Species distribution and antifungal susceptibility of fungi originating from positive blood cultures in Guangdong, 2019-2021 / 中国热带医学

@#Abstract: Objective　To investigate the species distribution and the antifungal susceptibility of fungi originating from positive blood cultures in Guangdong, so as to provide a basis for the rational use of antifungal drugs in clinical fungal bloodstream infections. Methods All data were collected for retrospective study from monitoring units of the Guangdong Fungal Disease Surveillance Network between 2019-2021, including clinical characteristics, species distribution and antifungal susceptibility. Results A total of 3 589 fungi strains were isolated, most of which were Candida spp. (86.5%, 3 105/3 589). The most common species was Candida albicans (36.6%, 1 315/3 589), followed by Candida tropicalis (17.4%, 1 626/3 589) and Candida parapsilosis (14.5%, 520/3 589). There were 42.1%(1 512/3 589) of strains isolated from ICU. The proportions of Candida albicans strains were 40.0%-50.0% among ICU, general surgery, organ transplantation and emergency department. Candida tropicalis (60.0%, 144/240) was the most common species in hematology department. Both Cryptococcus neoformans (35.4%, 69/195) and Talaromyces marneffei (35.9%,70/195) were common in infection department. All of the Candida isolates were of wild-type (WT) phenotype to amphotericin B. Resistance rates of caspofungin and micafungin for Candida spp. ranged from 0.0% to 4.2%. The resistance rates of Candida tropicalis to fluconazole and voriconazole were 42.3% and 38.9%, which were significantly higher than other common Candida spp. The cryptococcus neoformans strains were totally of WT phenotype to fluconazole and voriconazole. Conclusions Candida albicans is the most common species originating from positive blood cultures in Guangdong Province. Common Candida strains are highly sensitive to echinocandins and amphotericin B. Candida tropicalis has a high resistance rate to triazole drugs.

RNA-sequencing identifies differentially expressed genes in T helper 17 cells in peritoneal fluid of patients with endometriosis.

Innate and adaptive immune factors play significant roles in the pathophysiology of endometriosis. T helper 17 (Th17) cells, a pro-inflammatory T cell subset, were considered to contribute to the progression of endometriosis lesions. However, the regulatory mechanisms of Th17 cells in endometriosis remain unidentified, partially due to the difficulty in recovering live Th17 cells from endometriosis patients. In this study, by flow cytometry analysis of a set of chemokine receptors including CXCR3, CCR4, CCR10, and CCR6, live RORγt-and-IL-17A-expressing Th17 cells were enriched from peritoneal fluid (PF) of patients with different stages of endometriosis for the first time, RNA-sequencing (RNA-Seq) of these PF Th17 cells revealed significantly up-regulated genes and down-regulated genes in stage I-II and stage III-IV endometriosis, compared with their counterparts in normal PF. In conclusion, this study provides a novel method to isolate live Th17 cells from endometriosis patients, unveils an array of differentially expressed genes in endometriosis Th17 cells, and offers valuable gene expression profile information for endometriosis clinical research.

Effects of amino acid substitutions in hepatitis B virus surface protein on virion secretion, antigenicity, HBsAg and viral DNA.

