Identification and analysis of a clinically isolated strain of Halomonas based on whole-genome sequencing and comparative genomics.

OBJECTIVE: The aim of this study was to identify the species of a Halomonas strain isolated from a neonatal blood sample and to understand the potential pathogenicity and characteristic genes of the strain. METHODS: The genomic DNA of strain 18071143 (identified as Halomonas by matrix-assisted laser desorption-ionization time of flight-mass spectrometry and the 16S ribosomal RNA (rRNA) gene sequence) was sequenced using Nanopore PromethION platforms. The average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) were calculated using the complete genome sequences of the strain. Comparative genomic analyses were performed on strain 18071143 and 3 strains of Halomonas (Halomonas stevensii S18214, Halomonas hamiltonii KCTC 22154, and Halomonas johnsoniae KCTC 22157) that were associated with human infections and had high genomic similarity to strain 18071143. RESULTS: Phylogenetic, ANI, and dDDH similarity analyses based on genome sequence indicated that strain 18071143 belonged to the species H stevensii. Similarities exist between strain 18071143 and the other 3 Halomonas strains in terms of gene structure and protein function. Nonetheless, strain 18071143 has greater potential for DNA replication, recombination, repair, and horizontal transfer. CONCLUSION: Whole-genome sequencing holds great promise for accurate strain identification in clinical microbiology. In addition, the results of this study provide data for understanding Halomonas from the perspective of pathogenic bacteria.

Impact of COVID-19 pandemic on influenza virus prevalence in children in Sichuan, China.

We performed a retrospective analysis of influenza A and B virus antigen detection data in children in Sichuan Province from January 2019 to December 2021, with the goal of studying the impact of the COVID-19 pandemic on influenza circulation in children in Sichuan, China. During the pandemic, both the number of specimens and the positive rates of the influenza virus fell dramatically. The positivity for influenza A virus decreased from 22.5% in 2019 to 9.9% in 2020 to 0.2% in 2021 (p < 0.001). The lowest and highest positive rates for the influenza B virus occurred in 2020 and 2021, respectively, with a statistically significant 3-year comparison (p < 0.001). During the pandemic, the annual positivity remained higher in school-age than in preschoolers, while there was no difference in the annual positivity between the two gender groups, both consistent with the prepandemic results. During the pandemic, the seasonality of influenza A and B was different from that before the pandemic. In 2019, the epidemic season for influenza A was autumn and winter, while the epidemic season for influenza B was winter and spring. Seasonal changes in influenza A were insignificant after the pandemic, and influenza B became predominant in 2021, with a high prevalence in the autumn. Although influenza activity decreased during the COVID-19 pandemic, one should be on the lookout for a possible rebound in influenza circulation in the future.

An imbalanced ratio between PC(16:0/16:0) and LPC(16:0) revealed by lipidomics supports the role of the Lands cycle in ischemic brain injury.

Promoting brain recovery after stroke is challenging as a plethora of inhibitory molecules are produced in the brain preventing it from full healing. Moreover, the full scope of inhibitory molecules produced is not well understood. Here, using a high-sensitivity UPLC-MS-based shotgun lipidomics strategy, we semiquantitively measured the differential lipid contents in the mouse cerebral cortex recovering from a transient middle cerebral artery occlusion (MCAO). The lipidomic data were interrogated using the soft independent modeling of class analogy (SIMCA) method involving principal component analysis (PCA) and orthogonal partial least squares discriminant analysis (OPLS-DA). Statistics of the 578 confirmed lipids revealed 84 species were differentially changed during MCAO/reperfusion. The most dynamic changes in lipids occurred between 1 and 7 days post-MCAO, whereas concentrations had subsided to the Sham group level at 14 and 28 days post-MCAO. Quantitative analyses revealed a strong monotonic relationship between the reduction in phosphatidylcholine (PC)(16:0/16:0) and the increase in lysophosphatidylcholine (LPC)(16:0) levels (Spearman's Rs = -0.86) during the 1 to 7 days reperfusion period. Inhibition of cPLA2 prevented changes in the ratio between PC(16:0/16:0) and LPC(16:0), indicating altered Land's cycle of PC. A series of in vitro studies showed that LPC(16:0), but not PC(16:0/16:0), was detrimental to the integrity of neuronal growth cones and neuronal viability through evoking intracellular calcium influx. In contrast, PC(16:0/16:0) significantly suppressed microglial secretion of IL-1ß and TNF-α, limiting neuroinflammation pathways. Together, these data support the role of the imbalanced ratio between PC(16:0/16:0) and LPC(16:0), maintained by Lands' cycle, in neuronal damage and microglia-mediated inflammatory response during ischemic recovery.

