3 results
Colonization of carbapenem-resistant Klebsiella pneumoniae in a sink-drain model biofilm system
- Maria Burgos-Garay, Christine Ganim, Tom J.B. de Man, Terri Davy, Amy J. Mathers, Shireen Kotay, Jonathan Daniels, K. Allison Perry, Erin Breaker, Rodney M. Donlan
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- Journal:
- Infection Control & Hospital Epidemiology / Volume 42 / Issue 6 / June 2021
- Published online by Cambridge University Press:
- 25 November 2020, pp. 722-730
- Print publication:
- June 2021
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Background:
Sink drains in healthcare facilities may provide an environment for antimicrobial-resistant microorganisms, including carbapenemase-producing Klebsiella pneumoniae (CPKP).
Methods:We investigated the colonization of a biofilm consortia by CPKP in a model system simulating a sink-drain P-trap. Centers for Disease Control (CDC) biofilm reactors (CBRs) were inoculated with microbial consortia originally recovered from 2 P-traps collected from separate patient rooms (designated rooms A and B) in a hospital. Biofilms were grown on stainless steel (SS) or polyvinyl chloride (PVC) coupons in autoclaved municipal drinking water (ATW) for 7 or 28 days.
Results:Microbial communities in model systems (designated CBR-A or CBR-B) were less diverse than communities in respective P-traps A and B, and they were primarily composed of β and γ Proteobacteria, as determined using 16S rRNA community analysis. Following biofilm development CBRs were inoculated with either K. pneumoniae ST45 (ie, strain CAV1016) or K. pneumoniae ST258 KPC+ (ie, strain 258), and samples were collected over 21 days. Under most conditions tested (CBR-A: SS, 7-day biofilm; CBR-A: PVC, 28-day biofilm; CBR-B: SS, 7-day and 28-day biofilm; CBR-B: PVC, 28-day biofilm) significantly higher numbers of CAV1016 were observed compared to 258. CAV1016 showed no significant difference in quantity or persistence based on biofilm age (7 days vs 28 days) or substratum type (SS vs PVC). However, counts of 258 were significantly higher on 28-day biofilms and on SS.
Conclusions:These results suggest that CPKP persistence in P-trap biofilms may be strain specific or may be related to the type of P-trap material or age of the biofilm.
Establishment of a Sink Gallery to Investigate Growth of Carbapenemase-Producing Klebsiella pneumoniae and Biofilms in P-Traps
- Christine Ganim, Mustafa Mazher, Erin Breaker,
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- Journal:
- Infection Control & Hospital Epidemiology / Volume 41 / Issue S1 / October 2020
- Published online by Cambridge University Press:
- 02 November 2020, pp. s219-s220
- Print publication:
- October 2020
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Background: Hand-hygiene sink drains in healthcare facilities may provide an environment for the survival and dissemination of various multidrug-resistant organisms (MDROs), including carbapenemase-producing Klebsiella pneumoniae (CPKP). We developed a sink model system to establish and test native drinking water biofilms containing CPKP in the p-traps of hand-hygiene sink drains. Methods: A handwashing sink gallery was designed to consist of 6-wall mounted stainless-steel sink basins connected to the same municipal water line. Each sink’s plumbing included a chrome-plated brass p-trap. Healthcare facility conditions were simulated to include handwashing events with the addition of hand-soap and municipal water 4 per day, and nutritional shake (simulating liquid waste) 1 per day. Resultant biofilms in the p-traps of each sink were harvested after 28 days for community analysis. Microbial community analyses were performed on selected biofilm samples using 16S rRNA sequencing of the V4 hypervariable region of genomic DNA. Another experiment evaluated 28-day p-trap biofilm inoculated with CPKP CAV1016 (10 mL 7.010E 7 CFU/mL) and was assessed over 14 days. Heterotrophic plate counts (HPCs) were determined on R2A medium (7 days of incubation at 25C). CPKP was quantified on mEndo selective medium (48 hours of incubation at 36C). Results: Biofilms developed in all p-traps, but biofilm HPC (5.78 mean log CFU/cm2, range 4.35–7.16) and community diversity (15–20 genera per p-trap) varied with sink position. Community analysis showed similarities in bacterial community composition and diversity between sinks 1 and 2, and between sinks 3, 5 and 6, but with differences between the 2 groups. The most abundant family in sinks 3, 5, and 6 was Erythrobacteriaceae (76%, 78%, and 55% of the total reads, respectively), whereas sinks 1 and 2 were dominated by Sphingomonadaceae (63% and 36%) and Methylobacteriaceae (19% and 55%). Also, 16S sequencing revealed the presence of potential opportunistic pathogens in the biofilms, including reads attributed to Pseudomonas and Acinetobacter. CPKP CAV1016 inoculated into 28-day p-trap biofilms colonized and persisted in all 6 sinks for 12 days after inoculation. Conclusions: Despite all 6 sinks sharing an incoming water line, soap, and carbon and energy source, there was a significant variation in the bacterial community composition observed between the sinks. CPKP can colonize and persist in the p-trap biofilms; however, additional work is needed to achieve a reproducible model system. Once this is achieved, the sink gallery will be used to investigate interventions to mitigate colonization or persistence of CPKP in p-trap biofilms.
