Case-control analysis of endemic Serratia marcescens bacteremia in a neonatal intensive care unit

Attributable Mortality for Pediatric and Neonatal Central Line-Associated Bloodstream Infections in Greece

Central line-associated bloodstream infections (CLABSIs) are the most frequent pediatric hospital-acquired infections and significantly impact outcomes. The aim of this study was to estimate the attributable mortality for CLABSIs in pediatric and neonatal patients in Greece. A retrospective matched-cohort study was performed, in two tertiary pediatric hospitals. Inpatients with a central line in neonatal and pediatric intensive care units (NICUs and PICUs), hematology/oncology units, and a bone marrow transplantation unit between June 2012 and June 2015 were eligible. Patients with confirmed CLABSI were enrolled on the day of the event and were matched (1:1) to non-CLABSI patients by hospital, hospitalization unit, and length of stay prior to study enrollment (188 children enrolled, 94 CLABSIs). Attributable mortality was estimated. During the study period, 22 patients with CLABSI and nine non-CLABSI patients died (23.4 vs. 9.6%, respectively, p  = 0.011), leading to an attributable mortality of 13.8% (95% confidence interval [CI] = 3.4-24.3%). Children in PICUs were more likely to die, presenting an attributable mortality of 20.2% (95% CI = - 1.4-41.8%), without reaching, however, statistical significance. After multiple logistic regression, patients with CLABSI were four times more likely to die (odds ratio [OR] = 4.29, 95% CI = 1.28-14.36, p  = 0.018). Survival analysis showed no difference in time to death after study enrollment between patients with CLABSI and non-CLABSI patients (log-rank p  = 0.137, overall median survival time = 7.8 months). Greek pediatric mortality rates are increased by the CLABSI occurrence, highlighting the importance of infection prevention strategies.

Serratia Infection Epidemiology Among Very Preterm Infants in the Neonatal Intensive Care Unit

BACKGROUND

Serratia spp. are opportunistic, multidrug resistant, Gram-negative pathogens, previously described among preterm infants in case reports or outbreaks of infection. We describe Serratia late-onset infection (LOI) in very preterm infants in a large, contemporary, nationally representative cohort.

METHODS

In this secondary analysis of prospectively collected data of preterm infants born 401-1500 grams and/or 22-29 weeks gestational age from 2018 to 2020 at 774 Vermont Oxford Network members, LOI was defined as culture-confirmed blood and/or cerebrospinal fluid infection > 3 days after birth. The primary outcome was incidence of Serratia LOI. Secondary outcomes compared rates of survival and discharge morbidities between infants with Serratia and non-Serratia LOI.

RESULTS

Among 119,565 infants, LOI occurred in 10,687 (8.9%). Serratia was isolated in 279 cases (2.6% of all LOI; 2.3 Serratia infections per 1000 infants). Of 774 hospitals, 161 (21%) reported at least one Serratia LOI; 170 of 271 (63%) cases occurred at hospitals reporting 1 or 2 Serratia infections, and 53 of 271 (20%) occurred at hospitals reporting ≥5 Serratia infections. Serratia LOI was associated with a lower rate of survival to discharge compared with those with non-Serratia LOI (adjusted relative risk 0.88, 95% CI: 0.82-0.95). Among survivors, infants with Serratia LOI had higher rates of tracheostomy, gastrostomy and home oxygen use compared with those with non-Serratia LOI.

CONCLUSIONS

The incidence of Serratia LOI was 2.3 infections per 1000 very preterm infants in this cohort. Lower survival and significant morbidity among Serratia LOI survivors highlight the need for recognition and targeted prevention strategies for this opportunistic nosocomial infection.

Serratia Chorioamnionitis and Culture Proven Sepsis in a Preterm Neonate: A Case Report and Review of the Literature

BACKGROUND

Serratia marcescens is a well-known cause of nosocomial infectious outbreaks in the neonatal intensive care unit, with a high mortality rate in the vulnerable preterm population. However, it is not typically associated with neonatal sepsis secondary to intrapartum vertical transmission. We present the case of a preterm male born at 25 weeks and 4 days of gestation in Okinawa, Japan with culture-proven S. marcescens chorioamnionitis and sepsis, as well as a review of the previously published literature.

METHODS

We conducted a literature search utilizing MeSH indexing with the headings [chorioamnionitis], [Serratia], and [infant, newborn] limited to "humans" with a publication date range between 1950 and 2020.

