Findings could lead to new therapies and clinical laboratory biomarkers for detecting and defeating antibiotic-resistant bacteria
Once again, new research shows that human gut bacteria (microbiota) may be useful in fighting antibiotic-resistant bacterial infections. The study findings could provide new therapeutics and clinical laboratory biomarkers for diagnosing and treating severe gastrointestinal disorders.
Antibiotic-resistant bacterial infections often appear in patients with chronic intestinal conditions and in those with long-term antibiotic use. Enterobacteriaceae is a large family of gram-negative bacteria that includes more than 30 genera and over 100 species.
“Despite two decades of microbiome research, we are just beginning to understand how to define health-promoting features of the gut microbiome,” said Marie-Madlen Pust, PhD, a computational postdoctoral researcher at the Broad Institute and co-first author of the paper, in the news release.
“Part of the challenge is that each person’s microbiome is unique. This collaborative effort allowed us to functionally characterize the different mechanisms of action these bacteria use to reduce pathogen load and gut inflammation,” she added.
The researchers identified a way to treat patients infected by antibiotic-resistant strains of bacteria that does not involve antibiotics. Should further research validate these early findings, this could be a viable approach to treating patients with this condition.
“Microbiome studies can often consist of analyzing collections of genetic sequences, without understanding what each gene does or why certain microbes are beneficial,” said Ramnik Xavier, MD (above), director of Broad Institute’s immunology program, co-director of the infectious disease and microbiome program, and co-senior author on the study, in a news release. “Trying to uncover that function is the next frontier, and this is a nice first step towards figuring out how microbial metabolites influence health and inflammation.” Clinical laboratories that test for intestinal conditions caused by antibiotic resistance will want to follow the Broad Institute’s research. (Photo copyright: Broad Institute.)
Suppressing Growth of Antibiotic-resistant Bacteria
To perform their research, the scientists isolated about 40 strains of bacteria from the stools of five healthy fecal donors. They then used those stool samples in fecal microbiota transplants to treat mice that had been infected with either Escherichia coli (E. coli) or Klebsiella, both forms of Enterobacteriaceae. The scientists tested different combinations of the 40 strains and identified 18 that suppressed the growth of Enterobacteriaceae.
“Antibiotic-resistant Enterobacteriaceae such as E. coli and Klebsiella bacteria are common in hospitals, where they can proliferate in the gut of patients and cause dangerous systemic infections that are difficult to treat. Some research suggests that Enterobacteriaceae also perpetuates inflammation in the intestine and infection by other microbes,” the Broad Institute news release notes.
The researchers discovered that Klebsiella changed the gene expression in carbohydrate uptake and metabolism in the Klebsiella-infected mice that were treated with the 18 beneficial strains. The gene expression included the downregulating of gluconate kinase and transporter genes, which revealed there is increased competition among gut bacteria for nutrients.
When combined, these 18 strains alleviated inflammation in the guts of the treated mice by depriving the harmful gut bacteria of carbohydrates. This non-antibiotic approach also prevented harmful bacteria from colonizing in the gut.
“In partnership with the Broad’s Metabolomics Platform, led by senior director and study co-author Clary Clish, PhD, they analyzed samples from pediatric patients with ulcerative colitis, looking for the presence of alternate gluconate pathway genes of gut microbes and fecal gluconate levels. They found higher levels of gluconate linked to more gluconate-consuming Enterobacteriaceae in samples from pediatric patients with ongoing inflammation, indicated by high levels of the protein calprotectin,” the study authors wrote in Nature.
“Together, the findings suggest that Enterobacteriaceae processes gluconate as a key nutrient and contributes to inflammation in patients. But when a gut microbiome includes the 18 helpful strains, they likely compete with Enterobacteriaceae for gluconate and other nutrient sources, limiting the proliferation of the harmful bacteria,” the scientists concluded.
Promising New Bacterial Therapies
This research could ultimately lead to the development of fecal microbiota transplants for individuals to eradicate antibiotic-resistant bacteria in a more objective and specific manner, with fewer side effects than current treatments.
“Harnessing these activities in the form of live bacterial therapies may represent a promising solution to combat the growing threat of proinflammatory, antimicrobial-resistant Enterobacteriaceae infection,” the scientists wrote in Nature.
