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ABSTRACT: Three kinds of PMQR determinants (qnr genes, aac(6')-Ib-cr, and qepA) have been discovered and shown to be widely distributed among clinical isolates. To characterize the prevalence of PMQR determinants in ESBL or AmpC-producing E. coli clinical isolates in Chinese children, a total of 292 ESBL or AmpC-producing E. coli clinical isolates collected from five children's hospitals in China from 2005 to 2006 were screened for PMQR determinants by PCR. Twenty (6.8%) of the 292 isolates were positive for PMQR determinants. A total of 12 (4.1%) isolates were positive for qnr genes, comprising three positive for qnrA (1.0%), three for qnrB (1.0%), and six for qnrS (2.1%). Twenty-four (8.2%) isolates were positive for aac(6')-Ib, of which 10 (3.4% of 292) had the -cr variant. There was no qepA gene detected in the isolates. Conjugation revealed that qnr, aac(6')-Ib-cr, and ESBL-encoding genes were transferred together.
Microbiology and Immunology 03/2010; 54(3):123-8. · 1.30 Impact Factor
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Lian Xue,
Kaihu Yao,
Guilin Xie,
Yuejie Zheng,
Chuanqing Wang,
Yunxiao Shang,
Huiyun Wang,
Liya Wan,
Lan Liu,
Changchong Li,
Wei Ji, Xiwei Xu,
Yating Wang,
Peiru Xu,
Zunjie Liu,
Sangjie Yu,
Yonghong Yang
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ABSTRACT: A total of 171 Streptococcus pneumoniae isolates causing invasive disease were isolated from Chinese children. The serotype distribution and antimicrobial resistance were tested. The results suggested that the 7-valent pneumococcal conjugate vaccine has a preventive effect among children and that there should be long-term surveillance for serotype 19A.
Clinical Infectious Diseases 03/2010; 50(5):741-4. · 9.15 Impact Factor
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ABSTRACT: Human astroviruses (HAstVs) have been recognized as one of the major causes of acute gastroenteritis in children. To provide more insight into the prevalence of HAstV gastroenteritis in China, 664 fecal samples were collected from children affected with acute gastroenteritis in Beijing from March 2005 to November 2007. The samples were analyzed genetically. All eight serotypes (genotypes) of HAstVs were screened using RT-PCR assays targeting the ORF2 region in the study. The assays detected HAstVs in 52 (7.8%) of the patients, with HAstV-1 (50/52) being the dominant genotype during the study period. Two minor genotypes, HAstV-6 and HAstV-3, were also detected. Partial sequencing of the 50 HAstV-1 strains showed that the homology of the nucleotide sequence of the ORF1a region between these strains was 88.4-100%, whereas the homology of the amino acid sequences was 95.6-100%. In the ORF2 partial region, the nucleotide identities ranged from 91.5% to 100%, and amino acid identities ranged from 97.3% to 100%. The identity of the whole genome sequence between four randomly examined HAstV-1 strains was 91-99%. No recombination events were observed in HAstVs in this study. The findings of this study will provide baseline data for HAstVs surveillance and control. J. Med. Virol. 82:415-423, 2010. (c) 2010 Wiley-Liss, Inc.
Journal of Medical Virology 03/2010; 82(3):415-23. · 2.82 Impact Factor
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ABSTRACT: To understand Saffold cardiovirus (SAFV) distribution, prevalence, and clinical relevance in China, we retrospectively studied SAFV in children with acute gastroenteritis and found SAFV in 12 (3.2%) of 373. Sequence homology of virus protein 1 genes suggested these strains belong to the SAFV-1 sublineage. SAFVs were found in samples positive for other diarrhea-causing viruses.
Emerging Infectious Diseases 09/2009; 15(9):1509-11. · 6.79 Impact Factor
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Emerging Infectious Diseases 02/2009; 15(1):134-5. · 6.79 Impact Factor
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ABSTRACT: Noroviruses (NoVs) are a major cause of acute gastroenteritis in children, but prevalence and circulation of NoVs in China have not been well characterized.
To determine the dominant circulating NoV genotypes and strains associated with pediatric cases of acute gastroenteritis in Beijing, China.
Fecal samples were obtained from 1126 children affected with acute gastroenteritis in Beijing from March 2004 to November 2007. NoV RNA was amplified, sequenced, and phylogenetically analyzed to determine the dominant circulating genotypes and strains.
NoVs were detected in 8.88% of patients, GII.4 being the dominant genotype. Ehime/05-30 was the dominant strain during 2004-2005, whereas 2006b dominated during 2006-2007. The homology of nucleotide and amino acid sequences among full-length VP1 of 15 randomly selected NoV strains was 91.6-99.6% and 94.5-99.6%, respectively. Recombination between NoV genotypes was frequent among the isolates.