RESULTS

All reported cases of preterm S. marcescens chorioamnionitis occurred in coastal locations. The majority of cases resulted in spontaneous abortion, and we found no published reports of confirmed S. marcescens chorioamnionitis in conjunction with viable preterm delivery and positive neonatal cultures. In the case presented herein, S. marcescens chorioamnionitis with associated neonatal sepsis was confirmed by positive placental and blood cultures. Bacterial clearance was achieved following an antibiotic course consisting of 5 days of gentamicin and 14 days of meropenem therapy.

CONCLUSIONS

S. marcescens is an uncommon cause of chorioamnionitis that can have devastating neonatal consequences, especially in the at-risk preterm population.

Outcome of Late-onset Neonatal Sepsis at a Tertiary Hospital in Oman

Objectives

We sought to determine the prevalence, pattern of causative organisms, and mortality of newborns with culture-proven late-onset sepsis (LOS) and to determine and compare the risk factors linked to late-onset gram-positive and late-onset gram-negative sepsis in Sultan Qaboos University Hospital (SQUH).

Methods

We conducted a cross-sectional retrospective study of data obtained between 1 January 2007 and 31 December 2014 (eight years) from infants in the neonatal intensive care unit (NICU) at SQUH. Infants born in SQUH (inborn) and other institutions (outborn) with positive blood cultures were included in the study.

Results

The total number of live births and admissions during the study period were 26 289 and 3559, respectively. The total number of infants identified with LOS were 125 of whom 69 (55.2%) were gram-positive, 52 (41.6%) were gram-negative, and four (3.2%) were due to Candida species (spp.). The majority of infants (n = 113, 90.4%) were inborn; 69 (55.2%) were males and 56 (44.8%) were females. The prevalence of LOS among inborn admissions was 4.3 per 1000 live births. Most infections occurred in very low birth weight infants (n = 81, 64.8%). Eleven (8.8%) infants died due to gram-negative sepsis. Klebsiella pneumoniae followed by Pseudomonas aeruginosa were the leading cause of death. Maternal intrapartum antibiotics were the only independent risk factor correlating with gram-negative organisms in multivariate analysis (p = 0.003).

Conclusions

LOS poses a burden in the NICU, which could be due to the increasing survival of premature babies. The main contributing organisms to LOS are gram-positive bacteria. Klebsiella spp. is a major cause of mortality in LOS. The use of intrapartum antibiotic prophylaxis in mothers might explain the positive correlation of maternal antibiotics as a risk factor with gram-negative infections.

Endogenous microbial contamination of melons (Cucumis melo) from international trade: an underestimated risk for the consumer?

BACKGROUND

Fruits and vegetables have increasingly been related to foodborne outbreaks. Besides surface contamination, a possible internalization of microorganisms into edible parts of plants during growth has already been observed. To examine an actual risk for the consumer, microbial contamination of the rind and pulp of 147 muskmelons from international trade was assessed using cultural and biochemical methods, polymerase chain reaction and matrix-assisted laser desorption/ionization-time of flight mass spectrometry.

RESULTS

One hundred percent of the rind samples [3.69-8.92 log colony forming units (CFU) g^-1 ] and 89.8% of the pulp samples (maximum load 3.66 log CFU g^-1 ) were microbiologically contaminated. Among the 432 pulp isolates, opportunistic and potentially pathogenic bacteria were identified, mainly Staphylococcus spp. (48.9%), Clostridium spp. (42.9%) and Enterobacteriaceae (27.9%). Salmonella spp., Escherichia coli and isolates of the Bacillus cereus group were found on the rind (1.4%, 0.7% and 42.9%, respectively) and in the pulp (0.7%, 1.4% and 4.7%). Clostridium perfringens was isolated from the rind of seven melons.

CONCLUSION

The present study revealed a regularly occurring internal contamination of melons. Possible health risks for consumers because of an occurrence of microorganisms in melon pulp should be considered in future food safety assessments. © 2018 Society of Chemical Industry.

Serratia Marcescens Sepsis in a Child with Deep Venous Thrombosis - A Case Report

Introduction

Venous thromboembolism is a rare condition in paediatrics that included both deep venous thrombosis and pulmonary embolism. Serratia marcescens is a gram-negative bacterium that belongs to the Enterobacteriaceae family and tends to affect immunocompromised hosts.

