کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
5800113 1555353 2015 8 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Characterization of persistent and transient Escherichia coli isolates recovered from clinical mastitis episodes in dairy cows
موضوعات مرتبط
علوم زیستی و بیوفناوری علوم کشاورزی و بیولوژیک علوم دامی و جانورشناسی
پیش نمایش صفحه اول مقاله
Characterization of persistent and transient Escherichia coli isolates recovered from clinical mastitis episodes in dairy cows
چکیده انگلیسی


- Transient and persistent Escherichia coli from clinical mastitis cases in dairy cows differ.
- Resistance to numerous antimicrobials increases odds of persistence.
- Resistance to ampicillin or cephalothin increases odds of persistence.
- Virulence genes associated with iron acquisition increases odds of persistence.

Escherichia coli usually cause transient intramammary infections in dairy cows, but persistent intramammary infections have been observed. The objective of the study was to compare antimicrobial resistance and virulence genes found in persistent and transient E. coli isolated from clinical mastitis cases in a cohort of 91 Canadian dairy herds monitored over a 2-year period. Antimicrobial susceptibility was determined by broth microdilution and the presence of 27 virulence genes associated with extra-intestinal E. coli infections was determined by colony hybridization. Proportion of resistance in persistent E. coli ranged from 0.0% (enrofloxacin) to 27.8% (ampicillin and tetracycline). Proportion of resistance in transient E. coli ranged from 0.0% (enrofloxacin) to 16.8% (tetracycline). Odds of being classified as a persistent isolate increased by a factor of 1.6 (95% CI: 1.1, 2.4) for each aditional resistance observed (e.g. isolates resistant to four antimicrobial agents had 1.6 times higher odds of belonging to the persistent groups compared to isolates demonstrating resistance to three agents). Persistency was associated with higher odds of resistance to ampicillin (OR: 9.8, P < 0.01) or cephalothin (OR: 7.6, P = 0.02). Persistent isolates had 5.4 times higher odds (95% CI: 1.2, 24.0) of harboring virulence gene iroN. Similarly, persistent isolates had 8.6 times higher odds (95% CI: 2.8, 27.1) of possessing the virulence gene sitA. In conclusion, this study confirmed that persistency of intramammary E. coli isolates is associated with certain traits. Findings concerning iron-acquisition shed new light on the mechanisms of intramammary survival.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Veterinary Microbiology - Volume 176, Issues 1–2, 23 March 2015, Pages 126-133
نویسندگان
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