tetracycline and Poultry-Diseases

Avibacterium paragallinarum is the etiological agent of infectious coryza, an acute respiratory disease of chickens that is globally distributed and causes serious economic losses for chicken production.

Topics: Animals; Anti-Bacterial Agents; Chickens; Chloramphenicol; Deoxyribonucleases; Drug Resistance, Microbial; Erythromycin; Genomics; Gram-Negative Bacteria; Haemophilus Infections; Haemophilus paragallinarum; Poultry Diseases; Streptomycin; Tetracycline

To analyse the prevalence, genetic diversity and antimicrobial susceptibility of Campylobacter spp. in northern Spain.. Campylobacter was isolated from 139 samples of broiler meat and faecal dropping of broiler and swine with a prevalence of 35·4, 62 and 42·8%, respectively. Campylobacter jejuni (n = 55) and Campylobacter coli (n = 31) were identified by multiplex-PCR in meat, faeces and human clinical samples while Campylobacter fetus (n = 3) was exclusively detected in the latter. Fingerprinting by flaA-RFLP and PFGE revealed 68 different genotypes from the 89 isolates with a Biodiversity Simpson's index of 0·98. The 86·5% of the isolates were resistant to ciprofloxacin, 85·4% to tetracycline and 49·4% to erythromycin; only three genotypes were susceptible to the three antimicrobial drugs. Multidrug resistance was detected in the 40·7% of the isolates.. Campylobacter remains prevalent in northern Spain with a high biodiversity degree. About 93·3% of the isolates were resistant to one or more drugs.. Although different measures are taken to control Campylobacter, the detection of isolates resistant to the drugs used in the treatment of campylobacteriosis is still high, including different species and genotypes. This evidences the need of additional strategies against this pathogen.

Topics: Animals; Anti-Bacterial Agents; Campylobacter coli; Campylobacter Infections; Campylobacter jejuni; Chickens; Ciprofloxacin; Drug Resistance, Bacterial; Erythromycin; Meat; Microbial Sensitivity Tests; Molecular Typing; Phylogeny; Poultry Diseases; Prevalence; Spain; Swine; Swine Diseases; Tetracycline

Avian pathogenic Escherichia coli (APEC) is a specific group of extraintestinal pathogenic E. coli that causes a variety of extraintestinal diseases in chickens, ducks, pigeons, turkeys, and other avian species. These diseases lead to significant economic losses in the poultry industry worldwide. However, owing to excessive use of antibiotics in the treatment of infectious diseases, bacteria have developed antibiotic resistance. The development of multidrug efflux pumps is one important bacterial antibiotic resistance mechanism. A multidrug efflux pump, MdtH, which belongs to the major facilitator superfamily of transporters, confers resistance to quinolone antibiotics such as norfloxacin and enoxacin. LsrR regulates hundreds of genes that participate in myriad biological processes, including mobility, biofilm formation, and antibiotic susceptibility. However, whether LsrR regulates mdtH transcription and then affects bacterial resistance to various antibiotics in APEC has not been reported. In the present study, the lsrR mutant was constructed from its parent strain APECX40 (WT), and high-throughput sequencing was performed to analyze the transcriptional profile of the WT and mutant XY10 strains. The results showed that lsrR gene deletion upregulated the mdtH transcript level. Furthermore, we also constructed the lsrR- and mdtH-overexpressing strains and performed antimicrobial susceptibility testing, antibacterial activity assays, real-time reverse transcription PCR, and electrophoretic mobility shift assays to investigate the molecular regulatory mechanism of LsrR on the MdtH multidrug efflux pump. The lsrR mutation and the mdtH-overexpressing strain decreased cell susceptibility to norfloxacin, ofloxacin, ciprofloxacin, and tetracycline by upregulating mdtH transcript levels. In addition, the lsrR-overexpressing strain increased cell susceptibility to norfloxacin, ofloxacin, ciprofloxacin, and tetracycline by downregulating mdtH transcript levels. Electrophoretic mobility shift assays indicated that LsrR directly binds to the mdtH promoter. Therefore, this study is the first to demonstrate that LsrR inhibits mdtH transcription by directly binding to its promoter region. This action subsequently increases susceptibility to the aforementioned four antibiotics in APECX40.

Topics: Animals; Anti-Bacterial Agents; Antiporters; Chickens; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Fluoroquinolones; Microbial Sensitivity Tests; Poultry Diseases; Repressor Proteins; Tetracycline

Antibiotics have long been the first line of defense to prevent Escherichia coli infections, but they have lost their potency since bacteria have grown increasingly resistant to treatment. The present research aimed to study the drug resistance and the prevalence of tetracycline resistance genes in E. coli isolated from broilers with colibacillosis.. The results showed that the most prevalent type of drug resistance was to tetracycline at 95.0%, and the least was to gentamicin at 21.7%. The prevalences of antimicrobial resistance among the tested antibiotics were significantly different (p < 0.001). A statistically significant difference was observed between the prevalence of the tet genes (p < 0.001). The tetD positive isolates and antibiotic sensitivity to tetracycline showed statistical significant differences (p = 0.017).. Considering the results, tetA is the most common tetracycline resistance gene, and the presence of tetD and antibiotic sensitivity to tetracycline had a significant relationship in E. coli isolated from colibacillosis infections.

Topics: Animals; Anti-Bacterial Agents; Chickens; Escherichia coli; Escherichia coli Infections; Iran; Poultry Diseases; Tetracycline; Tetracycline Resistance

In 2014, antimicrobial drug-resistant Campylobacter jejuni sequence type 6964 emerged contemporaneously in poultry from 3 supply companies in the North Island of New Zealand and as a major cause of campylobacteriosis in humans in New Zealand. This lineage, not previously identified in New Zealand, was resistant to tetracycline and fluoroquinolones. Genomic analysis revealed divergence into 2 major clades; both clades were associated with human infection, 1 with poultry companies A and B and the other with company C. Accessory genome evolution was associated with a plasmid, phage insertions, and natural transformation. We hypothesize that the tetO gene and a phage were inserted into the chromosome after conjugation, leaving a remnant plasmid that was lost from isolates from company C. The emergence and rapid spread of a resistant clone of C. jejuni in New Zealand, coupled with evolutionary change in the accessory genome, demonstrate the need for ongoing Campylobacter surveillance among poultry and humans.

