Acute metastatic infection of a revision total hip arthroplasty with oral bacteria after noninvasive dental treatment.

The risk of hematogenous bacterial infection of a total joint prosthesis is currently considered to be greatest in the 2 years after arthroplasty or when the patient is chronically ill or immunocompromised, for dental treatments that are considered invasive, with a higher incidence of bacteremia. We report the case of a healthy man who had undergone revision hip arthroplasty 11 months previously and who developed acute signs of infection of the hip prosthesis with an oral organism 30 hours after supragingival dental cleaning, performed with the specific intention to be noninvasive, without antibiotic prophylaxis.

Bacteria for the nineties.

Staphylococcus aureus and Enterococci have gained prominence as the causes of wound infections during this decade. Methicillin-resistant Staphylococcus aureus (MRSA) became commonplace in the United States during the 1980s. In Canada, infections with MRSA have been increasing in frequency since 1995. MRSA develops resistance by producing an altered penicillin-binding protein, PBP 2a, coded for by the mecA gene. Vancomycin is the usual drug of choice. Recently, strains with intermediate resistance to vancomycin (VISA) have been isolated from patients in Japan and the United States. Interim guidelines for their control have been developed by the Centers for Disease Control. Enterococci have developed a resistance to a variety of antimicrobials during the past three decades, including beta-lactams and aminoglycosides. Recently, strains resistant to vancomycin (VRE) have been found in the United States and Canada. They are particularly difficult to treat, although some success has been achieved with experimental drugs. These microorganisms have the ability to escape control by antimicrobials almost as soon as they are developed. Thus, we must practice good infection control and reserve antimicrobials only for clear cases of infection if we are to prevent or delay the emergence of resistance.

Pasteurella multocida meningitis in an adult: case report and review.

Pasteurella multocida is a rare cause of adult meningitis. Close animal contact prior to onset of illness is frequent and represents the usual mode of introduction of the organism. In reports of a total of 21 cases of P. multocida meningitis in adults (this case report and 20 described previously in the English-language literature), 18 researchers commented on the occurrence of animal contact: two cases (11%) involved cat bite, 13 (72%) involved animal contact without bite, and three (17%) occurred in the absence of recognized animal contact. Clinical presentation was typical of bacterial meningitides. Overall mortality rate was 30%. The best predictors of poor outcome were initial hemodynamic instability and age greater than 60 years. Documented bacteremia (40% of cases) was not predictive of higher mortality. Effective therapy is based on early recognition of the possibility of P. multocida meningitis and prompt initiation of treatment with penicillin, ampicillin, or a third-generation cephalosporin.

The synergistic effect of cefotaxime and desacetylcefotaxime against clinical isolates of anaerobic bacteria.

The synergistic interaction of cefotaxime and desacetylcefotaxime against 187 clinically significant anaerobic organisms was investigated. Fusobacterium nucleatum, Actinomyces odontolyticus, propionibacteria, lactobacilli, peptostreptococci, Streptococcus intermedius and Veillonella were sensitive to cefotaxime. Both Eubacterium lentum and Streptococcus morbillorum were resistant. The susceptibility of the clostridia varied from 0.125 to greater than 256 mg/L; only 20% of species demonstrated synergy between cefotaxime and desacetylcefotaxime. The minimum inhibitory concentration (MIC) of cefotaxime against members of the genus Bacteroides ranged from 0.0625 to greater than 256 mg/L. The MIC50 of cefotaxime to Bacteroides fragilis and B. vulgatus was lowered from 6 and 4 mg/L, respectively, to 2 and 1 mg/L, respectively, when 4 mg/L desacetylcefotaxime was added to the medium. Full or partial synergy was demonstrated by 50.7% of the Bacteroides species tested. While cefotaxime and desacetylcefotaxime act synergistically against many members of the genus Bacteroides, the MIC of at least 10% of strains is not affected by this combination.

Restriction endonuclease analysis of nosocomial isolates of Clostridium difficile.

A total of 110 clinical isolates of Clostridium difficile were analyzed by agarose gel electrophoresis by using both bacterial restriction endonuclease analysis (REA) and plasmid profiles. A total of 72 isolates were divided into 12 groups according to their REA patterns. Some 38 isolates exhibited unique patterns. Pattern A occurred in 20% of isolates. Isolates with patterns B, E, and G were cytotoxin negative. The remaining groups were cytotoxin positive. Multiple isolates obtained from two stool specimens were studied to examine the variation in REA profiles found in single specimens. In these specimens no variation in REA profiles was found. The stability of C. difficile was studied by examining sequential in vitro subcultures of a single isolate and strains isolated over a 4-month period from two long-term carriers. REA patterns were stable over time, both in vitro and in vivo. Because plasmid DNA was observed in 53% of isolates, plasmid profiles alone could not be used to study the spread of C. difficile; however, they were necessary for the interpretation of REA patterns in some instances.

Ticarcillin/clavulanic acid (Timentin) compared to metronidazole/netilmicin in preventing postoperative infection after elective colorectal surgery.

A randomized controlled trial was performed to compare the effectiveness of ticarcillin/clavulanic acid to metronidazole/netilmicin in preventing postoperative infections after elective colorectal surgery. Ninety-two patients were randomly allocated to receive three doses of ticarcillin, 3 g, with clavulanic acid, 100 mg every 8 hours, or three doses of metronidazole, 500 mg, and netilmicin, 80 mg intravenously every 8 hours. All patients received a mechanical bowel preparation with 3 L of Go-lytely solution. There were no operative deaths. Eight patients had wound infections--three in the ticarcillin/clavulanic acid group and five in the metronidazole/netilmicin group. One patient in the ticarcillin/clavulanic acid group had an intra-abdominal abscess. There were two anastomotic leaks, one in each group. Ticarcillin/clavulanic acid and metronidazole/netilmicin appear to be equally effective in preventing postoperative infections after elective colorectal surgery.

Campylobacter fetus subsp. fetus in homosexual males.

Campylobacter fetus subsp. fetus was isolated from the stools of two homosexual males. One was asymptomatic at the time of isolation. The other presented with diarrhea. Both isolates were initially grown at 42 degrees C. This organism should be included among the list of organisms that are found in homosexual males.

Microassay foramphotericin B.

Depending on the hematocrit, duplicate or triplicate determinations of serum amphotericin B concentration may be made on as little as 100 mul of capillary blood obtained by finger prick. In an accurate plate diffusion bioassay, using Paecilomyces varioti as the indicator organism, levels of the drug in the therapeutic range can be determined fast enough for clinicians to modify their next dose.