Antimicrobial resistance profiles of bacteria associated with lower respiratory tract infections in cats and dogs in England

Abstract

Background: Bacterial lower respiratory tract infections (bLRTIs) are common and potentially life threatening in cats and dogs. Antibiotic treatment is often initiated before the diagnosis of bLRTI; therefore improved knowledge of the aetiology and antibiotic susceptibility patterns of these infections is essential to inform empiric antibiotic choices. Methods: A retrospective study of microbiological, cytological results and their drug susceptibilities from lower respiratory samples (n = 1989) processed in a UK commercial laboratory between 2002 and 2012 was carried out. Results: Thirty-nine per cent of feline samples and 50% of canine samples were positive for bacterial growth with most yielding a single organism (72 % and 69%, respectively). Bordetella bronchiseptica (20.2% from dogs and 2.3% from cats), Pasteurella spp. (23.2%, 31.8%), E. coli (16.2%, 13.6%) and Pseudomonas spp. (11.1%, 11.4%) were most frequently isolated from cytologically positive samples which contained intracellular bacteria (10%, 14%). Amoxycillin-clavulanate, cephalothin, cefovecin, oxytetracycline and trimethoprim/sulfamethoxazole showed modest in vitro activity against E. coli from dogs (approximately 70% susceptibility). Pseudomonas spp. were resistant to enrofloxacin (50%), ticarcillin (25%) and marbofloxacin (13%) but showed lower or zero resistance to aminoglycosides (approximately 7%) and ciprofloxacin (0%). Multi drug resistance (acquired resistance to three or more antimicrobial drug classes) was particularly common among E. coli isolates, with 23% from feline samples and 43% from canine samples. Conclusion:Resistance to certain first-choice antibiotics was detected in bLRTIs highlighting the need for continued monitoring and sound evidence to inform decision-making in the management of these infections.

Outbreak management of multidrug-resistant Bordetella bronchiseptica in 16 shelter-housed cats

“…While the literature provides multiple examples of B bronchiseptica isolates demonstrating antibiotic resistance in dogs, pigs and cats, 19 , 20 , 23 , 36 , 37 this is the first report of managing an MDR B bronchiseptica infection outbreak in a shelter setting. The presentation of four cats with pneumonia on the same day, and following the previous treatment for URD, prompted concern for atypical infectious disease.…”

“…2 However, B bronchiseptica isolates have demonstrated resistance to multiple classes of antibiotics, most commonly penicillins and cephalosporins. 7,[19][20][21][22] Resistance to doxycycline and other tetracyclines has also been identified. 16,[20][21][22][23] A bacterial pathogen demonstrating resistance to three or more classes of antibiotics is considered to be multidrugresistant (MDR).…”

“… 2 However, B bronchiseptica isolates have demonstrated resistance to multiple classes of antibiotics, most commonly penicillins and cephalosporins. 7 , 19 – 22 Resistance to doxycycline and other tetracyclines has also been identified. 16 , 20 – 23 …”

Patient weight has diverse effects on the prescribing of different antibiotics to dogs

“…Marbofloxacin also tended to be used in older patients, perhaps due to clinician perception of high potency with low toxicity ( 53 ), the convenience of once-daily dosing ( 16 ), or concerns about antimicrobial resistance with alternative options ( 54 ). Erythromycin was used almost exclusively in young animals, suggesting association with juvenile Campylobacter enteritis ( 16 , 55 , 56 ).…”

Knowledge and Attitudes of Small Animal Veterinarians on Antimicrobial Use Practices Impacting the Selection of Antimicrobial Resistance in Dogs and Cats in Illinois, United States: A Spatial Epidemiological Approach

“…Furthermore, only 10.4% of the veterinarians stated that they always performed cytology for suspected bacterial infections before initiating treatments (36.4% reported often, and 45.5% stated they sometimes perform cytology). Performing cytology before starting antimicrobial treatment of certain bacterial infections was described by previous studies as an important tool in limiting the selection of AMR [ 35 , 36 , 37 ].…”