Funding: None
Disclosures: None
A Survey of Antibiotic-Resistant Microorganisms in Hospital Sink Drains
- Lauren Franco, Christine Ganim, Windy Tanner
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- Journal:
- Infection Control & Hospital Epidemiology / Volume 41 / Issue S1 / October 2020
- Published online by Cambridge University Press:
- 02 November 2020, p. s108
- Print publication:
- October 2020
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Background: Handwashing sinks in healthcare environments are reservoirs for healthcare pathogens and antibiotic-resistant microorganisms (ARO). We investigated the distribution of HCP and ARO within and among handwashing sinks in healthcare settings. To do this, we determined the differences in the number of ARO between samples within a sink (biofilm vs planktonic samples), between sink types (healthcare worker [HCW] vs patient room sinks), and between hospitals in the same city. Methods: Tap water, sink surface, drain cover, tail pipe, p-trap water and p-trap samples were collected from 2 patient room sinks and 2 HCW sinks over 11 months in 2 acute-care hospitals. Suspected pathogens were isolated from selective media (Pseudosel, Chromagar KPC, and MacConkey with 2 mg/L cefotaxime) and identified via MALDI-ToF. Isolates confirmed to be healthcare pathogens were characterized via disk diffusion to determine their antibiotic susceptibility according to CLSI guidelines. Isolates not susceptible to carbapenems (meropenem or ertapenem) were tested further via the modified carbapenem inactivation method to detect carbapenemase production. Results:Pseudomonas aeruginosa and Enterobacteriaceae (Enterobacter spp, Klebsiella spp, and Citrobacter spp) were the most frequently isolated pathogens. Among these isolates (195 P. aeruginosa and 42 Enterobacteriaceae isolates), 28.5% of P. aeruginosa and 85.7% of Enterobacteriaceae were nonsusceptible to 1 or more of the antibiotics tested. Of the isolates that were nonsusceptible to a carbapenem (46 of 237; 19%), none displayed phenotypic carbapenemase production. Other mechanisms of resistance have not been confirmed. There was no significant difference in the percentage of nonsusceptible HCP isolated from biofilm samples (from p-trap and tail pipe) compared to planktonic (p-trap water) samples (P > .05 for P. aeruginosa and Enterobacteriaceae). A greater percentage of resistant or intermediate isolates was recovered from patient room sinks than from HCW sinks (P < .05) for both P. aeruginosa and Enterobacteriaceae isolates (76.4 vs 32.9% for Enterobacteriaceae, 25.6 vs 0.3% for P. aeruginosa). We detected no significant difference in percentage of nonsusceptible isolates between the 2 hospitals sampled (P > .05). Conclusions: This survey of healthcare sinks supports previous work citing that they are reservoirs for HCP and ARO. This work further examines the distribution of HCP and ARO within and among sinks in these environments. Our findings thus far in the 2 hospitals studied reveal a higher percentage of ARO in patient sinks than in HCW sinks. This finding may suggest a higher input of ARO from patient use or greater selective pressure in patient room sinks.
Disclosures: None
Funding: Lauren Franco, Centers for Disease Control and Prevention