Phylogenetic inference enables reconstruction of a long-overlooked outbreak of almond leaf scorch disease (Xylella fastidiosa) in Europe

The recent introductions of the bacterium Xylella fastidiosa (Xf) into Europe are linked to the international plant trade. However, both how and when these entries occurred remains poorly understood. Here, we show how almond scorch leaf disease, which affects ~79% of almond trees in Majorca (Spain) and was previously attributed to fungal pathogens, was in fact triggered by the introduction of Xf around 1993 and subsequently spread to grapevines (Pierceʼs disease). We reconstructed the progression of almond leaf scorch disease by using broad phylogenetic evidence supported by epidemiological data. Bayesian phylogenetic inference predicted that both Xf subspecies found in Majorca, fastidiosa ST1 (95% highest posterior density, HPD: 1990–1997) and multiplex ST81 (95% HPD: 1991–1998), shared their most recent common ancestors with Californian Xf populations associated with almonds and grapevines. Consistent with this chronology, Xf-DNA infections were identified in tree rings dating to 1998. Our findings uncover a previously unknown scenario in Europe and reveal how Pierce’s disease reached the continent.

Eduardo Moralejo et al. report a phylogenetic reconstruction tracing the origin and progression of a European outbreak of the almond scorch disease pathogen Xylella fastidiosa (Xf). Their data suggest Xf was introduced into Europe via grafting from infected Californian buds and was subsequently spread by the meadow spittlebug to multiple plant hosts.

Digital sucking induced trophic ulcers caused by nerve deficit from amniotic constriction band

Two infants presented with amniotic constriction bands (ACB) in the distal third of the forearm. After teeth eruption they developed recurrent skin ulcerations mainly in the distribution of the median nerve from digital sucking. Both patients underwent reconstruction with multiple Z-plasties, followed by neurolysis of the ulnar nerve and sural nerve grafting of the median nerve. This neurological complication presented late in ACB as ulcerative lesions and secondary infection from digital sucking on the insensate digits. Thorough physical examination of the extremities at an early stage in children with ACB is essential to exclude an occult neurological dysfunction. Exploration of peripheral nerves is warranted in cases of deep forearm ACB during their soft tissue reconstruction.