OBJECTIVES: The prevalence of carbapenem-resistant Enterobacterales (CRE) presents a significant challenge in clinical anti-infective treatment. This study aims to investigate drug resistance and the molecular epidemiological characteristics of CRE in our area. Additionally, we seek to evaluate practicality of utilizing carbapenemase inhibitor enhancement test in clinical laboratory. METHODS: Non-repeated CREs isolated from clinical specimens at Xiangya Hospital, Central South University, were collected. Minimum inhibitory concentration (MIC) combined with Kirby-Bauer (KB) assay was used to detect the drug susceptibility of the strains, and 13 carbapenemase-producing genes were detected by PCR. The phenotype of 126 strains of carbapenemase-producing Enterobacterales identified by PCR was detected by the carbapenemase inhibitor enhancement test to understand the agreement between the method and the gold standard PCR results. RESULTS: Among 704 CRE strains examined, we observed significant drug resistance in 501 strains dentified as carbapenemase-producing Enterobacterales (CPE). Klebsiella pneumoniae was the predominant CPE strain, followed by Enterobacter cloacae and Escherichia coli. A total of 9 carbapenemase types were detected, including Klebsiella pneumoniae carbapenemase (KPC), New Delhi metallo-β-lactamase (NDM), Verona integron- encoded metallo-β-lactamases (VIM), imipenemase (IMP), oxacillinase-48 (OXA-48), and rare imipenem-hydrolyzing β-lactamase (IMI), adelaide imipenemase (AIM), Bicêtre carbapenemase (BIC), and guiana extended-spectrum β-lactamase (GES). The detection rate of KPC serine carbapenemase was 61.7% (309/501). The carbapenemase inhibitor enhancement test exhibited a 100% consistency rate for the strains producing Class A serine carbapenemase and/or Class B metallo-β-lactamases. CONCLUSIONS CRE strains in Changsha, Hunan, China, are wide distribution and exhibit carbapenemase production. The main mechanism of carbapenem resistance in these bacterias is predominatly attributed to the production of KPC serine carbapenemase. The presence of GES and IMI genes carried by Enterobacterales has been detected for the first time in this region. The carbapenemase inhibitor enhancement test has been proven to be an accurate method for detecting CRE producing Class A serine carbapenemase and/or Class B metallo-β-lactamases. This method offers simpicity of operation and ease of results interpretation, making it weel-suited meeting the clinical microbiology laboratory's reguirements for the detection of serine carbapenemase and metallo-β-lactamases.
Humans ; Carbapenems/pharmacology* ; Molecular Epidemiology ; Bacterial Proteins/analysis* ; beta-Lactamases/analysis* ; Klebsiella pneumoniae/genetics* ; Escherichia coli ; Microbial Sensitivity Tests ; Serine ; Anti-Bacterial Agents/pharmacology*

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

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 study the effect of β-lactamase (BLs) detection and β-lactam/β-lactamase inhibitor (BL/BLI) on the incidence of antibiotic-associated diarrhea (AAD) in children with severe bacterial pneumonia.

METHODSThe clinical data of the children with bacterial severe pneumonia were retrospectively studied. Of all the patients, 248 using amoxicillin/clavulanate but without BLs detection and 323 using amoxicillin (BLs negative) or amoxicillin/clavulanate (BLs positive) were used as the amoxicillin group; 208 patients using piperacillin/tazobactam but without BLs detection and 291 patients using piperacillin (BLs negative) or piperacillin/tazobactam (BLs positive) were used as the piperacillin group; and 191 patients using cefoperazone/sulbactam but without BLs detection and 341 patients using cefoperazone (BLs negative) or cefoperazone/sulbactam (BLs positive) were used as the cefoperazone group. The incidence and clinical symptoms of AAD between the undetected and detected BLs patients were compared.

RESULTSThe incidences of AAD in the amoxicillin, piperacillin and cefoperazone groups without BLs detection groups were significantly higher than those in the corresponding groups with negative or positive results of BLs detection (P<0.01). The durations of diarrhea, antibiotic use and hospitalization stay in AAD patients receiving BLs detection were shorter than in those without receiving BLs detection (P<0.01).

CONCLUSIONSIt is very important to detect BLs for reducing the incidence and relieving symptoms of AAD in children with severe bacterial pneumonia.