Topics: Animals; Anti-Bacterial Agents; Campylobacter Infections; Campylobacter jejuni; Communicable Diseases, Emerging; Drug Resistance, Bacterial; Fluoroquinolones; Genome, Bacterial; Genomics; History, 21st Century; Humans; Multilocus Sequence Typing; New Zealand; Phylogeny; Plasmids; Polymorphism, Single Nucleotide; Poultry Diseases; Tetracycline; Whole Genome Sequencing

Serotypes and antimicrobial susceptibility of Salmonella's isolates from broiler production chain were determined. A total of 239 isolated strains from chicken, carcasses, breeding environments, and slaughter was analyzed by disk diffusion test, in the period of 2009 to 2010. For antibiotics with a high number of resistant strains, the minimal inhibitory concentration (MIC) was performed. We identified 24 serotypes, being the most frequent, Minnesota (31.4%) and Infantis (22.6%). The highest percentages of resistance were obtained for sulfonamide (42.7%), followed by tetracycline with 37.6% and amoxicillin with 27.6%. From the total, 32 resistance profiles were identified, being 60.7% of the strains were resistant to at least one antibiotic. Of these, 31.7% of the isolates showed multidrug resistance profiles belonging to serovar Minnesota, Saintpaul, and S. enterica. The highest resistance was found in isolates from slaughterhouse (66.9%) and aviary (58.7%). A large number of strains showed MIC above the maximum tested concentration for the antibiotics amoxicillin and sulfamethoxazole. The high number of Salmonella's resistant strains indicates the need for prudent use of these drugs in poultry production in order to reduce the occurrence and spread of antibiotic resistance profiles, and the risk that multiresistant strains isolated from broilers may pose a risk to human health.

Topics: Abattoirs; Amoxicillin; Animals; Anti-Bacterial Agents; Chickens; Disk Diffusion Antimicrobial Tests; Drug Resistance, Multiple, Bacterial; Food Microbiology; Poultry Diseases; Salmonella enterica; Serogroup; Sulfonamides; Tetracycline

During the hatching process, chicks are exposed to opportunistic and/or pathogenic organisms, such as virulent or avirulent Escherichia coli. Virulent E. coli strains have not been feasible for induction of neonatal colibacillosis via in ovo challenge due to high embryonic mortality. In this manuscript, we describe the addition and co-administration of the bacteriostatic antibiotic tetracycline to a virulent E. coli challenge culture, improving hatchability and livability of seeder chicks while allowing robust horizontal transmission in the hatching cabinet to contact chicks. Experiment 1 consisted of 3 trials. Experiment 1, trial 1 was conducted to determine an effective ratio of E. coli challenge and tetracycline dose to be utilized in the seeder model. Trials 2 and 3 were conducted to evaluate the transmission of E. coli from seeder to contact chicks. Experiment 2 consisted of 3 independent 7-D trials where body weight gain (BWG), mortality, and selected enteric bacterial recovery were evaluated. In trials 1 to 3, significantly (P < 0.05) more Gram-negative bacteria were recovered from whole gut samples (GIT) vs. negative controls on day of hatch, from both seeder and contact chicks. At day 7 in trial 1, contact chicks had significantly (P < 0.05) more Gram-negative bacteria recovered from the GIT than the negative control, but not in trials 2 and 3. Presumptive lactic acid bacterial recovery was elevated in contact and seeder chicks compared to the negative control in all 3 trials. Contact challenge caused a significant (P < 0.05) reduction in BWG in 2 out of 3 trials at day 7, and there was a significant (P < 0.05) increase in mortality as compared to the negative controls in all trials. These data suggest that co-administration of a virulent E. coli strain with tetracycline allows for hatch of direct challenged chicks and effective horizontal transmission to contact chicks during the hatching process, as evidenced by reduced day 7 performance and altered selected enteric bacterial recovery.

Topics: Animals; Anti-Bacterial Agents; Chickens; Disease Models, Animal; Escherichia coli; Escherichia coli Infections; Ovum; Poultry Diseases; Tetracycline; Virulence

Campylobacter spp. is a major cause of foodborne diseases in humans, particularly when transmitted by the handling or consumption of undercooked poultry meat. Most Campylobacter infections are self-limiting, but antimicrobial treatment (e.g., fluoroquinolones and macrolides) is necessary in severe or prolonged cases. The indiscriminate use of these drugs, both in clinical medicine and animal production, has a major impact on public health. The aim of the present study was to identify Campylobacter strains, isolated from turkey and broilers, using both PCR and the matrix-assisted laser desorption-ionization time-of-flight (MALDI-TOF) methods to reveal the accuracy of identification, as well to evaluate the antimicrobial and genetic resistance of the investigated strains. MALDI-TOF and PCR methods were used to show differences, if any, in the specificity of that test. In this study, MALDI-TOF mass spectrometry gave the same results as multiplex PCR, in all cases. The highest rate of resistance (i.e., 100% of turkey and broiler strains) was detected against ciprofloxacin, whereas 58.1% of turkey and 78.6% of broiler strains were resistant to tetracycline. Multidrug-resistant isolates were not found in the study. All ciprofloxacin-resistant strains had a mutation in the gyrA gene, at the Thr-86 position. The presence of the tetO gene was found in 71% of turkey and in 100% of broiler strains. All resistant to tetracycline strains included tetO gene. Additionally, in five turkey and three broiler strains, susceptible to tetracycline, tetO gene was present. These results indicate the high prevalence of Campylobacter strains, which are phenotypically and genetically resistant to fluoroquinolones and tetracycline.

