Detección de esporas de Clostridium botulinum en mieles / Detection of Clostridium botulinum in honey

Se examinaron 177 muestras de miel para la detección de Clostridium botulinum; 68 procedentes del comercio, 95 de apiarios envasados en origen, 8 de apiarios rurales para consumo familiar y 6 de establecimientos fraccionadores en las provincias de San Luis y Mendoza. Utilizando el método de dilución-centrifugación, se detectó C. botulinum tipo A en 2 muestras de apiarios rurales de San Luis (1,1 o/o); en una de ellas se logró la recuperación de la cepa y el recuento de esporas fue de 55/g de miel. Si bien el porcentaje de positividad fue inferior al de otros países, se recomienda no suministrar miel a niños menores de 1 año como prevención de botulismo del lactante

Utilidad de la detección de pirrolidonil-arilamidasa en la diferenciación de enterobacterias y bacilos gram-negativos no fermentadores / [Utility of pyrrolidonyl-arylamidase detection for typing Enterobacteriaceae and non-fermenting Gram-negative bacteria]

Detection of pyrrolidonyl-aryl-amidase activity (PYR) is an important tool to identify gram-positive cocci, such as staphylococci, enterococci, streptococci, and other related genera. However, only few studies evaluating its usefulness with gram-negative rods have been published. Thus, a prospective study including 542 and 215 unique clinical isolates of Enterobacteriaceae and non-fermentative gram-negative rods, respectively, was undertaken. Strains were identified by conventional methods. PYR test was performed using a commercial kit, according to the manufacturer recommendations. Positive results were uniformly obtained for the PYR test with the following species: Citrobacter spp, Klebsiella spp, Enterobacter aerogenes, Enterobacter agglomerans group, Serratia marcescens and S. odorifera. On the other hand, negative results were uniformly displayed by E. coli (including inactive E. coli), Protease group, Salmonellia spp, Shigella spp, Acinetobacter spp, Burkholderia (Pseudomonas) cepacia and Flavobacterium spp. Variable results were shown in Pseudomonas aeruginosa, Stenotrophomonas (xanthomonas) malthophilia, Kluyvera cryocrescens, and Enterobacter cloacae. PYR test proved to be a reliable and simple tool to rapidly distinguish certain species belonging to Enterobacteriaceae (ie. Citrobacter freundii from Salmonella spp, and inactive E. coli from K. ozaenae). Further studies, including a wide diversity of species, are required to assess usefulness of the PYR test for the identification of non-fermentative gram-negative rods.

Análisis bacteriológico e investigación de esporas de Clostridium botulinum en mieles / [Bacteriologic analysis and detection of Clostridium botulinum spores in honey]

The bacteriological analysis and, particularly, the detection of Clostridium botulinum spores from 42 honey samples collected in apiaries of the province of San Luis as well as neighbouring areas of La Pampa, Córdoba and Mendoza, were carried out. Samples were processed by the dilution and centrifugation procedures. For spores detection, culture of the pellets were performed in 2 tubes with cooked meat medium (MCC), one of them warmed up to 80 degrees C for 15 min, and both incubated at 30 degrees C during 7 days. Mice were used to search for toxin in the supernatant. Sediments were also searched for anaerobic bacteria detection in yolk agar plates and in nutritive agar plates for the aerobics. Botulinum toxin type A production was found in one of the MCC cultures. No anaerobic bacteria were isolated. All samples contained Bacillus spp.; 21.4

of the strains, were tentatively classified as B. alvei. A working model for the bacteriological analysis of honey and guides that could be enclosed in publications of official institutions (Figure 1) is proposed.