scholarly journals A rare case of emphysematous endocarditis caused by Escherichia coli

Author(s):  
Ahmed S. Al-Dhahli ◽  
Rashid Al-Umairi ◽  
Osama Elkadi

Infective endocarditis (IE) is an infection of the heart endocardium with significant morbidity and mortality. Gram negative infection particularly emphysematous type of IE is an extremely rare and life-threatening disease. We report a 59-year-old diabetic woman who was admitted to the Rustaq Hospital, Rustaq, Oman in 2017 with the diagnosis of pneumonia for which she was started on antibiotics. Shortly afterwards, she developed facial and mouth deviation and became more tachypneic. Computed tomography of the brain demonstrated bilateral multiple small infarcts. Pulmonary angiography computed tomography (CTPA) was performed which ruled out pulmonary embolism. Nonetheless, it revealed an air containing lesion around the mitral valve. Transthoracic echocardiography demonstrated a hyperechoic mobile lesion related to the mitral valve. Blood culture grew Escherichia Coli (E. coli). Diagnosis of E. coli Emphysematous IE was made based on modified Duke criteria. Recommended treatment for non-HACEK IE includes extended antibiotic course and surgery for selected patients. Keywords: Endocarditis; Escherichia coli; Mitral Valve; Echocardiography; Embolism, Intracranial; Emphysema; Case Reports; Oman.

2006 ◽  
Vol 74 (8) ◽  
pp. 4685-4693 ◽  
Author(s):  
Haiqing Sheng ◽  
Ji Youn Lim ◽  
Hannah J. Knecht ◽  
Jie Li ◽  
Carolyn J. Hovde

ABSTRACT The human pathogen Escherichia coli O157:H7 causes hemorrhagic colitis and life-threatening sequelae and transiently colonizes healthy cattle at the terminal rectal mucosa. This study analyzed virulence factors important for the clinical manifestations of human E. coli O157:H7 infection for their contribution to the persistence of E. coli in cattle. The colonizing ability of E. coli O157:H7 was compared with those of nonpathogenic E. coli K-12 and isogenic deletion mutants missing Shiga toxin (Stx), the adhesin intimin, its receptor Tir, hemolysin, or the ∼92-kb pO157. Fully ruminant steers received a single rectal application of one E. coli strain so that effects of mucosal attachment and survival at the terminal rectum could be measured without the impact of bacterial passage through the entire gastrointestinal tract. Colonization was monitored by sensitive recto-anal junction mucosal swab culture. Nonpathogenic E. coli K-12 did not colonize as well as E. coli O157:H7 at the bovine terminal rectal mucosa. The E. coli O157:H7 best able to persist had intimin, Tir, and the pO157. Strains missing even one of these factors were recovered in lower numbers and were cleared faster than the wild type. In contrast, E. coli O157:H7 strains that were missing Stx or hemolysin colonized like the wild type. For these three strains, the number of bacteria increased between days 1 and 4 postapplication and then decreased slowly. In contrast, the numbers of noncolonizing strains (K-12, Δtir, and Δeae) decreased from the day of application. These patterns consistently predicted long-term colonization or clearance of the bacteria from the bovine terminal rectal mucosa.


1992 ◽  
Vol 55 (7) ◽  
pp. 555-565 ◽  
Author(s):  
NISHA V. PADHYE ◽  
MICHAEL P. DOYLE

Escherichia coli O157:H7 is now recognized as an important human pathogen. Illnesses caused by E. coli O157:H7 infection can range from self-limited, watery diarrhea to life-threatening manifestations such as hemolytic uremic syndrome or thrombotic thrombocytopenic purpura. The mode of transmission is primarily through food; however, person-to-person transmission also has been identified in some day-care center and nursing home out-breaks. Studies to date indicate that cattle are an important reservoir of the organism. Although adhesion to intestinal epithelial cells and verotoxins are considered important virulence factors in the pathogenesis of the organism, more research is are necessary to determine the exact mechanism of pathogenicity. There is need for a rapid diagnostic test for the detection of E. coli O157:H7 in food and in clinical samples. Several useful research reagents have been developed for detecting E. coli O157:H7; however, they must be applied to a procedure that is specific, sensitive, rapid, easy to use, and commercially available so that microbiological laboratories can readily use them.


2009 ◽  
Vol 77 (8) ◽  
pp. 3234-3243 ◽  
Author(s):  
Sylvia Herold ◽  
James C. Paton ◽  
Adrienne W. Paton

ABSTRACT Shiga-toxigenic Escherichia coli (STEC) strains cause serious gastrointestinal disease, which can lead to potentially life-threatening systemic complications such as hemolytic-uremic syndrome. Although the production of Shiga toxin has been considered to be the main virulence trait of STEC for many years, the capacity to colonize the host intestinal epithelium is a crucial step in pathogenesis. In this study, we have characterized a novel megaplasmid-encoded outer membrane protein in locus of enterocyte effacement (LEE)-negative O113:H21 STEC strain 98NK2, termed Sab (for STEC autotransporter [AT] contributing to biofilm formation). The 4,296-bp sab gene encodes a 1,431-amino-acid protein with the features of members of the AT protein family. When expressed in E. coli JM109, Sab contributed to the diffuse adherence to human epithelial (HEp-2) cells and promoted biofilm formation on polystyrene surfaces. A 98NK2 sab deletion mutant was also defective in biofilm formation relative to its otherwise isogenic wild-type parent, and this was complemented by transformation with a sab-carrying plasmid. Interestingly, an unrelated O113:H21 STEC isolate that had a naturally occurring deletion in sab was similarly defective in biofilm formation. PCR analysis indicated that sab is present in LEE-negative STEC strains belonging to serotypes/groups O113:H21, O23, and O82:H8. These findings raise the possibility that Sab may contribute to colonization in a subset of LEE-negative STEC strains.


