Antimicrobial activity of copper surfaces against suspensions of Salmonella enterica and Campylobacter jejuni.

BACKGROUND: Salmonella enterica and Campylobacter jejuni are amongst the more prevalent bacterial pathogens that cause foodborne diseases. These microorganisms are common contaminants of poultry and poultry products. This study was aimed to evaluate the antibacterial activity of metallic copper surfaces on these important enteropathogens, and to determine the potential acquisition of copper by food exposed to this metal. RESULTS: The antibacterial activity of copper surfaces was evaluated overlying them with suspensions of 10(6) CFU/ml of S. enterica and C. jejuni. Bacterial counts obtained after 0, 2, 4 and 8 hours at 10 degrees C and 25 degrees C were compared with those obtained in stainless steel and a synthetic polymer as control surfaces. The results showed that when these enteropathogens were kept in contact with copper a significant antibacterial activity was noted, on the contrary when the same load of pathogen suspensions were tested over the control surfaces it was found that the bacterial counts remained unchanged or even increased with time. The potential acquisition of copper by food exposed to this surface was also evaluated. Meat exposed for one hour to a copper surface adsorbed residual copper in a time dependent manner. CONCLUSIONS: These results shows that metallic copper surfaces have an antibacterial activity against S. enterica and C. jejuni and suggest its potential application as an inhibitory agent in the various stages of the food processing operations.

[Carriage of enterotoxigenic Staphylococcus aureus in food handlers]. / Portación de Staphylococcus aureus enterotoxigénicos en manipuladores de alimentos.

BACKGROUND: One of the most common pathogens causing alimentary toxi-infections is Staphylococcus aureus (S aureus). The presence of S aureus in food, indicates flaws during food manipulations. For this reason most sanitary norms require the detection of S aureus carriers. AIM: To determine the carriage rate of enterotoxin producing S aureus strains in food handlers, and to evaluate the antibiotic susceptibility to six antimicrobial agents. MATERIALS AND METHODS: A total of 102 food handlers from 19 restaurants in Santiago, were analyzed. Samples for microbiological analysis were obtained with a swab from the retropharynx. RESULTS: S aureus grew in 35 out of the 102 samples obtained (34%). Further analysis revealed that 19/35 (54%) strains were able to produce enterotoxins. Therefore the corrected carriage rate was 19% (19/102). The most frequently detected enterotoxin was the type A (12/19). All S aureus isolates were resistant to penicillin and susceptible to oxacillin, clindamycin, kanamycin, vancomycin and linezolid. CONCLUSIONS: The carriage rate of S aureus in food handlers in similar to the rate reported in the general population in our country. These results confirm the need for education and training programs in food safety, directed to food handlers.

cagA and vacA in strains of Helicobacter pylori from ulcer and non-ulcerative dyspepsia patients.

BACKGROUND: The cytotoxin associated gene A (cagA), and the vacuolating cytotoxin gene A (vacA) of Helicobacter pylori have been associated to phenotypic characteristics of virulence. The objectives of this study were to detect the presence of cagA and to characterize the allelic variants of vacA in 63 strains of H. pylori isolated from colonized individuals with different clinical outcomes. METHODS: 38 strains were isolated from patients with non-ulcerative dyspepsia (NUD) and 25 were isolated from colonized individuals with peptic ulcers. The genotypic characterization was carried out utilizing PCR methodology. The presence of the cagA gene was detected using two set of primers from the middle conservative region of the cagA, and primers for the signal and middle region were used for the genotyping of vacA. RESULTS: The presence of cagA showed similar rates in strains from peptic ulcers (60%) and NUD patients (55%). Also similar was the prevalence of the allelic form s1 of vacA between the strains obtained from ulcers or NUD patients. However, the combination cagA+/vacA s1m1 was found more frequently among the H. pylori strains from peptic ulcer patients (52%) than among strains isolated from NUD patients (26%), this difference was statistically significant (p = 0.035). CONCLUSIONS: The presence of either cagA or the allelic variant s1 vacA alone do not have a predictive value as as a risk markers of severe gastric pathologies in the Chilean population. However, being infected by a H. pylori strain with the genotype cagA+/vacA s1m1 may be associated to an increased risk of acquiring a peptic ulcer disease.