OBJECTIVETo study the effects of Zuojin Pill and Fanzuojin Pill (ZJP and FZJP) on the growth metabolism of enterobacteria from the biothermodynamic viewpoint, and to objectively validate the difference between the two drugs for investigating a new way in congener Chinese drugs research.

METHODSThe growth metabolism power-time curves of enterobacteria affected by ZJP and FZJP in different concentrations were obtained by microcalorimetry. And the activities of the two drugs were assessed depending some related characteristic parameters, including growth rate constant (k), maximum output power (P(max)), peak time (T(p)) , maximum heat-output (Q1), and bacteria inhibition rate (I).

RESULTSWith the drugs' concentration increasing, T(p) was prolonged, k value reduced in enterobacteria, i.e. , the two drugs both inhibited the growth of enterobacteria in different extents. Comparison of inhibiting rates showed that the bacteriostasis activity of ZJP was greater than that of FZJP.

CONCLUSIONSThere was objective difference in activities of inhibiting enterobacteria between ZJP and FZJP. Microcalorimetry could express the features at real-time, on-line and sensitively. It was able to determine the activity of drugs accurately and quickly in appraising congener Chinese drugs, like ZJP and FZJP, by microcalorimetry.

Animals ; Calorimetry ; Drugs, Chinese Herbal ; pharmacology ; Enterobacteriaceae ; drug effects ; Male ; Mice ; Mice, Inbred Strains

INTRODUCTIONTigecycline is an antibiotic belonging to the glycylcycline class with in vitro activity against most Gram-negative bacteria, other than Pseudomonas aeruginosa. This study investigated the in vitro activity of tigecycline against multi-resistant isolates of Enterobacteriaceae and Acinetobacter spp. isolated from clinical specimens in Singapore.

MATERIALS AND METHODSMinimum inhibitory concentrations (MICs) to tigecycline were determined for 173 isolates of multi-resistant Escherichia coli, Klebsiella spp., Enterobacter spp. and Acinetobacter spp. using agar dilution.

RESULTSThe MIC required to inhibit the growth of 90% of organisms varied from 0.5 to 4 mg/L for the study isolates. Based on a resistance breakpoint of >or=8 mg/L, resistance rates varied from 0% to 9%.

CONCLUSIONSTigecycline demonstrates good in vitro activity against multi-resistant strains of Enterobacteriaceae, with more variable activity against multi-resistant strains of Acinetobacter spp.

Acinetobacter ; drug effects ; Anti-Bacterial Agents ; pharmacology ; Drug Resistance, Multiple, Bacterial ; Enterobacteriaceae ; drug effects ; Escherichia coli ; drug effects ; Klebsiella ; drug effects ; Minocycline ; analogs & derivatives ; pharmacology ; Singapore

OBJECTIVETo investigate the drug resistance of enteric bacilli and its relation to the drug resistance gene cassette in the variable region and molecular evolution of class-I integron.

METHODSK-B assay was applied to measure the drug resistance of E.coli, E.cloacae and A.baumannii isolated against twelve antibiotics. The class-I integron and drug resistance gene cassettes in the variable region of the integron were detected by PCR and sequencing of amplification products. The molecular evolution of drug resistance genes in the class-I integrons was analyzed using Clustal X and MEGA software.

RESULTS54.2%-100% of A.baumannii isolates were resistant to the penicillin and cephem antibiotics, while E.coli and E.cloacae isolates had resistance rates of 41.6%-62.5% to cephem antibiotics. 62.5%(15/24) of E.coli, 67.9%(19/28) of E.cloacae and 83.3%(20/24) of A.baumannii isolates were positive for class-I integrons. 81.5% (44/54) of class-I integrons showed 4 different single band spectrums and the other class-I integrons displayed 3 different double band spectrums. In the drug resistance gene cassettes in variable regions of class-I integrons there were 7 types in 4 groups of drug resistance genes, including aac(6'), sad(3"), aad(2"), cat(4') and dfr (types 7, A13 and 15), which induced the resistance to aminoglycosides and sulfamido antibiotics and chloromycin. The class-I integrons in the isolates might be divided into 4 molecular evolution groups according to the diversity of dihydrofolate reductase encoding gene sequences.

