Study results from Switzerland come as clinical laboratory scientists seek new ways to tackle the problem of antimicrobial resistance in hospitals
Microbiologists and clinical laboratory scientists engaged in the fight against antibiotic-resistant (aka, antimicrobial resistant) bacteria will be interested in a recent study conducted at the University of Basel and University Hospital Basel in Switzerland. The epidemiologists involved in the study discovered that some of these so-called “superbugs” can remain in the body for as long as nine years continuing to infect the host and others.
The researchers wanted to see how two species of drug-resistant bacteria—K. pneumoniae and E. coli—changed over time in the body, according to a press release from the university. They analyzed samples of the bacteria collected from patients who were admitted to the hospital over a 10-year period, focusing on older individuals with pre-existing conditions. They found that K. pneumoniae persisted for up to 4.5 years (1,704 days) and E. coli persisted for up to nine years (3,376 days).
“These patients not only repeatedly become ill themselves, but they also act as a source of infection for other people—a reservoir for these pathogens,” said Lisandra Aguilar-Bultet, PhD, the study’s lead author, in the press release.
“This is crucial information for choosing a treatment,” explained Sarah Tschudin Sutter, MD, Head of the Division of Infectious Diseases and Hospital Epidemiology, and of the Division of Hospital Epidemiology, who specializes in hospital-acquired infections and drug-resistant pathogens. Sutter led the Basel University study.
“The issue is that when patients have infections with these drug-resistant bacteria, they can still carry that organism in or on their bodies even after treatment,” said epidemiologist Maroya Spalding Walters, MD (above), who leads the Antimicrobial Resistance Team in the Division of Healthcare Quality Promotion at the federal Centers for Disease Control and Prevention (CDC). “They don’t show any signs or symptoms of illness, but they can get infections again, and they can also transmit the bacteria to other people.” Clinical laboratories working with microbiologists on antibiotic resistance will want to follow the research conducted into these deadly pathogens. (Photo copyright: Centers for Disease Control and Prevention.)
COVID-19 Pandemic Increased Antibiotic Resistance
The Basel researchers looked at 76 K. pneumoniae isolates recovered from 19 patients and 284 E. coli isolates taken from 61 patients, all between 2008 and 2018. The study was limited to patients in which the bacterial strains were detected from at least two consecutive screenings on admission to the hospital.
“DNA analysis indicates that the bacteria initially adapt quite quickly to the conditions in the colonized parts of the body, but undergo few genetic changes thereafter,” the Basel University press release states.
The researchers also discovered that some of the samples, including those from different species, had identical mechanisms of drug resistance, suggesting that the bacteria transmitted mobile genetic elements such as plasmids to each other.
One limitation of the study, the authors acknowledged, was that they could not assess the patients’ exposure to antibiotics.
Meanwhile, recent data from the World Health Organization (WHO) suggests that the COVID-19 pandemic might have exacerbated the challenges of antibiotic resistance. Even though COVID-19 is a viral infection, WHO scientists found that high percentages of patients hospitalized with the disease between 2020 and 2023 received antibiotics.
“While only 8% of hospitalized patients with COVID-19 had bacterial co-infections requiring antibiotics, three out of four or some 75% of patients have been treated with antibiotics ‘just in case’ they help,” the WHO stated in a press release.
WHO uses an antibiotic categorization system known as AWaRe (Access, Watch, Reserve) to classify antibiotics based on risk of resistance. The most frequently prescribed antibiotics were in the “Watch” group, indicating that they are “more prone to be a target of antibiotic resistance and thus prioritized as targets of stewardship programs and monitoring.”
“When a patient requires antibiotics, the benefits often outweigh the risks associated with side effects or antibiotic resistance,” said Silvia Bertagnolio, MD, Unit Head in the Antimicrobial resistance (AMR) Division at the WHO in the press release. “However, when they are unnecessary, they offer no benefit while posing risks, and their use contributes to the emergence and spread of antimicrobial resistance.”
Citing research from the National Institutes of Health (NIH), NPR reported that in the US, hospital-acquired antibiotic-resistant infections increased 32% during the pandemic compared with data from just before the outbreak.
