Sludge Watch ==> Sewage plants and antibiotic / antimicrobial resistance

[Maureen Reilly]

Sludgewatch Admin:

Dr Edo McGowan has been looking at the role of sewer plants in creating and 
spreading antibiotic resistance.  Sludge, effluent, and 'reclaimed 
water'....all play a role.


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Fm: Dr. Edo McGowan, specialty---Medical Geo-hydrology

Re: Comments on article by Amy Pruden, et al relating to Resistance Genes as 
Emerging Contaminants.

The appended comment extends the conversation supplied by Dr Pruden, et al., 
thus adding to the perspective and knowledge on this subject. The underlying 
driver for this effort stems from the advancing resistance and virulence 
within the pathogen community, the advancing newly emerging infectious 
diseases and importantly the need to revisit the antiquated standards 
currently underlying wastewater treatment. The fact that Dr Pruden and her 
team were able to see, within the environment, genetic material from 
antibiotic resistant pathogens indicates that sewer plants are failing to 
protect the public. This is understandable when one considers the sewer 
plant designs and their standards are antiquated. Additionally, those 
operating, designing, or regulating such works have limited training in 
areas now found emerging as diseases within the community and importantly 
the causes of this spread.

That an extension of the subject is now needed seems fairly evident from the 
constant necessity to 1) rid communities of generated waste, 2) the use of 
this waste in either irrigation or land application of food crops, 3) the 
use of reclaimed sewage wastewater, for ground water recharge, and 4) the 
rapidly rising cases of food-borne illnesses related to salad and other 
vegetable and fruit crops. The last point may show irrigation with reclaimed 
sewage water to be a critically weak link in the Salinas Valley’s frequent 
outbreaks of food-borne illness associated with freshly consumed produce. 
This entire valley is irrigated with reclaimed sewage water, including 
certified organic produce. Accordingly if one really looks at the protection 
from the underlying standards, one soon realizes that there is actually very 
little actual protection. Thus Dr Pruden’s paper is a critical link into 
expanding the discussion to reopen reviews on standards.

++++++++++++++++++++++++

COMMENT-----400 word version

Pruden , et al, [1] discuss genetic material within wastewater. Uptake may 
lead to enhanced virulence and resistance. Sewer plants augment this [2,3] 
through selective pressures [4] transferring genetic information to 
non-related organisms within completely different kingdoms [5]. In the VBNC 
state organisms are invisible to laboratory tests [6]. Other materials 
confer resistance [7,8]. There may be the development of cross-resistance 
[9].

Antimicrobials transit the body essentially unchanged inducing resistance 
[10]. Kummerer [10] and others [11] note the levels of pharmaceuticals in 
sewage induce or maintain resistance.

Wastewater industry holds that released effluent, its use for irrigation or 
land application of sludge are benign and beneficial activities [12]. 
Current literature raises questions about this activity and the standards 
[12].

Citations

[1] Pruden, A.; Pei, R.; Storteboom, H.; Carlson, K. H. Antibiotic 
Resistance Genes as Emerging Contaminants: Studies in Northern Colorado. 
Environ. Sci. Technol.; (Article); 2006; 40(23); 7445-7450.

[2] Ribeiro-Dias JC, Vicente AC, Hofer E. Fecal coliforms in sewage waters. 
I. Resistance to antibiotics, heavy metals and colicinogeny. Appl Environ 
Microbiol 1983 Jul;46(1):227-32.

[3] Fontaine TD et al. Transferable drug resistance associated with 
coliforms from hospital and domentic sewage. Health Lab Sci. 1976 Oct; 
13(4): 238-45.

[4] Nakamura S, Shirota H. Behavior of drug resistant fecal coliforms and R 
plasmids in a wastewater treatment plant. Nippon Koshu Eisei Zasshi 1990 
Feb;37(2):83-90.

[5] Faguy DM. Lateral gene transfer (LGT) between Archaea and Escherichia 
coli is a contributor to the emergence of novel infectious disease.BMC 
Infect Dis. 2003 Jun 19;3:13.

[6] Higgins MJ, S Murthy. Examination of Reactivation and Regrowth of Fecal 
Coliforms in Anaerobically Digested Sludge WERF Report: Biosolids and 
Residuals (03-CTS-13T)

[7] Randall LP et al. Effect of Triclosan or phenolic farm disinfectant on 
the selection of antibiotic resistant Salmonella enterica. J. Antimicrob. 
Chemother.2004, 54, 621-27

[8] Kinney CA, et al. Survey of Organic Wastewater Contaminants in Biosolids 
Destined for Land Application. ES&T 10.1021/es0603406 CCC, web pub 9/13/06.