Infectio ◽  
2017 ◽  
Vol 21 (2) ◽  
Author(s):  
Eman Fathi Sharafa ◽  
Iman I. Shabanaa

Shiga toxin-producing Escherichia coli (STEC) strains have emerged as important foodborne pathogens of global public health concern, causing life-threatening diseases. Sheep and their products have been documented as important reservoirs for STECs, especially E. coli O157. The aim of this study was to investigate STECs from diarrheal human and sheep in Al-Madinah Al-Munawarah, Saudi Arabia. Fecal samples were collected between June and August, 2015 from diarrheal humans (n = 134) and sheep (n = 87). Presumptive E. coli human-and sheep-isolated strains were identified for their serotypes, the associated virulence genes (Shiga toxin [stx1 , stx2 ], haemolysin [ehxA] and intimin [eae]) by polymerase chain reaction and their susceptibility to antibiotics. Pulsed-field gel electrophoresis (PFGE) was used to demonstrate the genetic relatedness between Serotype O157:H7 human- and sheep-isolated strains. Forty eight (48/221; 21.7%) STECs were recovered from both human and sheep, their serotypes were as follows: O157:H7, O26:H11, O157:HNM, O26:HNM, O128:H2, O48:HNM, O111:HNM and OUT:HUT. Various virulence profiles and multiple antibiotic resistance were observed among the isolates. Twenty eight O157:H7 serotypes (17 human isolates and 11 sheep isolates) were identified in 13 PFGE pulsotypes, where human and sheep isolates were highly related. PFGE banding profiles together with serotypes and genotypes afford proof that human and sheep can be colonized and infected with similar E. coli O157:H7 strains. Our findings highlight the importance of epidemiological and microbiological surveillance of STECs; as well as the development of control measures to decrease risks associated with zoonotic O157:H7.


2005 ◽  
Vol 56 (3) ◽  
pp. 219 ◽  
Author(s):  
B. A. Vanselow ◽  
D. O. Krause ◽  
C. S. McSweeney

The emergence of Shiga toxin-producing Escherichia coli serotype O157:H7 as a major human pathogen over the last 2 decades has focused attention on this organism’s ruminant hosts. Despite implementation of conventional control methods, people continue to become seriously ill from contaminated meat or other food products, manure-contaminated drinking and recreational water, and direct contact with ruminants. E. coli O157:H7 can cause life-threatening disease, and is a particular threat to children, through acute and chronic kidney damage. Compared with other food-borne bacteria, E. coli O157:H7 has a remarkably low infectious dose and is environmentally robust. Cattle are largely unaffected by this organism and have been identified as the major source of E. coli O157:H7 entering the human food chain. Other Shiga toxin-producing E. coli can be pathogenic to humans and there is increasing evidence that their significance has been underestimated. Governments around the world have acted to tighten food safety regulations, and to investigate animal sources and on-farm control of this and related organisms. Potential intervention strategies on-farm include: feed and water hygiene, altered feeding regimes, specific E. coli vaccines, antibacterials, antibiotics, probiotics, and biological agents or products such as bacteriophages, bacteriocins, or colicins.


2013 ◽  
Vol 7 (05) ◽  
pp. 424-431 ◽  
Author(s):  
Nazif Elaldi ◽  
Mustafa Gokhan Gozel ◽  
Fetiye Kolayli ◽  
Aynur Engin ◽  
Cem Celik ◽  
...  

In this report, a case of community-acquired acute bacterial meningitis (CA-ABM) caused by CTX-M-15-producing Escherichia coli in an elderly male patient was presented in the light of literature. Cultures of cerebrospinal fluid, blood, ear discharge, and stool samples yielded CTX-M-15-producing E. coli in-vitro, which was resistant to the extended-spectrum cephalosporins and ciprofloxacin and susceptible to imipenem, meropenem and amikacin. Meningitis was treated with parenteral meropenem plus parenteral and intraventricular amikacin administration. Since bacterial meningitis is a life-threatening infection, empiric antibiotic therapy with carbapenem can be started before the culture results are obtained, mainly in areas where the ESBL epidemiology is well known.


2011 ◽  
Vol 6 (02) ◽  
pp. 102-108 ◽  
Author(s):  
Willie Kipkemboi Sang ◽  
Hamadi Iddi Boga ◽  
Peter Gichuhi Waiyaki ◽  
David Schnabel ◽  
Njeri C Wamae ◽  
...  

