oxytetracycline--anhydrous and Swine-Diseases

Topics: Animals; Anti-Bacterial Agents; Cattle; Cattle Diseases; Chloramphenicol; Female; Humans; Kinetics; Mathematics; Oxytetracycline; Penicillin G; Pregnancy; Premedication; Surgical Wound Infection; Swine; Swine Diseases; Tissue Distribution

The majority of antimicrobials given during the production of pigs are given to nursery pigs. The influence of antimicrobial use on the levels of antimicrobial resistant (AMR) genes is important to quantify to be able to assess the impact of resistance on the food chain and risk to human and animal health.. This study investigated the response on the levels of nine AMR genes to five different treatment strategies with oxytetracycline, and the dynamics of gene abundance over time by following 1167 pigs from five different farms in Denmark. The results showed no significant difference between treatments and an increase in abundance for the efflux pump encoding tet(A) gene and the genes encoding the ribosomal protection proteins tet(O) and tet(W) tetracycline resistant genes following treatment, while tet(M) showed no response to treatment. However, it was also observed that the levels of tet(O), tet(W), and ermB in some farms would drift more over time compared to a single treatment-course with antibiotic.. This study underlines the large variation in AMR levels under natural conditions and the need for increased investigation of the complex interactions of antimicrobial treatment and other environmental and managerial practices in swine production on AMR gene abundance.

Topics: Animal Husbandry; Animals; Anti-Bacterial Agents; Bacteria; Denmark; Desulfovibrionaceae Infections; Diarrhea; Farms; Feces; Genes, MDR; Lawsonia Bacteria; Oxytetracycline; Swine; Swine Diseases; Tetracycline Resistance

A major concern derived from using antimicrobials in pig production is the development of resistance. This study aimed to assess the impact of selected combinations of oral dose and duration of treatment with oxytetracycline (OTC) on selection of tetracycline resistant (TET-R) coliforms recovered from swine feces. The work encompassed two studies: 1) OTC 5mg/kg and 20mg/kg were administered to nursery pigs for 3 and 10days, respectively, under controlled experimental conditions, and 2) 10mg/kg, 20mg/kg and 30mg/kg OTC were given to a higher number of pigs for 6, 3 and 2days, respectively, under field conditions. Statistical modeling was applied to analyze trends in the proportion of TET-R coliforms. In the experimental study, no statistical difference in proportion of TET-R coliforms was observed between treatments at the end of the trial (day 18) and compared to day 0. In the field study, treatment had a significant effect on the proportion of TET-R bacteria two days after the end of treatment (2dAT) with the regimes "low dose-six days" and "medium dose-three days" yielding the highest and lowest proportions of TET-R strains, respectively. No indication of co-selection for ampicillin- and sulphonamide -R bacteria was observed for any treatment at 2dAT. By the end of the nursery period, the proportion of TET-R bacteria was not significantly different between treatments and compared to day 0. Our results suggest that similar resistance levels might be obtained by using different treatment regimes regardless of the combinations of oral dose-duration of treatment.

Topics: Administration, Oral; Animals; Anti-Bacterial Agents; Drug Administration Schedule; Drug Resistance, Bacterial; Enterobacteriaceae; Feces; Female; Male; Oxytetracycline; Swine; Swine Diseases

Oral treatment with antimicrobials is widely used in pig production for the control of gastrointestinal infections. Lawsonia intracellularis (LI) causes enteritis in pigs older than six weeks of age and is commonly treated with antimicrobials. The objective of this study was to evaluate the efficacy of three oral dosage regimens (5, 10 and 20mg/kg body weight) of oxytetracycline (OTC) in drinking water over a five-day period on diarrhoea, faecal shedding of LI and average daily weight gain (ADG). A randomised clinical trial was carried out in four Danish pig herds. In total, 539 animals from 37 batches of nursery pigs were included in the study. The dosage regimens were randomly allocated to each batch and initiated at presence of assumed LI-related diarrhoea. In general, all OTC doses used for the treatment of LI infection resulted in reduced diarrhoea and LI shedding after treatment. Treatment with a low dose of 5mg/kg OTC per kg body weight, however, tended to cause more watery faeces and resulted in higher odds of pigs shedding LI above detection level when compared to medium and high doses (with odds ratios of 5.5 and 8.4, respectively). No association was found between the dose of OTC and the ADG. In conclusion, a dose of 5mg OTC per kg body weight was adequate for reducing the high-level LI shedding associated with enteropathy, but a dose of 10mg OTC per kg body weight was necessary to obtain a maximum reduction in LI shedding.

Topics: Administration, Oral; Animals; Anti-Bacterial Agents; Bacterial Shedding; Desulfovibrionaceae Infections; Diarrhea; Dose-Response Relationship, Drug; Feces; Female; Lawsonia Bacteria; Male; Oxytetracycline; Swine; Swine Diseases; Weight Gain

Antimicrobial consumption in animal husbandry is of great scientific and political concern due to the risk of selection of resistant bacteria. Whilst a reduction in the use of antimicrobials is therefore preferable, the efficacy of treatment must be maintained in order to ensure animal welfare and profitability of pig production. The objective of this study was to evaluate the efficacy of three treatment strategies under field conditions against Lawsonia intracellularis (LI)-related diarrhoea. A randomised clinical trial was carried out in four Danish pig herds, including a total of 520 pigs from 36 nursery batches. A high prevalence of LI was demonstrated in all herds prior to the initiation of the study. Treatment efficacy was assessed by faecal shedding of LI, the occurrence of diarrhoea and average daily weight gain (ADG) after treatment. All strategies were implemented at batch level at presence of LI-related diarrhoea and included daily treatment with 10mg oxytetracycline (OTC) per kilogram of bodyweight for 5 days, though the OTC was administered differently: either by oral treatment of all pigs in a batch, by oral treatment of pigs in diarrhoeic pens only, or by intramuscular treatment of individual diarrhoeic pigs only. The treatment strategies were randomly allocated to batches and were initiated at the presence of diarrhoea. From the included batches, 100% of the trial pigs were medicated in the batch treatment strategy, 87% in the pen treatment strategy and 55% in the individual treatment strategy. All strategies reduced the occurrence of diarrhoea and faecal shedding of LI after treatment. However, batch treatment was found to be most efficient in reducing both high-level LI shedding and diarrhoea when compared to the treatment of diarrhoeic pens or individual diarrhoeic pigs. There was no significant difference identified in ADG between the treatment strategies. In conclusion, batch treatment of all pigs in a section resulted in the highest efficacy for reducing diarrhoea and faecal shedding of LI.

Topics: Administration, Oral; Animals; Anti-Infective Agents; Bacterial Shedding; Desulfovibrionaceae Infections; Diarrhea; Feces; Female; Injections, Intramuscular; Lawsonia Bacteria; Male; Oxytetracycline; Swine; Swine Diseases; Treatment Outcome; Weight Gain

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

A double blind randomized clinical trial was performed with pigs suffering from clinical respiratory disease. The goal of the trial was to test the null hypothesis that the clinical recovery after treatment with two oxytetracycline injectables with different pharmacokinetic profiles (high peak concentration and low persistence versus low peak concentrations and long persistence) was similar. Fattening pigs (n = 529) were treated intramuscularly with either product A or product B at a dose of 20 mg OTC per kg b.w. when they showed signs of acute pneumonia, i.e., coughing, tachypnoea or dyspnoea combined with a rectal temperature of 40 degrees C or higher. When necessary, treatment was given again after 3 and/or 6 days. Both treatments resulted in a rapid fall in mean temperature and an improved clinical condition. In this trial no significant differences were found in clinical recovery between the two therapies as measured by group mean temperature, number of pigs requiring retreatment, and time to recovery. The conclusion that there was no important difference in clinical recovery between the treatment groups was made with a power of at least 90%.