“While that number has dropped, it still hasn’t returned to pre-pandemic levels,” NPR noted.
The UPenn researchers have already developed an antimicrobial treatment derived from guava plants that has proved effective in mice, Vox reported. They’ve also trained an AI model to scan the proteomes of extinct organisms.
“The AI identified peptides from the woolly mammoth and the ancient sea cow, among other ancient animals, as promising candidates,” Vox noted. These, too, showed antimicrobial properties in tests on mice.
These findings can be used by clinical laboratories and microbiologists in their work with hospital infection control teams to better identify patients with antibiotic resistant strains of bacteria who, after discharge, may show up at the hospital months or years later.
New vaccine could give clinical laboratories and antimicrobial stewardship programs the tool they need to dramatically reduce hospital-acquired infections
The innovative approach focuses on bolstering the patient’s immune system itself, rather than relying on proteins to fight infections, according to a USC Today article.
Developed by senior study author Brad Spellberg, MD, Chief Medical Officer at the Los Angeles General Medical Center, and colleagues, “The experimental vaccine takes an entirely different approach: It gooses the body’s preexisting supply of pathogen-gobbling immune cells called macrophages, which engulf and digest bacteria, fungi, and other bad actors. These activated fighters, found in all tissues, quickly neutralize incoming invaders which might otherwise multiply rapidly and overwhelm the body’s defenses,” USC Today reported.
“This is very different from developing new antibiotics,” Jun Yan, a doctoral student at Keck School of Medicine and the study’s first author, told USC Today. “This is using our own immune system to fight against different superbugs, which is a different approach than everybody else.”
To develop the vaccine [the USC researchers] formed a biotechnology startup called ExBaq LLC in Bethesda, Md.
“The pandemic stimulated unprecedented innovation in vaccine development, where federal funding and university-industry partnerships were game changers for translating promising discoveries from academic labs for the good of all,” said Ishwar K. Puri, PhD (above), senior vice president of research and innovation at USC. “We are both pleased and proud of the critical support the USC Stevens Center provided to enable the development of ExBaq’s experimental vaccine that protects vulnerable populations from serious infections.” Clinical laboratories that work with hospitals in the fight against hospital-acquired infections understand the importance of this discovery. (Photo copyright: University of Southern California.)
USC Vaccine Details
The USC team developed a “protein-free vaccine, composed of aluminum hydroxide, monophosphoryl lipid A, and fungal mannan, that stimulates the innate immune system and confers protection,” the researchers wrote in Science Translational Medicine.
“Tested in two independent labs, the vaccine works within 24 hours and lasts for up to 28 days. In lab models, the number of pathogen-eating immune cells in the blood increased dramatically, and survival time of invasive blood and lung infections improved. Early data suggest that a second dose could extend the window to prevent infection,” USC Today reported.
Unlike anything currently available, the new vaccine focuses on boosting the body itself instead of creating antibodies against certain pathogens. A mere dose of the vaccine is described to “provide rapid protection against nine different bacteria and fungi species,” USC Today noted.
“It’s an early warning system. It’s like Homeland Security putting out a terror alert. Everybody, keep your eyes open. Keep an eye out for suspicious packages. You’re alerting the soldiers and tanks of your immune system. The vaccine activates them,” Spellberg told USC Today.
“The vaccine acted through stimulation of the innate, rather than the adaptive, immune system, as demonstrated by efficacy in the absence of lymphocytes that were abrogated by macrophage depletion. A role for macrophages was further supported by the finding that vaccination induced macrophage epigenetic alterations that modulated phagocytosis and the inflammatory response to infection. Together, these data show that this protein-free vaccine is a promising strategy to prevent deadly antimicrobial-resistant healthcare-associated infections,” the researchers wrote in Science Translational Medicine.
“Patients who acquire infections from surgery spend, on average, an additional 6.5 days in the hospital, are five times more likely to be readmitted after discharge and twice as likely to die. Moreover, surgical patients who develop infections are 60% more likely to require admission to a hospital’s intensive care unit. Surgical infections are believed to account for up to 10 billion dollars annually in healthcare expenditures,” the CDC reports.
