title: Emergence of clinical Salmonella enterica serovar Typhimurium isolates with concurrent resistance to ciprofloxacin, ceftriaxone, and azithromycin.
abstract: Salmonella infection is an important public health issue for which the needs of antimicrobial treatment are increasing. A total of 546 human clinical S. enterica serovar Typhimurium isolates were recovered from patients in hospitals in China during the period of 2005 to ∼ 2011. Twenty percent of the isolates exhibited resistance to ciprofloxacin, and 4% were resistant to ceftriaxone. Importantly, for the first time, 12 (2%) S. Typhimurium isolates resistant to both ciprofloxacin and ceftriaxone were recovered; among these 12 isolates, two were also resistant to azithromycin, and one was resistant to all other drugs tested. The combined effects of various transferrable extended-spectrum β-lactamase determinants and a novel efflux-based ciprofloxacin resistance mechanism encoded by the mobile efflux gene oqxAB were responsible for the emergence of these extremely (highly) drug-resistant (XDR) S. Typhimurium isolates. The dissemination of resistance genes, such as those encoding ESBLs and the OqxAB pump, among Salmonella organisms will speed up the selection of XDR Salmonella, posing a huge threat to public health and Salmonella infection control.
authors.affiliation: Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, SAR Food Safety and Technology Research Center, Hong Kong PolyU Shenzhen Research Institute, Shenzhen, People's Republic of China.
authors.forename: Marcus Ho Yin
authors.initials: MH
authors.lastname: Wong
authors.affiliation: State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention (ICDC), Chinese Center for Disease Control and Prevention, Beijing, People's Republic of China.
authors.forename: Meiying
authors.initials: M
authors.lastname: Yan
authors.affiliation: Department of Microbiology, The Chinese University of Hong Kong, The Prince of Wales Hospital, Shatin, New Territories, Hong Kong, SAR.
authors.forename: Edward Wai Chi
authors.initials: EW
authors.lastname: Chan
authors.affiliation: State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention (ICDC), Chinese Center for Disease Control and Prevention, Beijing, People's Republic of China.
authors.forename: Kan
authors.initials: K
authors.lastname: Biao
authors.affiliation: Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, SAR Food Safety and Technology Research Center, Hong Kong PolyU Shenzhen Research Institute, Shenzhen, People's Republic of China sheng.chen@polyu.edu.hk.
authors.forename: Sheng
authors.initials: S
authors.lastname: Chen
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D017963:Azithromycin / Q000494:pharmacology*; D002443:Ceftriaxone / Q000494:pharmacology*; D002939:Ciprofloxacin / Q000494:pharmacology*; D003227:Conjugation, Genetic; D024901:Drug Resistance, Multiple, Bacterial / Q000187:drug effects / Q000235:genetics*; D006801:Humans; D008826:Microbial Sensitivity Tests; D009154:Mutation / Q000235:genetics; D012480:Salmonella Infections / Q000382:microbiology*; D012486:Salmonella typhimurium / Q000187:drug effects* / Q000235:genetics
chemical_list: D000900:Anti-Bacterial Agents; D002939:Ciprofloxacin; D002443:Ceftriaxone; D017963:Azithromycin
references.citation: J Bacteriol. 2008 Dec;190(24):8155-62
references.pmid: 18849424
references.citation: Antimicrob Agents Chemother. 2006 Sep;50(9):3203-6
references.pmid: 16940132
references.citation: N Engl J Med. 2001 Oct 18;345(16):1147-54
references.pmid: 11642230
references.citation: Int J Antimicrob Agents. 2012 Apr;39(4):305-10
references.pmid: 22325120
references.citation: Clin Microbiol Infect. 2011 Nov;17(11):1740-5
references.pmid: 21375663
references.citation: J Antimicrob Chemother. 2013 Oct;68(10):2263-8
references.pmid: 23737490
references.citation: Emerg Infect Dis. 2011 Jun;17(6):1086-90
references.pmid: 21749777
references.citation: Foodborne Pathog Dis. 2006 Spring;3(1):59-67
references.pmid: 16602980
references.citation: J Antimicrob Chemother. 2010 Oct;65(10):2097-100
references.pmid: 20685754
references.citation: Foodborne Pathog Dis. 2013 Jan;10(1):42-6
references.pmid: 23320422
references.citation: Antimicrob Agents Chemother. 2011 Sep;55(9):3985-9
references.pmid: 21690279
references.citation: Antimicrob Agents Chemother. 2013 Sep;57(9):4599-4601
references.pmid: 23796940
references.citation: J Antimicrob Chemother. 2011 Sep;66(9):2028-32
references.pmid: 21697179
references.citation: J Infect Dev Ctries. 2011 Jul 04;5(6):496-8
references.pmid: 21727652
references.citation: J Antimicrob Chemother. 2004 Aug;54(2):429-34
references.pmid: 15243023
references.citation: J Microbiol Methods. 2005 Dec;63(3):219-28
references.pmid: 15935499
references.citation: Antimicrob Agents Chemother. 2013 Jan;57(1):658-60
references.pmid: 23147728
references.citation: J Antimicrob Chemother. 2009 Oct;64(4):723-30
references.pmid: 19638354
references.citation: J Antimicrob Chemother. 2012 Oct;67(10):2350-3
references.pmid: 22809702
references.citation: Avian Pathol. 2013;42(3):221-9
references.pmid: 23607509
references.citation: J Antimicrob Chemother. 2005 Jul;56(1):115-21
references.pmid: 15941775
references.citation: Lancet Infect Dis. 2013 Aug;13(8):672-9
references.pmid: 23721756
references.citation: Emerg Infect Dis. 2001 Mar-Apr;7(2):337-41
references.pmid: 11294736
references.citation: J Clin Microbiol. 2005 Mar;43(3):1037-44
references.pmid: 15750057
references.citation: Antimicrob Agents Chemother. 2003 Feb;47(2):559-62
references.pmid: 12543659
references.citation: Antimicrob Agents Chemother. 2007 Feb;51(2):535-42
references.pmid: 17043131
references.citation: N Engl J Med. 1998 May 7;338(19):1333-8
references.pmid: 9571252
references.citation: J Clin Microbiol. 2013 Jan;51(1):284-6
references.pmid: 23077128