Complete Genome Sequence of a Ciprofloxacin-Resistant Salmonella enterica subsp. enterica Serovar Kentucky Sequence Type 198 Strain, PU131, Isolated from a Human Patient in Washington State.
ABSTRACT: Strains of the ciprofloxacin-resistant (Cipr) Salmonella enterica subsp. enterica serovar Kentucky sequence type 198 (ST198) have rapidly and extensively disseminated globally to become a major food safety and public health concern. Here, we report the complete genome sequence of a CiprS. Kentucky ST198 strain, PU131, isolated from a human patient in Washington State (USA).
Project description:Salmonella enterica serovar Kentucky (S. Kentucky) sequence type 198 has emerged as a global zoonotic pathogen. We explored Salmonella enterica serovar Kentucky ST198 samples from the broiler chicken supply chain and patients between 2010 and 2016. Here, we collected 180 S. Kentucky isolates from clinical cases and the poultry supply chain. We performed XbaI pulsed-field gel electrophoresis and multilocus sequence typing. We assessed mutations in the quinolone resistance-determining regions and screened for the presence of the Salmonella genomic island 1 (SGI1). We determined that 63 (35.0%) of the 180 isolates were S. Kentucky ST198. Chinese strains of S. Kentucky ST198 have a high transmission of ciprofloxacin resistance (38/63, 60.3%) and a high risk of multidrug resistance. The quinolone resistance of the S. Kentucky ST198 strain found in China may be due to mutations in its quinolone resistance-determining region. Our study firstly revealed that ciprofloxacin-resistant S. Kentucky ST198 strains can undergo cross-host transmission, thereby causing a serious foodborne public health problem in China.
Project description:Salmonella genomic island 1 (SGI1) is a 43-kb integrative mobilizable element that harbors a great diversity of multidrug resistance gene clusters described in numerous Salmonella enterica serovars and also in Proteus mirabilis. The majority of SGI1 variants contain an In104-derivative complex class 1 integron inserted between resolvase gene res and open reading frame (ORF) S044 in SGI1. Recently, the international spread of ciprofloxacin-resistant S. enterica serovar Kentucky sequence type 198 (ST198) containing SGI1-K variants has been reported. A retrospective study was undertaken to characterize ST198 S. Kentucky strains isolated before the spread of the epidemic ST198-SGI1-K population in Africa and the Middle East. Here, we characterized 12 ST198 S. Kentucky strains isolated between 1969 and 1999, mainly from humans returning from Southeast Asia (n = 10 strains) or Israel (n = 1 strain) or from meat in Egypt (n = 1 strain). All these ST198 S. Kentucky strains did not belong to the XbaI pulsotype X1 associated with the African epidemic clone but to pulsotype X2. SGI1-J subgroup variants containing different complex integrons with a partial transposition module and inserted within ORF S023 of SGI1 were detected in six strains. The SGI1-J4 variant containing a partially deleted class 1 integron and thus showing a narrow resistance phenotype to sulfonamides was identified in two epidemiologically unrelated strains from Indonesia. The four remaining strains harbored a novel SGI1-J variant, named SGI1-J6, which contained aadA2, floR2, tetR(G)-tetA(G), and sul1 resistance genes within its complex integron. Moreover, in all these S. Kentucky isolates, a novel insertion sequence related to the IS630 family and named ISSen5 was found inserted upstream of the SGI1 complex integron in ORF S023. Thus, two subpopulations of S. Kentucky ST198 independently and exclusively acquired the SGI1 during the 1980s and 1990s. Unlike the ST198-X1 African epidemic subpopulation, the ST198-X2 subpopulation mainly from Asia harbors variants of the SGI1-J subgroup that are encountered mainly in the Far East, as previously described for S. enterica serovars Emek and Virchow.
Project description:Since its emergence in the beginning of the 90's, multidrug-resistant (MDR) <i>Salmonella enterica</i> subsp<i>. enterica</i> serovar Kentucky has become a significant public health problem, especially in East Africa. This study aimed to investigate the antimicrobial resistance profile and the genotypic relatedness of <i>Salmonella</i> Kentucky isolated from animal sources in Ethiopia and Kenya (n=19). We also investigated population evolutionary dynamics through phylogenetic and pangenome analyses with additional publicly available <i>Salmonella</i> Kentucky ST198 genomes (n=229). All the 19 sequenced <i>Salmonella</i> Kentucky isolates were identified as ST198. Among these isolates, the predominant genotypic antimicrobial resistance profile observed in ten (59.7%) isolates included the <i>aac(3)-Id</i>, <i>aadA7</i>, <i>strA</i>-<i>strB</i>, <i>bla</i> <sub>TEM-1B</sub>, <i>sul1</i>, and <i>tet</i>(A) genes, which mediated resistance to gentamicin, streptomycin/spectinomycin, streptomycin, ampicillin, sulfamethoxazole and tetracycline, respectively; and <i>gyr</i>A and <i>par</i>C mutations associated to ciprofloxacin resistance. Four isolates harbored plasmid types Incl1 and/or Col8282; two of them carried both plasmids. <i>Salmonella</i> Pathogenicity islands (SPI-1 to SPI-5) were highly conserved in the 19 sequenced <i>Salmonella</i> Kentucky isolates. Moreover, at least one Pathogenicity Island (SPI 1-4, SPI 9 or C63PI) was identified among the 229 public <i>Salmonella</i> Kentucky genomes. The phylogenetic analysis revealed that almost all <i>Salmonella</i> Kentucky ST198 isolates (17/19) stemmed from a single strain that has accumulated ciprofloxacin resistance-mediating mutations. A total of 8,104 different genes were identified in a heterogenic and still open <i>Salmonella</i> Kentucky ST198 pangenome. Considering the virulence factors and antimicrobial resistance genes detected in <i>Salmonella</i> Kentucky, the implications of this pathogen to public health and the epidemiological drivers for its dissemination must be investigated.
