A three-point time series study of antibiotic usage on an intensive care unit, following an antibiotic stewardship programme, after an outbreak of multi-resistant Acinetobacter baumannii.

Antibiotic use in intensive care units (ICUs) can promote antimicrobial resistance. Outbreaks of multi-resistant bacteria significantly affect patient outcomes and delivery of care. Antibiotic stewardship programmes (ASPs), combining root-cause analyses and multi-faceted prevention strategies, are necessary, often at significant cost and time. Which elements of such strategies have the largest impact on antibiotic usage following an outbreak is unclear. The aim of this study was to investigate how antibiotic usage in a university hospital ICU changed with a non-protocolised ASP following a disruptive outbreak of multi-resistant Acinetobacter baumannii (MRAB). This was a three time-period observational cohort study. The primary endpoint was the change in overall antibiotic usage (daily defined dose, DDD, antibiotic-days, antibiotic-courses) for consecutive ICU patients staying >48 h, over three 6-month study time periods pre-MRAB (2008, n = 84) and post-MRAB (2010, n = 88; 2012, n = 122). Secondary endpoints were changes in antibiotic usage and patient demographics, in predefined admission categories (Medical Emergency, ME; Surgical Elective, SEL; and Surgical Emergency, SE). The mean age (54.6 ± 17.7, 58.1 ± 17.9, 62.8 ± 19.1 years*) and severity of illness (APACHE 14.8 ± 8.0, 16.7 ± 6.8, 18.3 ± 6.1*) increased, particularly medical admissions. There was a sustained reduction in DDD antibiotic usage [1895.1 (2008), 1224.2 (2010), 1236.6 (2012) per 1000 patient-days] but no overall change in antibiotic-days or antibiotic-courses. Antibiotic usage (antibiotic-days) fell significantly in surgical emergency admissions [20.2 ± 32.1, 4.6 ± 7.4*, 5.9 ± 7.3]. There was a sustained drop in beta-lactam, quinolone, glycopeptide and macrolide usage. Following an MRAB outbreak, and subsequent operational changes including enhanced ASPs (non-protocolised), there was a sustained overall fall in antibiotic usage in spite of an increase in disease severity over 5 years.

Antiseptic Efficacy of Povidone Iodine and Chlorhexidine Gluconate Skin Preparation Solutions Used in Burns Surgery.

The authors devised a comparative prospective study to determine the in vitro microbicidal efficacy of skin preparation solutions in the concentrations and temperatures used in the burns theatre against common bacterial and fungal microorganisms. A panel of 10 microorganisms Staphylococcus aureus, streptococcus pyogenes, enterococcus faecalis, escherichia coli, pseudomonas aeruginosa, candida albicans, bacillus cereus were assembled comprising 8 common strains of S. aureus (including methicillin resistant staphylococcus aureus (MRSA)), S. pyogenes, E. faecalis, E. coli, P. aeruginosa, C. albicans, B. cereus, and multi-drug resistant Klebsiella and Acinetobacter. These were cultured in the following formulations: 1) povidone iodine (PVP-iodine) 10% stored at room temperature (250C), 2) PVP-iodine stored at 40 to 420C, 3) chlorhexidine digluconate stored at room temperature diluted with warmed saline to concentrations of 4%, 2%, 1%, 0.8%, and 0.5%. All 3 formulations met DIN EN (Deutsches Institut für Normung) (European Standards) requirements for antiseptics. Both antiseptics showed the same high bactericidal and fungicidal efficacy (P = < 0.05). For chlorhexidine, all minimum inhibitory concentrations at both 24 and 48 hours were very low (< 0.5mg/L), but for PVP-iodine the minimum inhibitory concentrations were much higher and ranged from 64 to 512 mg/L. All concentrations of chlorhexidine tested were superior to PVP-iodine with no bacterial growth. There was a small amount of growth in some of the PVP-iodine treated groups, but this was not clinically significant.

Characterisation of VanA and VanB elements from glycopeptide-resistant Enterococcus faecium from Greece.

Ten glycopeptide-resistant Enterococcus faecium isolates from separate patients in Laikon General Hospital, Athens were studied. Eight isolates had the VanA phenotype and represented variants of three strains based on SmaI macrorestriction banding patterns. Their VanA elements were compared with the prototype element, Tn1546, by an overlapping PCR method. Three related isolates contained resistance elements indistinguishable from Tn1546 (designated Greek type I). The other five isolates all contained identical elements that differed from Tn1546 by the presence of IS1251 between vanS and vanH, by a point mutation (G --> T) at nucleotide position 8234 within vanX and by a partial loss of transposition gene orf1 (designated Greek type II). Two distinct strains of E. faecium with the VanB phenotype were obtained. HhaI digestion of an amplified fragment of the vanB gene indicated that both strains contained the vanB2 allele, and further PCR assays confirmed that the vanB2 gene cluster was located within a Tn5382-like element.