Disinfection of sink drains to reduce a source of three opportunistic pathogens, during Serratia marcescens clusters in a neonatal intensive care unit.

OBJECTIVE: Evaluate the effects of five disinfection methods on bacterial concentrations in hospital sink drains, focusing on three opportunistic pathogens (OPs): Serratia marcescens, Pseudomonas aeruginosa and Stenotrophomonas maltophilia. DESIGN: Over two years, three sampling campaigns were conducted in a neonatal intensive care unit (NICU). Samples from 19 sink drains were taken at three time points: before, during, and after disinfection. Bacterial concentration was measured using culture-based and flow cytometry methods. High-throughput short sequence typing was performed to identify the three OPs and assess S. marcescens persistence after disinfection at the genotypic level. SETTING: This study was conducted in a pediatric hospitals NICU in Montréal, Canada, which is divided in an intensive and intermediate care side, with individual rooms equipped with a sink. INTERVENTIONS: Five treatments were compared: self-disinfecting drains, chlorine disinfection, boiling water disinfection, hot tap water flushing, and steam disinfection. RESULTS: This study highlights significant differences in the effectiveness of disinfection methods. Chlorine treatment proved ineffective in reducing bacterial concentration, including the three OPs. In contrast, all other drain interventions resulted in an immediate reduction in culturable bacteria (4-8 log) and intact cells (2-3 log). Thermal methods, particularly boiling water and steam treatments, exhibited superior effectiveness in reducing bacterial loads, including OPs. However, in drains with well-established bacterial biofilms, clonal strains of S. marcescens recolonized the drains after heat treatments. CONCLUSIONS: Our study supports thermal disinfection (>80°C) for pathogen reduction in drains but highlights the need for additional trials and the implementation of specific measures to limit biofilm formation.

Implementation of a PCR-based strategy to control an outbreak by Serratia marcescens in a Neonatal Intensive Care Unit.

OBJECTIVES: To evaluate the clinical and epidemiological impact of a new molecular surveillance strategy based on qPCR to control an outbreak by Serratia marcescens in a Neonatal Intensive Care Unit (NICU). METHODS: We design a specific qPCR for the detection of S. marcescens in rectal swabs of patients admitted to a NICU. We divided the surveillance study into two periods: (a) the pre-PCR, from the outbreak declaration to the qPCR introduction, and (b) the PCR period, from the introduction of the qPCR until the outbreak was solved. In all cases, S. marcescens isolates were recovered and their clonal relationship was analysed by PFGE. Control measures were implemented during the outbreak. Finally, the number of bloodstream infections (BSI) was investigated in order to evaluate the clinical impact of this molecular strategy. RESULTS: Nineteen patients colonized/infected by S. marcescens were detected in the pre-PCR period (October 2020-April 2021). On the contrary, after the PCR implementation, 16 new patients were detected. The PFGE revealed 24 different pulsotypes belonging to 7 different clonal groups, that were not overlapping at the same time. Regarding the clinical impact, 18 months after the qPCR implementation, no more outbreaks by S. marcescens have been declared in the NICU of our hospital, and only 1 episode of BSI has occurred, compared with 11 BSI episodes declared previously to the outbreak control. CONCLUSIONS: The implementation of this qPCR strategy has proved to be a useful tool to control the nosocomial spread of S. marcescens in the NICU.

Validation of a New PCR-Based Screening Method for Prevention of Serratia marcescens Outbreaks in the Neonatal Intensive Care Unit.