Project description:<i>Salmonella enterica</i> serotype Kentucky is frequently associated with high-level fluoroquinolone resistance and has gained epidemiological importance globally. A retrospective screening was performed to understand the national prevalence of ciprofloxacin-resistant <i>S</i> Kentucky in China. <i>S. enterica</i> strains (<i>n </i>=<i> </i>15,405) were collected within the frame of two national surveillance networks between 2013 and 2017. Thirty-three <i>S.</i> Kentucky strains were detected in 5 of 10 provinces, and 27 were assigned to sequence type 198 (ST198). The 27 isolates were multidrug resistant, with high-level resistance to ciprofloxacin, and 21 isolates were further resistant to extended-spectrum cephalosporins (ESCs). Phylogenomic analysis classified ST198 isolates into two clades (198.1 and 198.2), and recent occurrences of inter-/intraregion and interhost transmission were identified. Phylogenetic reconstruction with a global collection showed that one subclade of clade 198.2 was clustered with historical strains from Egypt, and the other one was clustered with strains from Southeast Asia. Isolates of clade 198.1 were clustered with strains isolated from North America. The various patterns of mutations detected in quinolone resistance-determining regions of GyrA and ParC are accordant with the phylogenetic structure. These findings indicate that our isolates may have various origins. SGI1 was exclusively detected in isolates of clade 198.2 with a highly mosaic structure, which were mainly identified as SGI1-K derivatives. Plasmid-mediated quinolone resistance genes <i>qnrS1</i> and <i>aac(6')-Ib-cr</i> were identified in three isolates, and <i>bla</i> <sub>CTX-M-9</sub> and <i>bla</i> <sub>CTX-M-27</sub> were detected in 20 of 21 ESC-resistant isolates. This is the first report of the genetic and epidemiological characterization for the <i>S</i> Kentucky epidemic clone ST198 in China, warranting the necessity of surveillance for the high-risk clone.<b>IMPORTANCE</b> Ciprofloxacin and extended-spectrum cephalosporins are the choice for treatment of severe nontyphoidal <i>S. enterica</i> infections in adults. <i>S. enterica</i> serotype Kentucky ST198 has gained epidemiological importance globally, because the clone is frequently resistant to both of these high-level-resistance drug groups. The genetic and epidemiological characterization of <i>S.</i> Kentucky has been well studied in Western countries; however, the information is unclear for China. To fill in the gap, we here did a retrospective screening on a large collection in China, and ST198 isolates were systematically analyzed by whole-genome sequencing. Our study revealed that multidrug-resistant ST198 has spread in five provinces, and the occurrences of interregion and cross-host clonal disseminations were detected. Of note, phylogenomic analysis suggests that the Chinese isolates may have emerged with diverse origins, including Egypt, Southeast Asia, and North America. This study warrants the necessity of surveillance for the high-risk clone to prevent its further dissemination in China.
Project description:<h4>Background</h4><i>Salmonella</i> Kentucky belongs to zoonotic serotypes that demonstrate that the high antimicrobial resistance and multidrug resistance (including fluoroquinolones) is an emerging problem. To the best of our knowledge, clinical <i>S.</i> Kentucky strains isolated in Poland remain undescribed.<h4>Methods</h4>Eighteen clinical <i>S.</i> Kentucky strains collected in the years 2018-2019 in Poland were investigated. All the strains were tested for susceptibility to 11 antimicrobials using the disc diffusion and E-test methods. Whole genome sequences were analysed for antimicrobial resistance genes, mutations, the presence and structure of SGI1-K (Salmonella Genomic Island and the genetic relationship of the isolates.<h4>Results</h4>Sixteen of 18 isolates (88.9%) were assigned as ST198 and were found to be high-level resistant to ampicillin (>256 mg/L) and quinolones (nalidixic acid MIC ≥ 1024 mg/L, ciprofloxacin MIC range 6-16 mg/L). All the 16 strains revealed three mutations in QRDR of GyrA and ParC. The substitutions of Ser83 → Phe and Asp87 → Tyr of the GyrA subunit and Ser80→Ile of the ParC subunit were the most common. One <i>S.</i> Kentucky isolate had <i>qnrS1</i> in addition to the QRDR mutations. Five of the ST198 strains, grouped in cluster A, had multiple resistant determinants like <i>bla</i>TEM1-B, <i>aac(6')-Iaa</i>, <i>sul1</i> or <i>tetA</i>, mostly in SGI1 K. Seven strains, grouped in cluster B, had shorter SGI1-K with deletions of many regions and with few resistance genes detected.<h4>Conclusion</h4>The results of this study demonstrated that a significant part of <i>S.</i> Kentucky isolates from humans in Poland belonged to ST198 and were high-level resistant to ampicillin and quinolones.
