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The capsule gene cluster arrangement in L. garvieae Lg2 and L. lactis strains. Genes and their orientations are depicted with arrows using the following colours: orange, conserved genes in the capsule gene cluster; blue, transposase genes; white, other genes in the capsule gene cluster. Gray bars indicate orthologous regions. (A) Comparisons of the genomic location of the capsule gene cluster in L. garvieae Lg2 and the corresponding region in L. garvieae ATCC 49156. (B) The capsule gene cluster arrangement in L. lactis strains and the human gut bacteria (Subjects 2 and 17). Genes and their orientations are depicted with arrows using the same colour coding as described in (A). Accession numbers of the sequences used in this figure are as follows: L. lactis subsp. cremoris NIZO B40, AF036485; L. lactis subsp. cremoris HO2, AF142639; L. lactis subsp. cremoris SMQ461, AY741550; Subject 2, AB612914; Subject 17, AB612915. doi:10.1371/journal.pone.0023184.g004
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Lactococcus garvieae causes fatal haemorrhagic septicaemia in fish such as yellowtail. The comparative analysis of genomes of a virulent strain Lg2 and a non-virulent strain ATCC 49156 of L. garvieae revealed that the two strains shared a high degree of sequence identity, but Lg2 had a 16.5-kb capsule gene cluster that is absent in ATCC 49156. The...
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... strains of L. garvieae have been reported to be resistant to opsonophagocytosis and host serum killing [6,7]. The 16.5-kb capsule gene cluster found in Lg2 was composed of 15 genes flanked on both ends by IS982 elements (LCGL_0431 and LCGL_0448) ( Table 3 and Fig. 4A). The GC content (31%) of this 16.5-kb gene cluster differed from the chromosomal average (39%). Comparison of this genetic locus with the corresponding locus in the sequenced L. lactis genomes revealed that the gene cluster was apparently inserted into the locus syntenic to the sequenced lactococci (Fig. S2). These structural features ...
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... the 15 genes, eight genes (epsRXABCD and cpsLW) were conserved in the exopolysaccharide (EPS) biosynthesis gene cluster in four L. lactis strains with amino acid identity of .93% to their orthologs as well as IS982 in two L. lactis strains (Table 3 and Fig. 4B) [23][24][25][26]. Also, the L. lactis KF147 genome had almost identical gene organization to that in Lg2 (Fig. 4B) at a different locus on the chromosome (Fig. S2). Again, these data indicate that the capsule gene cluster may have been wildly spread among lactococci as genomic islands. The predicted genes located between cpsL and epsD ...
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... genes (epsRXABCD and cpsLW) were conserved in the exopolysaccharide (EPS) biosynthesis gene cluster in four L. lactis strains with amino acid identity of .93% to their orthologs as well as IS982 in two L. lactis strains (Table 3 and Fig. 4B) [23][24][25][26]. Also, the L. lactis KF147 genome had almost identical gene organization to that in Lg2 (Fig. 4B) at a different locus on the chromosome (Fig. S2). Again, these data indicate that the capsule gene cluster may have been wildly spread among lactococci as genomic islands. The predicted genes located between cpsL and epsD in the five strains were much less conserved and varied in number among them. The seven genes (LCGL_0438-LCGL_0444) ...
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... a single base deletion in the cpsL (conserved hypothetical protein) and epsD (glycosyl- transferase) genes, respectively. RT-PCR revealed that mRNAs of all 15 genes in the capsule gene cluster were expressed in Lg2-S at the almost same level as in capsulated Lg2 (Fig. S3). The cpsL and epsD genes were highly conserved among L. lactis strains (Fig. 4), suggesting the importance of these two genes in EPS synthesis. Glycosyltransferase encoded by epsD mediates the first step of EPS biosynthesis [22,24] and the frameshift in epsD of Lg2-S resulted in the loss of C-terminal functional domain (Pfam PF02397). Thus, mutations in cpsL and epsD may be responsible for the non- encapsulated ...
