Prevalence of pathogens and microbiological quality of milk marketed in the region of the Recôncavo da Bahia, Brazil
Abstract
Current study evaluates the sanitary quality and the presence of pathogens of crude and processed bovine milk samples. Fifty -five samples from five municipalities in the Recôncavo da Bahia region were analyzed between May and July 2015. Psichrotrophic, mesophilic and thermophile rates were counted by depth plating method in standard agar; HiCrome ™ selective ECC was employed to quantify total coliforms and Escherichia coli. Escherichia coli O157: H7 was identified with fast method Singlepath® - E. coli O157. Staphylococcus aureuspopulation was estimated with Petrifilm ™ plates and Listeria monocytogeneswas identified by Singlepath L'Mono® kit. There was a greater contamination and presence of pathogens in the raw milk when compared to processed milk. However, total coliformswere detected in 14.28 %,Escherichia coliin 7.14 % and Escherichia coli O157: H7 in 2.04 % of processed milk. The enforcement by authorities against the illegal sale of raw milk and the monitoring of steps in milk production up to marketing should be mandatory.
Keywords
Download Options
Introduction
Brazil currently ranks fourth in milk production worldwide (USDA, 2015), with more than 24 billion liters of raw milk in 2015. The Brazilian state of Minas Geraishad the greatest milk production, with 6,439,650liters, whilst, during the same year, the state of Bahia produced 332,449,000liters, featuring the greatest milk producers in the northeastern region of Brazil in 2015 (Instituto Brasileiro de Geografia e Estatística, 2016).
However, deficient hygiene conditions during milking, handling and conservation are the main factors for decrease in milk quality produced in Brazil (Menezes et al., 2015), damaging the country´s economic development in milk production.
Although Brazilian law forbids selling of milk in natura, it is still common practice in Brazil, associated with cultural, regional and social factors (Bersot et al., 2010). Such practice may be harmful to consumer´s health since milk is a good vector of pathogenic microorganisms which cause Food-Transmitted Diseases (FTD) (Claeys et al., 2013).
Dairies use thermal processes that reduce initial microbial load of raw milk, such as pasteurization and Ultra High Temperature (UHT), to commercialize safer food with regard to sanitary hygiene and shelf time increase.
Further, several studies have revealed the bad quality of milk produced in Brazil (Tamanini et al., 2011; Pereira et al., 2013; Weschenfelder et al., 2016), affected not merely by prime matter used but by lack of post-processing health control, especially during bottling and packaging. Prevention against milk contamination during milking and storing is mandatory to reduce microbial multiplication and to produce quality milk products (Salvador, 2012).
Since milk is a high economic asset in Brazil and its intake may be a health risk for the population due to microbial multiplication, current paper assesses raw and UHT milk quality sold in the towns of the Recôncavo da Bahia region. The study may also be a warning for authorities for drastic control on milk producing farms and in the region´s market.
Conclusion
- The commercialization of raw milk is highly dangerous for consumers due to rates of pathogenic microorganisms found in it.
- Contamination of UHT milk may have been due to flaws in post -processing sanitary control that favored strains of total coliforms, E.coli and E.coli O157:H7 in the commercializ ed milk.
- Negative results occurred for L. monocytogenes in all samples under analysis.