apramycin and Swine-Diseases

An experiment was conducted to determine (i) the effects of antibiotic regimens on the shedding patterns of pigs infected with Salmonella Typhimurium and (ii) whether antibiotic resistance increases the incidence of pathogen shedding. The experiment involved 48 50-day-old pigs challenged with Salmonella Typhimurium and receiving one of four antibiotic regimens including (i) intramuscular injection of ceftiofur sodium followed by inclusion of oxytetracycline in the feed; (ii) apramycin in the feed for 14 days followed by oxytetracycline; (iii) carbadox in the feed until pigs reached 35 kg followed by oxytetracycline; (iv) no antibiotics (control). Fecal samples were collected preinoculation, 2 and 4 days postinoculation (DPI) and at weekly and biweekly intervals thereafter to determine shedding patterns. Salmonella Typhimurium isolates from 2, 4, 7, 21, 42, and 70 DPI were analyzed for antibiotic resistance. A time effect (P < 0.05) was observed, indicating that the proportion of isolates resistant to at least one antibiotic varied over time. Overall resistance was determined to be 46% at 2 DPI and increased significantly (P < .05) thereafter. Treatment x time and antibiotic x time interactions were also observed (P < 0.05) as the percentage of isolates resistant to each test antibiotic increased over time. In no case did the development of antibiotic resistance result in an increased incidence of shedding of the original inoculate. The incidence of shedding was reduced in pigs receiving the apramycin-oxytetracycline treatment, when compared to control pigs; however, no differences were observed between antibiotic treatments.

Topics: Animals; Anti-Bacterial Agents; Drug Therapy, Combination; Feces; Female; Male; Nebramycin; Oxytetracycline; Salmonella Infections, Animal; Salmonella typhimurium; Swine; Swine Diseases; Time Factors

Apramycin is used exclusively for the treatment of Escherichia coli (E.coli) infections in swine around the world since the early 1980s. Recently, many research papers have demonstrated that apramycin has significant in vitro activity against multidrug-resistant E.coli isolated in hospitals. Therefore, ensuring the proper use of apramycin in veterinary clinics is of great significance of public health. The objectives of this study were to develop a wild-type cutoff for apramycin against E.coli using a statistical method recommended by Clinical and Laboratory Standards Institute (CLSI) and to investigate the prevalence of resistance genes that confer resistance to apramycin in E. coli.. The wild-type cutoff for apramycin against E.coli was defined as 32 μg/mL. The prevelance of aac(3)-IV gene mainly concentrated in these MIC subsets 'MIC ≥ 64 μg/ mL', which indicates that the wild-type cutoff established in our study is reliable. The wild-type cutoff offers interpretion criteria of apramycin susceptibility testing of E.coli.

Topics: Animals; Anti-Bacterial Agents; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Microbial Sensitivity Tests; Nebramycin; Swine; Swine Diseases

The effect of apramycin treatment on transfer and selection of an Escherichia coli strain (E. coli 912) in the intestine of pigs was analyzed through an in vivo experiment. The strain was sequenced and assigned to the sequence type ST101 and serotype O11. It carried resistance genes to apramycin/gentamicin, sulphonamide, tetracycline, hygromycin B, β-lactams and streptomycin [aac(3)-IV, sul2, tet(X), aph(4), bla TEM-1 and strA/B], with all but tet(X) located on the same conjugative plasmid. Nineteen pigs were randomly allocated into two inoculation groups, one treated with apramycin (pen 2) and one non-treated (pen 3), along with a non-inoculated control group (pen 1). Two pigs of pen 2 and 3 were inoculated intragastrically with a rifampicin resistant variant of the strain. Apramycin treatment in pen 2 was initiated immediately after inoculation. Strain colonization was assessed in the feces from all pigs. E. coli 912 was shown to spread to non-inoculated pigs in both groups. The selective effect did not persist beyond 3 days post-treatment, and the strain was not detected from this time point in pen 2. We demonstrated that E. coli 912 was able to spread between pigs in the same pen irrespective of treatment, and apramycin treatment resulted in significantly higher counts compared to the non-treated group. This represents the first demonstration of how antimicrobial treatment affects spread of resistant bacteria in pig production. The use of apramycin may lead to enhanced spread of gentamicin-resistant E. coli. Since gentamicin is a first-choice drug for human bacteremia, this is of concern.

