SICKENING SLUDGE? Some bacteria is a good thing for sewage treatment, but good bacteria turn bad when they become resistant to the melange of drugs that end up in the water system.
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A wastewater treatment plant's job description is pretty straightforward: Remove contaminants from sewage so it can be returned to the environment without harming people or wildlife.
But a new study suggests that the treatment process can have an unintended consequence of promoting the spread of extra-hardy bacteria.
Some bugs are resistant to antibiotics, so they dodge the medical bullets that wipe out others. The more drugs that are used, the more robust they become. Since bacteria reproduce quickly – one organism might turn into a billion overnight – and they share DNA with others, antibiotic-resistant genes spread like Darwinian wildfire when conditions are right.
And at sewage treatment plants, it seems, the conditions are right, said microbiologist Chuanwu Xi, whose University of Michigan lab conducted the study.
"Wastewater treatment plants are most effective at treating sewage when they have conditions that allow beneficial bacteria to thrive and improve the quality of the water," said Karen Kidd, a University of New Brunswick ecotoxicologist familiar with the study.
"However, this study indicates that these conditions can also favor the mutation of some and act as a source of antibiotic resistant bacteria to the environment."
"To me," she added, "that's sobering."
These "super" organisms in the treated sewage wind up in rivers and other waters, potentially infecting people with infections that are difficult to treat.
To determine if sewage-treatment plants might be a source of resistant bugs, Chuanwu and fellow researchers collected several species of the common bacteria Acinetobacter from a plant in Ann Arbor, Mich. that dumps its effluent into the Huron River.
They exposed the bacteria to various antibiotics and cocktails of drugs, and found a significant increase in the percentage of Acinetobacter that were resistant after each stage of treatment. And while the final treatment process killed all but a tiny fraction of the bugs before releasing the water to the environment, the proportion of resistant bacteria was much higher among those that made it back to the river than those collected upstream from the plant.
The bacteria were as much as 10 times more resistant to some antibiotics after secondary treatment at the Michigan plant. Also, in the river downstream of the plant, they were up to 2.7 times more resistant than bacteria upstream, according to the study.
Chuanwu said people and wildlife that swim in or drink from the Huron River downstream may be exposed to the more stalwart strains. However, the human health risk is not well understood.
Acinetobacter were chosen for their "remarkable ability" to develop resistance to antimicrobial agents, according to the Michigan study, which was published online in March in the journal Science of the Total Environment. The bacterium can cause pneumonia along with serious infections in wounds and in the bloodstream, according to the Centers for Disease Control and Prevention. Most infections affect people in hospitals, where common use of antibiotics promotes growth of resistant strains.
"We don't know whether other bacteria would respond to the treatment process in the same way the Acinetobacter did," Chuanwu said. "We have some unpublished data suggesting a similar trend of resistance increase among all bacterial populations."
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8 Comments
Add CommentThis makes no sense whatsoever. The concentration of antibiotics in wastewater is vanishingly low. Unlike hormones and other potentially nasty molecules, antibiotics have no effect on cells at very low concentrations. Thus, there is no reasonable explanation here for a selection pressure that would cause an enrichment of resistant bugs. In a dense, competitive environment, resistance will decrease, not increase, in the absence of selective pressure. This is true irrespective of whether lateral gene transfer is occurring. Something is very wrong about this paper.
Reply | Report Abuse | Link to thisIt is true that the concentration of antibiotics in wastewater is far below the concentration used in clinics; however, the low concentration does have effects on cell growth. Together with other stress factors in wastewater, it is reasonable to believe that wastewater could enrich antibiotic resistant bugs.
Reply | Report Abuse | Link to thisWould like to see the data on that.
Reply | Report Abuse | Link to thisWith medical institutional infections in particular, sometimes death is a good thing- for a vicious multi-cellular organism.
Reply | Report Abuse | Link to thisThere are a variety of different types of bacterial infections one can get from many different sources, yet some locations are more common than others. If bacteria are not beneficial for your health, as many bacteria are, they should die in order to restore your health.
Bacteria are a simple life form, yet are incredibly productive and efficient. As with other life forms, they exist to reproduce, and does so about every hour. Bacteria mutate, evolve, and adapt according to the host in which they exist.
To do this, it fully utilizes all available resources and energy to develop the protein that is essential for its survival in their host. Bacteria need exactly 7 genes to produce the essential ribosomes for their existence. Any more or less genes than 7, the bacteria is not maximizing its efficiency to survive and reproduce. Amazing.
Strep infections are caused by what are called gram positive bacteria, and they are the most common bacteria that infect other humans. . Group A strep infections can cause diseases such as strep throat and pneumonia. Also, staph bacterial infections are gram positive as well that potentially infect humans, and do so often.
Of all pathogenic, or disease-causing bacteria that exist, it is the MRSA, the methicillin resistant staff aureus bacteria, that are most concerning to health care providers in particular. This is because MRSA bacterial infections are the most difficult to cure when a patient suffers from their damage from being infected by these bacteria.
Another difficult situation is when a patient is infected by VRE, Vancomycin Resistant Enterococci, which is another type of gram positive bacteria that exist.