Topics: Animals; Body Temperature; Oxytetracycline; Respiratory Tract Infections; Swine; Swine Diseases

The diarrhoea incidence rate is often high among weaning piglets. In light of the fact that Cortex phellodendri has long been used to treat diarrhoea in China, this study aimed to evaluate the effects of Cortex Phellodendri Extract (CPE) on diarrhoea in weaning piglets and the mechanism behind such effects. In the first trial, 36 diarrhoeal weaning piglets were randomly divided into three groups. The control group was injected with 20 mg oxytetracycline/kg BW, while the two treatment groups were orally administered with 10 mg and 20 mg CPE/kg BW respectively. In the second trial, 96 weaning piglets were randomly divided into two groups. The control group was fed basal diet, while 300 mg CPE/kg BW was added to the diet of the treatment group. The pathogenic bacteria were then isolated and identified from the diarrhoeal faecal samples. Cell adhesion and RT-PCR tests were used to investigate the effect of CPE on the adhesion of pathogenic bacteria to IPEC-J2 cells. 16S rDNA-based high-throughput sequencing was used to analyse faecal microflora. The results showed that CPE reduced the diarrhoea incidence rate (p < 0.05) and diarrhoea index (p < 0.05) compared to control group, and increased the richness and evenness of weaning piglets' gut microbiota. Escherichia coli (E. coil) was identified as the causative organism. Cell adhesion and RT-PCR tests suggested that CPE reduced the adhesion of E. coli to IPEC-J2 cells (p < 0.05) and the expression of fae and faeG gene (p < 0.05) responsible for encoding E. coli fimbriae protein.

Topics: Administration, Oral; Animal Feed; Animals; Diarrhea; Diet; Dietary Supplements; Dose-Response Relationship, Drug; Drugs, Chinese Herbal; Escherichia coli Infections; Female; Injections; Male; Oxytetracycline; Plant Extracts; Random Allocation; Sus scrofa; Swine; Swine Diseases; Weaning

The most widely used measure of potency of antimicrobial drugs is Minimum Inhibitory Concentration (MIC). MIC is usually determined under standardised conditions in broths formulated to optimise bacterial growth on a species-by-species basis. This ensures comparability of data between laboratories. However, differences in values of MIC may arise between broths of differing chemical composition and for some drug classes major differences occur between broths and biological fluids such as serum and inflammatory exudate. Such differences must be taken into account, when breakpoint PK/PD indices are derived and used to predict dosages for clinical use. There is therefore interest in comparing MIC values in several broths and, in particular, in comparing broth values with those generated in serum. For the pig pneumonia pathogens, Actinobacillus pleuropneumoniae and Pasteurella multocida, MICs were determined for three drugs, florfenicol, oxytetracycline and marbofloxacin, in five broths [Mueller Hinton Broth (MHB), cation-adjusted Mueller Hinton Broth (CAMHB), Columbia Broth supplemented with NAD (CB), Brain Heart Infusion Broth (BHI) and Tryptic Soy Broth (TSB)] and in pig serum.. For each drug, similar MIC values were obtained in all broths, with one exception, marbofloxacin having similar MICs for three broths and 4-5-fold higher MICs for two broths. In contrast, for both organisms, quantitative differences between broth and pig serum MICs were obtained after correction of MICs for drug binding to serum protein (fu serum MIC). Potency was greater (fu serum MIC lower) in serum than in broths for marbofloxacin and florfenicol for both organisms. For oxytetracycline fu serum:broth MIC ratios were 6.30:1 (P. multocida) and 0.35:1 (A. pleuropneumoniae), so that potency of this drug was reduced for the former species and increased for the latter species. The chemical composition of pig serum and broths was compared; major matrix differences in 14 constituents did not account for MIC differences. Bacterial growth rates were compared in broths and pig serum in the absence of drugs; it was concluded that broth/serum MIC differences might be due to differing growth rates in some but not all instances.. For all organisms and all drugs investigated in this study, it is suggested that broth MICs should be adjusted by an appropriate scaling factor when used to determine pharmacokinetic/pharmacodynamic breakpoints for dosage prediction.

Topics: Actinobacillus Infections; Actinobacillus pleuropneumoniae; Animals; Anti-Bacterial Agents; Fluoroquinolones; Microbial Sensitivity Tests; Oxytetracycline; Pasteurella Infections; Pasteurella multocida; Pneumonia, Bacterial; Swine; Swine Diseases; Thiamphenicol

The pharmacodynamics of oxytetracycline was determined for pig respiratory tract pathogens, Actinobacillus pleuropneumoniae and Pasteurella multocida. Indices of potency were determined for the following: (i) two matrices, broth and pig serum; (ii) five overlapping sets of twofold dilutions; and (iii) a high strength starting culture. For A. pleuropneumoniae, minimum inhibitory concentration (MIC) was similar for the two matrices, but for P. multocida, differences were marked and significantly different. MIC and minimum bactericidal concentration (MBC) serum: broth ratios for A. pleuropneumoniae were 0.83:1 and 1.22:1, respectively, and corresponding values for P. multocida were 22.0:1 and 7.34:1. For mutant prevention concentration (MPC) serum: broth ratios were 0.79:1 (A. pleuropneumoniae) and 20.9:1 (P. multocida). These ratios were corrected for serum protein binding to yield fraction unbound (fu) serum: broth MIC ratios of 0.24:1 (A. pleuropneumoniae) and 6.30:1 (P. multocida). Corresponding fu serum: broth ratios for MPC were almost identical, 0.23:1 and 6.08:1. These corrections for protein binding did not account for potency differences between serum and broth for either species; based on fu serum MICs, potency in serum was approximately fourfold greater than predicted for A. pleuropneumoniae and sixfold smaller than predicted for P. multocida. For both broth and serum and both bacterial species, MICs were also dependent on initial inoculum strength. The killing action of oxytetracycline had the characteristics of codependency for both A. pleuropneumoniae and P. multocida in both growth media. The in vitro potency of oxytetracycline in pig serum is likely to be closer to the in vivo plasma/serum concentration required for efficacy than potency estimated in broths.

Topics: Actinobacillus Infections; Actinobacillus pleuropneumoniae; Animals; Anti-Bacterial Agents; Microbial Sensitivity Tests; Oxytetracycline; Pasteurella Infections; Pasteurella multocida; Pneumonia, Bacterial; Swine; Swine Diseases; Treatment Outcome

Swine brucellosis caused by Brucella suis biovar 2 is an emerging disease in continental Europe. Without effective vaccines being available, the European Food Safety Authority (EFSA) recommends the full depopulation of infected herds as the only strategy to eradicate B. suis outbreaks. Using data collected from 8 herds suffering natural swine brucellosis outbreaks, we assessed the efficacy of four control strategies: (i) oxytetracycline treatment only, as a default scenario, (ii) oxytetracycline treatment combined with skin testing and removal of positive animals, (iii) oxytetracycline treatment combined with serological testing (Rose Bengal test-RBT-and indirect ELISA -iELISA-) and removal of seropositive animals and (iv) oxytetracycline treatment combined with both serological (RBT/iELISA) and skin testing and removal of positive animals. A Susceptible-Infectious-Removal model was used to estimate the reproduction ratio (R) for each strategy. According to this model, the oxytetracycline treatment alone was not effective enough to eradicate the infection. However, this antibiotic treatment combined with diagnostic testing at 4-monthly intervals plus immediate removal of positive animals showed to be effective to eradicate brucellosis independent of the diagnostic test strategy used in an acceptable time interval (1-2 years), depending on the initial number of infected animals.

