OBJECTIVETo analyze the isolation and the in vitro susceptibility of P. aeruginosa to antibiotics in our burn ward.

METHODSFive hundred and thirty six burn patients admitted to our ward from 1997 to 2003 were enrolled in the study, and the wound excretion, the tips of the venous catheter, the subeschar tissue samples, and the blood samples were collected for bacterial identification and antibiotic susceptibility test with VITEK-AMS system.

RESULTSThe isolation rate of P. aeruginosa from 1997 to 2003 was 24.51%, 23.94%, 21.01%, 40.06%, 36.17%, 46.76% and 55.72%, respectively. The antibiotic effect of the third generation of Cephalosporins against the said bacteria showed a tendency to decline. The susceptibility rate to Cefoperazone, Ceftazidime and Cefotaxime were respectively 71%, 66% and 79% in 1997; 47%, 25%, 39% in 1998; 22%, 16%, 25% in 2002; The third generation cephalosporins had almost lost their antibiotic activity against P. aeruginosa in 2003, with the susceptibility rate to Cefotaxime lowered to 2%. The susceptibility rate to Imipenem from 1997 to 2003 was 76%, 33%, 45%, 11%, 41%, 31%and 4%, respectively.

CONCLUSIONThe isolation rates of P. aeruginosa were steady during the period from 1997 to 1999, and they began to increase in 2000. The bacterial resistance to antibiotics increased gradually in recent years, and the strains of P. aeruginosa had become multi-drug resistant.

Anti-Bacterial Agents ; pharmacology ; Burn Units ; Burns ; microbiology ; Drug Resistance, Multiple, Bacterial ; Humans ; In Vitro Techniques ; Microbial Sensitivity Tests ; Pseudomonas Infections ; microbiology ; Pseudomonas aeruginosa ; drug effects ; isolation & purification

Aged ; Cross Infection ; microbiology ; Female ; Humans ; Intensive Care Units ; Male ; Microbial Sensitivity Tests ; Pneumonia, Bacterial ; microbiology ; Pseudomonas Infections ; microbiology ; Pseudomonas aeruginosa ; classification ; isolation & purification

BACKGROUND: Delayed entry of blood culture bottles is inevitable when microbiological laboratories do not operate for 24 hr. There are few studies reported for prestorage of these bottles. The growth dynamics of Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa were investigated with respect to various preincubation conditions. METHODS: Fifteen or 150 colony-forming units (CFU) of bacteria were inoculated into standard aerobic or anaerobic blood culture bottles. Bottles were preincubated at 25degrees C or 37degrees C for 0, 2, 4, 8, 12, 24, or 48 hr. The time to detection (TTD) then was monitored using the BacT/Alert 3D system (bioMerieux Inc., USA). RESULTS: Significant difference in TTD was observed following preincubation for 8 hr at 25degrees C vs. 4 hr at 37degrees C for S. aureus, 4 hr at 25degrees C vs. 4 hr at 37degrees C for E. coli, 12 hr at 25degrees C vs. 4 hr at 37degrees C for P. aeruginosa, compared to no preincubation (P<0.005). TTD values did not vary significantly with bacterial CFU or with aerobic or anaerobic bottle type. The BacT/Alert 3D system returned false negatives following preincubation of P. aeruginosa for 48 hr at 25degrees C or 24 hr at 37degrees C. CONCLUSIONS: TTD was mainly affected by preincubation temperature and duration rather than by input CFU quantity or bottle type for the 3 experimental bacteria.
Bacteriological Techniques/instrumentation/*methods ; Culture Media ; Escherichia coli/growth & development/*isolation & purification ; Pseudomonas aeruginosa/growth & development/*isolation & purification ; Staphylococcus aureus/growth & development/*isolation & purification ; Temperature ; Time Factors

OBJECTIVETo develop a high-throughput diagnostic method with suspension array technique for detecting pathogenic microbes.

