Endocarditis caused by penicillin-resistant viridans streptococci: 2 cases and controversies in therapy.

Although penicillin-resistant viridans streptococci have been isolated from samples from the mouth, blood, and wounds in increasing numbers, viridans streptococci isolated from patients with endocarditis have remained sensitive to penicillin for the past 5 decades. We report the cases of 2 patients with penicillin-resistant viridans streptococcal endocarditis, review 6 other cases from the literature, and summarize 2 studies that used an animal model of penicillin-resistant viridans streptococcal endocarditis.

Antimicrobial prophylaxis for arthroplasty: a comparative study of cefonicid and cefazolin.

A double-blind, multicenter trial compared cefonicid and cefazolin for prophylaxis against postoperative infection in 117 patients undergoing joint replacement. Cefonicid, which has an extended serum half-life, was administered once daily, while cefazolin was given every eight hours. The drug was administered one half to one hour before surgery and continued for up to 72 hours. Patients were observed throughout their hospitalization period and followed for 30 days after discharge. No evidence of wound or joint infection was observed in any of the patients who met the criteria for evaluation. Adverse reactions consisted mainly of infrequent gastrointestinal symptoms and laboratory abnormalities. Three patients died from causes unrelated to study medication. No differences between the two regimens were found with respect to safety or efficacy in the prevention of postoperative infection after arthroplasty. The effectiveness of once-daily administration should make cefonicid a highly cost-effective alternative to many of the more expensive first- and second-generation cephalosporin antibiotics currently used in hospital practice.

Cost and quality in the use of blood bank services for normal deliveries, cesarean sections, and hysterectomies.

To reduce costs, preserve blood supplies, and enhance the safety of blood use during emergencies, the Department of Obstetrics and Gynecology and the blood bank at a teaching hospital recommended replacing pre-delivery crossmatch on selected patients with typing and screening for all patients undergoing normal or cesarean section delivery. Using an automated data system, it was shown that 75% and 50% reductions in the ordering of crossmatching for these two groups of patients promptly resulted, endured over a one-year follow-up period, and also spread to include patients undergoing hysterectomy. However, the cost of the increased use of typing and screening outweighed the reduced cost of crossmatching: actual annual costs increased by $11 151. We conclude that test-ordering practices can be changed surprisingly easily if a specific and reasonable policy is advocated by influential clinicians. However, changes in test use can cause unexpected cost increases. Only detailed study of practice patterns can reveal cost consequences for a specific institution.

Cephalosporins: bridging the generation gap.

More than a dozen compounds are now available. Although very effective and generally safe, the cephalosporins are often misused. The second- and third-generation drugs have provided progressively wider spectra of activity, although none has surpassed the activity of cephalothin against beta-lactamase-producing staphylococci. Cefotaxime and moxalactam have been shown to be useful in meningitis, whereas most of their predecessors have shown poor penetration into the cerebrospinal fluid.

Antibiotic prophylaxis in ventricular shunt surgery. I. Reduction of operative infection rates with methicillin.

Administration of prophylactic antibiotics is not a proven or universal practice in cerebrospinal fluid (CSF) shunt surgery although case and operative infection rates in hydrocephalic patients average 20 and 8%, respectively. In sequential series from 1969 through 1978 the authors achieved a reduction in case infection rates from 10.9 to 8.9% and in operative infections from 8 to 2.6% with the use of short-term prophylactic methicillin. Comparison of these results to those of other reported series supports the case for short-term prophylactic antibiotics in shunt surgery. Further reduction in shunt sepsis may be possible with the appropriate selection of other semisynthetic penicillins which achieve higher levels in CSF.

Antibiotic prophylaxis in ventricular shunt surgery. II. Antibiotic concentrations in cerebrospinal fluid.

Investigation of cerebrospinal fluid (CSF) antibiotic levels from patients operated upon under short-term prophylactic protocols for shunt insertions or revisions revealed low-level CSF penetration by nafcillin and virtually no methicillin activity. Nafcillin levels were not influenced by route of injection or CSF sampling time, but were inversely proportional to ventricular size. The authors recommend nafcillin over methicillin as the preferred prophylactic agent in shunt surgery. Although the 25 mg/kg preoperative dose may be adequate for reducing infection risk, higher dosages should be considered when the ventricles are markedly dilated.

False-positive cryptococcal antigen test and cervical prevertebral abscess.

A false-positive latex agglutination test for cryptococcal antigen occurred in a patient with a cervical prevertebral abscess and vertebral osteomyelitis caused by Klebsiella pneumoniae. Using a commercial latex agglutination test kit, a cryptococcal antigen titer of 1:32 was found in the CSF, but no cryptococcal antigen was found when the CSF was retested at a reference laboratory. The false-positive test resulted in unnecessary therapy with amphotericin B and delay in appropriate diagnostic studies and therapy.

Human aeromonas infections: a review of the literature and a case report of endocarditis.

