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

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

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

Carbapenemase-producing organisms (CPO) are rapidly disseminating worldwide, and their presence in tertiary care hospitals poses a significant threat to the management of nosocomial infections. There is a need to control CPO, especially in intensive care unit (ICU) patients, because these organisms are resistant to most beta-lactam antibiotics and are easily transmitted. At present, the identification of CPO is time-consuming; hence, this study focused on the use of the Xpert CARBA-R assay (Cepheid, USA) to determine intestinal colonization rates of CPO in patients admitted to the ICU of a tertiary care hospital in Korea. Forty clinical stool samples were collected and inoculated both in a CARBA-R cartridge and in conventional culture plates. The CARBA-R assay required only ~one hour to screen CPO, while the time required for conventional culture was over three days. We also found that the prevalences of intestinal colonization by carbapenem-resistant organisms and Enterobacteriaceae were 17.5% (7 out of 40) and 7.5% (3 out of 40), respectively. Among the colonizing strains, three that contained carbapenemase, including Klebsiella pneumonia carbapenemase (KPC), and imipenem (IMP) and Verona integron-mediated metallo-beta-lactamase (VIM) were found. With its convenience, the Xpert CARBA-R assay can be included in CPO surveillance strategies.
Anti-Bacterial Agents/pharmacology ; Bacterial Proteins/*genetics/metabolism ; DNA, Bacterial/analysis ; Drug Resistance, Multiple, Bacterial/genetics ; Enterobacteriaceae/drug effects/genetics/*isolation & purification ; Feces/microbiology ; Humans ; Imipenem/pharmacology ; Intensive Care Units ; Klebsiella pneumoniae/drug effects/genetics/*isolation & purification ; Reagent Kits, Diagnostic ; Real-Time Polymerase Chain Reaction ; Republic of Korea ; Tertiary Healthcare ; beta-Lactamases/*genetics/metabolism

BACKGROUND: The emergence of carbapenem-resistant Klebsiella pneumoniae poses a serious problem to antibiotic management. We investigated the beta-lactamases in a group of carbapenem-resistant K. pneumoniae clinical isolates from Turkey. METHODS: Thirty-seven strains of K. pneumoniae isolated from various clinical specimens were analyzed by antimicrobial susceptibility testing, PCR for the detection of beta-lactamase genes, DNA sequencing, and repetitive extragenic palindronic (REP)-PCR analysis. RESULTS: All 37 isolates were resistant to ampicillin, ampicillin/sulbactam, piperacillin, piperacillin/tazobactam, ceftazidime, cefoperazone/sulbactam, cefepime, imipenem, and meropenem. The lowest resistance rates were observed for colistin (2.7%), tigecycline (11%), and amikacin (19%). According to PCR and sequencing results, 98% (36/37) of strains carried at least one carbapenemase gene, with 32 (86%) carrying OXA-48 and 7 (19%) carrying NDM-1. No other carbapenemase genes were identified. All strains carried a CTX-M-2-like beta-lactamase, and some carried SHV- (97%), TEM- (9%), and CTX-M-1-like (62%) beta-lactamases. Sequence analysis of bla(TEM) genes identified a bla(TEM-166) with an amino acid change at position 53 (Arg53Gly) from bla(TEM-1b), the first report of a mutation in this region. REP-PCR analysis revealed that there were seven different clonal groups, and temporo-spatial links were identified within these groups. CONCLUSIONS: Combinations of beta-lactamases were found in all strains, with the most common being OXA-48, SHV, TEM, and CTX-M-type (76% of strains). We have reported, for the first time, a high prevalence of the NDM-1 (19%) carbapenemase in carbapenem-resistant K. pneumoniae from Turkey. These enzymes often co-exist with other beta-lactamases, such as TEM, SHV, and CTX-M beta-lactamases.
Anti-Bacterial Agents/*pharmacology ; Bacterial Proteins/*genetics/metabolism ; Carbapenems/*pharmacology ; DNA, Bacterial/chemistry/genetics/metabolism ; Drug Resistance, Bacterial ; Genotype ; Humans ; Klebsiella Infections/diagnosis/microbiology ; Klebsiella pneumoniae/*drug effects/enzymology/isolation & purification ; Microbial Sensitivity Tests ; Polymerase Chain Reaction ; Sequence Analysis, DNA ; Turkey ; beta-Lactamases/*genetics/metabolism