Topics: Animals; Anti-Bacterial Agents; Bacterial Shedding; Drug Resistance, Multiple, Bacterial; Escherichia coli; Escherichia coli Infections; Feces; Female; Humans; Intestines; Male; Nebramycin; Selection, Genetic; Swine; Swine Diseases; Time Factors; Zoonoses

To determine the relationships between RepA/C2 plasmids carrying several antibiotic resistance genes found in isolates of Salmonella enterica serovars Ohio and Senftenberg from pigs.. Illumina HiSeq was used to sequence seven S. enterica isolates. BLAST searches identified relevant A/C2 plasmid contigs and contigs were assembled using PCR.. Two serovar Ohio isolates were ST329 and the five Senftenberg isolates were ST210. The A/C2 plasmids recovered from the seven isolates belong to type 2 and contain two resistance islands. Their backbones are closely related, differing by five or fewer SNPs. The sul2-containing resistance island ARI-B is 19.9 kb and also contains the kanamycin and neomycin resistance gene aphA1, the tetracycline resistance gene tetA(D) and an erythromycin resistance gene, erm(42), not previously seen in A/C2 plasmids. A second 30.3 kb resistance island, RI-119, is in a unique location in the A/C2 backbone 8.2 kb downstream of rhs. RI-119 contained genes conferring resistance to apramycin, netilmicin and tobramycin (aacC4), hygromycin (hph), sulphonamides (sul1) and spectinomycin and streptomycin (aadA2). In one of the seven plasmids, this resistance region contained two IS26-mediated deletions. A discrete 5.7 kb segment containing the aacC4 and hph genes and bounded by IS26 on one side and the inverted repeat of Tn5393 on the other was identified.. The presence of almost identical A/C2 plasmids in two serovars indicates a common origin. Type 2 A/C2 plasmids continue to evolve via addition of new resistance regions such as RI-119 and evolution of existing ones.

Topics: Animals; Anti-Bacterial Agents; DNA Helicases; Drug Resistance, Bacterial; Erythromycin; Evolution, Molecular; Genes, Bacterial; Genome, Bacterial; Molecular Sequence Data; Nebramycin; Plasmids; Salmonella enterica; Salmonella Infections, Animal; Sequence Analysis, DNA; Swine; Swine Diseases

The aminoglycoside apramycin has been used widely in animal production in China since 1999. This study was aimed to investigate the resistance pattern of apramycin-resistant Escherichia coli isolated from farm animals and farm workers in northeastern of China during 2004-2007 and to determine whether resistance to apramycin was mediated by plasmid containing the aac(3)-IV gene and the mode for the transfer of genetic information between bacteria of farm animals and farm workers. Thirty six E. coli isolates of swine, chicken, and human origins, chosen randomly from 318 apramycin-resistant E. coli isolates of six farms in northeastern of China during 2004-2007, were multi-resistant and carried the aac(3)-IV gene encoding resistance to apramycin. Conjugation experiments demonstrated that in all 36 cases, the gene encoding resistance to apramycin was borne on a mobilisable plasmid. Homology analysis of the cloned aac(3)-IV gene with the sequence (accession no. X01385) in GenBank showed 99.3% identity at a nucleotide level, but only with a deletion of guanosine in position 813 of the gene in all 36 cases. The results indicted that resistance to apramycin in these isolates was closely related to aac(3)-IV gene. Therefore, the multi-resistance of E.coli could complicate therapeutic practices for enteric infections in both farm animals and human.