These MRSA and VRE bacteria are difficult to eradicate due to the fact that most antibiotics that are available to rid the patient of other bacterial infections, MRSA and VRE are resistant to the effectiveness of these antibiotics.
MRSA and VRE infected patients are quite challenging for the health care provider who is attempting to cure patients infected with these particular bacterial infections.
In many situations, pathogenic bacteria infect a patient already within a medical institution for another disease. When this occurs, it is called a nosocomial infection.
Greater than 5 percent of nosocomial infections are determined to be MRSA infections, it has been reported. As a result, there are about 100,000 serious hospital infections, as well as about 20,000 deaths from MRSA infections annually.
Since there are several types of pathogenic bacteria that exist, a diagnostic test called a culture and sensitivity is usually performed at a clinical laboratory to assure the correct antibiotic is selected for treatment, as the bacteria are identified with this diagnostic method.
Typically, fluid from the area suspected of being infected is obtained from the patient suspected to have an infection and smeared on what is called a petrie dish. And then these dishes are incubated for 2 to 3 days. Gram positive bacteria stain during this process a dark violet or blue. Gram negative bacteria would be pink in color, and are capable of harm as well to a human being.
When the culture is complete, technology that is available offers recommendations on the appropriate class or brand of antibiotic to treat the pathogenic bacteria present in another person- presuming the bacteria will not be resistant to the antibiotic recommended, as this happens on occasion.
Usually, classes of antibiotics that are used to treat gram positive strep infections that are not VRE or MRSA bacteria are cephalosporins, macrolides, or general penicillins. If the microbe that is causing the infection is resistant to the antibiotic from such classes that are administered to the infected patient, other options should be considered for anti-microbial therapy.
With two very powerful antibiotics in particular, which are methicillin and vancomycin, their frequent use in infected patients has resulted in VRE and MRSA bacteria that are now resistant to these antibiotics.
When a patient is infected with VRE or MRSA bacteria, other selections for antimicrobial therapy that provide more efficacy should be selected for a patient infected with these types of infections. Such brands and types of antibiotics for MRSA and VRE bacteria include Zyvox, which has both IV and oral dosage options, and an antibiotic called Cubicin.
However these antibiotics for antibiotic resistant bacteria are given usually due to infections that have progressed to a more serious nature within a patient infected in such a way, so a cure is not immediate when these antibiotics are selected for such patients.
Progressive medical conditions with such infected patients include sepsis, or blood infection, osteomyelitis, or bone infection, as well as pneumonia, which is a serious lung infection. A hospital stay is normally required with such patients infected with MRSA and VRE infections that cause such diseases.
This is because when the antibiotics that potentially cure the patient of these microbes are selected, they are usually given via IV administration, and are administered normally for several days, if not several weeks.
There are numerous classes and types of antibiotics available, yet bacterial resistance to most of these antibiotics, with the exception of the two mentioned earlier, constantly remain a serious concern for the health care provider, and the MRSA and VRE infected patient.
With MRSA at the top of the list of concerns for the health care providers, this infection continue to occur progressively, which amplifies the concerns of others.
Medical institutions should possibly consider quarantine for those patients at their locations that have been determined to be infected with the MRSA and VRE bacteria more often in the future.
http://www.cdc.gov/ncidod/dhqp/ar_mrsa_spotlight_2006.html
Dan Abshear
Easy solution
Reply | Report Abuse | Link to this1. Disallow antibiotics in farm animals except to cure an infection. Prophylactic use is a bad idea.
2. Disallow antibiotic prescriptions to human patients for off-label use, especially for viral infections like common cold and flu.
3. Require warning labels on all medications to not dispose of them in the trash or the toilet but to return leftovers to the point of sale.
Easier and more potent solution. Chlorine Dioxide kills all pathogens and is infinitely safer than chlorine alone since chlorine recombines to form known carcinogens while Chlorine Dioxide breaks down to salt and water. Many waste treatment facilities are going for this easier, more potent solution. It is also potent in the human body with 100% cure rates common.
Reply | Report Abuse | Link to thisTry this. Make a 28% solution of Sodium Chlorite (NaClO2) and mix 15 drops with 1 teaspoon of either pure lemon or lime juice, or acetic acid, or 5% vinnegar. Let it sit for 3 minutes to make Chlorine Dioxide. Dilute the Chlorine Dioxide with 4 ounces of water or, if preferred, apple juice (No vitamin C added) and drink.
Jim Humble did this with thousands of Malaria victims in Africa (some had Aids, some other diseases) and got a 100% cure rate. Is Jim up for the Noble Prize? Nope. He is in hiding somewhere in Mexico or ???
I agree with Ralf123. I live in the UK where my doctor gives antibiotics only when an obvious bacterial infection is present. However, my friend lives in Germany and is constantly being prescribed antibiotics for any illness, even the common cold, as a prophilactic measure. Any cough she has - Antibiotics. Any muscle pains - Antibiotics. Headaches - Antibiotics. It is ridiculous and no wonder that resistant strains have developed.
Reply | Report Abuse | Link to thisprescript assist probiotic is sewage bacteria, it killed my sister.
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