Stomatococcus mucilaginosus endocarditis in an intravenous drug abuser

Native valve endocarditis complicated by abscess formation caused by Rothia mucilaginosa

Rothia mucilaginosa is increasingly recognized as an emerging pathogen associated with endocarditis. It has mostly been reported a causative agent for prosthetic valve endocarditis. The previously reported cases of native valve endocarditis caused by this organism only required medical treatment with no surgical intervention. We report a case of R. mucilaginosa native valve endocarditis complicated by abscess formation requiring surgical intervention and review the literature of native valve endocarditis caused by this organism.

Characterization of the Rothia spp. and their role in human clinical infections

The genus Rothia are emerging as opportunistic pathogens associated with various infections in immunocompromised and immunocompetent individuals. This review describes the taxonomy, cell wall structure, pathogenesis, phenotypic and molecular characteristics, clinical diseases, treatment and, as well as, the related genera that may be misidentified by Rothia species.

Rothia spp. infective endocarditis: A systematic literature review

OBJECTIVE

To describe the epidemiological, clinical, microbiological, and therapeutic features and outcomes of Rothia infective endocarditis (RIE) and extracardiac infections (ECRI).

METHODS

We performed a systematic literature review of published cases of RIE and ECRI.

RESULTS

After inclusion of a personal case report, 51 cases of RIE and 215 cases of ECRI were reported. Compared with ECRI patients, RIE patients were significantly more often males (80% versus 59%), intravenous drug users (IVDU) (20% versus 3%), immunocompetent (76% versus 31%), and infected with R. dentocariosa (55% versus 13%) but lacked significant differences with regard to median age (45 years [6-79]), rate of orodental abnormalities (33%), and six-month mortality (14%). Following microbiological documentation, RIE was most often treated with a beta-lactam antibiotic alone (39%) for a median duration of six weeks and required surgery in 39% of cases.

CONCLUSION

RIE is rare and likely secondary to a dental portal of entry or cutaneous inoculation in IVDU. Its prognosis seems to be favorable.

Stomatococcus mucilaginosus meningitis in a healthy 2-month-old child

Stomatococcus mucilaginosus is a Gram-positive, catalase-variable organism considered part of the normal human oral and upper respiratory tract flora. Although traditionally believed to be an organism of low virulence, Stomatococcus mucilaginosus has been reported to be an opportunistic pathogen in immunocompromised patients. We describe what we believe is the first reported case of Stomatococcus mucilaginosus meningitis in a healthy child. The isolate was multidrug-resistant, susceptible only to vancomycin. The patient was treated successfully with vancomycin after initial trials with amikacin and cefotaxime.

Structural and serological characterization of the major glycolipid from Rothia mucilaginosa

Structural studies on the major glycolipid isolated from Rothia mucilaginosa were carried out utilising specific chemical degradation, NMR spectroscopy and matrix-assisted laser-desorption/ionization time of flight mass spectrometry (MALDI TOF-MS). The glycolipid was found to be a dimannosylacylmonoglyceride in which the carbohydrate part was the glycerol-linked dimannoside alpha-D-Manp-(1-->3)-alpha-D-Manp-(1-->3)-sn-Gro (Man A-Man B-Gro), of which Man B was esterified at O-6 by a fatty acid residue. A second fatty acid substituted the secondary methylene position of the glycerol residue, in contrast to the glycolipid previously found in R. dentocariosa and Saccharopolyspora strains, in which the second fatty acid esterified the primary methylene position of glycerol. Results of the ELISA experiment with rabbit specific antibacterial sera indicate that these two major glycolipids are antigenic, and the patterns of serological reactivity are similar but not identical.

Endocarditis due to rare and fastidious bacteria

The etiologic diagnosis of infective endocarditis is easily made in the presence of continuous bacteremia with gram-positive cocci. However, the blood culture may contain a bacterium rarely associated with endocarditis, such as Lactobacillus spp., Klebsiella spp., or nontoxigenic Corynebacterium, Salmonella, Gemella, Campylobacter, Aeromonas, Yersinia, Nocardia, Pasteurella, Listeria, or Erysipelothrix spp., that requires further investigation to establish the relationship with endocarditis, or the blood culture may be uninformative despite a supportive clinical evaluation. In the latter case, the etiologic agents are either fastidious extracellular or intracellular bacteria. Fastidious extracellular bacteria such as Abiotrophia, HACEK group bacteria, Clostridium, Brucella, Legionella, Mycobacterium, and Bartonella spp. need supplemented media, prolonged incubation time, and special culture conditions. Intracellular bacteria such as Coxiella burnetii cannot be isolated routinely. The two most prevalent etiologic agents of culture-negative endocarditis are C. burnetti and Bartonella spp. Their diagnosis is usually carried out serologically. A systemic pathologic examination of excised heart valves including periodic acid-Schiff (PAS) staining and molecular methods has allowed the identification of Whipple's bacillus endocarditis. Pathologic examination of the valve using special staining, such as Warthin-Starry, Gimenez, and PAS, and broad-spectrum PCR should be performed systematically when no etiologic diagnosis is evident through routine laboratory evaluation.

