Objective: To explore the drug resistance mechanism and gene structure characteristics of a carbapenemase-producing novel incompatibility group plasmid pNY2385-KPC from Citrobacter freundii. Methods: A multi-drug resistant strain was obtained from urine samples of patients with fever in the emergency ward of Li Huili Hospital, Ningbo Medical Center. Bacterial species was preliminary identified and finally confirmed by 16S rRNA gene amplification and the average nucleotide identity alignment, respectively. The minimum inhibitory concentrations of the antimicrobial agents were determined by VITEK 2 Compact System. The complete genome sequence was obtained by "third-generation" sequencing methods, and then detailed annotation of gene function and comparative genomic analysis of plasmid structure were carried out by BLASTP/BLASTN, RefSeq, ConservedDomains, ResFinder, Isfinder, etc. Results: The pNY2385-KPC carried by citrobacter freundii NY2385 belonged a novel incompatibility group, and contained bla_KPC-2 and conjugative transfer (type Ⅳ secretory system, T4SS) genes, which could induce conjugative transfer. A total of 15 plasmids of the same type as pNY2385-KPC were retrieved by NCBI, which were from Citrobacter freundii, and the rest were from Serratia marcescens, Escherichia coli, Enterobacter cloacae, Klebsiella pneumoniae, Raoultella planticola and other bacteria, and were broad-host-range plasmids. The sequence comparative analysis of all 6 of the novel plasmid from Citrobacter freundii showed that the structure of the novel plasmid had certain conserved property, with Tn6296 variant structure carrying bla_KPC-2, and plasmid pCF1807-3 had both repA_pNY2385-KPC and repA_IncX8. Conclusion: The pNY2385-KPC type plasmids in Citrobacter freundii carried bla_KPC-2 resistance gene, which were divided into two subtypes: repA_pNY2385-KPC single replicator and repA_pNY2385-KPC/repA_IncX8 complex replicator, belonging to broad-host-range plasmids. And as a mobile genetic element, the plasmids promote the spread of bla_KPC-2.
Humans ; Citrobacter freundii/genetics* ; RNA, Ribosomal, 16S/genetics* ; Emergency Service, Hospital ; Escherichia coli ; Genomics

Objective: To explore the drug resistance mechanism and gene structure characteristics of a carbapenemase-producing novel incompatibility group plasmid pNY2385-KPC from Citrobacter freundii. Methods: A multi-drug resistant strain was obtained from urine samples of patients with fever in the emergency ward of Li Huili Hospital, Ningbo Medical Center. Bacterial species was preliminary identified and finally confirmed by 16S rRNA gene amplification and the average nucleotide identity alignment, respectively. The minimum inhibitory concentrations of the antimicrobial agents were determined by VITEK 2 Compact System. The complete genome sequence was obtained by "third-generation" sequencing methods, and then detailed annotation of gene function and comparative genomic analysis of plasmid structure were carried out by BLASTP/BLASTN, RefSeq, ConservedDomains, ResFinder, Isfinder, etc. Results: The pNY2385-KPC carried by citrobacter freundii NY2385 belonged a novel incompatibility group, and contained bla_KPC-2 and conjugative transfer (type Ⅳ secretory system, T4SS) genes, which could induce conjugative transfer. A total of 15 plasmids of the same type as pNY2385-KPC were retrieved by NCBI, which were from Citrobacter freundii, and the rest were from Serratia marcescens, Escherichia coli, Enterobacter cloacae, Klebsiella pneumoniae, Raoultella planticola and other bacteria, and were broad-host-range plasmids. The sequence comparative analysis of all 6 of the novel plasmid from Citrobacter freundii showed that the structure of the novel plasmid had certain conserved property, with Tn6296 variant structure carrying bla_KPC-2, and plasmid pCF1807-3 had both repA_pNY2385-KPC and repA_IncX8. Conclusion: The pNY2385-KPC type plasmids in Citrobacter freundii carried bla_KPC-2 resistance gene, which were divided into two subtypes: repA_pNY2385-KPC single replicator and repA_pNY2385-KPC/repA_IncX8 complex replicator, belonging to broad-host-range plasmids. And as a mobile genetic element, the plasmids promote the spread of bla_KPC-2.
Humans ; Citrobacter freundii/genetics* ; RNA, Ribosomal, 16S/genetics* ; Emergency Service, Hospital ; Escherichia coli ; Genomics

