Escherichia coli O157 H7-associated disease: epidemiology and antibiotic resistance
Creators: name: Yusuf, Afeez
name: kabiru, Akinyemi
name: Samuel, Ajoseh
Publisher: name: figshare
Year: 2022
Subjects: subject: 60501 Bacteriology
subject: FOS: Biological sciences
subject: Genetics
subject: 110309 Infectious Diseases
subject: FOS: Health sciences
subject: Microbiology
subject: 60599 Microbiology not elsewhere classified

description: Escherichia coli (E. coli) are bacterium which belongs to family Enterobacteriaceae and are gram negative rod up to 3 um in length, ferment glucose and wide range of sugars. These lactase fermenters produce pink colonies on Mac Conkey agar. Hemolytic activity on blood agar is characteristics of certain strain of E. coli. It’s motile with peritrichous flagella and often fimbriate (Jay et al 2000,Quinn et al 2001). The O is the major serotype that was recognized as a cause of human illness. E. coli O 157: H is one of the more than 60 serotypes of verotoxin producing E. coli that cause that a variety of human illness such as mild diarrhea, hemorrhagic colitis and hemolytic curemic syndrome (HUS) (Bryan 1971). Escherichia coli were initially considered to only be a commensally residing in the gastrointestinal tract. However, several pathogenic variants (patho types) are now recognized and associated with diarrheal diseases. Although E. coliis easy to identify to species level,it is extremely difficult to recognize strains belonging to different pathos types of diarrheagenic E. coli, as these are defined by the expression of one or more group-septic virulence factors.The six major diarrheagenic patho types described to date are enteropathogenic E. coli, Shiga toxin-producing E. coli (STEC), entero invasive E. coli (EIEC), enterotoxigenic E. Coli, entering aggregative E. Coli and adherent invasive E. coli (Croxen 2013). Of these, only STEC is routinely denied by most clinical and public health laboratories, and it will be the focus of the discussion here. STEC is defined by the presence of a Shiga toxin 1 (Stx1) and/or Shiga toxin 2(Stx2) genes. Historically, these isolates were called enterohemorrhagic E. Coli (EHEC) or verocytotoxin-producing E. coli (VTEC).STEC includes both O157 and non-O157 serotypes of E. coli. Ruminants, such as cattle, are the major reservoir for STEC. Poor sanitation, fecal runoff into rivers and streams, and inadequate control measures in the meat and food processing industries have all led to the recovery of STEC from virtually any consumable product. Infection with STEC occurs following consumption of these contaminated products. Infections occur predominantly in the summer months but can be observed year round (Gould 2009). The chief symptoms included bloody diarrhea, abdominal pain, nausea, and vomiting (Rohde et al 2011). Importantly, not all STEC infections are associated with bloody diarrhea (Nanning et al 2007), and so laboratory algorithms that only test bloody specimens for STEC are no longer considered standard of care. The most common and serious complication of STEC infection is the development of HUS, which typically presents 5 to 13 days after the onset of diarrhea (Van Duynhove et al 2008). HUS is life-threatening and consists of the triad of renal failure, microangiopathic hemolytic anemia, and thrombocytopenia. The mortality rate connected with HUS is 3% to 5% (Dupont et al 2004). It has been estimated that 61% of all HUS casesare related to STEC infection (Dupont et al 2004). HUS has been observed more frequently in O157 (11% of cases) versus non-O157 (1% of cases) STEC infections (Walker et al 2012). Approximately 15% of children10years of age develop HUS following STEC infection. However, in the recent outbreak of O104 STEC in Germany, 22% of children developed HUS (Gould et al 2013,Tarr et al 2005,Frank et al2011). It should be noted that this outbreak was caused by an atypical STEC strain that harbored enteroaggregative E. coli virulence factors in addition to the Shiga toxins. HUS occurs much less frequently among adults and is associated predominantly with advanced age (75 years) (Wong et al 2012). Increased rates of HUS have been more frequently associated withStx2-expressing STEC strains. Exposure to antibiotics also increases the risk of HUS in children Frank et al 2011) . However, recent data demonstrated that treatment with ciprofloxacin reduced the risk of HUS in patients infected with the 2011 German O104 STEC strain (Zoufaly et al 2013). These data are supported by a recent meta-analysis of studies between 1980 and 2011 (Geerdes et al 2013). Despite this, the decision to treata patient with STEC infection with antimicrobials remains controversial. In addition, use of ant motility agents has been associated with longer duration of bloody diarrhea, as well as progression to HUS (Borgatta et al 2012).The incubation period is 72-120 hours. The clinical sign initially may be diarrhea with abdominal cramps, which may turn into grossly bloody diarrhea in a few days. There is however, no fever. The symptoms of E. colisepticemia are mainly referable to bacteremia, end toxemia and the effect of bacteria localization in a variety of tissue spaces throughout the body (Bell et al 1997)