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Objective To evaluate the in vitro antifungal activity of osthole against Talaromyces marneffei (TM) in yeast phase,in order to provide an experimental reference for the clinical treatment of TM infection with Chinese medicine.Methods There were 20 TM strains,including 1 standard strain,2 fluconazole-spontaneously resistant strains,11 clinical isolates,and 6 isolates from wild bamboo rats.A microdilution method was used to prepare 96-well antifungal sensitivity test plates containing osthole,fluconazole,amphotericin B,itraconazole and voriconazole at different concentrations,which were incubated with (1-5) × 103 CFU/ml of tested TM strain suspensions at 37 ℃ for 48 hours.Meanwhile,TM strains cultured in the media without antifungal drugs served as positive (growth) control group,and culture media served as negative group.The minimum inhibitory concentrations (MICs) of antifungal drugs against yeasts were determined using the Clinical and Laboratory Standards Institute (CLSI) broth microdilution susceptibility method (M27-A2 Document).Fluconazole MIC was defined as the lowest drug concentration that resulted in ≥ 80％ growth inhibition,and MICs of other antifungal drugs were the lowest drug concentrations that resulted in 100％ growth inhibition,compared with growth control wells.Results The MICs among the quality control strains were all within the reference range,and TM grew well in the positive control wells.The MIC ranges of fluconazole,amphotericin B,itraconazole and voriconazole against TM strains were 2.0-8.0 mg/L,1.0-4.0 mg/L,0.03-0.25 mg/L and 0.06-0.25 mg/L respectively,and the MIC of fluconazole against fluconazole-spontaneously resistant strains was 128 mg/L.The MICs of osthole against the TM standard strain (FRR2161),fluconazole-spontaneously resistant strains and 1 isolate from wild bamboo rats were 16,32 and 128 mg/L respectively,and the MIC range of osthole against other 16 TM strains was 16-64 mg/L.The MICs of osthole at which 90％ and 50％ of the TM strains were inhibited were 64 and 32 mg/L respectively.Conclusion Osthole exhibits the antifungal activity against the yeast form of TM.
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Objective To investigate the clinical manifestations and pathogenic characteristics of nosocomial bacterial infection in children with infectious mononucleosis (IM).Methods A retrospective analysis was performed for IM children from January to December 2015 in West China Second University Hospital.According to whether there was the process of secondary bacterial infection,the patients were divided into the secondary infection group and the non-infection group.The clinical manifestations and pathogenic bacteria were analyzed.Results Two hundred and sixteen children with IM were enrolled,of whom,177 cases (81.9％) were in the non-infection group,and 39 cases (18.1％) were in the secondary infection group.The patients in non-infection group were (4.7 ± 3.2) years old,and the patients in secondary infection group were (7.0 ± 3.8) years old,and the difference was statistically significant (t =3.066,P ＜ 0.05).The secondary infection group included bacterial tonsillitis in 17 cases,bronchial pneumonia in 11 cases,otitis media in 5 cases,cervical bacterial lymphadenitis in 3 cases,periorbital cellulitis in 2 cases,and sepsis in 1 case.Meanwhile,3 cases of concomitant thrush were observed in the secondary infection group.The rate of nosocomial bacterial infection in IM children [18.1％ (39/216 cases)] was significantly higher than the incidence of nosocomial infection [1.53％ (644/41 992 cases)] in the same period,and the difference was statistically significant (x2 =368.474,P ＜ 0.01).The patients with secondary bacterial infection were treated with antibiotics,and the pathogenic bacteria were mainly gram-negative bacteria,which was consistent with pharyngeal tonsil colonization bacteria on admission.In 212 cases (98.1％) with IM,variant lymphocytes increased,and there was no significant difference between 2 groups in the variation of lymphocyte composition (x2 =2.087,P ＞ 0.05).C-reactive protein (CRP) level of IM children on admission was (11.3 ± 17.4) mg/L,while the secondary infection group was (10.2 ±9.7) mg/L and the non-infection group was (11.5 ± 18.1) mg/L,and there was no significant difference between the 2 groups (t =1.309,P ＞ 0.05).CD3 +,CD4+,CD8 + lymphocytes in the secondary infection group were 0.877 6 ± 0.031 8,0.079 0 ± 0.032 5 and 0.682 1 ± 0.053 5,compared with the non-infection group,while CD3 + lymphocytes (t =12.652,P ＜ 0.01) and CD8 + lymphocytes (t =-9.723,P ＜ 0.01) increased significantly,but the proportion of CD4+ lymphocytes decreased significantly (t =18.341,P ＜0.01).Conclusions The IM children are susceptible to nosocomial bacterial infection,which is more obvious in school-age children.Secondary respiratory tract infections are the most common type,and pathogenic bacteria may be caused by the dissemination of colonization bacteria in the pharyngeal tonsils.The CRP and variant lymphocytes on admission could not be used as the marker for predicting noscoomial bacterial infection in IM.
