ceftiofur and Poultry-Diseases

The in vitro susceptibilities of 50 field isolates of Riemerella anatipestifer from ducks to ceftiofur and 16 other commonly used antimicrobials were determined. The MIC90 values (MIC refers to minimum inhibitory concentrations) for the antimicrobials used in this study are as follows: penicillin was 16 microg/ml; ceftiofur was 32 microg/ml; cephalothin, chloramphenicol, flumequine, and kanamycin were 64 microg/ml; nalidixic acid, nitrofurantoin, and sulfamethoxazole were 128 microg/ml; amikacin, ampicillin, gentamicin, lincomycin, spectinomycin, streptomycin, tetracycline, and trimethoprim were > or = 256 microg/ml. The therapeutic efficacy of ceftiofur against a highly lethal experimental R. anatipestifer infection in ducks was also evaluated. All experimental ducks were infected through the infraorbital sinus with 1 ml of 9 x 10(9) CFU of R. anatipestifer. Ceftiofur (0, 0.25, 0.5, 1, and 2 mg/kg) was injected subcutaneously 5 hours after infection. A single dose of 2 mg/kg resulted in 73% survival as compared with 10% survival in the infected, but untreated controls.

Topics: Animals; Cephalosporins; Drug Resistance, Multiple, Bacterial; Ducks; Gram-Negative Bacteria; Gram-Negative Bacterial Infections; Microbial Sensitivity Tests; Poultry Diseases

We investigated the characteristics and persistence of Escherichia coli resistant to third-generation cephalosporins (3GCs) by early administration of ceftiofur or gentamicin and to analyze the impact of 3GC use in hatcheries. We studied 10 ceftiofur-treated flocks (CTFs) and 10 gentamicin-treated flocks (GTFs) of layers. Fecal samples were collected at 1, 2, 4, 8, 18, and 30 weeks of age for all flocks. Among the 446 E. coli isolates, 58 (29.0 %) of 200 isolates in CTFs were identified as 3GC-resistant E. coli and 28 (11.4 %) of 246 isolates in GTFs were identified as 3GC-resistant E. coli. The presence of 3GC-resistant E. coli isolates at 1, 2, and 4 weeks was significantly higher in CTFs than in GTFs (p < 0.05). Moreover, the rate of resistance to 3GCs gradually decreased from 83.3 % at 1 week of age to 4.4 % at 30 weeks of age in CTFs. Of the 86 3GC-resistant E. coli isolates, 32 isolates had β-lactamase-encoding gene: bla

Topics: Animals; Anti-Bacterial Agents; beta-Lactamases; Cephalosporins; Chickens; Drug Resistance, Multiple, Bacterial; Escherichia coli; Feces; Gentamicins; Poultry; Poultry Diseases

1. The aim of this study was to analyse the association between Escherichia coli isolates recovered from turkeys and the expression of beta-lactamase genes, such as extended spectrum beta-lactamase (ESBL) and ampicillin class C (AmpC). The phenotype of the resistance profile was examined using the association between amoxicillin and ceftiofur resistance. 2. Results showed that 84% from the turkey isolates harboured 4 or 5 genes associated with the CoIV plasmid. In an antibiogram test, 82% of the isolates were multidrug-resistant, the highest levels of resistance being against erythromycin (99%) and amoxicillin (76.1%). ESBL-positive groups were 31% positive for the ctx-m-2 gene, 6.8% were positive for ctx-m-8 and 70% harboured the tem wild gene. 3. All positive isolates from the AmpC beta-lactamase-positive group harboured the cmy-2 gene. The presence of the cmy-2 gene was associated with both the CTX-group genes and resistance to ceftiofur. 4. There was a high prevalence of avian pathogenic E. coli in suspected cases of colibacillosis in turkeys and a high antimicrobial resistance index. The results highlighted the risk of ceftiofur resistance and the presence of both ESBL and AmpC beta-lactamase E. coli in the turkey production chain.

