Evaluation of multiple antibiotic resistance (MAR) index and Doxycycline susceptibility of Acinetobacter species among inpatients

Abstract

Background: Background: Acinetobacter is contributing to increased morbidity and mortality with its strong propensity to colonize and disseminate among humans and environmental sources. Methods & Materials: Clinical isolates of Acinetobacter species recovered from inpatients of tertiary care institute in North West India were analyzed retrospectively along with their antibiogram to evaluate in vitro activity of Doxycycline. Isolates resistant to more than three different groups of antimicrobials were considered to be multidrug resistant (MDR).MAR index was calculated and interpreted. Results: A total 93 isolates of Acinetobacter species were recovered from inpatients, out of which predominant were from urine 47(50.54%) followed by blood 27(29.03%) samples. MDR isolates were 57(61.29%) with majority from urine 35 (61.40%) and blood samples 8(14.04%). Overall antimicrobial susceptibility pattern revealed Imipenem (75.27%), Meropenem (68.82%) and Doxycycline (68.82%) to be most efficacious drugs whereas in MDR Acinetobacter spp most promising drug was Doxycycline,with highest sensitivity rate (66.67%) followed by carbapenems namely Imipenem (61.40%) and Meropenem (52.63%) . MAR index revealed 71 isolates (76.34%) with MAR index greater than 0.2 and 22 (23.66%) less than 0.2. However, three isolates had shown MAR index of 01 (i.e. resistant to all the antimicrobials tested), out of which two were recovered from intensive care unit and one from general surgery ward. Isolates with MAR index greater than 0.2 were mainly isolated from patients admitted in General surgery ward 20 (28.17%), intensive care units 19 (26.76%) and gynecology/ obstetrics ward 17 (23.94%). Twenty six multi drug resistance patterns were observed for Acinetobacter species for the nine antimicrobials tested. Resistance to COT, CIP, GEN, AK, A/S, CPM, IMP, MRP (R8)̊̊ was most frequently observed pattern in 8(14.04%) of MDR isolates Conclusion: MDR Acinetobacter is emerging as predominant pathogen in hospital settings . In current study Doxycycline has exhibited efficacy against MDR Acinetobacter, which can be considered as an alternative therapy to down regulate selective pressure on carbapenems. In low resource settings, antibiogram along with MAR index serve an important epidemiological tool to monitor drug resistance in Acinetobacter species among inpatients as it is becoming more difficult to treat this pathogen due to the restricted pharmaceutical and therapeutic armamentarium.