HYPOTHESIS/OBJECTIVES: To determine the in vitro interaction of ionophores (narasin or monensin) with antimicrobial adjuvants (N-acetylcysteine (NAC), Tris-EDTA or disodium EDTA) against bacterial strains representing pathogens associated with canine otitis externa (OE).
ANIMAL/ISOLATES: American Type Culture Collection (ATCC) strains Staphylococcus aureus 29213, Pseudomonas aeruginosa 27853 and P. aeruginosa biofilm producer PAO1, and a clinical isolate of Proteus mirabilis from a case of canine OE were tested.
METHODS AND MATERIALS: A 2D microdilution checkerboard method was used, allowing calculation of fractional inhibitory concentration index (FICI), dose reduction index (DRI) and plotting of isobolograms.
RESULTS: The combination of narasin with either Tris-EDTA or disodium EDTA produced additive effects (FICI = 0.75) against P. aeruginosa ATCC 27853 and P. aeruginosa biofilm producer ATCC PAO1. An additive effect (FICI = 0.53-0.75) was found against S. aureus ATCC 29213 when narasin or monensin were combined with NAC. The highest DRI (32-fold) was found with monensin/NAC where the MIC of monensin was reduced from 4 to 0.125 μg/mL.
CONCLUSIONS AND CLINICAL IMPORTANCE: The combination of narasin with Tris-EDTA or disodium EDTA is a promising strategy to inhibit the intrinsic resistance elements of Gram-negative bacteria. These novel combinations potentially could be useful as a multimodal approach to treat mixed infections in canine OE.
OBJECTIVES: We assessed the health and economic impact of the 10-valent pneumococcal nontypeable Haemophilus influenzae protein D conjugate vaccine (PCV-10) compared with the current 13-valent pneumococcal conjugate vaccine (PCV-13) recommended for Hong Kong in 2011, providing new elements to be considered by public health authorities in the future decision-making process for pneumococcal vaccines in this country.
METHODS: An analytical model was used to estimate the annual economic and health outcomes of invasive pneumococcal disease (IPD), community-acquired pneumonia, and acute otitis media (AOM), including nontypeable H. influenzae-related AOM, for a birth cohort in Hong Kong from the payer perspective with a 10-year horizon. Clinical impact including morbidity-mortality, quality-adjusted life-years (QALYs), incremental costs, and cost-effectiveness comparing PCV-10 and PCV-13 were estimated. Probabilistic sensitivity analyses by using alternate scenarios were performed.
RESULTS: Model projections indicate that PCV-13 and PCV-10 have approximately equivalent impact on the prevention of deaths caused by IPD and pneumonia. PCV-13 is projected to prevent 6 additional cases of IPD, whereas PCV-10 is projected to prevent 13,229 additional AOM cases and 101 additional QALYs. For the base case, PCV-10 vaccination is estimated to save 44.6 million Hong Kong dollars (34.1 million Hong Kong dollars discounted). Sensitivity analysis indicated that PCV-10 would generate more QALYs and save costs as compared with PCV-13.
CONCLUSIONS: Universal infant vaccination with new available pneumococcal vaccines is expected to generate a significant additional impact on reducing the burden of pneumococcal diseases in Hong Kong. PCV-10 vaccination would be potentially a cost-saving strategy compared with PCV-13 vaccination, generating better cost offsets and higher QALY gains.
METHODS: A case-control study was carried out among patients with CSOM (cases) and controls were those with no ear pathology. The presence of CSOM was made through a medical history and otoscopic examination. Allergen testing was done by the skin prick test.
RESULTS: In all 124 subjects were recruited in this study with equal number of the cases and controls. The commonest positive reaction in the skin prick test in both groups was to house dust mites. Among CSOM cases, half (50%) of them had an allergy to Blomia tropicalis and 48.4% to Dermatophagoides while in the control group, 27.4% to Dermatophagoides and 25.8% to B. tropicalis. There were significant associations between CSOM and allergy to B. tropicalis (p=0.005), Dermatophagoides (p=0.016) and Felis domesticus (p=0.040). The prevalence of allergy at 95% confidence interval (95%CI) in CSOM and control groups were demonstrated as 59.7% (95%CI: 47.5, 71.9) and 30.6 % (95%CI: 19.1, 42.1) respectively. There was a significant association between allergy and CSOM (p=0.001).
CONCLUSION: Indoor allergens are the most prevalent in our environment and therefore good control may difficult to achieve. The hypersensitivity states of the subject are likely to have a role in the pathogenesis of CSOM especially in the tropical countries where allergy occurs perennially.