Streptomycin resistance and copper tolerance testing

14 January 2016

As part of the ongoing Streptomycin resistance and copper tolerance testing programme, KVH commissioned two rounds of testing over spring 2015.
The first round of testing was carried out on the seven orchards where resistance was identified in autumn of 2015.

Up to 30 symptomatic samples from each orchard where collected and forwarded to Dnature for resistance testing using a new PCR test method. The test results confirmed Streptomycin resistance was still present on six of the seven orchards tested. Of the six orchards, the percentage of positive Psa results showing resistances was below 5% on three orchards; between 20% and 25% on one orchard and above 25% on the other orchard.

KVH continues to liaise with these growers over how to best minimise the risk of resistance spreading throughout the orchard and onto neighbouring properties.

As part of the wider resistance monitoring programme, a total of 276 samples from 99 KPINs were collected from across the country in November and December and forwarded to Hills laboratory for streptomycin resistance and copper tolerance testing. No copper tolerance was identified in any of the samples. Three KPINs in the Edgecumbe/Whakatane area were confirmed as positive for Streptomycin resistant Psa.

KVH has met with the owners of the three orchards and will be working with these growers to minimise the spread of streptomycin resistant Psa. The next round of resistance testing will be undertaken in February.