Topics: Animals; Anti-Bacterial Agents; Bacterial Proteins; Campylobacter coli; Campylobacter Infections; Campylobacter jejuni; Carrier Proteins; Chickens; Ciprofloxacin; DNA Gyrase; Drug Resistance, Bacterial; Farms; Feces; Gene Expression; Humans; Microbial Sensitivity Tests; Multiplex Polymerase Chain Reaction; Poland; Poultry; Poultry Diseases; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; Tetracycline; Turkeys

To estimate the prevalence of antibiotic resistance in indicator bacteria Escherichia coli and Enterococci isolated from duck faeces in Morogoro Municipality, Tanzania.. Escherichia coli and Enterococcus isolation rates from ducks faeces were 91 and 100% respectively. The prevalence of antibiotic resistance of E. coli and Enterococcus was 70.3 and 42%, respectively. E. coli resistant to four antibiotics were 28 (30.8%) and showed high resistance to ampicillin (81.3), tetracycline (75.8) and trimethoprim-sulphamethoxine (62.3). Multiple antibiotic resistance of Enterococcus were more than 65%. High resistance rates shown by Enterococcus were observed in rifampin (62%), ampicillin (62%) and tetracycline (42%). Almost all farmers (92.3%) left their ducks to scavenge for food around their houses. Antibiotics used in animal treatments were oxytetracyclines, sulfonamides, penicillin dihydrostreptomycin while in humans were tetracycline, ampicillin, and amoxicillin.

Topics: Ampicillin; Animals; Anti-Bacterial Agents; Asymptomatic Diseases; Drug Resistance, Multiple, Bacterial; Ducks; Enterococcus; Escherichia coli; Escherichia coli Infections; Feces; Female; Humans; Male; Microbial Sensitivity Tests; Poultry; Poultry Diseases; Rifampin; Streptococcal Infections; Tanzania; Tetracycline; Trimethoprim, Sulfamethoxazole Drug Combination

Topics: Animals; Anti-Bacterial Agents; Chickens; Culture Media; Disease Outbreaks; Drug Resistance, Multiple, Bacterial; Haemophilus Infections; Haemophilus paragallinarum; Microbial Sensitivity Tests; Netherlands; Polymerase Chain Reaction; Poultry; Poultry Diseases; Serogroup; Tetracycline

The presence of Staphylococcus aureus in poultry and poultry products, including eggs, increases its potential to enter the food chain, resulting in foodborne diseases. In this context, eggshell colonization by staphylococci may represent a risk factor. This study aimed to investigate the contamination of rural eggshell by S. aureus and to characterize the key features of the isolated strains.. Antibiotic resistance was assessed by disc diffusion. Resistant isolates were analysed by PCR for the identification of associated genetic determinants of resistance. PCR was also used to screen for the presence of genes coding for toxins, namely, sea, sec, sei, sem, seo and tst. The genetic characterization was extended by means of agr locus typing and spa typing.. 34 S. aureus were isolated. Macrolide- and tetracycline-resistant strains were prevalent. All strains were susceptible to oxacillin, cefoxitin and trimethoprim-sulfamethoxazole. PCR screening for genes encoding enterotoxins detected several virulence patterns, which, together with spa-typing and agr-locus typing, allowed cluster analysis and the description of novel clones.. Continuous monitoring of staphylococci is needed also in rural or natural settings. Increasing the number of samples and expanding the geographical region will be needed to further extend the significance of the study.

Topics: Animals; Anti-Bacterial Agents; Chickens; Drug Resistance, Bacterial; Egg Shell; Humans; Macrolides; Microbial Sensitivity Tests; Poultry Diseases; Staphylococcal Infections; Staphylococcus aureus; Tetracycline

There is an urgent need for novel antibiotics as the current antibiotics are losing their value due to increased resistance among clinically important bacteria. Sertraline, an on-marked anti-depressive drug, has been shown to modify bacterial activity in vitro, including increasing the susceptibility of Escherichia coli to antibiotics. The aim of the present study was to investigate if the antimicrobial activity of sertraline could be documented under clinical settings, hereunder if sertraline could potentiate the effect of tetracycline in treatment of an experimentally induced ascending infection in poultry. A total of 40 chickens were divided in four groups of 10 chickens each. All chickens were challenged with 4x103 colony forming units (CFU) of a tetracycline resistant E. coli strain using a surgical infection model, and subsequently treated with either high-dose sertraline, tetracycline, a combination hereof or received no treatment. Seven days post challenge all birds were submitted to necropsy and scored pathologically for lesions. The average lesion scores were significantly higher (P<0.05) in the groups that were treated with high-dose sertraline or high-dose sertraline combined with tetracycline. In conclusion high-dose treatments (four times the maximum therapeutic dose for treating human depression) with sertraline as an adjuvant for treatment of antibiotic resistant E. coli infections exacerbate the pathological outcome of infection in chickens.

Topics: Animals; Antidepressive Agents; Body Weight; Chickens; Colony Count, Microbial; Disease Progression; Dose-Response Relationship, Drug; Drug Synergism; Escherichia coli; Escherichia coli Infections; Fallopian Tubes; Female; Immunohistochemistry; Liver; Poultry Diseases; Sertraline; Tetracycline

In Campylobacter spp., resistance to the antimicrobials kanamycin and tetracycline is frequently associated with plasmid-borne genes. However, relatively few plasmids of Campylobacter jejuni have been fully characterized to date. A novel plasmid (p11601MD; 44,095nt) harboring tet(O) was identified in C. jejuni strain 11601MD, which was isolated from the jejunum of a turkey produced conventionally in North Carolina. Analysis of the p11601MD sequence revealed the presence of a high-GC content cassette with four genes that included tet(O) and a putative aminoglycoside transferase gene (aphA-3) highly similar to kanamycin resistance determinants. Several genes putatively involved in conjugative transfer were also identified on the plasmid. These findings will contribute to a better understanding of the distribution of potentially self-mobilizing plasmids harboring antibiotic resistance determinants in Campylobacter spp. from turkeys and other sources.