Topics: Agriculture; Animal Culling; Animals; Anti-Bacterial Agents; Brucellosis; Combined Modality Therapy; Communicable Diseases, Emerging; Disease Eradication; Europe; Oxytetracycline; Swine; Swine Diseases

The aim of this work was developing effective treatments against Brucella suis biovar 2, responsible for swine brucellosis in Europe. MICs for antibiotics used classically in brucellosis and two new macrolides (tulathromycin and tildipirosin) were determined for 33 B. suis biovar 2 field and B. suis reference strains. MIC90 values ranged from 0.01 to 0.25 μg/mL. The best candidates, given alone or combined, were then evaluated in mice. Ten groups (n = 7) of BALB/c mice were inoculated (1 × 10(5) CFU/mouse) with a virulent B. suis biovar 2 field strain. All groups, excepting untreated control, were treated for 14 days with, respectively, doxycycline, dihydrostreptomycin, tulathromycin (one or two doses), or tildipirosin (one or two doses) given alone, and doxycycline combined with dihydrostreptomycin, tulathromycin, or tildipirosin. Combined tildipirosin treatment was the most effective, then selected for pig studies. Sixteen B. suis biovar 2 naturally infected sows were treated with oxytetracycline (20 mg/kg BW/daily) for 21 days. The half of these received also tildipirosin (4 mg/kg BW) in two doses with a 10-day interval. An extensive bacteriological study conducted ten days after ceasing treatments proved the efficacy of this combined oxytetracycline/tildipirosin treatment.

Topics: Animals; Anti-Bacterial Agents; Brucella suis; Brucellosis; Disaccharides; Drug Therapy, Combination; Female; Heterocyclic Compounds; Mice; Mice, Inbred BALB C; Microbial Sensitivity Tests; Oxytetracycline; Swine; Swine Diseases; Tylosin

A total of 349 Salmonella enterica subspecies enterica serovar Choleraesuis (S. Choleraesuis) strains, which were isolated between 2008 and 2012 from 349 pigs at two slaughterhouses in Okinawa Prefecture, Japan, were investigated for antimicrobial susceptibility and the presence of antimicrobial resistance genes. All isolates were resistant to at least four antimicrobial agents. The antimicrobial agents for which isolates showed a high incidence of resistance were as follows: ampicillin (100%) and streptomycin (100%), followed by gentamicin (99.7%), oxytetracycline (99.7%), sulfamethoxazole/trimethoprim (99.4%), nalidixic acid (40.1%) and oxolinic acid (40.1%). All isolates were sensitive to cefuroxime, ceftiofur, colistin, fosfomycin, enrofloxacin, orbifloxacin and danofloxacin. The predominant resistance phenotypes and genotypes were: resistance to ampicillin, streptomycin, gentamicin, oxytetracycline and sulfamethoxazole/trimethoprim (58.5%, 204/349) and blaTEM-strA-strB-aadA1-aadA2-aacC2-tet (B)-sul1-sul2-dhfrXII-dhfrXIII (36.1%, 126/349). The quinolone resistance-determining regions (QRDRs) of gyrA, gyrB, parC and parE of the quinolone-resistant isolates (n=12) showed amino acid substitutions of Ser-83→Phe or Asp-87→Tyr in GyrA and Ser-107→Ala in ParC. To our knowledge, this is the first report on the molecular characterization of antimicrobial resistance among S. Choleraesuis strains in Japan.

Topics: Abattoirs; Ampicillin; Animals; Base Sequence; DNA Gyrase; DNA Primers; DNA Topoisomerase IV; Drug Resistance, Microbial; Genes, Bacterial; Genotype; Gentamicins; Islands; Japan; Microbial Sensitivity Tests; Molecular Sequence Data; Nalidixic Acid; Oxolinic Acid; Oxytetracycline; Phenotype; Salmonella enterica; Sequence Analysis, DNA; Species Specificity; Streptomycin; Sulfamethoxazole; Swine; Swine Diseases

Actinobacillus pleuropneumoniae (App) is a Gram-negative bacterium that causes porcine pleuropneumonia, leading to economic losses in the swine industry. Due to bacterial resistance to antibiotics, new treatments for this disease are currently being sought. Lactoferrin (Lf) is an innate immune system glycoprotein of mammals that is microbiostatic and microbicidal and affects several bacterial virulence factors. The aim of this study was to investigate whether bovine iron-free Lf (BapoLf) has an effect on the growth and virulence of App. Two serotype 1 strains (reference strain S4074 and the isolate BC52) and a serotype 7 reference strain (WF83) were analyzed. First, the ability of App to grow in iron-charged BLf was discarded because in vivo, BapoLf sequesters iron and could be a potential source of this element favoring the infection. The minimum inhibitory concentration of BapoLf was 14.62, 11.78 and 10.56 µM for the strain BC52, S4074 and WF83, respectively. A subinhibitory concentration (0.8 µM) was tested by assessing App adhesion to porcine buccal epithelial cells, biofilm production, and the secretion and function of toxins and proteases. Decrease in adhesion (24-42 %) was found in the serotype 1 strains. Biofilm production decreased (27 %) for only the strain 4074 of serotype 1. Interestingly, biofilm was decreased (60-70 %) in the three strains by BholoLf. Hemolysis of erythrocytes and toxicity towards HeLa cells were not affected by BapoLf. In contrast, proteolytic activity in all strains was suppressed in the presence of BapoLf. Finally, oxytetracycline produced synergistic effect with BapoLf against App. Our results suggest that BapoLf affects the growth and several of the virulence factors in App.

Topics: Actinobacillus Infections; Actinobacillus pleuropneumoniae; Animals; Anti-Bacterial Agents; Antimicrobial Cationic Peptides; Apoproteins; Bacterial Adhesion; Bacterial Toxins; Biofilms; Cattle; Drug Synergism; HeLa Cells; Humans; Iron; Lactoferrin; Oxytetracycline; Pleuropneumonia; Swine; Swine Diseases; Virulence

When considering the development of antimicrobial resistance in food animals, comparing gross use estimates of different antimicrobials is of little value due to differences in potencies, duration of activity, relative effect on target and commensal bacteria, and mechanisms of resistance. However, it may be valuable to understand quantities of different antimicrobials used in different ages of swine and for what applications. Therefore, the objective of this project was to construct an estimate of antimicrobial use through the feed in swine production in the United States. Estimates were based on data from the National Animal Health Monitoring System (NAHMS) Swine 2006 Study and from a 2009 survey of swine-exclusive practitioners. Inputs consisted of number of pigs in a production phase, feed intake per day, dose of the antimicrobial in the feed, and duration of administration. Calculations were performed for a total of 102 combinations of antimicrobials (n=17), production phases (n=2), and reasons for use (n=3). Calculations were first conducted on farm-level data, and then extrapolated to the U.S. swine population. Among the nursery phase estimates, chlortetracycline had the largest estimate of use, followed by oxytetracycline and tilmicosin. In the grower/finisher phase, chlortetracycline also had the largest use estimate, followed by tylosin and oxytetracycline. As an annual industry estimate for all phases, chlortetracycline had the highest estimated use at 533,973 kg. The second and third highest estimates were tylosin and oxytetracycline with estimated annual uses of 165,803 kg and 154,956 kg, respectively. The estimates presented here were constructed to accurately reflect available data related to production practices, and to provide an example of a scientific approach to estimating use of compounds in production animals.

