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We describe 2 cases of endocarditis caused by methicillin-resistant Staphylococcus aureus that failed to respond to intravenous linezolid therapy but were successfully treated with trimethoprim-sulfamethoxazole plus gentamicin and vancomycin plus rifampin.

From 1994 through 1996-1997, high-level ciprofloxacin resistance (minimum inhibitory concentration [MIC], > or = 4.0 microg/mL) increased from 9% to 49% of gonococcal isolates recovered from consecutive female sex workers in Cebu and Manila, The Philippines (P < .01). During 1996-1997, 105 female sex workers with gonorrhea were prospectively randomized to receive treatment with oral ciprofloxacin, 500 mg, or cefixime, 400 mg, and followed for test of cure. Neisseria gonorrhoeae was reisolated within 28 days after treatment from 1 (3.8%) of 26 women given cefixime versus 24 (32.3%) of 72 women given ciprofloxacin (P < .01). Treatment failure (reisolation of pretreatment auxotype/serovar) occurred in 14 (46.7%) of 30 women infected with strains with MICs of ciprofloxacin > or = 4.0 microg/mL versus 1 (3.6%) of 28 infected by strains with MICs < 4.0 microg/mL (P < .01). High-level, clinically significant gonococcal resistance to ciprofloxacin has rapidly emerged in The Philippines, and spread of fluoroquinolone resistance through commercial sex poses a threat to control of gonorrhea and prevention of human immunodeficiency virus infection and the acquired immunodeficiency syndrome.

This study was designed to compare the effectiveness of fluconazole vs. itraconazole as maintenance therapy for AIDS-associated cryptococcal meningitis. HIV-infected patients who had been successfully treated (achieved negative culture of CSF) for a first episode of cryptococcal meningitis were randomized to receive fluconazole or itraconazole, both at 200 mg/d, for 12 months. The study was stopped prematurely on the recommendation of an independent Data Safety and Monitoring Board. At the time, 13 (23%) of 57 itraconazole recipients had experienced culture-positive relapse, compared with 2 relapses (4%) noted among 51 fluconazole recipients (P = .006). The factor best associated with relapse was the patient having not received flucytosine during the initial 2 weeks of primary treatment for cryptococcal disease (relative risk = 5.88; 95% confidence interval, 1.27-27.14; P = .04). Fluconazole remains the treatment of choice for maintenance therapy for AIDS-associated cryptococcal disease. Flucytosine may contribute to the prevention of relapse if used during the first 2 weeks of primary therapy.

We present a systematic review of meningitis associated with transsphenoidal surgery. Patients present within the first 4 days after surgery with symptoms of headache, fever, and confusion. Overt cerebrospinal rhinorrhea or nuchal rigidity at the time of presentation is an infrequent finding. Although postoperative aseptic meningitis may be difficult to distinguish from early bacterial meningitis, the findings of hypoglycorrhachia, pleocytosis, and hyperproteinemia in the setting of fever and neurological deficit strongly suggest bacterial infection. The preponderance of cases of gram-negative meningitis observed in this series and in previous reports related to posttraumatic CSF leaks indicates that empirical regimens should include agents suitable for treating infections caused by nosocomial pathogens. In general, patients with uncomplicated meningitis in this setting can be expected to recover and do well. Questions remain as to the role of prophylactic antibiotics in the development of gram-negative meningitis in the setting of transsphenoidal surgery. A multicenter trial might be better able to define this role.

Fasciola hepatica, a zoonotic liver fluke, can cause disease in humans. Fascioliasis, while common in some tropical and developing countries, is uncommon in the United States. We report two cases of fascioliasis that illustrate both the hepatic and biliary stages of the disease. Clinical features and diagnostic aspects including serologic, radiographic, and histopathologic studies are emphasized. Praziquantel was ineffective in treatment of both patients. Bithionol appears to be an effective treatment for fascioliasis.