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... eight genes (epsRXABCD and cpsWL) in Subject 2 and the seven genes (epsXABCD and cpsWL) in Subject 17 were highly conserved among the capsule gene clusters in lactococci (Fig. 4B), showing high similarity (93-100% amino acid sequence identity) to those of L. lactis and S. thermophilus, which have been involved in fermenting dairy products as GRAS (Table S5). The genes except transposase genes located between cpsL and epsD in Subjects 2 and 17 also showed high similarity (98-100% amino acid sequence identity) to ...
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... The prevalence of the capsule gene cluster was low among the three Lactococcus species. It has been observed that the presence of capsule is not essential for the virulence of L. garvieae in fish, as many lactococcosis outbreaks were caused by noncapsulated strains (2,41). ...
... Virulence factors were predicted using blastp on all deduced protein sequences against the Virulence Factor Database (VFDB) 2022 (52) and a customized L. garvieae virulence gene database, which was curated referring to literature (2,30,37,41). All hits were filtered with 80% identity and 70% coverage as cutoffs and parsed into categories designated by VFDB or the relevant publications. ...
Lactococcus garvieae is a fish pathogen that can cause diseases in humans and cows. Two genetically related species, Lactococcus formosensis and Lactococcus petauri, may be misidentified as L. garvieae. It is unclear if these species differ in host specificity and virulence genes. This study analyzed the genomes of 120 L. petauri, 53 L. formosensis, and 39 L. garvieae isolates from various sources. The genetic diversity and virulence gene content of these isolates were compared. The results showed that 77 isolates previously reported as L. garvieae were actually L. formosensis or L. petauri. The distribution of the three species varied across different collection sources, with L. petauri being predominant in human infections, human fecal sources, and rainbow trout, while L. formosensis was more common in bovine isolates. The genetic diversity of isolates within each species was high and similar. Using a genomic clustering method, L. petauri, L. formosensis, and L. garvieae were divided into 45, 22, and 13 clusters, respectively. Most rainbow trout and human isolates of L. petauri belonged to different clusters, while L. formosensis isolates from bovine and human sources were also segregated into separate clusters. In L. garvieae, most human isolates were grouped into three clusters that also included isolates from food or other sources. Non-metric multidimensional scaling ordination revealed the differential association of 15 virulence genes, including 14 adherence genes and a bile salt hydrolase gene, with bacterial species and certain collection sources. In conclusion, this work provides evidence of host specificity among the three species.
IMPORTANCE
Lactococcus formosensis and Lactococcus petauri are two newly discovered bacteria, which are closely related to Lactococcus garvieae, a pathogen that affects farmed rainbow trout, as well as causes cow mastitis and human infections. It is unclear whether the three bacteria differ in their host preference and the presence of genes that contribute to the development of disease. This study shows that L. formosensis and L. petauri were commonly misidentified as L. garvieae. The three bacteria showed different distribution patterns across various sources. L. petauri was predominantly found in human infections and rainbow trout, while L. formosensis was more commonly detected in cow mastitis. Fifteen genes displayed a differential distribution among the three bacteria from certain sources, indicating a genetic basis for the observed host preference. This work indicates the importance of differentiating the three bacteria in diagnostic laboratories for surveillance and outbreak investigation purposes.
... Further in silico analyses were performed to screen the presence of virulence-related genes in the sea bass strains. The presence of the 16.5 kb capsule gene cluster described by Morita et al. [40] was investigated using Geneious Prime software, version 2023.2; in all these strains, this genomic region was absent. The strains were also investigated for the presence of other genes related to virulence, such as those codifying haemolysin (hlyIII), the fibronectin-binding protein As shown in Figure 5, the strains isolated from sea bass were different to those from Italian farmed rainbow trout and clustered with the L. garvieae strain MS210922A (accession number: NZ_AP026069.1) ...
... Further in silico analyses were performed to screen the presence of virulence-related genes in the sea bass strains. The presence of the 16.5 kb capsule gene cluster described by Morita et al. [40] was investigated using Geneious Prime software, version 2023.2; in all these strains, this genomic region was absent. The strains were also investigated for the presence of other genes related to virulence, such as those codifying haemolysin (hlyIII), the fibronectin-binding protein (fpb), penicillin acylase (pva) and bile salt hydrolase (bsh1 and bsh2), using the sequences reported by Eraclio et al. [41] or their comparisons. ...