Topics: Animals; Anti-Bacterial Agents; Chickens; China; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Humans; Nebramycin; Occupational Exposure; Poultry Diseases; Swine; Swine Diseases

To determine effects of exposure of parental animals to antibiotics on antibiotic resistance in bacteria of offspring, sows were either treated or not treated with oxytetracycline prior to farrowing and their pigs were challenged with Salmonella enterica Typhimurium and treated or not treated with oxytetracycline and apramycin. Fecal Escherichia coli were obtained from sows, and E. coli and salmonella were recovered from pigs. Antibiotic resistance patterns of isolates were determined using a minimum inhibitory concentration (MIC) analysis. Polymerase chain reaction (PCR) and electroporation were used to characterize the genetic basis for the resistance and to determine the location of resistance genes. Treatments had little effect on resistance of the salmonella challenge organism. The greatest resistance to apramycin occurred in E. coli from pigs treated with apramycin and whose sows had earlier exposure to oxytetracycline. Resistance to oxytetracycline was consistently high throughout the study in isolates from all pigs and sows; however, greater resistance was noted in pigs nursing sows that had previous exposure to that drug. The aac(3)-IV gene, responsible for apramycin resistance, was found in approximately 90% of apramycin-resistant isolates and its location was determined to be on plasmids. Several resistant E. coli bio-types were found to contain the resistance gene. These results indicate that resistance to apramycin and oxytetracycline in E. coli of pigs is affected by previous use of oxytetracycline in sows.

Topics: Animals; Animals, Newborn; Animals, Suckling; Anti-Bacterial Agents; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Feces; Female; Microbial Sensitivity Tests; Nebramycin; Oxytetracycline; Pregnancy; Random Allocation; Salmonella Infections, Animal; Salmonella typhimurium; Swine; Swine Diseases

Weaned pigs were separated into eight treatments including a control without exposure to apramycin; a control with exposure to apramycin; and apramycin plus either cold stress, heat stress, overcrowding, intermingling, poor sanitation, or intervention with oxytetracycline, to determine the effects of management and environmental conditions on antibiotic resistance among indigenous Escherichia coli. Pigs exposed to apramycin sulfate received that antibiotic in the feed at a concentration of 150 g/ton for 14 days. Environmental treatments were applied 5 days following initial antibiotic administration and maintained throughout the study. Fecal samples were obtained on day 0 (prior to antibiotic treatment) and on days 2, 7, 14, 28, 64, 148, and 149. E. coli were isolated and tested for resistance to apramycin using a minimum inhibitory concentration (MIC) broth microdilution method. Macrorestriction profiling, arbitrarily primed PCR, PCR targeting a gene coding for apramycin resistance, and DNA hybridization were used to characterize genetic elements of resistance. Increased (P<0.0001) resistance to apramycin was noted in E. coli from all treatment groups administered apramycin. MICs of isolates from control pigs receiving apramycin returned to pretreatment levels following removal of the antibiotic, whereas isolates from cold stress, overcrowding, and oxytetracycline groups expressed greater (P<0.05) MICs through day 64, before returning to pretreatment levels. Genetic analysis indicated that all resistant isolates carried the aac(3)IV gene sequence and this sequence was found in a variety of E. coli isotypes. Our data indicate that E. coli resistance to apramycin is increased upon exposure to various stressors.

Topics: Animal Husbandry; Animals; Anti-Bacterial Agents; Colony Count, Microbial; DNA, Bacterial; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Feces; Microbial Sensitivity Tests; Nebramycin; Polymerase Chain Reaction; Random Allocation; Swine; Swine Diseases

