From June 2011 to August 2014, 21 cases of infection by severe fever with thrombocytopenia syndrome bunyavirus (SFTSV) were confirmed in Zhoushan Islands in the Eastern coast of China. To identify the source of SFTSV in Zhoushan Islands, the whole SFTSV genomes were amplified and sequenced from 17 of 21 patients. The L, M and S genomic segments of these SFTSV strains were phylogenetically analyzed together with those of 188 SFTSV strains available from GenBank. Phylogenetic analysis demonstrated SFTSV could be classified into six genotypes. The genotypes F, A and D were dominant in mainland China. Additionally, seven types of SFTSV genetic reassortants (abbreviated as AFA, CCD, DDF, DFD, DFF, FAF and FFA for the L, M and S segments) were identified from 10 strains in mainland China. Genotype B was dominant in Zhoushan Islands, Japan and South Korea, but not found in mainland China. Phylogeographic analysis also revealed South Korea possible be the origin area for genotype B and transmitted into Japan and Zhoushan islands in the later part of 20^th century. Therefore, we propose that genotype B isolates were probable transmitted from South Korea to Japan and Zhoushan Islands.

With increasing attention paid to the concept of the microbiota–gut–brain axis, mounting evidence reveals that the gut microbiota is involved in a variety of neurological and psychiatric diseases. However, gut microbiota changes in major depressive disorder (MDD) patients and their association with disease mechanisms remain undefined. Fifty MDD patients and sixty healthy controls were recruited from the Shanghai Healthy Mental Center, China. Fecal samples were collected, and the compositional characteristics of the intestinal flora were determined in MDD patients by MiSeq sequencing. Venous blood was collected for the detection of plasma indoleamine-2,3-dioxygenase (Ido), kynurenine (Kyn) and tryptophan (Trp) levels. Stool samples of bacterial 16S sequencing was carried out. A total of 2,705,809 optimized sequences were obtained, with an average of 54,116 per sample. More unique OTUs were observed at the family, genus and species levels in the control group compared with the MDD cases. Further analysis showed significant changes in the α- and β-diversities and relative abundance levels of gut microbial entities in MDD patients, as well as elevated amounts of Ido and Kyn indicating Kyn pathway activation, KEGG bacterial 16S function prediction analysis shows a variety of amino acids and metabolic (including Ido, Trp and Kyn) changes in the body of patients with MDD. These may result in increased neurotoxic metabolites and reduced generation of serotonin in the disease process. These changed factors may potentially be utilized as biomarkers for MDD in the future, playing more important roles in the disease course.

Among various genera of free-living amoebae prevalent in nature, some members are identified as causative agents of human encephalitis, in whichNaegleria fowlerifollowed byAcanthamoebaspp. andBalamuthia mandrillarishave been successively discovered. As the three dominant genera responsible for infections,AcanthamoebaandBalamuthiawork as opportunistic pathogens of granulomatous amoebic encephalitis in immunocompetent and immunocompromised individuals, whereasNaegleriainduces primary amoebic meningoencephalitis mostly in healthy children and young adults as a more violent and deadly disease. Due to the lack of typical symptoms and laboratory findings, all these amoebic encephalitic diseases are difficult to diagnose. Considering that subsequent therapies are also affected, all these brain infections cause significant mortality worldwide, with more than 90% of the cases being fatal. Along with global warming and population explosion, expanding areas of human and amoebae activity in some regions lead to increased contact, resulting in more serious infections and drawing increased public attention. In this review, we summarize the present information of these pathogenic free-living amoebae, including their phylogeny, classification, biology, and ecology. The mechanisms of pathogenesis, immunology, pathophysiology, clinical manifestations, epidemiology, diagnosis, and therapies are also discussed.

Babesiosis is an uncommon but emerging tick-borne disease caused by the genus Babesia. In this case study, we report a case of human infection with a novel Babesia sp. in China. The patient in question had been suffering from repetitive occurrences of mild fever of unknown origin and fatigue for 10 years. Ring forms, tetrads, and one or two dots of chromatin or trophozoite-like organisms were observed in the patient’s thin blood smears and bone marrow smears. Using a confocal laser-scanning microscope, it was observed that the patient’s serum had reactivity with the surface proteins of the B. microti strain. Electron microscopy revealed oval red blood cells with 1 ~ 2 μm of knob protrusions in the cellular membrane. The results of the Babesia-specific nested PCR assay for 18S rRNA confirmed the presence of Babesia infection. The construction of a phylogenetic relationship showed clustering with B. microti and B. duncani, which was identified as a novel Babesia species and named as Babesia sp. XXB/HangZhou. Azithromycin, doxycycline, and moxifloxacin hydrochloride were shown to relieve symptoms but were not as effective after continuous usage. After atovaquone (Mepron®) administration, the patient recovered from fever and tested negative for detection of Babesia-specific genes. Babesia sp. XXB/HangZhou is a novel Babesia species, which causes mild babesiosis in an immunocompetent patient.