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Objective. The aim of this study is to obtain helpful information for an effective antimicrobial therapy against orofacial odontogenic infections; such information would be obtained from recent bacteriologic features and antimicrobial susceptibility data.Study design. The bacteriology and antimicrobial susceptibility of major pathogens in 163 patients with orofacial odontogenic infections to seven antibiotics was examined.Results. Mixed infection of strict anaerobes with facultative anaerobes (especially viridans streptococci) was observed most often in dentoalveolar infections, periodontitis, and pericoronitis. Penicillin (penicillin G) was effective against almost all pathogens, although it did not work well against ß-lactamase-positive Prevotella. Cefmetazole was effective against all test pathogens. Erythromycin was ineffective against viridans streptococci and most Fusobacterium. Clindamycin exerted a strong antimicrobial activity on anaerobes. Minocycline was effective against almost all of the test pathogens. The antimicrobial activity of levofloxacin against viridans streptococci was not strong.Conclusions. An antibiotic that possesses antimicrobial activity against both viridans streptococci and oral anaerobes should be suitable for treatment of dentoalveolar infection, periodontitis, and pericoronitis. Penicillin remains effective as an antimicrobial against most major pathogens in orofacial odontogenic infections.Cefmetazole, clindamycin, and minocycline may be effective against most pathogens, including penicillin-unsusceptible bacteria. 2Although numerous patients suffer from orofacial odontogenic infections, many of these infections can be managed without the use of antibiotics, e.g., by tooth extraction, endodontic therapy, and surgical treatment, including drainage. However, when an acute bacterial infection has progressed or antimicrobial therapy might be of benefit to patients, antibiotics are prescribed. [1][2][3][4][5][6] When antibiotics are prescribed for the treatment of orofacial odontogenic infections, clinicians should choose them on a case-specific basis, and the choice should be based on several factors, e.g., laboratory data, patient's health, age, allergies, drug absorption and distribution ability, and plasma levels. [1][2][3][4][5][6] Penetration and metabolism of the drug, type or location of the infection, previous use of antibiotics, and cost are other factors to be considered. [1][2][3][4][5][6] The laboratory data regarding bacteriology and antimicrobial susceptibility is crucial information for the clinician considering the administration of the antimicrobial therapy. 3,6,[7][8][9] However, it may take several days or even longer to obtain such data. Hence, antibiotics may be chosen empirically. ß-Lactam antibiotics, especially penicillins, have traditionally been recommended as a first-line antibiotic because they work well against most causative bacteria and because penicillins have a low incidence of side effects. [1][2][3][4][5][6] Furthermore, such medicines are relativ...

Minimal requirements of amino acids and vitamins were determined in chemically defined medium for five strains of Clostridium difficile. Cysteine, isoleucine, leucine, proline, tryptophan and valine were essential amino acids for growth of C. difficile. Arginine, glycine, histidine, methionine and threonine enhanced growth. Biotin, pantothenate and pyridoxine were essential vitamins. A defined medium containing the minimal requirements of amino acids and vitamins produced a rapid and heavy growth which was comparable to that in modified brain heart infusion, a complex medium. Adenine was able to substitute for glycine and threonine, suggesting that the two amino acids may be utilized as precursors of purine nucleotides. The defined medium developed here will assist physiological and biochemical studies on C. difficile.

Septic shock is a severe systemic response to bacterial infection. Receptor for advanced glycation end products (RAGE) plays a role in immune reactions to recognize specific molecular patterns as pathogen recognition receptors. However, the interaction between LPS, the bioactive component of bacterial cell walls, and RAGE is unclear. In this study, we found direct LPS binding to RAGE by a surface plasmon resonance assay, a plate competition assay, and flow cytometry. LPS increased TNF-α secretion from peritoneal macrophages and an NF-κB promoter-driven luciferase activity through RAGE. Blood neutrophils and monocytes expressed RAGE, and TLR2 was counterregulated in RAGE−/− mice. After LPS injection, RAGE+/+ mice showed a higher mortality, higher serum levels of IL-6, TNF-α, high mobility group box 1, and endothelin-1, and severe lung and liver pathologies compared with RAGE−/− mice without significant differences in plasma LPS level. Administration of soluble RAGE significantly reduced the LPS-induced cytokine release and tissue damage and improved the LPS-induced lethality even in RAGE−/− as well as RAGE+/+ mice. The results thus suggest that RAGE can associate with LPS and that RAGE system can regulate inflammatory responses. Soluble RAGE would be a therapeutic tool for LPS-induced septic shock.

