ABSTRACT
To improve the diagnosis and treatment of Mycoplasma pneumoniae (Mp) infection and reduce the misuse of antibiotics, we sought to establish a loop-mediated isothermal amplification (LAMP) assay for rapid detection of Mp.Six primers specific for the Mp P1 gene were designed, and the LAMP method was used to rapidly detect Mp. The sensitivity of the LAMP method was determined by serial dilution of the standard Mp strain FH (standard strains of Mycoplasma pneumoniae). Specificity was assessed with 17 common pathogenic microorganisms in the respiratory tract. Patient samples were collected from the Department of Respiratory and Critical Care Medicine at the 307th Hospital of Chinese People's Liberation Army from March 2016 to May 2017, examined prospectively, and compared with diagnosis by quantitative real-time polymerase chain reaction (qRT-PCR).The LAMP assay for Mp detection can be completed within 60âminutes. The minimum detection limit was 39âpg/µL, and no cross-reaction was observed with 17 common respiratory tract pathogens. Of the 125 clinical specimens tested, 43 cases were positive by LAMP assay, and 40 cases were positive by qRT-PCR (Pâ=â.162). All 43 samples determined as positive by LAMP test were confirmed to be Mp by Mp P1 protein sequencing.The LAMP assay is suitable for rapid detection of Mp. It has high sensitivity and specificity, and the detection results are not inferior to those of qRT-PCR.
Subject(s)
Molecular Diagnostic Techniques , Mycoplasma pneumoniae , Pneumonia, Mycoplasma/diagnosis , Respiratory Tract Infections , Adult , China , Female , Genes, Bacterial , Humans , Male , Molecular Diagnostic Techniques/methods , Molecular Diagnostic Techniques/standards , Mycoplasma pneumoniae/genetics , Mycoplasma pneumoniae/isolation & purification , Real-Time Polymerase Chain Reaction/methods , Respiratory Tract Infections/diagnosis , Respiratory Tract Infections/microbiology , Sensitivity and SpecificityABSTRACT
AIM: The ability of Acinetobacter baumannii to form biofilms and develop antibiotic resistance makes it difficult to control infections caused by this bacterium. In this study, we explored the potential of a lytic bacteriophage to disrupt A. baumannii biofilms. MATERIALS & METHODS: The potential of the lytic bacteriophage to disrupt A. baumannii biofilms was assessed by performing electron microscopy, live/dead bacterial staining, crystal violet staining and by determining adenosine triphosphate release. RESULTS: The bacteriophage inhibited the formation of and disrupted preformed A. baumannii biofilms. Results of disinfection assay showed that the lytic bacteriophage lysed A. baumannii cells suspended in blood or grown on metal surfaces. CONCLUSION: These results suggest the potential of the lytic bacteriophage to disrupt A. baumannii biofilms.
Subject(s)
Acinetobacter baumannii/virology , Bacteriophages/pathogenicity , Biofilms/drug effects , Biofilms/growth & development , Phage Therapy/methods , Acinetobacter Infections/microbiology , Acinetobacter Infections/therapy , Acinetobacter Infections/virology , Acinetobacter baumannii/drug effects , Acinetobacter baumannii/growth & development , Acinetobacter baumannii/isolation & purification , Adenosine Triphosphate/analysis , Anti-Bacterial Agents/pharmacology , Bacteriophages/isolation & purification , Bacteriophages/physiology , China , Disinfection/methods , Drug Resistance, Multiple, Bacterial , Humans , Sputum/microbiology , Staining and LabelingABSTRACT
AIM: With the emergence of drug-resistant bacteria, finding alternative agents to treat antibiotic-resistant bacterial infections is imperative. MATERIALS & METHODS: A mouse pneumonia model was developed by combining cyclophosphamide pretreatment and Acinetobacter baumannii challenge, and a lytic bacteriophage was evaluated for its therapeutic efficacy in this model by examining the survival rate, bacterial load in the lung and lung pathology. RESULTS: Intranasal instillation with bacteriophage rescued 100% of mice following lethal challenge with A. baumannii. Phage treatment reduced bacterial load in the lung. Microcomputed tomography indicated a reduction in lung inflammation in mice given phage. CONCLUSION: This research demonstrates that intranasal application of bacteriophage is viable, and could provide complete protection from pneumonia caused by A. baumannii.
