Journal of Clinical Microbiology
Rapid and accurate detection of carriers of carbapenemase-producing organisms (CPO) in hospitalized patients is critical for infection control and prevention. This study aimed to evaluate a pooling strategy for the detection of carbapenem resistance genes (CRG) in multiple specimens using the Xpert Carba-R test. Two rectal swabs each were collected from 415 unique patients. One swab was tested by Carba-R on the five specimen-pooled strategy. The other swab was tested individually by culture followed by DNA sequence analysis for CRG as the reference. At the first 5:1 pooling testing, 22 of 83 pools were positive, which yielded 34 positives from individual specimens when positive pools were subsequently retested. All individual specimens in the 61 negative pools were retested as negative by Carba-R. Among the 34 Carba-R-positive samples, 30 and four were positive and negative, respectively, by culture and sequencing. The remaining 381 Carba-R-negative specimens were also negative by culture and sequencing. Overall sensitivity, specificity, positive predictive value, and negative predictive value of the 5:1 pooled screening were 100.0% (95% confidence interval [CI] = 85.9% to 100%), 99.0% (95% CI = 97.2% to 99.7%), 88.2% (95% CI = 71.6% to 96.2%), and 100.0% (95% CI = 98.8% to 100%), respectively. Using the 5:1 pooling strategy, our study completed CRG screening in 414 patients with 193 reagents with significant cost savings. The 5:1 pooling strategy using the Carba-R test showed a potential method for screening CRG from rectal swabs with good sensitivity and decreased cost.
Print ISSN: 0095-1137; Online ISSN: 1098-660X
American Society for Microbiology
carbapenemase-producing organisms, carbapenem resistance genes, pooling, Xpert Carba-R test, screening
This study was partly supported by the National Natural Science Foundation of China (no. 32141001 and no. 81991533 to H.W.; no. 82172310 to Q.W.), the Cepheid Investigator-Initiated Study award (no. Cepheid-IIS-2020-0024 to H.W.) and Development Fund of Peking University People’s Hospital (no. RS2020-02 to Q.W.).
Tenover, Fred C.; Zhang, Peng; Wang, Qi; Zhou, Chaoe; Zhang, Feifei; Gao, Xinghui; Tang, Yi-Wei; and Wang, Hui, "A Pooling Strategy for Detecting Carbapenem Resistance Genes by the Xpert Carba-R Test in Rectal Swab Specimens" (2022). Biology Faculty Publications. 352.