... Although the pathogenic mechanism of L. garvieae is poorly understood, the presence of a capsule represents a known virulence factor in fish infection [40,57,58]. Nevertheless, in Asia, where vaccination is widely used in the farming of seawater fish, recently isolated strains showed the modification or even complete loss of such a capsule [7]. ...
In aquaculture, Lactococcus garvieae is a common fish pathogen that can cause significant economic losses in several fresh and saltwater species. Despite the extensive range of hosts, L. garvieae infection in sea bass (Dicentrarchus labrax) has rarely been reported. During the summer of 2023, an outbreak occurred in an inland farm in the Gulf of Follonica (Tuscany, Italy). Fish of various sizes were affected, showing apathy, inappetence, erratic swimming and eye lesions, while the mortality was low (2–3% per month). Anatomopathological examinations suggested a septicaemic infection characterised by melanosis, diffuse redness (skin and fins), paleness (gills and internal organs), haemorrhages and splenomegaly. Seventy swabs from the viscera of 14 subjects were collected and colonies similar to Streptococcus spp. grew from all the samples. Lactococcus garvieae was identified via the biochemical tests, API20STREP, MALDI-TOF, 16S rDNA and whole genome sequencing. Genetical characterisation revealed remarkable differences between this isolate and the strains previously isolated in Italian fish farms. Feed treatments with flumequine and erythromycin were ineffective. Considering the limited effects of antimicrobials, preventive measures, such as vaccination and biosecurity, should be implemented.
... The possible explanation probably related to the existence of highly developed capsule wrapped the cell wall of L. garvieae. Additionally, most of Gram-positive bacteria cell wall characterized by the presence of thicker peptidoglycan layers and lipoteichoic acids that make them more rigid and thick [36]. ...
Streptococcosis is an important bacterial disease affects fresh, brackish and marine fish. The disease caused annual severe economic losses in Egyptian Mari-culture. S. iniae and L. garvieae usually the main causative agents isolated. The presented study conducted to prepare bacterial ghost vaccine (BGV) candidates from isolated strains of marine streptococcosis outbreaks using NaOH chemical approach. Selected strains confirmed as pathogenic for Nile tilapia, therefore the fish selected as an experimental model. In such respect, the re-isolated S. iniae and L. garvieae were used for ghost preparations, BGVs evaluation and fish challenges. Apart of four, three fish groups namely, A, B, C designated for BGVs evaluations, while the fourth one (D) designated as control. Vaccination experiments performed via intra-peritoneal injection with 0.1 mL (1.5 × 108 CFU/mL/fish) of their corresponding BGVs twice with 2 weeks' interval; however, control fish received 0.1 mL of fish saline instead. Blood, serum, and tissue samples collected from all groups at 2 and 4 weeks post immunization (PI) for estimation of hematological, innate, and specific immune parameters. At the end, all remained fish challenged with appropriated pathogen (s) and the relative percentage of survival (RPS) calculated. Three BGVs generated namely, SiG, in addition to, novel contributions of LgG and SiLgG. Ghosts were corresponding to S. iniae, L. garvieae and their both ghost mixtures, respectively. Fish groups immunized with prepared BGVs revealed variable significant increases in PCV, GLB, PP, SOD, CAT, C5, IL-β1, LZM, specific antibody titers and CD4 expression 2 and 4 weeks PI. MDA decreased in all vaccinated groups that was significantly with group C. Expression of MHC-II showed elevations 2 weeks PI, however, it significantly decreased at 4 weeks. The RPS recorded 90, 88.89 and 95.46% in immunized groups A, B and C, respectively. At all levels tested, obtained results proposed SiG, LgG and SiLgG as innovative vaccine candidates, which can protect cultured fish from being attacked by S. iniae, and/or L. garvieae.
... Although L. garvieae was first isolated as a causative agent of bovine mastitis (27), most reports have focused on epidemiology of isolates from fish or humans. In addition, many studies used sequencing to investigate genotypic characteristics of L. garvieae isolates (8,(28)(29)(30)(31)(32)(33)(34)(35)(36)(37)(38)(39)(40). Therefore, we collected 39 L. garvieae isolates from bovine mastitis in China and conducted comparative genome sequence analyses. ...
