Clinical Characteristics and Antimicrobial Susceptibility Trends inCitrobacterBacteremia: An 11-Year Single-Center Experience

Abstract

Background Recently, Citrobacter freundii bacteremia outbreak in a neonatal intensive care unit has attracted public attention in Korea. However, Citrobacter bacteremia is uncommon and usually occurs in patients with underlying diseases such as malignancy and hepatobiliary diseases. Increase in resistance and emerging of multidrug resistance among Citrobacter species have gradually been reported. The aim of this study was to investigate the clinical characteristics and outcome of C. freundii and non- freundii bacteremia and antimicrobial susceptibility trends. Materials and Methods We reviewed the medical records of patients with Citrobacter bacteremia at St. Mary's Hospital, from 2007 to 2017. Results A total of 43 patients with a median age of 72 (24-93) years was identified and 90.7% of them had comorbidities. Twenty-nine (67.4%) patients had C. freundii bacteremia while 14 had non- freundii bacteremia (six of C. braakii , five of C. koseri , two of C. amalonaticus and one of C. youngae ). A total of 26 (51.2%) patients had community-acquired infection and intra-abdominal infection including hepatobiliary tract was the most common portal of entry (24/43, 55.8%). Moreover, hepatobiliary tract was the leading primary site of nosocomial infection (9/17, 52.9%). Polymicrobial bacteremia was observed in 21 (48.8%) patients. The percentages of Citrobacter species susceptible to ampicillin, amikacin, aztreonam, cefazolin, cefoxitin, cefotaxime, cefepime, piperacillin-tazobactam, ciprofloxacin, and imipenem were 9.5%, 97.6%, 73.8%, 9.5%, 14.3%, 71.4%, 92.9%, 83.3%, 83.3% and 100%, respectively. The resistance rate did not increase during the study period. Of 39 patients treated with antibiotics, 36 (92.3%) received appropriate empirical antibiotics. Overall mortality was 18.6%. High Charlson comorbidity index and Pitt bacteremia score were significant risk factors for death in univariate analysis and showed trends in the multivariate analysis. No significant difference in clinical features and antimicrobial susceptibility rate was observed between C. freundii and non- freundii bacteremia. Conclusion Citrobacter bacteremia was predominant in the elderly with comorbidities, while no pediatric case was observed. Hepatobiliary tract is the leading primary focus of bacteremia both in community-acquired and nosocomial infection. The rate of susceptibility to antibiotics has not changed in the last 11 years.

Aeromonas hydrophila RIT668 and Citrobacter portucalensis RIT669—Potential Zoonotic Pathogens Isolated from Spotted Turtles

“…It has been reported to cure C. freundii infections even when other drugs have failed [ 113 ]. Over 70% of Citrobacter isolates in a 11-year single center study were reported to be susceptible to cotrimoxazole [ 60 ]. Neomycin has also been reported to clear infections caused by C. freundii [ 61 ].…”

“…Both A. hydrophila and C. freundii have been shown to be susceptible to neomycin and cotrimoxazole in the planktonic phase [ 60 , 61 , 62 , 63 , 64 ]. We have previously predicted using whole genome sequencing that A. hydrophila RIT668 contains resistance genes for six classes of antibiotics, while C. freundii RIT669 contains resistance genes for 19 classes of antibiotics [ 17 ].…”

Heterologous Immunity Between SARS-CoV-2 and Pathogenic Bacteria

“…The pathogenic bacteria that share homology with SARS-CoV-2 are K. pneumoniae, K. grimontii, E. coli, S. Enteritidis, E. faecalis, S. aureus, C. freundii, C. difficile, C. haemolyticum and C. novyi. They can cause infections ranging from common to rare and previous research has demonstrated T cell involvement in combatting the infections (27)(28)(29)(30)(31)(32)(33)(34)(35)(36)(37)(38)(39)(40)(41)(42)(43)(44)(45)(46). They also have the potential to respond via heterologous mechanisms to cross-reactive epitopes and some of these bacteria have been isolated from the lower airways of COVID-19 patients (Table S3).…”

Development and validation of a scoring system for mortality prediction and application of standardized W statistics to assess the performance of emergency departments

“…The outcome variable was defined as mortality, which included mortality in the ED, hospital mortality after admission. Discharge with almost no chance of recovery and the expectation of death in the short term were also regarded as mortality [ 19 , 20 ].…”