At an intensive care unit, four neonates died consecutively within 80 minutes. Citrobacter freundii was isolated from blood samples of the 4 patients. It was also cultured from the leftover SMOFlipid that had been infused intravenously into the patients. In this in vitro study, we evaluated the bacterial growth kinetics and change in size of fat globules in SMOFlipid contaminated with C. freundii. Following the growth of bacteria, pH of SMOFlipid decreased to < 6, and the number of fat globules larger than 5 µm increased. Pulmonary fat embolism is proposed as a possible cause of the sudden deaths as well as fulminant sepsis.
Bacteria ; Citrobacter freundii* ; Citrobacter* ; Death, Sudden* ; Embolism, Fat ; Fat Emulsions, Intravenous ; Humans ; Hydrogen-Ion Concentration ; In Vitro Techniques ; Infant, Newborn* ; Infusions, Intravenous* ; Intensive Care Units ; Kinetics ; Sepsis

The usage of essential oils as antimicrobial agents is gaining attention. Besides, pet turtles were known to harbor a range of pathogenic bacteria while the turtle keeping is a growing trend worldwide.The current study examined the antimicrobial activity of lemon grass oil (LGO) against seven species of Gram negative bacteria namely; Aeromonas hydrophila, A. caviae, Citrobacter freundii, Salmonella enterica, Edwardsiella tarda, Pseudomonas aeruginosa, and Proteus mirabilis isolated from three popular species of pet turtles. Along with the results of disc diffusion, minimum inhibitory and minimum bactericidal concentration (MIC and MBC) tests, LGO was detected as effective against 6 species of bacteria excluding P. aeruginosa. MIC of LGO for the strains except P. aeruginosa ranged from 0.016 to 0.5% (V/V). The lowest MIC recorded in the E. tarda strain followed by A. hydrophilla, C. freundii, P. mirabilis, and S. enterica. Interestingly, all the bacterial species except E. tarda were showing high multiple antimicrobial resistance (MAR) index values ranging from 0.36 to 0.91 upon the 11 antibiotics tested although they were sensitive to LGO.
Aeromonas hydrophila ; Animals ; Anti-Bacterial Agents ; Anti-Infective Agents ; Bacteria* ; Citrobacter freundii ; Cymbopogon* ; Diffusion ; Edwardsiella tarda ; Gram-Negative Bacteria ; Guinea Pigs ; Mirabilis ; Oils, Volatile ; Proteus mirabilis ; Pseudomonas aeruginosa ; Salmonella enterica ; Turtles*

Pet turtles are well-known to harbor an array of bacterial pathogens which can cause zoonotic infections in humans as well as opportunistic infections in the turtles itself. Essential oils are the natural plant extracts which have been traditionally used for disease treatment. In the present study, the essential oil of lavender (EOL) was examined for its antibacterial activity against thirty-eight strains of turtle-borne pathogenic bacteria belonging to seven species; Aeromonas hydrophila, A. caviae, A. dhakensis, Citrobacter freundii, Proteus mirabilis, Salmonella enterica and Pseudomonas aeruginosa. Antibacterial activity of EOL was tested by means of disk diffusion, minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC) tests. In addition, the antimicrobial susceptibility pattern of 11 commonly used antimicrobials was examined and the multiple antibiotic resistance (MAR) index was calculated. The results revealed that EOL was active against all tested turtle-borne pathogenic bacteria except P. aeruginosa. The range of MIC and MBC values of EOL against isolates except P. aeruginosa were recorded as 0.5-1% (V/V) and 0.5-2% (V/V), respectively. The MBC/MIC ratio was detected as <4, revealing that the tested EOL was bactericidal. Besides, most of the isolates were resistant to different antimicrobials in antimicrobial disk diffusion test. MAR index values of the tested strains were ranging from 0.27 to 0.91. The outcomes indicate that EOL has a potential to be used as an antibacterial agent against pathogenic bacteria isolated from pet turtles.
Aeromonas hydrophila ; Animals ; Bacteria* ; Citrobacter freundii ; Diffusion ; Drug Resistance, Microbial ; Guinea Pigs ; Humans ; Lavandula* ; Microbial Sensitivity Tests ; Oils, Volatile ; Opportunistic Infections ; Plant Extracts ; Proteus mirabilis ; Pseudomonas aeruginosa ; Salmonella enterica ; Turtles ; Zoonoses

