Qualidade microbiológica, veiculação de bactérias resistentes e caracterização genotípica do pescado comercializado em feiras livres em Municípios do Recôncavo da Bahia

Abstract

CAPÍTULO 1 = Fish is a food that has high nutritional value, however, it can have its quality compromised due to contaminations along the production chain. In markets and street markets this fact can be aggravated due to inadequate sales and handling. The objective of this study was to evaluate the microbiological quality of fish marketed in street markets in municipalities of the Recôncavo of Bahia and characterize the isolates for antimicrobial susceptibility and the presence of virulence genes. On a weekly basis, from April to June 2018, 54 fish samples commercialized in the municipalities of Cachoeira, Cruz das Almas and Santo Antônio de Jesus were analyzed. In each collect, two tainha samples (Mugil sp.), two of sururu (Mytella sp.) and two of chumbinho (Anomalocardia brasiliana), three repetitions were performed in each municipality. For microbiological analysis, the total count of mesophilic heterotrophic bacteria by pour plate in Plate Count Agar (PCA), molds and yeasts by spread plate in Agar Sabouraud Dextrose. For counting of total coliforms and Escherichia coli was done using Chromocult® Coliform Agar and for quantification of Staphylococcus aureus the rapid method Petrifilm ™ STX (3M Company) was used. The sensitivity profile of S. aureus and E. coli isolates to commercial antimicrobials was determined by the disc-diffusion method. The DNA was extracted from the E. coli isolates and the Polymerase Chain Reaction (PCR) was used to screen for the stx virulence gene. The quantification of total coliforms ranged from 0 to 9.50 log CFU / g. Molds and yeasts and heterotrophic mesophilic bacteria presented the highest quantification, 9.95 log CFU / g and 9.78 log CFU / g, respectively. For S. aureus, 85.4% of the isolates were resistant to penicillin, 79.2% to clindamycin and 75% to oxacillin. E. coli was resistant to nine antimicrobials, with higher resistance to amoxicillin (88.4%), ampicillin (85.5%) and cefoxitin (82.6%). The presence of the stx gene was not detected in any sample studied. In view of the results found, it is possible to conclude that samples of fish marketed in street markets in the municipalities of Cachoeira, Cruz das Almas and Santo Antônio de Jesus have unsatisfactory microbiological quality, besides serving as vehicles for resistant microorganisms. CAPÍTULO 2 = Informal marketing of fish is an important source of food and income for many families, but it is a public health concern since it can be compromised during marketing. The objective of this work was to evaluate the microbiological quality of the fish marketed in open fairs in municipalities of the Bahia Reconcavo, to characterize the isolates for antimicrobial susceptibility and to investigate virulence genes. Samples of tainha (Mugil sp.), sururu (Mytella sp.) and chumbinho (Anomalocardia brasiliana) were collected in street market in the municipalities of Cachoeira, Cruz das Almas and Santo Antônio de Jesus. The presence of mesophiles, molds and yeasts, total coliforms, Escherichia coli and Staphylococcus aureus. The isolates of E. coli and S. aureus were submitted to the antimicrobial susceptibility test. Research on gene stx in E. coli isolates was performed. Quantifications of total coliforms and S. aureus ranged from 0 to 9.50 log CFU / g, and high counts of mesophiles and molds and yeasts were found. E. coli presented greater resistance (76.8%) to amoxicillin. S. aureus presented greater sensitivity to gentamicin. The stx gene was not identified in any of the samples studied. It is concluded that part of the fish marketed in the free trade fairs of these three municipalities presents unsatisfactory microbiological quality, which may cause risks to the consumer's health, besides serving as a vehicle for the dissemination of bacteria resistant to different antimicrobials.