No abstract available.
Anti-Bacterial Agents/*pharmacology ; Azabicyclo Compounds/*pharmacology ; Bacterial Proteins/genetics ; Ceftazidime/*pharmacology ; Cephalosporins/*pharmacology ; DNA, Bacterial/genetics/metabolism ; Drug Resistance, Bacterial/*drug effects ; Gram-Negative Bacteria/drug effects/*isolation & purification ; Humans ; Microbial Sensitivity Tests ; Penicillanic Acid/*analogs & derivatives/pharmacology ; Pseudomonas aeruginosa/drug effects/isolation & purification ; Real-Time Polymerase Chain Reaction

No abstract available.
Anti-Bacterial Agents/pharmacology ; DNA, Bacterial/chemistry/genetics/metabolism ; Drug Resistance, Bacterial ; Integrons/*genetics ; Microbial Sensitivity Tests ; Pseudomonas aeruginosa/drug effects/*enzymology/isolation & purification ; Sequence Analysis, DNA ; beta-Lactamases/*genetics

OBJECTIVETo investigate antimicrobial resistance of Klebsiella pneumoniae and Pseudomonas aeruginosa isolates in fecal samples from rat-like animals.

METHODSRat-like animals were captured using cages around a hospital and the neighboring residential area between March and October, 2015. K. pneumoniae and P. aeruginosa were isolated from the fecal samples of the captured animals. Antimicrobial susceptibility test was performed according to the guidelines of Clinical and Laboratory Standards Institute (2014).

RESULTSA total of 329 rat-like animals were captured, including 205 Suncus murinus, 111 Rattus norvegicus, 5 Rattus flavipectus and 8 Mus musculus. The positivity rates of K. pneumoniae and P. aeruginosa were 78.4% and 34.7% in the fecal samples from the captured animals, respectively. K. pneumoniae isolates from Suncus murinus showed a high resistance to ampicillin, cephazolin, nitrofurantoin, piperacillin and cefotaxime (with resistance rates of 100%, 51.2%, 44.2%, 37.2%, and 23.3%, respectively), and K. pneumoniae isolates from Rattus spp. showed a similar drug-resistance profile. The prevalence rates of multidrug resistance and ESBLs were 40.9% and 10.7%, respectively. P. aeruginosa from both Suncus murinus and Rattus spp. exhibited the highest resistance rates to aztreonam (12.4% and 16.0%, respectively), followed by penicillins and fluoroquinolones. P. aeruginosa isolates were susceptible to cephems, aminoglycosides and carbapenems (with resistance rates below 5%).

CONCLUSIONK. pneumoniae and P. aeruginosa isolated from rat-like animals showed drug-resistance profiles similar to those of the strains isolated from clinical patients, suggesting that the possible transmission of K. pneumoniae and P. aeruginosa between rat-like animals and human beings.

Animals ; Anti-Bacterial Agents ; pharmacology ; Carbapenems ; pharmacology ; Drug Resistance, Bacterial ; Fluoroquinolones ; pharmacology ; Humans ; Klebsiella pneumoniae ; drug effects ; isolation & purification ; Mice ; Murinae ; microbiology ; Pseudomonas aeruginosa ; drug effects ; isolation & purification ; Rats