This multicenter study was undertaken to determine the efficacy of antibiotic prophylaxis and identify the risk factors for infectious complications after prostate surgery in Korean patients. A total of 424 patients who underwent surgery of the prostate were reviewed. All patients underwent urinalysis and urine culture preoperatively and postoperatively. Efficacy of antibiotic prophylaxis and risk factors for infectious complications were investigated. Infectious complications were observed in 34.9% of all patients. Factors independently associated with infectious complications were diabetes mellitus (adjusted OR, 1.99; 95% CI, 1.09-3.65, P=0.025) and operation time (adjusted OR, 1.08; 95% CI, 1.03-1.13, P=0.004). Clinicians should be aware of the high risk of infectious complications in patients with diabetes and those who undergo a prolonged operation time. Neither the type nor duration of prophylactic antibiotics resulted in differences in infectious complications.
Aged ; Anti-Bacterial Agents/pharmacology/therapeutic use ; Antibiotic Prophylaxis ; Diabetes Mellitus, Type 2/complications ; Drug Resistance, Bacterial/drug effects ; Enterococcus/drug effects/isolation & purification ; Escherichia coli/isolation & purification ; Humans ; Klebsiella pneumoniae/drug effects/isolation & purification ; Male ; Middle Aged ; Odds Ratio ; Postoperative Complications/microbiology/prevention & control ; Prospective Studies ; Prostatic Neoplasms/complications/*surgery ; Quinolones/pharmacology ; Risk Factors ; Time Factors ; Transurethral Resection of Prostate ; Urinalysis ; Urinary Tract Infections/microbiology

BACKGROUND/AIMS: We evaluated changes of causative pathogen in acute cholangitis and their antimicrobial susceptibility over six years and differences between community-acquired and hospital-acquired acute cholangitis at our institution. METHODS: Medical records of 1,596 patients with acute cholangitis and biliary drainage between August 2006 and August 2012 were reviewed retrospectively. Cases were divided according to time: period 1 (August 2006-December 2008, n=645, 40.4%), period 2 (January 2009-August 2012, n=951, 59.6%). Cases were divided according to community-acquired cholangitis (n=1,397, 87.5%) and hospital-acquired cholangitis (n=199, 12.5%). Causative pathogens and antimicrobial susceptibility were investigated in each group. RESULTS: Causative pathogen was isolated from bile culture in 1,520 out of 1,596 cases (95.2%). The three most frequently isolated Gram-negative bacteria were extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli (n=485, 30.4%), E. coli (n=237, 13.2%), and Citrobacter freundii (n=110, 6.9%). Between periods 1 and 2, prevalence of ESBL-producing E. coli and Klebsiella pneumoniae did not show significant change (36.7% vs. 32.1%, p=0.073; 6.6% vs. 6.2%, p=0.732). C. freundii showed a significant increase from period 1 to period 2 (1.7% vs. 13.2%, p=0.000). In both time periods, imipenem was the antimicrobial agent showing the highest rate of susceptibility (93.3% vs. 93.9%, p=0.783). Higher prevalence of ESBL-producing E. coli and C. freundii was observed in the hospital-acquired cholangitis group (52.1% vs. 31.2%, p=0.000; 15.9% vs. 7.3%, p=0.001). CONCLUSIONS: The most common causative pathogen of acute cholangitis was ESBL-producing E. coli. Prevalence of C. freundii increased over the time period. Imipenem should be reserved as an alternative for resistant pathogens.
Acute Disease ; Aged ; Aged, 80 and over ; Anti-Bacterial Agents/*pharmacology ; Cholangitis/diagnosis/*microbiology ; *Citrobacter freundii/drug effects/isolation & purification ; Community-Acquired Infections/microbiology ; Cross Infection/microbiology ; Drug Resistance, Bacterial ; *Escherichia coli/drug effects/isolation & purification ; Female ; Humans ; Imipenem/pharmacology ; *Klebsiella pneumoniae/drug effects/isolation & purification ; Male ; Microbial Sensitivity Tests ; Middle Aged ; Retrospective Studies ; Time Factors ; beta-Lactamases/metabolism

