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OBJECTIVE: To analyze carbapenemases genotype of imipenem-resistant Gram-negative bacilli in intensive care unit (ICU) of 3 third grade class A hospitals from Qingdao area, so as to provide reference for drug-resistant bacteria infection prevention and treatment in clinic. METHODS: From Jan. 2013 to Jun. 2016, each 60 strains of imipenem-resistant Klebsiella pneumoniae (IRKP), imipenem-resistant Pseudomonas aeruginosa (IRPA) and imipenem-resistant Acinetobacter baumanii (IRAB) were collected from 3 third grade class A hospitals from Qingdao area. Drug sensitivity test was performed by using Kirby-Bauer method. Phenotypes of carbapenemases were determined by Carba NP trial. PCR was applied to amplify carbapenemase gene; Sanger seqnencing method was adopted for bi-directional sequencing; Blast comparison with GenBank database was conducted. RESULTS: Three kinds of imipenem-resistant Gram-negative bacilli showed high drug resistance to majority commonly used antibiotics as piperacillin, cefazolin, imipenem and cilastatin sodium, gentamicin, etc., but were sensitive to polymyxin B (resistance rate of 0). Among 180 drug-resistant strains, there were 52 strains of class A carbapenems, 13 strains of class B carbapenems and 39 strains of class D carbapenems; the detection rates of them were 28. 89％, 7. 22％ and 21. 67％, respectively. There were 52 strains of KPC-2 gene (IRKP), 4 strains of IMP-1 gene (IRPA), 8 strains of VIM-2 gene (7 strains of IRPA, 1 strain of IRAB), 39 strains of OXA-23 gene (IRAB); the detection rates of them were 28. 89％, 2. 22％, 4. 44％, 21. 67％; all strains were not detected 1MP-2, VIM-1, NDM-1, OXA-24, OXA-58 genes. Results of Blast comparison showed that above detected genes were absolutely homology with the corresponding genes in GenBank database. CONCLUSIONS: Drug resistance of imipenem-resistant Gram-negative bacilli in ICU of 3 third grade class A hospitals is serious in this region, which are nearly no-sensitive to most of commonly used antibiotics in clinic. Main genotypes included KPC-2 (K. pneumoniae), OXA-23 (A. baumanii) and IMP-1 and VIM-2 (P. aeruginosa).
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Objective To investigate the risk factors of nosocomial infection of imipenem‐resistant Acinetobacter and prevalence situation of class Ⅰ integron to provide references for preventing and controlling its nosocomial infection .Methods The strains of imipenem‐resistant Acinetobacter causing nosocomial infection were performed the drug resistance analysis and multivariate re‐search .The class Ⅰ integron gene was detected by using PCR .Results Admission to ICU ,joint use of antibacterial agents and high APACHEⅡ score were the independent risk factors of nosocomial infection induced by imipenem resistant Acinetobacter .The posi‐tive rate of class Ⅰ integron was up to 98 .6% .Conclusion The nosocomial infection of imipenem‐resistant Acinetobacter is affect‐ed by multiple factors .The class Ⅰ integron is widely prevalent in this hospital ,which is associated with the multidrug resistance of imipenem‐resistant Acinetobacter .The infection prevention measures in severe patients should be strengthened for timely finding the infection source ,protecting the susceptible populations and cutting off dissemination approach .
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Objective To investigate the drug resistance status quo of imipenem-resistant Pseudomonas aeruginosa and carbap-enemase gene carrying in Xi′an area for guiding the clinical rational use of antibacterial drugs.Methods 151 strains of imipenem-re-sistant Pseudomonas aeruginosa isolated from clinical samples in 4 hospitals from August 2012 to July 2013 were continuously col-lected.Then the drug resistance characteristics of imipenem-resistant Pseudomonas aeruginosa were investigated by the antimicrobi-al drug sensitivity test.The PCR technique was adopted to detect the carrying situation of carbapenemase drug-resistance genes in imipenem-resistant Pseudomonas aeruginosa.Results Totally isolated 151 strains of imipenem-resistant Pseudomonas aeruginosa were mainly distributed in the neurosurgery ICU (37.1%),neurology ICU (27.1%)and the burn department (19.9%);the detec-ted strains were sensitive to polymyxin B and resistant to other 9 kinds of antibacterial drugs in different degrees;94 strains carried VIM gene,32 strains carried IMP gene,5 strains carried SPM gene and 3 strains carried SIM gene.Conclusion The multidrug re-sistance and pan-drug resistance phenomenon of imipenem-resistant Pseudomonas aeruginosa is serious,its cause might be related with the carbapenemases-producing drug resistant gene expression,the drug resistance genes are dominated by VIM and IMP.Clinic should strengthen the bacterial drug resistance monitoring and use antibacterial drugs rationally and effectively for preventing the spreading of imipenem-resistant Pseudomonas aeruginosa.
