Two adolescent patients with high IgE levels and hypereosinophilia are associated with cockroach allergen

Molecular detection of knockdown resistance (kdr) in Blattella germanica (Blattodea: Blattellidae) from northwestern Iran

Pyrethroid insecticides are highly insecticidal compounds that are widely used against the German cockroach, a significant household insect pest. In several insect species, there is a point mutation in the para-type sodium channel gene associated with knockdown resistance (kdr). In the current study, genomic DNA was analyzed in the region where the kdr and super-kdr (an enhanced form of pyrethroid resistance) mutations reside in Blatella germanica (L., 1767) (Blattodea: Blattellidae) collected from Iran. Studies on the extracted DNA from hand-captured German cockroach specimens were conducted by polymerase chain reaction and sequencing to detect related mutations. The kdr mutation, substitution of G for C (L1014F), which results in amino acid replacement (leucine with phenylalanine), was detected in all 18 sequenced specimens from three different locations. However, the super-kdr mutation (M918T), which is detected in super-kdr house flies, was not found in the sequences of the current study. The high ratio of the kdr mutation in a field population of B. germanica in Urmia confirms that the individuals are homozygous. These data should be helpful in designing and implementing a control program and resistance management.