Abstract
ObjectivesThis prospective study was carried out to investigate molecular characteristics and antimicrobial susceptibility patterns of Citrobacter spp. from extraintestinal infections.MethodsForty-six clinical Citrobacter spp. isolates were isolated from hospital patients with extraintestinal infections and analyzed by multilocus sequence typing (MLST) using seven housekeeping genes. Antimicrobial susceptibility testing was performed by disk diffusion method according to the Clinical and Laboratory Standards Institute (CLSI) recommendations. Adhesion and cytotoxicity to HEp-2 cells were assessed.ResultsThe 46 clinical Citrobacter spp. isolates were typed into 38 sequence types (STs), 9 of which belonged to four clonal complexes (CCs). None of the isolates shared the same ST or CCs with isolates from other countries or from other parts of China. Over half of the isolates were multidrug-resistant (MDR), with 17/26 C. freundii, 5/6 C. braakii, and 3/14 C. koseri isolates being MDR. Moreover, four isolates were carbapenem resistant with resistance to imipenem or meropenem. Among eight quinolone resistant C. freundii, all had a mutation in codon 59 (Thr59Ile) in quinolone resistance determining region of the gyrA gene. Only a small proportion of the isolates were found to be highly cytotoxic and adhesive with no correlation to sample sources.ConclusionsThere was a diverse range of Citrobacter isolates causing extraintestinal infections and a high prevalence of MDR.
Highlights
Citrobacter spp. are facultative anaerobic Gram negative bacteria within the family Enterobacteriaceae
The 46 clinical Citrobacter spp. isolates were typed into 38 sequence types (STs), 9 of which belonged to four clonal complexes (CCs)
Among eight quinolone resistant C. freundii, all had a mutation in codon 59 (Thr59Ile) in quinolone resistance determining region of the gyrA gene
Summary
Citrobacter spp. are facultative anaerobic Gram negative bacteria within the family Enterobacteriaceae. MDR Citrobacter spp. with production of b-lactamase (Amp-C), broad-spectrum b-lactamase, extended-spectrum blactamase (ESBL), or even carbapenemase has been reported by several international surveillance programs (Wang et al, 2000; Mohanty et al, 2007; Zhang et al, 2008; Samonis et al, 2009; Kanamori et al, 2011; Lee et al, 2015; Liu et al, 2018b). Fluoroquinolone resistance is associated with mutations in gyrA and parC genes (Minarini and Darini, 2012). Mutations in gyrA were found in fluoroquinolone resistant C. freundii isolates (Weigel et al, 1998; Minarini and Darini, 2012)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
