TetAB(46), a predicted heterodimeric ABC transporter conferring tetracycline resistance in Streptococcus australis isolated from the oral cavity

Warburton, Philip; Ciric, Lena; Lerner, Avi; Seville, Lorna A.; Roberts, Adam P.; Mullany, Peter; Allan, Elaine

doi:10.1093/jac/dks351

Cited by 30 publications

(30 citation statements)

References 32 publications

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“…Several bacterial species were more abundant in the gut microbiota of CP patients compared to those of AIP patients. Among them, Streptococcus australis and Streptococcus gordonii are generally present in the oral cavity, sometimes causing bacterial endocarditis (Warburton et al 2013;Dadon et al 2017). A greater abundance of Streptococcus has also been found in patients with intestinal diseases in a meta-analysis (Mancabelli et al 2017), suggesting a possible contribution of these bacterial species during the dysbiosis of CP patients.…”

Section: Discussionmentioning

confidence: 99%

Differences in Gut Microbiota Profiles between Autoimmune Pancreatitis and Chronic Pancreatitis

Hamada

Masamune

Nabeshima

et al. 2018

Tohoku J. Exp. Med.

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Host-derived factors alter gut microenvironment, and changes in gut microbiota also affect biological functions of host. Alterations of gut microbiota have been reported in a wide variety of diseases, but the whole picture of alterations in pancreatic diseases remains to be clarified. In particular, the gut microbiota may be affected by malnutrition or impaired exocrine pancreas function that is associated with pancreatic diseases. We here conducted comprehensive analysis of gut microbiota in patients with type 1 autoimmune pancreatitis (AIP), a pancreatic manifestation of the systemic IgG4-related disease, and chronic pancreatitis (CP). The two diseases were selected, because altered immune reactions in AIP and/ or long-standing malnutrition in CP may influence the gut microbiota. Fecal samples were obtained from 12 patients with AIP before the steroid therapy and 8 patients with CP. Metagenome DNA was extracted, and microbiota was analyzed by next generation sequencing. Gut microbiota profiles were different between patients with AIP and those with CP; namely, the proportions of Bacteroides, Streptococcus and Clostridium species were higher in patients with CP. The reasons for the increased proportion of these bacterial species remain unknown, but may reflect malabsorption and/or decreased pancreatic enzymes, both of which are associated with CP. Incidentally, the identified Streptococcus species are oral cavity inhabitants and also known as pathogens for endocarditis. Despite the small sample size, this study has shown the differences in gut microbiota profiles between AIP and CP. Comprehensive analysis of the gut microbiota may be useful for the differential diagnosis of pancreatic diseases.

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Section: Discussionmentioning

confidence: 99%

Differences in Gut Microbiota Profiles between Autoimmune Pancreatitis and Chronic Pancreatitis

Hamada

Masamune

Nabeshima

et al. 2018

Tohoku J. Exp. Med.

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“…Each PCR product was gel purified, and 100 ng of each fragment was fused by using PCR, as described previously (51). PCR products were excised from an agarose gel, purified, and used to transform A12 by using a modification of a method originally developed for Streptococcus australis (52). Briefly, a single colony was inoculated into Todd-Hewitt broth (THB) containing 10% heat-inactivated horse serum and incubated for 16 to 18 h. Cells were diluted 1:40 into THB supplemented with 10% horse serum and incubated until the optical density at 600 nm (OD 600 ) reached 0.05 to 0.08.…”

Section: Methodsmentioning

confidence: 99%

A Highly Arginolytic Streptococcus Species That Potently Antagonizes Streptococcus mutans

Huang

Palmer

Ahn

et al. 2016

Appl Environ Microbiol

106

128

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The ability of certain oral biofilm bacteria to moderate pH through arginine metabolism by the arginine deiminase system (ADS) is a deterrent to the development of dental caries. Here, we characterize a novel Streptococcus strain, designated strain A12, isolated from supragingival dental plaque of a caries-free individual. A12 not only expressed the ADS pathway at high levels under a variety of conditions but also effectively inhibited growth and two intercellular signaling pathways of the dental caries pathogen Streptococcus mutans. A12 produced copious amounts of H 2 O 2 via the pyruvate oxidase enzyme that were sufficient to arrest the growth of S. mutans. A12 also produced a protease similar to challisin (Sgc) of Streptococcus gordonii that was able to block the competence-stimulating peptide (CSP)-ComDE signaling system, which is essential for bacteriocin production by S. mutans. Wild-type A12, but not an sgc mutant derivative, could protect the sensitive indicator strain Streptococcus sanguinis SK150 from killing by the bacteriocins of S. mutans. A12, but not S. gordonii, could also block the XIP (comX-inducing peptide) signaling pathway, which is the proximal regulator of genetic competence in S. mutans, but Sgc was not required for this activity. The complete genome sequence of A12 was determined, and phylogenomic analyses compared A12 to streptococcal reference genomes. A12 was most similar to Streptococcus australis and Streptococcus parasanguinis but sufficiently different that it may represent a new species. A12-like organisms may play crucial roles in the promotion of stable, health-associated oral biofilm communities by moderating plaque pH and interfering with the growth and virulence of caries pathogens. Dental caries remains an enormous health problem worldwide (1-4). The current view of the initiation and progression of dental caries is one of a dynamic process in which the normal balance between the complex environmental factors that control demineralization and remineralization of the tooth is disrupted in a way that favors the loss of tooth mineral. Demineralization is driven primarily by microbial fermentation of carbohydrates to organic acids, which can lower the pH of oral biofilms to the extent that there is significant dissolution of tooth mineral. Alkalization of oral biofilms occurs during fasting periods and is attributable to salivary clearance of acids, buffering of oral biofilms by host-derived and microbially derived components, and the production of basic compounds by microbial metabolism of amino acids, polyamines, urea, and other compounds (5-10). Development or worsening of a carious lesion occurs when acid-mediated enamel demineralization predominates and is associated with changes in the composition and biochemical activities of the associated microflora. Evidence is now accumulating from a variety of sources that supports that alkali generation, particularly in the form of ammonia, plays a major role in pH homeostasis in oral biofilms and inhibits the initiation and progre...

