Occurrence and enterotoxin gene profiles of Staphylococcus aureus isolated from retail chicken meat

Potential of Natural Phenolic Compounds as Antimicrobial Agents against Multidrug-Resistant Staphylococcus aureus in Chicken Meat

Staphylococcus aureus is one of the most widespread foodborne bacteria that cause high morbidity, mortality, and economic loss, primarily if foodborne diseases are caused by pathogenic and multidrug-resistant (MDR) strains. This study aimed to determine the prevalence of S. aureus in chicken meat in Egyptian markets. Thus, this study might be the first to assess the efficiency of different natural phenolic compounds as novel antibacterial agents against MDR S. aureus pathogens isolated from raw chicken meat in the Egyptian market. The incidence and quantification of pathogenic S. aureus were detected in retail raw chicken meat parts (breast, thigh, fillet, and giblets). In total, 73 out of 80 (91.3%) of the chicken meat parts were contaminated, with S. aureus as the only species isolated. Of the 192 identified S. aureus isolates, 143 were coagulase-positive S. aureus and 117 isolates were MDR (81.8%, 117/143). Twenty-two antibiotic resistance profile patterns were detected. One strain was randomly selected from each pattern to further analyze virulence and resistance genes. Extracted DNA was assessed for the presence of antibiotic-resistance genes, i.e., vancomycin-resistance (vanA), aminoglycosides-resistance (aacA-aphD), apramycin-resistance (apmA), and methicillin-resistance (mecA), penicillin-resistance (blaZ), and virulence genes staphylococcal enterotoxins (sea and seb), Panton-Valentine leucocidin (pvl), clumping factor A (clfA), and toxic shock syndrome toxin (tst). Clustering analyses revealed that six S. aureus strains harbored the most virulence and resistance genes. The activity of hydroquinone was significantly higher than thymol, carvacrol, eugenol, and protocatechuic acid. Therefore, phenolic compounds, particularly hydroquinone, could potentially alternate with conventional antibiotics against the pathogenic MDR S. aureus inhabiting raw chicken meat. Hence, this study indicates that urgent interventions are necessary to improve hygiene for safer meat in Egyptian markets. Moreover, hydroquinone could be a natural phenolic compound for inhibiting foodborne pathogens.

Prevalence, antimicrobial resistance, and enterotoxin gene profiles of Staphylococcus aureus isolated from mobile phones of the food vendors in Phayao province, Thailand

BACKGROUND

Mobile phones are widely used and may cause bacterial pathogens to spread among various professionals. Staphylococcus aureus from the mobile phones can contaminate the hands of food vendors and food during the cooking or packaging process. This research aimed to determine the prevalence, enterotoxin genes, and antimicrobial resistance (AMR) profiles of S. aureus contaminating the vendors' mobile phones.

METHODS

In this study, 266 mobile phone samples were randomly collected from food vendors selling food on walking streets (n = 139) and in food centers (n = 127) in Phayao province. All samples were identified as S. aureus by the conventional culture method and confirmed species-specific gene by polymerase chain reaction (PCR). Then, all identified S. aureus isolates were tested for antimicrobial susceptibility by broth microdilution method and for the presence of staphylococcal enterotoxin (SE) genes by PCR.

RESULTS

The results showed that 12.8% of the mobile phones collected were contaminated with S. aureus. Of 49 S. aureus isolates obtained, 30 (61.2%) were positive for SE genes. The most common SE gene was sea followed by sec, seb, sem, seq, and sel. Moreover, S. aureus was most frequently resistant to penicillin, followed by chloramphenicol and tetracycline, erythromycin, clindamycin, and gentamicin. Methicillin-resistant S. aureus (MRSA), vancomycin-resistant S. aureus (VRSA), and multidrug-resistant (MDR) strains were also detected.

CONCLUSIONS

This study showed that mobile phones were an intermediate surface for the transmission of S. aureus, including MDR variants. It indicates that hand hygiene and the decontamination of mobile phones are essential to prevent cross-contamination of S. aureus in food settings.

Analysis of Volatile Markers and Their Biotransformation in Raw Chicken during Staphylococcus aureus Early Contamination

To address the potential risks to food safety, headspace solid-phase microextraction coupled with gas chromatography-mass spectrometry (HS-SPME-GC-MS) and headspace gas chromatography-ion mobility spectrometry (HS-GC-IMS) were used to analyze the volatile organic compounds (VOCs) generated from chilled chicken contaminated with Staphylococcus aureus during early storage. Together with the KEGG database, we analyzed differential metabolites and their possible biotransformation pathways. Orthogonal partial least squares discriminant analysis (OPLS-DA) was applied to characterize VOCs and identify biomarkers associated with the early stage of chicken meat contamination with S. aureus. The results showed 2,6,10,15-tetramethylheptadecane, ethyl acetate, hexanal, 2-methylbutanal, butan-2-one, 3-hydroxy-2-butanone, 3-methylbutanal, and cyclohexanone as characteristic biomarkers, and 1-octen-3-ol, tetradecane, 2-hexanol, 3-methyl-1-butanol, and ethyl 2-methylpropanoate as potential characteristic biomarkers. This provides a theoretical basis for the study of biomarkers of Staphylococcus aureus in poultry meat.

