May 7, 2018 | Instruments & Equipment, Laboratory Instruments & Laboratory Equipment, Laboratory Management and Operations, Laboratory Pathology, Laboratory Testing
Genomic analysis of pipes and sewers leading from the National Institutes of Health Clinical Care Center in Bethesda, Md., reveals the presence of carbapenem-resistant organisms; raises concern about the presence of multi-drug-resistant bacteria previously undetected in hospital settings
If hospitals and medical laboratories are battlegrounds, then microbiologists and clinical laboratory professionals are frontline soldiers in the ongoing fight against hospital-acquired infections (HAIs) and antibiotic resistance. These warriors, armed with advanced testing and diagnostic skills, bring expertise to antimicrobial stewardship programs that help block the spread of infectious disease. In this war, however, microbiologists and medical laboratory scientists (AKA, medical technologists) also often discover and identify new and potential strains of antibiotic resistance.
One such discovery involves a study published in mBio, a journal of the American Society for Microbiology (ASM), conducted by microbiologist Karen Frank, MD, PhD, D(AMBB), Chief of the Microbiology Service Department at the National Institutes of Health (NIH), and past-president of the Academy of Clinical Laboratory Physicians and Scientists (ACLPS). She and her colleagues identified a surprising source of carbapenem-resistant organisms—the plumbing, sewers, and wastewater beneath the National Institutes of Health Center (NIHCC) in Bethesda, Md. And they theorize similar “reservoirs” could exist beneath other healthcare centers as well.
Potential Source of Superbugs and Hospital-Acquired Infections
According to the mBio study, “Carbapenemase-producing organisms (CPOs) are a global concern because of the morbidity and mortality associated with these resistant Gram-negative bacteria. Horizontal plasmid transfer spreads the resistance mechanism to new bacteria, and understanding the plasmid ecology of the hospital environment can assist in the design of control strategies to prevent nosocomial infections.”
Karen Frank, MD, PhD (above), is Chief of the Microbiology Service Department at the National Institutes of Health and past-president of the Academy of Clinical Laboratory Physicians and Scientists. She suggests hospitals begin tracking the spread of the bacteria. “In the big picture, the concern is the spread of these resistant organisms worldwide, and some regions of the world are not tracking the spread of the hospital isolates.” (Photo copyright: National Institutes of Health.)
Frank’s team used Illumina’s MiSeq next-generation sequencer and single-molecule real-time (SMRT) sequencing paired with genome libraries, genomics viewers, and software to analyze the genomic DNA of more than 700 samples from the plumbing and sewers. They discovered a “potential environmental reservoir of mobile elements that may contribute to the spread of resistance genes, and increase the risk of antibiotic resistant ‘superbugs’ and difficult to treat hospital-acquired infections (HAIs).”
Genomic Sequencing Identifies Silent Threat Lurking in Sewers
Frank’s study was motivated by a 2011 outbreak of antibiotic-resistant Klebsiella pneumoniae bacteria that spread through the NIHCC via plumbing in ICU, ultimately resulting in the deaths of 11 patients. Although the hospital, like many others, had dedicated teams working to reduce environmental spread of infectious materials, overlooked sinks and pipes were eventually determined to be a disease vector.
In an NBC News report on Frank’s study, Amy Mathers, MD, Director of The Sink Lab at the University of Virginia, noted that sinks are often a locus of infection. In a study published in Applied and Environmental Microbiology, another journal of the ASM, Mathers noted that bacteria in drains form a difficult to clean biofilm that spreads to neighboring sinks through pipes. Mathers told NBC News that despite cleaning, “bacteria stayed adherent to the wall of the pipe” and even “splashed out” into the rooms with sink use.
During the 2011-2012 outbreak, David Henderson, MD, Deputy Director for Clinical Care at the NIHCC, told the LA Times of the increased need for surveillance, and predicted that clinical laboratory methods like genome sequencing “will become a critical tool for epidemiology in the future.”
Frank’s research fulfilled Henderson’s prediction and proved the importance of genomic sequencing and analysis in tracking new potential sources of infection. Frank’s team used the latest tools in genomic sequencing to identify and profile microbes found in locations ranging from internal plumbing and floor drains to sink traps and even external manhole covers outside the hospital proper. It is through that analysis that they identified the vast collection of CPOs thriving in hospital wastewater.
In an article, GenomeWeb quoted Frank’s study, noting that “Over two dozen carbapenemase gene-containing plasmids were identified in the samples considered” and CPOs turned up in nearly all 700 surveillance samples, including “all seven of the wastewater samples taken from the hospital’s intensive care unit pipes.” Although the hospital environment, including “high-touch surfaces,” remained free of similar CPOs, Frank’s team noted potential associations between patient and environmental isolates. GenomeWeb noted Frank’s findings that CPO levels were in “contrast to the low positivity rate in both the patient population and the patient-accessible environment” at NIHCC, but still held the potential for transmission to vulnerable patients.
