title: Outbreak of PER-1 and diversity of β-lactamases among ceftazidime-resistant Pseudomonas aeruginosa clinical isolates.
abstract: A growing number of β-lactamases have been reported in Pseudomonas aeruginosa clinical isolates. The aim of this study was to investigate the diversity of β-lactamases in the collection of 51 ceftazidime-resistant P. aeruginosa clinical isolates in four hospitals of southern China. Among these isolates, variable degrees of resistance to other β-lactam and non-β-lactam agents were observed. Pulsed-field gel electrophoresis (PFGE) revealed a high degree of clonality with five main genotypes. Of the 51 isolates tested, 35 (68.6%) were identified as extended-spectrum β-lactamase (ESBL) producers, with 35 producing PER-1, 1 CTX-M-3, 7 CTX-M-15 and 1 CTX-M-14. Most (82.9%, 29/35) PER-1-producing isolates were collected from two hospitals between January and April in 2008 and belonged to the same PFGE pattern (pattern B) with similar antibiogram and β-lactamase profiles, which suggested an outbreak of this clone at the time. The prevalence of CTX-M-type ESBL (17.6%, 9/51) was unexpectedly high. One isolate was identified as producing VIM-2. Furthermore, we also reported an occurrence of a novel OXA-10 variant, OXA-246, in 14 P. aeruginosa isolates. In addition, AmpC overproduction was found to be the β-lactamase-mediated mechanism responsible for ceftazidime resistance in 6 isolates (11.8%). Our results revealed an overall diversity of β-lactamases and outbreak of a PER-1-producing clone among ceftazidime-resistant P. aeruginosa in southern China.
authors.affiliation: Department of Immunology, Institute of Human Virology, Zhongshan School of Medicine, Sun Yat-sen University, 74 Zhongshan 2nd Road, Guangzhou 510080, PR China.|State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510060, PR China.|Key Laboratory of Tropical Diseases Control (Sun Yat-sen University), Ministry of Education, Guangzhou 510080, PR China.
authors.forename: Yun
authors.initials: Y
authors.lastname: Qing
authors.affiliation: Department of Microbiology, Zhongshan School of Medicine, Sun Yat-sen University, 74 Zhongshan 2nd Road, Guangzhou 510080, PR China.
authors.forename: Kai-Yuan
authors.initials: KY
authors.lastname: Cao
authors.affiliation: Key Laboratory of Tropical Diseases Control (Sun Yat-sen University), Ministry of Education, Guangzhou 510080, PR China.|State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510060, PR China.|Department of Immunology, Institute of Human Virology, Zhongshan School of Medicine, Sun Yat-sen University, 74 Zhongshan 2nd Road, Guangzhou 510080, PR China.
authors.forename: Zhi-Li
authors.initials: ZL
authors.lastname: Fang
authors.affiliation: Key Laboratory of Tropical Diseases Control (Sun Yat-sen University), Ministry of Education, Guangzhou 510080, PR China.|State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510060, PR China.|Department of Immunology, Institute of Human Virology, Zhongshan School of Medicine, Sun Yat-sen University, 74 Zhongshan 2nd Road, Guangzhou 510080, PR China.
authors.forename: Ying-Min
authors.initials: YM
authors.lastname: Huang
authors.affiliation: Key Laboratory of Tropical Diseases Control (Sun Yat-sen University), Ministry of Education, Guangzhou 510080, PR China.|Department of Immunology, Institute of Human Virology, Zhongshan School of Medicine, Sun Yat-sen University, 74 Zhongshan 2nd Road, Guangzhou 510080, PR China.
authors.forename: Xue-Fei
authors.initials: XF
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Tropical Diseases Control (Sun Yat-sen University), Ministry of Education, Guangzhou 510080, PR China.|Department of Immunology, Institute of Human Virology, Zhongshan School of Medicine, Sun Yat-sen University, 74 Zhongshan 2nd Road, Guangzhou 510080, PR China.
authors.forename: Guo-Bao
authors.initials: GB
authors.lastname: Tian
authors.affiliation: Key Laboratory of Tropical Diseases Control (Sun Yat-sen University), Ministry of Education, Guangzhou 510080, PR China.|State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510060, PR China.|Department of Immunology, Institute of Human Virology, Zhongshan School of Medicine, Sun Yat-sen University, 74 Zhongshan 2nd Road, Guangzhou 510080, PR China.
authors.forename: Xi
authors.initials: X
authors.lastname: Huang
mesh_terms: D000890:Anti-Infective Agents / Q000494:pharmacology*; D001426:Bacterial Proteins / Q000235:genetics / Q000302:isolation & purification; D015373:Bacterial Typing Techniques; D001483:Base Sequence; D002442:Ceftazidime / Q000494:pharmacology*; D002681:China / Q000453:epidemiology; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004196:Disease Outbreaks; D016521:Electrophoresis, Gel, Pulsed-Field; D014644:Genetic Variation; D005838:Genotype; D006801:Humans; D008826:Microbial Sensitivity Tests; D008969:Molecular Sequence Data; D010641:Phenotype; D011552:Pseudomonas Infections / Q000453:epidemiology / Q000382:microbiology*; D011550:Pseudomonas aeruginosa / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics; D017422:Sequence Analysis, DNA; D018440:beta-Lactam Resistance; D001618:beta-Lactamases / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism
chemical_list: D000890:Anti-Infective Agents; D001426:Bacterial Proteins; D004269:DNA, Bacterial; D002442:Ceftazidime; C425107:beta-lactamase OXA-10; C108863:beta-lactamase PER-1; C048795:AmpC beta-lactamases; D001618:beta-Lactamases