Nancy K. Henry

Leuconostoc Bacteremia in an Infant With Short-Gut Syndrome: Case Report and Literature Review

In this article, we report a case of Leuconostoc bacteremia in a 7-month-old infant who had short-gut syndrome after a gastroschisis repair and who was dependent on total parenteral nutrition through a central venous catheter. The organism was initially misidentified as viridans group streptococcus. Detection of vancomycin resistance led to the correct diagnosis of Leuconostoc species. The patient was successfully treated with ampicillin and an aminoglycoside. A review of the literature revealed prematurity, short-gut syndrome, prior vancomycin use, and central venous catheters as important predisposing factors. Leuconostoc species is an emerging pathogen that should be considered in the differential diagnosis of vancomycin-resistant gram-positive bacteremia, particularly in these clinical settings.

Empiric antibiotic therapy for acute osteoarticular infections with suspected methicillin-resistant Staphylococcus aureus or Kingella.

The bacterial agents causing bone and joint infections have been changing. Currently, methicillin-resistant Staphylococcus aureus (MRSA) and Kingella kingae are emerging pathogens. For treatment of MRSA infections, clindamycin, vancomycin, and linezolid are commonly prescribed antibiotics. Kingella are sensitive to most penicillins and cephalosporins. Because MRSA osteoarticular infections tend to be severe, longer periods of antibiotic treatment with more frequent monitoring of inflammatory markers are sometimes required to obtain a complete cure with no residual complications. To assist management, we have included a clinical decision tree with antibiotic treatment protocols.

Ciprofloxacin Versus Trimethoprim-Sulfamethoxazole: Treatment of Community-Acquired Urinary Tract Infections in a Prospective, Controlled, Double-Blind Comparison

In this study, we determined the safety and efficacy of the treatment of adults with urinary tract infection with ciprofloxacin hydrochloride (250 mg twice daily for 10 days) in comparison with trimethoprim-sulfamethoxazole (160 mg of trimethoprim and 800 mg of sulfamethoxazole twice daily for 10 days). Patients with signs and symptoms of urinary tract infection were randomized to receive ciprofloxacin (98 women and 5 men) or trimethoprim-sulfamethoxazole (92 women and 8 men). The success rate of therapy was 91% for both treatment arms of the study. Among seven failures after ciprofloxacin therapy, three were due to relapse of infection and two to side effects that necessitated a change in medication; in addition, two patients had persistent symptoms and required hospitalization. Among the six failures associated with trimethoprim-sulfamethoxazole therapy, four were due to relapse, one to persistence of infection, and one to a side effect that necessitated a change in medication. Among the patients treated with trimethoprim-sulfamethoxazole, 32% had mild or moderate adverse reactions; in comparison, 17% of the ciprofloxacin-treated patients had adverse reactions (P = 0.026). For the treatment of urinary tract infection in adult patients in this study, ciprofloxacin and trimethoprim-sulfamethoxazole were equally effective, but ciprofloxacin was associated with fewer adverse reactions.

Fatal post-operative Trichoderma longibrachiatum mediastinitis and peritonitis in a paediatric patient with complex congenital cardiac disease on peritoneal dialysis.

Trichoderma longibrachiatum is an emerging pathogen in immunocompromised patients. We report a case of Trichoderma post-operative mediastinitis and peritonitis in a child with complex congenital cardiac disease and functional asplenia. The patient was treated unsuccessfully, initially with caspofungin alone followed by a combination of voriconazole (systemic and topical), caspofungin and intraperitoneal amphotericin B.

Empiric Therapy With Moxalactam Alone in Patients With Bacteremia

Moxalactam was administered (20 mg/kg intravenously every 8 hours) as single-drug empiric antimicrobial therapy to 63 patients with bacteremia who were neither neutropenic nor immunosuppressed. Six patients (10%) had microorganisms that were susceptible to moxalactam and resistant to all other antimicrobial agents tested; two patients (3%) had microorganisms that were resistant to moxalactam and other agents tested. Of these 63 patients, 47 (75%) were cured with moxalactam therapy. Nine patients (14%) had breakthrough bacteremia while receiving other antimicrobial therapy and were cured subsequently with moxalactam therapy alone. The two major risk factors for failure of moxalactam therapy were polymicrobial bacteremia and an extrahepatic intra-abdominal source of infection; these two conditions frequently coexisted. Six of nine patients with polymicrobial bacteremia died. Superinfection (one pseudomonal, five enterococcal) was responsible for 6 of the 16 treatment failures. Enterococcal superinfection occurred exclusively among patients who had received relatively prolonged therapy with moxalactam for extrahepatic intra-abdominal infection, especially intraabdominal abscess. These five patients died, and postmortem examination showed that enterococcal superinfection was the major cause of death in all. Mild, reversible adverse reactions associated with use of moxalactam occurred in 14 of the 63 patients (22%). None had clinically overt bleeding. The use of moxalactam alone seems to be safe and effective and a cost-effective alternative empiric antimicrobial therapy for most patients with bacteremia who are not immunosuppressed or neutropenic and who are not at high risk of having Pseudomonas or polymicrobial bacteremia.