Lactococcus garvieae is an emerging zoonotic pathogen, but there are few reports regarding bovine mastitis. The prevalence of L. garvieae represents an increasing disease threat and global public health risk. Thirty-nine L. garvieae isolates were obtained from 2,899 bovine clinical mastitis milk samples in 6 provinces of China from 2017 to 2021. Five clonal complexes were determined from 32 multilocus sequence types (MLSTs) of L. garvieae: sequence type 46 (ST46) was the predominant sequence type, and 13 novel MLSTs were identified. All isolates were resistant to chloramphenicol and clindamycin, but susceptible to penicillin, ampicillin, amoxicillin-clavulanic acid, imipenem, ceftiofur, enrofloxacin, and marbofloxacin. Based on genomic analyses, L. garvieae had 6,310 genes, including 1,015 core, 3,641 accessory, and 1,654 unique genes. All isolates had virulence genes coding for collagenase, fibronectin-binding protein, glyceraldehyde-3-phosphate dehydrogenase, superoxide dismutase, and NADH oxidase. Most isolates had lsaD and mdtA antimicrobial resistance (AMR) genes. Based on COG (Clusters of Orthologous Genes database) results, the functions of defense, transcription and replication, and recombination and repair were enhanced in unique genes, whereas functions of translation, ribosomal structure, and biogenesis were enhanced in core genes. The KEGG functional categories enriched in unique genes included human disease and membrane transport, whereas COG functional categories enriched in core genes included energy metabolism, nucleotide metabolism, and translation. No gene was significantly associated with host specificity. In addition, analysis of core genome single nucleotide polymorphisms (SNPs) implied potential host adaptation of some isolates in several sequence types. In conclusion, this study characterized L. garvieae isolated from mastitis and detected potential adaptations of L. garvieae to various hosts. IMPORTANCE This study provides important genomic insights into a bovine mastitis pathogen, Lactococcus garvieae. Comprehensive genomic analyses of L. garvieae from dairy farms have not been reported. This study is a detailed and comprehensive report of novel features of isolates of L. garvieae, an important but poorly characterized bacterium, recovered in the past 5 years in 6 Chinese provinces. We documented diverse genetic features, including predominant sequence type ST46 and 13 novel MLSTs. Lactococcus garvieae had 6,310 genes, including 1,015 core, 3,641 accessory, and 1,654 unique genes. All isolates had virulence genes coding for collagenase, fibronectin-binding protein, glyceraldehyde-3-phosphate dehydrogenase, superoxide dismutase, and NADH oxidase and resistance to chloramphenicol and clindamycin. Most isolates had lsaD and mdtA antimicrobial resistance genes. However, no gene was significantly associated with host specificity. This is the first report that characterized L. garvieae isolates from bovine mastitis and revealed potential host adaptations of L. garvieae to various hosts.
... LPxTG is a surface protein that covalently binds peptidoglycans isolated from many gram-positive bacteria including L. garvieae, and has an adhesive effect [36]. The formation of a capsule improved the resistance of pathogenic bacteria to phagocytosis in fish-derived L. garvieae [37]. The polysaccharide capsule of L. garvieae has been widely described as a major virulence factor involved mainly in the evasion of the host's immune response [7]. ...
... The following potential virulence genes were detected by PCR, with primers listed in Table 1, for 49 L. garvieae isolates: hly1 [34], hly2 [34], Hemolysin 3 (hly3) [34], NADHO [34], SOD [34], Phosphoglucomutase (pgm) [34], Pav [34], PsaA [34], eno [34], containing surface proteins-1, -2, -3, -4 (LP1, LP2, LP3, LP4) [34], AC1 [34], AC2 [34], Adhesin (Adh) [34], capsule gene cluster (1020-F, 1323-R) [34], capsule gene cluster (851-F, 1399-R) [34], capsule gene cluster (6329-F, 7175-R) [34], capsule gene cluster (5358-F, 6007-R) [34], conserved hypothetical protein (CHP) [34], exopolysaccharide R, X, A, B, C, D, and L (epsRXABCDL) [34], oligosaccharide repeat unit polymerase (ORUP) [37], rhamnosyltransferase (RIF) [37], and 30S rRNA gene [37]. The reaction mixtures (25 µL) consisted of 12.5 µL of Green Teq Mix, 1 µL of template DNA, 1 µL of each primer, and 9.5 µL of ultra-pure distilled water. ...