Antibiotic-Resistance: A Global Concern
The Centers for Disease Control and Prevention (CDC) reports that more than two million illnesses and 23,000 deaths in the US are caused each year by antibiotic resistance, with 14,000 deaths alone linked to antibiotic resistance associated with Clostridium difficile infections (CDI). Worldwide those numbers are even higher.
Second only to CDI on the CDC’s categorized list of “18 drug-resistant threats to the United States” are carbapenem-resistant Enterobacteriaceae (CRE).
Since carbapenems are a “last resort” antibiotic for bacteria resistant to other antibiotics, the NIHCC “reservoir” of CPOs is a frightening discovery for physicians, clinical laboratory professionals, and the patients they serve.
The high CPO environment in NIHCC wastewater has the capability to spread resistance to bacteria even without the formal introduction of antibiotics. In an interview with Healthcare Finance News, Frank indicated that lateral gene transfer via plasmids was not only possible, but likely.
“The bacteria fight with each other and plasmids can carry genes that help them survive. As part of a complex bacterial community, they can transfer the plasmids carrying resistance genes to each other,” she noted. “That lateral gene transfer means bacteria can gain resistance, even without exposure to the antibiotics.”
The discovery of this new potential “reservoir” of CPOs may mean new focused genomic work for microbiologists and clinical laboratories. The knowledge gained by the discovery of CPOs in hospital waste water and sinks offers a new target for study and research that, as Frank concludes, will “benefit healthcare facilities worldwide” and “broaden our understanding of antimicrobial resistance genes in multi-drug resistant (MDR) bacteria in the environment and hospital settings.”
—Amanda Warren
Related Information:
Genomic Analysis of Hospital Plumbing Reveals Diverse Reservoir of Bacterial Plasmids Conferring Carbapenem Resistance
Snooping Around in Hospital Pipes, Scientists Find DNA That Fuels the Spread of Superbugs
CSI Bethesda: Sleuths Used Sequenced Genome to Track Down Killer
Antibiotic/Antimicrobial Resistance
Study Tracks How Superbugs Splash Out of Hospital Sink Drains
CDC: Biggest Threats
Antimicrobial Stewardship: How the Microbiology Laboratory Can Right the Ship
Superbugs Breeding in Hospital Plumbing Put Patients at Risk
Microbiologists at Weill Cornell Use Next-Generation Gene Sequencing to Map the Microbiome of New York City Subways
Aug 9, 2017 | Instruments & Equipment, Laboratory Instruments & Laboratory Equipment, Laboratory Management and Operations, Laboratory News, Laboratory Operations, Laboratory Pathology, Laboratory Testing, Management & Operations
Additionally, the device also could help reduce antibiotic-resistant infections and other HAIs and HACs, though this result was not part of the study
Research findings indicate how a new system-in-a-box device that phlebotomists and clinical laboratories would use when drawing blood could reduce contamination of blood cultures and lower patients’ use of antibiotics. In a study involving 1,800 blood cultures done on 904 patients at the University of Nebraska Medical Center (UNMC), use of the device was attributed to an 88% reduction in the blood culture contamination rate.
Developed by Magnolia Medical Technologies, the SteriPath Initial Specimen Diversion Device (ISDD) is compatible with standard BD and bioMérieux blood collection tubes and culture bottles, and has been approved by the US Food and Drug Administration (FDA) for marketing in the United States.
According to a press release by researchers at UNMC who studied the device, “With traditional blood draws, about 30% to 40% of patients with contaminated blood cultures are prescribed antibiotics unnecessarily. This contributes to antibiotic resistance and undermines nationwide efforts to improve antimicrobial stewardship.” The researchers reported their findings in an article published in the Oxford Academic journal Clinical Infectious Diseases (CID).
Blood Culture Contamination Harms Patients and Increases Cost of Care
The UNMC researchers noted that, during a blood draw, a significant percentage of blood cultures become contaminated when skin fragments containing bacteria are dislodged and mix with the patient’s blood. For the thousands of patients each day who have their blood drawn, contaminated blood cultures, which lead to false positive results for sepsis, often result in unnecessary antibiotic treatment. This in turn can lead to serious and deadly antibiotic-resistant infections with various multi-drug-resistant organisms such as Clostridium difficile infection (C. diff), as well as, other hospital-acquired infections and conditions (HAIs & HACs) due to unnecessary extended length of stay, according to Mark Rupp, MD, Professor, Department of Internal Medicine, Section of Infectious Diseases, and Medical Director, Department of Healthcare Epidemiology-Infection Control at UNMC.
In the CID article, Rupp and colleagues reported on a prospective, controlled trial conducted in the emergency department (ED) at UNMC’s partner hospital Nebraska Medicine. Results of the trial showed that the SteriPath ISDD diverts and sequesters the first 1.5 to 2 mL portion of blood. The researchers presumed that these initial drops of blood would contain the contaminating skin cells and microbes.
