Development of an Ex Vivo Porcine Eye Model for Exploring the Pathogenicity of Acanthamoeba.

Acanthamoeba, a widely distributed free-living amoeba found in various environments, is an opportunistic pathogen responsible for causing Acanthamoeba keratitis, a condition that may lead to blindness. However, identifying the pathogenicity of Acanthamoeba is challenging due to its complex life cycle, ability to adapt to different environments, variable virulence factors, and intricate interactions with the host immune system. Additionally, the development of an effective model for studying Acanthamoeba pathogenicity is limited, hindering a comprehensive understanding of the mechanisms underlying its virulence and host interactions. The aim of this study was to develop an ex vivo model for Acanthamoeba infection using porcine eyeballs and to evaluate the pathogenicity of the Acanthamoeba isolates. Based on slit lamp and biopsy analysis, the developed ex vivo model is capable of successfully infecting Acanthamoeba within 3 days. Histopathological staining revealed that clinical isolates of Acanthamoeba exhibited greater corneal stroma destruction and invasion in this model than environmental isolates. Our results highlight the importance of an ex vivo porcine eye model in elucidating the pathogenesis of Acanthamoeba infection and its potential implications for understanding and managing Acanthamoeba-related ocular diseases.

Ouabain, ATPase inhibitor, potentially enhances the effect of polyhexamethylene biguanide on Acanthamoeba castellanii.

Acanthamoeba, a free-living amoeba, is commonly found in various natural environments, such as rivers and soil, as well as in public baths, swimming pools, and sewers. Acanthamoeba can cause severe illness such as granulomatous amoebic encephalitis and Acanthamoeba keratitis (AK) in humans. AK, the most recognized disease, can cause permanent visual impairment or blindness by affecting the cornea. AK commonly affects contact lens wearers who neglect proper cleaning habits. The symptoms of AK include epithelial and stromal destruction, corneal infiltrate, and intense ocular pain, occasionally necessitating surgical removal of the entire eyeball. Current AK treatment involves the hourly application of eye drops containing polyhexamethylene biocide (PHMB). However, studies have revealed their ineffectiveness against drug-resistant strains. Acanthamoeba can form cysts as a survival mechanism in adverse environments, though the exact mechanism remains unknown. Our experiments revealed that sodium P-type ATPase (ACA1_065450) is closely linked to encystation. In addition, various encystation buffers, such as MgCl2 or NaCl, induced the expression of P-type ATPase. Furthermore, we used ouabain, an ATPase inhibitor, to inhibit the Na+/K+ ion pump, consequently decreasing the encystation rate of Acanthamoeba. Our primary objective is to develop an advanced treatment for AK. We anticipate that the combination of ouabain and PHMB may serve as an effective therapeutic approach against AK in the future.

Enhancement of capsular hypermucoviscosity in Klebsiella pneumoniae by Acanthamoeba.

BACKGROUND: Acanthamoeba and Klebsiella pneumoniae are both environmental commensals. Recently, clinical harm caused by hypermucoviscous K. pneumoniae has been observed. However, the interaction between these microbes and the origin of hypermucoviscous K. pneumoniae have not been reported. METHODOLOGY/PRINCIPAL FINDINGS: Here, we report that the bacterial capsule is enlarged when co-cultured with Acanthamoeba using India ink staining, and this effect depends on the number of parasites present. This interaction results in an enhancement of capsular polysaccharide production in the subsequent generations of K. pneumoniae, even without co-culturing with Acanthamoeba. The hypermucoviscosity of the capsule was examined using the sedimentation assay and string test. We also screened other K. pneumoniae serotypes, including K1, K2, K5, and K20, for interaction with Acanthamoeba using India ink staining, and found the same interaction effect. CONCLUSIONS/SIGNIFICANCE: These findings suggest that the interaction between Acanthamoeba and K. pneumoniae could lead to harmful consequences in public health and nosocomial disease control, particularly hypermucoviscous K. pneumoniae infections.

