Primary sternal osteomyelitis due to community-associated methicillin-resistant<Emphasis Type="Italic"> Staphylococcus aureus</Emphasis>: case report and literature review

Primary sternal osteomyelitis is a rare infectious disease in paediatric patients. It has not been previously reported as caused by community-associated methicillin-resistant Staphylococcus aureus. We describe a 9-year-old boy with a painful erythematous mid-sternal mass diagnosed as primary sternal osteomyelitis. The aetiological agent was community-associated methicillin-resistant Staphylococcus aureus, carrying a type IV staphylococcal cassette chromosome for mec. Conclusion:Methicillin resistance should be taken into considered in patient with community-associated staphylococcal infections.     

Low prevalence of methicillin-resistant Staphylococcus aureus (MRSA) in a southwestern region of Germany

Introduction Methicillin-resistant Staphylococcus aureus (MRSA) has developed into an important human pathogen and is increasingly being found to be the cause of skin and soft tissue infections or invasive infections in many communities. We have determined the prevalence of MRSA among S. aureus isolates from pediatric in- and outpatients of the University Children’s Hospital of Freiburg, from children attending primary care pediatricians and from healthy children entering school in a prospective study carried out in a southwestern region of Germany. Of the healthy children tested, all between 5 and 7 years of age, 25.8% were intra-nasally colonized with S. aureus. A total of 1455 S. aureus isolates were tested for antibiotic susceptibility. Apart from penicillin resistance (82.1%), an overall high susceptibility of S. aureus to antibiotics, including clindamycin, was common, while resistance among the S. aureus isolates to erythromycin and clindamycin had even significantly decreased from 2002 to 2004. Methicillin-resistance was exceedingly rare (0.3%).Conclusion In the southwestern region of Germany, about one quarter of the healthy children tested at school entry were found to be colonized with S. aureus. The prevalence of MRSA among healthy as well as hospitalized children colonized with S. aureus is still extremely rare in this region.     

Specific Responses to Staphylococcus aureus in Patients with Hyper-lgE Syndrome

Specific responses to Staphylococcus aureus (S.aureus) were assessed to prove a decrease or defect of specific protection against S.aureus in patients with hyper-IgE syndrome (HIES). Interleukin-1 (IL-1) production, interleukin-2 (IL-2) production and response to IL-2 were studied in three groups (A —patients with HIES, B — control patients with S.aureus infections, C — healthy controls). When lymphocytes or monocytes (Mo) were stimulated by lectins, there was no difference in the three groups. In the experiments concerning IL-1 derived from Mo activated by S.aureus, the proliferation of cultured fibroblasts showed higher levels of DNA synthesis in the A or B group than in the C group. The IL-2 derived from peripheral blood lymphocytes (PBL) activated by S.aureus showed higher levels of activity in the B group than in the A or C group. The response to IL-2 in the A group was decreased as compared with the C group, and a control patient aged 7 years showed the highest level of all subjects. When PBL were activated by S.aureus as a specific antigen, both IL-2 production and response to IL-2 showed lower levels of activity in the A group than in the B group. These results indicated that there was a defect or decrease of specific protection against S.aureus in patients with HIES.     

False aneurysm of the right ventricle due to endocarditis in a child

Summary An eight-year-old boy with supravalvular pulmonic stenosis, supravalvular aortic stenosis, and ventricular septal defect developedStaphylococcus aureus endocarditis. The infection was complicated by formation of a false aneurysm of the right ventricular outflow tract, which was demonstrated by contrast echocardiogram. Surgical treatment was successful. This is a unique case of false aneurysm of the outflow tract of the right ventricle, because it is secondary to endocarditis without known previous trauma to the right ventricular wall.     

