Impact of an Urban Effluent on Antibiotic Resistance of Riverine Enterobacteriaceae and Aeromonas spp

Abstract

In order to evaluate the impact of an urban effluent on antibiotic resistance of freshwater bacterial populations, water samples were collected from the Arga river (Spain), upstream and downstream from the wastewater discharge of the city of Pamplona. Strains of Enterobacteriaceae (representative of the human and animal commensal flora) (110 isolates) and Aeromonas (typically waterborne bacteria) (118 isolates) were selected for antibiotic susceptibility testing. Most of the Aeromonas strains (72%) and many of the Enterobacteriaceae (20%) were resistant to nalidixic acid. Singly nalidixic acid-resistant strains were frequent regardless of the sampling site for Aeromonas, whereas they were more common upstream from the discharge for enterobacteria. The most common resistances to antibiotics other than quinolones were to tetracycline (24.3%) and beta-lactams (20.5%) for Enterobacteriaceae and to tetracycline (27.5%) and co-trimoxazole (26.6%) for Aeromonas. The rates of these antibiotic resistances increased downstream from the discharge at similar degrees for the two bacterial groups; it remained at high levels for enterobacteria but decreased along the 30-km study zone for Aeromonas. Genetic analysis of representative strains demonstrated that these resistances were mostly (enterobacteria) or exclusively (Aeromonas) chromosomally mediated. Moreover, a reference strain of Aeromonas caviae (CIP 7616) could not be transformed with conjugative R plasmids of enterobacteria. Thus, the urban effluent resulted in an increase of the rates of resistance to antibiotics other than quinolones in the riverine bacterial populations, despite limited genetic exchanges between enterobacteria and Aeromonas. Quinolone resistance probably was selected by heavy antibiotic discharges of unknown origin upstream from the urban effluent.

Impact of treated wastewater on organismic biosensors at various levels of biological organization

“…Relatively low levels of fecal coliforms could nevertheless accumulate in the fish digestive system, posing a risk of transmission to consumers by cross-contamination of tissues, in case of inadequate hygiene standards in fish preparation (El-Shafai et al, 2004;Harnisz and Tucholski, 2010) Goni-Urriza et al, 2000;Lehane and Rawlin, 2000;Huddleston et al, 2006;. With the popularity of recreational fishing in watersheds downstream from the investigated WWTP, medical personnel may expect more aeromonad-related infections, whereas their diagnosis and treatment may be difficult, particularly taking into consideration the emerging antibiotic resistance of fish pathogens.…”

“…salmonicida is a fish pathogen . As contact-borne, A. hydrophyila, A. sobria, and A. caviae 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 26 may cause fish handler disease through skin wound infections and systemic infections, while as food-borne, A. hydrophyila may lead to gastroenteritis, diarrhoea and systemic infections Goni-Urriza et al, 2000;Lehane and Rawlin, 2000;Huddleston et al, 2006;. With the popularity of recreational fishing in watersheds downstream from the investigated WWTP, medical personnel may expect more aeromonad-related infections, whereas their diagnosis and treatment may be difficult, particularly taking into consideration the emerging antibiotic resistance of fish pathogens.…”

“…Amoxicillin is closely related to ampicillin, towards which aeromonads have a natural resistance (Harnisz and Tucholski, 2010), therefore this result was expected. One possible reason for such a high resistance to SMX is that it alone is not very active against Aeromonas spp., but in combination with trimethoprim it is generally efficient (Goni-Urriza et al, 2000). The incidence of resistance of environmental Aeromonas spp.…”

Biodegradation of sulfamethoxazole: current knowledge and perspectives

“…The greatest anxiety is that their presence will lead to antibacterial resistance in biological wastewater (WW) treatment and the environment (Andersson 2003;Costanzo et al 2005;Daughton 2003;Daughton and Ternes 1999;Goni-Urriza et al 2000;Halling-Sorensen et al 1998;Kümmerer 2009b;Reinthaler et al 2003;Volkmann et al 2004). Recently, this has been demonstrated by the observed increase in antibacterial resistance in Acinetobacter spp.…”

The involvement of tetA and tetE tetracycline resistance genes in plasmid and chromosomal resistance of Aeromonas in Brazilian strains

“…Indeed, for several decades, tetracycline has been widely used in clinical medicine, veterinary and agriculture (Gilchrist et al 2007), contributing to higher levels of microbial resistance, especially among the genus Aeromonas (Goñi-Urriza et al 2000).…”