Antimicrobial susceptibility of Salmonella isolates from healthy pigs and chickens (2008-2011).

Using the agar dilution method, antimicrobial susceptibility to human-use antibiotics was determined among Belgian faecal Salmonella isolates from healthy pigs and broiler chickens. Both epidemiological cut-off values and clinical breakpoints were applied for interpretation of the results. Cephalosporin-resistant isolates were examined for the presence of genes encoding CTX-M, SHV, TEM and CMY ß-lactamases. All isolates with decreased quinolone susceptibility were screened for plasmid-borne genes qnr, qepA and aac(6')-Ib-cr. In all, 368 Salmonella isolates were recovered from pigs and 452 from chickens. Clinical resistance to ciprofloxacin was absent in isolates of both host species, and was 1.9 and 13.1% to cefotaxime in pig and poultry isolates, respectively. Decreased susceptibility to cefotaxime amounted to 2.2 and 0.7%, whereas for ciprofloxacin this was 3.0 and 23.0% in pig and poultry isolates, respectively. Ciprofloxacin decreased susceptibility was limited to few serovars, mainly Paratyphi B. Multidrug resistance was markedly higher for pig isolates (39.7%) than for chicken isolates (17.3%). Sixty-six cefotaxime-resistant isolates, 59 from chickens and 7 from pigs, were phenotypically determined as ESBL/AmpC producers; predominantly Paratyphi B and Typhimurium serovars. BlaCTX-M (mostly blaCTXM-1, but also blaCTXM-2 and blaCTXM-9) and blaTEM-52 were the predominant ESBL genes. Only few isolates expressed SHV-12 or an AmpC enzyme (CMY-2). Isolates of four serovars carried qnr genes: Brandenburg and Llandof from pigs, both qnrS; Indiana and Paratyphi B from chickens with qnrB and qnrA. The latter isolate carried blaCTX-M-9 and was the only strain with a plasmid-borne quinolone resistance gene among the ESBL/AmpC producers. This Salmonella survey confirms that the ESBL/AmpC producers are particularly prevalent in chickens (12.8%), and much less in pigs (1.9%). A link between plasmid-borne quinolone resistance genes and ESBLs/AmpC was uncommon.

Susceptibility of canine and feline bacterial pathogens to pradofloxacin and comparison with other fluoroquinolones approved for companion animals.

In this study, 908 bacterial pathogens from defined infections of dogs and cats were tested for their susceptibility to the novel fluoroquinolone pradofloxacin, which was approved in 2011 for use in cats and dogs. Most of the bacteria tested (Staphylococcus aureus, Staphylococcus pseudintermedius, Escherichia coli, ß-haemolytic streptococci, Pasteurella multocida and Bordetella bronchiseptica) exhibited low pradofloxacin MIC(90) values of ≤ 0.25 µg/ml. Solely Proteus spp. and Pseudomonas aeruginosa had higher MIC(90) values of ≥ 4 µg/ml. Only six (3.4%) of 177 S. pseudintermedius and 12 (5.3%) of 227 E. coli isolates showed pradofloxacin MICs of ≥ 2 µg/ml. Analysis of the quinolone resistance determining regions of the target genes identified double mutations in GyrA that resulted in amino acid exchanges S83L+D87N or S83L+D87Y and single or double mutations in ParC that resulted in amino acid exchanges S80I or S80I+E84G in all 12 E. coli isolates. The six S. pseudintermedius isolates exhibited amino acid exchanges S84L or E88K in GyrA and S80I in GrlA. Comparative analysis of the MICs of pradofloxacin and the MICs determined for enrofloxacin and its main metabolite ciprofloxacin, but also marbofloxacin, orbifloxacin, difloxacin and ibafloxacin was conducted for the target pathogens S. pseudintermedius, E. coli and P. multocida. This comparison confirmed that pradofloxacin MICs were significantly lower than those of the other tested fluoroquinolones.

Bactericidal properties of pradofloxacin against veterinary pathogens.