Topics: Animal Feed; Animal Husbandry; Animals; Anti-Infective Agents; Chlortetracycline; Foodborne Diseases; Models, Statistical; Oxytetracycline; Practice Patterns, Physicians'; Surveys and Questionnaires; Sus scrofa; Swine; Swine Diseases; Time Factors; Tylosin; United States; Veterinarians; Veterinary Drugs

The present study explored whether the use of group medication with antibiotics in a Danish pig herd was reduced after vaccination of the pigs against proliferative enteropathy (PE) caused by Lawsonia intracellularis. 7900 pigs originating from a single commercial sow herd were vaccinated against L. intracellularis, whereas 7756 pigs were kept as non-vaccinated controls. The pigs were included batch-wise in the study with every second batch being vaccinated. In the vaccinated batches, the consumption of oxytetracykline to treat PE was reduced by 79%, with a significantly lower number of pigs being treated (P < 0.0001). Vaccination also resulted in a highly significant improvement of average daily weight gain (+ 46 g/day; P = 9.55 x 10(-31)) and carcase weight (+ 1.25 kg; P = 4.54 x 10(-05)) as well as a shortened fattening period (-8 days; P = 2.01 x 10(-45)).

Topics: Administration, Oral; Animals; Anti-Infective Agents; Bacterial Vaccines; Body Weight; Desulfovibrionaceae Infections; Female; Lawsonia Bacteria; Oxytetracycline; Specific Pathogen-Free Organisms; Swine; Swine Diseases; Vaccination

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

The effect of surgery (insertion of an ileo-caecal cannula) and a subsequent parenteral treatment with oxytetracycline on the ileo-caecal and rectal coliform populations in 7 Swedish Yorkshire castrates were studied. Samples were collected during surgery as well as 3, 7, 14 and 20 days post surgery. The diversity of the enteric coliform flora was initially high both in the ileo-caecal ostium and in rectum. No alteration in the diversity of the enteric coliform flora was observed following surgery and treatment with oxytetracycline. As the insertion of ileo-caecal cannulas did not affect the intestinal coliform flora this study gives support to the use of this technique to mirror processes in the small intestine of pigs. Further, the diversity of the enteric coliform flora was unaffected by the parenteral treatment with oxytetracycline.

Topics: Animals; Anti-Bacterial Agents; Antibiotic Prophylaxis; Bacterial Infections; Catheterization; Cecum; Enterobacteriaceae; Ileum; Male; Oxytetracycline; Postoperative Complications; Rectum; Swine; Swine Diseases

Forty-two pigs in a herd of 117 displayed various clinical signs of progressive atrophic rhinitis. The main signs included sneezing, coughing, lachrymation, serous to mucopurulent nasal discharge, and nasal bleeding in 1 pig. Three pigs had lateral deviation of the snout, while 4 had brachygnathia superior with obvious deformation of the face. Four acutely affected weaner pigs appeared weak, while the 7 chronically-affected pigs appeared smaller than their apparently unaffected penmates of the same age. Treatment of the acutely affected pigs with long-acting oxytetracycline at 20 mg/kg body weight intramuscularly, repeated once after 7 days, reduced the severity but did not clear the sneezing from all the pigs. Fifteen pigs were slaughtered 2 months after the clinical diagnosis was made. The carcasses of the chronically affected pigs were about 15% lighter than those of the apparently normal pigs of the same age and from the same pen, which translated to a loss of 921.00 Kenya shillings per pig (US$13.7). Diagnosis of progressive atrophic rhinitis was confirmed by sectioning the snouts of randomly selected slaughtered pigs with obvious deformation of the snout. Sections were made at the level of the 1st/2nd upper premolar tooth. Varying degrees of turbinate atrophy, from mild to complete, were noted. Histopathology of the turbinates revealed metaplasia of nasal epithelium and fibrosis in the lamina propria.

Topics: Animals; Anti-Bacterial Agents; Atrophy; Female; Kenya; Male; Oxytetracycline; Rhinitis, Atrophic; Swine; Swine Diseases; Turbinates

Eperythrozoon suis infection was identified in a pig herd during an investigation into anaemia and low viability in newborn piglets and severe regenerative macrocytic anaemia in older piglets. The organisms were identified in the erythrocytes of piglets a few days old. Extensive investigations failed to detect other causes of the anaemia and low viability. There was no response to parenteral iron administration alone but the piglets' viability and anaemia responded to the administration of tetracyclines. This is the first report of E suis infection in Northern Ireland.

Topics: Anemia; Animals; Animals, Newborn; Anti-Bacterial Agents; Chlortetracycline; Female; Mycoplasma; Mycoplasma Infections; Oxytetracycline; Swine; Swine Diseases

Minimum inhibitory concentrations of doxycycline and oxytetracycline were determined against 55 Pasteurella multocida strains, 59 Actinobacillus pleuropneumoniae strains and 26 Mycoplasma hyopneumoniae strains isolated from the respiratory tract of pigs. An additional set of 76 P multocida strains isolated from pneumonic pigs was tested for their minimum inhibitory concentrations of doxycycline. The P multocida and A pleuropneumoniae strains were isolated in France and the minimum inhibitory concentrations were determined by an agar dilution method. The M hyopneumoniae strains were isolated in the United Kingdom and minimum inhibitory concentrations were determined by a serial broth dilution method. All the strains tested were susceptible to doxycycline whereas 15 per cent of the P multocida strains and 22 per cent of the A pleuropneumoniae strains were resistant to oxytetracycline. Doxycycline concentrations inhibiting 90 per cent of strains were 1 microgram/ml for P multocida and 2 micrograms/ml for A pleuropneumoniae. The ratio of the minimum inhibitory concentrations of doxycycline and oxytetracycline ranged between 1/1 and 1/4 for the oxytetracycline-susceptible strains and between 1/16 and 1/64 for the oxytetracycline-resistant strains. All the M hyopneumoniae strains were susceptible to doxycycline and oxytetracycline, the concentrations inhibiting 90 per cent of strains being 1 microgram/ml and 2 micrograms/ml, respectively. These data confirm that doxycycline has a higher in vitro activity against pig respiratory pathogens than oxytetracycline.

Topics: Actinobacillus Infections; Actinobacillus pleuropneumoniae; Animals; Anti-Bacterial Agents; Colony Count, Microbial; Doxycycline; Drug Resistance, Microbial; France; Microbial Sensitivity Tests; Mycoplasma; Mycoplasma Infections; Oxytetracycline; Pasteurella Infections; Pasteurella multocida; Respiratory Tract Infections; Swine; Swine Diseases; United Kingdom

Factors associated with foot abscess were evaluated in a cohort of 3,322 suckling pigs reared on a woven-wire floor (wire diameter, 0.5 cm; size of openings, 1 x 3.8 cm). In bivariate analysis, foot abscess was significantly (P < 0.05) associated with postpartum sow illness, number of pigs born alive, and parity, but not with birthweight (P = 0.31) or time spent on wire flooring (P = 0.89). One oxytetracycline treatment (100 mg, IM) at birth or 1 treatment at birth and a second 5 to 7 days later reduced (P < 0.05) the risk of lesions by about half. Multivariate analyses indicated that pigs in large litters (> 10 pigs at birth) born to sows with postpartum illnesses had an increased risk (relative risk [RR], 3.77) of developing foot abscess, compared with pigs in small litters (< or = 10 pigs) born to unaffected sows. For sows without evidence of postpartum illness, pigs in large litters had a slightly increased risk (RR, 1.32) of developing foot abscess, compared with pigs in small litters. Pigs born to multiparous sows also had an increased risk (RR, 1.69) of developing foot abscess, compared with pigs born to primiparous sows. Similar risk estimates were obtained when logistic regression models included location farrowed (crate number) as a fixed effect, and when litter was a random effect in a logistic-binomial regression.