METHODSThe probes and positive controls of 56 kinds of pathogenic microbes were designed, synthesized, and used to detect pathogenic microbes with suspension array technique.

RESULTSFluorescence signals of 56 positive controls were higher than those of the negative controls, and there was no cross-reaction between the probes and positive controls of different microbes.

CONCLUSIONBased on suspension array technique, the high-throughput diagnostic method may be useful in clinical detection of pathogenic microbes.

Animals ; Communicable Diseases ; microbiology ; virology ; Enterovirus ; isolation & purification ; Humans ; Microbiological Techniques ; Mumps virus ; isolation & purification ; Oligonucleotide Array Sequence Analysis ; methods ; Pseudomonas aeruginosa ; isolation & purification

OBJECTIVETo investigate the resistance genes and antibiotic resistance patterns against beta-lactams in Pseudomonas aeruginosa prevalent in burn ward.

METHODSK-B method was performed to test bacterial resistance patterns against 9 species of beta-lactams in Pseudomonas aeruginosa isolated from wounds and dressings of the patient in burn wards. Seven species of resistance genes against beta-lactams were detected with PCR. Tazobactam-inhibited piperacillin resistance test was performed to study whether the above strains produce extended spectrum beta-lactams.

RESULTSAll 12 strains of bacteria with resistance genes detected were resistant to penicillin and cephalosporins (100%), among them 11 were resistant to all antibiotics. Tazobactam-inhibited piperacillin resistance test demonstrated that all strains with resistance genes were ESBLs.

CONCLUSIONHigh incidence of beta-lactams resistance genes is found in Pseudomonas aeruginosa isolated from burn ward, and they have close relationship with the occurrence of multiple drug-resistance.

Burn Units ; Burns ; microbiology ; Genes, Bacterial ; Humans ; Pseudomonas aeruginosa ; drug effects ; genetics ; isolation & purification ; beta-Lactam Resistance ; genetics

BACKGROUND: Carbapenem-resistant Pseudomonas aeruginosa (CRPA) and Acinetobacter baumannii (CRAB) are the leading causes of nosocomial infections. A rapid and sensitive test to detect CRPA and CRAB is required for appropriate antibiotic treatment. We optimized a loop-mediated isothermal amplification (LAMP) assay to detect the presence of bla(VIM-2), bla(IMP-1), and bla OXA-23, which are critical components for carbapenem resistance. METHODS: Two sets of primers, inner and outer primers, were manually designed as previously described. The LAMP buffer was optimized (at 2mM MgSO4) by testing different concentrations of MgSO4. The optimal reaction temperature and incubation time were determined by using a gradient thermocycler. Then, the optimized bla(VIM-2), bla(IMP-1), and bla(OXA-23) LAMP reactions were evaluated by using 120 P. aeruginosa and 99 A. baumannii clinical isolates. RESULTS: Only one strain of the 100 CRPA isolates harbored bla(IMP-1), whereas none of them harbored bla(VIM-2). These results indicate that the acquisition of bla(VIM-2) or bla(IMP-1) may not play a major role in carbapenem resistance in Korea. Fifty two strains of the 75 CRAB isolates contained bla(OXA-23), but none contained bla(VIM-2) and bla(IMP-1) alleles. CONCLUSIONS: Our results demonstrate the usefulness of LAMP for the diagnosis of CRPA and CRAB.
Acinetobacter baumannii/genetics/*isolation & purification ; Anti-Bacterial Agents/*pharmacology ; Carbapenems/*pharmacology ; Drug Resistance, Bacterial/*genetics ; *Genes, Bacterial ; Nucleic Acid Amplification Techniques ; Pseudomonas aeruginosa/genetics/*isolation & purification ; Sensitivity and Specificity