TUFTSIN DEFICIENCY SYNDROME A Report of Two New Cases

Two families with deficiency in the phagocytosis stimulating peptide, tuftsin, are reported. Both cases gave a history of recurrent infections. In the first case, (D. I.) all infection involved only external surfaces. The second patient (W. M.) showed involvement of internal organs with septicimia pneumonia and liver abcess in addition to skin lesions. In both cases, Staphylococcus aureus was the infecting organism.     

Bacteremia in children at the University Hospital in Riyadh, Saudi Arabia

Background  Bacteremia is a major pediatric health care problem despite the availability of new modalities in the management of this disease. The aim of the present study was to determine the incidence and pattern of bacteremia in pediatric group at a tertiary hospital in Riyadh, Saudi Arabia. Methods  This retrospective study was conducted at the Department of Pediatrics, College of Medicine, King Khalid University Hospital, Riyadh in the period of January 2003 to January 2005. Positive culture was found in 259 patients aged below 15 years with a total of 8244 admissions in the period. Results  The highest incidence of bacteremia was found in patients aged less than 1 year (57.9%), and the majority of patients (30.5%) were infants aged less than 1 month. Staphylococcus aureus was the most common isolated pathogen (18.7%). Prematurity was associated with 13.2% of the cases, and respiratory tract infection (10.1%) and fever (76.1%) were chief complaints. Conclusions   Staphylococcus aureus is the most common isolated pathogen. The most common primary infections are respiratory tract infection and septic meningitis. Klebsiella pneumoniae and E. coli are the most common isolated Gram-negative organisms.     

Staphylococcus aureus epidemic in a neonatal nursery: a strategy of infection control

The risk of nosocomial infection due to Staphylococcus aureus in fullterm newborns is higher under hospital conditions where there are overcrowded nurseries and inadequate infection control techniques. We report on an outbreak of skin infection in a Maternity Nursery (May 21, 2000) and the measures undertaken to bring the epidemic under control. These measures included: separating neonates already present in the nursery on August 23, 2000 from ones newly arriving by creating two different cohorts, one of neonates born before this date and one of neonates born later; restricting healthcare workers caring for S. aureus- infected infants from working with non-infected infants; disallowing carrier healthcare workers from caring for patients; introducing contact and droplet precautions (including the routine use of gowns, gloves, and mask); ensuring appropriate disinfection of potential sources of contamination. A representative number of isolates were typed by genomic DNA restriction length polymorphism analysis by means of pulsed-field gel electrophoresis (PFGE). Among the 227 cases of skin lesions, microbiological laboratory analyses confirmed that 175 were staphylococcal infections. The outbreak showed a gradual reduction in magnitude when the overcrowding of the Nursery was reduced by separating the newborns into the two different Nurseries (two cohorts). The genotyping of the strains by PFGE confirmed the nurse-to-newborn transmission of S. aureus. The measures adopted for controlling the S. aureus outbreak can, in retrospect, be assessed to have been very effective.     

Abdominal wall and psoas abscesses in children

Seventy-seven cases of pyogenic abdominal wall abscess and 33 cases of psoas abscess admitted to the Red Cross Children's Hospital are reviewed separately. The difficulty encountered in diagnosis, particularly in deep-seated abdominal wall abscesses, is emphasised as resulting in delays in treatment. Ultrasound accurately delineated the abscess in 80% of cases submitted for this investigation. Surgical drainage proved effective therapy, and Staphylococcus aureus was the causative organism in more than 80%. No long-term sequelae were encountered. Offprint requests to: R. A. Brown     

Evaluation of humoral immunity and protective efficacy of biofilm producing Staphylococcus aureus bacterin-toxoid prepared from a bovine mastitis isolate in rabbit