BACKGROUND: Extensively drug-resistant (XDR) Pseudomonas aeruginosa and Acinetobacter baumannii are a threat to hospitalized patients. We evaluated the effects of antimicrobial combinations on XDR P. aeruginosa and A. baumannii isolates. METHODS: P. aeruginosa and A. baumannii isolates, which were resistant to all antibiotics except colistin (CL), were collected from eight hospitals in Korea. Genes encoding metallo-beta-lactamases (MBLs) and OXA carbapenemases were detected by PCR in eight P. aeruginosa and 30 A. baumannii isolates. In vitro synergy of antimicrobial combinations was tested by using the checkerboard method. RESULTS: Minimum inhibitory concentrations of beta-lactams, aminoglycosides, and fluoroquinolones were very high, while that of CL was low for majority of XDR P. aeruginosa and A. baumannii isolates. Antimicrobial combinations including Imipenem (IPM)-CL, ceftazidime (CAZ)-CL, and rifampin (RIF)-CL exerted only additive/indifferent effects on majority of XDR P. aeruginosa isolates. Proportions of XDR A. baumannii isolates that showed synergistic and additive/indifferent inhibition after treatment with antimicrobial combinations used are as follows: IPM-ampicillin-sulbactam (AMS), 17% and 80% isolates, respectively; IPM-rifampin (RIF), 13% and 81% isolates, respectively; IPM-CL, 13% and 87% isolates, respectively; and RIF-COL, 20% and 73% isolates, respectively. Significant proportion (19%) of XDR P. aeruginosa isolates produced MBLs, and majority (82%) of A. baumannii isolates produced either MBLs or OXA-23. CONCLUSIONS: Our results suggest that combinations of IPM-AMS, IPM-RIF, IPM-CL, and RIF-CL are more useful than individual drugs for treating 13-20% of XDR A. baumannii infections.
Acinetobacter baumannii/*drug effects/genetics/isolation & purification ; Aminoglycosides/pharmacology ; Anti-Infective Agents/*pharmacology ; Bacterial Proteins/genetics/metabolism ; Drug Resistance, Multiple, Bacterial/*drug effects ; Drug Synergism ; Fluoroquinolones/pharmacology ; Imipenem/pharmacology ; Microbial Sensitivity Tests ; Polymerase Chain Reaction ; Pseudomonas aeruginosa/*drug effects/genetics/isolation & purification ; beta-Lactamases/genetics/metabolism

OBJECTIVETo analyze the drug resistance and drug resistance genes of imipenem-resistant Pseudomonas aeruginosa (IRPA) strains isolated from burn wards.

METHODSFrom June 2011 to June 2012, 30 strains of IRPA were isolated from wound excretion, sputum, and venous catheter attachment from burn patients hospitalized in Guangzhou Hospital of Integrated Traditional Chinese and Western Medicine. Drug resistance of the IRPA to 12 antibiotics commonly used in clinic, including ceftazidime, amikacin, ciprofloxacin, etc., was tested with K-B paper agar disk diffusion method. Metallo-β-lactamase (MBL)-producing IRPA was detected by synergism test with imipenem-2-mercaptoethanol. Plasmid of IRPA was extracted, and it was inserted into competent cells, producing transformation strains (TSs). Drug resistance of TSs to imipenem and the MBL-producing TSs were detected. The genes blaIMP, blaVIM, blaOXA-1, blaOXA-2 and blaOXA-10 of IRPA and the TSs were detected by polymerase chain reaction. The drug resistance of IRPA producing MBL or OXA enzyme was summed up.

RESULTSThe sensitive rates of the 30 strains of IRPA to the 12 antibiotics were equal to or above 60.0%. Six strains of MBL-producing IRPA were screened. Twenty-four TSs were resistant to imipenem, and 6 strains among them were MBL-producing positive. Among the 30 strains of IRPA, 6 strains and their corresponding TSs carried blaVIM; 20 strains and their corresponding TSs carried blaOXA-10; no strain was detected to carry blaIMP, blaOXA-1 or blaOXA-2. Two strains and their corresponding TSs were detected carrying both blaVIM and blaOXA-10. No significant difference of drug resistance was observed between strains producing only MBL or OXA enzyme, with the same high resistance to β-lactam antibiotics and some degree of sensitivity to aminoglycoside antibiotics. Strains producing enzymes MBL and OXA were all resistant to the 12 antibiotics.

CONCLUSIONSIRPA strains isolated from burn wards of Guangzhou Hospital of Integrated Traditional Chinese and Western Medicine are multidrug-resistant, and they mainly produce type B and D carbapenemases.