BACKGROUND: Serratia marcescens may cause severe nosocomial infections, mostly in very low birth weight infants. Since S. marcescens exhibits by far the highest adjusted incidence rate for horizontal transmission, it can cause complex outbreak situations in neonatal intensive care units. OBJECTIVE: The aim of this study was to establish a fast and highly sensitive colonization screening for prompt cohorting and barrier nursing strategies. METHODS: A probe-based duplex PCR assay targeting the 16S rRNA gene of S. marcescens was developed and validated by using 36 reference strains, 14 S. marcescens outbreak- and nonoutbreak isolates, defined by epidemiological linkage and molecular typing, and applied in 1,347 clinical specimens from 505 patients. RESULTS AND CONCLUSIONS: The novel PCR assay proved to be highly specific and had an in vitro sensitivity of 100 gene copies per reaction (∼15 bacteria). It showed a similar (in laryngeal/tracheal specimens) or even higher (in rectal/stoma swabs) in vivo sensitivity in comparison to routine microbial culture and was much quicker (<24 h vs. 2 days). By combining different oligonucleotide primers, there was robust detection of genetic variants of S. marcescens strains. PCR inhibition was low (1.6%) and observed with rectal swabs only. Cohort analysis illustrated applicability of the PCR assay as a quick tool to prevent outbreak scenarios by allowing rapid decisions on cohorting and barrier nursing. In summary, this novel molecular screening for colonization by S. marcescens is specific, highly sensitive, and substantially accelerates detection.

Epidemiology of Serratia marcescens infections in NICU of a Teaching and Research Hospital in Northern Italy.

BACKGROUND: Serratia marcescens (Sm) is a known cause of infection and colonization in neonates receiving intensive care. The aim of this study was to identify the risk factors for colonization and infection with Sm in Neonatal Intensive Care Unit (NICU) of a tertiary care Hospital. METHODS: A case-control study was conducted from January to December 2011 in neonates admitted to the NICU. Cases are patients with a microbiologically confirmed infection or colonization, controls were randomly chosen among patients admitted to the same NICU. RESULTS: Globally, 39 acquired infections or colonizations were identified. Among factors related to pregnancy, only premature delivery was independently associated to the risk of infection; as well as mechanical ventilation and catheterization for parenteral nutrition, considering indwelling devices. Prolonged administration with antibiotics were also related to the risk of infection. Among Sm strains which have been tested to antibiotics, all have been resistant to amoxicillin/clavulanic acid and to colistin. CONCLUSIONS: This study confirms the association between Sm infection or colonization and low gestational age. Invasive medical devices and medications, strictly necessary in care-support of preterm neonates, are likely related to Sm infection too. Preventive control strategies are expected to be effective in the control of Sm spread in NICUs.

Rapid Detection of Microbial Contamination in Intravenous Fluids by ATP-Based Monitoring System.

In this study, we investigated four clinical cases of microbial contamination of in-use intravenous infusion fluid, detected by measuring "Adenosine triphosphate (ATP) + adenosine monophosphate (AMP)" ("ATP+AMP") levels. High "ATP+AMP" values correlate with microbial contamination, and by utilizing these values as indicator for microbial contamination possibility, we were able to rapidly detect the contamination and recommend replacement of catheters and administration sets. In three out of four cases, changing the infusion fluid led to improvement in the condition of the patients. "ATP+AMP" levels can be used to confirm microbial contamination of in-use intravenous infusion fluids, as it is fast (several minites) and convenient to measure them.

Serratia marcescens in the neonatal intensive care unit: A cluster investigation using molecular methods.

BACKGROUND: Serratia marcescens (S. marcescens) is associated with nosocomial infections with significant morbidity and mortality in the neonatal intensive care units (NICU). We describe the control of a multi-clonal S. marcescens infections outbreak in our tertiary-level NICU and the application of molecular typing using repetitive element palindromic PCR (rep-PCR) and next generation sequencing (NGS) in the investigation. METHODS: Outbreak investigation was performed where clinical, spatial and epidemiologic links were established. Screening of all infants in the NICU and the environment was performed. Rep-PCR and NGS methods were used to identify potential environmental sources of infections and clustering among cases. RESULTS: Eleven cases were detected during the outbreak period: mean gestational age 27 weeks (range: 24-32), predominantly male (82%), mean age of infection 24 days (range: 6-51). Six infants were treated for conjunctivitis and one for bacteraemia. Identification of colonized infant via a point prevalence survey and cohorting of all infected/colonized patients were implemented. We performed environmental swabbing of surfaces, water outlets, chlorhexidine hand wash solutions and hand hygiene hand rubs. Both rep-PCR and NGS classified the 11 case isolates into 5 types. No point source was identified except for a single positive environmental isolate from a sink which was clonally distinct from the cases. CONCLUSION: Identification and cohorting of infected/colonized patient was important in the control of S. marcescens outbreak in the NICU. The utility of rep-PCR was comparable to NGS in providing molecular information to develop S. marcescens outbreak control strategies.

