Livestock, pets and humans as carriers of methicillin-resistant Staphylococcus aureus and comparative evaluation of two PCR protocols for detection

Staphylococcus aureus are Gram positive bacteria known to acquire antibiotic resistance rapidly and pose a major challenge to clinicians worldwide. Infections by methicillin resistant Staphylococcus aureus (MRSA) are usually associated with increased mortality and prolonging of treatment. Samples (n = 706) from diverse sources (livestock, pets, animal handlers, human hospital) were collected and screened for the presence of MRSA by phenotypic and genotypic methods. The incidence of Staphylococcus aureus was greater in goats (42.00%; 28.20 -56.80%, confidence interval [CI] 95.00%) followed by cattle (13.50%; 9.20 -18.80%, CI 95.00%), humans (12.90%; 9.30 -17.40%, CI 95.00%) and dogs (12.90%; 8.10 -19.20%, CI 95.00%). Significantly higher incidence of MRSA was observed in dogs (65.00%; 40.80 -84.60%, CI 95.00%), compared to other hosts namely cattle (48.00%; 26.50 -64.30%, CI 95.00%), humans (35.00%; 20.20 -52.50%, CI 95.00%) and goats (10.00%; 1.20 -30.40%, CI 95.00%). All the S. aureus isolates were further screened for thermostable nuclease (nuc gene) by polymerase chain reaction (PCR). The incidence of nuc gene in cattle, dog, goat and human were found to be 3.30% (1.30 -6.60%, CI 95.00%), 5.20% (2.30 -9.90%, CI 95.00%), 28.00% (16.20 -42.50%, CI 95.00%) and 9.10% (6.00 -13.00%, CI 95.00%), respectively. Comparative evaluation of two PCR primers (mecA-162 and mecA-310) indicated the former one as more rational choice for detection of MRSA. Overall, the results of our study indicated possible risk of zoonotic transmission of MRSA from canines.& COPY; 2023 Urmia University. All rights reserved.

Automated summary

Staphylococcus aureus is a Gram positive bacteria that rapidly acquires antibiotic resistance and poses a major challenge to clinicians worldwide. Methicillin resistant Staphylococcus aureus (MRSA) infections are associated with increased mortality and treatment prolongation. Samples from diverse sources were collected and screened for MRSA, with a higher incidence observed in goats (42.00%), followed by cattle (13.50%), humans (12.90%), and dogs (12.90%). Dogs had a significantly higher incidence of MRSA compared to other hosts. All S. aureus isolates were further screened for the nuc gene, with varying incidence rates observed among different hosts. The study indicates a possible risk of zoonotic transmission of MRSA from canines.