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Prevalence and Characterization of Integrons in Multidrug Resistant Acinetobacter baumannii in Eastern China: A Multiple-Hospital Study.

Chen J, Li H, Yang J, Zhan R, Chen A, Yan Y - Int J Environ Res Public Health (2015)

Bottom Line: The prevalence of resistance to ampicillin/sulbactam, piperacillin/tazobactam, ceftazidime, ceftriaxone, cefepime, aztreonam, imipenem, meropenem, amikacin, gentamicin, tobramycin, ciprofloxacin, levofloxacin and sulfamethoxazole/trimenthoprim was significantly higher in integron-positive A. baumannii isolates than in negative isolates (all p values <0.05), while no significant difference was observed in the prevalence of minocycline resistance (p > 0.05).The results of this study demonstrate a high prevalence of class 1 integrons in MDRAB in Eastern China, and a greater prevalence of antimicrobial resistance in intI1 gene-positive MDRAB isolates than in negative isolates.The gene cassette dfrXII-orfF-aadA2 is reported, for the first time, in A. baumannii strains isolated from Fujian Province, Eastern China.

View Article: PubMed Central - PubMed

Affiliation: Fujian Medical University Union Hospital, No. 29 Xinquan Road, Fuzhou 350001, China. jingchen389@126.com.

ABSTRACT

Objective: The aim of this multiple-hospital study was to investigate the prevalence of integrons in multidrug-resistant Acinetobacter baumannii (MDRAB) in Eastern China, and characterize the integron-integrase genes, so as to provide evidence for the management and appropriate antibiotic use of MDRAB infections.

Methods: A total of 425 clinical isolates of A. baumannii were collected from 16 tertiary hospitals in 11 cities of four provinces (Fujian, Jiangsu, Zhejiang and Shandong) from January 2009 to June 2012. The susceptibility of A. baumannii isolates to ampicillin/sulbactam, piperacillin/tazobactam, ceftazidime, ceftriaxone, cefepime, aztreonam, meropenem, amikacin, gentamicin, tobramycin, ciprofloxacin, levofloxacin, sulfamethoxazole/trimenthoprim, minocycline and imipenem was tested, and integrons and their gene cassettes were characterized in these isolates using PCR assay. In addition, integron-positive A. baumannii isolates were genotyped using pulsed-field gel electrophoresis (PFGE) assay, and intI1 gene cassette was sequenced.

Results: intI1 gene was carried in 69.6% of total A. baumannii isolates, while intI2 and intI3 genes were not detected. The prevalence of resistance to ampicillin/sulbactam, piperacillin/tazobactam, ceftazidime, ceftriaxone, cefepime, aztreonam, imipenem, meropenem, amikacin, gentamicin, tobramycin, ciprofloxacin, levofloxacin and sulfamethoxazole/trimenthoprim was significantly higher in integron-positive A. baumannii isolates than in negative isolates (all p values <0.05), while no significant difference was observed in the prevalence of minocycline resistance (p > 0.05). PFGE assay revealed 27 PFGE genotypes and 4 predominant genotypes, P1, P4, P7 and P19. The PFGE genotype P1 contained 13 extensive-drug resistant and 89 non-extensive-drug resistant A. baumannii isolates, while the genotype P4 contained 34 extensive-drug resistant and 67 non-extensive-drug resistant isolates, appearing a significant antimicrobial resistance pattern (both p values <0.05). Sequencing analysis revealed two gene cassette assays of aacA4-catB8-aadA1 and dfrXII-orfF-aadA2 in MDRAB isolates.

Conclusions: The results of this study demonstrate a high prevalence of class 1 integrons in MDRAB in Eastern China, and a greater prevalence of antimicrobial resistance in intI1 gene-positive MDRAB isolates than in negative isolates. Four predominant PFGE genotypes are identified in intI1 gene-positive MDRAB isolates, in which P4 is an epidemic PFGE genotype in Fujian Province, and it has a high proportion of extensive drug resistant A. baumannii. The gene cassette dfrXII-orfF-aadA2 is reported, for the first time, in A. baumannii strains isolated from Fujian Province, Eastern China.

No MeSH data available.


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Distribution of A. baumannii isolates with PFGE genotype P4.
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ijerph-12-10093-f004: Distribution of A. baumannii isolates with PFGE genotype P4.

Mentions: The intI1 gene was detected in the clinical strains of A. baumannii isolated from 15 hospitals. The PFGE genotype P1, which contained 102 A. baumannii isolates, was detected in the A. baumannii strains isolated from hospitals A (48%) and J (43.1%) (Figure 3). The PFGE genotype P4, which contained 101 A. baumannii isolates, was found in the A. baumannii strains isolated from four hospitals in two cities (Figure 4), 96% of which was detected in the A. baumannii strains isolated from A hospital. The PFGE genotype P7, which contained 25 A. baumannii isolates, was prevalent in the A. baumannii strains isolated from four hospitals in three cities (Figure 5), 64% of which was detected in the A. baumannii strains isolated from hospital E. The PFGE genotype P9 contained 10 A. baumannii strains, which were isolated from hospitals A (seven isolates), I (two isolates) and D (one isolate).


