Distribution of integrons and SGI1 among antibiotic-resistant Salmonella enterica isolates of animal origin
VETERINARY MICROBIOLOGY
Authors: Havlickova, H.; Hradecka, H.; Bernardyova, I.; Rychlik, I.
Abstract
In Salmonella enterica, resistance to antibiotics can be caused by the presence of SGI1, transposons or conjuctive plasmids. In this study we were interested in the relative contribution of these genetic elements to the antibiotic resistance of S. enterica isolates collected within a single year in the Czech Republic from animal sources. Altogether 123 antibiotic-resistant isolates belonging to 16 different S. enterica serovars were classified into 3 groups according to the presence of SGI1 and the presence of integrons. The first group consisted of 62 strains in which neither SGI1 nor class 1 integron was detected. A high diversity among serovars and resistance phenotypes was found ill this group. The second group consisted of 56 strains positive for both the SGI1 and class I integron. Out Of Which 55 belonged to serovar Typhimurium and one to a nonmotile serovar [4,12] which harboured the SGI1-B variant. The third group Comprised five strains which were positive for class 1 integron but negative for the SGI1. Sequencing of the integrons in these isolates identified integron with sat1 and aadA1 gene cassettes in S. Sandiego and S. Pullorum, dfrA1 and aadA1 gene cassettes in S. Typhimurium integron, and aadA21 gene cassette in S. Braenderub and S. Zanzibar. (C) 2008 Elsevier B.V. All rights reserved.
Characterization of transboundary foot-and-mouth disease viruses in Nigeria and Cameroon during 2016
TRANSBOUNDARY AND EMERGING DISEASES
Authors: Ehizibolo, David Odion; Fish, Ian H.; Brito, Barbara; Bertram, Miranda R.; Ardo, Abdullahi; Ularamu, Hussaini G.; Lazarus, David D.; Wungak, Yiltawe S.; Nwosuh, Chika I.; Smoliga, George R.; Hartwig, Ethan J.; Pauszek, Steven James; Dickmu, Simon; Abdoulkadiri, Souley; Arzt, Jonathan
Abstract
Continuous surveillance for foot-and-mouth disease (FMD) in endemic settings such as West Africa is imperative to support improved local and regional control plans, with the long-term goal of regional eradication. This paper describes the genetic characterization of FMD viruses (FMDV) obtained from outbreaks in Nigeria (n = 45) and Cameroon (n = 15) during 2016 and from archival samples (n = 3) retrieved from a 2014 outbreak in Nigeria. These viruses were analysed in the context of previously published FMDV sequences from the region. Four FMDV serotypes: O, A, SAT1 and SAT2, were detected. Phylogenetic analyses of the VP1 coding sequences indicate the continuity of FMDV serotype O East Africa-3 (O/EA-3), serotype A AFRICA genotype G-IV (A/AFRICA/G-IV) and serotype South African Territories (SAT) 2 lineage VII (SAT2/VII). The FMDV SAT1 topotype X (SAT1/X), which emerged in Nigeria in 2015, continued to be associated with outbreaks in the region during 2016, and SAT1 is reported for the first time from Cameroon. Additionally, a re-emergence or re-introduction of the serotype O West Africa (O/WA) topotype in Nigeria is described herein. Our findings indicate a consistent, pan-serotypic relationship between FMDV strains detected in Cameroon and Nigeria. Additionally, FMDV strains from West Africa obtained in this study were genetically related to those occurring in East and North Africa. These phylogenetic relationships suggest that animal movements (pastoralism and/or trade) are important factors for virus spread across the African continent. These data provide critical baselines which are a necessary component of Stages 0 and 1 of the Progressive Control Pathway of FMD (PCP-FMD). Specifically, characterizing the existing virus strains (risk) provides the basis for the comprehensive risk-based control plan which is the requisite criteria for Nigeria's transition to Stage 2 of PCP-FMD, and for coordinated regional control of FMD.