Escherichia coli and Salmonella enterica isolated from Egyptian dairy cattle herds: The prevalence and molecular characteristics

The pathogens and that caused substantial health problems and financial losses were believed to have originated primarily from Egypt's dairy farms. The purpose of this study was to ascertain the occurrence of and in three large dairy farms located in the Egyptian governorate of Sharkia. Furthermore, biochemical and serological characteristics of the isolated isolates were described. Further analysis revealed that several serovars had the genes and , while genes were found in several serotypes using a multi-plex PCR. A total of 540 samples of fresh raw cow milk, water, feedstuffs, feces, (108 each), as well as swabs from feeders, milker hands and cattle crushes (36 each ), were gathered and analyzed. The recovery of from various sampling sources was shown to have an overall prevalence of 62.2% (336/540) in the results. Fecal samples had isolated , with a frequency of 0.74% (4/540). The existence of various groups of serovars, such as O26, O44, O55, O78 and O111 for and and for was revealed by serological identification of the two species. However, it was discovered that a number of serovars had much higher percentages of the and genes as well as shiga-toxin types 1 and 2 ( and ). The presence of the gene, a diagnostic marker for was 100% across all serovars. possessed both the enterotoxin gene ( ) and the hyper-invasive locus gene ( ). had the gene, whereas had the gene. and recovered in this study have significant genetic risk factors for high pathogenicity and virulence, posing a real threat to dairy population productivity and health, which could spread to the general public through milk.