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

Anti-Bacterial Agents/therapeutic use* ; Carbapenem-Resistant Enterobacteriaceae ; Carbapenems ; Child ; Cross Infection/epidemiology* ; Enterobacteriaceae Infections/epidemiology* ; Humans ; Microbial Sensitivity Tests ; Risk Factors ; beta-Lactamases

With the abuse of antimicrobial agents in developing countries, increasing number of carbapenem-resistant Enterobacteriaceae (CRE) attracted considerable public concern. A retrospective study was conducted based on 242 CRE strains from a tertiary hospital in Hangzhou, China to investigate prevalence and drug resistance characteristics of CRE in southeast China. Bacterial species were identified. Antimicrobial susceptibility was examined by broth microdilution method or epsilometer test. Resistant β-lactamase genes were identified by polymerase chain reaction and sequencing. Genotypes were investigated by phylogenetic analysis. Klebsiella pneumoniae and Escherichia coli were the most prevalent types of species, with occurrence in 71.9% and 21.9% of the strains, respectively. All strains exhibited high resistance (> 70%) against β-lactam antibiotics, ciprofloxacin, trimethoprim-sulfamethoxazole, and nitrofurantoin but exhibited low resistance against tigecycline (0.8%) and minocycline (8.3%). A total of 123 strains harbored more than two kinds of β-lactamase genes. bla, bla, bla, and bla were the predominant genotypes, with detection rates of 60.3%, 61.6%, 43.4%, and 16.5%, respectively, and were highly identical with reference sequences in different countries, indicating potential horizontal dissemination. IMP-4 was the most frequent class B metallo-lactamases in this study. In conclusion, continuous surveillance and effective prevention should be emphasized to reduce spread of CRE.
Anti-Bacterial Agents ; therapeutic use ; Carbapenem-Resistant Enterobacteriaceae ; drug effects ; enzymology ; genetics ; China ; epidemiology ; Enterobacteriaceae Infections ; epidemiology ; microbiology ; Genotype ; Humans ; Microbial Sensitivity Tests ; Phylogeny ; Prevalence ; Retrospective Studies ; beta-Lactam Resistance ; beta-Lactamases ; genetics

OBJECTIVETo explore and establish fast and sensitive typing diagnostic methods on intestinal pathogen.

METHODSAll 29 isolates of Shigella. sonnei and 12 strains of Escherichia coli O157:H7 (EHEC O157:H7) isolated in 1999 were carried out for typing by using pulse-field gel electrophoresis (PFGE) and phage typing.

RESULTSPFGE results of 4 outbreak incidents caused by Shigella. sonnei showed that the PFGE patterns of the strains isolated from the same incident were almost the same. It was also the same during analysing the 2 outbreak incidents caused by EHEC O157:H7, however, the PFGE patterns of the 3 individual strains of EHEC O157:H7 were different. Moreover, the phage typing method showed its fine typing ability while its being used in the analysing 12 strains of EHEC O157:H7.

CONCLUSIONThe fine typing ability and reliability of PFGE was helpful for finding out the heredity background of intestinal pathogen and the infectious resource of the outbreak. And the epidemic situation might thus be effectively prevented from spreading.

Bacteriophage Typing ; methods ; Disease Outbreaks ; Electrophoresis, Gel, Pulsed-Field ; Enterobacteriaceae Infections ; epidemiology ; Escherichia coli O157 ; classification ; Humans ; Japan ; epidemiology ; Shigella sonnei ; classification

OBJECTIVETo study the risk factors of infection of extended-spectrum beta-lactamases (ESBL)-producing strains and drug resistance of Enterobacteriaceae that infected burn patients.

METHODSA retrospective study was performed on clinical information of 92 patients with Enterobacteriaceae infection in our burn unit from January 2001 to December 2008. The distribution and drug resistance of Enterobacteriaceae, and the detection rate, drug resistance of ESBL-producing strains, and its risk factors of nosocomial infection were analyzed. Data were processed with Chi-square test.

RESULTSOne hundred and nine strains of Enterobacteriaceae were isolated, with 38 (34.9%) strains of Enterobacter cloacae, 25 (22.9%) strains of Escherichia coli, 22 (20.2%) strains of Klebsiella pneumoniae, 13 (11.9%) strains of Proteus mirabilis, and 11 (10.1%) other strains of Enterobacteriaceae. Enterobacteriaceae were moderately or highly resistant to antibiotics except imipenem, resistance rate of which was less than 8.0%. ESBL-producing strains accounted for 44.0% in Escherichia coli, and 77.3% in Klebsiella pneumoniae. Drug-resistance rate of ESBL-producing strains to antibiotics was obviously higher than that of non ESBL-producing strains. Length of hospital stay longer than 20 days, and use of the third-generation cephalosporin longer than 5 days, quinolone antibiotics longer than 7 days, and topical antibiotics longer than 5 days were the risk factors of nosocomial infection caused by ESBL-producing strains, comparing with non ESBL-producing strains, the difference was statistically significant (with chi2 value respectively 5.491, 4.441, 15.186, 4.938, P values all below 0.05).

