The Resistome of Farmed Fish Feces Contributes to the Enrichment of Antibiotic Resistance Genes in Sediments below Baltic Sea Fish Farms

Our previous studies showed that particular antibiotic resistance genes (ARGs) were enriched locally in sediments below fish farms in the Northern Baltic Sea, Finland, even when the selection pressure from antibiotics was negligible. We assumed that a constant influx of farmed fish feces could be the plausible source of the ARGs enriched in the farm sediments. In the present study, we analyzed the composition of the antibiotic resistome from the intestinal contents of 20 fish from the Baltic Sea farms. We used a high-throughput method, WaferGen qPCR array with 364 primer sets to detect and quantify ARGs, mobile genetic elements (MGE), and the 16S rRNA gene. Despite a considerably wide selection of qPCR primer sets, only 28 genes were detected in the intestinal contents. The detected genes were ARGs encoding resistance to sulfonamide (sul1), trimethoprim (dfrA1), tetracycline [tet(32), tetM, tetO, tetW], aminoglycoside (aadA1, aadA2), chloramphenicol (catA1), and efflux-pumps resistance genes (emrB, matA, mefA, msrA). The detected genes also included class 1 integron-associated genes (intI1, qacE?1) and transposases (tnpA). Importantly, most of the detected genes were the same genes enriched in the farm sediments. This preliminary study suggests that feces from farmed fish contribute to the ARG enrichment in farm sediments despite the lack of contemporaneous antibiotic treatments at the farms. We observed that the intestinal contents of individual farmed fish had their own resistome compositions. Our result also showed that the total relative abundances of transposases and tet genes were significantly correlated (p = 0.001, R-2 = 0.71). In addition, we analyzed the mucosal skin and gill filament resistomes of the farmed fish but only one multidrug-efflux resistance gene (emrB) was detected. To our knowledge, this is the first study reporting the resistome of farmed fish using a culture-independent method. Determining the possible sources of ARGs, especially mobilized ARGs, is essential for controlling the occurrence and spread of ARGs at fish farming facilities and for lowering the risk of ARG spread from the farms to surrounding environments.Peer reviewe

Surgical Treatment as a Principle for Patients with High-Grade Pancreatic Neuroendocrine Carcinoma : A Nordic Multicenter Comparative Study

This study aimed to evaluate the role of surgery for patients with high-grade pancreatic neuroendocrine carcinoma (hgPNEC) in a large Nordic multicenter cohort study. Prior studies evaluating the role of surgery for patients with hgPNEC are limited, and the benefit of the surgery is uncertain. Data from patients with a diagnosis of hgPNEC determined between 1998 and 2012 were retrospectively registered at 10 Nordic university hospitals. Kaplan-Meier curves were used to compare the overall survival of different treatment groups, and Cox-regression analysis was used to evaluate factors potentially influencing survival. The study registered 119 patients. The median survival period from the time of metastasis was 23 months for patients undergoing initial resection of localized nonmetastatic disease and chemotherapy at the time of recurrence (n = 14), 29 months for patients undergoing resection of the primary tumor and resection/radiofrequency ablation of synchronous metastatic liver disease (n = 12), and 13 months for patients with synchronous metastatic disease given systemic chemotherapy alone (n = 78). The 3-year survival rate after surgery of the primary tumor and metastatic disease was 69 %. Resection of the primary tumor was an independent factor for improved survival after occurrence of metastatic disease. Patients with resected localized nonmetastatic hgPNEC and later metastatic disease seemed to benefit from initial resection of the primary tumor. Patients selected for resection of the primary tumor and synchronous liver metastases had a high 3-year survival rate. Selected patients with both localized hgPNEC and metastatic hgPNEC should be considered for radical surgical treatment.Peer reviewe

abaware advanced biotechnology for intensive freshwater aquaculture wastewater reuse

Aquaculture is currently estimated to be the fastest-growing area of food production in the world. Although aquaculture can provide an important food source, these types of farms must be developed in a responsible and sustainable way. The rapid growth of intensive aquaculture systems has already caused important damage affecting both the environment and human health. The surrounding waters are affected by the chaotic algae growth generated by the high quantity of discharged pollutants (organic matters, P and N compounds etc.). This water pollution in some cases can prove deadly for certain aquatic species and indirectly constitute a danger to human population, who end up eating contaminated fishes and uses an inadequate quality water. [More](http://http://www.waterjpi.eu/joint-calls/joint-call-2016-1/abaware