... The following potential virulence genes were detected by PCR, with primers listed in Table 1, for 49 L. garvieae isolates: hly1 [34], hly2 [34], Hemolysin 3 (hly3) [34], NADHO [34], SOD [34], Phosphoglucomutase (pgm) [34], Pav [34], PsaA [34], eno [34], containing surface proteins-1, -2, -3, -4 (LP1, LP2, LP3, LP4) [34], AC1 [34], AC2 [34], Adhesin (Adh) [34], capsule gene cluster (1020-F, 1323-R) [34], capsule gene cluster (851-F, 1399-R) [34], capsule gene cluster (6329-F, 7175-R) [34], capsule gene cluster (5358-F, 6007-R) [34], conserved hypothetical protein (CHP) [34], exopolysaccharide R, X, A, B, C, D, and L (epsRXABCDL) [34], oligosaccharide repeat unit polymerase (ORUP) [37], rhamnosyltransferase (RIF) [37], and 30S rRNA gene [37]. The reaction mixtures (25 µL) consisted of 12.5 µL of Green Teq Mix, 1 µL of template DNA, 1 µL of each primer, and 9.5 µL of ultra-pure distilled water. ...
Lactococcus garvieae (L. garvieae) is a pathogenic gram-positive, catalase-negative (GPCN) bacterium that causes bovine mastitis. A total of 49 L. garvieae isolates were identified from 1441 clinical mastitis (CM) samples. The pathogenic effects of L. garvieae were studied with two infection models: bovine mammary epithelial cells cultured in vitro and murine mammary infections in vivo. The overall farm prevalence was 15.5% (13/84 farms in 9/19 provinces) and sample prevalence was 3.40% (49/1441). Post-treatment somatic cell count (SCC) post L. garvieae infection was significantly higher than the other GPCN pathogens isolated, and the bacteriological cure fraction was 41.94% (13/31) after intramammary antibiotic treatment. All L. garvieae isolates were resistant to rifaximin, 12.24% of isolates were resistant to cephalexin, and 10.20% (5/49) were multidrug-resistant (MDR). The most prevalent virulence genes were Hemolysin 1 (hly1)(100%), Hemolysin 2 (hly2) (97.96%), NADH oxidase (NADHO) (100%), Superoxide dismutase (SOD) (100%), Adhesin Pav (Pav) (100%), Adhesin PsaA (PsaA) (100%), Enolase (eno) (100%), Adhesin cluster 1(AC1) (100%), Adhesin cluster 2 (AC2) (100%), and several exopolysaccharides. L. garvieae rapidly adhered to bovine mammary epithelial cells, resulting in an elevated lactate dehydrogenase release. Edema and congestion were observed in challenged murine mammary glands and bacteria were consistently isolated at 12, 24, 48, 72, and 120 h after infection. We concluded that L. garvieae had good adaptive ability in the bovine and murine mammary cells and tissue. Given the resistance profile, penicillin and ampicillin are potential treatments for CM cases caused by L. garvieae.
... In the serological tests, L. garvieae strains have been divided into two serotypes named KGand KG + that can be differentiated by an agglutination test (Kitao, 1982;Yoshida et al., 1997;Romalde and Toranzo, 2002). In addition, the KGstrain produces a capsule on its cell surface, which is pathogenic to fish (Yoshida et al., 1997) however, isolates might have result with losing capsule due to subculturing (Morita et al., 2011) In this study, the major bacterial fish pathogens (V. anguillarum, Y. ruckeri, L. garvieae) isolated from different rainbow trout farms between 2014-2021 in the South Aegean region of Turkey were tested for serological diagnosis and classification of serotypes. ...