Topics: Abscess; Analysis of Variance; Animals; Animals, Newborn; Animals, Suckling; Cohort Studies; Female; Foot Diseases; Housing, Animal; Incidence; Litter Size; Male; Oxytetracycline; Parity; Puerperal Disorders; Regression Analysis; Risk Factors; Swine; Swine Diseases

The prophylactic effect of in-feed medication with oxytetracycline was tested by using an Actinobacillus pleuropneumoniae aerosol challenge model. Groups of 10 conventional pigs were provided with feed containing 400, 800, 1200 or 1600 mg oxytetracycline/kg and fed ad libitum. After six days of medication the pigs were challenged and clinical signs were recorded. Two groups of four unmedicated pigs served as controls and were euthanased 36 to 48 hours after challenge and dissected. The feed medication was continued for nine days after the challenge, and the different treatment groups were then moved to separate accommodation where they were mixed with seronegative tracer pigs. The steady state concentrations of oxytetracycline in the pigs' serum after six days medication with feed containing 400, 800, 1200 or 1600 mg oxytetracycline/kg ranged from 0.07 to 0.13, 0.21 to 0.46, 0.27 to 0.46 and 0.35 to 0.56 microgram/ml, respectively. One of the eight unmedicated control pigs died, and the other seven showed signs of pleuropneumonia post mortem. Medication with feed containing 400 mg and 800 mg oxytetracycline/kg failed to prevent pleuropneumonia in the challenged pigs, and the mortality rates in these groups were two out of 10 and one out of nine pigs, respectively. All the pigs given feed containing 1200 and 1600 mg oxytetracycline/kg survived and only two of the pigs in the first treatment group showed mild clinical signs. No clinical signs were observed in the tracer pigs which were mixed with the pigs medicated with 400, 800 or 1200 mg oxytetracycline/kg.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Actinobacillus Infections; Actinobacillus pleuropneumoniae; Aerosols; Animal Feed; Animals; Netherlands; Oxytetracycline; Pleuropneumonia; Swine; Swine Diseases

The usefulness of the prophylactic or therapeutic application of Propionibacterium avidum KP-40, a potent stimulator of the monocyte-macrophage-system, was demonstrated in piglets and calves. After a 3-month-period of observation PA-treated piglets showed a significantly improved development (decreased number of infections, gain of body weight). In piglets and calves the therapeutic use of PA together with oxytetracycline proved to be superior in the treatment of acute endemic enzootic bronchopneumonia (AEB) as compared to groups of animals receiving PA or oxytetracycline alone.

Topics: Animals; Bronchopneumonia; Cattle; Cattle Diseases; Macrophage Activation; Oxytetracycline; Propionibacterium; Swine; Swine Diseases

The sensitivity of ten Bordetella bronchiseptica and ten Pasteurella multocida strains, each isolated from cases of atrophic rhinitis (AR), was examined in tube dilution test. Getroxel, chlorquinaldol and oxytetracycline and the former two ones combined with trimethoprim inhibited the growth of both species in vitro. The minimum inhibitory and the minimum bactericidal concentration was less than 0.5 microgram/ml. When efficacy was tested in SPF in the group fed a combination of Getroxel, chlorquinaldol and oxytetracycline (60 mg, 240 mg and 360 mg/kg of feed, respectively), P. multocida disappeared from the nasal cavity by the end of a 30-day treatment. B. bronchiseptica was reisolated in low numbers from 2 out of 9 piglets. The daily body mass gain was by 7.9% higher and the feed conversion rate was by 19% better than in the control group. After slaughter, only mild signs of AR were seen in 3 out of 9 piglets treated with the above-mentioned drug combination, while in the control group severe lesions were observed in 8 out of 9 pigs. In treated commercial herds P. multocida disappeared from the nasal cavity of the piglets by the end of the treatment (42nd day of life), but the B. bronchiseptica strains could not be completely eliminated. Due to the treatment, mortality between 2 and 6 weeks of age decreased by 0.8-7.6%. Daily body mass gain was, on the average, 16.4% higher, the amount of feed needed for 1 kg body mass gain was by 15.3% lower and the duration of fattening was by 30.8 days shorter than in the control groups.

Topics: Animals; Bordetella bronchiseptica; Carbadox; Chlorquinaldol; Oxytetracycline; Pasteurella multocida; Rhinitis, Atrophic; Specific Pathogen-Free Organisms; Swine; Swine Diseases

In the present study the feed and water consumption and pharmacokinetic parameters of orally administered oxytetracycline were compared in clinically healthy pigs and in the same pigs following a challenge with Actinobacillus (Haemophilus) pleuropneumoniae toxins. Endobronchial challenge with A. pleuropneumniae toxins was accompanied by anorexia, increased lassitude, labored breathing, fever, and increased white blood cell counts. Pleuropneumonia was evident in all pigs on autopsy. Following the challenge, both feed and water consumption were markedly reduced. In contrast to recommendations in the literature, it is concluded that drugs should not be administered to pneumonic pigs via water. In healthy pigs the oral bioavailability of oxytetracycline (50 mg/kg), given on an empty stomach, was 4.8% and the elimination half-life (t1/2 beta) was 5.92 h. After challenge, the pigs showed great variation in oxytetracycline plasma concentrations. In addition, the mean computed elimination rate constant (beta), t1/2 beta, the area under the plasma concentration-time curve (AUC), and clearance in pneumonic pigs differed significantly (P less than .05) from the values found in healthy pigs. The elimination half-life (t1/2 beta), AUC, and volume of distribution (Vd area) were increased. In diseased pigs the mean of maximum plasma concentrations (.87 micrograms/ml) was reached after 7 h, in contrast to 1.74 h (1.87 micrograms/ml) in the healthy pigs.

Topics: Actinobacillus Infections; Administration, Oral; Animals; Biological Availability; Body Temperature; Drinking; Eating; Half-Life; Male; Oxytetracycline; Pleuropneumonia; Swine; Swine Diseases

The pharmacokinetics of oxytetracycline (OTC) were studied in healthy pigs and in pigs endobronchially inoculated with Actinobacillus pleuropneumoniae toxins. In two groups of seven pigs OTC was administered intravenously in a single dose of 10 or 50 mg/kg, respectively. OTC was administered to clinically healthy pigs and 7 days later at 3 h after a challenge with A. pleuropneumoniae toxins. Pneumonia developed in toxin-treated pigs. In the challenged pigs there was a decreased distribution-rate constant (alpha) and a significantly increased elimination-rate constant (beta) (P less than 0.05). Moreover, the apparent volume of distribution (Vd beta) was decreased. The elimination half-lives (t1/2 beta) were approximately 6 h in the healthy pigs and 5 h in the diseased animals. There was no difference in the pharmacokinetic profile of OTC following administration of 50 mg/kg compared to 10 mg/kg.

Topics: Actinobacillus Infections; Animals; Dose-Response Relationship, Drug; Half-Life; Injections, Intravenous; Male; Oxytetracycline; Pneumonia; Swine; Swine Diseases; Tissue Distribution

These experiments tested the hypothesis that long-acting oxytetracycline (oxytetracycline-LA) was more effective than regular oxytetracycline in preventing porcine pleuropneumonia when administered either 24 or 48 h prior to experimental challenge with virulent strains of Actinobacillus pleuropneumoniae. Two experiments (1 and 2) were conducted using growing pigs (average weight 12-15 kg). Antibiotic treatments were administered once intramuscularly at 20 mg/kg body weight; controls received an equivalent volume of saline. Clinical signs were recorded over seven days, and mortality rates and pathological lesions were analyzed using analysis of variance. Serum oxytetracycline levels were compared 48 and 72 h postinjection. All pigs developed clinical disease following experimental infection. Actinobacillus pleuropneumoniae was recovered from 42% of experiment 1 pigs and all of experiment 2 pigs. The data showed that both oxytetracycline and oxytetracycline-LA given at the same dose protected pigs against experimental infection when given 24 h prior to challenge, and there was no difference between the efficacy of the two drugs in this experiment. When administered 48 h prior to challenge, only oxytetracycline-LA reduced the clinical signs and pathological changes following A. pleuropneumoniae challenge. Between 48 and 72 h postinjection, oxytetracycline-LA blood levels were significantly greater compared to oxytetracycline-treated pigs.

