Due to the wide application of silver-containing dressings and silver-coated medical devices in clinical treatment; the extensive use of antibacterial agents and heavy metal agents in feed factories, Escherichia coli has formed the tolerance to silver ions. To systematically understand the known silver ion resistance mechanisms of E. coli, this article reviews the complex regulatory network and various physiological mechanisms of silver ion tolerance in E. coli, including the regulation of outer membrane porins, energy metabolism modulation, the role of efflux systems, motility regulation, and silver ion reduction. E. coli reduces the influx of silver ions by missing or mutating outer membrane porins such as OmpR, OmpC, and OmpF. It adapts to high concentrations of silver ions by altering the expression of ArcA/B and enhances the efflux capacity of silver ions under high-concentration silver stress via the endogenous Cus system and exogenous Sil system. Furthermore, the motility of bacteria is related to silver tolerance. E. coli has the ability to reduce silver ions, thereby alleviating the oxidative stress induced by silver ions. These findings provide a new perspective for understanding the formation and spread of bacterial tolerance and provide directions for the development of next-generation silver-based antimicrobials and therapies.
Escherichia coli/genetics* ; Silver/pharmacology* ; Drug Resistance, Bacterial ; Anti-Bacterial Agents/pharmacology* ; Porins/metabolism*

Objective:To explore the dynamic changes of inflammatory cytokines and T lymphocyte activation in the peripheral blood of human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome (AIDS) patients during anti-retroviral therapy (ART).Methods:Two hundred and six HIV/AIDS patients with ART at clinic of the Department of Infectious Diseases in Second Xiangya Hospital, Central-South University between January 2017 and December 2019 were selected as HIV infection group. They were followed up regularly and the blood samples before treatment and at month 6, month 12, month 24 of treatment were collected. Meanwhile, 52 healthy cases were enrolled in the healthy control group and their blood samples were collected. Enzyme-linked immunosorbent assay was used to detect the plasma concentrations of interleukin (IL)-6, hypersensitive C-reactive protein (hsCRP) and tumor necrosis factor (TNF)-α. Flow cytometry was used to detect the CD3 + CD4 + T lymphocytes count and the percentage of CD4 + CD38 + T lymphocytes and CD8 + CD38 + T lymphocytes in the peripheral blood mononuclear cells. Plasma HIV RNA viral load was determined using a quantitative real-time polymerase chain reaction technique. Statistical methods used paired t test and Pearson correlation analysis. Results:The concentrations of IL-6, hsCRP and TNF-α in HIV infection group were (13.42±2.35) pg/mL, (4 012.46±1 012.35) μg/L and (51.78±11.32) μg/L, respectively, which were higher than those in healthy control group ((6.14±0.78) pg/mL, (707.21±305.76) μg/L and (19.01±6.48) μg/L, respectively). The differences were all statistically significant ( t=12.56, 16.79 and 13.45, respectively, all P<0.001). They decreased gradually after initiation of ART in HIV infection group, and returned to normal levels at month 24 of ART. CD3 + CD4 + T cells count was (256.00±65.32)/μL and HIV RNA viral load was (4.467±4.244) lg copies/mL before ART in HIV infection group, which were negatively correlated ( r=-0.625, P=0.041). The percentages of CD8 + CD38 + T lymphocytes before treatment and at month 12 or month 24 of treatment in HIV infection group were higher than those in healthy control group. The differences were all statistically significant ( t=3.85, 6.84 and 2.57, respectively, all P<0.050). The percentage of CD8 + CD38 + T lymphocytes was positively correlated with HIV RNA viral load before ART ( r=0.768, P=0.026). The percentages of CD4 + CD38 + T lymphocytes before treatment and at month 12 or month 24 of treatment in the HIV infection group were lower than those in the healthy control group, and the differences were all statistically significant ( t=6.80, 1.10, and 2.11, respectively, all P<0.050). Conclusions:HIV infection could not only cause insufficiency in immune system, but also abnormal activation of immune system, which could get better gradually with ART.