Comparative prevalence of oral bacteria and protozoa in patients with periodontitis in Taiwan.

OBJECTIVES: Periodontitis is an inflammatory disease caused by bacteria present in the dental biofilm. However, the presence of two oral protozoans, Entamoeba gingivalis and Trichomonas tenax, in patients with the periodontal disease remains largely unknown in Taiwan. Therefore, we investigated the prevalence of oral microbial infections between the sites with mild gingivitis and chronic periodontitis in patients. MATERIALS AND METHODS: We collected 60 dental biofilm samples from sites with mild gingivitis (probing depth <5 mm) and chronic periodontitis (probing depth ≥5 mm) from 30 patients at the National Cheng Kung University Hospital. The samples were analyzed via polymerase chain reaction and gel electrophoresis. RESULTS: Among oral protozoans, E. gingivalis and T. tenax were detected in 44 (74.07%) and 14 (23.33%) of all samples, respectively. Among oral bacteria, Porphyromonas gingivalis, Treponema denticola, and Tannerella forsythia were detected in 50 (83.33%), 47 (78.33%), and 48 (80.0%) samples, respectively. CONCLUSIONS: This study, which is the first to analyze E. gingivalis and T. tenax presence among patients with periodontitis in Taiwan, revealed an association between periodontitis and oral microbes.

Negative correlation between circulating integrin α4+ group 3 innate lymphoid cells and the severity of type 2 diabetes.

BACKGROUND: Impaired intestinal barrier and immune dysfunction promote the development of type 2 diabetes (T2D). Group 3 innate lymphoid cells (ILC3s), which are enriched in the intestinal lamina propria, are key for intestinal barrier integrity. However, there is a paucity of data on circulating ILC3s in patients with T2D. PURPOSE: To examine the characteristics of ILC3s in patients with T2D and identify the relationship between ILC3s and clinical indicators of T2D. METHODS: Fifty-nine patients with T2D and thirty controls were enrolled in this retrospective study. Peripheral blood mononuclear cells were isolated and analyzed by flow cytometry and plasma cytokine levels were measured by enzyme-linked immunosorbent assays. RESULTS: The proportion of circulating ILC3s in the T2D group was significantly lower than that in controls and showed a negative correlation with fasting glucose and glycated hemoglobin and a positive correlation with granulocyte-macrophage colony-stimulating factor (GM-CSF). Similarly, the proportion of circulating integrin α4+ ILC3s was also significantly lower in the T2D group and showed a negative correlation with fasting glucose and glycated hemoglobin and a positive correlation with GM-CSF. Moreover, the level of circulating integrin α4+ ILC3s showed a positive correlation with the proportion of circulating dendritic cells (DCs), which was also decreased in patients with T2D and positively associated with GM-CSF. CONCLUSION: ILC3s, especially integrin α4+ ILC3s, were decreased in patients with T2D and showed a negative correlation with disease severity. These cell subsets may delay the progression of T2D by promoting DC differentiation via the secretion of GM-CSF.

Real-world applications of PARPi maintenance therapy for recurrent ovarian cancer: A single-center study in China.

OBJECTIVE: To assess the actual clinical application of poly (adenosine diphosphate-ribose) polymerase inhibitor (PARPi) maintenance therapy in Chinese patients with recurrent ovarian cancer, and to explore prognostic factors associated with progression-free survival (PFS). METHODS: We retrospectively assessed real-world clinical data from our hospital using the inclusion and exclusion criteria of representative randomized controlled trials, analyzed the prognosis, and performed univariate and multivariate analyses of prognostic factors. RESULTS: Between 2019 and 2022, the proportion of platinum-sensitive recurrence ovarian cancer patients who received PARPi maintenance therapy increased to 29.6%, 53.3%, 43.8% and 62.2%, respectively, each year. A total of 48 patients were included in the prognostic analysis, of which 32 and 16 received olaparib and niraparib, respectively. Using the criteria of the Study19 and SOLO2 studies, the olaparib group in our patients had coincidence rates of 56.3% and 18.8%, respectively. Using the criteria of the NOVA and NORA studies, the niraparib group had coincidence rates of 31.3% and 37.5%, respectively. Median PFS was 26.1 months (95% CI 20.2-32.1). Response to primary therapy was an independent prognostic factor for PFS (relative risk, 3.248; 95% CI 1.081-9.757, P = 0.036). CONCLUSIONS: PARPi maintenance therapy was also effective in real world applications. Complete response (CR) to primary therapy was an independent factor favorably affecting PFS. Therefore, primary treatment choices aimed at optimal cytoreduction during primary surgery and improving the CR rate should still be considered, which positively affects the long-term prognosis of patients in the new treatment mode.