Burns ; microbiology ; Cross Infection ; microbiology ; Drug Resistance, Multiple, Bacterial ; genetics ; Humans ; Imipenem ; Microbial Sensitivity Tests ; Pseudomonas aeruginosa ; drug effects ; genetics ; isolation & purification

OBJECTIVETo study the resistance mechanism and homology of carbapenems-resistant Pseudomonas aeruginosa (PA).

METHODSA total of 812 strains of PA (identified) were isolated from sputum, urine, blood, pus, and drainage of patients with burn, severe pneumonia, diabetes, chronic obstructive pneumonia, myocarditis, liver transplantation, or brainstem hemorrhage hospitalized from January to September 2012. Drug resistance of the 812 strains of PA to 15 antibiotics commonly used in clinic, including piperacillin, imipenem, etc., was tested using the automatic microorganism identifying and drug sensitivity analyzer. Among the carbapenems-resistant PA isolates, synergism test with imipenem-ethylene diamine tetraacetic acid (EDTA) and enhancement test with imipenem-EDTA and ceftazidime-EDTA were used to screen metallo-β-lactamase (MBL)-producing strains; modified Hodge test was used to screen strains producing Klebsiella pneumoniae carbapenemases (KPC); the carbapenemase gene, plasmid mediated quinolone resistant (PMQR) gene, and mobile genetic elements (MGE) were detected by polymerase chain reaction (PCR). In addition, a comparative analysis of the PMQR gene carrying level between the carbapenemase gene positive strains and carbapenemase gene negative strains was carried out. The repetitive consensus sequence of Enterobacteriaceae genome PCR (ERIC-PCR) was carried out for gene typing. Moreover, the source and resistance genes of strains with the same genotype were analyzed. Data were processed with Fisher's exact probability test.

RESULTSThe sensitive rates of the 812 strains of PA to ceftriaxone and trimethoprim-sulfamethoxazole were high, respectively 83.07% and 88.19%, and those of the other antibiotics ranged from 17.30% to 55.18%. Twenty-four carbapenems-resistant PA strains were screened, including 11 MBL-producing strains and 2 KPC-producing strains. Eleven carbapenems-resistant PA strains were found to harbor the blaVIM-2 gene, accounting for 45.83%; 2 carbapenems-resistant PA strains carried the blaKPC-2 gene, accounting for 8.33%. Fourteen carbapenems-resistant PA strains only harbored the PMQR gene acc (6')-Ib-cr, accounting for 58.33%; 3 carbapenems-resistant PA strains (12.50%) harbored the PMQR genes acc (6')-Ib-cr and qnr, including 1 strain with qnr A1 and 2 strains with qnr B4. Ten carbapenems-resistant PA strains carried the MGE gene ISCR1, accounting for 41.67%; 6 carbapenems-resistant PA strains carried the MGE gene ISEcp1, accounting for 25.00%. In addition, 3 carbapenems-resistant PA strains co-harbored the MGE genes ISCR1 and ISEcp1 (accounting for 12.50%), while only 1 carbapenems-resistant PA strain co-harbored the MGE genes class 1 integron and ISEcp1, accounting for 4.17%. Twelve out of the 13 carbapenemase gene positive strains carried one or two PMQR gene (s), which was significantly higher than that of the carbapenemase gene negative strains (with only five strains harboring one PMQR gene, P = 0.023). The 24 carbapenems-resistant PA strains were classified into 6 genotypes by the ERIC-PCR. Thirteen strains (accounting for 54.17%), mainly isolated from pus and blood samples, which were collected from burn department, were in genotype A. Eight out of the 13 strains harbored genes blaVIM-2, acc (6')-Ib-cr, and ISCR1. Five strains (accounting for 20.83%), mainly isolated from sputum samples which were collected from ICU, were in genotype B. Only 2 out of the 5 strains co-harbored the carbapenemase gene, PMQR gene, and MGE gene. There were respectively 2 strains in genotypes C and D, both accounting for 8.33%; the strains in different pattern were isolated from different wards, and they harbored diverse resistance genes. There were respectively 1 strain in genotypes E and F, both accounting for 4.17%.