Topics: Animals; Anti-Bacterial Agents; Bacterial Proteins; Base Composition; Base Sequence; Campylobacter jejuni; Carrier Proteins; Conjugation, Genetic; DNA, Bacterial; Jejunum; Kanamycin; Kanamycin Kinase; Microbial Sensitivity Tests; North Carolina; Plasmids; Poultry Diseases; Sequence Analysis, DNA; Tetracycline; Tetracycline Resistance; Turkeys

1. Tetracycline resistance determinants are widespread among bacterial species. Resistance to tetracycline occurs by different mechanisms regulated by various genes. 2. The study was conducted to determine the tetracycline resistance and prevalence of tetracycline resistance determinants among Escherichia coli strains isolated from broilers in northern Iran. 3. Minimum inhibitory concentration (MIC) of tetracycline and susceptibility pattern of the isolates were screened using micro-dilution and disk diffusion methods, respectively. The presence of 7 tetracycline resistance genes including tetA, tetB, tetC, tetD, tetE, tetG and tetM was tested using the polymerase chain reaction. 4. Among 100 strains isolated from broilers, 73% were identified as tetracycline resistant. All isolates showed the presence of tetracycline-associated genes. The most prevalent genes were tetA (46%) and tetB (41%) and totally, 17 different genotypes were recognised according to the presence of tetracycline resistance genes. Statistical analysis revealed that concomitant presence of the resistance genes significantly increased the tetracycline MIC and effectiveness of phenotypic characterisation. 5. The results demonstrated a high occurrence of tetracycline-resistant E. coli and related genes among broilers which presents a risk of increasing these strains in human infections associated with food animals.

Topics: Animals; Anti-Bacterial Agents; Chickens; Escherichia coli; Escherichia coli Infections; Iran; Microbial Sensitivity Tests; Polymerase Chain Reaction; Poultry Diseases; Prevalence; Tetracycline; Tetracycline Resistance

Topics: Animals; Anti-Infective Agents; Chickens; Child; Diagnosis, Differential; Drug Eruptions; Eggs; Food Contamination; Humans; Male; Poultry Diseases; Pyrimethamine; Sulfadiazine; Tetracycline

The aim of this study was to investigate the resistance mechanisms of quinolones, macrolides and tetracycline in campylobacter isolates from grandparent and parent broiler breeders in Spain. Twenty-six isolates were investigated for quinolone resistance, three isolates for macrolide resistance and 39 for tetracycline resistance. All of the quinolone-resistant isolates possessed the mutation Thr86Ile in the quinolone resistance-determining region of gyrA and one isolate possessed the mutation Pro104Ser. Only one Campylobacter coli population (defined by restriction fragment length polymorphism-polymerase chain reaction of flaA and pulsed field gel electrophoresis) was resistant to erythromycin, and the mutation A2075G (23S rDNA) was responsible for macrolide resistance. The tetO gene was found in all of the tetracycline-resistant isolates. Twenty-two out of the 39 isolates investigated by Southern blot possessed chromosomic location of tetO and 17 were located on plasmids. Most of the plasmids with tetO were of around 60 kb and conjugation was demonstrated in a selection of them. In conclusion, we showed that Thr86Ile is highly prevalent in quinolone-resistant isolates as well as mutation A2075G in macrolide-resistant isolates of poultry origin. More variability was found for tetO. The possibility of horizontal transmission of tetO among campylobacter isolates is also an issue of concern in public health.

Topics: Amino Acid Substitution; Animals; Anti-Bacterial Agents; Bacterial Typing Techniques; Base Sequence; Campylobacter; Campylobacter Infections; Chickens; Drug Resistance, Multiple, Bacterial; Macrolides; Microbial Sensitivity Tests; Molecular Sequence Data; Mutation; Plasmids; Polymorphism, Restriction Fragment Length; Poultry Diseases; Quinolones; Sequence Analysis, DNA; Spain; Tetracycline

Methicillin-resistant Staphylococcus aureus (MRSA) has long been recognized as an important pathogen in human medicine leading to hospital and community-acquired infections. However, it is now also considered a growing problem in veterinary medicine, although causing little or no disease. Although MRSA has already been detected in livestock including poultry, little is known about the epidemiology of MRSA in broiler and layer chickens. We therefore investigated 372 poultry farms in Belgium. We also compared the isolation method recommended by the European Food Safety Authority using two enrichment steps with an isolation method using only one enrichment step. Isolated MRSA was characterized by means of antimicrobial resistance profiling, spa typing, multi-locus sequence typing, and SCCmec typing. MRSA prevalence was 0.8% using the double broth enrichment method, while using the single broth enrichment method it was 1.8%. Five MRSA strains belonged to the livestock-associated (LA) MRSA ST398 (four with spa type t011 and one with t899), and three to the hospital-acquired MRSA ST239 spa type t037. The ST239 strains carried SCCmec type III while those belonging to ST398 carried SCCmec type IV or V. All isolates showed additional resistance to erythromycin and tetracycline apart from the expected resistance to cefoxitin and penicillin. All strains were susceptible to linezolid, mupirocin and vancomycin. In conclusion, a higher sensitivity for the isolation of LA-MRSA was obtained using only one enrichment step. While the typical LA-MRSA ST398 was present at low prevalence in poultry, human-associated strains have also been found.

Topics: Animals; Belgium; Cell Culture Techniques; Chickens; Drug Resistance, Bacterial; Erythromycin; Likelihood Functions; Methicillin-Resistant Staphylococcus aureus; Multilocus Sequence Typing; Poultry Diseases; Prevalence; Staphylococcal Infections; Tetracycline

The objective of this study was to determine the prevalence of Campylobacter and Salmonella in broilers and their distribution in the indoor and outdoor farm environment. Nine hundred samples (400 faecal; 300 indoor environment; 200 outdoor environment), were collected from 10 individual broiler houses on 10 farms. Campylobacter jejuni prevalence was significantly higher (P=0.003) in faeces (29.5%; 118/400) than the environment (0.8%; 4/500) in contrast to Salmonella Typhimurium from faecal (8.8%; 35/400) and environmental (8.4%; n=42/500) sources (P=0.217). S. Typhimurium predominantly exhibited antimicrobial resistance (AR) to streptomycin (46%) and tetracycline (31.5%). C. jejuni isolates exhibited AR only to tetracycline (55.5%). The PFGE profile revealed 100% similarity between S. Typhimurium isolates from faecal and environmental sources. No relationship was detected between C. jejuni isolates. The low prevalence of Campylobacter and Salmonella in the outdoor environment indicates that it may not be a significant reservoir for transmission of these pathogens on broiler farms.

