Effects of decontamination of the oropharynx and intestinal tract on antibiotic resistance in ICUs: a randomized clinical trial.

IMPORTANCE: Selective decontamination of the digestive tract (SDD) and selective oropharyngeal decontamination (SOD) are prophylactic antibiotic regimens used in intensive care units (ICUs) and associated with improved patient outcome. Controversy exists regarding the relative effects of both measures on patient outcome and antibiotic resistance. OBJECTIVE: To compare the effects of SDD and SOD, applied as unit-wide interventions, on antibiotic resistance and patient outcome. DESIGN, SETTING, AND PARTICIPANTS: Pragmatic, cluster randomized crossover trial comparing 12 months of SOD with 12 months of SDD in 16 Dutch ICUs between August 1, 2009, and February 1, 2013. Patients with an expected length of ICU stay longer than 48 hours were eligible to receive the regimens, and 5881 and 6116 patients were included in the clinical outcome analysis for SOD and SDD, respectively. INTERVENTIONS: Intensive care units were randomized to administer either SDD or SOD. MAIN OUTCOMES AND MEASURES: Unit-wide prevalence of antibiotic-resistant gram-negative bacteria. Secondary outcomes were day-28 mortality, ICU-acquired bacteremia, and length of ICU stay. RESULTS: In point-prevalence surveys, prevalences of antibiotic-resistant gram-negative bacteria in perianal swabs were significantly lower during SDD compared with SOD; for aminoglycoside resistance, average prevalence was 5.6% (95% CI, 4.6%-6.7%) during SDD and 11.8% (95% CI, 10.3%-13.2%) during SOD (P < .001). During both interventions the prevalence of rectal carriage of aminoglycoside-resistant gram-negative bacteria increased 7% per month (95% CI, 1%-13%) during SDD (P = .02) and 4% per month (95% CI, 0%-8%) during SOD (P = .046; P = .40 for difference). Day 28-mortality was 25.4% and 24.1% during SOD and SDD, respectively (adjusted odds ratio, 0.96 [95% CI, 0.88-1.06]; P = .42), and there were no statistically significant differences in other outcome parameters or between surgical and nonsurgical patients. Intensive care unit-acquired bacteremia occurred in 5.9% and 4.6% of the patients during SOD and SDD, respectively (odds ratio, 0.77 [95% CI, 0.65-0.91]; P = .002; number needed to treat, 77). CONCLUSIONS AND RELEVANCE: Unit-wide application of SDD and SOD was associated with low levels of antibiotic resistance and no differences in day-28 mortality. Compared with SOD, SDD was associated with lower rectal carriage of antibiotic-resistant gram-negative bacteria and ICU-acquired bacteremia but a more pronounced gradual increase in aminoglycoside-resistant gram-negative bacteria. TRIAL REGISTRATION: trialregister.nlIdentifier: NTR1780.

Clinical and molecular characteristics of extended-spectrum-beta-lactamase-producing Escherichia coli causing bacteremia in the Rotterdam Area, Netherlands.

We investigated the clinical and molecular characteristics of bacteremia caused by extended-spectrum-ß-lactamase (ESBL)-producing Escherichia coli over a 2-year period (2008 to 2009) in the Rotterdam region (including 1 teaching hospital and 2 community hospitals) of Netherlands. The majority of patients presented with community onset urinary and intra-abdominal infections, with an increase in prevalence during 2009. The majority of E. coli isolates produced CTX-M-15, and 4 sequence types (ST38, ST131, ST405, and ST648) predominated. There were significant differences in clinical and molecular characteristics between the 2 community hospitals.

Risk factors for bacteremia with uropathogen not cultured from urine in adults with febrile urinary tract infection.

In a prospective study involving 642 patients with febrile urinary tract infection (UTI), we found antimicrobial pretreatment (odds ratio [OR], 3.3), an indwelling urinary catheter (OR, 2.8), and malignancy (OR, 2.7) to be independent risk factors for bacteremia with a uropathogen that was not cultured or recognized in the urine. Although the diagnostic value of blood cultures has been questioned in UTI, we advocate performing blood cultures for patients with these risk factors.

Duration of carriage of multidrug resistant Enterobacterales in discharged hospital and general practice patients and factors associated with clearance.

