48 Monte Carlo Crescent Kyalami Business Park, Kyalami Johannesburg, 1684 South Africa www.thistle.co.za Tel: +27 (011) 463 3260 Fax to Email: + 27 (0) 86-557-2232 e-mail : [email protected] Please read this section first The HPCSA and the Med Tech Society have confirmed that this clinical case study, plus your routine review of your EQA reports from Thistle QA, should be documented as a “Journal Club” activity. This means that you must record those attending for CEU purposes. Thistle will not issue a certificate to cover these activities, nor send out “correct” answers to the CEU questions at the end of this case study.

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MICROBIOLOGY LEGEND CYCLE 40 ORGANISM 5

Veillonella parvula

The genus was first isolated by Veillon and Zuber in 1898. Veillonella parvula is a gram negative, strict anaerobic, non-spore-forming -shaped bacterium. It is found in the gut of humans and . While considered non-pathogenic, it has been linked with rare cases of meningitis, osteomyelitis, and periodontal disease.

An article in the South African Medical Journal (cited below) mentioned Viellonella purvula in connection with increasing antibiotic sensitivity in clinically significant anaerobic . http://www.samj.org.za/index.php/samj/article/view/5053/3578

This prospective study of one hundred and eighty anaerobic isolates collected from 165 patients over about eighteen months took place in the Charlotte Maxeke Johannesburg Academic Hospital. All patients were suspected of anaerobic and the results of sensitivity tests were interpreted according to the CLSI guidelines for amoxicillin-clavulanate, clindamycin, metronidazole, penicillin, ertapenem, cefoxitin, ceftriaxone, chloramphenicol and piperacillin-tazobactam.

It noted that anaerobes are “the predominant flora on human skin and mucous membranes and are a common cause of endogenous infections.” Of the 165 patients, eight were classified as children, but the source of the organisms was not identified. While the most common organism found was B. fragilis, two isolates of Veilonella purvula were identified, both being resistant to penicillin. This is in contrast to other articles which state that “V. parvula is susceptible to penicillin”. Interestingly enough, penicillin was only effective in 33.3% of organisms overall, with the most effective being chloramphenicol (100%), ertapenem (97.2%) and pipericillin-tazobactam (99.4%).

In the authors view, their study highlights “the necessity for periodic active surveillance to identify and record” changes in antibiotic susceptibility of anaerobic bacteria.

V. parvula is significantly involved in where it co-aggregates with other organisms, most notably with mutans, onto dental plaque. This is a synergistic relationship as V. parvula cannot adhere to the surface of teeth by itself alone. It also utilises the lactate product formed by S. mutans for its metabolism and the has been found to be more resistant to antibiotics than either species of bacteria alone.

The cells of V. parvula are coccus shaped, non-motile, roughly 0.4 µm in diameter, and predominantly occur in chains. Like other gram negative bacteria, V. parvula has an outer layer of which is a known virulence factor. Page 1 of 2

48 Monte Carlo Crescent Kyalami Business Park, Kyalami Johannesburg, 1684 South Africa www.thistle.co.za Tel: +27 (011) 463 3260 Fax to Email: + 27 (0) 86-557-2232 e-mail : [email protected]

V.parvula Gram Stain

V. parvula is usually not considered a pathogen but it has been implicated with rare cases of meningitis, osteomyelitis, and periodontal disease, especially in the biofilm with S. mutans, and therefore V. parvula could be indirectly involved with the pathogenesis of other microbes.

References 1. http://www.samj.org.za/index.php/samj/article/view/5053/3578 2. http://www.medschool.lsuhsc.edu/microbiology/DMIP/veillgs.jpg

Questions 1. With which diseases has V. parvula been implicated? 2. With which microbe does V. parvula form a synergistic relationship? 3. Describe the growth conditions of V. parvula.

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