A nationwide antimicrobial resistance surveillance has been conducted since 1997 in Korea. In this study, susceptibility test data generated in 2004 by KONSAR group hospitals were analyzed and compared to those at a commercial laboratory. In hospitals, the rank orders of organisms in 2004 were identical to those in 2003. The most prevalent species was Staphylococcus aureus (20.2%) in hospitals, but Escherichia coli (29.7%) in the commercial laboratory. The proportions of Enterococcus faecium to all isolates of Enterococcus faecalis plus E. faecium were 47.2% in hospitals and 24.9% in the commercial laboratory. The mean resistance rates of significant antimicrobial-organism combinations in hospitals were: oxacillin-resistant S. aureus (68%), oxacillin-resistant (penicillin- nonsusceptible) Streptococcus pneumoniae (68%), vancomycin-resistant E. faecium (25%), cefotaxime-resistant E. coli (14%), ceftazidime- and cefoxitin-resistant Klebsiella pneumoniae (34% and 32%, respectively), and imipenem-resistant Acinetobacter spp. and Pseudomonas aeruginosa (17% and 24%, respectively). In conclusion, oxacillin-resistant staphylococci, expanded-spectrum cephalosporin-resistant K. pneumoniae, and imipenem-resistant Acinetobacter spp. and P. aeruginosa were prevalent in 2004. Increasing trends were observed for vancomycin-resistant E. faecium, cefoxitin- resistant E. coli and K. pneumoniae, and imipenem-resistant Acinetobacter spp. and P. aeruginosa. Certain antimicrobial- organism combinations were also prevalent among the commercial laboratory-tested strains.
Pseudomonas aeruginosa/drug effects/isolation & purification ; Microbial Sensitivity Tests ; Laboratories ; Korea ; Klebsiella pneumoniae/drug effects/isolation & purification ; Imipenem/*pharmacology ; Hospitals ; Gammaproteobacteria/*drug effects/isolation & purification ; Drug Resistance, Multiple, Bacterial ; Ceftazidime/*pharmacology ; Anti-Bacterial Agents/*pharmacology ; Acinetobacter/drug effects/isolation & purification

OBJECTIVETo investigate the distribution of burn pathogens and their antibiotic resistance in a burn unit, so as to provide reference for clinical practice.

METHODSThree hundred and forty-eight burn patients hospitalized in our department were enrolled in this study. The pathogens isolated from the wounds, blood, venous catheter, sputum, urine, purulent discharge of wounds in these patients, and their antibiotic resistance were surveyed by retrospective analysis from Jan, 2001 to Dec, 2006.

RESULTSTotal-ly 464 strains were isolated, among which Gram negative (G-) bacilli accounted for 52.6%, Gram positive microorganisms (G+) accounted for 40.5%, and fungi accounted for 6.9%. The main pathogens were Staphylococcus aureus, Pseudomonas aeruginosa, Acinetobacter species and Escherichia coli, among which Staphylococcus aureus (MRSA) was predominant (93.5%). MRSA was 100% resistant to levofloxacin, penicillium, oxacillin, and it was also resistant to other antibiotics except Vancomycin. The resistance rate of Pseudomonas aeruginosa to Cefoperazone/Sulbactam, Imipenem and cefepime were 15.8%, 36.8%, 33.3%, respectively.

CONCLUSIONStaphylococcus aureus, Pseudomonas aeruginosa, Acinetobacter species and Escherichia coli were predominant in the burn unit,among them Staphylococcus aureus and Acinetobacter were more resistant to antibiotics.

Acinetobacter baumannii ; drug effects ; isolation & purification ; Burn Units ; Burns ; microbiology ; Cross Infection ; microbiology ; Drug Resistance, Bacterial ; Escherichia coli ; drug effects ; isolation & purification ; Humans ; Pseudomonas aeruginosa ; drug effects ; isolation & purification ; Retrospective Studies ; Staphylococcus aureus ; drug effects ; isolation & purification

OBJECTIVETo study changes in the drug-resistance of Pseudomonas aeruginosa (PA) and the use of antibiotics in burn wards so as to optimize the use of antibiotic in the future.