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OBJECTIVE To investigate the clinical characteristics of imipenem-resistant Pseudomonas aeruginosa sepsis in neutropenic hematological malignancy patients. METHODS A retrospective review of the medical records of 3 cases in neutropenic hematological malignancy patients with P.aeruginosa sepsis in June 2008 were taken. RESULTS All they died within 3 days,2 times blood culture results indicated.With imipenem-resistant P.aeruginosa growth. CONCLUSIONS Neutropenic hematological malignancy patients with imipenem-resistant P.aeruginosa sepsis have rapid progress of the disease and high mortality rates,we should step up surveillance.
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Objective To investigate the molecular mechanism of resistance to carbapenems in Pseudomonas aeruginasa from 5 teaching hospitals in Beijing. Methods A total of 213 non-duplicate imipenem-resistant Pseudomonas aernginosa (IRPA) isolates were collected from 5 hospitals in Beijing from June 2004 to December 2005. The minimal inhibitory concentrations (MICs) of meropenem, imipenem and others antibiotics were determined by agar dilution method. Disk diffusion test was used for screening metalloenzymes. The bla IMP,bla VIM and OprD2 genes were amplified by PCR and only sequenced. Results Out of 213 isolates, OprD2 loss was detected in 84 isolates and IMP-1 enzyme was detected in 6 isolates simultaneously. Thirteen IRPAs only produced IMP-1 and 2 isolates only produced VIM-2. Conclusion OprD2 loss and metallo-β-lactamuse production are the parts of the mechanisms of resistance to carbapenems in Pseudomonas aeruginosa in Beijing.
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PURPOSE: Since November 2006, imipenem-resistant Acinetobacter baumannii isolates have increased in Kyung Hee University Hospital in Seoul, Korea. The purpose of this study was to determine the genetic basis and molecular epidemiology of outbreak isolates. MATERIALS AND METHODS: Forty-nine non-repetitive isolates of the 734 IRAB strains were investigated in order to determine their characteristics. The modified Hodge and the ethylenediaminetetraacetic acid (EDTA)-disk synergy test were performed for the screening of carbapenemase and metallo-beta-lactamase production. Multiplex polymerase chain reaction (PCR) assays were performed for the detection of genes encoding for OXA-23-like, OXA-24-like, OXA-58-like and OXA-51-like carbapenemase. Pulsed-field gel electrophoresis (PFGE) was performed for strain identification. RESULTS: All isolates showed 100% resistance to ciprofloxacin and gentamicin, 97.9% resistance to cefepime, piperacillin/tazobactam, aztreonam, ceftazidime and piperacillin, 93.9% resistance to tobramycin and 57.1% resistance to amikacin. All of the 49 isolates (100%) showed positive results in the modified Hodge test and negative results in the EDTA-disk synergy test. They all (100%) possessed the encoding gene for an intrinsic OXA-51-like carbapenemase and an acquired OXA-23-like carbapenemase in the multiplex PCR assay. PFGE patterns revealed that all isolates were clonally related from A1 to A14. CONCLUSION: It is concluded that all of the 49 IRAB isolates acquired resistance to imipenem by producing OXA-23 carbapenemase and they might have originated from a common source.
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Humans , Acinetobacter Infections/epidemiology , Acinetobacter baumannii/drug effects , Anti-Bacterial Agents/pharmacology , Cephalosporins/pharmacology , Ciprofloxacin/pharmacology , Disease Outbreaks , Drug Resistance, Multiple, Bacterial/genetics , Electrophoresis, Gel, Pulsed-Field , Gentamicins/pharmacology , Imipenem/pharmacology , Korea/epidemiology , Microbial Sensitivity Tests , beta-Lactamases/genetics , beta-Lactams/pharmacologyABSTRACT
BACKGROUND: Most imipenem-resistant Acinetobacter baumannii (IRAB) isolates are multiresistant, leaving few options for an effective antimicrobial therapy. We purposed to select possible candidates for the combinations of antimicrobials that are synergistic in vitro for inhibitory or bactericidal activities against IRAB and evaluate the usefulness of double disk synergy test (DDS) in predicting synergistic bactericidal activity. METHODS: Fifty-five IRAB isolates recovered from patients during the period from August 1999 to November 2000 were tested for susceptibilities to amikacin, gentamicin, tobramycin, piperacillin, piperacillin/tazobactam, cefotaxime, cefepime, cefoperazone/sulbactam (C/S), imipenem, meropenem, ciprofloxacin, levofloxacin, trimethoprim/sulfamethoxazole, chloramphenicol, minocycline, and colistin by the Clinical and Laboratory Standard Institute agar dilution method. Three isolates showing different susceptibility profiles were tested for antimicrobial synergy by DDS and then by timekill study (TKS) using DDS-positive combinations. RESULTS: Colistin, C/S, and minocycline were active in 50 (90.9%), 50, and 44 (80.0%) isolates, respectively, and all the other drugs were active in less than 20% of isolates. Minocycline-imipenem, minocycline-C/S, minocycline-amikacin, imipenem-tobramycin, C/S-amikacin, and C/S-tobramycin combinations showed synergistic inhibitory or bactericidal activity by TKS when the same combinations were synergistic in DDS; however, C/S-imipenem was found synergistic on DDS, but not by TKS. CONCLUSIONS: Colistin, C/S, and minocycline were relatively active against IRAB. DDS might help predict the synergistic antimicrobial effect of TKS if one of the combinations was susceptible.
