Methicillin-resistant Staphylococcus aureus mandibular osteomyelitis in an extremely low birth weight preterm infant.

Methicillin-resistant Staphylococcus aureus (MRSA) is an established nosocomial pathogen with frequent multidrug resistance. The immaturity of the immune system along with intravascular lines and empirical antibiotic treatments place hospitalized preterm infants at major risk of MRSA infection.We report a case of MRSA mandibular osteomyelitis complicating a persistent S. aureus bacteremia in a 23-week preterm infant. From the first weeks of life, the infant showed recurrent C-reactive protein (CRP) elevation, associated with S. aureus bacteremia. Antibiotic courses, including vancomycin and linezolid, were performed with transitory normalization of blood parameters. On day 74, the infant suddenly deteriorated and showed a significant increase of both CRP and procalcitonin. Empiric vancomycin and piperacillin-tazobactam treatment was started; nevertheless, she developed a progressive hard swelling of neck and mandible. Radiological evaluation revealed a mandibular osteomyelitis complicated by an abscess, whose culture grew MRSA. Vancomycin was thus changed to teicoplanin and complete clinical and radiological healing was gradually achieved.In the presence of major risk factors, persistent bacteremia and nonspecific symptoms, a localized focus of infection should be suspected. Microbiological diagnosis should always be attempted and antibiotic treatment should be guided by both susceptibility results and clinical response.

Role of cerebral ultrasound and magnetic resonance imaging in newborns with congenital cytomegalovirus infection.

PURPOSE: To assess the diagnostic and prognostic value of cerebral magnetic resonance imaging (cMRI) in comparison with that of cerebral ultrasound (cUS) in predicting neurodevelopmental outcome in newborns with congenital cytomegalovirus (CMV) infection. METHODS: Forty CMV-congenitally infected newborns underwent cUS and cMRI within the first month of life. Clinical course, laboratory findings, visual/hearing function and neurodevelopmental outcome were documented. RESULTS: Thirty newborns showed normal cMRI, cUS and hearing/visual function in the first month of life; none showed CMV-related abnormalities at follow-up. Six newborns showed pathological cMRI and cUS findings (pseudocystis, ventriculomegaly, calcifications, cerebellar hypoplasia) but cMRI provided additional information (white matter abnormalities in three cases, lissencephaly/polymicrogyria in one and a cyst of the temporal lobe in another one); cerebral calcifications were detected in 3/6 infants by cUS but only in 2/6 by cMRI. Four of these 6 infants showed severe neurodevelopmental impairment and five showed deafness during follow-up. Three newborns had a normal cUS, but cMRI documented white matter abnormalities and in one case also cerebellar hypoplasia; all showed neurodevelopmental impairment and two were deaf at follow-up. One more newborn showed normal cUS and cMRI, but brainstem auditory evoked responses were abnormal; psychomotor development was normal at follow-up. CONCLUSIONS: Compared with cUS, cMRI disclosed additional pathological findings in CMV-congenitally infected newborns. cUS is a readily available screening tool useful in the identification of infected newborns with major cerebral involvement. Further studies with a larger sample size are needed to determine the prognostic role of MRI, particularly regarding isolated white matter lesions.