According to the news release, they plan to continue research to “uncover the identity and function of unknown metabolites that contribute to gut health and inflammation.” The team hopes to discover how different bacteria compete with each other, and to develop microbial therapeutics that improve gut microbiome and curb bacterial infections.
More studies are needed to prove the efficacy of this type of fecal bacterial treatment. However, this research demonstrates how using nano processes enabled by new technologies to identify the actual work of proteins, RNA, and DNA in the body cheaply, faster, and with greater precision, will open doors to both therapeutic and diagnostic clinical laboratory biomarkers.
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 technology could enable genetic scientists to identify antibiotic resistant genes and help physicians choose better treatments for genetic diseases
Genomic scientists at the Icahn School of Medicine at Mount Sinai Medical Center in New York City have developed what they call a “smart tweezer” that enables researchers to isolate a single bacterium from a patient’s microbiome in preparation for genetic sequencing. Though primarily intended for research purposes, the new technology could someday be used by clinical laboratories and microbiologists to help physicians diagnose chronic disease and choose appropriate genetic therapies.
The researchers designed their new technology—called mEnrich-seq—to improve the effectiveness of research into the complex communities of microorganisms that reside in the microbiomes within the human body. The discovery “ushers in a new era of precision in microbiome research,” according to a Mount Sinai Hospital press release.
“Imagine you’re a scientist who needs to study one particular type of bacteria in a complex environment. It’s like trying to find a needle in a large haystack,” said the study’s senior author Gang Fang, PhD (above), Professor of Genetics and Genomic Sciences at Icahn School of Medicine at Mount Sinai Medical Center, in a press release. “mEnrich-seq essentially gives researchers a ‘smart tweezer’ to pick up the needle they’re interested in,” he added. Might smart tweezers one day be used to help physicians and clinical laboratories diagnose and treat genetic diseases? (Photo copyright: Icahn School of Medicine.)
Addressing a Technology Gap in Genetic Research
Any imbalance or decrease in the variety of the body’s microorganisms can lead to an increased risk of illness and disease.
In researching the microbiome, many scientists “focus on studying specific types of bacteria within a sample, rather than looking at each type of bacteria present,” the press release states. The limitation of this method is that a specific bacterium is just one part of a complicated environment that includes other bacteria, viruses, fungi and host cells, each with their own unique DNA.
“mEnrich-seq effectively distinguishes bacteria of interest from the vast background by exploiting the ‘secret codes’ written on bacterial DNA that bacteria use naturally to differentiate among each other as part of their native immune systems,” the press release notes. “This new strategy addresses a critical technology gap, as previously researchers would need to isolate specific bacterial strains from a given sample using culture media that selectively grow the specific bacterium—a time-consuming process that works for some bacteria, but not others. mEnrich-seq, in contrast, can directly recover the genome(s) of bacteria of interest from the microbiome sample without culturing.”
Isolating Hard to Culture Bacteria
To conduct their study, the Icahn researchers used mEnrich-seq to analyze urine samples taken from three patients with urinary tract infections (UTIs) to reconstruct Escherichia coli (E. Coli) genomes. They discovered their “smart tweezer” covered more than 99.97% of the genomes across all samples. This facilitated a comprehensive examination of antibiotic-resistant genes in each genome. They found mEnrich-seq had better sensitivity than standard study methods of the urine microbiome.
They also used mEnrich-seq to selectively examine the genomes of Akkermansia muciniphila (A. muciniphila), a bacterium that colonizes the intestinal tract and has been shown to have benefits for obesity and Type 2 diabetes as well as a response to cancer immunotherapies.
“Akkermansia is very hard to culture,” Fang told GenomeWeb. “It would take weeks for you to culture it, and you need special equipment, special expertise. It’s very tedious.”
mEnrich-seq was able to quickly segregate it from more than 99.7% of A. muciniphila genomes in the samples.
Combatting Antibiotic Resistance Worldwide
According to the press release, mEnrich-seq could potentially be beneficial to future microbiome research due to:
Cost-Effectiveness: It offers a more economical approach to microbiome research, particularly beneficial in large-scale studies where resources may be limited.
Broad Applicability: The method can focus on a wide range of bacteria, making it a versatile tool for both research and clinical applications.
Medical Breakthroughs: By enabling more targeted research, mEnrich-seq could accelerate the development of new diagnostic tools and treatments.
