This study describes the pathologic findings and most probable causes of death (CD) of 224 cetaceans stranded along the coastline of the Canary Islands (Spain) over a 7-year period, 2006–2012. Most probable CD, grouped as pathologic categories (PCs), was identified in 208/224 (92.8%) examined animals. Within natural PCs, those associated with good nutritional status represented 70/208 (33.6%), whereas, those associated with significant loss of nutritional status represented 49/208 (23.5%). Fatal intra- and interspecific traumatic interactions were 37/208 (17.8%). Vessel collisions included 24/208 (11.5%). Neonatal/perinatal pathology involved 13/208 (6.2%). Fatal interaction with fishing activities comprised 10/208 (4.8%). Within anthropogenic PCs, foreign body-associated pathology represented 5/208 (2.4%). A CD could not be determined in 16/208 (7.7%) cases. Natural PCs were dominated by infectious and parasitic disease processes. Herein, our results suggest that between 2006 and 2012, in the Canary Islands, direct human activity appeared responsible for 19% of cetaceans deaths, while natural pathologies accounted for 81%. These results, integrating novel findings and published reports, aid in delineating baseline knowledge on cetacean pathology and may be of value to rehabilitators, caregivers, diagnosticians and future conservation policies.
Streptococcus suis is one of the most important bacterial pathogens in the porcine industry and also a zoonotic agent. Serotype 9 is becoming one of the most prevalent serotypes within the S. suis population in certain European countries. In the present study, serotype 9 strains isolated from a country where infection due to this serotype is endemic (Spain), were compared to those recovered from Canada, where this serotype is rarely isolated from diseased pigs. For comparison purposes, strains from Brazil and the only strain isolated from a human case, in Thailand, were also incorporated. Firstly, sequence types (STs) were obtained followed by detection of putative virulence factors. Phylogenetic trees were constructed using the non-recombinant single nucleotide polymorphisms from core genomes of tested strains. Most Spanish strains were either ST123 or ST125, whereas Canadian strains were highly heterogeneous. However, the distribution of putative virulence factors was similar in both groups of strains. The fact that ST16 strains harbored more putative virulence genes and shared greater similarity with the genome of human serotype 2 strains suggests that they present a higher zoonotic and virulence potential than those from Canada and Spain. More than 80% of the strains included in this study carried genes associated with resistance to tetracycline, lincosamides and macrolides. Serotype 9 strains may be nearly 400 years old and have evolved in parallel into 2 lineages. The rapid population expansion of dominant lineage 1 occurred within the last 40 years probably due to the rapid development of the porcine industry.Electronic supplementary materialThe online version of this article (10.1186/s13567-017-0498-2) contains supplementary material, which is available to authorized users.
The phenotypic and genetic analysis results for 84 isolates ofLactococcus garvieae (including 62 strains from trout with lactococcosis from four different countries, 7 strains from cows and water buffalos with subclinical mastitis, 3 from water, and 10 from human clinical samples) are presented. There was great phenotypic heterogeneity (13 different biotypes) based on the acidification of saccharose, tagatose, mannitol, and cyclodextrin and the presence of the enzymes pyroglutamic acid arylamidase andN-acetyl-β-glucosaminidase. L. garvieaealso exhibited high genetic diversity by pulsed-field gel electrophoresis (PFGE), with 19 different pulsotypes among the isolates of L. garvieae studied. Only epidemiologically related strains, like the Spanish and Italian fish isolates and the cow and water buffalo isolates, displayed a close genetic relationship by PFGE, while the strains isolated from sporadic clinical cases, like the human isolates, were genetically unrelated. Overall, a general correlation between phenotypic and genetic data was observed. Epidemiological analysis of biotype and PFGE results indicated that the trout lactococcosis outbreaks in Spain and Portugal and those in France and Italy were produced by genetically unrelated clones. In Spain, two different clones were detected; the outbreaks diagnosed from 1995 onward were produced by a clone (biotype 2, pulsotype A1) which, although genetically related, was different from the one that was responsible for the outbreaks studied between 1991 and 1994 (biotype 1, pulsotype B). The Portuguese isolate had a biochemical profile identical to that of the Spanish strain isolated from 1995 onward and is also genetically closely related to this strain (pulsotype A2). There was a close relationship between the two pulsotypes (E and F) found in the Italian isolates. The French isolate (biotype 3, pulsotype D) was not genetically related to any other L. garvieaefish isolate. These results suggest the existence of diverse infection sources for the different lactococcosis outbreaks.