CONCLUSIONSThe resistance mechanism of PA to carbapenems is mainly mediated by the VIM-2 type MBL in our hospital during 2012, followed by KPC-2 type carbapenemase, and the prevalent genotype is type A. The carbapenemase genes and PMQR genes co-carrying phenomenon exists among these strains of PA, which disseminated by clones.

Anti-Bacterial Agents ; pharmacology ; Bacterial Proteins ; genetics ; Carbapenems ; pharmacology ; DNA, Bacterial ; Drug Resistance, Bacterial ; Humans ; Microbial Sensitivity Tests ; Pseudomonas aeruginosa ; drug effects ; genetics ; isolation & purification ; beta-Lactamases ; genetics

OBJECTIVETo study the distribution characteristics of pathogens, the drug resistance of Pseudomonas aeruginosa (PA), and the use of antibiotics against Gram negative bacilli (GNB) in burn wards, so as to provide a guide for future treatment.

METHODSA total of 2 758 strains of pathogens were isolated from specimens of wound excretion, venous catheter attachment, blood, stool, urine, and sputum from 7 441 patients hospitalized in our burn wards from January 2007 to December 2012. After being identified by API strips and automatic microorganism identification and drug sensitivity analyzer, drug resistance of all the pathogens to 13 antibiotics commonly used in clinic, including amikacin, cefoperazone/sulbactam, ceftazidime, etc., was tested by K-B paper disk diffusion method. The defined daily doses per 1 000 patient-day of 5 antibiotics including amikacin, cefoperazone/sulbactam, ceftazidime, imipenem, and ciprofloxacin each year was set as use intensity. The WHONET 5.6 software was used to analyze the distribution of pathogens and the drug resistance of PA to 13 antibiotics. The SPSS 19.0 software was used to analyze the relation between changes in drug-resistant rates of PA to 13 antibiotics and year, the relation between the proportion of PA in all the pathogens and the use intensity of 5 antibiotics commonly used against GNB, and the relation between the use intensity of ciprofloxacin and the change in drug-resistant rates of PA to amikacin, cefoperazone/sulbactam, and imipenem with Pearson correlation analysis.

RESULTS(1) In 6 years, Staphylococcus aureus ranked the first with the highest proportion (31%, 865/2 758). The proportion of PA increased to tie in with Acinetobacter baumannii (both accounting for 17%, 458/2 758), both taking the second place. (2) Drug-resistant rates of PA to amikacin, gentamicin, aztreonam, piperacillin, cefoperazone, cefepime, piperacillin/tazobactam, cefoperazone/sulbactam, imipenem, and meropenem were significantly increased and positively correlated with year (with r values from 0.844 to 0.988, P < 0.05 or P < 0.01), while the drug-resistant rate of PA to ciprofloxacin was decreased and negatively correlated with year (r = -0.836, P < 0.05). (3) In 6 years, the use intensity of amikacin (from 8.65 to 91.44), cefoperazone/sulbactam (from 9.62 to 63.56), imipenem (from 7.63 to 157.25), ceftazidime (from 18.39 to 86.11), and ciprofloxacin (from 0 to 19.77) was increased. (4) The proportion of PA in all the pathogens was positively correlated with the use intensity of imipenem and ciprofloxacin (with r values respectively 0.849, 0.933, P < 0.05 or P < 0.01), while it was not significantly correlated with the use intensity of amikacin, cefoperazone/sulbactam, or ceftazidime (with r values respectively 0.672, 0.668, 0.794, P values all above 0.05). (5) The use intensity of ciprofloxacin was positively correlated with the drug-resistant rates of PA to amikacin, cefoperazone/sulbactam, and imipenem (with r values respectively 0.878, 0.934, 0.928, P < 0.05 or P < 0.01).

CONCLUSIONSIn our burn wards, drug-resistant PA was prevalent, with positive correlation with the use intensity of antibiotics. The sensitive rate can be increased by a decrease in the use of amikacin, cefoperazone/sulbactam, and imipenem periodically.

