Endocarditis caused by Actinobacillus actinomycetemcomitans.

Actinobacillus actinomycetemcomitans is a gram-negative coccobacillus which is a very rare cause of bacterial endocarditis. Preexisting cardiac lesions are a main contributing factor, and antibiotic prophylaxis has long been felt necessary before dental or other manipulation to prevent endocarditis. Penicillin in combination with an aminoglycoside has been the most often used treatment regimen. We present a case of endocarditis caused by this organism which developed after antibiotic prophylaxis for dental cleaning. Streptomycin and rifampin therapy resulted in the cure of the infection. The treatment and epidemiology of Actinobacillus endocarditis are reviewed.     

Bacterial endocarditis due to Eikenella corrodens: a case report

Of all the causes of bacterial endocarditis, HACEK group consisting of Haemophilus, Actinobacillus actinomycetemcomitans, Cardiobacterium hominis, Eikenella corrodens, and Kingella Kingae are rare causative agents. We report a case of bacterial endocarditis by E. corrodens, which is one of the members of the HACEK group.     

Efficacy of neonatal ocular prophylaxis for the prevention of chlamydial and gonococcal conjunctivitis

Opinions differ concerning the efficacy of prophylaxis against neonatal chlamydial and gonococcal conjunctivitis. From January 1986 through June 1988, we gave all infants born at Kings County Hospital Medical Center one of three prophylactic agents -- silver nitrate drops, erythromycin ophthalmic ointment, or tetracycline ophthalmic ointment. The treatments were rotated monthly. Gonococcal ophthalmia occurred in 8 of the 12,431 infants born during the study (0.06 percent), 1 in the silver nitrate group, 4 in the erythromycin group, and 3 in the tetracycline group (P not significant). Seven of these infants were born to women who had received no prenatal care. From September 1985 through December 1987, we screened 4357 pregnant women for cervical chlamydial infection, of whom 341 (8 percent) had positive cultures. Of their offspring, 230 were evaluated for neonatal chlamydial conjunctivitis; the incidence was 20 percent in the silver nitrate group, 14 percent in the erythromycin group, and 11 percent in the tetracycline group (P not significant). We conclude that neonatal ocular prophylaxis with either erythromycin or tetracycline ophthalmic ointment does not significantly reduce the incidence of chlamydial conjunctivitis in the offspring of mothers with chlamydial infection as compared with silver nitrate, and that better management of maternal chlamydial infection is therefore required. We also conclude that there is a small but appreciable incidence of neonatal gonococcal ophthalmia that could be prevented by better prenatal screening and treatment of maternal gonococcal infection.     

Antimicrobial susceptibility ofGemella haemolysans isolated from patients with subacute endocarditis

Gemella haemolysans, a member of the familyStreptococcacae, was isolated from patients with subacute endocarditis. The minimal inhibitory concentrations of 21 antimicrobial agents for five strains of the organism were determined. All strains were highly sensitive to penicillin G and ampicillin. Cefotaxime was the most active cephalosporin tested. All strains were sensitive to vancomycin, chloramphenicol and rifampin. Four strains were sensitive to tetracycline and erythromycin. All strains demonstrated a low level of resistance to aminoglycosides and were highly resistant to sulfonamides and trimethoprim. Killing curves and checker-board titration demonstrated synergism between penicillin G and streptomycin or gentamicin, and also between vancomycin and streptomycin or gentamicin. The results suggest that penicillin G combined with an aminoglycoside can be recommended for the treatment of subacute endocarditis caused byGemella haemolysans.     