The sera of human immunodeficiency virus type 1 (HIV-1)-infected subjects were examined for the presence of infectious HIV-1-antibody complexes by their ability to infect Fc gamma receptor (Fc gamma R)-bearing cells. Infection of Fc gamma R-bearing cells by a serum in which half of the p24 antigen was present in a form of immune complexes was inhibited by aggregated human immunoglobulin. Then in studies on 22 sera, 9 sera produced p24 antigen during 14 days of culture in U937 cells. HIV-1 p24 production was inhibited or delayed by the pretreatment of cells with aggregated human immunoglobulin in 6 of the 9 sera that were infectious. These results may reflect interactions between virus-antibody complexes and Fc gamma R-bearing cells in vivo because serum itself was used as the source of virus and virus-antibody complexes. The results indicate that infectious HIV-1 immune complexes are present in the circulation of HIV-1-infected patients.

The clinical efficacy of trimetrexate, a dihydrofolate reductase inhibitor with potent in vitro antitoxoplasma activity, was assessed in 9 sulfonamide-intolerant patients with AIDS and biopsy-proven cerebral toxoplasmosis. The 9 patients were treated for 28-149 days with trimetrexate (30-280 mg/m2/day) plus leucovorin (20-90 mg/m2 every 6 h). Radiographic responses were documented in 8 patients, and clinical responses in 5 patients. Despite continued therapy, all patients deteriorated clinically and radiographically within 13-109 days of their initial improvement. Trimetrexate at very high doses for extended periods was not associated with serious toxicity. Trimetrexate alone had dramatic but transient activity in sulfonamide-intolerant patients and thus is not adequate as single-agent therapy for AIDS-associated toxoplasmosis.

The patterns of migration and attrition of Schistosoma japonicum larvae were studied in a mouse model. Control and immunized mice were challenged with 100 S. japonicum cercariae tagged with 75Se-labeled methionine. Skin, lungs, liver, and other organs were analyzed by compressed organ autoradiography for the presence of larvae that appeared as reduced silver foci. The pattern of migration of S. japonicum was similar in mice with primary infection and in mice immunized with irradiated cercariae. Skin was not a site of attrition after primary infection nor after immunization. Attrition occurred after migration to the lungs and continued until after migration to the liver in mice with primary infection, while in immunized mice attrition occurred before lung migration and continued at a faster rate than in normal mice. In both control and immunized mice, the lungs and liver were the major sites of attrition.

A unique epitope on the gag protein of human immunodeficiency virus type 1 (HIV-1), located at amino acid 145 to 150, has been mapped by using a CD8+ cytotoxic T-lymphocyte (CTL) clone. This epitope is highly conserved among 18 HIV-1 strains. The HIV-1 gag-specific human leukocyte antigen (HLA) class I-restricted CD8+ CTL clone was generated from fresh peripheral blood mononuclear cells of an HIV-seropositive donor by stimulation with gamma-irradiated allogeneic peripheral blood mononuclear cells in the presence of an anti-CD3 monoclonal antibody and recombinant interleukin-2. This gag-specific CTL clone killed autologous target cells infected with a recombinant vaccinia virus containing the gag gene of HIV-1 and target cells pulsed with an authentic p24gag construct expressed in Escherichia coli. Fine specificity was determined by using a panel of overlapping 30-amino-acid-long synthetic peptides and subsequently using smaller peptides to precisely map the CTL domain on p24. The epitope is on a highly conserved region, and it overlaps with a major B-cell epitope of gag. This CD8+ T-cell epitope is restricted by HLA-Cw3, which has not been previously identified as a restricting element for human CTL responses.

