Publications

4424

ABSTRACT. A 59-year-old female living in Rayong Province, eastern Thailand, presented with painless, right upper eyelid nodule for 3 months. Upon removal of the eyelid mass, a well-circumscribed, firm globular mass with diameter about 1 cm was found. Histopathological examination revealed an immature female dirofilarial worm reminiscent of Dirofilaria repens, characterized by prominent sharp longitudinal ridges at external surface of the cuticle. Analysis of the mitochondrial 12S rRNA sequence showed that the worm belongs to Candidatus Dirofilaria hongkongensis. It is likely that some infections previously reported as D. repens based on histological examination may have actually been due to Candidatus D. hongkongensis.

Objective: Coxiella burnetii and Coxiella-like endosymbionts (CLEs) have been widely discovered in various ticks, animals, and even human beings. To estimate the possible origin of C. burnetii and its relatives CLEs, the prevalence of C. burnetii and CLEs has been intensively surveyed all over the world. Method: In the present study, the possible infection of C. burnetii and CLEs in host-seeking Haemaphysalis concinna was performed with meta-transcript analysis with tick specimens harvested from Mudanjiang City, Heilongjiang province, China. The meta-transcript results were subsequently confirmed by the specific sequence of partial 16S rRNA. Results: A total of three arrays of gene transcripts were harvested, including pyrophosphate-fructose 6-phosphate 1-phosphotransferase-eda-thiol-disulfide isomerase and thioredoxin-greA, carB-carA-DnaJ-DnaK-grpE-ppnk, ropC-ropB, and ubiA-non-canonical purine NTP pyrophosphatase-hemK-prfA, which suggest the infection of Candidatus Coxiella mudorwiae in H. concinna. The high identity of the 16S rRNA gene of Candidatus C. mudorwiae achieved in our study strongly supports our meta-transcripts analysis. Conclusion: The prevalence of Candidatus C. mudorwiae in hard ticks has been discovered in China. More detailed surveys are imperative to clarify the emergence of CLEs and their implication in the epidemiologic characteristics of Q fever.

A large (47.75 ± 3.56 µm in diameter) Thiovulum bacterial strain forming white veils is described from a marine mangrove ecosystem. High sulfide concentrations (up to 8 mM of H2S) were measured on sunken organic matter (wood/bone debris) under laboratory conditions. This sulfur-oxidizing bacterium colonized the organic matter, forming a white veil. According to conventional scanning electron microscope (SEM) observations, bacterial cells are ovoid and slightly motile by numerous small flagella present on the cell surface. Large intracytoplasmic internal sulfur granules were observed, suggesting a sulfidic-based metabolism. Observations were confirmed by elemental sulfur distribution detected by energy-dispersive X-ray spectroscopy (EDXS) analysis using an environmental scanning electron microscope (ESEM) on non-dehydrated samples. Phylogenetic analysis of the partial sequence of 16S rDNA obtained from purified fractions of this Epsilonproteobacteraeota strain indicates that this bacterium belongs to the Thiovulaceae cluster and could be one of the largest Thiovulum ever described. We propose to name this species Candidatus Thiovulum sp. strain imperiosus.