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- W1438895963 abstract "Haemorrhagic septicaemia (HS) is an acute fatal septicaemic disease of cattle and buffaloes associated with strains of serotypes B:2 and E:2 of the bacterium Pasteurella multocida. Asia and Africa are currently the regions where HS occurs with the highest prevalence and has the greatest economic importance. There is currently only limited information available on the diversity of P. multocida strains that cause HS in these regions. A retrospective epidemiological case-control study was performed in Karachi, Pakistan from January to April 2013 looking at HS cases that occurred in the 2012 calendar year. The owners from 217 dairy cattle and dairy buffalo farms from six different locations around Karachi were interviewed. The study was based on a questionnaire that was designed to identify independent variables that were statistically associated with the presence of HS on the farm. The final multivariable logistic model contained five factors. Two protective factors were identified: HS vaccination (Odds Ratio (OR) = 0.22) and the length of time cattle were kept on farm (months): for every extra month cattle were kept, the odds of disease were reduced by a factor of 0.9. In contrast, supplying underground water and the presence of foot and mouth disease on the farm increased the risk of infection by 2.90 and 2.37, respectively. In addition, for every extra animal on the farm, the risk of infection increased by a factor of 1.01. To understand the epidemiology of HS in Karachi dairy herds more fully, further in-depth research is required to study the risk and protective factors identified in this survey and to evaluate risk mitigation strategies where possible. The study also showed the need for developing a point-of-care diagnostic test that can be used by veterinarians to diagnose the disease on the farm. Haemorrhagic septicaemia-associated strains of P. multocida were then analysed using molecular methods. Haemorrhagic septicaemia vaccine strains and HS-associated field isolates were obtained from different places in Pakistan and as a comparison group, vaccine strains and HS-associated field strains were obtained from Thailand to investigate the genetic diversity of strains associated with the disease from two endemic countries. Initially, 21 field isolates and three vaccine strains from different regions within these countries were analysed by multilocus sequence typing (MLST) and pulsed field gel electrophoresis (PFGE). The MLST technique was not able to differentiate between the strains from Pakistan and Thailand as all of the tested isolates (n = 21) were sequence type (ST) 122. The PFGE technique showed a difference of one band between the Thai and Pakistani isolates. Neither technique was able to show any variation between isolates from the same country. Based on the MLST and PFGE results, 12 of the 24 HS-associated strains were selected for next generation sequencing (NGS). Analyses of the genome data identified a core set of 1824 genes that were shared by the 12 HS-associated Asian strains, M1404 (North American HS-associated strain), and the available P. multocida complete genomes of strains Pm70, 3480, 36950 and HN06. Four sets of unique genes were found. One set (96 genes) was shared by all HS-associated strains. The second set (59 genes) was shared by the Asian HS-associated strains only. The third set (39 genes) was shared by seven out of nine Pakistani HS-associated strains. The last set (42 genes) was shared by the remaining two Pakistani HS-associated strains that were studied. The set of 96 unique genes, found in all HS-associated strains but absent from the non-HS-associated strains Pm70, 3480, 36950 and HN06, was identified by the PHAST bacteriophage detection algorithm to encode two putative temperate phages. It seems reasonable to suspect that the presence of these putative prophages may provide virulence genes that contribute to the pathogenesis of HS. The set of 59 unique genes shared by the 12 Asian HS-associated strains but not the North American HS-associated strain M1404, was also predicted to encode a temperate phage. Likewise, another putative temperate phage was predicted in the seven Pakistani strains that accounted for the set of 39 unique genes they shared. Interestingly, two Pakistani strains (BUKK and TX1) carried acquired antimicrobial resistance genes as predicted by the Resfinder tool. BUKK and TX1 strains shared 42 unique genes that were not present in any other HS strains. Some of these unique genes may contribute to a putative integrative conjugative element (ICE). The putative ICE of BUKK and TX1 is not identical to ICEPmu1, the first ICE that was found in P. multocida (strain 36950), and therefore, it may be the second ICE to be discovered in P. multocida strains. Phylogenetic analysis, predicted by analysis of core genome single nucleotide polymorphisms, demonstrated a strong correlation between the individual strains and their countries of origin. The Pakistani and Thai strains were more closely related to each other than the North American strain. Similarly, the isolates from Pakistan clustered together, and were distinctly separate from Thai isolates. A specific rapid diagnostic test, based on loop-mediated isothermal amplification (LAMP), for HS-associated B:2 strains, was developed using the previously-identified 96 unique genes obtained from NGS. Duplicates of each reaction were run, and this allowed two different definitions of a positive result to be applied to the experimental data. The first definition, “singlets”, treated each reaction tube as an independent entity. The second definition, “duplicates”, required that both tubes containing the same reactants must be positive for the overall reaction to be considered positive. The best sensitivity and specificity for HS-LAMP singlets (96.7% and 92.5%) and duplicates (100% and 100%) was achieved at 27 and 28 minutes, respectively. The detection limit for template DNA amount was 5 pg. The sensitivity and specificity have not yet been determined using clinical specimens in the field. This thesis looked at HS in a funnel-shape pattern, from theoretical research to application. We first conducted a survey to understand the husbandry conditions in Pakistan and identify the variables that were statistically associated with the disease. Molecular epidemiology was then used to compare the genetics of different field and vaccine strains. Consequently, unique genes found only in HS-associated strains were identified. This allowed the design of a rapid and cheap diagnostic test suitable for the limited infrastructure in developing countries like Pakistan. Two important future directions of research are identifying potential virulence genes and validating the LAMP test under field conditions to evaluate its performance." @default.
