Investigation of the Abundance of Escherichia coli and Staphylococcus aureus (Including Virulence Gene Profiles) and Heavy Metal Contamination in Camel Milk.

Camel milk (CM) may include foodborne pathogens, including Staphylococcus aureus and Escherichia coli, posing a health risk to consumers. The presence of heavy metals, including lead (Pb), cadmium (Cd) and arsenic (As), in CM may pose adverse health effects. This research attempted to assess the frequency of S. aureus and E. coli, together with their virulence characteristics, and to quantify the quantity of heavy metals in CM. In this research, 115 raw CM samples were collected from different rural areas of Chaharmahal Bakhtiari province of Iran. E. coli and S. aureus isolates were determined using a combination of traditional biochemical techniques and PCR. Antimicrobial susceptibility testing was performed using a panel of antibiotics from different classes. The identification of virulence genes in the isolated strains of E. coli and S. aureus was conducted by multiplex PCR. The levels of heavy metals in milk specimens were quantified using an atomic absorption spectrophotometer. E. coli was identified in 19.13% of the samples, whereas S. aureus was present in 23.47%. S. aureus isolates showed high resistance to penicillin (95.59%), tetracycline (TE) (81.48%) and clindamycin (59.29%). Moreover, E. coli strains showed high resistance to TE (90.90%), amikacin (81.81%), enrofloxacin (77.27%) and gentamicin (59.09%). S. aureus isolates frequently harboured sea, nuc, tst and pvl genes. In E. coli isolates, eaeA and bfp genes, indicative of enteropathogenic E. coli (EPEC), were most common. The average concentrations of heavy metals Cd, As and Pb in this investigation ranged from 0.0020 to 0.0053 ppm. This study found E. coli and S. aureus in some CM samples, emphasizing the need for improved hygiene. Although heavy metals were detected, their levels were generally low, requiring ongoing monitoring for consumer safety.