Inhibitory effect of host ocular microenvironmental factors on chlorhexidine digluconate activity.

Acanthamoeba spp. are free-living protozoan that cause a serious human eye disease called Acanthamoeba keratitis (AK). Several new and effective medical therapy for AK patients remains highly debated and therefore, CHG is still considered one of the first lines of treatment for AK patients. We hypothesized that ocular microenvironmental factors are responsible for Acanthamoeba drug resistance and clinical AK treatment failure. To investigate the influence of the ocular surface on CHG treatment, we tested the effect of several ocular elements on the anti-amoeba activity of CHG. The suspected inhibitory elements, including mucin, albumin, human and amoeba cell lysates, live and heat-killed bacteria, and cornea, were added to the amoebicidal activity platform, where amoeba was incubated with CHG at varying concentrations. Mucin showed a significant inhibitory effect on CHG activity against Acanthamoeba castellanii In contrast, albumin did not affect CHG treatment. Furthermore, human and amoeba cell lysates as well as live and heat-killed bacterial suspensions also significantly inhibited CHG activity. Additionally, we found that pig corneas also reduced CHG activity. In contrast, dry eye drops and their major component, propylene glycol, which is commonly used as eyewash material, did not have an impact on CHG activity. Our results demonstrate the effect of ocular microenvironmental factors on CHG activity and suggest that these factors may play a role in the development of amoeba resistance to CHG and treatment failure.

Cardiac safety analysis of first-line chemotherapy drug pegylated liposomal doxorubicin in ovarian cancer.

Pegylated liposomal doxorubicin (PLD) is a nano-doxorubicin anticancer agent. It was used as early as 2014 to treat ovarian and breast cancer, multiple myeloma and Kaposi's sarcoma. The 2018 National Comprehensive Cancer Network guidelines listed PLD as first-line chemotherapy for ovarian cancer. PLD has significant anticancer efficacy and good tolerance. Although PLD significantly reduces the cardiotoxicity of conventional doxorubicin, its cumulative-dose cardiotoxicity remains a clinical concern. This study summarizes the high-risk factors for PLD-induced cardiotoxicity, clinical dose thresholds, and cardiac function testing modalities. For patients with advanced, refractory, and recurrent malignant tumors, the use of PLD is still one of the most effective strategies in the absence of evidence of high risk such as cardiac dysfunction, and the lifetime treatment dose should be unlimited. Of course, they should also be comprehensively evaluated in combination with the high-risk factors of the patients themselves and indicators of cardiac function. This review can help guide better clinical use of PLD.

Potential role of Acanthamoeba Rab7.

Acanthamoeba castellanii is a free-living protozoan that causes several severe human parasitic diseases such as Acanthamoeba keratitis and granulomatous encephalitis. A. castellanii feeds on bacteria, yeasts, and other organic particles as food sources, but the mechanisms of digestion in acanthamoebal cells are unclear. Rab GTPases participate in endosomal delivery in eukaryotes after phagocytosis. This study aimed to determine the potential functions of A. castellanii Rab7 (AcRab7), which is involved in phagocytosis, and the relationship between AcRab7 and further cellular physiological phenomena. In this study, the inhibitor CID1067700 (CID) was used to specifically inhibit the binding of nucleotides to confirm the potential functions of AcRab7. Cellular proliferation and ATP assays were also used to detect underlying cellular physiological functions after blocking the phagocytosis pathway. We found that AcRab7 expression increased as the co-culture time with Escherichia coli increased. Immunofluorescence staining showed that AcRab7 colocalized with lysosomes in its GTP-activating form. In addition, AcRab7 inhibition resulted in a reduction in cell proliferation and ATP levels. Our results suggest that AcRab7 participates in endosomal delivery and dominates energy production and cell growth.