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Humans , Acinetobacter baumannii/drug effects , Anti-Bacterial Agents/pharmacology , Drug Resistance, Bacterial , Drug Synergism , Imipenem/pharmacology , Microbial Sensitivity Tests , Time FactorsABSTRACT
OBJECTIVE To investigate the nosocomial status and drug resistance of imipenem-resistant Pseudomonas aeruginosa(IRPA) to provide the reference for doctor′s use of the antibiotics.METHODS Totally 178 strains of imipenem-resistant P.aeruginosa were identified by the routine methods.And drug sensitivity was determined by Kirby-Bauer method.RESULTS All strains of IRPA were mainly from departments of respiratory diseases,tumor and geriatrics,most of them were isolated from sputum(62.4%).The susceptibility test showed that 100.0% IRPA were resistant to imipenem.Drug resistance rates to piperacillin,cefotaxim,gentamicin,ciprofloxacin and SMZ-TMP were all over 50.0%.CONCLUSIONS The status of nosocomial infection caused by IRPA is very serious.To detect and control the infection is very important.
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Objectives: The demand for mobile bathing service (MBS) is increasing in the Japanese society. Therefore, we assessed the risk of MBS-associated infection in MBS clients and their caregivers by examining the bacterial colonization of MBS equipment and utensils. Methods: Bacterial isolates collected by the stamp agar culture method were examined by disk diffusion assay for their susceptibility to the following drugs: imipenem, ciprofloxacin, amikacin, azutreonam, ceftazidim, meropenem, piperacillin, tobramycin, ofloxacin and cefoperazone. Furthermore, these isolates were subtyped by SpeI-pulsed field gel electrophoresis (SpeI-PFGE). Results: Fifty-four P. aeruginosa isolates were recovered from different sampling sites, and of these, 26 (47.3%) were isolated from pillows. Eighteen isolates (33.3%) were imipenem (IPM) resistant. The minimum inhibitory concentrations (MICs) of 17 isolates were between 16 and 32 μg/ml, and the MIC of one isolate was greater than 32 μg/ml. The SpeI-PFGE typing of IPM-resistant isolates revealed that 13 of the 18 isolates were closely related (F=1.0−0.87). Conclusion: Our findings suggest that MBS equipment and utensils, particularly pillows, are the primary sources of bacterial contamination and transmission and that there is a risk of MBS-mediated infection among MBS clients and their caregivers.
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Risk , Imipenem , Electrophoresis, Gel, Pulsed-Field , Pseudomonas aeruginosaABSTRACT
PURPOSE: This retrospective study was done to evaluate the status of nosocomial urinary tract infections and to determine the risk factors andtransmission route of causal IRPA through molecular epidemiology. METHOD: Two hundred ninety-nine of 423 patients admitted to the internal medicine and surgery ICU at a university hospital incity B had a positiveurine culture. Twelve of the 299 patients who had a urinary tract infection had IRPA strains. The data was collected from November 1, 2004 to January 31, 2005. The following results were obtained after the data was analyzed using percentile and UPGMA. RESULT: The rate of nosocomial urinary tract infections in the ICU was 10.8%. Therewere 16.8 cases of infection based on the period of hospitalization. There were 16.9 cases of infection based on the use of a foley catheter. The rate of nosocomial urinary tract infection in the ICU and urinary tract infections related to IRPA were higher in patients with the following characteristics: men, old age, admission through the emergency room, longer than seven days admission, severity of admitting causes, disturbance of consciousness, hydration less than 300cc in 24hours, a long course of antibiotics, a long period of foley catheterization and perineal care. Most of the microorganisms that caused the urinary tract infection were gram negative bacilli, among which P. aeruginosa was found in 70 patients (18.5%) and IRPA in 12 (4.0%). Among the 12 IRPA strains that were tested with PFGE, eight showed a dice coefficient higher than 80%, suggesting a genetic relationship. They were related with the period of hospitalization in the same ICU. These patients all received direct care for a urinary tract infection. CONCLUSION: Through these results, IRPA can be consideredas a contributing factors to urinary tract infections thus, active preventative measures are needed by the medical staff.