Integrative analysis provides multi-omics evidence for the pathogenesis of placenta percreta.

Pernicious placenta previa with placenta percreta (PP) is a catastrophic condition during pregnancy. However, the underlying pathogenesis remains unclear. In the present study, the placental tissues of normal cases and PP tissues of pernicious placenta previa cases were collected to determine the expression profile of protein-coding genes, miRNAs, and lncRNAs through sequencing. Weighted gene co-expression network analysis (WGCNA), accompanied by miRNA target prediction and correlation analysis, were employed to select potential hub protein-coding genes and lncRNAs. The expression levels of selected protein-coding genes, Wnt5A and MAPK13, were determined by quantitative PCR and immunohistochemical staining, and lncRNA PTCHD1-AS and PAPPA-AS1 expression levels were determined by quantitative PCR and fluorescence in situ hybridization. The results indicated that 790 protein-coding genes, 382 miRNAs, and 541 lncRNAs were dysregulated in PP tissues, compared with normal tissues. WGCNA identified coding genes in the module (ME) black and ME turquoise modules that may be involved in the pathogenesis of PP. The selected potential hub protein-coding genes, Wnt5A and MAPK13, were down-regulated in PP tissues, and their expression levels were positively correlated with the expression levels of PTCHD1-AS and PAPPA-AS1. Further analysis demonstrated that PTCHD1-AS and PAPPA-AS1 regulated Wnt5A and MAPK13 expression by interacting with specific miRNAs. Collectively, our results provided multi-omics data to better understand the pathogenesis of PP and help identify predictive biomarkers and therapeutic targets for PP.

Molecular Characteristics of Methicillin-Resistant Staphylococcus epidermidis on the Abdominal Skin of Females before Laparotomy.

Staphylococcus epidermidis, especially methicillin-resistant strains, may be the source of surgical site infections and may be a reservoir of staphylococcal cassette chromosome mec (SCCmec) for S. aureus. The aim of this study was to investigate the prevalence of methicillin-resistant S. epidermidis (MRSE) on the abdominal skin of females before laparotomy and determine the molecular characteristics and antimicrobial susceptibility patterns of these isolates. MRSE was found in 54 of 157 isolates based on mecA gene detection, and there was no difference in icaA gene carriage rate between MRSE and methicillin-susceptible S. epidermidis (MSSE) isolates. Antimicrobial susceptibility profiles were determined by broth microdilution antimicrobial susceptibility testing according to the latest CLSI manuals. All MRSE isolates had unfavorable antimicrobial susceptibility patterns. Twenty-three MRSE strains (42.6%) were multi-drug resistant. SCCmec typing and pulsed field gel electrophoresis (PFGE) typing was performed. Thirty-nine (72.2%) had a single SCCmec type, whereas 1.9% had two types. Fourteen strains (25.9%) were non-typeable (NT). The most frequent MRSE genotype was SCCmec type IVa. High diversity with PFGE patterns was obtained for MRSE, and there were no isolates exhibiting identical pulsotype. The results confirm that methicillin-resistant strains are frequently present among S. epidermidis on the abdominal skin of females before laparotomy. Moreover, resistance profiles seem to have no association with the SCCmec types or PFGE types for most common antibiotics.

Anti-Trichomonas vaginalis properties of the oil of Amomum tsao-ko and its major component, geraniol.