Mastitis is a one of the major diseases of dairy animals. Staphylococcus aureus is the most common microorganism associated with this dairy scourge. Cure rates of mastitis associated with this pathogen are appallingly low. Biofilm is an important virulence factor and immunogenic structure of S. aureus that makes it resistant to phagocytosis and antibiotics. Reports on the efficacy of vaccine prepared from a biofilm producing S. aureus are infrequent. The present study was designed to evaluate the role of a bacterin-toxoid prepared from a strong biofilm producing S. aureus in effective immunization of rabbits. The strong biofilm producing S. aureus selected from 64 isolates of staphylococci was used to prepare bacterin-toxoid and aluminum hydroxide gel was added as an adjuvant. The vaccine was evaluated in rabbits by challenge protection assay and humoral immune response. The mortality rates in control and vaccinated groups were 80% and 10% at day 7 post challenge and 100% and 20% at day 15 post challenge, respectively. Serum antibody titer (GMT) was significantly higher (294.0) in vaccinated group as compared to control group of rabbits (2.63) at day 45. The results showed that the vaccine has significantly elicited humoral immune response in rabbit and developed protective efficacy against new infections.Key Words: Mastitis, Staphylococcus aureus, Biofilm production, Immune response, Rabbit     

Neutrophil Receptors

We studied two interesting patients with neutrophil dysfunction: one is a patient with hyper-IgE syndrome with the serum inhibitor which belongs to IgE class and the other is characterized by defective phagocytosis confined to S. aureus. These patients suggested to us the presence of IgE receptors and receptors for S. aureus on neutrophils. The presence of IgE receptors on neutrophils was proved by the fact that neutrophils preincubated with 10 μg of pure IgE generated O^-₂ on stimulation with F(ab')₂, fragments of pure anti-K chain antibody or anti-K chain antibody. The presence of IgE receptors was also suggested by the suppressive effect of IgE soluble immune complexes on neutrophil chemotaxis. Neutrophils of the patient with defective phagocytosis confined to S. aureus could not generate O^-₂ with unopsonized S. aureus, while control neutrophils generated a significant amount of O^-₂ on addition of unopsonized S. aureus. Colchicine treated control neutrophils also could not generate O^-₂ by unopsonized S. aureus. These data suggested the presence of receptors for S. aureus on neutrophils.     

Thigh pain due to obturator internus phlegmon: A diagnostic challenge

A 9-year-old boy with thigh pain, high fever, hyperleukocytosis and positive blood cultures forStaphylococcus aureus had a left obturator internus phlegmon. Lack of evidence for hip infection or osteomyelitis in a child with thigh pain, high fever and hyperleukocytosis points to a possible infection of pelvic structures. Abscess or phlegmon of the obturator internus muscle is a very rare condition. The most frequent agent isStaphylococcus aureus. CT of the pelvis is the procedure of choice to show diffuse swelling of the muscle or collection of pus. Conservative treatment with adequate antibiotics is the treatment of choice.     

Neonatal orbital abscess

Orbital abscess is life‐threatening and rare in children. Reported herein is a term male neonate who had methicillin‐resistant Staphylococcus aureus orbital abscess, and a literature review of this disease. A total of 16 neonates diagnosed with neonatal orbital abscess are reported in the literature. There is a mild male predilection and two neonates were delivered prematurely. Leukocytosis, fever, ethmoiditis and associated upper respiratory tract infection were found in approximately half of them. Eight neonates had sepsis and 14 patients underwent surgical intervention. One patient died. Staphylococcus aureus was identified in 14 out of 17 patients. Neonatal orbital abscess is rarely encountered but may be fatal. Although streptococci are prevalent in childhood orbital infection, S. aureus was predominant in neonatal orbital abscess in the present series. Appropriate antimicrobial therapy against S. aureus is essential in treating neonatal orbital abscess. This case suggests that a higher initial dose of vancomycin may be an effective and safe strategy for severe S. aureus infection in neonates.     