Pradofloxacin is a new veterinary 8-cyano-fluoroquinolone developed for use against bacterial infections in dogs and cats involving both aerobic and anaerobic bacteria. The minimal bactericidal concentrations have been determined against clinical isolates of Staphylococcus pseudintermedius, Staphylococcus aureus, Escherichia coli, Pasteurella multocida, Streptococcus canis, Proteus spp., Fusobacterium spp., Porphyromonas gingivalis and Prevotella species. A subset of these species was selected, and the in vitro rate of kill by pradofloxacin was determined. For 27 of the 30 tested aerobic strains the pradofloxacin MBC was within two doubling dilutions of the MIC. For the remaining strains, the MIC and MBC were within three to four doubling dilutions. Pradofloxacin also demonstrated bactericidal activity against all anaerobic strains, and the MBC was equal to the MIC for four of the strains, within 1 doubling dilution for three strains, within 2 dilutions for a further 3 strains and within 3 dilutions for the remaining five strains. As pradofloxacin concentration was increased, a faster rate of killing was observed; bactericidal effects were seen in all cases at concentrations ≤ 0.25 µg/mL. The bactericidal activity against the anaerobic strains was marked, of particular relevance was the complete absence of regrowth even at 48 h at concentrations as low as 0.125 µg/mL. In conclusion, pradofloxacin exhibits clear bactericidal activity in terms of MBC and kill kinetics against aerobic and anaerobic clinical isolates from dogs and cats at concentrations that are greatly exceeded within the systemic circulation after administration of the recommended therapeutic doses to the target animals. It is expected that such a rapid rate of kill will play a significant role in clinical efficacy. These data demonstrate the complete and rapid killing of anaerobic bacteria by a veterinary 8-cyano-fluoroquinolone.

Activity of pradofloxacin against Porphyromonas and Prevotella spp. Implicated in periodontal disease in dogs: susceptibility test data from a European multicenter study.

Collaborating veterinarians from five European countries collected subgingival bacterial samples from dogs exhibiting clinical periodontal disease. Sterile endodontic paper points were used for collection of the samples, which were transported to a central laboratory for susceptibility testing. Anaerobic bacteria were isolated and Porphyromonas and Prevotella isolates identified to the species level; susceptibility to pradofloxacin and metronidazole was determined using the CLSI agar dilution methodology. A total of 630 isolates, 310 of Porphyromonas spp. and 320 of Prevotella spp., were isolated. Pradofloxacin MIC data for all isolates were in the range of < or =0.016 to 1 microg/ml, the overall MIC(50) was 0.062, and the overall MIC(90) was 0.25 microg/ml. There were no differences in activity against Porphyromonas and Prevotella isolates or in the pradofloxacin susceptibility distributions from the different European countries. All isolates were within the wild-type distribution and were fully susceptible to pradofloxacin. Metronidazole was also highly active against these strains: 316 of 320 Prevotella strains (98.8%) and 309 of 310 Porphyromonas strains (99.7%) were susceptible (MICs of < or =8 microg/ml). However, three Prevotella strains had intermediate metronidazole susceptibility (MICs of 16 microg/ml), while one Prevotella and one Porphyromonas strain were metronidazole resistant (MICs of 128 and 256 microg/ml, respectively). Pradofloxacin, a novel broad-spectrum fluoroquinolone, demonstrates a high degree of antianaerobic activity against strains isolated from clinical cases of periodontal disease and shows activity against metronidazole-resistant isolates. The broad-spectrum activity of pradofloxacin makes it a suitable candidate for the treatment of periodontal disease in dogs.

Comparative activity of pradofloxacin against anaerobic bacteria isolated from dogs and cats.

OBJECTIVES: To compare the intrinsic activity of pradofloxacin, a new fluoroquinolone developed for use in veterinary medicine, with other fluoroquinolones, against anaerobic bacteria isolated from dogs and cats. METHODS: One hundred and forty-one anaerobes were isolated from dogs and cats and comparative MICs of pradofloxacin, marbofloxacin, enrofloxacin, difloxacin and ibafloxacin were determined according to standardized agar dilution methodology. RESULTS: Pradofloxacin exerted the greatest antibacterial activity followed by marbofloxacin, enrofloxacin, difloxacin and ibafloxacin. Based on the distinctly lower MIC(50), MIC(90) and mode MIC values, pradofloxacin exhibited a higher in vitro activity than any of the comparator fluoroquinolones. CONCLUSIONS: Pradofloxacin, a novel third-generation fluoroquinolone, has broad-spectrum anti-anaerobe activity and offers utility as single-drug therapy for mixed aerobic/anaerobic infections.

