Prevalence and molecular characterization of Trichomonas gallinae from pigeons in Anhui, China.

Trichomonas gallinae, a protozoan parasite causing avian trichomonosis, exhibits a widespread global prevalence. It primarily affects the upper digestive tract of birds and has resulted in significant ecological problems worldwide. This study aimed to investigate the prevalence and genotypes of T. gallinae in Anhui Province, China. A total of 1612 oropharyngeal swab samples were collected from pigeon farms in Anhui Province to determine the prevalence of T. gallinae infection. The results revealed 565 (35.1%) positive samples of T. gallinae. Significant differences in infection rates were observed among different regions and age groups. Furthermore, the ITS1/5.8 S/ITS2 region was amplified, sequenced, and subjected to phylogenetic analysis. Genotypes A and B of T. gallinae were identified, and genotype B was the dominant genotype in Anhui Province. This is the first report on the prevalence and molecular characterization of T. gallinae in Anhui Province, China. Additionally, we integrated reports on the prevalence and genotype of T. gallinae in relevant provinces in China.

APDDD: Animal parasitic diseases and drugs database.

Animal parasitic diseases not only have an economic impact, but also have serious social and public health impacts. Although antiparasitic drugs can treat these diseases, it seems difficult for users to comprehensively utilize the information, due to incomplete and difficult data collection. Thus, there is an urgent need to establish a comprehensive database, that includes parasitic diseases and related drugs. In this paper, we develop a knowledge database dedicated to collecting and analyzing animal parasitic diseases and related drugs, named Animal Parasitic Diseases and Drugs Database (APDDD). The current version of APDDD includes animal parasitic disease data of 8 major parasite classifications that cause common parasitic diseases and 96 subclass samples mined from many literature and authoritative books, as well as 182 antiparasitic drugs. Furthermore, we utilized APDDD data to add a knowledge graph representing the relationships between parasitic diseases, drugs, and the targeted gene of drugs acting on parasites. We hope that APDDD will become a good database for animal parasitic diseases and antiparasitic drugs research and that users can gain a more intuitive understanding of the relationships between parasitic diseases, drugs, and targeted genes through the knowledge graph.

First screening for tick-borne pathogens in Chinese Milu deer (Elaphurus davidianus).

Ticks are primary vectors for many tick-borne pathogens (TBPs) and pose a serious threat to veterinary and public health. Information on the presence of TBPs in Chinese Milu deer (Elaphurus davidianus) is limited. In this study, a total of 102 Chinese Milu deer blood samples were examined for Anaplasma spp., Theileria spp., Babesia spp., Rickettsia spp., and Borrelia spp., and three TBPs were identified: Anaplasma phagocytophilum (48; 47.1 %), Candidatus Anaplasma boleense (47; 46.1%), and Theileria capreoli (8; 7.8 %). Genetic and phylogenetic analysis of the 16S rRNA and 18S rRNA confirmed their identity with corresponding TBPs. To our knowledge, this is the first report on Candidatus A. boleense and T. capreoli detection in Chinese Milu deer. A high prevalence of A. phagocytophilum with veterinary and medical significance was identified in endangered Chinese Milu deer, which could act as potential zoonotic reservoirs. The identification of the TBPs in Chinese Milu deer provides useful information for the prevention and control of tick-borne diseases.

Epidemiological survey of tick-borne pathogens in dogs in Anhui Province, China.

Tick-borne diseases have continued to increase worldwide in both developing and many developed countries due to the widespread of different tick species and tick's adaptability to different climatic weather. In order to investigate the prevalence of the tick-borne pathogens, EDTA-anticoagulated whole blood samples were aseptically collected from 765 pet dogs in twenty veterinary clinics located in sixteen prefecture-level cities in Anhui Province, China, and the samples were examined and analyzed for tick-borne pathogens using both microscopy and PCR. Our result analysis revealed 17(2.22%) positive samples to Babesia spp and 4(0.52%) positive samples to Hepatozoon spp, of which case of co-infection was recorded in Lu'An and Chuzhou. The BLAST analysis results of the 18S rRNA gene revealed that the dogs were infected with Babesia gibsoni and Hepatozoon canis. All samples were negative for Anaplasma spp., Ehrlichia spp., and Rickettsia spp. This is the first molecular report of B. gibsoni and H. canis in dogs in Anhui, China.