CONCLUSIONSEnterobacteriaceae strains in burn unit of our hospital are highly drug resistant, with high lactamase-producing rates, calling for intense monitor to control the risk factors that predispose the infection of ESBL-producing strains in order to lower the infection rate.

Adolescent ; Adult ; Burn Units ; Child ; Drug Resistance, Bacterial ; Enterobacteriaceae ; drug effects ; Enterobacteriaceae Infections ; epidemiology ; microbiology ; Female ; Humans ; Male ; Microbial Sensitivity Tests ; Middle Aged ; Retrospective Studies ; Risk Factors ; Young Adult ; beta-Lactam Resistance

The global emergence and spread of multidrug resistant bacterial infections in communities and hospitals has become an important issue in public health. The resistance rate of gram-positive cocci to vancomycin and the resistance rate of several gram-negative bacilli against cefotaxime and carbapenem have been continuously increasing. Surveillance of antimicrobial resistance is essential for providing information on the magnitude of and trend in multidrug resistance. Therefore, beginning 2011, more robust and effective management is to be legally required for six multidrug-resistant bacteria that have been linked to healthcare-related infections: vancomycin-resistant Staphylococcus aureus (VRSA), vancomycin-resistant enterococci (VRE), methicillin-resistant S. aureus (MRSA), multidrug-resistant Pseudomonas aeruginosa (MRPA), multidrug-resistant Acinetobacter baumannii (MRAB), and carbapenem-resistant Enterobactericeae (CRE). We have also performed laboratory-based sentinel surveillance for VRSA/VISA since 2002 and carbapenemase-producing Enterobacteriaceae since November, 2010. This article reviews the national surveillance programs, and molecular epidemiology of multidrug-resistant bacteria.
Acinetobacter baumannii ; Bacteria ; Bacterial Infections ; Cefotaxime ; Drug Resistance, Multiple ; Enterobacteriaceae ; Gram-Positive Cocci ; Methicillin Resistance ; Molecular Epidemiology ; Nitriles ; Pseudomonas aeruginosa ; Public Health ; Pyrethrins ; Sentinel Surveillance ; Staphylococcus aureus ; Vancomycin

BACKGROUND: We investigated the rates of fecal transmission of extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae (ESBL-E) and carbapenem-resistant Enterobacteriaceae (CRE) among patients admitted to intensive care units (ICUs). METHODS: From June to August 2012, rectal cultures were acquired from all patients at ICU admission. For patients not carrying ESBL-E or CRE at admission, follow-up cultures were performed to detect acquisition. A chromogenic assay was used to screen for ESBL-E and CRE. Bacterial species identification and antibiotic susceptibility tests were performed using the Vitek 2 system (bioMerieux, France). ESBL genotypes were determined by PCR, and clonal relatedness of the isolates was assessed by pulsed-field gel electrophoresis. RESULTS: Out of 347 ICU admissions, 98 patients were found to be carriers of ESBL-E (28.2%, 98/347). Follow-up cultures were acquired from 91 of the patients who tested negative for ESBL-E at admission; the acquisition rate in this group was 12.1% (11/91), although none was a nosocomial transmission. For CRE, the prevalence of fecal carriage was 0.3% (1/347), and the acquisition rate was 2.9% (4/140). None of the CRE isolates were carbapenemase-producers. CONCLUSIONS: The high prevalence of ESBL-E carriage on admission (28.2%), coupled with rare nosocomial transmission and the very low carriage rate of CRE (0.3%), challenge the routine use of active surveillance in non-epidemic settings. Nevertheless, passive surveillance measures, such as rapid and accurate screening of clinical specimens, will be critical for controlling the spread of CRE.
Anti-Bacterial Agents/pharmacology ; Bacterial Proteins/*metabolism ; Carbapenems/*pharmacology ; Carrier State/epidemiology ; Cross Infection/epidemiology/*transmission ; DNA, Bacterial/analysis ; Drug Resistance, Bacterial/drug effects ; Electrophoresis, Gel, Pulsed-Field ; Enterobacteriaceae/enzymology/genetics/*physiology ; Enterobacteriaceae Infections/epidemiology/*transmission ; Feces/*microbiology ; Genotype ; Humans ; Intensive Care Units ; Polymerase Chain Reaction ; Prevalence ; Republic of Korea/epidemiology ; beta-Lactamases/*metabolism

