Probiotics have shown excellent application prospects in preventing and treating many diseases. However, their sensitivity to the harsh environment in vivo always leads to a massive loss of viability and insufficient therapeutic effect. Fortunately, modified probiotics have emerged and provide multiple possibilities for their use in various diseases. Modification not only endows probiotics with extra capacity to resist severe environments but also gives them exogenous characteristics, such as prolonged retention time and improved therapeutic effects. Modified probiotics could combine with other therapies, which has opened up new avenues to enhance the efficacy of probiotic-based therapy. In this review, we have summarized the current physicochemical and biological modification strategies of probiotics. In addition, the progress of research on probiotic-based combination therapy has also been extensively reviewed, which contributes to the enhanced delivery of probiotics or other active constituents and provides new ideas for disease treatment, bioimaging, and diagnosis.

OBJECTIVE To understand the disinfectant-resistant genes in the gram-negative bacteria isolated from the dirt retention on air recure filters of air conditioners and observe the drug resistance.METHODS The dirt re-tention samples were collected from the air return filters of air conditioners of some wards in 3 hospitals of Wuhan(Tongji Hospital of Tongji Medical College of Huazhong University of Science and Technology,Wuhan Central Hospital,and Hubei Provincial Maternal and Child Health Hospital)from 2018 to 2024.The gram-negative bac-teria were screened out,the disinfectant-resistant genes in the strains were detected by polymerase chain reaction(PCR),and the results of drug susceptibility test were analyzed.RESULTS Of 354 dirt retention samples that were collected from the air return filers of air conditioners,77 were detected with 138 strains of gram-negative bacteria,87 of which were Acinetobacter baumannii,50 were Enterobacteriaceae,and 1 was Pseudomonas aerug-inosa.The detection rates of qacEΔ1,qacEΔ1-sul1,aceI and qacA/B were 73.19％,82.61％,69.57％and 2.90％,respectively.None of the strains were detected with qacC,qacH or qacJ.The result of drug susceptibility test showed that 76.81％of the gram-negative bacteria were resistant to at least 1 type of antibiotic;93 strains of multidrug-resistant gram-negative bacteria were isolated,most of which were isolated from intensive care unit(ICU).The detection rates of qacEΔ1 and qacEΔ1-sul1 were higher in the drug-resistant strains than those in the non-drug-resistant strains;there were significant differences in the drug resistance rates to carbapenems,quin-olones and β-lactams between the qacEΔ1-sul 1-positive strains and the qacEΔ1-sul1-negative strains(P＜0.05).CONCLUSIONS There are drug-resistant gram-negative bacteria contaminations in some wards of the 3 hospitals in Wuhan.The carrying rates of disinfectant-resistant genes of the strains are high,and the strains show varying degree of resistance to the commonly used antibiotics;the strains carrying the qacEΔ1-sul1 have certain statistical association with the drug resistance.It is suggested that the hospital should take targeted disinfec-tion measures for the environment and reasonably use antibiotics.

