No abstract

Antibiotics are commonly added to animal feed as supplements to promote growth of food animals. However, absorption of antibiotics in the animal gut is not complete and as a result substantial amounts of antibiotics are excreted in urine and feces that end up in manure. Manure is used worldwide not only as a source of plant nutrients but also as a source of organic matter to improve soil quality especially in organic and sustainable agriculture. Greenhouse studies were conducted to determine whether or not plants grown in manure-applied soil absorb antibiotics present in manure. The test crops were corn (Zea mays L.), green onion (Allium cepa L.), and cabbage (Brassica oleracea L. Capitata group). All three crops absorbed chlortetracycline but not tylosin. The concentrations of chlortetracycline in plant tissues were small (2-17 ng g(-1) fresh weight), but these concentrations increased with increasing amount of antibiotics present in the manure. This study points out the potential human health risks associated with consumption of fresh vegetables grown in soil amended with antibiotic laden manures. The risks may be higher for people who are allergic to antibiotics and there is also the possibility of enhanced antimicrobial resistance as a result of human consumption of these vegetables.

HPV was virucidal for structurally distinct viruses dried on surfaces, suggesting that HPV can be considered for the disinfection of virus-contaminated surfaces.

This study quantified the uptake of five antibiotics (chlortetracycline, monensin, sulfamethazine, tylosin, and virginiamycin) by 11 vegetable crops in two different soils that were fertilized with raw versus composted turkey and hog manures or inorganic fertilizer. Almost all vegetables showed some uptake of antibiotics from manure treatments. However, statistical testing showed that except for a few isolated treatments the concentrations of all antibiotics in vegetable tissues were generally less than the limits of quantification. Further testing of the significant treatments showed that antibiotic concentrations in vegetables from many of these treatments were not significantly different than the corresponding concentrations from the fertilizer treatment (matrix effect). All five antibiotic concentrations in the studied vegetables were <10 μg kg(-1). On the basis of the standards for maximum residue levels in animal tissues and suggested maximum daily intake based on body weight, this concentration would not pose any health risk unless one is allergic to that particular antibiotic.

Abstract. Since 2007, outbreaks of severe bloody diarrhea and hemorrhagic colitis have been reported in the United States and Canada. Though the primary causative agent of swine dysentery is Brachyspira hyodysenteriae, which is strongly hemolytic, the current report describes the isolation of a novel strongly hemolytic Brachyspira sp. This novel Brachyspira sp. was identified from clinical submissions at the Minnesota Veterinary Diagnostic Laboratory, and 40 of such isolates were obtained from 22 clinical submissions representing 5 states. Isolates were confirmed to be different from any known Brachyspira sp. on the basis of phylogenetic analysis of nucleotide sequences of nox and 16S ribosomal RNA (rRNA) genes. Phylogenetic analyses grouped all isolates into 2 clades (clades I and II), and grouping patterns were similar for both nox and 16S rRNA gene sequence analyses. Phenotypically, all isolates were indole and hippurate negative, and enzymatic profiling indicated 2 types of profiles, irrespective of the phylogenetic grouping, differing only in the production of β-glucosidase. The results suggest that a potentially virulent new species of Brachyspira sp., provisionally named "Brachyspira hampsonii ", is circulating among swine herds in the United States.