elimination of bacteria and viruses in treated sewage by different flocculants varied between 47.9 and 99.5%. Ferric and aluminum chloride reduced both groups of microorganisms in a greater extent than polyelectrolytes, among those the cationic polymers were better suitable than nonionic and anionic types. With a combination of an anorganic flocculant and an polyelectrolyte no increased effect was seen according to the elimination of the colony number and the number of viruses.

Aluminum↗
PubMed1981

[Hygienical assessment of swimming pool water covers made of plastic (author's transl)].

Swimming pool water covers made of different plastics were investigated in laboratory experiments. The possible influence on the chemical and the bacteriological water quality (test bacterium Ps. (fluorescens) was observed. Strong-PVC-plastics proved to have no respectively hardly any chemical or bacteriological influence on the water quality. PE-soft-plastics showed clearly higher chlorine consumption and TOC counts. The influence on bacterial growth was here either inhibition or of nutrient character. A direct colonisation of the plastic was not to be seen--neither in vivo nor in vitro. There are no principal objections against the use of plastics swimming pool covers from hygienical point of view. Some limitating aspects are discussed.

Chlorine↗
PubMed1980

[Examination and experiences with the fish-test according to the German Sewer Charge Law (AbwAG) (author's transl)].

Different domestic and industrial waste waters were tested by the fishtest with orfes (breeding form of Leuciscus idus melanotus) to determine their toxicity. There was no reaction of the test fishes in receiving waters. Domestic sewages from secondary treatment proved also nontoxic in 50% of the tested waste waters. Other sewages yielded very low toxicity concentrations (highest concentration: LD50 = 660 l/m3). The fishtest of industrial effluents resulted maximal LD50 concentrations of 62.5 l/m3. A comparison to the chemical analysis reveal no correlation between results of the fishtest and the pollution of sewage samples. Observations and experiences with the methods of the orfetest are critically discussed especially according to routine examinations.

Animals↗
PubMed1978

[About the importance of chemical flocculation of wastewater in regard to hygienical aspects (microbiological and virological examinations in a wastewater treatment plant) (author's transl)].

In a small wastewater treatment plant corresponding samples from the intake and outtake of the chemical flocculation were chemically, microbiologically and virologically investigated and compared. It was found that both, the plate count and the number of coliforms, decreased about 90% to 95%. The phosphate content went down about 88%. The BOD5 reduction was ca. 80%, the COD reduction ca. 50%. Poliomyelitisviruses were found regularly in the intake but never in the outtake. Specially in regard to the high plate count- and virusreduction the chemical flocculation seems to be remarkable from the hygienical point of view not only for limnic but also for coastal waters.

Escherichia coli↗
PubMed1977

[Examination of the growth of pathogenic organisms on the elastic joints made of plastic material in swimming baths (author's transl)].

Roughly three months after a swimming bath had been put into operation a growth was observed on the permanently elastic joints made of plastic material at the bottom of the pool. Samples were taken and examined and bacteria, fungi, green algae as well as many monocellular organisms were found. The repeated identification of a pathogenic dermatophyte and of P. aeruginosa was of hygienic significance.

Chlorophyta↗
PubMed1975

[Qualitative und quantitative salmonella investigations and their hygienic valuation in connection with the E. coli titre, demonstrated with examples from the coastal waters of Kiel bight (Western Baltic Sea) (author's transl)].

Qualitative salmonella investigations and E. coli titre determinations were carried out in about 4,000 water samples taken from the coastal region of Kiel Bight (Western Baltic) in 1972 and 1973, and evaluated in connection with epidemiological data. Further, about 100 samples were determined quantitatively by the MPN method and set in relation to the E. coli titre. The significance to be attributed to positive salmonella findings particularly in relation to the assessment of risk of infection and as impurity indicators was investigated with reference to this material. A comparison of salmonella findings and E. coli titre showed that with increasing E. coli contamination the proportion of positive salmonella findings also increased (paraboloid curve). Salmonella frequencies and the frequency with which the limiting values of the E. coli titre is exceeded run approximately parallel; the frequency of exceeding a limiting value of E. coli titre of 1.0 and the frequency of salmonella (determination in 100 ml) in sewage laden areas largely coincide. The quantitative salmonella investigations (MPN method) also showed that up to an E. coli titre of 1.0 extremely low salmonella counts only are to be expected (on the average, less than 2/100 ml). With an E. coli titre of 0.1, a marked increase can be seen. A limiting value of 1.0 is proposed for the E. coli titre in coastal waters. Epidemiological data have also shown that an increased risk of infection could not be deduced from positive salmonella findings. According to the present investigations, the value of the information obtained from salmonella findings is small compared with the E. coli titre. Considering the great expense of laboratory investigations, tests for salmonella should be dispensed with in routine examination of water.

Cell Count↗