Adolescent ; Adult ; Aged ; Aged, 80 and over ; Anti-Bacterial Agents ; pharmacology ; therapeutic use ; Burns ; drug therapy ; microbiology ; Child ; Child, Preschool ; Cross Infection ; microbiology ; Drug Resistance, Bacterial ; Female ; Humans ; Infant ; Male ; Microbial Sensitivity Tests ; Middle Aged ; Pseudomonas aeruginosa ; drug effects ; isolation & purification ; Young Adult

BACKGROUND: Pseudomonas aeruginosa is a clinically important pathogen that causes opportunistic infections and nosocomial outbreaks. Recently, the type III secretion system (TTSS) has been shown to play an important role in the virulence of P. aeruginosa. ExoU, in particular, has the greatest impact on disease severity. We examined the relationship among the TTSS effector genotype (exoS and exoU), fluoroquinolone resistance, and target site mutations in 66 carbapenem-resistant P. aeruginosa strains. METHODS: Sixty-six carbapenem-resistant P. aeruginosa strains were collected from patients in a university hospital in Daejeon, Korea, from January 2008 to May 2012. Minimum inhibitory concentrations (MICs) of fluoroquinolones (ciprofloxacin and levofloxacin) were determined by using the agar dilution method. We used PCR and sequencing to determine the TTSS effector genotype and quinolone resistance-determining regions (QRDRs) of the respective target genes gyrA, gyrB, parC, and parE. RESULTS: A higher proportion of exoU+ strains were fluoroquinolone-resistant than exoS+ strains (93.2%, 41/44 vs. 45.0%, 9/20; P< or =0.0001). Additionally, exoU+ strains were more likely to carry combined mutations than exoS+ strains (97.6%, 40/41 vs. 70%, 7/10; P=0.021), and MIC increased as the number of active mutations increased. CONCLUSIONS: The recent overuse of fluoroquinolone has led to both increased resistance and enhanced virulence of carbapenem-resistant P. aeruginosa. These data indicate a specific relationship among exoU genotype, fluoroquinolone resistance, and resistance-conferring mutations.
ADP Ribose Transferases/genetics ; Anti-Bacterial Agents/*pharmacology ; Bacterial Proteins/genetics ; Bacterial Toxins/genetics ; Carbapenems/pharmacology ; Drug Resistance, Bacterial/*drug effects ; Fluoroquinolones/*pharmacology ; Genotype ; Humans ; Microbial Sensitivity Tests ; Multilocus Sequence Typing ; Mutation ; Pseudomonas aeruginosa/*genetics/isolation & purification/pathogenicity ; Sputum/microbiology ; Virulence

OBJECTIVEPseudomonas aeruginosa is an important cause of nosocomial infection, severe sepsis and death which associated with a trends of rising rates of resistance to a broad array of antimicrobial agents. To explore a feasible treatment protocol for such patients, we analyzed the susceptibility patterns of Pseudomonas aeruginosa in pediatric intensive care unit (PICU).

METHODThe age distribution, outcome of patients, sources of strains and susceptibility patterns of Pseudomonas aeruginosa in PICU from Jan 1, 2007 to Dec 31, 2011 were analyzed. Susceptibility to amikacin, piperacillin/tazobactam, aztreonam, ampicillin, ciprofloxacin, imipenem, meropenem, cefepime, cefoperazone, cefotaxime, ceftriaxone, ceftazidime, cefoperazone/sulbactam, cephazolin, cefuroxime, and polymyxin were determined by the disk-diffusion technique (K-B test method) and broth microdilution. P. aeruginosa ATCC 27853 was used as reference strain.