CONCLUSIONThe enteric bacilli have a high drug resistance and frequently carry class-I integrons with 7 drug resistance gene cassettes which present 4 different evolutionary pathways.

Anti-Bacterial Agents ; pharmacology ; Drug Resistance, Multiple, Bacterial ; genetics ; Enterobacteriaceae ; drug effects ; genetics ; Evolution, Molecular ; Integrons ; genetics

BACKGROUND: Our study was to investigate the prevalence of carbapenemase genes in strains of Enterobacteriaceae species exhibiting decreased susceptibility to carbapenems in our hospital. METHODS: The carbapenemase producing Enterobacteriaceae species were confirmed by modified Hodge test (MHT) and EDTA-disc synergy test which indicating the production of class B carbapenemases. PCR and sequencing analysis were used to identify the drug-resistant genes. DNA fingerprinting based on enterobacterial repetitive intergenic consensus (ERIC)-PCR was applied to investigate the homology of Enterobacteriaceae species. RESULTS: From a collection of 1,472 Enterobacteriaceae species, 18 isolates with decreased susceptibility to carbapenem treatment were identified and 9 of which were positive by MHT, and 6 of which produced class B carbapenemases. PCR and sequencing analysis of the 18 isolates revealed 4 different carbapenemase genes (blaIMP-8, blaoxa-1, blaIMP-26, and blaoxa-47) in 10 isolates, with the blaIMP-8 and blaoxa-1 genes being the most common (60-70% prevalence). ERIC-PCR showed 5, 2, and 2 unique genotypes for Enterobacter cloacae, Escherichia coli, and Klebsiella pneumoniae, respectively. Three E. coli strains isolated from different patients from the urologic surgery department exhibited the same DNA banding pattern, suggesting a possible clonal dissemination. Majority (17/18) of the carbapenem-unsusceptible Enterobacteriaceae species isolates was obtained from the surgery department of our hospital. CONCLUSIONS: The main carbapenemase genes of Enterobacteriaceae species in our hospital were blaIMP-8 and blaoxa-1. Prevalence of carbapenem resistance may be existed in surgery department and infection control should be taken for preventing further dissemination of drug-resistant strains.
Anti-Bacterial Agents/*pharmacology ; Bacterial Proteins/*genetics ; Carbapenems/*pharmacology ; China ; DNA Fingerprinting ; Drug Resistance, Bacterial/drug effects/genetics ; Enterobacteriaceae/*drug effects/*enzymology/isolation & purification ; Enterobacteriaceae Infections/microbiology ; Genotype ; Hospitals, University ; Humans ; Microbial Sensitivity Tests ; Sequence Analysis, DNA ; beta-Lactamases/*genetics