Sir, The recent identification of the first plasmid-mediated polymyxin resistance determinants, namely the MCR-1 and MCR-2 enzymes, has constituted an ultimate threat of pandrug resistance in Gramnegative organisms. [1][2][3] These enzymes have been reported only in Enterobacteriaceae, mainly in Escherichia coli and Klebsiella pneumoniae; however, there have been reports from other enterobacterial genera, including Enterobacter, Salmonella and Shigella. 1 The mcr-1 and mcr-2 genes have both been identified from cattle and pigs. [1][2][3] In addition, the mcr-1 gene has been identified from chickens, 4 but also from river samples and vegetables. 5 MCR-1 and MCR-2, sharing 81% amino acid identity, are phosphoethanolamine transferases of 541 and 538 amino acids, respectively. 2,3 They add phosphoethanolamine to the lipid A moiety of LPS, leading to a more cationic LPS structure and consequently to resistance to polymyxins. 1 We recently showed that some Moraxella species might constitute putative reservoirs of MCR-like proteins, with corresponding genes located on the chromosome of these species. 6 Hence, MCRlike proteins were identified in Moraxella catarrhalis, Moraxella lincolnii, Moraxella porci and Moraxella osloensis. They all share significant amino acid identities with MCR-1 and MCR-2, ranging from 59% to 64%. 6 Even though these Moraxella species have been shown to carry intrinsic mcr-like genes, these genes remain quite distantly related to the plasmid-borne mcr-1 and mcr-2.We recently had the opportunity to investigate another Moraxella species. Moraxella pluranimalium strain 248-01 T has been isolated from the nasal turbinate of a healthy pig in Spain. 7 M. pluranimalium is an aerobic and catalase-and oxidase-positive Gram-negative coccus that grows at temperatures of 22-37 C. 7 PCR assays with internal primers specific for both mcr-1 and mcr-2, as published, 1 allowed us to obtain an amplicon that was further sequenced. Internal outward primers were then designed and used for an inverse PCR strategy, as previously performed. 6 The sequence of the entire mcr gene was thus obtained and it revealed that this new enzyme (termed MCR-2.2) was almost identical to MCR-2 (99% amino acid identity), with only 8 amino acid differences out of the 538 constituting the MCR-2 enzyme, and shared 82% amino acid identity with MCR-1.Interestingly, the mcr-2.2 gene exhibits a G ! C content of 49.1%, which is in accordance with the total G ! C content of the genomes of different Moraxella species ( 45%), which agrees with the intrinsic origin of this gene in M. pluranimalium.The corresponding gene, named mcr-2.2, was cloned into plasmid pBADb, the recombinant plasmid being then expressed in E. coli TOP10 by adding L-arabinose 1% (necessary for the expression of the cloned genes in this inducible vector), as performed for other mcr-like genes. 6 Then MICs of colistin were determined for the recombinant strains expressing mcr-1, mcr-2 and mcr-2.2 by broth microdilution (BMD), 1 and this showed that MCR-2.2 conferred exactly t...
Streptococcus suis is one of the important emerging zoonotic pathogens. Serotype 2 is most prevalent in patients worldwide. In the present study, we first isolated one S. suis serotype 7 strain GX69 from the blood culture of a patient with septicemia complicated with pneumonia in China. In order to deepen the understanding of S. suis serotype 7 population characteristics, we investigated the phylogenetic structure, genomic features, and virulence of S. suis serotype 7 population, including 35 strains and 79 genomes. Significant diversities were revealed in S. suis serotype 7 population, which were clustered into 22 sequence types (STs), five minimum core genome (MCG) groups, and six lineages. Lineages 1, 3a, and 6 were mainly constituted by genomes from Asia. Genomes of Lineages 2, 3b, and 5a were mainly from Northern America. Most of genomes from Europe (41/48) were clustered into Lineage 5b. In addition to strain GX69, 13 of 21 S. suis serotype 7 representative strains were classified as virulent strains using the C57BL/6 mouse model. Virulence-associated genes preferentially present in highly pathogenic S. suis serotype 2 strains were not suitable as virulence indicators for S. suis serotype 7 strains. Integrative mobilizable elements were widespread and may play a critical role in disseminating antibiotic resistance genes of S. suis serotype 7 strains. Our study confirmed S. suis serotype 7 is a non-negligible pathotype and deepened the understanding of the population structure of S. suis serotype 7, which provided valuable information for the improved surveillance of this serotype.
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