Adolescent ; Anti-Bacterial Agents ; adverse effects ; Child ; Child, Preschool ; Diarrhea ; chemically induced ; epidemiology ; prevention & control ; Humans ; Incidence ; Infant ; Pneumonia, Bacterial ; complications ; beta-Lactamases ; analysis

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

In this study, 78 isolates of Escherichia coli isolated from Korean beef cattle farms were investigated for the production of extended-spectrum beta-lactamase (ESBL) and/or AmpC beta-lactamase. In the disc diffusion test with ampicillin, amoxicillin, cephalothin, ceftiofur, cefotaxime, ceftazidime, and cefoxitin, 38.5% of the isolates showed resistance to all of ampicillin, amoxicillin, and cephalothin. The double disc synergy method revealed that none of the isolates produced ESBL or AmpC beta-lactamases. DNA sequencing showed that all isolates encoded genes for TEM-1-type beta-lactamase. Moreover, 78.2% of the isolates transferred the TEM-1-type beta-lactamase gene via conjugation. In plasmid replicon typing of all donors, IncFIB and IncFIA were identified in 71.4% and 41.0% of plasmids, respectively. In transconjugants, IncFIB and IncFIA were the most frequent types detected (61.5% and 41.0%, respectively). Overall, the present study indicates that selection pressures of antimicrobials on beta-lactamases in beef cattle may be low relative to other livestock animals in Korea. Moreover, to reduce selection pressure and dissemination of beta-lactamase, the long-term surveillance of antimicrobial use in domestic beef cattle should be established.
Amoxicillin ; Ampicillin ; Animals ; beta-Lactamases* ; Cattle* ; Cefotaxime ; Cefoxitin ; Ceftazidime ; Cephalothin ; Diffusion ; Escherichia coli* ; Escherichia* ; Humans ; Korea ; Livestock ; Plasmids* ; Replicon* ; Sequence Analysis, DNA ; Tissue Donors

BACKGROUND: We investigated the rates of fecal transmission of extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae (ESBL-E) and carbapenem-resistant Enterobacteriaceae (CRE) among patients admitted to intensive care units (ICUs). METHODS: From June to August 2012, rectal cultures were acquired from all patients at ICU admission. For patients not carrying ESBL-E or CRE at admission, follow-up cultures were performed to detect acquisition. A chromogenic assay was used to screen for ESBL-E and CRE. Bacterial species identification and antibiotic susceptibility tests were performed using the Vitek 2 system (bioMerieux, France). ESBL genotypes were determined by PCR, and clonal relatedness of the isolates was assessed by pulsed-field gel electrophoresis. RESULTS: Out of 347 ICU admissions, 98 patients were found to be carriers of ESBL-E (28.2%, 98/347). Follow-up cultures were acquired from 91 of the patients who tested negative for ESBL-E at admission; the acquisition rate in this group was 12.1% (11/91), although none was a nosocomial transmission. For CRE, the prevalence of fecal carriage was 0.3% (1/347), and the acquisition rate was 2.9% (4/140). None of the CRE isolates were carbapenemase-producers. CONCLUSIONS: The high prevalence of ESBL-E carriage on admission (28.2%), coupled with rare nosocomial transmission and the very low carriage rate of CRE (0.3%), challenge the routine use of active surveillance in non-epidemic settings. Nevertheless, passive surveillance measures, such as rapid and accurate screening of clinical specimens, will be critical for controlling the spread of CRE.
Anti-Bacterial Agents/pharmacology ; Bacterial Proteins/*metabolism ; Carbapenems/*pharmacology ; Carrier State/epidemiology ; Cross Infection/epidemiology/*transmission ; DNA, Bacterial/analysis ; Drug Resistance, Bacterial/drug effects ; Electrophoresis, Gel, Pulsed-Field ; Enterobacteriaceae/enzymology/genetics/*physiology ; Enterobacteriaceae Infections/epidemiology/*transmission ; Feces/*microbiology ; Genotype ; Humans ; Intensive Care Units ; Polymerase Chain Reaction ; Prevalence ; Republic of Korea/epidemiology ; beta-Lactamases/*metabolism

PURPOSE: The prevalence of antibiotic-resistant bacteria on rectal swabs in patients undergoing transrectal ultrasound (TRUS)-guided prostate biopsy and the factors affecting resistance to antibiotics were evaluated. MATERIALS AND METHODS: Two hundred twenty-three men who underwent TRUS-guided prostate biopsy from November 2011 to December 2012 were retrospectively evaluated. Rectal swabs were cultured on MacConkey agar to identify antibiotic-resistant bacteria in rectal flora before TRUS-guided prostate biopsy. All patients were admitted and received intravenous antibiotics before prostate biopsy. Clinical variables including underlying disease, infectious complications, and antibiotics associated with resistance were evaluated. Logistic regression was used to determine the factors influencing antibiotic resistance. RESULTS: Of the 233 patients, 161 had positive rectal cultures. Escherichia coli was cultured in 130 (80.7%) and Klebsiella pneumonia in 16 (9.9%). The prevalence of quinolone resistance was 16.8% and the prevalence of extended-spectrum beta-lactamase (ESBL) positivity was 9.3%. A previous history of prostatitis was correlated with quinolone resistance and ESBL positivity (both p=0.001). The factors affecting quinolone resistance in the univariate analysis were a previous history of prostatitis (p=0.003) and previous exposure to antibiotics (p=0.040). Only a previous history of prostatitis was statistically significant in the multivariate analysis (p=0.014). Four patients had infectious complications. CONCLUSIONS: The prevalence of quinolone resistance was 16.8% in rectal swabs performed before TRUS-guided prostate biopsy. A previous history of prostatitis was influential. In patients with a history of prostatitis, selection of prophylactic antibiotics before the biopsy may be reconsidered.
Agar ; Anti-Bacterial Agents* ; Bacteria* ; beta-Lactamases ; Biopsy* ; Communicable Diseases ; Drug Resistance ; Drug Resistance, Microbial ; Escherichia coli ; Humans ; Klebsiella ; Logistic Models ; Male ; Multivariate Analysis ; Pneumonia ; Prevalence* ; Prostate* ; Prostatitis ; Retrospective Studies ; Risk Factors ; Ultrasonography