Pradofloxacin in the treatment of canine deep pyoderma: a multicentred, blinded, randomized parallel trial.

A multicentre, randomized, blinded study compared the efficacy of pradofloxacin with that of a combination of amoxycillin/clavulanic acid in the treatment of deep pyoderma in dogs. Dogs with clinical lesions of deep pyoderma and a positive bacterial culture were included in the study. At each visit, they were evaluated with lesion, pruritus and general condition scores. Dogs were treated either with pradofloxacin at 3 mg kg-1 once daily or with amoxycillin at 10 mg kg-1 and clavulanic acid at 2.5 mg kg-1 twice daily and evaluated weekly for 3 weeks and every 2 weeks thereafter until 2 weeks past clinical remission. Maximal treatment duration was 9 weeks, and maximal evaluation period was 11 weeks. Of the 56 dogs treated with pradofloxacin (group 1), 48 dogs (86%) achieved clinical remission, four dogs improved, four dogs did not respond and a recurrence of clinical signs was not seen in any patient after 11 weeks. Of the 51 dogs treated with amoxycillin/clavulanic acid (group 2), 37 dogs achieved clinical remission (73%), three dogs showed improvement, five dogs showed no response and in six dogs, clinical signs recurred within 2 weeks of cessation of therapy. These results indicate that pradofloxacin is an efficacious therapy comparable to amoxycillin/clavulanic acid for deep bacterial pyoderma in dogs.

[Bacteriological and virological status in upper respiratory tract infections of cats (cat common cold complex)]. / Bakteriologischer und virologischer Status bei Katzen mit Erkrankungen der oberen Atemwege (Katzenschnupfenkomplex).

Between October 2002 and January 2005,460 bacteriological samples from cats with an acute upper respiratory tract infection were analysed in clinical field studies in two accredited laboratories in Germany. Oropharyngeal swabs were taken from these cats and sent to the laboratories for routine diagnostics. In the swab samples of 460 cats 382 bacteria strains were isolated. The following bacteria were isolated most frequently: Pasteurella spp. (32.5 %), Staphylococcus spp. (18.5 %), Escherichia coli (17.0 %), Streptococcus spp. (9.1 %), Pseudomonas spp. (6.9 %) and Klebsiella spp. (3.0 %). Bordetella bronchiseptica was found in 0.4 % of the animals To evaluate possible regional and time influences, the animals were split into three populations: 1: Germany, laboratory A; 2: Germany, laboratory B; 3: France and Belgium, laboratory B. In population 1 an 2 Pasteurella spp. were found most frequently with 42.2 % and 36.5 %, respectively. The second most frequently isolated bacterial species were Staphylococcus spp. with 14.1 % and 21.4 % and E. coli with 13.6 % and 17.5 % respectively. In population 3 Staphylococcus spp., E. coli (20 % each) and Pasteurella spp. (18.5 %) were isolated at almost the same frequency. Virological parameter were additionally analysed in 328 cats (population 2 and 3). Serum samples were analysed for antibodies specific for Feline Calicivirus (FCV) and Feline Immunodeficiency Virus (FIV) and for Feline Leukaemia Virus (FeLV) antigen. Oropharyngeal swabs were analysed for Feline Herpesvirus (FHV) by using PCR. Calicivirus-specific antibodies were found in 99.6 % of the cats of population 2 and in 100 % of the animals in population 3. Herpesvirus was detected in 15.3 % and 23.3 % of the cats, respectively. FeLV-Antigen was found in 0.4 % of the animals in population 2 and in 10.1 % of the cats in population 3, while FIV-antibodies were identified in 8.7 % of the animals of population 2 and in 6.1 % of the cats of population 3. In total FHV was found in 19.3 % and FCV-specific antibodies in 99.7 % of the animals. 5.3 % of the cats carried FeLV-Antigen, and 7.4 % FIV-specific antibodies. The results of the bacteriological analysis as well as the results of the virological examination confirm previously published data. In this study Pasteurella spp. were most frequently isolated (32.5 %).