Prophylaxis of gonococcal and chlamydial ophthalmia neonatorum. A comparison of silver nitrate and tetracycline

We evaluated the use of silver nitrate drops and tetracycline ointment for the prophylaxis of ophthalmia neonatorum in a controlled trial involving 2732 newborns in Nairobi, Kenya. The overall rates of prevalence of intrapartum maternal gonococcal and chlamydial infection were 6.4 and 8.9 percent, respectively. After prophylaxis with silver nitrate, the incidence rates of gonococcal, chlamydial, and nongonococcal, nonchlamydial ophthalmia neonatorum were 0.4, 0.7, and 6.2 percent, respectively, whereas after prophylaxis with tetracycline, the rates were 0.1, 0.5, and 4.5 percent. The attack rates of gonococcal ophthalmia neonatorum in newborns exposed to Neisseria gonorrhoeae at birth were 7.0 percent in those receiving silver nitrate and 3.0 percent in those receiving tetracycline (95 percent confidence interval for the difference in rates, -3.4 to 11.4 percent). As compared with historical controls, the incidence of gonococcal ophthalmia neonatorum decreased 83 percent among infants treated with silver nitrate and 93 percent among those treated with tetracycline. Failure of prophylaxis was associated with postpartum maternal endometritis (P = 0.05). Among newborns exposed to maternal infection with Chlamydia trachomatis, chlamydial conjunctivitis developed in 10.1 percent given silver nitrate and in 7.2 percent given tetracycline (95 percent confidence interval for the difference in rates, -4.7 to 10.5 percent), yielding reductions in the incidence of chlamydial ophthalmia of 68 and 77 percent, respectively, as compared with the historical controls. We conclude that tetracycline is as effective as silver nitrate in preventing gonococcal ophthalmia neonatorum.     

The value of new antimicrobial agents

New antimicrobial agents require careful assessment to determine whether they possess the appropriate properties for clinical use. Many new compounds of value in the prophylaxis and therapy of infections have been included in the current armamentarium. Close monitoring to identify possible adverse effects of new agents is essential. Alternative uses of older agents also expands therapeutic opportunities in the combat against infectious diseases. Inappropriate use of antimicrobial agents contributes to the worldwide problem of increasing bacterial resistance. The dramatic spread of such bacterial strains is partially responsible for the rising costs of infectious diseases. A rational and strict antibiotic policy is thus of great importance for the optimal use of these agents.     

Antibiotic-resistant oral streptococci in dental patients susceptible to infective endocarditis

The aim of this study was to determine the incidence of amoxycillin and erythromycin resistance in oral streptococci in patients at risk from infective endocarditis. Samples of gingival crevicular flora were taken from 65 patients at the site of dental treatment, prior to the prophylactic administration of amoxycillin (54 patients) or erythromycin (11 patients). Samples were also taken from 65 dental patients who were not considered to be at risk from infective endocarditis. No isolate had a minimum inhibitory concentration (MIC) of amoxycillin greater than 24 mg/L. However, erythromycin-resistant oral streptococci with MIC values greater than 3.5 mg/L were isolated from 22% of patients receiving amoxycillin prophylaxis, 9% of patients receiving amoxycillin prophylaxis, 9% of patients given erythromycin prophylaxis and 9% of patients not at risk from infective endocarditis. The antibiotic-resistant streptococci comprised mainly Streptococcus sanguis biotype II, although S. sanguis biotype I, S. mitis and S. salivarius were also frequently recovered.     

Value of the serum bactericidal test in management of patients with bacterial endocarditis

A review is given of the available clinical data on the prognostic value of the serum bactericidal test in the treatment of patients with bacterial endocarditis. It is concluded that the test, even when performed in a standardized manner, does not provide useful information for the majority of patients with bacterial endocarditis. Until further clinical data are available, routine performance of the test in patients with bacterial endocarditis is not recommended.     

Experimental Bacterial Endocarditis: III. Production and Progress of the Disease in Rabbits

A simple and reliable model for endocarditis in rabbits has been studied and standardized. Non-bacterial thrombotic endocarditis was produced on either side of the heart by the presence of a polyethylene catheter. One day later, this was converted into bacterial endocarditis by single intravenous injections of streptococci, staphylococci, Proteus and Candida. No infection resulted from injection of L-forms or virus. Reduction of inoculum size or withdrawal of the catheter reduced the incidence of bacterial endocarditis, but the presence of a catheter in the heart for only a few minutes predisposed to infection. Left-sided Streptococcus viridans infection was uniformly fatal, with average survival of about two weeks. Right-sided infection was not always fatal; approximately 25% of infected vegetations healed spontaneously.The advantages of a standardized model for endocarditis which allows exact timing of infection are discussed.     

