The molecular epidemiology of Stenotrophomonas maltophilia bacteraemia in a tertiary referral hospital in the United Arab Emirates 2000–2004

BACKGROUND: Stenotrophomonas maltophilia is recognised as an important cause of nosocomial infection, especially in immunocompromised patients, resulting in significant morbidity and mortality. The treatment of S. maltophilia infection presents a therapeutic challenge. The precise modes of transmission of S. maltophilia in the hospital environment are not known and such knowledge is essential to target interventions to prevent spread. There are few published data on the patterns of nosocomial infection in the United Arab Emirates (UAE). A recent study showed that S. maltophilia is an established cause of bloodstream infection in Tawam Hospital in the UAE. Little is known about its epidemiology in the hospital. METHODS: We describe the clinical characteristics of 25 episodes of S. maltophilia bacteraemia which occurred from 2000–2004. The strains were characterised using pulsed field gel electrophoresis (PFGE). RESULTS: All episodes were hospital-acquired and malignancy and central venous catheters were predisposing factors. Catheter-associated infection comprised 88% infection. Catheter removal was important for the successful management of catheter-associated infection. The results of PFGE suggested that there were as many strains as patients. S. maltophilia strains isolated from the same patient had indistinguishable PFGE profiles. CONCLUSION: PFGE is a valid and reproducible typing method for S. maltophilia. The precise sources and modes of spread of S. maltophilia in the hospital are still not known. Knowledge that person to person transmission was not a major mode of transmission enabled infection control interventions for S. maltophilia to be targeted more effectively

Clonal emergence of Klebsiella pneumoniae ST14 co-producing OXA-48-type and NDM carbapenemases with high rate of colistin resistance in Dubai, United Arab Emirates

© 2018 Elsevier Ltd Few studies have addressed the molecular epidemiology of carbapenem-resistant Enterobacteriaceae (CRE) isolates in the Arabian Peninsula, and such investigations have been missing from Dubai, a major economical, tourism and medical centre of the region. The antibiotic susceptibility, the carbapenemase type produced, and the clonality of 89 CRE strains isolated in five major Dubai hospitals in June 2015 to June 2016 were determined. Thirty-three percent of the collection of 70 Klebsiella pneumoniae, 13 Escherichia coli and 6 other Enterobacteriaceae were extremely drug resistant, 27% were resistant to colistin, and 4.5% (4 K. pneumoniae isolates) were resistant to all antibiotics tested. The colistin resistance rate in K. pneumoniae was 31.4%. None of the isolates carried mobile colistin resistance genes. Seventy-seven isolates produced carbapenemase: 53.3% OXA-48-like, 24.7% NDM and 22.1% both OXA-48-like and NDM, respectively. Pulsed-field gel electrophoresis clustered 50% of K. pneumoniae into a 35-membered group, which showed significant association with double carbapenemase production, with extreme drug resistance, and with being isolated from Emirati patients. Members of the cluster belonged to sequence type ST14. The rate of colistin resistance in K. pneumoniae ST14 was 37.1% vs. 27.1% of K. pneumoniae isolates outside of the cluster. Two of the panresistant K. pneumoniae isolates also belonged to ST14, whereas the other two were ST15 and ST231, respectively. In conclusion, beyond the overall high colistin resistance rate in CRE, the emergence of a highly resistant clone of K. pneumoniae ST14 in all Dubai hospitals investigated is a serious problem requiring immediate attention

Central Path Curvature and Iteration-Complexity for Redundant Klee—Minty Cubes

We consider a family of linear optimization problems over the n-dimensional Klee—Minty cube and show that the central path may visit all of its vertices in the same order as simplex methods do. This is achieved by carefully adding an exponential number of redundant constraints that forces the central path to take at least 2n − 2 sharp turns. This fact sug-gests that any feasible path-following interior-point method will take at least O(2n) iterations to solve this problem, whereas in practice typically only a few iterations (e.g., 50) suffices to obtain a high-quality solution. Thus, the construction potentially exhibits the worst-case iteration-complexity known to date which almost matches the theoretical iteration-complexity bound for this type of methods. In addition, this construction gives a counterexample to a conjecture that the total central path curvature is O(n)

Retroactive causation and the temporal construction of news: contingency and necessity, content and form

This article affords particular attention to the relationship between memory, the narrativization of news and its linear construction, conceived as journalism’s ‘memory- work’. In elaborating upon this ‘work’, it is proposed that the Hegelian notion of retroactive causation (as used by Slavoj Žižek) can examine how analyses of news journalists ‘retroactively’ employ the past in the temporal construction of news. In fact, such retroactive (re)ordering directs attention to the ways in which journalists contingently select ‘a past’ to confer meaning on the present. With regard to current literature, it is noted that a retroactive analysis can highlight two important dialectics within the practice of news journalism: 1) the relation between contingency and necessity; and, 2) the relation between content and form. Indeed, it is argued that this theoretical account offers a novel approach to examining the significance of memory in news journalism as well as the inconsistencies which underscore journalism’s memory-work. It is in accordance with such inconsistency that broader reflections on time, temporality and our relations to the past can be made