Disseminated intravascular coagulation (DIC) may complicate severe septicemia caused by Staphylococcus aureus. S. aureus can induce spontaneous platelet aggregation in vitro, the rapidity and degree of which correlates with the severity of DIC in patients with sepsis. Purified peptidoglycan from DIC isolates aggregated human platelets in the presence of staphylococcal protein A with significantly shorter aggregation times than did peptidoglycan from non-DIC isolates. Purified teichoic acid from DIC and non-DIC isolates failed to aggregate platelets in vitro, or in vivo in guinea pigs but inhibited the peptidoglycan-induced aggregation in a dose-response manner. These studies suggest that peptidoglycan may mediate S. aureus-induced spontaneous platelet aggregation in vitro and DIC in vivo. The variability among strains of S. aureus to induce DIC and platelet aggregation may depend on the unique composition of their peptidoglycan and perhaps also the extent of exposure or availability of cell wall teichoic acid.

Five patients with AIDS and Listeria monocytogenes infection (three cases of bacteremia and two of meningitis) are reviewed. Four patients had prior or concurrent gastrointestinal illness. Two patients received corticosteroids. A 7- to 21-day course of ampicillin was administered with or without a 7- to 14-day course of gentamicin. This regimen was effective, with no evidence of relapse 7-8 months after therapy was discontinued. The relative infrequency of infection with L. monocytogenes in AIDS patients is unexpected. Tumor necrosis factor (TNF) appears to be essential in the inhibition of Listeria in vivo. Elevated levels of TNF in AIDS patients may be protective against listeriosis and thus help explain the low prevalence of listerial infection in this population. Nonetheless, although L. monocytogenes is an uncommon cause of illness in patients infected with the human immunodeficiency virus, it cannot be dismissed as a cause of undefined meningitis or sepsis.

A case of bacteremia due to Campylobacter fetus subspecies fetus with concomitant pleuropericarditis in a previously healthy patient is presented. The organism is ubiquitous, but most commonly causes infection in patients with chronic underlying illnesses. The pathogenesis of human infection has not been definitively elucidated. Bacteremia is the most common clinical manifestation of this infection, although cases of thrombophlebitis, mycotic aneurysm, endocarditis, and pericarditis have also been reported. The treatment of choice for most infections is gentamicin, with chloramphenicol recommended for infection involving the central nervous system. Tetracyclines and erythromycin are alternative agents. Prolonged therapy is essential to the prevention of relapse. A high index of suspicion is necessary for the recognition of this organism in the appropriate clinical settings.

To determine the maximal tolerable dosage of trimetrexate for treatment of pneumocystis pneumonia, 25 patients were treated each day with 45 mg/m2 of trimetrexate and 80 mg/m2 of leucovorin; 10 received 60 mg/m2 and 80 mg/m2; 12 received 60 mg/m2 and 160 mg/m2; and 6 received 90 mg/m2 and 160 mg/m2, respectively. Leucovorin was increased twofold and trimetrexate reduced by 50% or suspended briefly for various levels of neutropenia and thrombocytopenia until blood counts increased. Dosage-modifying hematologic toxicity occurred in 12 (46%), 8 (80%), 9 (75%), and 4 (67%) patients with the respective groups. Cytopenias were in each case reversible and other toxicities were well tolerated. All survivors but one were able to receive a full 21 doses of trimetrexate. Twenty-four (92%), 10 (100%), 7 (58%), and 4 (80%) of patients in the respective groups survived. Thus, the 45 mg/m2/day dosage of trimetrexate with 80 mg/m2/day of leucovorin resulted in the least dosage-modifying toxicity and excellent efficacy. This combination should be selected for studies to compare trimetrexate with other therapies for pneumocystis pneumonia.

Sera from 55 parenteral drug abusers with endocarditis due to Staphylococcus aureus were assayed for the presence and titer of rheumatoid factor. Thirteen (24%) of the 55 patients with endocarditis had sera positive for rheumatoid factor at one point or another in their courses; only 2 (7%) of 30 noninfected drug users were found to be positive. It appeared that more severe cases, as evidenced by duration of fever after initiation of antibiotic therapy, were more likely to develop rheumatoid factor.

