The First Swedish Outbreak with VIM-2-Producing Pseudomonas aeruginosa, Occurring between 2006 and 2007, Was Probably Due to Contaminated Hospital Sinks.

Multidrug-resistant Pseudomonas aeruginosa is an increasing clinical problem worldwide. The aim of this study was to describe the first outbreak of a Verona integron-borne metallo-ß-lactamase (VIM)-2-producing P. aeruginosa strain in Sweden and its expansion in the region. A cluster of multidrug-resistant P. aeruginosa appeared at two neighbouring hospitals in 2006. The isolates were characterized by PCR, pulsed-field gel electrophoresis (PFGE), and whole-genome sequencing. Patient charts, laboratory records, and hygiene routines were reviewed, and patients, staff, and the environment were screened. The investigation revealed a clonal outbreak of a VIM-2-producing P. aeruginosa strain belonging to the high-risk clonal complex 111, susceptible only to gentamicin and colistin. No direct contact between patients could be established, but most of them had stayed in certain rooms/wards weeks to months apart. Cultures from two sinks yielded growth of the same strain. The outbreak ended when control measures against the sinks were taken, but new cases occurred in a tertiary care hospital in the region. In conclusion, when facing prolonged outbreaks with this bacterium, sinks and other water sources in the hospital environment should be considered. By implementing proactive control measures to limit the bacterial load in sinks, the waterborne transmission of P. aeruginosa may be reduced.

Cluster of infections caused by methicillin-resistant Staphylococcus pseudintermedius in humans in a tertiary hospital.

The dog-associated Staphylococcus pseudintermedius is a rare pathogen in humans. Here we describe a cluster of infections caused by the methicillin-resistant S. pseudintermedius clone ST71-J-t02-II-III. It involved four elderly patients at a tertiary hospital. Three patients had wound infections, and the strain had a tendency to cause bullous skin lesions.

Survival in the environment is a possible key factor for the expansion of Escherichia coli strains producing extended-spectrum ß-lactamases.

Acquired resistance to cephalosporins in Enterobacteriaceae is a global problem. After an outbreak at Uppsala University Hospital of extended-spectrum ß-lactamase (ESBL)-positive Klebsiella pneumoniae producing CTX-M-15, there was a shift from AmpC to ESBL production among Escherichia coli isolates. To explore the basis for this epidemiological shift, 46 E. coli isolates (ESBLs, n = 23; AmpC, n = 23) were characterized with regard to genetic relatedness, ß-lactamase, replicon and integron types, antibiotic resistance profiles, and genes encoding virulence factors. In addition, the survival in the environment and on hospital-associated materials was analysed. CTX-M-15 was the most frequent ESBL (78%). Only three (13%) of the AmpC enzymes were harboured on plasmids (CMY-2, DHA-1). Independent of plasmid-mediated beta-lactamase, IncF plasmids predominated and only class I integrons were detected. The ESBL producers carried more virulence genes (p = 0.04), exhibited a broader resistance phenotype (p = 0.01) and survived significantly longer (p = 0.03) on different materials than the AmpC-producing isolates. In conclusion, ESBL-producing isolates had properties which are likely to augment their competitiveness. Apart from antibiotic resistance and virulence factors, extended survival in the environment could be a selective trait for successful ESBL-producing E. coli strains.

First documented case of a Staphylococcus lugdunensis strain carrying the mecA gene in Northern Europe.

Staphylococcus lugdunensis is a clinically common wound pathogen belonging to coagulase-negative staphylococci. We herein report the first case of a S. lugdunensis isolate carrying the mecA gene in Northern Europe.

Lack of hygiene routines among patients and family members at patient hotels--a possible route for transmitting puerperal fever.

The use of patient hotels for ambulatory care of women with uncomplicated deliveries has become a routine in Sweden. This report describes a minor outbreak of a group A Streptococcus strain in 2 newly delivered mothers and their newborn babies at a patient hotel.