Acinetobacter Alert

Acinetobactor concern over disinfectant impact

Link: Reduction of disinfectant bactericidal activities in clinically isolated Acinetobacter species in the presence of organic material -- Kawamura-Sato et al., 10.1093/jac/dkm498 -- Journal of Antimicrobial Chemotherapy.

Methods: The bactericidal activities of the four disinfectants against 283 strains of Acinetobacter species recovered from 97 Japanese hospitals in March 2002 were investigated by four different tests: MIC measurements, MBC measurements, time-killing assays and adaptation assays. Moreover, disinfectant efficacy was examined in the presence of BSA in two tests: MBC measurements and time-killing assays.

Results: No clinical isolates were able to withstand the in-use concentrations of the four disinfectants, although the MIC90 of ADH reached 100 mg/L. Strains for which MICs of at least two disinfectants were higher than MIC90 measured by the broth microdilution method were defined as isolates with ‘disinfectant reduced susceptibility (DRS)’. In the presence of 3.0% BSA, the MBCs of BZK, BZT and ADH for DRS isolates rose to 512 and 1024 mg/L, which were about half their in-use concentrations. Moreover, the times for bacterial complete killing were remarkably prolonged in DRS isolates even after a 10 min of exposure to 1000 mg/L of ADH, a half of its in-use concentration. The MICs of CHX for DRS isolates rose to 640 mg/L after repetitive passages in subinhibitory concentrations of CHX.

Conclusions: Given that the bactericidal effects of the four major disinfectants were considerably reduced in the presence of organic material (BSA) and DRS isolates tended to adapt to CHX, continuous surveys of the profiles of susceptibility to disinfectants among clinically isolated Acinetobacter species are very necessary from the standpoint of nosocomial infection control.

Copper, Silver better than steel when it comes to hygiene

Link: The Associated Press: Copper, Silver Tested As Germ Wards.

In a British study published last year, drug-resistant staph germs survived for three days on stainless steel plates kept at room temperature, but the researchers found no sign of the germs on pure copper after 90 minutes.

The new study, funded by a government grant to the Copper Development Association, is putting that finding to a real-world test involving three drug-resistant bugs — staph, enterococci and acinetobacter.

First, researchers are swabbing down a handful of ICU rooms at New York's Memorial Sloan-Kettering Cancer Center, the Medical University of South Carolina and Charleston's Veterans Affairs Medical Center. They must learn where the germs lurk, explains Sloan-Kettering lead researcher Dr. Kent Sepkowitz.

Then the hospitals will substitute copper for some germ-prone surfaces in those rooms, and track if the change makes a difference.

Copper is expensive, but so are hospital-caused infections, Sepkowitz says.

"The question is will it save more money than it costs," he says.