Prevalence, multiple antibiotic resistance and virulence profile of methicillin-resistant Staphylococcus aureus (MRSA) in retail poultry meat from Edo, Nigeria

Introduction

Staphylococcus aureus causes staphylococcal food poisoning and several difficult-to-treat infections. The occurrence and dissemination of methicillin-resistance S. aureus (MRSA) in Nigeria is crucial and well documented in hospitals. However, findings on MRSA from meat in the country are yet to be adequately reported. The current study determined the prevalence, virulence profile and antibiogram characteristics of MRSA from a raw chicken product from retail outlets within Edo.

Methods

A total of 368 poultry meat samples were assessed for MRSA using a standard culture-based approach and characterized further using a molecular method. The antimicrobial susceptibility profile of the isolates was determined using the disc diffusion method. The biofilm profile of the isolates was assayed via the crystal violet microtitre-plate method. Virulence and antimicrobial resistance genes were screened using polymerase chain reaction via specific primers.

Results

Of the samples tested, 110 (29.9%) were positive for MRSA. All the isolates were positive for deoxyribonuclease (DNase), coagulase and beta-hemolysis production. Biofilm profile revealed 27 (24.55%) weak biofilm formers, 18 (16.36%) moderate biofilm formers, and 39 (35.45%) strong biofilm formers. The isolates harboured 2 and ≤17 virulence genes. Enterotoxin gene profiling revealed that 100 (90.9%) isolates harboured one or more genes. Resistance against the tested antibiotics followed the order: tetracycline 64(58.2%), ciprofloxacin 71(64.6%), trimethoprim 71(64.6%) and rifampin 103(93.6%). A total of 89 isolates were multidrug-resistant, while 3 isolates were resistant to all 22 antibiotics tested. The isolates harboured antimicrobial-resistant determinants such as methicillin-resistant gene (mecA), tetracycline resistance genes (tetK, tetL), erythromycin resistance genes (ermA, ermC), trimethoprim resistance gene (dfrK). All the staphylococcal cassette chromosome mec (SCCmec) IVa and SCCmec V positive isolates harboured the Panton-Valentine Leukocidin Gene (PVL).

Conclusion

In conclusion, S. aureus was resistant to commonly used antibiotics; a concern to public health concerning the transmission of these pathogens after consuming these highlight the significance of antimicrobial and enterotoxigenic monitoring of S. aureus in food chains.

Genomic analysis, antibiotic resistance, and virulence of Staphylococcus aureus from food and food outbreaks: A potential public concern

Transmission and outbreaks of Staphylococcus aureus among retail food highlights the need to comprehensive analysis the molecular characteristic of Staphylococcus aureus in foods. However, the information about Staphylococcus aureus in north China is limited. In this study, 97 and 28 S. aureus strains were isolated for analysis from 4262 samples of retail food and 61 samples food outbreaks with prevalence rate 2.28 % and 45.9 %, respectively in Jilin, China from 2014 to 2018. This study aimed to investigate the prevalence of S. aureus isolates and characterize by antimicrobial resistance testing, virulence profiles, spa typing, and multilocus sequence typing (MLST) analysis. 60 % (75/125) of the isolates contained at least enterotoxin genes including classic and new SEs genes as following: sea (40/125,32 %), see (36/125,28.8 %), sec (29/125,23.2 %), sell (29/125,23.2 %), seb (25/125,20 %), seh (22/125,17.6 %), sed (6/125,4.8 %), selq (6/125,4.8 %), and selk (6/125,4.8 %). In antimicrobial susceptibility tests, 59.2 % of the isolates (74/125) were considered as multi-drug-resistant isolates and four MRSA strains were all found with high multi-drug-resistance. Phenotype resistance to penicillin (94.4 %), erythromycin (84.2 %), clindamycin (63.9 %), and tetracycline (47.2 %) was observed which was corresponding with genotype resistance. The strains were classified to twenty-two sequence types (STs), fourteen clonal complexes (CCs), and forty-seven spa types. The predominant ST and spa types were ST1(22/125,17.6 %), ST25(20/125,16.00 %), ST398 (14/125,11.2 %) and t127 (20/125,16 %), t078 (14/125,11.2 %), t803 (7/125,5.6 %). The wgSNP analysis of these isolates in food represents showed close relatedness with food outbreaks which pose a potential health risk for consumers and warrants further attention.

Detection of microbial contamination in chicken meat from local markets in Surabaya, East Java, Indonesia

Background and Aim:

Chicken meat can be contaminated by microorganisms anywhere in the supply chain, from farm to market, and these microorganisms can be transmitted to humans through direct contact, contact with the environment, and food consumption. The microbial contamination has a serious impact on public health. This study aimed to analyze the microbial contamination of chicken meat sampled from local markets in Surabaya, East Java, Indonesia.

Materials and Methods:

A total of 60 samples of fresh chicken meat obtained from 10 traditional markets (six samples per market) were examined for the presence of bacteria. Staphylococcus aureus, Salmonella spp., and Escherichia coli were identified using Gram staining, culturing, and biochemical tests. The most probable number (MPN) method was used to identify E. coli.

Results:

Most chicken meat samples were positive for S. aureus (58.3%), Salmonella spp. (48.3%), and E. coli (40%). The samples were considered positive for E. coli if the MPN value was higher than 1×10¹ CFU/g.

Conclusion:

High microbial contamination was found in all the chicken meat sampled from local markets in Surabaya. Such contamination can lead to foodborne diseases so, proper hygiene and sanitation standards should be followed from slaughterhouses to the end-users.