Effects of storage temperature on microbiota shifts in raw milk biofilm developed on stainless steel

This study aimed to investigate the microbiota in raw milk and the influence of storage temperature on the microbiota shift after biofilm formation. Raw milk stored at 4 degrees C and biofilms developed in raw milk incubated at 4 degrees C or 25 degrees C for 7 days were subjected to microbiota analysis as well as quantitative analyses of aerobic or anaerobic bacteria. The levels of aerobic bacteria increased during biofilm formation, while no significant changes were observed within anaerobic bacteria. In addition, there was a difference between aerobic and anaerobic bacterial counts in raw milk and biofilm stored for 7 days. The pattern of microbial composition differed by temperature. In addition, the genus Pseudomonas (53-71%) occupied a high proportion in raw milk, and the raw milk biofilm developed at 4 degrees C, while the genus Lactobacillus (75-83%) was predominant in biofilms developed at 25 degrees C. Intriguingly, bacterial richness was higher in raw milk on day 0 and biofilm developed at 4 degrees C than raw milk after 7 days of storage at 4 degrees C. These findings suggest that temperature critically affects the bacterial composition of both raw milk and its associated biofilm.N

Distribution and Characterization of Antimicrobial Resistant Pathogens in a Pig Farm, Slaughterhouse, Meat Processing Plant, and in Retail Stores

The emergence of antibiotic resistance in foodborne pathogens isolated from meat pro-ducts and their producing environment has been an increasing and leading threat to public health. The aim of the study was to identify pathogens and their antimicrobial resistance isolated from pig production to pork meat distribution phases. Through this study, food spoilage and foodborne or clinical pathogenic bacteria were isolated and identified from pork (belly and neck) meat product and its related environmental samples that include pig swabs, diets, feces, liquid manure, workers’ gloves, dust fan swabs, carcass swabs, floor swabs, and drain water in the affiliated farm, slaughterhouse, meat processing plant, and in retail stores. All carcasses at the slaughterhouse and meat products at the meat processing plant were tracked from pigs at a targeted farm. Nine different selective media agars were used to effectively isolate various pathogenic bacteria. A total of 283 presumptive pathogenic bacteria isolated from 126 samples were selected and identified using MALDI-ToF MS. Twenty-three important foodborne pathogens were identified, and some of them, Shiga-toxin-producing E. coli (STEC), Listeria monocytogenes, Staphylococcus aureus, and Yersinia enterocolitica, were further confirmed using PCR. The PFGE patterns of 12 STEC isolates were grouped by sample source or site. All the foodborne pathogens used in the study were not resistant to amoxicillin/clavulanate, ciprofloxacin, and gentamicin, whereas some of the STEC, L. monocytogenes, and S. aureus isolates were resistant to various antibiotics, including ampicillin, erythromycin, tetracycline, and vancomycin. The most common antimicrobial resistance pattern in the pathogenic STEC isolates was AMP-KAN-STR-SXT-TET. Consequently, this study provides valuable information for the distribution of antimicrobial-resistant pathogens along the pork meat production chain and can assist farmers and stakeholders to develop a systematic strategy for reducing the current emergence and spread of antimicrobial resistance in the different phases of pig production and distribution