BORDETELLA PERTUSSIS PERTACTIN DEFICIENT CLINICAL ISOLATES WERE NOT DETECTED IN WHOLE CELL VACCINATED POPULATION FROM ARGENTINA

CARRIQUIRIBORDE F; BARTEL E; BOTTERO D; BRAVO S; HOZBOR D

BUENOS AIRES

Simposio; 11th International Bordetella Symposium; 2016

A recent increase in Bordetella pertussis without the pertactin protein, an acellular vaccine immunogen, has been reported in several countries that only used acellular vaccine in the calendar. Determining whether pertactindeficient (PRN(-)) B. pertussis is also present in whole cell vaccinated population is needed.OBJECTIVE: Molecular characterization of Bordetella pertussis clinical isolates obtained during 1969-2014 period in Argentina, a country where whole cell vaccines are used for primary doses.MATERIALS AND METHODS: Three hundred and twenty two isolates of B. pertussis were mainly obtained at our laboratory within the surveillance of pertussis in Argentina between 2000 and 2014. Nine isolates obtained during 1969 and 1998 (old isolates) were also  included. To detect the appearance of B. pertussis pertactin deficient isolates, molecular PCR-based methodology and immunoblotting with specific pertactin sera were used.RESULTS: Isolates were screened for the prevalent mutations (IS481 insertion or deletion in prn gene) that have been documented to cause pertactin deficiency by previously reported polymerase chain reaction amplification methods. Neither IS481 insertion nor prn gene deletion were detected in all isolates analyzed. To perform the immunoblot assays a subset of 20 isolates harboring prn1 or prn2 allele were selected. From this subset, only 1 prn1 isolate from2006 expressed PRN in a very low level.CONCLUSIONS: The results presented here are in agreement with the hypothesis that pertactin-deficient B. pertussis isolates circulate only in acellular vaccinated population probably as a consequence of selective advantage for these strains in such-immunized population.