CONTEXT: Trichomonosis, caused by the flagellate protozoan Trichomonas vaginalis, is the most common non-viral sexually transmitted disease (STD) and 5-nitroimidazole drugs are used for the treatment. However, a growing number of T. vaginalis isolates are resistant to these drugs, which make it becomes an urgent issue. OBJECTIVE: The current study was designed to evaluate the anti-T. vaginalis activity of the essential oil from A. tsao-ko used in traditional Chinese medicine and as a spice and its main component, geraniol. MATERIALS AND METHODS: The anti-T. vaginalis activities of A. tsao-ko essential oil and geraniol were evaluated by the minimum lethal concentration (MLC) and 50% inhibitory concentration (IC50) in vitro. The morphological changes of T. vaginalis were observed by transmission electron microscopy (TEM). Additionally, sub-MLC concentration treatment with sub-MLC A. tsao-ko essential oil and geraniol was also performed. RESULTS: This study shows that MLC/IC50 of A. tsao-ko essential oil was 44.97 µg/ml/22.49 µg/ml for T. vaginalis isolate Tv1, and 89.93 µg/ml/44.97 µg/ml for T. vaginalis isolate Tv2. Those of geraniol were 342.96 µg/ml/171.48 µg/ml, respectively. After A. tsao-ko essential oil or geraniol treatment, obvious similar morphological changes of T. vaginalis were observed by TEM: the nuclear membrane was damaged, nuclei were dissolved, and the chromatin was accumulated; in the cytoplasm, numerous vacuoles appeared, rough endoplasmic reticulum dilated, the number of ribosomes were reduced, organelles disintegrated, the cell membrane was partially damaged, with cytoplasmic leakage, and cell disintegration was observed. The action time did not increase the effect of A. tsao-ko essential oil or geraniol against T. vaginalis, as no significant difference was observed after sub-MLC concentration treatment for 1, 3, and 5 h with A. tsao-ko essential oil and geraniol. DISCUSSION AND CONCLUSION: The study describes the first report on the activity and morphological changes of A. tsao-ko essential oil and geraniol against T. vaginalis. The results obtained herein presented new opportunities for antitrichomonal drugs.

[Mycoplasma hominis symbiosis and Trichomonas vaginalis metronidazole resistance].

OBJECTIVE: To investigate the relation of Mycoplasma hominis symbiosis and the resistance of Trichomonas vaginalis to metronidazole. METHODS: From November 2010 to July 2011, 160 isolates of T. vaginalis were collected from the genital tract secretion of gynecological out-patients at the Sichuan Provincial Hospital for Women and Children. The minimum lethal concentration (MLC) to metronidazole of these isolates was determined by an in vitro sensitivity assay with different concentration gradients of metronidazole (from 1 to 1 024 microg/ml), and M. hominis DNA in T. vaginalis was detected by polymerase chain reaction (PCR) technique with specific 16S rRNA primers. After clearance of M. hominis from the parasites by 32 microg/ml doxycycline, MLC was determined and compared with that before clearance. RESULTS: MLC of metronidazole in T. vaginalis ranged from 1 to 256 microg/ml, with 61.3% isolates (98/160) ranging from 1 to 8 microg/ml, 26.3% isolates (42/160) ranging from 16 to 32 microg/ml, and 12.5% isolates (20/160) ranging from 64 to 256 microg/ml. 61 isolates were PCR positive for M. hominis DNA in the 160 isolates of T. vaginalis. The M. hominis DNA positive rate was significantly higher in the T. vaginalis isolates with higher MLC than those isolates with lower MLC (P<0.01). However, when M. hominis was cleared by doxycycline from 8 isolates among the 61 ones, no change was observed in sensitivity of the isolates to metronidazole. CONCLUSION: M. hominis symbiosis might be associated with the metronidazole-resistance of T. vaginalis. However, it needs direct evidence.

[Influence of bifidobacterial whole peptidoglycan on cellular immune response induced by recombinant HBsAg].

AIM: To explore the effect of bifidobacterial whole peptidoglycan (BWPG) on cellular immune response to recombinant hepatitis B surface antigen (rHBsAg). METHODS: BWPG was used as an adjuvant of rHBsAg to immunize BALB/c mice. The growth state and development of central lymphoid organ of immunized mice were observed. Then the killing activities of NK cells and CTLs, the proliferation and cytokine production of splenic lymphocytes were examined. RESULTS: After immunization with BWPG, no visible side effect was observed in immunized mice. The thymus and spleen tissues assumed hyperplasia appearance. The killing activities of NK cells and CTLs in spleen were enhanced. The proliferation of splenic lymphocytes was active and cytokine production was increased. CONCLUSION: BWPG can promote hyperplasia of central lymphoid organ and enhance the cellular immune response to rHBsAg.