Development and validation of a machine learning algorithm prediction for dense granule proteins in Apicomplexa.

BACKGROUND: Apicomplexa consist of numerous pathogenic parasitic protistan genera that invade host cells and reside and replicate within the parasitophorous vacuole (PV). Through this interface, the parasite exchanges nutrients and affects transport and immune modulation. During the intracellular life-cycle, the specialized secretory organelles of the parasite secrete an array of proteins, among which dense granule proteins (GRAs) play a major role in the modification of the PV. Despite this important role of GRAs, a large number of potential GRAs remain unidentified in Apicomplexa. METHODS: A multi-view attention graph convolutional network (MVA-GCN) prediction model with multiple features was constructed using a combination of machine learning and genomic datasets, and the prediction was performed on selected Neospora caninum protein data. The candidate GRAs were verified by a CRISPR/Cas9 gene editing system, and the complete NcGRA64(a,b) gene knockout strain was constructed and the phenotypes of the mutant were analyzed. RESULTS: The MVA-GCN prediction model was used to screen N. caninum candidate GRAs, and two novel GRAs (NcGRA64a and NcGRA64b) were verified by gene endogenous tagging. Knockout of complete genes of NcGRA64(a,b) in N. caninum did not affect the parasite's growth and replication in vitro and virulence in vivo. CONCLUSIONS: Our study showcases the utility of the MVA-GCN deep learning model for mining Apicomplexa GRAs in genomic datasets, and the prediction model also has certain potential in mining other functional proteins of apicomplexan parasites.

GRA-GCN: Dense Granule Protein Prediction in Apicomplexa Protozoa Through Graph Convolutional Network.

Dense granule proteins (GRAs) are secreted by Apicomplexa protozoa, which are closely related to an extensive variety of farm animal diseases. Predicting GRAs is an integral part in prevention and treatment of parasitic diseases. Considering that biological experiment approach is time-consuming and labor-intensive, computational method is a superior choice. Hence, developing an effective computational method for GRAs prediction is of urgency. In this paper, we present a novel computational method named GRA-GCN through graph convolutional network. In terms of the graph theory, the GRAs prediction can be regarded as a node classification task. GRA-GCN leverages k-nearest neighbor algorithm to construct the feature graph for aggregating more informative representation. To our knowledge, this is the first attempt to utilize computational approach for GRAs prediction. Evaluated by 5-fold cross-validations, the GRA-GCN method achieves satisfactory performance, and is superior to four classic machine learning-based methods and three state-of-the-art models. The analysis of the comprehensive experiment results and a case study could offer valuable information for understanding complex mechanisms, and would contribute to accurate prediction of GRAs. Moreover, we also implement a web server at http://dgpd.tlds.cc/GRAGCN/index/, for facilitating the process of using our model.

DGPD: a knowledge database of dense granule proteins of the Apicomplexa.

Apicomplexan parasites cause severe diseases in human and livestock. Dense granule proteins (GRAs), specific to the Apicomplexa, participate in the maintenance of intracellular parasitism of host cells. GRAs have better immunogenicity and they can be emerged as important players in vaccine development. Although studies on GRAs have increased gradually in recent years, due to incompleteness and complexity of data collection, biologists have difficulty in the comprehensive utilization of information. Thus, there is a desperate need of user-friendly resource to integrate with existing GRAs. In this paper, we developed the Dense Granule Protein Database (DGPD), the first knowledge database dedicated to the integration and analysis of typical GRAs properties. The current version of DGPD includes annotated GRAs metadata of 245 samples derived from multiple web repositories and literature mining, involving five species that cause common diseases (Plasmodium falciparum, Toxoplasma gondii, Hammondia hammondi, Neospora caninum and Cystoisospora suis). We explored the baseline characteristics of GRAs and found that the number of introns and transmembrane domains in GRAs are markedly different from those of non-GRAs. Furthermore, we utilized the data in DGPD to explore the prediction algorithms for GRAs. We hope DGPD will be a good database for researchers to study GRAs. Database URL: http://dgpd.tlds.cc/DGPD/index/.

