Efficacy and Safety of 4.7 mg Deslorelin Acetate Implants in Suppressing Oestrus Cycle in Prepubertal Female Dogs.

Our multicentric, masked, controlled and randomised study aimed to assess the efficacy and safety of Suprelorin® 4.7 mg (Virbac, Carros, France) regarding oestrus prevention in prepubertal intact bitches. Twelve- to eighteen-week-old females (n = 83) were allocated either a deslorelin implant (n = 62) or 0.9% sodium chloride (n = 21) group. Clinical assessment (heat signs), 17ß oestradiol and progesterone assays, and vaginal cytology were performed at day (D)0, D7, D21, month (M)3 and M6 after product administration, and were then performed every other month until reaching puberty. Trained owners assessed heat signs between each veterinary visit. All bitches (n = 83) reached puberty before M30. Deslorelin significantly extended the median time to sexual maturity when compared to the control group (377 days versus 217 days after D0, p < 0.0001). Three females, implanted between 16 and 18 weeks of age, expressed an induced oestrus. Additional descriptive data, collected over a 24 month-period, showed functional reproductive abilities in both deslorelin (n = 52) and control (n = 21) groups once puberty was achieved. In conclusion, Suprelorin® 4.7 mg seems to be an effective and safe option for postponing the onset of oestrus when administered to prepubertal female dogs aged from 12 to 16 weeks.

Antimicrobial susceptibility monitoring of Mycoplasma hyopneumoniae isolated from seven European countries during 2015-2016.

Mycoplasma hyopneumoniae is the causative agent of porcine enzootic pneumonia, a chronic respiratory disease, causing significant economic losses. Results from the 2015-2016 MycoPath pan-European antimicrobial susceptibility monitoring survey of M. hyopneumoniae are presented. In total, 147 M. hyopneumoniae porcine isolates from Belgium, France, Germany, Great Britain, Hungary, Italy, and Spain were tested. One isolate per farm was retained from pigs that had not been recently treated with antimicrobial agents. The minimal inhibitory concentration (MIC) of 13 antimicrobial agents was determined in a central laboratory using a broth microdilution method, with Friis Medium, incubated at 35 ± 1 °C for 5-12 days. M. hyopneumoniae NCTC 10110 was used as Quality Control. MIC50/MIC90 (mg/L) values were: enrofloxacin 0.06/1; marbofloxacin 0.06/2; spiramycin 0.06/0.25; tulathromycin ≤0.001/0.004; gamithromycin 0.06/0.5; tylosin 0.016/0.06; tilmicosin 0.06/0.5; florfenicol 0.5/1; doxycycline 0.25/1; oxytetracycline 0.25/2; lincomycin 0.06/0.25; tiamulin 0.016/0.06 and valnemulin ≤0.001/0.004. Compared with the data from 2010 to 2012 MycoPath study (50 isolates), MIC50/90 results were similar and the majority were within ± two dilution steps, except for the MIC50 of oxytetracycline which is more than two dilution steps higher in the present study. Between-country comparisons show some differences in the MIC values for the fluoroquinolones, tulathromycin and tylosin, but the limited sample size per country precludes performing meaningful country comparisons for several countries. Standardized laboratory methods and interpretive criteria for MIC testing of veterinary mycoplasmas are clearly needed; there are currently no clinical breakpoints available to facilitate data interpretation and correlation of MICs with in vivo efficacy.

Minimal inhibitory concentration of seven antimicrobials to Mycoplasma gallisepticum and Mycoplasma synoviae isolates from six European countries.