Serratia marcescens outbreak in a neonatology unit of a Spanish tertiary hospital: Risk factors and control measures.

BACKGROUND: We describe the investigation undertaken and the measures adopted to control a Serratia marcescens outbreak in the neonatology unit of La Paz University Hospital in Madrid, Spain. METHODS: Weekly rectal and pharyngeal screenings for S marcescens were performed in the neonates starting after detection of the outbreak. Environmental samples and samples from health care workers (HCWs) were obtained for microbiological analysis. An unmatched case-control study was carried out to investigate risk factors for infection/colonization. RESULTS: The outbreak began in June 2016 and ended in March 2017, affecting a total of 59 neonates. Twenty-five (42.37%) neonates sustained an infection, most frequently conjunctivitis and sepsis. Multivariate logistic regression identified the following risk factors: parenteral nutrition (odds ratio [OR], 103.4; 95% confidence interval [CI], 11.9-894.8), history of previous radiography (OR, 15.3; 95% CI, 2.4-95.6), and prematurity (OR, 5.65; 95% CI, 1.5-21.8). Various measures were adopted to control the outbreak, such as strict contact precautions, daily multidisciplinary team meetings, cohorting, allocation of dedicated staff, unit disinfection, and partial closure. Hands of HCWs were the main suspected mechanism of transmission, based on the inconclusive results of the environmental investigation and the high number of HCWs and procedures performed in the unit. CONCLUSIONS: S marcescens spreads easily in neonatology units, mainly in neonatal intensive care units, and is often difficult to control, requiring a multidisciplinary approach. Strict measures, including cohorting and medical attention by exclusive staff, are often needed to get these outbreaks under control.

A Serratia marcescens outbreak in a neonatal intensive care unit was successfully managed by rapid hospital hygiene interventions and screening.

AIM: Serratia marcescens is a rare, but important, pathogen in hospital-acquired infections, especially in neonatal units. Outbreaks may cause significant mortality among neonates. This study describes how an outbreak of S. marcescens was handled in a neonatal intensive care unit in Finland in June 2015. METHODS: Tampere University Hospital is the only hospital that offers intensive care for preterm neonates in the Pirkanmaa health district area in Finland. Between June 9, 2015 and June 29, 2015, seven neonates were screened positive for S. marcescens in the hospital. We examined the management and outcomes, including environmental sampling. RESULTS: Two of the seven neonates developed a bloodstream infection, and one with S. marcescens sepsis died after six days of antibiotic treatment. The outbreak was rapidly managed with active hospital hygiene interventions, including strict hand hygiene, cleaning, patient screening, contact precautions and education. Environmental sampling was limited to one water tap and a ventilator, and the results were negative. The outbreak was contained within three weeks, and no further cases appeared. The screening of healthcare workers was not necessary. CONCLUSION: A S. marcescens outbreak caused significant morbidity in neonates and one death. Rapid hospital hygiene interventions and patient screening effectively contained the outbreak.

Serratia marcescens Bacteremia: Nosocomial Cluster Following Narcotic Diversion.