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Objective To observe the ultrastructure of dimorphic Penicillium marneffeiisolates from wild bamboo rats (Rhizomys pruinosus) in Guangxi region as well as from a patient with penieilliosis marneffei,and to compare their biological characteristics and anti-oxidative mechanisms.Methods Two Penicillium marneffei strains,including one isolated from wild bamboo rats (Rhizomys pruinosus) in Guangxi region and one from a patient with penicilliosis marneffei,were cultured with or without the presence of 2.0 mmol/L hydrogen peroxide in potato dextrose agar (PDA) at 25 ℃ and in brain-heart infusion (BHI) broth at 37℃ for seven days.The shape of colony and growth of both strains were observed.Light microscopy was carried out to study the morphology,and transmission electron microscopy to observe the ultrastructure,of both isolates.Results Ater incubation with hydrogen peroxide,there was a slowdown in the growth of both Penicillium marneffei isolates at both mycelial phase and yeast phase,with an increase in the production of pigment at mycelial phase at 25℃.No obvious changes were observed at 37 ℃ in the morphology of either the clinical isolate or the bamboo rat isolate when cultured with hydrogen peroxide compared with those cultured without hydrogen peroxide.Light microscopy showed attenuated spore formation by the clinical isolate when cultured at 25 ℃ with hydrogen peroxide,crenation of both isolates when cultured at 37 ℃ with hydrogen peroxide.Under a transmission electron microscope,the mycelial cells of both isolates exhibited smooth cell walls,intact cell membranes,with nuclei,mitochondria,endoplasmic reticulum,lipid body,vacuoles of various sizes in the cytoplasm at 25 ℃,and even microbodies at 37 ℃,when cultured without the presence of hydrogen peroxide.After incubation with hydrogen peroxide,the cell wall of both isolates became incomplete with defects in some areas and uneven thickness,the cell membrane discontinuous with shrinkages and projections,and the cytoplasm was inhomogeneous with obvious phagocytosis and numerous phagocytic vacuoles.Conclusions The clinical and bamboo rat isolates of Penicillium marneffei experience different biological and morphological changes under oxidative stress,hinting differences in antioxidative mechanism between them.
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Both innate and adaptive immunity contribute to the pathogenesis of ischemia-reperfusion injury (IRI).During acute phase of kidney IRI,kidney endothelial cells promote inflammation after IRI by increasing adhesion molecule expression and vascular permeability,and tubular epithelial cells increase complement C3 binding and Toll-like receptor 2 and Toll-like receptor 4 expression.Early activation of kidney dendritic cells initiates a cascade of events leading to accumulation of neutrophils,macrophage,natural killer cells,CD4 + T cells and B cells in the early phase of renal IRI.Soluble components of the immune system,such as complement activation production,cytokines and chemokines,also are implicated in the injury and repair of post-ischemic kidneys.Foxp3 + regulatory T cells and alternatively activated macrophage participate in attenuating the inflammation and initiating the repair of kidney IRI,while B lymphocytes limit repair of kidney IRI.