Reisolation of Staphylococcus salivarius from the human oral cavity

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.

Meningitis for Streptococcus salivarius Secondary to Paradoxical Cerebrospinal Fluid Rhinorrhea as a Complication of Retrosigmoid Approach

Rhinorrhea secondary to a retrosigmoid approach is rare, but when it manifests, it is due to a paradoxical cerebrospinal fluid (CSF) leak, as a result of the communication between the mastoid cells, middle ear, and eustachian tube, which finally ends on the release of CSF through the nasopharynx. Abnormal communications increases the risk of infections, not only at the surgical site but also through an ascending path. Magnetic resonance cisternography (MRC) with intrathecal gadolinium injection through a lumbar puncture not only allows an adequate diagnosis but also helps to establish management plans. Here, we present an eighty-three-year-old female patient, with a history of trigeminal neuralgia, who underwent retrosigmoid approach to perform trigeminal microvascular decompression. After intervention, the patient consulted for rhinorrhea, fever, and headache. Lumbar puncture was performed, resulting on the isolation of Streptococcus salivarius in CSF. Nuclear MRC with intrathecal gadolinium injection was performed, identifying a paradoxical CSF leak. Failure in medical management with conservative treatment ends in surgical reexploration, identifying a bone defect in mastoid cells, which was corrected.

Bacterial meningitis from Rothia mucilaginosa in patients with malignancy or undergoing hematopoietic stem cell transplantation

Opportunistic infections contribute to morbidity and mortality of patients undergoing hematopoietic stem cell transplantation and treatment for malignancies. Rothia mucilaginosa, a gram-positive bacterium, is responsible for rare, but often fatal meningitis in severely immunocompromised patients. We describe two cases of meningitis from discrete strains of R. mucilaginosa on our pediatric bone marrow transplant unit, summarize the published cases of R. mucilaginosa meningitis in oncology and stem cell transplant patients, and provide updated recommendations regarding the use of antibiotic therapy in this patient population.

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.

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.

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.

Stomatococcus mucilaginosus catheter-associated infection with septicemia

A case of Stomatococcus mucilaginosus catheter-associated infection is reported. The organism was isolated from the catheter and from two blood cultures.

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.

Microbiology of the early colonization of human enamel and root surfaces in vivo

This study describes the predominant early microflora on human teeth on the basis of microbiologic identification of 1742 fresh isolates. The isolates were obtained from four dental students who carried test pieces of enamel and root surface in the oral cavity for 4, 8, 12, and 24 h. During the experimental periods oral hygiene was discontinued. Under equal conditions root surfaces were more heavily colonized than were enamel surfaces. However, the composition of the microbiota was the same. Within the first 24 h the microflora was dominated by streptococci and Gram-positive pleomorphic rods. S. sanguis contributed only 6-18% of the early colonizers whereas S. mitis and S. oralis varied between 24-42% and 1-27% (mean values), respectively. The relative proportion of S. oralis increased significantly within the observation period while the proportion of S. salivarius and arginine-positive S. mitis showed a declining tendency. Actinomyces species adsorbed to the tooth surfaces within the first 4 h but did not increase their relative proportions until after 8-12 h, possibly due to a long doubling time. In one individual, encapsulated bacteria resembling Stomatococcus mucilaginosus were observed among the early colonizers. The time-dependent shifts in the bacterial populations within 24 h corroborate parallel ultrastructural findings.

Isolation of Stomatococcus mucilaginosus from drug user with endocarditis

Stomatococcus mucilaginosus was isolated from the blood of a patient with endocarditis and a past history of drug abuse and aortic valve replacement. At autopsy, Gram stain of the aortic valve revealed gram-positive cocci. Our isolate was atypical for S. mucilaginosus in that colonies were nonmucoid and nonadherent to agar surfaces. Cellular capsules were demonstrated by light and electron microscopy. Phenotypic characteristics identified by conventional methods as well as profile numbers obtained by using two commercial identification systems for staphylococci, the API Staph-Ident and the dms Staph Trac, are presented. Practical tests that differentiate S. mucilaginosus from the genera Micrococcus and Staphylococcus include growth on nutrient agar containing salt and lysostaphin susceptibility. Additional tests that helped differentiate our isolate from group D streptococci included hydrolysis of L-pyrrolidonyl-beta-naphthylamide and streptococcal serogrouping.

Stomatococcus mucilaginosus endocarditis

A case of non-nosocomial, spontaneously occurring endocarditis caused by growth of Stomatococcus mucilaginosus on a prolapsed mitral valve is reported. Despite the organism's high susceptibility in vitro the patient responded slowly to antibiotic treatment. Colony adherence to agar surface and absent or weak catalase reaction differentiated this gram-positive coccus from coagulase-negative staphylococci and micrococci.

[Stomatococcus mucilaginosus: cultural and biochemical properties of 100 strains isolated from the ORL area]

A study of the growth characteristics and 80 biochemical tests using API System micromethods (API-50CH, API-20E, API-Zym) was carried out on 100 strains of Stomatococcus mucilaginosus isolated from the human oral cavity. Seventy-seven other enzymatic tests from the API system (AP-arylamidases, osidases and esterases) were also performed on 10 of these strains. The results of these tests were compared to those of 24 type strains of Micrococcaceae and Aerococcus viridans. A simple identification scheme for S. mucilaginosus is proposed.

Endocarditis associated with cardiac catheterization due to a Gram-positive coccus designated Micrococcus mucilaginosus incertae sedis

A gram-positive coccus, presently named Micrococcus mucilaginosus incertae sedis, was isolated from 14 blood cultures from a patient with endocarditis. The first positive blood culture was drawn 5 days after the patient underwent cardiac catheterization.

The gram positive cocci

Recent changes in taxonomy of the gram positive cocci are discussed. Views on these changes and practical methods of differentiating the staphylococci, micrococci, streptococci, and aerococci are presented. Simplified schemes, using acceptable clinical laboratory techniques, are presented that either differentiate or categorize the pathologically important gram positive coccal species.

Presumptive identification of group A, B, and D streptococci

A battery of five tests was used for presumptive identification of the pathogenic streptococci. The non-serological methods included determination of hemolysis for all strains, bacitracin susceptibility for group A streptococci, hippurate hydrolysis by group B streptococci, and bile-esculin reaction for group D streptococci. Enterococcal group D streptococci were differentiated from non-enterococcal group D streptococci by 6.5% NaCl tolerance. Two other categories of streptococci resulted: beta-hemolytic streptococci non-groups A, B, or D; and alpha- or nonhemolytic streptococci, not enterococci, not further identified (viridans streptococci). The tests were used as a battery and not as single entities. In this manner more than 99% of the group A, 99% of the group B, 81% of the beta-hemolytic streptococci non-group A, B, or D, 99% of the group D enterococci, 97% of the group D non-enterococci, and 94% of the viridans streptococci were correctly identified.

Peptidoglycan types of bacterial cell walls and their taxonomic implications

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