Enterobacteriaceae Colonization Research Articles

Risk associated with a systematic search of extended-spectrum β-lactamase–producing Enterobacteriaceae

We evaluated 74 children with previous fecal extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae colonization who were hospitalized and receiving a course of antibiotic therapy for suspected infection. Sixty-four patients (86.5%) received a carbapenem agent. Only 3 patients were infected with an ESBL-producing Enterobacteriaceae. Sixty-one (95%) initial antibiotic courses were considered excessive and required deescalation; however, deescalation was accomplished in only 38 patients (62%). This suggests the need for an ESBL control program to decrease carbapenem use and thereby limit carbapenem resistance in gram-negative bacilli.

Extended Spectrum Beta-Lactamase-Producing Enterobacteriaceae in International Travelers and Non-Travelers in New York City

BackgroundWe performed this study 1) to determine the prevalence of community-associated extended spectrum beta-lactamase producing Enterobacteriaceae (ESBLPE) colonization and infection in New York City (NYC); 2) to determine the prevalence of newly-acquired ESBLPE during travel; 3) to look for similarilties in contemporaneous hospital-associated bloodstream ESBLPE and travel-associated ESBLPE.MethodsSubjects were recruited from a travel medicine practice and consented to submit pre- and post-travel stools, which were assessed for the presence of ESBLPE. Pre-travel stools and stools submitted for culture were used to estimate the prevalence of community-associated ESBLPE. The prevalence of ESBLPE-associated urinary tract infections was calculated from available retrospective data. Hospital-associated ESBLPE were acquired from saved bloodstream isolates. All ESBLPE underwent multilocus sequence typing (MLST) and ESBL characterization.ResultsOne of 60 (1.7%) pre- or non-travel associated stool was colonized with ESBLPE. Among community-associated urine specimens, 1.3% of Escherichia coli and 1.4% of Klebsiella pneumoniae were identified as ESBLPE. Seven of 28 travelers (25.0%) acquired a new ESBLPE during travel. No similarities were found between travel-associated ESBLPE and hospital-associated ESBLPE. A range of imported ESBL genes were found, including CTX-M-14 and CTX-15.ConclusionESBL colonization and infection were relatively low during the study period in NYC. A signficant minority of travelers acquired new ESBLPE during travel.

Bacteroides fragilis decrease intestinal Enterobacteriacease colonization and reverse metronidazole-induced bacterial translocation (120.22)

Abstract Bacteroides, one of the major bacterial groups in the intestine, maintain a complex relationship with the host. In this study, the role of B. fragilis in intestinal permeability and immunity were examined in C57BL/6 mice receiving oral treatment of metronidazole for 6 days. Metronidazole treatment significantly decreased the number of B. fragilis but increased that of Enterobacteriaceae in intestinal mucosa and lumen. Metronidazole treatment increased intestinal permeability and pathogenic Klebsiella pneumoniae translocation. However, metronidazole did not change the bacterial killing activity and expression of TLR4, TLR2, MyD88, RegIIIβ, RegIIIγ, CRP-ductin, RELMβ, as well as defensin proteins in intestinal mucosa. Supplementation of dead B. fragilis in drinking water reversed the effects of metronidazole on intestinal permeability, Enterobacteriaceae colonization, and bacterial translocation (BT), suggesting that B. fragilis maintains intestinal permeability and decreases BT through reducing the colonization of Enterobacteriaceae rather than enhancing the expression of antibacterial proteins or the bacterial killing activity. This is further supported by that B. fragilis monoassociated mice showed a decrease of K. pneumoniae translocation and no change in bacterial killing activity as well as expression of defensin and nondefensin protein expression except of CRP-ductin when compared with germ free mice.

Infections néonatales tardives à entérobactéries multirésistantes

The objective of this study was to determine the incidence of extended-spectrum beta-lactamase (ESBLS) enterobacteriaceae colonization and infection in hospitalized children. This prospective study was conducted in a neonatal intensive care unit from 2000 to 2009. We recorded all isolations of ESBLs enterobacteriaceae from clinical samples that were obtained from hospitalized children. Anorectal samples were taken at admission and every 10 days. We systematically recorded cases of confirmed infections that was caused by ESBLs enterobacteriacea. A total of 46 ESBL(S) pathogens (E coli 58.7 %, Enterobacter cloacae 10.8 %, Klebsiella Pneumonia 19.5%, K. oxytoca 6.5 %, Citrobacter 4.5 %) were isolated during 10 years, the global incidence was 5.1 cases per 1000 admissions. Three infants developed nosocomial infections, E. coli sepsis and pneumonia and Enterobacter cloacae omphalitis. These patients were treated with carbapenem with significant clinical improvement. ESBLs enterobacteriaceae were found first in Klebsiella pneumonia and then predominantly in E. coli. Current efforts have focused on monitoring proper hand hygiene, evaluation of potential reservoirs of bacterial acquisition and transmission, cohorting and isolation of colonized infants, and fostering of effective inter- and intrahospital communication. Carbapenem seems to be safe in newborn and is recommended for the treatment of EBLSEs enterobacteriaceae infections.