Project description:A screening for non-target mutations affecting fluoroquinolone susceptibility was conducted in epidemic multidrug-resistant Salmonella enterica serovar Kentucky ST198. Among a panel of representative isolates (n = 27), covering the epidemic, only three showed distinct mutations in ramR resulting in enhanced expression of genes encoding the AcrAB-TolC efflux system and low increase in ciprofloxacin MIC. No mutations were detected in other regulatory regions of this efflux system. Ciprofloxacin resistance in serovar Kentucky ST198 is thus currently mainly due to multiple target gene mutations.
Project description:Salmonella enterica subsp. enterica serovar Kentucky is frequently isolated from healthy poultry and dairy cows and is occasionally isolated from people with clinical disease. A genomic analysis of 119 isolates collected in the United States from dairy cows, ground beef, poultry and poultry products, and human clinical cases was conducted. Results of the analysis demonstrated that the majority of poultry and bovine-associated S. Kentucky were sequence type (ST) 152. Several bovine-associated (n = 3) and food product isolates (n = 3) collected from the United States and the majority of human clinical isolates were ST198, a sequence type that is frequently isolated from poultry and occasionally from human clinical cases in Northern Africa, Europe and Southeast Asia. A phylogenetic analysis indicated that both STs are more closely related to other Salmonella serovars than they are to each other. Additionally, there was strong evidence of an evolutionary divergence between the poultry-associated and bovine-associated ST152 isolates that was due to polymorphisms in four core genome genes. The ST198 isolates recovered from dairy farms in the United States were phylogenetically distinct from those collected from human clinical cases with 66 core genome SNPs differentiating the two groups, but more isolates are needed to determine the significance of this distinction. Identification of S. Kentucky ST198 from dairy animals in the United States suggests that the presence of this pathogen should be monitored in food-producing animals.
Project description:Salmonellaenterica serovar Kentucky is an emergent human pathogen. Human infection with ciprofloxacin-resistant S. enterica Kentucky ST198 has been reported in Europe and North America as a consequence of travel to Asia/the Middle East. This is, to the best of our knowledge, the first study reporting the identification of this epidemic clone in India and South Asia.
Project description:H2S-producing multiresistant Salmonella enterica serovar Kentucky strain sequence type (ST) 198 and its non-H2S-producing variant were isolated from a patient. Whole-genome comparison showed a base addition in the gene encoding molybdenum cofactor biosynthesis protein C, which could affect H2S production in the variant. Lack of H2S production has implications for diagnosis of salmonella.
Project description:Salmonella enterica serotype Kentucky can be a common causative agent of salmonellosis, usually associated with consumption of contaminated poultry. Antimicrobial resistance (AMR) to multiple drugs, including ciprofloxacin, is an emerging problem within this serotype. We used whole-genome sequencing (WGS) to investigate the phylogenetic structure and AMR content of 121 S.enterica serotype Kentucky sequence type 198 isolates from five continents. Population structure was inferred using phylogenomic analysis and whole genomes were compared to investigate changes in gene content, with a focus on acquired AMR genes. Our analysis showed that multidrug-resistant (MDR) S.enterica serotype Kentucky isolates belonged to a single lineage, which we estimate emerged circa 1989 following the acquisition of the AMR-associated Salmonella genomic island (SGI) 1 (variant SGI1-K) conferring resistance to ampicillin, streptomycin, gentamicin, sulfamethoxazole and tetracycline. Phylogeographical analysis indicates this clone emerged in Egypt before disseminating into Northern, Southern and Western Africa, then to the Middle East, Asia and the European Union. The MDR clone has since accumulated various substitution mutations in the quinolone-resistance-determining regions (QRDRs) of DNA gyrase (gyrA) and DNA topoisomerase IV (parC), such that most strains carry three QRDR mutations which together confer resistance to ciprofloxacin. The majority of AMR genes in the S. enterica serotype Kentucky genomes were carried either on plasmids or SGI structures. Remarkably, each genome of the MDR clone carried a different SGI1-K derivative structure; this variation could be attributed to IS26-mediated insertions and deletions, which appear to have hampered previous attempts to trace the clone's evolution using sub-WGS resolution approaches. Several different AMR plasmids were also identified, encoding resistance to chloramphenicol, third-generation cephalosporins, carbapenems and/or azithromycin. These results indicate that most MDR S. enterica serotype Kentucky circulating globally result from the clonal expansion of a single lineage that acquired chromosomal AMR genes 30 years ago, and has continued to diversify and accumulate additional resistances to last-line oral antimicrobials. This article contains data hosted by Microreact.