Topics: Animal Husbandry; Animals; Campylobacter Infections; Campylobacter jejuni; Chickens; Drug Resistance, Microbial; Environmental Microbiology; Feces; Housing, Animal; Microbial Sensitivity Tests; Poultry Diseases; Salmonella Infections, Animal; Salmonella typhimurium; Streptomycin; Tetracycline

The experiment was performed to investigate the tetracycline resistance and antibiotic-resistant genotype of avian Escherichia coli in North China and to analyze the correlation of genotype and phenotype. The resistance of 164 E. coli isolates (from Beijing, Tianjin, inner Mongolia, Shanxi, and Hebei regions of China) to tetracycline, doxycycline, and minocycline was investigated by using a drug susceptibility test. The results show that the rate of resistance to tetracycline antibiotics was 89.63% (147/164). The higher resistance rate was 84.76% (139/164) to tetracycline and 70.12% (115/164) to doxycycline, and the lowest resistance rate was 4.88% (8/164) to minocycline. The distribution of tetracycline resistance (Tcr) genes (tetA, tetB, tetC, and tetM) in avian E. coli isolates was detected by PCR. Of the isolates, 82.32% (135/164) carried tetracycline resistance genes. The positive rates of tetA, tetB, and tetM were 57.93% (95/164), 38.41% (63/164), and 10.97% (18/164), respectively. No tetC was amplified in avian E. coli isolates. The total positive rate of resistance genes (82.32%) was almost equal to the total rate of resistance to tetracycline antibiotics (89.63%). Thus, the positive rate of genotype was basically in line with that of phenotype for tetracycline resistance. The tetracycline resistance genes are widely distributed in E. coli and their main resistance mechanism to tetracycline is the active efflux effect mediated by tetA and tetB.

Topics: Animals; Anti-Bacterial Agents; Chickens; China; Escherichia coli; Escherichia coli Infections; Genotype; Poultry Diseases; Tetracycline; Tetracycline Resistance

The present investigation was undertaken to identify and characterize the tetracycline resistance determinant in 22 Gallibacterium anatis strains for which no determinant was identified using primers specific for tet(A, B, C, D, E, G, H, K, L, M, O). A recent study found tet(B) to be the most prevalent tetracycline resistance determinant in a larger collection of G. anatis field strains from Mexico and Denmark. However, in 41% of the tetracycline resistant strains no determinant could be assigned. Here we demonstrate that tet(31) is a common determinant in G. anatis originating from chickens from very different production systems and localities. In addition, tet(31) was identified in strains isolated over a 30-year period. This is the first report on tet(31) since its original identification in Aeromonas salmonicida.

Topics: Animals; Anti-Bacterial Agents; Chickens; Denmark; Genes, Bacterial; Mexico; Pasteurellaceae; Pasteurellaceae Infections; Poultry Diseases; Tetracycline; Tetracycline Resistance

Enterococcus hirae infections are reported to cause growth depression, encephalomalacia, endocarditis, and septicemia in chickens. This report describes osteomyelitis in the proximal femur of a 3-week-old broiler chicken that also suffered from valvular endocarditis and liver necrosis. Histologically, clusters of gram-positive coccoid bacteria were found in many organs, including bone lesions. In tissues from 5 of 6 examined chickens from the same flock, E hirae was isolated in large numbers. To the authors' knowledge, this is the first report of spontaneous bacterial osteomyelitis where E hirae was cultured from bone and where coccoid bacteria consistent with Enterococcus spp were simultaneously demonstrated within bone lesions.

Topics: Ampicillin; Animals; Anti-Bacterial Agents; Bacterial Typing Techniques; Chickens; DNA, Bacterial; DNA, Ribosomal; Endocarditis, Bacterial; Enterococcus; Gram-Positive Bacterial Infections; Norway; Osteomyelitis; Poultry Diseases; RNA, Ribosomal, 16S; Sequence Analysis, DNA; Tetracycline

To detect antimicrobial resistance genes in Salmonella isolates from turkey flocks using the microarray technology.. A 775 gene probe oligonucleotide microarray was used to detect antimicrobial resistance genes in 34 isolates. All tetracycline-resistant Salmonella harboured tet(A), tet(C) or tet(R), with the exception of one Salmonella serotype Heidelberg isolate. The sul1 gene was detected in 11 of 16 sulfisoxazole-resistant isolates. The aadA, aadA1, aadA2, strA or strB genes were found in aminoglycoside-resistant isolates of Salm. Heidelberg, Salmonella serotype Senftenberg and untypeable Salmonella. The prevalence of mobile genetic elements, such as class I integron and transposon genes, in drug-resistant Salmonella isolates suggested that these elements may contribute to the dissemination of antimicrobial resistance genes in the preharvest poultry environment. Hierarchical clustering analysis demonstrated a close relationship between drug-resistant phenotypes and the corresponding antimicrobial resistance gene profiles.. Salmonella serotypes isolated from the poultry environment carry multiple genes that can render them resistant to several antimicrobials used in poultry and humans.. Multiple antimicrobial resistance genes in environmental Salmonella isolates could be identified efficiently by microarray analysis. Hierarchical clustering analysis of the data was also found to be a useful tool for analysing emerging patterns of drug resistance.

Topics: Animals; Anti-Bacterial Agents; Cluster Analysis; DNA Probes; DNA, Bacterial; Drug Resistance, Multiple, Bacterial; Environmental Microbiology; Microbial Sensitivity Tests; Oligonucleotide Array Sequence Analysis; Poultry Diseases; Salmonella enterica; Salmonella Infections, Animal; Serotyping; Tetracycline; Turkeys

Campylobacter jejuni antibiotic resistance is rising with a variable geographical pattern; but there is limited data from the Arabian Gulf region. We assessed the sensitivity of human (117) and chicken (33) C. jejuni isolates to erythromycin, ciprofloxacin, tetracycline and trimethoprim-sulfamethoxazole by agar dilution, disc diffusion and the E test. Only 2 human isolates were resistant to erythromycin. In contrast, over 80% of chicken and human isolates were resistant to ciprofloxacin. A significantly higher proportion of chicken isolates than human isolates were resistant to tetracycline, with much higher MIC(50) values (P < 0.001). The MIC(90) for trimethoprim-sulfamethoxazole by agar dilution was 40 microg/ml. Comparison of the results of the agar dilution method and E test showed 1 major disagreement and 8 minor disagreements for erythromycin, 4 major disagreements for ciprofloxacin and 23 disagreements for tetracycline (19 were major disagreements). This was the first study to describe the pattern of antibiotic resistance in Campylobacter isolates in this region; the results indicate a high degree of erythromycin sensitivity that validates the continued use of this agent as a first-line therapy for Campylobacter enteritis. These findings have wide implications because of the large, highly mobile expatriate population in this setting. In addition, the correlation between agar dilution and disc diffusion supports the use of the latter as an alternative susceptibility testing method for Campylobacter.