OBJECTIVES: Dutch guidelines recommend contact precautions in patients with multidrug resistant microorganisms cultured during the previous 12 months. To evaluate this policy, duration of carriage of multidrug resistant Enterobacterales was assessed among discharged hospital patients and patients attending their general practitioner (GP). Additionally, we assessed factors associated with clearance. METHODS: From January 2013 until May 2016, rectal or faecal samples accompanied by questionnaires on patient characteristics were obtained at time of study inclusion and 3, 6 and 12 months later, in 72 patients with multidrug resistant Enterobacterales. Clearance was defined as one or more negative cultures without a subsequent positive culture at 12 months after study inclusion. The percentage of clearance, intermittent carriage and persistence was determined and associated factors were assessed by logistic regression analysis. RESULTS: Clearance was found in 31 patients (43.1% [95%CI: 32.3-54.6]) of which 23 patients had two or more subsequent negative cultures. Twelve patients were classified as intermittent carriers (16.7% [95%CI: 9.8-26.9]) and 29 patients (40.3% [95% CI: 29.7-51.8]) as persistent carriers. Of the intermittent carriers, the majority (n=9) had two negative cultures during the study period. There was no difference in clearance between discharged hospitalized patients and GP patients. The only factor associated with clearance at 12 months in both univariable and multivariable analyses was not traveling to a foreign country (OR=3.5 [95%CI: 1.0-12.4]). CONCLUSION: Active screening for clearance of multidrug resistant Enterobacterales in patients within the health care setting is probably not beneficial due to high levels of intermittent and persistent carriage.

Prevention of severe infectious complications after colorectal surgery using oral non-absorbable antimicrobial prophylaxis: results of a multicenter randomized placebo-controlled clinical trial.

BACKGROUND: Surgical site infections (SSIs) are common complications after colorectal surgery. Oral non-absorbable antibiotic prophylaxis (OAP) can be administered preoperatively to reduce the risk of SSIs. Its efficacy without simultaneous mechanical cleaning is unknown. METHODS: The Precaution trial was a double-blind, placebo-controlled randomized clinical trial conducted in six Dutch hospitals. Adult patients who underwent elective colorectal surgery were randomized to receive either a three-day course of preoperative OAP with tobramycin and colistin or placebo. The primary composite endpoint was the incidence of deep SSI or mortality within 30 days after surgery. Secondary endpoints included both infectious and non-infectious complications at 30 days and six months after surgery. RESULTS: The study was prematurely ended due to the loss of clinical equipoise. At that time, 39 patients had been randomized to active OAP and 39 to placebo, which reflected 8.1% of the initially pursued sample size. Nine (11.5%) patients developed the primary outcome, of whom four had been randomized to OAP (4/39; 10.3%) and five to placebo (5/39; 12.8%). This corresponds to a risk ratio in the intention-to-treat analysis of 0.80 (95% confidence interval (CI) 0.23-2.78). In the per-protocol analysis, the relative risk was 0.64 (95% CI 0.12-3.46). CONCLUSIONS: Observational data emerging during the study provided new evidence for the effectiveness of OAP that changed both the clinical and medical ethical landscape for infection prevention in colorectal surgery. We therefore consider it unethical to continue randomizing patients to placebo. We recommend the implementation of OAP in clinical practice and continuing monitoring of infection rates and antibiotic susceptibilities. TRIAL REGISTRATION: The PreCaution trial is registered in the Netherlands Trial Register under NL5932 (previously: NTR6113) as well as in the EudraCT register under 2015-005736-17.

Evaluation of real-time PCR and conventional diagnostic methods for the detection of Clostridium difficile-associated diarrhoea in a prospective multicentre study.

