D. Cipolla

Prevention of nosocomial infections and surveillance of emerging resistances in NICU

Neonates hospitalized in NICU are at risk for healthcare associated infections because of their poor immune defenses, related to gestational age, colonization of mucous membranes and skin with nosocomial microorganisms, exposure to antibiotics, invasive procedures and frequent contacts with healthcare workers (HCWs). Healthcare associated infections are the major source of morbidity and mortality in NICU in the developed world. Most infections are caused by Gram-positive organisms, fulminant sepsis are often associated to Gram-negative organisms, fungal sepsis occurs frequently in ELBW infants. Hand hygiene is the most important preventive procedure, nevertheless hand hygiene compliance among HCWs remains low. Continuous educational strategies can improve hand hygiene and contribute to reducing the incidence of neonatal infections. Other important prevention strategies include early enteral feeding with human milk, minimization and safety in the use of invasive devices, limiting unnecessary empiric broadspectrum antibiotics, eventual use of lactoferrin bifidobacteria and lactobacilli, prophylactic administration of fluconazole in VLBW. Emergence of multi drug resistant organisms (MDRO) is a worrying perspective. Methicillin-resistant Staphylococcus aureus (MRSA) is an important healthcare-associated pathogen. Active surveillance culturing for MRSA carriers, in combination with contact precautions and decolonization in some hyperendemic settings, has been proved to reduce MRSA transmission and infection rates. Multidrug-resistant Gram-negatives are frequently reported. Overuse of antimicrobial drugs and crosstransmission via caregiver hands, contaminated equipment or inanimate objects are the major drivers of selection and dissemination. Strategies to control outbreaks of MDRO colonization/infection in the NICU may include performing hand hygiene, cohorting and isolating patients, screening healthcare workers and performing admission and periodic surveillance cultures.

Outbreak of colonizations by extended-spectrum β-lactamase-producing Escherichia coli sequence type 131 in a neonatal intensive care unit, Italy

BackgroundExtended spectrum β-lactamases (ESBLs) often associated with resistance to aminoglycosides and fluoroquinolones have recently emerged in community-associated Escherichia coli. The worldwide clonal dissemination of E. coli sequence type (ST)131 is playing a prominent role.We describe an outbreak of colonizations by ESBL-producing E. coli (ESBL-E. coli) in the neonatal intensive care unit (NICU) of the University Hospital, Palermo, Italy.MethodsAn epidemiological investigation was conducted with the support of molecular typing. All children admitted to the NICU and colonized by ESBL-E. coli between January and June 2012, were included in the study. Cases were defined as infants colonized by E. coli resistant to third generation cephalosporins and fluoroquinolones. A case–control study was also performed to identify possible risk factors.ResultsDuring the outbreak period, 15 infants were found to be colonized by ESBL-E. coli. The epidemic strain demonstrated continuous transmission throughout the outbreak period. Case–control study identified a lower birth weight as the only risk factor for colonization. The strain belonged to the sequence-type 131 community-associated clone. Transmission control interventions, including contact precautions and cohorting, restriction of the new admissions, sanitization of surfaces and equipment and targeted training sessions of the NICU staff, were successful in interrupting the outbreak.ConclusionsAlthough invasive infections did not develop in any of the 15 colonized neonates, our report highlights the need to strictly monitor the spill in the NICU setting of multidrug resistant community-associated organisms. Our findings confirm also the role of active surveillance in detecting the silent spread of ESBL-producing Gram negatives in a critical healthcare setting and trigging the implementation of infection control measures. As β-lactam and fluoroquinolone resistant E. coli strains are increasingly spreading in the community, this event could become a more serious challenge.

