Microbial Quality and Nutritional Aspects of Norwegian Brand Waters

The microbiological quality of the five leading brands of Norwegian bottled still waters was investigated. All brands were free for the enteric indicator organisms and named pathogens whose absence is demanded in current quality directives. The relatively nutrient-poor agar R2A revealed large heterogeneous bacterial populations which grew slowly, or not at all, on clinical media specified for use in substrate-utilization approaches to identification. The main approach used for identification was cultivation of microbes on R2A, followed by amplication and partial sequencing of 16S rDNA genes. The identity of the heterotrophic plate count of the brands differed significantly to that found in many other similar studies with respect to the dominating species. The bacterial flora was dominated by beta- and alphaproteobacteria most of which were psychrotolerant. Several brands contained Sphingomonas and large populations of Methylobacterium species which have been associated with a variety of opportunistic infections of immunocompromised hosts. Analysis of the isolated strains nutritional capabilities using the Biolog GN2® system, gave in most instances low positive scores, and strain identifications using the system were generally inconclusive. Measures of assimilable organic carbon in the water revealed that some brands contained levels higher than those which have been associated with biological stability and restricted or no growth of heterotrophs in distribution systems. The relationship between assimilable organic carbon and R2A plate counts was significant and moderately positive for bottled waters. Assimilable organic carbon correlated strongly with the survival time of Escherichia coli when introduced into bottles as a contaminant. Those brands having high values (~ 100 µg/L) supported protracted survival, but not growth of E. coli, whereas E. coli quickly became nonculturable in brands with low values. Thus measures of assimilable organic carbon may have a particular value in predicting the survival of this and nutritionally similar species of hygienic relevance. Only small numbers of fungi were found. However, one isolate (Aureobasidium pullans) has been associated with infections of humans

Undersøkelse av forandringer i mikrobiologisk kvalitet under produksjon og distribusjon av drikkevann ved Vansjø interkommunale vannverk

Innholdet av bakterier etter hvert trinn i behandlingsprosessen ved Vansjø vannverk og ved 19 punkter fra distribusjonsnettet ble målt. I tillegg ble tilstedeværelsen av sopp og protozoer i vannet under produksjon undersøkt. Parallelt med kimtallsanalyser ble det utført tester (Biolog® GN2) som gir en indikasjon på bakterienes samlede metabolske potensial i vannet. Vannverket produserer et drikkevann fritt for mikrober og som ikke ga utslag i panelet av 95 metabolske tester. Filtreringstrinn tilførte vannet bakterier og sopparten Cryptococcus magnus (som ikke regnes som sykdomsframkallende). Både UV-anlegget og postklorering inaktiverte effektivt den mikrobielle populasjonen. Amøber ble dyrket fra råvannet, men var ikke til stede i rentvannet. Nettprøvene inneholdt bakterier, men det var ingen klar sammenheng mellom avstand fra vannverket og kimtallet eller metabolsk aktivitet i vannet. Kimtalls- og GN2-data viste bedre og mer signifikante korrelasjoner for prøver tatt ved hvert rensetrinn enn for rentvannsprøver tatt under distribusjon. Dette kan tyde på at bakterier med naturlig opphold i råvannet har andre egenskaper enn de som finnes i ledningsnettet. GN2 ga et datarikt utrykk for det samlede metabolske potensialet i vannet under rensing. Det ville være nyttig å bruke denne testen til å karakterisere andre vannbehandlingsregimer (f. eks. membranfiltrering) for å se om et samlet datasett generer behandlingsspesifikke profiler.Changes in the microbiological quality of drinking water during its production and distribution at Vansjø waterworks. The bacterial content of drinking water after each stage in its production at Vansjø waterworks and at 19 points on the distribution system was investigated. In addition the content of fungi and protozoa in the raw and finished waters was measured. Parallel analyses of the total metabolic capabilities of the indigenous bacteria were performed using the Biolog® GN2 system. The waterworks produces a drinking water which was free for microbes and which scored negative for all of the 95 individual GN2 reactions. Filtration steps increased the bacterial load and contaminated the water with Cryptococcus magnus (a non-pathogenic yeast). Both UV-treatment and post chloronination effectively inactivated the microbial population. Amoeba were grown from the raw water, but were not present in the finished drinking water. Distribution net samples contained bacteria but there was no clear correlation between distance from the treatment plant and the bacterial count. Bacterial counts and GN2-data were more strongly and more significantly correlated for samples taken during the production process than samples taken during distribution. This could be explained by bacteria in the raw water having different growth characteristics than those in the distribution system. GN2 provides a data-rich measure of the total metabolic character of a drinking water particularly during its production. It would be useful to apply the test to other water-treatment types (eg membrane filtration) in order to see if treatment-specific profiles emerge from the data

Hva finnes på innsiden av kranarmaturer?

