Diabetes Mellitus ; Enterobacter cloacae ; Humans ; Maxilla ; Osteonecrosis

BACKGROUND: From January 2014 to December 2015, 69 clones of Enterobacter cloacae showing multidrug resistance to six classes of antimicrobial agents were collected from two medical centers in Korea. METHODS: Minimum inhibitory concentrations were determined using the E-test method, and 17 genes were detected using polymerase chain reaction (PCR). The epidemiological relatedness of the strains was identified using repetitive element sequence-based PCR and multilocus sequence typing. RESULTS: The 69 E. cloacae clones produced extended spectrum β lactamase (ESBL) and AmpC and showed multidrug resistance to cefotaxime, ceftazidime, and aztreonam. We identified the following sequence types: ST56 of type VI for ESBL SHV (N=12, 17.4%); ST53, ST114, ST113, and ST550 of types I, IV, VI, and VII, respectively, for CTX-M (N=11, 15.9%); and ST668 of type III for the carbapenemase NDM gene (N=1, 1.5%). The AmpC DHA gene (N=2, 2.89%) was confirmed as ST134, although its type was not identified, whereas EBC (MIR/ACT; N=18, 26.1%) was identified as ST53, ST24, ST41, ST114, ST442, ST446, ST484, and ST550 of types V, I, III, IV, VII, and VI, respectively. The formed subclasses were bla CTX-M-3 and bla CTX-M-22 by CTX-M-1, bla CTX-M-9 and bla CTX-M-125 by CTX-M-9, bla DHA-1 by DHA, and bla MIR-7 and bla ACT-15,17,18,25,27,28 by EBC (MIR/ACT). CONCLUSIONS: There were no epidemiological relationships between the gene products and the occurrence of resistance among the strains.
Anti-Infective Agents ; Aztreonam ; Cefotaxime ; Ceftazidime ; Cloaca ; Clone Cells ; Drug Resistance, Multiple* ; Enterobacter cloacae* ; Enterobacter* ; Korea ; Methods ; Microbial Sensitivity Tests ; Multilocus Sequence Typing ; Polymerase Chain Reaction

BACKGROUND: This study was conducted to evaluate the impact of the media type used for direct identification of colonies on the surveillance culture of carbapenem-resistant Enterobacteriaceae (CRE) by matrix assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS). METHODS: CRE surveillance culture isolates were subjected to species identification using the MALDI Biotyper (Bruker Daltonics, Germany) for 2 months starting in March 2017. Four types of media were evaluated: blood agar (BA), Mueller Hinton agar (MH), MacConkey agar (Mac), and MacConkey agar containing imipenem of 1 µg/mL (IMP-Mac). CRE-like colonies on IMP-Mac and their subculture colonies on the other media were tested after overnight incubation and extended incubation for one additional day. The percent identification and score value were analyzed for each media types and incubation time when the identification was correct at the genus level. RESULTS: A total of 117 isolates were identified as 84 Klebsiella pneumoniae, 12 Escherichia coli, 9 Enterobacter cloacae, 5 Klebsiella oxytoca, 4 Enterobacter aerogenes, and 2 Raoultella ornithinolytica. The successful identification rates (SIR) for BA and MH were 98.3% and 97.4% (P=0.9), respectively, while those for Mac and IMP-Mac were 82.1% (P < 0.001) and 70.9% (P < 0.001), respectively. After extended incubation, SIRs were decreased to 96.6%, 96.6% (P=1.0), 61.5% (P < 0.001), and 58.1% (P < 0.001) on BA, MH, Mac, and IMP-Mac, respectively. The average score values were significantly lower for Mac (2.017±0.22) and IMP-Mac (1.978±0.24) than for BA (2.213±0.16) (P < 0.001). CONCLUSIONS: The low performance of the MALDI Biotyper applied directly to the colonies grown on Mac or IMP-Mac indicates that subculture on BA or MH is preferable before identification by MALDI-TOF MS.
Agar ; Enterobacter aerogenes ; Enterobacter cloacae ; Enterobacteriaceae* ; Escherichia coli ; Imipenem ; Klebsiella oxytoca ; Klebsiella pneumoniae ; Mass Spectrometry ; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization*