Characterization and expression of the gyrA gene from quinolone resistant Yersinia ruckeri strains isolated from Atlantic salmon (Salmo salar L.) in Norway

Yersinia ruckeri, the causative agent of yersiniosis has been reported in a number of fish species but the most vulnerable are the salmonids including Atlantic salmon (Salmo salar L.). In the present study Y. ruckeri isolates were collected from diseased Atlantic salmon juveniles and characterized for resistance against quinolones. Isolates were screened using disk diffusion assays and MIC determination. The QRDR regions of the gyrA, gyrB, parC and parE genes were sequenced. Quinolone resistant isolates revealed a single bp mutation which replaced serine by arginine at position 83 in the GyrA protein while no mutations were found in gyrB, parC and parE genes. Isolates were also screened for plasmid encoded qnrA, qnrB and qnrS genes but they were found absent. Cloning of gyrA from susceptible and resistant isolates into heterologous Y. ruckeri was not successful. The different gyrA alleles from susceptible and resistant isolates of Y. ruckeri were cloned into Escherichia coli TOPO 10 and E. coli DH5 alpha. While cloning of the resistant allele into the sensitive host had no effect, cloning of the quinolone susceptible gyrA allele into quinolone resistant E. coli DH5 alpha increased the inhibition zone diameter from 25 mm to 38 mm and decreased the MIC from 4 mu g/ml to 2 mu g/ml, suggesting dominance of wild type gyrA over the mutant allele. It is assumed that the wild type GyrA protein has more affinity to form the gyrase-DNA complex than mutant GyrA even in the presence of high levels of the mutated enzyme. (C) 2012 Elsevier B.V. All rights reserved

Antimicrobial Resistance and Antimicrobial Resistance Genes in Marine Bacteria From Salmon Aquaculture and Non-aquaculture Sites

Antimicrobial resistance (AR) detected by disc diffusion and antimicrobial resistance genes detected by DNA hybridization and polymerase chain reaction with amplicon sequencing were studied in 124 marine bacterial isolates from a Chilean salmon aquaculture site and 76 from a site without aquaculture 8 km distant. Resistance to one or more antimicrobials was present in 81% of the isolates regardless of site. Resistance to tetracycline was most commonly encoded by tetA and tetG; to trimethoprim, by dfrA1, dfrA5 and dfrA12; to sulfamethizole, by sul1 and sul2; to amoxicillin, by blaTEM ; and to streptomycin, by strA-strB. Integron integrase intl1 was detected in 14 sul1-positive isolates, associated with aad9 gene cassettes in two from the aquaculture site. intl2 Integrase was only detected in three dfrA1-positive isolates from the aquaculture site and was not associated with gene cassettes in any. Of nine isolates tested for conjugation, two from the aquaculture site transferred AR determinants to Escherichia coli. High levels of AR in marine sediments from aquaculture and non-aquaculture sites suggest that dispersion of the large amounts of antimicrobials used in Chilean salmon aquaculture has created selective pressure in areas of the marine environment far removed from the initial site of use of these agents

Antibiotic resistance in European wastewater treatment plants mirrors the pattern of clinical antibiotic resistance prevalence

Integrated antibiotic resistance (AR) surveillance is one of the objectives of the World Health Organization global action plan on antimicrobial resistance. Urban wastewater treatment plants (UWTPs) are among the most important receptors and sources of environmental AR. On the basis of the consistent observation of an increasing north-to-south clinical AR prevalence in Europe, this study compared the influent and final effluent of 12 UWTPs located in seven countries (Portugal, Spain, Ireland, Cyprus, Germany, Finland, and Norway). Using highly parallel quantitative polymerase chain reaction, we analyzed 229 resistance genes and 25 mobile genetic elements. This first trans-Europe surveillance showed that UWTP AR profiles mirror the AR gradient observed in clinics. Antibiotic use, environmental temperature, and UWTP size were important factors related with resistance persistence and spread in the environment. These results highlight the need to implement regular surveillance and control measures, which may need to be appropriate for the geographic regions.Peer reviewe