Origins of Wohlfahrtia magnifica in Italy based on the identification of mitochondrial cytochrome b gene haplotypes.

To identify the geographical origins of larvae of Wohlfahrtia magnifica (Diptera: Sarcophagidae) causing myiasis of sheep in Italy, comparative DNA sequence analysis of the mitochondrial cytochrome b gene was performed, based on gene fragments amplified by PCR from genomic DNA isolated from individual specimens. DNA extractions of 19 larvae from Lazio, Molise, Puglia, and Sicilia generated 17 readable sequences homologous to 2 haplotypes, either CB_magn01 or CB_magn02; DNA extracts from 4 adult flies from Calabria (reared from larvae) produced 4 readable sequences belonging to the haplotype CB_magn01. The two haplotypes found represent both the East and West phylogenetic lineages of W. magnifica, which is consistent with the species' arrival from central/southeast Europe (East lineage) and/or from southwest Europe/northwest Africa (West lineage). This is the first report of the sympatric occurrence of the two lineages, which could have resulted from natural or human-assisted dispersal. Polymorphic nuclear loci will have to be characterized in order to explain the origins and lack of mitochondrial haplotype diversity of this pest in Italy, where it poses increasing veterinary problems.

Arthropeptide A, an antifungal cyclic tetrapeptide from Arthrobacter psychrophenolicus isolated from disease suppressive compost.

In an effort to describe bioactive antifungal compounds from antagonistic bacteria with potential for biocontrol of plant pathogens, a strain of Arthrobacter psychrophenolicus was collected from plant disease suppressive compost prepared from composted material of marine origin. Few natural products have been characterized from the non-filamentous Actinobacteria genus Arthrobacter. A new cyclic tetrapeptide, cyclo-(L-Pro-L-Leu-L-γHyp-L-Tyr); arthropeptide A (1), was isolated from the EtOAc soluble culture filtrate extract of A. psychrophenolicus M9-17 grown in MOLP broth. Its structure was confirmed by HRMS, interpretation of NMR data, and a modified Marfey's method. Arthropeptide A (1) displayed antifungal activity towards Alternaria alternata, the causal agent of disease in numerous host plant species, which had shown the previous susceptibility to A. psychrophenolicus. The newly identified compound may be responsible, in part, for the inhibitory activity of the bacterium against fungal plant pathogens.