Background In the present study, we characterized multidrug-resistant Pseudomonas aeruginosa （MDRP） clinical isolates from a paediatric facility and investigated the types and features of the metallo-β-lactamases ...Background In the present study, we characterized multidrug-resistant Pseudomonas aeruginosa （MDRP） clinical isolates from a paediatric facility and investigated the types and features of the metallo-β-lactamases （MBLs） produced by carbapenem-resistant strains. Methods Four hundred and ninety-eight strains of Pseudomonas aeruginosa were isolated from patients at Beijing Children＇s Hospital between January 2005 and December 2006. The minimal inhibition concentrations （MICs） of the strains for 13 antibiotics were measured. A combination of the E test and PCR amplification/DNA sequencing was used to define the carbapenem-resistant strains. Results We found that 24.1% （120/498） of the isolates were MDRP. The frequencies of resistance to imipenem and meropenem were 34.2% and 35.8%, respectively, and the MIC50 and MIC90values for the two antibiotics were identical at 4 pg/ml and 32 pg/ml, respectively. The detection rate for carbapenem resistance was 49.2% （59/120）. Among the 59 carbapenem-resistant Pseudomonas aeruginosa strains, 39 （66.1%） were positive for the MBL genotype; 35 （89.7%） strains carried the blaiMp gene and 4 （10.3%） strains carried the blavm gene. Neither blasPM nor blaGiM was amplified from any of the 59 isolates. DNA sequencing revealed that IMP-1 was present in 35 IMP-producing isolates and VIM-2 was detected in four VIM-producing isolates. Conclusions These MDRP isolates exhibited high frequencies of resistance to carbapenems among clinical isolates from a paediatric facility in Beijing, China. The production of MBL appears to be an important mechanism for carbapenem resistance in Pseudomonas aeruginosa.展开更多
Background:Acinetobacter baumannii(A.baumannii)is known as an opportunistic pathogen related to health-care-associated infection that has a high antibiotic resistance potential,notably against carbapenems that are wid...Background:Acinetobacter baumannii(A.baumannii)is known as an opportunistic pathogen related to health-care-associated infection that has a high antibiotic resistance potential,notably against carbapenems that are widely used to combat A.baumannii infections.This study aimed to detect oxacillin-hydrolyzing(OXA)carbapenemases and metallo-β-lactamases(MBL)among carbapenem-resistant A.baumannii isolated strains and to determine their clonal relationship by repetitive extragenic palindromic PCR(rep-PCR).Methods:In the present study,a total of 211 non-repetitive isolates of A.baumannii were collected from Qazvin educational hospitals(2016–2017).The disk diffusion method was used to investigate the antibiotic susceptibility of studied strains,followed by the detection of MBL and OXA-type genes using polymerase chain reaction(PCR)and sequencing methods.The rep-PCR method assessed the clonal relationship of carbapenem-non-susceptible A.baumannii isolates.Result:The obtained results showed that 87.2%and 86.7%of isolates were non-susceptible to imipenem and meropenem.The blaOXA-24(93.5%)was the most frequent gene,followed by the blaOXA-23(4.34%),blaIMP-1(1.63%),and blaVIM-1(0.54%).Meanwhile,blaOXA-58 and blaOXA-143 genes were not found.81.5%and 66.1%of isolates contained ISAba1 upstream of the blaOXA-23 and blaOXA-58 genes,respectively.Rep-PCR results revealed the carbapenem non-susceptible isolates belonged to three distinct clones:A 171(81%),B 34(16.1%),and C 6(2.8%).Conclusions:The results indicated a high prevalence of carbapenem-non-susceptible A.baumannii,with the emergence of the blaOXA-24 gene as the most common gene and the notable prevalence of MBL genes.These results revealed the need for appropriate therapeutic and infection control strategies and monitoring susceptibility patterns for controlling A.baumannii infections.展开更多
文摘Background In the present study, we characterized multidrug-resistant Pseudomonas aeruginosa （MDRP） clinical isolates from a paediatric facility and investigated the types and features of the metallo-β-lactamases （MBLs） produced by carbapenem-resistant strains. Methods Four hundred and ninety-eight strains of Pseudomonas aeruginosa were isolated from patients at Beijing Children＇s Hospital between January 2005 and December 2006. The minimal inhibition concentrations （MICs） of the strains for 13 antibiotics were measured. A combination of the E test and PCR amplification/DNA sequencing was used to define the carbapenem-resistant strains. Results We found that 24.1% （120/498） of the isolates were MDRP. The frequencies of resistance to imipenem and meropenem were 34.2% and 35.8%, respectively, and the MIC50 and MIC90values for the two antibiotics were identical at 4 pg/ml and 32 pg/ml, respectively. The detection rate for carbapenem resistance was 49.2% （59/120）. Among the 59 carbapenem-resistant Pseudomonas aeruginosa strains, 39 （66.1%） were positive for the MBL genotype; 35 （89.7%） strains carried the blaiMp gene and 4 （10.3%） strains carried the blavm gene. Neither blasPM nor blaGiM was amplified from any of the 59 isolates. DNA sequencing revealed that IMP-1 was present in 35 IMP-producing isolates and VIM-2 was detected in four VIM-producing isolates. Conclusions These MDRP isolates exhibited high frequencies of resistance to carbapenems among clinical isolates from a paediatric facility in Beijing, China. The production of MBL appears to be an important mechanism for carbapenem resistance in Pseudomonas aeruginosa.
基金Qazvin University of Medical Sciences for supporting the project(Grant number:10016).
文摘Background:Acinetobacter baumannii(A.baumannii)is known as an opportunistic pathogen related to health-care-associated infection that has a high antibiotic resistance potential,notably against carbapenems that are widely used to combat A.baumannii infections.This study aimed to detect oxacillin-hydrolyzing(OXA)carbapenemases and metallo-β-lactamases(MBL)among carbapenem-resistant A.baumannii isolated strains and to determine their clonal relationship by repetitive extragenic palindromic PCR(rep-PCR).Methods:In the present study,a total of 211 non-repetitive isolates of A.baumannii were collected from Qazvin educational hospitals(2016–2017).The disk diffusion method was used to investigate the antibiotic susceptibility of studied strains,followed by the detection of MBL and OXA-type genes using polymerase chain reaction(PCR)and sequencing methods.The rep-PCR method assessed the clonal relationship of carbapenem-non-susceptible A.baumannii isolates.Result:The obtained results showed that 87.2%and 86.7%of isolates were non-susceptible to imipenem and meropenem.The blaOXA-24(93.5%)was the most frequent gene,followed by the blaOXA-23(4.34%),blaIMP-1(1.63%),and blaVIM-1(0.54%).Meanwhile,blaOXA-58 and blaOXA-143 genes were not found.81.5%and 66.1%of isolates contained ISAba1 upstream of the blaOXA-23 and blaOXA-58 genes,respectively.Rep-PCR results revealed the carbapenem non-susceptible isolates belonged to three distinct clones:A 171(81%),B 34(16.1%),and C 6(2.8%).Conclusions:The results indicated a high prevalence of carbapenem-non-susceptible A.baumannii,with the emergence of the blaOXA-24 gene as the most common gene and the notable prevalence of MBL genes.These results revealed the need for appropriate therapeutic and infection control strategies and monitoring susceptibility patterns for controlling A.baumannii infections.
