tetracycline and flumequine

The fate of four widely used veterinary antibiotics (doxycycline, flumequine, oxytetracycline and tetracycline) during manure upcycling was investigated at laboratory and pilot scale. The pilot was operated continuously, while the laboratory scale in batch mode. Both set-ups consisted of anaerobic digestion, ammonia stripping and a solid liquid separation step. A partial nitritation anammox process was used to treat the laboratory scale effluent. In the pilot installation, pig manure as feed, natural occurring antibiotics levels were reduced by 92% for doxycycline, 88% for flumequine, 95% for oxytetracycline and 100% for tetracycline. In the laboratory scale set-up, antibiotic free sludge was used and the four substances were spiked. The input antibiotics concentration was reduced by 85% for doxycycline, 46% for flumequine, 97% for oxytetracycline and 100% for tetracycline. In both set-ups the centrifuge cake was identified as the major emission pathway for residual antibiotics. Manure upcycling, while producing fertilizers, can be considered effective in reducing the residual antibiotic load.

Topics: Animals; Anti-Bacterial Agents; Doxycycline; Fertilizers; Fluoroquinolones; Manure; Oxytetracycline; Swine; Tetracycline

Selective pressure in the aquatic environment of intensive fish farms leads to acquired antibiotic resistance. This study used the broth microdilution method to measure minimum inhibitory concentrations (MICs) of 15 antibiotics against 104 Aeromonas spp. strains randomly selected among bacteria isolated from Sparus aurata reared in six Italian mariculture farms. The antimicrobial agents chosen were representative of those primarily used in aquaculture and human therapy and included oxolinic acid (OXA), ampicillin (AM), amoxicillin (AMX), cephalothin (CF), cloramphenicol (CL), erythromycin (E), florfenicol (FF), flumequine (FM), gentamicin (GM), kanamycin (K), oxytetracycline (OT), streptomycin (S), sulfadiazine (SZ), tetracycline (TE) and trimethoprim (TMP). The most prevalent species selected from positive samples was Aeromonas media (15 strains). The bacterial strains showed high resistance to SZ, AMX, AM, E, CF, S and TMP antibiotics. Conversely, TE and CL showed MIC

Topics: Aeromonas; Animals; Anti-Bacterial Agents; Drug Resistance, Multiple, Bacterial; Erythromycin; Fisheries; Fluoroquinolones; Humans; Italy; Microbial Sensitivity Tests; Sea Bream; Tetracycline

The transfer of R plasmids between bacteria has been well studied under laboratory conditions and the transfer frequency has been found to vary between plasmids and under various physical conditions. For the first time, we here study the expression of the selected plasmid mobility genes traD, virB11 and virD4 in the 45 kb IncU plasmid, pRAS1, conferring resistance to tetracycline, trimethoprim and sulphonamide, using an in vivo zebrafish infection- treatment model.. Three days after oral infection of adult zebrafish with Aeromonas hydrophila harboring pRAS1, elevated expression of pro-inflammatory cytokine (TNF α, IL-1β and IL-8) and complement C3 genes in the intestine coincided with disease symptoms. Tetracycline, trimethoprim and an ineffective concentration of flumequine given 48 h prior to sampling, strongly increased expression of plasmid mobility genes, whereas an effective dosage of flumequine resulted in lower levels of mRNA copies of these genes relative to placebo treatment. Following effective treatment with flumequine, and ineffective treatments with a low concentration of flumequine, with trimethoprim or with sulphonamide, the intestinal expression of immune genes was strongly induced compared to placebo treated control fish.. Treatment of zebrafish infected with an antibiotic resistant (TcR, TmR, SuR) A. hydrophila with ineffective concentrations of flumequine or the ineffective antimicrobials tetracycline and trimethoprim strongly induced expression of genes mediating conjugative transfer of the R-plasmid pRAS1. Simultaneously, there was a strong induction of selected inflammatory and immune response genes, which was again evident in fish subjected to ineffective treatment protocols. Our findings point to the essential role of therapeutic practices in escalation or control of antibiotic resistance transfer, and suggest that antibiotic substances, even in sub-inhibitory concentrations, may stimulate innate defenses against bacterial infections.

Topics: Aeromonas hydrophila; Animals; Anti-Bacterial Agents; Conjugation, Genetic; Drug Resistance, Multiple, Bacterial; Female; Fish Diseases; Fluoroquinolones; Gene Expression Regulation, Bacterial; Gene Transfer, Horizontal; Gram-Negative Bacterial Infections; Immunity, Innate; Intestines; Male; Metagenome; R Factors; RNA, Ribosomal, 16S; Tetracycline; Trimethoprim; Zebrafish

This study presents the development of an automated on-line solid phase extraction (SPE)-liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the determination of 23 antibiotics in environmental water samples. After optimisation of LC-MS/MS conditions, SPE parameters such as sorbent type, sample pH or sample volume were optimised. Antibiotic recoveries ranged from 64% to 98% and compared favourably with those achieved using off-line SPE. Limits of detection were in the range 0.5-13.7 ng L(-1). This on-line SPE-LC-MS/MS procedure was applied to the analysis of water samples taken in three rivers within the Seine River basin, near Paris (France). The obtained results revealed the occurrence of 12 antibiotics, including tylosin, erythromycin, tetracycline, amoxicillin, trimethoprim, sulfamethoxazole, oxolinic acid, flumequine, norfloxacin, ciprofloxacin, ofloxacin, and vancomycin (2-1435 ng L(-1)).

Topics: Amoxicillin; Anti-Bacterial Agents; Chromatography, Liquid; Ciprofloxacin; Erythromycin; Fluoroquinolones; Hydrogen-Ion Concentration; Norfloxacin; Ofloxacin; Oxolinic Acid; Reproducibility of Results; Rivers; Solid Phase Extraction; Sulfamethoxazole; Tandem Mass Spectrometry; Tetracycline; Trimethoprim; Tylosin; Vancomycin; Water Pollutants, Chemical