P. Leidinger-Kaufmannâ, M. Steimer, W. Carman. Fast Track Diagnostics, Esch-sur-Alzette/LU. Purpose: Zika virus (ZIKV), is a mosquito born (Aedes species) ...
Abstracts / International Journal of Infectious Diseases 53S (2016) 4–163
Bundibugyo virus (BDBV), Tai forest virus (TAFV), Sudan virus (SUDV), and Reston virus (RESTV); two related marburgviruses: Marburg virus (MARV) and Ravn virus (RAVN); and three henipaviruses: Nipah virus (NiV), Hendra virus (HeV), and Cedar virus (CedPV). A mammalian cell culture system was used to produce soluble viral envelope glycoproteins (sGp) that retain their native oligomeric conformations. Following purification by affinity and size exclusion chromatography, the sGps were coupled to colorcoded Bio-Plex carboxylated microspheres. Monoclonal antibodies (mAbs) and polyclonal sera from EBOV, MARV, and NiV infected non-human primates (NHP) were used to investigate specificity and cross-reactivity with the panel of sGps. Results: EBOV, BDBV, and TAFV sGp-conjugated microspheres had the highest median fluorescence intensity (MFI) when tested with anti-EBOV NHP sera. The Bio-Plex MFI data paralleled the phylogenetic relatedness of the ebolaviruses with EBOV, BDBV, and TAFV sGp-conjugated microspheres exhibiting similarly high MFI while SUDV and RESTV sGp-conjugated microspheres had MFIs higher than sGps from marburgviruses and henipaviruses, but lower than EBOV, BDBV, and TAFV. An additional EBOV sGp was created that lacked the mucin domain (EBOV sGpmucin). We compared MFI between EBOV sGp and EBOV sGpmucin and saw that MFI was higher with EBOV sGp-conjugated microspheres, which confirmed research that the mucin domain is an immunodominant epitope. MARV and RAVN sGp-conjugated microspheres reacted most strongly with anti-MARV NHP sera. Conclusion: The multiplex assay is able to differentiate antibody reactivity between ebolaviruses, marburgviruses, and henipaviruses. This multiplex assay has the potential to be integrated into surveillance programs to screen domestic animals, wildlife, and humans for evidence of exposure to these EIDs. http://dx.doi.org/10.1016/j.ijid.2016.11.272 20.033 Fast track diagnostics Zika virus kit – A real-time PCR based diagnostics assay P. Leidinger-Kaufmann ∗ , M. Steimer, W. Carman Fast Track Diagnostics, Esch-sur-Alzette/LU Purpose: Zika virus (ZIKV), is a mosquito born (Aedes species) flavivirus, which was fistly isolated from a rhesus monkey in Uganda in 1947. In humans, it causes a mild illness with a range from asymptomatic to influenza like symptoms. In 2014, the virus spread eastward across the Pacific Ocean to French Polynesia, then to Easter Island and in 2015 to Central America, the Caribbean, and South America, where the Zika outbreak has reached pandemic levels. In May 2015, PAHO issued an alert regarding the first confirmed ZIKV infection in Brazil. The outbreak in Brazil led to reports of Guillain-Barre syndrome and pregnant women giving birth to babies with birth defects. On 1 February 2016, based on recommendations of the International Health Regulations Emergency Committee, WHO declared the growing Zika outbreak a Public Health Emergency of International Concern. Methods & Materials: Fast Track Diagnostics developed an in vitro test based on real-time reverse transcriptase PCR for the qualitative detection of ZIKV specific nucleic acid as an aid in the evaluation of infections by ZIKV. As recommended by WHO FTD Zika virus targets the non-structural protein 5 genomic region. This test is for use with extracted nucleic acid from serum, plasma, or urine of human origin. Results: In silico and in vitro studies confirmed 100% sensitivity and specificity of FTD Zika virus. Extended precision studies showed a high inter- and intra-assay performance, as well as a high repro-
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ducibility between different production charges. FTD Zika virus detects down to 32 copies per reaction in 100% of cases and less than copies per reaction in around 80% of cases of RNA from the Asian lineage. In a clinical study conducted in Brazil, 100% sensitivity and specificity was received for the detection of ZIKV specific RNA with FTD Zika virus and the in-house singleplex RT-PCR assay. Testing EQA samples (INSTAND-Ringversuch) with FTD Zika virus and a competitor kit revealed nearly identical results. Conclusion: FTD Zika virus is a highly sensitive and specific assay for the qualitative detection of zika virus specific RNA. Our assay performed comparably to other zika virus detection methods. http://dx.doi.org/10.1016/j.ijid.2016.11.273 20.034 Early identification and antimicrobial susceptibility testing from positive blood culture bottles using MALDI-TOF MS M.G. Elanany a , R. Mostafa b,∗ , T. Mansoor c , H. Maher b a
CCH, Microbiology, Cairo/EG CCH, microbiology, Cairo/EG c CH, molecular, Cairo/EG b
Purpose: Timely diagnosis of the etiology of infection is imperative, with mortality increasing nearly 8% for every hour of inappropriate antimicrobial therapy administered to patients with sepsis. definitive organism identification and antimicrobial susceptibility testing (AST) results of positive blood cultures are generally not available to the treating physician for approximately 24 to 72 h after culture positivity is first noted. MALDI-TOF MS has the potential to identify any organism from a positive blood culture. The work aimed to detected the earliest time with the most accurate results to perform identification and susceptibility. Methods & Materials: Positive blood culture broths were subjected to direct Gram staining and inoculated to two blood agar plates and and incubated at 35 ◦ C. One plate was used for serial identification and susceptibility by MALDI-TOF MS (bioMérieux Vitek MS IVD system) and Vitek 2 cards every 2 hours, and the other was used for conventional biochemical identification tests after overnight incubation. The results of the 2 plates were compared. ontaminated and mixed samples were excluded. A total of positive 25 blood culture bottles were included Results: The study included 13 gram positive isolates and 12 gram negative isolates. All isolates showed 100% concordance in identification when tested at 4 hours incubation post inoculation . All Gram negative showed 100% concordance in AST results when tested at four hours incubation except Pseudomonas sp which showed concordance at 6 hours incubation post inoculation . The AST in vitek 2 was completed after 8 & 10 hours for gram negative & positive respectively. The final results wer obtained with 99% accuracy after 12-14 hours post inoculation Conclusion: The result of identification and AST could be obtained accurately from postive blood culture bottles in short time using MALDI-TOF MS http://dx.doi.org/10.1016/j.ijid.2016.11.274
