A case of laboratory acquired infection with Escherichia coli O157:H7

Genome Sequence Analysis and Characterization of Shiga Toxin 2 Production by Escherichia coli O157:H7 Strains Associated With a Laboratory Infection

A laboratory-acquired E. coli O157:H7 infection with associated severe sequelae including hemolytic uremic syndrome occurred in an individual working in the laboratory with a mixture of nalidixic acid-resistant (Nal^R) O157:H7 mutant strains in a soil-biochar blend. The patient was hospitalized and treated with an intravenous combination of metronidazole and levofloxacin. The present study investigated the source of this severe laboratory acquired infection and further examined the influence of the antibiotics used during treatment on the expression and production of Shiga toxin. Genomes of two Stx_2a-and eae-positive O157:H7 strains isolated from the patient's stool were sequenced along with two pairs of the wt strains and their derived Nal^R mutants used in the laboratory experiments. High-resolution SNP typing determined the strains' individual genetic relatedness and unambiguously identified the two laboratory-derived Nal^R mutant strains as the source of the researcher's life-threatening disease, rather than a conceivable ingestion of unrelated O157:H7 isolates circulating at the same time. It was further confirmed that in sublethal doses, the antibiotics increased toxin expression and production. Our results support a simultaneous co-infection with clinical strains in the laboratory, which were the causative agents of previous O157:H7 outbreaks, and further that the administration of antibiotics may have impacted the outcome of the infection.

Four laboratory-associated cases of infection with Escherichia coli O157:H7

An investigation of four cases of infection with Escherichia coli O157:H7 among laboratorians from different clinical laboratories revealed that the DNA fingerprint pattern of each case isolate was indistinguishable from that of an isolate handled in the laboratory prior to illness. These data suggest that the infections were laboratory acquired, and they demonstrate the importance of laboratorians strictly adhering to biosafety practices recommended for the handling of infectious materials.

Hemolytic uremic syndrome in a child with laboratory-acquired Escherichia coli O157:H7

A 6-year-old girl touched an agar plate containing Escherichia coli O157:H7 while visiting a hospital laboratory, and subsequently, colitis and hemolytic uremic syndrome developed. Pulsed-field gel electrophoresis patterns of the isolate cultured from her stool and that from the laboratory were identical.

Nosocomial and laboratory-acquired infection with Escherichia coli O157

Infections caused by verocytotoxigenic Escherichia coli O157 (VTEC O157) have emerged as a major public health concern. The nature and severity of associated clinical sequelae are such that symptomatic cases often require hospitalization, with possible exposure to other patients and healthcare workers, including laboratory personnel, to the risk of acquiring VTEC O157. The occurrence of such episodes of hospital- and laboratory-acquired infections has demonstrated that these concerns are justified. Hospital infection control teams must ensure that staff are aware of this potential hazard, and laboratories must review their operating procedures to ensure that their personnel are not unnecessarily exposed, particularly in the light of revised guidance on the safe handling of these organisms.

Clinical, microbiological and epidemiological aspects of Escherichia coli O157 infection

In the last decade infections caused by Escherichia coli O157:H7 and other verocytotoxigenic E. coli (VTEC) have emerged as a major public health concern in North America and in Europe, and increasingly in other areas of the world. Although absolute numbers of infections are low in comparison with other enteric pathogens such as Salmonella or Campylobacter, it is well-recognised that E. coli O157 can produce severe, potentially life-threatening, illness. As a consequence of this awareness, there has been a rapid expansion of our knowledge about these organisms and the diseases which they cause. In this article, the clinical, microbiological and epidemiological features of VTEC O157 infection are reviewed.