“All hospitalized patients are susceptible to contracting a [hospital-acquired] infection. Some patients are at greater risk than others: young children, the elderly, and persons with compromised immune systems are more likely to get an infection. Other risk factors are long hospital stays, the use of indwelling catheters, failure of healthcare workers to wash their hands, and overuse of antibiotics,” the CDC notes.
Therefore, USC’s new vaccine may be just what the doctor ordered to protect patients in hospitals and other healthcare settings from deadly HAIs.
Looking Ahead
There are currently no vaccines that are FDA-approved that treat “the most serious antibiotic resistant infections,” USC Today reported.
“Even if there were such vaccines, multiple vaccines would have to be deployed simultaneously to protect against the full slate of antibiotic-resistant microbes that cause healthcare-acquired infections,” Brian Luna, PhD, assistant professor of molecular microbiology and immunology at USC’s Keck School of Medicine, told USC Today.
Thus, USC’s new vaccine could be a boon to hospital antimicrobial stewardship programs. But so far, it has only been tested on mice.
“The next step is getting guidance from the US Food and Drug Administration (FDA) on the design of a clinical trial. The first such trial would be done in healthy volunteers to find the right dose of vaccine that is safe and triggers the same kind of immune response in people as seen in the mice,” USC Today reported.
ExBaq LLC has begun talking with potential larger partners who might be willing to help develop the vaccine into clinical testing.
For years hospitals and other healthcare settings—such as long-term care facilities, urgent care clinics, and clinical laboratories—have fought an uphill battle against superbugs. So, for a vaccine to be on the horizon that can prevent life-threatening hospital-acquired infections would be a game changer.
With antimicrobial stewardships being a requirement in all hospitals, medical laboratory managers and microbiologists may celebrate this new development and its potential to be a useful tool in fighting antimicrobial resistant bacteria in their facilities.
On top of everything else during this pandemic, drug-resistant infections are threatening the most vulnerable patients in COVID-19 ICUs
New study by researchers at the University of Minnesota highlights the continuing need for microbiologists and clinical laboratories to stay alert for COVID-19 patients with drug-resistant infections. In their study, researchers highlighted CDC statistics about the number of Candida auris (C. auris) infections reported in the United States during 2020, for example.
In a paper, titled, “Three Cases of Worrisome Pan-Resistant C Auris Found in New York,” the Center for Infectious Disease Research and Policy (CIDRAP) at the University of Minnesota reported that “As of Dec 11, the CDC said 941 confirmed and probable C. auris cases have been reported in 13 states, and an additional 1,830 patients have been found to be colonized with the multidrug-resistant fungus. Most of the cases have been detected in the New York City area, New Jersey, and the Chicago area.”
Candida auris is a particularly nasty fungus. It spreads easily, is difficult to remove from surfaces, and can kill. Worst of all, modern drugs designed to combat this potentially deadly fungus are becoming less effective at eradicating it, and COVID-19 ICU patients appear especially vulnerable to C. auris infections.
COVID-19 and C. auris a Potentially Devastating Combination
Hospitals in many areas are at a critical capacity. Thus, hospital-acquired infections such as sepsis can be particularly dangerous for COVID-19 patients. Adding to the problem, C. auris requires special equipment to identify, and standard medical laboratory methods are not always enough. Misidentification is possible, even probable.
A paper in the Journal of Global Antimicrobial Resistance (JGAR), titled, “The Lurking Scourge of Multidrug Resistant Candida Auris in Times of COVID-19 Pandemic,” notes that “A particularly disturbing feature of COVID-19 patients is their tendency to develop acute respiratory distress syndrome that requires ICU admission, mechanical ventilation, and/or extracorporeal membrane oxygenation. … This haunting facet of COVID-19 pandemic has severely challenged even the most advanced hospital settings. Yet one potential confounder, not in the immediate attention of most healthcare professionals, is the secondary transmission of multidrug resistant organisms like the fungus Candida auris in COVID-19 ICUs. … C. auris outbreaks occur in critically ill hospitalized patients and can result in mortalities rates ranging from 30% to 72%. … Both C. auris and SARS-CoV-2 have been found on hospital surfaces including on bedrails, IV poles, beds, air conditioner ducts, windows and hospital floors. Therefore, the standard COVID-19 critical care of mechanical ventilation and protracted ventilator-assisted management makes these patients potentially susceptible to colonization and infections by C. auris.”
