Opportunities to optimise colistin stewardship in hospitalised patients in South Africa: Results of a multisite utilisation audit

Background. Colistin is an old antibiotic that has been reintroduced as salvage therapy in hospitalised patients because it is frequently the only agent active against Gram-negative bacteria. Various guidelines for colistin administration have led to confusion in establishing the appropriate dose, which has potential for adverse consequences including treatment failure or toxicity. The emergence and spread of colistin resistance has been documented in South Africa (SA), but no local information exists on how and why colistin is used in hospitals, and similarly, compliance with current dosing guidelines is unknown.Objectives. To evaluate the current utilisation of colistin in SA hospitals, in order to identify stewardship opportunities that could enhance the appropriate use of this antibiotic.Methods. Electronic patient records of adult patients on intravenous (IV) colistin therapy for >72 hours in four private hospitals were retrospectively audited over a 10-month period (1 September 2015 - 30 June 2016). The following data were recorded: patient demographics, culture and susceptibility profiles, diagnosis, and indication for use. Compliance with six colistin process measures was audited: obtaining a culture prior to initiation, administration of a loading dose, administration of the correct loading dose, adjustments to maintenance dose according to renal function, whether colistin was administered in combination with another antibiotic, and whether de-escalation following culture and sensitivity results occurred. Outcome measures included effects on renal function, overall hospital mortality, intensive care unit length of stay (LoS), and hospital LoS.Results. Records of 199 patients on IV colistin were reviewed. There was 99.0% compliance with obtaining a culture prior to antibiotic therapy, 93.5% compliance with prescription of a loading dose, and 98.5% compliance regarding prescription of colistin in combination with another agent. However, overall composite compliance with the six colistin stewardship process measures was 82.0%. Non-compliance related to inappropriate loading and maintenance doses, lack of adjustment according to renal function and lack of de-escalation following culture sensitivity was evident. Significantly shorter durations of treatment were noted in patients who received higher loading doses (p=0.040) and in those who received maintenance doses of 4.5 MU twice daily v. 3 MU three times daily (p=0.0027). In addition, compared with patients who survived, more patients who died received the 3 MU three times daily maintenance dose (p=0.0037; phi coefficient 0.26).Conclusions. The study identified multiple stewardship opportunities to optimise colistin therapy in hospitalised patients. Urgent implementation of a stewardship bundle to improve colistin utilisation is warranted

Comparison of the Efficacy of Colistin Monotherapy and Colistin Combination Therapies in the Treatment of Nosocomial Pneumonia and Ventilator-Associated Pneumonia Caused by Acinetobacter baumannii

Objective. To investigate whether there was a difference in mortality; clinical response and bacterial eradication between colistin monotherapy and colistin combination therapies for the treatment of nosocomial pneumonia/ventilator-associated pneumonia (VAP) caused by Acinetobacter baumannii in a medical intensive care unit (ICU).Methods. This retrospective; observational and single-centre study included all patients who were in the medical ICU of Gazi University Medical Faculty Hospital and diagnosed with nosocomial pneumonia/VAP caused by A. baumannii between January 2009 and September 2014. Results. The median age of the 134 patients was 68 years and 53.3% were male. The most common causes of admission were respiratory insufficiency (66.7%) and sepsis/septic shock (54.8%). In patients with nosocomial pneumonia/VAP caused by A. baumannii; on median day 5 of admission; colistin monotherapy was used in 23 (21.6%) patients; a carbapenem combination was used in 80 (59.7%) patients; sulbactam-ampicillin combination was used in 42 (31.4%) patients; tigecycline combination was used in 26 (19.4%) patients; and sulbactam-cefoperazone combination was used in 17 (12.7%) patients. Median ICU stay of the patients was 15.5 days; and 112 (83.6%) patients died. Colistin monotherapy and combination therapies had no superiority over each other in clinical response for the treatment of A. baumannii-associated nosocomial pneumonia/VAP. Mortality was found to be higher in patients receiving the colistin-carbapenem combination (64.3% v. 36.4%; p=0.016). Discharge/day-of-death Sequential Organ Failure Assessment score (odds ratio (OR) 2.017; 95% confidence interval (CI) 1.330 - 3.061) and vasopressor use (OR 9.014; 95% CI 1.360 - 59.464) were independent risk factors for ICU mortality. Conclusion. Colistin monotherapy and combination therapies have no superiority over each other for clinical response in the treatment of nosocomial pneumonia/VAP caused by multidrug-resistant A. baumannii. Colistin-SAM was associated with improved microbiological eradication and colistin-carbapenem combination was associated with increased mortality

Susceptibility to colistin of multi-resistant pseudomonas aeruginosa isolated in Douala Laquintinie Hospital, Cameroon

Pseudomonas aeruginosa is a germ of hospitalism responsible for nosocomial infections; it is naturally resistant to many antibiotics and has a high susceptibility to the acquisition of acquiring new resistance. The observation of strains highly resistant to antibiotics; has led us to look for possible alternative therapeutics. This study was a descriptive and cross-sectional one; conducted from October 2010 to March 2011. All patients hospitalized for at least 48 hours and showing sign of infection were included after obtaining their consent. Forty nine of 150 samples were positive to the cultivation of Pseudomonas aeruginosa showing a prevalence of 32.66%. For the antibiotic susceptibility; we obtain amikacin 57.14%; netilmicin 59.20%; ceftazidime 52.60%; imipenem 33%; colistin 97.95%; and ciprofloxacin 51%. Seven strains were resistant to all antibiotics tested other than colistin. One strain was resistant to colistin. Colistin retains high sensitivity to Pseudomonas aeruginosa. However; there are some strains multiresistant to antibiotics

Resistance aux antibiotiques de 2187 souches bacteriennes isolees au Mali

Cette etude concerne l'evolution de la resistance des bacteries isolees au cours des 12 annees allant de 1980 a 1991. Les resultats sont les suivants : pour S. aureus; la la gentamicine; les macrolides et affilies sont les plus actifs. Pour E. coli; cefotaxine; gentamicine; colistine; acide malidixique; nitroflurantes et nitroxoline sont les plus actifs. Pour enterobacte; cefotaxime; gentamicine; acide nalidixique et colistine sont les plus actifs. Pour P. aeruginosa; la colistine est tres active et la gentamicine assez active