Multidrug resistant (MDR) Acinetobacter is an important pathogen which has a number of virulence characteristics that enable them to render resistance to antibiotics thus complicates the treatment options, thereby forcing clinicians to rely on last resort antibiotic such as colistin. However, resistance to colistin has also been reported, further increasing the challenge. To detect the virulence attributes, colistin resistance and carbapenemase production in MDR Acinetobacter baumannii from a tertiary care hospital in South India. This is a prospective study conducted over a period of 15 months from August 2023 to October 2024 with 110 isolates of MDR Acinetobacter baumannii. All the isolates were subjected to colistin resistance detection using microbroth dilution method, carbapenemase detection using mCIM and eCIM methods, virulence detection like biofilm production by tissue culture plate method, haemolytic activity on blood agar, proteolytic activity on milk agar and siderophore production on Chrome Azurol S agar. Of the 110 isolates of MDR A. baumannii, 19 (17.27%) showed colistin resistance, 89 (80.90%) showed biofilm production, 35 (31.81%) showed haemolysis, 60 (54.54%) showed proteolysis and 49 (44.54%) showed siderophore production. The serine carbapenemase from mCIM and metallo beta-lactamase producers from eCIM tests were 61 (55.45%) serine carbapenemase and 70 (63.63%) respectively. This study underscores the concerning prevalence of virulence and resistance determinants among MDR A. baumannii, providing clinicians and infection control specialists with essential data to guide the formulation of effective empirical treatment strategies and infection control measures.
Basavaraju et al. (Sun,) studied this question.