Plasmid carriage and antibiotic susceptibility ofNeisseria meningitidis strains isolated in Sweden 1981–1990

A random selection ofNeisseria meningitidis strains isolated in Sweden in the period 1981–1990 were investigated for plasmid carriage and susceptibility to antimicrobial agents commonly used for treatment and prophylaxis of meningococcal disease. The MICs were determined by the agar dilution method for penicillin V, penicillin G, rifampicin, sulfadiazine, erythromycin and tetracycline. In 13 % of the invasive strains the MIC of penicillin V was 0.5 mg/l which may cause concern regarding the usefulness of penicillin V in prophylaxis. In strains isolated from the urogenital tract the MICs of penicillin V and penicillin G were higher than in the invasive strains. In about 82 % of the strains isolated in 1987–1988 the MIC of tetracycline was 0.5 mg/l whereas no such strains were found in 1981–1982. Plasmids were found in 2 of 119 invasive strains, in 1 of 50 strains from the respiratory tract and in 1 of 19 strains from the urogenital tract. The plasmid sizes were 1.3, 2.6, 25 and 40 Mda. None of these strains were beta-lactamase producing and no relation to a high degree antibiotic resistance was observed.     

The effect of antibiotics on bacterial colonisation of vascular cannulae in a novel in-vitro model

An in-vitro model for studying semi-quantitatively the bacterial colonisation of the external and internal surfaces of peripheral intravascular cannulae is described. Using this model, we studied the effect of ciprofloxacin, teicoplanin and fusidic acid on cannula colonisation by Staphylococcus epidermidis. Exposure of colonised cannulae to sub-MICs of ciprofloxacin and fusidic acid reduced bacterial attachment, whereas sub-MIC levels of teicoplanin had little effect. Pre-exposure of S. epidermidis to sub-MICs of ciprofloxacin and fusidic acid also reduced slime production and colonisation. In comparison, pre-exposure of S. epidermidis to teicoplanin 1.0 mg/L did not influence colonisation, whereas at 0.1 mg/L it was reduced. The model allowed investigation of bacterial colonisation of cannulae and offers a screening system for the assessment of potential agents for the prophylaxis and treatment of these infections.     

Neisseria sicca endocarditis: report of a case and review of the literature.

A rare case of bacterial endocarditis caused by Neisseria sicca is reported. Review of the literature revealed only five other cases where sufficient data existed to confirm this particular organism as the etiological agent of bacterial endocarditis.     

Severe backache as a presenting sign of bacterial endocarditis

We report on two patients whose presenting sign of bacterial endocarditis was a sudden and severe backache. According to the literature, 25-44% of patients with bacterial endocarditis have musculoskeletal symptoms and in about 27% these symptoms are the first sign of the disease. The most probable pathogenetic mechanism of these symptoms is arterial microembolization consisting of bacteria and immune complexes.     

Coagulase-negative staphylococci causing endocarditis after cardiac surgery

The laboratory findings in seven cases of endocarditis caused by coagulase-negative staphylococci are presented. The usefulness of biochemical characterization of the strains in diagnosis and the selection of antibiotics for prophylaxis and treatment are discussed.     

Detection of circulating antigen in experimental Candida albicans endocarditis by an enzyme-linked immunosorbent assay.

