Carbapenems ; pharmacology ; Drug Resistance, Bacterial ; Humans ; Klebsiella Infections ; drug therapy ; microbiology ; Klebsiella pneumoniae ; drug effects

Objective To explore the effects of Scutellaria baicalensis on activity and biofilm formation of Klebsiella pneumonia (Kp).Methods The broth and agar dilution Methods were carried out to determine minimum inhibitory concentration and minimum bactericidal concentration of Scutellaria baicalensis for TW518. VITEK-32 system was used to assay TW518 susceptibility to antibiotics. Kp biofilms were formed in vitro and stained with BacLight Live/Dead stain. The class integron geneⅠ1 mRNA expression was analyzed with RT-PCR.Results The minimum inhibitory concentration of Scutellaria baicalensis on TW518 identified as a Kp colony was 32 mg/ml, and minimum bactericidal concentration was 64 mg/ml. Scutellaria baicalensis and broad-spectrum penicillin, cephalosporin, quinolones, or beta-lactamase had synergistic bactericidal effects. Biofilm formation activity of Kp treated with Scutellaria baicalensis was significantly lower than that of the control group. And class integron geneⅠ1 mRNA expression of TW518 was significantly inhibited by Scutellaria baicalensis.Conclusions Scutellaria baicalensis has sterilization effect on Kp, and Scutellaria baicalensis could effectively inhibit Kp biofilm formation with prolonged treatment. Scutellaria baicalensis might inhibit Kp biofilm formation through down-regulating integron geneⅠ1 expression.
Biofilms ; drug effects ; Integrons ; drug effects ; Klebsiella pneumoniae ; drug effects ; physiology ; Microbial Sensitivity Tests ; Scutellaria baicalensis

Cross Infection ; microbiology ; Humans ; Klebsiella pneumoniae ; classification ; drug effects ; isolation & purification ; Microbial Sensitivity Tests

OBJECTIVETo investigate the epidemiological status of extended-spectrum beta-lactamase (ESBL) producing Escherichia coli (E. coli) and Klebsiella pneumoniae (K. pneumoniae) and the drug resistance profiles of such organisms.

METHODSA total of 282 clinical isolates of E. coli and 180 of K. pneumoniae were collected from different districts of Zhejiang Province. Inhibitor potentiated broth dilution tests were performed for detecting extended-spectrum beta-lactamases. Etests were performed to detect the drug resistance of these strains against nine commonly used antibiotics.

RESULTSThe prevalence of extended-spectrum beta-lactamases in E. coli and K. pneumoniae was 34.0% and 38.3%, respectively. The average prevalence of extended-spectrum beta-lactamases in E. coli and K. pneumoniae was 35.7%. The resistance prevalence of extended spectrum beta-lactamase producing strains to ceftazidime and cefotaxime was 40% and 26% respectively, so were those to cefepime, cefoxitin, piperacillin-tazobactam, cefoperazone-sulbactam, amikacin and ciprofloxacin. All these strains were sensitive to imipenem.

CONCLUSIONThe results in this study showed that the prevalence of extended-spectrum beta-lactamases was high, while extended-spectrum beta-lactamase producing strains were resistant to most antimicrobial agents except imipenem.

Drug Resistance, Bacterial ; Escherichia coli ; drug effects ; enzymology ; Humans ; Klebsiella pneumoniae ; drug effects ; enzymology ; Microbial Sensitivity Tests ; beta-Lactamases ; biosynthesis

OBJECTIVETo study the clinical features and antimicrobial resistance of community-acquired pneumonia caused by Klebsiella pneumoniae in infants.

METHODSThe clinical data of 65 infants with community-acquired pneumonia caused by Klebsiella pneumoniae between 2007 and 2011 were retrospectively studied.

