Antimicrobial susceptibility ofArcanobacterium pyogenesisolated from the lungs of white-tailed deer (Odocoileus virginianus) with pneumonia

Abstract

Abstract. In vitro susceptibilities of 29 strains of Arcanobacterium pyogenes isolated from lung lesions of white-tailed deer (Odocoileus virginianus) with pneumonia were determined using the broth microdilution method to ascertain efficacious treatment options for pneumonic white-tailed deer. All 29 A. pyogenes strains tested were susceptible to ceftiofur, spectinomycin, tiamulin, and trimethoprim-sulfamethoxazole but were resistant to both danofloxacin and sulfadimethoxine. Likewise, all 29 isolates were either fully susceptible or intermediately susceptible to gentamicin (25 susceptible; 4 intermediate) and tulathromycin (25 susceptible; 4 intermediate). At least one isolate of A. pyogenes tested was resistant to ampicillin, chlortetracycline, clindamycin, enrofloxacin, florfenicol, oxytetracycline, penicillin, and tilmicosin suggesting their ineffectiveness in treating A. pyogenes-associated lung infections in white-tailed deer. Minimum inhibitory concentration (MIC) data for tylosin and neomycin could not be interpreted due to unavailability of Clinical and Laboratory Standards Institute (CLSI)-approved breakpoints for these 2 agents. In summary, based on MIC values, ceftiofur, spectinomycin, tiamulin, and trimethoprimsulfamethoxazole are more efficacious than other antimicrobial agents for treating A. pyogenes-related pneumonia in whitetailed deer. However, ceftiofur may be preferred over the other 4 drugs as it is being widely used to treat respiratory disease in cattle and other animal species, as well as is available for single dose parenteral administration.

Aminoglycoside resistance of <i>Trueperella pyogenes</i> isolated from pigs in China

“…T. pyogenes is rarely reported to be resistant to aminoglycosides. In the United States, 29 T. pyogenes isolates were collected from the lung lesions of white-tailed deer with pneumonia, and all isolates were found to be show full or intermediate susceptibility to gentamicin (25 susceptible, 4 intermediate) and high susceptibility to spectinomycin [ 19 ]. Antimicrobial susceptibility testing of a T. pyogenes isolate obtained from a 65-year-old man with an oozing ulcer in India revealed that the isolated strain was susceptible to gentamicin [ 10 ].…”

Pharmacokinetics and lung and muscle concentrations of tulathromycin following subcutaneous administration in white‐tailed deer (Odocoileus virginianus)

“…Furthermore, the AUC:MIC ratio suggests the dose approved and used in cattle (2.5 mg/kg [1.1 mg/lb]) might exhibit adequate clinical efficacy in deer. However, tulathromycin may not have adequate efficacy against pneumonia due to Trueperella pyogenes in white‐tailed deer Tell et al ., . With a reported MIC of ≤16 μg/mL for tulathromycin against this pathogen Tell et al ., ; the lung C max at 14 days (4.6 μg/mL) is well below the effective concentration for this respiratory pathogen in deer, as is the AUC:MIC ratio.…”

“…However, tulathromycin may not have adequate efficacy against pneumonia due to Trueperella pyogenes in white‐tailed deer Tell et al ., . With a reported MIC of ≤16 μg/mL for tulathromycin against this pathogen Tell et al ., ; the lung C max at 14 days (4.6 μg/mL) is well below the effective concentration for this respiratory pathogen in deer, as is the AUC:MIC ratio. This pilot study identifies the need to assess lung concentrations at earlier time points after tulathromycin administration to further understand tulathromycin pharmacodynamics in deer.…”

“…Farming of white‐tailed deer ( Odocoileus virginianus ) is a growing industry in North America where deer are raised commercially for meat and for hunting on harvest preserves North American Deer Farmers Association; Alberta Whitetail and Mule Deer Association; Tell et al ., . Respiratory infections are a common cause of morbidity and mortality in captive white‐tailed deer herds Tell et al ., ; Dyer et al ., .…”

“…Farming of white-tailed deer (Odocoileus virginianus) is a growing industry in North America where deer are raised commercially for meat and for hunting on harvest preserves North American Deer Farmers Association; Alberta Whitetail and Mule Deer Association; Tell et al, 2011. Respiratory infections are a common cause of morbidity and mortality in captive white-tailed deer herds Tell et al, 2011;Dyer et al, 2004. With no antimicrobial drugs currently approved in North America for use in deer, antibiotics approved for use in cattle at the recommended cattle dose are typically employed to treat deer. This practice requires an assumption that deer share similar drug absorption and disposition characteristics with cattle.…”