"Perfume Grass" Could Solve Problem of Antibiotics in Water Supply

While the article looks at antibiotics within the water supply, I would like to expand the discussion to include antibiotic resistance that is developed because of antibiotics in the wastewater (sewer) supply, which is where antibiotics in the drinking water arise. From the discharge of antibiotics into the waste stream, we find antibiotics and resistant pathogens now in our major water supplies, including drinking water. A significant portion of those antibiotics arise from nursing homes. This is because of a fiat by the US Drug Enforcement Agency. Nursing homes must dump all non-used drugs into the toilet.

Sewer plants are major cauldrons where antibiotic resistance is generated. Here is some information from a 1982 US EPA study on antibiotic resistance and sewer plants: The author is Meckes—-http://aem.asm.org/cgi/reprint/43/2/371.pdf)

“It is evident from this work as well as the work of others (10,13-15,29) that antibiotic resistant coliforms are entering the aquatic environment via treated municipal wastewater effluence. When bacteria which carry transmissible R-factors (R+ bacteria) (R=resistance) are ingested by a human host, the R-factors may transfer into commonly occurring bacteria of the gastrointestinal tract (32). These organisms may subsequently transfer this resistance to pathogenic organisms, resulting in reduced efficacy of antimicrobial chemotherapy in the event of an infection. In vivo studies have shown that when individuals carrying R+bacteria are subjected to antibiotic therapy, these organisms flourish and transfer their resistance to other bacteria (25). Several researchers have pointed out that waste water, treated or untreated, is a primary contributor of bacteria to the aquatic ecosystem (12,16,17,20,27,29). Studies have been conducted which demonstrate that significant numbers of mutli-drug-resistant coliforms occur in rivers (17), bays (9), bathing beaches (28) and coastal canals (13). Waters contaminated by bacteria capable of transferring drug resistance are of great concern since there is the potential for transfer of antibiotic resistance to a pathogenic species. Available information documents that conventional wastewater purification methods without disinfection are not adequate for removal of antibiotic-resistant bacteria (14,15,29).”

Of critical discussion here is that this paper by Meckes will not be found within the publicly accessible web of EPA. Thus its absence cripples efforts to deal with the issue.

Additionally, as noted by Dr Amy Pruden, we are seeing hard to control gene fragments in the drinking water. These can be virulence factors as well as genes that confer antibiotic resistance. These fragments because they are not “alive” cells are not controlled by residual chlorine and are so small that they traverse many of the current filtering systems, thus into that glass of water you just drank. From there the genetic infrmation passes to the gut bacteria and thus augmenting the enhancement of other pathogens. When we deficate, these bacteria form part of the fecal veener that is on the perineium, thence these resistant bacteria can move to adjacent orifices and up into the body.

Further work by Matt Wook Chang on chlorine and the enhancement of virulence on MRSA has shown that chlorine up-regulates virulence factors.

What is seldom discussed is the effect on biofilms that exist in almost all water systems. The combined effects of gene fragments and low-level concentrations of antibiotics and other pharmaceuticals , as well as chlorine within the delivery systems (drinking water or purple pipe reclaimed water), makes a witches brew coming through the pipe at the point of use. To give you some idea of this, one of the students in the medical microbiology class who happened to have a part time job in a local national chain pharmacy brought in some sterile water for testing. This was water produced by equipment within the pharmacy for mixing prescription medications. The medical micro class was in that section of the course doing waterborne disease studies. The “sterile” water was run in the lab and it showed antibiotic resistant pathogens that were resistant to 11 of the 12 challenge antibiotics. We surmised that the filters from the starting potable supply had been contaminated and thus a biofilm had developed in the equipment. This biofilm then spread further into the equipment and into the end product. This is also an issue facing dental clinics.

The use of reclaimed (recycled) water for irrigation, especially for crops consumed raw warrants some discussion here. The work by Harwood, et al (http://aem.asm.org/cgi/content/short/71/6/3163) shows that significant numbers of pathogens are making it through in the finished reclaimed (recycled water). This is water that has been approved by the state for such use. Here is a bit from the Harwood report discussing reclaimed water tested across the U.S.: ”Microorganisms were detected in disinfected effluent samples at the following frequencies: total coliforms, 63%; fecal coliforms, 27%; enterococci, 27%; C. perfringens, 61%; F-specific coliphages, 40%; and enteric viruses, 31%. Cryptosporidium oocysts and Giardia cysts were detected in 70% and 80%, respectively, of reclaimed water samples. Viable Cryptosporidium, based on cell culture infectivity assays, was detected in 20% of the reclaimed water samples. No strong correlation was found for any indicator-pathogen combination. When data for all indicators were tested using discriminant analysis, the presence/absence patterns for Giardia cysts, Cryptosporidium oocysts, infectious Cryptosporidium, and infectious enteric viruses were predicted for over 71% of disinfected effluents. The failure of measurements of single indicator organism to correlate with pathogens suggests that public health is not adequately protected by simple monitoring schemes based on detection of a single indicator, particularly at the detection limits routinely employed. ”

There are a number of good papers in the literature that discuss the tracking up inside of crops by pathogens found in irrigated fields. Since certified organic produce does use this reclaimed water for irrigation, one must wonder about pathogens tracking up into the edible portions that are consumed raw. No amount of surface washing at the kitchen sink will be effective in removing these internalized pathogens. Once consumed, the genetic information can be transferred and maintained by the gut bacteria and later passed to an incoming pathogen. This may see failure of antibiotics.

San Diego, for example, is running out of water and has a serious water supply problem. There is much interest in the use of reclaimed (recycled) water to off set potable supplies for non-potable uses. The problem of short water supply in San Diego finds it initiation in the willingness of politicians to believe in the theory of “paper water”. This was a mythical water supply that was imagined by the big water agencies and welcomed by politicians and developers to allow unbridled expansion. Now the chickens have come home to roost and the citizens of the San Diego area will be paying the expense. Remember, MRSA is but one of the multi-antibiotic-resistant pathogens. MRSA alone of all the antibiotic resistant pathogens now, according to the CDC, kills more Americans than AIDS.

Dr Edo McGowan