Urinary tract infections by multidrug resistant Acinetobacter species- A Retrospective Analysis

Abstract

Abstract Background: Acinetobacter species have emerged as important cause of nosocomial infections like pneumonia and urinary tract infections. Acinetobacter species are known to be highly resistant to commonly used antimicrobial agents. SinceAcinetobacter species are ubiquitous and have tremendous colonizing capacity, it is difficult to explain the role of Acinetobacter acquisition in the ICU and medical wards. The objective of this study was to determine the frequency of urinary tract infection (UTI) caused by different Acinetobacter species in hospitalized patients and in the community and to analyze their antimicrobial susceptibility pattern. Materials and Methods: This is a retrospective analysisfrom January 2016 to December 2017. Urine samples collected in appropriate sterile manner were screened for polymorphonuclear leucocytes and bacteria by routine microscopic examination. This was followed by plating on MacConkey's agar and Blood agar. Isolated Acinetobacter strains which are oxidase negative and non-lactose fermenters from MacConkey's agar were identified with Matrix assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF MS) to confirm the TM identification. Antibiotic susceptibility was performed by VitekCompact™ 2 (Biomeuriux, France) as per CLSI standards establishing MIC (Minimum Inhibitory Concentration). Results: Of the 429 isolates of Acinetobacterspecies from urinary tract, Acinetobacterbaumannii complex (78%) found to be the most common species followed by Acinetobacterjunii(10%) and Acinetobacterbaumannii(8%). Of the 334 (78%) isolates of Acinetobacterbaumannii complex from urinary tract, 73 (21.85%) isolates were resistant with doripenem, 62 (18.56%) with imipenem and 59 (17.66%) were resistant with meropenem with MIC values >=8 μg/ml. The rest of the isolates like Acinetobacterjunii, Acinetobacterjohnsonii, andAcinetobacterlwoffiiare found to be more sensitive with carbapenems with lower MIC values. Discussion: The treatment of multidrug-resistant bacteria in hospitalized patients continues to be a challenge for the clinician's in routine practice. Acinetobacter baumannii complex has proven to be an important pathogen in health care associated infections with significant mortality and morbidity. The drug resistant nature of the pathogen and its unpredictable susceptibility patterns make empirical and therapeutic decisions even more difficult. Conclusion: A. baumanniiis an important opportunistic agent of nosocomial UTI, especially in patients with longer hospitalization, antibiotic exposure, urinary catheterization and decreased immunity. High antimicrobial resistance and patient co-morbidities limit therapeutic choices. Hence, alternative therapeutic options are urgently needed to treat a patient with A. baumanniiinfection.