Comparative genomic analysis of antibiotic resistance and virulence genes in Staphylococcus aureus isolates from patients and retail meat

Introduction

Staphylococcus aureus is a significant human pathogen that poses a threat to public health due to its association with foodborne contamination and a variety of infections. The factors contributing to the pathogenicity of S. aureus include virulence, drug resistance, and toxin production, making it essential to monitor their prevalence and genetic profiles. This study investigated and compared the genomic characteristics of S. aureus isolates from retail meat and patients in Saudi Arabia.

Methods

A total of 136 S. aureus isolates were obtained between October 2021 and June 2022:84 from patients and 53 from meat samples in Riyadh, Saudi Arabia. S. aureus isolates were identified using conventional methods and MALDI-TOF MS, and methicillin-resistant S. aureus (MRSA) was identified using VITEK2 and BD Phoenix systems. MRSA was confirmed phenotypically using chromogenic agar, and genotypically by detecting mecA. Genomic data were analyzed using BactopiaV2 pipeline, local BLAST, and MLST databases.

Results

Antibiotic resistance genes were prevalent in both meat and patient S. aureus isolates, with high prevalence of tet38, blaZ, and fosB. Notably, all S. aureus isolates from patients carried multidrug-resistant (MDR) genes, and a high percentage of S. aureus isolates from meat also harbored MDR genes. Phenotypically, 43% of the S. aureus isolates from meat and 100% of the patients' isolates were MDR. Enterotoxin genes, including selX, sem, and sei, exhibited high compatibility between meat and patient S. aureus isolates. Virulence genes such as cap, hly/hla, sbi, and isd were found in all S. aureus isolates from both sources.

Conclusion

Our study established a genetic connection between S. aureus isolates from meat and patients, showing shared antibiotic resistance and virulence genes. The presence of these genes in meat derived isolates underscores its role as a reservoir. Genomic relatedness also suggests potential transmission of resistance between different settings. These findings emphasize the necessity for a comprehensive approach to monitor and control S. aureus infections in both animals and humans.

Food Safety Practices during Hajj: On-Site Inspections of Food-Serving Establishments

The presence of crowds during Hajj increases the risk of foodborne infection. Yet, research on the practices of food handlers during Hajj is limited. This study aimed to assess compliance with food safety practices and its associated factors during Hajj 2022. An observational cross-sectional study was conducted in Mecca and Madinah before and during Hajj 2022 and involved 195 food-serving establishments (FSEs) contracted for Hajj catering. Collected data included visit time, establishment location, licensure, whether food handlers had food safety training (professional training), and whether FSEs were under supervision from a consulting office (professional supervision). The included FSEs were 168/195 (86.2%). Two-thirds of FSEs surveyed (113, 67.3%) were under professional supervision, and 91 (54.2%) hired trained food safety workers. Compliance rates varied between outcomes (72.67 ± 17.21% to 88.3 ± 18.8%). Compared to Mecca, Madinah FSEs were more adherent to cleanliness (80.5 ± 27.9% vs. 91.5 ± 19.9%, respectively, p = 0.006). FSEs with trained workers were more likely to comply with proper food safety practices compared to those with untrained workers: cleanliness (OR: 7.2, 95% CI [2.6-20.23], p < 0.001); workers' commitment to health requirements (OR: 2.8, 95% CI [1.1-6.9], p = 0.025); handling of refrigerated and frozen food (OR: 5.27, 95% CI [1.83-15.20], p = 0.004); and food storage practices (OR: 12.5, 95% CI [2.0-12.5], p < 0.001). The role of professional training in increasing food safety practices compliance was highlighted. FSEs in Madinah were more compliant with food safety practices than those in Mecca. Therefore, Mecca FSEs may need stringent safety measures.