Seroprevalence and risk factors of Toxoplasma gondii in urban cats from China.

BACKGROUND: Toxoplasma gondii infects almost all warm-blooded animals, and cats play a crucial role in the epidemiology of T. gondii as the definitive host. Despite sporadic reports on the seroprevalence of T. gondii in domestic cats, systematic surveys are lacking and some regions remain in China uninvestigated. METHODS: A total of 1,521 serum samples were collected from 10 regions of China and analyzed by antibodies against T. gondii by ELISA with the purpose of identifying risk factors of T. gondii infection in cats across China and obtaining seroprevalence data from some previously uninvestigated areas. RESULTS: Antibodies to T. gondii were detected in 62 of 1,478 (4.2%) urban pet cats and in 9 of 43 (20.9%) stray cats. Among the regions examined, the prevalence was 13% in Sichuan, 12.8% in Chongqing, 6.4% in Hunan, 2.5% in Hubei and 0.9% in Guangdong. Additionally, this is the first report on the seroprevalence of T. gondii in urban pet cats from Qinghai (6.2%), Anhui (3.1%), Jiangxi (2.5%), Shaanxi (2.4%) and Ningxia (1.6%). The age and lifestyle (stray or pet) of cats were identified as the risk factors for seropositivity by multivariate analysis of the data. CONCLUSIONS: Our findings improve our understanding of seroprevalence and risk factors of T. gondii infection in cats across China, and provide useful information for the formulating of preventive and control measures against this widespread zoonotic parasite.

Pharmacokinetic/Pharmacodynamic Parameters of Linezolid in the Epithelial Lining Fluid of Patients With Sepsis.

The aim of this study was to investigate the pharmacokinetic/pharmacodynamic parameters of linezolid in both the plasma and epithelial lining fluid (ELF) of patients with pneumonia-induced sepsis. Blood specimens and bronchoalveolar lavage samples were collected at defined time points after administration of linezolid. The concentration in the ELF was calculated by urea dilution method. PK parameters were calculated, and probability of target attainment was evaluated by Monte Carlo simulations. Twenty-three patients were enrolled, 8 of whom had septic shock. The maximum concentration of linezolid was higher in the ELF than in the plasma (36.02 ± 13.17 vs 19.51±4.83 mg/L, P < .001) in all of the patients. In patients with septic shock, the maximum concentration in the ELF was significantly higher than that in the non-septic shock group (45.25 ± 11.70 vs 31.10 ± 11.38 mg/L, P = .01), while there was no significant difference in the plasma. The corresponding probability of target attainment values were 90.5% and 65.1% in ELF and plasma, respectively, with a minimum inhibitory concentration of 2 mg/L, which were 99.9% in the ELF in the patients with septic shock. Linezolid possesses an efficient penetration into the ELF of patients with pneumonia-induced sepsis with mechanical ventilation. When minimum inhibitory concentration ≤ 2 mg/L, 600 mg of linezolid every 12 hours could achieve the optimal therapeutic targets in the ELF rather than in the plasma of patients with pneumonia-induced sepsis.

Development and application of an indirect ELISA to detect antibodies to Neospora caninum in cattle based on a chimeric protein rSRS2-SAG1-GRA7.

