Frequency, Microbial Interactions, and Antimicrobial Susceptibility of Fusobacterium nucleatum and Fusobacterium necrophorum Isolated from Primary Endodontic Infections

Coevolution of the human host and its associated microbiota has led to sophisticated interactions to maintain a delicate homeostasis. Emerging evidence suggests that in addition to small molecules, peptides, and proteins, small regulatory noncoding RNAs (sRNAs) might play an important role in cross-domain interactions. In this study, we revealed the presence of diverse host transfer RNA–derived small RNAs (tsRNAs) among human salivary sRNAs. We selected 2 tsRNAs (tsRNA-000794 and tsRNA-020498) for further study based on their high sequence similarity to specific tRNAs from a group of Gram-negative oral bacteria, including Fusobacterium nucleatum, a key oral commensal and opportunistic pathogen. We showed that the presence of F. nucleatum triggers exosome-mediated release of tsRNA-000794 and tsRNA-020498 by human normal oral keratinocyte cells. Furthermore, both tsRNA candidates exerted a growth inhibition effect on F. nucleatum, likely through interference with bacterial protein biosynthesis, but did not affect the growth of Streptococcus mitis, a health-associated oral Gram-positive bacterium whose genome does not carry sequences bearing high similarity to either tsRNA. Our data provide the first line of evidence for the modulatory role of host-derived tsRNAs in the microbial-host interaction.

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β-Lactamase Production and Antimicrobial Susceptibility of Oral Heterogeneous Fusobacterium nucleatum Populations in Young Children

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.43.5.1270 ◽

1999 ◽

Vol 43 (5) ◽

pp. 1270-1273 ◽

Cited By ~ 31

Author(s):

E. Könönen ◽

A. Kanervo ◽

K. Salminen ◽

H. Jousimies-Somer

Keyword(s):

Young Children ◽

Clavulanic Acid ◽

Antimicrobial Susceptibility ◽

Fusobacterium Nucleatum ◽

Penicillin G ◽

Healthy Children ◽

Good Activity ◽

In Vitro Susceptibility ◽

Amoxicillin Clavulanic Acid

ABSTRACT Oral Fusobacterium nucleatum populations from 20 young, healthy children were examined for β-lactamase production. Ten children (50%) harbored, altogether, 25 β-lactamase-positiveF. nucleatum isolates that were identified as F. nucleatum subsp. polymorphum, F. nucleatum subsp. nucleatum, and F. nucleatum subsp. vincentii (J. L. Dzink, M. T. Sheenan, and S. S. Socransky, Int. J. Syst. Bacteriol. 40:74–78, 1990). In vitro susceptibility of these β-lactamase-producing and 26 non-β-lactamase-producing F. nucleatum isolates was tested with penicillin G, amoxicillin-clavulanic acid, tetracycline hydrochloride, metronidazole, trovafloxacin, and azithromycin. Except for penicillin G, the antimicrobials exhibited good activity against all F. nucleatum isolates.

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In Vitro Activity of Gemifloxacin (SB 265805) against Anaerobes

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.43.9.2231 ◽

1999 ◽

Vol 43 (9) ◽

pp. 2231-2235 ◽

Cited By ~ 34

Author(s):

Ellie J. C. Goldstein ◽

Diane M. Citron ◽

Yumi Warren ◽

Kerin Tyrrell ◽

C. Vreni Merriam

Keyword(s):

