Chlorhexidine and octenidine susceptibility of bacterial isolates from clinical samples in a three-armed cluster randomised decolonisation trial.

BackgroundRoutine use of chlorhexidine or octenidine for antiseptic bathing may have unintended consequences. Our analysis aimed to assess the phenotypic susceptibility of bacterial isolates from clinical samples to chlorhexidine and octenidine collected from intensive care units (ICU) that routinely used 2% chlorhexidine-impregnated wash cloths or 0.08% octenidine wash mitts (intervention) or water and soap (control) for daily patient care.MethodsThis study was conducted within the context of a three armed cluster-randomised controlled decolonisation trial (Registration number DRKS00010475, registration date August 18, 2016). Bacterial isolates were collected prior to and at the end of a 12-month-intervention period from patients with ≥ 3 days length of stay at an ICU assigned to one of two intervention groups or the control group. Phenotypic susceptibility to chlorhexidine and octenidine was assessed by an accredited contract research laboratory determining minimal inhibitory concentrations (MIC) as percentage of extraction solutions used. MIC were reported as estimated concentrations in μg/ml derived from the chlorhexidine and octenidine extraction solutions. Statistical analyses including generalized estimating equation models were applied.ResultsIn total, 790 ICU-attributable bacterial isolates from clinical samples (e.g. blood, urine, tracheal aspirate) were eligible for all analyses. Pathogens included were Staphylococcus aureus (n = 155), coagulase-negative staphylococci (CoNS, n = 122), Escherichia coli (n = 227), Klebsiella spp. (n = 150) and Pseudomonas aeruginosa (n = 136). For all species, chlorhexidine and octenidine MIC did not increase from baseline to intervention period in the antiseptic bathing groups. For proportions of bacterial isolates with elevated chlorhexidine / octenidine MIC (≥ species-specific chlorhexidine / octenidine MIC50), adjusted incidence rate ratios (aIRR) showed no differences between the intervention groups and the control group (intervention period).ConclusionWe found no evidence for reduced phenotypic susceptibilities of bacterial isolates from clinical samples to chlorhexidine or octenidine in ICUs 12 months after implementation of routine antiseptic bathing with the respective substances

Extended-Spectrum Beta-Lactamase (ESBL)-Producing <i>Escherichia coli</i> Isolated from Flies in the Urban Center of Berlin, Germany

Background: The monitoring of antimicrobial resistance (AMR) in microorganisms that circulate in the environment is an important topic of scientific research and contributes to the development of action plans to combat the spread of multidrug-resistant (MDR) bacteria. As a synanthropic vector for multiple pathogens and a reservoir for AMR, flies can be used for surveillance. Methods: We collected 163 flies in the inner city of Berlin and examined them for extended-spectrum &#946;-lactamase (ESBL)-producing Escherichia coli genotypically and phenotypically. Results: The prevalence of ESBL-producing E. coli in flies was 12.9%. Almost half (47.6%) of the ESBL-positive samples showed a co-resistance to ciprofloxacin. Resistance to carbapenems or colistin was not detected. The predominant ESBL-type was CTX-M-1, which is associated with wildlife, livestock, and companion animals as a potential major source of transmission of MDR E. coli to flies. Conclusions: This field study confirms the permanent presence of ESBL-producing E. coli in an urban fly population. For continuous monitoring of environmental contamination with multidrug-resistant (MDR) bacteria, flies can be used as indicators without much effort

Central-line associated bloodstream infections in intensive care units before and after implementation of daily antiseptic bathing with chlorhexidine or octenidine: a post-hoc analysis of a cluster-randomised controlled trial

Abstract Backgrounds Antiseptic bathing did not reduce central-line (CL) associated bloodstream infection (CLABSI) rates in intensive care units (ICU) according to a recent cluster randomised controlled trial (cRCT). However, this analysis did not consider baseline infection rates. Our post-hoc analysis of this cRCT aimed to use a before-after comparison to examine the effect of daily bathing with chlorhexidine, octenidine or water and soap (control) on ICU-attributable CLABSI rates. Methods A post-hoc analysis of a multi-center cRCT was done. ICUs that did not yet perform routine antiseptic bathing were randomly assigned to one of three study groups applying daily bathing with 2% chlorhexidine-impregnated cloths, 0.08% octenidine wash mitts or water and soap (control) for 12 months. Baseline data was assessed 12 months before the intervention started when all ICUs routinely used water and soap. Poisson regression and generalised estimating equation models were applied to identify changes of CLABSI rates per 1000 CL days between intervention and baseline periods in each study group. Results The cRCT was conducted in 72 ICUs (24 per study group) including 76,139 patients in the baseline and 76,815 patients in the intervention period. In the chlorhexidine group, incidence density of CLABSI was reduced from 1.48 to 0.90 CLABSI per 1000 CL days comparing baseline versus intervention period (P = 0.0085). No reduction was observed in the octenidine group (1.26 versus 1.47 CLABSI per 1000 CL days, P = 0.8735) and the control group (1.20 versus 1.17, P = 0.3298). Adjusted incidence rate ratios (intervention versus baseline) were 0.63 (95%CI 0.46–0.87, P = 0.0172) in the chlorhexidine, 1.17 (95% CI 0.79–1.72, P = 0.5111) in the octenidine and 0.98 (95% CI 0.60–1.58, P = 0.9190) in the control group. Chlorhexidine bathing reduced CLABSI with gram-positive bacteria, mainly coagulase-negative staphylococci (CoNS). Conclusions In this post-hoc analysis of a cRCT, the application of 2% chlorhexidine-impregnated cloths reduced ICU-attributable CLABSI. This preventive effect of chlorhexidine was restricted to CLABSI caused by gram-positive pathogens (CoNS). In contrast, 0.08% octenidine wash mitts did not reduce CLABSI rates in ICUs. Trial registration Registration number DRKS00010475, registration date August 18, 2016

Reference strains with minimal inhibitory concentrations (μg/ml) to chlorhexidine and octenidine.

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Chlorhexidine and octenidine minimal inhibitory concentrations (MIC) of bacterial isolates from clinical samples in percentage of extraction solution.

Median MIC (MIC50) with inter quartile ranges (IQR) and MIC90 are given in in [%] of extraction solution and are reported for Staphylococcus aureus, coagulase-negative staphylococci, Escherichia coli, Klebsiella spp. and Pseudomonas aeruginosa stratified by study group (chlorhexidine, octenidine, routine care) and period (baseline = prior to the intervention period, intervention = at the end of the intervention period). (DOCX)</p

Generalized estimating equation models for the outcomes chlorhexidine and octenidine susceptibility of bacterial isolates (reported by MIC ≥ species-specific chlorhexidine and octenidine MIC₅₀ (yes / no)).

Generalized estimating equation models for the outcomes chlorhexidine and octenidine susceptibility of bacterial isolates (reported by MIC ≥ species-specific chlorhexidine and octenidine MIC50 (yes / no)).</p

Chlorhexidine and octenidine minimal inhibitory concentrations (MIC) of ICU-attributable bacterial isolates from clinical samples reported by study group and period.

Chlorhexidine and octenidine minimal inhibitory concentrations (MIC) of ICU-attributable bacterial isolates from clinical samples reported by study group and period.</p