cefquinome and Enterobacteriaceae-Infections

Cefquinome is the first 4th generation cephalosporin antibiotic developed for use in veterinary medicine. A European multicentre study established a high in vitro activity for this modern antimicrobial drug against a wide spectrum of bovine pathogens. Gram-positive and gram-negative mastitis agents were inactivated even at very low active ingredient concentrations, including Enterobacteriaceae which are often resistant to other drugs. The results of clinical trials using experimental E. coli mastitis as an example demonstrate the efficacy of cefquinome in vivo. Parenteral administration at a dose rate of 1 mg/kg body weight when compared with conventional therapy using a control drug with equally good in vitro activity, produced significantly better therapeutic results.

Topics: Animals; Cattle; Cephalosporins; Clinical Trials as Topic; Enterobacteriaceae Infections; Escherichia coli Infections; Female; Gram-Negative Bacterial Infections; Gram-Positive Bacterial Infections; Mastitis, Bovine; Multicenter Studies as Topic

The objectives of the present study were to evaluate the efficacy of intra-mammary-administered cefquinome for the treatment of sub-clinical mastitis in lactating dairy cows and to determine if extended therapy would enhance treatment efficacy. Seventy-three Holstein dairy cows from a single farm with 150 infected quarters were enrolled in the study. Infected cows were allocated randomly to one of three treatment regimens: (1) conventional (standard) regimen: 75 mg of cefquinome administered three times at 16-h intervals (25 infected cows, 52 intra-mammary infections (IMI)), (2) extended regimen: 75 mg of cefquinome administered six times at 16-h intervals (26 infected cows, 58 IMI) and (3) negative untreated control group (22 cows, 40 IMI). Most IMI were caused by coagulase-negative staphylococci, streptococci other than Streptococcus agalactiae and coliforms. The overall bacteriological cure (BC) rates for sub-clinical IMI were 84.61%, 91.37% and 20% for the conventional, extended and the control groups, respectively, indicating a higher BC rate for the treated groups than the control group (P < 0.001). Significant differences in somatic cell count (SCC) were detected between the treated versus the control group (P < 0.001). No differences, concerning the BC rate or SCC, were observed between the extended and the conventional groups. Although fat and protein percentages increased in the treated groups, there were no significant differences in post-treatment milk production between the groups. Results of this study indicate that cefquinome therapy was effective in reducing SCC and eliminating sub-clinical IMI in lactating dairy cows, but extended therapy did not enhance treatment efficacy.

Topics: Animals; Anti-Bacterial Agents; Asymptomatic Infections; Cattle; Cell Count; Cephalosporins; Enterobacteriaceae; Enterobacteriaceae Infections; Female; Injections, Intradermal; Iran; Mammary Glands, Animal; Mastitis, Bovine; Staphylococcal Infections; Staphylococcus; Streptococcal Infections; Streptococcus; Time Factors

Three kinds of plasmid-mediated quinolone resistance (PMQR) determinants have been discovered and have been shown to be widely distributed among clinical isolates: qnr genes, aac(6')-Ib-cr, and qepA. Few data on the prevalence of these determinants in strains from animals are available. The presence of PMQR genes in isolates from animals was determined by PCR amplification and DNA sequencing. The production of extended-spectrum beta-lactamases (ESBLs) and AmpC beta-lactamases in the strains was detected, and their genotypes were determined. The genetic environment of PMQR determinants in selected plasmids was analyzed. All samples of ceftiofur-resistant (MICs > or = 8 microg/ml) isolates of the family Enterobacteriaceae were selected from 36 companion animals and 65 food-producing animals in Guangdong Province, China, between November 2003 and April 2007, including 89 Escherichia coli isolates, 9 Klebsiella pneumoniae isolates, and isolates of three other genera. A total of 68.3% (69/101) of the isolates produced ESBLs and/or AmpC beta-lactamases, mainly those of the CTX-M and CMY types. Of the 101 strains, PMQR determinants were present in 35 (34.7%) isolates, with qnr, aac(6')-Ib-cr, and qepA detected alone or in combination in 8 (7.9%), 19 (18.8%), and 16 (15.8%) strains, respectively. The qnr genes detected included one qnrB4 gene, four qnrB6 genes, and three qnrS1 genes. Five strains were positive for both aac(6')-Ib-cr and qepA, while one strain was positive for qnrS1, aac(6')-Ib-cr, and qepA. qnrB6 was flanked by two copies of ISCR1 with an intervening dfr gene downstream and sul1 and qacEDelta1 genes upstream. In another plasmid, aac(6')-Ib-cr followed intI1 and arr-3 was downstream. PMQR determinants are highly prevalent in ceftiofur-resistant Enterobacteriaceae strains isolated from animals in China. This is the first report of the occurrence of PMQR determinants among isolates from companion animals.

Topics: Acetyltransferases; Adolescent; Adult; Aged; Animals; Animals, Domestic; Anti-Bacterial Agents; Bacterial Proteins; beta-Lactamases; Cambodia; Cephalosporins; China; Conjugation, Genetic; Drug Resistance, Bacterial; Enterobacteriaceae; Enterobacteriaceae Infections; Escherichia coli Proteins; Female; Humans; Male; Mali; Microbial Sensitivity Tests; Middle Aged; Nasal Cavity; Plasmids; Quinolones; Young Adult