The 1,815,783-bp genome of a serotype M49 strain of Streptococcus pyogenes (group A streptococcus [GAS]), strain NZ131, has been determined. This GAS strain (FCT type 3; emm pattern E), originally isolated from a case of acute post-streptococcal glomerulonephritis, is unusually competent for electrotransformation and has been used extensively as a model organism for both basic genetic and pathogenesis investigations. As with the previously sequenced S. pyogenes genomes, three unique prophages are a major source of genetic diversity. Two clustered regularly interspaced short palindromic repeat (CRISPR) regions were present in the genome, providing genetic information on previous prophage encounters. A unique cluster of genes was found in the pathogenicity island-like emm region that included a novel Nudix hydrolase, and, further, this cluster appears to be specific for serotype M49 and M82 strains. Nudix hydrolases eliminate potentially hazardous materials or prevent the unbalanced accumulation of normal metabolites; in bacteria, these enzymes may play a role in host cell invasion. Since M49 S. pyogenes strains have been known to be associated with skin infections, the Nudix hydrolase and its associated genes may have a role in facilitating survival in an environment that is more variable and unpredictable than the uniform warmth and moisture of the throat. The genome of NZ131 continues to shed light upon the evolutionary history of this human pathogen. Apparent horizontal transfer of genetic material has led to the existence of highly variable virulence-associated regions that are marked by multiple rearrangements and genetic diversification while other regions, even those associated with virulence, vary little between genomes. The genome regions that encode surface gene products that will interact with host targets or aid in immune avoidance are the ones that display the most sequence diversity. Thus, while natural selection favors stability in much of the genome, it favors diversity in these regions. Group A streptococcus ([GAS] Streptococcus pyogenes)causes a wide range of human diseases ranging from uncomplicated pharyngitis to life-threatening invasive disease. Acute post-streptococcal glomerulonephritis (APSGN) is one of the nonsuppurative sequelae that can occur following a GAS infection; the other common postinfection sequelae are rheumatic heart disease. Worldwide, it is estimated that approximately 470,000 cases of APSGN occur annually (23). Children and young adults are affected most commonly, with males having twice the incidence as females (74). By the 1940s, evidence was found that streptococcal skin infections were associated with APSGN, and these infections usually did not cause rheumatic fever, leading to the hypothesis that certain GAS strains were "rheumatogenic" while others were "nephritogenic" (41, 72). Further, divergent seasonal patterns of peak incidence exist separating nephritogenic and rheumatogenic GAS, with APSGN cases peaking in the late summer simultaneously with skin infections w...

Healthy adults who had not been exposed to antimicrobial agents for the preceding 4 weeks were examined for intestinal carriage of Clostridium dif®cile. The 1234 individuals examined were composed of seven groups: three classes of university students, hospital workers at two hospitals, employees of a company and self-defence force personnel at a local station. Overall, 94 (7.6%) individuals were positive for C. dif®cile by faecal culture but carriage rates among the study groups ranged from 4.2% to 15.3%. Typing by PCR ribotyping and pulsed-®eld gel electrophoresis demonstrated clusters of carriers colonised by a single type in each of three groups, indicating that cross-transmission of C. dif®cile can occur in community settings. Follow-up culture was performed on 38 C. dif®cile-positive individuals and C. dif®cile was isolated again from 12 (32%) of them 5± 7 months after the initial culture; six (50%) of these 12 individuals had a new strain on repeat culture. Two or more family members were C. dif®cile-positive in ®ve of 22 families examined. C. dif®cile with an identical type was isolated from persons within a family in only one family. These results suggest that intestinal carriage by healthy adults may play a role as a reservoir for community-acquired C. dif®cile-associated diarrhoea, but that cross-transmission of C. dif®cile does not occur frequently among family members at home.

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Amoxicillin would still be advocated therefore as being a suitable first-line agent, while reduced susceptibility of Prevotella strains remains a matter of concern with penicillins. Amoxicillin/clavulanate, clindamycin, and metronidazole are useful alternatives in combating the anaerobic bacteria involved in dentoalveolar infection.