Introduction: Shigatoxigenic Escherichia coli strains are food-borne bacterial pathogens that may cause haemorrhagic colitis (HC) in humans which can lead to life-threatening systemic complication, including haemolytic uremic syndrome (HUS). This study aimed to characterize and analyze virulence properties of pathogenic E. coli isolates among patients with diarrhoea from a Maasai community in Kenya. Methodology: Stool samples from 380 patients of all ages from the Kajiado and Narok districts of Kenya were investigated for the presence of enteric bacterial pathogens by conventional and molecular methods. Results: Bacterial diarrhoea was diagnosed in 141/380 (37.1%) cases, of which enterotoxigenic E. coli (ETEC) compromised 29.8%, shigatoxigenic E. coli (STEC) 24.1%, enteroaggregative E. coli (EAEC) 14.2%, enteroinvasive E. coli (EIEC) 12.8% and enteropathogenic E. coli (EPEC) 3.5%. Gene analysis for STEC virulence factors showed that 52.9% isolates carried stx1, 29.4% possessed stx2, 14.7% carried both stx1 and stx2, and 2.9% had stx2e. 23.5% isolates carried enterohaemolysin and 20.5% isolates possessed the Intimin gene. From 9 strains that exhibited adherence, 7 contained both Intimin and Haemolysin genes. Infections with Intimin-positive STEC strains (46%) were more frequent in patients with bloody diarrhoea, especially in children under 5 years of age, whereas Intimin-negative STEC infections dominated in adults. Conclusion: Although STEC infection as a cause of bloody diarrhoea has not attracted much attention as a medical problem in Kenya, our findings indicate that this is a problem that must be investigated. The 24.1% isolation rate of STEC among the Maasai is one of the highest reported rates worldwide.


2002 ◽  
Vol 3 (2) ◽  
pp. 10-13
Author(s):  
ALT Wilson ◽  
MW Salter

Escherichia coli O157 can cause a life threatening infection. Over a two-week period in September 2000, 32 prisoners in North Dorset became infected with E. coli O157. None of the staff were affected. An outbreak caused by this organism had occurred in the prison four years previously. Investigations revealed that certain conditions in the prison provided an ideal environment for the transmission of gastrointestinal infections.


2015 ◽  
Vol 83 (8) ◽  
pp. 3243-3256 ◽  
Author(s):  
Sabrina I. Green ◽  
Nadim J. Ajami ◽  
Li Ma ◽  
Nina M. Poole ◽  
Roger E. Price ◽  
...  

Escherichia coliis a major cause of life-threatening infections in patients with neutropenia, particularly those receiving chemotherapy for the treatment of cancer. In most cases, these infections originate from opportunistic strains living within the patient's gastrointestinal tract which then translocate to major organ systems. There are no animal models that faithfully recapitulate these infections, and, as such, the host or bacterial factors that govern this process remain unidentified. We present here a novel model of chemotherapy-induced bacterial translocation ofE. coli. Oral gavage of BALB/c mice with a clinical isolate of extraintestinal pathogenicE. coli(ExPEC) leads to stable and long-term colonization of the murine intestine. Following the induction of neutropenia with the chemotherapeutic drug cyclophosphamide, ExPEC translocates from the intestine to the lungs, liver, spleen, and kidneys with concomitant morbidity in infected animals. Translocation can also occur in mice bearing mammary tumors, even in the absence of chemotherapy. Translocation of ExPEC is also associated with an increase of the diversity of bacterial DNA detected in the blood. This is the first report of a chemotherapy-based animal model of ExPEC translocation in cancerous mice, a system that can be readily used to identify important virulence factors for this process.


2021 ◽  
Vol 9 (11) ◽  
pp. 2374
Author(s):  
Xiangning Bai ◽  
Flemming Scheutz ◽  
Henrik Mellström Dahlgren ◽  
Ingela Hedenström ◽  
Cecilia Jernberg

Shiga toxin (Stx) is the key virulence factor in the Shiga Toxin-Producing Escherichia coli (STEC), which can cause diarrhea and hemorrhagic colitis with potential life-threatening complications. There are two major types of Stx: Stx1 and Stx2. Several Stx1/Stx2 subtypes have been identified in E. coli, varying in sequences, toxicity and host specificity. Here, we report a novel Stx2 subtype (designated Stx2m) from three clinical E. coli strains isolated from diarrheal patients and asymptomatic carriers in Sweden and Denmark. The Stx2m toxin was functional and exhibited cytotoxicity in vitro. The two Swedish Stx2m-producing strains belonged to the same serotype O148:H39 and Multilocus Sequencing Typing (MLST) Sequence Type (ST) 5825, while the Danish strain belonged to the O96:H19 serotype and ST99 type. Whole-genome sequencing (WGS) data analysis revealed that the three Stx2m-producing strains harbored additional virulence genes and the macrolide resistance gene mdf (A). Our findings expand the pool of Stx2 subtypes and highlight the clinical significance of emerging STEC variants. Given the clinical relevance of the Stx2m-producing strains, we propose to include Stx2m in epidemiological surveillance of STEC infections and clinical diagnosis.


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