Clinical Laboratory ◽

Fusobacterium Nucleatum ◽

Fusobacterium Necrophorum ◽

Penicillin G ◽

National Committee ◽

Dilution Method ◽

Agar Dilution Method ◽

Prevotella Melaninogenica ◽

Amoxicillin Clavulanate

ABSTRACT Gemifloxacin mesylate (SB 265805), a new fluoronaphthyridone, was tested against 359 recent clinical anaerobic isolates by the National Committee for Clinical Laboratory Standards reference agar dilution method with supplemented brucella blood agar and an inoculum of 105 CFU/spot. Comparative antimicrobials tested included trovafloxacin, levofloxacin, grepafloxacin, sparfloxacin, sitafloxacin (DU-6859a), penicillin G, amoxicillin clavulanate, imipenem, cefoxitin, clindamycin, and metronidazole. The MIC50 and MIC90 (MICs at which 50 and 90% of the isolates were inhibited) of gemifloxacin against various organisms (with the number of strains tested in parentheses) were as follows (in micrograms per milliliter): for Bacteroides fragilis (28), 0.5 and 2; forBacteroides thetaiotaomicron (24), 1 and 16; forBacteroides caccae (12), 1 and 16; for Bacteroides distasonis (12), 8 and >16; for Bacteroides ovatus(12), 4 and >16; for Bacteroides stercoris (12), 0.5 and 0.5; for Bacteroides uniformis (12), 1 and 4; forBacteroides vulgatus (11), 4 and 4; for Clostridium clostridioforme (15), 0.5 and 0.5; for Clostridium difficile (15), 1 and >16; for Clostridium innocuum(13), 0.125 and 2; for Clostridium perfringens (13), 0.06 and 0.06; for Clostridium ramosum (14), 0.25 and 8; forFusobacterium nucleatum (12), 0.125 and 0.25; forFusobacterium necrophorum (11), 0.25 and 0.5; forFusobacterium varium (13), 0.5 and 1; forFusobacterium spp. (12), 1 and 2; forPeptostreptococcus anaerobius (13), 0.06 and 0.06; forPeptostreptococcus asaccharolyticus (13), 0.125 and 0.125; for Peptostreptococcus magnus (14), 0.03 and 0.03; forPeptostreptococcus micros (12), 0.06 and 0.06; forPeptostreptococcus prevotii (14), 0.06 and 0.25; forPorphyromonas asaccharolytica (11), 0.125 and 0.125; forPrevotella bivia (10), 8 and 16; for Prevotella buccae (10), 2 and 2; for Prevotella intermedia (10), 0.5 and 0.5; and for Prevotella melaninogenica (11), 1 and 1. Gemifloxacin mesylate (SB 265805) was 1 to 4 dilutions more active than trovafloxacin against fusobacteria and peptostreptococci, and the two drugs were equivalent against clostridia and P. asaccharolytica. Gemifloxacin was equivalent to sitafloxacin (DU 6859a) against peptostreptococci, C. perfringens, andC. ramosum, and sitafloxacin was 2 to 3 dilutions more active against fusobacteria. Sparfloxacin, grepafloxacin, and levofloxacin were generally less active than gemifloxacin against all anaerobes.

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Filling the Void: An Optimized Polymicrobial Interkingdom Biofilm Model for Assessing Novel Antimicrobial Agents in Endodontic Infection

Microorganisms ◽

10.3390/microorganisms8121988 ◽

2020 ◽

Vol 8 (12) ◽

pp. 1988

Author(s):

Sumaya Abusrewil ◽

Jason L. Brown ◽

Christopher D. Delaney ◽

Mark C. Butcher ◽

Ryan Kean ◽

...

Keyword(s):

Antimicrobial Agents ◽

Fusobacterium Nucleatum ◽

Atmospheric Conditions ◽

Candida Spp ◽

Biofilm Growth ◽

Log Reduction ◽

Biofilm Model ◽

Endodontic Infection ◽

Endodontic Infections ◽

Ontological Analysis

There is a growing realization that endodontic infections are often polymicrobial, and may contain Candida spp. Despite this understanding, the development of new endodontic irrigants and models of pathogenesis remains limited to mono-species biofilm models and is bacterially focused. The purpose of this study was to develop and optimize an interkingdom biofilm model of endodontic infection and use this to test suitable anti-biofilm actives. Biofilms containing Streptococcus gordonii, Fusobacterium nucleatum, Porphyromonas gingivalis, and Candida albicans were established from ontological analysis. Biofilms were optimized in different media and atmospheric conditions, prior to quantification and imaging, and subsequently treated with chlorhexidine, EDTA, and chitosan. These studies demonstrated that either media supplemented with serum were equally optimal for biofilm growth, which were dominated by S. gordonii, followed by C. albicans. Assessment of antimicrobial activity showed significant effectiveness of each antimicrobial, irrespective of serum. Chitosan was most effective (3 log reduction), and preferentially targeted C. albicans in both biofilm treatment and inhibition models. Chitosan was similarly effective at preventing biofilm growth on a dentine substrate. This study has shown that a reproducible and robust complex interkingdom model, which when tested with the antifungal chitosan, supports the notion of C. albicans as a key structural component.

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