OBJECTIVE To describe the investigation and control of a cluster of Serratia marcescens bacteremia in a 505-bed tertiary-care center. METHODS Cluster cases were defined as all patients with S. marcescens bacteremia between March 2 and April 7, 2014, who were found to have identical or related blood isolates determined by molecular typing with pulsed-field gel electrophoresis. Cases were compared using bivariate analysis with controls admitted at the same time and to the same service as the cases, in a 4:1 ratio. RESULTS In total, 6 patients developed S. marcescens bacteremia within 48 hours after admission within the above period. Of these, 5 patients had identical Serratia isolates determined by molecular typing, and were included in a case-control study. Exposure to the post-anesthesia care unit was a risk factor identified in bivariate analysis. Evidence of tampered opioid-containing syringes on several hospital units was discovered soon after the initial cluster case presented, and a full narcotic diversion investigation was conducted. A nurse working in the post-anesthesia care unit was identified as the employee responsible for the drug diversion and was epidemiologically linked to all 5 patients in the cluster. No further cases were identified once the implicated employee's job was terminated. CONCLUSION Illicit drug use by healthcare workers remains an important mechanism for the development of bloodstream infections in hospitalized patients. Active mechanisms and systems should remain in place to prevent, detect, and control narcotic drug diversions and associated patient harm in the healthcare setting. Infect Control Hosp Epidemiol 2017;38:1027-1031.

A Hospital-wide Outbreak of Serratia marcescens, and Ishikawa's "Fishbone" Analysis to Support Outbreak Control.

A nosocomial outbreak of Serratia marcescens in respiratory samples predominantly from patients in a surgical intensive care unit is reported. Most of these patients were cardiac surgical patients. Initially, a vigorous but inconclusive investigation was implemented on the basis of standardized (according the US Centers for Disease Control and Prevention) steps of outbreak investigation. Then, a systemic quality management approach with "fishbone" analysis was added. As a consequence, plausible causes for the outbreak were identified: (i) S marcescens was found on the transesophageal echocardiography probe used during cardiac surgery; and (ii) the quality of the surface disinfection was insufficient due to multiple reasons and was completely reengineered. In conclusion, in addition to the standardized steps of outbreak investigation, the complementary use of quality management tools such as the Ishikawa "fishbone" analysis is helpful for outbreak control. The complete reengineering of the disinfectant procurement and logistics is assumed to have been the most effective measure to control the described outbreak.

Caracterización clínica y epidemiológica de brote a Serratia marcescens en una Unidad de Cuidado Intensivo Pediátrico Hospital Nacional de Itaugua. Paraguay. Abril a setiembre 2015 / Clinical and epidemiological characterization of an outbreak of Serratia marcescens in a Pediatric Intensive Care Unit National Hospital of Itaugua. Paraguay. April to September 2015

Introducción: Serratia marcescens, bacilo Gram negativo, familia enterobacteriaceae; se encuentra en la flora intestinal del hombre y animales, en el medio ambiente y en reservorios como agua, cañerías, llaves, en insumos hospitalarios como jabones y antisépticos. Objetivos: determinar la presencia de un brote, localizaciones, comorbilidades presentes; serotipo del agente causal, cortar la cadena de transmisión. Metodología: estudio descriptivo de un brote epidémico por S. marcescens en el periodo comprendido entre 27 de Abril del 2015 a 19 de Junio del 2015. Se definió como caso a cualquier paciente con cultivo positivo para S. marcescens durante el período epidémico, ya que no se había identificado ningún cultivo positivo para esta bacteria con dicha resistencia en los años previos de vigilancia. Hipótesis: Transmisión por contacto, mano portada. Resultados durante el período epidémico se identificaron 5 pacientes con cultivos positivos para S. marcescens. Las comorbilidades fueron, choque séptico de origen enteral 1/5, cardiopatía/ bronquiolitis 1/5, pos operado de hemorragia ventricular 1/5, oclusión intestinal/ sepsis neonatal tardia1/5. Con procedimientos invasivos tales como, asistencia respiratoria mecánica, catéter venoso central, catéter urinario 5/5, cirugía 2/5, catéter de derivación externa 1/5, antibiótico de amplio espectro con 2 o más asociaciones 4/5, promedio de 43 DDI. Localizaciones: S. Traqueal 3/5, PC 2/5, liq. Peritoneal, HMC 1/5. Tasa de ataque 9.4%(5/53), letalidad 60%(3/5) Intervenciones: precauciones de contacto, cohorte, higiene hospitalaria. Conclusiones: brote a Serratia marcescens, productora de carbapenemasa, detectada mediante vigilancia activa en UCIP, más frecuentemente aislado en S. traqueal y PC. Se controló con medidas de prevención y control.