Our patient, with cirrhosis and chronic renal failure, represents an example of the susceptibility of a compromised host to Aeromonas infections. This patient, however, differs from previously reported cases in at least two important aspects. First, it is possible that her portal of entry was a fresh A-V fistula puncture site rather than an intestinal site. The temporal relationship of exposure to flood water prior to the onset of sepsis lends support to this possibility. Epidemiologic investigation of the dialysis center failed to reveal Aeromonas isolates from cultures of the water supply, machinery, or other patients. Second, this case is unique in that our patient developed a destructive aortic valve endocarditis resulting in valvular perforations and acute aortic insufficiency. Furthermore, this infection was initiated on what appears to have been a previously normal valve. Based on a review of the literature and the virulence demonstrated by A. hydrophila in our patient, we conclude that organisms of the genus Aeromonas are capable of inducing serious human infection. Such infections are more likely to occur in compromised hosts. A. hydrophila has accounted for the majority of reported infections.

Nafcillin concentration in cerebrospinal fluid during treatment of staphylococcal infections.

The nafcillin concentration of simultaneous cerebrospinal fluid (CSF) and serum specimens from nine patients being treated with parenteral nafcillin for staphylococcal infection were measured. Marked variations in the ratio of CSF/serum nafcillin concentration were observed. However, the concentration of nafcillin in the CSF was greater than the minimum lethal concentration (MLC) for Staphylococcus aureus in eight of the nine patients. In five patients with CSF pleocytosis, the nafcillin concentration was three to 100 times the MLC. These results support the recommendation to use nafcillin in doses of at least 100 to 200 mg/kg body weight-day for treatment of meningitis caused by S. aureus.

Pharmacokinetics of nafcillin in patients with renal failure.

Nafcillin, a pencillinase-resistant penicillin, is frequently used for treatment of staphylococcal infections in hemodialysis patients. Despite its widespread use, there is a paucity of available data regarding the pharmacokinetics of nafcillin in hemodialysis patients. Therefore, sodium nafcillin, 25 mg/kg, was given intravenously over a 5- to 15-min period to 12 hemodialysis patients. Eleven patients were studied during dialysis, and eight of these were studied again during the interdialysis period. The initial serum half-life for nafcillin was 0.208 h during dialyses and 0.278 h between dialyses. The terminal half-life was 1.48 h during dialyses and 1.89 h between dialyses. There was no statistically significant difference between these values. These data indicate that renal failure does not appreciably affect the serum half-life of nafcillin, and hemodialysis does not accelerate the rate of clearance of nafcillin from the blood. Therefore, no modification of the usual nafcillin dosage is necessary when using this drug in hemodialysis patients.

Nafcillin entry into human cerebrospinal fluid.

The entry of nafcillin into the cerebrospinal fluid (CSF) of humans was studied in the absence of meningeal inflammation. Twenty studies were performed in 18 patients receiving 40 mg of sodium nafcillin per kg intravenously over 30 min. The CSF specimens were obtained at 1, 2, 3, and 4 h postinfusion, and sera were obtained at 5 min and 1, 2, 3, and 4 h. Nafcillin was uniformly detected in the lumbar CSF at 1 h, peaked at 2 h postinfusion, and was still detectable in the CSF of three of four patients studied at 4 h.

Crepitant cellulitis and myonecrosis caused by Klebsiella.

A fatal case of crepitant cellulitis with myonecrosis, the first caused by Klebsiella pneumoniae, is reported. The infection started in the left thigh but progressed rapidly despite appropriate antibiotics and surgery, which included incision and drainage and later a left-hip disarticulation. This case emphasizes that nonclostridial crepitant cellulitis is potentially severe and that the presence of myonecrosis is an indication for early radical surgery.

Haemophilus parainfluenzae and influenzae endocarditis: a review of forty cases.

Two cases of bacterial endocarditis caused by Haemophilus parainfluenzae are reported with a review of 33 other cases of H. parainfluenzae endocarditis and 5 cases of H. influenzae endocarditis. Although H. parainfluenzae is usually considered a non-pathogenic microorganism, this review firmly establishes its role as a causative agent in endocarditis. Furthermore, several clinical features were noted which were atypical when compared to findings usually present in patients with bacterial endocarditis. The mean age of the patients was only 27 years. Over 60% of the patients had no identifiable predisposing illness, an unexpected finding in view of the low degree of pathogenicity associated with this microorganism. Polymicrobial bacteremia, usually with viridans streptococci, was found in 11% of patients. Major arterial emboli were documented in 57% of patients, an incidence unchanged from the pre-antibiotic era. Diagnosis of the disease is dependent upon an awareness of the fastidious cultural requirements necessary for isolation of Haemophilus species. Culture media must contain a source of X and V factors. Mortality from H. parainfluenzae endocarditis has been reduced from 100 per cent prior to 1940 to about 12 per cent by use of appropriate antimicrobial agents. Awareness that Haemophilus species can cause bacterial endocarditis is important because the diagnosis is dependent upon utilization of special culture methods and the patient may not respond to some of the empiric regimens used for treating bacterial endocarditis. It should be especially considered as a possible cause of "culture-negative" or "abacteremic" endocarditis.

Diarrhoea caused by Candida.

Candida proliferation in the gastrointestinal tract was responsible for diarrhoea in six patients. Their common presentation was multiple loose or watery bowel movements, without blood or mucus but sometimes associated with abdominal cramps, and lasting as long as 3 months. Yeast cells were most easily identified by direct microscopic examination of stool specimens. Symptoms disappeared in all patients after 3 to 4 days of oral nystatin therapy.