Methicillin-resistant Staphylococcus aureus (MRSA) in hospitalized children: correlation of molecular analysis with clinical presentation and antibiotic susceptibility testing (ABST) results.

The molecular analysis of methicillin-resistant Staphylococcus aureus (MRSA) from 98 children admitted to the Children's Hospital of Michigan, Detroit, MI, with serious MRSA infections during 2006-2007 was correlated with risk factors, clinical features, and antibiotic susceptibility testing (ABST) results. Isolates were characterized by staphylococcal cassette chromosome (SCC) mec type, the presence of Panton-Valentine leukocidin (PVL) genes, repetitive sequence (rep) polymerase chain reaction (PCR) and pulsed-field gel electrophoresis (PFGE), requirement for surgical intervention, antibiograms, and response to therapy. rep-PCR was more rapid than PFGE typing and correlated well. SCCmec type IV-containing isolates caused 92.8% of all infections, but the demographics and diseases associated with subtypes IVa and IVd differed. Subtype IVa (all PFGE type USA300 and PVL-positive) was identified in 81/93 (87.1%) of patients with community-onset (CO) MRSA, including 21/35 of those with risk factors for health care-associated (HA) infection. All other clones were PVL-negative. Subtype IVd (10 isolates; 9 USA800 and 1 eMRSA15) caused mainly HA-MRSA and no skin and soft tissue infections (SSTI). Seven classic HA-MRSA strains (SCCmec types II [6; 3 USA100 and 3 USA600] and III [1; USA200]) caused HA and hospital-onset (HO) infections. Surgical intervention was required in 68/81 patients infected with USA300 and 8/17 of the others. Most USA300 were susceptible (S) to clindamycin (CD) and patients were treated with CD alone or in combination. The other isolates were generally treated with vancomycin (VA) alone or in combination.

Anti-herpes viruses agents.

Antiviral agents with demonstrated efficacy are currently available for the management of infections in children caused by the herpes viruses including herpes simples type 1 (HSV1) and type 2 (HSV2), varicella-zoster virus (VZV), and cytomegalovirus (CMV). Recently, progress has been made in the development of newer agents with enhanced activity against these viruses including resistant strains. This review focuses on the activity, clinical pharmacology, and clinical indications of antiviral agents used in the treatment of infections caused by the different herpes viruses in children.

Antiviral therapy: respiratory infections, chronic hepatitis.

This review focuses on the activity, clinical pharmacology, and clinical indications of antiviral agents used in the management of influenza, respiratory syncytial virus infections, and chronic hepatitis B and C. Two neuraminidase inhibitors, a new class of antiviral agents, were recently approved for the treatment of influenza A and B in children.

Prevalence of penicillin-nonsusceptible Streptococcus pneumoniae in nasopharyngeal cultures from patients with sickle cell disease.

BACKGROUND: Prevention of pneumococcal sepsis in children with sickle cell disease (SCD) is threatened by the emergence of penicillin-nonsusceptible pneumococci. METHODS: In this study, nasopharyngeal colonization with Streptococcus pneumoniae and penicillin susceptibility were compared in children with SCD and a control group. Nasopharyngeal cultures were obtained from 130 children with SCD and 123 control children. Penicillin susceptibility was determined by Epsilometer test. Compliance with penicillin prophylaxis in SCD patients was determined by parent interviews and review of patients' medical and pharmacy records. RESULTS: Streptococcus pneumoniae was isolated from 8 (6%) of 130 SCD patients, and 21 (17%) of 123 control patients. Of the 29 S pneumoniae isolates, 6 (21%) were nonsusceptible to penicillin; 4 of 8 (50%) were from the SCD group and 2 of 21 (10%) from the control group. CONCLUSIONS: Penicillin prophylaxis decreased the rate of S pneumoniae colonization in SCD patients; however, it also increased the risk of selective colonization with penicillin-nonsusceptible S pneumoniae.

Yersinia enterocolitica infection in children.

