Pesquisa de Salmonella spp. em queijos de coalho comercializados em feiras livres de Garanhuns - PE

Abstract

The “coalho” cheese is a handmade cheese highly produced and consumed in the northeastern region of Brazil. Although the production and selling of this product is regulated by state and federal regulations, informal manufacturing and sale are quite common. Among the pathogenic microorganisms, Salmonella spp. is one of the main agents of foodborne diseases and should be absent in products of animal origin. The objective of the present work was to perform the detection of Salmonella spp. in “coalho” cheeses from street fairs the Garanhuns – PE. Twelve samples of “coalho” cheese, marketed in open fairs in six districts of the city, were evaluated during the months of November and December 2017. The samples were transported in isothermal boxes with recyclable ice to the food microbiology laboratory of CENLAG at UAG-UFRPE. The detection of Salmonella spp. was performed using the standard isolation method, along with the immunochromatographic Singlepath Salmonella rapid test (Merck-Millipore), according to the manufacturer's recommendations. Initially, 25g of each sample was added in 225mL of Buffered Peptone Water (APT), and incubated for 24h at 37 °C. After, 0.1mL of APT broth was added in 10mL Rappaport-Vassiliadis broth (RV) and then incubated for approximately 18h at 42 °C. At the end of this period, RV broths showing turbidity were used to perform the Singlepath Salmonella rapid test. In parallel, RV broth samples were plated on Xylose Lysine Deoxycholate (XLD) and Hektoen Enteric (HE) agar plates, the characteristic colonies being submitted to biochemical tests of Triple Iron Sugar (TSI), Iron Lysine (LIA) and Urease. Finally, the isolates colonies were submitted to the serology test for confirmation. The presence of Salmonella spp. was confirmed in 66.7% (8/12) of the rennet cheese samples analyzed using conventional analysis, according to the Singlepath Salmonella (Merck-millipore) test 83.33% (10/12) of the samples were positive for Salmonella spp.. The high occurrence of Salmonella spp. in cheeses marketed at the Garanhuns fairs, shows a great concern for public health. As well as, it shows the lack of adoption of good manufacturing practices in the preparation of the product, which together with the precarious conditions of hygiene, storage and lack of refrigeration in the commercialization thereof, culminate in the compromise of its microbiological quality.