BACKGROUND: The emergence of carbapenemase-producing Enterobacteriaceae (CPE) represents a major clinical problem because these bacteria are resistant to most antibiotics. CPE remain relatively uncommon in Korea. We report the prevalence, clinical characteristics, and molecular epidemiology of CPE isolates collected from five university hospitals in Korea. METHODS: Between January and December 2015, 393 non-duplicated isolates that were nonsusceptible to ertapenem were analyzed. Production of carbapenemase, extended-spectrum β-lactamase, and AmpC β-lactamase was determined by genotypic tests. Antimicrobial susceptibility profiles were determined by using an Etest. Clonality of Klebsiella pneumoniae carbapenemase (KPC)-2-producing and oxacillinase (OXA)-232-producing Klebsiella pneumoniae isolates was determined by pulsed-field gel electrophoresis (PFGE). RESULTS: Of the 393 isolates tested, 79 (20.1%) were CPE. Of these 79 isolates, 47 (59.5%) harbored the bla(OXA-232) gene while the remaining isolates carried genes bla(KPC-2) (n=27), bla(IMP-1) (n=4), and bla(NDM-1) (n=1). Among the 24 KPC-2 K. pneumoniae isolates from hospital B, 100% were resistant to carbapenems, 8% to colistin, and 0% to tigecycline. Among the 45 OXA-232 K. pneumoniae at hospital C, 95% were resistant to ertapenem, 68% to imipenem, 95% to meropenem, 10% to colistin, and 24% to tigecycline. PFGE analysis revealed a unique pattern for KPC-2 K. pneumoniae and identified 30 isolates belonging to the dominant pulsotypes (PT)1 and PT2 among 41 OXA-232 K. pneumoniae isolates. CONCLUSIONS: CPE strains are present in Korea, with the majority of K. pneumoniae isolates producing OXA-232 and KPC-2. The prevalence and predominant genotypes of CPE show hospital-specific differences.
Aged ; Anti-Bacterial Agents/pharmacology ; Bacterial Proteins/*genetics/metabolism ; Drug Resistance, Bacterial ; Electrophoresis, Gel, Pulsed-Field ; Enterobacteriaceae/drug effects/*enzymology/isolation & purification ; Enterobacteriaceae Infections/diagnosis/epidemiology/*microbiology ; Female ; Genotype ; Hospitals ; Humans ; Male ; Microbial Sensitivity Tests ; Middle Aged ; Prevalence ; Republic of Korea/epidemiology ; beta-Lactamases/*genetics/metabolism

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*

We investigated the occurrence and genetic basis of AmpC beta-lactamase (AmpC)-mediated antibiotic resistance, by examining Escherichia coli, Klebsiella pneumoniae, and Proteus mirabilis isolates at a university hospital, from 2007 to 2010. The ampC genes were detected by multiplex AmpC PCR, and AmpC-positive strains were subjected to DNA sequencing. Extended-spectrum beta-lactamase (ESBL) production was assessed using the ESBL disk test based on the utilization of boronic acid. Carbapenem-resistant isolates were further investigated by the modified Hodge test, a carbapenemase inhibition test and SDS-PAGE experiments. AmpC expression was detected in 1.6% of E. coli (39 DHA-1, 45 CMY-2, and 1 CMY-1) isolates, 7.2% of K. pneumoniae (39 DHA-1, 45 CMY-2, and 1 CMY-1) isolates, and 2.5% of P. mirabilis (8 CMY-2 and 1 CMY-1) isolates. Of the 198 acquired AmpC producers, 58 isolates (29.3%) also produced an ESBL enzyme. Among the acquired AmpC-producing K. pneumoniae isolates, the minimum inhibitory concentration (MIC) MIC50/MIC90 values for cefoxitin, cefotaxime, cefepime, imipenem, and meropenem were >32/>32, 16/>32, 1/16, 0.25/0.5, and <0.125/0.125 microg/mL, respectively. The MIC values for carbapenem were > or =2 microg/mL for 2 K. pneumoniae isolates, both of which carried the blaDHA-1 gene with a loss of OmpK36 expression, but were negative for carbapenemase production. The acquisition of AmpC-mediated resistance in K. pneumoniae isolates increased, as did the proportion of AmpC and ESBL co-producers among the hospital isolates. The accurate identification of isolates producing AmpCs and ESBLs may aid in infection control and will assist physicians in selecting an appropriate antibiotic regimen.
Anti-Bacterial Agents/pharmacology ; Bacterial Proteins/*genetics ; DNA, Bacterial/genetics ; Enterobacteriaceae Infections/*epidemiology/*microbiology ; Escherichia coli/drug effects/enzymology/isolation & purification ; Hospitals, University/statistics & numerical data ; Humans ; Klebsiella pneumoniae/drug effects/enzymology/isolation & purification/*physiology ; Microbial Sensitivity Tests ; Multiplex Polymerase Chain Reaction ; Proteus mirabilis/drug effects/enzymology/isolation & purification ; Republic of Korea/epidemiology ; beta-Lactamases/*genetics