Neospora caninum is an important apicomplexan parasite causing neosporosis in cattle. The disease is recognized as one of the most important cause of reproductive problems and abortion in cattle worldwide. In this context, we developed an indirect enzyme-linked immunosorbent assays (ELISA) with chimeric protein rSRS2-SAG1-GRA7 to diagnose antibodies to Neospora-infection. This indirect ELISA was compared to indirect fluorescent antibody test (IFAT) and western blotting (WB), and the sensitivity and specificity results of ELISA were calculated to be 86.7 and 96.1%, respectively. The overall coincidence rate was 92.6% using IFAT and WB. Additionally, 329 aborting dairy cattle serum samples were tested using this ELISA to evaluate the prevalence of N. caninum in Ningxia, China. The positive rate of N. caninum in these farms was from 19.05 to 57.89%, and the mean rate was 41.64% (±11.01%), indicating that infection with N. caninum may be one of the important causes of cattle abortion in this region. This established rSRS2-SAG1-GRA7 indirect ELISA is capable for detecting the antibodies against N. caninum, and it could be a useful screening tool for monitoring the epidemiology of neosporosis in cattle.

Biotinylation of the Neospora caninum parasitophorous vacuole reveals novel dense granule proteins.

BACKGROUND: Neospora caninum is an obligate intracellular parasite that invades host cells and replicates within the parasitophorous vacuole (PV), which resists fusion with host cell lysosomal compartments. To modify the PV, the parasite secretes an array of proteins, including dense granule proteins (GRAs). The vital role of GRAs in the Neospora life cycle cannot be overestimated. Despite this important role, only a subset of these proteins have been identified, and most of their functions have not been elucidated. Our previous study demonstrated that NcGRA17 is specifically targeted to the delimiting membrane of the parasitophorous vacuole membrane (PVM). In this study, we utilize proximity-dependent biotin identification (BioID) to identify novel components of the dense granules. METHODS: NcGRA17 was BirA* epitope-tagged in the Nc1 strain utilizing the CRISPR/Cas9 system to create a fusion of NcGRA17 with the biotin ligase BirA*. The biotinylated proteins were affinity-purified for mass spectrometric analysis, and the candidate GRA proteins from BioID data set were identified by gene tagging. To verify the biological role of novel identified GRA proteins, we constructed the NcGRA23 and NcGRA11 (a-e) knockout strains using the CRISPR/Cas9 system and analyzed the phenotypes of these mutants. RESULTS: Using NcGRA17-BirA* fusion protein as bait, we have identified some known GRAs and verified localization of 11 novel GRA proteins by gene endogenous tagging or overexpression in the Nc1 strain. We proceeded to functionally characterize NcGRA23 and NcGRA11 (a-e) by gene knockout. The lack of NcGRA23 or NcGRA11 (a-e) did not affect the parasite propagation in vitro and virulence in vivo. CONCLUSIONS: In summary, our findings reveal that BioID is effective in discovering novel constituents of N. caninum dense granules. The exact biological functions of the novel GRA proteins are yet unknown, but this could be explored in future studies.

mTORC2 Activation Mediated by Mesenchymal Stem Cell-Secreted Hepatocyte Growth Factors for the Recovery of Lipopolysaccharide-Induced Vascular Endothelial Barrier.

Acute lung injury (ALI)/acute respiratory distress syndrome (ARDS) is characterized by pulmonary microvascular endothelial barrier dysfunction. Mesenchymal stem cell-secreted hepatocyte growth factor (HGF) has positive effects of lipopolysaccharide- (LPS-) induced pulmonary endothelial barrier. Studies have exhibited the mammalian TORC1 (mTORC1) signaling is of potent angiogenesis effects. The mTOR protein kinase has two distinct multiprotein complexes mTORC1 and mTORC2 that regulate different branches of the mTOR network. However, detailed mTORC2 mechanisms of HGF protective effects remain poorly defined. Therefore, the aim of this study was to determine whether mTORC2 mediated protective effects of MSC-secreted HGF against LPS-induced pulmonary microvascular endothelial barrier dysfunction activated like mTORC1 activation. We introduced MSC-PMVEC coculture transwell system and recombinant murine HGF on LPS-induced endothelial cell barrier dysfunction in vitro and then explored potential mechanisms by lentivirus vector-mediated HGF, mTORC1 (raptor), and mTORC2 (rictor) gene knockdown modification. Endothelial paracellular and transcellular permeability, adherent junction protein (VE-Cadherin), cell proliferation, apoptosis, and mTOR-associated proteins were tested. These revealed that HGF could promote quick reestablishment of adherent junction VE-cadherin and decrease endothelial paracellular and transcellular permeability during LSP-induced endothelial dysfunction with the involvement of mTORC2 (rictor) and mTORC1 (raptor) pathways. Raptor and rictor knockdown in LPS-induced PMEVECs with stimulation of HGF increased apoptosis ratio, activated Cleaved-Caspase-3 expression, and downregulated cell proliferation. Moreover, mTORC2/Akt but not mTORC2/PKC had significance on HGF endothelial protective effects. Taken together, these highlight activation mTORC2 pathway could also contribute to vascular endothelial barrier recovery by MSC-secreted HGF in LPS stimulation.