“One of the most exciting aspects of mEnrich-seq is its potential to uncover previously missed details, like antibiotic resistance genes that traditional sequencing methods couldn’t detect due to a lack of sensitivity,” Fang said in the news release. “This could be a significant step forward in combating the global issue of antibiotic resistance.”
More research and clinical trials are needed before mEnrich-seq can be used in the medical field. The Icahn researchers plan to refine their novel genetic tool to improve its efficiency and broaden its range of applications. They also intend to collaborate with physicians and other healthcare professionals to validate how it could be used in clinical environments.
Should all this come to pass, hospital infection control teams, clinical laboratories, and microbiology labs would welcome a technology that would improve their ability to detect details—such as antibiotic resistant genes—that enable a faster and more accurate diagnosis of a patient’s infection. In turn, that could contribute to better patient outcomes.
The self-cleaning material has been proven to repel even the deadliest forms of antibiotic resistant (ABR) superbugs and viruses. This ultimate non-stick coating is a chemically treated form of transparent plastic wrap which can be adhered to surfaces prone to gathering germs, such as door handles, railings, and intravenous therapy (IV) stands.
“We developed the wrap to address the major threat that is posed by multi-drug resistant bacteria,” Leyla Soleymani, PhD, Associate Professor at McMaster University and one of the leaders of the study, told CNN. “Given the limited treatment options for these bugs, it is key to reduce their spread from one person to another.”
According to research published in the peer-reviewed Southern Medical Journal, “KPC-producing bacteria are a group of emerging highly drug-resistant Gram-negative bacilli causing infections associated with significant morbidity and mortality.”
Were those surfaces covered in this new bacterial-resistant
coating, life-threatening infections in hospital ICUs could be prevented.
Taking Inspiration from Nature
In designing their new anti-microbial wrap, McMaster researchers took their inspiration from natural lotus leaves, which are effectively water-resistant and self-cleaning thanks to microscopic wrinkles that repel external molecules. Substances that come in contact with surfaces covered in the new non-stick coating—such as a water, blood, or germs—simply bounce off. They do not adhere to the material.
The “shrink-wrap” is flexible, durable, and inexpensive to
manufacture. And, the researchers hope to locate a commercial partner to
develop useful applications for their discovery.
“We’re structurally tuning that plastic,” Soleymani told SciTechDaily. “This material gives us something that can be applied to all kinds of things.”
Industries Outside of Healthcare Also Would Benefit
According to the US Centers for Disease Control and Prevention (CDC), at least 2.8 million people get an antibiotic-resistant infection in the US each year. More than 35,000 people die from these infections, making it one of the biggest health challenges of our time and a threat that needs to be eradicated. This innovative plastic coating could help alleviate these types of infections.
And it’s not just for healthcare. The researchers said the coating could be beneficial to the food industry as well. The plastic surface could help curtail the accidental transfer of bacteria, such as E. coli, Salmonella, and Listeria in food preparation and packaging, according to the published study.
“We can see this technology being used in all kinds of institutional and domestic settings,” Tohid Didar, PhD, Assistant Professor at McMaster University and co-author of the study, told SciTechDaily. “As the world confronts the crisis of anti-microbial resistance, we hope it will become an important part of the anti-bacterial toolbox.”
Clinical laboratories also are tasked with preventing the
transference of dangerous bacteria to patients and lab personnel. Constant
diligence in application of cleaning protocols is key. If this new anti-bacterial
shrink wrap becomes widely available, medical laboratory managers and
microbiologists will have a new tool to fight bacterial contamination.
As infectious bacteria become even more resistant to antibiotics, chronic disease patients with weakened immune systems are in particular danger
Microbiologists
and clinical
laboratory managers in the United States may find it useful to learn that
exceptionally virulent strains of bacteria are causing increasing numbers of cancer
patient deaths in India. Given the speed with which infectious diseases spread
throughout the world, it’s not surprising that deaths due to similar hospital-acquired
infections (HAIs) are increasing in the US as well.
Recent news reporting indicates that an ever-growing number
of cancer patients in the world’s second most populous nation are struggling to
survive these infections while undergoing chemotherapy and other treatments for
their cancers.
In some ways, this situation is the result of more powerful antibiotics. Today’s modern antibiotics help physicians, pathologists, and clinical laboratories protect patients from infectious disease. However, it’s a tragic fact that those same powerful drugs are making patients with chronic diseases, such as cancer, more susceptible to death from HAIs caused by bacteria that are becoming increasingly resistant to those same antibiotics.