RESULTSeventy-five patients were Pseudomonas aeruginosa positive. 26(34.7%) were < 6 m, 49 (65.4%) were < 2 y. The percentages of cases who were Pseudomonas aeruginosa positive in different age groups in the same time was basically similar; 18 (24.0%) cases died. Pseudomonas aeruginosa accounted for 10.9% of G(-) germs, 6.5% of all pathogens in 2010 - 2011. Of the 126 strains, 83 (65.9%) were from sputum sample, 31 (24.6%) were from catheter sample of tracheal cannula, 10 (7.9%) were from blood sample and 2 (1.6%) were from secretion sample. The sensitivity to antibiotics of Pseudomonas aeruginosa in pediatric common treatments was 72.4% to cefoperazone/sulbactam, 71.5% to meropenem, 48.4% to imipenem, 66.7% to ceftazidime, 49.2% to piperacillin/tazobactam. Absolute resistance to ampicillin, cephazolin, cefuroxime and cefotaxime. Multiple-drug resistance was still severe, but a decreasing tendency was observed, 90.5% in 2007, 81.3% in 2008, 51.1% in 2009, 53.8% in 2010, 33.3% in 2011. Pan-drug resistance in different years was similar, 12.5% in 2008, 2.2% in 2009, 7.7% in 2010, 6.7% in 2011.

CONCLUSIONThe condition of drug resistance of Pseudomonas aeruginosa was still rigorous, we should conduct surveillance and prevent abusing antibiotics in order to avoid exacerbating drug resistance. We should improve testing technique, early and appropriate empirical antibiotics therapy is crucial according to clinical experience and antibiotic sensitivity. The effective treatment of P. aeruginosa is paramount to prevent multidrug resistance. The use of combination therapies for P. aeruginosa infection has been a long-advocated practice. To prevent hospital acquired cross infection, health care workers must pay close attention to hand sanitation and sterile operation strictly.

Adolescent ; Ampicillin ; pharmacology ; Anti-Bacterial Agents ; pharmacology ; Cefazolin ; pharmacology ; Child ; Child, Preschool ; Cross Infection ; microbiology ; prevention & control ; Drug Resistance, Multiple, Bacterial ; Female ; Humans ; Imipenem ; pharmacology ; Infant ; Intensive Care Units, Pediatric ; Male ; Microbial Sensitivity Tests ; Pseudomonas Infections ; drug therapy ; microbiology ; Pseudomonas aeruginosa ; drug effects ; isolation & purification

OBJECTIVETo synthesize the ecofriendly nanoparticles, which is viewed as an alternative to the chemical method which initiated the use of microbes like bacteria and fungi in their synthesis.

METHODSThe current study uses the endophytic bacterium Bacillus cereus isolated from the Garcinia xanthochymus to synthesize the silver nanoparticles (AgNPs). The AgNPs were synthesized by reduction of silver nitrate solution by the endophytic bacterium after incubation for 3-5 d at room temperature. The synthesis was initially observed by colour change from pale white to brown which was confirmed by UV-Vis spectroscopy. The AgNPs were further characterized using FTIR, SEM-EDX and TEM analyses.

RESULTSThe synthesized nanoparticles were found to be spherical with the size in the range of 20-40 nm which showed a slight aggregation. The energy-dispersive spectra of the nanoparticle dispersion confirmed the presence of elemental silver. The AgNPs were found to have antibacterial activity against a few pathogenic bacteria like Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Salmonella typhi and Klebsiella pneumoniae.

CONCLUSIONSThe endophytic bacteria identified as Bacillus cereus was able to synthesize silver nanoparticles with potential antibacterial activity.

Anti-Bacterial Agents ; chemistry ; pharmacology ; Bacillus cereus ; drug effects ; isolation & purification ; Escherichia coli ; drug effects ; Garcinia ; chemistry ; Klebsiella pneumoniae ; drug effects ; Metal Nanoparticles ; chemistry ; Microbial Sensitivity Tests ; Nanoparticles ; chemistry ; Phytotherapy ; methods ; Plant Extracts ; chemistry ; pharmacology ; Pseudomonas aeruginosa ; drug effects ; Silver ; chemistry ; pharmacology ; Staphylococcus aureus ; drug effects