A crucial first step in preventing the introduction and spread of harmful microorganisms in poultry farms is biosecurity. The objectives of this investigation were to assess biosecurity measures and the prevalence of different E. coli species in commercial chicken farms in Sharkia province, Egypt. Sensitivity of E. coli strains was identified, and their susceptibility to antibiotics and disinfection was evaluated as well. Four farms provided 21 samples each, for a total of 84 samples. Three samples of each were collected for water, feed, litter, cloaca, wall, hand, and foot boots. All the studied farms obtained a "poor biosecurity" grade, meaning that their overall biosecurity score, which is comprised of 40% external and 36.54% internal biosecurity, was less than 50%. Escherichia coli species were found in 79.76% of the samples. It was isolated from water, feed, litter, cloaca, walls, hands, and foot boots with percentages of 91.6; 83.3; 91.6; 100; 58.3; 58.3 and 75%, respectively. Biosecurity level had significant negative correlations with the isolated E. coil species. Escherichia coli O119 was the most common serotype in litter and the cloaca, while E. coli O1 was the most prevalent serotype in walls and hands. Additionally, serotypes for E. coli O26, O159, O128 and O78 were included. According to the patterns of antibiotic sensitivity, amikacin, nitrofurantoin, gentamycin, and levofloxacin showed intermediate sensitivity, whereas E. coli O119 bacteria were highly sensitive to ciprofloxacin. In the absence and presence of organic matter, Virocid, Cid 2000 and finally Virkon S were the most efficient against E. coli O119. According to this study, there were differences in the investigated farms' biosecurity levels in relation to the occurrence of Escherichia coli. To reduce the introduction and persistence of E. coli in poultry farms, several biosecurity practices and management, including stringent cleaning and disinfection measures should be applied.

Biosecurity is a set of practices applied to prevent the introduction and spread of diseases in animal farms. Mastitis is one of the most important diseases affecting dairy cows worldwide.This work aimed to evaluate the impact of biosecurity practices, environmental hygiene, and sanitation on milk quality, quantity, and prevalence of subclinical mastitis in some Egyptian dairy cattle farms. Along six months, Daily milk yield (DMY) was recorded and the total average milk production (TAMP) was calculated for six randomly selected cows of each of three farms (in Giza, Ismailia, and Alexandria Governorates, Egypt). A detailed questionnaire was also designed and filled out to detect the different biosecurity practices and hygienic levels. Milk, water, feed, and bedding samples were collected. In addition, swabs from workers' hands, cows' teats (before and after sanitation with Iodine 1% solution), equipment, and milking parlour surfaces were collected to assess the milk quality and environmental hygiene. Total bacterial count (TBC) and total coliform count (TCC) were determined. Subclinical mastitis (SCM) was detected using the White Side Test (WST). The obtained data revealed variable biosecurity practices in the investigated farms with different levels of environmental hygiene. A negative correlation was detected between the produced quantity and microbial quality of produced milk, besides the prevalence of SCM. Data reflected the negative impact of poor environmental hygiene on milk production and highlighted the role of following proper sanitary measures and biosecurity practices for improving milk production in dairy farms.