We evaluated the impact of revised Clinical and Laboratory Standards Institute (CLSI) breakpoints for broad-spectrum cephalosporins (BSCs) on the susceptibilities of 1,742 isolates of Enterobacter species, Serratia marcescens, Citrobacter freundii, and Morganella morganii. The 2011 CLSI criteria for cefotaxime and ceftazidime reduced the rates of susceptibility by 2.9% and 5.9%, respectively. The 2014 CLSI criteria for cefepime reduced the rate of susceptibility by 13.9%, and categorized 11.8% isolates as susceptible-dose dependent (SDD) for cefepime. Among 183 isolates with extended-spectrum ß-lactamase (ESBL) phenotype, implementation of the new criteria reduced the rates of susceptibility to cefotaxime, ceftazidime, and cefepime by 2.8%, 14.8%, and 53.6%, respectively. The proportion of ESBL phenotype among BSC-susceptible isolates was low (0.9% for cefotaxime, 3.0% for ceftazidime, and 3.3% for cefepime). In summary, implementation of new CLSI criteria led to little change in susceptibility to cefotaxime and ceftazidime but a substantial change in susceptibility to cefepime. The recognition of revised CLSI criteria for BSC and SDD will help clinicians to select the optimal antibiotic and dosing regimen.
Cefotaxime ; Ceftazidime ; Cephalosporins ; Citrobacter freundii ; Enterobacter ; Enterobacteriaceae* ; Morganella morganii ; Phenotype ; Serratia marcescens

Contamination with sanitary microorganisms from Enterobacteriaceae, Pseudomonadaceae, Staphylococcaceae, Micrococcaceae and Bacillaceae families in flower bee pollen from Bulgaria after one-year vacuum-packed cold storage has been found. Dried flower bee pollens intended for human consumption were with high incidence rate of contamination with Pantoea sp. (P. agglomerans and P. agglomerans bgp6) (100%), Citrobacter freundii (47%), Proteus mirabilis (31.6%), Serratia odorifera (15.8%) and Proteus vulgaris (5.3%). Bee pollens were also positive for the culture of microorganisms from Staphylococcaceae, Micrococcaceae and Bacillaceae families: Staphylococcus hominis subsp hominis, Staphylococcus epidermidis, Arthrobacter globiformis, Bacillus pumilis, Bacillus subtilis and Bacillus amyloliquefaciens. It was concluded that, if consumed directly, the vacuum-packed cold stored dried bee pollen, harvested according hygienic requirements from bee hives in industrial pollution-free areas without intensive crop production, is not problem for healthy human.
Arthrobacter ; Bacillaceae ; Bacillus ; Bacillus subtilis ; Bees* ; Bulgaria ; Citrobacter freundii ; Crop Production ; Enterobacteriaceae ; Flowers* ; Humans ; Incidence ; Micrococcaceae ; Pantoea ; Pollen* ; Proteus mirabilis ; Proteus vulgaris ; Pseudomonadaceae ; Serratia ; Staphylococcaceae ; Staphylococcus epidermidis ; Staphylococcus hominis ; Urticaria ; Vacuum*