Topics: Actinobacillus Infections; Analysis of Variance; Animals; Delayed-Action Preparations; Haemophilus Infections; Oxytetracycline; Pleuropneumonia; Random Allocation; Specific Pathogen-Free Organisms; Swine; Swine Diseases

The minimal inhibitory concentrations (MIC) of five tetracyclines and ten other antimicrobial agents were determined for four porcine bacterial respiratory tract pathogens by the agar dilution method. For the following oxytetracycline-susceptible strains, the MIC50 ranges of the tetracyclines were: P. multocida (n = 17) 0.25-0.5 micrograms/ml; B. bronchiseptica (n = 20) 0.25-1.0 micrograms/ml; H. pleuropneumoniae (n = 20) 0.25-0.5 micrograms/ml; S. suis Type 2 (n = 20) 0.06-0.25 micrograms/ml. For 19 oxytetracycline-resistant P. multocida strains the MIC50 of the tetracyclines varied from 64 micrograms/ml for oxytetracycline to 0.5 micrograms/ml for minocycline. Strikingly, minocycline showed no cross-resistance with oxytetracycline, tetracycline, chlortetracycline and doxycycline in P. multocida and in H. pleuropneumoniae. Moreover, in susceptible strains minocycline showed the highest in vitro activity followed by doxycycline. Low MIC50 values were observed for chloramphenicol, ampicillin, flumequine, ofloxacin and ciprofloxacin against P. multocida and H. pleuropneumoniae. B. bronchiseptica was moderately susceptible or resistant to these compounds. As expected tiamulin, lincomycin, tylosin and spiramycin were not active against H. pleuropneumoniae. Except for flumequine, the MIC50 values of nine antimicrobial agents were low for S. suis Type 2. Six strains of this species showed resistance to the macrolides and lincomycin.

Topics: Animals; Anti-Bacterial Agents; Bacteria; Bordetella; Chlortetracycline; Doxycycline; Haemophilus; Microbial Sensitivity Tests; Minocycline; Oxytetracycline; Pasteurella; Respiratory Tract Infections; Streptococcus; Swine; Swine Diseases; Tetracycline; Tetracyclines

Prophylactic efficacy of 100 mg of long-acting oxytetracycline (OTC) given IM to neonatal pigs within 12 hours of birth was evaluated in a swine herd. The herd had a history of increased neonatal mortality, diarrhea, foot abscess, and arthritis in nursing pigs. Two trials were conducted in which liters and individual pigs were the treatment groups of interest. In both trials, OTC treatment failed to reduce mortality, diarrhea, or arthritis or the need for subsequent antimicrobial therapy (P greater than 0.05). Preweaning weight gains were not increased (P greater than 0.05) in treated pigs. However, in the individual pig trial, foot abscess rates were significantly (P = 0.01) lower in treated pigs (3.7%) than in nontreated pigs (8%). Aerobic bacteria isolated from pigs with diarrhea, arthritis, or foot abscess had minimum inhibitory concentrations for OTC greater than or equal to 64 micrograms/ml or were classed as resistant on the basis of disk-diffusion tests.

Topics: Abscess; Animals; Animals, Newborn; Arthritis, Infectious; Bacterial Infections; Diarrhea; Female; Foot Diseases; Male; Oxytetracycline; Prognosis; Random Allocation; Swine; Swine Diseases; Weight Gain

Investigators have found that oxytetracycline decreases the adhesion of K88+ Escherichia coli to intestinal epithelial cells in vitro. This occurs with oxytetracycline-sensitive E coli at drug concentrations less than those required to prevent growth and with E coli that are resistant to the drug. We conducted experiments to determine whether oxytetracycline alters the disease caused by an oxytetracycline-resistant K88+ enterotoxigenic strain of E coli. Oxytetracycline-treated pigs (inoculated with K88+ E coli) did not differ from nontreated pigs in the incidence or severity of diarrhea, nor in the shedding of K88+ E coli. However, during recovery, weight gain by treated pigs was slower than that of nontreated pigs. The control pigs were not inoculated with E coli, and they remained clinically normal. Oxytetracycline-treated controls gained weight faster than nontreated controls. Some controls were genetically resistant to K88+ E coli, others were susceptible. The K88-resistant oxytetracycline-treated controls gained weight faster than the K88-susceptible oxytetracycline-treated and non-treated controls.

Topics: Animals; Animals, Newborn; Body Weight; Diarrhea; Escherichia coli; Escherichia coli Infections; Oxytetracycline; Swine; Swine Diseases; Time Factors; Weaning

Topics: Animals; Kidney; Leptospira; Leptospirosis; Oxytetracycline; Swine; Swine Diseases

Topics: Anaplasmataceae Infections; Animals; Erythrocytes; Female; Leukocytes; Mycoplasma; Mycoplasma Infections; Oxytetracycline; Swine; Swine Diseases

A long-acting oxytetracycline formulation was evaluated for control of rhinitis induced experimentally in pigs with a capsular type A, toxin-negative, low-passage strain of Pasteurella multocida. The pigs were 6 to 7 weeks old and were naturally infected with Haemophilus parasuis. The H parasuis infection was thought to predispose to establishment of P multocida in the nasal cavity. A long-acting oxytetracycline formulation was given IM at the rate of 20 mg/kg, 4 times at 5-day intervals. Medication reduced (P less than 0.05) the severity of turbinate atrophy and the proportion of pigs with P multocida and H parasuis in their nasal cavities. Numbers of colonies of P multocida and H parasuis isolated were also less in medicated pigs.

Topics: Animals; Haemophilus Infections; Oxytetracycline; Pasteurella Infections; Rhinitis, Atrophic; Swine; Swine Diseases

Four scientific-and-economic experiments were carried out with 4 groups of sows each, the animals being equated in terms of age and period of farrowing (+/- 4 days). Both test and control groups were offered rations of one and the same composition and amount. The feed of the test groups contained medicated premixes MNDm (neomycin and dimetridazol) or MODm (oxatetracyclin and dimetridazol) at the rate of 1 per cent. The medicated feed was fed to the sows 3 days prior to and 7 days after farrowing. At the time of weaning newborn pigs were given combined feed in the course of 5-6 days with the inclusion of medicated premixe MOSdf (oxatetracyclin, sulfadimezin, and furazolidan) also at the rate of 1 per cent. A total of 1774 pigs were obtained from all 182 test sows at an average fertility rate of 9.8 pigs per sow. The control of 182 cows yielded 1747 pigs (fertility rate of 9.7). The average weight gain of the test pigs during the suckling period amounted to 212 g against 197 g for the controls (an increase of 15 g -- 7.6 per cent). Mortality ranged from 78 pigs for the test groups to 101 pigs for the control ones. Up to 7 cases of diseased sows were established with the test animals against 24 ones with the controls. The number of impregnated sows up to the 20th day after weaning the newborns was 90 for the test animals against 77 for the control ones, and the number of returns was 27 and 34, respectively. Owing to sterility 5 sows of the test groups and 11 sows of the control groups were culled (4.2 vs. 9.0 per cent). Conclusions were drawn that the medicated premixes MNDm and MODm, used in amounts of 1 per cent with the combined feed prevented endometritis, mastitis, agalaxia, enteritis, and other diseases in sows. The treated animals exhibited joint estrus by groups after weaning the newborns, manifesting a higher conception rate. Parallel to this, the weight development of newborn pigs was improved, and mortality during the sucking period was reduced.

