| 1. |
- Dube, Faruk, et al.
(författare)
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Benzylpenicillin-producing Trichophyton erinacei and methicillin resistant Staphylococcus aureus carrying the mecC gene on European hedgehogs : a pilot-study
- 2021
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Ingår i: BMC Microbiology. - : BioMed Central (BMC). - 1471-2180. ; 21
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: A high carriage rate of methicillin-resistant Staphylococcus aureus with the mecC gene (mecC-MRSA) has been described among Wild European hedgehogs (Europeaus erineaus). Due to this frequent occurrence, it has been suggested that hedgehogs could be a natural reservoir for mecC-MRSA. However, the reason why hedgehogs carry mecC-MRSA remains unknown, but it has been hypothesized that mecC-MRSA could have evolved on the skin of hedgehogs due to the co-occurrence with antibiotic producing dermatophytes. The aim of this pilot-study was therefore to investigate if hedgehogs in Sweden carry Trichophyton spp. and to provide evidence that these dermatophytes are able to produce penicillin or similar substances. In addition, the study aimed to identify if dermatophytes co-occurred with mecC-MRSA.METHODS: Samples were collected from hedgehogs (Europeaus erineaus) that were euthanized or died of natural causes. All samples were screened for dermatophytes and mecC-MRSA using selective cultivation methods. Suspected isolates were characterized using PCR-based methods, genome sequencing and bioinformatic analyses. Identification of penicillin was performed by ultra-high-performance liquid chromatography-tandem mass spectrometry.RESULTS: In total 23 hedgehogs were investigated, and it was shown that two carried Trichophyton erinacei producing benzyl-penicillin, and that these hedgehogs also carried mecC-MRSA. The study also showed that 60% of the hedgehogs carried mecC-MRSA.CONCLUSION: The pilot-study demonstrated that Trichophyton erinacei, isolated from Swedish hedgehogs, can produce benzylpenicillin and that these benzylpenicillin-producing T. erinacei co-occurred with mecC-MRSA. The study also reconfirmed the high occurrence of mecC-MRSA among hedgehogs.
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| 2. |
- Lampinen Salomonsson, Matilda, 1978-
(författare)
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Chemical Derivatization in Combination with Liquid Chromatography Tandem Mass Spectrometry for Detection and Structural Investigation of Glucuronides
- 2008
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis presents novel approaches for structural investigation of glucuronides using chemical derivatization in combination with liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MSn).Today, LC-ESI-MSn is the dominant technique for quantitative as well as qualitative analyses of metabolites, due to its high sensitivity and selectivity. However, for compounds without an easily ionizable group, e.g., steroids, the sensitivity is limited. In the work presented in this thesis, a derivatization procedure forming a basic oxime significantly increased the detection sensitivity for the altrenogest glucuronide. Furthermore, in structural evaluations of glucuronides, the limitation of LC-MSn becomes evident due to the initial neutral loss of 176 u, i.e. monodehydrated glucuronic acid, which often makes it impossible to elucidate the structures of the conjugates. To solve this problem, the main part of the work described in this thesis was devoted to chemical derivatization as a means of facilitating the determination of the site of conjugation. For the first time, the isomeric estriol glucuronides were evaluated using a combination of three reagents 2-chloro-1-methylpyridinium iodide (CMPI), 1-ethyl-3-(3-dimethyl- aminopropyl)-carbodiimide (EDC), and 2-picolylamine (PA). Interestingly, the derivatization gave a selective fragmentation pattern leading to differentiation of the isomers. Another derivatization reagent, 1,2-dimethylimidazole-4-sulfonyl chloride (DMISC), was also tested for the first time in structural investigations. The isomeric glucuronides of morphine, formoterol, and hydroxypropranolol were evaluated. They can all be conjugated in aliphatic as well as aromatic positions. DMISC was proven to be useful in two ways. Firstly, the morphine and formoterol glucuronides that contained a free phenol could be differentiated from those that were conjugated in the aromatic position based on different reactivity. Secondly, for the aromatic O-glucuronide of 4’-hydroxypropranolol, DMISC was proven to react with the amine. This product gave a different fragmentation pattern compared to the corresponding derivative of the aliphatic glucuronide.
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| 3. |
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| 4. |
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| 5. |
- Lampinen Salomonsson, Matilda, et al.
(författare)
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In vitro formation of phase I and II metabolites of propranolol and determination of their structures using chemical derivatization and liquid chromatography tandem mass spectrometry
- 2009
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Ingår i: Journal of Mass Spectrometry. - : Wiley. - 1076-5174 .- 1096-9888. ; 44:5, s. 742-754
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Tidskriftsartikel (refereegranskat)abstract
- Derivatization with 1,2-dimethylimidazole-4-sulfonyl chloride (DMISC) has been successfully used as a tool to differentiate between aromatic and aliphatic O-glucuronides of hydroxypropranolol. The analyses were performed with liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS) with both a triple quadrupole and an ion trap instrument. Hydroxylated forms of propranolol can be glucuronidated in aliphatic as well as aromatic positions. These isoforms are not distinguishable by tandem MS alone, as they both initially lose 176 Da, i.e. monodehydrated glucuronic acid, giving back the aglycone. Two in vitro systems were set up for the production of propranolol metabolites. The obtained isomers of 4'-hydroxypropranolol glucuronide were determined to correspond to one aliphatic and one aromatic form, using chemical derivatization with DMISC and LC-MSn. DMISC was shown to react with the secondary amine in the case where the naphtol was occupied by the glucuronyl moiety, resulting in a different fragmentation pattern compared with that of the aliphatic glucuronide, where the naphtol group was accessible to derivatization.