In this prospective multicentre study, an enzyme-linked fluorescent assay (VIDAS CDA2; bioMérieux), an enzyme-linked assay [Premier Toxins A and B (PTAB); Meridian] and an in-house real-time PCR amplifying the tcdB gene were compared with the cell cytotoxicity assay used as the 'gold standard' for diagnosis of Clostridium difficile-associated diarrhoea (CDAD). Faecal samples from patients with a request for C. difficile diagnosis and samples from patients with diarrhoea hospitalized for at least 72 h were collected for 3 consecutive months from four university medical centres in The Netherlands. In total, 547 faecal samples were obtained from 450 patients. Of 540 samples available for all of the assays, 84 (15.6 %) showed a positive result in one or more assays. The cell cytotoxicity assay was positive in 31 samples (5.7 %) from 28 patients. A diagnosis of CDAD was not considered by the physician in 5 (23.8 %) of 21 patients with CDAD who were hospitalized for at least 72 h. Compared with the cell cytotoxicity assay, the sensitivity of VIDAS, PTAB and PCR was 83.9, 96.8 and 87.1 %, respectively. The specificity of VIDAS, PTAB and PCR was 97.1, 94.3 and 96.5 %, respectively. The positive and negative predictive values for VIDAS, PTAB and PCR were 63.4 and 99.0 %, 50.9 and 99.8 %, and 60.0 and 99.2 %, respectively. Of 61 samples that were positive in one, two or three of the assays, 56 were available for discordance analysis. Discordance analysis was performed by culture of toxinogenic strains. The concordance of VIDAS, PTAB and PCR with culture was 53.6 % (30/56), 55.4 % (31/56) and 71.4 % (40/56), respectively. It was concluded that real-time PCR had the highest concordance with toxinogenic culture and is therefore the preferred method for diagnosing CDAD in faecal samples. It was also concluded that diagnosis of patients with diarrhoea who have been hospitalized for more than 72 h should focus mainly on the detection of C. difficile, irrespective of the physician's request.

Coexistence of multiple PCR-ribotype strains of Clostridium difficile in faecal samples limits epidemiological studies.

Clostridium difficile is an important cause of antibiotic-associated diarrhoea. The simultaneous presence of different strains in individual faecal samples has not yet been established, but is important for epidemiological studies. Recurrences of Clostridium difficile-associated diarrhoea (CDAD) are observed in 15-20 % of patients and have been reported as relapses or reinfections with a new strain. In a period of 1 year, 28 faecal samples from 23 patients with a first episode of CDAD were collected at the Leiden University Medical Centre. In addition, 52 faecal samples from 23 patients, from three different hospitals, with one (n = 19), two (n = 2) or three (n = 2) recurrences were studied. PCR-ribotyping was applied as the standard typing method for the isolates. The toxinogenic and clindamycin-resistance profiles of the isolates was determined by PCR. Of 23 patients with a first episode of CDAD, two (8.7 %) harboured two different types, with no differences in toxinogenicity or clindamycin resistance, within one faecal sample. One of these 23 patients showed two types in three faecal samples from the same episode. Of the 23 patients with recurrences, six (26 %) showed a different strain type isolated in a recurrent episode. The number of cases of multiple C. difficile strains in faecal samples from patients with a first episode of CDAD did not differ significantly from the number of different strains present in recurrent episodes (chi-square test, P < or = 0.2). This observation limits the application of typing methods for studying the epidemiology of CDAD.

Bacterial contamination of inhalation chambers: results of a pilot study.

Spacers are used in the treatment of children with asthma. It is advised to clean the spacers regularly. However, cleaning can influence drug delivery. One obvious reason to clean a spacer is prevention of bacterial contamination. Whether spacers are contaminated or not is unknown. We cultured spacers, brought in by children with asthma or recurrent wheeze who visited our outpatient clinic during a 4-month period. The spacers of 64 children were studied, and 24 (38%) were contaminated; most often (13 cases), Bacillus species were found. Only one spacer grew a potential pathogenic bacterium (Pseudomonas aeruginosa). No correlation with type of inhaler, duration of usage, drug, or visual aspect was found. Spacers, cleaned according to national guidelines, were not less contaminated. Bacterial contamination of spacers is frequent, but the bacteria cultured are not pathogenic. Intensive cleaning of spacers does not influence the level of contamination with environmental bacteria.

Prospective multicenter evaluation of a new immunoassay and real-time PCR for rapid diagnosis of Clostridium difficile-associated diarrhea in hospitalized patients.

In a prospective multicenter study, 367 fecal samples from 300 patients with diarrhea were tested for Clostridium difficile-associated diarrhea (CDAD) with a new immunochromatography assay for toxins A and B (ICTAB), a real-time PCR on the toxin B gene, and the cell cytotoxicity assay. Twenty-three (6.2%) of the 367 fecal samples were positive by the cell cytotoxicity assay. With the cell cytotoxicity assay as the "gold standard," the sensitivity, specificity, positive predictive value, and negative predictive value for the ICTAB assay and real-time PCR were 91, 97, 70, and 99%, and 87, 96, 57 and 99%, respectively. In conclusion, both the ICTAB and the real-time PCR can be implemented as rapid screening methods for patients suspected of having CDAD.