Antimicrobial therapy for diabetic foot infections. A practical approach.

Infection of the diabetic foot is a common problem in clinical practice and is associated with significant morbidity. Optimal management requires a multidisciplinary approach. Aggressive surgical debridement and wound management, carefully chosen antimicrobial therapy, and modification of host factors (i.e., hyperglycemia, concomitant arterial insufficiency) are all equally important for a successful outcome. Empirical antibiotic selection should be followed by culture-guided definitive therapy.

Emergence of antimicrobial resistance in community-acquired pulmonary pathogens.

Antibiotic resistance to the common respiratory tract pathogens is increasing worldwide. Penicillin-resistant pneumococci are of particular concern. Most strains of penicillin-resistant Streptococcus pneumoniae have intermediate resistance to penicillin, and highly resistant strains are rare at present. Careful selection of antibiotics with low resistance potential and excellent activity against highly penicillin-resistant pneumococci (ie, cefotaxime, ceftriaxone, cefepime, cefprozil, doxycycline, levofloxacin, sparfloxacin, and meropenem) is the best current strategy to delay or increase the emergence of highly penicillin-resistant strains of S pneumoniae.

Fever in the intensive care unit.

In the ICU, fever can be expected to accompany an extensive number of conditions of both infectious and noninfectious etiologies. It is crucial to identify the precise cause of fever, because certain conditions in either category may be life-threatening, whereas others require no treatment at all. It is important to rule out the most common infections that may be present based on historical and physical signs and symptoms and epidemiologic factors. The extent of evaluation should be based on the likelihood of the disease process being present and is highly variable for each individual patient. Therefore, "routine fever work-up" should not be advocated. If overt infection is not found upon initial evaluation, antibiotics should be withheld if possible. Alternatively, in the unstable patient, empiric therapy may be started, and if no infection is evident, it may be stopped within a reasonable time frame. In no case should prolonged antibiotics be given for presumed but unproven infection. Thorough knowledge of the more common infectious and noninfectious conditions, as well as the awareness of less frequent ones and their predisposing risk factors, is essential for adequate evaluation of the febrile ICU patient. Likewise, familiarity with the techniques used for diagnosis of these infections and their appropriate interpretation and limitations in specific instances is immensely helpful to the clinician providing appropriate care for the critically ill patient.

Bacteremia associated with percutaneous transluminal coronary angioplasty.

Bacteremia after diagnostic cardiac catheterization is uncommon, but bacteremia after percutaneous transluminal coronary angioplasty (PTCA) has not been studied prospectively. Unlike diagnostic cardiac catheterization, PTCA involves the use of an indwelling arterial sheath after completion of the procedure, which is connected to a pressurized heparin solution, both of which increase the risk of local infection and/or bacteremia. During a 16-week period, we prospectively evaluated patients undergoing 164 PTCA procedures in order to determine the frequency of bacteremia and the significance of fever in this patient population. Blood cultures were obtained from the femoral catheter at the conclusion of the procedure and again 30 min later from the indwelling arterial sheath. Temperature was recorded every 30 min for 2 h following PTCA, then every 4 h over the subsequent 36-hr period. Bacterial isolates were recovered from 23/286 blood cultures (8.0%), with Staphylococcus epidermidis the most common organism present (74%). Only one isolate of Staphylococcus aureus was considered to represent true bacteremia and corresponded with the only documented infectious complication. Fever, defined as > or = 101 degrees F developed in four (2.4%) patients but was procedure related in only one case. The use of the ipsilateral femoral artery for repeat procedures was not associated with either positive blood cultures or difference in maximum temperature elevation. We conclude the overall risk of bacteremia after PTCA is low; therefore, antimicrobial prophylaxis is not warranted.

Teicoplanin.

Teicoplanin, a new glycopeptide antibiotic similar to vancomycin, has proved effective in the treatment of various gram-positive infections in both the normal and the immunocompromised host. In vitro activity against most gram-positive organisms is equal to or greater than that of vancomycin. In both open and comparative clinical trials, teicoplanin has been well tolerated, rarely prompting discontinuation of treatment. Nephrotoxicity caused by teicoplanin is uncommon, even when used concomitantly with aminoglycosides or cyclosporin A. Favorable pharmacokinetics allow for intramuscular administration as well as intravenous bolus dosing, and, after appropriate loading doses, maintenance therapy may be given on a once-daily basis. The combination of all of these factors makes teicoplanin an effective, safe alternative to vancomycin in the treatment of gram-positive infections.

Escherichia coli sternal osteomyelitis after open heart surgery.

Deep-seated infections after open-heart surgical procedures, fortunately, are uncommon with appropriate prophylactic antibiotics and careful aseptic technique. When serious infection, such as sternal osteomyelitis, does occur, the effects are devastating and usually require one or more debridement procedures. The organisms usually implanted in postoperative sternal infections are primarily Staphylococcus aureus and aquatically based gram-negative bacilli. Common gram-negative pathogens such as Escherichia coli are very unusual in this setting. We report a case of E. coli sternal osteomyelitis in a diabetic patient after coronary artery bypass grafting.

A broadly neutralizing monoclonal antibody that recognizes the V3 region of human immunodeficiency virus type 1 glycoprotein gp120.

Previous studies have demonstrated that the principal neutralizing determinant of human immunodeficiency virus type 1 (HIV-1) is located in the V3 loop of glycoprotein gp120. Antibodies prepared against this region using gp120 or peptides as immunogens have been predominantly HIV-1-isolate-specific. In the present studies, murine monoclonal antibodies (mAbs) were prepared against the HIV-1MN strain. One mAb, designated NM-01, was selected for its ability to neutralize both the MN and IIIB strains. Neutralization of H9-cell infectivity as determined by reverse transcriptase assay demonstrated an ID50 of less than 1 microgram/ml for both MN and IIIB. mAb NM-01 also blocked MN and IIIB infectivity in the MT-2 assay and inhibited their reactivity in syncytium formation. The results further demonstrate that mAb NM-01 binds to the V3 loop of gp120 at amino acids 312-326. This mAb reacted equally well with loop peptides from the MN, IIIB, RF, and CDC4 isolates. In contrast, there was less affinity with a similar peptide from the NY5 strain and little if any reactivity with loop peptides from the Z2, Z6, and ELI strains. We also demonstrate that peptides corresponding to the V3 loops of MN and IIIB, but not Z6, block neutralization of IIIB virus by mAb NM-01. These findings indicate that mAb NM-01 reacts with diverse HIV-1 isolates through the Gly-Pro-Gly-Arg sequence of the V3 loop.