BACKGROUND: The emerging mobile colistin resistance gene, mcr-1, is an ongoing worldwide concern and an evaluation of clinical isolates harboring this gene is required in Korea. We investigated mcr-1-possessing Enterobacteriaceae among Enterobacteriaceae strains isolated in Korea, and compared the genetic details of the plasmids with those in Escherichia coli isolates from livestock. METHODS: Among 9,396 Enterobacteriaceae clinical isolates collected between 2010 and 2015, 1,347 (14.3%) strains were resistant to colistin and those were screened for mcr-1 by PCR. Colistin minimum inhibitory concentrations (MICs) were determined by microdilution, and conjugal transfer of the mcr-1-harboring plasmids was assessed by direct mating. Whole genomes of three mcr-1-positive Enterobacteriaceae clinical isolates and 11 livestock-origin mcr-1-positive E. coli isolates were sequenced. RESULTS: Two E. coli and one Enterobacter aerogenes clinical isolates carried carried IncI2 plasmids harboring mcr-1, which conferred colistin resistance (E. coli MIC, 4 mg/L; E. aerogenes MIC, 32 mg/L). The strains possessed the complete conjugal machinery except for E. aerogenes harboring a truncated prepilin peptidase. The E. coli plasmid transferred more efficiently to E. coli than to Klebsiella pneumoniae or Enterobacter cloacae recipients. Among the three bacterial hosts, the colistin MIC was the highest for E. coli owing to the higher mcr-1-plasmid copy number and mcr-1 expression levels. Ten mcr-1-positive chicken-origin E. coli strains also possessed mcr-1-harboring IncI2 plasmids closely related to that in the clinical E. aerogenes isolate, and the remaining one porcine-origin E. coli possessed an mcr-1-harboring IncX4 plasmid. CONCLUSIONS: mcr-1-harboring IncI2 plasmids were identified in clinical Enterobacteriaceae isolates. These plasmids were closely associated with those in chicken-origin E. coli strains in Korea, supporting the concept of mcr-1 dissemination between humans and livestock.
Colistin ; Enterobacter aerogenes ; Enterobacter cloacae ; Enterobacteriaceae* ; Escherichia coli* ; Escherichia* ; Genome ; Humans* ; Klebsiella pneumoniae ; Korea* ; Livestock* ; Microbial Sensitivity Tests ; Plasmids* ; Polymerase Chain Reaction

STUDY DESIGN: A retrospective clinical review. PURPOSE: To investigate the difference in clinical manifestations and severity between polymicrobial and monomicrobial infections after spinal surgery. OVERVIEW OF LITERATURE: Surgical site infections (SSIs) after spinal surgery are a major diagnostic and therapeutic challenge for spinal surgeons. Polymicrobial infections after spinal surgery seem to result in poorer outcomes than monomicrobial infections because of complementary resistance to antibiotics. However, comparison of the clinical manifestations and severity between polymicrobial and monomicrobial infections are limited. METHODS: Sixty-seven patients with SSIs after spinal surgery were studied: 20 patients with polymicrobial infections and 47 with monomicrobial infections. Pathogenic bacteria identified were counted and classified. Age, sex, and body mass index were compared between the two groups to identify homogeneity. The groups were compared for clinical manifestations by surgical site, postoperative time to infection, infection site, incisional drainage, incisional swelling, incisional pain, neurological signs, temperature, white blood cell count, and the percentage of neutrophils. Finally, the groups were compared for severity by hospital stay, number of rehospitalizations, number of debridements, duration of antibiotics administration, number of antibiotics administered, and implant removal. RESULTS: Polymicrobial infections comprised 29.9% of SSIs after spinal surgery, and most polymicrobial infections (70.0%) were caused by two species of bacteria only. There was no difference between the groups in terms of clinical manifestations and severity. In total, 96 bacterial strains were isolated from the spinal wounds: 60 strains were gram-positive and 36 were gram-negative pathogenic bacteria. Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli, and Enterobacter cloacae were cultured in order of the frequency of appearance. CONCLUSIONS: Most polymicrobial infections were caused by two bacterial species after spinal surgery. There was no difference in clinical manifestations or severity between polymicrobial and monomicrobial infections.
Anti-Bacterial Agents ; Bacteria ; Body Mass Index ; Coinfection ; Debridement ; Drainage ; Enterobacter cloacae ; Escherichia coli ; Humans ; Length of Stay ; Leukocyte Count ; Neutrophils ; Postoperative Complications ; Retrospective Studies* ; Spine ; Staphylococcus aureus ; Staphylococcus epidermidis ; Surgeons ; Surgical Wound Infection ; Wounds and Injuries