Cytochrome P450 monooxygenase of Acanthamoeba castellanii participates in resistance to polyhexamethylene biguanide treatment.

Acanthamoeba spp. are free-living parasites that can cause severe infections such as granulomatous amoebic encephalitis (GAE) and amoebic keratitis (AK). Polyhexamethylene biguanide (PHMB) is a topical application for AK treatment. However, PHMB is not entirely effective against all Acanthamoeba strains or isolates. The mechanisms by which Acanthamoeba protects itself against extreme drug conditions without encystation are still unknown. According to a previous study, cytochrome P450 monooxygenase (CYP450MO) plays an important role in the oxidative biotransformation of numerous drugs related to metabolism. In this study, a CYP450MO fragment was inserted into the pGAPDH-EGFP vector and transfected into Acanthamoeba castellanii. We found that CYP450MO-overexpressing Acanthamoeba had higher survival rates than those of the control cells after PHMB treatment. Moreover, we also found that encystation-related genes such as cellulose synthase I (CSI), encystation-mediating serine proteinase (EMSP), and autophagy-related protein 8 (ATG8) expression levels were not significantly different between Acanthamoeba transfected by pGAPDH-EGFP or pGAPDH-EGFP-CYP450MO. We suggest that Acanthamoeba transfected by pGAPDH-EGFP-CYP450MO may not induce encystation-related genes to resist PHMB treatment. In conclusion, these findings indicate that CYP450MO may be an additional target when PHMB is used for treatment of amoebic keratitis.

TITLE: La monooxygénase du cytochrome P450 d'Acanthamoeba castellanii participe à la résistance au traitement par le polyhexaméthylène biguanide. ABSTRACT: Les Acanthamoeba spp. sont des parasites libres qui peuvent provoquer des infections graves telles que l'encéphalite amibienne granulomateuse (EAG) et la kératite amibienne (KA). Le polyhexaméthylène biguanide (PHMB) est une application topique pour le traitement de la KA. Cependant, le PHMB n'est pas entièrement efficace contre toutes les souches ou isolats d'Acanthamoeba. Les mécanismes par lesquels Acanthamoeba se protège contre des conditions médicamenteuses extrêmes sans enkystation sont encore inconnus. Selon une étude précédente, la monooxygénase du cytochrome P450 (CYP450MO) joue un rôle important dans la biotransformation oxydative de nombreux médicaments liés au métabolisme. Dans cette étude, un fragment CYP450MO a été inséré dans le vecteur pGAPDH-EGFP et transfecté dans Acanthamoeba castellanii. Nous avons constaté que les Acanthamoeba surexprimant le CYP450MO avaient des taux de survie plus élevés que ceux des cellules témoins après un traitement au PHMB. De plus, nous avons également constaté que les gènes liés aux enkystations tels que la cellulose synthase I (CSI), la sérine protéinase médiatrice de l'enkystation (EMSP) et les niveaux d'expression de la protéine 8 liée à l'autophagie (ATG8) n'étaient pas significativement différents entre les Acanthamoeba transfectés par pGAPDH-EGFP ou par pGAPDH-EGFP-CYP450MO. Nous suggérons que les Acanthamoeba transfectés par pGAPDH-EGFP-CYP450MO ne peuvent pas induire les gènes liés à l'enkystation pour résister au traitement PHMB. En conclusion, ces résultats peuvent indiquer que la monooxygénase du cytochrome P450 peut être une cible potentielle pour le traitement par PHMB de la kératite amibienne.

