Mjms2012-0242.pmd

Macedonian Journal of Medical Sciences. 2012 Oct 15; 5(3):324-327.
http://dx.doi.org/10.3889/MJMS.1857-5773.2012.0242 Case Report
Actinomyces Odontolyticus - Associated Bacteremia
Anika Považan1, Anka Vukelic1, Nevena Secen2, 3, Danica Sazdanic-Velikic2, Daliborka Bursac2 1Institute for Pulmonary Diseases of Vojvodina, Center for Microbiology, Immunology and Virology, Sremska Kamenica, Serbia; 2Institute forPulmonary Diseases of Vojvodina, Pulmonary Oncology Clinic, Sremska Kamenica, Serbia; 3Faculty of Medicine, University of Novi Sad,Department of Internal Medicine, Novi Sad, Serbia Abstract
Citation: Považan A, Vukelic A, Secen N,
Many Actinomyces species are part of the oral microflora of humans. Actinomyces odontolyticus - Sazdanic-Velikic D, Bursac D. Actinomyces associated infections are exceptionally rare, presenting an endogenous infection originating from Odontolyticus - Associated Bacteremia. Maced JMed Sci. 2012 Oct 15; 5(3):324-327. http:// mucous membranes. Immunodeficiency is often complicated by severe opportunistic bacterial infections dx.doi.org/10.3889/MJMS.1957-5773.2012.0242.
leading to critical condition of the patient. We report a case of an immunosuppressed patient with fever Key words: Actinomyces odontolyticus;
and Actinomyces odontolyticus bacteremia. The patient poorly responded to the applied antimicrobial Correspondence: Dr. Anika Považan. Institute
for Pulmonary Diseases of Vojvodina, Center for
Microbiology, Immunology and Virology, Put
doktora Goldmana 4, Sremska Kamenica 21204,
Serbia. Phone: +381/21/4805348. Fax: +381/21/
527960. E-Mail: anikapovazan@yahoo.com
Received: 03-Apr-2012; Revised: 08-May-2012;Accepted: 09-May-2012; Online first:23-Sep-2012 Copyright: 2012 Považan A. This is an open-
access article distributed under the terms of the
Creative Commons Attribution License, which
permits unrestricted use, distribution, and
reproduction in any medium, provided the original
author and source are credited.
Competing Interests: The author have declared
that no competing interests exist.
Introduction
[1, 3]. Most frequently, Actinomyces israelii enters thebody either through a damaged skin or mucosa, or via Actinomyces odontolyticus is a Gram-positive, inhalation [3]. Actinomyces odontolyticus infections are facultative anaerobic bacterium [1, 2]. It was initially exceptionally rare, presenting an endogenous infection isolated from dental caries in 1958. As other Actinomyces arising most frequently from mucous membranes.
species, this organism colonizes the oral cavity [1]. The Clinically the disease caused by Actinomyces most significant pathogen of the genus Actinomyces is odontolyticus closely resembles to the disease caused Actinomyces israelii, which causes actinomycosis of the by Actinomyces israelii and other representatives of the cervico-facial, thoraco-pulmonary and abdominal region genus. Pulmonary infections [4], bacteremia [2] and Považan et al. Actinomyces Odontolyticus - Associated Bacteremia abscess of various organs [1, 5-7] caused by thispathogen have been reported.
Case presentation
A 62-year male patient was admitted to hospital to enlighten the etiology of the lesion presented on hischest X-ray, localized in the right upper lobe. He reporteda two-month history of back pains, fatigue, exhaustion,appetite and body mass losses (8 kg in two months).
Having noticed a tumorous lesion on the patient’s chestX-ray (Figure 1, 2), chest computed tomography (CT)was performed delineating an infiltration of 27 mm in histopathological finding of the biopsy samples takenfrom the right upper lobe confirmed adenocarcinoma.
Due to the right jaw and right lower leg pains, scintigraphyof the skeleton was performed, detecting pathologicalhyperfixation foci in the projection of the right parietalbone, along all spinal column segments, bilaterally in theribs, shoulder region bones, left humerus diaphysis,sacroiliac joint and proximal femur tips. Due to theadvanced stage of the disease, the chemotherapy Figure 1: PA chest X-ray at the first day of hospitalization. regimen with paclitaxel/carboplatin was recommended,accompanied with bisphosphonate administration.
diameter localized in the right upper lobe, with adjacent However, on the 10th hospital day, the patient’s condition reactive pneumonitis and a few micronodular subpleural deteriorated, developing fever (390C) and blood lesions contralaterally, the 9th rib fracture with infiltrated leukocytosis (35.5 x 109/L), with predominating pleura and subpleural fat tissue, as well as enlarged granulocytes (96.5); procalcitonin levels also increased retrocaval, bronchopulmonary lymph nodes on the right, (2.58 ng/ml), as well as nitrogenous substances in the and those in the subcarinal region (Figure 3).
blood (blood urea 28.2 mmol/l, creatinine 311 ìmol/L).
Gas analysis of the arterial blood at rest revealed asevere partial respiratory insufficiency (SaO2 81.7%,PaO2 6.16 kPa, PaCO2 5.41kPa, pH 7.396). The chestX-ray finding was presented with a bronchopneumonicinfiltration paracardially on the right (Figure 4).
Parenteral antibiotic treatment was initiated, amoxicillin with clavulanic acid. After two days, due toelevated procalcitonin levels (138.24 ng/ml) andworsened medical condition, the therapy was switchedto ceftazidime and ciprofloxacin, according to the NCCN(National Comprehensive Cancer Network) guidelinesfor immunosuppressed patients and hospital-acquiredpneumonia. In the mean time, one set of blood cultures Figure 2: Profile chest X-ray at the first day of hospitalization. Maced J Med Sci. 2012 Oct 15; 5(3):324-327.
result. The identification was performed by anaerobicbacterial identification systems (BBL Crystal IdentificationSystems Gram Anaerobe Kit, Beckton Dickinskon, USA)and Actinomyces odontolyticus was identified.
