OBJECTIVES: To investigate the therapeutic mechanism of Thesium chinense Turcz. (TCT) for antibiotic-associated diarrhea (AAD). METHODS: Network pharmacology, KEGG pathway enrichment analysis and molecular docking were used to identify the shared targets and genes of TCT and AAD, the key signaling pathways and the binding between the active components in TCT and the core protein targets. In a Kunming mouse model of AAD established by intragastric administration of lincomycin hydrochloride, the effects of daily gavage of 1% carboxymethyl cellulose sodium or TCT gel solutions at 1.5 g/kg and 3 g/kg (n=10) on body weight and diarrhea were observed. HE staining, ELISA, 16S rRNA sequencing, and Western blotting were used to examine pathologies, expression levels of IL-6 and TNF-α, changes in gut microbiota, and protein expressions of EGFR, p-EGFR, PI3K, p-PI3K, Akt, and p-Akt in the colon tissues of the mice. RESULTS: We identified a total of 66 active components of TCT and 68 core targets including EGFR, STAT3 and PIK3CA. KEGG pathway enrichment analysis suggested that the therapeutic effects of TCT was mediated primarily through the PI3K/Akt signaling pathway. Molecular docking showed that EGFR had the highest binding affinity with coniferin, and the EGFR-coniferin complex maintained a stable conformation at 10 ns, whose stability was also confirmed by Gibbs free energy analysis. In the mouse models of AAD, treatment with TCT significantly improved colonic tissue morphology, decreased colonic levels of TNF-α and IL-6, increased gut microbiota diversity, and modulated the relative abundances of the key genera including Lactobacillus and Bacteroides. TCT treatment also markedly reduced protein expressions of p-EGFR, p-PI3K and p-Akt in the colon tissues of the mice. CONCLUSIONS TCT can alleviate AAD in mice by modulating gut microbiota composition, regulating the EGFR/PI3K/Akt signaling pathway, and reducing TNF‑α and IL-6 expressions.
Animals ; Gastrointestinal Microbiome/drug effects* ; Signal Transduction/drug effects* ; Mice ; ErbB Receptors/metabolism* ; Proto-Oncogene Proteins c-akt/metabolism* ; Diarrhea/drug therapy* ; Phosphatidylinositol 3-Kinases/metabolism* ; Anti-Bacterial Agents/adverse effects* ; Drugs, Chinese Herbal/therapeutic use* ; Molecular Docking Simulation

Anti-Bacterial Agents/therapeutic use* ; Cytokines ; Humans ; Inflammation/drug therapy* ; Pore Forming Cytotoxic Proteins ; Psoriasis/drug therapy*

PURPOSE: Tigecycline is one of the drugs used to treat multi-drug resistant Klebsiella pneumoniae (K. pneumoniae) infections, including complicated skin and soft tissue infections, complicated intra-abdominal infection, and community-acquired pneumonia in the Republic of Korea. However, since its commercial release, K. pneumoniae resistance against tigecycline has been reported, and there is a serious concern about the spread of tigecycline resistant bacteria. MATERIALS AND METHODS: In this study, we collected and analyzed 342 isolates from 23 hospitals in the Republic of Korea to determine the mechanisms of tigecycline susceptibility and their clonal types. The hospitals include several from each province in the Republic of Korea, except Jeju, an island province, and nonsusceptibility among the isolates was tested by the disk diffusion method. In our lab, susceptibility was checked again using the broth dilution method, and clonal types were determined using the multilocus sequence typing protocol. Real-time PCR was performed to measure the ramR mutation in the isolates nonsusceptible to tigecycline, which would suggest an increased expression of the AcrAB multidrug pump. RESULTS: Fifty-six K. pneumoniae isolates were found to be nonsusceptible, 16% of the 342 collected. Twenty-seven and nine isolates of the tigecycline nonsusceptible isolates had mutations in the ramR and rpsJ genes, respectively; while 18 nonsusceptible isolates harbored the tetA gene. Comparison of isolates with and without ramR mutation showed a significant statistical difference (p<0.05) for expression of AcrAB. Moreover, the most common clonal types, as observed in our study, appear to be ST11 and ST789. CONCLUSION: Several dominate clonal types infer tigecycline resistance to K. pneumoniae, including ST11, ST768, ST15, ST23, ST48, and ST307. There does not seem to be a transferrable medium, such as plasmid, for the resistance yet, although mutation of the ramR gene may be a common event, accounting for 48% of the nonsusceptibility in this study.
Anti-Bacterial Agents/*pharmacology/therapeutic use ; Bacterial Proteins ; *Drug Resistance, Bacterial ; Humans ; Klebsiella Infections/*drug therapy ; Klebsiella pneumoniae/*drug effects/genetics/*isolation & purification ; Microbial Sensitivity Tests ; Minocycline/*analogs & derivatives/pharmacology/therapeutic use ; Multilocus Sequence Typing ; Plasmids ; Polymerase Chain Reaction ; Real-Time Polymerase Chain Reaction ; Republic of Korea