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“…Previous studies demonstrated links between ABC transporter proteins and drug resistance. For example, the enterococcal ABC transporter gene lsa(E) conferred resistance to lincosamides in Staphylococcus aureus (42), and a predicted heterodimeric ABC transporter, TetAB, conferred tetracycline resistance in Streptococcus australis (43). Moreover, ABC transporters together with neighboring two-component systems, which regulate their expression, could coevolve to form self-sufficient detoxification modules against antimicrobial peptides in Firmicutes bacteria (44).…”

Section: Discussionmentioning

confidence: 99%

Novel Genes Related to Ceftriaxone Resistance Found among Ceftriaxone-Resistant Neisseria gonorrhoeae Strains Selected In Vitro

Gong

Lai

Liu

et al. 2016

Antimicrob Agents Chemother

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dThe emergence of ceftriaxone-resistant Neisseria gonorrhoeae is currently a global public health concern. However, the mechanism of ceftriaxone resistance is not yet fully understood. To investigate the potential genes related to ceftriaxone resistance in Neisseria gonorrhoeae, we subcultured six gonococcal strains with increasing concentrations of ceftriaxone and isolated the strains that became resistant. After analyzing several frequently reported genes involved in ceftriaxone resistance, we found only a single mutation in penA (A501V). However, differential analysis of the genomes and transcriptomes between pre-and postselection strains revealed many other mutated genes as well as up-and downregulated genes. Transformation of the mutated penA gene into nonresistant strains increased the MIC between 2.0-and 5.3-fold, and transformation of mutated ftsX increased the MIC between 3.3-and 13.3-fold. Genes encoding the ABC transporters FarB, Tfq, Hfq, and ExbB were overexpressed, while pilM, pilN, and pilQ were downregulated. Furthermore, the resistant strain developed cross-resistance to penicillin and cefuroxime, had an increased biochemical metabolic rate, and presented fitness defects such as prolonged growth time and downregulated PilMNQ. In conclusion, antimicrobial pressure could result in the emergence of ceftriaxone resistance, and the evolution of resistance of Neisseria gonorrhoeae to ceftriaxone is a complicated process at both the pretranscriptional and posttranscriptional levels, involving several resistance mechanisms of increased efflux and decreased entry. Gonorrhea is one of the most prevalent sexually transmitted infections (STIs), and it is associated with many severe clinical symptoms such as prostatitis, seminal vesiculitis, pelvic inflammation, infertility, and ophthalmia neonatorum (1). Although epidemiological data show a decreased trend in gonorrhea incidence as a whole, in some countries, the incidence is increasing, especially in specific population groups (adolescents, men who have sex with men, or sex workers) or specific venues (brothels) (2-5). The pathogen responsible for this disease is Neisseria gonorrhoeae. According to worldwide surveillance reports, N. gonorrhoeae has developed resistance to several kinds of antibiotics over the past decades (6-10). Of increasing concern is the prevalence of ceftriaxone (CRO)-resistant N. gonorrhoeae (11), because CRO is the first-line empirical drug for gonorrhea treatment in dual therapy with azithromycin or doxycycline recommended by the WHO (covering the Western Pacific region and the Southeast Asian region) and the CDC (12-14). Several CRO-resistant gonococcal strains, such as H041 and F89, were isolated recently from patients who had a treatment failure with CRO (H041) and cefixime (F89) (15-18). Highlighting the seriousness of these resistant strains, Ohnishi et al. proposed the concept of an N. gonorrhoeae "superbug" in 2011 (17). Uncovering the mechanisms of CRO resistance is now a critical topic of N. gonorrhoeae research.Previous s...

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TetAB(46), a predicted heterodimeric ABC transporter conferring tetracycline resistance in Streptococcus australis isolated from the oral cavity

Cited by 30 publications

References 32 publications

Differences in Gut Microbiota Profiles between Autoimmune Pancreatitis and Chronic Pancreatitis

Differences in Gut Microbiota Profiles between Autoimmune Pancreatitis and Chronic Pancreatitis

A Highly Arginolytic Streptococcus Species That Potently Antagonizes Streptococcus mutans

Novel Genes Related to Ceftriaxone Resistance Found among Ceftriaxone-Resistant Neisseria gonorrhoeae Strains Selected In Vitro

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