Bacterial fish pathogens cause significant losses in rainbow trout farms. In fish farms, bacterial pathogens cause threatening diseases which has made it necessary to develop rapid methods for disease diagnosis. Serological techniques which are applied with a small amount of antiserum and sample, are preferred for the rapid diagnosis of fish diseases. In this study, formalin-killed antigens prepared from reference strains of Lactococcus garvieae, Yersinia ruckeri, and Vibrio (Listonella) anguillarum were injected intravenously in consecutive doses to New Zealand rabbits. One week after the last injection, the sera separated to use in the slide agglutination tests. A total of 42 strains were studied, including Y. ruckeri (18 isolates), V. anguillarum (14 isolates), and L. garvieae (7 isolates) and 3 references (ATCC 43305, ATCC 29473, ATCC 49156) strains. Serotype O1 determined the predominant serotype (86%) in V. anguillarum and Y. ruckeri (84%) strains examined by the slide agglutination method. L. garvieae strains did not react against Japanese antisera but positively reacted against Turkish L. garvieae antisera.
... The presence of seventeen putative virulence factors, hly1, -2, -3 (haemolysins 1, 2 and 3), NADH oxidase, sod (superoxide dismutase), pgm (phosphoglucomutase), adhPav (adhesin Pav), adhPsaA (adhesin PsaA), eno (enolase), LPxTG-1, -2, -3, -4 (LPxTG surface proteins 1, 2, 3 and 4), adhCI, -CII (adhesin clusters I and II), adh (adhesin) and CGC (capsule gene cluster) (Miyauchi et al., 2012;Morita et al., 2011) in the 61 L. garvieae isolates was evaluated by PCR with the primers reported in Table 2. Concisely, PCR reactions and imaging were performed as described in 2.2. ...
... In this respect, the presence of capsule and its association with virulence has been a long-discussed issue and different approaches have been used to reveal its existence, from classical staining techniques to exploiting its resistance to tetrazolium chloride (TTC) (Algöet et al., 2009;Chang et al., 2014;Eraclio et al., 2018;Vardanian, Kurzbaum, Farber, Butnariu, & Armon, 2018). Several authors have reported that capsule is compulsory for L. garvieae virulence (Barnes et al., 2002;Miyauchi et al., 2012;Morita et al., 2011), and reports describing highly pathogenic capsulated isolates have been published (Kang et al., 2004;Kawanishi et al., 2006;Miyauchi et al., 2012). However, several reports described the identification of virulent L. garvieae strains isolated from diseased fish not presenting capsule, which may be due to its lost after repeated subculturing under laboratory conditions (Meyburgh, Bragg, & Boucher, 2018;Shahi, Mallik, Sahoo, Chandra, & Singh, 2018;Ture & Altinok, 2016). ...
Lactococcus garvieae is the aetiological agent of lactococcosis, an ichthyopathology affecting rainbow trout (Oncorhynchus mykiss, Walbaum) farming and having recently been considered as a potential food-borne zoonotic agent. This work aims to characterise a population of 53 L. garvieae isolates from healthy cultured rainbow trout and rearing environment by using microbiological, biochemical and genetic assays to unveil the potential impact that their presence may have, not only for fish, but also for consumers. The lactococci exhibited a broad antimicrobial spectrum against Gram-negative ichthyopathogens, likely due to production of organic acids. The 53 L. garvieae isolates were grouped into two and five genetic clusters by PFGE and ERIC-PCR, respectively. All the lactococcal isolates produce α-haemolysis and harbour, at least, 10 putative virulence factors (hly-1, hly-2, hly-3, NADH oxidase, sod, pgm, adhPsaA, eno, LPxTG-3 and adhCI). While all the lactococci were resistant to streptomycin and clindamycin, no resistance genes were found. The manuscript concludes that the non-existence of active lactococcosis does not guarantee the absence of potentially virulent L. garvieae, which also exhibit a great capacity for adaptation and persistence in the environment. Furthermore, the antibiotic resistance profile shown may lead to re-evaluate the treatments of choice in human patients.