Objective The plasma levels of interleukin 6 (IL-6),high sensitive C reactive protein (hs-CRP) and the level of T cell activation were detected in the peripheral blood inflammatory factors of acquired immunodeficiency syndrome (AIDS) patients,and the relationship with opportunistic infection and prognosis was analyzed.Methods 79 human immunodeficiency virus (HIV)-positive/aids cases from May 2014 to January 2015 in first hospital of Changsha were enrolled in the study.They were divided into three groups:HIV-infected without opportunistic infections group (n =20),HIV-infected with infections group (n =43,including HIV-infected with tuberculosis group,HIV-infected with merge fungus group.HIV combined hepatitis C),death group (n =16).Serum IL-6 and the concentration of hs-CRP were detected by enzyme-linked immunosorbent assay (ELISA).Flow cytometry was used to test the CD3 + CD4 + cell count,the percentage of CD4 + CD38 + cell and CD8 + CD38 + cell in peripheral blood mononuclear cell (PBMC).Compare the differences among the three groups.Results The results showed that:the concentration of hsCRP and IL-6 in peripheral blood of HIV death group was significantly higher than that in other three groups (P ＜ 0.05).The concentration of hs-CRP and IL-6 in the peripheral blood of the HIV-infected with tuberculosis group and HIV-infected with merge fungus group were significantly higher than that in the HIV-infected without opportunistic infections group (P ＜ 0.05),and the hs-CRP in the peripheral blood of the HIV combined with the hepatitis C group was higher than that in the HIV-infected without opportunistic infections group (P ＜ 0.05).The number of CD3,CD4T lymph nodes in the death group and the combined opportunistic infection group was significantly lower than that in the HIV-infected without opportunistic infections group (P ＜ 0.05).The HIV-RNA expression in peripheral blood of the death group and the combined opportunistic infection group was significantly lower than that in the HIV-infected without opportunistic infections group (P ＜ 0.05).The expression of CD8+CD38+ on PBMC in the HIV-infected without opportunistic infections group was significantly lower than that in the death group,the tuberculosis group,the fungus group and the hepatitis C group (P ＜ 0.05).The expression of CD4+ CD38 + on PBMC in the HIV-infected without opportunistic infections group was higher than that in the death group (P ＜ 0,05).Conclusions The concentration of inflammatory cytokines (IL-6,hs-CRP) and the expression level of T cell surface CD8 + CD38 + related to immune activation were associated with opportunistic infection and prognosis of AIDS.

Objective To observe the expression of apoptosis related protein c-inhibitor of apoptosis protein (IAP)2 by RNA interference of human immunodeficiency virus-1 (HIV-1)vpr gene and analyze the apoptosis of Jurkat cells.Methods Vector (NC),HIV-1vpr (vpr),vpr+ pRNAT-U6.1/Neo-vpr-56 (Si56) and vpr+ pRNAT-U6.1/Neo-vpr-160 (Si160) were transfected to Jurkat cells and cultured for 48 hours.The total RNA and protein were extracted.Expression of vpr gene was detected by reverse transcription (RT)-polymerase chain reaction (PCR) to confirm the success of transfection.Expression of c IAP2 was detected by RT-PCR and Western Blot.The apoptosis of Jurkat cells was observed by flow cytometry.Results Expression of vpr gene was detected in vpr,Si56 and Si160 groups.The mRNA expression levels in Si56 and Si160 groups were significantly lower than that in vpr group,which declined 87.2％ and 82.2％,respectively (P＜0.05).The levels of c IAP2 mRNA expression in vpr,Si56 and Si160 groups were increased by 3.75,2.49 and 2.65 folds,respectively,compared to that in NC group.However,the c-IAP2 mRNA expressions in Si56 and Si160 groups were lower than that in vpr group,which declined 33.7％ and 29.5％,respectively (P ＜ 0.05).The c-IAP2 protein expression was consistent with mRNA by immunoblotting,and those in Si56 and Si160 groups were declined 42.2％ and 46.8％,respectively,compared to that in vpr group (P＜0.05).The apoptosis of J urkat cells was detected in all groups.Compared to NC group,the apoptotic rate in vpr group was increased by 1.76 folds.However,the differences of apoptosis rate among NC,Si56 and Si160 groups were not statistically significant (all P＞0.05).Compared to vpr group,the apoptotic rates in Si56 and Si160 were significantly decreased by 19.26％ and 18.05％,respectively (P＜0.05).Conclusions The expression of c-IAP2 could be downregulated by knockdown of HIV-1 vpr gene in transcription and protein levels,and the apoptosis of Jurkat cells is inhibited.