BACKGROUND: We evaluated the combined use of the modified Hodge test (MHT) and carbapenemase inhibition test (CIT) using phenylboronic acid (PBA) and EDTA to detect carbapenemase-producing Enterobacteriaceae (CPE) and metallo-beta-lactamase (MBL)-producing Pseudomonas spp. METHODS: A total of 49 isolates of CPE (15 Klebsiella pneumoniae carbapenemase [KPC], 5 Guiana extended-spectrum beta-lactamase [GES]-5, 9 New Delhi metallo-beta-lactamase [NDM]-1, 5 Verona integron-encoded metallo-beta-lactamase [VIM]-2, 3 imipenem-hydrolyzing beta-lactamase [IMP], and 12 oxacillinase [OXA]-48-like), 25 isolates of MBL-producing Pseudomonas spp. (14 VIM-2 and 11 IMP), and 35 carbapenemase-negative controls were included. The MHT was performed for all isolates as recommended by the Clinical and Laboratory Standards Institute. Enhanced growth of the indicator strain was measured in mm with a ruler. The CIT was performed by directly dripping PBA and EDTA solutions onto carbapenem disks that were placed on Mueller-Hinton agar plates seeded with the test strain. RESULTS: Considering the results of the MHT with the ertapenem disk in Enterobacteriaceae and Pseudomonas spp., the CIT with the meropenem disk in Enterobacteriaceae, and the imipenem disk in Pseudomonas spp., three combined disk tests, namely MHT-positive plus PBA-positive, EDTA-positive, and MHT-positive plus PBA-negative plus EDTA-negative, had excellent sensitivity and specificity for the detection of KPC- (100% sensitivity and 100% specificity), MBL- (94% sensitivity and 100% specificity), and OXA-48-like-producing isolates (100% sensitivity and 100% specificity), respectively. CONCLUSIONS: Combined use of the MHT and CIT with PBA and EDTA, for the detection of CPE and MBL-producing Pseudomonas spp., is effective in detecting and characterizing carbapenemases in routine laboratories.
Bacterial Proteins/antagonists & inhibitors/*metabolism ; Boronic Acids/chemistry/pharmacology ; Disk Diffusion Antimicrobial Tests/*methods ; Edetic Acid/chemistry/pharmacology ; Enterobacteriaceae/drug effects/*enzymology ; Enterobacteriaceae Infections/diagnosis ; Humans ; Pseudomonas/drug effects/*enzymology ; Pseudomonas Infections/diagnosis ; Sensitivity and Specificity ; beta-Lactamases/chemistry/*metabolism

OBJECTIVETo review the origin, diagnosis, treatment and public health concern of New Delhi metallo-β-lactamase (NDM)-producing bacteria.

DATA SOURCESWe searched database for studies published in English. The database of PubMed from 2007 to 2015 was used to conduct a search using the keyword term "NDM and Acinetobacter or Enterobacteriaceae or Pseudomonas aeruginosa."

STUDY SELECTIONWe collected data including the relevant articles on international transmission, testing methods and treatment strategies of NDM-positive bacteria. Worldwide NDM cases were reviewed based on 22 case reports.

RESULTSThe first documented case of infection caused by bacteria producing NDM-1 occurred in India, in 2008. Since then, 13 blaNDM variants have been reported. The rise of NDM is not only due to its high rate of genetic transfer among unrelated bacterial species, but also to human factors such as travel, sanitation and food production and preparation. With limited treatment options, scientists try to improve available therapies and create new ones.

CONCLUSIONSIn order to slow down the spread of these NDM-positive bacteria, a series of measures must be implemented. The creation and transmission of blaNDM are potentially global health issues, which are not issues for one country or one medical community, but for global priorities in general and for individual wound care practitioners specifically.

Carbapenems ; pharmacology ; Drug Resistance, Multiple, Bacterial ; Enterobacteriaceae ; drug effects ; Humans ; Microbial Sensitivity Tests ; Pseudomonas aeruginosa ; drug effects ; Public Health ; beta-Lactamases ; metabolism

Ampicillin ; therapeutic use ; Anti-Infective Agents ; therapeutic use ; Enterobacteriaceae ; drug effects ; pathogenicity ; Enterobacteriaceae Infections ; drug therapy ; microbiology ; Female ; Hospitals, Military ; Humans ; Male ; Sulbactam ; therapeutic use ; Urinary Tract Infections ; drug therapy ; microbiology