METHODSBacteria were isolated from specimens of blood, venous catheter, stool, sputum, urine, wound tissue from 5717 patients hospitalized in our burn wards within the duration of January 2005 to December 2009. The number of specimens examined and positive rates of bacteria were calculated. Changes in constituent ratio of cocci and bacilli, spectrum of bacteria, the drug-resistance rate of PA, and the usage of antibiotics were analyzed. The number of specimens examined, constituent ratio of cocci and bacilli, drug-resistance rate were processed with chi-square test. Bivariate correlation analysis was performed between the usage of antibiotics and the drug-resistance rate.

RESULTS(1) The number of specimens examined showed no statistical difference during the five years (with rates from 73.2% to 76.1%, χ(2) = 5.583, P > 0.05), while constituent ratio of cocci and bacilli showed statistical difference (with ratios from 105:134 to 169:126, χ(2) = 14.806, P < 0.01). The positive rates of bacteria were increasing in the five years. (2) One thousand six hundred and seventy-five strains were identified during the five years from different kinds of specimens, with 29 from blood, 39 from venous catheter, 3 from stool, 157 from sputum, 13 from urine, and 1434 from wound tissue. Among them, Staphylococcus aureus accounted for 28% to 42%, PA accounted for 10% to 25%, Acinetobacter baumannii accounted for 10% to 19%, and they were the predominant strains. (3) The difference among drug-resistance rates of PA to each kind of 12 antibiotics during the five years were statistically significant (with χ(2) values from 47.911 to 308.095, P values all below 0.01). The drug-resistance rates of PA to some antibiotics showed downward trend in the former four years, including amikacin, ceftazidime, and imipenem/cilastatin, but it rebounded in the fifth year. (4) There was descending trend in usage of cefoperazone/sulbactam and levofloxacin, but vancomycin was always used widely. (5) Drug-resistance rates of PA to 7 antibiotics, including amikacin, imipenem/cilastatin, and ciprofloxacin, etc., were positively correlated with usage of various antibiotics (with r values from 0.879 to 0.978, P < 0.05 or P < 0.01).

CONCLUSIONSIn our burn wards, drug-resistant PA was prevalent. Disinfection and isolation measures, appropriate use of antibiotics, etc. can reduce PA infection.

Anti-Bacterial Agents ; therapeutic use ; Burn Units ; Burns ; drug therapy ; microbiology ; Drug Resistance, Bacterial ; drug effects ; Female ; Humans ; Male ; Pseudomonas Infections ; drug therapy ; microbiology ; Pseudomonas aeruginosa ; drug effects ; isolation & purification

Bronchiectasis is a chronic lung disorder and a number of bacterial pathogens are involved. However, 30%-40% of sputum and purulent samples in good quality failed to grow any pathogenic bacteria, making it difficult to confirm the pathogen. In this study, we collected bronchoalveolar lavage fluid from a bronchiectasis patient undergoing acute exacerbation, and sent for 16S rDNA pyrosequencing by a 454 GS Junior machine. Metagenomic analysis showed the composition of bacterial community in sample was complex. More than a half of reads (51.3%) were from Pseudomonas aeruginosa. This result was corresponding with the culture result but came out 2 d earlier, which is meaningful for early diagnosis and treatment. The detection with 16S rDNA pyrosequencing technology is more sensitive and rapid than routine culture, and can detect the co-infection or symbiosis in airway, giving us a novel and convenient approach to perform rapid diagnosis.
Bronchiectasis ; microbiology ; Bronchoalveolar Lavage Fluid ; chemistry ; microbiology ; Early Diagnosis ; Female ; Humans ; Metagenome ; genetics ; Metagenomics ; methods ; Middle Aged ; Pseudomonas Infections ; microbiology ; Pseudomonas aeruginosa ; genetics ; isolation & purification ; RNA, Ribosomal, 16S ; genetics ; Time Factors