A double-antibody sandwich enzyme-linked immunosorbent assay was developed for the detection of circulating Candida albicans antigen during the course of experimental C. albicans endocarditis. The enzyme-linked immunosorbent assay was positive in 75% of rabbits with polyethylene catheter-induced experimental aortic valve C. albicans endocarditis but was negative in all controls, including catheterized animals that received intravenous Candida or catheterized but uninfected animals, and in rabbits with experimental fungal or bacterial endocarditis of other etiologies. The enzyme-linked immunosorbent assay was much more sensitive than blood culturing or fever determinations in experimental C. albicans endocarditis. This assay is more sensitive than currently available serological techniques, is highly specific, and deserves further study in the diagnosis of invasive, disseminated C. albicans infections, including endocarditis.     

Bacterial and fungal profile of corneal ulcers--a prospective study

Corneal ulceration continues to be one of the most important causes of ocular morbidity and blindness worldwide. Between April 1999 and May 2001, 80 patients with corneal ulceration were examined to find the causative microorganisms, the sensitivity pattern of bacterial isolates to antibiotics, the predisposing factorsfor ulcerative keratitis and the comparison between culture and gram staining results. Corneal ulceration was seen more in males than females, predominantly in farmers (61.25%) and trauma was the commonest predisposing factor, the agents being mainly organic agricultural materials. Of the 80 corneal ulcers, 32(40%) yielded pure bacterial growth while fungal growth was seen in 10(12.5%). Streptococcus pneumoniae was the commonest bacterium while Aspergillus fumigatus and Fusarium species were the commonest fungi isolated. Most of the bacterial isolates were sensitive to chloramphenicol and tetracycline followed by the quinolones. The overall sensitivity and specificity of Gram staining as compared to culture was 57.14% and 94.7% respectively.     

Experimental Bacterial Endocarditis: II. Survival of Bacteria in Endocardial Vegetations

A method has been developed for assessing metabolic activity of bacteria in the vegetations of bacterial endocarditis using a labelled metabolite and autoradiography. Evidence provided by this technique suggests that there are different degrees of activity between superficial and more deeply placed bacterial colonies, and that variations in activity also exist within a single group of organisms. The possible relevance of these findings to the antibiotic therapy of endocarditis is discussed.     

Effects of a restrictive antibiotic policy on clinical efficacy of antibiotics and susceptibility patterns of organisms

To assess the impact of a restrictive antimicrobial policy, the efficacy of therapeutic and prophylatic antibiotic regimens and the susceptibility patterns of infecting bacterial microorganisms were studied during a two-month period in 1986 in inpatients in a general hospital. Twenty-eight percent of patients received antimicrobial agents, 21 % as treatment and 7 % as prophylaxis. In the 359 evaluable episodes of infection cure was obtained in 88 % of cases with the initial therapy and in 7 % after a change of drugs, but treatment failed in 5 %. Of the 18 cases of failure, improvement was seen in eight although the infection persisted. Ten patients died but in seven of them the infection only partially contributed to this outcome. Ten (8 %) of 127 patients receiving antimicrobial prophylaxis developed an infection but in three there was no relation to the condition for which the prophylactic regimen was originally prescribed. No changes were found in the susceptibility patterns of microorganisms.     

Bacterial Clearance and Endocarditis in American Opossums

The American opossum is the only experimental animal that regularly develops bacterial endocarditis spontaneously. There was no relation between the ability of opossums to clear bacteria from the bloodstream and the subsequent development of endocarditis.     

Morphology of infectious endocarditis affecting bioprostheses of the cardiac valves

Four varieties of infectious endocarditis were identified after cardiac valve bioprostheses: early acute, early subacute, late acute, and late subacute forms. Any of these forms may be of bacterial, fungal, or mixed (bacterial and fungal) origin. In the early forms, the infection was of exogenous origin, with a predominance of Gram-positive organisms, whereas in the late forms it was endogenous with a preponderance of Gram-negative flora. The hallmarks of fungal thromboendocarditis were an early massive thrombosis of the bioprosthesis, multiple thromboembolism, and an absence of cellular reaction in the cuspal tissue. In the subacute bacterial endocarditis, progressive dysfunction of the bioprosthesis resulting from calcination of bacteria-containing cusps and thrombi was noted.