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

Abstract

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.

Detection, Genophenotypic Characterization, and Antimicrobial Resistance of Microbial Contaminants

“…Understanding the risk factors associated with different microorganisms has led to improvements in controlling microbial contamination [ 1 , 2 ]. This Special Issue was established to gather and share high-quality scientific articles on microbial contamination and contains six original research articles covering a range of diverse topics related to microbial contamination [ 3 , 4 , 5 , 6 , 7 , 8 ]. As revealed from the retrospective analysis of the articles, microbial contamination challenges are often focused around three key issues—the detection, genophenotypic characterization, and antimicrobial resistance (AMR) of microbial contaminants, whereby all of which are interconnected in a pleiotropic and epistatic manner.…”

“…Detecting microbial contaminants in samples with low biomass and complex matrices is a challenging task that requires rapid, sensitive, and accurate detection methods for effective safety interventions. In this Special Issue, several articles explore ways to overcome these challenges and improve microbial detection outcomes [ 3 , 4 , 5 , 6 , 8 ].…”

“…Genophenotypic characterization is a crucial process in understanding and controlling the spread of microbial contaminants. There are various genotypic characterization techniques such as serotyping, multilocus sequence typing (MLST), PFGE, random amplified polymorphism DNA (RAPD), matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS), AMR testing, and whole genome sequencing [ 3 , 8 ]. These methods provide important information on the genetic differences that can impact phenotypic features of microbial contaminants, which can help to identify their sources, modes of transmission, resistance mechanisms, and potential health impacts.…”

“…In the study by Bae et al, PFGE pattern analysis was used to track the transmission of STEC from the farm to throughout food processing and distribution [ 8 ]. The authors were able to group the isolates based on their sample source and identified four pulsotypes with high similarity in their PFGE banding patterns (≥99% similarity).…”

Prevalence and characteristics of foodborne pathogens from slaughtered pig carcasses in Korea

“…Recently, Bae et al (8) reported the first study tracking foodborne pathogens in pigs and related pork products at all points along the pork supply chain, including farms, slaughterhouses, meat processing plants, and retail stores, in Korea. In particular, Y. enterocolitica and Shiga toxin-producing E. coli were the major pathogens isolated from carcasses in slaughterhouses.…”