Assessment of microbiological quality of food preparation process in some restaurants of Makkah city

Microbiological contamination of food processing surfaces and utensils increases considerably the risk of food-borne illnesses via cross-contamination. Hence, the safety of served meals and beverages can be evaluated through the assessment of the microbiological quality of food contact surfaces in food-serving establishments. This study carried out in Makkah city aimed to assess the microbiological contamination levels on food processing surfaces and utensils in 43 restaurants from the 9 main districts in the city. A total of 294 swab preparations were taken from 16 types of food contact surfaces including cutting boards, food containers, knives, serving dishes and other utensils were examined. Ninety samples (31%) showed more than 10 CFU/cm² which were considered positive for microbiological contamination. Meat chopping devices and cutting boards were found as the most contaminated food contact surfaces (60% and 50%), while washed serving dishes and fridge handles were the least contaminated (21% and 18%). Microorganisms detected in the study were Klebsiella spp. (18.7%), Escherichia coli (17,7%), Staphylococcus aureus (4,4%), Pseudomonas spp. (1.7%), Proteus spp. (0.7%), Bacillus cereus (0.7%), and Candida sp. (0.3%). Klebsiella spp. and E. coli were observed in at least one sample from each of the sixteen different food contact surfaces. The incidence of restaurants with contaminated food contact surfaces was significantly variable among the different districts, with a value as high as 57% in the most affected district and 20% in the less affected. No contamination with Salmonella spp. or Listeria spp. was detected, however, the detection of Bacillus cereus, a toxin-forming microorganism, in two different restaurants underlines the need for continuous microbiological assessment to ensure standard sanitation levels in restaurants and catering establishments of Makkah city.

The Emergence, Persistence, and Dissemination of Antimicrobial-Resistant Bacteria in Environmental Hajj Settings and Implications for Public Health

The emergence of antimicrobial resistance is causing the loss of what was once considered the miracle cure. The transmission of antimicrobial resistance during mass gathering is a potential threat in addition to other infectious diseases. Here, we review the English language literature on the rate and the acquisition of antimicrobial resistance during the Hajj. There is a variable incidence of methicillin-resistant Staphylococcus aureus, Escherichia coli, and Enterobacteriaceae. There had been no report of multi-drug-resistant Mycobacterium tuberculosis. Continued surveillance of antimicrobial resistance coupled with public health measures are needed to decrease the rate of emergence of resistance.

Diarrhea at the Hajj and Umrah

This systematic review aims to summarize the incidence and etiology of diarrheal illness among pilgrims attending the Hajj and Umrah. Gastroenteritis and diarrhea have been potential threats during previous Hajj pilgrimages. The last cases of Hajj related cholera were reported in 1989. Currently, respiratory tract infections account for the majority of health problems during the Hajj. This shift in epidemiology reflects the improvement of sanitary conditions in Saudi Arabia in general, and at religious sites in particular. Nevertheless, gastrointestinal diseases, food-poisoning outbreaks, and diarrhea continue to occur among pilgrims. Available studies about diarrhea among Hajj pilgrims indicate a mean prevalence of 2% with the highest prevalence of 23% among a group of French pilgrims in 2013. There is an obvious lack of information about the etiology of diarrheal disease at the Hajj. Further studies addressing this issue in hospitalized patients as well as prospective cohort studies would be of interest. During the Hajj, hand washing is regularly carried out by pilgrims under a ritual purification, often called ablution. We recommend implementation of effective hand hygiene practices focusing on the regular use of alcohol-based hand rubs, as they require less time than traditional hand washing, act more rapidly, and contribute to sustained improvement in compliance associated with decreased infection rates.

Potential risk for drug resistance globalization at the Hajj

Antibiotics were once considered the miracle cure for infectious diseases. The tragedy would be the loss of these miracles as we witness increased antibiotic resistance throughout the world. One of the concerns during mass gatherings is the transmission of antibiotic resistance. Hajj is one of the most common recurring mass gatherings, attracting millions of people from around the world. The transmission of drug-resistant organisms during the Hajj is not well described. In the current review, we summarize the available literature on the transmission and acquisition of antibiotic resistance during the Hajj and present possible solutions.