OBJECTIVE To understand the disinfectant-resistant genes in the gram-negative bacteria isolated from the dirt retention on air recure filters of air conditioners and observe the drug resistance.METHODS The dirt re-tention samples were collected from the air return filters of air conditioners of some wards in 3 hospitals of Wuhan(Tongji Hospital of Tongji Medical College of Huazhong University of Science and Technology,Wuhan Central Hospital,and Hubei Provincial Maternal and Child Health Hospital)from 2018 to 2024.The gram-negative bac-teria were screened out,the disinfectant-resistant genes in the strains were detected by polymerase chain reaction(PCR),and the results of drug susceptibility test were analyzed.RESULTS Of 354 dirt retention samples that were collected from the air return filers of air conditioners,77 were detected with 138 strains of gram-negative bacteria,87 of which were Acinetobacter baumannii,50 were Enterobacteriaceae,and 1 was Pseudomonas aerug-inosa.The detection rates of qacEΔ1,qacEΔ1-sul1,aceI and qacA/B were 73.19％,82.61％,69.57％and 2.90％,respectively.None of the strains were detected with qacC,qacH or qacJ.The result of drug susceptibility test showed that 76.81％of the gram-negative bacteria were resistant to at least 1 type of antibiotic;93 strains of multidrug-resistant gram-negative bacteria were isolated,most of which were isolated from intensive care unit(ICU).The detection rates of qacEΔ1 and qacEΔ1-sul1 were higher in the drug-resistant strains than those in the non-drug-resistant strains;there were significant differences in the drug resistance rates to carbapenems,quin-olones and β-lactams between the qacEΔ1-sul 1-positive strains and the qacEΔ1-sul1-negative strains(P＜0.05).CONCLUSIONS There are drug-resistant gram-negative bacteria contaminations in some wards of the 3 hospitals in Wuhan.The carrying rates of disinfectant-resistant genes of the strains are high,and the strains show varying degree of resistance to the commonly used antibiotics;the strains carrying the qacEΔ1-sul1 have certain statistical association with the drug resistance.It is suggested that the hospital should take targeted disinfec-tion measures for the environment and reasonably use antibiotics.

Objective To analyze the influence of meteorological factors on the number of influenza-like illness (ILI) cases in Urumqi, Xinjiang, and establish an ARIMAX (autoregressive integrated moving average model-X) model to make short-term prediction of the number of ILI cases, so as to provide theoretical basis for the prevention and control of influenza in Urumqi. Methods The number of ILI cases in Urumqi from January 2015 to September 2017 and meteorological data of the same period were used to establish ARIMAX model and predict the number of ILI cases in Urumqi from October 2017 to March 2018. Results The ARIMA (0,1,1) (1,1,0)₁₂ model was established from January 2015 to September 2017, AIC = 200.09. According to residual correlation function (CCF), there was a positive correlation between monthly average relative humidity and ILI cases, and a negative correlation between monthly sunshine hours and ILI cases. The average monthly relative humidity and monthly sunshine hours were taken as influencing variables to establish the ARIMAX model. Among them, the ARIMAX model incorporating the lagging order of 0 of monthly sunshine hours had the smallest AIC (AIC=197.63), and all parameters of the model were statistically significant. Compared with the univariate time series ARIMA model, the mean absolute percentage error (MAPE) of fitting was reduced by 1.3687%, the predicted MAPE was reduced by 5.25%, and the prediction accuracy was improved. Conclusion The ARIMAX model with meteorological factors established in this study can better predict the incidence trend of ILI cases in a short time, providing evidence for influenza surveillance and prevention and control.

In order to investigate the role of the MexA-MexB-OprM efflux pump system in the pathogenesis of Pseudomonas aeruginosa (PA)-induced pulmonary infection, pulmonary infection models were established by intratracheal injection of K767 (wild type), nalB (MexA-MexB-OprM up-regulated mutant), and ΔmexB (knockout) strains, separately. All mice were treated with Meropenem (intraper Δ itoneal injection, 100 mg/kg body weight, twice every day), and strain-related pathology, bacteria count, cytokine level, myeloperoxidase (MPO, indicator of neutrophil recruitment) activity, and macrophage inflammatory protein-2 (MIP-2) expression were evaluated at early (3rd day post-infection) and late (7th and 14th day post-infection) stages of infection. E-test showed that ΔmexB was more significantly Δ sensitive to panipenan (ETP), meropenem (MP) and imipenem (IP) than K767 and nalB strains. There was no significant difference in sensitivity to cefepime (TM) among the three stains. In contrast to the K767 and nalB groups, the ΔmexB group showed decreased bacteria burden over time and less exte Δ nsive pathological change. Additionally, MPO activity and levels of inflammatory cytokines (IL-1b, IL-12, and TNF-α) were increased at the early stage (day 3) and decreased at the later stage (day 14). Serum MIP-2 expression level was steadily increased in all three groups from early to late stages, but significantly higher in ΔmexB group than in K767 and nalB groups ( Δ P<0.05). In conclusion, the MexA-MexB-OprM efflux pump system might play an important role in PA-induced chronic pulmonary infection. High expression of the MexA-MexB-OprM efflux pump could increase antibacterial resistance and promote infection.
Animals ; Bacterial Outer Membrane Proteins ; metabolism ; Lung ; microbiology ; Membrane Transport Proteins ; metabolism ; Mice ; Mice, Inbred BALB C ; Pseudomonas Infections ; metabolism ; microbiology ; Pseudomonas aeruginosa ; metabolism