No abstract available.
Anti-Bacterial Agents/pharmacology ; Bacterial Proteins/genetics ; Ceftriaxone/pharmacology/therapeutic use ; Ciprofloxacin/pharmacology/therapeutic use ; DNA, Bacterial/analysis/metabolism ; Disk Diffusion Antimicrobial Tests ; *Drug Resistance, Bacterial ; Female ; Humans ; Neisseria meningitidis/drug effects/genetics/*isolation & purification ; Polymerase Chain Reaction ; Sepsis/*diagnosis/drug therapy/microbiology ; Transcription Factors/genetics ; Young Adult

No abstract available.
Adult ; Anti-Bacterial Agents/therapeutic use ; Bacterial Proteins/chemistry/genetics/metabolism ; Brucella melitensis/classification/genetics/*isolation & purification ; Brucellosis/*diagnosis/drug therapy/microbiology ; Doxycycline/therapeutic use ; Humans ; Magnetic Resonance Imaging ; Male ; Phylogeny ; Polymerase Chain Reaction ; Republic of Korea ; Rifampin/therapeutic use ; Sequence Analysis, DNA ; Spondylitis/diagnostic imaging

BACKGROUND: We investigated the whole genome sequence (WGS) of a carbapenem-resistant Acinetobacter baumannii isolate belonging to the global clone 2 (GC2) and predicted resistance islands using a software tool. METHODS: A. baumannii strain YU-R612 was isolated from the sputum of a 61-yr-old man with sepsis. The WGS of the YU-R612 strain was obtained by using the PacBio RS II Sequencing System (Pacific Biosciences Inc., USA). Antimicrobial resistance genes and resistance islands were analyzed by using ResFinder and Genomic Island Prediction software (GIPSy), respectively. RESULTS: The YU-R612 genome consisted of a circular chromosome (ca. 4,075 kb) and two plasmids (ca. 74 kb and 5 kb). Its sequence type (ST) under the Oxford scheme was ST191, consistent with assignment to GC2. ResFinder analysis showed that YU-R612 possessed the following resistance genes: four β-lactamase genes bla(ADC-30), bla(OXA-66), bla(OXA-23), and bla(TEM-1); armA, aadA1, and aacA4 as aminoglycoside resistance-encoding genes; aac(6')Ib-cr for fluoroquinolone resistance; msr(E) for macrolide, lincosamide, and streptogramin B resistance; catB8 for phenicol resistance; and sul1 for sulfonamide resistance. By GIPSy analysis, six putative resistant islands (PRIs) were determined on the YU-R612 chromosome. Among them, PRI1 possessed two copies of Tn2009 carrying bla(OXA-23), and PRI5 carried two copies of a class I integron carrying sul1 and armA genes. CONCLUSIONS: By prediction of resistance islands in the carbapenem-resistant A. baumannii YU-R612 GC2 strain isolated in Korea, PRIs were detected on the chromosome that possessed Tn2009 and class I integrons. The prediction of resistance islands using software tools was useful for analysis of the WGS.
Acinetobacter Infections/*drug therapy/microbiology ; Acinetobacter baumannii/drug effects/*genetics/isolation & purification ; Anti-Bacterial Agents/pharmacology/*therapeutic use ; Bacterial Proteins/genetics ; Carbapenems/*therapeutic use ; DNA, Bacterial/chemistry/*genetics/metabolism ; Drug Resistance, Bacterial ; Genomic Islands/genetics ; Humans ; Microbial Sensitivity Tests ; Multilocus Sequence Typing ; Plasmids/genetics/metabolism ; Polymerase Chain Reaction ; Sequence Analysis, DNA