Introduction: Serratia marcescens, Gram negative bacillus, family enterobacteriaceae; Is found in the intestinal flora of man and animals, in the environment and in reservoirs such as water, pipes, keys, in hospital supplies such as soaps and antiseptics. Objectives: to determine the presence of an outbreak, localizations, present comorbidities; Serotype of the causative agent, cut the transmission chain. Methodology: a descriptive study of an outbreak of S. marcescens in the period from April 27, 2015 to June 19, 2015. Any patient with positive culture for S. marcescens during the epidemic period was defined as the case, since No positive culture for this bacterium had been identified with such resistance in previous years of surveillance. Hypothesis: Transmission by contact, hand cover. Results: 5 patients with S. marcescens positive cultures were identified during the epidemic period. Comorbidities were septic shock of enteral origin 1/5, heart disease / bronchiolitis 1/5, postoperative of ventricular hemorrhage 1/5, intestinal occlusion / late neonatal sepsis1 / 5. With invasive procedures such as mechanical ventilation, central venous catheter, urinary catheter 5/5, surgery 2/5, external lead catheter 1/5, broad spectrum antibiotic with 2 or more associations 4/5, average of 43 DDI . Locations: S. Traqueal 3/5, PC 2/5, liq. Peritoneal, HMC 1/5. Attack rate 9.4% (5/53), lethality 60% (3/5) Interventions: contact precautions, cohort, hospital hygiene. Conclusions: outbreak of Serratia marcescens, a producer of carbapenemase, detected by active surveillance in PICU, most frequently isolated in S. tracheal and PC. It was controlled with prevention and control measures.

Determinantes do envelhecimento ativo segundo a qualidade de vida e gênero / Determinants of active aging according to quality of life and gender

Resumo Os objetivos deste estudo foram construir um indicador de envelhecimento ativo e testar sua associação com qualidade de vida e possíveis determinantes segundo gênero. O estudo AGEQOL (Aging, Gender and Quality of Life) entrevistou 2052 indivíduos com 60 anos e mais de idade residentes em Sete Lagoas, MG, Brasil. A associação entre envelhecimento ativo, qualidade de vida e possíveis determinantes foi realizada por meio da regressão logística múltipla, com nível de 5% de significância estatística, separadamente para cada gênero. A maioria dos homens pertenceu ao grupo com envelhecimento ativo (58,0%), enquanto 51,8% das mulheres foram alocadas no grupo com envelhecimento normal (p < 0,001). A qualidade de vida nos domínios Físico, Psicológico e Escore total mantiveram-se associada ao desfecho no modelo final para ambos os gêneros. Entre os homens, os fatores comportamentais e participação comunitária foram preditores positivos para envelhecimento ativo. Mulheres com maior renda, que não sofreram quedas e com participação comunitária tiveram maior chance de pertencer ao grupo com envelhecimento ativo. Conclui-se que qualidade de vida e a participação em grupos são os principais determinantes de envelhecimento ativo, e que os demais fatores determinantes associados são diferentes para cada gênero.

Abstract The scope of this study was to construct an indicator of active aging and assess its association with quality of life and possible determinants according to gender. The AGEQOL (Aging, Gender and Quality of Life) study was used to interview 2052 individuals aged 60 years and older residing in Sete Lagoas in the State of Minas Gerais. The association between active aging, quality of life and possible determinants was performed by multiple logistic regression with a 5% level of statistical significance separately for each gender. Most men were in the active aging group (58%), and 51.8% of women were in the normal aging group (p < 0.001). The quality of life in the Physical, Psychological, and total Score domains remained associated with the outcome in the final model for both genders. Among the men, the behavioral and community participation factors were positive predictors of active aging. Women with higher incomes, who did not suffer falls and engaged in community participation, had a better chance of belonging to the active aging group. The conclusion drawn is that quality of life and participation in groups are the main determinants of active aging, and the other factors associated with active aging are different for each gender.