BACKGROUND: Yersinia enterocolitica can cause illness ranging from self-limited enteritis to life-threatening systemic infection. The present study was undertaken to review the epidemiology, clinical manifestations, complications and outcome of Y. enterocolitica enteritis in children seen at a large children's hospital. METHODS: The project consisted of a retrospective chart review of medical and microbiologic records of all children with stool cultures positive for Y. enterocolitica during a 7-year period. RESULTS: The review included 142 patients with Y. enterocolitica enteritis. Patients' ages ranged from 18 days to 12 years, and the majority (85%) were younger than 1 year. Most patients presented during November, December and January. History of exposure to chitterlings (raw pork intestines) at home was elicited in 25 of 30 cases. Y. enterocolitica accounted for 12.6% (142 of 1,120) of all bacterial intestinal pathogens isolated during the study period. Blood cultures were positive in 7(9%) of 78 patients; 6 were younger than 1 year and one 12-year-old had sickle cell disease. Of 132 isolates tested all were susceptible to trimethoprim-sulfamethoxazole, tobramycin and gentamicin; the majority were susceptible to cefotaxime (99%), ceftazidime (89%) and cefuroxime (88%). All bacteremic patients responded to cefotaxime treatment. Follow-up evaluation of 40 ambulatory patients revealed no difference in clinical improvement between those treated with oral trimethoprim-sulfamethoxazole (17 of 23) and those who were not treated (8 of 17) (P = 0.1). CONCLUSION: Y. enterocolitica is an important cause of enteritis in our young patient population during the winter holidays. Exposure of infants to chitterlings appears to be a risk factor. Infants younger than 3 months are at increased risk for bacteremia. Cefotaxime is effective in the treatment of Y. enterocolitica bacteremia; however, the role of oral antibiotics in the management of enteritis needs further evaluation.

Moraxella catarrhalis bacteremia: a 10-year experience.

BACKGROUND: Moraxella catarrhalis commonly inhabits the upper respiratory tract and is a cause of acute otitis media and sinusitis in children. It is an infrequent cause of invasive disease. METHODS: We reviewed records of all patients with positive blood cultures for M catarrhalis admitted to our hospital during the 10-year period (1988 through 1997). RESULTS: Eleven cases were identified. Age range was 11 to 32 months. Four (44%) had risk factors for infection, including sickle cell disease (2), acquired immunodeficiency syndrome (AIDS) (1), and leukopenia (1). Upper respiratory symptoms and fever were present in all patients. Ten had acute otitis media, five had sinusitis, and three had pneumonia. All isolates were beta-lactamase producers. Treatment included intravenous cefuroxime (8), cefotaxime (2), and ceftazidime (1), followed by oral amoxicillin/clavulanate or cefuroxime axetil. CONCLUSION: Moraxella catarrhalis bacteremia should be considered in febrile young children with upper respiratory infections and/or acute otitis media especially in those with underlying immune dysfunction.

Cytokine regulation of CD40 expression in fetal human astrocyte cultures.

CD40 can participate in inflammatory processes after binding its cognate ligand (CD40L). We found that fetal human astrocytes constitutively express CD40 mRNA and protein. Upon incubating cultures with proinflammatory cytokines (TNF-alpha, IL-1beta and IFN-gamma) or with lipopolysaccharide (LPS), CD40 expression was increased. No change in CD40 expression was noted in astrocyte cultures incubated with IL-6, HIV or gp41. Astrocytes also showed increased release of proinflammatory cytokines TNF-alpha, IL-1beta and IL-6 after incubation with CD40L peptide. These observations suggest a role for CD40 in central nervous system (CNS) inflammation and that CD40/CD40L autocrine or paracrine pathways may mediate this role.

Are the Duke criteria superior to the Beth Israel criteria for the diagnosis of infective endocarditis in children?

Accurate diagnosis of infective endocarditis may be difficult. The Beth Israel criteria and the newer Duke criteria assign probability to the diagnosis of infective endocarditis on the basis of the presence of common features and manifestations. We reviewed 111 cases of pediatric infective endocarditis diagnosed and treated over 19 years. Each case was classified by the two criteria, and the results were compared. Of 111 cases, 73 (66%) and 18 (16%) were classified as definite by the Duke criteria and the Beth Israel criteria, respectively. No cases were rejected by the Duke criteria, while 21 (19%) of 111 were rejected by the Beth Israel criteria. In 18 pathologically proven cases, reanalysis without pathological data showed that the Duke criteria had significantly greater sensitivity (83%) than the Beth Israel criteria (67%) (P < .03). Echocardiographic evidence was required in 22 cases for definite classification by the Duke criteria; none were rejected, however, when echocardiographic findings were ignored. Our results suggest that the Duke criteria are superior to the Beth Israel criteria for the diagnosis of pediatric infective endocarditis.