No abstract available.
Citrobacter freundii* ; Citrobacter* ; Osteomyelitis*

No abstract available.
Citrobacter freundii* ; Citrobacter* ; Osteomyelitis*

No abstract available.
Citrobacter* ; Enterobacter*

No abstract available.
Citrobacter freundii* ; Citrobacter* ; Humans ; Infant, Newborn* ; Meningitis*

No abstract available.
Abscess* ; Citrobacter koseri

No abstract available.
Abscess* ; Citrobacter* ; Humans ; Paronychia*

Citrobacter species is a gram-negative bacilli that can cause opportunistic infections in immunocompromised hosts. Citrobacter braakii refers to the genomospecies 6 of the Citrobacter freundii complex. There are no detailed studies on infections caused by this newly identified specific genetic species in Korea. We herein report a case of a patient with hepatocellular carcinoma who, after undergoing transcatheter arterial chemoembolization, developed biloma which later progressed to C.braakii sepsis and did not respond to treatment. To our knowledge, this is the first reported case in Korea on C. braakii infection resulting in septic shock in a patient with malignancy in Korea.
Carcinoma, Hepatocellular ; Citrobacter ; Citrobacter freundii ; Humans ; Immunocompromised Host ; Korea ; Opportunistic Infections ; Sepsis ; Shock, Septic

BACKGROUND: Antimicrobial resistance to third-generation cephalosporins in gram-negative bacteria, especially Enterobacter, Citrobacter, and Serratia spp., is increasing. The resistance mechanism of these organisms are hyperproduction of AmpC beta-lactamase and plasmid-mediated extended-spectrum beta-lactamase (ESBL). This study was to determine the occurrence of AmpC hyperproduction and ESBLs in E. cloacae, C. freundii, and S. marcescens over a 3-month period in 2002. METHODS: We tested total of 619 consecutive, nonduplicate isolates (229 E. cloacae, 183 C. freundii, 207 S. marcescens) from 12 university hospitals and a commercial laboratory in Korea. Antimicrobial susceptibilities were tested using the disk diffusion method. AmpC hyperproduction was defined as nonsusceptible to cefotaxime or ceftazidime for E. cloacae and C. freundii and as nonsusceptible to cefotaxime for S. marcescens. ESBL production was determined by the double disk synergy test. RESULTS: Among the E. cloacae, C. freundii and S. marcescens derepressed strains were 20.5%, 30.1%, and 31.4% and ESBL producers were 23.6%, 10.9%, and 15.5%, respectively. The AmpC derepressed strains and ESBL producers revealed lower susceptibility rates for ciprofloxacin, piperacillin, piperacillin-tazobactam and aminoglycosides. CONCLUSIONS: These data reveal that the occurrence of AmpC derepressants and ESBL producers among E. cloacae, C. freundii and S. marcescens is relatively high. Continued nationwide surveillance is necessary to provide information on the spread of these important mechanisms of resistance to beta-lactams.
Aminoglycosides ; beta-Lactamases ; beta-Lactams ; Cefotaxime ; Ceftazidime ; Cephalosporins ; Ciprofloxacin ; Citrobacter ; Citrobacter freundii* ; Cloaca ; Diffusion ; Enterobacter ; Enterobacter cloacae* ; Gram-Negative Bacteria ; Hospitals, University ; Korea ; Piperacillin ; Serratia ; Serratia marcescens*

BACKGROUND: The occurrence of extended-spectrum beta-lactamases (ESBLs) in enterobacteria that possess inducible Bush group 1 chromosomal beta-lactamases is being increasingly reported worldwide. The current National Committee for Clinical Laboratory Standards documents do not indicate the tests that should be used for the detection of ESBLs in Enterobacteriaceae except Klebsiella spp. and Escherichia coli. We determined the occurrence and detection of ESBL-producing Enterobacteriaceae isolates. METHODS: One hundred fifty-six consecutive, non-repeated isolates of Citrobacter freundii, Enterobacter spp., Proteus spp., and Serratia marcescens were collected. These isolates were performed broth microdilution antimicrobial susceptibility test, Vitek ESBL detection test, and double disk synergy (DDS) test. All the DDS-positive strains were tested PCR amplification of the blaTEM and blaSHV alleles. RESULTS: S. marcescens (27.3%) was the most frequently isolated ESBL producers followed by E. cloacae (23.8%), E. aerogenes (18.2%), C. freundii (13.3%), and P. mirabilis (8.3%). Among the total of 30 isolates that were considered ESBL producers, the Vitek ESBL detection test was positive for 26 (86.7%) strains. The genotypes of ESBLs were predominently SHV type (10 isolates) followed by others (8 isolates), SHV and TEM (7 isolates), and TEM type (5 isolates). CONCLUSIONS: Our findings indicate that 19.2% of all Enterobacteriaceae except E. coli and Klebsiella spp. tested produced ESBLs. The Vitek ESBL detection test seems to be a useful test to identify ESBL-producing strains of C. freundii, Enterobacter spp., Proteus spp., and S. marcescens isolates.
Alleles ; beta-Lactamases ; Citrobacter freundii* ; Citrobacter* ; Cloaca ; Enterobacter* ; Enterobacteriaceae ; Escherichia coli ; Genotype ; Klebsiella ; Mirabilis ; Polymerase Chain Reaction ; Proteus* ; Serratia marcescens* ; Serratia*

BACKGROUND: Derepressed AmpC beta-lactamase producing Enterobacter cloacae, Citrobacter f reundii, and Serratia marcescens are important nosocomial pathogens and the infections are difficult to treat, because they are multi-drug resistant. The aim of this study was to determine the isolation rate and trend, and antimicrobial susceptibility of derepressed strains isolated from clinical specimens. METHODS: E. cloacae, S. marcescens, and C. f reundii isolated from 1996 through 2000 were enrolled in the study. Antimicrobial susceptibility was tested by NCCLS disk diffusion method. Derepressed strain was defined as strain non-susceptible to third generation cephalosporin. The isolation patterns of important gram-negative bacilli with the derepressed strains were analyzed with respect to years, patient's locations and specimens. RESULTS: Among the clinical isolates, the derepressed strains of E. cloacae, S. marcescens, and C. f reundii were 65%, 70%, and 56%. The proportion of the derepressed strains : E. cloacae increased from 68% in 1996 to 71% in 1998, however, decreased to 59% in 2000, S. marcescens increased from 68% in 1996 to 73% in 2000, C. f reundii decreased from 69% in 1996 to 41% in 2000. The proportion of the derepressed strains were high among the isolates from blood and respiratory specimens of inpatient and intensive care patient. The resistance rates of the depressed strains were 47~62% to third generation cephalosporin and aztreonam, 15~85% to aminoglycoside, 68% to cotrimoxazole, and 31% to levofloxacin. CONCLUSION: Among the clinical isolates of E. cloacae, S. marcescens, and C. f reundii, the derepressed strains were as high as 56~70%, and they were commonly isolated from blood and sputum specimens of inpatient and intensive care patient, and showed high resistance rates to the most antimicrobial agents.
Anti-Infective Agents ; Aztreonam ; beta-Lactamases* ; Citrobacter freundii ; Citrobacter* ; Cloaca ; Diffusion ; Enterobacter cloacae ; Enterobacter* ; Humans ; Inpatients ; Critical Care ; Levofloxacin ; Serratia marcescens ; Serratia* ; Sputum ; Trimethoprim, Sulfamethoxazole Drug Combination