Antimicrobial susceptibility of Acinetobacter clinical isolates and emerging antibiogram trends for nosocomial infection management

Abstract

Introduction:The drug resistant Acinetobacter strains are important causes of nosocomial infections that are difficult to control and treat. This study aimed to determine the antimicrobial susceptibility patterns of Acinetobacter strains isolated from different clinical specimens obtained from patients belonging to different age groups. Methods: In total, 716 non-duplicate Acinetobacter isolates were collected from the infected patients admitted to tertiary-care hospitals at Lahore, Pakistan, over a period of 28 months. The Acinetobacter isolates were identified using API 20E, and antimicrobial susceptibility testing was performed and interpreted according to Clinical and Laboratory Standards Institute (CLSI) guidelines. Results: The isolation rate of Acinetobacter was high from the respiratory specimens, followed by wound samples. Antibiotic susceptibility analyses of the isolates revealed that the resistance to cefotaxime and ceftazidime was the most common, in 710 (99.2%) specimens each, followed by the resistance to gentamicin in 670 (93.6%) isolates, and to imipenem in 651 (90.9%) isolates. However, almost all isolates were susceptible to tigecycline, colistin, and polymyxin B. Conclusions: The present study showed the alarming trends of resistance of Acinetobacter strains isolated from clinical specimens to the various classes of antimicrobials. The improvement of microbiological techniques for earlier and more accurate identification of bacteria is necessary for the selection of appropriate treatments.

Acinetobacter Species

“…5 Among these, the multi-drug resistant Acinetobacter strains are important cause of nosocomial infections that are difficult to control and treat globally including in Pakistan. 6 In the present study the prevalence of Acinetobacter spp. was found to be higher which is inconsistent with other studies conducted in Pakistan.…”

Karbapeneme dirençli, çoklu ilaç direnci fenotipi gösteren Acinetobacter baumannii suşlarında polimiksin B, minosiklin, kolistin ve fosfomisin duyarlılıklarının belirlenmesi

“…In our study, the minocycline in the tetracycline group, such as tigecycline, was found to be resistant to only one strain. Resistance rates of polymyxin B in MDR-A.baumannii strains have been reported between 1% and 13% in different studies in the literature (17 Shail et al (19) reported that they did not detect resistance to colistin and tigecycline by broth dilution method in 716 A. baumannii strain and against polymyxin B by disc diffusion method.…”

Evaluation of the synergistic effect of a combination of colistin and tigecycline against multidrug-resistant Acinetobacter baumannii

“…Colistin exhibits concentration-dependent bactericidal activity and is still highly effective against MDR A. baumannii , especially when used in combination therapies 2,5,18,19. Resistance to colistin can develop because of its pharmacokinetic and pharmacodynamics properties 20…”

“…The main disadvantage of tigecycline is that it achieves low peak serum concentrations after administration of a standard 100 mg loading dose, which may increase the development of resistance during therapy 22,23. Studies investigating the antibiotic susceptibility of Acinetobacter species revealed that these bacteria are most susceptible to colistin and tigecycline, and a combination of these antibiotics has the lowest antagonistic interaction when compared to combinations of colistin or tigecycline with carbapenems 2,18,19. Taken together, these results indicated that combinations with colistin and tigecycline remain the best choice for the treatment of MDR Acinetobacter infections.…”