Distribution and in vitro antimicrobial susceptibility of Acinetobacter species on the skin of healthy humans.

BACKGROUND: Acinetobacter spp. are ubiquitous in the environment and have emerged as important nosocomial pathogens. The distribution of Acinetobacter spp. In some temperate European countries has been reported. However, similar data from a tropical country such as India are not available.
METHODS: Six body sites (antecubital fossa, axilla, forehead with hairline, neck, outer surface of nose and toe webs) from men and women volunteers were sampled with saline-soaked cotton swabs enriched in Baumann's enrichment medium. The isolates were identified to the genus level by chromosomal DNA transformation assay and to the species level by a 16-test biochemical system. The minimum inhibitory concentration for 39 antibiotics was determined by the two-fold agar dilution method.
RESULTS: Seven genospecies of Acinetobacter were found at 6 body sites on healthy human skin. Acinetobacter lwoffii was the most dominant comprising 40% of the total number of isolates, followed by A. junii (35%) and A. haemolyticus (16.5%). The antecubital fossa had the highest colonization frequency (48.5%). The overall positivity rate of samples was higher from women (26.3%) compared to men volunteers (25%). Only two Acinetobacter genospecies 1-3 isolates were isolated while no A. radioresistens were isolated. Susceptibility testing revealed no major differences among the 7 Acinetobacter spp. tested. Fluoroquinolones were the most active, while low-to-intermediate resistance was exhibited towards beta-lactams and aminoglycosides. Acinetobacter spp. isolated from the skin showed susceptibility to commonly used antibiotics.
CONCLUSION: Seven Acinetobacter genospecies were isolated from 6 different body sites from the skin of healthy human volunteers. Acinetobacter lwoffii was the dominant isolate. The rate of skin carriage was higher in men than in women and the maximally colonized site was the antecubital fossa. All the genospecies displayed susceptibility to most of the commonly used antimicrobials.