Trasmissione post-natale del citomegalovirus attraverso il latte materno al neonato VLBW

Introduction Postnatal human cytomegalovirus (CMV) infection is usually asymptomatic in term babies, while preterm infants are more susceptible to symptomatic CMV infection. Breastfeeding plays a dominant role in the epidemiology of transmission of postnatal CMV infection, but the risk factors of symptomatic CMV infection in preterm infants are unknown. Patients and Methods Between December 2003 and August 2006, eighty Very Low Birth Weight (VLBW) preterm infants (gestational age ≤ 32 weeks and birth weight < 1500 g), admitted to the Neonatal Intensive Care Unit of St Orsola-Malpighi General Hospital, Bologna were recruited. All of them were breastfed for at least one month. During the first week of life, serological test for CMV was performed on maternal blood. Furthermore, urinary CMV culture was performed in all the infants in order to exclude a congenital CMV infection. Urine samples from each infant were collected and processed for CMV culture once a week. Once every 15 days a blood sample was taken from each infant to evaluate the complete blood count, the hepatic function and the C reactive protein. In addition, samples of fresh breast milk were processed weekly for CMV culture. A genetic analysis of virus variant was performed in the urine of the infected infants and in their mother’s milk to confirm the origin of infection. Results We evaluated 80 VLBW infants and their 68 mothers. Fifty-three mothers (78%) were positive for CMV IgG antibodies, and 15 (22%) were seronegative. In the seronegative group, CMV was never isolated in breast milk, and none of the 18 infants developed viruria; in the seropositive group, CMV was isolated in 21 out of 53 (40%) mother’s milk. CMV was detected in the urine samples of 9 out of 26 (35%) preterm infants, who were born from 21 virolactia positive mothers. Six of these infants had clinically asymptomatic CMV infection, while 3 showed a sepsis-like illness with bradycardia, tachypnea and repeated desaturations. Eight out of nine infants showed abnormal hematologic values. The detection of neutropenia was strictly related to CMV infection (8/9 infected infants vs 17/53 non infected infants, P<.005), such as the detection of an increase in conjugated bilirubin (3/9 infected infants vs 2/53 non infected infants, P<.05). The degree of neutropenia was not different between the two groups (infected/non infected). The use of hemoderivatives (plasma and/or IgM–enriched immunoglobulin) in order to treat a suspected/certain infection in newborn with GE< 28 ws was seen as protective against CMV infection (1/4 infected infants vs 18/20 non infected infants [GE<28 ws]; P<.05). Furthermore, bronchopulmonary dysplasia (defined both as oxygen-dependency at 30 days of life and 36 ws of postmenstrual age) correlated with symptomatic infection (3/3 symptomatic vs 0/6 asymptomatic: P<.05). Conclusion Our data suggest that CMV infection transmitted to preterm newborn through human milk is always asymptomatic when newborns are clinically stable. Otherwise, the infection can worsen a preexisting disease such as bronchopulmonary dysplasia. Human milk offers many nutritional and psychological advantages to preterm newborns: according to our data, there’s no reason to contraindicate it neither to pasteurize the milk of all the mothers of preterm infants who are CMV seropositive.

Functional and Genetic characterization of new genomic islands from an E. coli strain associated with neonatal meningitis.

Enterobacteriaceae genomes evolve through mutations, rearrangements and horizontal gene transfer (HGT). The latter evolutionary pathway works through the acquisition DNA (GEI) modules of foreign origin that enhances fitness of the host to a given environment. The genome of E. coli IHE3034, a strain isolated from a case of neonatal meningitis, has recently been sequenced and its subsequent sequence analysis has predicted 18 possible GEIs, of which: 8 have not been previously described, 5 fully meet the pathogenic island definition and at least 10 that seem to be of prophagic origin. In order to study the GEI distribution of our reference strain, we screened for the presence 18 GEIs a panel of 132 strains, representative of E. coli diversity. Also, using an inverse nested PCR approach we identified 9 GEI that can form an extrachromosomal circular intermediate (CI) and their respective attachment sites (att). Further, we set up a qPCR approach that allowed us to determine the excision rates of 5 genomic islands in different growth conditions. Four islands, specific for strains appertaining to the sequence type complex 95 (STC95), have been deleted in order to assess their function in a Dictyostelium discoideum grazing assays. Overall, the distribution data presented here indicate that 16 IHE3034 GEIs are more associated to the STC95 strains. Also the functional and genetic characterization has uncovered that GEI 13, 17 and 19 are involved in the resistance to phagocitation by Dictyostelium d thus suggesting a possible role in the adaptation of the pathogen during certain stages of infection.