DIFFERENTIATION BETWEEN Nocardia spp. AND Mycobacterium spp.: CRITICAL ASPECTS FOR BACTERIOLOGICAL DIAGNOSIS

New methodologies were developed for the identification of Nocardia but the initial diagnosis still requires a fast and accurate method, mainly due to the similarity to Mycobacterium, both clinical and bacteriologically. Growth on Löwenstein-Jensen (LJ) medium, presence of acid-fast bacilli through Ziehl-Neelsen staining, and colony morphology can be confusing aspects between Nocardia and Mycobacterium. This study describes the occurrence of Nocardia spp. in a mycobacterial-reference laboratory, observing the main difficulties in differentiating Nocardia spp. from Mycobacterium spp., and correlating isolates with nocardiosis cases. Laboratory records for the period between 2008 and 2012 were analyzed, and the isolates identified as Nocardia sp. or as non-acid-fast filamentous bacilli were selected. Epidemiological and bacteriological data were analyzed as well. Thirty-three isolates identified as Nocardia sp. and 22 as non-acid-fast bacilli were selected for this study, and represented 0.12% of isolates during the study period. The presumptive identification was based on macroscopic and microscopic morphology, resistance to lysozyme and restriction profiles using the PRA-hsp65 method. Nocardia spp. can grow on media for mycobacteria isolation (LJ and BBL MGIT™) and microscopy and colony morphology are very similar to some mycobacteria species. Seventeen patients (54.8%) were reported and treated for tuberculosis, but presented signs and symptoms of nocardiosis. It was concluded that the occurrence of Nocardia sp. during the study period was 0.12%. Isolates with characteristics of filamentous bacilli, forming aerial hyphae, with colonies that may be pigmented, rough and without the BstEII digestion pattern in PRA-hsp65 method are suggestive of Nocardia spp. For a mycobacterial routine laboratory, a flow for the presumptive identification of Nocardia is essential, allowing the use of more accurate techniques for the correct identification, proper treatment and better quality of life for patients

Long-term persistence with antihypertensive drugs in new patients.

The objective of this study was to investigate stay-on-therapy patterns over 3 years among patients prescribed different classes of antihypertensive drugs for the first time. A retrospective analysis of information recorded in the drugs database of the Local Health Unit of Ravenna (Italy) was carried out on 7312 subjects receiving a first prescription for diuretics, beta-blockers, calcium channel blockers, angiotensin-converting enzyme (ACE) inhibitors or angiotensin II antagonists between 1 January and 31 December 1997. Patients were followed up for 3 years. All prescriptions of antihypertensive drugs filled during the follow-up periods were considered. The patients continuing or discontinuing the initial treatment, the duration of treatment, and the doses taken were all calculated, as well as main factors influencing the persistence rate. The drugs prescribed were predominantly ACE-inhibitors, followed by calcium channel blockers, diuretics, beta-blockers and angiotensin II antagonists. A total of 57.9% of patients continued their initial treatment during the 3-year follow-up period, 34.5% discontinued the treatment, whilst 7.6% were restarted on a treatment in the third year. Persistence with treatment was influenced by: age of patient (persistence rate increasing proportionately with advancing years), type of drug first prescribed (persistence rate higher with angiotensin II antagonists, progressively lower with ACE-inhibitors, beta-blockers, calcium channel blockers and diuretics), gender of patient (persistence was better in males), age of general practitioner (GP) (the younger the GP, the better the persistence rate) and gender of GP (better stay-on-therapy rate with male GP prescribing). In the case of patients treated continuously, mean daily dose increased progressively over the 3 years. With adequate markers, helpful data can be collected from prescription claims databases for the purpose of monitoring the persistence of patients in continuing their medication, and the quality of antihypertensive treatment in a general practice setting