[9] Al-Ahmad A, Daschner FD, Kummerer K. Biodegradability of cefotiam, 
ciprofloxacin, meropenem, penicillin G, and sulfamethoxazole and inhibition 
of waste water bacteria. Arch Environ Contam Toxicol. 1999 Aug;37(2):158-63.

[10] Kummerer K. Resistance in the environment. J Antimicrob Chemother. 2004 
Aug;54(2):311-20. Epub 2004 Jun 23.

[11] Rooklidge SJ. Environmental antimicrobial contamination from 
terraccumulation and diffuse pollution pathways. Sci Total Environ. 2004 Jun 
5;325(1-3):1-13. Review.

[12] Snyder C. The Dirty Work of Promoting "Recycling" of America’s Sewage 
Sludge. Int J. Occup Health. 2005; 11:415-27.

+++++++++++++++++++++++

SUPPLEMENTAL INFORMATION---1000 WORDS

These comments are merely qualifications, not criticisms of Dr. Pruden’s 
fine paper [1]. Resistance has been attributed to drug over-use. Pruden 
notes a less well-understood mechanism for the amplification of multi-drug 
resistance, sewage. The local sewer-treatment plant releases pathogens and 
resistance to the environment and agriculture[2]. Wastewater treatment 
intermixes organisms otherwise seldom coming together. Selective pressures 
increase survival mechanisms [3].

Defense strategies include going dormant, entering the viable but 
non-culturable (VBNC) state. These VBNC organisms are essentially invisible 
to laboratory tests used in the wastewater industry. Higgins & Murthy 
recently reconfirmed this [4] in a paper that raises some serious questions 
about the efficacy of current standards. Those authors noted that during 
centrifuged dewatering of sewer sludge, indicators in a VBNC state were 
resuscitated. The results were several magnitudes greater than standard 
plate counts had indicated [4]. Such findings raise logical questions. If 
dewatering by centrifuge brought out the essence of VBNC, would other 
products of sewage that had not been subjected to the centrifuge also in the 
VBNC state? If so would they revive in the field following agricultural 
application of sludge or irrigation with reclaimed wastewater? This seems 
plausible but needs further study.

Additionally, as stresses increase organisms can acquire genes from or 
transfer genes to non-related organisms, organisms even within completely 
different kingdoms [5,6]. There are other materials dumped into the drain 
that confer resistance. This includes industrial chemicals, heavy metals, 
and disinfectants. Triclosan a ubiquitous biocide is suspected of inducing 
resistance, as are many other industrial materials found in sewage [7,8]. 
Changes to the cellular machinery afford the ability to deal with numerous 
insults, hence cross-resistance [9].

Many antimicrobials including metabolites enter sewage essentially unchanged 
to induce resistance in the environment [10]. Kummerer [11,12,13,14,15] and 
others [16] note levels of antibiotics/pharmaceuticals in sewage able to 
induce or maintain resistance, hence adding to the risks in crop production 
through irrigation.

Based on wastewater (sewage) industry and regulatory opinion, the standards, 
the released effluent, and its use for crop irrigation or the land 
application of sewage sludge are benign and beneficial activities [17]. If 
however, one reviews the current medical and scientific literature, a 
different picture emerges, one that raises serious questions about the 
benevolence of this activity and efficacy of the underlying standards [18]. 
Thus, the issue takes on aspects of a political and not a scientific 
argument [18,19]. In the interim, most regulatory agencies have backed off 
[20]. This leaves the citizens and patient base essentially standing naked.





In 2002 the NAS/NRC [21] called into question the U.S. EPA Part 503 
guidelines for land application of sewage sludge (biosolids) and 
specifically EPA’s failure to consider antibiotic resistance. As of writing 
this comment, EPA has shown little if any progress in investigating 
resistance. A Freedom of Information Act request to EPA on this subject was 
submitted in February 2005. The agency has not answered that request [20]. 
Additionally, the agency has not done health hazards risk analyses for 
pathogens. Notwithstanding these shortcomings, the agency and the wastewater 
industry continue to promote the use of sewage byproducts in crop 
production. Salinas Valley is an example.