BACKGROUND: Extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae are resistant to most β-lactam antibiotics except carbapenems. In recent years, infrequently isolated Enterobacteriaceae that produce carbapenemase pose a serious threat in the selection of appropriate therapeutic antibiotics. The rapid detection method of carbapenemase-producing Enterobacteriaceae (CPE) is necessary to prevent the spread of CPE into healthcare facilities. METHODS: One hundred clinical Enterobacteriaceae isolates (Klebsiella pneumoniae 40, Escherichia coli 40, others 20) showing susceptibility to carbapenems and positivity in the CLSI ESBL phenotypic test from November 2015 to March 2016 and 59 stocked Enterobacteriaceae isolates harboring resistance genes producing carbapenemase (K. pneumoniae 56, Enterobacter cloacae 2, E. coli 1; types of CPE: KPC 36, GES 12, NDM 6, VIM 2, OXA 2, IMP 1) were subjected to the RAPIDEC CARBA NP test (bioMérieux, France) and CPE phenotypic test using the modified Hodge test (MHT) and carbapenemase inhibition test. RESULTS: All of the 100 Enterobacteriaceae isolates with carbapenem susceptibility and ESBL positivity were negative on the RAPIDEC CARBA NP test and CPE phenotypic test. Of 59 stock CPE isolates, 53 and 42 showed positive results to the RAPIDEC CARBA NP test and MHT, respectively. The sensitivity and specificity of the RAPIDEC CARBA NP test for detecting CPE were 89.8% and 100%, respectively. CONCLUSION: The RAPIDEC CARBA NP test is simple and produces a result within 3 hr. In conclusion, the test is a useful screen for detecting CPE because it shows high sensitivity and specificity for CPE detection.
Anti-Bacterial Agents ; Carbapenems ; Delivery of Health Care ; Enterobacter cloacae ; Enterobacteriaceae* ; Escherichia coli ; Methods ; Pneumonia ; Sensitivity and Specificity

BACKGROUND: Carbapenemase-producing Enterobacteriaceae (CPE) are Gram-negative bacteria with increasing prevalence of infection worldwide. In Korea, 25 cases of CPE isolates were reported by the Korea Centers for Disease Control and Prevention in 2011. Most CPE cases were detected mainly at tertiary referral hospitals. We analyzed the prevalence and risk factors for carbapenem-resistant Enterobacteriaceae (CRE) in a mid-sized community-based hospital in Korea. MATERIALS AND METHODS: We retrospectively analyzed all consecutive episodes of Enterobacteriaceae in a mid-sized community-based hospital from January 2013 to February 2014. CRE was defined as organisms of Enterobacteriaceae showing decreased susceptibility to carbapenems. Risk factors for CRE were evaluated by a case–double control design. Carbapenemase was confirmed for CRE using a combined disc test. RESULTS: During 229,710 patient-days, 2,510 Enterobacteriaceae isolates were obtained. A total of 41 (1.6%) CRE isolates were enrolled in the study period. Thirteen species (31.7%) were Enterobacter aerogenes, 8 (19.5%) Klebsiella pneumoniae, 5 (12.2%) Enterobacter cloacae, and 15 other species of Enterobacteriaceae, respectively. Among the 41 isolates, only one (2.4%) E. aerogenes isolate belonged to CPE. For evaluation of risk factors, a total of 111 patients were enrolled and this included 37 patients in the CRE group, 37 in control group I (identical species), and 37 in control group II (different species). Based on multivariate analysis, regularly visiting the outpatient clinic was a risk factor for CRE acquisition in the control group I (P = 0.003), while vascular catheter and Charlson comorbidity index score ≥ 3 were risk factors in control group II (P = 0.010 and 0.011, each). Patients with CRE were more likely to experience a reduced level of consciousness, use a vasopressor, be under intensive care, and suffer from acute kidney injury. However, CRE was not an independent predictor of mortality compared with both control groups. CONCLUSION: In conclusion, the prevalence of CRE was higher than expected in a mid-sized community-based hospital in Korea. CRE should be considered when patients have a vascular catheter, high comorbidity score, and regular visits to the outpatient clinic. This study suggests the need for appropriate prevention efforts and constant attention to CRE infection control in a mid-sized community-based hospital.
Acute Kidney Injury ; Ambulatory Care Facilities ; Carbapenems ; Centers for Disease Control and Prevention (U.S.) ; Comorbidity ; Consciousness ; Critical Care ; Drug Resistance ; Enterobacter aerogenes ; Enterobacter cloacae ; Enterobacteriaceae* ; Gram-Negative Bacteria ; Humans ; Infection Control ; Klebsiella pneumoniae ; Korea* ; Mortality ; Multivariate Analysis ; Prevalence* ; Retrospective Studies ; Risk Factors* ; Tertiary Care Centers ; Vascular Access Devices

