Leishmaniasis is a debilitating infectious disease that has a variety of clinical forms. In China, visceral leishmaniasis (VL) is the most common symptom, and L. donovani and/or L. infantum are the likely pathogens. In this study, multilocus sequence typing (MLST) of five enzyme-coding genes (fh, g6pdh, icd, mpi, pgd) and two conserved genes (hsp70, lack) was used to investigate the phylogenetic relationships of Chinese Leishmania strains. Concatenated alignment of the nucleotide sequences of the seven genes was analyzed and phylogenetic trees were constructed using neighbor-joining and maximum parsimony models. A set of additional sequences from 25 strains (24 strains belong to the L. donovani complex and one strain belongs to L. gerbilli) were retrieved from GenBank to infer the molecular evolutionary history of Leishmania from China and other endemic areas worldwide. Phylogenetic analyses consolidated Chinese Leishmania into four groups: (i) one clade A population comprised 13 isolates from different foci in China, which were pathogenic to humans and canines. This population was subdivided into two subclades, clade A1 and clade A2, which comprised sister organisms to the remaining members of the worldwide L. donovani complex; (ii) a population in clade B consisted of one reference strain of L. turanica and five Chinese strains from Xinjiang; (iii) clade C (SELF-7 and EJNI-154) formed a population that was closely related to clade B, and both isolates were identified as L. gerbilli; and (iv) the final group, clade D, included Sauroleishmania (LIZRD and KXG-E) and was distinct from the other strains. We hypothesize that the phylogeny of Chinese Leishmania is associated with the geographical origins rather than with the clinical forms (VL or CL) of leishmaniasis. To conclude, this study provides further molecular information on Chinese Leishmania isolates and the Chinese isolates appear to have a more complex evolutionary history than previously thought.

Proline-glutamic acid (PE)- and proline-proline-glutamic acid (PPE)-containing proteins are exclusive to Mycobacterium tuberculosis (MTB), the leading cause of tuberculosis (TB). In this study, we performed global transcriptome sequencing (RNA-Seq) on PPE57-stimulated peripheral blood mononuclear cells (PBMCs) and control samples to quantitatively measure the expression level of key transcripts of interest. A total of 1367 differentially expressed genes (DEGs) were observed in response to a 6 h exposure to PPE57, with 685 being up-regulated and 682 down-regulated. Immune-related gene functions and pathways associated with these genes were evaluated, revealing that the type I IFN signaling pathway was the most significantly enriched pathway in our RNA-seq dataset, with 14 DEGs identified therein including ISG15, MX2, IRF9, IFIT3, IFIT2, OAS3, IFIT1, IFI6, OAS2, OASL, RSAD2, OAS1, IRF7, and MX1. These PPE57-related transcriptomic profiles have implications for a better understanding of host global immune mechanisms underlying MTB infection outcomes. However, more studies regarding these DEGs and type I IFN signaling in this infectious context are necessary to more fully clarify the underlying mechanisms that arise in response to PPE57 during MTB infection.

The aim of this study was to investigate the current status of candidemia and evaluate the clinical characteristics, risk factors and outcomes among different species. We conducted a retrospective study by univariate and multivariate analysis between Candida albicans and non-albicans Candida (NAC) species in a Chinese national medical center from 2016 to 2020. Among the 259 episodes, C. albicans (38.6%) was the leading species, followed by C. tropicalis (24.3%), C. parapsilosis (20.5%), and C. glabrata (12.4%). Most C. albicans and C. parapsilosis were susceptible to nine tested antifungal agents, whereas C. tropicalis showed 30.2~65.9% resistance/non-wild-type to four azoles with great cross-resistance, indicating that fluconazole should not be used for empirical antifungal treatment. In multivariable models, the factor related to an increased risk of NAC was glucocorticoid exposure, whereas gastrointestinal hemorrhage and thoracoabdominal drainage catheters were associated with an increased risk in C. albicans. Subgroup analysis revealed leukemia and lymphoma, as well as glucocorticoid exposure, to be factors independently associated with C. tropicalis in comparison with C. albicans candidemia. No significant differences in 7-day mortality or 30-day mortality were observed between C. albicans and NAC. This study may provide useful information with respect to choosing empirical antifungal agents and exploring differences in molecular mechanisms.

A 50-year-old Chinese woman with a history of weakness and paroxysmal seizures of the left limb presented to our hospital with a ten-day history of neck pain. Imaging showed that there was a mass in the frontal lobe of her brain. On resection of the mass, a motile worm was identified. Morphological observation and molecular analysis of the mitochondrial COX1 and 28S rRNA genes of the worm extracted from the brain identified the causative agent as Spirometra mansoni. Homology search of the polymerase chain reaction (PCR)-amplified products from the case was conducted against gene fragments from local wild frogs. High homology was found between them, showing her likely exposure was frog consumption.