Browsing by Author "Ibok, U. I."

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Development of Echovirus 29 Cytopathology in RD Cell Line Might not Happen within 10 Days Post Inoculation
(SciTechnol, 2017) Adewumi, M. O.; Faleye, T. O. C.; Ayinde, O. T.; Ibok, U. I.; Adeniji, J. A.
Classically in enterovirology, isolation in RD cell culture required inoculation and incubation for 14 days before any sample is declared negative for enteroviruses. To reduce the turn-around time for confirming suspected cases of poliomyelitis, in 2010, the required incubation period, post inoculation was reduced to 10days. In this study we set out to determine why an Echovirus 29 (E29) strain we isolated in 2016 showed no cytopathology on RDcell culture despite the fact that other members of the clade to which it belongs do so. We found that the problem was not the 2016 E29 strain but the new 10 days incubation algorithm. To be precise, the 2016 E29 strain did not show cytopathology in RD cell line within the recommended 10 days but replicated with evident cytopathology when allowed to stay in culture for 13 to 14 days. This shows that some samples declared negative for enteroviruses by the 10 days incubation algorithm might be false negatives that will eventually develop cytopathology if allowed to remain in incubation for 13 to 14 days. It is therefore encouraged that those particularly interested in Non-Polio Enteroviruses endeavour to maintain at least 14 days incubation in cell culture in a bid to accommodate the likes of E29 that might need 13-14 days to develop CPE especially when present at low titre.
Enterovirus A119 in A Child with Acute Flaccid Paralysis, Nigeria
(MedCrave Group, 2016) Adeniji, J. A.; Oragwa, A. O.; George, U. E.; Ibok, U. I.; Faleye, T. O. C.; Adewumi, M. O.
The oldest EV-A119 record was in 2008 in a chimpanzee in Cameroon and subsequently in more non-human primates and healthy children. Here we report for the first time the detection of EV-A119 in a child with Acute Flaccid Paralysis, thus suggesting possible association with a clinical condition in humans
Preponderance of enterovirus C in RD-L20B-cell-culture-negative stool samples from children diagnosed with acute flaccid paralysis in Nigeria
(Springer Nature, 2017) Adeniji, J. A.; Oragwa, A. O.; George, U. E.; Ibok, U. I.; Faleye, T. O. C.; Adewumi, M. O
Recently, a reverse transcriptase semi-nested polymerase chain reaction (RT-snPCR) assay was recommended by the WHO for direct detection of enteroviruses in clinical specimens. In this study, we use this assay and a modification thereof to screen acute flaccid paralysis (AFP) samples that had previously tested negative for enteroviruses by the RD-L20B algorithm. Thirty paired stool suspensions collected in 2015 as part of the national AFP surveillance program in different states of Nigeria were analyzed in this study. The samples had previously tested negative for enteroviruses in the polio laboratory in accordance with the WHO-recommended RD-L20B-cellculture- based algorithm. Two samples that had previously been found to contain enteroviruses were included as positive controls. All samples were subjected to RNA extraction, the RT-snPCR assay and a modified version of the RT-snPCR. All amplicons were sequenced, and enteroviruses were identified using the enterovirus genotyping tool and phylogenetic analysis. Amplicons were recovered from the two controls and 50% (15/30) of the samples screened. Fourteen were successfully typed, of which, 7.1% (1/14), 21.4% (3/14), 64.3% (9/14) and 7.1% (1/14) were enterovirus (EV) -A, EV-B, EV-C and a mixture of EV-B and C (EV-C99 and E25), respectively. The two controls were identified as EV-C99 and coxsackievirus (CV) -A1, both of which belong to the species Enterovirus C. In one sample, poliovirus serotype 2 was detected and found to have the VP1 ILE143 variation and was therefore identified as a vaccine strain. The results of this study showed that significant proportion of enterovirus infections (including some with Sabin PV2) are being missed by the RD-L20B-cell-culture-based algorithm, thus highlighting the value of the RT-snPCR assay and its modifications. The circulation and preponderance of EV-C in Nigeria was also confirmed.
Recovery of nonpolio enteroviruses from l20b cell line with non-reproducible cytopathic effect
(BioMed Central, 2018) Adeniji, J. A.; Ibok, U. I.; Ayinde,O. T.; Oragwa, A. O.; George, U. E.; Faleye. T. O. C.; Adewumi, M. O.
Background and Aim of the Study: Samples showing cytopathic effect (CPE) on initial inoculation into L20B cell line but with no observed or reproducible CPE on passage in L20B or RD are considered negative for both poliovirus and nonpolio enteroviruses (NPEVs). The phenomenon is termed ‘non-reproducible CPE’. Its occurrence is usually ascribed to the likely presence of reoviruses, adenoviruses and other non-enteroviruses. This study aimed to investigate the likelihood that NPEVs are also present in cases with non-reproducible CPE. Place and Duration of Study: This study was carried out in the Department of Virology, College of Medicine, University of Ibadan using twenty-six (26) cell culture suspensions collected from the WHO National Polio Laboratory, Department of Virology, College of Medicine, University of Ibadan. The suspensions emanated from 13 L20B cell culture tubes that showed cytopathology within 5 days of inoculation with faecal suspension from AFP cases. However, on passage into one each of RD and L20B cell lines, the CPE was not reproducible. The study lasted for three (3) months from samples collection to report writing. Methodology: All samples were subjected to RNA extraction, cDNA synthesis, the WHO recommended VP1 RT-seminested PCR assay, species resolution PCR assay, sequencing andphylogenetic analysis. Results: Six (6) samples were positive for the VP1 RT-seminested PCR assay. Only four of which were positive by the species resolution PCR assay. The four amplicons were sequenced, however, only three (3) were successfully identified as Coxsackievirus A20 (2 isolates) and Echovirus 29 (1isolate). Conclusion: The results of this study unambiguously showed the presence of NPEVs (particularly CVA20 and E29) in cell culture supernatants of samples with CPE on initial inoculation into L20B cell line but with no observed or reproducible CPE on passage in RD cell line. Therefore, like reoviruses, adenoviruses and other non-enteroviruses, NPEVs can also be recovered in cases with non-reproducible CPE.