Methicillin (Oxacillin)-Resistant Staphylococcus aureus Strains Isolated from Major Food Animals and Their Potential Transmission to Humans

Abstract

, various types of specimens from cattle, pigs, and chickens were collected and examined for the presence of methicillin (oxacillin)-resistant Staphylococcus aureus (MRSA). S. aureus was isolated and positively identified by using Gram staining, colony morphology, tests for coagulase and urease activities, and an API Staph Ident system. Among 1,913 specimens collected from the animals, 421 contained S. aureus; of these, 28 contained S. aureus resistant to concentrations of oxacillin higher than 2 g/ml. Isolates from 15 of the 28 specimens were positive by PCR for the mecA gene. Of the 15 mecA-positive MRSA isolates, 12 were from dairy cows and 3 were from chickens. Antimicrobial susceptibility tests of mecA-positive MRSA strains were performed by the disk diffusion method. All isolates were resistant to members of the penicillin family, such as ampicillin, oxacillin, and penicillin. All isolates were also susceptible to amikacin, vancomycin, and trimethoprim-sulfamethoxazole. To determine molecular epidemiological relatedness of these 15 animal MRSA isolates to isolates from humans, random amplified polymorphic DNA (RAPD) patterns were generated by arbitrarily primed PCR. The RAPD patterns of six of the isolates from animals were identical to the patterns of certain isolates from humans. The antibiotypes of the six animal isolates revealed types similar to those of the human isolates. These data suggested that the genomes of the six animal MRSA isolates were very closely related to those of some human MRSA isolates and were a possible source of human infections caused by consuming contaminated food products made from these animals.

Phenogenotyping of Closely Related Methicillin Resistant Staphylococcus aureus Isolated from Milk and Meat Products

“…In the current work, the strains under the study showed high resistance to the mostly widely used antimicrobials and they were resistant to three or more of antimicrobials. Meanwhile, lower percentages were previously recorded in other localities [30]. This high resistance in the studied S. aureus to antimicrobials may be attributed to random use of antibiotics or the public hygienic conditions.…”

Prevalence and antibiogram study of Salmonella and Staphylococcus aureus in poultry meat

“…Atanassova et al found 51.1% S. aureus contamination in raw pork meat by PCR detection while he claimed 57.7% S. aureus contamination by using classical microbiological procedures [27] . Heo et al reported 11% S. aureus prevalence in meat, while Lee reported 13% S. aureus presence in poultry meat of Korea [15,28] .…”

Antimicrobial resistance profiles of Staphylococcus aureus clusters on small dairy farms in southern Brazil

“…Particularly, methicillin-resistant S. aureus (MRSA), which are resistant to almost all types of β-lactam antimicrobials, have been a concern worldwide (Lee 2003, Van Duijkeren et al 2004. The presence of MRSA in dairy cows has been investigated because it was demonstrated that cattle may serve as a source of emergence of new MRSA strains in humans (Juhász-Kaszanyitzky et al 2007, Vanderhaeghen et al 2010.…”