The importance of the determination of resistance mechanisms

Early diagnosis and treatment has an important impact on the morbidity and mortality of infections caused by multidrug-resistant bacteria. Multidrug-resistant gram-negative bacilli (MR-GNB) constitute the main current threat in hospitals and especially in intensive care units (ICU). The role of the microbiology laboratory is essential in providing a rapid and effective response. This review updates the microbiology laboratory procedures for the rapid detection of BGN-MR and its resistance determinants. The role of the laboratory in the surveillance and control of outbreaks caused by these bacteria, including typing techniques, is also studied. The importance of providing standardized resistance maps that allow knowing the epidemiological situation of the different units is emphasized. Finally, the importance of effective communication systems for the transmission of results and decision making in the management of patients infected by BGN-MR is reviewed.

In vitro activity of arbekacin against multidrug-resistant gram-negative bacilli

BACKGROUND

Arbekacin is a broad-spectrum aminoglycoside with activity against some Gram-positive and Gram-negative bacteria.

METHODS

Arbekacin minimum inhibitory concentration (MIC) values were determined for 296 drug-resistant Gram-negative bacilli, and compared to previously determined plazomicin, amikacin, gentamicin, and tobramycin MIC values.

RESULTS

The MIC values required to inhibit 50% and 90% of isolates (MIC₅₀ and MIC₉₀, respectively) were 16 and >128 μg/ml, respectively.

CONCLUSIONS

Arbekacin showed similar MIC₅₀ values to amikacin and gentamicin, a lower MIC₅₀ value than tobramycin, and a higher MIC₅₀ value than plazomicin.

A cold hard menace: A contaminated ice machine as a potential source for transmission of carbapenem-resistant Acinetobacter baumannii

During an investigation of potential sources of transmission of multidrug-resistant gram-negative bacilli on a spinal cord injury unit, we recovered genetically related carbapenem-resistant Acinetobacter baumannii isolates from the stool of 3 patients, the hands of a nurse, and an ice machine water outlet spout and drain. Our findings suggest that contaminated ice machines could serve as a potential reservoir for dissemination of multidrug-resistant gram-negative bacilli.

Multidrug-resistant gram-negative bacilli colonization risk factors among trauma patients

Prior studies have demonstrated high rates of colonization and infection with multidrug-resistant gram-negative bacilli (MDR-GNB) in injured military personnel. Our analysis shows that injuries inflicted during peak combat periods, massive blood transfusion requirement, and posttrauma cefazolin prophylaxis (additive effect with fluoroquinolones) were risk factors for MDR-GNB colonization.