Chronic recalcitrant dermatophytoses, due to Trichophyton (T.) mentagrophytes Type VIII are on the rise in India and are noteworthy for their predominance. It would not be wrong to assume that travel and migration would be responsible for the spread of T. mentagrophytes Type VIII from India, with many strains resistant to terbinafine, to other parts of the world. From September 2016 until March 2020, a total of 29 strains of T. mentagrophytes Type VIII (India) were isolated. All patients were residents of Germany: 12 females, 15 males and the gender of the remaining two was not assignable. Patients originated from India (11), Pakistan (two), Bangladesh (one), Iraq (two), Bahrain (one), Libya (one) and other unspecified countries (10). At least two patients were German-born residents. Most samples (21) were collected in 2019 and 2020. All 29 T. mentagrophytes isolates were sequenced (internal transcribed spacer (ITS) and translation elongation factor 1-α gene (TEF1-α)). All were identified as genotype VIII (India) of T. mentagrophytes. In vitro resistance testing revealed 13/29 strains (45%) to be terbinafine-resistant with minimum inhibitory concentration (MIC) breakpoints ≥0.2 µg/mL. The remaining 16 strains (55%) were terbinafine-sensitive. Point mutation analysis revealed that 10/13 resistant strains exhibited Phe397Leu amino acid substitution of squalene epoxidase (SQLE), indicative for in vitro resistance to terbinafine. Two resistant strains showed combined Phe397Leu and Ala448Thr amino acid substitutions, and one strain a single Leu393Phe amino acid substitution. Out of 16 terbinafine-sensitive strains, in eight Ala448Thr, and in one Ala448Thr +, new Val444 Ile amino acid substitutions were detected. Resistance to both itraconazole and voriconazole was observed in three out of 13 analyzed strains. Treatment included topical ciclopirox olamine plus topical miconazole or sertaconazole. Oral itraconazole 200 mg twice daily for four to eight weeks was found to be adequate. Terbinafine-resistant T. mentagrophytes Type VIII are being increasingly isolated. In Germany, transmission of T. mentagrophytes Type VIII from the Indian subcontinent to Europe should be viewed as a significant public health issue.
We have used combinatorial biosynthesis to synthesize novel lipophilic carotenoids that are powerful cellular antioxidants. By co-expressing three different carotenoid desaturases in combination with a carotenoid hydratase, a cyclase, and a hydroxylase on compatible plasmids in Escherichia coli, we synthesized four novel carotenoids not previously detected in biological material or chemically synthesized. Their identification was based on their relative retention times on HPLC, spectroscopic properties, molecular weights, number of hydroxy groups, and 1H-NMR spectra. The carotenoids were designated as 1-HO-3', 4'-didehydrolycopene, 3, 1'-(HO)2-gamma-carotene, 1,1'-(HO)2-3, 4, 3', 4'-tetradehydrolycopene, and 1, 1'-(HO)2-3, 4-didehydrolycopene. These novel acyclic derivatives differ from structurally related compounds by extension of the conjugated polyene chain as well as additional hydroxy groups at position C-1'. We determined their antioxidative activity in a liposome-membrane model system, which showed that their ability to protect against photooxidation and radical-mediated peroxidation reactions was linked to the length of the conjugated double-bond system and the presence of a single hydroxy group. The protection of membrane degradation was superior to the related 1-HO and 1, 1'-(HO)2 lycopene derivatives, making them interesting pharmaceutical candidates.
~bstract We have cloned a cDNA from the plant Capsicum annuum which encodes a novel enzyme mediating the dehydrogenation of ~-carotene and neurosporene to lycopene when expressed in E. coli cells accumulating ~-carotene or neurosporene. this enzyme is unable to dehydrogenate either phytoene or lycopene. The deduced amino acid sequence suggests that this cDNA encodes a polypeptide whose mature size is ca. 59 kDa and which is synthesized as a precursor with a NH2-terminal extension resembling transit peptides for plastid targeting. Sequence comparison reveals 33-35% similarity with previously cloned plant or cyanobacterial phytoene desaturases. In contrast, only limited sequence similarity is found with a ~-carotene desaturase from the cyanobacterium Anabaena.
Light-stimulated carotenoid biosynthesis associated with the transformation of etioplasts to chloroplasts was investigated after dark-grown maize (Zea mays) seedlings were transferred into light.These studies focused on the enzymes of the pathway to detect those enzyme activities that were stimulated in the light and thus that were responsible for increased biosynthesis of carotenoids. In preliminary experiments, norflurazon, an inhibitor of phytoene desaturase, was used to prevent phytoene being further metabolized to carotenoids. Light-dependent stimulation of phytoene accumulation indicated that the light-regulated steps are located in the pathway leading to phytoene synthesis. The use of the "Clabeled precursors mevalonic acid, isopentenyl pyrophosphate, and farnesyl pyrophosphate pointed to increased activity of an enzyme involved in the biosynthetic steps between isopentenyl pyrophosphate and farnesyl pyrophosphate. Determination of the adivities of all five enzymes of the pathway involved in the sequence from mevalonic acid to phytoene revealed that the only enzyme activity stimulated by light was isopentenyl pyrophosphate isomerase. Over a 3-h period of illumination, this enzyme activity, like carotenoid biosynthesis, was stimulated 2.8-fold.Light is essential for plant life. It serves not only as an energy source in photosynthesis but also influences plant growth and development. During leaf formation, the maturation of proplastids into chloroplasts requires light. In nonilluminated plants etioplasts are formed instead, which can be recognized by their crystal-like structure (Boardman, 1977); after illumination, however, etioplasts are converted very rapidly into fully functioning chloroplasts. During this photomorphogenic event, massive structural and biochemical modifications occur. The most prominent changes are in leaf pigmentation. Light stimulates Chl biosynthesis by stimulating the reduction of Pchlide but, more particularly, by stimulating the synthesis of severa1 early regulatory enzymes of this pathway (Mohr et al., 1984; Rüdiger and Schoch, 1988).Not only Chl but also the carotenoid content is increased during light-dependent transition from etioplasts to chloroplasts. Carotenoids are present in etioplasts but in a lower amount than in the corresponding chloroplasts (Grumbach, 1981; Bany et al., 1991 529light to chloroplasts, the formation of carotenoids is also stimulated in parallel to the biosynthesis of Chl (Cohen and Goodwin, 1962; Virgin, 1967;Frosch and Mohr, 1980).It is generally assumed that photomorphogenesis and photoinduction of metabolism proceed via light-mediated gene expression, followed by enhanced protein synthesis including increased concentrations of appropriate enzymes leading to enhanced biosynthetic capacities (Hoober, 1987). This model may also apply for photoregulation of carotenogenesis (Tobin and Silverthome, 1985).In the present investigation, work was focused on the last step in this chain of events: the formation of enzymes of the carotenoid biosynthetic pathw...
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