Epidemiology of Multidrug-Resistant Bacteria in Patients With Long Hospital Stays

To determine rates of colonization with multidrug-resistant (MDR) bacteria (ie, methicillin-resistant Staphylococcus aureus [MRSA], vancomycin-resistant Enterococcus [VRE], extended-spectrum beta -lactamase [ESBL]-producing Enterobacteriaceae, and Acinetobacter baumannii) after prolonged hospitalization and to assess the yield of surveillance cultures and variables associated with colonization with MDR bacteria. Prospective observational cohort study conducted from February 6 to May 26, 2006. All patients who spent more than 30 days in our university hospital (Paris, France) were included. Rectal and nasal swab samples obtained during day 30 screening were examined for MRSA, VRE, ESBL-producing Enterobacteriaceae, and A. baumannii. Of 470 eligible patients, 439 had surveillance culture samples available for analysis, including 51 patients (11.6%) with a history of colonization or infection due to 1 or more types of MDR bacteria (MRSA, recovered from 35 patients; ESBL-producing Enterobacteriaceae, from 16 patients; A. baumannii, from 6 patients; and VRE, from 0 patients) and 37 patients (9.5% of the 388 patients not known to have any of the 4 MDR bacteria before day 30 screening) newly identified as colonized by 1 or more MDR bacteria (MRSA, recovered from 20 patients; ESBL-producing Enterobacteriaceae, from 16 patients; A. baumannii, from 1 patient; and VRE, from 0 patients). A total of 87 (19.8%) of 439 patients were identified as colonized or infected with MDR bacteria at day 30. Factors that differed between patients with and without MRSA colonization included age, McCabe score, comorbidity score, receipt of surgery, and receipt of fluoroquinolone treatment. Patients with ESBL-producing Enterobacteriaceae colonization were younger than patients with MRSA colonization. Differences in the variables associated with MRSA colonization and ESBL-producing Enterobacteriaceae colonization suggest differences in the epidemiology of these 2 organisms. Day 30 screening resulted in a 72.5% increase in the number of patients identified as colonized with at least 1 type of MDR bacteria.

Screening for Extended-Spectrum -Lactamase-Producing Enterobacteriaceae among High-Risk Patients and Rates of Subsequent Bacteremia

Bloodstream infections due to extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae have been associated with increased hospital costs, length of stay, and patient mortality. However, the role of routine inpatient surveillance for ESBL colonization in predicting related infection is unclear. From 2000 through 2005, we screened 17,872 patients hospitalized in designated high-risk units for rectal colonization with vancomycin-resistant enterococci and ESBL-producing Enterobacteriaceae using a selective culture medium. In patients with a bloodstream infection due to ESBL-producing Enterobacteriaceae (ESBL-BI) during the study period, surveillance results were evaluated for evidence of antecedent ESBL-producing Enterobacteriaceae colonization. The rate of ESBL-producing Enterobacteriaceae colonization doubled during the 6-year study period, increasing from 1.33% of high-risk patients in 2000 to 3.21% in 2005. Among patients with ESBL-producing Enterobacteriaceae colonization, 49.6% also carried vancomycin-resistant enterococci. The number of ESBL-BIs increased >4-fold in 5 years, from 9 cases in 2001 to 40 cases in 2005. Of 413 patients colonized with ESBL-producing Enterobacteriaceae, 35 (8.5%) developed a subsequent ESBL-BI. Of concern, more than one-half of all ESBL-BIs occurred in patients who were not screened. These 56 patients received a diagnosis of ESBL-BI in the emergency department, when hospitalized in low-risk medical units, or at transfer from an acute or long-term health care facility. Colonization with ESBL-producing Enterobacteriaceae is increasing at a rapid rate, and routine rectal surveillance for ESBL-producing Enterobacteriaceae may have clinical implications. However, in our experience, over one-half of patients with an ESBL-BI did not undergo screening through our current surveillance measures. As a result, targeted screening for ESBL-producing Enterobacteriaceae among additional patient populations may be integral to future ESBL-BI prevention and management efforts.

Intestinal adherent bacteria and bacterial translocation in breast-fed and formula-fed rats in relation to susceptibility to infection.

The barrier function of the intestinal mucosa is immature in the newborn mammal, and is strengthened by breast milk. We investigated this effect of breast milk by comparing the susceptibility to infection assessed in terms of adherent bacterial colonization of the intestinal tissue (AdC) and bacterial translocation (BT) between breast-fed and formula-fed newborn rats. Three-day-old rat pups were assigned to one of three groups: mother-reared (MR), pseudo-cannulated (sham), and artificially reared (AR). AR rats were infused with formula through an intragastric cannula, under the control of a computer-regulated pumping machine. MR and sham rat pups were reared with their respective dams and received breast milk until weaning in a specially designed cage. In 10-d-old rats, there was no significant difference in the fecal or cecal flora between the AR and MR groups, whereas the AdC and the BT to the liver were greater in the AR than MR group. Enterobacteriaceae, Streptococcus and/or Enterococcus, and Staphylococcus were dominantly detected as microorganisms in AdC flora and BT. The AdC flora did not directly reflect the bacterial colonization flora. These findings suggest that AR rat pups mature normally, although there is a greater colonization of Enterobacteriaceae and BT in AR than MR pups. Consequently, the intestinal barrier function of the pups reared by artificial feeding may become susceptible to BT, and AdC may be more indicative than bacterial colonization of the susceptibility to BT.