Publications

4636

Huanglongbing (HLB), considered to be the most serious insect-vectored bacterial disease of citrus, is transmitted in nature by the Asian citrus psyllid Diaphorina citri and the African citrus psyllid Trioza erytreae. D. citri was discovered in southern Florida in 1998 and the HLB disease in 2005. Both have become established throughout citrus-producing areas of Florida. Murraya species are widely grown in southern Florida as ornamental hedges and are readily colonized by D. citri vectors. Colonies of D. citri, isolates of ‘Candidatus Liberibacter asiaticus’ from Taiwan and Florida, and the Murraya species were established in the BSL-3 biosecurity facility at Fort Detrick. In controlled inoculation experiments, D. citri transmitted ‘Ca. L. asiaticus’ into M. paniculata (34/36 plants) and M. exotica (22/23 plants), but not into Bergera (Murraya) koenigii. Disease symptoms rarely developed in Murraya plants; however, positive infections were determined by conventional and real-time polymerase chain reaction (PCR). Back-inoculations of ‘Ca. L. asiaticus’ from M. paniculata to Madam Vinous sweet orange resulted in disease development in 25% of the inoculated plants. Considerable variability was observed in infection rates, titer, and persistence of ‘Ca. L. asiaticus’ in infected Murraya.

A novel halophilic actinomycete, designated strain YIM 93223T, was isolated from a salt lake in Xinjiang Province, north-west China, and was subjected to a polyphasic taxonomic study. The isolate grew at 25–45 °C, at pH 6–8 and in the presence of 1–15 % (w/v) NaCl; no growth was observed in the absence of NaCl. Strain YIM 93223T contained meso-diaminopimelic acid, glutamic acid and alanine as cell-wall amino acids, and glucose and galactose as major whole-cell-wall sugars. Major fatty acids were iso-C16 : 0, C16 : 0 and C16 : 1 ω7c/iso-C15 : 0 2-OH. MK-8(H4) was the predominant menaquinone. The genomic DNA G+C content was 66.1 mol%. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain YIM 93223T belongs to the genus Amycolatopsis. It shared highest 16S rRNA gene sequence similarity with Amycolatopsis palatopharyngis 1BDZT (96.6 %) and Amycolatopsis marina Ms392AT (96.4 %), but lower values (94.5–96.2 %) with the type strains of other recognized species of the genus Amycolatopsis. On the basis of the data from this polyphasic study, strain YIM 93223T is considered to represent a novel species of the genus Amycolatopsis, for which the name Amycolatopsis halophila sp. nov. is proposed. The type strain is YIM 93223T (=DSM 45216T =KCTC 19403T).

ABSTRACT An immunocompromised patient presented with febrile episodes, an erysipelas-like rash, and thromboembolic complications. Amplification of 16S rRNA gene sequences from blood and sequence analysis revealed “ Candidatus Neoehrlichia mikurensis.” We report the first case of human disease caused by “ Ca . Neoehrlichia mikurensis.”

A Gram-negative, aerobic, rod-shaped bacterium, designated strain CL-33T, was isolated from the encrusting pore coral Montipora aequituberculata collected from seawater off the coast of southern Taiwan. 16S rRNA gene sequence analysis showed that the strain clustered closely with Endozoicomonas elysicola MKT110T (96.7 % similarity). The novel strain required NaCl for growth and exhibited optimal growth at 25 °C and in the presence of 2–3 % NaCl. Predominant cellular fatty acids were summed feature 3 (C16 : 1 ω7c and/or C16 : 1 ω6c; 39.6 %), summed feature 8 (C18 : 1 ω7c and/or C18 : 1 ω6c; 32.8 %) and C16 : 0 (12.0 %). The DNA G+C content of strain CL-33T was 50.0 mol%. The results of physiological and biochemical tests allowed the clear phenotypic differentiation of this isolate from E. elysicola. It is evident from the genotypic, phenotypic and chemotaxonomic data presented that strain CL-33T represents a novel species of the genus Endozoicomonas, for which the name Endozoicomonas montiporae sp. nov. is proposed. The type strain is CL-33T (=LMG 24815T =BCRC 17933T).