Street heroin and injection paraphernalia have been implicated as sources of bacteria causing infections in drug abusers [1]. Staphylococcus aureus, Pseudomonas aeruginosa, and Bacillus cereus are common etiologic agents. In a previous study of the microbiology of street heroin and injection paraphernalia, Bacillus species was the predominant isolate [2]. We did not find S. aureus, but one study reported isolates of identical phage type from heroin powder and from an infected patient [3]. To reconcile the results of our recent investigation among drug abusers with panophthalmitis, we theorized that the drug mixture might have an antibacterial effect. Of the samples of street heroin tested, all except one were bactericidal against S. aureus. The single sample with no heroin content was not bactericidal against one isolate of S. aureus and was the only sample that exhibited some degree of inhibitory and bactericidal activity against P. aeruginosa. All samples were bactericidal against the two isolates of B. cereus tested. Quinine exhibited bactericidal activity against S. aureus and B. cereus but was ineffective against P. aeruginosa. Our findings indicate that most samples of street heroin have antibacterial effects against S. aureus and B. cereus but no activity against P. aeruginosa. Such activity may be due to the quinine content of the mixture. The apparent lack of recovery of S. aureus from street heroin may be partially explained by this phenomenon.

Twenty strains of Staphylococcus aureus isolated from patients with endocarditis were examined in vitro for susceptibility to rifampin, nafcillin, and vancomycin and to combinations of rifampin with nafcillin or vancomycin. Minimum bactericidal concentrations of rifampin ranged from 0.0031 to 0.0125 mug/ml, of nafcillin ranged from 0.078 to 0.312 mug/ml, and of vancomycin ranged from 0.312 to 1.25 mug/ml. The combination of rifampin with nafcillin was synergistic for 12 strains; the combination of rifampin plus vancomycin was synergistic for 5 of the isolates.

Monocytes and macrophages, which may play a central role in the pathogenesis of infection with human immunodeficiency virus type 1 (HIV-1), express the CD4 molecule and Fc receptors (FcR) for immunoglobulin G (IgG). To explore the possibility that FcR mediate HIV-1 infection of monocytes, studies were conducted with the human monocytic cell line U937. These cells were exposed to HIV-1 complexed with various concentrations of serum from HIV-1 antibody-positive individuals and monitored for HIV-1 replication. Serum samples from antibody-negative normal individuals did not affect virus yields. High concentrations of antibody-positive sera showed virus-neutralizing activity; however, cells infected with HIV-1 in the presence of antibody-positive sera at subneutralizing concentrations significantly enhanced virus replication. This infection enhancement was blocked by heat-aggregated gamma-globulin. Moreover, the IgG fraction from an HIV-1 antibody-positive serum enhanced HIV-1 infection at the same serum dilution equivalents. In contrast, IgG-F(ab')2 did not enhance HIV-1 infection but showed neutralizing activity with HIV-1. These results are compatible with the concept of FcR-mediated infection enhancement and suggest that this immunological response to HIV-1, instead of protecting the host, potentially facilitates the infection.

To study the natural course of catheter-induced endocarditis secondarily infected with Staphylococcus epidermidis, 29 rabbits had catheters introduced surgically through the carotid artery to the aortic valve. Forty-eight hours later the catheters were removed from five rabbits. The rabbits were inoculated intravenously with 10(8) colony-forming units of S epidermidis. Autopsies done at various intervals showed all rabbits with indwelling catheters had noticeable aortic valve vegetations with positive cultures for S epidermidis. In the group with catheters removed after 48 hours, less severe valvular lesions were noted. Metastatic seeding to kidneys, spleen, and liver were noted in both groups. Because of low cure rate in the treatment of S epidermidis endocarditis, this rabbit model could be used to study antibiotic regimens for valvular endocarditis.