Prevalence and Characterization of Integrons in Multidrug Resistant Acinetobacter baumannii in Eastern China: A Multiple-Hospital Study.

Chen J, Li H, Yang J, Zhan R, Chen A, Yan Y - Int J Environ Res Public Health (2015)

Distribution of A. baumannii isolates with PFGE genotype P4.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4555331&req=5

ijerph-12-10093-f004: Distribution of A. baumannii isolates with PFGE genotype P4.
Mentions: The intI1 gene was detected in the clinical strains of A. baumannii isolated from 15 hospitals. The PFGE genotype P1, which contained 102 A. baumannii isolates, was detected in the A. baumannii strains isolated from hospitals A (48%) and J (43.1%) (Figure 3). The PFGE genotype P4, which contained 101 A. baumannii isolates, was found in the A. baumannii strains isolated from four hospitals in two cities (Figure 4), 96% of which was detected in the A. baumannii strains isolated from A hospital. The PFGE genotype P7, which contained 25 A. baumannii isolates, was prevalent in the A. baumannii strains isolated from four hospitals in three cities (Figure 5), 64% of which was detected in the A. baumannii strains isolated from hospital E. The PFGE genotype P9 contained 10 A. baumannii strains, which were isolated from hospitals A (seven isolates), I (two isolates) and D (one isolate).

Bottom Line: The prevalence of resistance to ampicillin/sulbactam, piperacillin/tazobactam, ceftazidime, ceftriaxone, cefepime, aztreonam, imipenem, meropenem, amikacin, gentamicin, tobramycin, ciprofloxacin, levofloxacin and sulfamethoxazole/trimenthoprim was significantly higher in integron-positive A. baumannii isolates than in negative isolates (all p values <0.05), while no significant difference was observed in the prevalence of minocycline resistance (p > 0.05).The results of this study demonstrate a high prevalence of class 1 integrons in MDRAB in Eastern China, and a greater prevalence of antimicrobial resistance in intI1 gene-positive MDRAB isolates than in negative isolates.The gene cassette dfrXII-orfF-aadA2 is reported, for the first time, in A. baumannii strains isolated from Fujian Province, Eastern China.

View Article: PubMed Central - PubMed

Affiliation: Fujian Medical University Union Hospital, No. 29 Xinquan Road, Fuzhou 350001, China. jingchen389@126.com.

ABSTRACT

Objective: The aim of this multiple-hospital study was to investigate the prevalence of integrons in multidrug-resistant Acinetobacter baumannii (MDRAB) in Eastern China, and characterize the integron-integrase genes, so as to provide evidence for the management and appropriate antibiotic use of MDRAB infections.

Methods: A total of 425 clinical isolates of A. baumannii were collected from 16 tertiary hospitals in 11 cities of four provinces (Fujian, Jiangsu, Zhejiang and Shandong) from January 2009 to June 2012. The susceptibility of A. baumannii isolates to ampicillin/sulbactam, piperacillin/tazobactam, ceftazidime, ceftriaxone, cefepime, aztreonam, meropenem, amikacin, gentamicin, tobramycin, ciprofloxacin, levofloxacin, sulfamethoxazole/trimenthoprim, minocycline and imipenem was tested, and integrons and their gene cassettes were characterized in these isolates using PCR assay. In addition, integron-positive A. baumannii isolates were genotyped using pulsed-field gel electrophoresis (PFGE) assay, and intI1 gene cassette was sequenced.

Results: intI1 gene was carried in 69.6% of total A. baumannii isolates, while intI2 and intI3 genes were not detected. The prevalence of resistance to ampicillin/sulbactam, piperacillin/tazobactam, ceftazidime, ceftriaxone, cefepime, aztreonam, imipenem, meropenem, amikacin, gentamicin, tobramycin, ciprofloxacin, levofloxacin and sulfamethoxazole/trimenthoprim was significantly higher in integron-positive A. baumannii isolates than in negative isolates (all p values <0.05), while no significant difference was observed in the prevalence of minocycline resistance (p > 0.05). PFGE assay revealed 27 PFGE genotypes and 4 predominant genotypes, P1, P4, P7 and P19. The PFGE genotype P1 contained 13 extensive-drug resistant and 89 non-extensive-drug resistant A. baumannii isolates, while the genotype P4 contained 34 extensive-drug resistant and 67 non-extensive-drug resistant isolates, appearing a significant antimicrobial resistance pattern (both p values <0.05). Sequencing analysis revealed two gene cassette assays of aacA4-catB8-aadA1 and dfrXII-orfF-aadA2 in MDRAB isolates.

Conclusions: The results of this study demonstrate a high prevalence of class 1 integrons in MDRAB in Eastern China, and a greater prevalence of antimicrobial resistance in intI1 gene-positive MDRAB isolates than in negative isolates. Four predominant PFGE genotypes are identified in intI1 gene-positive MDRAB isolates, in which P4 is an epidemic PFGE genotype in Fujian Province, and it has a high proportion of extensive drug resistant A. baumannii. The gene cassette dfrXII-orfF-aadA2 is reported, for the first time, in A. baumannii strains isolated from Fujian Province, Eastern China.

No MeSH data available.


Related in: MedlinePlus