Innsiden av vannkraner kommer i kontakt med både mikrober som er til stede i drikkevann og de som finnes på hender, matrester og i luften. En hypotese er at kranbiofilmer kan være tilholdssted for sykdomsfremkallende mikroorganismer med opphav i både drikkevann og omgivelsene. For å undersøke denne muligheten, ble den mikrobiologiske kvaliteten ved 87 kraner bedømt i forhold til de hygieniske indikatorene Enterobacteriaceae og Staphyloccus aureus (som begge kan gi mage-tarminfeksjoner og matforgiftning) og heterotroft kimtall som kan gi en indikasjon på dannelse av biofilm. I tillegg ble tilstedeværelsen av frittlevende aerobe protozoer undersøkt. Kun én kran 319 Innsendte artikler Vann I 03 2012 var kontaminert med S. aureus. To kraner var kontaminert med et fåtall Enterobacteriaceae. Tre kraner var kontaminert med cysteproduserende amøber, blant annet Acanthamoeba polyphaga, som kan være årsak til alvorlig hornhinnebetennelse. Det var stor spredning i det aerobe kimtallet (0/mL - 100, 000/mL). Kraner synes ikke å være en viktig kilde til de utvalgte patogene/indikatorbakteriene. Imidlertid gir den store variasjonen i heterotroft kimtall og tilstedeværelsen av frittlevende amøber grunn til ettertanke

Activity of 6-aryl-pyrrolo[2,3-d]pyrimidine-4-amines to Tetrahymena

A series 6-aryl-pyrrolo[2,3-d]pyrimidine-4-amines (43 compounds), some of which are epidermal growth 22 factor tyrosine kinase inhibitors, were tested for their protozoal toxicity using an environmental Tetrahy- 23 mena strain as model organism. The protozoacidal activity of the analogues was found to be highly 24 dependent on a 4-hydroxyl group at the 6-aryl ring, and a chiral 1-phenylethanamine substituent in posi- 25 tion 4. Further, the potency was affected by the aromatic substitution pattern of the phenylethanamine: 26 the unsubstituted, the meta-fluoro and the para-bromo substituted derivatives had the lowest minimum 27 protozoacidal concentrations (8–16 lg/mL). Surprisingly, both enantiomers were found to have high 28 potency suggesting that this compound class could have several modes of action. No correlation was 29 found between the compounds protozoacidal activity and the in vitro epidermal growth factor receptor 30 tyrosine kinase inhibitory potency. This suggests that the observed antimicrobial effects are related to 31 other targets. Testing towards a panel of kinases indicated several alternative modes of actio

Synthesis and antimycobacterial activities of non-purine analogs of 6-aryl-9-benzylpurines; imidazopyridines, pyrrolopyridines, benzimidazoles and indoles

6,9-Disubstituted purines and 7-deazapurines are known to be powerful inhibitors of Mycobacterium tuberculosis (Mtb) in vitro. Analogs modified in the six-membered ring (imidazopyridines, pyrrolopyridines, benzimidazoles, and indoles) were synthesized and evaluated as Mtb inhibitors. The targets were prepared by functionalization on the bicyclic heterocycle or from simple pyridines. The results reported herein, indicate that the purine N-1, but not N-3, is important for binding to the unknown target. The 3-deazapurines appears to be slightly more active compared to the parent purines and slightly less active than their 7-deazapurine isomers. Removal of both the purine N-3 and N-7 did not result in further enhanced antimycobacterial activity but the toxicity towards mammalian cells was increased. Both 3-deaza and 3,7-dideazapurines exhibited a modest activity against of the Mtb isolate in the state of non-replicating persistence

Synthesis of non-purine analogs of 6-aryl-9-benzylpurines, and their antimycobacterial activities : compounds modified in the imidazole ring