Mycoplasma gallisepticum and Mycoplasma synoviae are bacterial pathogens that cause disease in poultry, adversely affecting their health and welfare, and are a financial burden on producers. This manuscript describes the results of the MycoPath project that is the first international antimicrobial susceptibility programme for mycoplasma pathogens isolated from poultry. Improved comparative analysis of minimal inhibitory concentration (MIC) results from participating countries was facilitated by using one laboratory determining all MICs. Chicken and turkey isolates were obtained from France, Germany, Great Britain, Hungary, Italy and Spain during 2014-2016. One isolate per farm was retained. The MIC of seven antimicrobial agents was determined using a broth microdilution method, with Friis Medium (M. gallisepticum) or Modified Chanock's Medium (M. synoviae). Of the 222 isolates recovered, 82 were M. gallisepticum and 130 were M. synoviae. M. gallisepticum MIC50/90 values were 0.12/0.5, 2/8, 0.5/4, 0.12/>64, 0.008/0.062, 0.008/32, 0.062/4 mg/l for doxycycline, enrofloxacin, oxytetracycline, spiramycin, tiamulin, tilmicosin and tylosin, respectively. For M. synoviae, the values were 0.5/1, 8/16, 0.5/1, 0.5/8, 0.25/0.5, 0.062/2 and 0.062/16 mg/l respectively. A bimodal MIC distribution for the fluoroquinolone (enrofloxacin) and the macrolides (spiramycin, tilmicosin and tylosin) indicate that both species have sub-populations that are less susceptible in vitro to those antimicrobials. Some differences in susceptibilities were observed according to host species, Mycoplasma species, and country of origin. This study provides a baseline of novel data for future monitoring of antimicrobial resistance in poultry Mycoplasma species. Additionally, this information will facilitate the selection of the antimicrobial agents most likely to be effective, thus ensuring their minimal use with targeted and correct therapeutic treatments.Highlights First large-scale pan-European collection of representative Mg and Ms isolates.MIC values assessed in central laboratory for Mg and Ms from chickens and turkeys.Range of MIC values for 82 Mg and 130 Ms isolates to seven licenced antibiotics shown.Data can be used to help determine Mg and Ms veterinary-specific breakpoints.

Antimicrobial susceptibility monitoring of canine and feline skin and ear pathogens isolated from European veterinary clinics: results of the ComPath Surveillance programme.

BACKGROUND: The ComPath project is a pan-European programme dedicated to the monitoring of antimicrobial susceptibility of canine and feline pathogens using standardized methods and centralized minimal inhibitory concentration (MIC) determination. OBJECTIVES: To report antimicrobial susceptibilities of major pathogens isolated from nontreated animals with acute clinical signs of skin, wound or ear infections in 2013-2014. METHODS AND MATERIALS: MICs were determined by agar dilution for commonly used drugs and interpreted using Clinical and Laboratory Standards Institute (CLSI) breakpoints, if available. RESULTS: Of 1,676 isolates recovered, the main species isolated from dogs were Staphylococcus pseudintermedius, followed by Streptococcus spp., Pseudomonas aeruginosa and Escherichia coli. In cats, Pasteurella multocida, coagulase-negative staphylococci (CoNS) and Staphylococcus aureus were isolated most frequently. Resistance rates observed for S. pseudintermedius were <26.7% for penicillin, clindamycin and chloramphenicol, and ≤11.5% for ampicillin, amoxicillin/clavulanate, cefalexin, cefovecin, gentamicin and fluoroquinolones. For S. aureus, resistance rates ranged up to 90.9% for ß-lactams, and were 19.7% for clindamycin, 27% for fluoroquinolones and 0.0-6.1% for other drugs. The mecA gene was confirmed by PCR in 10.6% of S. pseudintermedius, 11.6% of CoNS and 31.4% of S. aureus isolates. In streptococci/enterococci, resistance to penicillin, ampicillin and chloramphenicol ranged from 0.0% to 11.3%, whereas fluoroquinolone resistance ranged from 0.0% to 8.5%. For E. coli, resistance ranged from 13.8 to 15.9% for fluoroquinolones and from 86.2% to 100.0% for ß-lactams. Low rates of resistance (0.0-6.3%) were observed in P. multocida, and for P. aeruginosa resistance to gentamicin was 10.3%. CONCLUSION: Overall, antimicrobial resistance of cutaneous/otic pathogens isolated from dogs and cats was low (1-10%) to moderate (10-20%). For several pathogens, the paucity of CLSI recommended breakpoints for veterinary use is a bottleneck.

Antimicrobial susceptibility of nine udder pathogens recovered from bovine clinical mastitis milk in Europe 2015-2016: VetPath results.

