Outbreak of VIM-producing Pseudomonas aeruginosa detected in Florida
Epidemiologists with the Florida Department of Health and the US Centers for Disease Control and Prevention (CDC) reported today on a small outbreak of carbapenemase-producing Pseudomonas aeruginosa at a long-term acute care hospital.
In the latest Morbidity and Mortality Weekly Report (MMWR), the epidemiologists report that on Jul 5, 2017, a patient at an Orange County hospital was found to be colonized with Verona integrin-encoded metallo-beta-lactamase (VIM)-producing P aeruginosa. After the patient was identified and placed on contact precautions, a facility-wide point prevalence survey was conducted and other patients were screened for colonization. From Jul 13 to Sep 22, six additional patients screened positive for colonization with the pathogen. No cases of infection or complications were reported.
The authors note that this is the first identification of VIM-producing P aeruginosa in Florida. VIM-producing P aeruginosa was first reported in France in 1996 and has been documented in several other countries, but it is less common in the United States. VIM is one of the carbapenem-resistance genes that the CDC highlighted in an April Vital Signs report, which found that 221 Enterobacteriaceae isolates collected in 2017 contained VIM and three other carbapenemase genes rarely found in the United States.
VIM genes can transfer their resistance to other bacterial species, but the mechanisms and frequency of exchange are poorly understood. "Thus, identification of colonization with VIM-resistant organisms is a sentinel event that warrants investigation and careful patient management," the authors write.
Measures taken in response to the outbreak investigation included implementing an enhanced prospective surveillance program for P aeruginosa isolates, conducting infection control and response assessments, observing and reinforcing environmental cleaning practices, and implementing outbreak notification signage.
Jun 1 MMWR Notes from the Field
French study finds MRSA rates dropping but other superbugs increasing
A French team of investigators has determined that national rates of methicillin-resistant Staphylococcus aureus (MRSA) decreased slowly from 2004 through 2016, while rates of extended-spectrum beta-lactamase (ESBL)-positive Escherichia coli and Klebsiella pneumoniae increased markedly, according to a study yesterday in Antimicrobial Resistance & Infection Control.
The researchers analyzed data on 26,486 isolates over the study period from 33 centers across France. From 2004 to 2016, 27.7% of S aureus isolates overall were MRSA, decreasing from 28.0% in 2013 to 23.5% in 2016. The rate of ESBL-positive E coli increased from 3.0% in 2004 to 23.1% in 2012 but then dropped to 19.8% in 2016 (19.8%). The proportion of ESBL-positive K pneumoniae isolates increased from 7.5% in 2004 to 43.6% in 2016.
On a positive note, the authors note that susceptibility of gram-positive isolates to vancomycin, tigecycline, meropenem, and linezolid was well conserved throughout the study period, as was susceptibility of gram-negative isolates to tigecycline and meropenem. But they caution that the spread of multidrug-resistant isolates must be carefully monitored.
May 31 Antimicrob Resist Infect Control study