Objective To investigate the regulatory effects of IFN-γon Treg cells from HIV/AIDS patients receiving highly active antiretroviral therapy (HAART) for one year.Methods Thirty HIV/A1DS patients whose CD4+T cells were below 350/μ1 were recruited for HAART therapy.Blood samples were collected at the time points of 0,24,48 weeks after HAART.PBMCs were isolated and randomly divided into two culture groups.One group was cultured directly in medium and another group was co-cultured with IFN-γ (40 pg/ml).The supernatants and cells were separated after 5 days of culture for analysis.The concentrations of IL-12 and CD4+CD25+Foxp3 Treg cells were measured by ELISA and flow cytometry,respectively.Results The levels of IL-12 in the supernatants from the culture without IFN-γ at time points of 0,24,48 weeks after HAART were lower than those from the co-cultured group [(37.02±12.76) vs (41.79± 15.02),t=2.336,P=0.03; (41.76±17.01) vs (47.2±14.26),t=2.702,P=0.014; (48.01± 11.84) vs (53.44± 11.30),t =3.14,P =0.003].The percentages of CD4+ CD25 + Foxp3 Treg cells in CD4+ T cells from the direct-cultured group were higher than those from the co-cultured group at the three time points [(10.41±1.10)％ vs (2.40±1.11)％,t=13.89,P=0.000; (8.33±2.03)％ vs (1.99± 0.86)％,t=12.93,P=0.000; (5.65±1.55)％ vs (1.32±0.73)％,t=10.61,P=0.000].Moreover,the results within the same group at the time points of 0,24,48 weeks upon HAART were also significantly different.Conclusion With the interference of HAART,IL-12 levels were increased,while CD4+CD25+ Foxp3 Treg cells were decreased in patients with HIV/AIDS.IFN-γ plays an important role in this process.

Anaerobic ammonium oxidation (ANAMMOX), as its essential advantages of high efficiency and low cost, is a promising novel biological nitrogen elimination process with attractive application prospects. Over the past two decades, many processes based on the ANAMMOX reaction have been continuously studied and applied to practical engineering, with the perspective of reaching 100 full-scale installations in operation worldwide by 2014. Our review summarizes various forms of ANAMMOX processes, including partial nitritation-ANAMMOX, completely autotrophic nitrogen removal over nitrite, oxygen limited autotrophic nitrification and denitrification, denitrifying ammonium oxidation, aerobic deammonification, simultaneous partial nitrification, ANAMMOX and denitrification, single-stage nitrogen removal using ANAMMOX and partial nitritation. We also compare the operating conditions for one-stage and two-stage processes and summarize the obstacles and countermeasures in engineering application of ANAMMOX systems, such as moving bed biofilm reactor, sequencing batch reactor and granular sludge reactor. Finally, we discuss the future research and application direction, which should focus on the optimization of operating conditions and applicability of the process to the actual wastewater, especially on automated control and the impact of special wastewater composition on process performance.
Ammonia ; chemistry ; Bioreactors ; Denitrification ; Nitrification ; Nitrites ; chemistry ; Nitrogen ; chemistry ; Oxygen ; chemistry ; Sewage ; chemistry ; Waste Disposal, Fluid ; methods ; Waste Water ; chemistry

