Engineering bacteriophages for enhanced host range and efficacy: insights from bacteriophage-bacteria interactions.

Bacteriophages, the most abundant organisms on earth, have the potential to address the rise of multidrug-resistant bacteria resulting from the overuse of antibiotics. However, their high specificity and limited host range can hinder their effectiveness. Phage engineering, through the use of gene editing techniques, offers a means to enhance the host range of bacteria, improve phage efficacy, and facilitate efficient cell-free production of phage drugs. To engineer phages effectively, it is necessary to understand the interaction between phages and host bacteria. Understanding the interaction between the receptor recognition protein of bacteriophages and host receptors can serve as a valuable guide for modifying or replacing these proteins, thereby altering the receptor range of the bacteriophage. Research and development focused on the CRISPR-Cas bacterial immune system against bacteriophage nucleic acids can provide the necessary tools to promote recombination and counter-selection in engineered bacteriophage programs. Additionally, studying the transcription and assembly functions of bacteriophages in host bacteria can facilitate the engineered assembly of bacteriophage genomes in non-host environments. This review highlights a comprehensive summary of phage engineering methods, including in-host and out-of-host engineering, and the use of high-throughput methods to understand their role. The main aim of these techniques is to harness the intricate interactions between bacteriophages and hosts to inform and guide the engineering of bacteriophages, particularly in the context of studying and manipulating the host range of bacteriophages. By employing advanced high-throughput methods to identify specific bacteriophage receptor recognition genes, and subsequently introducing modifications or performing gene swapping through in-host recombination or out-of-host synthesis, it becomes possible to strategically alter the host range of bacteriophages. This capability holds immense significance for leveraging bacteriophages as a promising therapeutic approach against antibiotic-resistant bacteria.

Risk Factors and Pathogen Spectrum in Continuous Ambulatory Peritoneal Dialysis-Associated Peritonitis: A Single Center Retrospective Study.

BACKGROUND To investigate the incidence, risk factors, pathogen distribution, and drug resistance patterns in continuous ambulatory peritoneal dialysis-associated peritonitis (CAPDP). MATERIAL AND METHODS Clinical data for 248 patients who underwent continuous ambulatory peritoneal dialysis (CAPD) treatment in a single center in China from March 2018 to January 2021 were retrospectively collected. The patients were divided into the CAPDP group (n=40) and the non-CAPDP group (n=208) according to whether peritonitis occurred. The incidence rate, risk factors, bacterial distribution, and drug sensitivity of CAPDP were analyzed. RESULTS The incidence of CAPDP was 16.13%, and 87.5% of patients with CAPDP continued CAPDP treatment after anti-infection treatment. Patients with and without CAPDP were clearly distinguished, on the basis of their clinical characteristics, by using principal component analysis (PCA) methods. Logistic regression analysis found that body mass index (BMI; P=0.0095), albumin (P=0.016), albumin/globulin ratio (P=0.018), C-reactive protein (P=0.0001), and rapid transport (P=0.034) were independent risk factors for CAPDP. The main pathogens causing the CAPDP were Staphylococcus epidermidis (50.00%), Staphylococcus capitis (13.33%), and Escherichia coli (10.00%). Among the pathogenic bacteria, the main drugs to which gram-negative cocci were sensitive were imipenem, meropenem, piperacillin/tazobactam, cefoperazone/sulbactam, ceftazidime, and tigecycline. The main drugs to which gram-positive cocci were sensitive were vancomycin, teicoplanin, and linezolid. The drug resistance rate of pathogenic bacteria to penicillin G, ampicillin, compound trimethoprim, cefepime, ceftriaxone, and amoxicillin-clavulanic acid drugs was 36.26-100%. CONCLUSIONS BMI, albumin, albumin/globulin ratio, C-reactive protein, and rapid transport are independent risk factors for CAPDP. Gram-positive bacteria are the main pathogens of CAPDP and are sensitive to vancomycin, teicoplanin, and linezolid.

Rituximab shows no effect on remission in patients with refractory nephrotic syndrome: A MOOSE-compliant meta-analysis.

To assess the efficacy of rituximab in treatment of refractory nephrotic syndrome (NS) compared with other agents.Studies were searched from Web of Science, PubMed, and CNKI up to April 2016. The standardized mean difference or relative risk or odds ratio and 95% confidence intervals were used to assess the efficacy of rituximab treatment compared with other agents in refractory NS.Totally, 8 studies were included. The present study showed that there was a significant higher relapse-free survival rate in rituximab group than that in the other agents group. Compared with other agents, rituximab did not significantly improve the complete and overall remission rate, serum albumin levels. Rituximab also did not decrease the serum creatinine, urinary protein, and serum cholesterol levels. However, compared with other agents, the adult patients had a higher serum cholesterol levels after treatment with rituximab.Rituximab promised to be a new agent in the treatment of refractory NS; it also could be used as an alternative to conventional immunosuppressive drugs-dependent or drugs-resistant. However, more high-quality, large sample, and multicenter randomized controlled trials are needed to further confirm the efficacy of rituximab in treatment of refractory NS.

Comparison of polymerase chain reaction and immunologic methods for the detection of nanobacterial infection in type-III prostatitis.

OBJECTIVE: To compare the results of polymerase chain reaction (PCR) and immunologic methods for the detection of nanobacteria (NB) in the expressed prostatic secretions (EPSs) of patients with type-III prostatitis. METHODS: In total, 150 patients with type-III prostatitis for whom conventional clinical treatment had failed were selected from September 2009 to April 2010. The EPS of each patient was divided into 3 parts, which were used for PCR analysis, indirect immunofluorescence staining (IIFS), and culture and subsequent indirect immunofluorescence staining (CIIFS). RESULTS: PCR analysis has a higher sensitivity than IIFS for the detection of NB in EPSs. Of 83 CIIFS-positive EPS samples, 79 (95.2%) were positive by PCR. Of 67 EPS samples that were negative by CIIFS, 60 (89.6%) were negative by PCR. The sensitivity of PCR for the detection of NB compared with the CIIFS method was 95.2%, with a specificity of 89.6%. The positive predictive value was 91.9%, and the negative predictive value was 93.8%. A comparative evaluation showed no statistically significant difference between PCR and CIIFS in the detection of NB in EPSs. A strong agreement in the positive and the negative results obtained by PCR and CIIFS for NB detection was found for all EPS samples. CONCLUSION: PCR analysis has a higher sensitivity than IIFS for NB detection in type-III prostatitis. PCR can detect nanobacterial infection in type-III prostatitis equally well as CIIFS and offers significant advantages for the rapid, simple, and economical detection of nanobacterial infection in type-III prostatitis.