Purine analogs modified in the five-membered ring have been synthesized and examined for antibacterial activity against Mycobacterium tuberculosis H37Rv in vitro employing the microplate alamar blue assay (MABA). The 9-deaza analogs were only found to be weak inhibitors, but the 8-aza-, 7-deaza- and 8-aza-7-deazapurine analogs studied displayed excellent antimycobacterial activities, some even substantially better than the parent purine. In the 7-deazapurine series, MIC values between 0.08 and 0.35 lM, values comparable or better than the reference drugs used in the study (MIC rifampicin 0.09 lM, MIC isoniazid 0.28 lM and MIC PA-824 0.44 lM). The five most active compounds were also examined against a panel of drug-resistant Mtb strain, and they all retained their activity. The compounds examined were significantly less active against M. tuberculosis in a state of non-replicating persistence (NRP). MIC in the low-oxygen-recovery assay (LORA)P60 lM. The 7-deazapurines were somewhat more toxic towards mammalian cells, but still the selectivity indexes were excellent. The non-purine analogs exhibit a selective antimycobacterial activity. They were essentially inactive against Staphylococcus aureus and Escherichia coli

2-Substituted agelasine analogs : synthesis and biological activity, and structure and reactivity of synthetic intermediates

2-Substituted N-methoxy-9-methyl-9H-purin-6-amines were synthesized either from their corresponding 6-chloro-9-methyl-9H-purines or 2-chloro-N-methoxy-9-methyl- 9H-purin-6-amine. Great diversity in the amino/imino tautomeric ratios was observed and calculated based on 1H NMR. The tautomers were identified by 1D and 2D 1H, 13C, and 15N NMR techniques, and showed significant variation both in 13C and 15N shift values. Comparison of the tautomeric ratios with Hammett F values revealed that as the field/inductive withdrawing abilities of the 2-substituent increased, the ratio of amino:imino tautomers was shifted toward the amino tautomer. Computational chemistry exposed the significance of hydrogen bonding between solvent and the compound in question to reach accurate predictions for tautomeric ratios. B3LYP/def2-TZVP density functional theory (DFT) calculations resulted in quantitatively more accurate predictions than when employing the less expensive BP86 functional. N-7-Alkylation of the 2-substituted N-methoxy-9-methyl-9H-purin-6- amines showed that when the field/inductive withdrawing ability of the 2-substituent reached a certain point the reactivity drastically dropped. This correlated with the atomic charges on N-7 calculated using a natural bond orbital (NBO) analysis. Biological screening of the final 2-substituted agelasine analogs indicated that the introduction of a methyl group in the 2-position is advantageous for antimycobacterial and antiprotozoal activity, and that an amino function may improve activity against several cancer cell lines

Detection of Aminoglycoside Resistant Bacteria in Sludge Samples From Norwegian Drinking Water Treatment Plants

Through a culture-based approach using sludge from drinking water treatment plants, this study reports on the presence of aminoglycoside resistant bacteria at 23 different geographical locations in Norway. Sludge samples are derived from a large environmental area including drinking water sources and their surrounding catchment areas. Aminoglycoside resistant bacteria were detected at 18 of the sample sites. Only five samples did not show any growth of isolates resistant to the selected aminoglycosides, kanamycin and gentamycin. There was a statistically significant correlation between the numbers of kanamycin and gentamycin resistant bacteria isolated from the 23 samples, perhaps suggesting common determinants of resistance. Based on 16S rRNA sequencing of 223 aminoglycoside resistant isolates, three different genera of Bacteroidetes were found to dominate across samples. These were Flavobacterium, Mucilaginibacter and Pedobacter. Further phenotypic and genotypic analyses showed that efflux pumps, reduced membrane permeability and four assayed genes coding for aminoglycoside modifying enzymes AAC(6′)-Ib, AAC(3′)-II, APH(3′)-II, APH(3′)-III, could only explain the resistance of a few of the isolates selected for testing. aph(3′)-II was detected in 1.6% of total isolates, aac(6′)-Ib and aph(3′)-III in 0.8%, while aac(3′)-II was not detected in any of the isolates. The isolates, for which potential resistance mechanisms were found, represented 13 different genera suggesting that aminoglycoside resistance is widespread in bacterial genera indigenous to sludge. The present study suggests that aminoglycoside resistant bacteria are present in Norwegian environments with limited anthropogenic exposures. However, the resistance mechanisms remain largely unknown, and further analyses, including culture-independent methods, could be performed to investigate other potential resistance mechanisms. This is, to our knowledge, the first large scale nationwide investigation of aminoglycoside resistance in the Norwegian environment

A simple and novel method for the production of polyethylene terephthalate containing agar plates for the growth and detection of bacteria able to hydrolyze this plastic

Polyethylene terephthalate is used in the manufacture of many products. Microbes able to hydrolyze the plastic are known, and offer promise for practical waste management. Screening for hydrolysis usually involves unwieldy culturing in the presence of film. A rapid screening method based on culturing on agar plates is here described