OBJECTIVE: To observe the dynamic changes of 3 types of viral reservoir cells (NK cells, T lymphocytes and monocytes), and its relationship with treatment effect in Chinese HIV-1 infected patients receiving highly active antiretroviral treatment (HAART) for 2 years. METHODS: A total of 40 chronic HIV-1-infected adults who initiated HAART were enrolled in this study and followed up for 2 years. Peripheral whole blood was obtained from each patient at baseline (0 month), 6, 12, 18 and 24 months. Real-time fluorescent quantitative PCR was used to detect the HIV-1 RNA in the plasma and HIV-1 DNA in NK cells, T lymphocytes and monocytes. All the data were statistically analyzed. RESULTS: CD4 count increased with the decrease of the viral load during HAART. After HAART initiation, HIV-1 DNA showed a significant decrease in NK cells, T lymphocytes and monocytes. The HIV-1 DNA from T lymphocytes, NK cells and monocytes correlated positively with the HIV- 1 RNA (P<0.05) while NK cells and T lymphocytes correlated negatively with CD4+ T cell count. However we did not find significant correlation between CD4+ T cell count and HIV-1 DNA in monocytes at the baseline of HAART. CONCLUSION This study found that NK cell was an important HIV cellular reservoir besides T lymphocytes and monocytes. T lymphocytes may be the main long lasting HIV reservoir. HIV-1 proviral DNA may play an important role in the efficacy of treatment and monitoring the disease progression.
Adult ; Antiretroviral Therapy, Highly Active ; DNA, Viral ; analysis ; Female ; HIV Infections ; drug therapy ; virology ; HIV-1 ; genetics ; Humans ; Killer Cells, Natural ; virology ; Male ; Middle Aged ; Monocytes ; virology ; RNA, Viral ; blood ; T-Lymphocytes ; virology ; Viral Load

Objective The objective of this study was to investigate the course of certain common gamma cytokines ( IL-2 and IL-7 ) and their role on the control of the viral infection in a short term antiviral therapy.Methods A total of 35 adults with chronic HIV infection,responding to combined antiretroviral therapy (cART) guideline criteria were enrolled in this one year follow-up study.After signing an informed consent,20 ml blood were collected from each patient at base line,week 0,week 24 and week 48.1 ml serum collected from each patient was kept at -80 * C until use.Serum concentration of IL-2 and IL-7 was determined using ELISA kit from ebioscience Beijing.CD4 and CD8 cells were counted and quantified using flux cytometry,and serum HIV RNA was quantified using real time PCR.Results All patients had a mean baseline IL-2 level [ (9.67 ± 2.6 ) pg/ml ]lower than the controls [ ( 27.36 ± 5.05 ) pg/ml ].After treatment for 48 weeks,IL-2 increased[ ( 19.8 ± 3.3 ) pg/ml ].However,the mean baseline 1L-7 [ ( 81.74± 20.47 ) pg/ml ]in patients was higher than controls [ ( 2.06 ± 1.52 ) pg/ml ].After treatment for 48 weeks,IL-7 decreased [ (8.36 ± 2.16)pg/ml ].IL-2 showed a significant increase and positive correlation with CD4 cells after HAART initiation (0week:R =0.21,P =0.063,24week:R =0.24,P =0.033,48week:R =0.19,P =0.103; IL-7 showed a significant decrease after HAART initiation but it did not show correlation with CD4 cells.We noted there was a negative correlation between IL-2 and CD4 count in HAART baseline (R =0.28,P =0.012 ),but no correlation between IL-7 and CD4 count from 6 month after HAART.IL-2 showed negative correlation with HIV RNA ( R =- 0.17,P =0.032),but IL-7 showed a relationship with the HIV RNA Conclusions The increase of IL-2 coupled with the decrease of IL-7 revealed a partial restoration of immune response during HAART.However,the absence of relationship with HIV RNA suggested that these cytokines might not be directly involved in the reduction of viral load.

