Francesca Silva Dias

Lactic Acid Bacteria as Biological Control of Staphylococcus aureus in Goat "Coalho" Cheese

SUMMARY The aim of this study is to investigate the bacterial population in coalho goat cheese produced in the semi-arid northeast region of Brazil, to analyse the antibiotic resistance profiles of the identified pathogenic bacteria, to detect the staphylococcal enterotoxin genes and to evaluate the addition of autochthonous lactic acid bacteria (LAB) with technofunctional properties for the control of Staphylococcus aureus growth. In the analysed samples, strains of Escherichia coli (N=11), Salmonella spp. (N=18), Listeria spp. (N=6) and S. aureus (N=9) were classified as multidrug resistant (MDR). The most commonly isolated pathogen from the studied coalho goat cheese was S. aureus. Its isolates were positive for the genes encoding enterotoxins A (sea), B (seb), C (sec) and D (sed). The autochthonous LAB with the potential to inhibit S. aureus were identified as Enterococcus faecium. These strains were selected for in vitro tests of protective, safety, technological and functional properties. In the coalho goat cheese food matrix, these selected autochthonous LAB were able to reduce the enterotoxigenic MDR S. aureus load by approx. 3 log units.

Verification of good practices in food establishments in Petrolina, semi-arid region of Pernambuco, Brazil

This study was conducted jointly with the Municipal Sanitary Surveillance Agency of Petrolina, in the period of August-October 2013, to evaluate the hygienic-sanitary conditions of food producing and commercializing establishments in the municipality of Petrolina. A total of 300 food manufacturer/trader establishments were evaluated based on a Good Manufacturing Practices (GMP) checklist. The evaluation was based on 25 items. The data were computed as 0 for nonconformity and 1 for conformity to the GMP checklist. Data from all districts were analyzed by Principal Component Analysis (PCA). Items such as presence of lamp protectors, clean windows and screens, presence of SOP and training programs for handlers, use of aprons, caps, gloves and disposable towels, and performing periodic examinations of the establishments were evaluated. Fourteen evaluation items showed significant differences (P<0.05) for frequency of conforming and 9 for nonconforming. The PCA identified five city districts (Centro Norte, Areia Branca, Santa Luzia, Rio Corrente and São Gonçalo) in the municipality that used GMP in their establishments. These results highlight the need to redouble efforts in establishments to ensure the safety of products offered.