One study mentioned in the JGAR paper conducted in New Delhi, India, looked at 596 cases where patients were admitted to the ICU with COVID-19. Fifteen of them had infections caused by C. auris. Eight of those patients died. “Of note, four patients who died experienced persistent fungemia and despite five days of micafungin therapy, C. auris again grew in blood culture,” according to reporting on the study in Infection Control Today (ICT).
Some C. auris mortality rates are as high as 72%. And patients with weakened immune systems are at particular risk, “making it an even more serious concern when 8% to 9% of roughly 530,000 ICU patients in the United States have COVID-19,” ICT reported.
Apparently, the COVID-19 pandemic has created circumstances that are particularly suited for C. auris to spread. “Given the nosocomial transmission of SARS-CoV-2 by those infected, many hospital environments may serve as venues for C. auris transmission as it is a known environmental colonizer of ICUs,” wrote the JGAR paper authors.
CDC Reports and Recommendations
Along with being especially dangerous for people with weakened immune systems, C. auris infections also produce symptoms similar to those of COVID-19, “including fever, cough, and shortness of breath,” according to the CDC’s website. People admitted to ICUs with COVID-19 are especially vulnerable to bacterial and fungal co-infections. “These fungal co-infections are reported with increasing frequency and can be associated with severe illness and death,” says the CDC.
C. auris outbreaks in the United States have mostly been in long-term care facilities, but the pandemic seems to be changing that and more outbreaks have been detected in acute care facilities, the CDC reported. The lack of appropriate personal protective equipment (PPE), changes in infection control routines, and other factors could be to blame for the increase.
Just as community spread is an issue with COVID-19 variants, so too is it a concern with C. auris infections. “New C. auris cases without links to known cases or healthcare abroad have been identified recently in multiple states, suggesting an increase in undetected transmission,” the CDC noted.
As of January 19, 2021, according to the CDC the case count of C. auris infections in the US was 1,625, with California, Florida, Illinois, New Jersey, and New York having more than 100 cases each.
According to a CDC report, “Candida auris (C. auris) is an emerging multidrug-resistant yeast (a type of fungus). It can cause severe infections and spreads easily between hospitalized patients and nursing home residents.” The graphic above, taken from the report, illustrates how “C. auris began spreading in the United States in 2015. Reported cases increased 318% in 2018 when compared to the average number of cases reported in 2015 to 2017.” (Graphic copyright: Centers for Disease Control and Prevention.)
Using Clinical Laboratory Tests to Identify C. Auris
One of the big concerns about C. auris is that it is so difficult to detect, and that medical laboratories in some countries simply do not have the technology and resources to identify and tackle the infection.
“As C. auris diagnostics in resource-limited countries is yet another challenge, we feel that alerting the global medical community about the potential of C. auris as a confounding factor in COVID-19 is a necessity,” wrote the authors of the paper published in the Journal of Global Antimicrobial Resistance.
As if the COVID-19 pandemic has not been enough, drug resistant bacteria, viruses, and deadly fungi are threatening to wreak havoc among SARS-CoV-2 infected patients. Microbiologists and medical laboratory scientists know that testing for all types of infections is vitally important, but especially when it comes to infections caused by antibiotic-resistant bacteria (ARB) and other dangerous organisms that demonstrate antimicrobial resistance (AMR).
Microbiologists and clinical laboratory professionals will want to stay informed about the number of C. auris cases identified in the US and the locations and settings where the fungus was detected. They will want to be on the alert within their hospitals and health networks, as well as with the doctor’s offices served by their labs.
In a separate study, HHS finds a 40% increase in sepsis cases, as more patients succumb to infections without effective antibiotics and antimicrobial drugs
Given the drastic steps being taken to slow the spread of the Coronavirus in America, it’s easy to forget that significant numbers of patients die each year due to antibiotic-resistant bacteria (ARB), other forms of antimicrobial resistance (AMR), and in thousands of cases the sepsis that follows the infections.
