Etiologic identification and drug susceptibility analysis of a Citrobacter freundii food poisoning event / 中国热带医学

ABSTRACT

@#Abstract Objective　In order to provide reference for emergency treatment of a sudden food poisoning incident, pathogen detection and drug resistance analysis were carried out. Methods　Diarrheal stool and surplus food samples were detected by GB 4789 and the isolates were identified by VITEK2 and matrix assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS), at the same time, the bacterial drug sensitivity test was carried out by using the method of microbroth dilution, and the isolates from different sources were molecularly classified by pulsed field gel electrophoresis (PFGE), and the correlation between the strains was analyzed by BioNumerics software. Results　Totaly 13 leftovers and 3 diarrhea patients were isolated and identified, The total number of colonies and coliforms in 7 leftovers samples all exceeded the standard, and Citrobacter freundii was detected in 5 leftovers and 2 stools. The results of drug sensitivity test showed that seven strains of Citrobacter freundii were sensitive to ciprofloxacin, tetracycline, chloramphenicol, gentamicin, amikacin, cefotaxime and meropenem, but completely resistant to ampicillin, and there was no multiple drug resistance. The results of pulsed field gel electrophoresis (PFGE) showed that 7 strains of Citrobacter freundii had the same PFGE bands and 100% homology, showing the same clone. Conclusions　This food poisoning incident was caused by Citrobacter freundii. The pathogen of food poisoning can be quickly and accurately determined by MALDI-TOF MS, which is beneficial to the early diagnosis and treatment of infectious diseases. It is suggested to strengthen the corresponding management, improve food safety awareness and prevent similar incidents.