Objective To investigate the immunological pathogenesis of immune reconstitution inflammatory syndrome (IRIS) during highly active antiretroviral therapy( HAART), in this prospective cohort study we analyzed the lymphocyte subsets, lymphocyte activation, changes in regulatory T cells, and levels of Th1 and Th2 cytokines in both IRIS and non-IRIS groups. Methods Two hundred and thirty-eight AIDS patients received HAART and participated prospective research cohort for 24 weeks follow-up. Forty-seven IRIS cases and 191 non-IRIS cases were enrolled in the IRIS group or non-IRIS group respectively. Blood samples were collected in both groups at pre- and post-HAART 12 weeks, 24 weeks. Using flow cytometer to detect the immunophenotypes of lymphocyte subsets (CD4 + CD45RA+ CD62L+, CD8+ CD45RA+ CD62L+naive T cells; CD4+ CD45RO+, CD8+ CD45RO+ memory T cells), activated T lymphocytes (CD4+CD38 +, CD8 + CD38 + cells), and regulatory T cell ( CD4 + CD25 + Foxp3 + ). Blood samples collected at pre-and post-HAART4 weeks, 12 weeks, 24 weeks and used ELISA to detect IL-2, IFN-γ, IL-4, IL-10and IL-7 cytokine serum levels. Results The percentages of CD4 + and CD8 + naive T cells and mlemory T cells exhibited no significant differences at the baseline, 12 weeks, 24 weeks of HAART initiation between both groups, but CD4 + and CD8 + memory T cells were demonstrated a trend towards to increase while compared to baseline during HAART. The percentages of CD4 + and CD8 + activated T cells are significantly higher at the baseline while compared to normal control and demonstrated a downward trend, but between both groups showed no significant difference. The percentages of CD4 + regulatory T cell was lower in IRIS group than non-IRIS group at the baseline, 12 weeks, 24 weeks and the onset of IRIS. Th1 cytokines, IL-2 and IFN-γshowed an upward trend during HAART at the levels of IRIS group had significantly increased at 4 weeks and the onset of IRIS. Th2 cytokines, IL-4 and IL-10 showed a downward trend during HAART,and the levels of IL-10 in IRIS group had significantly decreased at 4 weeks and the onset of IRIS. IL-7 was higher than normal control at the baseline in two groups and showed a downward trend during HAART. The level of IL-7 was higher than non-IRIS group at all follow-up points. Conclusion Memory T cells appear rapid increase in the early stage of HAART and may play a significant role in the inflammatory response of IRIS. CD4 + and CD8 + naive T cells, memory T cells and activated T cells showed no significant difference between IRIS and non-IRIS group within 24 weeks after HAART started. There was a significant reduction in the frequency of regulatory T cells in IRIS group without obvious upward trend during HAART, suggesting that the immune suppression function of regulatory T cells in IRIS was impaired. IL-2 and IFN-γ significantly increased while IL-10 significantly decreased at 4 weeks post-HAART initiation and onset of IRIS in IRISgroup than non-IRIS group, suggested that IRIS was related to cytokines environment disorder. That is, a significant increase in inflammatory cytokines, while the relative lack of non-inflammatory cytokines. The level of IL-7 decreased gradually after HAART started, and it was higher in IRIS group when compared to non-IRIS group in the first 24 weeks after HAART started. Also IL-7 may play a role in the pathogenesis of IRIS.

Objective To observe the Th17, IL-17 and Tr cells equilibrium state as well as their changes of HIV infected or AIDS suffered patients in one-year HAART treatment. Methods Select 33 HIV/AIDS patients received HAART treatment while 33 healthy volunteers as controls. Flow cytometry was used to analyze Th17 and Tr cells in venous blood at the time of pre-therapy, 6th, 12th month when IL-17 levels in serum are tested by ELISA. Results The ratio of Th17 cells in CD4 cells in HIV/AIDS patients and volunteers were (1.20±0.37)%, (2.50±1.03)%, (3.70±1.56)%, (4.70±1.43)%, respectively; The ratio of Tr cells were (9.16±3.33)%, (7.19±2.91)%, (5.53±1.88)%, (4.43±0.97)%, respectively; The levels of IL-17 in serum were (5.3±2.5) pg/ml, (7.7±2.4) pg/ml, (10.4±3.1) pg/ml, (17.7±6.6) pg/ml respectively. The Th17 cells' level was positively correlative with the amount of CD4 cells, negatively correlate with the count of viral load. However, the Tr cells level is positively correlative with the count of viral load, negatively relate to the quantity of CD4 cells. Conclusion HIV could make IL-17, Th17 cells and Tr cells lost their balance, but the immune equilibrium state may gradually recover after HAART treatment. Which indicates the IL-17, Th17 cells and Treg cells may play an important role in the pathogenesis of AIDS, and they are likely to be the effective indexes to observe the progress of AIDS and the treatment effect of highly active antiretroviral therapy(HAART).