Widespread Dissemination of CTX-M-15 Genotype Extended-Spectrum-β-Lactamase-Producing Enterobacteriaceae among Patients Presenting to Community Hospitals in the Southeastern United States

Abstract

e Extended-spectrum-␤-lactamase (ESBL)-producing organisms are increasingly prevalent. We determined the characteristics of 66 consecutive ESBL-producing isolates from six community hospitals in North Carolina and Virginia from 2010 to 2012. Fiftythree (80%) ESBL-producing isolates contained CTX-M enzymes; CTX-M-15 was found in 68% of Escherichia coli and 73% of Klebsiella isolates. Sequence type 131 (ST131) was the commonest type of E. coli, accounting for 48% of CTX-M-15-producing and 66% of CTX-M-14-producing isolates. In conclusion, the CTX-M genotype and ST131 E. coli were common among ESBL isolates from U.S. community hospitals. Infections associated with extended-spectrum-␤-lactamase (ESBL)-producing organisms are increasing worldwide (1, 2). The emergence of ESBL-producing organisms in the United States has been partially driven by the dissemination of the CTX-M family of ESBL enzymes, which are commonly associated with additional virulence factors and resistance determinants that confer selection advantages. We previously reported an increase in ESBL-producing E. coli infections among 16 community hospitals in the southeastern region of the United States from 2006 to 2008 (3). We hypothesized that CTX-M-producing organisms were widely disseminated and represented the majority of organisms with the ESBL phenotype in the community setting. Therefore, we conducted the current study to determine the clinical and molecular epidemiology of infections due to ESBL-producing organisms among community hospitals.Six community hospitals affiliated with the Duke Infection Control Outreach Network (DICON) in North Carolina and Virginia provided 66 consecutive phenotypically confirmed ESBL isolates for analysis from July 2010 to February 2012 (4, 5). Escherichia coli isolates were the most common (67%), followed by Klebsiella pneumoniae (29%), Klebsiella oxytoca (3%), and Enterobacter cloacae (2%). The patients' demographic and clinical characteristics are summarized in Table 1. Thirty-seven (56%) of these ESBL-producing isolates were detected from a urinary source; 63% of these urinary tract infections occurred in the absence of a urinary catheter.Using standard epidemiological definitions, 35 (65%) of these ESBL infections were categorized as community onset, health care associated, 10 (19%) were categorized as community acquired, and only 9 (17%) were categorized as hospital-onset ESBL infections (6, 7).Molecular epidemiology studies showed that 53 (80%) of these ESBL-producing isolates carried a CTX-M ␤-lactamase, including 37 (84%) isolates of E. coli, 15 (71%) Klebsiella isolates, and the single isolate of E. cloacae. Overall, 25 (68%) E. coli ESBL isolates had CTX-M-15 and 6 (16%) had CTX-M-14. One E. coli isolate (3%) had CTX-M-107. Of the 15 Klebsiella isolates that had CTX-M ␤-lactamase, 11 (73%) isolates were found to have CTX-M-15.Multilocus sequence typing (MLST) of E. coli isolates showed that sequence type 131 (ST131) was the predominant sequence type (8). Clonal analysis with pulsed-field gel electroph...

Widespread dissemination of extended-spectrum β-lactamase-producing, multidrug-resistant Escherichia coli in livestock and fishery products in Vietnam

“…Our results showed that 96.5 % of the ESBL-E. coli isolates encoded genes of the CTX-M group with or without TEM-encoding genes, suggesting the emergence of the CTX-M gene group as the main contributor to the antibiotic resistance of ESBL-E. coli in food, foodproducing animals, healthy people, and patients not only in developed countries but also in underdeveloped countries (Sasaki et al 2010;Overdevest et al 2011;Börjesson et al 2013;Chen et al 2014;Nakayama et al 2015).…”

“…The phylogenetic groups of ESBL-E. coli were identified by multiplex PCR amplification of a combination of two genes, chuA and yjaA, and a DNA fragment, TspE4C2, as described previously (Chen et al 2014). …”

Characteristics of Extended-Spectrum β-Lactamases-Producing <i>Escherichia coli</i> in Fecal Samples of Inpatients of Beijing Tongren Hospital

“…It has been reported that the ESBL prevalence is higher in Europe than in the USA but lower in Asia or South America (4). Sequence type (ST) 131 is the most common genotype of ES-BL-producing E. coli, and 54.2% of community-associated infections are caused by the ST131 strain (5,6).…”

The First Report of Extended-Spectrum β-Lactamase (ESBL) Genes in an Escherichia coli Isolate from a One-Month-Old Infant with Acute Lymphoblastic Leukemia (ALL) in Iran

“…Furthermore, ESBL-producing bacteria typically carry genetic determinants that confer resistance to fluoroquinolones and aminoglycosides. Thus, carbapenems, along with other drugs, such as Beta-lactam/beta-lactamase inhibitor combinations, may likely have an increasing role as empirical therapy for patients who are infected with ESBL-producing organisms in community and hospitals (15). In summary, we found an ESBL-producing E. coli in a 1-month-old infant with a blood cancer that carried CTX-M-1 group enzymes.…”

“…Furthermore, in cancer patients with prolonged hospitalization and with ALL who had received antibiotics for a prolonged period, the opportunity for these bacteria to cause infections enhances (14). Recent data have documented the importance of CTX-M enzymes in the ESBL epidemic around the world (15). ESBLproducing organisms, especially those carrying CTX-M-15, are commonly resistant to cephalosporins as the first-line choice for the treatment of bacteremic patients.…”