... The existence of a neighbouring gene (locus _02042) encoding an integrase could be also indicative of a vestigial integrative conjugative element (ICE) in the Lg-Granada chromosome. LPXTG proteins are surface proteins anchored to the cell-wall peptidoglycan by sortases, often being essential for the infectivity and survival of Gram-positive bacteria in the host, contributing to their pathogenicity [46][47][48]. ...
Lactococcus garvieae is a well-known pathogen of fish, but is rarely involved in infections in humans and other mammals. In humans, the main clinical manifestation of L. garvieae infections is endocarditis usually related to the ingestion of contaminated food, such as undercooked fish and shellfish. This study presents the first complete genomic sequence of a clinical L. garvieae strain isolated from a patient with endocarditis and its comparative analysis with other genomes. This human isolate contains a circular chromosome of 2 099 060 bp and one plasmid of 50 557 bp. In comparison with other fully sequenced L. garvieae strains, the chromosomal DNA of L. garvieae Lg-Granada carries a low proportion of insertion sequence elements and a higher number of putative prophages. Our results show that, in general, L. garvieae is a highly recombinogenic species with an open pangenome in which almost 30 % of its genome has undergone horizontal transfers. Within the genus Lactococcus, L. lactis is the main donor of genetic components to L. garvieae but, taking Lg-Granada as a representative, this bacterium tends to import more genes from Bacilli taxa than from other Lactococcus species.
... Comparative analysis of whole genomes makes available valuable information to identify unique genomic features (Zhang et al., 2014;de Vries et al., 2017). Thus, the availability of several L. garvieae genomes, isolated from different sources and locations, provides an excellent opportunity to determine genome features and biological structures (Morita, 2011). ...
Lactococcus garvieae is the Gram-positive cocci bacteria known as the causative agent of infectious systemic disease. It causes fatal hemorrhagic septicemia in mainly cultured fish species, animals, and humans worldwide. Comparative genome analyses provide valuable information about genome identification and unique genomic features. In this study, the available L. garvieae genomes are evaluated by comparative genomics approaches. The results indicated that there are four distinct genetic groups of L. garvieae based on the Average Nucleotide Identity (ANI) value. The phylogenetic tree was produced using 16S rRNA sequence has similar genetic variances with the publicly available L. garvieae genome data on NCBI and supports the ANI value. In silico analysis of antimicrobial resistance revealed that each L. garvieae genome groups have unique antimicrobial resistance class genes, even though, all genomes have a common antibiotic-resistant class. Analyzing results of the antimicrobial resistance supports the L. garvieae genetic variations. This extensively comparative approach will provide new insights into the understanding of L. garvieae genomic diversity and antimicrobial resistance.
... Lactococcus is a genus of gram-positive lactic acid bacteria which have been initially isolated from a variety of different sources (e.g., thermite gut [1], activated sludge foam [2], diseased fish [3,4], and fresh or fermented foods and milk [5][6][7]). The most well-known species of the genus, Lactococcus lactis, has undoubtedly been accompanying the "biotechnological" progress of mankind since the dawn of time (although unbeknownst to it for the most of its history), and its strains are still being widely used for the fermentation of milk as a part of starter cultures in the dairy industry [8,9]. ...
While looking for novel insect-associated phages, a unique siphophage, Nocturne116, was isolated from a deceased local moth specimen along with its host, which was identified by 16S rRNA gene sequencing as a strain of Lactococcus lactis. Next-generation sequencing and the subsequent genome annotation elaborated on herein revealed that the genome of Nocturne116 is a 25,554 bp long dsDNA molecule with 10 bp long 3′ cos overhangs and a GC content of 37.99%, comprising 52 predicted open reading frames. The complete nucleotide sequence of phage Nocturne116 genome is dissimilar to any of the already sequenced phages, save for a distant link with Lactococcus phage Q54. Functions for only 15/52 of Nocturne116 gene products could be reliably predicted using contemporary comparative genomics approaches, while 22 of its gene products do not yet have any homologous entries in the public biological sequence repositories. Despite the public availability of nearly 350 elucidated Lactococcus phage complete genomes as of now, Nocturne116 firmly stands out as a sole representative of novel phage genus.
