In vitro activity of chlorhexidine against enteric rods, pseudomonads and acinetobacter from human periodontitis.

Fifty-eight periodontal isolates of the families Enterobacteriaceae and Pseudomonadaceae, and the genera Acinetobacter and Achromobacter were studied to determine their susceptibility to Peridex (0.12% chlorhexidine digluconate solution; Procter & Gamble). In an agar dilution assay, about 50% of the study strains grew in the presence of 70 micrograms/ml of chlorhexidine. Enterobacter cloacae, Klebsiella pneumoniae, Pseudomonas aeruginosa, Pseudomonas cepacia, and Serratia marcescens comprised the most resistant species. Studies are needed to determine the microbiological and clinical effects of chlorhexidine usage in patients infected with enteric rods and pseudomonads.