Case report

We report the case of an 11-year-old boy, admitted in the Pediatric Clinic I from Emergency County Hospital Tîrgu Mureş, Romania with intense pain, swelling, cyanosis and claudication of the left foot. His personal history revealed a recent appendectomy. A close family was reported to have had a deep venous thrombosis. The laboratory tests, performed on the day of admission, revealed increased inflammatory biomarkers and D-dimer. Coagulation tests gave a low activated partial thromboplastin time (APTT). Doppler venous ultrasound and CT-exam established a diagnosis of deep venous thrombosis. Anticoagulant therapy was initiated, but on the tenth day of admission, the patient developed signs and symptoms of sepsis, and the blood culture revealed Serratia marcescens. After antibiotic and anticoagulant therapy, the patient progressed favourably. The patient was a carrier of the heterozygous form of Factor V Leiden.

Conclusions

The association between deep venous thrombosis and Serratia marcescens sepsis can compromise a condition in pediatric patients.

Serratia marcescens Sepsis in a Child with Deep Venous Thrombosis – A Case Report

Introduction: Venous thromboembolism is a rare condition in paediatrics that included both deep venous thrombosis and pulmonary embolism. Serratia marcescens is a gram-negative bacterium that belongs to the Enterobacteriaceae family and tends to affect immunocompromised hosts.

Case report: We report the case of an 11-year-old boy, admitted in the Pediatric Clinic I from Emergency County Hospital Tîrgu Mureș, Romania with intense pain, swelling, cyanosis and claudication of the left foot. His personal history revealed a recent appendectomy. A close family was reported to have had a deep venous thrombosis. The laboratory tests, performed on the day of admission, revealed increased inflammatory biomarkers and D-dimer. Coagulation tests gave a low activated partial thromboplastin time (APTT). Doppler venous ultrasound and CT-exam established a diagnosis of deep venous thrombosis. Anticoagulant therapy was initiated, but on the tenth day of admission, the patient developed signs and symptoms of sepsis, and the blood culture revealed Serratia marcescens. After antibiotic and anticoagulant therapy, the patient progressed favourably. The patient was a carrier of the heterozygous form of Factor V Leiden.

Conclusions: The association between deep venous thrombosis and Serratia marcescens sepsis can compromise a condition in pediatric patients.

Pathogen-Specific Clustering of Nosocomial Blood Stream Infections in Very Preterm Infants

BACKGROUND AND OBJECTIVES

Nosocomial infections in NICUs tend to cluster, sometimes as devastating outbreaks, but pathogen-specific transmission probabilities are unknown. We aimed to quantify the pathogen-specific risk of a blood stream infection (BSI) in preterm infants after an index case with that pathogen in the same department.

METHODS

Data of 44 818 infants below 1500 g birth weight of the German NICU surveillance system (2000-2011) were used to calculate the probability of a BSI in the presence or absence of another infant in the same unit with a same-pathogen BSI.

RESULTS

The relative risk was similar for the more common pathogens, Enterococcus spp (4.3; 95% confidence interval: 2.7-6.9; n = 243), Enterobacter spp (7.9, 5.4-11.4; n = 246), Escherichia coli (7.9; 5.1-12.1; n = 210), Candida albicans (8.7; 5.0-15.4; n = 138), Staphylococcus aureus (9.5; 7.6-12.1; n = 407) and Klebsiella spp (13.1; 9.0-19.1; n = 190) but markedly elevated for Serratia spp (77.5; 41.1-146.1; n = 58) and Pseudomonas aeruginosa (64.5; 25.7-162.1; n = 38). Rates of BSI per 100 exposed infants ranged between 2.21 (Enterococcus) and 8.15 (Serratia). The same pattern emerged after adjustments were made for patients' characteristics or when the analysis was restricted to positive blood cultures during the preceding 30 days.

CONCLUSIONS

Although BSIs with P aeruginosa or Serratia spp in preterm infants are rare, they are associated with a markedly elevated risk of secondary same-pathogen BSI and should prompt intensified active surveillance and infection control measures.

The Increasing Challenge of Multidrug-Resistant Gram-Negative Bacilli: Results of a 5-Year Active Surveillance Program in a Neonatal Intensive Care Unit

