Epidemiology and infection control implications of Acinetobacter spp. in Hong Kong

In a previous study, we showed that Acinetobacter genomic DNA group 3 was t he most common species among blood culture isolates and was commonly found on superficial carriage sites of the healthy and the sick, which are differ ent findings from those reported in Europe and North America. We used ampli fied ribosomal DNA restriction analysis and pulsed-field gel electrophoresi s to study further the molecular epidemiology of acinetobacters in our regi on. Over a study period of 6 weeks with 136 consecutive routine clinical is olates (1.33% of all specimens), genomic DNA groups 2 (Acinetobacter bauman nii), 3, and 13TU were obtained front 59 of 69 positive patients. There is a significant difference in the specimen sources of the three genomic DNA g roups, with group 13TU being significantly associated with the respiratory tract (chi-square exact test, P = 0.0064). Settle plates showed a significa ntly heavier environmental load from the intensive care unit (ICU) than fro m the four surgical wards examined (22 of 70 versus 76 of 120 plates with < 5 colonies; chi-square test, P < 0.0001). Genomic group 3 accounted for 6 o f 12 clusters of possibly related strains among patients, between patients and the ICU environment, and in the ICU environment. Genomic groups 2 and 3 accounted for 21% of the 132 genomically identified isolates recovered fro m 21 of II local vegetables, 53 of 74 fish and meat samples, and 22 of 60 s oil samples. Group 13TU was present only in patients' immediate surrounding s. The role played by the environment and by human carriage should be evalu ated in order to devise a cost-effective infection control program pertinen t to our situation of acinetobacter endemicity.