A case of milk-protein-induced enterocolitis associated with enterotoxigenic E. coli and MRSA infections

Food protein-induced enterocolitis (FPIE) is a severe, cell-mediated gastrointestinal food hypersensitivity typically provoked by cow’s milk [Joint Task Force of AAAAI and ACAAI Food allergy: a practice parameter. XVII. Differential diagnosis of adverse reaction to foods. Ann Allergy Asthma Immunol 96(3 Suppl 2):S40–S44 (2006)]. We present an infant who developed FPIE associated with enterotoxigenic E. coli (ETEC) and methicillin-resistant Staphylococcus aureus (MRSA) infections. The case suggests that enteral infection may have a role in the development of sensitization to food protein and the pathogenesis of FPIE.     

Lytic rib lesion in a 1-year-old child: group A beta streptococcal osteomyelitis mimicking tumor

Pediatric osteomyelitis commonly occurs in the long bones and has rarely been reported in small bones such as the vertebrae and ribs. Rib osteomyelitis occurs in approximately 1% or less of all cases of hematogenous osteomyelitis, and is usually caused by Staphylococcus aureus. We present a case of acute osteomyelitis in the rib of an otherwise healthy and afebrile 1-year-old infant that appeared as a lytic bone lesion on imaging studies and was mistaken for a tumor. Biopsy was needed to rule out malignancy and establish the diagnosis of osteomyelitis caused by group A Streptococcus. This is one of the few reported cases of pediatric rib osteomyelitis caused by this organism.     

A high prevalence of methicillin-resistant Staphylococcus aureus among surgically drained soft-tissue infections in pediatric patients

Over the past decade, methicillin-resistant Staphylococcus aureus (MRSA) has emerged as a global problem, prompting extensive surveillance efforts. A previous study of S. aureus isolates at our institution revealed alarming increases in the prevalence of MRSA with no sign of plateau. However, evidence of MRSA in pediatric surgical patients remains largely anecdotal, as there are no published reports of institutional MRSA surveillance in the pediatric surgical literature. We conducted a retrospective review of incision and drainage (I and D) procedures at our institution from 1998 through 2004. All I and D procedures performed at the University of Chicago Children’s Hospital were identified and the patients’ charts reviewed for pertinent information. A total of 99 I and D procedures were performed during the study period, ranging from 5 in 1998 to 32 in 2004. Among cultures with positive growth, 52 (65.8%) were MRSA, 14 (17.7%) were methicillin-sensitive S. aureus, and 13 (16.5%) were miscellaneous species. The number of MRSA isolates increases from 2 in 1998 to 20 in 2004, the largest increase occurring during the last 3 years of the study. A large proportion of MRSA isolates were resistant to antimicrobials from other classes, with over 70% being resistant to both erythromycin and cefazolin. A majority of MRSA isolates (71.4%) were obtained from patients with no record of prior hospitalization. Our analysis confirms a high prevalence of MRSA among soft-tissue infections requiring surgical drainage. In addition, a majority of MRSA isolates were resistant to multiple antimicrobials and were isolated from children without a previous documented exposure to the hospital milieu. Thus, pediatric surgeons should be aware of MRSA prevalence and resistance patterns in the local communities.     

IgE and IgG Antibodies to Staphylococcus aureus Solubilized Cell Wall Proteins and Teichoic Acid in Patients with the Hyper-IgE Syndrome

The anti-staphylococcal IgE and IgG antibody levels of patients with hyper-IgE syndrome (HIE) were measured by microtiter solid phase radioimmunoassay (MSPRIA) and enzyme-linked immunosorbent assay (ELISA) using solubilized cell wall proteins (SCWP) and teichoic acid extracted from Staphylococcus aureus. Using MSPRIA, specific IgE antibodies to SCWP were detected at significant levels in all 5 patients with HIE, but not in 23 patients with atopic allergy or Wiskott-Aldrich syndrome with or without staphylococcal infections. IgG antibodies to SCWP and teichoic acid were lower in the patients with HIE than those in non-allergic infectious controls. These findings suggest an abnormal immunologic response to Staphylococcus aureus in patients with HIE.     

