Multiplex PCR: Identifying Staphylococcus Species and Methicillin Resistance in Commercial Pork Products

Abstract

Many species of Staphylococcus bacteria, including Staphylococcus aureus and Staphylococcus epidermidis, make up the normal flora of bacteria that live on the skin of animals, such as humans and pigs (Nagase et al. 2001). S. aureus bacteria frequently contaminates pork meat (Jackson et al 2013; Buyukcangaz et. al 2013). Many species of Staphylococcus bacteria can act as opportunistic pathogens and infect hosts that exhibit weakened immune responses. Some diseases caused by Staphylococcus bacteria include: urinary tract infections, sepsis, dermal infections, food poisoning and toxic shock syndrome (Hirotaki et al. 2011; Martineau et al. 1998). Many Staphylococcus bacterial infections have become difficult to treat with antibiotics because several species have become methicillin resistant (Hirotaki et al. 2011). If pork products that contain Staphylococcus bacteria are not properly cooked, many diseases can result that may be antibiotic resistant. Our main objective or this study is to determine which species of Staphylococcus bacteria are most common in commercial pork products purchased in Tennessee and Kentucky, and if the pork products contain Staphylococcus samples that are methicillin resistant.  Currently, we have collected 270 bacterial isolates from 100 pork samples. Of the 270 bacterial isolates, 52 (19.3%) have been identified as S. aureus, 29 (10.7%) are S. epidermidis, one (0.4%) is S. haemolyticus, one (0.4%) is S. saprophyticus, and 22 (8.1%) are not Staphylococcus bacteria. Methicillin resistance was discovered in five isolates, three (10.3%) S. epidermidis isolates, and two (3.8%) S. aureus isolates.