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Organic chlorine pesticides (OCPs) and antibiotics represent persistent organic pollutants and emerging pollutants, respectively. They can coexist in various environmental matrix, while their combined effects were seldom explored. Lindane was chosen to represent OCPs, and sulfamethoxazole (SMX) and tetracycline hydrochloride (TET) were chosen to represent antibiotics. The present study focused on the influences on tumor migration which is essential for both carcinogenesis and cancer treatment and aimed to explore the effects of the binary mixtures on the model organism Drosophila melanogaster. The individual effects showed that lindane significantly enhanced the tumor migration from the eye and brain of the larvae to the ventral nerve cord (VNC) in the concentration range of 40 -100 ng-g-1( P<0.05). SMX enhanced the tumor migration at the highest concentration of 400 ng-g-1, while TET increased the tumor migration from 600 to 1 000 ng-g-1 with a concentration-dependence. The binary mixtures were designed by direct equipartition method. The binary mixtures that contained lindane and SMX or TET significantly enhanced the tumor migration, with a dependence on the lindane-s concentrations. Compared with the predicted effects by independent action (IA) model, the binary mixtures showed synergistic toxicity interactions. Determination on the antioxidant responses showed that, lindane, SMX, TET and the binary mixtures commonly increased reactive oxygen species (ROS) while decreased glutathione (GSH). The effects of binary mixtures containing lindane and SMX on tumor migration were negatively correlated with their influences on catalase (CAT) activities, while such correlation was not observed in the effects of mixtures containing lindane and TET. Such difference was attributed to the different effects of SMX and TET on the antioxidants. Moreover, the effects of binary mixtures containing lindane and SMX, and those containing lindane and TET showed different hierarchical clustering positions. The effects of binary mixtures containing lindane and SMX on tumor migration were closely connected with both ROS and superoxide dismutase (SOD), while those of binary mixtures containing lindane and TET were closely connected with ROS. Such differences supported the attribution to the individual effects of SMX or TET on the antioxidants and also indicated that the antibiotic types can influence the toxicity mechanism of the binary mixtures. [ABSTRACT FROM AUTHOR]

Abstract Adverse effects of sulfonamide antibiotics (SAs) include growth inhibition and antioxidant activation which showed trade-off effects. Yet, the influence of food availability on such effects have not been thoroughly investigated. Caenorhabditis elegans were exposed to four SAs at high and low food availabilities which were represented by the optical densities of bacteria at 600 nm. The nematode feeding, growth and antioxidants including superoxide dismutase (SOD), catalase (CAT) and glutathione (GSH) were determined. Results showed that the control nematodes at low food availability had less growth and greater antioxidant responses than the nematodes at high food availability. In SA exposure, the nematode growth in the presence of food (at both high and low food availability) was less than that in its absence, supporting the role of food as an exposure pathway. The nematode growth at low food availability showed significantly greater inhibition than at high food availability (p < 0.05). The nematode antioxidants showed stimulations, and CAT had the greatest stimulation. Moreover, the stimulation on CAT at low food availability were significantly higher than those at high food availability (p < 0.05). That is to say, SA exposure at low food availability further biased the trade-off effects towards more energy investment in antioxidant with less in growth. Further studies on the expression levels of CAT encoding genes demonstrated that cells in intestines were the main antioxidant response sites, which further supported the contributions of food to the observed toxicities. Highlights • In controls, low food availability caused trade-off between growth and antioxidants. • Sulfonamide exposure at low food availability biased trade-off toward antioxidants. • Sulfonamide exposure with food inhibited growth more than without food. • Sulfonamides stimulated intestinal catalase at high and low food availability. [ABSTRACT FROM AUTHOR]

Abstract: Sulfonamides are one typical antibiotic which is an emerging hazardous material to the ecological stability due to their continuously application and biological effects to non-target organisms. The parent–progeny transgenerational effects need investigations to indicate their long-term consequences. Currently, we tested the transgenerational effects of sulfadiazine (SD), sulfapyridine (SP) and sulfamethazine (SMZ) on L3 larva of Caenorhabditis elegans. The nematodes were exposed to aqueous sulfonamides at micromolar concentrations for 96h, and then the effects on the behavior and growth in the exposed parent and unexposed progeny were measured. Results showed that SD, SP and SMZ inhibited three behavior indicators including body bending frequency (BBF), reversal movement (RM) and Omega turn (OT), and the growth indicator (body length, BL). Behavior indicators showed higher sensitivities than the growth indicator, and BBF had the highest sensitivity among the behavior indicators. Moreover, the effects of sulfonamides were also observed in the unexposed progeny with partially rescued or more severe inhibitions on the indicators. The behavior also showed higher sensitivity than the growth in the progeny. The transgenerational effects of sulfonamides indicated that parental exposure can multiply the harmful effects of antibiotic pollution in following generations and their potential ecological risks at environmental concentrations were further raised. [Copyright &y& Elsevier]

The reproductive toxicities over generations are essential to assess the long-term impacts environmental fluoroquinolone antibiotics (FQs). In the present study, the multi-generational effects of ofloxacin (OFL) and norfloxacin (NOR) on reproduction were studied on Caenorhabditis elegans from 9 successive generations (F1-F9). Results showed that OFL showed no effects in F1, stimulation in F2 to F4, and inhibition F5 to F9. The effects of NOR also showed oscillation between stimulation and inhibition across generations. Further biochemical analysis demonstrated that the reproductive toxicities of OFL and NOR were more closely connected with total cholesterol (TCHO), progesterone (P) and testosterone (T), than major sperm protein (MSP) and vitellogenin (Vn). Moreover, OFL and NOR also showed significant trans-generational reproductive toxicities in T4 and T4′, the great-grand-daughter of F1 and F9. Differences between T4 and T4′ and between OFL and NOR, indicated influences of multi-generational exposure and urged more exploration on different mechanisms between FQs. [Display omitted] • Ofloxacin and norfloxacin significantly influenced reproduction of C. elegans. • Effects of OFL and NOR oscillated between stimulation and inhibition from F1 to F9. • Reproductive effects closely related to cholesterol, progesterone and testosterone. • Reproductive toxicities lasted to the non-exposed great-grand-daughter generations. • OFL and NOR showed different multi- and trans-generational effects. [ABSTRACT FROM AUTHOR]

Abstract: Water samples were collected from 19 sampling sites along the Huangpu River in June and December 2009. The occurrence, distribution and seasonal variation of 22 antibiotics, including four tetracyclines, three chloramphenicols, two macrolides, six fluoroquinolones, six sulfonamides and trimethoprim were investigated. It was found that all 19 sampling sites were contaminated by antibiotics. Four antibiotics (sulfamerazine, norfloxacin, fleroxacin and sarafloxacin) were not detected. The detection frequencies of the other 18 antibiotics were in the range of 5.3–100%. The median concentrations of the detected antibiotics ranged from quantification limits to 36.71ngL−1 (tetracycline) in June and to 313.44ngL−1 (sulfamethazine) in December. The number of detected antibiotics and the overall antibiotic concentrations were higher in December than in June due to the different river flow conditions. Different dominant antibiotics were observed for each group of antibiotics between June and December. Higher total concentrations of veterinary antibiotics such as tetracyclines were observed in suburban sampling sites than in unban sites, indicating the role of livestock and agricultural activities as an important source of antibiotic contamination. [ABSTRACT FROM AUTHOR]