Antimicrobial susceptibility of Staphylococcus aureus in children with atopic dermatitis

Background: Skin infection and/or nasal carriage of Staphylococcus aureus in children with atopic dermatitis (AD) is a risk factor for exacerbating disease or subsequent recurrent S. aureus infection. The purpose of the study is to evaluate the antibiotic susceptibilities of S. aureus strains from AD children and determine the most appropriate choice of antibiotics. Methods: Nasal swabs from 168 healthy children with AD and 20 AD children with concurrent skin and soft‐tissue infections (SSTI) were collected in 2005–2008. S. aureus strains were further analyzed for and compared with antibiotic susceptibilities. Results: There were 78 (46.4%) healthy children with AD colonized with S. aureus, and 24 (30.8%) were methicillin‐resistant S. aureus (MRSA). Among the 20 SSTI‐infecting strains, 12 (60%) were MRSA. Antimicrobial susceptibility testing showed that, after penicillin, colonizing and SSTI‐infecting strains had the highest rates of resistance to erythromycin (50% and 70%, respectively). All isolated strains were susceptible to vancomycin, rifampin, and mupirocin. Multi‐drug resistance was found in 70% of the colonizing and 50% of the SSTI‐infecting strains. D‐test assay revealed inducible clindamycin resistance in 75% of the colonizing strains. The most prevalent resistance gene was ermB which was present in 94.9% and 92.9% of colonizing and SSTI‐infecting strains, respectively. Conclusions: This study found that colonizing and SSTI‐infecting strains of S. aureus from AD children had a high prevalence of MRSA and multi‐drug resistance. Trimethoprim‐sulfamethoxazole, rifampin, fusidic acid and mupirocin appear to be more suitable for treatment and decolonization of S. aureus in AD children.     

Methicillin‐resistant Staphylococcus aureus bacteraemia and epidural abscess in a neonate

A 24‐day‐old boy presented with fever, irritability and poor feeding. Blood culture grew methicillin‐resistant Staphylococcus aureus. Cerebrospinal fluid analysis showed pleocytosis, and methicillin‐resistant Staphylococcus aureus grew from enrichment broth. Magnetic resonance imaging revealed an epidural abscess extending from C2–3 to T8–9. Staphylococcal infections of the central nervous system are uncommon in neonates. This case demonstrates the importance of performing a lumbar puncture in isolated staphylococcal bacteraemia. The case also highlights that cerebrospinal fluid pleocytosis may indicate a parameningeal focus of infection.     

Bacterial croup and toxic shock syndrome

An 8-year-old boy with bacterial tracheitis, treated by endotracheal intubation, humidification, airway toilet and antibiotics, experienced a toxic shock syndrome on the day after his admission. The course was favourable. Staphylococcus aureus was isolated from tracheal secretions. Bacterial tracheitis is an infrequent cause of non-menstrual toxic shock syndrome. The diagnosis of bacterial tracheitis should be suspected in a child with toxicity and croup who is not responding to the usual therapy. Endoscopy should be performed allowing for removal of the secretions. The maintenance of a clear airway is the main purpose of the treatment.Abbreviations TSS toxic shock syndrome - CNS central nervous system - CRP C-reactive protein - ICU intensive care unit     

Panton–Valentine leukocidin<Emphasis Type="Italic">-</Emphasis>associated <Emphasis Type="Italic">Staphylococcus aureus</Emphasis> necrotizing pneumonia in infants: a report of four cases and review of the literature

Four children under 16 months of age presented within an 18-month period with severe, rapidly progressive Panton–Valentine leukocidin-associated ST93 Staphylococcus aureus necrotizing pneumonia. Two of the cases that required extracorporeal membranous oxygenation and proved fatal had poor prognostic features of leukopaenia, rash and pulmonary haemorrhage. All four cases had recent contact with S. aureus infection in a family member. Reported cases of S. aureus necrotizing pneumonia in infants are reviewed, and approach to management is discussed.