Survival of Escherichia coli O157:H7 during the manufacture and ripening of Cacioricotta goat cheese.
The aim of this study was to assess the growth and survival of Escherichia coli O157:H7 during the manufacturing and ripening of Cacioricotta goat cheese. Goat milk was artificially contaminated with E. coli O157:H7 and the bacterial load was monitored from production up to 90 days of ripening. Goat milk was inoculated with 102 cfu ml-1 of E. coli O157:H7 and the bacterial count of the curd at time zero was 2.31 log10 cfu g-1. During the first day of ripening, the bacterial load has increased to 5.73 log10 cfu g-1 to more than 6.20 log10 cfu g-1 during the first week. The bacterial load remained constant up to 28 days and then slightly decreased until the end of ripening, with values of aw and pH of 0.88 and 5.41 respectively. The results of this study highlighted that E. coli O157:H7 is able to survive the manufacturing process and they suggest that the 90-day period of ripening alone is insufficient to remove E. coli O157:H7 in contaminated Cacioricotta goat cheese. Moreover, these results support the assumption that the presence of a low contamination of milk with E. coli O157:H7 could represent a potential source of infection and a threat to consumers.
Enumeration of Escherichia coli O157 in Outbreak-Associated Gouda Cheese Made with Raw Milk.
In this article, we discuss the enumerative analysis for Escherichia coli O157 in two raw milk Gouda cheese products (A and B), implicated in an outbreak of 29 cases of E. coli O157:H7 illness that occurred across Canada in 2013. Samples were enumerated for E. coli O157 by most probable number (MPN) over a period of 30 to 60 days after the end of the outbreak. Samples (55.55 g) of product A (n = 14) were analyzed at 146 to 180 days postproduction. E. coli O157 was isolated from six samples at 19.9 to 44.6 MPN/kg. The E. coli O157 concentration of product A estimated from the results of all 14 samples was 9.5 MPN/kg. Samples (55.55 g) of product B (n = 20) were analyzed at 133 to 149 days postproduction. E. coli O157 was isolated from four samples at 19.9 MPN/kg. The E. coli O157 concentration of product B estimated from the results of all 20 samples was 3.7 MPN/kg. Analysis of a 305-g sample of product A (n = 1) stored at 4°C until 306 days postproduction revealed that the E. coli O157 concentration had declined to 3.6 MPN/kg. E. coli O157 could not be isolated from 555-g samples of product B (n = 5) after 280 days postproduction. The physicochemical parameters (pH, water activity, percent moisture, and percent salt) of both cheese products were found to be in the normal range for this type of product. The results of this study demonstrate that E. coli O157 could not replicate during storage at 4°C in the products tested but was capable of survival following aging and prolonged storage. This indicates that, if contaminated, the minimum 60-day aging period, which is required for raw milk Gouda cheeses, is not sufficient in all cases to ensure that the product does not contain viable cells of E. coli O157. The results also indicate that samples sizes greater than 100 g may be required to reliably detect E. coli O157 in cheese products associated with outbreaks.
Axonal sensorimotor neuropathy in patients with β-thalassaemia
Objective: The purpose of this study was to investigate the prevalence of peripheral neuropathy in patients with β-thalassaemia. Methods: Thirty six patients with a mean age of 29.2±8.2 years and 17 healthy controls with a mean age of 27.6±9.1 were included in this study. Measurements included the neuropathy symptoms score (NSS), the neuropathy disability score (NDS) as well as nerve conduction studies of two motor (ulnar and peroneal) and two sensory (ulnar and sural) nerves of the right limbs. Results: A mainly sensory axonal polyneuropathy was present in 19 out of 36 patients (52.7%). Eight out of these 19 patients also had abnormal NDS values. The neuropathy correlated significantly with the age of the patients and the hematocrit. However, it did not correlate with the presence of antibodies against HCV, the ferritin levels, or with a history of transfusions, desferrioxamine treatment, or splenectomy. Conclusions: This study showed a high prevalence of a predominantly sensory neuropathy in patients with β-thalassaemia. The electrophysiological data suggest that the underlying pathology is an axonopathy. Chronic hypoxia of the nerves resulting from severe anaemia may contribute to the pathogenesis of this neuropathy.