India is a prime example of that devastating dichotomy. Bloomberg
reported that a study conducted by Abdul
Ghafur, MD, an infectious disease physician with Apollo Hospitals in Chennai, India,
et al, concluded that “Almost two-thirds of cancer patients with a
carbapenem-resistant infection are dead within four weeks, vs. a 28-day
mortality rate of 38% in patients whose infections are curable.”
This news should serve as an alert to pathologists, microbiologists,
and clinical laboratory leaders in the US as these same superbugs—which resist
not only antibiotics but other drugs as well—may become more prevalent in this
country.
‘We Don’t Know
What to Do’
The dire challenge facing India’s cancer patients is due to escalating
bloodstream infections associated with carbapenem-resistant
enterobacteriaceae (CRE), a particularly deadly bacteria that has become
resistant to even the most potent carbapenem antibiotics, generally
considered drugs of last resort for dealing with life-threatening infections.
Lately, the problem has only escalated. “We are facing a
difficult scenario—to give chemotherapy and cure the cancer and get a
drug-resistant infection and the patient dying of infections.” Ghafur told Bloomberg.
“We don’t know what to do. The world doesn’t know what to do in this scenario.”
Ghafur added, “However wonderful the developments in the
field of oncology, they are not going to be useful, because we know cancer
patients die of infections.”
The problem in India, Bloomberg reports, is
exacerbated by contaminated food and water. “Germs acquired through ingesting
contaminated food and water become part of the normal gut microbiome, but they can
turn deadly if they escape the bowel and infect the urinary tract, blood, and
other tissues.” And chemotherapy patients, who likely have weakened digestive
tracts, suffer most when the deadly germs reach the urinary tract, blood, and surrounding
tissues.
“Ten years ago, carbapenem-resistant superbug infections
were rare. Now, infections such as carbapenem-resistant klebsiella bloodstream
infection, urinary infection, pneumonia, and surgical site infections are a
day-to-day problem in our (Indian) hospitals. Even healthy adults in the
community may carry these bacteria in their gut in Indian metropolitan cities;
up to 5% of people carry these superbugs in their intestines,” Ghafur told The
Better India.
“These patients receive chemotherapy during treatment, which
lead to severe mucositis
of gastrointestinal tract and myelosuppression.
It was hypothesized that the gut colonizer translocate into blood circulation
causing [bloodstream infection],” the AIIMS paper states.
US Cases of C. auris Also Linked to CRE
Deaths in the US involving the fungus Candida auris (C. auris)
have been linked to CRE as well. And, people who were hospitalized outside the
US may be at particular risk.
The CDC reported on
a Maryland resident who was hospitalized in Kenya with a
carbapenemase-producing infection, which was later diagnosed as C. auris. The CDC
describes C. auris as “an emerging drug-resistant yeast of high public concern
… C auris frequently co-occurs with carbapenemase-producing organisms like
CRE.”
Drug-resistant germs are a public health threat that has
grown beyond overuse of antibiotics to an “explosion of resistant fungi,”
reported the New
York Times (NYT).
“It’s an enormous problem. We depend on being able to treat
those patients with antifungals,” Matthew Fisher, PhD,
Professor of Fungal Disease Epidemiology at Imperial College London, told the NYT.
The NYT article states that “Nearly half of patients
who contract C. auris die within 90 days, according to the CDC. Yet the world’s
experts have not nailed down where it came from in the first place.”
Cases of C. auris in the US are showing up in New York, New
Jersey, and Illinois and is arriving on travelers from many countries,
including India, Pakistan, South Africa, Spain, United Kingdom, and
Venezuela.
“It is a creature from the black lagoon,” Tom Chiller, MD,
Chief of the Mycotic
Diseases Branch at the CDC told the NYT. “It bubbled up and now it
is everywhere.”
Since antibiotics are used heavily in agriculture and
farming worldwide, the numbers of antibiotic-resistant infections will likely
increase. Things may get worse, before they get better.
Pathologists, microbiologists, oncologists, and clinical
laboratories involved in caring for patients with antibiotic-resistant
infections will want to fully understand the dangers involved, not just to
patients, but to healthcare workers as well.