Serious infections with the "nonpathogenic" Bacillus species are increasingly being recognized, especially in drug abusers. Cases of panophthalmitis secondary to infection with Bacillus cereus, with and without associated bacteremia, have been reported. Three drug abusers with panophthalmitis seen in our hospitals during a three-year period are described, and the similar cases reported in the literature are reviewed. The syndrome is characterized by an acute onset with a rapid fulminating course that eventually leads to enucleation or evisceration of the eye. The pathogenic mechanism is unknown, but is probably related to the production of toxin (lecithinase) by B. cereus. Clindamycin appears to be the antibiotic of choice in the treatment of this infection. In order to identify a possible source of the organism, 59 samples of heroin and injection paraphernalia were cultured. Twenty cultures yielded organisms; Bacillus species were the predominant isolates. Thirty-eight percent of the isolates were identified as B. cereus. Thus, infections caused by Bacillus species in drug abusers can probably be associated with intravenous heroin abuse because heroin mixtures and injection paraphernalia are frequently contaminated with this organism.

The in vitro and in vivo interaction of Schistosoma japonicum with salmonellae and other gram-negative bacteria was studied. In vitro, S. japonicum associated with salmonellae and other gram-negative bacteria, and more male than female schistosomes associated with the bacteria. By using the various strains and mutants of salmonellae, we showed that Salmonella typhimurium had a higher degree of association than did Salmonella enteritidis and that the piliated strains of S. typhimurium associated much more frequently than did the nonpiliated strains. However, in vivo studies demonstrated more frequent association of salmonellae with female than with male schistosomes and that the piliated and nonpiliated strains of salmonella did not differ in their association with the worms.

Disseminated infection caused by Mycobacterium avium complex (MAC) is common in patients with acquired immune deficiency syndrome and is difficult to treat because of the high degree of resistance to antimycobacterial agents. Early diagnosis and treatment may prolong survival of patients with acquired immune deficiency syndrome and MAC infection. Twenty patients with disseminated MAC infection were evaluated for recovery of the organism from bone marrow, bronchial washings or sputum, and stools before the organism was isolated in blood culture. For 40 to 67% of patients, MAC was recovered from these specimens before it was isolated in blood culture.

Four patients with acquired immunodeficiency syndrome with bacillemia from Mycobacterium avium-intracellulare presented with early pathologic clues of a disseminated mycobacterial infection. All had persistent fevers with negative diagnostic workups for other usual pathogens seen in patients with acquired immunodeficiency syndrome. Two patients had prolonged clearance of the bacillemia on a drug regimen of ansamycin, clofazimine, and amikacin sulfate.

An outbreak of giardiasis was investigated in one urban day care center; another day care center was selected as a control. In the study day care center, 35 per cent of the children were infected. Infection was spread to at least one household contact of 47 per cent of the infected children. The data suggest person-to-person transmission of giardiasis and the need for measures to prevent its dissemination. Early recognition and treatment of Giardia lamblia infections in children may be indicated.

Seven adults with multiple brain abscesses were successfully treated with antibiotic therapy alone at The George Washington University Medical Center, Washington, D.C., during 1976-1981. Fever, meningismus, and focal neurologic signs were common presenting features. No patient presented with coma or obtundation. Etiologic agents were identified in only three cases. Computerized tomographic (CT) scans were valuable in diagnosing and monitoring the response to therapy. Decrease in the size of the lesions was noted two to nine weeks after initiation of antibiotic therapy. In all patients, clinical signs of improvement preceded evidence of resolution of lesions on CT scan. These results indicate that, in carefully selected patients in whom surgical drainage is not feasible because of the anatomic location and/or multiplicity of lesions, a prolonged course of high-dose intravenous antibiotics alone can lead to a successful outcome.