Colonization and infection by multidrug-resistant gram-negative bacilli (MDR GNB) in neonatal intensive care units (NICUs) are increasingly reported.We conducted a 5-year prospective cohort surveillance study in a tertiary NICU of the hospital "Paolo Giaccone," Palermo, Italy. Our objectives were to describe incidence and trends of MDR GNB colonization and the characteristics of the most prevalent organisms and to identify the risk factors for colonization. Demographic, clinical, and microbiological data were prospectively collected. Active surveillance cultures (ASCs) were obtained weekly. Clusters of colonization by extended spectrum β-lactamase (ESBL) producing Escherichia coli and Klebsiella pneumoniae were analyzed by conventional and molecular epidemiological tools.During the study period, 1152 infants were enrolled in the study. Prevalences of colonization by MDR GNB, ESBL-producing GNB and multiple species/genera averaged, respectively, 28.8%, 11.7%, and 3.7%. Prevalence and incidence density of colonization by MDR GNB and ESBL-producing GNB showed an upward trend through the surveillance period. Rates of ESBL-producing E coli and K pneumoniae colonization showed wide fluctuations peaking over the last 2 years. The only independent variables associated with colonization by MDR GNB and ESBL-producing organisms and multiple colonization were, respectively, the days of NICU stay (odds ratio [OR] 1.041), the days of exposure to ampicillin-sulbactam (OR 1.040), and the days of formula feeding (OR 1.031). Most clusters of E coli and K pneumoniae colonization were associated with different lineages. Ten out of 12 clusters had an outborn infant as their index case.Our study confirms that MDR GNB are an increasing challenge to NICUs. The universal once-a-week approach allowed us to understand the epidemiology of MDR GNB, to timely detect new clones and institute contact precautions, and to assess risk factors. Collection of these data can be an important tool to optimize antimicrobials use and control the emergence and dissemination of resistances in NICU.

Clinical and Molecular Epidemiology of Methicillin-Resistant Staphylococcus aureus in a Neonatal Intensive Care Unit in the Decade following Implementation of an Active Detection and Isolation Program

Methicillin-resistant Staphylococcus aureus (MRSA) is a frequent source of infection in the neonatal intensive care unit (NICU), often associated with significant morbidity. Active detection and isolation (ADI) programs aim to reduce transmission. We describe a comprehensive analysis of the clinical and molecular epidemiology of MRSA in an NICU between 2003 and 2013, in the decade following the implementation of an MRSA ADI program. Molecular analyses included strain typing by pulsed-field gel electrophoresis, mec and accessory gene regulator group genotyping by multiplex PCR, and identification of toxin and potential virulence factor genes via PCR-based assays. Of 8,387 neonates, 115 (1.4%) had MRSA colonization and/or infection. The MRSA colonization rate declined significantly during the study period from 2.2 to 0.5/1,000 patient days (linear time, P = 0.0003; quadratic time, P = 0.006). There were 19 cases of MRSA infection (16.5%). Few epidemiologic or clinical differences were identified between MRSA-colonized and MRSA-infected infants. Thirty-one different strains of MRSA were identified with a shift from hospital-associated to combined hospital- and community-associated strains over time. Panton-Valentine leukocidin-positive USA300 strains caused 5 of the last 11 infections. Staphylococcal cassette chromosome mec (SCCmec) types II and IVa and agr groups 1 and 2 were most predominant. One isolate possessed the gene for toxic shock syndrome toxin; none had genes for exfoliative toxin A or B. These results highlight recent trends in MRSA colonization and infection and the corresponding changes in molecular epidemiology. Continued vigilance for this invasive pathogen remains critical, and specific attention to the unique host, the neonate, and the distinct environment, the NICU, is imperative.

A case report of pink breast milk

A woman presented for her postpartum examination alarmed about pink stains on her breast pads and on her infant's burp pads and diapers. The stains were also found in her breast pump and the infant's bottles. Out of concern, she stopped breastfeeding. The diagnosis was colonization of mother and infant with Serratia marcescens. They were managed conservatively without antibiotics. The mother was guided to restart breastfeeding. The infant resumed nursing and continued to thrive.

Long-term evolution of multiple outbreaks of Serratia marcescens bacteremia in a neonatal intensive care unit

The annual incidence of Serratia marcescens bacteremia in a neonatal intensive care unit increased significantly between 2002 and 2010. Molecular epidemiology studies revealed that 8 clones were responsible for 85.2% of cases. Given that these infections are potentially preventable, even the appearance of 1 case of bacteremia should be an indicator for outbreak management.

Risk of parenteral nutrition in neonates--an overview

Healthcare-associated infections (HAI) in preterm infants are a challenge to the care of these fragile patients. HAI-incidence rates range from 6 to 27 infections per 1000 patient-days. Most nosocomial infections are bloodstream infections and of these, the majority is associated with the use of central venous catheters. Many studies identified parenteral nutrition as an independent risk factor for HAI, catheter-associated bloodstream infection, and clinical sepsis. This fact and various published outbreaks due to contaminated parenteral nutrition preparations highlight the importance of appropriate standards in the preparation and handling of intravenous solutions and parenteral nutrition. Ready-to-use parenteral nutrition formulations may provide additional safety in this context. However, there is concern that such formulations may result in overfeeding and necrotizing enterocolitis. Given the risk for catheter-associated infection, handling with parenteral nutrition should be minimized and the duration shortened. Further research is required about this topic.