BACKGROUND: The modified Hodge test (MHT) was designed to detect carbapenemase-producing Enterobacteriaceae (CPE). This study evaluated variables to improve the performance of MHT. METHODS: Carbapenem-resistant Enterobacteriaceae isolated from November 2010 to March 2013 at the Asan Medical Center, were evaluated, including 33 metallo-beta-lactamase (MBL) producers and 103 non-CPEs. MHT was performed by using two carbapenem disks (ertapenem and meropenem; Becton Dickinson, USA), three media (Mueller-Hinton agar (MHA), MacConkey agar (MAC), and zinc-enriched MHA), and two inoculums (0.5-McFarland [McF] suspension and a 10-fold dilution of it.) PCR was performed to detect beta-lactamase genes of the MBL, AmpC, and CTX-M types. RESULTS: The sensitivity of MHT for detecting New Delhi metallo-beta-lactamase (NDM) producers was highest using ertapenem and 0.5-McF, 52.0% on MHA and 68.0% on MAC, respectively. NDM-producing Klebsiella pneumoniae (NDMKP) were detected with higher sensitivity on MAC (78.6%) vs. MHA (28.6%) (P=0.016), but VIM-producing Enterobacter, Citrobacter, and Serratia were detected with higher sensitivity on MHA (78.5%) vs. MAC (14.3%) (P=0.004). MBL producers were consistently identified with lower sensitivity using meropenem vs. ertapenem, 39.4% vs. 60.6% (P=0.0156), respectively. The effects of zinc and inoculum size were insignificant. Enterobacter aerogenes producing unspecified AmpC frequently demonstrated false positives, 66.7% with ertapenem and 22.2% with meropenem. CONCLUSIONS: The MHT should be adjusted for the local distribution of species and the carbapenemase type of MBL producers. MAC and ertapenem are preferable for assessing NDMKP, but MHA is better for VIM. Laboratory physicians should be aware of the limited sensitivity of MHT and its relatively high false-positive rate.
Anti-Bacterial Agents/pharmacology ; Carbapenems/pharmacology ; DNA, Bacterial/genetics/metabolism ; Disk Diffusion Antimicrobial Tests ; Drug Resistance, Bacterial ; Enterobacteriaceae/drug effects/*enzymology/isolation & purification ; Enterobacteriaceae Infections/microbiology ; Humans ; Multiplex Polymerase Chain Reaction ; Phenotype ; beta-Lactamases/genetics/*metabolism

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

BACKGROUNDIdentification of hospitalized carbapenem-resistant Enterobacteriaceae (CRE)-positive patient is important in preventing nosocomial transmission. The objective of this study was to illustrate the implementation of proactive infection control measures in preventing nosocomial transmission of CRE in a healthcare region of over 3200 beds in Hong Kong between October 1, 2010 and December 31, 2011.

METHODSThe program included active surveillance culture in patients with history of medical tourism with hospitalization and surgical operation outside Hong Kong within 12 months before admission, and "added test" as an opportunistic CRE screening in all fecal specimens submitted to the laboratory. Outbreak investigation and contact tracing were conducted for CRE-positive patients. Serial quantitative culture was performed on CRE-positive patients and the duration of fecal carriage of CRE was analyzed.

RESULTSDuring the study period, a total of 6533 patients were screened for CRE, of which 76 patients were positive (10 from active surveillance culture, 65 from "added test", and 1 secondary case from contact tracing of 223 patients with no nosocomial outbreak), resulting in an overall rate of CRE fecal carriage of 1.2%. The median time of fecal carriage of CRE was 43 days (range, 13-119 days). Beta-lactam-beta-lactamase-inhibitors, cephalosporins, and fluoroquinolones were associated significantly with high fecal bacterial load when used 90 days before CRE detection, while use of cephalosporins, carbapenems, and fluoroquinolones after CRE detection are significantly associated with longer duration of carriage. The duration of fecal carriage of CRE also correlates significantly with the initial fecal bacterial load (Pearson correlation: 0.53; P = 0.02).

CONCLUSIONProactive infection control measures by enhanced surveillance program identify CRE-positive patients and data obtained are useful for the planning of and resource allocation for CRE control.

Anti-Bacterial Agents ; therapeutic use ; Carbapenems ; therapeutic use ; Cephalosporins ; therapeutic use ; Drug Resistance, Bacterial ; Enterobacteriaceae ; drug effects ; Enterobacteriaceae Infections ; prevention & control ; transmission ; Fluoroquinolones ; therapeutic use ; Humans ; Infection Control ; methods