A. Sierra

Prevalence and Characteristics of Methicillin-Resistant Staphylococcus aureus in Pigs and Pig Workers in Tenerife, Spain

Methicillin-resistant Staphylococcus aureus (MRSA) strains belonging to sequence type (ST) 398 are being reported with increasing frequency in Europe and other countries. This MRSA type has been isolated from colonized and infected animals and humans. The aim of this study was to determine the prevalence of nasal MRSA carriage in pigs and pig workers. A total of 300 pigs from 15 different farms were sampled in the slaughterhouse of Tenerife. A total of 54 pig workers were screened for MRSA: 20 belonged to farms whose pigs had been sampled and 34 to the slaughterhouse. The percentage of positive samples of MRSA in pigs was 85.7%. The overall prevalence of nasal MRSA carriage in pig workers was 9.3%. All MRSA isolates from pigs and humans belonged to one clonal group showing multilocus sequence type (MLST) 398. Two types of Staphylococcal Chromosome Cassette (SCCmec) were found, IV and V. In conclusion, the prevalence of MRSA in nasal samples from pigs and pig workers in Tenerife was high. We therefore consider it essential to deepen epidemiological study of this strain of animal origin, as well as to increase surveillance and control measures at all stages of the food chain.

Comparison of Albicans ID2® agar plate with the germ tube for presumptive identification of Candida albicans

Albicans ID2 (bioMérieux, France) is a commercially available chromogenic medium that allows rapid and specific macroscopic identification of Candida albicans and facilitates the differentiation of species in mixed cultures. We compared it with the standard method for the identification of yeast species, the germ tube test (GT). This study involved 423 clinical isolates, including 163 C. albicans and 260 non-albicans yeasts. Sensitivity of Albicans ID2 agar plates regarding the identification of C. albicans were 98.2% after 48 h of incubation and specificity of 96.6%. This method using rapid enzymatic method shows the same similar sensitivity than the GT test The false negative rate (1.8%) for the GT test is consistent with that previously reported. None tests discriminated between C. albicans and C. dubliniensis isolates.

Phytic acid level in infant flours

This study determined the phytic acid content in the infant flour commonly consumed in the Canary Islands. A total of 400 samples from different cereals was analyzed. The method proposed by Garcia-Villanova et al. (1982) [Garcia-Villanova, R., Garcia-Villanova, R. J., Ruiz de Lope, C. (1982). Determination of phytic acid by complexometric titration of excess of iron (III). Analyst 107, 1503–1506] was the one used for determination of the phytic acid content in cereal flours. Phytic acid concentrations are within the range <1–⩾36 mg/g. The arithmetic mean obtained from all the samples studied is 24.6 mg/g. Most of the samples studied show a phytic acid content higher than 20 mg/g, and much lower values are observed in gluten-free flours (< 5 mg/g). Significant differences are observed for the different flour types. Gluten-free flour has a content lower than the rest; 9-cereal flour has a phytate concentration lower than the other flours tested but higher than gluten-free flour. Among wheat samples, phytate values are lower than in the varieties muesli-chocolate, 7-cereal, 8-cereal, multicereal and cereal-biscuit. Multicereal flour has a lower content than muesli-chocolate.

In vitro susceptibility of 545 isolates of Candida spp. to four antifungal agents

Summary. The in vitro susceptibility to amphotericin B, fluconazole, itraconazole and ketoconazole of 545 Candida strains from patients treated at the University Hospital of the Canaries was determined by means of a microdilution test. The distribution of the species was as follows: Candida albicans (342), Candida tropicalis (70), Candida glabrata (68), Candida parapsilosis (65). Of Candida albicans isolates, 8.5% and 7.6% showed resistance to itraconazole and fluconazole respectively. Of C. tropicalis isolates 34.3%, 27.1% and 2.9% were resistant to itraconazole, fluconazole and ketaconazole respectively. For C. glabrata, 10.3% and 4.4% of the isolates under study demonstrated resistance to fluconazole and itraconazole respectively. Only 4.6% and 1.5% of C. parapsilosis isolates demonstrated resistance to fluconazole and itraconazole respectively. C. tropicalis was the most resistant strain and C. parapsilosis the most sensitive. The greatest percentages of resistance in vitro were seen with the triazoles.

Candida glabrata: In vitro Susceptibility of 84 Isolates to Eight Antifungal Agents

The in vitro susceptibility of 84 isolates of Candida glabrata from patients treated at the University Hospital of the Canary islands to eight antifungal agents (amphotericin B, itraconazole, fluconazole, miconazole, clotrimazole, tioconazole and econazole) has been studied using the broth dilution micro-method. Among the eight antifungal agents tested, the smaller geometric mean corresponded to tioconazole, econazole, clotrimazole and miconazole. In contrast with fluconazole, a greater geometric mean has been achieved. All the C. glabrata isolates tested were sensitive to concentrations of 3.125 micrograms/ml of clotrimazole and miconazole, 6.25 micrograms/ml of amphotericin and ketoconazole. Concentrations of 12.5 micrograms/ml were needed to obtain 100% inhibition of isolates for econazole and tioconazole and concentrations of 25 and 50 micrograms/ml, respectively for itraconazole and fluconazole. Among our C. glabrata isolates, 2.4% were found to be resistant to amphotericin B. For fluconazole and itraconazole, 19.1% and 7.9% of isolates, respectively, were resistant. With reference to imidazoles, we obtained 2.4% and 3.6% resistance for tioconazole and econazole, respectively. No isolates were found to be resistant to ketoconazole, miconazole and clotrimazole. The results have shown a high activity of amphotericin B and itraconazole, observing a similar response with the five imidazole antifungals tested. The highest rate of resistance was found when fluconazole was used.

Concentration levels of sorbic and benzoic acids in soft drinks

The quantity of sorbic and benzoic acids in soft drinks is determined by reverse‐phase high performance liquid chromatography (HPLC) method. A good separation of the two preservatives was obtained by using a mobile phase composed of ammonic acetate 5 mM at pH 4.4 and aceto‐nitrile (80/20), and with UV detection. The average levels of benzoic acid varied between 73.4 ±2.51 (brand F) and 429 ±2.21 (brand K), and those of sorbic acid between 72.3 ±1.04 (brand M) and 199 ± 7.72 (brand A). Likewise, the estimated daily intake (EDI) for each additive was calculated, resulting in a higher intake of benzoic acid (38.3 mg) than sorbic acid (5.98 mg). In both cases, the values were lower than the acceptable daily intake (ADI).