Anaerobic cocci
Veillonellaceae -- Veillionella inhabitants of oral cavity, respiratory tract, intestinal tract of humans,
ruminants. Rodents and pigs

Veillonella parvula Bacteremia without an Underlying Source

Veillonella parvula is an anaerobic gram-negative coccus that is part of the normal human flora. It has rarely
been identified as a pathogen in humans, and the most frequently reported infection caused by V. parvula is
osteomyelitis. We report a case of bacteremia unrelated to a central venous catheter and without an underlying
source of infection.

Veillonella parvula is a small, nonfermentative anaerobic gram-negative coccus that is part of the normal flora of the
mouth, gastrointestinal tract, and vagina in humans. It fluoresces red under UV light and reduces nitrate. When
isolated from clinical specimens, it is often regarded as a contaminant or a commensal. However, it has been isolated
in pure culture from various sites and implicated as a pathogen in the sinuses, lungs, liver, central nervous system,
heart, and bone. Bacteremia in the absence of an underlying source, however, is extremely rare; to our knowledge,
there is only one prior case described in the literature (6). We report a case of V. parvula bacteremia.

Veillonella parvula Discitis and Secondary Bacteremia: a Rare Infection Complicating Endoscopy and

We report a case of Veillonella parvula lumbar discitis and secondary bacteremia confirmed by molecular
characterization of the 16S rRNA genes. Identification of the organism was essential for an appropriate choice of
antimicrobial therapy following the failure of empirical flucloxacillin. Veillonella spp. are normal flora of the
gastrointestinal tract, raising the possibility that an endoscopy and colonoscopy performed 8 weeks prior to
presentation, during which small intestinal and rectal biopsies were obtained, was the portal of entry. This case
highlights the importance of obtaining a microbiologic diagnosis, particularly in patients who previously have had
procedures involving instrumentation.
J Clin Microbiol. 2007 February; 45(2): 672–674.

Prosthetic Joint Infection due to Veillonella dispar


Described here is the first report of a monomicrobial joint infection caused by Veillonella dispar that resulted in
loosening of a prosthesis. This clinical case shows that Veillonella spp. should not be disregarded as contaminant
organisms, particularly when they are isolated in pure culture from clinical specimens involving cases of septic arthritis.
European Journal of Clinical Microbiology & Infectious Diseases Volume 20, Number 5 / May, 2001

Two fatal cases of Veillonella bacteremia
European Journal of Clinical Microbiology & Infectious Diseases  Volume 17, Number 1 / January, 1998

Prosthetic valve endocarditis caused by Veillonella parvula.
Veillonella species is a rare cause of endocarditis. We report a case of a 49-year-old man with Veillonella parvula
prosthetic valve endocarditis who presented with acute cardiac failure due to valvular dehiscence [Irish Republic]. His
clinical course was complicated by cortical blindness and limb paresis as a result of cerebral embolism. The
endocarditis was successfully treated with urgent valve replacement surgery and a prolonged course of metronidazole.

Journal of Infection, 2005 (Vol. 50) (No. 1) 81-83

Rapid Succession within the Veillonella Population of a Developing Human Oral Biofilm In Situ

Streptococci are the primary component of the multispecies oral biofilm known as supragingival dental plaque;
they grow by fermentation of sugars to organic acids, e.g., lactic acid.
Veillonellae, a ubiquitous component of early
plaque, are unable to use sugars; they ferment organic acids, such as lactate, to a mixture of shorter-chain-length
acids, CO2, and hydrogen. Certain
veillonellae bind to (coaggregate with) streptococci in vitro. We show that,
between 4 and 8 hours into plaque development, the dominant strains of Veillonella change in their phenotypic
characteristics (coaggregation and antibody reactivity) as well as in their genotypic characteristics (16S RNA gene
sequences as well as strain level fingerprint patterns). This succession is coordinated with the development of
mixed-species bacterial colonies. Changes in community structure can occur very rapidly in natural biofilm
development, and we suggest that this process may influence evolution within this ecosystem.

In nature, bacterial biofilms are inherently multispecies communities (6). Human dental plaque is a paradigm biofilm, a
complex community (20, 30) of intimately juxtaposed (19) microorganisms on which spatiotemporally resolved data are
easily collected (26, 28). This community is highly resilient; under good dental hygiene practices, supragingival
plaque is destroyed on a daily basis yet quickly and repeatedly reestablishes itself (22, 36). Two factors hypothesized
as important for the establishment of these complex networks of interorganismal relationships are coaggregation and
food webs. Bacterial coaggregation, a type of cell-cell recognition,
JOURNAL OF BACTERIOLOGY, June 2006, p. 4117–4124