Topics: Animal Feed; Animals; Animals, Suckling; Breeding; Dimetridazole; Drug Combinations; Female; Neomycin; Nitroimidazoles; Oxytetracycline; Swine; Swine Diseases; Syndrome

Topics: Animals; Drug Resistance, Microbial; Male; Oxytetracycline; Pasteurella; Pasteurella Infections; Pneumonia; Pyrrolidinones; Swine; Swine Diseases

Staphylococcus aureus strains from human nasal carriers without vocational contact with pigs could be differentiated from the majority of strains obtained from pathologically affected pigs by determination of host-specific-variety, according to Meyer (1966) and Witte et al. (1977). Less unambiguous findings regarding site variability were recorded from strains in nasal mucosa of pig-handling personnel, clinically intact pigs on farms, and slaughtered pigs. Antibiotics, such as oxytetracycline and macrolides were applied to pigs but failed for all practical purposes to have any bearings on the development of Staphylococcus aureus resistance in human probands with no vocational contact with animals. Personnel of pig units, however, exhibited moderate resistance to oxytetracycline and macrolides of Staphylococcus aureus strains which were typical of man. Macrolide resistance was determined, in that context, by one single-resistance plasmid.

Topics: Animal Husbandry; Animals; Anti-Bacterial Agents; Drug Resistance, Microbial; Humans; Leucomycins; Nasal Mucosa; Oxytetracycline; Staphylococcus aureus; Swine; Swine Diseases

Topics: Animals; Oxytetracycline; Pneumonia; Swine; Swine Diseases

The piglets of two multiplier herds (M and B) showing clinically apparent atrophic rhinitis (AR) were treated by the nasal-spray method. A solution of oxytetracycline hydrochloride (OTC, 50 mg/ml.) was used as a spray fluid. The course of the disease in the herds was followed by studying the development of foreshortening of the upper jaws in the heads. Brachygnathia superior (BS), from the eighth to tenth week of life. Efforts were made to gain an impression of the effects of treatment on the frequency with which Bordetella bronchiseptica and Pasteurella multocida were isolated by bacteriological examination of the nose. Treatment by the nasal-spray method up to an age of approximately five weeks, of seven weeks were treated at least once weekly. The proportion of animals in which the disease was clinically apparent decreased from 25 per cent to 0 per cent in herd M and from 41 per cent to 0 per cent in herd B. Treatment by the nasal-spray method up to an age approximately five weeks, in which feed medicated with OTC was also given up to the age of eight to ten weeks also had a satisfactory effect. The frequency with which Bordetella bronchiseptica and Pasteurella multocida were isolated, was reduced by treatment, elimination of these agents was not.

Topics: Administration, Intranasal; Animals; Bordetella; Nose; Oxytetracycline; Pasteurella; Rhinitis, Atrophic; Swine; Swine Diseases

Topics: Animals; Diarrhea; Dihydrostreptomycin Sulfate; Drug Resistance, Microbial; Escherichia coli; Escherichia coli Infections; Oxytetracycline; Swine; Swine Diseases

Topics: Animals; Escherichia coli Infections; Gentamicins; Oxytetracycline; Swine; Swine Diseases

Eperythrozoonosis was diagnosed in 23 herds of swine. Icterus and anemia were the major diagnostic criteria, with low packed cell volumes confirming the clinical impression of anemia. Indirect hemagglutination titers provided an indirect measure of infection rates and appeared to correlate positively with severity of signs. Treatment with oxytetracycline and arsanilic acid controlled the disease, but only when combined with efforts to limit transmission of the causative organism through control of lice.

Topics: Anaplasmataceae Infections; Anemia; Animals; Arsanilic Acid; Female; Insect Control; Jaundice; Mycoplasma Infections; Oxytetracycline; Phthiraptera; Pregnancy; Pregnancy Complications, Infectious; Swine; Swine Diseases

Topics: Animals; Anti-Bacterial Agents; Diterpenes; Leucomycins; Mycoplasma; Mycoplasma Infections; Oxytetracycline; Pneumonia; Swine; Swine Diseases

The strain classified as Enterobacter hafniae has been isolated in a severe epidemy of porcine diarrhoea. Its pathogenicity has been found to be cotransmissible with resistance to oxytetracycline when the strain was grown in a mixed culture with some nonpathogenic E. hafniae strains as well as with Escherichia coli. Toxinogenity seems to be responsible for virulence of the strain.

Topics: Animals; Conjugation, Genetic; Drug Resistance, Microbial; Dysentery, Bacillary; Enterobacter; Enterobacteriaceae; Escherichia coli; Oxytetracycline; Plasmids; R Factors; Swine; Swine Diseases; Virulence

Experiments were conducted to study transfer of an enterotoxin (Ent) plasmid from a porcine enteropathogenic Escherichia coli to an E coli K12 strain in the intestine of newly weaned pigs. The Ent plasmid carried genes for resistance to tetracycline, streptomycin, and sulfonamides, thereby permitting a selection for tetracycline-resistant exconjugants in the feces of the pigs. In vivo transfer of the Ent plasmid was demonstrated to occur when the pigs were given large oral inocula of donor and recipient cultures, 1 hour apart. Differences in extent of transfer were not detected in pigs given antibiotic-free feed compared with littermates on feed containing oxytetracycline at 50 g/ton. In one experiment, tetracycline-resistant Ent- exconjugants were found which appeared to have received an R plasmid from an enteropathogenic type of E coli resident in the intestine.

Topics: Animals; Diarrhea; Drug Resistance, Microbial; Enterotoxins; Escherichia coli; Escherichia coli Infections; Feces; Intestines; Oxytetracycline; Plasmids; R Factors; Swine; Swine Diseases; Tetracycline

The aetiology and pathogenesis of respiratory syndromes in pigs are reviewed with emphasis on the role of environmental factors and diagnosis. Therapeutic and control measures are suggested and the cost of various regimens is dealt with in detail.

Topics: Adenoviridae; Animals; Ascaris; Bordetella; Costs and Cost Analysis; Cytomegalovirus; Haemophilus; Leucomycins; Metastrongyloidea; Mycoplasma; Oxytetracycline; Pasteurella; Pseudomonas; Respiratory Tract Infections; South Africa; Swine; Swine Diseases

In an industrial pig farm in Lubumashi, Zaïre, Balantidium coli produced severe clinical and fatal disease. Terramycin at a dose rate of 15 mg/kg body weight administered twice daily with concentrates gave clinical recovery in all the pigs treated. The complete parasitological recovery was obtained in 14 out of 20 animals. In the remaining 6 there was significant reduction in the number of B. coli. Keeping in view the large spectrum of activity of terramycin in various infections as well as B. coli, terramycin can be useful in the treatment of balantidiosis of pigs.