BACKGROUND: Extended-spectrum ß-lactamase-producing Enterobacteriaceae (ESBL-PE) are increasingly reported as pathogens in urinary tract infections (UTIs). However, in Sri Lanka, the clinical and molecular epidemiology of ESBL-PE implicated in UTIs has not been well described. MATERIALS AND METHODS: We conducted prospective, laboratory-based surveillance from October to December 2013 at a tertiary care hospital in southern Sri Lanka and enrolled patients ≥1 year of age with clinically relevant UTIs due to ESBL-PE. Isolate identity, antimicrobial drug susceptibility, and ESBL production were determined. Presence of ß-lactamase genes, bla(SHV), bla(TEM), and bla(CTX-M), was identified by polymerase chain reaction. RESULTS: During the study period, Enterobacteriaceae were detected in 184 urine samples, with 74 (40.2%) being ESBL producers. Among 47 patients with ESBL-PE who had medical records available, 38 (80.9%) had clinically significant UTIs. Most UTIs (63.2%) were community acquired and 34.2% were in patients with diabetes. Among 36 cultured ESBL-PE isolates, significant susceptibility (>80%) was only retained to amikacin and the carbapenems. The group 1 bla(CTX-M) gene was present in 90.0% of Escherichia coli isolates and all Klebsiella pneumoniae and Enterobacter cloacae isolates. The bla(SHV) and bla(TEM) genes were more common in K. pneumoniae (75% and 50%) and E. cloacae (50% and 50%) isolates than in E. coli (10% and 20%) isolates, respectively. CONCLUSION: The majority of UTIs caused by ESBL-PE were acquired in the community and due to organisms carrying the group 1 CTX-M ß-lactamase. Further epidemiologic studies of infections due to ESBL-PE are urgently needed to better prevent and treat these infections in South Asia.
Amikacin ; Asia ; Carbapenems ; Cloaca ; Enterobacter cloacae ; Enterobacteriaceae* ; Epidemiologic Studies ; Escherichia coli ; Humans ; Klebsiella pneumoniae ; Medical Records ; Molecular Epidemiology ; Pneumonia ; Polymerase Chain Reaction ; Prospective Studies ; Sri Lanka* ; Tertiary Healthcare ; Urinary Tract Infections* ; Urinary Tract*

Infection with carbapenem-resistant Enterobacteriaceae (CRE) and other multidrug resistant bacteria has increased rapidly in Korea. The Korea Centers for Disease Control and Prevention reported 1,609 cases of CRE infection in the country in 2013. The risk factors for CRE infection include history of treatment with antibiotics such as cephalosporins or carbapenem, trauma, diabetes, cancer, and history of ventilator support. Herein, we report four cases of CRE infection seen during a 3-month period in our hospital in 2014. CRE infection is associated with a high mortality rate of 30% to 50%, even with combination antibiotic therapy. Prevention of CRE infection in hospital settings is fundamental to controlling its transmission. Key preventive measures include, contact precautions, hand hygiene, education of healthcare personnel, screening for CRE when indicated, and exercising discretion in prescribing carbapenem or cephalosporins.
Anti-Bacterial Agents ; Bacteria ; Centers for Disease Control and Prevention (U.S.) ; Cephalosporins ; Delivery of Health Care ; Drug Resistance, Bacterial ; Education ; Enterobacter cloacae ; Enterobacteriaceae ; Enterobacteriaceae Infections* ; Hand Hygiene ; Korea ; Mass Screening ; Mortality ; Risk Factors ; Ventilators, Mechanical

OBJECTIVETo characterize the time distribution of the incidence of Enterobacter cloacae nosocomial infections in children hospitalized in the pediatric intensive care unit (PICU) of the First Affiliated Hospital of Xinjiang Medical University.

METHODSThe clinical data of children with Enterobacter cloacae nosocomial infections in the PICU of the First Affiliated Hospital of Xinjiang Medical University between January 2010 and December 2013 were collected. The monthly number of cases of Enterobacter cloacae nosocomial infections was recorded, and time series analysis was performed using SPSS 21.0 software. The obtained prediction model was verified using the data from January to June in 2014.

RESULTSA total of 157 cases of Enterobacter cloacae nosocomial infections were reported in the PICU between January 2010 and December 2013, including 33 cases in 2010, 35 cases in 2011, 37 cases in 2012, and 52 cases in 2013. Time series analysis of the monthly number of cases of nosocomial infections reveals a fitted curve with a clear pattern of seasonal variation (R2=0.702, Ljung-Box Q(18)=36.021, P=0.004), with peaks in May, June, and July. The verification using the data from January to June in 2014 showed small differences between the predicted values and the actual values.

CONCLUSIONSIn the PICU of the First Affiliated Hospital of Xinjiang Medical University, the incidence of Enterobacter cloacae nosocomial infections is high in May, June, and July every year. The prediction model is accurate and can provide a reference for infection prevention.

Child ; Cross Infection ; epidemiology ; Enterobacter cloacae ; Enterobacteriaceae Infections ; epidemiology ; Hospitalization ; Humans ; Intensive Care Units, Pediatric ; Seasons