The predominant circulating genotype of NoV infections in Beijing is GII.4, but the dominant strains of this virus responsible for gastroenteritis epidemics are evolving rapidly. A global surveillance network may be needed to identify trends in molecular evolution of NoVs for prevention of future epidemics.
Journal of Clinical Virology 01/2009; 44(1):94-8. · 3.97 Impact Factor
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Aihua Wang,
Yonghong Yang,
Quan Lu,
Yi Wang,
Yuan Chen,
Li Deng,
Hui Ding,
Qiulian Deng,
Hong Zhang,
Chuanqing Wang,
Lan Liu, Xiwei Xu,
Li Wang,
Xuzhuang Shen
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ABSTRACT: Quinolone resistance in Enterobacteriaceae results mainly from mutations in type II DNA topoisomerase genes and/or changes in the expression of outer membrane and efflux pumps. Several recent studies have indicated that plasmid-mediated resistance mechanisms also play a significant role in fluoroquinolone resistance, and its prevalence is increasing worldwide. In China, the presence of the qnr gene in the clinical isolates of Enterobacteriaceae has been reported, but this transmissible quinolone resistance gene has not been detected in strains isolated singly from pediatric patients. Because quinolones associated with a variety of adverse side effects on children, they are not authorized for pediatric use. This study therefore aimed to investigate the presence of the qnr gene in clinical isolates of E. coli and K. pneumoniae from pediatric patients in China.
A total 213 of non-repetitive clinical isolates resistant to ciprofloxacin from E. coli and K. pneumoniae were collected from hospitalized patients at five children's hospital in Beijing, Shanghai, Guangzhou, and Chongqing. The isolates were screened for the plasmid-mediated quinolone resistance genes of qnrA, qnrB, and qnrS by PCR. Transferability was examined by conjugation with the sodium azide-resistant E. coli J53. All qnr-positive were analyzed for clonality by enterobacterial repetitive intergenic consensus (ERIC)-PCR.
The study found that 19 ciprofloxacin-resistant clinical isolates of E. coli and K. pneumoniae were positive for the qnr gene, and most of the qnr positive strains were ESBL producers. Conjugation experiments showed that quinolone resitance could be transferred to recipients. Apart from this, different DNA banding patterns were obtained by ERIC-PCR from positive strains, which means that most of them were not clonally related.
This report on transferable fluoroquinolone resistance due to the qnr gene among E. coli and K. pneumoniae strains indicated that plasmid-mediated quinolone resistance has emerged in pediatric patients in China.
BMC Infectious Diseases 02/2008; 8:68. · 3.12 Impact Factor
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Hui Ding,
Yonghong Yang,
Quan Lu,
Yi Wang,
Yuan Chen,
Li Deng,
Aihua Wang,
Qiulian Deng,
Hong Zhang,
Chuanqing Wang,
Lan Liu, Xiwei Xu,
Li Wang,
Xuzhuang Shen
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ABSTRACT: In order to demonstrate antibiotic usage in Chinese Pediatric Intensive Care Units (PICUs), and provide some data to further study on relation of antimicrobial use and resistance. We reviewed the use of antibiotics in Chinese PICUs from 2002 to 2006. All data, including general data and antibiotic use data, were obtained from five PICUs of pediatric teaching hospitals in China. The results of antibiotic use were expressed as defined daily doses (DDDs) per 100 patient-days by WHO in this study. All 12 743 patients were included from the five PICUs in this study. Length of stay in PICUs was essentially unchanged, but the percentage of antimicrobial costs vs. drug costs dramatically decreased in this study period (p < 0.01). The percentage of empiric treatment decreased by year (from 82.2% to 70.2%). while the percentage of therapeutic treatment increased by year (from 11.2% to 24.2%) from 2002 to 2006. Total antibiotic usage decreased from 72.1 DDDs per 100 patient-days to 35.5 DDDs per 100 patient-days from 2002 to 2006 (p < 0.05). The significant increase was found in the DDDs per 100 patient-days of second generation cephalosporins in this study (p < 0.05). While usages of the some antibiotics decreased, for example penicillins, third-generation cephalosporins, and macrolides in this study period. The data of antimicrobial use were obtained from five PICUs of biggest pediatric teaching hospital in this 5-year period, which could serve as a basis of antibiotic treatment and a benchmark in future study of antibiotic use.
Journal of Tropical Pediatrics 02/2008; 54(4):238-42. · 1.39 Impact Factor
