MATERIALS AND METHODS: Three hundred and four isolates of E. coli and Klebsiella sp. had been selected via convenient sampling. These isolates were identified using conventional laboratory methods and their antimicrobial susceptibilities were determined using disc diffusion method. Those isolates were then proceeded with ESBL confirmatory test, cloxacillin-containing Muller Hinton confirmatory test, modified double disk synergy test and AmpC disk test.
RESULTS: Out of 304 isolates, 159 isolates were E. coli and 145 were Klebsiella sp. The prevalence of organisms which co-produced AmpC β-lactamase and ESBL enzymes were 3.0%. Besides that, 39 cefoxitin resistant and three cefoxitin susceptible isolates (13.8%) were proven to produce AmpC β-lactamase through AmpC disk test. Through the CLSI confirmatory test, 252 (82.9%) isolates were identified as ESBLs producers and the prevalence increased slightly when cloxacillin-containing Muller Hinton were used. Only three ESBLs positive organisms were positive for modified double disk synergy test.
CONCLUSION: Distinguishing between AmpC β-lactamase and ESBL-producing organisms has epidemiological significance as well as therapeutic importance. Moreover, AmpC β-lactamase and ESBLs co-producing organisms can lead to false negative ESBL confirmatory test. Therefore, knowing the local prevalence can guide the clinician in navigating the treatment.
Methods: A systematic review and network meta-analysis was performed; searches of the Cochrane Library, PubMed, Embase, and CINAHL (Cumulative Index to Nursing and Allied Health Literature) included all randomized controlled trials and observational studies conducted in adult patients hospitalized in ICUs and evaluating standard care (STD), antimicrobial stewardship program (ASP), environmental cleaning (ENV), decolonization methods (DCL), or source control (SCT), simultaneously. The primary outcomes were MDR-GNB acquisition, colonization, and infection; secondary outcome was ICU mortality.
Results: Of 3805 publications retrieved, 42 met inclusion criteria (5 randomized controlled trials and 37 observational studies), involving 62068 patients (median age, 58.8 years; median APACHE [Acute Physiology and Chronic Health Evaluation] II score, 18.9). The majority of studies reported extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae and MDR Acinetobacter baumannii. Compared with STD, a 4-component strategy composed of STD, ASP, ENV, and SCT was the most effective intervention (rate ratio [RR], 0.05 [95% confidence interval {CI}, .01-.38]). When ENV was added to STD+ASP or SCT was added to STD+ENV, there was a significant reduction in the acquisition of MDR A. baumannii (RR, 0.28 [95% CI, .18-.43] and 0.48 [95% CI, .35-.66], respectively). Strategies with ASP as a core component showed a statistically significant reduction the acquisition of ESBL-producing Enterobacteriaceae (RR, 0.28 [95% CI, .11-.69] for STD+ASP+ENV and 0.23 [95% CI, .07-.80] for STD+ASP+DCL).
Conclusions: A 4-component strategy was the most effective intervention to prevent MDR-GNB acquisition. As some strategies were differential for certain bacteria, our study highlighted the need for further evaluation of the most effective prevention strategies.