- W1438895963 created "2016-06-24" @default.
- W1438895963 creator A5065785713 @default.
- W1438895963 date "2014-01-01" @default.
- W1438895963 modified "2023-09-24" @default.
- W1438895963 title "A molecular epidemiological study on Haemorrhagic septicaemia disease in Pakistan" @default.
- W1438895963 cites W1234842004 @default.
- W1438895963 cites W1530619192 @default.
- W1438895963 cites W1541711227 @default.
- W1438895963 cites W1558609477 @default.
- W1438895963 cites W1567124731 @default.
- W1438895963 cites W1588330003 @default.
- W1438895963 cites W1804891534 @default.
- W1438895963 cites W1813616861 @default.
- W1438895963 cites W182076163 @default.
- W1438895963 cites W1868773258 @default.
- W1438895963 cites W1884986429 @default.
- W1438895963 cites W1894503735 @default.
- W1438895963 cites W1896186489 @default.
- W1438895963 cites W1968114652 @default.
- W1438895963 cites W1973948212 @default.
- W1438895963 cites W1976946534 @default.
- W1438895963 cites W1979094116 @default.
- W1438895963 cites W1982583549 @default.
- W1438895963 cites W1983408059 @default.
- W1438895963 cites W1984966664 @default.
- W1438895963 cites W1990821641 @default.
- W1438895963 cites W1992978619 @default.
- W1438895963 cites W1999053510 @default.
- W1438895963 cites W2008078199 @default.
- W1438895963 cites W2009650851 @default.
- W1438895963 cites W2011878969 @default.
- W1438895963 cites W2015783955 @default.
- W1438895963 cites W2019786863 @default.
- W1438895963 cites W2022143979 @default.
- W1438895963 cites W2022890348 @default.
- W1438895963 cites W2027246443 @default.
- W1438895963 cites W2032737761 @default.
- W1438895963 cites W2043165033 @default.
- W1438895963 cites W2050515639 @default.
- W1438895963 cites W205231806 @default.
- W1438895963 cites W2055043387 @default.
- W1438895963 cites W2055432014 @default.
- W1438895963 cites W2057876450 @default.
- W1438895963 cites W2062945232 @default.
- W1438895963 cites W2065239641 @default.
- W1438895963 cites W2074680977 @default.
- W1438895963 cites W2080100789 @default.
- W1438895963 cites W2082317013 @default.
- W1438895963 cites W2083587510 @default.
- W1438895963 cites W2085154179 @default.
- W1438895963 cites W2086098075 @default.
- W1438895963 cites W2091030812 @default.
- W1438895963 cites W2094812121 @default.
- W1438895963 cites W2096025045 @default.
- W1438895963 cites W2104960492 @default.
- W1438895963 cites W2105275554 @default.
- W1438895963 cites W2106000944 @default.
- W1438895963 cites W2107772251 @default.
- W1438895963 cites W2108060898 @default.
- W1438895963 cites W2114117103 @default.
- W1438895963 cites W2117693434 @default.
- W1438895963 cites W2117747314 @default.
- W1438895963 cites W2119899367 @default.
- W1438895963 cites W2120902911 @default.
- W1438895963 cites W2124401047 @default.
- W1438895963 cites W2124470755 @default.
- W1438895963 cites W2126007649 @default.
- W1438895963 cites W2127836438 @default.
- W1438895963 cites W2133300547 @default.
- W1438895963 cites W2133659171 @default.
- W1438895963 cites W2134466641 @default.
- W1438895963 cites W2134852597 @default.
- W1438895963 cites W2141892829 @default.
- W1438895963 cites W2142503351 @default.
- W1438895963 cites W2151332074 @default.
- W1438895963 cites W2152760152 @default.
- W1438895963 cites W2157063705 @default.
- W1438895963 cites W2162098634 @default.
- W1438895963 cites W2169966852 @default.
- W1438895963 cites W2171123389 @default.
- W1438895963 cites W2185510411 @default.
- W1438895963 cites W2186419534 @default.
- W1438895963 cites W2244045269 @default.
- W1438895963 cites W2332576564 @default.
- W1438895963 cites W236468228 @default.
- W1438895963 cites W2409209916 @default.
- W1438895963 cites W2417253649 @default.
- W1438895963 cites W242555842 @default.
- W1438895963 cites W2430261561 @default.
- W1438895963 cites W2467621475 @default.
- W1438895963 cites W2472849275 @default.
- W1438895963 cites W958106874 @default.
- W1438895963 cites W99982463 @default.
- W1438895963 cites W3113127543 @default.
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