Day 1 :
Ain Shams University, Egypt
Keynote: Molecular detection and sequencing of Carbapenemase-Encoding Genes in Clinical strains of Pseudomonas aeruginosa
Time : 9.30AM-10.15AM
Ayman Kamal El Essawy received his PhD in Microbiology at Ain Shams University, Egypt and a Diploma in Hospital Infection Control at Claude Bernard-Lyone 1 University, France and a Diploma in Biostatistics at Ain Shams University, Egypt. He is a Fellow of Microbiology at Ain Shams University, Egypt. He worked at Al Azhar University and American Naval Medical Research Unit No.3 (NAMRU-3) and Ain Shams University Genetic Engineering/Biotechnology Center, Egypt. He is Head of laboratory and infection control at Magrabi Hospitals, KSA. He is publishing in the field of microbiology and molecular microbiology. He is particularly interested in the study of bacterial resistance to antibiotics.
In 2017 the World Health Organization (WHO) classified carbapenem resistant Pseudomonas among the most critical multidrug-resistant bacteria for urgent attention. In this study verigene-nanosphere microarray based assay and multiplex PCR were tested for detection of carbapenem encoding genes. Carbapenemase encoding gene sequencing of parent strain and its UV mutant followed by nucleotide sequence alignments were also conducted. Bacterial resistance to carbapenem was tested after induced plasmid curing by sodium dodecyl sulfate (SDS) and heat treatment. A set of genes including IMP, VIM and SME was detected in one reaction by multiplex PCR. Verigene-nanosphere detected 3, 0, 0 among 5, 4, 11 and previously determined positive strains for VIM, IMP, KPC genes respectively. Carbapenem resistance was preserved after treating CRPA strain by heat or SDS. The nucleotide sequence alignments of VIM, IMP and KPC genes showed relatedness to many gram negative species. VIM gene was lost in UV mutant and IMP and KPC genes were preserved but 1-2% sequence modification was occurred without change in resistance to imipenem and meropenem. In conclusion the developed multiplex PCR detected successfully a set of carbapenem encoding genes, while microarray based verigene-nanosphere failed to detect most of the genes under the current experimental conditions. Nucleotide alignments of VIM, IMP and KPC genes revealed that these gene sequences are distributed among species of gram negative bacteria. IMP and KPC genes were preserved in UV mutant with no damage, repaired damage or little modification of nucleotide sequence and meanwhile carbapenem resistance was preserved.
International Union against Tuberculosis and Lung Disease, Zimbabwe
Keynote: Increased Rifampicin mono-resistance prevalence in Zimbabwe. Is the higher prevalence of codon 523 to 529 mutation in the rpoB gene an attributable factor?
Time : 10.15AM-11.00AM
I am a medical doctor. I am the Progrmatic Management of Drug Resistant TB Technichal officer with The Union. Im currently enrolled with the London School of Tropical Hygiene and Medicine.
Background: Zimbabwe conducted a second anti-tuberculosis drug resistance survey (TB-DRS) in 2015/16 using the Xpert MTB/RIF assay. This assay uses molecular beacons in five overlapping regions of the rpoB DNA region. The probes detect mutations in the codons 507 to 511 (Probe A), 511 to 518 (Probe B), 518 to 523 (Probe C), 523 to 529 (Probe D), and 529 to 533 (Probe E). We report the frequencies of mutations in rpoB gene of the Mycobacterium tuberculosis (MTB) among the TB-DRS samples with rifampicin resistance tuberculosis (RR-TB) detected.
Method: A retrospective review of data collected through the TB-DRS and using the GxAlert platform to check the actual probe details for those tests from samples that had RR-TB strains. Sputum smear positive samples had an Xpert MTB/RIF assay done followed by phenotypic culture and drug susceptibility testing (DST) in those that had RR-TB detected.
Results: A total of 60 specimens had RR-TB detected on Xpert MTB/RIF assay. Of these, 50 (83.3%) had Mycobacterium tuberculosis growth on culture with 48 (96.0%) confirmed RR-TB on phenotypic DST. Among those confirmed RR-TB on phenotypic DST, 23 (47.9%) had rifampicin mono-resistance (RMR) detected and 25 had additional isoniazid resistance (MDR-TB). Probe E mutations occurred in 46% (23/50), probe D 34% (17/50), probe B 10% (5/50), probe A 2% (1/50) and probe C 2% (1/50) of the specimens. Among the RMR, probe D mutation occurred in 54.5% (12/22), probe E 36.4% (8/22), probe A 4.5% (1/22) and probe B 4.5% (1/22).
Conclusion: There is increase in the RMR prevalence from zero percent to 48% between the 1994/5 and 2015/6 TB-DRS. Rifampicin (RMP) seems to be associated with mutations in codons 523 to 529 of the rpoB gene of MTB DNA. GxAlert makes it possible to conduct such surveillance remotely and there is need for further studies to cement this.