Topics: Animals; Balantidiasis; Diarrhea; Oxytetracycline; Swine; Swine Diseases

Atrophic rhinitis (AR) caused serious losses in a breeding herd including approximately 120 sows. The extent to which piglets were affected by AR was assessed by determining the degree of shortening of the upper jaw. Animals showing a crooked nose or grade two or more of shortening of the upper jaw were considered to be clinically positive. Grades three and four of the upper jaw were observed in those animals which were severely affected by Atrophic rhinitis. Treatment of all piglets up to about eight weeks of age by the antibiotic oxytetracycline hydrochloride directed against the bacteria Bordetella bronchisepica and Pasteurella multocida was successful in reducing the proportion of clinically affected piglets from 30 per cent to 0 per cent within eight weeks. There was found to be a positive relationship between the proportion of piglets infected with the two above bacteria at an age of about five weeks and the incidence of shortening of the upper jaw at an age of about eight weeks. The proportion of piglets with shortening of the upper jaw rose following a marked increase in the number of piglets in farrowing and flat-deck houses and as a result of the supply of inadequately medicated feed.

Topics: Animals; Bordetella Infections; Maxilla; Oxytetracycline; Pasteurella Infections; Rhinitis, Atrophic; Swine; Swine Diseases

In the past, total uterine prolapse in the sow has been regarded as a grave condition because manipulative reposition through the vulva and vagina is extremely difficult, if not impossible, and amputation is merely a salvage procedure with a mortality rate approaching 100 percent. Laparotomy as a means of facilitating reduction of the prolapse in the sow appears to have been overlooked although it is a standard procedure in dogs and cats. This report describes a case of uterine prolapse in a sow successfully treated by laparotomy.

Topics: Anesthesia, Intravenous; Animals; Female; Laparotomy; Oxytetracycline; Pentobarbital; Pituitary Hormones; Swine; Swine Diseases; Uterine Prolapse

The following measures designed for the prevention of Atrophic rhinitis (AR) were compared. (1) Adopting the all in - all out system in separate farrowing quarters. The variation in age between piglets in a single farrowing house was confined to one to two weeks. (2) Treating the piglets with a combined preparation of penicillin, chloramphenicol, oxytetracycline hydrochloride or sulphonamides on the third, sixth and twelfth days of life. (3) Administering immune sera to piglets. (4) Vaccinating sows and piglets with Bordetella bronchiseptica vaccine and piggery--specific Pasteurella multocida vaccine. The various forms of treatment had a beneficial effect on the clinical picture in every case of Atrophic rhinitis. Moreover, the dosage of the antibiotic oxytetracycline hydrochloride as well as the titre of the immune serum were found to be factors in the prevention of AR. The pressure of infection with Bordetella bronchiseptica and/or Pasteurella multocida is a factor of major importance in the pathogenesis of clinically apparent AR in piglets under eight weeks. Maintaining infection at a low level is the main object in the control of AR. The more so as the knowledge available today does not make it possible to free piggeries from Bordetella bronchiseptica and Pasteurella multocida.

Topics: Animals; Bacterial Vaccines; Bordetella; Chloramphenicol; Housing, Animal; Immunization, Passive; Methods; Netherlands; Oxytetracycline; Pasteurella; Penicillins; Rhinitis, Atrophic; Sulfonamides; Swine; Swine Diseases

Distribution of tetracyclines and their effect on interaction of the cells in the immune response were studied on pigs and rabbits non-vaccinated, immunized with formolvaccin against paratyphoid fever and experimentally infected with the paratyphoid causative agent. It was found that oxytetracycline and tetracycline administered parentally to the animals formed complexes with the proteins and especially with albumins and gamma-globulins, were rapidly adsorbed by the lymphocytes and consumed by the cells of the reticulo-macro- and micro-phage systems, epithelium of the kidney cannaculi and the cells of the liver parenchyma. Immunomorphological changes accompanied by formation of antibodies to the antibiotics were found in the bloodforming-lymphoid system after repeated parental administrations of the tetracyclines. The titers of the antibodies to oxytetracycline and tetracycline were high by the 5th--14th day after the antibiotic administration and the relatively high levels persisted for 1.5 months. The use of tetracyclines during the induction stage of immunogenesis had a pronounced inhibitory effect on development of immunity against the paratyphoid fever antigen. On the basis of the tetracycline capacity for binding with immunoglobulins and intensive adsorption by the lymphocytes it is possible to suppose that the inhibitory effect of the antibiotics on immunogenesis was connected with their blocking the receptors of T- and B-lymphocytes.

Topics: Animals; Antibodies; Antibody Formation; Antibody-Producing Cells; Formaldehyde; Immunity, Cellular; Immunization; Leukocyte Count; Oxytetracycline; Paratyphoid Fever; Plasma Cells; Rabbits; Swine; Swine Diseases; Tetracycline; Tetracyclines; Time Factors

Some 115 R- and 143 S-streptococcal strains were isolated from 258 pigs that had died or been killed for disease, between 1969 and 1973. They were cultured and biochemically tested for sensitivity to chemotherapeutics. All R- and S-strains were of normal sensitivity to penicillin and, with few exceptions, to chloramphenicol and oxytetracycline as well. Most of the strains caused primary Sc.-infection, such as septicaemia, leptomeningitis, endocarditis, and arthritis. R-Sc.-infections were contracted mainly by store pigs and animals in advenced age, while S-Sc.-infections affected mainly piglets.

Topics: Animals; Arthritis; Chloramphenicol; Endocarditis; Meningitis; Oxytetracycline; Penicillins; Sepsis; Streptococcal Infections; Streptococcus; Swine; Swine Diseases

Acholeplasma axanthum sp. was isolated from the lung of swine with catarrhal pneumonia. Clinical symptoms of respiratory disease, gross and histological lesions of pneumonia, as well as serological response were produced by intranasal inoculation of ;miniature pigs' with the supernatant of lung suspension containing Acholeplasma axanthum and by a 48 hr. broth culture of the strain.A similar picture of disease was observed in animals held in contact with the animals inoculated with untreated lung suspension. Acholeplasma axanthum was isolated from the nasal cavity, lung and peribronchial lymph nodes 7-41 days after inoculation. No lesions were observed after inoculation of pigs with the supernatant of lung suspension pretreated with oxytetracycline or chloroform, and no successful isolation of Acholeplasma axanthum could be achieved after this treatment.

Topics: Animals; Bronchi; Chloroform; Fever; Hemagglutination Tests; Lung; Lymph Nodes; Mycoplasma; Nasal Mucosa; Oxytetracycline; Pneumonia; Pulmonary Alveoli; Swine; Swine Diseases

Topics: Administration, Oral; Animals; Oxytetracycline; Rhinitis, Atrophic; Sulfaphenazole; Swine; Swine Diseases

Topics: Abscess; Administration, Oral; Animal Feed; Animals; Anti-Bacterial Agents; Bacterial Vaccines; Chlortetracycline; Germ-Free Life; Lymphadenitis; Oxytetracycline; Penicillin G Benzathine; Streptococcal Infections; Streptococcus; Swine; Swine Diseases; Vaccination

Topics: Animals; Antibodies; Oxytetracycline; Phagocytosis; Salmonella Infections, Animal; Streptomycin; Swine; Swine Diseases

Topics: Agglutination Tests; Animals; Leptospirosis; Oxytetracycline; Swine; Swine Diseases

Topics: Animals; Anti-Bacterial Agents; Bacteria; Dihydrostreptomycin Sulfate; Mycoplasma; Mycoplasma Infections; Oxytetracycline; Penicillin G; Penicillin Resistance; Pneumonia; Swine; Swine Diseases

Topics: Animals; Erysipelothrix Infections; Oleandomycin; Oxytetracycline; Swine; Swine Diseases

Topics: Animals; Anti-Bacterial Agents; Infections; Mycoplasma; Mycoplasma Infections; Oxytetracycline; Swine; Swine Diseases; Tetracycline

Topics: Animals; Diarrhea; Enteritis; Oxytetracycline; Swine; Swine Diseases