Nucleotide polymorphism in ARDS outcome: a whole exome sequencing association study.

BACKGROUND: Genetic locus were identified associated with acute respiratory distress syndrome (ARDS). Our goal was to explore the associations between genetic variants and ARDS outcome, as well as subphenotypes. METHODS: This was a single-center, prospective observational trial enrolling adult ARDS patients. After baseline data were collected, blood samples were drawn to perform whole exome sequencing, single nucleotide polymorphism (SNP)/insertion-deletion to explore the quantitative and functional associations between genetic variants and ICU outcome, clinical subphenotypes. Then the lung injury burden (LIB), which was defined as the ratio of nonsynonymous SNP number per megabase of DNA, was used to evaluate its value in predicting ARDS outcome. RESULTS: A total of 105 ARDS patients were enrolled in the study, including 70 survivors and 35 nonsurvivors. Based on the analysis of a total of 65,542 nonsynonymous SNP, LIB in survivors was significantly higher than nonsurvivors [1,892 (1,848-1,942)/MB versus 1,864 (1,829-1,910)/MB, P=0.018], while GO analysis showed that 60 functions were correlated with ARDS outcome, KEGG enrichment analysis showed that SNP/InDels were enriched in 13 pathways. Several new SNPs were found potentially associated with ARDS outcome. Analysis of LIB was used to determine its outcome predicting ability, the area under the ROC curve of which was only 0.6103, and increase to 0.712 when combined with APACHE II score. CONCLUSIONS: Genetic variants are associated with ARDS outcome and subphenotypes; however, their prognostic value still need to be verified by larger trials. TRIAL REGISTRATION: Clinicaltrials.gov NCT02644798. Registered 20 April 2015.

[Chemokine receptor 7 promotes the paracrine of hepatocyte growth factor by mesenchymal stem cells via inhibitor of differentiation-1].