RESULTSOf the 65 infants, 37 cases (57%) were aged ≤3 months, 17 cases (26%) over 4 months, 7 cases (11%) over 7 months and 4 cases (6%) between 13 and 24 months. There were no significant differences in clinical manifestations and chest X-ray features between the infants with community-acquired pneumonia caused by Klebsiella pneumoniae and those with other bacterial pneumonia. Forty strains (62%) of ESBLs-producing Klebsiella pneumoniae were detected. Klebsiella pneumoniae was 100% sensitive to imipenem, meropenem and amikacin but resistant to penicillins and cephalosporins. The resistance rates of ESBLs-producing strains to penicillins, cephalosporins, amoxicillin/clavulanic acid, ampicillin/sulbactam, compound sulfamethoxazole, gentamycin, ciprofloxacin and aztreonam were significantly higher than for non-ESBLs-producing strains. ESBLs-producing strains also showed multiple-drug resistance.

CONCLUSIONSCommunity-acquired pneumonia caused by Klebsiella pneumoniae is common in infants aged ≤3 months. ESBLs-producing strains are prevalent in community-acquired pneumonia caused by Klebsiella pneumoniae and demonstrate both high rates of drug resistance and multiple-drug resistance.

Community-Acquired Infections ; drug therapy ; Drug Resistance, Bacterial ; Female ; Humans ; Infant ; Infant, Newborn ; Klebsiella Infections ; drug therapy ; Klebsiella pneumoniae ; drug effects ; Male ; Pneumonia, Bacterial ; drug therapy

Bacteria ; drug effects ; isolation & purification ; Drug Resistance ; Escherichia coli ; drug effects ; Female ; Haemophilus influenzae ; drug effects ; Humans ; Klebsiella pneumoniae ; drug effects ; Male ; Microbial Sensitivity Tests ; Respiratory Tract Infections ; microbiology ; Staphylococcus aureus ; drug effects ; Streptococcus pneumoniae ; drug effects

Anti-Bacterial Agents ; pharmacology ; Drug Resistance, Bacterial ; Humans ; Imipenem ; pharmacology ; Infant ; Klebsiella pneumoniae ; drug effects ; isolation & purification ; Ventilation ; methods

Objective The aim of our study is to investigate the prevalence of Carbapenem-resistant Klebsiella pneumoniae (CRKP) and the genetic characteristics of the class 1 integron in CRKP on multi-drug resistance.Methods Clinical Klebsiella pneumoniae strains were collected from multiple departments of a hospital in central China. CRKP strains were identified among the isolates, and antibiotics susceptibility of CRKP strains was analyzed. The polymerase chain reaction (PCR) was adopted to amplify the class 1 integron variable area. The integron genetic structure was analyzed with enzyme digestion and DNA sequencing technology. The relation between class 1 integron and drug resistance was analyzed statistically.Results Totally 955 strains of Klebsiella pneumoniae were isolated from varied sites of the hospital, and 117(12.3%) of them were identified as CRKP, with a separation rate of 8.9% (26/292) in 2013, 11.3% (38/336) in 2014 and 16.2% (53/327) in 2015, which shows an increasing trend by year. 44.4% (52/117) of CRKP strains were separated from specimen of ICU, and 61.5% (72/117) were from sputum. Over 95% CRKP strains were resistant to ampicillin/sulbactam, aztreonam, imipenem, meropenem, ceftazidme, cefotaxime, cefepime,and piperacillin, while relatively low resistant rates were found in tigecycline (12.8%) and colistin (35.9%). The class 1 integron was detected in 77.8% (91/117) of CRKP strains. Class 1 integron of CRKP was significantly correlated with the antibiotic resistance to the tobramycin, gentamicin and amikacin (all P<0.01). The gene cassette analysis of variable area of class 1 integron showed that aadA2 accounts for 64.8% (59/91), aacA4-catB8-aadA1 23.1% (21/91), and aadA2-dfrA25 12.1% (11/91).Conclusions CRKP has an increasing trend in a clinical setting in China, and most of them were resistant to multiple antibiotics. Class 1 integron in CRKP has strong ability to capture the genes resistant to aminoglycosides antibiotics from environment, with the aadA2 gene as the most popular one.
Anti-Bacterial Agents ; pharmacology ; Carbapenems ; pharmacology ; Drug Resistance, Bacterial ; Integrons ; Klebsiella pneumoniae ; drug effects ; genetics ; isolation & purification