Study of Stomatococcus mucilaginosus isolated in a hospital ward using phenotypic characterization

Thirty-one isolates of Stomatococcus mucilaginosus were cultured from the blood (n = 6), throat (n = 23) and sputum (n = 2) of 18 hospitalized patients, 13 of whom were neutropaneic and five of whom were non-neutropaneic. Antibiotic susceptibility testing, performed by means of a broth microdilution method, showed that the minimal inhibitory concentrations (MICs) of ciprofloxacin were > or = 4 mg/l for the isolates collected from neutropaenic patients. All these patients received ciprofloxacin as part of their prophylactic regimen. In contrast, the MICs for four of five isolates collected from non-neutropaenic patients, none of whom were receiving ciprofloxacin, were < or = 2 mg/l. In addition, 14 of the 31 isolates were cultured from seven neutropaenic patients, admitted to the same ward over a 12-week period. To evaluate possible cross-acquisition of strains between patients, cluster analysis of all 31 isolates was performed using phenotypic characteristics, MIC values and acid production from carbohydrates (API 50 CH). Overall, 22 isolate clusters were distinguished. In five of 18 patients, two or more isolates were cultured which belonged to different clusters. In only one patient, identical isolates were cultured from blood and from the throat. All six isolates of cluster 7 were cultured within the aforementioned 12-week period from three neutropaenic patients. These data support the possibility of cross-acquisition of strains between patients although its frequency seems to be low.

Bacteremia caused by Stomatococcus mucilaginosus: report of seven cases and review of the literature

During a three-year period eight patients with blood cultures positive for Stomatococcus mucilaginosus were identified at two university hospitals. One patient without any signs of infection had a central venous catheter that was colonized with this organism, two patients had transient bacteremia without definite relationship to underlying disease, whereas the remaining five patients suffered from clinically significant infections. Of these last five patients, one had undergone prior head and neck surgery and four had hematologic malignancy with mild to severe neutropenia; two of the latter patients developed the infection subsequent to dental surgery. Besides neutropenia and mucosal damage in the oropharynx, quinolone antibacterial prophylaxis may have been an additional risk factor for the development of S. mucilaginosus bacteremia in these patients. A thorough review of the literature revealed that in addition to our findings, endocarditis and foreign body infections are further typical clinical manifestations. Although the overall antibiotic susceptibility pattern of S. mucilaginosus resembles that of streptococci, it is suggested that penicillin G may not be the drug of choice for initial therapy of particularly severe infections. S. mucilaginosus can be easily differentiated from other gram-positive bacteria when certain key criteria (e.g. adherence to agar surfaces, poor growth on Mueller-Hinton agar, presence of a capsule) as well as an array of biochemical tests, including commercially available identification systems, are applied. Our own and published data emphasize that both microbiologists and clinicians should be increasingly aware of this opportunistic pathogen.

Susceptibility to aminoglycosides of 63 strains of Stomatococcus mucilaginosus isolated from sputum

The MIC of 63 Stomatococcus mucilaginosus for 7 aminoglycosides was determined. Most of the strains were resistant to these antibiotics except to streptomycin. A natural resistance due to impermeability may be involved. One single strain was resistant to all these aminoglycosides where the concentration level of streptomycin was greater than 1000 mg/l. A chromosomal mutation is probably involved.

Endocarditis in the emergency department

Clinical presentations and pathogeneses of endocarditis and aspects of its diagnosis and management relevant to emergency department practice are reviewed. Guidelines for admission, laboratory evaluation, and decisions regarding the initiation of therapy in the ED are offered. Also discussed are the role of the emergency physician in the prevention of iatrogenic infection and current recommendations regarding administration of prophylactic antibiotics for ED procedures.

Stomatococcus mucilaginosus bacteremias. Typical case presentations, simplified diagnostic criteria, and a literature review

Even though Stomatococcus mucilaginosus is considered indigenous oral-pharyngeal flora, cited literature and case reports indicate that it can be the cause of infectious conditions. Tested strains were isolated from blood, the oral region, and wound sources. The organism was routinely misidentified or not identified by conventional or commercial systems (Vitek, STAPH-Trac). Four antimicrobial diagnostic disks for example, bacitracin (0.04 units; Taxo A), furazolidone (100 micrograms), novobiocin (5 micrograms), and polymyxin B (300 units), were evaluated as possible addition to previously applied biochemical characteristics that differentiate between S. mucilaginosus, Micrococcus sp., and coagulase-negative staphylococci. Consistent antimicrobial susceptibility patterns among our isolates to the diagnostic disks produced applicable characteristics for discriminating S. mucilaginosus from similar microorganisms. However, therapeutic choices of antimicrobial agents should be guided by individual organism susceptibility test results because of variable, often resistant patterns to beta-lactams, aminoglycosides, macrolides, new fluoroquinolones, and sulfonamides.

Endocarditis caused by relatively penicillin-resistant Stomatococcus mucilaginosus

We report a case of Stomatococcus mucilaginosus endocarditis in which the isolate was relatively resistant to penicillins and cephalothin. The patient was treated successfully with vancomycin and valve replacement.

Stomatococcus mucilaginosus as an agent of CAPD peritonitis

We report a case of bacterial CAPD peritonitis in a 57 year old immunosuppressed woman with renal insufficiency caused by a rare species of the Micrococcaceae, Stomatococcus mucilaginosus. This uncommon case shows that the presence of gram-positive cocci in pairs, tetrads and clusters forming whitish-gummy colonies should remind us of the possibility of Stomatococcus mucilaginosus.