Characterization of Staphylococcus aureus isolates from pastry samples by rep-PCR and phage typing

Abstract

Background and Objectives: Staphylococcus aureus is one of the most common causes of food poisoning. This study aimed to identify S. aureus isolated from pastries, the virulence factors, antimicrobial resistance patterns, biofilm formation, and then classification based on SCCmec types, phage types, and also Rep types.
 Materials and Methods: In this study, 370 creamy and dried pastry samples have been randomly collected from different confectioneries in Hamadan city. The S. aureus isolates were identified by conventional microbiological methods and nuc gene amplification. The virulence factors and prophage genes were detected. After that, the biofilm production and antibiotic susceptibility assay of S. aureus isolates were examined. Finally, the isolates were classified by rep-PCR typing.
 Results: Among 370 samples, 97 creamy (34.64%) and 3 dried (3.33%) pastry samples were contaminated with S. aureus. Antibiotic sensitivity results showed the highest resistance to penicillin (90%) but none of them were MRSA. According to biofilm formation assay, 14 strains (45%) were strongly adhesive. The dominant phage among isolates was SGF, especially SGFa subgroup. About half of the isolates carried SCCmec Types I and III. Analysis of the genetic linkage between isolates by rep-PCR showed ≥80% genetic similarity and also different rep-types of S. aureus isolates.
 Conclusion: The presence of different prophage encoded virulence factors and antibiotic resistance enable S. aureus strains to produce a broad range of diseases. Thus, consumption of creamy pastries increases the risk of infection with S. aureus and it is a serious warning to the health system.

Detection of genes encoding enterotoxins (SEA-D) in Staphylococcus aureus strains isolated from workers’ nasal samples and creamy pastries of Shiraz confectioneries

“…Our results identified that 16.24 and 33 percent of workers' nasal and creamy pastries were contaminated with S. aureus , respectively. Other studies in Iran have been revealed that approximately 20 to 30 percent of creamy pastries contaminated with this pathogen ( 12 , 13 ). Sami et al (2013) showed that 20 percent of the cream-filled sweets offered in the confectioneries of Kerman were contaminated with S. aureus ( 14 ).…”

The genotypic and phenotypic characteristics contributing to high virulence and antibiotics resistance in Escherichia coli O25-B2-ST131 in comparison to non- O25-B2-ST131

“…The rep-PCR was performed according to the protocol of Arabestani el al. [38]. Phylogenetic group analysis for all isolates was accomplished based on electrophoresis results and isolates were classified into different groups.…”

Antibacterial effects of natural compounds on biofilm formation of Streptococcus mutans

“…Finally, different studies have examined the effects of extracts on the quorum-sensing systems of various bacteria and also the prevalence of virulence genes of different bacteria (Arabestani et al, 2022;Dadgar et al, 2014;Kamarehei et al, 2020;Kavyani et al, 2019;Nouri et al, 2022;Vaziriamjad et al, 2022) Therefore, in this study, the potential of some natural agents was investigated on the biofilm-promoting property of S. mutans. These natural agents exerted considerable biological effects and could protect the teeth from the injuries caused by S. mutans.…”

“…Finally, different studies have examined the effects of extracts on the quorum‐sensing systems of various bacteria and also the prevalence of virulence genes of different bacteria (Arabestani et al, 2022 ; Dadgar et al, 2014 ; Kamarehei et al, 2020 ; Kavyani et al, 2019 ; Nouri et al, 2022 ; Vaziriamjad et al, 2022 ). The properties and the antibacterial effects of different natural compounds against S. mutans are presented in Table 1 .…”