VetPath is an ongoing pan-European antimicrobial susceptibility monitoring programme collecting pathogens from diseased cattle, pigs and poultry not recently treated with antibiotics. Non-duplicate isolates (n = 1244) were obtained from cows with acute clinical mastitis in eight countries during 2015-2016 for centrally antimicrobial susceptibility testing according CLSI standards. Among Escherichia coli (n = 225), resistance was high to ampicillin and tetracycline, moderate to kanamycin and low to amoxicillin/clavulanic acid and cefazolin. The MIC50/90 of danofloxacin, enrofloxacin and marbofloxacin were 0.03 and 0.06 µg/mL. For Klebsiella spp. (n = 70), similar results were noted, except for ampicillin and kanamycin. We detected 3.7 % (11/295) Enterobacteriaceae isolates carrying an ESBL/AmpC gene. Staphylococcus aureus (n = 247) and coagulase-negative staphylococci (CoNS; n = 189) isolates were susceptible to most antimicrobials tested except to penicillin (25.1 and 29.1 % resistance). Two S. aureus and thirteen CoNS isolates harboured mecA gene. Streptococcus uberis isolates (n = 208) were susceptible to ß-lactam antibiotics (87.1-94.7 % susceptibility), 23.9 % were resistant to erythromycin and 37.5 % to tetracycline. Resistance to pirlimycin was moderate. For Streptococcus dysgalactiae (n = 132) the latter figures were 10.6 and 43.2 %; pirlimycin resistance was low. MIC values for Streptococcus agalactiae, Trueperella pyogenes and Corynebacterium spp. were generally low. This current VetPath study shows that mastitis pathogens were susceptible to most antimicrobials with exceptions of staphylococci against penicillin and streptococci against erythromycin or tetracycline. For most antimicrobials, the percentage resistance and MIC50/90 values among the major pathogens were comparable to that of the preceeding VetPath surveys. This work highlights the high need to set additional clinical breakpoints for antimicrobials frequently used to treat mastitis.

New antimicrobial susceptibility data from monitoring of Mycoplasma bovis isolated in Europe.

Mycoplasma bovis is an important respiratory pathogen of cattle across Europe and is included in the MycoPath pan-European antimicrobial susceptibility monitoring programme. M. bovis strains (232) were isolated from cattle, not recently treated with antimicrobials, at diverse geographical locations in France, Great Britain, Hungary, Italy and Spain during 2014 to 2016. Only one isolate per farm and per outbreak was retained. For each isolate, the MICs of ten antimicrobials were determined in a central laboratory using a broth microdilution method with modified Eaton's medium and incubation at 35 °C ± 1 °C for 24 ± 6 h. MIC50/MIC90 (mg/L) values for the 232 strains were: danofloxacin 0.25/1; enrofloxacin 0.5/8; marbofloxacin 1/4; gamithromycin >64/>64; spiramycin 8/16; tilmicosin >64/>64; tulathromycin >64/>64; tylosin 64/>64; florfenicol 4/8; oxytetracycline 8/32. Minor between-country differences in the MIC90 values were observed for the fluoroquinolones, spiramycin and oxytetracycline, whilst the MIC values for the other compounds were similar. Spain and Italy had the higher MIC90 values for the fluoroquinolones. Compared with the 2010-2012 study (156 isolates) results are similar, with an overall MIC50 increase of at most one doubling dilution for enrofloxacin, spiramycin, tylosin, florfenicol and oxytetracycline. In contrast, the MIC90 value for oxytetracycline decreased from >64 to 32 mg/L. Standardized laboratory methods and interpretive criteria for MIC testing of veterinary mycoplasmas are clearly needed; there are currently no clinical breakpoints available to facilitate data interpretation and correlation of MICs with in vivo efficacy.

Antimicrobial resistance monitoring in commensal enterococci from healthy cattle, pigs and chickens across Europe during 2004-14 (EASSA Study).

OBJECTIVES: The European Antimicrobial Susceptibility Surveillance in Animals (EASSA) programme collects zoonotic and commensal bacteria from healthy food-producing animals at slaughter and tracks their susceptibility to medically important antibiotics. Results for enterococci, collected over three time periods, are presented. METHODS: Intestinal contents from cattle, pigs and chickens were randomly sampled (five or six countries/host; at least four abattoirs/country; one sample/animal/farm) for isolation of enterococci; antimicrobial susceptibilities were centrally assessed by CLSI agar dilution. Clinical breakpoints (CLSI) and epidemiological cut-off values (EUCAST) were applied for data interpretation. RESULTS: In total, 2435 Enterococcus faecium and 1389 Enterococcus faecalis strains were recovered. Seven E. faecium/faecalis strains were linezolid resistant. One E. faecium strain was non-WT (NWT), with a daptomycin MIC of 8 mg/L. Clinical vancomycin resistance was very low or absent; eight strains had decreased susceptibility (MICs of 8 mg/L). Two strains were clinically resistant to tigecycline. Little resistance to ampicillin or gentamicin was observed. Clinical resistance of E. faecium to quinupristin/dalfopristin was slightly higher (2.2%-33.6%) and 38.5%-83.2% of the strains were classified NWT. Very high resistance to tetracycline (67.4%-79.1%) and erythromycin (27.1%-57.0%) was noted for E. faecium and E. faecalis in pigs and chickens. For both of these compounds, similar NWT results were observed for Enterococcus hirae (n = 935), Enterococcus durans (n = 286) and Enterococcus casseliflavus (n = 154) whereas the percentage of NWT for linezolid, tigecycline and vancomycin was generally zero or low. CONCLUSIONS: In this pan-EU survey of commensal enterococci, antibiotic susceptibility varied widely between antibiotics, animal species, countries and enterococcal species. Clinical resistance to antibiotics that are critically important for human medicine was absent or low, except for erythromycin.