Topics: Animals; Anti-Bacterial Agents; Bacterial Proteins; beta-Lactamases; Brazil; Cephalosporins; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Phenotype; Poultry Diseases; Prevalence; Turkeys

Topics: Animals; Anti-Bacterial Agents; Bacterial Proteins; beta-Lactamases; Cephalosporins; Chickens; Drug Resistance, Multiple, Bacterial; Food Contamination; Food Microbiology; Japan; Meat; Microbial Sensitivity Tests; Molecular Epidemiology; Poultry Diseases; Prevalence; Salmonella; Salmonella Infections, Animal

Antimicrobials are frequently used for the prevention of avian colibacillosis, with gentamicin used for this purpose in Québec until 2003. Ceftiofur was also used similarly, but voluntarily withdrawn in 2005 due to increasing resistance. Spectinomycin-lincomycin was employed as a replacement, but ceftiofur use was partially reinstated in 2007 until its definitive ban by the poultry industry in 2014. Gentamicin resistance frequency increased during the past decade in clinical Escherichia coli isolates from broiler chickens in Québec, despite this antimicrobial no longer being used. Since this increase coincided with the use of spectinomycin-lincomycin, co-selection of gentamicin resistance through spectinomycin was suspected. Therefore, relationships between spectinomycin, gentamicin, and ceftiofur resistance determinants were investigated here. The distribution of 13 avian pathogenic E. coli virulence-associated genes and their association with spectinomycin resistance were also assessed. A sample of 586 E. coli isolates from chickens with colibacillosis in Québec between 2009 and 2013 was used. The major genes identified for resistance to ceftiofur, gentamicin, and spectinomycin were bla

Topics: Animals; Anti-Bacterial Agents; Cephalosporins; Chickens; Drug Resistance, Multiple, Bacterial; Escherichia coli; Escherichia coli Infections; Gentamicins; Integrons; Plasmids; Poultry Diseases; Quebec; Spectinomycin; Virulence

The extra-label use of ceftiofur in Canadian hatcheries was cause for concern due to an increased prevalence of ceftiofur resistant Salmonella Heidelberg in chickens and humans in Québec. Due to on-going concerns related to human health the use of ceftiofur was eventually phased out of the poultry production industry in 2014-2015. Simultaneous resistance to amoxicillin-clavulanic acid, ceftiofur and cefoxitin, a pattern known as A2C, caused by the presence of bla

Topics: Amoxicillin; Animal Husbandry; Animals; Anti-Bacterial Agents; Canada; Cefoxitin; Cephalosporins; Chickens; Clavulanic Acid; Drug Resistance, Multiple, Bacterial; Escherichia coli; Escherichia coli Infections; Microbial Sensitivity Tests; Poultry Diseases; Risk Factors

The aim of the experiment was to evaluate under controlled conditions the impact on the excretion of 3GC-resistant Escherichia coli of the injection of one-day-old chicks with ceftiofur, a third-generation cephalosporin (3GC). Three isolators containing specific-pathogen-free chicks were used. In the first one, 20 birds were injected with ceftiofur then ten of them were orally inoculated with a weak inoculum of a 3GC-resistant E. coli field isolate containing an IncI1/ST3 plasmid encoding a blaCTX-M-1 beta-lactamase. The other chicks were kept as contact birds. None of the 20 birds in the second isolator were injected with ceftiofur, but ten of them were similarly inoculated with the 3GC-resistant strain and the others kept as contact birds. A third isolator contained ten non-injected, non-inoculated chicks. Fecal samples were collected regularly over one month and the E. coli isolated on non-supplemented media were characterized by antimicrobial agar dilution, detection of selected resistance genes and determination of phylogenetic group by PCR. The titers of 3GC-resistant E. coli in individual fecal samples were evaluated by culturing on 3GC-supplemented media. Results showed that the inoculated strain rapidly and abundantly colonized the inoculated and contact birds. The ceftiofur injection resulted in significantly higher percentages of 3GC-resistant E. coli isolates among the analyzed E. coli. No transfer of the 3GC-encoding plasmid to other isolates could be evidenced. In conclusion, these results highlight the dramatic capacity of 3GC-resistant E. coli to colonize and persist in chicks, and the selecting pressure imposed by the off-label use of ceftiofur.