[Aerosol salt damage is the main problem of landscaping in the coastal areas of southern China]. / 盐雾危害是南方滨海地区园林绿化的主要困难.

Both the growth and survival of landscape plants are difficult due to the harsh natural conditions in coastal areas of southern China. Many plants suffer from symptoms of salt damage. Different from the damages by salt in the soil, the symptoms of windblown salt are damage to young shoots and leaves. Plants at the windward side are damaged more than the leeward side. These cha-racteristics imply that the damage is due to salt in aerosols instead of salt in the soil. To test this hypothesis, we measured plant growth, soil and climate factors in 24 frontline coastal counties and cities of China. The results showed that the first-line coastal plants showed strong symptoms of salt damage, especially in the Taiwan Strait area (85.4% belonged to desalinized soil), and that the damage level was highly correlated with wind speed. Our results confirmed that aerosol salt is the major cause of plant damage in the coastal areas of southern China. We constructed the first distribution map of salt damage along frontline coastal regions of southern China and proposed methods for diagnosing aerosol salt damage. Selecting and configuring aerosol salt-tolerant plants, greening engineering measures, and follow-up maintenance were suggested for improving the overall effect and level of landscaping in the coastal areas of southern China.

The impact of Pegylated liposomal doxorubicin in recurrent ovarian cancer: an updated meta-analysis of randomized clinical trials.

BACKGROUND: Previous meta-analysis studies suggested that pegylated liposomal doxorubicin (PLD) may improve the survival rate of patients with recurrent ovarian cancer. The aim of the present meta-analysis, then, was to further update the role of PLD in the treatment of recurrent ovarian cancer. METHODS: We performed a literature search using the electronic databases Medicine, EMBASE, Web of Science, and the Cochrane Library to 27 July 2020. We only restricted the randomized clinical trials. Study-specific hazard ratios and 95% confidence interval (HR/95% CI) and risk ratios and 95% confidence interval (RR/95% CI) were pooled using a random-effects model. RESULTS: Ten studies (12 trials) were included after screening 940 articles. We categorized the eligible studies into two groups: the doublet regimens (four trials, 1767 patients) showed that PLD plus carbo provided superior progression-free survival (PFS) (HR, 0.85; 95% CI, 0.74-0.97) and similar overall survival (OS) (HR, 1.00; 95% CI, 0.88-1.14) compared to paclitaxel (PAC) plus carboplatin (carbo). PLD plus carbo was associated with significantly more anemia and thrombocytopenia, and other side effects were well tolerated. The monotherapy regimens (eight trials, 1980 patients) showed that PLD possessed a similar PFS (HR, 1.02; 95% CI, 0.90-1.16) and OS (HR, 0.88; 95% CI, 0.77-1.01) relative to other monotherapies. PLD alone was also more associated with mucositis/stomatitis and hand-foot syndrome, while other side effects were well tolerated. CONCLUSIONS: In platinum-sensitive recurrent ovarian cancer, PLD plus carbo was more effective than PAC plus carbo, while in platinum-resistant or -refractory recurrent ovarian cancer, PLD exhibited similar survival to other monotherapies. Regarding side effects, PLD plus carbo and mono chemotherapy were both well tolerated.

Determination of maytansinoids in Trewia nudiflora using QuEChERS extraction combined with HPLC.

