Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2024 Oct 27;14(1):25635.
doi: 10.1038/s41598-024-75076-y.

Characterization of Staphylococcus aureus isolated from milk samples for their virulence, biofilm, and antimicrobial resistance

Shankaregowdanakopalu Jagadeesh Deepak  1 , Porteen Kannan  2 , Wilfred Ruban Savariraj  3 , Elango Ayyasamy  4 , Senthil Kumar Tuticorin Maragatham Alagesan  5 , Narendra Babu Ravindran  6 , Sureshkannan Sundaram  1 , Nithya Quintoil Mohanadasse  7 , Qing Kang  8 , Charley A Cull  9 , Raghavendra G Amachawadi  10
Affiliations

Characterization of Staphylococcus aureus isolated from milk samples for their virulence, biofilm, and antimicrobial resistance

Shankaregowdanakopalu Jagadeesh Deepak et al. Sci Rep. .

Abstract

The Staphylococcus aureus (S. aureus) one of the important food borne pathogen from milk, which was investigated in this study. The isolates were screened for antimicrobial resistance, enterotoxin genes, biofilm formation, spa typing, coagulase gene polymorphism and accessory gene regulator types. The prevalence of S. aureus in milk samples was 34.4% (89/259). Methicillin resistant S. aureus (MRSA) was found at 27% (24/89) of the isolates, were classified as community acquired based on SCCmec typing. The 24.71% (22/89) isolates demonstrated multiple antimicrobial resistance (MAR) pattern. However, none of the isolates carried vancomycin and mupirocin resistance genes. The isolates were positive for sea and sed enterotoxin genes and exhibited high frequency of biofilm formation. The High-Resolution Melting and conventional spa typing revealed that the isolates had both animal and community-associated S. aureus clustered origins. Coagulase gene polymorphism and agr typing demonstrated variable genotypic patterns. The finding of this study establishes the prevalence of community associated, enterotoxigenic, biofilm forming and antimicrobial resistance among S. aureus from milk in Chennai city. This emphasizing a potential threat to public health which needs a continuous monitoring system and strategies to mitigate their spread across the food chain and achieve food safety.

Keywords: Spa typing; Staphylococcus aureus; Antimicrobial resistance (AMR); Biofilm; Coagulase gene; Enterotoxin; High Resolution Melting (HRM).

PubMed Disclaimer

Conflict of interest statement

The authors declare no Competing interests

Figures

Fig. 1
Fig. 1
The rate of biofilm production with different analytical test for biofilm production ability among S. aureus strains isolated from milk samples. (CRA- Congo red agar method, STA- Standard tube adherence method, Microtitr- Microtiter plate method).
Fig. 2
Fig. 2
The rate of biofilm production with ica(A) gene presence for biofilm production ability among S. aureus strains isolated from milk samples. (CRA- Congo red agar method, STA- Standard tube adherence method, Microtitr- Microtiter plate method).
Fig. 3
Fig. 3
The rate of multiple antimicrobial resistance (MAR) index among S. aureus strains isolated from milk samples.
Fig. 4
Fig. 4
The heat map representing data on characterization (virulence, antimicrobial susceptibility and biofilm analytical tests) of 89 S. aureus strains isolated from milk samples.
See this image and copyright information in PMC

References

    1. da Silva, A. C., Rodrigues, M. X. & Silva, N. C. C. Methicillin-resistant Staphylococcus aureus in food and the prevalence in Brazil: A review. Braz. J. Microbiol.51, 347–356. 10.1007/s42770-019-00168-1 (2020). - PMC - PubMed
    1. Argudín, M. Á., Mendoza, M. C. & Rodicio, M. R. Food poisoning and Staphylococcus aureus enterotoxins. Toxins (Basel)2, 1751–1773. 10.3390/toxins2071751 (2010). - PMC - PubMed
    1. Koreen, L. et al. spa typing method for discriminating among Staphylococcus aureus isolates: Implications for use of a single marker to detect genetic micro- and macrovariation. J. Clin. Microbiol.42, 792–799. 10.1128/JCM.42.2.792-799.2004 (2004). - PMC - PubMed
    1. Thompson, T. A. & Brown, P. D. Association between the agr locus and the presence of virulence genes and pathogenesis in Staphylococcus aureus using a Caenorhabditis elegans model. Int. J. Infect. Dis.54, 72–76. 10.1016/j.ijid.2016.11.411 (2017). - PubMed
    1. Javdan, S., Narimani, T., Shahini Shams Abadi, M. & Gholipour, A. Agr typing of Staphylococcus aureus species isolated from clinical samples in training hospitals of Isfahan and Shahrekord. BMC Res. Notes12, 363. 10.1186/s13104-019-4396-8 (2019). - PMC - PubMed

MeSH terms

LinkOut - more resources