Staphylococcus aureus (S. aureus) is an important human pathogen which can cause a chronic condition with a high relapse rate despite the aggressive antimicrobial treatment. Recent studies showed that intracellular pattern recognition receptors (including NOD) in response to bacteria or bacterial products play a proinflammatory role by activating nuclear transcription factor-κB (NF-κB). But how NOD2 mediates the proinflammatory response to S. aureus in mast cells (MCs) is unclear. So, in this study, we attempted to examine the role of NOD2 in inflammatory responses of MCs to S. aureus. P815 cells (a mouse mast cell line) were cultured. Real-time PCR was used to detect the NOD2 mRNA expression in P815 cells during S. aureus infection. The siRNA against NOD2 gene was synthesized and transfected into S. aureus-infected P815 cells. By using the methods of ELISA and flow cytometry, the effects of NOD2 gene silencing on cell phagocytosis, cytokine secretion, NF-κB activation and cell apoptosis of the S. aureus-infected P815 cells were examined. It was found that S. aureus infection could increase the expression of NOD2 mRNA in P815 cells. NOD2 gene interference in P815 cells reduced the number of S. aureus engulfed by P815 cells, the level of cytokines and the activation of NF-κB. In addition, S. aureus could induce the apoptosis of P815 cells, but NOD2 gene silencing did not affect the cell apoptosis rate. Our data suggested that NOD2 plays a key role in pathogen recognition, signal transduction, and NF-κB activation in the inflammatory responses of MCs infected by S. aureus.
Animals ; Cell Line ; Cytokines ; immunology ; Inflammation Mediators ; immunology ; Mast Cells ; immunology ; microbiology ; Mice ; NF-kappa B ; immunology ; Nod2 Signaling Adaptor Protein ; immunology ; Staphylococcus aureus ; physiology

Staphylococcus aureus (S. aureus) is an important human pathogen which can cause a chronic condition with a high relapse rate despite the aggressive antimicrobial treatment. Recent studies showed that intracellular pattern recognition receptors (including NOD) in response to bacteria or bacterial products play a proinflammatory role by activating nuclear transcription factor-κB (NF-κB). But how NOD2 mediates the proinflammatory response to S. aureus in mast cells (MCs) is unclear. So, in this study, we attempted to examine the role of NOD2 in inflammatory responses of MCs to S. aureus. P815 cells (a mouse mast cell line) were cultured. Real-time PCR was used to detect the NOD2 mRNA expression in P815 cells during S. aureus infection. The siRNA against NOD2 gene was synthesized and transfected into S. aureus-infected P815 cells. By using the methods of ELISA and flow cytometry, the effects of NOD2 gene silencing on cell phagocytosis, cytokine secretion, NF-κB activation and cell apoptosis of the S. aureus-infected P815 cells were examined. It was found that S. aureus infection could increase the expression of NOD2 mRNA in P815 cells. NOD2 gene interference in P815 cells reduced the number of S. aureus engulfed by P815 cells, the level of cytokines and the activation of NF-κB. In addition, S. aureus could induce the apoptosis of P815 cells, but NOD2 gene silencing did not affect the cell apoptosis rate. Our data suggested that NOD2 plays a key role in pathogen recognition, signal transduction, and NF-κB activation in the inflammatory responses of MCs infected by S. aureus.

