Background:Acinetobacter baumannii(A.baumannii)is one of the pivotal pathogens responsible for nosocomial infections,especially in patients with low immune response,and infection with carbapenem-resistant A.baumannii ...Background:Acinetobacter baumannii(A.baumannii)is one of the pivotal pathogens responsible for nosocomial infections,especially in patients with low immune response,and infection with carbapenem-resistant A.baumannii has been increasing in recent years.Rapid and accurate detection of carbapenem-resistance genes in A.baumannii could be of immense help to clinical staff.Methods:In this study,a 15-μL reaction system for recombinase polymerase amplification(RPA)was developed and tested.We collected 30 clinical isolates of A.baumannii from the Burn Institute of Southwest Hospital of Third Military Medical University(Army Medical University)for 6 months and tested antibiotic susceptibility using the VITEK 2 system.A.baumannii was detected based on the blaOXA-51 gene by PCR,qPCR and 15μL-RPA,respectively.Sensitivity and specificity were evaluated.In addition,PCR and 15μL-RPA data for detecting the carbapenem-resistance gene blaOXA-23 were comparatively assessed.Results:The detection limit of the blaOXA-51 gene by 15μL RPA was 2.86 CFU/ml,with sensitivity comparable to PCR and qPCR.No positive amplification signals were detected in non-Acinetobacter isolates,indicating high specificity.However,only 18 minutes were needed for the 15μL RPA assay.Furthermore,an antibiotic susceptibility test showed that up to 90%of A.baumannii strains were resistant to meropenem and imipenem;15μL RPA data for detecting blaOXA-23 showed that only 10%(n=3)of A.baumannii isolates did not show positive amplification signals,and the other 90%of(n=27)isolates were positive,corroborating PCR results.Conclusion:We demonstrated that the new 15μL RPA assay for detecting blaOXA-23 in A.baumannii is faster and simpler than qPCR and PCR.It is a promising alternative molecular diagnostic tool for rapid and effective detection of A.baumannii and drug-resistance genes in the field and point-ofcare testing.展开更多
Background: The characteristics of Staphylococcus aureus that made it the most important cause of wound infections are environmental spread antimicrobials resistance and virulence. Absence of molecular detection of dr...Background: The characteristics of Staphylococcus aureus that made it the most important cause of wound infections are environmental spread antimicrobials resistance and virulence. Absence of molecular detection of drug resistance and virulence factors in many developing countries limits the epidemiological information. This study conducted to identify PVL virulence gene, and blaOXA-23 and blaOXA-51 drug resistance genes of Staphylococcus aureus isolated from surgical-sites infections (SSIs) and traumatic wounds. Methods: A cross-sectional study was conducted from 2019 to 2021, in which 70 cefepime resistant Staphylococcus aureus were used, the strains were isolated from patients of SSIs and traumatic wounds admitted to the department of General Surgery in Wad Medani Teaching Hospital. Mannitol salt agar was used for primary culture followed by biochemical identification and Kirby Bauer susceptibility testing. Single and multiplex PCR protocols performed for bacterial confirmation and target genes detection. Results: Staphylococcus aureus strains from SSIs constituted 56% (39/70) from which 41% (16/39) possessed PVL gene while 42% (13/31) of wound infections strains were positive for PVL gene. Presence of PVL gene was significantly associated with resistance to meropenem (P. value 0.023) and ceftriaxone (P. value 0.037). blaOXA-23 was significantly detected with resistance to meropenem, augmentin and ceftriaxone. While blaOXA-51 was significantly identified among Staphylococcus aureus strains that showed resistance to meropenem and ciprofloxacin. Conclusion: This is the first study in Sudan that identified blaOXA-23 and blaOXA-51 in Staphylococcus aureus and correlated them to resistance to commonly used antimicrobials. Meropenem resistant Staphylococcus aureus were significantly positive for PVL, blaOXA-23 and baOXA-51 genes.展开更多
Background: Urosepsis is one of the most common infections that require empirical broad spectrum antibiotics immediately after diagnosis. This has led to development of bacterial resistance by acquiring the capability...Background: Urosepsis is one of the most common infections that require empirical broad spectrum antibiotics immediately after diagnosis. This has led to development of bacterial resistance by acquiring the capability to destroy the β-lactam ring. Methodology: This is a cross-sectional hospital-based study. The study was conducted from 2019 to 2020 at Gezira Hospital for Renal diseases and surgery (GHRDS). A hundred patients were diagnosed clinically with urosepsis and the isolated organisms were Escherichia coli, Staphylococcus aureus, Proteus mirabilis, Klebsiella pneumonia and Pseudomonas aeruginosa. The susceptibility test was conducted by Kirby Bauer disc diffusion technique according to clinical laboratory standard institute (CLSI) guidelines. Seventy eight samples of bacterial genomic DNA were confirmed by 16srRNA and multiplex PCR, were performed for genotypic blaOXA-51 and blaOXA-23 gene characterization of isolated bacteria. Then gel electrophoresis was used to identify the presence or absence of (blaOXA-51 and blaOXA-23) genes. Results: 88.5% (69/78) in 16srRNA detected. Using multiplex PCR, the frequencies of blaOXA-51 and blaOXA-23 genes were 13% and 10.1%, respectively. The percentages of isolates which yielded both blaOXA-51 and blaOXA-23 among P. aeruginosa was 25% (1/4), among K. pneumonia was 17% (1/6), and among E. coli was 8% (3/37). Only blaOXA-51 was detected in P. mirabilis 10% (1/10) and only blaOXA-23 was detected in S. aureus 5% (1/18). Conclusion: In this study, the presence of blaOXA-51 and blaOXA-23 genes was increased in the isolated bacteria.展开更多