IN the presence of septic shock, every hour in delaying the administration of effective antibiotics is associated with a measurable increase in mortality. This is especially true for neutropenic patients with septic shock.1 As there is a higher incidence of involving multi-drug resistant pathogens for neutropenic patients, the decision on antibiotics regime remains a challenge for physicians.2 Immunosuppression and previous antibacterial use are factors that promote the spread of multi-drug resistant pathogens, and the possibility of co-existing multi-drug resistant pathogens should be suspected when treating patients with these risk factors who developed refractory shock. Here we present a case with neutropenic fever and refractory shock whose blood culture yielded multi-drug resistant Acinetobacter baumannii and carbapenem- resistant Klebsiella pneumoniae.
Acinetobacter Infections ; blood ; drug therapy ; microbiology ; Acinetobacter baumannii ; drug effects ; isolation & purification ; Adult ; Bacteremia ; blood ; drug therapy ; microbiology ; Carbapenems ; administration & dosage ; pharmacology ; therapeutic use ; Drug Resistance, Multiple, Bacterial ; Fatal Outcome ; Humans ; Klebsiella Infections ; blood ; drug therapy ; microbiology ; Klebsiella pneumoniae ; drug effects ; isolation & purification ; Male ; Shock, Septic ; blood ; drug therapy ; microbiology

No abstract available.
Aged ; Drug Resistance, Bacterial ; Humans ; Imipenem/pharmacology/therapeutic use ; Klebsiella Infections/diagnosis/drug therapy/*microbiology ; Klebsiella pneumoniae/drug effects/isolation & purification/*physiology ; Male ; Microbial Sensitivity Tests ; Phenotype ; Sepsis/diagnosis/drug therapy/*microbiology ; Thienamycins/pharmacology/therapeutic use

We investigated the occurrence and genetic basis of AmpC beta-lactamase (AmpC)-mediated antibiotic resistance, by examining Escherichia coli, Klebsiella pneumoniae, and Proteus mirabilis isolates at a university hospital, from 2007 to 2010. The ampC genes were detected by multiplex AmpC PCR, and AmpC-positive strains were subjected to DNA sequencing. Extended-spectrum beta-lactamase (ESBL) production was assessed using the ESBL disk test based on the utilization of boronic acid. Carbapenem-resistant isolates were further investigated by the modified Hodge test, a carbapenemase inhibition test and SDS-PAGE experiments. AmpC expression was detected in 1.6% of E. coli (39 DHA-1, 45 CMY-2, and 1 CMY-1) isolates, 7.2% of K. pneumoniae (39 DHA-1, 45 CMY-2, and 1 CMY-1) isolates, and 2.5% of P. mirabilis (8 CMY-2 and 1 CMY-1) isolates. Of the 198 acquired AmpC producers, 58 isolates (29.3%) also produced an ESBL enzyme. Among the acquired AmpC-producing K. pneumoniae isolates, the minimum inhibitory concentration (MIC) MIC50/MIC90 values for cefoxitin, cefotaxime, cefepime, imipenem, and meropenem were >32/>32, 16/>32, 1/16, 0.25/0.5, and <0.125/0.125 microg/mL, respectively. The MIC values for carbapenem were > or =2 microg/mL for 2 K. pneumoniae isolates, both of which carried the blaDHA-1 gene with a loss of OmpK36 expression, but were negative for carbapenemase production. The acquisition of AmpC-mediated resistance in K. pneumoniae isolates increased, as did the proportion of AmpC and ESBL co-producers among the hospital isolates. The accurate identification of isolates producing AmpCs and ESBLs may aid in infection control and will assist physicians in selecting an appropriate antibiotic regimen.
Anti-Bacterial Agents/pharmacology ; Bacterial Proteins/*genetics ; DNA, Bacterial/genetics ; Enterobacteriaceae Infections/*epidemiology/*microbiology ; Escherichia coli/drug effects/enzymology/isolation & purification ; Hospitals, University/statistics & numerical data ; Humans ; Klebsiella pneumoniae/drug effects/enzymology/isolation & purification/*physiology ; Microbial Sensitivity Tests ; Multiplex Polymerase Chain Reaction ; Proteus mirabilis/drug effects/enzymology/isolation & purification ; Republic of Korea/epidemiology ; beta-Lactamases/*genetics