In order to investigate the role of the MexA-MexB-OprM efflux pump system in the pathogenesis of Pseudomonas aeruginosa (PA)-induced pulmonary infection, pulmonary infection models were established by intratracheal injection of K767 (wild type), nalB (MexA-MexB-OprM up-regulated mutant), and ΔmexB (knockout) strains, separately. All mice were treated with Meropenem (intraper Δ itoneal injection, 100 mg/kg body weight, twice every day), and strain-related pathology, bacteria count, cytokine level, myeloperoxidase (MPO, indicator of neutrophil recruitment) activity, and macrophage inflammatory protein-2 (MIP-2) expression were evaluated at early (3rd day post-infection) and late (7th and 14th day post-infection) stages of infection. E-test showed that ΔmexB was more significantly Δ sensitive to panipenan (ETP), meropenem (MP) and imipenem (IP) than K767 and nalB strains. There was no significant difference in sensitivity to cefepime (TM) among the three stains. In contrast to the K767 and nalB groups, the ΔmexB group showed decreased bacteria burden over time and less exte Δ nsive pathological change. Additionally, MPO activity and levels of inflammatory cytokines (IL-1b, IL-12, and TNF-α) were increased at the early stage (day 3) and decreased at the later stage (day 14). Serum MIP-2 expression level was steadily increased in all three groups from early to late stages, but significantly higher in ΔmexB group than in K767 and nalB groups ( Δ P<0.05). In conclusion, the MexA-MexB-OprM efflux pump system might play an important role in PA-induced chronic pulmonary infection. High expression of the MexA-MexB-OprM efflux pump could increase antibacterial resistance and promote infection.

Objective To investigate the efficacy of small interfering RNA against Pseudomonos aeruginosa expressing MexA-MexB-OprM multidrug efflux pump in vivo.Methods Two short hairpin (sh)RNA expression vectors targeting the MexB gene,and negative controls,were designed,synthesized,and electrotransformed into the P.aeruginosa strain PAO1.The in vivo therapeutic efficacy of the MexB small interfering (si)RNAs was determined by infecting a murine model of chronic P.aeruginosa lung infection (1 × 107 CFU/ml).The mice were killed on day 3,5 and 7 after infection with the Pseudomonas aeruginosa strains.Results In the murine infection model,treatment with MexB-siRNAs led to significantly reduced bacteria burden of the bellows by day 5 and 7 post-infection,and reduced the P.aeruginosa-induced pathological changes.In addition,MexB-siRNA2 treatment enhanced neutrophil recruitment and production of inflammatory cytokines (IL-1β,IL-12) in the early infection stage (day 3) (P＜0.05),both of which decreased by day 7.Conclusion MexB-siRNA could inhibit both mRNA expression and the activity of P.aeruginosa in vitro.siRNA was effective in reducing the bacterial load in a murine model of chronic lung infection.Targeting of MexB with siRNA appears to be a novel strategy for treating P.aeruginosa infections.

Objective To investigate the effects of NOD2 on inflammatory responses of macrophages to Staphylococcus aureus. Methods Real-time RT-PCR detected NOD2 gene expression of macrophages infected by S. aureus. Synthesis of siRNA against NOD2 and interfere with macrophages, observed the effects of NOD2 gene silencing to phagocytosis of 5. aureus, cytokine secretion, activation of nuclear transcription factors, cell apoptosis of the macrophages infected by S. aureus using F.I .IS A, flow cytometry etc. Results S. aureus infection of macrophages can cause increased expression of intracellular NOD2. NOD2 gene silencing of macrophage lead to the decreased ability of phagocytosis with S. aureus, the lower levels of cytokines secretion, deficiencies of NF-κB activation. S. aureus can cause macrophage apoptosis, with the apoptosis rate increased with time. Conclusion The intracellular pattern recognition receptor NOD2 play a key role in pathogen recognition, signal transduction, activation of nuclear transcription factors in the process of macrophages infected by S. aureus.