OBJECTIVE: To investigate the possible mechanism of mesenchymal stem cells (MSC) secreting hepatocyte growth factor (HGF). METHODS: (1) C57BL/6 mouse mesenchymal stem cells (mMSC) were cultured in vitro, and mMSC with high expression of chemokine receptor 7 (CXCR7) were transduced by lentivirus plasmid. Blank control group and empty carrier control group were set at the same time. After 20 generations of cell culture, the transfection efficiency was identified by fluorescence microscopy and flow cytometry. The mRNA expression levels of CXCR7 in mMSC were detected by real-time fluorescent quantitative reverse transcription-polymerase chain reaction (RT-PCR). (2) mMSC with passage number 4-6 were divided into MSC control group [MSC-blank group, 100 µg/L lipopolysaccharide (LPS) was added to wild-type MSC], highly expressed CXCR7 group (MSC-OE-CXCR7 group, 100 µg/L LPS was added to mMSC transduced by lentivirus plasmid with high expression of CXCR7), highly expressed CXCR7 control group (MSC-OENC-CXCR7 group, 100 µg/L LPS was added to mMSC transduced by no load lentivirus plasmid), CXCR4 inhibitor group (MSC-IE-CXCR4 group, 100 µg/L LPS was added to mMSC after 0.1 mg/L CXCR4 inhibitor TC14012 pretreatment for 24 hours), and CXCR4 inhibitor control group (MSC-IENC-CXCR4 group, 100 µg/L LPS was added to mMSC after DMEM culture medium with equal amount of TC14012 pretreatment for 24 hours). Cells in each group were collected after treatment with LPS, and mRNA expression of inhibitor of differentiation-1 (ID-1) was detected by RT-PCR. The cell supernatant was collected, and the levels of HGF were detected by enzyme linked immunosorbent assay (ELISA). RESULTS: (1) The high expression of CXCR7 for mMSC which were transduced through lentivirus plasmid were successfully constructed detected by fluorescence microscope and flow cytometry. Compared with the blank control group, the expression of CXCR7 mRNA in the lentivirus with high expression of CXCR7 group was significantly increased (2-ΔΔCt: 5.81±0.97 vs. 1.02±0.12, P < 0.05). There was no significant difference in CXCR7 mRNA expression between the empty carrier control group and the blank control group (2-ΔΔCt: 0.95±0.22 vs. 1.02±0.12, P > 0.05). (2) Compared with the MSC-blank group, high expression of CXCR7 in MSC-OE-CXCR7 group or inhibition of CXCR4 in MSC-IE-CXCR4 group could induce high expression of ID-1 mRNA in mMSC (2-ΔΔCt: 5.56±0.66, 2.47±0.58 vs. 1.00±0.10, both P < 0.05) and increase HGF exocrine level (ng/L: 632.02±149.98, 217.21±40.53 vs. 108.53±24.62, both P < 0.05). However, there were no significant differences in ID-1 mRNA expression and HGF exocrine level of mMSC among MSC-OENC-CXCR7 group, MSC-IENC-CXCR4 group and MSC-blank group [ID-1 mRNA (2-ΔΔCt): 1.01±0.27, 1.21±0.32 vs. 1.00±0.10, HGF (ng/L): 133.56±25.19, 107.11±25.30 vs. 108.53±24.62, both P > 0.05]. CONCLUSIONS: High expression of CXCR7 or inhibition of CXCR4 in MSC can increase the expression of ID-1 and promote the secretion of HGF, thus promoting pulmonary microvascular endothelial repair.

NcPuf1 Is a Key Virulence Factor in Neospora caninum.

BACKGROUND: Neospora caninum is an apicomplexan parasite that infects many mammals and particularly causes abortion in cattle. The key factors in its wide distribution are its virulence and ability to transform between tachyzoite and bradyzoite forms. However, the factors are not well understood. Although Puf protein (named after Pumilio from Drosophila melanogaster and fem-3 binding factor from Caenorhabditis elegans) have a functionally conserved role in promoting proliferation and inhibiting differentiation in many eukaryotes, the function of the Puf proteins in N. caninum is poorly understood. METHODS: The CRISPR/CAS9 system was used to identify and study the function of the Puf protein in N. caninum. RESULTS: We showed that N. caninum encodes a Puf protein, which was designated NcPuf1. NcPuf1 is found in the cytoplasm in intracellular parasites and in processing bodies (P-bodies), which are reported for the first time in N. caninum in extracellular parasites. NcPuf1 is not needed for the formation of P-bodies in N. caninum. The deletion of NcPuf1 (ΔNcPuf1) does not affect the differentiation in vitro and tissue cysts formation in the mouse brain. However, ΔNcPuf1 resulted in decreases in the proliferative capacity of N. caninum in vitro and virulence in mice. CONCLUSIONS: Altogether, the disruption of NcPuf1 does not affect bradyzoites differentiation, but seriously impairs tachyzoite proliferation in vitro and virulence in mice. These results can provide a theoretical basis for the development of attenuated vaccines to prevent the infection of N. caninum.