The CDC’s website states that “more than 2.8 million antibiotic-resistant infections occur in the US each year, and more than 35,000 people die as a result.” And a CDC news release states, “on average, someone in the United States gets an antibiotic-resistant infection every 11 seconds and every 15 minutes someone dies.”
Those are huge numbers.
Clinical laboratory leaders and microbiologists have learned to be vigilant as it relates to dangerously infectious antimicrobial-resistant agents that can result in severe patient harm and death. Therefore, new threats identified in the CDC’s Antibiotic Resistance Threats in the United States report will be of interest.
Drug-resistant Microbes That Pose Severe Risk
The CDC has added the fungus Candida auris (C. auris) and carbapenem-resistant Acinetobacter (a bacteria that can survive for a long time on surfaces) to its list of “urgent threats” to public health, CDC said in the news release. These drug-resistant microbes are among 18 bacteria and fungi posing a greater threat to patients’ health than CDC previously estimated, Live Science reported.
In 2013, the CDC estimated that about two million people each year acquired an antibiotic-resistant (AR) infection that killed as many as 23,000. However, in 2019, the CDC reported that those numbers were low and that the number of deaths due to AR infections in 2013 was about twice that amount. During a news conference following the CDC announcement, Michael Craig (above), a Senior Adviser for the CDC’s Antibiotic Resistance Coordination and Strategy Unit said, “We knew and said [in 2013] that our estimate was conservative … and we were right,” Live Science reported. In 2019, CDC reported 2.8 million antibiotic-resistant infections annually with more than 35,000 related deaths in the US alone. (Photo copyright: Centers for Disease Control and Prevention.)
The CDC considers five threats to be urgent. Including the
latest additions, they are:
Dark Daily has regularly covered the healthcare industry’s ongoing struggle with deadly fungus and bacteria that are responsible for hospital-acquired infections (HAI) and sepsis. This latest CDC report suggests healthcare providers continue to struggle with antimicrobial-resistant agents.
Acinetobacter Threat Increases and C. auris
a New Threat since 2013
Carbapenem-resistant Acinetobacter, a bacterium that
causes pneumonia and bloodstream and urinary tract infections, escalated from
serious to urgent in 2013. About 8,500 infections and 700 deaths were noted by the
CDC in 2017.
C. auris, however, was not addressed in the 2013
report at all. “It’s a pathogen that we didn’t even know about when we wrote
our last report in 2013, and since then it’s circumvented the globe,” said Michael
Craig, Senior Adviser for the CDC’s Antibiotic Resistance Coordination and
Strategy Unit, during a news conference following the CDC announcement, Live
Science reported.
Today, C. auris is better understood. The fungus
resists emerging drugs, can result in severe infections, and can be transmitted
between patients, CDC noted.
By year-end, CDC tracking showed 988 cases in the US.
More Patients Getting Sepsis as Antibiotics Fail: HHS
Study
In a separate study published in Critical Care Medicine, a journal of the Society of Critical Care Medicine (SCCM), the US Department of Health and Human Services (HHS) found that antibiotic-resistant bacteria and fungi are resulting in more people acquiring sepsis, a life-threatening condition, according to an HHS news release.
Sepsis increased by 40% among hospitalized Medicare patients
from 2012 through 2018, HHS reported.
“These (untreatable infections) are happening here and now in the United States in large numbers. This is isn’t some developing world thing. This isn’t a threat for 2050. It’s a threat for here and now,” Cornelius “Neil” Clancy, MD, Associate Chief of Veterans Affairs Pittsburg Health System (VAPHS) and Opportunistic Pathogens, told STAT.
It is troubling to see data about so many patient deaths
related to antibiotic-resistant infections and sepsis cases when the world is
transfixed by the Coronavirus. Nevertheless, it’s important that medical laboratory
leaders and microbiologists keep track of how the US healthcare system is or is
not responding to these new infectious agents. And, to contact infection
control and environmental services colleagues to enhance surveillance, ensure
safe healthcare environments and equipment, and adopt appropriate strategies to
prevent antibiotic-resistant infections.