Antimicrobial susceptibility of enterococci recovered from healthy cattle, pigs and chickens in nine EU countries (EASSA Study) to critically important antibiotics.

The European Antimicrobial Susceptibility Surveillance in Animals (EASSA) program collects zoonotic and commensal bacteria from food-producing animals at slaughter and tracks their susceptibility to medically important antibiotics. Results of commensal enterococci species (2013-2014) are presented here. Intestinal content from cattle, pigs and chickens were randomly sampled (5-6 countries/host; ≥4 abattoirs/country; 1 sample/animal/farm) for isolation of enterococci, MICs of 9 antibiotics were assessed by CLSI agar dilution in a central laboratory. Clinical breakpoints (CLSI) and epidemiological cut-off values (EUCAST) were applied for data interpretation. In total 960 Enterococcus faecium and 779 Enterococcus faecalis strains were recovered. Seven porcine E. faecium/faecalis strains of Spanish origin were resistant to linezolid. One avian E. faecalis and one porcine E. faecium strain were non-wild type (MICs 8 mg/L) to daptomycin. Clinical vancomycin resistance was absent; 2 poultry E. faecium and 1 bovine E. faecalis strains were non-wild type, all with MICs of 8 mg/L. None of the strains tested were clinically resistant to tigecycline. Little clinical resistance to ampicillin or gentamicin was observed. Clinical resistance of E. faecium to quinupristin/dalfopristin was slightly higher (2.2-12.0%) but 61.9-83.2% of the strains were classified as non-wild type. Very high percentages resistance to tetracycline (67.4-78.3%) and to erythromycin (27.1-57.0%) were noted for both E. faecium and E. faecalis in pigs and chickens compared to cattle (5.2-30.4 and 9.0-10.4%, respectively). Similar non-wild type results were observed for E. hirae (n = 557), E. durans (n = 218) and E. casseliflavus (n = 55) including percentage non-wild type for daptomycin, linezolid, tigecycline being absent and for vancomycin low. For these species percentage non-wild type to erythromycin was lower as compared to E. faecalis/faecium. This pan-EU survey shows high variability in antibiotic susceptibility of commensal enterococci from healthy food animals. Clinical resistance to critically important antibiotics for human medicine was absent or low, except for erythromycin.

Monitoring of antimicrobial susceptibility of udder pathogens recovered from cases of clinical mastitis in dairy cows across Europe: VetPath results.

VetPath is an ongoing pan-European antimicrobial susceptibility monitoring programme collecting pathogens from diseased cattle, pigs and poultry not recently treated with antibiotics. Non-duplicate milk samples were collected from cows with acute clinical mastitis in nine countries and 934 isolates were obtained during 2009-2012 for subsequent antimicrobial susceptibility testing in a central laboratory. CLSI broth microdilution methodology was used, and where available, MICs were interpreted using CLSI approved veterinary-specific (ceftiofur) otherwise human clinical breakpoints. Among Escherichia coli (n=207) and Klebsiella spp., (n=87), resistance was moderate to tetracycline and high to cephapirin (E. coli only) whereas resistance to other ß-lactam antibiotics was very low (ceftiofur) to low (amoxicillin/clavulanic acid, cephalexin, cephalonium). The MIC90 of enrofloxacin and marbofloxacin was 0.03 and 0.06µg/mL respectively (E. coli) with 0.5% strains displaying higher MICs. Staphylococcus aureus (n=192) and coagulase-negative staphylococci (CNS; n=165) strains were susceptible to most antibiotics tested except to penicillin (25.0 and 29.1% resistance), respectively. Three S. aureus and seven CNS strains were oxacillin-resistant and harboured mecA. Streptococcus uberis strains (n=188) were susceptible to the ß-lactam antibiotics although 35.6% were penicillin intermediately susceptible, and 20.2% were resistant to erythromycin, 36.7% to tetracycline. For Streptococcus dysgalactiae (n=95) the latter figures were 13.7 and 56.8%, respectively. For most antibiotics, the percentage resistance among E. coli, S. aureus and S. uberis was comparable to that of the VetPath 2002-2006 survey. This current, expanded VetPath study shows that mastitis pathogens were susceptible to most antibiotics with exceptions of staphylococci tested against penicillin and streptococci against erythromycin or tetracycline. This work highlights the high need to set additional clinical breakpoints for antibiotics frequently used to treat mastitis.