Long non-coding RNA Hsp4 alleviates lipopolysaccharide-induced apoptosis of lung epithelial cells via miRNA-466m-3p/DNAjb6 axis.

Acute lung injury (ALI), as a life-threatening syndrome, is mainly characterized with diffuse alveolar injury, excessive pulmonary inflammation, edema and apoptosis of lung epithelial cells. This study investigated the effects of LncRNA Hsp4 (Hsp4, ENSMUST00000175718) on lipopolysaccharide (LPS)-induced apoptosis of MLE-12 cells. In our research, we found that LPS treatment remarkably induced apoptosis of MLE-12 cells and decreased the expression of Hsp4. Overexpression of Hsp4 significantly reversed LPS-induced cell apoptosis through inhibiting mTOR signaling, while suppression of Hsp4 presented opposite effects. Further results showed that Hsp4 positively regulated the expression of miR-466m-3p. Knockdown of miR-466m-3p reversed LPS-induced cell apoptosis via increasing the levels of DNAjb6 which was confirmed to be the target gene of miR-466m-3p. This finding will be helpful for further understanding the critical roles of Hsp4 in ALI and may provide potential targets for ALI diagnosis and treatment.

Glutaredoxin 1 Deficiency Leads to Microneme Protein-Mediated Growth Defects in Neospora caninum.

Neospora caninum is an obligate intracellular protozoan parasite that infects a wide range of mammalian species and causes spontaneous abortion in cattle. N. caninum is exposed to oxidative stress during its life cycle. Oxidoreductase is crucial for parasite response to the environmental stresses. Glutaredoxins (Grxs) are small oxidoreductases of the thioredoxin family proteins that catalyze thiol-disulfide exchange reactions by utilizing electrons from the tripeptide glutathione (γGlu-Cys-Gly; GSH). Grxs are key elements in redox signaling and cell signal transduction. However, Grxs are an unexplored set of oxidoreductases in N. caninum. Here, we identified two cytoplasm located glutaredoxin domain-containing proteins (NcGrx1 and NcGrx3) in N. caninum. To better understand the functions of these Grx proteins, we generated NcGrx1 and NcGrx3 deficiency and overexpression strains. The deletion or overexpression of NcGrx3 had no significant effect on the growth of N. caninum in vitro and in vivo. NcGrx1 knockout parasites displayed a significant growth defect, which was due to the influence on invasion and egress abilities. Moreover, NcGrx1 deficiency decreased the ratio of reduced glutathione (GSH) to oxidized glutathione (GSSG) (GSH/GSSG ratio), caused a significant accumulation of hydroxyl radical in parasites, and an increase in apoptotic cells under oxidative stress (H2O2) condition. To determine the cause of growth defects in ΔNcGrx1, we examined the transcription levels of various invasion-egress related genes as measured by qPCR. We found a significant decrease in MIC1, MIC4, and MIC6 genes. Further investigation found that the secretion of MIC1, MIC4, and MIC6 proteins was significantly affected. Collectively, Ncgrx1 is important for microneme protein-mediated parasite growth, and maybe a potential intervention target for the N. caninum.

Early- and Late-Onset Bloodstream Infections in the Intensive Care Unit: A Retrospective 5-Year Study of Patients at a University Hospital in China.

BACKGROUND: Limited data are available regarding the current microbiological characteristics of bloodstream infections (BSIs) in intensive care units (ICUs) in China. This retrospective study aimed to determine the epidemiology of early- and late-onset BSIs in our ICU. METHODS: We retrospectively collected data about ICU patients with BSI from 2013 to 2017. The patients were divided into the early- and late-onset BSI groups according to if BSI occurred within or beyond 48 hours after ICU admission. Univariate and multivariate logistic regression analyses were used to assess the risk factors for infection with multidrug resistant organisms (MDROs). RESULTS: Of 5474 ICU admissions, 486 (8.9%) patients with BSIs and with 500 microorganisms were included in this study, 246 (50.6%) of whom had early-onset BSIs. Two hundred and seventy patients were infected with MDROs. The proportion of MDRO infections was significantly higher among patients with late-onset BSIs than among those with early-onset BSIs (57.9% vs. 41.5%, P = .017). The ICU mortality rate was significantly higher in the late-onset BSI group (44.6% vs. 33.8%, P = .014) and early and appropriate antimicrobial treatment significantly improved the survival rate among patients with BSI (P < .001). CONCLUSIONS: MDROs affected more than half of patients with BSI in the ICU. Early appropriate empirical antimicrobial therapy could improve clinical outcome of patients with BSIs.

