Escherichia coli is a gram-negative bacillus and considered to be the normal pathogen of intestinal and extraintestinal manifestations depending upon the strain. A variety of strains exist that are responsible for causing myriads of clinical presentation. E.coli O157: H7 being the most common and severe bacterial pathogen is the leading cause of bloody diarrhea. EHEC (Enterohemorrhagic E.coli) is responsible for causing severe complications like HC (Hemorrhagic colitis). Herein, we present the case of a young girl with E.coli O157:H7 infection and review the related literature. A previously healthy 37-year-old female presented with bloody diarrhea, fever, headache, and lower abdominal pain. As per history she had eaten a hamburger, denied any recent travel and absence of inflammatory bowel disease or bloody stools in family history. Physical examination revealed normal vital signs and the physical findings were unremarkable except for severe abdominal pain. Her stool was hem-occult positive. The complete blood count was within normal limits except neutrophilia and leukocytosis. An abdominal ultrasound showed thickened bowel loops consistent with colitis. First week of her hospital course, she continued to have bloody diarrhea and severe abdominal pain. Her final stool submitted to the laboratory on day 7 was consistent with a blood clot, following her developed low urine output and hematuria, with a serum creatinine of 2.1 mg/dl on day 5. Her renal symptoms were treated with fluids. She was given supportive treatment, and her platelet count and hemoglobin were stabilized. In early stages of bloody diarrhea, parental hydration plays a major role in accelerating volume expansion. Rapid stool analysis for these bacteria can alert specialists to deal with severe complications like HUS.

We report a hemolytic uremic syndrome (HUS) case due to Stx2f-producing E. coli illustrating the diagnostic difficulty of this Shiga-toxin subtype. Clinicians should be aware of limits of certain rapid molecular panels that are increasingly being used and may play a role in underestimating the global burden of such infections.

BACKGROUND: Diarrheagenic Escherichia coli (DEC) are among the leading pathogens associated with endemic diarrhea in low income countries. Yet, few epidemiological studies have focused the contribution of enterohemorrhagic E. coli (EHEC), enteroinvasive E. coli (EIEC) and diffusely adherent E. coli (DAEC).
METHODS: We assessed the contribution of EHEC, EIEC and DAEC isolated from stool samples from a case-control study conducted in children aged < 5 years in Southern Mozambique between December 2007 and November 2012. The isolates were screened by conventional PCR targeting stx1 and stx2 (EHEC), ial and ipaH (EIEC), and daaE (DAEC) genes.
RESULTS: We analyzed 297 samples from cases with less-severe diarrhea (LSD) matched to 297 controls, and 89 samples from cases with moderate-to-severe diarrhea (MSD) matched to 222 controls, collected between November 3, 2011 and November 2, 2012. DEC were more common among LSD cases (2.7%, [8/297] of cases vs. 1.3% [4/297] of controls; p = 0.243]) than in MSD cases (0%, [0/89] of cases vs. 0.4%, [1/222] of controls; p = 1.000). Detailed analysis revealed low frequency of EHEC, DAEC or EIEC and no association with diarrhea in all age strata. Although the low frequency, EIEC was predominant in LSD cases aged 24-59 months (4.1% for cases vs. 0% for controls), followed by DAEC in similar frequency for cases and controls in infants (1.9%) and lastly EHEC from one control. Analysis of a subset of samples from previous period (December 10, 2007 and October 31, 2011) showed high frequency of DEC in controls compared to MSD cases (16.2%, [25/154] vs. 11.9%, [14/118], p = 0.383, respectively). Among these, DAEC predominated, being detected in 7.7% of cases vs. 17.6% of controls aged 24-59 months, followed by EIEC in 7.7% of cases vs. 5.9% of controls for the same age category, although no association was observed. EHEC was detected in one sample from cases and two from controls.
CONCLUSIONS: Our data suggests that although EHEC, DAEC and EIEC are less frequent in endemic diarrhea in rural Mozambique, attention should be given to their transmission dynamics (e.g. the role on sporadic or epidemic diarrhea) considering that the role of asymptomatic individuals as source of dissemination remains unknown.

Hemolytic uremic syndrome (HUS) and acute encephalopathy caused by enterohemorrhagic Escherichia coli infection occur commonly in children, whereas adult-onset disease is rare. Here we report the case of a 24-year-old woman who developed acute encephalopathy and recovered without sequelae. She initially developed abdominal pain and diarrhea. On day 6, O-157 Shiga toxin was detected in her stool and she developed HUS. On day 11, acute encephalopathy developed and she required artificial ventilation. She was treated with steroid pulse therapy and plasma exchange (PE) and then discharged on day 53 without any sequelae. Globotriaosylceramide, a Shiga toxin receptor, is more frequently present on the cellular membranes of women than on those of men. Therefore, it is conceivable that adult women are at a higher risk of developing acute encephalopathy than men. Steroid pulse therapy and PE may effectively treat acute encephalopathy by reducing inflammatory cytokine levels in the blood; therefore, these treatments should be proactively considered.

