TY - JOUR

T1 - Biodegradability of Cefotiam, Ciprofloxacin, Meropenem, Penicillin G and Sulfamethoxazole and Inhibition of Waste Water Bacteria

AU - Al-Ahmad, Ali

AU - Daschner, Franz D.

AU - Kümmerer, Klaus

PY - 1999/8/1

Y1 - 1999/8/1

N2 - Most antibiotics are metabolized only incompletely by patients after administration and enter the municipal sewage with the patients' excretions. Little is known about their biodegradability in aquatic environments and their role with respect to growing bacterial resistance. Therefore, the biodegradability of some clinically important antibiotic drugs as a very first step of an environmental risk assessment was investigated with the OECD closed bottle test (CBT). To assess toxicity of the test compounds against aquatic bacteria (1) a growth inhibition test (GIT) with Pseudomonas putida was conducted; (2) a toxicity control was used in the CBT; and (3) the colony-forming units (CFUs) were monitored in the test vessels. Theoretical concentrations of the test substances in hospital effluents were calculated and compared with minimum inhibitory concentrations for susceptible pathogenic bacteria. None of the test compounds met the criteria for ready biodegradability. Only penicillin G was biodegradable to some degree (27%), even when the test was prolonged from 28 to 40 days (35%). The inhibition concentrations measured in the GIT were in the same range or lower than the 50% minimum inhibitory concentrations (MIC 50) known for susceptible pathogenic bacteria. CFU monitoring revealed high toxicity for sulfamethoxazole, whereas ciprofloxacin had a weak but significant effect; only for meropenem a weak but significant effect was measured in the toxicity control of the CBT. MIC 50 published for susceptible pathogenic bacteria were for all compounds in the same range as the concentrations expected for hospital effluents. Therefore, antibiotic drugs emitted into municipal sewage may affect the biological process in sewage treatment plants (STPs), and they may persist in the aquatic environment and contribute to the increasing resistance of pathogenic bacteria.

AB - Most antibiotics are metabolized only incompletely by patients after administration and enter the municipal sewage with the patients' excretions. Little is known about their biodegradability in aquatic environments and their role with respect to growing bacterial resistance. Therefore, the biodegradability of some clinically important antibiotic drugs as a very first step of an environmental risk assessment was investigated with the OECD closed bottle test (CBT). To assess toxicity of the test compounds against aquatic bacteria (1) a growth inhibition test (GIT) with Pseudomonas putida was conducted; (2) a toxicity control was used in the CBT; and (3) the colony-forming units (CFUs) were monitored in the test vessels. Theoretical concentrations of the test substances in hospital effluents were calculated and compared with minimum inhibitory concentrations for susceptible pathogenic bacteria. None of the test compounds met the criteria for ready biodegradability. Only penicillin G was biodegradable to some degree (27%), even when the test was prolonged from 28 to 40 days (35%). The inhibition concentrations measured in the GIT were in the same range or lower than the 50% minimum inhibitory concentrations (MIC 50) known for susceptible pathogenic bacteria. CFU monitoring revealed high toxicity for sulfamethoxazole, whereas ciprofloxacin had a weak but significant effect; only for meropenem a weak but significant effect was measured in the toxicity control of the CBT. MIC 50 published for susceptible pathogenic bacteria were for all compounds in the same range as the concentrations expected for hospital effluents. Therefore, antibiotic drugs emitted into municipal sewage may affect the biological process in sewage treatment plants (STPs), and they may persist in the aquatic environment and contribute to the increasing resistance of pathogenic bacteria.

KW - AEROBIC BIODEGRADATION

KW - ANTIBACTERIAL ACTIVITY

KW - ANTIBIOTIC

KW - Antibiotics

KW - aquatic

KW - aquatic environment

KW - AQUATIC ENVIRONMENTS

KW - AQUEOUS-SOLUTION

KW - bacteria

KW - BACTERIAL

KW - BACTERIAL-RESISTANCE

KW - BACTERIUM

KW - biodegradability

KW - Biological

KW - CEFOTIAM

KW - Ciprofloxacin

KW - Closed Bottle Test

KW - COMPOUND

KW - concentration

KW - Control

KW - drug

KW - DRUGS

KW - effect

KW - effluent

KW - EFFLUENTS

KW - ENVIRONMENT

KW - environmental

KW - environmental risk

KW - environmental risk assessment

KW - EXCRETION

KW - FLUOROQUINOLONE CARBOXYLIC-ACIDS

KW - GERMANY

KW - GROWTH

KW - hospital

KW - hospital effluent

KW - hospital effluents

KW - Inhibition

KW - Meropenem

KW - Monitoring

KW - MUNICIPAL SEWAGE

KW - OECD

KW - PATIENT

KW - Penicillin

KW - penicillin G

KW - PHOTOLYTIC DEGRADATION

KW - PLANT

KW - PLANTS

KW - Pseudomonas

KW - Pseudomonas putida

KW - PSEUDOMONAS-PUTIDA

KW - READY

KW - READY BIODEGRADABILITY

KW - RESISTANCE

KW - risk

KW - RISK ASSESSMENT

KW - Risk-Assessment

KW - sewage

KW - sewage treatment

KW - sewage treatment plant

KW - sewage treatment plants

KW - SEWAGE-TREATMENT

KW - soil

KW - STP

KW - SUBSTANCES

KW - SULFAMETHOXAZOLE

KW - Test

KW - TOXICITIES

KW - toxicity

KW - TOXICOLOGY

KW - treatment

KW - TREATMENT PLANTS

KW - TREATMENT-PLANT

KW - UNIT

KW - UNITS

KW - USA

KW - Waste

KW - waste water

KW - WATER

KW - WATER BACTERIA

KW - AEROBIC BIODEGRADATION

KW - ANTIBACTERIAL ACTIVITY

KW - ANTIBIOTIC

KW - Antibiotics

KW - aquatic

KW - aquatic environment

KW - AQUATIC ENVIRONMENTS

KW - AQUEOUS-SOLUTION

KW - bacteria

KW - Chemistry

UR - http://www.scopus.com/inward/record.url?scp=0032807198&partnerID=8YFLogxK

U2 - 10.1007/s002449900501

DO - 10.1007/s002449900501

M3 - Journal articles

VL - 37

SP - 158

EP - 163

JO - Archives of Environmental Contamination and Toxicology

JF - Archives of Environmental Contamination and Toxicology

SN - 0090-4341

IS - 2

ER -