Antimicrobial Susceptibility Monitoring of Bacterial Pathogens Isolated from Urinary Tract Infections in Dogs and Cats Across Europe: ComPath Results.

ComPath is a pan-European antimicrobial surveillance program collecting bacterial pathogens from dogs and cats not recently exposed to antimicrobials. We present minimum inhibitory concentration data obtained using Clinical and Laboratory Standards Institute methodology for 616 urinary tract infection (UTI) isolates collected between 2008 and 2010. In both dogs and cats, the most common pathogen was Escherichia coli (59.8% and 46.7%, respectively). Antimicrobial activity against E. coli in dogs and cats was similar with fluoroquinolone and trimethoprim/sulfamethoxazole susceptibility >90%. Ampicillin susceptibility was ∼80%. Staphylococcus intermedius Group isolates from dogs (67/437, 15.3%) had high antimicrobial susceptibility (>90%) toward beta-lactams, fluoroquinolones, and trimethoprim/sulfamethoxazole. Four canine isolates (6%) were oxacillin resistant, and harbored mecA. Proteus mirabilis from dogs (48/437, 11.0%) had high antimicrobial susceptibility (∼90%) to amoxicillin/clavulanic acid, enrofloxacin, and marbofloxacin and slightly lower susceptibility (∼80-85%) to ampicillin and orbifloxacin. Streptococcus canis isolates (35/437, 8.0%) from dogs were all susceptible to ampicillin and amoxicillin/clavulanic acid and >90% susceptible to marbofloxacin. Although resistance was not observed, high intermediate susceptibility was seen for both enrofloxacin (28.6%) and orbifloxacin (85.7%). Overall, antimicrobial in vitro activity appears to be high in UTI pathogens from dogs and cats with low multidrug resistance, although a lack of specific dog and cat breakpoints for important antimicrobials such as cefovecin, cephalexin, and ibafloxacin prevents analysis of susceptibility for these agents.

Antimicrobial susceptibility monitoring of bacterial pathogens isolated from respiratory tract infections in dogs and cats across Europe: ComPath results.

ComPath is a pan-European resistance monitoring programme collecting bacterial pathogens from dogs and cats. We present data for respiratory tract infection (RTI) isolates collected between 2008 and 2010. Antimicrobial minimal inhibitory concentrations (MICs) were determined and susceptibility calculated following Clinical Laboratory Standards Institute (CLSI) standards for veterinary medicine. The main pathogen from dogs was Staphylococcus intermedius Group (49/215, 22.8%) which was >90% susceptible to most antimicrobials (including oxacillin - 93.9%; 3 isolates confirmed mecA-positive) but only 59.2%, 73.5% and 87.8% susceptible to tetracycline, chloramphenicol and penicillin. Bordetella bronchiseptica (48/215, 22.3%), streptococci (36/215, 16.7%), Escherichia coli (24/215, 11.2%) and Pasteurella multocida (23/215, 10.7%) were also found in dog RTI. There are no breakpoints for Bordetella bronchiseptica. Most streptococci were penicillin- chloramphenicol-, ampicillin- and pradofloxacin-susceptible. None were enrofloxacin-resistant but 6 isolates (16.7%) were of intermediate susceptibility. The least active agent against streptococci was tetracycline (47.2% susceptible). For E. coli, 37.5% were ampicillin-susceptible but 83.3% were amoxicillin/clavulanic acid-susceptible. Only chloramphenicol showed susceptibility>90% against E. coli, with 66.7% tetracycline-susceptible and 79.2% to 87.5% susceptibility to enrofloxacin, trimethoprim-sulfamethoxazole or pradofloxacin. P. multocida were susceptible to pradofloxacin (no other breakpoints are available). The main pathogen from cats was P. multocida (82/186, 44.1%), where only pradofloxacin has breakpoints (100% susceptible). Streptococci were also collected from cats (25/186, 13.4%) and were >90% susceptible to all antimicrobials except tetracycline (36% susceptible). Most susceptibility was calculated with human-derived breakpoints and some antimicrobials had no breakpoints. Therefore predictions of clinical utility for dog and cat RTI will remain problematical unless specific breakpoints are set.