文摘Background:Acinetobacter baumannii(A.baumannii)is one of the pivotal pathogens responsible for nosocomial infections,especially in patients with low immune response,and infection with carbapenem-resistant A.baumannii has been increasing in recent years.Rapid and accurate detection of carbapenem-resistance genes in A.baumannii could be of immense help to clinical staff.Methods:In this study,a 15-μL reaction system for recombinase polymerase amplification(RPA)was developed and tested.We collected 30 clinical isolates of A.baumannii from the Burn Institute of Southwest Hospital of Third Military Medical University(Army Medical University)for 6 months and tested antibiotic susceptibility using the VITEK 2 system.A.baumannii was detected based on the blaOXA-51 gene by PCR,qPCR and 15μL-RPA,respectively.Sensitivity and specificity were evaluated.In addition,PCR and 15μL-RPA data for detecting the carbapenem-resistance gene blaOXA-23 were comparatively assessed.Results:The detection limit of the blaOXA-51 gene by 15μL RPA was 2.86 CFU/ml,with sensitivity comparable to PCR and qPCR.No positive amplification signals were detected in non-Acinetobacter isolates,indicating high specificity.However,only 18 minutes were needed for the 15μL RPA assay.Furthermore,an antibiotic susceptibility test showed that up to 90%of A.baumannii strains were resistant to meropenem and imipenem;15μL RPA data for detecting blaOXA-23 showed that only 10%(n=3)of A.baumannii isolates did not show positive amplification signals,and the other 90%of(n=27)isolates were positive,corroborating PCR results.Conclusion:We demonstrated that the new 15μL RPA assay for detecting blaOXA-23 in A.baumannii is faster and simpler than qPCR and PCR.It is a promising alternative molecular diagnostic tool for rapid and effective detection of A.baumannii and drug-resistance genes in the field and point-ofcare testing.
文摘Background: The characteristics of Staphylococcus aureus that made it the most important cause of wound infections are environmental spread antimicrobials resistance and virulence. Absence of molecular detection of drug resistance and virulence factors in many developing countries limits the epidemiological information. This study conducted to identify PVL virulence gene, and blaOXA-23 and blaOXA-51 drug resistance genes of Staphylococcus aureus isolated from surgical-sites infections (SSIs) and traumatic wounds. Methods: A cross-sectional study was conducted from 2019 to 2021, in which 70 cefepime resistant Staphylococcus aureus were used, the strains were isolated from patients of SSIs and traumatic wounds admitted to the department of General Surgery in Wad Medani Teaching Hospital. Mannitol salt agar was used for primary culture followed by biochemical identification and Kirby Bauer susceptibility testing. Single and multiplex PCR protocols performed for bacterial confirmation and target genes detection. Results: Staphylococcus aureus strains from SSIs constituted 56% (39/70) from which 41% (16/39) possessed PVL gene while 42% (13/31) of wound infections strains were positive for PVL gene. Presence of PVL gene was significantly associated with resistance to meropenem (P. value 0.023) and ceftriaxone (P. value 0.037). blaOXA-23 was significantly detected with resistance to meropenem, augmentin and ceftriaxone. While blaOXA-51 was significantly identified among Staphylococcus aureus strains that showed resistance to meropenem and ciprofloxacin. Conclusion: This is the first study in Sudan that identified blaOXA-23 and blaOXA-51 in Staphylococcus aureus and correlated them to resistance to commonly used antimicrobials. Meropenem resistant Staphylococcus aureus were significantly positive for PVL, blaOXA-23 and baOXA-51 genes.
文摘Background: Urosepsis is one of the most common infections that require empirical broad spectrum antibiotics immediately after diagnosis. This has led to development of bacterial resistance by acquiring the capability to destroy the β-lactam ring. Methodology: This is a cross-sectional hospital-based study. The study was conducted from 2019 to 2020 at Gezira Hospital for Renal diseases and surgery (GHRDS). A hundred patients were diagnosed clinically with urosepsis and the isolated organisms were Escherichia coli, Staphylococcus aureus, Proteus mirabilis, Klebsiella pneumonia and Pseudomonas aeruginosa. The susceptibility test was conducted by Kirby Bauer disc diffusion technique according to clinical laboratory standard institute (CLSI) guidelines. Seventy eight samples of bacterial genomic DNA were confirmed by 16srRNA and multiplex PCR, were performed for genotypic blaOXA-51 and blaOXA-23 gene characterization of isolated bacteria. Then gel electrophoresis was used to identify the presence or absence of (blaOXA-51 and blaOXA-23) genes. Results: 88.5% (69/78) in 16srRNA detected. Using multiplex PCR, the frequencies of blaOXA-51 and blaOXA-23 genes were 13% and 10.1%, respectively. The percentages of isolates which yielded both blaOXA-51 and blaOXA-23 among P. aeruginosa was 25% (1/4), among K. pneumonia was 17% (1/6), and among E. coli was 8% (3/37). Only blaOXA-51 was detected in P. mirabilis 10% (1/10) and only blaOXA-23 was detected in S. aureus 5% (1/18). Conclusion: In this study, the presence of blaOXA-51 and blaOXA-23 genes was increased in the isolated bacteria.