Antimicrobial Therapy for Infants and Children: Guidelines for the Inpatient and Outpatient Practice of Pediatric Infectious Diseases

In this article, we discuss antimicrobial regimens for both outpatient and inpatient use in infants and children. A substantial number of pediatric patient visits annually result in the prescribing of antimicrobial drugs. The emergence of bacteria resistant to commonly used antimicrobial agents is a growing concern. Information on newer drugs such as meropenem, which is active against penicillin-resistant Streptococcus pneumoniae and gram-negative bacilli, and cefepime, which has activity against gram-negative bacilli including Pseudomonas aeruginosa and against gram-positive cocci is also presented. Management of patients with congenital or acquired immunodeficiencies continues to be challenging in regard to the use of antimicrobial drugs to treat various fungal and viral infections. New formulations of older drugs such as aerosolized tobramycin and amphotericin B lipid complex are available. New antiviral agents have been approved, most of which are antiretroviral agents. Childhood tuberculosis is an ongoing concern, and regimens to treat Mycobacterium tuberculosis in children are discussed.

Antibiotic Therapy for Severe Infections in Infants and Children

In infants and children, the absorption, distribution, metabolism, and excretion of drugs may differ considerably in comparison with these factors in adults; consequently, differences exist in therapeutic efficacy and toxicity of various antibiotic agents. Because of known toxicity, certain drugs--such as chloramphenicol in high doses, the sulfonamides, and tetracycline--should not be used in neonates. Antibiotic therapy should be modified in neonates because of biologic immaturity of organs important for the termination of drug action. Because of poor conjugation, inactivation, or excretion, the serum concentrations of many antibiotics may be higher and more prolonged in neonates than in older infants; thus, lower doses and longer intervals between administration may be necessary. In this article, we suggest dosages of antimicrobial agents for severe infections in children, older infants, and neonates. Included in the discussion are the cephalosporins, especially the third-generation cephalosporins that have assumed an important role in empiric treatment of bacterial meningitis in pediatric patients because of their ability to penetrate the central nervous system and their effectiveness against beta-lactamase-positive and negative strains of Haemophilus influenzae type b, Streptococcus pneumoniae, Neisseria meningitidis, and many gram-negative bacteria in the Enterobacteriaceae group. In patients with congenital or acquired immunodeficiencies, antifungal, antiviral, or anti-Pneumocystis agents are often added to the antimicrobial regimen for severe infections. We review the agents available for such treatment in children, the drugs used for childhood tuberculosis, and certain new antibiotics (aztreonam, ticarcillin-clavulanate, ciprofloxacin, and imipenem-cilastatin) that have proved useful in select cases but whose precise role in pediatric practice will necessitate additional clinical experience.

Comparison of agar dilution, broth dilution, disk diffusion, and the E-test for susceptibility testing of penicillin-susceptible and penicillin-resistantStreptococcus pneumoniae

An evaluation to determine the optimal methods for the in vitro susceptibility testing of 41 clinical isolates and the ATCC 49619 strain ofStreptococcus pneumoniae to penicillin was undertaken. No very major or major interpretive errors were observed with the following test methods and media: agar dilution using either Mueller-Hinton medium with lysed horse blood or Haemophilus test medium; broth dilution using cation-adjusted Mueller-Hinton medium with lysed horse blood, Haemophilus test medium, or Todd-Hewitt medium; and the epsilometer test (E-test) using agar containing Mueller-Hinton medium and 5% sheep blood. The disk diffusion method using agar containing Mueller-Hinton medium and 5% sheep blood agar was an effective screening method, requiring confirmation by a dilution susceptibility test method.

Desulfovibrio legallii prosthetic shoulder joint infection and review of antimicrobial susceptibility and clinical characteristics of Desulfovibrio infections.

ABSTRACT We describe a case of shoulder hemiarthroplasty infection with Desulfovibrio legallii. Antimicrobial susceptibilities of 36 Desulfovibrio isolates are presented. Metronidazole and carbapenems exhibited reliable activity, although piperacillin-tazobactam did not. Eleven previous cases of Desulfovibrio infection are reviewed; most arose from a gastrointestinal tract-related source.

Initial detection of bacteremia by subculture of unvented tryptic soy broth blood culture bottles

Routine subculture of macroscopically negative blood cultures is a traditional blood culture procedure. The need to perform routine early (6-17 hr) and late (48 hr) subculture of unvented blood culture bottles when a simultaneous subculture of the vented bottle is performed has been questioned. Blood cultures in paired vented and unvented tryptic soy broth (TSB) bottles from 4574 patients were examined retrospectively. Subculture of unvented TSB bottles provided initial detection of 412 (5.0%) isolates from 277 (6.1%) patients and was comparable to that of vented TSB bottles for Pseudomonas and all other microorganisms, except for the Enterobacteriaceae (p less than 0.001; vented TSB), Candida (p less than 0.001; vented TSB), and Haemophilus influenzae (p less than 0.01; unvented TSB). Of the H. influenzae isolates, 46% were detected initially by subculture of the unvented TSB bottles; early subculture recovered 67% of these isolates. The value of subculture of unvented TSB bottles is minimized when subculture of the vented TSB bottle is routinely performed; however, routine subculture of the unvented bottle is recommended whenever TSB is used for detection of bacteremia in patients in whom H. influenzae infection is possible.