Infection Due to<i>Actinobacillus actinomycetemcomitans</i>and<i>Haemophilus aphrophilus</i>

Page, Malcolm I.; King, Elizabeth O.

doi:10.1056/nejm196607282750403

Cited by 193 publications

(79 citation statements)

References 12 publications

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“…Previous reports of limited in vitro susceptibility testing of A. actinomycetemcomitans agree that this organism is susceptible to low concentrations of tetracycline (8,11,16,22) and chloramphenicol (11,16) and is frequently resistant to ampicillin (16), erythromycin (8), penicillin (8,11,16), clindamycin (27), lincomycin (20,27), and vancomycin (7).…”

Section: Resultsmentioning

confidence: 98%

“…Cases of A. actinomycetemcomitans endocarditis which were not resolved by penicillin (2,12,15,16) or which followed a tooth extraction with penicillin prophylaxis (13) have also been reported. A. actinomycetemcomitans endocarditis has responded favorably to combinations of antibiotics, including ampicillin, chloramphenicol, erythromycin, and streptomycin, but fatal cases in which such therapeutic regimes were used have also been reported (2,16,19,27), raising doubt concerning the universal efficacy of these combinations.…”

Section: Resultsmentioning

confidence: 99%

“…actinomycetemcomitans strains vary in in vitro susceptibilities to penicillin, ampicillin, and other commonly used antibiotics (8,11,16). Evidence that this diversity affects therapy is suggested by the fact that a given antibiotic has been effective in certain cases of A. actinomycetemcomitans infection, but has failed in others (2,16,27 All strains utilized carbohydrates fermentatively, were capnophilic, decomposed H202, reduced nitrate, and were benzidine positive. None of the strains required X (hemin) and V (nicotinamide adenine dinucleotide) growth factors or hydrolyzed esculin, gelatin, starch, or urea, and none produced acetylmethylcarbinol, decarboxylases, H2S, oxidase, or indole.…”

mentioning

confidence: 99%

“…no. 244,1980), endocarditis (6,16,19,27), vertebral osteomyelitis (14), brain abscess (12), thyroid gland abscess (4), and urinary tract infection (26). A. actinomycetemcomitans is often a constituent of mixed bacterial infections, but it can also be the sole infecting agent (25,28).…”

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confidence: 99%

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In vitro antimicrobial susceptibility of Actinobacillus actinomycetemcomitans

Slots¹,

Evans²,

Lobbins³

et al. 1980

Antimicrob Agents Chemother

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The agar dilution technique was used for determination of the antibiotic susceptibilities of 57 oral isolates and 2 nonoral isolates of Actinobacillus actinomycetemcomitans. Tetracycline, minocycline, and chloramphenicol inhibited more than 96% of the strains tested at a concentration of c2 Atg/ml; 89% of the strains were inhibited by 2 ug of carbenicillin per ml. The other antimicrobial agents tested were less active. Approximately 10% of the A. actinomycetemcomitans strains were resistant to ampicillin, erythromycin, and penicillin G at concentrations of 32 to 64 ug/ml. These data suggest that tetracycline and minocycline may be valuable drugs in the treatment ofA. actinomycetemcomitans infections.Actinobacillus actinomycetemcomitans is a facultative, gram-negative bacterium of clinical importance. It has been isolated from actinomycosis (3, 5, 9, 10), periodontitis (24; J. Slots, H. S. Reynolds, P. M. Lobbins, and R. J. Genco, J. Dent. Res., 59: 328, Special Issue A, Am. Assoc. Dent. Res., abstr. no. 244, 1980), endocarditis (6, 16, 19, 27), vertebral osteomyelitis (14), brain abscess (12), thyroid gland abscess (4), and urinary tract infection (26). A. actinomycetemcomitans is often a constituent of mixed bacterial infections, but it can also be the sole infecting agent (25, 28). A. actinomycetemcomitans can be a part of the indigenous oral microflora (9), and the portal of entry of this organism is often assumed to be-the oral cavity and the upper respiratory tract.A. actinomycetemcomitans strains vary in in vitro susceptibilities to penicillin, ampicillin, and other commonly used antibiotics (8,11,16). Evidence that this diversity affects therapy is suggested by the fact that a given antibiotic has been effective in certain cases of A. actinomycetemcomitans infection, but has failed in others (2,16,27 All strains utilized carbohydrates fermentatively, were capnophilic, decomposed H202, reduced nitrate, and were benzidine positive. None of the strains required X (hemin) and V (nicotinamide adenine dinucleotide) growth factors or hydrolyzed esculin, gelatin, starch, or urea, and none produced acetylmethylcarbinol, decarboxylases, H2S, oxidase, or indole. All strains produced acid from glucose, fructose, and mannose but not from adonitol,

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Section: Resultsmentioning

confidence: 98%

Section: Resultsmentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

See 2 more Smart Citations

In vitro antimicrobial susceptibility of Actinobacillus actinomycetemcomitans

Slots¹,

Evans²,

Lobbins³

et al. 1980

Antimicrob Agents Chemother

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“…Aggregatibacter (Actinobacillus) actinomycetemcomitans is a capnophilic, Gram-negative bacterium that is associated with localized aggressive periodontitis (Haraszthy et al, 2000;Slots et al, 1980;Zambon, 1985;Zambon et al, 1983Zambon et al, , 1996, endocarditis (Block et al, 1973;Page & King, 1966) and subcutaneous abscesses (Page & King, 1966). A. actinomycetemcomitans expresses several virulence factors that may contribute to pathogenesis, including two toxins that may play a role in suppressing the host response to infection by targeting various components of the immune system.…”

Section: Introductionmentioning

confidence: 99%

Induction of Aggregatibacter actinomycetemcomitans leukotoxin expression by IS1301 and orfA

2008

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Most Aggregatibacter actinomycetemcomitans strains express relatively low levels of leukotoxin, encoded by the orfA-ltxCABD operon. However, several strains isolated from patients with localized aggressive periodontitis are hyperleukotoxic and transcribe the ltx operon at high levels. These strains possess a copy of IS1301 in the ltx promoter and previous studies have suggested that the presence of the insertion sequence increases ltx transcription by uncoupling a cis-acting negative regulator of ltx expression from the basal elements of the ltx promoter. However, we now report that replacing IS1301 with an equal length of random sequence has little effect on transcriptional activity of the ltx promoter, suggesting that the physical displacement of the negative regulatory element does not contribute to the hyperleukotoxic phenotype of IS1301-containing strains. Instead, we show that a "10-like element upstream of the transposase ORF of IS1301 is required for increased transcriptional activity of the ltx promoter. Site-specific mutation of the "10 sequence, or reversing the orientation of IS1301 relative to the basal ltx promoter elements, reduced transcriptional activity to levels exhibited by the native ltx promoter. However, no increase in transcription was observed when IS1301 was recombinantly inserted into a ltx promoter that contained a truncated copy of orfA, suggesting that an intact orfA may also be required for IS1301-mediated induction of ltxCABD. Therefore, to determine if orfA functions as a regulator of ltx expression, three independent ltx-promoter-lacZ-reporter constructs containing frameshift mutations in orfA were analysed. Each exhibited significantly lower expression of b-galactosidase than the control reporter with intact orfA. In addition, OrfA protein was shown, by mobility shift electrophoresis, to interact with the ltx promoter at or downstream of the "35 sequence. These results suggest that a potential transposase promoter and the OrfA polypeptide may modulate leukotoxin expression in hyperleukotoxic A. actinomycetemcomitans strains containing IS1301.

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