The antibiotics apramycin and carbadox were fed to growing swine, and the prevalence of Salmonella isolates that are resistant to apramycin and related aminoglycoside antibiotics was examined. Three hundred twelve Salmonella-positive pigs raised on one of five farms in an integrated swine operation and slaughtered at a central plant were used. All farms fed carbadox during the grower phase, and two farms administered apramycin during the first 21 days of age. Ileocolic lymph nodes and cecal contents were sampled at slaughter. One hundred of the 312 pigs were randomly selected to examine apramycin- and carbadox-resistant Salmonella infection, while all 312 pigs were used to evaluate the association between apramycin exposure and infection with Salmonella organisms resistant to amikacin, gentamicin, kanamycin, and streptomycin. Antimicrobial resistance was determined using disk diffusion and breakpoint concentrations. Apramycin treatment appeared to have little effect on apramycin- (12.5 versus 20.9%) or streptomycin- (76.4 versus 73.5%) resistant Salmonella isolates when averaged across farms and compared to control animals. Feeding carbadox resulted in carbadox-resistant Salmonella infection in only 5.3% of the isolates on one farm. The prevalence of amikacin-, gentamicin-, and kanamycin-resistant Salmonella isolates on farms feeding apramycin and carbadox were 0, 0, and 1.8%, respectively. Serogroup B was the most prevalent serogroup isolated, followed by C1 and E1. Apramycin and carbadox treatment did not appear to have any effect on the serogroup isolated. Subtherapeutic use of carbadox and apramycin did not appear to increase the prevalence of antimicrobial-resistant Salmonella in market-age swine.

Topics: Animals; Anti-Bacterial Agents; Carbadox; Drug Resistance, Multiple, Bacterial; Microbial Sensitivity Tests; Nebramycin; Prevalence; Salmonella; Salmonella Infections, Animal; Swine; Swine Diseases

Topics: Amoxicillin; Animals; Animals, Newborn; Anti-Bacterial Agents; Cephalosporins; Colistin; Diarrhea; Drug Resistance, Microbial; Enrofloxacin; Escherichia coli; Escherichia coli Infections; Fluoroquinolones; Microbial Sensitivity Tests; Nebramycin; Neomycin; Quinolones; Spain; Swine; Swine Diseases

Topics: Animals; Anti-Bacterial Agents; Bacterial Infections; Cattle; Cattle Diseases; Drug Resistance, Microbial; Humans; Nebramycin; Swine; Swine Diseases

Escherichia coli serotype O147:K89:K88a,c was found to be associated with outbreaks of diarrhoea in preweaner pigs of up to 4 weeks of age on a pig unit. Resistance to apramycin, gentamicin, netilmicin, tobramycin and other antibiotics was associated with conjugative plasmids of approximately 62 kb. The presence of a gene which encoded for the aminoglycoside acetyltransferase enzyme AAC(3)IV was confirmed by DNA hybridization. Samples collected during the following 12 months revealed widespread dissemination of these resistance plasmids in non-serotypable, non-haemolytic E. coli throughout the farm. Apramycin-resistant E. coli were also isolated from a stockman and it appeared from plasmid profile analysis and antibiotic sensitivity testing that the human isolates carried the same plasmid as that carried by the porcine E. coli. Klebsiella pneumoniae, with a slightly smaller conjugative plasmid and similar resistance pattern, was isolated from the stockman's wife.

Topics: Agricultural Workers' Diseases; Animals; Cats; Diarrhea; Disease Outbreaks; DNA Probes; Drug Resistance, Microbial; Escherichia coli; Escherichia coli Infections; Feces; Female; Humans; Klebsiella pneumoniae; Male; Microbial Sensitivity Tests; Nebramycin; Nucleic Acid Hybridization; R Factors; Serotyping; Swine; Swine Diseases

Avilamycin, an oligosaccharide antibiotic with growth-promoting properties in pigs, has proved to be effective in controlling stress-induced post-weaning diarrhoea in piglets, caused mainly by Escherichia coli. The present study includes two trials, in which 400 newly-weaned piglets were used (200/trial). The following five different treatments were tested; 0, 40 and 80 p.p.m. avilamycin, 50 p.p.m. olaquindox and 100 p.p.m. apramycin. In each trial there were four pens (each with five females and five males) per treatment. Avilamycin when given at 80 p.p.m. reduced average daily diarrhoea score (ADDS) and mortality, and improved liveweight gain and feed conversion ratio (FCR), compared with the untreated controls, the 40 p.p.m. avilamycin and the 50 p.p.m. olaquindox (P less than 0.05) treatments. The overall performance of 40 p.p.m. avilamycin and 50 p.p.m. olaquindox was similar. The results indicate that avilamycin at the dose level of 80 p.p.m. in the starter feed can control post-weaning diarrhoea of piglets and prevent loss of productivity. Nevertheless, the antibiotic apramycin, whose spectrum of activity is mainly against the Gram-negative bacteria, given at the therapeutic level of 100 p.p.m., was more effective than any other experimental treatment (P less than 0.05), except for ADDS and FCR which were not significantly different from that of avilamycin 80 p.p.m.

