First Evidence of Streptococcus pyogenes M1UK Clone in Pediatric Invasive Infections in Italy by Molecular Surveillance.

Invasive group A streptococci infections are increasing worldwide, mainly due to the emm1 lineage M1UK emergence. Although this variant has recently been described in adult Italian patients, its circulation in children has not yet been established. Characterizing by whole genome sequencing 6 invasive group A streptococci strains isolated between 2022 and 2023, we highlighted M1UK lineage circulation in pediatric patients in Italy.

The Prevalence of Carbapenemase-Producing Microorganisms and Use of Novel Cephalosporins for the Treatment of Severe Infections Caused by Carbapenem-Resistant Gram-Negative Bacteria in a Pediatric Cardiac Intensive Care Unit.

BACKGROUND: The spread of carbapenem-resistant organisms (CROs) is an increasingly serious threat globally, especially in vulnerable populations, such as intensive care unit (ICU) patients. Currently, the antibiotic options for CROs are very limited, particularly in pediatric settings. We describe a cohort of pediatric patients affected by CRO infections, highlighting the important changes in carbapenemase production in recent years and comparing the treatment with novel cephalosporins (N-CEFs) to Colistin-based regimens (COLI). METHODS: All patients admitted to the cardiac ICU of the Bambino Gesù Children's Hospital in Rome during the 2016-2022 period with an invasive infection caused by a CRO were enrolled. RESULTS: The data were collected from 42 patients. The most frequently detected pathogens were Pseudomonas aeruginosa (64%), Klebsiella pneumoniae (14%) and Enterobacter spp. (14%). Thirty-three percent of the isolated microorganisms were carbapenemase producers, with a majority of VIM (71%), followed by KPC (22%) and OXA-48 (7%). A total of 67% of patients in the N-CEF group and 29% of patients in the comparative group achieved clinical remission (p = 0.04). CONCLUSION: The increase over the years of MBL-producing pathogens in our hospital is challenging in terms of therapeutic options. According to the present study, N-CEFs are a safe and effective option in pediatric patients affected by CRO infections.

Clonal Spread of Hospital-Acquired NDM-1-Producing Klebsiella pneumoniae and Escherichia coli in an Italian Neonatal Surgery Unit: A Retrospective Study.

This article reports a rapid and unexpected spread of colonization cases of NDM-1 carbapenemase-producing Klebsiella pneumoniae and Escherichia coli in a neonatal surgical unit (NSU) at Bambino Gesù Children's Hospital in Rome, Italy. Between the 16th of November 2020 and the 18th of January 2021, a total of 20 NDM-1 carbapenemase-producing K. pneumoniae (n = 8) and E. coli (n = 12) were isolated from 17 out of 230 stool samples collected from neonates admitted in the aforementioned ward and time period by an active surveillance culture program routinely in place to monitor the prevalence of colonization/infection with multidrug-resistant Gram-negative microorganisms. All strains were characterized by antimicrobial susceptibility testing, detection of resistance determinants, PCR-based replicon typing (PBRT) and multilocus-sequence typing (MLST). All isolates were highly resistant to most of the tested antibiotics, and molecular characterization revealed that all of them harbored the blaNDM-1 gene. Overall, IncA/C was the most common Inc group (n = 20/20), followed by IncFIA (n = 17/20), IncFIIK (n = 14/20) and IncFII (n = 11/20). MLST analysis was performed on all 20 carbapenemase-producing Enterobacterales (CPE) strains, revealing three different Sequence Types (STs) among E. coli isolates, with the prevalence of ST131 (n = 10/12; 83%). Additionally, among the 8 K. pneumoniae strains we found 2 STs with the prevalence of ST37 (n = 7/8; 87.5%). Although patient results were positive for CPE colonization during their hospital stay, infection control interventions prevented their dissemination in the ward and no cases of infection were recorded in the same time period.

Prevalence and Molecular Typing of Carbapenemase-Producing Enterobacterales among Newborn Patients in Italy.