SteriPath is a self-contained, preassembled, sterile blood collection system. It provides proprietary vein-to-bottle technology that significantly reduces blood culture contamination, according to Magnolia Medical Technologies. This could be useful for helping phlebotomists and clinical laboratories improve the quality of specimens collected for use in blood culture testing. Click on the image above to view videos on the SteriPath ISDD. (Photo copyright: Magnolia Medical Technologies.)
The researchers tested the SteriPath ISDD during standard phlebotomy procedures in patients requiring blood cultures. After drawing 1,808 blood cultures from 904 study subjects, the researchers concluded that the ISDD significantly reduced blood culture contamination compared with standard phlebotomy procedures. The blood culture contamination among phlebotomists who used the ISDD decreased by nearly 90%, compared to phlebotomy procedures conducted by nurses who did not use the ISDD.
“We were able to decrease the false positive rate significantly through use of this device—from 1.78% down to 0.2%, which represents an 88% reduction,” Rupp noted in the UNMC press release. “The 1.78% baseline rate of contamination may seem small, but we should strive to decrease adverse events to the lowest possible level, because of the impact to the patient and the burden to our healthcare system.
“The device is innovative in that it diverts the first couple of milliliters of blood into the sequestration chamber,” Rupp explained. “That’s where we think the contaminants are. The remaining blood being drawn is then diverted into the sterile pathway into the blood culture vial, thereby preventing the contamination.”
Billions of Healthcare Dollars Could Be Saved with SteriPath’s ISDD
During a conference call with reporters, Rupp admitted that cynics might scoff at such a low rate of improvement. “Many of those folks don’t understand that we do tens of millions of blood cultures in this country every year,” he explained. “Every year, we do about 30 million or so blood cultures. That many cultures means a 2% contamination rate equates to somewhere in the neighborhood of about 600,000 contamination events. And 2% is a very respectable level. Usually clinicians are satisfied anywhere below about 3%, which is about 900,000 events each year.”
For about 40% to 50% of patients whose blood is contaminated, physicians will prescribe antibiotics, order another blood test, and require patients to stay several days in the hospital, he added. “All of this results in thousands of extra dollars being spent,” he declared. If each blood contamination case costs about $4,000, then reducing such contamination in potentially 600,000 cases each year could save more than $1 billion healthcare dollars.
According to the researchers, costs associated with blood culture contamination ranged from $1,000 per patient in 1998 to $8,700 per patient in 2009. “If a midpoint cost estimate of $4,850 is used, and the added cost of the device is not taken into account, it equates to a cost avoidance of $1.8 million per year at our institution alone,” Rupp stated. “If the low rate of contamination that we observed in the study, 0.22%, was applied to all blood cultures throughout the country, billions of dollars of excess costs could be avoided.”
This clinical study offers strong evidence that the SteriPath ISDD might prove to be a useful tool that clinical laboratories could use to help prevent unnecessary exposure to antibiotics and hospital stays, lower healthcare costs, and improve patient test outcomes. If the UNMC clinical study outcomes are replicated in future studies, then it is a technology and a solution that has the potential to be adopted by phlebotomists in medical laboratories and hospitals.
—Joseph Burns
Related Information:
Reduction in Blood Culture Contamination Through Use of Initial Specimen Diversion Device
Study Shows Device Reduces Blood Draw Contamination
Novel Device Significantly Reduces Blood Draw Contamination, Reduces Risks to Patients, Study Shows
Better Care by Reducing Blood Culture Contamination: Sepsis, SteriPath and Antimicrobial Stewardship
Study by Mark Rupp, MD, in Clinical Infectious Diseases: Reduction in Blood Culture Contamination Through Use of Initial Specimen Diversion Device (SteriPath)
Feb 10, 2017 | Digital Pathology, Instruments & Equipment, Laboratory Management and Operations, Laboratory News, Laboratory Operations, Laboratory Pathology, Laboratory Testing
Medical laboratories to become antimicrobial stewards in the fight against antibiotic resistance
At the start of 2017, new requirements for antimicrobial stewardship programs became effective for hospitals and other providers that must accredit to the standards of Medicare Conditions of Participation (COP) and The Joint Commission. Clinical laboratories serving hospitals are already engaged in efforts to improve the use of antibiotics in ways that slow the growth of antibiotic-resistant strains of infectious agents.
Even as the nation’s hospitals embark on efforts to implement effective antimicrobial stewardship programs, researchers continue to seek solutions to the same problem. They are following several paths to combat the growing resistance certain pathogens have to antibiotics. In particular, two approaches are interesting for pathologists and medical laboratory personnel. One involves understanding the processes that lead to antibiotic resistance. The other is to identify useful biomarkers associated with specific strains of pathogens. (more…)