Topics: Animals; Anti-Bacterial Agents; Cephalosporin Resistance; Cephalosporins; Chickens; Escherichia coli; Escherichia coli Infections; Feces; Gastrointestinal Microbiome; Poultry Diseases

This study investigated antimicrobial resistance, screened for the presence of virulence genes involved in intestinal infections, and determined phylogenetic groups of Escherichia coli isolates from untreated poultry and poultry treated with ceftiofur, an expanded-spectrum cephalosporin. Results show that none of the 76 isolates appeared to be Shiga toxin-producing E. coli or enteropathogenic E. coli. All isolates were negative for the major virulence factors/toxins tested (ehxA, cdt, heat-stable enterotoxin [ST], and heat-labile enterotoxin [LT]). The few virulence genes harbored in isolates generally did not correlate with isolate antimicrobial resistance or treatment status. However, some of the virulence genes were significantly associated with certain phylogenetic groups.

Topics: Animals; Anti-Bacterial Agents; Cephalosporins; Chickens; Drug Resistance, Multiple, Bacterial; Escherichia coli; Escherichia coli Infections; Microbial Sensitivity Tests; Poultry Diseases; Virulence Factors

This study determined the prevalence and antimicrobial susceptibility of Salmonella isolated from broiler flocks in Japan. Caecal dropping samples were collected from 288 broiler flocks between November 2007 and February 2010. Salmonella was prevalent in 248 (86·1%) broiler flocks. The top three serovars were S. Infantis, S. Manhattan and S. Schwarzengrund. S. Infantis was found in all regions tested in this study. However, S. Manhattan and S. Schwarzengrund were frequently found only in the western part of Japan. High antimicrobial resistance rates were observed against oxytetracycline (90·2%), dihydrostreptomycin (86·7%) and ampicillin (36·5%), and 258 (90·5%) of 285 isolates were resistant to two or more antimicrobial agents. Interestingly, 26·3% of isolates were resistant to ceftiofur, especially 38·1% of S. Infantis isolates, although its use in broilers has not been approved in Japan. This study showed that Salmonella is highly prevalent (86·1%) in Japanese broiler flocks, that 90·5% of Salmonella isolates were multidrug-resistant, and that S. Infantis frequently exhibited resistance to cephalosporin antimicrobial agents.

Topics: Ampicillin; Animals; Anti-Bacterial Agents; Cephalosporins; Chickens; Dihydrostreptomycin Sulfate; Drug Resistance, Bacterial; Drug Resistance, Multiple, Bacterial; Feces; Japan; Microbial Sensitivity Tests; Oxytetracycline; Poultry Diseases; Salmonella enterica; Salmonella Infections, Animal

The Canadian Integrated Program for Antimicrobial Resistance Surveillance describes a strong correlation (r = 0.9, p<0.0001) between ceftiofur-resistant Salmonella enterica serovar Heidelberg isolated from retail chicken and incidence of ceftiofur-resistant Salmonella serovar Heidelberg infections in humans across Canada. In Quebec, changes of ceftiofur resistance in chicken Salmonella Heidelberg and Escherichia coli isolates appear related to changing levels of ceftiofur use in hatcheries during the study period, from highest to lowest levels before and after a voluntary withdrawal, to increasing levels after reintroduction of use (62% to 7% to 20%, and 34% to 6% to 19%, respectively). These events provide evidence that ceftiofur use in chickens results in extended-spectrum cephalosporin resistance in bacteria from chicken and humans. To ensure the continued effectiveness of extended-spectrum cephalosporins for treating serious infections in humans, multidisciplinary efforts are needed to scrutinize and, where appropriate, limit use of ceftiofur in chicken production in Canada.

Topics: Animals; Anti-Bacterial Agents; Canada; Cephalosporins; Chickens; Drug Resistance, Bacterial; Humans; Meat; Microbial Sensitivity Tests; Poultry Diseases; Quebec; Salmonella enterica; Salmonella Food Poisoning; Salmonella Infections, Animal