Cefotiam, a new cephalosporin, was evaluated in the treatment of lower respiratory tract infections in 29 patients. The bacteria isolated from the sputum of these patients included Streptococcus pneumoniae (31%), Klebsiella pneumoniae (31%), and Haemophilus influenzae (28%). Satisfactory response was observed in 90% of the patients. There were three treatment failures, two superinfections, and four colonizations with gram-negative organisms resistant to the drug. Superficial phlebitis was noted in two patients. The results of this study suggest that cefotiam is an effective and well-tolerated antibiotic for the treatment of lower respiratory tract infections due to susceptible organisms.

Recently defined aspects of cellular and humoral antiviral immunity were evaluated in 10 young adults given influenza vaccines containing A/USSR/77 (H1N1) antigens. Cytotoxic lymphocytes were measured by using cryopreserved lymphocytes as effector cells and syngeneic, virus-infected lymphocytes as target cells. An assay previously developed in this laboratory was adapted for the measurement of antibody-dependent, complement-mediated cytotoxicity. Antiviral cytotoxic lymphocyte responses were detected in 5 of 10 volunteers between 3 and 10 days after the initial vaccination. These responses were found both in individuals who were previously primed and in individuals who were not primed to influenza A/USSR/77 antigens. The complement-mediated lysis assay was found to be more sensitive than the hemagglutination inhibition test and probably detected antibodies to both subtype-specific and cross-reactive antigenic determinants. These responses to influenza antigens are similar to those obtained in studies of murine influenza which indicate that cytotoxic lymphocytes and antibody-dependent, complement-mediated cytotoxicity have a role in the early response to acute infection.

Sera from patients with endocarditis and bacteremia due to Staphylococcus aureus were compared for peptidoglycan-binding capacity with those from normal blood donors. Those patients treated with beta-lactam antibiotics had higher antigen-binding levels than normal donors and patients treated exclusively with vancomycin (P less than 0.01). The factor responsible for this activity was purified by affinity chromatography from a normal donor and shown to be an immunoglobulin. Specificity studies indicated that the immunodominant determinant was a peptide sequence found in peptidoglycan precursors. Since soluble peptidoglycan molecules having the precursor peptide sequence are known to be secreted by some gram-positive bacteria like Micrococcus luteus when grown in the presence of beta-lactam antibiotics, these soluble molecules may constitute the "natural" immunogen. Such a hypothesis is consistent with the study of the peptidoglycan-binding capacities in the sera of these patients during the course of treatment. For most of the responding patients studied (four of four with bacteremia and seven of nine with endocarditis), a significant increase in peptidoglycan-binding capacity was observed in sera taken 1 to 5 weeks after the initiation of beta-lactam antibiotic therapy (compared with the initial serum studied). No such increase in the peptidoglycan-binding capacity over a similar time span was noted in the sera of people not receiving beta-lactam antibiotics (none of seven).

Twenty-six strains of Staphylococcus aureus obtained from patients with endocarditis were studied for the production of alpha- and/or beta-ribitol teichoic acid (TA), using highly specific anti-TA antibodies prepared in rabbits. A counterimmunoelectrophoretic assay was used. Beta-TA was the predominant residue produced by all strains; alpha-TA was found in all strains, but in smaller amounts and with much strain-to-strain variations. Antibodies in patients' sera were found against beta-TA in higher titers and for longer periods than were anti-alpha-TA antibodies. Antibodies against one or both TA residues were present in all but one of 26 patients.

Four isolates of Staphylococcus aureus from patients with endocarditis and bacteremia were capable of secreting high-molecular-weight soluble peptidoglycans when grown in a minimal cell wall medium containing penicillin G. Vancomycin was not able to substitute for penicillin G in triggering this secretion. Secretion reflected de novo synthesis of soluble peptidoglycan and was strongly dependent on time of incubation (30 to 60 min), and number of bacteria (2 X 10(8) to 5 X 10(8) colony-forming units per ml), but not on penicillin G concentration (10 to 250 micrograms/ml). The incorporation of alanine into the peptidoglycans secreted in vitro by these isolates incubated in the presence of penicillin G under optimal conditions was variable. The least incorporation of alanine into peptidoglycan occurred with an isolate from a patient treated with nafcillin who had no detectable antipeptidoglycan titer.

