Isolation and Speciation of Acinetobacter Species with Special Reference to Antibiotic Resistance in Tertiary Care Hospital

Abstract

Acinetobacter can survive longer in the environment and is also known for developing resistance against agents like disinfectants and nutritional deprivation. Very restricted information about Acinetobacter is available because of their confused taxonomic status. The isolation and identification of resistance pattern help in the selection and search for new antibiotics, reducing the morbidity and mortality of patients. The present study was conducted to find the different types of resistant mechanisms in Acinetobacter species and their antimicrobial susceptibility pattern from various clinical samples. Gram's stain and biochemical reactions identified Acinetobacter isolated from various clinical samples. Antibiotic susceptibility testing was done, and their resistant pattern was observed. Phenotypic methods for drug resistance were carried out -Detection of Extended Spectrum Beta Lactamase (ESBL) by Double disc synergy test (DDST), detection of Metallo Beta Lactamase (MBL) by Imipenem with EDTA, and detection of Carbapenemase production by Modified Hodge test (MHT). The results showed that out of 150 isolates of Acinetobacter species, Acinetobacter baumannii 138 (92%) was the most common species isolated, followed by Acinetobacter lwoffii 10 (7%) and Acinetobacter hemolytic 2 (1%). Of these, 22 (15%) isolates showed ESBL production by Double disc synergy test, 80 (53%) isolates were MBL producers, and 11 (7%) were Carbapenemase producers by Modified Hodge test. The study observed that ESBL production in Acinetobacter was 22(15%) and MBL 80(53%). It demonstrated that most of the Acinetobacter isolated were found to be Multi-Drug Resistant (95%). It brings out the need for active surveillance combined to eradicate the curtail of this organism in hospital settings.