Epidemic spread of ST1-MRSA-IVa in a neonatal intensive care unit, Italy

BackgroundCommunity-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) has recently emerged as an important pathogen in neonatal intensive care units (NICUs). The purposes of this study were to characterize methicillin-resistant isolates from an outbreak in a NICU, to examine the genetic traits and clonality of CA-MRSA, and to review the characteristics and outcomes of the neonatal cases and investigate the routes of entry and transmission of the MRSA outbreak strain in the NICU under study.MethodsThe study NICU practiced an active surveillance program for multidrug-resistant organisms, including weekly cultures for detection of MRSA from nasal swabs among all the admitted neonates. All first isolates from surveillance cultures and all clinical isolates were submitted for susceptibility testing and genotyping. Data from each infant’s medical records were prospectively included in a database, and the clinical features and outcomes of the colonized/infected infants were assessed.ResultsA total of 14 infants were colonized or infected by a strain of ST1-MRSA-IVa between April and August 2011. The CA-MRSA strain appeared to have been introduced to the NICU by an infected infant transferred from another hospital. The outbreak was successfully contained by multifaceted infection control interventions.ConclusionsThe results of this study confirm that NICU is a healthcare setting with a critical permeability to CA-MRSA. Active surveillance including molecular typing can help to detect and monitor the spread of antimicrobial drug-resistant organisms, and thus trigger timely control interventions.

MRSA infection in the neonatal intensive care unit

Methicillin-resistant Staphylococcus aureus (MRSA) is well known as one of the most frequent etiological agents of healthcare-associated infections. The epidemiology of MRSA is evolving with emergence of community-associated MRSA, the clonal spread of some successful clones, their spillover into healthcare settings and acquisition of antibacterial drug resistances. Neonatal intensive care unit (NICU) patients are at an especially high risk of acquiring colonization and infection by MRSA. Epidemiology of MRSA in NICU can be very complex because outbreaks can overlap endemic circulation and make it difficult to trace transmission routes. Moreover, increasing prevalence of community-associated MRSA can jeopardize epidemiological investigation, screening and effectiveness of control policies. Surveillance, prevention and control strategies and clinical management have been widely studied and are still the subject of scientific debate. More data are needed to determine the most cost-effective approach to MRSA control in NICU in light of the local epidemiology.

A novel VIM-type metallo-beta-lactamase (VIM-14) in a Pseudomonas aeruginosa clinical isolate from a neonatal intensive care unit.

A Pseudomonas aeruginosa highly resistant to carbapenems was isolated in a neonatal intensive care unit in Palermo, Italy. The strain was found to carry a novel VIM-type enzyme, classified as VIM-14. The novel enzyme differs from VIM-4 in a G31S mutation. VIM-14 was harboured in a class 1 integron with a new organization. The integron carried the genes aac7, blaVIM-14, blaOXA-20 and aac4 in that order.

Nosocomial colonization due to imipenem‐resistant Pseudomonas aeruginosa epidemiologically linked to breast milk feeding in a neonatal intensive care unit

AbstractAim:We describe a one-year investigation of colonization by imipenem-resistant, metallo-β-lactamase (MBL) producing Pseudomonas aeruginosa in a neonatal intensive care unit (NICU) of the University Hospital of Palermo, Italy.Methods:A prospective epidemiological investigation was conducted in the period 2003 January to 2004 January. Rectal swabs were collected twice a week from all neonates throughout their NICU stay. MBL production by imipenem-resistant strains of P aeruginosa was detected by phenotypic and molecular methods. Pulsed field gel electrophoresis (PFGE) was carried out on all isolates of P aeruginosa. The association between risk factors and colonization by imipenem-resistant, imipenem-susceptible P aeruginosa isolates and other multidrug-resistant Gram negative (MDRGN) organisms was analyzed for variables present at admission and during the NICU stay. Data analysis was carried out by the Cox proportional hazards regression model.Results:Twenty-two of 210 neonates were colonized with imipenem-resistant, MBL-producing P aeruginosa isolates and 14 by imipenem-susceptible P aeruginosa isolates. A single pulsotype, named A, was shared by all imipenem-resistant isolates. Colonization by P aeruginosa of pulsotype A was positively correlated with breast milk feeding and administration of ampicillin-sulbactam, and inversely correlated with exclusive feeding by formula. In the Cox proportional hazards regression model, birthweight of more than 2500 g and breast milk feeding were independently associated with an increased risk of colonization by MBL-producing P aeruginosa.Conclusion:The results strongly support an association between colonization by a well-defined imipenem-resistant, MBL producing P aeruginosa strain and breast milk feeding. Such a study may highlight the need for implementation of strategies to prevent expressed breast milk from becoming a vehicle of health care-associated infections.

