An outbreak of extended-spectrum, β-lactamase-producing Salmonella senftenberg in a burns ward

A strain of Salmonella senftenberg resistant to ceftazidime, gentamicin, chloramphenicol and ciprofloxacin was isolated from burn wounds of eight patients on a burns ward of a hospital in Delhi, India. The organism, which had probably been spread from patient to patient on staff hands, produced the extended-spectrum beta-lactamase SHV-5 and the aminoglycoside-modifying enzymes AAC(3)II + AAC(6′). The strain was not isolated from stool cultures of any of the patients or staff, apart from the index patient who had a history of diarrhoea and fever before admission. The outbreak ended in three weeks, after the implementation of strict handwashing. This is the first report of SHV-5 beta-lactamase in Salmonella spp. and also the first report of SHV-5 in India. The extended-spectrum beta-lactamases that have been reported in Salmonella spp. now include the Group 2 be enzymes SHV-2, SHV-5, TEM-3, TEM-25, TEM-27, CTX-M2, PER-1 and PER-2, and the Group 1 enzymes DHA-1 and CMY-2. The types of extended-spectrum beta-lactamases produced by salmonellas, their association with aminoglycoside resistance and their geographical distribution are now similar to those seen in klebsiella. Increasing antibiotic resistance in these organisms is reducing therapeutic options for the treatment of invasive disease.