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Adult , Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Anti-Bacterial Agents/pharmacology , Cross Infection/epidemiology , Drug Resistance, Bacterial , Imipenem/pharmacology , Intensive Care Units , Pseudomonas Infections/drug therapy , Pseudomonas aeruginosa/classification , Retrospective Studies , Risk Factors , Urinary Catheterization , Urinary Tract Infections/epidemiologyABSTRACT
The trend of antimicrobial resistance of bacteria isolated from patients in 30 Korean hospitals in 1999 was analyzed with a particular attention to cefotaxime- or fluoroquinolone-resistant gram-negative bacilli, imipenem-resistant Pseudomonas aeruginosa, and vancomycin-resistant enterococci. Adequacy of susceptibility testing, and any change in the frequencies of isolated species were also analyzed. The results showed that only 20% and 30% of hospitals tested the piperacillin-tazobactam and cefoxitin susceptibility of Enterobacteriaceae, respectively, only 24% of hospitals the piperacillin-tazobactam susceptibility of P. aeruginosa, and 17% of hospitals the fusidic acid susceptibility of staphylococci. Among the isolates 26.3% were glucose-nonfermenting gram-negative bacilli, and 34.7% of Enterococcus were Enterococcus faecium. Slight decline of cefotaxime-resistance rate to 20% was noted in Klebsiella pneumoniae, while fluoroquinolone-resistantce rate was 68% in Acinetobacter baumannii. The ceftazidime- and imipenem-resistance rates were 17% and 18%, respectively in P. aeruginosa. The vancomycin-resistance rate of E. faecium rose significantly to 15.1%, but the rates varied significantly depending on hospitals suggesting presence of different degree of selective pressure or nosocomial spread. In conclusion, the prevalence of imipenem-resistant P. aeruginosa and the increase of vancomycin-resistant E. faecium were the particularly worrisome phenomena observed in this study.
Subject(s)
Humans , /pharmacology , Anti-Bacterial Agents/pharmacology , Cephalosporins/pharmacology , Drug Resistance, Microbial , Enterobacteriaceae/drug effects , Enterococcus/drug effects , Gram-Negative Bacteria/drug effects , Imipenem/pharmacology , Korea , Microbial Sensitivity Tests , Pseudomonas aeruginosa/drug effects , Vancomycin ResistanceABSTRACT
BACKGROUND: With increase of antibiotics use and invasive procedures, infections caused by multi-resistant Acinetobacter baumannii (MRAB) are increasing. Recently, we experienced the outbreak of- nosocomial infections caused by MRAB resistant to imipenem and cefoperazone/sulbactam in intensive care units (ICU) and general ward. We analyzed the clinical characteristics of the infected patients and antibiotic susceptibility of the organisms. And surveillance cultures and IRS-PCR were performed to find out the transmission route. METHODS: We collected data from physical examination and clinical records. We performed surveillance cultures of environment, patients not infected with MRAB in ICU, and hands of health care workers. RESULTS: Between November 1996 and June 1997, 49 strains of MRAB were isolated from the 26 patients hospitalized in Kangnam St. Mary' s Hospital. The lower respiratory infection (13 cases) was the most common infection and sputum was the most common sources (47.1%). All strains of MRAB showed the same genotype. In disk diffusion test, all strains were resistant to piperacillin, gentamicin, amikacin, ceftazidime, cefoperazone/sulbactam, aztreonam, imipencm, ciprofloxacin. From the surveillance cultures, the genotypically identical strains were isolated from ventilator Y-piece, the floor of ICU, and hands of health care workers. It suggested that this strain was transmitted through ventilatory device or hands of health care workers. We instructed all the health care workers to wash hands, to disinfect hospital environment completely. Since July 1997, no further case has occurred. CONCLUSIONS: Since A. baumannii could be transmitted through ventilatory devices and the hands of health care workers, it is important to wash hands and to disinfect hospital environment completely.
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Humans , Acinetobacter baumannii , Acinetobacter , Amikacin , Anti-Bacterial Agents , Aztreonam , Ceftazidime , Ciprofloxacin , Cross Infection , Delivery of Health Care , Diffusion , Genotype , Gentamicins , Hand , Imipenem , Patients' Rooms , Physical Examination , Piperacillin , Sputum , Ventilators, MechanicalABSTRACT
85%of IRAB were resistant to the rest 12 antibacterials except polymyxin B,cefoperazone/sulbactam and minocycline.CONCLUSIONS It should be exactly detect and control IRAB due to extremely severity about hospital infections and multidrug resistantce.