Topics: Animals; Anti-Bacterial Agents; Campylobacter Infections; Campylobacter jejuni; Chickens; Ciprofloxacin; Colony Count, Microbial; Drug Resistance, Bacterial; Erythromycin; Humans; Microbial Sensitivity Tests; Poultry Diseases; Tetracycline; Trimethoprim, Sulfamethoxazole Drug Combination

Salmonella Hadar, Salmonella Brancaster and Salmonella Enteritidis are the main Salmonella enterica ssp. enterica serovars isolated from poultry in Senegal. Our objective was to analyse the pulsed-field gel electrophoresis (PFGE) and antibioresistance patterns of strains belonging to these serovars and to assess the significance of broiler-chicken meat as a source of human infection.. A total of 142 Salmonella isolates were analysed: 79 were isolated from Senegalese patients with sporadic diarrhoea (11 S. Hadar, nine S. Brancaster and 59 S. Enteritidis) and 63 from poultry (30 S. Hadar, 17 S. Brancaster and 16 S. Enteritidis). The PFGE of XbaI- and SpeI-digested chromosomal DNA gave 20 distinct profiles for S. Hadar, nine for S. Brancaster and 22 for S. Enteritidis. Each serovar was characterized by a major pulsotype which was X3S1 in 42% of S. Hadar, X8S1 in 53.8% of S. Brancaster and X1S2 in 43% of S. Enteritidis isolates. Human and poultry isolates of Salmonella had common PFGE patterns. Antibiosensitivity tests showed multiresistance (more than two drugs) was encountered in 14.5% of S. Hadar and in 5% of S. Enteritidis isolates. Resistance to quinolones was considered to be of particular importance and 14.5% of S. Hadar isolates were found to be resistant to nalidixic acid. CONLCUSIONS: The sharing of similar PFGE profiles among isolates from humans and poultry provided indirect evidence of Salmonella transmission from contaminated broiler meat. But most of the Salmonella isolates remained drug sensitive.. Efforts are needed to eliminate Salmonella from poultry meat intended for human consumption. This study has also highlighted the importance of continuous surveillance to monitor antimicrobial resistance in bacteria associated with animals and humans.

Topics: Ampicillin; Animals; Anti-Bacterial Agents; Anti-Infective Agents; Chickens; Chloramphenicol; DNA, Bacterial; Drug Resistance, Multiple, Bacterial; Electrophoresis, Gel, Pulsed-Field; Gentamicins; Humans; Nalidixic Acid; Phylogeny; Poultry Diseases; Quinolines; Salmonella enterica; Salmonella enteritidis; Salmonella Infections; Salmonella Infections, Animal; Senegal; Tetracycline; Trimethoprim, Sulfamethoxazole Drug Combination

The isolation and antimicrobial resistance of Campylobacter jejuni and Campylobacter coli strains from broilers arriving in French slaughterhouses, were analysed according to production types (i.e. standard, export or free-range) and antimicrobial (i.e. coccidiostats, growth promoters or therapeutic agents) administration in flocks. Prevalence was 56.6% in standard, 51.3% in export and 80.0% in free-range broilers. Three hundred and ninety-three strains were identified. Two-thirds of the strains belonged to the species C. jejuni. The others were C. coli. Antimicrobial susceptibility testing was carried out for ampicillin, nalidixic acid, enrofloxacin, tetracycline, erythromycin and gentamicin according to a dilution method. The percentages of resistant strains were, 23, 25, 17, 57, 0.3 and 0% for C. jejuni and 29, 43, 40, 70, 31 and 0% for C. coli. Statistical analysis revealed significant difference in distribution of C. jejuni and C. coli and antimicrobial resistance according to production type or antimicrobial administration.

Topics: Ampicillin; Animals; Anti-Bacterial Agents; Campylobacter coli; Campylobacter Infections; Campylobacter jejuni; Chickens; DNA, Bacterial; Drug Resistance, Multiple, Bacterial; Enrofloxacin; Erythromycin; Fluoroquinolones; Gentamicins; Microbial Sensitivity Tests; Nalidixic Acid; Polymerase Chain Reaction; Poultry Diseases; Quinolones; Tetracycline

Cecal contents (16 samples/each flock) of broilers derived from 212 flocks were investigated for colonization of Campylobacter from 1995 to 1999 in the southern part of Japan, and the isolates were tested for antimicrobial susceptibilities. C. jejuni-positive flocks numbered 42 (19.8%) and C. coli-positive ones 26 (12.3%); Campylobacter spp. were recovered from 68 flocks (32.1%) in total. MICs of ampicillin, erythromycin (EM), tetracycline, nalidixic acid (NA), norfloxacin (NFLX), and ofloxacin (OFLX) to these 68 Campylobacter isolates were determined. Quinolone-resistant Campylobacter isolates numbered 22 (32.4%). All the isolates except one were cross-resistant to NA, OFLX, and NFLX. A high frequency of quinolone-resistance was found in both C. jejuni and C. coli, whereas a high level of EM-resistance was found in only C. coli strains. All C. jejuni isolates were sensitive to EM.

Topics: Ampicillin; Animals; Anti-Bacterial Agents; Anti-Infective Agents; Campylobacter coli; Campylobacter Infections; Campylobacter jejuni; Cecum; Chickens; Drug Resistance, Microbial; Erythromycin; Japan; Microbial Sensitivity Tests; Nalidixic Acid; Norfloxacin; Ofloxacin; Penicillins; Poultry Diseases; Tetracycline

Fishy or unpleasant egg taint occurred in a high frequency (10%) in a herd of brown layers. The hens were fed a commercial standard diet, that did not contain the known critical ingredients as fish meal or rape seed and had an average choline concentration. Sensory tests of the drinking water did not reveal any abnormalities. In a subsequent feeding trial an oral antibiotic treatment with neomycin alone had no positive effects while neomycin and tetracycline reduced egg taint significantly until it became almost normal. Microbial activities in the GI tract were therefore obviously responsible for the egg taint.