Serratia marcescens outbreak in a neonatal intensive care unit: crucial role of implementing hand hygiene among external consultants.

BACKGROUND: Serratia marcescens represents an important pathogen involved in hospital acquired infections. Outbreaks are frequently reported and are difficult to eradicate. The aim of this study is to describe an outbreak of Serratia marcescens occurred from May to November 2012 in a neonatal intensive care unit, to discuss the control measures adopted, addressing the role of molecular biology in routine investigations during the outbreak. METHODS: After an outbreak of Serratia marcescens involving 14 neonates, all admitted patients were screened for rectal and ocular carriage every two weeks. Extensive environmental sampling procedure and hand sampling of the staff were performed. Antimicrobial susceptibility pattern and molecular analysis of isolates were carried out. Effective hand hygiene measures involving all the external consultants has been implemented. Colonized and infected babies were cohorted. Dedicated staff was established to care for the colonized or infected babies. RESULTS: During the surveillance, 65 newborns were sampled obtaining 297 ocular and rectal swabs in five times. Thirty-four Serratia marcescens isolates were collected: 11 out of 34 strains were isolated from eyes, being the remaining 23 isolated from rectal swabs. Two patients presented symptomatic conjunctivitis. Environmental and hand sampling resulted negative. During the fifth sampling procedure no colonized or infected patients have been identified. Two different clones have been identified. CONCLUSIONS: Ocular and rectal colonization played an important role in spread of infections. Implementation of infection control measures, involving also external specialists, allowed to control a serious Serratia marcescens outbreak in a neonatal intensive care unit.

Late-onset neonatal sepsis, risk factors and interventions: an analysis of recurrent outbreaks of Serratia marcescens, 2006-2011.

BACKGROUND: Between 2006 and 2011, 11 patients with Serratia marcescens sepsis and 47 patients colonized due to the spread of various clones were observed. These recurrent clusters brought about interventions to reduce spread between patients. AIM: To evaluate the effect of stepwise interventions to prevent S. marcescens colonization/sepsis and to analyse risk factors for late-onset sepsis (LOS). METHODS: An open retrospective observational study was performed to evaluate the interventions. A retrospective case-control study was performed to analyse the risk factors for LOS. FINDINGS: S. marcescens sepsis and colonization decreased after the stepwise adoption of hygiene interventions. Low gestational age, low birth weight, indwelling central venous or umbilical catheter, and ventilator treatment were identified as risk factors for LOS. Compliance with basic hygiene guidelines was the only intervention monitored continuously from late 2007. Compliance increased gradually to a steady high level in early 2009. There was a decrease in S. marcescens LOS, clustering after the second quarter of 2008. After the first quarter of 2009, S. marcescens colonization decreased. CONCLUSION: It was not possible to identify the specific effects of each intervention, but it is likely that an update of the hospital's antibiotic policy affected the occurrence of S. marcescens LOS. The delayed effect of interventions on S. marcescens colonization was probably due to the time it takes for new routines to have an effect, illustrated by the gradual increase in compliance with basic hygiene guidelines.

The "other" gram-negative bacteria in mastitis: Klebsiella, serratia, and more.