We present a case of continuous ambulatory peritoneal dialysis peritonitis caused by Citrobacter freundii complicated by a fungal infection with abscess formation. A 34-year-old woman was admitted to our hospital with abdominal pain. Isolate cultures were confirmed as Citrobacter freundii by DNA sequencing of the 16s ribosomal ribonucleic acid (RNA). Antibiotic therapy was ineffective and Candida tropicalis was isolated in follow-up blood cultures. We administered an antifungal agent and removed the peritoneal catheter. A sudden fever developed, and abdominal computed tomography showed intra-abdominal abscesses. Percutaneous drainage was performed, but no bacteria were cultured. After draining the abscesses, the patient recovered. Citrobacter species are unusual pathogens in peritonitis, and fungal peritonitis is a serious complication of bacterial peritonitis. Indwelling catheters should be removed and appropriate antibiotic therapy provided. Suspicion of a fungal infection combined with bacterial peritonitis will improve the prognosis of patients on peritoneal dialysis.
Abdominal Abscess ; Abdominal Pain ; Abscess ; Adult ; Bacteria ; Candida tropicalis ; Catheters ; Catheters, Indwelling ; Citrobacter ; Citrobacter freundii* ; Drainage ; Female ; Fever ; Follow-Up Studies ; Humans ; Peritoneal Dialysis ; Peritoneal Dialysis, Continuous Ambulatory* ; Peritonitis* ; Prognosis ; RNA ; RNA, Ribosomal, 16S* ; Sequence Analysis, DNA

BACKGROUND/AIMS: We evaluated changes of causative pathogen in acute cholangitis and their antimicrobial susceptibility over six years and differences between community-acquired and hospital-acquired acute cholangitis at our institution. METHODS: Medical records of 1,596 patients with acute cholangitis and biliary drainage between August 2006 and August 2012 were reviewed retrospectively. Cases were divided according to time: period 1 (August 2006-December 2008, n=645, 40.4%), period 2 (January 2009-August 2012, n=951, 59.6%). Cases were divided according to community-acquired cholangitis (n=1,397, 87.5%) and hospital-acquired cholangitis (n=199, 12.5%). Causative pathogens and antimicrobial susceptibility were investigated in each group. RESULTS: Causative pathogen was isolated from bile culture in 1,520 out of 1,596 cases (95.2%). The three most frequently isolated Gram-negative bacteria were extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli (n=485, 30.4%), E. coli (n=237, 13.2%), and Citrobacter freundii (n=110, 6.9%). Between periods 1 and 2, prevalence of ESBL-producing E. coli and Klebsiella pneumoniae did not show significant change (36.7% vs. 32.1%, p=0.073; 6.6% vs. 6.2%, p=0.732). C. freundii showed a significant increase from period 1 to period 2 (1.7% vs. 13.2%, p=0.000). In both time periods, imipenem was the antimicrobial agent showing the highest rate of susceptibility (93.3% vs. 93.9%, p=0.783). Higher prevalence of ESBL-producing E. coli and C. freundii was observed in the hospital-acquired cholangitis group (52.1% vs. 31.2%, p=0.000; 15.9% vs. 7.3%, p=0.001). CONCLUSIONS: The most common causative pathogen of acute cholangitis was ESBL-producing E. coli. Prevalence of C. freundii increased over the time period. Imipenem should be reserved as an alternative for resistant pathogens.
Acute Disease ; Aged ; Aged, 80 and over ; Anti-Bacterial Agents/*pharmacology ; Cholangitis/diagnosis/*microbiology ; *Citrobacter freundii/drug effects/isolation & purification ; Community-Acquired Infections/microbiology ; Cross Infection/microbiology ; Drug Resistance, Bacterial ; *Escherichia coli/drug effects/isolation & purification ; Female ; Humans ; Imipenem/pharmacology ; *Klebsiella pneumoniae/drug effects/isolation & purification ; Male ; Microbial Sensitivity Tests ; Middle Aged ; Retrospective Studies ; Time Factors ; beta-Lactamases/metabolism

No abstract available.
Aged ; Anti-Bacterial Agents/pharmacology/therapeutic use ; Asian Continental Ancestry Group ; Bacterial Proteins/genetics/*metabolism ; China ; Cilastatin/therapeutic use ; Citrobacter freundii/drug effects/*enzymology/isolation & purification ; Drug Combinations ; Drug Resistance, Multiple, Bacterial ; Humans ; Imipenem/therapeutic use ; Male ; Microbial Sensitivity Tests ; Plasmids/*metabolism ; Respiratory Tract Infections/*diagnosis/drug therapy/microbiology ; beta-Lactamases/genetics/*metabolism