A risk for returned travellers: the “post-antibiotic era” - MJA
Infections caused by multiresistant gram-negative organisms are difficult to treat. Carbapenems are often used as a last resort but even these are under threat with the emergence of acquired metallo-b-lactamases worldwide, including Australia,1,2 India, China and Europe.
We report the first case of a Providencia rettgeri producing the blaNDM-1 (New Delhi metallo-b-lactamase) type of metallo-b-lactamase in Australia. A man from Canberra, aged in his mid 50s, had elective plastic surgery in India in September 2009. This was complicated by a hypoxic brain injury, after which the patient spent 4 weeks in an intensive care unit. He was subsequently transferred to Canberra for ongoing hospital care. A urinary catheter specimen collected on admission in November 2009 showed a heavy growth of multidrug-resistant P. rettgeri and Pseudomonas aeruginosa. The P. rettgeri was resistant to all b-lactam antibiotics, including meropenem, as well as to all aminoglycosides, ciprofloxacin, tigecycline and colistin. The P. aeruginosa was resistant to all antipseudomonal antibiotics except for colistin (tigecycline was not tested as it has low or no antipseudomonal action). The patient was not given antibiotic therapy but the indwelling urinary catheter was changed and contact precautions were put in place. Both organisms were sent for molecular testing, which showed that the P. rettgeri had 100% homology with blaNDM-1.3 The patient cleared the organisms after 2 months, and since then has received ongoing inpatient care in the rehabilitation unit.
The first NDM-1 type of metallo-β-lactamase was found in Klebsiella pneumoniae isolated from a Swedish patient who had recent medical contact in India.3 Data from the United Kingdom's Antibiotic Resistance Monitoring and Reference Laboratory suggest that isolates with the NDM-1 enzyme have recently been repeatedly imported to the UK from the Indian subcontinent. There may now be circulation of these resistant isolates in the UK because some infected patients have no identifiable overseas links. Hospitals have been urged to be vigilant for multiresistant gram-negative bacteria in patients with recent hospital contact in the Indian subcontinent as well as the Eastern Mediterranean.4
Identification of an Enterobacteriaceae organism carrying blaNDM-1 is very concerning. No antibiotic may be available to treat patients who develop serious infection with such organisms, and there is the added concern regarding cross-infection in health care facilities. The plasmid carrying blaNDM-1 also contains genes that confer resistance to several other antibiotics.3 It appears likely that, in the near future, the NDM-1 enzyme will become a very successful metallo-b-lactamase globally. Patients infected with multiresistant gram-negative bacteria have entered the "post-antibiotic era".
This article is sourced from The Medical Journal of Australia
http://www.mja.com.au/public/issues/193_01_050710/letters_050710_fm-1.html