Wei-Chiun Yang1, Oi-Wa Chan1, Tsu-Lan Wu2, Chyi-Liang Chen3, Lin-Hui Su4, Cheng-Hsun Chiu5. 1. Division of Pediatric Gastroenterology, Department of Pediatrics, Chang Gung Children's Hospital, Chang Gung University College of Medicine, Taoyuan, Taiwan. 2. Department of Laboratory Medicine, Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Taoyuan, Taiwan. 3. Molecular Infectious Disease Research Centre, Chang Gung Memorial Hospital, Taoyuan, Taiwan. 4. Department of Laboratory Medicine, Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Taoyuan, Taiwan; Molecular Infectious Disease Research Centre, Chang Gung Memorial Hospital, Taoyuan, Taiwan; Department of Medical Biotechnology and Laboratory Science, Chang Gung University College of Medicine, Taoyuan, Taiwan. Electronic address: sulinhui@gmail.com. 5. Molecular Infectious Disease Research Centre, Chang Gung Memorial Hospital, Taoyuan, Taiwan; Division of Pediatric Infectious Diseases, Department of Pediatrics, Chang Gung Children's Hospital, Chang Gung University College of Medicine, Taoyuan, Taiwan. Electronic address: chchiu@adm.cgmh.org.tw.
Abstract
BACKGROUND: The majority of nontyphoid Salmonella infection is identified in children. When an invasive or severe Salmonella infection is encountered, ceftriaxone is recommended for such patients. A 2-year-old girl was hospitalized for the treatment of Salmonella bacteremia and discharged with standard ceftriaxone treatment. She was readmitted to the hospital after 2 days due to the recurrence of the Salmonella bacteremia. The study aimed to unveil the mechanism for the relapse. METHODS: Six isolates (4 blood and 2 stool) were recovered from the patient, with the last two blood isolates being ceftriaxone-resistant. Pulsed-field gel electrophoresis was used for genotyping. Ceftriaxone resistance genes and transferability of the resistance plasmid were examined by molecular methods. RESULTS: All isolates were identified as Salmonella enterica serotype Oranienburg. Five isolates demonstrated almost identical electrophoresis patterns, except that in the two ceftriaxone-resistant isolates an extra band (>100 kb) was noted. A blaCMY-2 gene, carried by a 120-kb conjugative IncI1 plasmid of the sequence type 53, was identified in the two ceftriaxone-resistant isolates. Transfer of the resistance plasmid from one blood isolate to Escherichia coli J53 resulted in the increase of ceftriaxone minimum inhibitory concentration from 0.125 μg/mL to 32 μg/mL in the recipient. CONCLUSION: Ceftriaxone is the standard therapeutic choice for invasive or serious Salmonella infections in children. Pediatricians should be aware of the possibility of resistance development during therapy, especially in areas with a widespread of ceftriaxone resistance genes that are carried by a self-transferrable plasmid, such as the blaCMY-2-carrying IncI1 plasmid identified herein.
BACKGROUND: The majority of nontyphoid Salmonella infection is identified in children. When an invasive or severe Salmonella infection is encountered, ceftriaxone is recommended for such patients. A 2-year-old girl was hospitalized for the treatment of Salmonella bacteremia and discharged with standard ceftriaxone treatment. She was readmitted to the hospital after 2 days due to the recurrence of the Salmonella bacteremia. The study aimed to unveil the mechanism for the relapse. METHODS: Six isolates (4 blood and 2 stool) were recovered from the patient, with the last two blood isolates being ceftriaxone-resistant. Pulsed-field gel electrophoresis was used for genotyping. Ceftriaxone resistance genes and transferability of the resistance plasmid were examined by molecular methods. RESULTS: All isolates were identified as Salmonella enterica serotype Oranienburg. Five isolates demonstrated almost identical electrophoresis patterns, except that in the two ceftriaxone-resistant isolates an extra band (>100 kb) was noted. A blaCMY-2 gene, carried by a 120-kb conjugative IncI1 plasmid of the sequence type 53, was identified in the two ceftriaxone-resistant isolates. Transfer of the resistance plasmid from one blood isolate to Escherichia coli J53 resulted in the increase of ceftriaxone minimum inhibitory concentration from 0.125 μg/mL to 32 μg/mL in the recipient. CONCLUSION:Ceftriaxone is the standard therapeutic choice for invasive or serious Salmonella infections in children. Pediatricians should be aware of the possibility of resistance development during therapy, especially in areas with a widespread of ceftriaxone resistance genes that are carried by a self-transferrable plasmid, such as the blaCMY-2-carrying IncI1 plasmid identified herein.
Authors: Bruce McCollister; Cassandra V Kotter; Daniel N Frank; Taylor Washburn; Michael G Jobling Journal: Antimicrob Agents Chemother Date: 2016-11-21 Impact factor: 5.191
Authors: Arif M Tanmoy; Emilie Westeel; Katrien De Bruyne; Johan Goris; Alain Rajoharison; Mohammad S I Sajib; Alex van Belkum; Samir K Saha; Florence Komurian-Pradel; Hubert P Endtz Journal: mBio Date: 2018-11-13 Impact factor: 7.867