The spread of carbapenemase-producing Enterobacterales (CPE), especially Klebsiella pneumoniae (K. pneumoniae) and Escherichia coli (E. coli), is a serious public health threat in pediatric hospitals. The associated risk in newborns is due to their underdeveloped immune system and limited treatment options. The aim was to estimate the prevalence and circulation of CPE among the neonatal intensive units of a major pediatric hospital in Italy and to investigate their molecular features. A total of 124 CPE were isolated from rectal swabs of 99 newborn patients at Bambino Gesù Children's Hospital between July 2016 and December 2019. All strains were characterized by antimicrobial susceptibility testing, detection of resistance genes, and PCR-based replicon typing (PBRT). One strain for each PBRT profile of K. pneumoniae or E. coli was characterized by multilocus-sequence typing (MLST). Interestingly, the majority of strains were multidrug-resistant and carried the blaNDM gene. A large part was characterized by a multireplicon status, and FII, A/C, FIA (15%) was the predominant. Despite the limited size of collection, MLST analysis revealed a high number of Sequence Types (STs): 14 STs among 28 K. pneumoniae and 8 STs among 11 E. coli, with the prevalence of the well-known clones ST307 and ST131, respectively. This issue indicated that some strains shared the same circulating clone. We identified a novel, so far never described, ST named ST10555, found in one E. coli strain. Our investigation showed a high heterogeneity of CPE circulating among neonatal units, confirming the need to monitor their dissemination in the hospital also through molecular methods.

Measles Cases in Children Requiring Hospital Access in an Academic Pediatric Hospital in Italy, 2008-2013.

BACKGROUND: The Lazio region is one of the Italian regions where sustained measles transmission continues to occur. We investigated measles cases reported by the emergency department (ED) of the largest pediatric hospital in Italy, located in Lazio. METHODS: We reviewed clinical records of all measles cases from 0 to 18 years of age evaluated in the ED in 2008-2013. We compared demographic and clinical characteristics of patients admitted to the inpatient setting with those of patients discharged home to assess possible determinants of hospital admission. RESULTS: Of 248 patients with measles evaluated in the ED, 113 (45.6%) were admitted as inpatients. The number of measles cases peaked in 2011 (N = 122; 49.2%), when epidemics were reported in Lazio. Median age was 2.7 years (range: 21 days to 17.9 years), and 31 patients (13%) had an underlying chronic illness. The strongest independent predictor of hospitalization was having an underlying chronic illness [adjusted odd ratio (OR): 9.87; 95% confidence interval: 3.13-31.13]. Other factors independently and significantly associated with higher risk of hospitalization were taking medications at the time of ED visit, being younger than 1 year of age and having altered liver enzyme values. Eighty-five percent of children >15 months of age who were hospitalized were not vaccinated. One hundred six hospitalized children (94%) had at least 1 measles complication; 1 child required intensive care for respiratory insufficiency. CONCLUSIONS: Hospitalizations of children with measles continue to occur in European areas where elimination has not been achieved. Children with chronic diseases represent a vulnerable population that is at higher risk of hospitalization.

An outbreak of extremely drug-resistant Pseudomonas aeruginosa in a tertiary care pediatric hospital in Italy.

BACKGROUND: Extensively drug-resistant Pseudomonas aeruginosa (XDR-PA) isolates are susceptible to only one or two classes of antibiotics. In 2011-2012, we investigated an outbreak of XDR-PA affecting children with onco-hematological diseases. METHODS: Outbreak investigation included ascertainment of cases, tracing of intestinal carriers and environmental surveillance. Contact precautions were adopted for patients with infection or colonization. Isolates were tested for antimicrobial susceptibility; phenotypic confirmation of carbapenemase production was performed, and carbapenemase genes were tested by multiplex polymerase-chain-reaction (PCR). Genotypes were determined by pulsed-field gel electrophoresis (PFGE). RESULTS: XDR-PA was isolated from 27 patients; 12 had bacteremia, 6 other infections and 9 were colonized. Severe neutropenia was significantly associated with bacteremia. Bloodstream-infection mortality rate was 67%. All isolates were resistant to carbapenems, cephalosporins and penicillins + ß-lactamase inhibitors. Isolates were susceptible only to colistin in 22 patients, to colistin and amikacin in 4, and to ciprofloxacin and colistin in 1. PFGE results identified 6 subtypes of a single genotype, associated with clusters of cases, and 4 sporadic genotypes. Two sporadic isolates were metallo-ß-lactamase producers, negative to PCR. All other isolates were metallo-ß-lactamase producers due to the presence of a VIM carbapenemase. Incidence of XDR-PA infections decreased from 0.72 cases/1,000 inpatient-days in March 2011-March 2012, to 0.34/1,000 in April-December 2012, after implementation of active finding of intestinal carriers on all onco-hematological inpatients. CONCLUSIONS: Control measures targeting intestinal carriers are crucial in limiting in-hospital transmission of XDR-PA polyclonal strains, protecting more vulnerable patients, such as severely neutropenic children, from developing clinical infections.