Three maytansinoids with strong cytotoxicities, dehydrotrewiasine, maytanbutine, and trewiasine, were isolated and identified from Trewia nudiflora, and maytanbutine was obtained from this plant for the first time. A quick, easy, cheap, effective, rugged, and safe (QuEChERS) extraction combined with high-performance liquid chromatography (HPLC) was established to determine the three maytansinoids in T. nudiflora. The effects of major factors on the extraction efficiency of the QuEChERS method were evaluated and the optimal conditions using acetonitrile-ethyl acetate (1:1, v/v) as the extraction solvent and PestiCarb as the clean-up sorbents were established. Compared with Soxhlet extraction (SE) and ultrasonic-assisted extraction (UAE), the QuEChERS method was easy-to-operate and afforded a cleaner extract. A phenomenex HyperClone BDS C18 column was used for HPLC analysis. Methanol-acetonitrile-water was chosen as mobile phase for gradient elution. Method validation showed that all analytes showed good linearity (r > 0.999) over the investigated ranges and satisfactory recoveries ranging from 95.0% to 105.0%. The developed QuEChERS-HPLC method was simple, efficient, and applicable to the determination of maytansinoids in T. nudiflora.

The first study to detect co-infection of Entamoeba gingivalis and periodontitis-associated bacteria in dental patients in Taiwan.

Periodontitis, an inflammatory disease of the oral cavity, was caused by microbes from bacteria to protozoa. In this study, we detected protozoa, Entamoeba gingivalis and other three common pathogenic bacteria, Porphyromonas gingivalis, Treponema denticola, and Tannerella forsythia by the Polymerase chain reaction (PCR) on patients.

A SAM-I riboswitch with the ability to sense and respond to uncharged initiator tRNA.

All known riboswitches use their aptamer to senese one metabolite signal and their expression platform to regulate gene expression. Here, we characterize a SAM-I riboswitch (SAM-IXcc) from the Xanthomonas campestris that regulates methionine synthesis via the met operon. In vitro and in vivo experiments show that SAM-IXcc controls the met operon primarily at the translational level in response to cellular S-adenosylmethionine (SAM) levels. Biochemical and genetic data demonstrate that SAM-IXcc expression platform not only can repress gene expression in response to SAM binding to SAM-IXcc aptamer but also can sense and bind uncharged initiator Met tRNA, resulting in the sequestering of the anti-Shine-Dalgarno (SD) sequence and freeing the SD for translation initiation. These findings identify a SAM-I riboswitch with a dual functioning expression platform that regulates methionine synthesis through a previously unrecognized mechanism and discover a natural tRNA-sensing RNA element. This SAM-I riboswitch appears to be highly conserved in Xanthomonas species.

The Biochemical and Functional Characterization of M28 Aminopeptidase Protein Secreted by Acanthamoeba spp. on Host Cell Interaction.

Acanthamoeba are a free-living protozoan whose pathogenic strain can cause severe human diseases, such as granulomatous encephalitis and keratitis. As such, the pathogenic mechanism between humans and Acanthamoeba is still unknown. In our previous study, we identified the secreted Acanthamoeba M28 aminopeptidase (M28AP) and then suggested that M28AP can degrade human C3b and iC3b for inhibiting the destruction of Acanthamoeba spp. with the human immune response. We constructed the produced the recombinant M28AP from a CHO cell, which is a mammalian expression system, to characterize the biochemical properties of Acanthamoeba M28AP. The recombinant M28AP more rapidly hydrolyzed Leu-AMC than Arg-AMC and could be inhibited by EDTA treatment. We show that recombinant M28AP can be delivered into the individual cell line and cause cell line apoptosis in a co-culture model. In conclusion, we successfully investigated the potential molecular characteristics of M28AP.

Quantitative proteomic analysis and functional characterization of Acanthamoeba castellanii exosome-like vesicles.