Mastitis caused by gram-negative infections is of increasing importance on modern and well-managed dairy farms. Without a doubt, E coli tends to be the most important cause of these gram-negative infections when the data are tallied across farms.1 However, more precise investigation of individual farms often reveals a farm-specific infection pattern where a single gram-negative bacterial species predominates. Several farms with a predominance of "other" gram-negative IMIs may be observed. We have shown the presence of outbreaks on individual dairy farms with K pneumoniae, S marcescens, and Enterobacter cloacae. On farms with a predominance of these "other" gram-negative infections, a detailed epidemiologic investigation may reveal the source of these infections. It is quite surprising to identify the difference in host immune response pattern and the associated clinical and subclinical presentations of IMIs due to the different gram-negative organisms. Experimental and field observations would suggest that among the gram-negative bacterial causes of mastitis, Klebsiella spp are causing the most severe cases, closely followed by E coli and then much less clinical severity is observed in Serratia spp and Enterobacter spp cases. The precise mechanisms that would explain the difference in clinical severity are not known, but the most likely explanation appears to be the structure of the lipid A fraction of the LPS of the bacterial species. Important differences in the lipid A fraction of LPS between and within bacterial species are observed. The prevention of IMIs with gram-negative bacteria has components that are generic across species and components that are species specific. Generic prevention may be obtained by improving hygiene and reducing exposure of teat ends to environmental contamination. Also the use of a J5 bacterin is expected to provide some reduction in severity of gram-negative IMIs across bacterial species. Specific prevention programs will depend on the actual transmission behavior of the dominant species causing IMIs in the herd. Several clonal outbreaks of gram-negative bacterial species have been described. In such situations, optimal milking procedures, segregation and culling of infected animals, and targeted treatment would be advisable. Even more specific are the prevention procedures associated with S marcescens outbreaks, where resistance against specific biocides will lead to transmission of infection through teat disinfectants. Removal of these biocides from the cow environment is than essential. Antimicrobial treatment of gram-negative bacteria has often considered to be of limited value and treatment should be more targeted toward cow survival and reduction of clinical symptoms. More recently, extended treatment with a third-generation cephalosporin was reported to be efficacious in the treatment of E coli and Klebsiella spp but not of E cloacae. Further investigations in effective treatment protocols for gram-negative IMIs are warranted.

Rapidly controlled outbreak of Serratia marcescens infection/colonisations in a neonatal intensive care unit, Pescara General Hospital, Pescara, Italy, April 2011.

In April 2011, an outbreak of Serratia marcescens infection/ colonisations occurred in the neonatal intensive care unit of Pescara General Hospital. Rapid microbiological investigations lead to identification of five cases of likely cross-transmission from a neonate hospitalised for S. marcescens sepsis: four infections and one neonate colonised post-mortem. Two low birth weight neonates died. The environmental investigation detected S. marcescens from two soap dispensers. Strict hygiene measures lead to early interruption of the outbreak, without recurrences to date.

Effect of platelet additive solution on bacterial dynamics and their influence on platelet quality in stored platelet concentrates.

BACKGROUND: Platelet additive solutions (PASs) are an alternative to plasma for the storage of platelet concentrates (PCs). However, little is known about the effect of PAS on the growth dynamics of contaminant bacteria. Conversely, there have been no studies on the influence of bacteria on platelet (PLT) quality indicators when suspended in PAS. STUDY DESIGN AND METHODS: Eight buffy coats were pooled, split, and processed into PCs suspended in either plasma or PAS (SSP+, MacoPharma). PCs were inoculated with 10 and 100 colony-forming units (CFUs)/bag of either Serratia liquefaciens or Staphylococcus epidermidis. Bacterial growth was measured over 5 days by colony counts and bacterial biofilm formation was assayed by scanning electron microscopy and crystal violet staining. Concurrently, PLT markers were measured by an assay panel and flow cytometry. RESULTS: S. liquefaciens exhibited an apparent slower doubling time in plasma-suspended PCs (plasma-PCs). Biofilm formation by S. liquefaciens and S. epidermidis was significantly greater in PCs stored in plasma than in PAS. Although S. liquefaciens altered several PLT quality markers by Days 3 to 4 postinoculation in both PAS- and plasma-PCs, S. epidermidis contamination did not produce measurable PLT changes. CONCLUSIONS: S. liquefaciens can be detected more quickly in PAS-suspended PCs (PAS-PCs) than in plasma-PCs by colony counting. Furthermore, reduced biofilm formation by S. liquefaciens and S. epidermidis during storage in PAS-PCs increases bacteria availability for sampling detection. Culture-based detection remains the earliest indicator of bacterial presence in PAS-PCs, while changes of PLT quality can herald S. liquefaciens contamination when in excess of 10(8) CFUs/mL.