BACKGROUND: The role of extended-spectrum beta-lactamase (ESBL)-producing or multidrug-resistant (MDR) organisms in patients with sepsis secondary to urinary traction infection (UTI) has not been investigated extensively in the intensive care unit (ICU) setting. METHODS: Patients with UTI sepsis admitted to the ICU were retrospectively enrolled in this study (January 2009-December 2012). We investigated the impact of ESBL-producing and ESBL-negative MDR organisms on hospital outcome. RESULTS: In total, 94 patients were enrolled (median age, 73.0 years; female, 81.9%), and ESBL-producing and ESBL-negative MDR organisms accounted for 20.2% (n = 19) and 30.9% (n = 29), respectively. Both patients with ESBL-producing and ESBL-negative MDR organisms were more likely to experience a delay in adequate antibiotic therapy than those with non-ESBL/non-MDR organisms (p < 0.001 and p = 0.032, respectively). However, only patients with ESBL-producing organisms showed a higher mortality rate (ESBL vs. ESBL-negative MDR vs. non-ESBL/non-MDR, 31.6% vs. 10.3%.vs. 10.9%, respectively). In multivariate analyses, ESBL production was significantly associated with hospital mortality (odds ratio, 11.547; 95micro confidence interval, 1.047-127.373), and prior admission was a significant predictor of ESBL production. CONCLUSIONS: Although both ESBL-producing and ESBL-negative MDR organisms are associated with delayed administration of appropriate antibiotics, only ESBL production is a significant predictor of hospital mortality among patients with UTI sepsis in the ICU setting.
Anti-Bacterial Agents ; beta-Lactamases* ; Drug Resistance, Multiple* ; Female ; Hospital Mortality ; Humans ; Intensive Care Units* ; Mortality ; Multivariate Analysis ; Retrospective Studies ; Sepsis* ; Urinary Tract ; Urinary Tract Infections

BACKGROUND: The role of extended-spectrum beta-lactamase (ESBL)-producing or multidrug-resistant (MDR) organisms in patients with sepsis secondary to urinary traction infection (UTI) has not been investigated extensively in the intensive care unit (ICU) setting. METHODS: Patients with UTI sepsis admitted to the ICU were retrospectively enrolled in this study (January 2009-December 2012). We investigated the impact of ESBL-producing and ESBL-negative MDR organisms on hospital outcome. RESULTS: In total, 94 patients were enrolled (median age, 73.0 years; female, 81.9%), and ESBL-producing and ESBL-negative MDR organisms accounted for 20.2% (n = 19) and 30.9% (n = 29), respectively. Both patients with ESBL-producing and ESBL-negative MDR organisms were more likely to experience a delay in adequate antibiotic therapy than those with non-ESBL/non-MDR organisms (p < 0.001 and p = 0.032, respectively). However, only patients with ESBL-producing organisms showed a higher mortality rate (ESBL vs. ESBL-negative MDR vs. non-ESBL/non-MDR, 31.6% vs. 10.3%.vs. 10.9%, respectively). In multivariate analyses, ESBL production was significantly associated with hospital mortality (odds ratio, 11.547; 95micro confidence interval, 1.047-127.373), and prior admission was a significant predictor of ESBL production. CONCLUSIONS: Although both ESBL-producing and ESBL-negative MDR organisms are associated with delayed administration of appropriate antibiotics, only ESBL production is a significant predictor of hospital mortality among patients with UTI sepsis in the ICU setting.
Anti-Bacterial Agents ; beta-Lactamases ; Drug Resistance, Multiple ; Female ; Hospital Mortality ; Humans ; Intensive Care Units ; Mortality ; Multivariate Analysis ; Retrospective Studies ; Sepsis ; Urinary Tract ; Urinary Tract Infections