Citations

[1] Pruden, A.; Pei, R.; Storteboom, H.; Carlson, K. H Antibiotic Resistance 
Genes as Emerging Contaminants: Studies in Northern Colorado. Environ. Sci. 
Technol.; (Article); 2006; 40(23); 7445-7450.

[2] Ribeiro-Dias JC, Vicente AC, Hofer E. Fecal coliforms in sewage waters. 
I. Resistance to antibiotics, heavy metals and colicinogeny. Appl Environ 
Microbiol 1983 Jul;46(1):227-32. Marcinek H, Wirth R, Muscholl-Silberhorn A, 
Gauer M. Enterococcus faecalis gene transfer under natural conditions in 
municipal sewage water treatment plants. Appl Environ Microbiol 1998 
Feb;64(2):626-32.

[3] Nakamura S, Shirota H. Behavior of drug resistant fecal coliforms and R 
plasmids in a wastewater treatment plant. Nippon Koshu Eisei Zasshi 1990 
Feb;37(2):83-90.

[4] Higgins MJ, S Murthy. Examination of Reactivation and Regrowth of Fecal 
Coliforms in Anaerobically Digested Sludge WERF Report: Biosolids and 
Residuals (03-CTS-13T)

[5] Faguy DM. Lateral gene transfer (LGT) between Archaea and Escherichia 
coli is a contributor to the emergence of novel infectious disease.BMC 
Infect Dis. 2003 Jun 19;3:13.

[6] Nesbo CL. Phylogenetic analyses of two "archaeal" genes in thermotoga 
maritima reveal multiple transfers between archaea and bacteria.Mol Biol 
Evol. 2001 Mar;18(3):362-75

[7] Randall LP et al. Effect of Triclosan or phenolic farm disinfectant on 
the selection of antibiotic resistant Salmonella enterica. J. Antimicrob. 
Chemother.2004, 54, 621-27

[8] Kinney CA, et al. Survey of Organic Wastewater Contaminants in Biosolids 
Destined for Land Application. ES&T 10.1021/es0603406 CCC, web pub 9/13/06.

[9] Al-Ahmad A, Daschner FD, Kummerer K. Biodegradability of cefotiam, 
ciprofloxacin, meropenem, penicillin G, and sulfamethoxazole and inhibition 
of waste water bacteria. Arch Environ Contam Toxicol. 1999 Aug;37(2):158-63.

[10] Kinney CA, et al. Presence and distribution of wastewater-derived 
pharmaceuticals in soil irrigated with reclaimed water. Eniron Tox Chem 2006 
Feb;25(2):317-26

[11] Kummerer K. Resistance in the environment. J Antimicrob Chemother. 2004 
Aug;54(2):311-20. Epub 2004 Jun 23.

[12] Kummerer K. Promoting resistance by the emission of antibiotics from 
hospitals and households into effluent. Clin Microbiol Infect. 2003 
Dec;9(12):1203-14.

[13] Kummerer K. Standardized tests fail to assess the effects of 
antibiotics on environmental bacteria. Water Res. 2004 Apr;38(8):2111-6.

[14] Kummerer K. Biodegradability of some antibiotics, elimination of the 
genotoxicity and affection of wastewater bacteria in a simple test. 
Chemosphere. 2000 Apr;40(7):701-10.

[15] Kummerer K. Drugs, diagnostic agents and disinfectants in wastewater 
and water--a review. Schriftenr Ver Wasser Boden Lufthyg. 2000;105:59-71.

[16] [17] Rooklidge SJ. Environmental antimicrobial contamination from 
terraccumulation and diffuse pollution pathways. Sci Total Environ. 2004 Jun 
5;325(1-3):1-13. Review.
[17] 503 Appendix B, subpart D of Part 503 Regulations, CFR Title 40, Vol 
21, revised July 1,1998.

[18] Snyder C. The Dirty Work of Promoting "Recycling" of America’s Sewage 
Sludge. Int J. Occup Health. 2005; 11:415-27.

[19] Mintz JA. "Treading Water": A Preliminary Assessment of EPA Enforcement 
During the Bush II Administration.

[20] Personal communications with both EPA and CDC.

[21] National Research Council of the National Academy of Sciences (NAS) 
Biosolids Applied to Land: Advancing Standards and Practices. Washington, 
DC: National Academy Press, 2002.