BACKGROUND & AIMS: As important virological markers, serum hepatitis B surface antigen (HBsAg) and hepatitis B virus (HBV) DNA levels show large fluctuations among chronic hepatitis B patients. The aim of this study was to reveal the potential impact and mechanisms of amino acid substitutions in small hepatitis B surface proteins (SHBs) on serum HBsAg and HBV DNA levels. METHODS: Serum samples from 230 untreated chronic hepatitis B patients with genotype C HBV were analyzed in terms of HBV DNA levels, serological markers of HBV infection and SHBs sequences. In vitro functional analysis of the identified SHBs mutants was performed. RESULTS: Among 230 SHBs sequences, there were 39 (16.96%) sequences with no mutation detected (wild-type) and 191 (83.04%) with single or multiple mutations. SHBs consist of 226 amino acids, of which 104 (46.02%) had mutations in our study. Some mutations (e.g., sE2G, sL21S, sR24K, sT47A/K, sC69stop (sC69∗), sL95W, sL98V, and sG145R) negatively correlated with serum HBsAg levels. HBsAg and HBV DNA levels from this group of patients had a positive correlation (r=0.61, p<0.001). In vitro analysis showed that these mutations reduced extracellular HBsAg and HBV DNA levels by restricting virion secretion and antibody binding capacity. Virion secretion could be rescued for sE2G, sC69∗, and sG145R by co-expression of wild-type HBsAg. CONCLUSION: The serum HBsAg levels were lower in untreated CHB patients with novel SHBs mutations outside the major antigenic region than those without mutations. Underlying mechanisms include impairment of virion secretion and lower binding affinity to antibodies used for HBsAg measurements. LAY SUMMARY: The hepatitis B surface antigen (HBsAg) is a major viral protein of the hepatitis B virus (HBV) secreted into patient blood serum and its quantification value serves as an important marker for the evaluation of chronic HBV infection and antiviral response. We found a few new amino acid substitutions in HBsAg associated with lower serum HBsAg and HBV DNA levels. These different substitutions might impair virion secretion, change the ability of HBsAg to bind to antibodies, or impact HBV replication. These could all result in decreased detectable levels of serum HBsAg. The factors affecting circulating HBsAg level and HBsAg detection are varied and caution is needed when interpreting clinical significance of serum HBsAg levels. Clinical trial number: NCT01088009.

[Determination the Change of Main Trace Elements in the Ovary with Self- and Cross-Pollination of Chinese Chestnut by ICP-MS].

Castanea mollissima Blume has potential as an non-wood forest trees that have been cultivated for thousands of years in China. In order to elucidate the trace elements of chestnut ovary, the major trace elements of self- and cross-pollination chestnut ovary were determined by inductively coupled plasma mass spectrometry. The results showed that self- and cross-pollination 5-50 d, six trace elements trends showed fluctuations. After cross-pollination 20 d, the content of Ca was up to 6.50 mg x g(-1), while the self-pollination 10 d, the content of Ca reached up to 7.77 mg x g(-1). After cross- and self-pollination pollination 30 d, the content of Mg were highest, 4.19 and 4.69 mg x g(-1), respectively. After cross-pollination 5 d, the content of Zn reached the highest, 0.038 7 mg x g(-1), while self-pollination 10d the content of Zn was 0.039 9 mg x g(-1). After self- and cross-pollination 35 d, the content of Fe were 0.022, 0.019 mg x g(-1), respectively. After cross- and self-pollination 20 d, the content of Cu were 0.056, 0.045 mg x g(-1), respectively. After self-pollination 40d, the content of Mn reaching the highest was 1.204 mg x g(-1), while cross-pollination 30 d, the content of Mn reached its maximum 0.845 mg x g(-1). The results can provide a reference for spraying fertilizer on the ovary development, thereby improving chestnut production.

Hepatitis B virus basal core promoter mutations A1762T/G1764A are associated with genotype C and a low serum HBsAg level in chronically-infected HBeAg-positive Chinese patients.

The present study was aimed to obtain baseline information of basal core promoter A1762T/G1764A and precore G1896A mutations of hepatitis B virus (HBV) in 192 HBeAg-positive chronically-infected Chinese patients, who were potential candidates for antiviral treatment. The detection of these mutations (including minor mutant subpopulations) was achieved by direct sequencing, whose sensitivity for minor mutant subpopulations identification was confirmed by clone sequencing. Patients enrolled were infected with either genotype B (46.35%) or C (53.65%) HBV identified by routine tests in our laboratory. The A1762T/G1764A or G1896A mutations were detected in 125specimens (125/192, 65.10%), in which 77 (77/125, 61.60%) existed as subpopulations. The A1762T/G1764A mutations were found to be more prevalent in genotype C than that in genotype B HBV [62.14% (64/103) vs. 20.22% (18/89), P<0.0001]. There is no statistically significant link between G1896A and genotypes. The emergence of A1762T/G1764A mutations was also found to be associated with an older age, an elevated ALT/AST level, and a lower HBsAg level in serum [wild-type vs. mutant: 4.57 (3.46-5.42) vs. 3.93 (2.51-5.36), P<0.0001]. In conclusion, HBV basal core promoter mutations A1762T/G1764A are associated with genotype C and a low serum HBsAg level in chronically-infected HBeAg-positive Chinese patients.