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| 6. |
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| 7. |
- Lampinen Salomonsson, Matilda, et al.
(författare)
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Structural evaluation of the glucuronides of morphine and formoterol using chemical derivatization with 1,2-dimethylimidazole-4-sulfonyl chloride and liquid chromatography/ion trap mass spectrometry
- 2008
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Ingår i: Rapid Communications in Mass Spectrometry. - : Wiley. - 0951-4198 .- 1097-0231. ; 22:17, s. 2685-2697
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Tidskriftsartikel (refereegranskat)abstract
- For the first time chemical derivatization of isomeric drug glucuronides with 1,2-dimethylimidazole-4-sulfonyl chloride (DMISC) has been successfully applied as a tool for determining the site of conjugation. This provides a way to differentiate between glucuronide isomers containing aliphatic and phenolic hydroxyl groups. The analyses were performed with liquid chromatography/electrospray ion trap mass spectrometry (LC/ESI-MSn). DMISC has previously been shown to react selectively with phenols in estrogens, thus improving sensitivity in ESI-MS. The model compounds selected for this study were commercially available standards of formoterol, morphine, morphine-3-glucuronide (M3G), and morphine-6-glucuronide (M6G). Formoterol glucuronides were produced with an enzymatic method in house. Both formoterol and morphine possess one phenolic and one aliphatic hydroxyl group where glucuronidation could take place. The product ion mass spectra of the native morphine glucuronides were indistinguishable due to the initial neutral loss of monodehydrated glucuronic acid (1.76u). However, a significant difference between the isomers was observed with DMISC derivatization, as only the form with a free phenol, M6G, gave a detectable reaction product. Formoterol formed two detectable glucuronide isomers in the enzymatic reaction. Their respective sites of conjugation could not be directly determined from the product ion spectra. Reaction with DMISC, however, gave a detectable product with only one of the isomers. Based on previous experience of the preferred DMISC reactions with phenols, and interpretation of the fragmentation pattern of the derivative, it was concluded that the reactive isomer had a free phenol, and was thus conjugated on the aliphatic chain.
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| 8. |
- Salomonsson, Matilda Lampinen, et al.
(författare)
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Development and in-house validation of a method for quantification of BMAA in mussels using dansyl chloride derivatization and ultra performance liquid chromatography tandem mass spectrometry
- 2013
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Ingår i: Analytical Methods. - : Royal Society of Chemistry (RSC). - 1759-9660 .- 1759-9679. ; 5:18, s. 4865-4874
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Tidskriftsartikel (refereegranskat)abstract
- A new approach for the detection and quantification of beta-N-methylamino-L-alanine (BMAA) in mussels using chemical derivatization with dansyl chloride and ultra performance liquid chromatography-electrospray ionization-tandem mass spectrometry (UPLC-ESI-MS/MS) is presented. The method, using dansyl chloride as the reagent, is simple, robust and cost efficient. Comparing the fragmentation patterns for derivatized BMAA and its isomer L-2,4-diaminobutyric acid derivatized a selective fragment for the derivatized BMAA was formed m/z 585 > m/z 71. To ensure an actual detection of BMAA, the ion ratio of the daughter ions m/z 71 and m/z 277 was calculated and compared with the calculated mean ion ratio. The method development resulted in a simplified sample preparation excluding solid phase extraction and, instead, performing filtration and dilution of the samples before the derivatization. Validation was performed and the limit of quantification was determined to be 0.15 mu g g(-1) wet mussel homogenate (33 fmol per injection) and the limit of detection was estimated to be 16 ng g(-1) (4 fmol per injection). The intra-and inter-day precisions were within the accepted criteria and the recovery was about 83%. The stability of BMAA in the stock solution was at least 3 months and the stability of derivatized extracts in vials for the quantification was good for 27 days. This is the first quantification method for BMAA in mussels with extensive validation data published and the method was also applied on real mussel samples collected on the west coast of Sweden. The concentrations of BMAA in the mussel samples were determined to be between 0.27 and 1.6 mu g g(-1) wet mussel homogenates.
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| 9. |
- Salomonsson, Matilda Lampinen, et al.
(författare)
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Seafood sold in Sweden contains BMAA : A study of free and total concentrations with UHPLC-MS/MS and dansyl chloride derivatization
- 2015
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Ingår i: Toxicology reports. - : Elsevier BV. - 2214-7500. ; 2, s. 1473-1481
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Tidskriftsartikel (refereegranskat)abstract
- β-N-Methylamino-l-alanine (BMAA) is a potential neurotoxin associated with the aquatic environment. Validated analytical methods for the quantification of both free and total concentrations of BMAA were used in an investigation of seafood purchased from different grocery stores in Uppsala, Sweden. The analysis was performed using ultra high performance liquid chromatography-electrospray ionization-tandem mass spectrometry (UHPLC-ESI–MS/MS) and detection of BMAA as a dansyl derivate. The determined concentrations of free BMAA (after a simple trichloroacetic acid extraction) in mussels and scallops were up to 0.46 μg g−1 wet homogenate. The total BMAA (after hydrochloric acid hydrolysis) levels were between 0.29 and 7.08 μg g−1 wet mussel homogenate. The highest concentration of total BMAA was found in imported cooked and canned mussels which contained about ten times the quantity of BMAA measured in domestic cooked and frozen mussels. In this study it was also concluded that BMAA could be detected in seafood origin from four different continents. The risks associated with human exposure to BMAA through food are unknown today. However, the results of this study show that imported seafood in Sweden contain BMAA, indicating that this area needs more investigation, including a risk assessment regarding the consumption of e.g., mussels, scallops and crab.
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