Case report: Mycobacterium monacense isolated from the blood culture of a patient with pulmonary infection.

BACKGROUND: The poorly known mycobacterial species Mycobacterium monacense is a rapidly growing non-tuberculous mycobacterium that was first described in 2006 (Reischl et al., Int J Syst Evol Microbiol 56:2575-8, 2006); it has been reported that its isolation is usually associated with skin and lung infections, especially in immunosuppressed patients (Hogardt et al., Jpn J Infect Dis 61:77-8, 2008; Taieb et al., J Hand Surg Am 33:94-6, 2008; Therese et al., Lung India 28:124-6, 2011; Shojaei et al., Ann Lab Med 32:87-90, 2012; Romero et al., New Microbes New Infect 10:112-5, 2016 ). The clinical significance of Mycobacterium monacense is not yet fully understood. Here, we report the first isolation of Mycobacterium monacense from the blood culture of a patient in China with severe pneumonia. CASE PRESENTATION: On June 26, 2018, a 38-year-old man was admitted to the intensive care unit with breathing difficulty. One day prior, he was discovered with his face immersed in a small pond (non-chlorinated water) and with limb convulsions. He had undergone craniocerebral surgery after trauma 5 years earlier, which left him with epilepsy as a sequela. Bilateral diffuse ground-glass opacity was found in the lungs on chest X ray and chest CT image at admission. The result of the HIV serology test of the patient was negative. The patient was diagnosed with severe pneumonia. Drug-susceptible Klebsiella pneumoniae and Candida glabrata were isolated in the BALF, and yellow-pigmented colonies were isolated from blood cultures of the patient. The strain isolated from blood was identified by 16S rDNA sequencing as Mycobacteria monacense, which is a rapidly growing mycobacterium (RGM). The patient was treated with a combination of cefoperazone sulbactam, linezolid and voriconazole for 10 days, and the symptoms improved. During the one-year follow-up time, the patient did not relapse. CONCLUSIONS: We report the first case of M. monacense isolated from blood cultures in a patient with severe pneumonia, which provided evidence that the environmental microorganism possessed pathogenic characteristics.

Triclosan inhibits the growth of Neospora caninum in vitro and in vivo.

Neospora caninum is an apicomplexan parasite considered one of the main causes of abortion in cattle worldwide; thus, there is an urgent need to develop novel therapeutic agents to control the neosporosis. Enoyl acyl carrier protein reductase (ENR) is a key enzyme of the type II fatty acid synthesis pathway (FAS II), which is essential for apicomplexan parasite survival. The antimicrobial agent triclosan has been shown to be a very potent inhibitor of ENR. In this study, we identified an E. coli ENR-like protein in N. caninum. Multiple sequence alignment showed all the requisite features of ENR existed in this protein, so we named this protein NcENR. Swiss-Model analysis showed NcENR interacts with triclosan. We observed that ENR is localized in the apicoplast, a plastid-like organelle. Similar to the potent inhibition of triclosan on other apicomplexa parasites, this compound markedly inhibits the growth of N. caninum at low concentrations. Further research showed that triclosan attenuated the invasion ability and proliferation ability of N. caninum at low concentrations. The results from in vivo studies in the mouse showed that triclosan attenuated the virulence of N. caninum in mice mildly and reduced the parasite burden in the brain significantly. Taken together, triclosan inhibits the growth of N. caninum both in vitro and in vivo at low concentrations.