Most cases of hemolytic uremic syndrome (HUS) are caused by infection with enterohemorrhagic Escherichia coli (EHEC). Genetic defects causing uncontrolled complement activation are associated with the more severe atypical HUS (aHUS). Non-EHEC infections can trigger the disease, however, complement defects predisposing to such infections have not yet been studied. We describe a 2-month-old patient infected with different Gram-negative bacterial species resulting in aHUS. Serum analysis revealed slow complement activation kinetics. Rare variant R229C was found in complement inhibitor vitronectin. Recombinant mutated vitronectin showed enhanced complement inhibition in vitro and may have been a predisposing factor for infection. Our work indicates that genetic changes in aHUS can not only result in uncontrolled complement activation but also increase vulnerability to infections contributing to aHUS.

A 4-year-old girl with diarrhea-associated hemolytic uremic syndrome (D+HUS) was transferred to the PICU of our center due to deteriorating renal function and neurological involvement. On admission, a comatous child was seen with hypoventilation and she was placed on mechanical ventilation. Hemodialysis was commenced but plasma exchange was discontinued due to repeated hypersensitivity reactions. A trial of eculizumab was given in light of the worsening of her neurologic condition with development of a pyramidal syndrome and deepening of the coma. Hematological and renal improvement were noted but severe neurologic involvement persisted. MRI revealed extensive bilateral zones of corticocerebral infarction and neurological damage proved to be irreversible. Diarrhea-associated hemolytic uremic syndrome is a common cause of Acute Kidney Injury associated with severe short- and long-term complications. Neurologic involvement is frequent but often reversible. Currently, no effective treatment strategies are available and a paucity of data exists concerning the efficacy of potential treatment options such as early plasma exchange, eculizumab, and high dose corticosteroids. A concerted effort is needed to early identify patients at risk for poor outcome with trials aimed at evaluating the efficacy of potential treatment options for this subgroup.

We report the unusual case of a 5-year-old male hospitalized for management of diabetic ketoacidosis (DKA) and new-onset type 1 diabetes mellitus (T1DM) who developed acute renal injury secondary to hemolytic uremic syndrome (HUS). He was diagnosed with Shiga toxin-producing entero-hemorrhagic Escherichia coli (EHEC) 0157:H7-positive HUS 48 hours after being diagnosed with new-onset T1DM/DKA. His hospital course was complicated by Clostridium septicum sepsis with colonic perforation. This patient\'s diagnosis of new-onset T1DM just prior to HUS is novel. Furthermore, some cases of HUS and concurrent atraumatic C. septicum infection have been documented, but only two other survivor cases have been found, and no previous cases report of concurrent T1DM complicating atraumatic C. septicum infection have been documented so far. Aggressive surgical management and appropriate early antibiotic therapy may have been important for this child\'s survival.
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Hemolytic-uremic syndrome due to enterohemorrhagic Escherichia coli, belonging to serogroup O91 has rarely been described. We report here a case of post-diarrheal HUS due to EHEC O91 in an elderly patient for whom diagnosis was delayed given a previously diagnosed C. difficile infection. This case highlights the usefulness of Shiga-toxin detection.

OBJECTIVE: To evaluate the effect of different treatment strategies on enterohaemorrhagic Escherichia coli O104:H4 induced haemolytic uraemic syndrome.
METHODS: Multicentre retrospective case-control study.
METHODS: 23 hospitals in northern Germany.
METHODS: 298 adults with enterohaemorrhagic E coli induced haemolytic uraemic syndrome.
METHODS: Dialysis, seizures, mechanical ventilation, abdominal surgery owing to perforation of the bowel or bowel necrosis, and death.
RESULTS: 160 of the 298 patients (54%) temporarily required dialysis, with only three needing treatment long term. 37 patients (12%) had seizures, 54 (18%) required mechanical ventilation, and 12 (4%) died. No clear benefit was found from use of plasmapheresis or plasmapheresis with glucocorticoids. 67 of the patients were treated with eculizumab, a monoclonal antibody directed against the complement cascade. No short term benefit was detected that could be attributed to this treatment. 52 patients in one centre that used a strategy of aggressive treatment with combined antibiotics had fewer seizures (2% v 15%, P = 0.03), fewer deaths (0% v 5%, p = 0.029), required no abdominal surgery, and excreted E coli for a shorter duration.
CONCLUSIONS: Enterohaemorrhagic E coli induced haemolytic uraemic syndrome is a severe self limiting acute condition. Our findings question the benefit of eculizumab and of plasmapheresis with or without glucocorticoids. Patients with established haemolytic uraemic syndrome seemed to benefit from antibiotic treatment and this should be investigated in a controlled trial.

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