Comparing the in vitro efficacy of chlorhexidine and povidone-iodine in the prevention of post-surgical endophthalmitis.

BACKGROUND: Intravitreal injections are a common ophthalmologic procedure. While infections following these injections are rare, they can lead to endophthalmitis, with potentially serious consequences. Various methods have been proposed to prevent endophthalmitis, including the use of antisepsis and antibiotics in patient preparation. PURPOSE: To evaluate the antiseptic efficacy of aqueous chlorhexidine (CHX) and povidone-iodine (PI) when used alone and in combination with lidocaine gel (LG) in vitro. METHODS: Two independent experimental trials were conducted. The first trial determined the minimum inhibitory concentrations (MICs) and the minimum bactericidal concentrations (MBCs) of CHX and PI against six bacterial strains. The second trial evaluated the bactericidal efficacy of the antiseptic agents (CHX 0.1% and PI 5%) and their combination with LG against the same bacterial strains. RESULTS: CHX was more effective than PI in reducing the number of colonies forming units (cfus) of the tested bacteria. The order in which the antiseptic and LG were administered affected their effectiveness, with CHX administered before LG resulting in greater reduction of bacterial growth. CONCLUSIONS: CHX 0.1% is more effective than PI 5% as an antiseptic agent. Application of CHX and PI prior to the use of lidocaine gel results in a more effective reduction of microorganisms.

Efficacy of the FilmArray blood culture identification panel for direct molecular diagnosis of infectious diseases from samples other than blood.

Molecular-based techniques reduce the delay in diagnosing infectious diseases and therefore contribute to better patient outcomes. We assessed the FilmArray blood culture identification (BCID) panel (Biofire Diagnostics/bioMérieux) directly on clinical specimens other than blood: cerebrospinal, joint, pleural and ascitic fluids, bronchoscopy samples and abscesses. We compared the results from 88 samples obtained by culture-based techniques. The percentage of agreement between the two methods was 75 % with a Cohen κ value of 0.51. Global sensitivity and specificity using the FilmArray BCID panel were 71 and 97 %, respectively. Sensitivity was poorer in samples with a low bacterial load, such as ascitic and pleural fluids (25 %), whereas the sensitivity for abscess samples was high (89 %). These findings suggest that the FilmArray BCID panel could be useful to perform microbiological diagnosis directly from samples other than positive blood cultures, as it offers acceptable sensitivity and moderate agreement with conventional microbiological methods. Nevertheless, cost-benefit studies should be performed before introducing this method into algorithms for microbiological diagnostics.