BACKGROUND: Pathogenic protozoans use extracellular vesicles (EVs) for intercellular communication and host manipulation. Acanthamoeba castellanii is a free-living protozoan that may cause severe keratitis and fatal granulomatous encephalitis. Although several secreted molecules have been shown to play crucial roles in the pathogenesis of Acanthamoeba, the functions and components of parasite-derived EVs are far from understood. METHODS: Purified EVs from A. castellanii were confirmed by electron microscopy and nanoparticle tracking analysis. The functional roles of parasite-derived EVs in the cytotoxicity to and immune response of host cells were examined. The protein composition in EVs from A. castellanii was identified and quantified by LC-MS/MS analysis. RESULTS: EVs from A. castellanii fused with rat glioma C6 cells. The parasite-derived EVs induced an immune response from human THP-1 cells and a cytotoxic effect in C6 cells. Quantitative proteomic analysis identified a total of 130 proteins in EVs. Among the identified proteins, hydrolases (50.2%) and oxidoreductases (31.7%) were the largest protein families in EVs. Furthermore, aminopeptidase activities were confirmed in EVs from A. castellanii. CONCLUSIONS: The proteomic profiling and functional characterization of EVs from A. castellanii provide an in-depth understanding of the molecules packaged into EVs and their potential mechanisms mediating the pathogenesis of this parasite.

Perineural invasion in cervical cancer: pay attention to the indications of nerve-sparing radical hysterectomy.

Perineural invasion (PNI) in early-stage cervical cancer, is associated with multiple high-risk factors and represents a poor outcome in the patients. For nerve-sparing radical hysterectomy (NSRH) to become a standard and widely used treatment for cervical cancer, we need to define its oncological safety, and to establish standardized surgical procedures and indications of NSRH. Here, we review the definition and mechanisms, and clinical significance of PNI in cervical cancer, and discuss the indications of NSRH. PNI should be regarded as one of the main pathological features of cervical cancer and a factor affecting prognosis. A deeper understanding of PNI in cervical cancer, hopefully, will provide clear indications of NSRH.

Identification and characterization of a secreted M28 aminopeptidase protein in Acanthamoeba.

Acanthamoeba is a free-living pathogenic protozoan that is distributed in different environmental reservoirs, including lakes and soil. Pathogenic Acanthamoeba can cause severe human diseases, such as blinding keratitis and granulomatous encephalitis. Therefore, it is important to understand the pathogenic relationship between humans and Acanthamoeba. By comparison of systemic analysis results for Acanthamoeba isolates, we identified a novel secreted protein of Acanthamoeba, an M28 aminopeptidase (M28AP), which targets of the human innate immune defense. We investigated the molecular functions and characteristics of the M28AP protein by anti-M28 antibodies and a M28AP mutant strain generated by the CRISPR/Cas9 system. Human complement proteins such as C3b and iC3b were degraded by Acanthamoeba M28AP. We believe that M28AP is an important factor in human innate immunity. This study provides new insight for the development of more efficient medicines to treat Acanthamoeba infection.

[Simultaneous Nitrification and Denitrifying Phosphorus Removal in Continuous Flow Reactor with Intermittent Aeration].

A continuous flow reactor (TCFR) with 10 compartments was used to treat domestic sewage. The anaerobic compartments of TCFR were kept at 3. The anoxic compartments of TCFR were reduced from 2 to 0. Therefore, the aerobic compartments of TCFR were increased gradually from 5 to 7. The aerobic compartments were set to continual aeration in Run1 and intermittent aeration from Run2 to Run4. The aeration/non-aeration ratios were 40 min/20 min,40 min/30 min, and 40 min/40 min, respectively. The nitrification liquid reflux ratios were reduced gradually from 150% to 0%. When the average influent concentrations of COD, NH4+-N, TN, and PO43--P were 259.34, 60.26, 64.42, and 6.10 mg·L-1, respectively, the corresponding effluent concentrations were 26.40, 1.03, 5.84, and 0.3 mg·L-1, respectively in Run4. The nitrogen removal amounts increased gradually from 192.30 mg·h-1 in Run1 to 244.00 mg·h-1 in Run4, and the corresponding removal rates increased from 65.40% to 95.30%. The activity of denitrifying phosphorus accumulating organisms (DPAOs) and phosphorus accumulating organisms (PAOs) increased from 36.05% and 38.20% in Run1 to 140.50% and 133.40% in Run4, respectively. Simultaneous nitrification and denitrifying phosphorus removal was achieved in TCFR by adopting intermittent aeration, which provided a reference for the reformation of sewage treatment plants.