Prevalence of Methicillin-Resistant Staphylococcus aureus from Equine Nasopharyngeal and Guttural Pouch Wash Samples.

BACKGROUND: Methicillin-resistant Staphylococcus aureus (MRSA) is recognized as a cause of nosocomial infections in both human and veterinary medicine. Studies that examine the nasopharynx and guttural pouches of the horse as carriage sites for MRSA have not been reported. HYPOTHESIS/OBJECTIVE: MRSA colonizes the nasopharynx and guttural pouch of horses. To determine the prevalence of MRSA in equine nasopharyngeal wash (NPW) and guttural pouch lavage (GPL) samples in a field population of horses. SAMPLES: One hundred seventy-eight samples (123 NPW and 55 GPL) from 108 horses. METHODS: Prospective study. Samples were collected from a convenience population of clinically ill horses with suspected Streptococcus equi subsp. equi (S. equi) infection, horses convalescing from a known S. equi infection, and asymptomatic horses undergoing S. equi screening. Samples were submitted for S. aureus aerobic bacterial culture with mannitol salt broth and two selective agars (cefoxitin CHROMagar as the PBP2a inducer and mannitol salt agar with oxacillin). Biochemical identification of Staphylococcus species and pulsed-field gel electrophoresis (PFGE), to determine clonal relationships between isolates, were performed. RESULTS: Methicillin-resistant Staphylococcus (MRS) was isolated from the nasopharynx of 7/108 (4%) horses. Three horses had MRSA (2.7%), and 4 had MR-Staphylococcus pseudintermedius (MRSP). MRSA was isolated from horses on the same farm. PFGE revealed the 3 MRSA as USA 500 strains. CONCLUSIONS AND CLINICAL IMPORTANCE: Sampling the nasopharynx and guttural pouch of community-based horses revealed a similarly low prevalence rate of MRSA as other studies sampling the nares of community-based horses. More study is required to determine the need for sampling multiple anatomic sites when screening horses for MRSA.

A comparison of fresh, pasta filata, and aged Hispanic cheeses using sensory, chemical, functional, and microbiological assessments.

Anecdotal information suggests that some Hispanic consumers may consider US-made Hispanic cheeses as having a general lack of authenticity compared with those made in their countries of origin. To characterize the potential differences, samples of fresh, pasta filata, and aged Hispanic cheeses were acquired from both the United States (total n=39) and countries of origin (total n=30) purchased from Mexico, Central America (Costa Rica and El Salvador), and the Caribbean (Puerto Rico). The proximate composition, microbial counts, melt profile, and sensory characteristics were evaluated and compared in country-of-origin cheeses and the US-made counterparts. The presence of Listeria spp. was confirmed for 1 Mexican aged cheese sample and 6 cheese samples from Central America (3 fresh, 2 pasta filata, and 1 aged). The chemical composition, melt profile, and sensory characteristics of fresh and pasta filata US Hispanic cheeses were not significantly different from their Mexican counterparts. Likewise, the chemical composition and melt profile of US aged Hispanic cheeses was not significantly different from the aged Mexican cheeses, but sensory characteristics varied among all aged cheeses. These results demonstrate the similarities and differences among US fresh, pasta filata, and aged Hispanic cheeses relative to their counterparts made in the countries of origin.

The role of the eosinophil-selective chemokine, eotaxin, in allergic and non-allergic airways inflammation.

Blood eosinophilia and tissue infiltration by eosinophils are frequently observed in allergic inflammation and parasitic infections. This selective accumulation of eosinophils suggested the existence of endogenous eosinophil-selective chemoattractants. We have discovered a novel eosinophil-selective chemoattractant which we called eotaxin in an animal model of allergic airways disease. Eotaxin is generated in both allergic and non-allergic bronchopulmonary inflammation. The early increase in eotaxin paralleled eosinophil infiltration in the lung tissue in both models. An antibody to IL-5 suppressed lung eosinophilia, correlating with an inhibition of eosinophil release from bone marrow, without affecting eotaxin generation. This suggests that endogenous IL-5 is important for eosinophil migration but does not appear to be a stimulus for eotaxin production. Constitutive levels of eotaxin observed in guinea-pig lung may be responsible for the basal lung eosinophilia observed in this species. Allergen-induced eotaxin was present mainly in the epithelium and alveolar macrophages, as detected by immunostaining. In contrast there was no upregulation of eotaxin by the epithelial cells following the injection of sephadex beads and the alveolar macrophage and mononuclear cells surrounding the granuloma were the predominant positive staining cells. Eotaxin and related chemokines acting through the CCR3 receptor may play a major role in eosinophil recruitment in allergic inflammation and parasitic diseases and thus offer and attractive target for therapeutic intervention.