BACKGROUND: Acinetobacter baumannii infections are difficult to treat owing to the emergence of various antibiotic resistant isolates. Because treatment options are limited for multidrug-resistant (MDR) A. baumannii infection, the discovery of new therapies, including combination therapy, is required. We evaluated the synergistic activity of colistin, doripenem, and tigecycline combinations against extensively drug-resistant (XDR) A. baumannii and MDR A. baumannii. METHODS: Time-kill assays were performed for 41 XDR and 28 MDR clinical isolates of A. baumannii by using colistin, doripenem, and tigecycline combinations. Concentrations representative of clinically achievable levels (colistin 2 microg/mL, doripenem 8 microg/mL) and achievable tissue levels (tigecycline 2 microg/mL) for each antibiotic were used in this study. RESULTS: The colistin-doripenem combination displayed the highest rate of synergy (53.6%) and bactericidal activity (75.4%) in 69 clinical isolates of A. baumannii. Among them, thedoripenem-tigecycline combination showed the lowest rate of synergy (14.5%) and bacteri-cidal activity (24.6%). The doripenem-tigecycline combination showed a higher antagonistic interaction (5.8%) compared with the colistin-tigecycline (1.4%) combination. No antagonism was observed for the colistin-doripenem combination. CONCLUSIONS: The colistin-doripenem combination is supported in vitro by the high rate of synergy and bactericidal activity and lack of antagonistic reaction in XDR and MDR A. baumannii. It seems to be necessary to perform synergy tests to determine the appropri-ate combination therapy considering the antagonistic reaction found in several isolates against the doripenem-tigecycline and colistin-tigecycline combinations. These findings should be further examined in clinical studies.
Acinetobacter Infections/drug therapy/microbiology ; Acinetobacter baumannii/*drug effects/genetics/isolation & purification ; Anti-Bacterial Agents/*pharmacology/therapeutic use ; Bacterial Proteins/genetics ; Carbapenems/*pharmacology/therapeutic use ; Colistin/*pharmacology/therapeutic use ; Drug Resistance, Multiple, Bacterial/*drug effects ; Drug Synergism ; Drug Therapy, Combination ; Humans ; Microbial Sensitivity Tests ; Minocycline/*analogs & derivatives/pharmacology/therapeutic use ; Multilocus Sequence Typing ; beta-Lactamases/genetics

BACKGROUND: We determined the epidemiological characteristics of erythromycin (EM)-resistant Streptococcus pyogenes (group A streptococci, GAS) strains isolated from Korea and Japan, using emm genotyping and multilocus sequence typing (MLST). METHODS: Clinical isolates of GAS had been collected from 1992 to 2012 in Korea and from 2004 to 2009 in Japan. EM resistance was determined by the microdilution method, and resistance genotypes were assessed by PCR. The emm genotyping and MLST were performed by DNA sequencing. RESULTS: The emm genotypes and sequence types (STs) were concordant in 143 (85.1%) of 168 EM-resistant GAS strains from Korea. ST36/emm12 (35.1%), ST52/emm28 (22.6%), and ST49/emm75 (16.1%) were the most common types. Most of the ST36 (93.9%) and ST52 (95.8%) strains harbored erm(B), whereas strains ST49, ST42, and ST15 contained mef(A). The concordance between emm genotypes and STs was 41 (93.2%) among 44 EM-resistant GAS strains from Japan. ST36/emm12 (34.1%), ST49/emm75 (18.2%), and ST28/emm1 (15.9%) were the major types. ST36 isolates harbored either erm(B) (56.3%) or mef(A) (37.5%), whereas isolates ST28, ST49, and ST38 carried only mef(A). The proportion of erm(B) and mef(A) was 66.1% and 33.3% in Korea and 22.7% and 68.2% in Japan, respectively. CONCLUSIONS: The common STs in Korea and Japan were ST36 and ST49, whereas ST52 was present only in Korea and ST28 only in Japan. Genotype erm(B) was predominant in Korea, whereas mef(A) was frequent in Japan. There were differences between Korea and Japan regarding the frequencies of emm genotypes, STs, and EM resistance genes among the EM-resistant GAS.
Anti-Bacterial Agents/*pharmacology/therapeutic use ; Bacterial Proteins/*genetics ; Bacterial Typing Techniques ; *Drug Resistance, Bacterial ; Epidemiologic Studies ; Erythromycin/*pharmacology/therapeutic use ; Genotype ; Humans ; Japan/epidemiology ; Microbial Sensitivity Tests ; Multilocus Sequence Typing ; Republic of Korea/epidemiology ; Streptococcal Infections/drug therapy/*microbiology ; Streptococcus pyogenes/drug effects/*genetics/isolation & purification

OBJECTIVETo study the drug resistance of Acinetobacter baumannii (AB) producing VIM-2-type metallo-β-lactamase (MBL) isolated from burn patients of our ward against carbapenem antibiotics and its homology.

