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BMC Vet Res

Phenotypic and genotypic characterization of Enterococcus cecorum strains associated with infections in poultry.

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Phenotypic and genotypic characterization of Enterococcus cecorum strains associated with infections in poultry.

BMC Vet Res. 2016;12(1):129

Authors: Dolka B, Chrobak-Chmiel D, Makrai L, Szeleszczuk P

Abstract
BACKGROUND: From the beginning of the 21(st) century Enterococcus cecorum has emerged as a significant health problem for poultry raised under intensive production systems. To obtain new insights into this bacterial species, we investigated 82 clinical isolates originating from different poultry flocks in Poland between 2011 and 2014.
RESULTS: Phenotypically, isolates from clinical cases showed ability to growth at low temperatures (4 °C, 10 °C), and differences in growth at 45 °C (74.4 %). Survival at high temperatures (60 °C, 70 °C) was observed for 15, 30 min. More than half of strains survived at 60 °C even after prolonged incubation (1 h), but none survived after 1 h at 70 °C. Total growth inhibition was observed on agar supplemented with tergitol or potassium tellurite. Relatively high number of isolates gave positive reactions for β-galactosidase (βGAL 80 %), Voges Proskauer test (60 %), less for β-mannosidase (17 %), glycogen and mannitol (12 %). The metabolic fingerprinting for E. cecorum obtained in Biolog system revealed ability to metabolise 22 carbon sources. Only 27/82 strains contained ≥ 1 virulence genes of tested 7, however 2.4 % isolates carried 6. Increased antimicrobial resistance was observed to enrofloxacin (87 %), teicoplanin (85 %), doxycycline (83 %), erythromycin (46 %). Most strains (75/82) showed multidrug resistance. The single isolate was resistant to vancomycin (VRE) and high level gentamicin (HLGR). Linezolid resistance among clinical isolates was not found. PFGE revealed diversity of E. cecorum from cases. It could be assumed that transmission of pathogenic strains between flocks regardless of type of production or geographical region may be possible.
CONCLUSIONS: Clinical infections in poultry caused by E. cecorum may indicated on new properties of this bacterial species, previously known as a commensal. Despite many common phenotypic features, differences were found among clinical isolates. Several, widely distributed pathogenic E. cecorum strains seemed to be responsible for infection cases found in different poultry types.

PMID: 27350248 [PubMed – in process]

Genome-wide association study reveals a locus for nasal carriage of Staphylococcus aureus in Danish crossbred pigs.

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Genome-wide association study reveals a locus for nasal carriage of Staphylococcus aureus in Danish crossbred pigs.

BMC Vet Res. 2015;11(1):290

Authors: Skallerup P, Espinosa-Gongora C, Jørgensen CB, Guardabassi L, Fredholm M

Abstract
BACKGROUND: Staphylococcus aureus is an important human opportunistic pathogen residing on skin and mucosae of healthy people. Pigs have been identified as a source of human colonization and infection with methicillin-resistant Staphylococcus aureus (MRSA) and novel measures are needed to control zoonotic transmission. A recent longitudinal study indicated that a minority of pigs characterized by high nasal load and stable carriage may be responsible for the maintenance of S. aureus within farms. The primary objective of the present study was to detect genetic loci associated with nasal carriage of S. aureus in Danish crossbred pigs (Danish Landrace/Yorkshire/Duroc).
RESULTS: Fifty-six persistent carriers and 65 non-carriers selected from 15 farms surveyed in the previous longitudinal study were genotyped using Illumina’s Porcine SNP60 beadchip. In addition, spa typing was performed on 126 S. aureus isolates from 37 pigs to investigate possible relationships between host and S. aureus genotypes. A single SNP (MARC0099960) on chromosome 12 was found to be associated with nasal carriage of S. aureus at a genome-wide level after permutation testing (p = 0.0497) whereas the association of a neighboring SNP was found to be borderline (p = 0.114). Typing of S. aureus isolates led to detection of 11 spa types belonging to the three main S. aureus clonal complexes (CC) previously described in pigs (CC9, CC30 and CC398). Individual carriers often harbored multiple S. aureus genotypes and the host-pathogen interaction seems to be independent of S. aureus genotype.
CONCLUSION: Our results suggest it may be possible to select pigs genetically resistant to S. aureus nasal colonization as a tool to control transmission of livestock-associated MRSA to humans.

PMID: 26612358 [PubMed – as supplied by publisher]

Describing antimicrobial use and reported treatment efficacy in Ontario swine using the Ontario Swine Veterinary-based Surveillance program.

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Describing antimicrobial use and reported treatment efficacy in Ontario swine using the Ontario Swine Veterinary-based Surveillance program.

BMC Vet Res. 2013;9:238

Authors: Glass-Kaastra SK, Pearl DL, Reid-Smith RJ, McEwen B, McEwen SA, Amezcua R, Friendship RM

Abstract
BACKGROUND: The objective of this work was to retrospectively assess records received through the Ontario Swine Veterinary-based Surveillance program July 2007 – July 2009 to describe and assess relationships between reported treatment failure, antimicrobial use, diagnosis and body system affected.
RESULTS: Antimicrobial use occurred in 676 records, 80.4% of all records recording treatment (840). The most commonly used antimicrobials were penicillin (34.9%), tetracyclines (10.7%) and ceftiofur (7.8%), and the use of multiple antimicrobials occurred in 141/676 records (20.9%). A multi-level logistic regression model was built to describe the probability of reported treatment failure. The odds of reported treatment failure were significantly reduced if the record indicated that the gastro-intestinal (GI) system was affected, as compared to all other body systems (p < 0.05). In contrast, the odds of reported treatment failure increased by 1.98 times if two antimicrobials were used as compared to one antimicrobial (p = 0.009) and by 6.52 times if three or more antimicrobials were used as compared to one antimicrobial (p = 0.005). No significant increase in reported treatment failure was seen between the use of two antimicrobials and three or more antimicrobials. No other antimicrobials were significantly associated with reported treatment failure after controlling for body system and the number of antimicrobials used.
CONCLUSIONS: Failure of antimicrobial treatment is more likely to occur in non-GI conditions, as compared to GI conditions and the use of multiple antimicrobial products is also associated with an increased probability of antimicrobial treatment failure. The authors suggest that a more preventative approach to herd health should be taken in order to reduce antimicrobial inputs on-farm, including improved immunity via vaccination, management and biosecurity strategies. Furthermore, improved immunity may be viewed as a form of antimicrobial stewardship to the industry by reducing required antimicrobial inputs and consequently, reduced selection pressure for AMR.

PMID: 24289212 [PubMed – indexed for MEDLINE]