Inactivated influenza A/New Jersey/76 virus vaccines were administered intramuscularly to 199 normal adults, aged 19-59, in doses of 200, 400, or 800 chick cell-agglutinating units in a double-blind, placebo-controlled trial. Systemic reactions (including fever) were uncommon, were mild, lasted less than 24 hr, and were more frequently associated with the largest dose. Local reactions were common but mild. A single, rapidly reversible, allergic reaction was noted in a volunteer 2 hr after vaccination. There was a trend toward fewer systemic reactions in vaccines who had preexisting hemagglutination-inhibiting (HAI) antibodies to the vaccine virus in their sera as compared with seronegative vaccines. All vaccine preparations at all three dosages evoked serum HAI titers of greater than or equal to 20 to greater than or equal to 40 in a high proportion of seronegative recipients, with significantly greater geometric mean titers at the highest dosage. Vaccines between the ages of 19 and 23 years manifested significantly lower serologic responses than did vaccinees over the age of 23. Thus, normal adults over the age of 23 can be immunized with a single, well-tolerated dose of A/New Jersey/76 vaccines.

Of 50 patients with bacteremia due to Staphylococcus aureus but without clinical evidence of endocarditis, 24 developed antibodies to the cell wall teichoic acid of S. aureus that were demonstrable by counterimmunoelectrophoresis. However, only 16 of the 24 patients developed titers of antibodies high enough for detection by passive gel diffusion. Eleven of the 16 patients developed evidence of complications due to metastatic infection. In contrast, of the 34 patients who were antibody-negative by gel diffusion, only one patient developed evidence of metastatic seeding. Thus, the development of antibodies to teichoic acid at a level detectable by the gel diffusion technique is regularly associated with complicated infections due to S. aureus that require more prolonged therapy, whereas bacteremic patients not developing such an antibody response rarely develop complications and may be treated with a two-week course of therapy.

Antibiotic susceptibility and synergy were studied in 12 clinical isolates of Listeria monocytogenes from patients with meningitis and septicemia. Rifampin and trimethoprim-sulfamethoxazole (TMP-SMX) were the most potent single drugs tested. Approximately 80% of the strains demonstrated full synergistic bactericidal activity with rifampin in combination with penicillin or ampicillin. Clinical experience dictates that ampicillin or penicillin should remain the antibiotic of choice in the treatment of severe infections, such as meningitis caused by L. monocytogenes. Where the use of penicillin is contraindicated (e.g., allergy or failure to respond), use of TMP-SMX might be considered. Further in vitro and vivo studies are needed before therapy with rifampin or TMP-SMX in combination with penicillin or ampicillin can be recommended.

The activity of teichomycin A2 was compared with that of vancomycin in vitro against clinical isolates of staphylococci and enterococci. Teichomycin A2 was more active than vancomycin active against all isolates tested. Synergistic studies also demonstrated that teichomycin A2 combined with rifampin is more active than vancomycin combined with rifampin against Staphylococcus aureus and Staphylococcus epidermidis isolates. Teichomycin A2, either singly or in combination with an aminoglycoside, was more active against Streptococcus faecalis isolates.

Forty-eight patients with 51 episodes of infective endocarditis caused by streptococci were studied in a comparison of the efficacy of single antibiotic therapy versus that of combination therapy. There was no statistical difference in terms of clinical course, toxicity, and mortality between the group given a single drug and that given combination therapy. However, one patient experienced two relapses, in both instances after high-dose penicillin therapy. The species and antibiotic susceptibilities of the infecting organisms were determined. The majority of isolates were alpha-hemolytic, with Streptococcus sanguis recovered most commonly. Streptococcus bovis and group B beta-hemolytic streptococci were the next most frequent isolates.