AIM: To determine the susceptibility of A. baumannii isolates to commonly-used biocides, investigate their biofilm-forming capacities and the prevalence of biocide resistance and biofilm-associated genes.
METHODOLOGY: . The minimum inhibitory concentration (MIC) values of 100 A. baumannii hospital isolates from Terengganu, Malaysia, towards the biocides benzalkonium chloride (BZK), benzethonium chloride (BZT) and chlorhexidine digluconate (CLX), were determined by broth microdilution. The isolates were also examined for their ability to form biofilms in 96-well microplates. The prevalence of biocide resistance genes qacA, qacE and qacDE1 and the biofilm-associated genes bap and abaI were determined by polymerase chain reaction (PCR).
RESULTS: Majority of the A. baumannii isolates (43%) showed higher MIC values (> 50 µg/mL) for CLX than for BZK (5% for MIC > 50 µg/mL) and BZT (9% for MIC > 50 µg/mL). The qacDE1 gene was predominant (63%) followed by qacE (28%) whereas no isolate was found harbouring qacA. All isolates were positive for the bap and abaI genes although the biofilm-forming capacity varied among the isolates.
CONCLUSION: The Terengganu A. baumannii isolates showed higher prevalence of qacDE1 compared to qacE although no correlation was found with the biocides' MIC values. No correlation was also observed between the isolates' biofilm-forming capacity and the MIC values for the biocides.
Methods: We searched PubMed, Embase and the Cochrane register of trials systematically for studies that examined treatment options for patients with MDR- and XDR-AB infections until April 2016. Network meta-analysis (NMA) was performed to estimate the risk ratio (RR) and 95% CI from both direct and indirect evidence. Primary outcomes were clinical cure and microbiological cure. Secondary outcomes were all-cause mortality and nephrotoxic and non-nephrotoxic adverse events.
Results: A total of 29 studies with 2529 patients (median age 60 years; 65% male; median APACHE II score 19.0) were included. Although there were no statistically significant differences between treatment options, triple therapy with colistin, sulbactam and tigecycline had the highest clinical cure rate. Colistin in combination with sulbactam was associated with a significantly higher microbiological cure rate compared with colistin in combination with tigecycline (RR 1.23; 95% CI 1.03-1.47) and colistin monotherapy (RR 1.21; 95% CI 1.06-1.38). No significant differences in all-cause mortality were noted between treatment options. Tigecycline-based therapy also appeared less effective for achieving a microbiological cure and is not appropriate for treating bloodstream MDR- and XDR-AB infections.
Conclusions: Combination therapy of colistin with sulbactam demonstrates superiority in terms of microbiological cure with a safety profile similar to that of colistin monotherapy. Thus, our findings support the use of this combination as a treatment for MDR- and XDR-AB infections.
METHODS: Demographic data, underlying diseases, procedures and details on polymyxin B therapy were retrospectively analyzed in a cohort of 84 patients who received intravenous polymyxin B in an intensive care unit from 2010 to 2014.
RESULTS: Polymyxin B was used to treat bacteremia (46.4% of cases) and pneumonia (53.6%). Majority of the pathogens isolated were Acinetobacter spp. (96.4%). The mortality rate was 48.8%, of which 82.9% was attributed to polymyxin B treatment failure. The independent predictors of treatment failure were low doses of polymyxin B (p = 0.002), shorter duration of therapy (p = 0.009), not combining with cefoperazone/sulbactam (p = 0.030), female gender (p = 0.004), administered for treatment of bacteremia (p = 0.023) and renal impairment (p = 0.021). Low polymyxin B doses (p = 0.007), not combining with cefoperazone/sulbactam (p = 0.024), female gender (p = 0.048) and renal impairment (p = 0.022) were also significant predictors for in-hospital mortality.
CONCLUSIONS: To the best of our knowledge, this is the first report on the association of inadequate dose of polymyxin B (<15,000 units/kg/day) with poor outcome in critically ill patients. Besides that, further clinical studies are warranted to evaluate the use of cefoperazone/sulbactam as second antibiotic in the combination therapy.
METHODS: The recruitment of participants' was carried out at Selayang Hospital, Selangor, Malaysia. Vaginal swabs were prospectively taken from 104 patients of PPROM and 111 with spontaneous onset of labour at term. Swabs were also taken from the axillae and ears of their babies. These swabs were cultured to isolate A. baumannii. Maternal and neonatal adverse outcomes were documented.
RESULTS: Sixteen mothers were A. baumannii positive, eight from each group respectively. None of the cases developed chorioamnionitis or sepsis. Those positive were four cases of PPROM and two babies of term labour. None of the babies developed sepsis.
CONCLUSIONS: This study does not support the suggestion that A. baumannii colonisation during pregnancy is associated with adverse maternal and neonatal outcomes.