Neonatal sepsis caused by Ralstonia pickettii.

e describe the clinical case of apremature newborn, born at 26weeks by cesarean delivery, followed inthe neonatal intensive care unit. Themother was diabetic with adequate con-trol during pregnancy.Neonatal weight was 930 g;APGAR score 3 at 1 minute and 8 at 5minutes. She received forced ventilationby endotracheal tube and parenteralnutrition by a central venous catheter.She was treated with ampicillin for thefirst 20 days of life. At 25 days, apneaand bradychardia episodes occurredwith a progressive increment in sever-ity and frequency. Leukocytes, C-re-active protein, cerebral echography,and echocardiogram were normal.Oralfeeding was transiently stopped and rani-tidine treatment was started for presumedgastroesophageal reflux. Mechanical ven-tilation, previously stopped, was reintro-duced.

MRSA ST22-IVa (EMRSA-15 clone) in Palermo, Italy

Epidemic spread of methicillin-resistant Staphylococcus aureus (MRSA) strains carrying the Staphylococcal Chromosomal Cassettes (SCC) mec type IV is being increasingly reported in many geographical areas. A survey to determine the prevalence and characteristics of MRSA SCCmec IV isolates identified in four general hospitals in Palermo, Italy, was carried out. During the period February-June 2009, SCCmec type IVa has been found in 12 out of 94 isolates. Nine isolates from all hospitals and all strains from a NICU outbreak occurring in the same period were attributed with the ST22-IVa (EMRSA-15) clone. In our setting, due to the changing MRSA epidemiology, detection of SCCmec IV could be poorly predictive of CA-MRSA.

Exposure to Gastric Acid Inhibitors Increases the Risk of Infection in Preterm Very Low Birth Weight Infants but Concomitant Administration of Lactoferrin Counteracts This Effect

Objective To investigate whether exposure to inhibitors of gastric acidity, such as H2 blockers or proton pump inhibitors, can independently increase the risk of infections in very low birth weight (VLBW) preterm infants in the neonatal intensive care unit. Study design This is a secondary analysis of prospectively collected data from a multicenter, randomized controlled trial of bovine lactoferrin (BLF) supplementation (with or without the probiotic Lactobacillus rhamnosus GG) vs placebo in prevention of late‐onset sepsis (LOS) and necrotizing enterocolitis (NEC) in preterm infants. Inhibitors of gastric acidity were used at the recommended dosages/schedules based on the clinical judgment of attending physicians. The distribution of days of inhibitors of gastric acidity exposure between infants with and without LOS/NEC was assessed. The mutually adjusted effects of birth weight, gestational age, duration of inhibitors of gastric acidity treatment, and exposure to BLF were controlled through multivariable logistic regression. Interaction between inhibitors of gastric acidity and BLF was tested; the effects of any day of inhibitors of gastric acidity exposure were then computed for BLF‐treated vs ‐untreated infants. Results Two hundred thirty‐five of 743 infants underwent treatment with inhibitors of gastric acidity, and 86 LOS episodes occurred. After multivariate analysis, exposure to inhibitors of gastric acidity remained significantly and independently associated with LOS (OR, 1.03; 95% CI, 1.008‐1.067; P = .01); each day of inhibitors of gastric acidity exposure conferred an additional 3.7% odds of developing LOS. Risk was significant for Gram‐negative (P < .001) and fungal (P = .001) pathogens, but not for Gram‐positive pathogens (P = .97). On the test for interaction, 1 additional day of exposure to inhibitors of gastric acidity conferred an additional 7.7% risk for LOS (P = .003) in BLF‐untreated infants, compared with 1.2% (P = .58) in BLF‐treated infants. Conclusion Exposure to inhibitors of gastric acidity is significantly associated with the occurrence of LOS in preterm VLBW infants. Concomitant administration of BLF counteracts this selective disadvantage. Trial registration isrctn.org: ISRCTN53107700.