Topics: Animal Feed; Animals; Anti-Bacterial Agents; Chickens; Color; Digestive System; Eggs; Female; Neomycin; Odorants; Poultry Diseases; Tetracycline

Avian leukosis virus (ALV) is an economically important pathogen of chickens. Both antisense RNA and antisense oligodeoxynucleotides (ODN) have been used to diminish the replication and spread of other retroviruses. The use of antisense RNA and ODN to inhibit ALV replication has been examined in cultured RP30 cells. Using an expression system that constitutively transcribes antisense ALV RNA, one transfected cell clone showed a significant reduction in virus growth. However, this effect was not reproducibly observed in other transfected cell lines or in cells in which the antisense transcript was expressed from a regulatable promoter, even though a substantial amount of antisense transcript was generated. Antisense ODN complementary to several different target sites near the 5' end of the ALV genome were also tested for antiviral activity, by comparison of antisense ODN effects to those of randomized sequence controls. An antisense ODN complementary to the ALV primer binding site demonstrated a reproducible reduction in viral replication. However, when the corresponding region was specifically employed as a target for intracellular antisense RNA expression, there again was no significant inhibition of ALV. These results suggest that in vivo expression of antisense RNA is unlikely to be an effective way to generate transgenic poultry that are resistant to field strains of ALV.

Topics: Animals; Avian Leukosis Virus; Cell Line, Transformed; Gene Expression; Genes, Viral; Lymphocytes; Oligodeoxyribonucleotides, Antisense; Poultry Diseases; Reverse Transcriptase Polymerase Chain Reaction; RNA, Antisense; Tetracycline; Transfection; Turkeys; Virus Replication

A series of experiments was carried out to investigate the efficacy of the competitive exclusion technique in the control of Salmonella in broiler chicks. Anaerobic overnight culture obtained using 10(-3) g ml-1 caecal material in VL-broth medium provided total exclusion of a moderate S. enteritidis challenge (1.2 x 10(2) cells/chick). Increasing the challenge level resulted in less protection, but significant protection occurred at an excessive S. enteritidis challenge level of 1.5 x 10(6) cells/chick. The effectiveness of protection using both moderate and excessive challenges was monitored in newly hatched chicks until they were 22 days old. An improvement in growth performance in terms of higher body weight, feed consumption and feed conversion, in addition to lower mortality, was observed. The use of other control measures such as antimicrobial feed additives or lactose sugar (1.5% w/v) in the drinking water in combination with the competitive microflora treatment resulted in a better overall protection and performance.

Topics: Animals; Anti-Bacterial Agents; Anti-Infective Agents, Local; Bacitracin; Chickens; Poultry Diseases; Salmonella enteritidis; Salmonella Infections, Animal; Tetracycline

Recently, an increased resistance of Campylobacter to fluoroquinolones, a newer class of antimicrobial agents in both human and veterinary medicine, has been reported. Campylobacter isolates (617) from 150 broiler flocks were tested for their susceptibility to cephalothin (control), ampicillin, tetracycline, erythromycin, and the quinolones nalidixic acid, flumequine, enrofloxacin, and ciprofloxacin by a disc diffusion method. Almost complete cross-resistance was found between the quinolones tested. Campylobacter isolates (181, 29%), originating from 55 flocks (37%), were quinolone resistant. Salmonella isolates (94) from 40 flocks were also tested for their antimicrobial susceptibility. Eight isolates (8.5%), from three broiler flocks (7.5%), showed resistance to nalidixic acid and flumequine (and tetracycline), but not to ciprofloxacin or enrofloxacin.

Topics: 4-Quinolones; Ampicillin; Animals; Anti-Bacterial Agents; Anti-Infective Agents; Campylobacter; Campylobacter Infections; Chickens; Erythromycin; Microbial Sensitivity Tests; Netherlands; Poultry Diseases; Salmonella; Salmonella Infections, Animal; Tetracycline

Topics: Agglutination Tests; Animals; Antibodies, Bacterial; Bordetella; Bordetella Infections; Drug Therapy, Combination; Poultry; Poultry Diseases; Sulfanilamides; Sulfaquinoxaline; Tetracycline; Trimethoprim; Turkeys

Topics: Aminoglycosides; Animals; Animals, Domestic; Anti-Bacterial Agents; Cat Diseases; Cats; Cattle; Cattle Diseases; Cephalosporins; Chickens; Chloramphenicol; Dog Diseases; Dogs; Erythromycin; Gentamicins; Haplorhini; Kanamycin; Lactones; Lincomycin; Neomycin; Novobiocin; Penicillins; Poultry Diseases; Rabbits; Streptomycin; Sulfonamides; Tetracycline

Topics: Animal Feed; Animals; Anti-Bacterial Agents; Cattle; Cattle Diseases; Chickens; Chloramphenicol; Drug Resistance, Microbial; Escherichia coli; Extrachromosomal Inheritance; Feces; Furazolidone; Humans; Intestines; Oxytetracycline; Poultry Diseases; Public Health; R Factors; Salmonella; Salmonella Infections; Salmonella Infections, Animal; Salmonella Phages; Salmonella typhimurium; Shigella; Swine; Tetracycline

Topics: Animal Feed; Animals; Bacterial Infections; Chickens; Drug Evaluation; Poultry Diseases; Tetracycline

Topics: Animals; Bacitracin; Cecum; Chickens; Diet; Food Additives; Intestines; Poultry Diseases; Salmonella; Salmonella Infections, Animal; Tetracycline; Zinc

Topics: Administration, Oral; Animal Feed; Animals; Cecum; Chickens; Crop, Avian; Female; Intestine, Small; Male; Poultry Diseases; Salmonella; Salmonella Infections, Animal; Tetracycline

Topics: Air Sacs; Alkaline Phosphatase; Animals; Bone Diseases; Calcium; Femur; Locomotion; Microscopy, Electron, Scanning; Periosteum; Phosphorus; Poultry Diseases; Selenium; Tetracycline; Tibia; Turkeys; Vitamin E

