الفهرس 
IntroductionOnly 14 pages are availabe for public view
 |  | from | 107 |  |  |
| | | from | 107 | | |
Abstract
Shiga toxin-producing E. coli (STEC) also called enterohemorrhagic E. coli/ verocytotoxin-producing E. coli (EHEC/VTEC), is the most important recently foodborne pathogenic outbreak. The virulence genes involved in STEC pathogenesis as Shiga toxins (stx1 and stx2), and Intimin (eaeA). These virulence genes are the main cause of bloody diarrhea, hemorrhagic colitis, and can lead to life-threatening systemic complications such as acute renal failure syndrome (also known as a hemolytic uremic syndrome, HUS) and CNS abnormalities.
Pathogenicity may also evolve on its own when antibiotic resistance rises. As a result, we must not only prevent antibiotic resistance but also virulence spread. The world is in peril because the rate of discovery of new medications lags behind the rate of development of antibiotic resistance, increasing concerns that there may one day be no effective antibiotics available to treat resistant bacterial diseases. Antibiotic-resistant organisms in food, such as E. coli, have the potential to harm birds, animals, and humans.
In this study, a total of 410 samples were collected from infected broiler chickens suffering from diarrhea (one-day-old to 42 days old) from various locations in the Kafr El-Sheikh governorate in northern Egypt between March and July 2021. There were 230 cloacal swabs and 180 internal organ samples among the samples collected (liver, spleen, kidney, gall bladder, yolk sac, and heart blood).
The identified STEC belonged to 12 different serogroups and revealed the predominance of serotypes; O78 (7 isolates), O26:H11 and O128:H2 (4 isolates, each), O1:H7 (3 isolates), O91:H21, O119:H6 (2 isolates, each), and one isolate for each O146:H21, O121:H7 and O44:H18.
All E. coli isolates were examined for STEC virulence genes by multiple PCR. As a result of the molecular screening, 18 isolates (62.1%) carried Shiga toxin genes were detected. Out of 18 isolates, 5 (17.24 %) carried stx1, 5 (17.24 %) carried stx2, and 4 (13.79%) gave positive amplicon for both stx1 and stx2 genes, while 4 (13.79%) carried stx1, stx2 and eaeA genes. Of note, 11(37.93%) isolates don’t carry any of examined genes.
In vitro sensitivity of the isolated E. coli to various antimicrobial agents revealed that complete resistance was observed against amoxicillin, ampicillin, cefpodoxime, and cefoperazone; high resistance was observed against ampicillin/sulbactam, nalidixic acid, cefuroxime, aztreonam, ciprofloxacin, ceftriaxone, chloramphenicol, sulphamethoxazole/trimethoprim, and ceftazidime; moderate resistance against gentamicin; low resistance against cefoxitin, while lower resistance was detected against norfloxacin, cefotetan, and amikacin, and the lowest resistance against imipenem. All E. coli isolates demonstrated multidrug-resistance features against at least four antibiotic classes.