METHODSA total of 400 strains of AB (identified) were isolated from sputum, urine, blood, pus, and wound drainage. of burn patients hospitalized in our ward from September 2011 to March 2014. Drug resistance of the 400 strains of AB to 15 antibiotics, including compound sulfamothoxazole, aztreonam, etc. , was tested using the automatic microorganism identifying and drug sensitivity analyzer. Among the carbapenems-resistant AB isolates, modified Hodge test was applied to screen carbapenemase-producing strains. The carbapenemase genes of the carbapenemase-producing strains, and the mobile genetic elements class I-integron (Intl1) gene and conserved sequence (CS) of carbapenemase-producing strains carrying blaVIM-2 gene were determined with PCR and DNA sequencing. For carbapenemase-producing strains carrying blaVIM-2 gene, synergism test with imipenem-ethylene diamine tetraacetic acid (EDTA) and enhancement test with imipenem-EDTA and ceftazidime-EDTA were used to verify the MBL-producing status. Drug resistance of the VIM-2-type MBL-producing AB strains was analyzed. For VIM-2-type MBL-producing AB strains, plasmid conjugation experiment was used to explore the transfer of plasmid; outer membrane protein (OMP) CarO gene was detected by PCR. For VIM-2-type MBL-producing AB strains carrying CarO gene, the protein content of CarO was analyzed with sodium dodecyl sulfate polyacrylamide gel electro- phoresis. The repetitive consensus sequence of Enterobacteriaceae genome PCR (ERIC-PCR) was carried out for gene typing of VIM-2-type MBL-producing AB strains to analyze their homology.

RESULTS(1) The resistant rates of the 400 strains of AB against levofloxacin and compound sulfamethoxazole were low. A total of 381 carbapenems-resistant AB strains were screened, including 240 carbepenemase-producing strains. (2) Out of the 240 carbepenemase-producing strains, 18 strains were found to harbor the blaVIM-2 gene, accounting for 7.5%; 133 strains carried the blaTEM-1 gene, accounting for 55.42%; 195 strains carried the blaOXA23 gene, accounting for 81.25%; 188 strains carried the bla(armA) gene, accounting for 78.33%. (3) Eighteen carbepenemase-producing strains which carried the bla(VIM-2) gene were found to carry the Intl1 gene, showing the Intl1-VIM linkage. Simultaneously, Intl1 variable area CS showed diversity. (4) Eighteen carbepenemase-producing strains which carried the blaVIM-2 gene were verified to produce MBL. The resistant rates of the 18 strains of AB against compound sulfamethoxazole were the lowest, followed by levofloxacin and cefoperazone/sulbactam, and those against the other antibiotics were above 60.00%. (5) Through multiple joint tests, plasmid conjugation experiment positive transfer strain was not found in 18 VIM-2-type MBL-producing AB strains. (6) Nine out of the 18 VIM-2-type MBL-producing AB strains were found to carry CarO gene. The OMP CarO of VIM-2-type MBL-producing AB strains carrying CarO gene was lost or lowered in the protein content. (7) The 18 VIM-2-type MBL-producing AB strains were classified into 6 genotypes by the ERIC-PCR. There were respectively 6, 4, 3, and 1 stain (s) in genotypes A, B, C, and F, and there were 2 strains in genotypes D and E respectively.

CONCLUSIONSThe resistance mechanism of AB against carbapenems is mainly mediated by blaTEM-1, blaOXA-23, and bla(arma); meanwhile, VIM-2-type MBL-producing and lack or change in OMP CarO are attributable to carbapenems resistance of clinically isolated AB from burn wards, and the Intl1 gene may take a part in blaVIM-2 gene transmission.

Acinetobacter baumannii ; drug effects ; enzymology ; genetics ; isolation & purification ; Anti-Bacterial Agents ; pharmacology ; therapeutic use ; Bacterial Proteins ; Burns ; drug therapy ; microbiology ; Carbapenems ; pharmacology ; Drug Resistance, Bacterial ; Genes, Bacterial ; Humans ; Imipenem ; pharmacology ; Microbial Sensitivity Tests ; Sulbactam ; pharmacology ; beta-Lactamases ; genetics

The emergence and spread of carbapenems-resistant Klebsiella pneumoniae (CRKP) in burn ward is an important threat to burn management. CRKP isolates are resistant to almost all available antibiotics and are susceptible only to polymyxins and tigecycline. The mechanism of the drug resistance of CRKP is associated with the plasmid-encoded carbapenemase Klebsiella pneumoniae carbapenemase (KPC), a carbapenem-hydrolyzing β-lactamase. Antibiotics which can currently be used to treat CRKP infection include polymyxins, tigecycline, and some aminoglycosides. The efficacy of using antibiotics in combination is better than that of single-agent therapy for the treatment of CRKP infection in bloodstream. In order to control CRKP infection in burn patients, strategies for preventing CRKP dissemination in burn ward are strongly advocated.
Anti-Bacterial Agents ; therapeutic use ; Bacterial Proteins ; Burns ; drug therapy ; Carbapenems ; pharmacology ; Drug Resistance, Bacterial ; Humans ; Klebsiella Infections ; drug therapy ; microbiology ; prevention & control ; Klebsiella pneumoniae ; drug effects ; Microbial Sensitivity Tests ; Minocycline ; analogs & derivatives ; therapeutic use ; beta-Lactam Resistance ; beta-Lactamases