Researchers believe new findings about genetic changes in C. difficile are a sign that it is becoming more difficult to eradicate
Hospital infection control teams, microbiologists, and clinical laboratory professionals soon may be battling a strain of Clostridium difficile (C. difficile) that is even more resistant to disinfectants and other forms of infection control.
A WSI news release states the researchers “identified genetic changes in the newly-emerging species that allow it to thrive on the Western sugar-rich diet, evade common hospital disinfectants, and spread easily.”
Microbiologists and infectious disease doctors know full well that this means the battle to control HAIs is far from won.
“C. difficile is currently forming a new species with one group specialized to spread in hospital environments. This emerging species has existed for thousands of years, but this is the first time anyone has studied C. difficile genomics in this way to identify it. This particular [bacterium] was primed to take advantage of modern healthcare practices and human diets,” said Nitin Kumar, PhD (above), in the news release. (Photo copyright: Wellcome Sanger Institute.)
Genomic Study Finds New Species of Bacteria Thrive in
Western Hospitals
In the published paper, Nitin Kumar, PhD, Senior Bioinformatician at the Wellcome Sanger Institute and Joint First Author of the study, described a need to better understand the formation of the new bacterial species. To do so, the researchers first collected and cultured 906 strains of C. difficile from humans, animals, and the environment. Next, they sequenced each DNA strain. Then, they compared and analyzed all genomes.
The researchers found that “about 70% of the strain collected specifically from hospital patients shared many notable characteristics,” the New York Post (NYPost) reported.
Hospital medical laboratory leaders will be intrigued by the
researchers’ conclusion that C. difficile is dividing into two separate
species. The new type—dubbed C. difficile clade A—seems to be targeting
sugar-laden foods common in Western diets and easily spreads in hospital
environments, the study notes.
“It’s not uncommon for bacteria to evolve, but this time we actually see what factors are responsible for the evolution,” Kumar told Live Science.
New C. Difficile Loves Sugar, Spreads
Researchers found changes in the DNA and ability of the C.
difficile clade A to metabolize
simple sugars. Common hospital fare, such as “the pudding cups and instant
mashed potatoes that define hospital dining are prime targets for these strains”,
the NYPost explained.
Indeed, C. difficile clade A does have a sweet tooth. It was associated with infection in mice that were put on a sugary “Western” diet, according to the Daily Mail, which reported the researchers found that “tougher” spores enabled the bacteria to fight disinfectants and were, therefore, likely to spread in healthcare environments and among patients.
“The new C. difficile produces spores that are more
resistant and have increased sporulation
and host colonization capacity when glucose or fructose is available for
metabolism. Thus, we report the formation of an emerging C. difficile
species, selected for metabolizing simple dietary sugars and producing high
levels or resistant spores, that is adapted for healthcare-mediated
transmission,” the researchers wrote in Nature Genetics.
Bacteria Pose Risk to Patients
The findings about the new strains of C. difficile bacteria
now taking hold in provider settings are important because hospitalized
patients are among those likely to develop life-threatening diarrhea due to
infection. In particular, people being treated with antibiotics are vulnerable
to hospital-acquired infections, because the drugs eliminate normal gut
bacteria that control the spread of C. difficile bacteria, the
researchers explained.
According to the Centers for Disease Control and Prevention (CDC), C. difficile causes about a half-million infections in patients annually and 15,000 of those infections lead to deaths in the US each year.
New Hospital Foods and Disinfectants Needed
The WSI/LSHTM study suggests hospital representatives should
serve low-sugar diets to patients and purchase stronger disinfectants.
“We show that strains of C. difficile bacteria have continued to evolve in response to modern diets and healthcare systems and reveal that focusing on diet and looking for new disinfectants could help in the fight against this bacteria,” said Trevor Lawley, PhD, Senior Author and Group Leader of the Lawley Lab at the Wellcome Sanger Institute, in the news release.
Microbiologists, infectious disease physicians, and their
associates in nutrition and environmental services can help by understanding
and watching development of the new C. difficile species and offering
possible therapies and approaches toward prevention.
Meanwhile, clinical laboratories and microbiology labs will
want to keep up with research into these new forms of C. difficile, so
that they can identify the strains of this bacteria that are more resistant to
disinfectants and other infection control methods.