Consecutive Serratia marcescens multiclone outbreaks in a neonatal intensive care unit

BACKGROUND

This report describes 3 consecutive outbreaks caused by genetically unrelated Serratia marcescens clones that occurred in a neonatal intensive care unit (NICU) over a 35-month period.

METHODS

Carriage testing in neonates and health care workers and environmental investigation were performed. An unmatched case-control study was conducted to identify risk factors for S marcescens isolation.

RESULTS

During the 35-month period, there were 57 neonates with S marcescens isolation in the NICU, including 37 carriers and 20 infected neonates. The prevalence rate of S marcescens isolation was 12.3% in outbreak 1, 47.4% in outbreak 2, and 42% in outbreak 3. Nine of the 20 infected neonates died (45% case fatality rate). A total of 10 pulsed field gel electrophoresis types were introduced in the NICU in various times; 4 of these types accounted for the 9 fatal cases. During outbreak 3, a type VIII S marcescens strain, the prevalent clinical clone during this period, was detected in the milk kitchen sink drain. Multiple logistic regression revealed that the only statistically significant factor for S marcencens isolation was the administration of total parenteral nutrition.

CONCLUSIONS

Total parenteral nutrition solution might constitute a possible route for the introduction of microorganisms in the NICU. Gaps in infection control should be identified and strict measures implemented to ensure patient safety.

Fatal aortic endocarditis associated with community-acquired Serratia marcescens infection in a dog

A 12 yr old Dalmatian was referred for evaluation of acute lethargy, fever, neurologic signs, and a recently ausculted heart murmur. Echocardiography in combination with blood cultures resulted in a diagnosis of nonhospital-acquired Serratia marcescens bacteremia and aortic valve endocarditis. Despite early diagnosis and aggressive therapy, the dog failed to respond to antimicrobials and died within 6 hr after admission. Necropsy findings included aortic valve endocarditis, septicemia, and diffuse thromboembolic disease. There was no history of pre-existing underlying disease or immunosuppressive therapy, and the dog had not been hospitalized before referral.

[Description and investigation of an outbreak of extended-spectrum beta-lactamase producing Escherichia coli strain in a neonatal unit]

An outbreak of colonization and infection with an Escherichia coli strain producing extended-spectrum beta-lactamase (ESBL) occurred in a neonatal unit : a high rate of cases was observed, 27/59 neonates were colonized : one of them developed meningitis with favourable outcome and another baby developed conjunctivitis. Despite intensive efforts to control the outbreak by standard methods of hand hygiene, patients screening and isolation, the spread was uncontrolled and the unit was closed to all admission in order to stop the outbreak. The investigation was not able to identify a single outbreak's source. Emergence and spread of ESBL producing E. coli strains from community and hospital acquired infections are a significant public health problem with difficult choice of treatment for serious infections.

Serratia sp. bacteremia in Canberra, Australia: a population-based study over 10 years

The purpose of this paper was to determine the population incidence and clinical features of Serratia sp. bacteremia in Canberra, Australia. Demographic and clinical data were collected prospectively for episodes of Serratia sp. bacteremia over a 10-year period, and was confined to Canberra residents using residential postal codes. Thirty-eight episodes of Serratia sp. bacteremia occurred, with a yearly incidence of 1.03 per 100,000 population. The majority of episodes occurred in males (68%). The respiratory tract was the most common focus of infection (21%). Twenty-nine percent of episodes were community-associated. A further 18% of episodes had their onset in the community but were healthcare-associated. The 7-day and 6-month mortality rates were 5 and 37%, respectively. Antibiotic resistance to gentamicin (3%) and ciprofloxacin (0%) was low. Serratia sp. bacteremia is more common than generally appreciated, with a large proportion (47%) of episodes having their onset in the community.

Which factors predict hospital-acquired late-onset neonatal sepsis?

Neonates are one of the highest risk groups of hospitalized patients for sepsis. There is a wide variation in the incidence and microbial causes of late-onset neonatal sepsis, owing to differences in both patient populations and standards of care in the individual neonatal units. Stratification according to risk factors is required to allow the meaningful comparison of infection rates between units. Knowledge of risk factors is also important in order to target interventions on high-risk aspects of neonatal care. Few independent risk factors for late-onset sepsis have been identified, the most common being birth gestational age and parenteral nutrition. Further work is required to validate that these observations can be generalized, and that they could, therefore, be used to stratify infection rates in multicenter surveillance schemes.