Topics: Animal Feed; Animals; Diarrhea; Eating; Female; Growth Substances; Male; Nebramycin; Quinoxalines; Random Allocation; Stress, Physiological; Swine; Swine Diseases; Weaning; Weight Gain

Apramycin-modifying strains isolated from pigs with coli bacteriosis, from humans and hospital environment were studied comparatively. Production of enzymes modifying the aminoglycoside was estimated with the radioactive cofactor procedure. E. coli isolates from the animals were phenotypically resistant to apramycin and a number of other aminoglycosides. They produced acetyltransferase AAC(3)IV, phosphotransferase APH(3')(5"), APH(3") and other enzymes. Resistance of the strains to gentamicin was also conditioned by AAC(3)IV since these strains did not produce AAD(2") and AAC(6'). In the resistant strains of E. coli and their transconjugates there were detected plasmids with a relative molecular weight of 60-80 MD. Some of the belonged to the compatibility group I1, the others belonged to the compatibility group H1. Strains of S. marcescens, K. pneumoniae. K. oxytoca and S. aureus isolated from humans and hospital environment were sensitive to apramycin. Only isolates of P. aeruginosa were resistant to this antibiotic. However, all the isolates produced AAC(3)IV. Some of them additionally produced AAC(6'), an enzyme modifying amikacin, kanamycin and other antibiotics and not acetylating apramycin. Almost all the strains produced kanamycin- and streptomycin phosphotransferases. Possible coselection of strains resistant to apramycin and gentamicin using one of these aminoglycosides is discussed.

Topics: Animals; Anti-Bacterial Agents; Bacteria; Cross Infection; Drug Resistance, Microbial; Environmental Microbiology; Escherichia coli Infections; Humans; Microbial Sensitivity Tests; Nebramycin; Swine; Swine Diseases

Use was made of four groups of six pigs each, weighing 40 to 50 kg to follow up the toxicity of Pharmachim's apramycin in the form of water-soluble powder of apramycin sulfate, given at the rate of (nil), 300, 500, and 1,000 mg per liter of drinking water in the course of 35 days. It was found that such treatment did not lead to changes in the general status of the animals. On the contrary, apramycin sulfate stimulated growth and improved feed conversion. In concentrations of up to 300 mg/l the preparation did not produce an essential effect on the clinico-laboratory indices, and did not lead to toxic alterations of the viscera. In concentrations of 500 and 1,000 mg/l and extending the period to more than 15 days an occasional drop of the percent of lobular neutrophilic leukocytes and rise of the percent of lymphocytes in the blood might occur. This could lead to dystrophic processes in the liver and to negligible changes of the same character in both the kidneys and the heart.

Topics: Animals; Anti-Bacterial Agents; Blood Cell Count; Body Weight; Chronic Disease; Dose-Response Relationship, Drug; Female; Hemoglobins; Male; Nebramycin; Swine; Swine Diseases; Time Factors

To compare the effectiveness of furazolidone and apramycin (Apralan) in the treatment of oedema disease in pigs, a trial was made on a commercial farm on which colibacillosis was a recurrent problem. Medicated feed containing 100 ppm of apramycin and 400 ppm of furazolidone respectively was given for three weeks after weaning. 112 Piglets were distributed over 10 battery houses at random. Results are summarized in Figure 1.

Topics: Animals; Anti-Bacterial Agents; Edema Disease of Swine; Escherichia coli Infections; Furazolidone; Nebramycin; Swine; Swine Diseases