Ecological Distribution of Virulent Multidrug-Resistant Staphylococcus aureus in Livestock, Environment, and Dairy Products

Abstract

Staphylococcus aureus is one of the most common causes of mastitis, leading to severe economic losses in the dairy industry. It is also zoonotic, with potential risks to public health. This study aimed to detect the occurrence of S. aureus-resistant strains isolated from cattle, buffalo, their environment, milk and dairy products; and to investigate the extent of animal, ecological, and food contamination by methicillin-resistant (MRSA) or enterotoxigenic S. aureus. Samples (n = 350) were collected from four animal (two cattle and two buffalo) farms, i.e., their environment. Thirty Karish cheese samples were collected from 10 markets in Mansoura, Egypt. S. aureus was detected in 17.9%, 17.6%, and 16.7% of samples collected from cattle, buffalo and Karish cheese, respectively. About 19% of isolated S. aureus strains carried the mecA gene. The distribution of the mecA gene was high in isolates from Karish cheese (60%), followed by samples collected from buffalo (16.2%) and cattle (16%). More than 34% of isolated S. aureus strains were enterotoxigenic, and the presence of enterotoxin genes was higher in isolates from Karish cheese (80%) than those from cattle (48%) and buffalo (18.9%). The most predominant enterotoxin gene among isolated S. aureus strains was the sea gene (26.9%), followed by sec (4.5%) and sed (3%) genes. Isolated strains were resistant to clindamycin (100%), kanamycin (97%), nalidixic acid (86.6%), cefotaxime (73.1%) sulphamethazole—trimethoprim (65.6%). Meanwhile, 95.5%, 94%, 86.6% and 77.7% of S. aureus strains were sensitive to ciprofloxacin, amikacin, imipenem and both cefoxitin and gentamycin, respectively. In conclusion, the presence of enterotoxigenic- and methicillin-resistant S. aureus strains in animals, their environment, and dairy products represents a public health concern, particularly in small-scale dairy farms in Egypt. To reduce the risk of infection of livestock and humans with resistant strains, strict regulations and guidelines for antimicrobial use in such a system are urgently required.

Prevalence and antimicrobial resistance profile of bacterial foodborne pathogens in Nile tilapia fish (Oreochromis niloticus) at points of retail sale in Nairobi, Kenya

“…Continued research on the antibiotic resistance of pathogenic bacteria that infect fish is needed because it is essential for controlling the occurrence of multidrug-resistant bacteria and for the selection of appropriate therapeutic agents. The high percentage of MDR S. aureus in the current study is slightly higher than in a previous study conducted in Egypt (Badawy et al, 2022) where 83.3% of S. aureus isolates were MDR.…”

“…S. aureus has been reported in fish and fishery products (Vaiyapuri et al, 2019). S. aureus is not a natural microbiota of fish and therefore its presence in fish is associated with unhygienic handling by fish handlers, processors or sellers, cross-contamination during transport and storage, and contamination by workers, due to the presence of this pathogen in the microbiome of most humans (Saito et al, 2011;Hammad et al, 2012;Sergelidis et al, 2014;Badawy et al, 2022). Proteus mirabilis is a Gram-negative, rod-shaped bacterium found in the environment, animal microbiota and humans (Drzewiecka, 2016), and an important zoonotic pathogen that causes infections in animals and humans.…”

Whole-genome sequencing of Listeria innocua recovered from retail milk and dairy products in Egypt

“…As reported in these studies, most L. monocytogenes as well as strains of other Listeria spp., were found to be susceptible to a wide range of antimicrobials and there was no increase in antimicrobial resistance genes except for cephalosporin, fosfomycin, lincosamide and tetracycline resistance genes. Despite the few occurrences of antimicrobial resistance genes among the examined L. innocua isolates, which is considered a good sign for infection treatment, the spread of antimicrobial resistance among different bacterial species remains a major problem in Egyptian dairy farms ( Tartor et al, 2021 ; Badawy et al, 2022 ). Further studies on larger sets would be helpful to determine the state of antimicrobial resistance in Listeria from milk and dairy products, since high antimicrobial resistances among different bacterial species from dairy farms in Egypt prevail.…”

Prevalence and antimicrobial susceptibility profile of Staphylococcus aureus isolated from marketed milk and cheese in Ilorin, Nigeria

“…Ensuring the safety of food products, especially those consumed daily like milk and cheese, is paramount. Contamination of these dairy products with S. aureus can lead to foodborne illnesses, ranging from mild gastrointestinal discomfort to severe infections (Badawy et al, 2022;Sayed-Ahmed et al, 2020). The zoonotic S. aureus is of public health significance (Odetokun et al, 2018).…”

“…Such extensively drug-resistant (XDR) strains are especially difficult to treat and are associated with poor clinical outcomes. Other studies have also identified multidrug-resistant S. aureus strains from milk and other dairy products and this portends a serious risk to animal and human health (Oloso et al, 2018;Oludairo et al, 2020;Sayed-Ahmed et al, 2020;Tibebu et al, 2021;Badawy et al, 2022;Murray et al, 2022;Alembo & Torka, 2023;Gaddafi et al, 2023). The multidrug resistance patterns expressed by the S. aureus isolates suggest a broader resistance profile, encompassing multiple antibiotic classes, which further complicates treatment options.…”