BACKGROUNDCarbapenems are used to treat severe infections caused by multi-drug-resistant organisms, however, the emergence of carbapenem-resistant bacterial isolates is becoming an increasing therapeutic challenge. Since the first Klebsiella (K.) pneumoniae carbapenemase (KPC)-producing K. pneumoniae was reported in 2001, KPC-producing isolates have been found increasingly, specially in Enterobacteriaceae. The aim of this study was to characterize the mechanisms of a carbapenem-resistant Proteus (P.) mirabilis.

METHODSA carbapenem-resistant P. mirabilis isolate was recovered from pleural drainage fluid of a patient admitted to surgical intensive care unit. Antimicrobial susceptibility testing of the isolate was performed by disk diffusion according to Clinical and Laboratory Standards Institute guidelines, and subsequent minimal inhibitory concentrations were determined with the E-test. Amplification of the bla(KPC) gene generated a positive band and the PCR products were sequenced subsequently. The plasmid of the isolate was extracted and was successfully transformed into Escherichia (E.) coli DH5α.

RESULTSThe P. mirabilis isolate was resistant to all detected antimicrobial agents except tigecycline. KPC-2 was confirmed by DNA sequence analysis. The transformant E. coli was resistant to carbapenems. Further study demonstrated that upstream and downstream regions of bla(KPC-2) were identical to that observed in K. pneumoniae submitted to GenBank from China in 2007.

CONCLUSIONCarbapenem resistance in the P. mirabilis isolate in this study is mainly due to production of KPC-2.

Anti-Bacterial Agents ; pharmacology ; Bacterial Proteins ; metabolism ; China ; Klebsiella pneumoniae ; enzymology ; Proteus mirabilis ; drug effects ; enzymology ; beta-Lactamases ; metabolism

INTRODUCTIONAt the time of the study, 3 plasmid-borne qnr determinants (qnrA, qnrB and qnrS) and 1 plasmid-borne aminoglycoside-modifying enzyme determinant that confers quinolone resistance (aac(6')-Ib-cr) had been described in the literature.

MATERIALS AND METHODSWe studied the prevalence of the 3 qnr determinants in a total of 117 nalidixic acid-resistant urinary isolates of Klebsiella pneumoniae (61 isolates) and Escherichia coli (56 isolates) using multiplex polymerase chain reaction (PCR). Further, a subset of the original strains (comprising 14 E. coli and 38 K. pneumoniae) showing reduced susceptibility to the aminoglycosides underwent PCR for aac(6')-Ib, followed by restriction digestion with BtsCI to detect the variant aac(6')-Ib-cr.

RESULTSTwenty-eight of 61 (45.9%) Klebsiella isolates were found to possess at least 1 qnr determinant. Only 1/56 (1.8%) E. coli isolates were found to possess a qnr determinant. Two of the Klebsiella isolates possessed 2 qnr determinants each (qnrB and qnrS). The predominant determinant was qnrB (19 isolates). There were 11 isolates harbouring qnrS, and only 1 with qnrA. 1/14 (7.1%) E. coli and 35/38 K. pneumoniae (92.1%) were found to possess aac(6')-Ib-cr. There was pairwise association between each of qnr, aac(6')-Ib-cr and the presence of an extended-spectrum beta-lactamase.

CONCLUSIONSA high prevalence of plasmid-mediated quinolone resistance determinants [i.e., qnrS, qnrB and aac(6')-Ib-cr] was found in quinolone-resistant K. pneumoniae isolated in a large hospital in Singapore.

Drug Resistance, Bacterial ; Escherichia coli ; drug effects ; isolation & purification ; Hospitals ; Humans ; Klebsiella pneumoniae ; drug effects ; isolation & purification ; Molecular Sequence Data ; Quinolones ; pharmacology ; R Factors ; Singapore ; Urine ; microbiology