Of 173 epidemiologically unrelated strains of Escherichia coli isolated from the pericardial sac of chickens that had died from infection with these organisms in England in 1972, approximately 1 year after the introduction of legislation forbidding the routine use of feeds containing ;therapeutic' antibiotics, 83.8% were resistant to sulphonamides, 31.2% to tetracyclines, 20.8% to furazolidone, 18.5% to streptomycin, 2.9% to spectinomycin and 1.2% to ampicillin; none of the strains were resistant to chloramphenicol, neomycin, polymixin, trimethoprim or nalidixic acid. The sulphonamide resistance and possibly some of the resistance to other agents might have been the consequence of sulphonamides being exempted from the legislation. Much of the resistance, with the exception of that to furazolidone, was of the transferable type. Many strains possessed transfer factors in the absence of any known transferable characteristic. Colicine production was twice as common in the pathogenic strains as in a collection of strains isolated from the faeces of healthy chickens; about half of it was transferable.By means of serology, antibiotic resistance and other markers, it was found that several different kinds of E. coli were usually incriminated in any one outbreak of E. coli infection in broiler chickens. Sometimes the same kinds of E. coli were found in outbreaks in consecutive crops of chickens on the same farm. New kinds, too, appeared to be brought in by replacement chickens.

Topics: Ampicillin; Animals; Chickens; Colicins; Epidemiologic Methods; Escherichia coli; Escherichia coli Infections; Furazolidone; Penicillin Resistance; Poultry Diseases; Serotyping; Spectinomycin; Streptomycin; Sulfonamides; Tetracycline

Topics: Animals; Anti-Bacterial Agents; Chloramphenicol; Mycoplasma Infections; Poultry Diseases; Salts; Tetracycline

Topics: Aerosols; Animals; Chickens; Escherichia coli Infections; Methods; Mycoplasma Infections; Poultry Diseases; Tetracycline

Topics: Animals; Catalase; Chick Embryo; Cilia; Culture Media; Glucose; Mycoplasma; Neuraminidase; Organ Culture Techniques; Poultry Diseases; Tetracycline; Toxins, Biological; Trachea

Topics: Aerosols; Animal Feed; Animals; Anti-Bacterial Agents; Injections; Poultry; Poultry Diseases; Tetracycline; Water

Topics: Animal Feed; Animals; Anti-Bacterial Agents; Bacitracin; Copper; Costs and Cost Analysis; Growth; Poultry Diseases; Swine; Swine Diseases; Tetracycline; United Kingdom

Topics: Animals; Chickens; Food Analysis; Food Contamination; Poultry Diseases; Tetracycline

Topics: Animals; Chickens; Drug Resistance, Microbial; Ducks; Poultry Diseases; Salmonella; Salmonella Infections, Animal; Streptomycin; Sulfonamides; Tetracycline; Turkeys

Topics: Animals; Chickens; Chlortetracycline; Poultry Diseases; Protozoan Infections; Protozoan Infections, Animal; Tetracycline

Topics: Animals; Chickens; Chlortetracycline; Oxytetracycline; Poultry Diseases; Protozoan Infections; Protozoan Infections, Animal; Tetracycline

Topics: Age Factors; Animal Diseases; Animals; Bronchopneumonia; Cattle; Chickens; Chlortetracycline; Delayed-Action Preparations; Ducks; Pasteurella Infections; Poultry Diseases; Rhinitis, Atrophic; Salmonella Infections, Animal; Swine; Swine Diseases; Tetracycline

Topics: Animals; Cattle; Cattle Diseases; Drug Resistance, Microbial; Escherichia coli; Escherichia coli Infections; Poultry Diseases; Salmonella typhi; Salmonella typhimurium; Streptomycin; Sulfonamides; Swine; Swine Diseases; Tetracycline

Topics: Animals; Chickens; Chloramphenicol; Escherichia coli; Poultry Diseases; Serotyping; Streptomycin; Tetracycline

Topics: Animals; Anti-Bacterial Agents; Chickens; Chlortetracycline; Dihydrostreptomycin Sulfate; Drug Synergism; Mycoplasma Infections; Oxytetracycline; Poultry Diseases; Sulfates; Tetracycline

Topics: Acridines; Animals; Antiprotozoal Agents; Apicomplexa; Chickens; Chlortetracycline; Oxytetracycline; Poultry Diseases; Protozoan Infections; Protozoan Infections, Animal; Tetracycline

Topics: Animals; Penicillin Resistance; Penicillins; Poultry Diseases; Respiratory Tract Infections; Skin; Staphylococcal Infections; Staphylococcus; Tetracycline

Topics: Animals; Bird Diseases; Paranasal Sinuses; Penicillin Resistance; Penicillins; Poultry Diseases; Respiratory Tract Infections; Skin; Staphylococcal Infections; Staphylococcus; Tetracycline

Topics: Agglutination Tests; Animals; Chick Embryo; Joint Diseases; Penicillins; Poultry Diseases; Precipitin Tests; Rats; Streptobacillus; Tetracycline

Osteopetrosis was experimentally produced and lesion development in time was studied by fluorescent illumination of tetracycline labels in the bone. Bones from birds 84, 115, 186 and 354 days of age were examined by ground section under ultraviolet light. Periosteal activity of the tibia and femur was present in normal bones at 84 days of age but had stopped at 115 days. Focal periosteal activity of osteopetrotic lesions was present at 186 days but not at 354 days of age. Slight endosteal activity of osteopetrotic bones was present at 354 days of age. Osteopetrotic bone formed at a rate of 1.26 mm. per week or 6 times faster than normal bone in some of these lesions. Tetracycline diffused throughout the 354-day-old osteopetrotic lesion but not normal compact bone indicating that the osteopetrotic bone is porous and spongy.

Topics: Animals; Fluorescence; In Vitro Techniques; Osteopetrosis; Poultry Diseases; Tetracycline

Topics: Animals; Oleandomycin; Pasteurella Infections; Poultry Diseases; Tetracycline

Topics: Animals; Birds; Pasteurella Infections; Pharmacology; Poultry; Poultry Diseases; Research; Tetracycline

Topics: Animals; Anti-Bacterial Agents; Drug Resistance; Drug Resistance, Microbial; Furazolidone; Kanamycin; Penicillin G; Poultry Diseases; Research; Staphylococcal Infections; Staphylococcus; Streptomycin; Tetracycline