Antimicrobial susceptibility testing could not be donedue to technical difficulties. Similar cases ofimmunocompromised patients with Actinomycesodontolyticus infection suggested the efficiency oftetracyclines besides penicillin and cephalosporins inthe treatment of such infection [2]. It was decided to Figure 4: PA chest X-ray with pneumonic shadow. include doxycycline in the treatment.
Procalcitonin level and white blood count tended was sent for microbiological examination. Blood cultures to decrease, and the control chest X-ray finding showed where cultivated in the automated BacT/Alert system an initial regression of the pneumonic infiltration in the using both anaerobe and aerobe liquid media. The instrument indicated positive cultures after the 24 hour-incubation. Gram staining of the liquid cultures revealed However, on the 10th day of antimicrobial therapy, short Gram-positive bacilli. The blood cultures were the medical state of the patient worsened, developing subcultured on the blood agar and MacConkey agar in the symptoms of endogenous intoxication, resulting in a aerobic conditions and on Shaedler agar in anaerobic lethal outcome on the same day. The patient’s dental conditions. After 48h of incubation on the blood and status was normal, did not reveal any possible infection Shaedler agar, a noticeable growth was registered.
Colonies were small, smooth and slightly whitish. Gramstain of the culture revealed Gram-positive short rodsresembling diphteroids in pattern. The oxidase and Discussion
catalase tests were performed, producing a negative Actinomyces odontolyticus is a Gram-positive facultative anaerobic, non sporulating, non-motilebacterium [1, 2]. The Gram-smear may be presentedwith shorter bacilli resembling diphteroids in pattern.
Small, whitish, smooth or slightly granular colonies appearon the blood agar, developing dark red pigment in 2-14days [1, 4]. Pigmentation is best recognized when thecultures, following the primary anaerobic isolation, areleft on the room temperature. Actinomyces odontolyticusalso grows well on the CDC and Brucella agar [2].
Actinomyces odontolyticus shows negative catalase and oxidase tests, reduces nitrates to nitrites,and does not grow at pH 5.5 [2]. The final identificationcan be done by identification systems based onbiochemical reactions [8], or by polymerase chain reaction(PCR), analyzing the 16S rRNA gene sequence [7].
Moreover, the 16S rRNA gene sequence is recomendedin final identification of Actinomyces species [7], but it isstill not routinely used in clinical microbiology laboratories.
Actinomyces odontolyticus is susceptible to penicillin,cephalosporins, tetracycline, clindamycin,chloramphenicol and erythromycin [2].
The identification of Actinomyces odontolyticus in blood cultures of the patient with advanced lung Figure 5: Control PA chest X-ray after antibiotics. Považan et al. Actinomyces Odontolyticus - Associated Bacteremia malignancy was made according to microscopic, cultural References
and biochemical characteristics of the subculture grown 1. Chao CT, Liao CH, Lai CC, Hsueh PR. Liver abscess due to on the blood and Shaedler agar and using the BBL Actinomyces odontolyticus in an immunocompetent patient.
The representatives of the genus Actinomyces 2. Cone LA, Leung MM, Hirschberg J. Actinomyces are commensals of the oral cavity microflora which odontolyticus bacteremia. Emerg Infect Dis. 2003;12:1629– participate in development of dental caries, periodontitis and other infections [9]. Actinomyces odontoyticus 3. Mabeza GF, Macfarlane J. Pulmonary actinomycosis. Eur infections are endogenous, originating from mucous membranes [2]. Actinomyces odontoyticus growspredominantly on the surface of the tongue in supra and 4. Takiguchi Y, Terano T, Hirai A. Lung abscess caused by subgingival regions [9], which may account for a normal Actinomyces odontolyticus. Intern Med. 2003; 42:732-5.
5. Simpson AJ, Das SS, Mitchelmore IJ. Polymicrobial brainabscess involving Haemophilus paraphrophilus and Infections caused by Actinomyces odontolyticus Actinomyces odontolyticus. Postgrad Med J. 1996;72:297–8.
are rarely found, more frequently affectingimmunosuppressed patients, predominantly middle-aged 6. Sugano S, Matuda T, Suzuki T, Makino H, Iinuma M, Ishii K, males [2]. The reported patient is a middle-aged male Ohe K, Mogami K. Hepatic actinomycosis: case report and review of the literature in Japan. J Gastroenterol.1997;32:672–6.
7. Woo PC, Fung AM, Lau SK, Hon E, Yuen KY. Diagnosis of Conclusion
pelvic actinomycosis by 16S ribosomal RNA gene sequencingand its clinical significance. Diagn Microbiol Infect Dis.
complicated with severe infections caused byopportunistic bacteria, such as the reported infection 8. Cavallaro JJ, Wiggs LS, Miller JM. Evaluation of the BBLCrystal Anaerobe Identification System. J Clin Microbiol.
induced by Actinomyces odontolyticus in the patient with advanced lung malignancy. Such infections often havea variable outcome despite the applied antimicrobial 9. Drobni M, Hallberg K, Öhman U, Birve A, Persson K, treatment. Better understanding of the pathogenetic Johansson I, et al. Sequence analyses of fimbriae subunit FimA mechanism of such opportunistic agents may help in proteins on Actinomyces naeslundii genospecies 1 and 2 and developing some other treating strategies.
Actinomyces odontolyticus with variant carbohydrate bindingspecificities. BMC Microbiol. 2006; 6: 43.
Maced J Med Sci. 2012 Oct 15; 5(3):324-327.

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