ampicillin (9.4-71.1%), trimethoprim/sulfamethoxazole (11.1-67.5%) and streptomycin (21.9-69.3%), whereas none were resistant to imipenem or amikacin.Resistance was detected, albeit at low frequency, to ESCs (bovine isolates, 1%; porcine isolates, 3%) and FQs (porcine isolates, 1%). Most ESC-and FQ-resistant isolates represented globally disseminated E. coli lineages (ST117, ST744, ST10 and ST1). Only a single porcine E. coli isolate (ST100) was identified as a classic porcine enterotoxigenic E. coli strain (non-zoonotic animal pathogen) that exhibited ESC resistance via acquisition of bla CMY-2 . This study uniquely establishes the presence of resistance to CIAs among clinical E. coli isolates from Australian foodproducing animals, largely attributed to globally disseminated FQ-and ESC-resistant E. coli lineages.

No abstract

Commercial poultry production is growing rapidly in Bangladesh to address the increasing demand for poultry meat and eggs. Challenges faced by producers include the occurrence of poultry diseases, which are usually treated or controlled by antimicrobials. A cross-sectional study was conducted on 57 commercial layer and 83 broiler farms in eight subdistricts of the Chattogram district, Bangladesh, to assess antimicrobial usage in relation to clinical signs observed in chicken flocks on these farms. Of the 140 commercial chicken farms, 137 (97.9%) used antimicrobials and 24 different antimicrobial agents were administered. On layer farms, the most commonly used antimicrobials were ciprofloxacin (37.0% of farms, 20/54), amoxicillin (33.3%, 18/54), and tiamulin (31.5%, 17/54), while on broiler farms, colistin (56.6%, 47/83), doxycycline (50.6%, 42/83), and neomycin (38.6%, 32/83) were most commonly administered. Only 15.3% (21/137) of farmers used antimicrobials exclusively for therapeutic purposes, while 84.7% (116/137) of farmers used them prophylactically, administering them either for prophylactic purposes only (22.6% of farmers, 31/137) or in combination with therapeutic purposes (62.1% of farmers, 85/137). About 83.3% (45/54) of layer farmers were selling eggs while antimicrobials were being administered compared to 36.1% (30/83) of the broiler farmers selling broiler chickens while administering antimicrobials. Overall, 75.2% (103/137) of farmers reported clinical signs for which they administered antimicrobials, while 24.8% (34/137) of farmers reported no clinical signs but still administered antimicrobials. Respiratory signs (71.8% of farms with clinical signs, 74/103) were most commonly reported, followed by enteric signs (32.0%, 33/103) and increased mortality (16.5%, 17/103). About 37.2% (51/137) of farmers bought antimicrobials exclusively from feed and chick traders, followed by veterinary medical stores (35.0%, 48/137). Purchasing antimicrobials from feed and chick traders was more common among broiler than layer farmers. It is recommended that commercial poultry farmers should keep records of antimicrobials used with dosage and duration of administration along with indication of use. This would allow farmers and veterinarians to review if antimicrobial usage had the desired effects and to evaluate the appropriate use of antimicrobial agents under an antimicrobial stewardship approach.

Background: Extraintestinal infections caused by multidrug-resistant (MDR) Escherichia coli and Enterobacter are becoming more common in veterinary medicine.Objective Methods: Retrospective case series assembled from hospital records data, including clinical history before 1st MDR isolation and treatment outcome. Identity and antimicrobial susceptibility profiles were confirmed by standard microbiological techniques for 57 isolates.Results: Most dogs had an underlying disease condition (97%), received prior antimicrobial treatment (87%), were hospitalized for !3 days (82%), and had a surgical intervention (57%). The urinary tract was the most common infection site (62%), and urinary catheterization, bladder stasis, or both were common among dogs (24%). Some dogs were treated with high doses of co-amoxyclavulanate (n 5 14) and subsequently recovered even though the isolates showed in vitro resistance to this antimicrobial. Other dogs were successfully treated with chloramphenicol (n 5 11) and imipenem (n 5 2).Conclusion and Clinical Importance: Predisposing disease condition, any prior antimicrobial use rather than a specific class of antimicrobial, duration of hospitalization, and type of surgical procedure might be risk factors for acquiring MDR extraintestinal infections. Whereas culture and sensitivity results can indicate use of last-resort antimicrobials such as imipenem for MDR infections, some affected dogs can recover after administration of high doses of co-amoxyclavulanate.

Non-immunological incurred due to unmarketable milk or milk-products contaminated with antibiotic residues originating from treatment in the developing nations as well as from the use of antibiotics as growth promoters particularly in dairy feedlots in the developed world. The prolonged use of antibiotics in the treatment of mastitis has led to the additional problem of emergence antibiotic resistant strains, hence the constant concern about the resistant strains entering the food chain [23-25]. Many organisms associated with mastitis also have zoonotic importance and can cause diseases like brucellosis, tuberculosis, leptospirosis, Q-fever etc. [26].